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O A K RIDGE N A T I O N A L LABORATORY

HELP

operated by U N I O N CARBIDE CORPORATION for the

U. S. A T O M I C ENERGY C O M M I S S I O N

ORNL- TM- 522-

DATE

- October 10, 1962

DESIGN STUDIES AND COST ESTIMATES OF TWO FLUORIDE VOUTILIW PUNTS

W, L. Carter, R . P. Milford, and W. G. Stockdale ABSTRACT

b

'Ir t

Design studies and cost estimates were made for two on-site, fluoride volat i l i t y processing plants. Each plant was assumed to be processing continuously irradiated LiF-BeFz-ThF4-UF4fuel *om a one-region Molten Salt Converter Reactor (MSCR) capable of producing 1000 Mwe (E. 2500 Mwt). One plant processed fuel at a rate of 1.2 ft3/day, the second at 12 ft3/day. The smaller plant was designed and cost estimated for two processing conditions: (1)retention of the waste salt for Pa-233 decay and recovery by a second fluorination, and ( 2 ) discard of all Pa-233 as waste after the first fluorination, The larger plant was considered only for the case of Pa-233 decay and recovery. The following capital and direct operating charges were estimated: Capital Cost 1.2 f't"/day Plant with Pa-233 Recovery 12 ft3/day Plant with Pa-233 Recovery 1.2 f't3/day Plant with Pa-233 Discard

Operating Cost

($1

($/v 1

12,556,000

1,103,000

25,750, 000

2,241,000

10,188,000

The chemical processing scheme consisted of volatilizing uranium as UF'6 by treating the molten salt with elemental fluorine at about 53째C. The hexafluoride was then collected by absorption on NaF and condensation in cold traps, reduced to UF4 in a HpF2 flame, dissolved in make-up salt, and recycled to the reactor. Make-up fuel was supplied by purchasing M l y enriched TJ-235. The Li, Be and Th components of the fuel were discarded with fission product waste. NOTICE T h i s document contaiits information of a preliminary nature and was prepared primarily for internal use a t the Oak Ridge National Laboratory. It i s subject to revision or correction and therefore does not represent a final report. The information i s not t o be abstrocttd, reprinted or otherwise given public dissemination without the approval of the ORNL patent branch, L e g a i and Informnrion Control DeDartment.


LEGAL NOTICE

.

T h i s report was propored as an account of Government sponsored work.

-

Neither the Unitod States,

nor the Commission, nor any person octing on behalf of the Commission: A. Makes any warranty or npmsentatian, expressed or implied, with respect to the accuracy, completeness, or usefulness of the information contained in this report, or that the use of ony information, apparatus, method. or process disclosed in thir report may not infringe privotely owned rights; or i 6 . Assumes any l i a b i l i t i e s w i t h n i p a c t to the use of, or for damoges resulting from the use of any information, apparatus, mothod, or process disclosed In t h i s report. As used in the obove, '*porsm acting MI bohalf of the Commission" includes any employeo or contractor of the Commission, or employee of such contractor, to

or contractor of the Commission.

01

provides access to, any information pursuant to h i s employment

or h i s *mployment w i t h such contractor.

the

extent that such employee

ornployee o f such contractor propans, disseminates, or

or contract with the Commisslon,


1 CONTENTS L

Page

r

1,O SUMWARY

1 3

2.0

9

ABSTHACT INTRODUCTION

2.1

Reactor Description

2.2

Design Bases

9 10

3 .O PROCESSING MOLTXN FWORIDE SALTS 3.1 Pre-Fluorination Storage

4.0

NaF Absorption Cold Trap

16

Reduction and Fuel Make-up

17

Waste Storage

PROCESSING PLANT DESIGN

17

4.1 Decay

17

4.2

Heat Reaaoval

Equipment Design

23

Prefluorinatbon Storage Tanks Fluorinator

23 29

CRP Trap and Absorbers

31

Cold Trap

32

Reduction Reactor

37 37 37

Fuel Make-up

Pa-233 Decay Storage

System

Samplers

38 38 38 38

Refrigeration

38

Shielding Calculations

41

Source Strength

1c1

Geometry

42

Interim Waste Storage Tanks

Freeze Valves Line Heating

4

3

3

4 04 Process Equipment Layout 4.5 Plant layout V

11

14 1-5 1-5

3 . 2 Fluorination

3.3 3.4 3.5 3.6

11

Site kcation

46 46 47


2

CONTENTS

- contd Page

4 3 Over-all Plant Layout Processing Area Pa-233 Decay Storage Waste Storage Crane Maintenance Area Contaminated Equipment Storage Decontamination Cell Canyon Shop Railroad Dock Control Room Sample Gallery Laboratories Offices Service keas

5.0 CAPITAL COST ESTIMATE 5.1 Accounting Procedure 5.2 Bases of Estimates Process Equipment Building 5.3 Process Equipment Capital Cost 5.4 Building Capital Cost 3 o y Total Capital Cost 6.0 OPERATING COST ESTIMATE 6 1 Operating Manpower 6.2 Summary of Direct Operating Costs 7 .o CAPITAL COST ESTIMATE OF MODIFIED 1.2 FI’’/DAY PIANT 7.1 Modifications 7,2 Process Equipment 7.3 Waste Storage 7.4 Process Building 7.5 Total Plant Cost 7 6 Economic Advantage e

47 47 48 48 48 49 49 49 49 49 49 50

50 50

50 50

51 51 52 52

56 56 60

60 60

64 64 65 65 66 66 70


3 1.0 SUMMARY Capital cost and operating cost estimates have been prepared f o r two f

o n - s i t e f l u o r i d e v o l a t i l i t y processing p l a n t s . The respective p l a n t s a r e designed t o t r e a t 1 . 2 and 12 f t 3/day of an irradiated LiF-BeF2-ThFk-UF2 f u e l from a Molten S a l t Converter Reactor (MSCR) which has a conversion r a t i o of about 0 , 8

The uranium-free f u e l has t h e composition 68-23-9

mole '$ LiF-BeF2-ThF4; approximately 0.66 mole

4 i s required f o r c r i t -

UF

I c a l i t y i n the equilibrium r e a e t a r . The assumd rea",tf)r and chemical processing p l a n t environment i s a 1000 Mwe (ea

s

2506 Mwt ) c e n t r a l pawer s t a t i o n .

This power i s generated

i n a single r e a c t o r which i s 15 13 i n diameter by

3.3

f't high,

The one-

region system i s 90 vol '$ graphite and 10 vol $ fuel contained i n an INOR-8 s h e l l .

Heat i s removed by c i r c u l a t i n g t h e molten f u e l salt through

t h e core and e x t e r n a l heat exchangers a t an average temperature of approximately l200'F.

Spent fuel is removed semi-continuously every 3-5 days

f o r reprocessing; make-up f u e l (U-235 Total f u e l volume i s 1780 f't 3

+

Th) is aaded on t h e same schedule.

a

The chemical repreeessfng plant u t i l i z e s f l u o r i d e v o l a t i l i t y t o r e cover decontaminated uranium. (LiF

+

BeF

2

1 is

Neither thorium nor t h e c a r r i e r salt

recovered; both a r e discarded as waste w i t h t h e accom-

panying f i s s i o n products.

I n one phase of t h i s study t h e waste s a l t was

r e t a i n e d 135-175 days t o allow Pa-233 decay andl recovery by a second fluorination.

I n a second phase of this study protactinium was discarded

with t h e waste s a l t immediately a f t e r f l u o r i n a t i o n ,

After fluorination,

a l l of t h e recovered UF is burned i n a H -F flame f o r reduction t o UF4 6 2 2 which i s dissolved i n make-up LiF-BeF2-ThF and returned t o t h e r e a c t o r .

4

Make-up uranium (U-235) is a l s o added a t t h i s p o i n t , The accuracy and confidence l e v e l of any cost estimate depends upon t h e m o u n t of design d e t a i l ,

I n t h i s study a l l of t h e process operations

were considered i n enough detail f o r preliminary designs of vessels and equipment; complex vessels were considered more c a r e f i l l y t o permit more r e l i a b l e cost estimation,

The process building was l a i d out f o r conven-

ience of process operations and maintenance and was patterned after designs of other remctteky operated plants'

t h a t a r e t h e products of s e v e r a l


4 years experience and study.

Cognizance was taken of t h e f a c t that t h e

r e a c t o r and chemical plant are an i n t e g r a l operation and can share certain facilities. The treatment of protactinium i n t h i s study was made i n t h e two ways mentioned above t o determine i f there were s u f f i c i e n t value i n t h e protactinium t o j u s t i f y i t s recovery from the waste.

The c a p i t a l cost

cf t h e 1 . 2 ft3/day plant was estimated for t h e cases of complete Pa-233

discard and for Pa r e t e n t i o n u n t i l t h e undecayed Pa amounted t o only 0 ,I% of t h e bred uranium.

The economics favored complete Pa discard

since considerable process equipment and building space were required f o r t h i s "dead" storage.

A more complete evaluation of t h e process might

reveal t h a t more favorable economics r e s u l t from a nominal extension of t h e prefluorination storage period allowing more Pa-233 decay a t t h i s point.

Increased process equipment, building and inventory charges would have t o be compared with t h e value of a d d i t i o n a l Pa recovery. This l a t -

ter analysis w a s not made i n t h i s study. The estimated c a p i t a l costs c f t h e two f l u o r i d e v o l a t i l i t y p l a n t s

a r e $12,536,000 and $ 2 3 Q 7 p 5 0 0 0 respectively, , f o r t h e 1 . 2 ft3/day and 12 ft3/day p l a n t s f o r t h e case i n which t h e waste i s retained f o r Pa-233

decay and recovery.

For t h e case of complete Pa-233 discard, a c a p i t a l

c c s t o f $10,h88,000 was estimated fer t h e 1 . 2 ft'/day

plant

A summary

cBf t h e ccet data i s given i n Table 1,1,and these same data a r e p l o t t e d in F L g Z 1 ' 2 .

I n drawing the curve, it i s assumed t h a t t h e cost data can

bc represent,& by a s t r a l g h t l i n e on a log-log p l o t .

The slope a f t h i s

curve I s 0,312 vhich may be compared with a value o f 0.6 t h a t i s custom-

a r i l y assmiazed with a c a p i t a l c c s t vs capacity curve f o r a chemical plant.

Tne lower value far t h e slope suggests t h a t more favorable r e -

prccessing eccnomics w i l l be r e a l i z e d with l a r g e processing p l a n t s . Direct cperating costs f o r each of t h e p l a n t s employing Pa recovery

were calculated and a r e summarized i n Table 1.2. The labor charges correspcnd te 1Ok employees f o r t h e 1 . 2 f-k3/day p l a n t and 133 f o r t h e 1 2 ft3/day plant.

It i s of i n t e r e s t t o note t h e r e l a t i o n s h i p between operating and

c a p i t a l costs f o r each of t h e p l a n t s .

When t h e operating cost is divided

by t h e corresponding c a p i t a l investment, t h e operating charge rate be-

3

comes 8.77$/year and 8.6l$/year f o r the 1.2 and 12 f t /day capacities,

1


5 respectively.

These charges may be compared t o a value of l$/year

that

has been found t o be generally applicable i n t h e chemical industry.

I n t h e analysis

0%

t h e 1.2 ft3/day plant, employing pa-233 discard,

t h e on-site, interim waste stcarage time was optimized,

The optimization

was c a r r i e d out by considering on-site storage e ~ s % sversus s a l t mine permanent storage ec;s%s as a fiM1ct.isn of t h e age of t h e waste s a l t .

The

lowest total storage cost appeared t o o e m r for an on-site holdup of about 1100 days befcre sh$ppfng t c ' F e m n e n t storage ,.


Table

1.1 I

Summary of Capital Fluoride Volatility lo2 ft3/Day Plant with Pa-233 Recovery

Costs for On-Site, Plants 12 f't3/Day Plant with Pa-233 Recovery

Total Installed Equipment and Dullding Cost

7y458ploo

K%294,700

General Construction of Total Installed Ruilding Cost)

l&40,800

3,364,800

Total

Construction

Overhead (22s Equipment and Cost

Total

Project

(20s of Subtotal

18,659,500

9PWhW

Architect Engineering and Inspection (13s of Total Construction Cost) Subtotal Project Cost Contingency cost )

1,364,800 10,463,700

2,798,900

21,

1,33.1,000 7,383,OOO 1,107,000 ~,4%000

Project 2,092>300

Cost

1.2 ft3/Day Plant xith Pa-233 Discard

12,556,~~

1.

.

4,291,300

1,698,000

25,'75o,OfJO

10,188,000

*

.(


7 Table 1.2.

Summary of Direct Operating Costs f o r Two Fluoride V o l a t i l i t y Plants

Chemical Consmpt ion Utilities

Labor Maintenance Materials Total Direct Operating Cost Ratio of Operating Cast: Capital Cost

f

Lr

300, LOO

19102,600

1,085,800

, ,

2 240 600


UNCLASSIFIED ORNL-LR-

IO2

DWG 74109

I I

I

I

FL1.0 PLANT

Fig.

(

I

1.1

Fluoride

Volatility

Processing

10.0 CAPACITY,

Plant

Ft’

Cost for

Salt / Day

an On-Site Facility

to Process MSCRFuel.

*

,(


9

2.0

INTRODUCTION

The u t i l i z a t i o n of thorium as a reactor f u e l i s being investigated ir, i

several r e a c t o r systems which show promise of having a breedirg r a t i o

g r e a t e r than u n i t y o r a t least a high conversion r a t i o , t h a t i s , a conversion r a t i o greakrr %ha-r, about 0.5.

T h i s r e p o r t covers tha.t p o r t i o n

of a study concerned with pr3cessic.g spent m o l t m fiiiloride salt fro% a

me-region, zonverfer reactor f o r recovery of decontaminated uraniuxr, It is t h e purpose af t h i s strxdy valat,i:ity

$0

develop c a p i t a l c o s t data f o r f l u o r i d e

processiig p l a n t s czipabile of proc:essing 1.2 and 12 ftg/day of

m l t e n f l u o r i d e fuei. e 2.1

Reactor Description The r e a c t o r f o r which t h e chemical p l a n t has been designed i s

fueled w i t h a molten salt zlxtlire t h a t i s b a s i c a l l y 68-23-9 mcle

$J

-

LiF-BeF2-ThF4 contaiP.ing s u f f i c i e n t Wj+, ca. 0.66 mole $, t o maintain criticality.

The r e a c t o r i s a one-region assembly whose core has t h e

approximate composition. of 10 v o l $ f u e l solutioc aQd 90 v o l $ graphite; %he geametry i s a r i g h t c i r c u l a r cylinder about

high,

15

f t diameter by

15

ft

F i s s i o n energy i s removed by c i r c u l a t i n g t h e f u e l solution through

Lhc core and an intermediate heat exchanger which i s cooled by a barren

sslt solution,

The barren s a l t i n t u r n d i s s i p a t e s t h e 'neat i n a steam

generator which produces U?OOOF steam a t 2000 p s i a .

The average r e a c t o r

temperature i s ~ 2 0 0 % The assumed environment f o r t h e r e a c t o r i s t h a t of a c e n t r a l ,

power-producing f a c i l i t y generating LOO0 Mwe a t a thermodynamic e f f i c i e n c y

of approximately 42,3$$

This load i s committed t o one r e a c t o r supplying

steam t o two turbo-gelerator sets.

s t a t i o n i s 1780 f t 3 ,

The calculated f u e l volume f o r t h e

The t o t a l uranium inventory, which includes a l l

isotopes from U-233 t o U-238, i s about 4200 kg; of t k l s t o t a l t h e f i s s i o n a b l e component, U-233

+ U-235>

i s i n t h e range 2627 t o 2815 kg

c3.ependin.g upon t h e processing rate,

I n a d d i t i o n t h e system contains

52,000 kg Th and 90.7-96 kg Pa-233,

For t h i s study it was assumed t h a t

Lht: system had a nominal conversion r a t i o of

0.8, t h e remainder of t h e

f u e i being supplied by purchase of f u l l y enrisked U-255.


10

2.2

Design Bases 1

I n any study of t h i s type the accuracy and confidence l e v e l of the r e s u l t s depends upon the amount of design detail.

More or l e s s a r b i t r a r y

design bases were established t o govern the extent of the study and t o

I

In

augment those design conditions which were more firmly established. t h i s respect the following rules were followed: 1.

The chemical processing p l a n t and reac'ecr power s t a t i o n would be an integrated f a c i l i t y ; i . e . ,

2.

on-site processing,

The design would be based a s much as possible on e x i s t i n g technology; extrapolation of t.echnology would be done only when absolutely necessary.

3 . A cost estimate would be m a d e f o r each of two plants-one processing f u e l a t a r a t e corresponding t o an estimated optimum reactor cycle time, and a second processing f u e l a t an estimated minimum r e a c t o r cycle time.

These two estimates would then be

used t o determine processing c o s t s a t other processing r a t e s by I n doing t h i s it would be

i n t e r p o l a t i o n or e x t r a p l a t i o n .

assumed that. the c a p i t a l cost versus throughput data could be represented by a st.raight l i n e on a log-log p l o t .

For t h i s

study the processing rates were 1.2 and 12 ft3/day of f u e l containing respectively 2.83 and. 28.3 kg U/day.

4.

The f l u o r i d e v c h t i l i z ~ yprocess would be ased t o recover

--

tlranium which voul5 %e returned i n t o t o t o the reactor.

No

thorium or LiF-BeF2 c a r r i e r salt would be recovered b u t would be discarded a s wame w i t h the accompanying f i s s i o n products. This was a necessary decision because no developed process

e x i s t s for separating LiF-BeFpWq salt from f i s s i o n products.

5.

The waste sal^;, which contains Pa-233, would be held f o r Pa decay and recovery u n t i l the undecayed Pa mounted t o only about Oel$ of t h e bred U-233.

After the second f l u o r i n a t i o n ,

waste salt would be held 1000 days f o r f i s s i o n product decay before transport t.0 permanent, waste storage e (See Section 7 .O

for a modifieaSion of t h i s basis

.


6. The chemical processing plant would share certain facilit-ies with the reactor plant; a.g ., cooling water, potable water, stack, electrical services, steam, compressedair, storm and sanitary sewers, railroad and barge docks, shipping and receiving facilities, etc. These services were assumedavailable.frcan the reactor site. The chemical plant bore the cost of extending the services and, in the case of the stack, bore the cost of increasing the stack size. 7. The extent of the design would be that which completely defined the process to the point of having a preliminary design on all major process equipment. Building and auxiliary service space would be determinedin the light of biological shield requirements and accepted operating practices for a remotely maintained radiochemical plant, 'In this regard experience and studies 192 on the SavannahRiver type plant were referred to,for design of several 'areas of the building. l

it 3.0 FROCESSINC MOLTEN FLUORIDESALTS f

The fluoride volatility plant for processing the irradiated fuel .is assumedto be located adjacent to the reactor area so that fuel transfer Inside the chemical plant can be made by appropriately'heated pipe lines, the process operations are carried out according to the flowsheets of Fdgs. 3.1 and 3.2 for the 1.2 and 12 ft3/day plants, respectively. The two flowsheets are quite similar and incorporate the same process steps. There are slight differences, however> brought about by the quantity of fuel handled and size of process equipment, for-example, in preflorination storage and Pa-233 decay storage. The fuel solution is a rather complex mixture of molten fluoride salts of fertile, fissionable, and fission product nuclides. The major components are LiF, BeF2, ThF4, UFb, and PaFb. 3;l

Prefluorination Storage Extremely rad%oactive fuel solution, which will be only a few minutes old, must be allowed to decay before fluorin&ion to preclude


UNCLASSlFlED ORNL-LR-DWG 65595

- i9k d ---

Uf

1.901 =2.638

u RE-FLUORINATION STORAGE

ow8

Th

-

35.w

12W.F

UF

?:4. LF2

-

3.76

u,

FLUORlNATION

!dirt%

U DAYS

-- !&

Uf 5W.C

3.65

46.54 4.22

F2

32.62 31.70 19.99 19.42

-

-

UF6

1.904 2.638

w $4.

-

:i;: ::

V

PO

- i9k

awe

r)l = 35.w

L

dk

E;4--

BoF2 = MaF = V

46.54 44.60 32.62 19.99

* 35.84 l/d

31.26 19.16 4.98

h-233 DECAY STORAGE 130 DAYS 12oo.F

wt%

-49.27 32.62

u,

4

UF4

4.22 W d

-

I

u u:

REWlON

OF6

3.0 k d d

.u

n!

33.98 l/d

-50%

I

dF6 0.4% W d q

1.957 2.89

4am 31.79 19.48

CUD TRAP

w

--

Y!

=1.w 2.89

4.n)

MINER COLLECTION

4.30 W d

$-aQcsw

-0.341 -37.11 ... .

wzs

-la3a-

4.54 4.w w4 49.w 46.30 E 4 . 32.62 me b~~ w.w la78

!.& ---

V

aouw

-

35.m

& k

-

c

2:;:

% ! ?&

-a -

0.M252

nl

--

Uf

FUEL MAKE UP 1200.F

0.716 0.70

LF2

UF6

1.904 2.638

lU2X

2.498

kdd

100-4@IY

-- k@&

0.462 k d d

MF

U,

ut

mmmm

4.22 W d

33.98 l/d

V

Uf

NOF

FLUORINATION

% %

UF4 0.0696 0.067 ThF4-46.54 44.57 LIF = 32.62 31.24 bF2 -19.99 19.14 NaF 5.2 4.98 m 2 V 35.84 l/d

A

-

F2

-

p

5w.c

I

-

i9k

m -ao02063 Th

35.0

&k m46.54

3-TmXr F;4=

0.00866 W d

COLD TRAP -5O.C

32.62 19.99

= 5.2

V

-

wL%

44.60 31.26 19.16 4.98

-

33.98 l/d

t+

-

OW52

Wd

UF6 * 0.0782 to/d

WASTE STORAGE INCANAL FP MCAY loo0 DAYS

,

L ,

PERMANENT WASTE STORAGE

N1o-(oo4

34.85 l/d

Fig. 3.1 Molten S a l t Converter Reactor. Probess Flowsheet f o r a 1.2 f t3/day Fluoride Volatility Plant.

C) #


r

U = 29.494 Tht = 352.6

- UF

=

kdd

w t 96

39.076

3.78

LiF = 326.2 BeF2 = 199.9

kg/d _ wt % ThF LiF4=

465.4 326.2 BeF - 199.9 Na? -= 10.0

1w1.5

V

~

46.47 32.57 19.96 1.00

343.4 l/d

Pa-233 DECAY STORAGE 175 DAYS 1200T

kg/d _ 90 0.422 0.04

h

=

46.45 32.56 19.95 1.00

e

kdd UF 0.716 0,072 Tht4-= 468.1 47.a LiF = 326.2 32.79

F2

I 0.a2 kg/d

COLD TRAP

0.318 kg/d

UF6 = 0.474 kg/d

500'C

-

LiF = 326.2 BeF2 = 199.9 NoF = 1001.9 V = 343.4 l/d

10.0

UF

-

CYLINDER COLLECTION

UFg = 43.074 kg/d

90T 46 p i a

H2 = 0.248 tg/d

Uf = 0.541 Th = 352.6

339.8 l/d

FLUORINATION

wt.

UF

UFq

994.9

Uf = 0.318 Po = 0.0039 Th = 350.5

Tht4 = 465.4

UFg-

Uf = 18.353 Ut = 28.953

kg/d

31.57 19.35

@

kg/d Pa = 0.322 Th = 350.5

=

REDUCTION

UF4 - 38.36 kg/d

1200'F

13333 V

Uf = 18.353 U, = 28.953

FUEL MAKE UP

-5OT

kg/d Pa = 0.0039 Th = 350.5 kg/d wt %

_ _ _

ThF4 = 465.4 LiF = 326.2 BeF2 = 199.9

46.47 32.57 19.96

uf =

0.318 kg/d

UF6 - 0.474 kg/d WASTE STORAGE IN CANAL FP DECAY IOW DAYS

200-8OO'F

h

PERMANENT WASTE STORAGE

-

t-'


3.4

extremely s t r i n g e n t design requirements on t h e f l u o r i n a t o r .

Because of

a r a t h e r high corrosion rate of about one m i l p e r hour of f l u o r i n a t i o n t i m e , it i s desirable t o have the f l u o r i n a t o r designed as inexpensively

as possible and accessible f a r quick replaceme&.

If t h e f l u o r i n a t o r were

required t o d i s s i p a t e excessive quantites of f i s s i m product decay h e a t plus heat from the exothermic f l u o r i n a t i o n rea&ion,

t h e v e s s e l would have

t o be construc5ed somewhat l i k e an expensive heat exchanger; 3* frequent replacement of such a vessel would c r e a t e an i n t o l e r a b l e expense.

Conse-

p e n t l y , a basis of design was t h a t f u e l would be held u n t i l t h e f i s s i o n product a c t i v i t y was low enough t h a t the f l u o r i n a t o r could d i s s i p a t e i t s heat load by radiation and convection t o the c e l l environment.

For t h e

two p1ant.s the following prefbuorina%ion conditio?zs were established: 1 . 2 f t3 /Day Plant

12 ft3/Day P l a n t

Batch size ( f ? ' )

3.6

60

Withdraw batch fron! reactor every

3 days

5 days

No. storage vessels Average storage time (days)

2

b

4.5

27.5

1200

1200

0

Average storage temperature ( F)

3.2

,

Fluorination After prefluorination cooling the molten salt mixture i s f l u o r i n 0

dted hatnhwise a t about 500 C t o q u a n t i t a t i v e l y remove uranium as

-dolatile W6. Rela%ively few f i s s i o n products form v o l a t i l e f l u o r i d e s so t h e 2econtaiiination f a c t o r i n f l u o r i n a t i o n i s q u i t e high.

The prfncipai f i s s i o n prrAuc5 f l u o r i d e s t h a t v o l a t i l i z e are "chose of Ru, Nb, Zr, C s , Mo and ?le,

Fuel from t h e small p l a n t (4.5-day cooling)

would alss contain Some 8-day 1-131 which would be exhausted w i t h the product i n f l u o r i n a t i o n ,

However, laboratory testsx3 have shown t h a t

f u i i o e car, be e f f e c t i v e l y separated f r Q m m6 i n the NaF absarption s t e p o

e;:

.

Ncfe Figs. 4,3 and 4.4 f o r examples of cooling equipment f o r radioactive

mol+,er. salt solutions.

Y


L i t t l e , i f any, protactinium i s expected t o v o l a t i l i z e during f l u o r i n a t i o n s o t h a t t h e barren waste s a l t contains p o t e n t i a l l y f i s s i l e material.

The waste stream i s retained t o allow Pa-233 t o decay t o a

t o l e r a b l y low l e v e l ; U-233 i s then recovered i n a second f l u o r i n a t i o n .

3.3 Waste Storage After t h e second fluorination, barren s a l t containing t h e bulk of t h e f i s s i o n p r o d w t s i s held i n interim storage f o r akou5 1000 days t o permit f i s s i o n product a c t i v i t y t o decrease t o a l e v e l t h a t does not coaplicate transportation t o pernianent waste storage.

Daring t h i s period

c m t a i n e r s of waste s a l t wo%d be s t a r e d i n thimbles i n a canal f o r heat dissipa-klom t o t h e canal water.

The chosen storage period i s a more or

l e s s a r b i t r w y f i g u r e and might be shorbened appreciably by appropriate

waste c a r r i e r design.

Af’ter 1000 days cooling, it should be possible

f o t r a n s p o r t t h e waste coritafners wft.hout a u x i l i a r y cooling f a c i l i t i e s on t h e c a r r i e r . A t t h i s point it; should be noted t h a t a l l c a r r i e r s a l t plus thorium i s discarcled 8 s vasto.

This i s necessary s i c c e t h e r e i s EC developed

process f o r removing f i s s i o n producSs from t h e mixture.

Lithium i s the

most valuable component since it i s 99.993 a t . $ Li-7; however, t h e l a r g e r amount of th.orium present; makes it, almost a s important i n terms sf t c t a l c o s t ,

3.4

NaF Absorption

Afker leaving %lie flaorfnator, UF6 and t h e accompanying v o l a t i l e f i s s i o n products pass izlto a NaF absorption system. This system b a s i c a l l y consists of two d i s t l c c t zones defined according t o f’unction:

Zone 1

-

i s a high temperature (- 4OO0C) zone (.the so-called CRP o r Complexible

Radioactive Products t r a p ) for removal by cmplexing o r f i l t r a t i o n of Tission or corrosion product f l u o r i d e s and entrained s a l t . Zone 2 i F 8 s

t h e U F absorption-desorp.tion zone operated a t 100°C f o r absorption

6

and a t 4OO0C f o r desorption. Chromium i s q u i t e e f f e c t i v e l y removed i n t h e CRP t r a p , ruthenium i s d i s t r i b u t e d throughoxt t h e NaF beds with some


passing i n t o the Fg disposal system, and zirconium, niobium, cesium, strontium and rare earths are q u i t e e f f e c t i v e l y removed i n the CRP t r a p and the NaF absorption-desorpthon system, Uranium hexafluoride absorbs on sodium f l u o r i d e by formation of t h e m6'3 N a F complex.

as high as k O o C ,

However, t h e complex does n ~ , ff, o m a%temperatures

s o UF6 passes through t h e CRP t r a p and i s caught i n

0

tkie 100 C absorption zone;

A t the x m p l e t i o n of the batch f l u o r i n a t i o n ,

the 100째C absorption zone i s heated t o 4OO0C a t which temperature UF6

is desorbed and moved from %he bed with f l u o r i n e c a r r i e r gas, product, f l u o r i d e s are not

53

Fission

e a s i l y descrrbed and remain on t h e bed.

Decontamination f a c t o r s of t h e order of 1030 are observed i n the absorption-desorption step.

4

The CRP t r a p and absorption zone may be i n t e g r a t e d i n t o a s i n g l e u n i t f o r convenience of disposing of spent NaF by discharge i n t o t h e f i u o r i n a t o r and then t=,waste storage.

This method of disposing of NaF

has Seen employed i n p i l o t p l a n t operation where there i s no protactinium

i n t h e salt.

For these p l a n t s i n which protactinium recovery i s necessary

it may not be p r a c t i c a l t o use t h i s design.

Instead it may be necessary

t o discharge NaF' i n t o t h e waste salt a f t e r t h e second f l u o r i n a t i o n . The design capacity of NaF f o r UF6 i s 2 1 kg UFG p e r cubic f o o t of NaF.

For l a r g e batch f l u o r i n a t i o n s , t h e CRP t r a p and IF6 absorber

3e ;tions may f o r

convenienne be separated.

The se-ond f l u o r i n a k i o - 3fter Pa-233 decay storage i s n o t followed

by NU absorption (see Figs. 3 $ 1 and 3 . 2 ) for %wo reasons.

First, at

t h i s p c i n t there are n3 v o l a t i l e f i s s i o n producrt f l u o r i d e s t o contazninate zhe product,; second, t h e quantity of UF6 i s s n a r l and can be caught i n a

cold t r a p ,

3 , 5 CrJid Trap During the desorption cyzle UF/ i s moved frm t h e absorber i n a 0

strea?? of f l u o r i n e i n t o

'3.

0

cold t r a p naintained at. about -50 C.

Uranium

hexafluoride desublines ana i s collected; f l u o r i n e i s recovered f o r reuse o r discarded,

A coiivenient m a n s of iiisposfng of f l u w i n e i s by J


reaction with charcoal,

When a batch has been collected on t h e cold

t r a p , temperature and pressure are r a i s e d t o s l i g h t l y above t r i p l e point conditions and UFtS i s drained i n t o a c o l l e c t i o n cylinder.

3.6 Reduction and Fuel Make-up The f u e l cycle i s completed by reducing UFG t o IZF and r e c o n s t i tuting t h e t e t r a f l u o r i d e i r r t o molten salt r e a c t o r f u e l .

rc

The hexaf luorii3e

i s evaporated fron! the caLlection cylincier i n t o a H2-F2 flame i n th?

presence of excess hyd-rogen where redixAiio;r occursI

'W6

+

H2 =

m4 +

2"

By-product hydrogen fltloride may be recovered o r absorbed i n a c a u s t i c s o l u t i on Green salt ( W4) f a l l s d i r e c t l y i n t o a d i s s o l v e r containing molten LiF-BeF2-ThF4-UF4 make-up salt,

Before entering the d i s s o l v e r ,

make-up s a l t i s given a pretreatment H2-HF' sparge l a s t i n g about f o u r days as a p u r i f i c a t i o n measure t o removz oxides,

Oxides are detrimental t o

molten f l u o r i d e fuel. s t z k i l l t j - i n t h a t t h e y c s a c p r c c i p i t a t i o n of uranium oxide After recycled UFs has dissclved, t h e f u e l mixture i s fed d i r e c t l y t o t h e r e a c t o r f u e l system,

4 - 0 PROCESSING PLANT DESIGN

4.1 Decay Heat; Remova: A major problem i n t h e desi@,nof a l l process v e s s e l s which contain

short-cooled, highly irradiated f u e l i s t h a t of heat removal.

Heat

d e n g i t i e s are so high t h a t l a r g e cooling areas have t o be designed i n t o r e l a t i v e l y small volumes.

I n t h e case of t h e molten salt system t h e

temperature of t h e heat source i s considerably g r e a t e r than t h a t of a coaventional heat sink such as cooling water, a f a c t which introduces design problems i n thermal stress and maximum allowable heat t r a n s f e r

rates.

An a l t e r n a t e cooling system t h a t can be considered i s an

liitermediate heat 5rransfer medium capable of convenient use up t o rrolten f l u o r i d e salt temperaturesp thereby considerakiy lesscuing t h e proklerfis


Such a eooling niedium could be molten NaK alloy,

mentioned above.

sodium o r barren s a l t ,

Since a considerable quantity of heat i s

associated w i t h t h e decaying f u e l (Note Tables 4.1 and 4,2),

it i s

pertinent t o consider whether or not t h e heat should be rejected o r recovered.

The l a r g e plant has an average heat release rate of about

3.6 M w t ; the small plant, 1,8 Mwt. O,O7$,

These rates represent O,lb$ and

respectively, of t h e nominal 2500 M w t power s t a t i o n output.

The ehoice of the cooling system depends upon t h e decision t o r e j e c t o r recover heat, and, i f recovered, t o what ultimate use w i l l t h e energy be put,

A l o g i c a l choice would be t o u s e t h e heat i n t h e

reheat o r superheat cycles i n the power s t a t i o n or, perhaps, as preheat

f o r b o i l e r feed water.

I n the f i r s t instance a high temperature coolant

such as NaK would be required t o transport t h e heat a t an elevated

For heating feed water e i t h e r eooling water or l i q u i d metal transport of t h e heat should be s a t i s f a c t o r y , I n t h i s

temperature l e v e l -

design it was decided t h a t a l l decay heat would be rejected and t h a t cooling water would be used f o r transport around a l l vessels except the f l u o r i n a t o r s which would be a i r cooled.

It did not appear t o be economic

t o design a l i q u i d metal eooling and heat recovery system i n t o t h e chemical plant

-

reactor p l a n t eouplex i n t h e case of either; of t h e two

p i a n t s i n t h i s study.

Furthermore, t h i s study i n d i e a t e s t h a t a process-

ing rate of 1 2 f'r,3 /day i s uneconoriic f o r a power s t a t i o n as small

as

2500 Mwt; a chemical p l a n t of t h i s s i z e would be b u i l t only i n conjunc-

t i o n w i t h a much l a r g e r power-producing complex

- perhaps

5 t o 10

I n such a multi-megawatt system, it i s reasonable t o t h i n k of t h i s waste heat being recovered i n one of t h e r e a c t o r s t a t i o n s , titnes as large.

The eomplete cooling system f o r decay heat removal from both p l a n t s i s shown schematically i n Fig,

4.1. For

t h e most part heat i s

transferred across an a i r gaplfor secondary containment of e i t h e r leaking

salt o r water,int?o eooling water surrounding the seeondary v e s s e l o r thimble,

The p r i n c i p a l heat t r a n s f e r mechanism i s radiation; convection

accoun%s f o r perhaps 5 t o 10 percent of t h e t r a n s f e r ,

%re cooled by a i r c i r c u l a t i n g through the c e l l ,

The f l u o r i n a t o r s

Only i n t h e case of the

i n i t i a l catch tanks i n prefluorination storage i s if,necessary -to use a


TABLE 4.1

DECAY HEAT

IN MOLTEN SALT COIWWTER REACTOR

FUEL WITWRAWN FOR CHEMICAL PROCESSING 1.2 Ft3/Dag.

Tank No.

Length of Time Fuel Has Been Out of Reactor (days)

Tank Volume

(ft3) Pre

1

2

0-3 3-6

1

6-12

2

12-18

3 4

18-24 24-30 30-36 36-42 42-48 48-54 54-6c 60-66 66-72

7 8 9 10

11 12

13 14 15

16 17 18 1-9

3.6

3.6 7.2

Total

5 6

- Fluorination

72-78 78-84 84-90 90-96 96-102 102-108

108-114 114-120

Plant Maximum Heat Release kW -

BTU/hr

Storage 9.748 105 1.552 x LO5 11.300 x LO5

Pa-233 Decay Storage 24.39 x 7.2 19.91 x 7.2 17.21 x 7.2 15.29 x 7.2 15.84 x 7.2 12.71 x 7-2 11.79 x 7.2 11.03 x 7.2 10.38 x 7.2 9.82 x 7.2 7.2 9.33 x 8.90 x 7.2 8.50 x 7.2 8.14 x 7.2 7.82 x 7.2 7.52 x 7.2 7.24 x 7.2 5.99 x 7.2 6.75 x 7.2

4 4 10 4 io 4 10 4 10 io4 4 10 4 10 4 10 4 10 4 10 4 10 4 10 4 10 4 10 4 10 4 10 4 10 4 10

10

286

45.5 331* 5

71.5 58.3 50.4 44.8 40.6 37.2 34.5 32.3 30.4 28.8 27.3 26.1 24.9 23.8 22.9 22.0 21.2

20.5 19.8

Average Heat Release kW -

BTU/hr

2.000

1.356 3.356

23.14 19.18 16.69 14.91 13.55 12.47 11.59 10.86 10.23 9.69 9.22 8.80

8.41 8.06 7.74 7.45 7.18 6.93 6.69

105 105 105

4 x 10 4 x 10 x i o4 4 x 10 4 x 10 4 x 10 4 x 10 4 x 10 4 x io 4 x 10 4 x 10 4 x 10 4 x 10 4 x io 4 x 10 4 x 10 4 x 10 4 x 10 4 x 10

58.6 39.7 97.3

57.8 56.2 48.9 43.7 39.7 36.5 34.0 31.8 30.0 28.4 27.0 25.8 24.6 23.6 22.7 21.8 21.0

20.3 19.6

!-J W


TABLE 4.1

Tank No. 20

21 22

Length of Time Fuel Has Been O u t of React or ( days )

120-126 12~-132 132-138

Total

Tank Volume (ft3)

7.2 7-2 7.2 158.4

-

Interim 1

13 25 38 50 63 75 87 100 112

125 Total

138-146 234-242 350-333 434-442 530-5.38 Oj4-{:42 730-738 825-834

930-938 102~-1034 1130-1138

- contd

Waste

9.6 9.6 9.6 9.0 9.5 9.6 9.6 9.6 9.6 9.6 9.6 1200

Maximum Heat Release BTU/hr

6.52 6.31 6.12 236

4

x 10

x x

x

Storage

7.861 5.167 3.809 3.029 2.517 2.175 1.919 1.723 1.569 1.443 1.339 351

k" lo4 i o4 lo4

4 4 10 4 10 4 10 4 10 4 10 4 10 4 10 4 10 4 10 4

x 10

x

x x x x

x x x

x

x 10

lo4

19.1 18.5

17.9 693

23.0 15.1 11.2

8.9 7.4 6.4 5.6 5-0 4.6 4.2 3.9

1028

Average Heat Release kW BTU/hr

6.47 x 104 6.26 x 104 4 6.07 x 10 232 lo4

4 x 10 4 x 10 x 104 4 x 10 x 104 4 x 10 x 104 1.723 x 104 1,569 x i o4 1.443 x i o4 1.339 x 104 350 1.0~

7.845 5.160 3.805 3.027 2.515 2.173 1.917

-

19.0 18.3 17.8 678

ru

23.0 15.1 11.1

8.9 7.4 6.4 5.6 5.0 4.6 4.2 3.9 1025

-

0


TABLE 4.2

DECAY HEAT

IN MOLTEN SALT CONVE8TE33 REACTOR

FUEL WITHDRAWN FOR CHEMICAL PROCESSING 12 Ft3/Day

Tank No.

Length of Time Fuel Has Been Out of Reactor (days)

Tank Volume (f t 3 )

Be 1 2

3 4 5

0-5 5-10 10-15

15-20 20-25

Total

1 2

3 4 5 6 7 8

25-30 30-35 35-40 40-45 45-50 50-55 55-60 60-65

12

65-70 70-75 75-80 80-85

13 14 15

85-90 90-95 95-100

9 10 11

Plant

- Fluorination 60 60 60 60 60 300

Maximum Heat Release kw BTU/hr Storage

7.126 x lo6 0.812 x i o 0.627 x 10 0.522 x i o 0.448 x 10 9.535 x lo6

Pa-233 Decay Storage 60 3.935 3.505 60 3.166 60 2.886 60 60 2.655 60 2.459 2.290 60 2.144 60 2.016 60 1.902 60 1.800 60 60 1.707 1.623 60 1.547 60 1.476 60

x x

lo5 lo5 lo5 105

x

lo5

2087 238 184 153 131 2793

-

115 103 92.8 84.6

lo5

77.8 72.0 67.1 62.8

x lo5 x 105 105

59.1 55.7 52.7

lo5 lo5

50.0

x LO5

45.3 43.2

x lo5 105 x

x x

x

lo5

47.6

Average Heat Release BTU/hr kw

6 1.071 x i o 0.757 x 106

222

0.598 0.502 0.434 3.362

3.720 3.336 3.026 2.770 2.557 2.374 2.217

314

x

lo6

175 147 127 985

x

lo5 lo5 lo5

log 97.7 88.7

x 10 x 10 x 10

x

x x 105 x lo5 x lo5 x lo5 2.080 105 1.959 x lo5 1.851 x lo5 1.754 x lo5 1.665 x 105

1.585 1.512 x 1.444 x

lo5 i o5 lo5

-

81.2

74.9 69.6 65.0 60.9 57.4 54.2 51.4 48.8 46.4 44.3 42.3

[u

P


TABLE 4.2

-

cmtd

Length of Time Fuel Has Been O u t of

Rrnk No.

16 17 18 19 20

21

22

23 24 25 26 27

28

29 30 31 32 33 34 35 Tdal

Reactor

Avktrape

(days)

100-105 105-110 110-115 115-120 120-125 =S-l30 130-135 135-140 140-145 145-150 150-155 155-160 160-165 165-170 170-175 175-180 180-185 185-1W 190-195 195-200

1.412 x

bo

1.352 x 1.296 105 1.243 x lo5 1.194 x 16 1.147 x lo5 1.104 x lo5 1.063 x 16 1.024 105 0.w 105 0.955 x 16 0.920 105 0.a 105 o.sse 105 0.830 105 0.w 105 0.776 x 16 0.752 x Id

60 60

60 60 Go 60

bo 60

Go 60 60 bo Go â‚Ź0

60 60 60 60

-

2100

Interim waste 1

50 100

150 200

250

m 350 400 450 500 Total

Id 16

60

24 24 24 24

24 24 24 24 24 24 24

lxloo

0.728 x

16

% 2.737 x 104 1.584 x 104 1.040 x lo4 0.749 x 104 0.571 x 104 0.454 x 104 0.377 x 104 0,321 x io4 4 6.278 x 10 0.246 x 104 0.222

lo4

355

104 J

I

41.4 3% 6 9.0

36.4 35.0 33.6 32.3 31.1

16 16 1.270 x 1 6 1.218 x 16 1.170 x Id 1.126 x 16 1.m 105 1.044 x 16 x

40.5 g.0

105

J0.0

1.006 0.9-l x

21.0

0.9% x

26.0 25.1 24.3 6.5

0.813 x

0.936 x

16 16 16

16 0.m x 1 6 0.816 x 16 0.m x 16 0.764 x Id

21.3

0.740 x 0.717 x

20.7

0.695 x

22.0

kw

1.324 x

l.*

28.9 21.9

22.7

Heat Release

16 ld 16

1615 4

2.720 x 10

4.64 3.05 2.19

1.576

lo4

0.81

0.m x

4 4 10 io4 4 10 4 10 4 10 4 10

0.72

0.246

lo4

0.65

0.222 x 10

1.036 x lo

1.10

0.747 0.570 0.453 0.376

0.94

0.320 x

1.33

1040

21.0

20.4 -

1568

8.02

1.61

37.2 35.7 34.3 33.0 31.8 30.6 4.5 28.4 21.4 26.5 25.6 24.3 23.9 23.1 22.4 21.7

x x x x

354 x

7.97 4.62 3.04 2.19 1.67 1.33 1.10

0.94 0.81 0.72

4

0.65

loK

1037

I


L.

For these tanks a triple-walled

d i f f e r e n t design f o r removing heat.

bayonet arrangement i s used t o vaporize water i n a large number of these bayonets immrsed i n t h e s a l t .

4.2

Equipment Design Inasmuch as possible process eqilipment f o r t h i s design study w a s

patterned a f t e r previvusly designed s;nd t e s t e d equipmen? f o r t h e OIWL v o l a t i l i t y p i l o t p l a n t as described by Milford and ca-workers and co-workers.

'

6

and C a x

I n other instances, equipment and design ex;?erience

a t ORGDP and Y-12 were c l a s e i y fcillowed..

Extrapolations i n s i z e s were

made i n some cases f o r t h e l a r g e :plant; however, it is believed t h a t t h e l i m i t s of current technology liave not been exceeded.

Pertinent data on process equipment f o r both f l u o r i d e v o l a t i l l t y p l a n t s are given

ir;

the Appendix on t h e equipment flowsheets, drawfings

E-46081 and E-46059. Prefluorination Storage Tanks, -

Seven of these tanks are required

f o r t h e 12 ft3/day plert. ani two l o r ?;he 1.2 ft3/dag p l a n t .

Because

Df

t h e l a r g e amount of f i s s i o n p r d w z t decay heat is PFgreen''f u e l which is only a few minutes old, these vessels are i n effect heat exchangers. %'he proposed design'

for the Molten S a l t Reactor Experiment d r a i n tanks

has been adopted f o r the tanks which receive salt d i r e c t i y fkon t h e

reactor.

The MSRE design, shcvm. i n Fig, 4,2, was s u i t a b l e in a scale$-

down version for tine 1.2 ft31 /clay plant, b u t further modification w a s

necessary f o r t h e 12 ft3/day p l a n t as shown i n Fig. 4.3 because of t h e exceptionally high heat release per u n i t volume of s a l t ,

Heat, i s

d i s s i p a t e d by b o i l i n g water i n t h e i n t e r i o r annuli of t h e bayonets which penetrate t h e vessel heads,

The outer annulus of each bayonet

contains an i n e r t gas which i s monitored f o r leak detection. of t h e bayonets are shown i n F i g s , 4.4 and 4.5.

Details

The bayonet i n Fig, 4,4

corresponds t o t h e v e s s e l design of Fig. 4.2; t h e design of Fig. 4.5 corresponds t o t h e vessel ~f Fig. 4.3.

The 2 1 / 2 i n . NPS, sch 10,

sleeve surrounding each bayonet i n Fig. 4.5 i s required to maintain a s u f f i c i e n t l y t h i n s a l t l a y e r around each bayonet,


UNCLASSIFIED ORNL-LR NO. 66611-RI

Cooling Water Dmcharga To River J-T-P-

----1

--

1.

L-

---

I-I--B--~-~--1,----L---

_ PRE-FLUORINATION

.---i

-.._

STORAGE 12 1.2 f,‘/dOY f?J/paU 2 6 3.6 60* 3 25 331.5 2793 973 985 2 73 0.41 * * 6d.h ** 57.3

No. Tanks “olume Per Tank (11’) Days Holdup Maximum Heal Rslsare (kw) Average Heal R.?lea,e (km’) Wafer Vaporized in 11, Tank (mox gpml water Vaporized in 1st Tank (wQ Ppm) water Flop to ofhar Tanks (ma Qpm) Water Flow lo Other Tonkr(w 9Pm) ++z8 SIWII plant contains only MSRE typa boyomt ceders ++?Capocifles of Tanks No. ($2 30 ff? ea

I-.--FLUORINATION

No Tanks “dune Per Fluorination (0’1 liwrs Holdup Mawn”nl He4 Release (hwl Averape Had Release (kw) Coolant Air Flow

PO

3.6 5 45.5 39.7

DECAY

STORAGE

“oh Per Tank (ff’) D-ayr Holdup Maximm Heat Rck~ase (kwl tNeruJe Meat Release (hwl 57.5 Coobnt Wafer Flow (mm gpm) Coolant Water Flov (mq qin~) 55 6 5

r-----------I Water Discharge To River

L---------------

-----

- ________ INTERIM

STORAGE 1.2 ftkov& No. Tanks 125 W,,,e Per Tank IfI’) 9.6 IO00 Days Holdup IO28 Maximum Heat Release (kw) Averqe Heat Release (kw) 1025 88 coolmt Wohr Fkw (mox 9pm) Coolon, Water Flw (0~9 9pm 1 87

Fig.

4.1

Decay Heat Removal System for 1.2 ft3/day

-I

---___---------

WASTE

500 24 1000 1040 1027 88 88

and 12 ft3/d.ay Fluoride

Volatility

Plant.


25

UNCLASSIFIED ORNL-LR-DWG 6t719

r

INSPECTION, SAMPLER, AND L E V E L PROBE ACCESS

S T E A M OUTLET

CONDENSATE RETURN

WATER DOWNCOMER INLETS

BAYONET SUPPORT P L A T E

CORRUGATED F L E X I B L E HOSE STEAM RISER

STRIP WOUND F L E X I B L E

BAYONET SUPPORT PLATE HANGER C A B L E

HOSE WATER DOWNCOME GAS PRESSURI AND VENT L I N

INSTRUMENT T H I M B L E

F U E L SALT SYSTEM F I L L AND DRAIN LINE

SUPPORT RING

F U E L SALT DRAIN TANK

TANK F I L L LINE

H I M B L E POSITIONING RINGS

F U E L SALT SYSTEM F I L L AND DRAIN L I N E

Fig.

4.2

1

.L

TANK F I L L L I N E

Primary Drain and Fill Tank for MSRE


26

'5-k

-6" Soli

@I

t

UNCLASSIFIED ORNL-LR Dwg. NO.66622

4

-1"

NPS

3

0.25

/ I ,

,

ii

4

7

Salt

In

I

a''

Sch. 402

24" NPS

Fig

. 4.3

pipe

c a p 4

Pre-fluori n a t ion Storage Tank 12 f t3/day P l a n t .


27 UNCLASSIFIED 60838A

ORNL-LR-OWG

STEAM OUTLET

WATER INLET

STEAM DOME LOWER HEAD

FLEXIBLE HOSE

BAYONET SUPPORT PI-ATE

DRAIN TANK HEAD

Fig.

4.4

Bayonet Cooling Thimble.


20 UNCLASSIFIED 3RYL-LR DWQ No 66623

STEAM O ~ T L E ~

VrATER I L L T

S E A M DOME LOWER HiAC

.

__ -

I’

FLEXIBLE HOSE

~

h . i

F i g . 4.5

Typical Cooling Bayonet 12 f t3/day Plant.


The 1.2 ft’/day

L

p l a n t contains two of t h e MSRE type tanks i n t h e

prefluorination storage system, The two tanks are used a l t e r n a t e l y , The 12 ft3/day p l a n t contains two bayonet-filled tanks of 30 f t3 capacity each and f i v e other tanks of 60 f t 3 capacity each.

The f i v e tanks i r e

cooled by radiation and convection t o water-jacketed thimbles as shown i n Fig. 4.1.

Four of %he group of fiTre tanks are f o r f i s s i o n product decay

storage and t h e f i f t h i s a feed tank f o r t h e flQoririator.

I n operation,

f u e l i s held f o r f i v e days i n t h e two 30-ft3 tanks and then t r a n s f e r r e d t o one of t h e other storage tanks f o r t h e remainirg 20 days storage. A brief descrfption of t h e tanks required f o r preflxorination

storage i s given is=Table 4.5 f o r fmth t h e 1.2 and 12 f%’/day plants.

Table 4.3.

Days Storage

Pref luorination Starage Tank Requirements

No. Tanks Method of Cooling 1.2 rt3/11ay Plant

0 -3

2

$9 bayonet “cJbes

Nominal Size (ft) -

1.94D x 1.9413*

12 ft3/Day Plant

0-5 5 -15

2**

2

5.5D x 5.5H* water-jacketed thimble 3.2D x 7.6H

15-25

2

water- jacketed thLmble

1

water- jacketed thimble

Fluorinator feed

295 bayonet tribes

3.2D x 7.6H 3 2D x 7.6H e

-n

Does n o t . i n c l u d e stem dome

*x-These

two tanks have 30 f t3 capacity. The l a r g e diameter i s necessary

t o home the l a r g e number of bayonet tubes i n the i n e f f i c e n t s a l t storage arrangement required by t h e high heat release of t h e salt. Fluorinator.

The f l u o r i n a t o r design5 i s showr, i n Fig. 4.6; t h i s

i s t h e v e s s e 1 , t h a t has been successfully operated i n t h e ORNL f l u o r i d e v o l a t i l i t y p i l o t plant. The v e s s e l i s shaped like a dumbbell having a lower f l u o r i n a t i o n chmber and an -Jpper de-eatmimerit section; t h e


UNCLASSIFIED ORNL-LR-DWG 39150

+ PRODUCT OUTLET

SOLIDS SETTLING CHAMBER

VESSEL SUPPORT

CORROSION SPECIMEN

FURNACE LINER -

,FLUORINATION

CHAMBER

DRAFT TUBE

FLUORINE INLET

WASTE SALT

0

5

- - - - - - - - - - I

10

INCHES

Fig.

4.6 Fluorinator.

15

20


lower assembly i s enclosed i n an e l e c t r i c a l l y heated furnace, and t h e upper assembly i s heated with e l e c t r i c s t r i p heaters.

Similar designs

were used f o r these two studies; t l n e l a r g e p l a n t f l u o r i n a t e d 6-ft 3 'outches, t h e small p l a n t f l u o r i n a t e d 3.6-ft3 batehes, The p r i n c i p a l design c r i t e r i m for t h e f l u o r i n a t o r i s t h a t t h e vessel be able t o d i s s i p a t e f i s s i o 3 product decay heat and heat of r e a c t i o n by radiatiol- and convection t o t h e cell.. exironment.

Whereas,

t h e v e s s e l might be cornstmcted l i k e %he p r e f l u o r i n a t i o n decay tanks wi-bh a l a r g e heat tracsfer capacity, it; i s ucdesirable t o do so because

of t h e high corrasio9 rate duri3g fluorinatiorr.

construct t h e vessel

&E

It i s advisable t o

simply arid cheaply as possible sinee it must The v e s s e l i s made with thick, 1/2-:'inch,

be rather frequently replaced.

walls w i t h a corrosion rate allowame of one m i l p e r hour of f l u o r i n a t i o n

time The preferred materials of construction f o r %he f l u o r i n a t o r are

e i t h e r INOR-8 o r Alloy 79-4 (79$ N i , 4% MG, 17%Fe),

L-nickel has been

used f o r f l u o r i n a t o r constyuction, but t h i s material i s q u i t e susceptible

t o i n t e r g r a n u l a r attack.

-radioactive -product,s) CW Trap and Absorpers. The CRP (complexible . be ar? i n t e g r a l par% of the N a F absorber or t h e two u n i t s might t r a p6 may be separated. In e i t h e r case, operation of t h e uzzits i s a batzh process, ar?d t h e choice of an i n t e g r a l o r separate i n s t a l l a t i o n depends upon t h e

physical. s i z e of t h e miLs.

I n t h i s case the 1.2 ft3/day plant could

employ t h e i n t e g r a l u n i t ; t h e 12 ft3/day plan% required separate u n i t s , The CRP t r a p and absorber are f i l l e d w i t h sodium f l u o r i d e p e l l e t s having a, bulk s p e c i f i c g r a v i t y of 0.9.

The design absorption capacity of IJaF i s

21 kg UF6/ft3 NaF.

The movable-bed absorber

6 (Fig, 4.7) has been designed f o r the small

p l a n t t o handle t h e quasrtity of UFlj from batch. f l u o r i n a t i o n s every Ghree days,

The bed operates semicontinuously by receiving f r e s h NaF pellet:; a t

t h e top and discharging fission-product saturated p e l l e t s a t t h e bo'ztorn,

It may not be f e a s i b l e t o discharge p e l l e t s i n t o t h e f l u o r i n a t o r as shown I n Fig. 4.7 i n these p l a n t s because of contamication of Pa-233 sti1:L i n


32

the waste s a l t .

Important f e a t u r e s of the u n i t a r e four separate

e l e c t r i c a l l y heated zones and an i n t e r n a l pipe f o r a i r cooling and thermocouples

.

The stationsry-bed absorber (Fig. 4.8) as used i n %he 12 f t3/day

plant contains j u s t over one cubic f o o t of NaF; six absorbers a r e required for the 42.6 kg UF6/day rate.

Ekch absorber i s mounted i n a

light.weight, low-heat, capacity e l e c t r i c furnace which i s hinged f o r easy 0

removal; t h e furnace permits operation between sorption (100 C) and desorption ( h O ° C ) temperatures.

A 2.5-in.

outside diameter tube extends

down the center of the bed for admission of cooling air; the tube a l s o contains e l e c t r i c heaters.

An i n t e r i o r c y l i n d r i c a l b a f f l e causes gases

t o take U-shaped path through the bed, The governing design c r i t e r i a f o r an absorber are t h e r a t e a t which the bed can be temperature cycled and the bed thickness.

The

granular bed i s a r a t h e r e f f e c t i v e i n s u l a t o r and has t o be made i n t h i n sections t o f a c i l i t a t e heating and cooling. a large L/D rat.io,

Each absorber therefore has

When t.he bed becomes sat;clrated w i t h f i s s i o n products,

the absorber i s removed, emptied and recharged remotely on a 4-5 day cycle. Cold Traps.

Cold t r a p s f o r desublimaticn of m6 being desorbed

f r m the NaP beds a r e similar t o those used i n the ORNL v o l a t i l i t y p i l o t plant..

TWCITrsps a r e mounted i n s e r i e s :

The f i r s t , o r primary

0

Trap, i s operated %T zdm~t -=b C; t h e second t r a p i s a back-up t r a p

operated a5 abour. - 6 0 ’ ~ t o c a k h any product t h a t might have passed through the prlmsry trap.

The two t r a p s a r e shown i n Figs. 4.9 and 4.10.

These two traps are i d e n t i c a l t o the ones required f o r the 1.2 f t3/day plant; the l a r g e r p l a n t requires a longer primary t r a p , but t h e second t r a p i s The same as f o r t h e small p l a n t , The p r i n c i p a l fact-or i n design i s t h e heat t r a n s f e r r a t e . surface f o r UF6 coilectLor, must a l s o be provided,

Adequate

Also t h e u n i t should

have a l a w heat capacity t o expedite temperatme cycling between batchwise c o l l e c t i o n s ,

During defrosting the cold t r a p s are heated t o about

90°C at a pressure of around 46 p s i a t o allow melted UF6 t o d r a i n t o c c l l e c 5 i m cylinders


33

UNCLASSIFIED ORNL- LR- DWG 5045f

NaF CHARGING CHUTE

1 V2-h. NPS, SCHED -40 ( AIR COOLING AND THERMOCOUPLES )

5-in. NPS, SCHED-40 INCONEL 100 OR 4 0 0 째 C

TO CHEMICALTRAP

100 OR 400째C

TRANSITION

5-in. NPS, SCHED-80 INCONEL HYDRAULIC CYLINDER

FLUOR1NATOR

F ig

. 4.7

Movable Bed Temperature-Zoned Absorber.


34 UNCLASSIFIED ORNL-LR- DWG 39257

COOLING AIR INLET *OUTLET

1 I

SCHED 40

,b t >-’

ELECTRICAL RODTYPE HEATERS 4000 - W TOTAL

‘43 x b8-in. DIA NaF PELLETS-.

MATER I A L : INCONEL

‘/8-in. WALL---

- -

‘7

1,.’

’14-h. PLATE-

THERMOCOUPLE WELL& Fig. 4.8

L

,. -

- ..

Sodium Fluoride Absorber for UF6.


UNCLASS IF1ED ORNL-LR-DWG 19091 R-l

OUTLET

,

/

, /

OUTLET END

w

u7

CARTRIDGES

'\.-5-m

SPS COPPER PIPE

-GALROD HEATERS ( 6 ) INLE

12 c I c I - c I c J -'i-:-o-

12 SCALE IN INCHES

--INLET END HEATER

- - Fig.

4.9 Primary Cold

Trap.

24


UNCLASSIFIED ORNL-LR-DWG 19088 R-l

WELL -

-1-

.

i _-

o

c .c d - ' c

t

m

I

4

WELL 0

i

INCHES F i g . 4.10

6-in. Cold Trap.

-~

j


37 The rigorous design of a cold t r a p t o prevent dusting o r fogging of UF6 i s d i f f i c u l t ,

However, considerable design and operating experi-

ence i n both f i e l d s has been gained a$ 0RGDPe7 The design shown i n

Yig. 4.9 was developed a t ORGDP whi;..e t h a t h;hown i n Fig. 4.10 i s an ORNL adaptation of ORGDP develo2men-k.

Reduction R e a c t n ,

The UF6

+

TJF, r e d u c t i x r e a c t o r f o r these plarrts 4

'4

i s patterned a f t e r t h e one described by Murray,"

The reac5or is a 4-in.,

diametel. by 1 0 - f t high c o l x m having a capacity of 10-13 kg UF6/hr, even s x h a, a n a l l reac",r

Since

has a ncch g r e a t e r ea2acfty than required by

e i t h e r of these plants, t h e operatiorl i s hat-.hwise,

Uranium hexafluoride

and f l u o r i n e a r e csxtactod with excess hydrogen in a nozzle a t t h e t o p of t h e r e a c t o r l

The hexafluoride i s reduced t o t h e t e t r a f l u o r i d e i n

t h e H -F flame and i s collected i n a tank of molten c a r r i e r s a l t a t t h e 2 2 bottom of t h e column. Gaseous reac:;ion products leave t h e r e a c t o r through

a filter, Fuel Make-ug.

Fuel make-ilp vessels a r e nothing more than heated,

insulated vessels located p a r t l y i n t h e radioactive processing area and p a r t l y i n a cold make-up area.

The cold make-up tanks a r e provided with

l i n e s f o r admissiofi and removal of aparge gases, â‚ŹI+. HF, needed i n !;he 2 p u r i f i c a t i o n procedure. Yurificatfon requires gas sparging f o r four

days; t h e tanks a r e designed t o ope:rat,e on a five-day cycle, Pa-233 Decay Stora&?-Systex, _y__-

wasbe & r e a m

sipat903 *om

The destgn of a system fcjr holding t h e

f o r Pa-233 decay resolves i n t o providing adequatie bea% dis-

t h e several tanks.

Bstches have t o he kept separated be-

cause of t h e fixed decay storage requirement. I n t h e 1 2 fi3/day plan%, storage i s c a r r i e d out i n 60-ft 3 batches equivalent t o t h e q u a c t i t y withdrax2 every f i v e days from t h e r e a c t o r . Fission product decay heat i s removed by allowing t h e vessel t o r a d i a t e t o a water-Jacketed thimble which surrounds t h e s i d e and bottom of t h e

mere a r e 36 tanks i n t h e array; each tank has a noninal capacity of 60 fi3. Dbensions a r e 4.5 f't d i a a e t e r by 4,5 f% high. The jacketed t h h b l e i s a b m t one foot l a r g e r i n i n s i d e d i m e t e r than t h e storage tank. tank.


38 The storage problem i n the 1.2 f t3/day p l a n t i s similar t o that of Heat i s d i s s i p a t e d by r a d i a t i o n and convection from

the larger plant.

Twenty-four tanks are

the vessel surface t o a water-jacketed thimble.

needed, each having a nominal capacity of 7.2 f t 3 and nominal dimensions of 1.66 f t diameter by 3.32 f t high. The jacketed thimble i s about one f o o t l a r g e r i n inside diameter than the storage tank. Interim Waste Storage Tanks.

Interim waste storage tanks are sealed

c y l i n d r i c a l containers made of s t a i n l e s s steel which can be used f o r permanent waste storage a f t e r t h e interim period.

The tanks f o r t h e small

p l a n t are 16 i n . diameter by 7 f t long and for the l a r g e plant, 2 - f t diameter by 7.5 f t long. Thimbles i n which the waste tanks rest while i n t h e storage canal Each p l a n t has l 5 - f t long thimbles, but

a r e made of s t a i n l e s s s t e e l .

those i n t h e s m a l l p l a n t are 2 - f t diameter while those i n the large p l a n t

are 2.75-ft diameter. Freeze Valves. process l i n e s .

Conventional valves cannot be used on molten salt

Instead, closures i n l i n e s are made by f r e e z i n g a plug

i n the l i n e using a j e t of cooling air blowing across t h e area t o be frozen.

Conveniently located e l e c t r i c h e a t e r s a r e then used t o thaw

the Line when flow i s desired.

A photograph of a proposed f r e e z e valve

i n s t a l l a t i o n for the MSRE i s presented i n Fig. 4.11. Line Heating.

Whenever p r a c t i c a l autoresistance heating w i l l be

used, Samplers.

6 i s required t o remove

A r a t h e r complicated mechanism

a n a l y t i c a l samples from a molten salt system as shown i n Fig. 4.12. pictured apparatus i s being t e s t e d f o r use i n t h e MSRE a t ORNL.

The

Essential

f e a t u r e s of the sampler are t h e h o i s t and capsule f o r removing the sample from t h e vessel; a lead shielded cubicle w i t h manipulator, heating elements and service piping; and a t r a n s p o r t cask for removing the sample from t h e process area.

"he sampling cubicle i s mounted on t h e c e l l b i o l o g i c a l

s h i e l d i n an accessible area. Refrigeration. traps,

Low-temperature r e f r i g e r a t i o n i s needed f o r t h e cold

One trap operates a t

-hoc

and a second o2erates a t -75OC.


39

Fig. 4.11 Freeze Valve.


40 om-mmg.

59206

Unclassified

@

INDICATES BUFFER ZONE

J OUTER 5TKL 5fld-L

F i g . 4.12

Sckematic Layout of MSRE Sampler-Enricher System.


4.3

Shielding Calculations Shielding calculations were made t o compute biological s h i e l d r e -

q1JfremerAs f o r processing areas. radioactive "green" fie:

1% was recognized t h a t t h e extremely

only a few minutes out of t h e r e a c t o r would r e -

quire t h i c k sklelding, sfgnif$%ntly a f f e c t i n g building s i z e an.d cos%*

8

The c a l m i a t f o c s were m d e using a program far the IBM 7090 computer; ths program i s able tc ",Pea% cylir-ldrieal, voltune.tsic: so~upceswhich a r e

applicable i n these casesI, The code employs such parame%ers a s souxce streng-t,kz, s o ~ r c egeame5k.y and dimensions, vessel maf,eriaL and lona-bion wiSh rzspec3 t o %op a2d side shfeld t o calculate efthey chfeld thickr-ess

o r dose r a t e .

S&lf-aksorptEon by Lkie scmree i s a l s o taken i n t o acr,n.;,Tt

a

Shield material w a s ordinary eancrete. Source Strength.

m-e s h f e l d i r g program w a s m i t t e n more s p e c i f i -

c a l l y f o r a solid-,%eied

r e a c t o r thtin f o r a c i r c u l a t i n g f i e 1 reactor, and

minor modifications had 50 be made f.n calclllatfng t h e source s t r e n g t h , The ac%ivi-t;yof W-235 fLssi02 prodccts as a finctlon of i r r a d i a t i o n time

and cooling t i m e has been rr=pol-i;ed Fy B1mek.e md Toddg f o r s o l i d fuel normalized to one atom of origfaal ffssEle feed.

This implies a kr-owlecige

of f u e l burn-u2, a q a a n t i t y %ha% i s no$ so well defined f o r a c i r c u l a t i n g

fJel

For these cizlcz2af,fans J;k$ fractLm. b a x - s p was determined usfng;

terms defined i n Fig.

4.I3

where q u a n t i t i e s in $he frac"cm are expressed i n coln,sEstent wits such as &/day,

Feed ineludes bQth make-up f i s s i l e material and t h a t p a r t of

f e r t i l e material t h a t i s cowerteed -to f i s s i l e material.

The number of

o r i g i n a l atoms of f i s s i l e material present was the3 calculated from equllibrfum r e a c t o r concentrations. Original concen%ra+,ionU presernt =

Equilibrium coicentra%ion U-233 1 BU

-

-k

U-233

"he data of EXLmeke a r d Todd were %net used with this calculated o r i g i n a l

eoacen5ration t o oktaain source sSre:rrg",s

An terms of d i s i n t e g r a t i o n s l s e c

.


42

It was assumed t h a t the f u e l had been i r r a d i a t e d f o r an i n f i n i t e time a t a thermal 'neutron f l u of 1013 neutrons/cm 2 sec. The f u e l i n t h i s system i s predominately U-233. However the data of Blomeke and Todd f o r U-235 f i s s i o n product-s were used because no comparable data f o r U-233 were available. Geometry.

In a l l calculations shielding requirements were determined

f o r top and side shields as shown i n Fig. 4.14 using t h e c r i t e r i o n of 0.25 mrad/hr dose r a t e a t the shield's external surface. When several process vessels were aligned along a wall as shown i n Fig. 4.14b9 t h e dose r a t e was eanputed f o r several shield thicknesses, tl,

tij t:,

---9

.taking i n t o

account contributions from adjacent tanks. The data were plotted t o determine the required shield thickness f o r a 0.25 mrad/hr dose rate. Comput a t i o n s were made for arrays of 3 and 5 tanks, and it was observed t h a t the dose cont-ribution from the fourth and f i f t h tanks (extreme end tanks) could be ignored, Summary of Shielding Requirements,

Shielding requirements for process, storage and maintenance areas i n t h e two p l a n t s a r e given i n Table 4.4,


43

UNCLASSI FlED ORNL-LR-DWG 65605

Chemical Processing Plant

Recycle

-

Burn-u p (as fission products)

Feed (thori urn

+

uranium make-up)

Fig. 4.13

Schematic Diagram f o r Computing Fraction Burn-Up.


44 UNCLASSIFIED ORNL-LR-DWG 65606 Dose Point on Top Shield

I

(a) Elevation

(b) Plan

Fig.

4.14

Geometry Considerations i n Calculating Shield Thickness.


45 Table 4.4 L

Shield Thicknesses f o r t h e 12-ft3/day and 1.2.-ft3/day

Molten S a l t Fluoride V o l a t i l i t y Processing Plants Thickness of Ordinary Concrete ( f t )

Prefluorination storage top shield Prefluorination seorage side shield 1 s t f l u o r i c a t i o n top shield

is% f l u o r i n a t i o n side shield 2!nd f l u o r i n a t i o n top shield

2nd f l u o r i n a t i o n side shield

12 ft3/day p l a n t

1.2 f t3/day p l a n t

7.5 71.5 7*5 7.5 4.0 7.5

6.25

7.5 6.25

7.5 6,25*

7.5

Pa-233 decay storage s i d e shield

5.5 545

6.25* 6.5*

Redliction and f u e l make-up area top shield

4.0

4.0

Reduction and f u e l make-up area side s h i e l d

4.0

4.0

Interim waste storage t o p s h i e l d

4.75

4.5

Interim waste storage side s h i e l d Crane maintenance area top s h i e l d

5.0 4.0

5.0

Crane maintenance area side s h i e l d S%ornge area top shield

4.0 6.5 4.0 6*5 4.0 4.0 4.0

Pa-233 decay storage top shield

Stcrage area side s h i e l d Decontamination area top s h i e l d Decontamination area s i d e s h i e l d Shop area t o p shield Shop area s i d e s h i e l d

*Shield

~

~- __

3.0 4.0

6.0 4.0 6.0 4.0

4.0 4.0 ~

-

-

thickness detemined by prefluorination s h i e l d requirements since

a l l eqtlipment i s same area.


46 4.4 Process Equipment Layout Process e q u i p e n t has been l a i d out i n a r e a s according t o the major process operations:

prefluorination storage, first f l u o r i n a t i o n , Pa-233

decay storage, second f l u o r i n a t i o n , Na;F absorption, cold t r a p s and product collection, uF6-+w

4 reduction, and interim waste storage.

Equipment i s

grouped i n c e l l s according t o a c t i v i t y l e v e l and i n an arrangement t h a t minimizes distances for molten salt t r a n s f e r between vessels.

Five trans-

fers of molten salt are required i n the processing sequence f o r t h e

1.2 f t3/day plant.

F i r s t , t h e irradiated f u e l i s t r a n s f e r r e d from the

r e a c t o r t o prefluorination storage; second, t o the f i r s t fluorination;

third, t o Pa-233 decay storage; fourth, t o the second fluorination;, and f i f t h , t o waste storage. The operational sequence i n the 12 ft3/day p l a n t i s the same with an a d d i t i o n a l t r a n s f e r i n p r e f l u o r i m t i o n storage brought about by economic heat remcval considerations. Interim waste storage v e s s e l s can most conveniently be stored i n an a r e a immediately a j a c e n t t o but not d i r e c t l y a pa& processing area.

of t h e p r i n c i p a l

A r a t h e r large canal i s required t o contain t h e large

number of waste tanks.

After approximately lo00 days residence, the

waste tanks are t r a n s f e r r e d t o permanent storage. A very important consideration i n equipment layout i n s i d e t h e c e l l s

i s the remote maintenance aspect which has beer, assumed f o r these processing operations.

Vessels must be arranged so t h a t all. pro6ess and service

?mr,eztim.s can be remotely broken and remade and a11 equipment must be a x e s s i b l e from above.

O v e r - a l l b u i l d i n g apace i s often d i c t a t e d by

remote maintenance cansiderations rather than by a c t u a l v e s s e l size.

It

s h m l d be poin%ed out t h a t t h e r e has been no a c t u a l experience i n remote

main-5enmc.e of a molten salt f l u o r i d e v o l a t i l i t y p l a n t and khat the necessary space requirements for such a p l a n t may not have been f u l l y rewgnized i n t h i s study.

Considerable development of both equipment and

oyera%ing technique w i l l be required t o f u r n i s h adequate design information.

4.5

Plant ~ y 0 u . t ; I n order t o establish uniformity i n cost, estimation of nuclear power

plants, t h e A t m i c Ehergy Coxnissionll has specified c e r t a i n ground rules


47 covering s i t e location, topography, meteorology, climatology, geology, L

a v a i l a b i l i t y of labor, accounting procedures, f i x e d charge r a t e s , e t c . These recommendations were followed i n t h i s study.

A concurrent c o s t

evaluation f o r a molten salt r e a c t o r p l a n t by ORNL and Sargent and Lundy 12 Engineers used t h e sane basic ground r u l e s making the two p l a n t evalu-

&$ions congruent. S i t e Location.

The hypothetical s i t e location i s 35 miles north of

Middletown, a c i t y of 25O,GOO population,

The p l a n t i s located on the North

River, a stream t h a t i s navigabie t o boats having up t o 6 f t draft.

There

i s ccnvenient highway and railroad access. The p l a n t i s located. OE l e v e l t e r r a i n i n a grass-ewered f i e l d .

The

e a r t h overburden i s 8 f t deep; below t h i s depth i s bedrock. Over-all Plant Layout.

A remote maintenance chemical p l a n t i s most

conveniently laid out i n a canyon-type arrangement, which i s a long, heavily shielded s e r i e s of i n - l i n e c e l l s semiced by an over-head crane.

The depth

of t h e canyon i s determined by location and s i z e of i n s t a l l e d equipment; the width i s determined by v e s s e l s i z e and span l i m i t a t i o n s f o r the crane. The over-all building length i s more o r l e s s determined by the length of t h e canyon.

Offices, control room, laboratories, sample gallery, ware-

house, shop and other service a r e a s are placed along a f a c e of t h e canyon i n a manner t h a t i s consistent w i t h good design and functional f a c i l i t y . In t h i s study advantage was taken of a design study and operating experience with a remotely maintained radioactive chemical p l a n t by FarrowL t o obtain over-all p l a n t arrangements shown on drawings E-46059,

E-46067, E-46079, E-46068, E-46069, E-46081, and E-46080 i n t h e Appendix. Processing Area.

Processing c e l l s a r e located i n the c e n t r a l section

of t h e canyon and a r e the most heavily shielded p a r t s of t h e plant.

In

the 12 f t3/day plant, f o u r c e l l s are employed; i n the 1.2 f t3/day p l a n t , C,hree c e l l s are used.

Because of t h e lower t o t a l a c t i v i t y and fewer

process v e s s e l s i n t h e small p l a n t , one of the shielding p a r t i t i o n s

could be eliminated. Prefluorination storage and first f l u o r i n a t i o n v e s s e l s a r e located near t h e center of the canyon and convenient t o ,the r e a c t o r area,


48 Immediat;ely adjoining ( i n t h e same c e l l f o r %he small p l a n t ) i s t h e c e l l containing t h e second f l u o r i n a t i o n and absorption equipment.

This arrangement permits carrying out t h e most radioactive operations i n a compac-5 baya t minimizing the amaculf cf t h i c k (7.5 ff,shieldin& )

J

The remaining pzwcess area contains produe% cc;llez$ian and reduction

equipment f a r carrying cut +,he UF6

3

UF4 reaction.

Al-khuagh t h e product

6

at, t h i s point. has been decontaminated by a f a c t c r of 10 or greater, shielding i s r e q u b e d Lo a t t e m a t e t h e ganma a c t i v i t y of U-237.

Four feet; of

ordinary concrete s u f f i c e s t o s h i e l d t h i s a r e a ,

This c e l l a l s o contains ?-,be d i s s c l v e r f o r blending recovered fie1 with make-.%p fuel introduced *om t h e outside, Fuel is recycled t o t h e r e a c t o r e o n t h i s tank. The larges+, process area a f t h e canyon i s

Pa-233 Decay Storage.

occupied by "dead" storage t o segregate batches of waste s a l t while allowing Pa-233

decay.

For convenience t h e area i s l o c a t e d adgacent t o 5he first fluorinator. An area 27 ft wide by 92 f-1; long was provided f o r t h e l a r g e plant and one 23 ft wfde by 74 fc, l ~ n gfor t h e snall p l a n t . $0

Was5e Storage,

Waste ssorage geed not be Located i n %he process

canyon because %ere i s negligible f i s s i l e material i n t h e waste and no f w t h e r pr~eessopera5ions are performed on $he was%e. F a c i l i t i e s a r e prcvided i n a caaal ac2Jshb.g %he canyon ?e sSme wasze conzainers until

eact zari

tramspc.r5ed

The area is rec+,a?&a_r TZ 6

c m w m,s5

50

permanen*, s t x a g e a% sme remote Loeation.

wffh t h e w5.d-C.h b e b g t h e deperdent dimension.

S;e prcxtded 50 service the areag t h e width is governed

In shese plant,s over-all canal dimensions a r e 48 f% wide ky 181'5 h'f lcng and 37 ft; wide by $ M; long 7y

crane s p a and c ~ s esr,sidesations. t

fcr she l a r g e and small p l m t s , respectively. :r

a de?%h cqf 16 5 f% e

.

Ehch canal contains water

Wasfe containers a r e transported from i n s i d e 5he canyon t o tihe waste s 5 x a g e area v i a a car3 an a t r a c k which runs fnrough t h e s i d e s h i e l d .

A

dkxtle door arrangemen3 Ss used i;c? maiztain T*,scla%Jo:zof %he two areas

dwiw Lrmsfer Crane Maintenance Area.

Since t h e overhead czane is t h e p r i n c i p a l

tr.oc.i f o r carrying cu.% a l l mait;fer,anze operat;iou?s in the a r e riwessary -x keep I: i, n gmd aperat,ing c m d i f k o n ,

C ~ E ~ O M f,a c i l i t i e s

An area a t one end

J


of the canyon i s s e t aside f o r crane maintenance; t h i s area i s equipped with a small crane t o service t h e l a r g e r crane.

Decontamination pro-

v i s i m s a r e made for this area t o allow persorael access,

Canyon Shc3~. This cell. i s a 1fn;ited persomel access area for perforrnir4 maintenar,ce

C :I

cm.ic,amSnated equipmen%. Before entering t h e shop,

vessels and other eqaEpmmt FratAd have been decontaminated s u f f i e i e n 5 l y

f o r controlled corrtazi; work bxt as5 sGfficiently for removal t o "cold" sho2, Railroad Dock.

A raiLroad dsclr Es prcjvided a% one end of t h e canyon

far receiving $nto c.r remwhg l2m %Be canyctn vessels and other equipment, The dock i s i n a nmradicmcS3f're area 5-xt c m be served by t h e l a r g e bridge crane csed over dbe c4as~c9n. R o l l - - p steel dcors separate t h e dock and crane bay over the pm~":+sc ceils, Cos,tml R o m e %a e*mk0:3. rooa is located ad3acen-h t o t k e biological s h i e l d a t c e l l t a p level. DE roan extends alcmg the s h i e l d face d i r e c t l y opposite t h e c e l l s 22 which t h e pri:ncipal process operations of fluorina-

t i o n , absorption, pr&x=.C,c@.l,leeticrnand reduction a r e c a r r i e d out as well

one area t3 another.

F r o m t h i s area sS1 process

operations can be contrro12ed and performed.

Remote naahtenance i s a l s o

as salt tramfera

f!rcllm

c a r r i e d out from t h e control room with t h e aid of t e l e v i s i o n . Sample Gallery. cubicles (see Fig,

mis

space contains t h e heavily shielded sampling

4A2) and transport; equipmeat, The g a l l e r y

i s located

over t h e control rotm ~n t h e s h i e l d Face cear t h e f l u o r i n a t i o n and re-

1% I s anticipated Sha$ process controZ and accountability zac be aeeomp2ishecl hy sam-$.:'.ng t h e f"lljwin_aJ:c~r;s and grod?iet dissolver

ductim cells.


Laboratories.

Adequate a n a l y t i c a l f a c i l i t i e s a r e provided i n t h e

chemical plant t o process all samples f'romthe r e a c t o r plant as well as t h e chemical p l a n t , Analytical caves a r e prcvided f o r highly radica c t i v e analyses. The analy%icaL area i s a cont,rc1led access area separa%ed

*om

from t h e nonrestricted areas by an a i r l o c k , Offices.

Office space i s provided a t grmnd leve.1 n e a r t h e center of

t h e building e Service Areas,

The remainder of t h e building spaee is occupied by

service f a c i l i t i e s necessary f o r an integrated chemical p l a n t ,

These i n -

clude mechanical and instrument shops, f i r s t a i d room, lunch roomg change room, t o i l e t s , warehouse and receiving dock, elevators, @oldchemical makea p space, e l e c t r i c a l %ramformer and sW-tch gear room, refkigeration equfp-

ment spaee, a i r conditioning equipment space, compressor space and pipe corridors, Most of these areas a r e located below grade along t h e face of t h e process canyon, 5.0

CAPITAL COST ESTIMAlT

The c a p i t a l cos? estimate w a s divided i n t c t h r e e prrEncipa1 categcries: bufjding costs, process equcipment costs, and a u x i l i a r y process equipment and services e o s t s a The building cosss included such items as s i t e prepaT~+LGD,

sCmckral materials and la$cr, permanefitly i n s t a l l e d equipment,

ar,d marerial and l a b o r f o r service facili+,ies

Prccess equipmen3 cos%s

w e r e c a l m i a f ; e d f o r those J;anks, Tressels, f-wnaces and similar items whose

prhary

~~JCSSPCD is

dfrecZly ccficerned v i t h prccess o p e r a t i m s

Process

ser;tse f a c i l i t a e s a r e izems such as sampling f a c f l i f ; i e s , process piping a i d prccess inst,rumenr,as,ios which a r e intimately associated with process cqera+,Tors 5.1

Aczi7tir=r,fs! PPocedga e

-

The ac:%n",ng p r c c e d u e s e t f o r t h i n t h e Guide 50 Nuclear Power plant 11 Cos5 E m k a t i i was used as a guide i n t h i s e s t i m w . This handbook was w$%eE as a a i d e f o r c o s t e s t h a t i n g reactGr plants, and t h e a c e o u t i n g

b x a k d o m is no5 specfffc for a chemical processin@;p l a n t .

Where necessary

f x c l a r 2 f f z a t l o n and comple%eness, t h e acscoaxtirig pmcedures of %he handPcck were ai-xgmexrt,ed by establfshed Chemical Technohgy Division methods.

'


3.2

Bases f o r Estimates Process Equipment,

A l a r g e nuraber of process vessels and a u x i l i a r y

equipmest i z n these plants i s s i m i l a r t o equipnent previously purchased by OR?& for the fluoride =mla".,ility pi:-&

available

plant f o r wkfch cost records were

Extensive u s e was made of these records i n cornpiking material,

fabrica-Lion and over-a11 ecpipment c m t s ,

I n some cases it was necessary

zrj exlzapolate t k e da-Ltz t o obtsin costs f o r l a r g e r vessels; however, f o r some eqxipment i n t h e small plant, t h e data were d i r e c t l y a p p l i c a b l e ,

X"z,ms

f;i.;at were estimated i n t h i s mtanner were ",fie

Na.F ab~fri-beraand CRP tzraps.

flaorinatcsr*s, Prrrnncer;,

'The c o s t of t h e W

6- to-UF4 reduction u n i t 14 was based on a uni$ described by Murray. The u n i t had a l a r g e r cagaci-ty than was needed f o r these plants, but it was assumed t h a t +,he required u n i t w c d d have about the same over-all c o s t .

Refrigeration eq-aipment ant? cold

t r a p s were est5n;ated f'rom c a s t data f o r ORGDP7 and ORNL equipment, Some items o f process equipmen-; were of special design and s i g n i f i caritly differect, from any vessels f o r which cost data were a v a i l a b l e .

The

prefluorinatior, s3orage tmks which receive i r r a d i a t e d f k e l d i r e c t l y from t h e r e a c t o r a r e exampLes.

The cost of t h e s e vessels was calcula%ed from a

preTiious cost, estimate made by $he V-12 machine shop on a similar v e s s e l

fcr the Molten S a l t Reactor Ex-perhent.

For vessels aDd tanks of more

c o r v e n t i o m l and f m S i n r desigc, t h e c c s t w a s cmputsd from t h e cost of material (INOR-8 for most vessels ) -$us an estimated f a b r i c a t i o n charge, both charges being Sased or. %tieweight of t h e vessel.

A surnnary of values

tised 2x1 estl.m.%icg process vessels by weight i s given belay.

FGr

the

s h e l l s of the s r e f l w r i n a t i o n storage tanks, t h e high f a b r i c a t i o n cost values skown were obtained by back calculating from a Y-12 shop estimate f o r a similar v e s s e l .

Sta i d e s s Metal Cost $/lb

Fabrication Cost, $/lb Shell, p r e f l u o r i c a t ion storage 1.2 rct3/day Shell Frefluorination storage, 1 2 %$/day, tarLks 3. ar-d 2

INOR-8 Alloy 79-4 3 .oo 2.56 7 .oo 8 *35

Steel

304

0.65


INOR-8

Fabrication Cost, $/lb (contd )

Alloy

79-4

S ta i d e s s S t e e l 304

Prefluorination storage, 1 2 ft'/day

3-6

taaks

l?luorina%ors, 1.2 and 12 f't 3/day Pa-233 decay storage, 1 . 2 f% 3/day

3 050 4 ,OO

3e 5 0

Waste storage vessel, 1.2 and 12 fd/day

2a 5 0

Waste storage thimbles, 1 . 2 and 1 2 f d / d a y

1.85

vF4 dissolvers, 1,2 and 1 2 ft3/day

3.Y

Pipe and tubing p r i c e s were based on t h e following schedule. Description l/Q in. OD x 0.042 w a l l tube (INOR-8) 1 i n . N E , Sch, 40 pipe (INOR-8) 1 1/2 i n . NPS,

Sch. 40 pipe

(INOR-8)

$/ft;

$/lb

6.06

26.40

30

03

41.67

16.04 1 3 *71

Auxiliary process items such as process piping, process e l e c t r i c a l service, instrumentation, sampling connections and t h e i r i n s t a l l a t i o n were not, considered. i n s u f f i c i e n t design d e t a i l t o permit d i r e c t estimation.

A

value w a s assigned t o these i t e m s which was based upon previous experience I n design and cost estimation of radiochemical processing p l a n t s . In assigning these values cognizance was taken of t h e f a c t t h a t t h e p l a n t i s remotely lnafntafned. Building.

The building estimate included t h e cost of land acquisition,

s i t e preparation, concrete, s t r u c t u r a l s t e e l , painting, heating, v e n t i l a t i o n , a i r canditioning, elevaters, cranes, service piping, laboratory and hot c e l l equipment, e t c .

.The individual costs were calculated using current

da%a for materials and labor, and a r e based on t h e drawings shown i n t h e

Appendix

e

5.3 Process Equipment Capital Cost Prccess equipment c a p i t a l c o s t s f o r t h e two f l u o r i d e v o l a t i l i t y p l a n t s a r e presented in Table

2.1. These c o s t s a r e t h e t o t a l s of material,

f a b r i c a t i o n and i n s t a l l a t i o n chargesc

J


TABLE 5.1

ESTIMATED COST OF MAJOR PROCESS EQUIPMENT FOR TWO FLUORIDE VOLATILITY PLANTS (Values i n Dollars) 1.2 Ft3/Day Plant Description

No.

cost

12 Ft3/Day P l a n t Description

No.

cost

Pre-Fluorination Storage Storage tank

2

2 f t D x 2 f t H; 49 bayonet coolers; INOR-8;0.375 i n . s h e l l ; 0.5 in. head

100,000

Storage tank Furnace

2

5 2

2.7 f t D x 3 f t H; 45.8 kw

2

Heater

5

5.5 f t D x 5.5 f t H; 295 bayonet coolers; INOR-8; 0.5 i n . s h e l l ; 0.625 i n . head 3.17 f t D x 7.61 f t H; 0.5 i n . s h e l l ; 0.5 in. head 6.25 f t I D x 7 f t H; 250 kw 4 f t D x 9.9 f t H; 225 kw; t u b u l a r

1,354, ooo 57,500 50,000 110,

ooo

with s t a i n l e s s steel sheath Jacketed thimble Condenser

1

1 f t D x 3 f t L; 19 f t steel; admiralty tubes

2

5 465

stainless

2

4 f t D x 9.4 f t H; INOR-8 14 i n . D x 16 f t L; 470 f t 2 s t a i n l e s s

58,125 8,200

steel; admiralty tubes

107,465

1,637,825

Fluorination

1.5 f t D x 2.34

Fluorinator

t H (lower section); 3.b f t salt; a l l o y 79-4; 0.5 i n . s h e l l ; 0.5 i n . head

Furnace

2.33 f t D x 3.75 f t H; 49.4

f

12,000

2

1.75 f t D x 9 f t H (lower s e c t i o n ) ; 6 f t 3 salt; a l l o y 79-4; 0.5 i n . s h e l l ; 0.5 i n . head

8,W

2

2.67 f t D x 5 f t â‚Ź1; 75.5 kw 6 i n . D x 4 f t H; outside heaters;

kw

CRP t r a p

2

16,000

13,ooo 10,000

ai r-operated p i ston 20,000

39,000

Absorbers and Cold Traps

NaF absorber and CRP t r a p

1

8 i n . sch. 40 pipe; 1 f t horizontal + 5 f t v e r t i c a l ; 12.66 kq uF6 capacity; Inconel

Furnace

1

Included i n absorber c o s t

Cold t r a p

1

-hoc

Cold t r a p

1

-75'~ unit; copper

u n i t ; copper

5,000

6

6 i n . sch. 40 pipe x 6.33 f t E; 21.1 kg

Up6

capacity; Inconel

9,000 21,000

I

-b0c 8'700

u n i t ; copper

-75'~ u n i t ; copper

22,500 7,500

ul

w


TABLE 5.1

No.

- contd

1.2 Ft3/Day Plant Description

cost

6 in. sch.

800

NaF chem trap

2

40 pipe x 3.5 ft H; heated; 12.66 kg UFB capacity; Inconel

Vacuum pump

1

40 cfm displacement; < !X) p Hg final 2,620 pressure 17,120

Pa-233 Decay System Storage tank

24

Jacketed thimble

24

Heater

24

1.66 f t D x 3.32 ft H; 7.2 ft3 salt; INOR-8; 0.375 in. shell; 0.375 in. head Cooling unit for storage tank 3 ft D x 3.1 H; 52.5 kw

3

rJW 100,800

12 Ft3/Day Plant Description

No.

6 in. sch. 40 pipe x 6 ft H; heated; 21 kg UF6 capacity; Inconel

36

4.5 ft D x 4.5 ft H; 60 ft3 salt; INOR-8

36

Cooling unit for storage tank Sectional units to surround tank

36

cost

1,624,500 u1

Reduction and Fuel Make-up

&-

Reduction unit

1

Dissolver

1

Cold make-up and sparge tank Heater f o r dissolver Heater for make-up tank

2 1 2

4 in. sch. 40 pipe

x 8 ft

H;

1

10-15 kg UF6/hr capacity; Inconel 1.67 ft D x 3.3 ft H; 7.2 ft3 salt; INOR-8; 0.5 in. shell; 0.5 in. head 1.3 ft D x 7.3 ft H; INOR-8; 10.2 ft3 capacity 2 ft D x 2.25 ft H; 26 kw 2.3 ft D x

4 ft

6.7 ft

66,150 5,500

2

3.4 ft D

H; INOR-8;

26,000

1

48 ft3 capacity 3.4 ft D x 3.7 ft H; 71 kw 4.1 ft D x 7.7 ft H; 178 kw

34,000

2

H; 52 kw

4 in. sch. 4 0 pipe x 8 f t H; 10-15 kg w6/hr capacity; Inconel 2.7 ft D x 2.7 ft H; 12 ft3 salt; INOR-8; 0.5 in. shell; 0.5 in. head x

6,000

137,650

85,300 Waste Storage Waste tank

128

1.33 ft D x 7 ft H; stainless steel 304 L; 9.84 ft3 salt;

Waste tank thimbles

128

2 ft D x 15 ft H; stainless steel 304 L; 0.1875 in. shell; 0.1875 in. head

118,600

510

175 360

510

0.25 in. shell; 0.25 in. head

293,960

i

2 ft D x 7.5 ft H; stainless steel 304 L; 24 ft3 salt; 0.25 in. shell; 0.25 in. head 2.75 ft D x 15 ft H; stainless steel 304 L; 0.1875 in. shell; 0.1875 in.

841,500

892,500

1,734,000


TAELE 5.1

No.

1.2 Ft3/Day Plant Description

- conM cost

No.

12 Ft3/Day P l a n t Description

cost

Miscellaneous Equipment Refrigeration u n i t

1

Refrigeration u n i t

1

Refrigeration u n i t

1

A i r chiller

1

g,ooO ETll/hr a t -2OOC 1 f t x 1 f t x 4 rows finned tube

HF d i s p o s a l u n i t

1

2.8 f t D x 5.3 f t H; monel

F

1

Tank and t r a i l e r

2

supply system

24,000 BTU/hr a t - b 0 C 4,000 ETIT/hr a t -75OC

3,500 3,200 1,235 135 500

6,770

1

48,W BTU/hr a t - b 0 C

1

8,000 BTU/hr a t -75OC

5,400 4,900 Ln

u

1

2.8 f t D x 5.3 f t H; monel

2

Tank and trailer

1.59340 T o t a l Process Equipnent Cost

705,985

5,259,075


5.4 Building Capital Cost Building cost data f o r t h e two f l u o r i d e v o l a t i l i t y p l a n t s a r e given i n Table 5.2. These costs a r e divided i n t o f i v e categories: processing c e l l , interim waste storage, operations and l a b o r a t o r i e s , outside u t i l i t i e s and land improvements. The t a b u l a t i o n presents both material and labor eosts,

5.5

Total Capital Cost A s mentioned above, process equipment and buildings were t h e only

items considered in s u f f i c i e n t design detail t o permit d i r e c t estimation. The remainder of t h e c a p i t a l costs were estimated from previous knowledge and experience with radiochemical processing plants. The f a c t t h a t t h e plant i s remotely maintained was an important f a c t o r in estimating process instrumentation and e l e c t r i c a l and sampling connections.

These items become considerably more expensive because of counterbalancing, spacing and a c c e s s i b i l i t y requirements, Construction overhead fees were taken as 22% of d i r e c t materials and l a b o r f o r all buildings, i n s t a l l e d process equipment, piping, instrumentaThis rate i s i n agreement with current charges f o r t h i s type of construction and estimate. Architect

t i o n , e l e c t r i c a l and other d i r e c t charges,

engineering and inspection fees were taken as 15%of all charges including construction overhead. This fee may be as l a r g e as 20% f o r some designs; however, f o r t h i s plant t h e lower

15% value w a s used because of considera-

b l e r e p e t i t i o n i n t h e design of a l a r g e number of process v e s s e l s .

,


TABLE

BUILDING ON-SITE

COSTS FOR 540 FLUORIDE PROCESSING

OF MOLTEN (Values

PLANTS REXTOR

FOR FUEL

Dollars)

Ft3/Day Labor

Plant Total

--Material

12 Ft'/Day Labor

Plant Total

Cells

Excavation

and back

Concrete,

forms,

Structural

Crane

137,300

fill

reinforcing,

steel

area

Doors,

and

etc.

miscellaneous

380,ooO metal

roofing

painting,

crane

bay

doors,

etc.

Services Building

movable

Viewing

equipment

Waste Excavation Concrete, Crane

2,313,720 and back

fill etc.

and miscellaneous

metal

roofing

Services

950,O~ 456,600 209,@343 113,100 60,900 163,050 554,100 138,680 352,630 24,250 1,101,750 42,cm 2,@33 l,457,570

movable

equipment

3,771,290

28,000

490,770

248,970

739,740

50,330

23,600 87,400

73,930 150,200 159,040 8,790 49,500 36,730

6,510

61,200 71,500

91,800

9,600

11,200

5,430

5,430 37,310

W,l~ 220,000

Sub total Operations

201,110

20,450 153,000 140,220 20,8ciJ 10,860 146,410 248,occI

13,940

reinforcing,

Painting Building

63,810 570,m

187,420 568,200 369,500 75,600 397,100 329,700 862,500 40,000

87,100 852,300 315,800 88,200 169,100 207,580 253,250 2,000

274,520 1,420,500 685,300 163,800 556,200 537,280 1,=5,750

~~~

2,830,020

1,975,330

4,805,350

!Wm

25,590 307,200 243,700 53,900 24,010 161,100 30,000

80,390 512,000 488,700

514,400 255,000

845,500

1,998,610

30,270 106,100 38,910 3,750 22,920 29,390

94,510 182,500 211,540 11,280 85,410 56,500

Storage

steel area

391,050 213,950 40,ooO

forms,

Structural

246,720 52,200

852,500

windows

Sub total Interim

VOLATILITY

SALT CONVERTER

in 1.2

Material -Processing

5.2

68,720

204,800 245,m 46,200 24,010 353,300 225,m 1,l53,llO

lCO,lOO 48,020

and Laboratories

Excavation

and back

Concrete,

forms,

Structural

steel

fill

reinforcing,

etc.

and miscellaneous

Roofing Superstructure Miscellaneous

structural

material

62,800 metal

129,130 5,870 34,530 17,980

29,910 2,920

14,970 18,750

64,240 76,400 172,630 7,530 62,490 27,110

u-i 4


TAmx

Material Services

238,510

Miscellaneous

equipment

Sub total Outside

( .

1.2

Ft'/LAay -Labor 178,510

Plant Total 417,020

Material -315,270

292,800

12 Ft3/Day Labor 243,350

Total

558,~3

272,800

34,goo

307,7~

811,950

390,960

1,202,g10

00,5co

29,500

110,000

252,ooO

36,000

28a,cxxl

@,;oo

28,600

118,200

100,540

36,5@J

137,040

1,018,470

40,900

Plant

515,590

333,700 1,534,oGo

electricity,

drains,

etc.

Improvements Grading,

Total

- contd

Utilities Water,

Land

5.2

roads,

sidewalks,

etc.

3,786,540

2,155,600

5,9@,140

5,354,140

3,%920

8,763,060


59

Total

capital

cost data for the two plants

Table 5.3*

Summary of Capital Fluoride Volatility

are given in Table 5>3,

Cost Estimate for Processing Plants Plant

Prozess cells Interim waste storage Operations area and laboratories Oiitside utilities Land improvements Process equipment Process piping Froeess instrumentation Process electrical connections Sampling connections

Capacity 1.2

739,700 1,202,500 l10,000 118,260

20.000

9,098,90~

Contingency cost) T&al

project

cost

(2076 of subtotal

KD

1,364,800 ro,443,70e

project 2,092,300

cost

i37,CJlj.c

10,000

Total

project

288 1~000

500,300 80,06c

1,640,800

Subtotal

$ 498~5,h~~i l,s;~8,60!~ ;,533,, i/32

3OC)000 50,000

General construction overhead (22% of total installed equipment and bul.Lding cost)

Architect engineering and inspection (15% of total construction cost)

(Ft3 SaZ.t/I&ty), 12

5,252,600

7,458,

cost

On-Site

706, ooo 450,000

Total installed equipment and building cost

construction

Twc,

$12356,000

680,OC~O


60

6.0

OPERATING COST ESTIMATE

Direct operating c o s t s were calculated f o r both p l a n t s t o cover manpower requirements, chemical consumption, u t i l i t i e s , and maintenance materials,

Current data on labor and materials c o s t s were used i n making

t h e estimates.

6.1 Operating Manpower Operating manpower requirements f o r t h e 1,2 and 12 f t3/day p l a n t s

are estimated i n Table 6.1, 6.2

Summary of Direct Operating Costs Direet operating c o s t s and t h e bases upon which they were computed

a r e given i n Table 6 e 2 0 Labor c o s t s were obtained from Table 6.1 b u t are presented i n a s l i g h t l y d i f f e r e n t manner t o e x h i b i t t h e charges associated w i t h the major c l a s s i f i c a t i o n s of operations, laboratory, maiqtenance and

supervision.

materials.

The l a r g e s t s i n g l e d i r e c t c o s t s are l a b o r and maintenance There i s no d i r e c t way t o c a l c u l a t e yearly c o s t s f o r main-

tenance materials; these charges must be estimated as c e r t a i n percentages ($/year) of t h e corresponding c a p i t a l investment.

The rates that have

been used a r e average rates which have been observed t o apply t o a l a r g e number of chemical reprocessing operations.


61 TABU

6.1

m

OPERATING MANPOWER ESTXMATES FO3 F ' dk7, I3'S-SITE _ l y -

( $/year)

NO a _

D

_

_

-

Nc. ( $/yew) -

Malzagernent, Nmager Assistant manager Secret;ary

P r d u c t i on Superintendent Shift supervisor Operator Helper Secretary

2

9' 600

37.17+5?7 Maintenance Superintendent Mechanical engineer Neehacic Machinist I n stiztment maE Clerk Storeroom keeper

Labratory S q e r v i sor Chemist Technician Helper EeaLth Physics Supeuvi sur Monitor Clerk

Records keeper

1

3' 6ic

-fy$Tin


62

TABU 6.1

- contd 1.2 F t3 Salt/Day

Cost

12 F t 3 Salt/Day cost

No.

-

(S/Y-9

No. -

1 1

7,000

1 1

($/year>

Accountabilitv Engineer Clerk

P

4,000

11,000

7,000 4,000

P

11,000

2

*

Engineering Mechanical engineer Chemical engineer Draftsman Secr e t a r y

1

8,

3

.27,000

4

1

5

10,600 4,500 50,100

1 10

1

5,000

1 1

2

3

General Office Manager Accountant Payroll c l e r k Purchasing agent Secretary

1 2 1 2

7

4,800 8,000 4,800

g$%

2

1 2

16,000 36,000 15 900

5,000

4,800 8,000 4,800

7

&%

Miscellaneous Guard Fireman Recept i oni st Laundry worker

Nurse Janitor Total

8 4

32,000

8 4

32,000

16,000

1

4,000

1

2 1 2

7,200

3

4,000 10,800 4,800

iâ&#x201A;Ź7 SO4

4,800 7,200 71,200

631,ooo

1

m3

16,000


TABLE 6.2 SUMMARY OF DIRECT OPERATING COSTS FOR TWO, ON-SITE

FLUORIDE VOLATILITY PLANTS

1.2 Ft3 Salt/Day

($/year) Chemical Consumption Fluorine (at $2.00/lb) KOH (at $O.lO/lb) Hydrogen (at $2.00/lb) NaF (at $0.15/lb) Nitrogen (at $0.05/ft3) Inert gases (guess) HF (at $0.20/lb) Graphite (at $0.15/lb) Miscellaneous

48,000

4J

1,600

8,500

180

1,800 190 2,200 500 3,300

60 750 200 700

460

50 2,000

1o,jK, Utilities Electricity (at $O.Ol/kw hr) Water (at $0.015/1000 gal) Heating (based on steam at $0.25/1000 lbs)

174,000

4,300 7,200

=Tm

Labor Operating (from Table 6.1) Laboratory (from Table 6.1) Maintenance (from Table 6.1) Supervision (from Table 6.1) Overhead (at 2% of above) Maintenance Materials Site (guess) Cell structures and buildings (at 2Kyr of capital cost)a Services and utilities (at W/yr of capital cost) Process equipment (at 15$/yr of capital cost)b Total Direct Operating Cost

'Building

357,300

386,450

82,800

119,800 163,000 81,000 150,050

109,900 81,000 126,200 757,200

900,300

10,000

10,000 13%500

94;900

64,400 876,900

36,600 158,&XI 300,100 1,102,600

services excluded

bIncludes process equipment, process instrumentation and sampling connections

1 , -

2,240,600


64 7 .O CAPITAL COST ESTIMATE OF MODIFIED 1.2 d / D A Y PLANT

7.1 Modifications In examining the large amount of process equipment and cell space required for Pa-233 decay storage, it becomes questionable if there is an economic advantage in recovering the protactinium. Accordingly the 1.2 ft3/day plant was redesigned to remove Pa-233 decay storage and associated equipment, and relocate the interim waste storage cell area to a more economic location, the process building was thus reduced in size. These changes brought about corresponding savings in process electrical, instrumentation and piping charges. In the modified plant the process operations now consist of seven principal steps: 1. Prefluorination holdup (4.5 days average) 2. Fluorination 3. Absorption -desorption of UF6 4. uF6 collection on cold traps Reduction UF6 -* UF4 6. Fuel make-up 7. Waste storage Eliminated from the operations were Pa-233 decay storage and a second fluorination as well as two transfers of molten salt. Only the 1.2 fâ&#x20AC;&#x2122;t 3/day plant was considered in making the revised cost estimate. The initial estimate discussed in Section 5.0 indicated that the large fluoride volatility plant (12 ft3/day) was not economic for processing only a lo00 Mwe reactor system, but rather would find its utility in a large, central processing location. It was beyond the scope of this study to include cost estimates of centrally located processing plants

In making the revised estimate it was not deemed necessary to redesign the process building. A revised building cost estimate was prepared from marked up drawings showing the areas that would not be needed. Likewise no new process equipment and layout drawings were prepared for the revised process equipment estimate, In this regard the drawings in the Appendix are not representative of the modified plant.

w

.


7.2 Process Equipment A study o f t h e modified process indicated t h a t t h e items l i s t e d i n Table

7 . 1 would not be needed.

The savings r e s u l t i n g therefrom were c a l -

culated by using t h e i n i t i a l process equipment estimate o f Table A saving of

5.1.

$183,700 i s indicated f o r the modified system.

'7.3 Vaste Storage I n the design bases of Section 2.2 an interim waste storage period of 1000 days a f t e r The second f l u o r i n a t i o n was chosen.

This amounted t o

a t o t a l holdup of about 1138 days f o r t h e processed s a l t before it was shipped t o permanent waste storage.

The 1000-day figure was an a r b i t r a r y

choice; t h e proper interim waste holdup should r e s u l t from an economic com parison of t h e on-site storage cost versus the permanent s i t e storage c o s t using t h e age o f t h e waste after r e a c t o r discharge a s t h e independent v a r i a b l e . For t h e modified p l a n t study, t h e data of Perona and Bradshaw15316 on waste storage costs i n s a l t mines were used t o determine t h e optimum o n - s i t e storage period; on-site storage f o r 1100 days appeared t o give t h e most economic t o t a l storage cost (Fig. 7.1). The required mine storage area i s a function of t h e decay heat r e l e a s e of f i s s i o n products, and hence i s inversely r e l a t e d t o t h e age of t h e waste.

On t h e other.hand, on-site building and process equipment

costs increase with on-site waste holdup.

For t h i s optimization, building

and equipment costs were estimated for four interim storage times, and t h e

required cost of s a l t mine permanent storage space was estimated f o r the corresponding periods.

S a l t mine space w a s charged a t a r a t e of $500,000

per a c r e f o r each f i r s t year of use.

This charge includes development

of the mine s i t e , mining t h e salt, hot c e l l f a c i l i t i e s on t h e surface and i n t h e mine f o r handling t h e waste containers, motorized shielded c a r r i e r and d r i l l i n g equipment i n t h e mine. It i s e s t i m t e d t h a t t h e optimized building cost should be about

$570,500.

This value includes savings r e s u l t i n g from a relocation of t h e

waste storage area from t h e p o s i t i o n shown on drawing E-46079 i n t h e Ap-

pendix t o a new p o s i t i o n a t t h e end of t h e process canyon.

I n t h e new

l o c a t i o n t h e waste area can be served by t h e canyon crane thereby e l i m i nating a second crane f o r use i n t h e interim waste storage area.


66 Table 7.1. Capital Cost of Process Equipment for 1.2 Ft3/Day On-Site, Fluoride Volatility Processing Plant. Values of Table 5.1 Revised to Exclude Pa-233 Storage and Associated Equipment Equipment Removed Pa decay storage tanks and thimbles Heaters

No.

$

24 24

66,000 100,800

Fluorinator Furnace

1 1

Waste storage tanks Waste storage thimbles

3

4,000 2,800

3

4,100

6,000

Process equipment cost for plmt with Pa-233 decay storage Less removed equipment

706,000

Process equipment cost with no Pa-233 decay storage

522,300

183,700

7.4 Process Building The revised cost estimate for the process building reflecting the removal of Pa-233 decay storage space is given in Table 7.2. The costs are classjfied according to the major divisions of processing cells, interim wast.e storage, operations and laboratories, outside utilities and land improvements. These costs reflect an allowance for facilities that are shared with t.he reactor station.

7 0 5 Total Plant Cost A summary of the total plant costs is given in Table 7.3. There were insignificant changes in the accounts of land improvements, outside utilities and sampling connections in the modified plant, so these accounts retain the same charges as in the initial part of this study. Process piping and process instrumentation charges were appreciably reduced reflecting the removal of a number of items of process equipment. Application of the same construction overhead, architect engineering and contingency fees as in the initial part of this study obtains a total plant cost of $10,188,000

J


UNCLASSIFIED ORNL- L R - D W G

10

I os

741 I O

IO'

STORAGE TIME AT PROCESSING PLANT BEFORE SHIPPING TO PERMANENT STORAGE ( days)

Fig. 7.1 Determination of Minimum Total Cost f o r Handling 1.2 ft3/day Waste S a l t from a Fluoride V o l a t i l i t y Plant and Optimum Storage Time a t Processing Plant Before Shipping t o S a l t Mine.


68

Table

7.2. Building Costs for a 1.2 ft3/Day Fluoride Volatility, On-Site Processing Plant. Values of Table 5.2 Revised to Exclude Pa-233 Decay Storage Space (Values in Dollars) Material

Labor

Processing Cells

47,432,000 133,700 44,800 156,493 111,250 249,250

Excavation and back fill Concrete, forms, reinforcing, etc. Structural steel and miscellaneous metal Crane area roofing Doors, painting, crane bay doors, etc. Services Building movable equipment viewing windows

2,000

1,176,693

Sub total Interim Waste Storage

6,400

Ekcavation and back fill Concrete, forms, reinforcing, etc. Structural steel snd miscellaneous metal Crane area roofing Painting Services Building movable equipment

82,000

91,800 11,200

5,500 39,100 10,Ooo

246,000

Sub total Operations and Laboratories

23,600 87,400

Eccavation and back fill Concrete, forms, reinforcing, etc. Structural steel and miscellaneous metal Roofing Superstructure Miscellaneous structural material Services Miscellaneous equipment

29,910

2,920 14,970 18,750 178,510 35,900 391,960

Sub total Outside Utilities Water, electricity, drains, etc.

80,700

29,700

73,000

45,1,821,000

Iand Improvements Grading, roads, sidewalks, etc. Total (rounded)

3,399,000


Table 7.3. Summary of Capital Cost Estimate f o r a 1 . 2 f t 3/day On-Site, Fluoride V o l a t i l i t y Plant. Values of Table 5 , 3 Revised t o Ekclude Cost of Retaining Waste S a l t f o r Pa-233 Decay I r r a d i a t i o n = 70,000 Mwd/tonne Th cost ($) Process c e l l s I n t e r i m waste storage

Operations area and laboratories Outside u t i l i t i e s

110,400

Land improvements

118, zoo

Process equipment

522,300

Process piping

180,000

Process instrumentation

100,000

Process e l e c t r i c a l connections

20,000

Sampling connections

10,000

Total i n s t a l l e d equipment and building cost (rounded )

6,052,000

General construction overhead (22% of t o t a l i n s t a l l e d equipment and building cost )

1,331,000

Total construction cost

7,383,000

Architect engineering and inspection (15% of t o t a l construction c o s t )

1,107,000

Subtotal p r o j e c t cost

8,490,000

Contingency

(a$of

Total p r o j e c t cost

L

37 216,530 570,500 1,203 t 910

subtotal project cost )

1,698,000 10,188,000


70

7 6 Economic Advantage e

The economic advantage of eliminating Pa-233 decay storage facilities from the 1.2 ft3/day fluoride volatility plant can be found by coqaring the savings in capital cost with the value of protactinium that is discarded as waste. Subtracting the total plant cost of Table 7.3 from that of Table 5.3, there obtains

the estimated savings in capital investment. If this amount is amortized at 14,46$/year, which is the charge applied to the capital investment, an annual gross economic advantage of

$2,368,000 x 0.1446 = $342,400 per year is realized. "here would be some savings on operating cost which should

be added to this number; this saving was not estimated and is probably not a very significant amount because it does not cost much to operate a dead storage area. The process flowsheet (Fig. 3.1) shows that there are 54.6 g Pa-233/day entering the fluorinator. Valuing this material at $12/g for 292 days operation per year, there obtains 9 . 6 x 292 x 12 = $191,30o/year

lost by discarding protactinium. The net economic advantage from eliminating Pa-233 decay storage from the 1,2 ft3 /day fluoride volatility plant is about $l5l,lOO per year. Although it was not considered in this study, there might be some economic advantage to a nominal increase in prefluorination holdup to allow more Pa-233 to decay. The value of the increased U-233 yield would have to be weighed against the additional process equipment and inventory charges for the longer storage.


i

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WERENCES

I

1.

W. H. Farrow, Jr.-, Radiochemicai Separations Plant Study Part II Design and Cost Estimates, DP-566 (March 1961).

2,

Personal communication R. P. Milford with W. H. Farrow, Jr. (Feb. 16; 1962).

3.

R. B. Briggs, Molten Salt Reactor Program Progress Report for Period from March 1 to August 31, 1961, oRNLL3215(Jan. 12, 1962).

4,

G, I. Gathers, M, R, Bennet and R. L. Jolley, The Fused Salt Fluoride Volatility Process for Recovering Uranium, ORNL-2661(Apr. 1, 1959).

5.

W.;H. Carr, S. Mann and E. C, Moncrief, "Uranium~!&iraoniumAlloy Fuel Processing in the ORNLVolatility Pilot Plant," Paper for Presentation at the A1Ch.E. Symposium,fiVolatility Reprocessing of Nuclear Reactor Fuels," New York, New York, Dec. 1961, CRNLCF 61-7-13 (July 10, 1961).

6. R. P. Milford, 6. Mann, J. B. Ruth and W. 11. Carr, Jr., â&#x20AC;&#x153;Recovering Uranium Submarine Reactor Fuels," s, Chem., 53, 357-362 (May 1961).

7.

Personal communication R. PI Milford with S. H, Smiley (ORGDP),

8. Personal communication R. P. Milford and W. L. Carter with E. D. Arnold (Feb. 1962). 9.

10.

J. 0. Blomeke and Mary F. Todd, Uranium Fission-Product Production as a Function of Thermal Neutron Flux, Irradiation Time, and Decay Time. 1. Atcanic Concentrations and Gross Totals, ORNL-2127,Part I, Vol. 2 '(Dec. 15, 1958). H. Etherington, ed., Nuclear Engineering Handbook, McGraw-Hill Company, Inc., New York (1956).

Book

11. United States Atomic Energy Commission, Guide-to Nuolear Power Cost Evaluation (Dec. 31, 1961). 12. Cost evaluation of molten salt reactor plant joint effort Sargent and Lundy Engineers,- Chicago; work in progress.

of CRNLand

13. F. I,. Culler, Chemical Technology Division Annual Progress Report for the Period Ending May 31, 1962, ORNL-3314, in publication. 14. J, 'P. Murray, et. al,, "ECOnOmic6 of Unirradiated Proaessing Phases of Uranium Fuel.CElez Second International Conference.on the Peaceful Uses of Atomic Energy, Vol. 13, paper No. P/439, page 582, United Nations, New York, 1958.


80

REFERENCES - conta J. J. Perona and R. L. Rradshaw, Oak Ridge National Laboratory, personal canmnmication, Aug. n, 1962. P

16.

R. E. Blanc0 and E. G. Struxness, Waste ltreatnent and Disposal Progress Report for February-March 1962, ORNLlM-252, p- 3g1 @ept.10,1%2). \


-

f

â&#x20AC;&#x2DC;i

81

.

Internal

Distribution c

1. 2,

3. 4.

5.

6. '7* 8, 910. 11. 12.

130 14. 15. 16.

17.

f L

18. 19. 20. 21. 22.

23. 24. 25. 26.' 27. 28. 29.

L. G., Alexander E. D. Arnold S. E, Beall M. Bender L. L. Bennett E. S. Bettis R, E. Blanco F. F. Blankenship A. L. Both J. C. Bresee R. B. Briggs K. B. Brown D. 0. Campbell R. S. Carlsmith W. H.'Carr W. L. Carter G. I. Cathers C. W. Craven F. L. Culler D. E. Ferguson A. P- Fraas E. H. Gift 11. E. Goeller C. $3. Guthrie R. W. Horton P. R. Kasten T. W. Kerlin J. A. Lane R. B. Lindauer

R. N. Lyon H. G. M&Pherson W. D. Manly Ht F. McDuffie R. P, Milford A. J. Miller A. M. Perry M. W. Rosenthal H. W. Savage A. W. Savolainen M. J. Skinner I. Spiewak W, G. Stookdale J. A. Swartout D. B. Trauger J.'W. Ullmann W. E. Unger R. 'VanWinkle A. M. Weinberg I$ E. Whatley Central: Researhh..Library Y-$2: Document.R~ferenee Section Laboratory Records Department (LRD) Laboratory Records Department (LRD-RC) Reactor Division Library 59a

External Distribution 6Q. R. E. Pahler (AEC, Washington)

61. F. P. Self (AEC-ORO) 62. Research and Development Division (AEC-ORO) 63-64. Reactor actor D$vision (AEC-ORO) 65-79.

Division vision of Technical Information Extension (J.YIIE)


ORNL-TM-0522