Design Features An essential element in the design of an MSBRprocessing plant is that of keeping the out-of-reactor inventory low to decrease inventory charges and improve the fuel yield, which is the fraction of fissile inventory bred per year. The logical way to achieve this low inventory is to close-couple the processing plant with the reactor, and it is,proposed to integrate the two operations. Processing equipment will be located in cells adjacent to the reactor cell, and a small portion of each circulating stream will be metered semicontinuously to the processing plant. Most processing operations are continuous: the fuel stream being purged of fission products, fortified with makeupfuel and carrier, and returned to the reactor core; the fertile stream being stripped of its ', protactinium and uranium, fortified with makeupthorium and returned to the blanket. It is not necessary to allow long decay periods before processing since the reactants are either gaseous (Fp) or solid (granular Cooling periods NaF) and are not affected by strong radiation fields. before processing no longer than one day and perhaps as low as a few hours should suffice. The length of this period depends upon the design of the continuous fluorinator and the ability to control the fluorination temperature. Removal of fission product decay heat is a principal consideration throughout the plant. In the integrated plant all services available to the reactor are available to the chemical plant. These include mechanical equipment, compressed gases, heating and ventilating equipment, electricity, shop services, supervision, etc. The cost savings for an integrated facility are immediately apparent when one considers the large amount of duplicaonly a relatively small,space is needed tion required for separate plants. for the processing equipment as compared to that needed for the reactor and power conversion equipment so that the additional building cost is small. Process Cperations Four major operations are needed to sufficiently decontaminate the sorption of UF6, vacuum fuel stream of an MSBR. These are fluorination,
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