6-38
be located i n energy centers and 368 kg o f f i s s i l e plutonium i n f r e s h f u e l per GWe o f i n s t a l l ed capacity must be handled each year i n those centers. This i s n o t meant t o imply t h a t a decrease i n t h e amount o f nuclear capacity which must be placed i n secure regions i s synonymous w i t h an increase i n diversion-resistance. Neither i s i t meant t o imply t h a t a decrease i n the amount of f i s s i l e plutonium which must be handled as f r e s h f u e l i s synonymous w i t h an increase i n p r o l i f e r a t i o n resistance. I f e i t h e r o f these items i s desirable, however, t h i s o p t i o n minimizing t h e production and use o f plutonium does o f f e r a s i g n i f i c a n t increase i n t h e energy support r a t i o and a s i g n i f i c a n t decrease i n t h e amount o f f r e s h - f u e l plutonium t h a t must be handled. I t i s important t o note t h a t t h e deployment o f the plutonium m i n i m i z a t i o n and
u t i l i z a t i o n o p t i o n would r e q u i r e t h e development o f a nuclear i n d u s t r y capable o f reprocessing f u e l containing thorium and r e f a b r i c a t i n g f u e l containing 232U. As Fig. 6.2-24 indicates, o n l y o n e > r e a c t o r p r o v i d i n g 3% o f t h e i n s t a l l e d capacity i n year 2035 does n o t u t i l i z e thorium. Thus, i n order t o s u c c e s s f u l l y implement t h i s option, 97% o f t h e reprocessing capacity i n year 2035 must be capable o f handling f u e l containing thorium, and 51% o f t h e f a b r i c a t i o n capacity must be capable o f handling f u e l containing 232U. I n sumnary, a converter s t r a t e g y based on t h e LWR which minimizes t h e amount of plutonium produced, b u t uses t h a t which i s produced, could supply a maximum nuclear cont r i b u t 4 o n of 700 GWe w i t h t h e high-cost U308 supply. This i s approximately 100 GWe g r e a t e r than t h e maximum nuclear c o n t r i b u t i o n obtained i n t h e case o f plutonium throwaway and f i s s i l e uranium recycle.
The s t r a t e g y does, however, r e q u i r e t h a t approximately
100 GWe be l o c a t e d i n an energy center.
With t h e intermediate-cost U308 supply, t h e system
could make a maximum nuclear c o n t r i b u t i o n o f more than 1000 GWe. I n e i t h e r case, t h e development of f u e l designs capable o f minimizing t h e amount of plutonium produced and a l s o t h e development o f a nuclear i n d u s t r y capable o f hand1 i n g thorium-based f u e l s must be developed. 6.2.5.
Converter System w i t h Plutonium Production Not ~ ~ U Minimi zed; P u - ~ o - ~ "Transmutation"
This o p t i o n d i f f e r s from t h e preceding o p t i o n
i n t h a t t h e dispersed reactors are n o t designed t o minimize t h e amount o f plutonium produced. Thus more plutonium i s handled as fresh f u e l and more i s "transmuted" i n t o 233U. Again a converter w i t h a plutonium-thorium core i s located i n t h e energy center, and o t h e r reactors are l o c a t e d o u t s i d e t h e center (see Fig. 6.1-3, Option 5T). Figure 6.2-25
shows t h a t t h e nuclear c o n t r i b u t i o n f o r t h i s o p t i o n using LWRs o n l y
(Case 5TL) reaches a maximum o f approximately 640 GWe s h o r t l y before year 2025. The maximum c o n t r i b u t i o n i s l e s s than t h e 700-GWe maximum i n t h e preceding case p r i m a r i l y because o f t h e d i f f e r e n t amounts o f f i s s i l e plutonium u t i l i z e d i n t h e two systems.
Since 239Pu i s worth l e s s i o a thermal r e a c t o r than e i t h e r 235U o r 233U, t h e system which minimizes t h e amount o f p l u tonium should (and does) make a s l i g h t l y l a r g e r nuclear c o n t r i b u t i o n .