Determination of the proper operating range for the CAFCA IIB fuel cycle model

Abstract

The fuel cycle simulation tool, CAFCA II was previously modified to produce the most recent version, CAFCA IIB. The code tracks the mass distribution of transuranics in the fuel cycle in one model and also projects costs for various fuel cycle schemes. The mass distribution model also shows the schedule for deployment of recycling plants. All of these models are dependent on user inputs, some of which specify advanced technology type and capacity, plant lifetime and recycling facility capacity. The behavior of CAFCA IIB resulting from the most recent modifications are investigated through extensive modeling of various nuclear fuel cycles. By re-modeling nuclear fuel cycle schemes in CAFCA IIB that were modeled in CAFCA II, the two results can be compared and conclusions can be drawn as to an discrepancies between the two. Specifically, the results representing TRU mass balance accumulation in the system, spent fuel separation plant construction and fertile free fuel spent fuel reprocessing plant construction are compared. Thus, these new runs will substantiate the accuracy of past work and expand the number of reactor options that have been evaluated by CAFCA IIB. Additionally, the new data help pinpoint the operating range for CAFCA IIB in which the code is accurate. Overall, none of the results from the same conditions in CAFCA II and CAFCA IIB matched up perfectly. Therefore, in an effort to further evaluate the effectiveness of CAFCA IIB, the plant lifetime input is tested in order to determine system sensitivities to that factor. This is done by modeling of nuclear fuel cycles while varying that single input, and comparing the results to the base or control case. Results suggest that different combinations of the various parameters are ideal for each different strategy of reactor type.