Summary report for ITER design task D10: Updating the activation code RACC for ITER design analysis. Final report, December 15, 1993--December 14, 1994

摘要

The computational capability of the RACC radioactivity code has been extended by the addition of routines for the calculation of pulsed/intermittent histories. These routines allow for an accurate treatment of the pulsed irradiation history of the International Thermonuclear Experimental Reactor (ITER) facility. The transmutation of stable and radioactive nuclides and the decay of the radioactive nuclides are accounted for during each pulse and decay period. The code now has the capability to model varying flux levels, pulse widths and dwell periods, varying pulsing schedules and maintenance periods. This flexibility allows the user to model virtually any irradiation history that may be encountered during the operation of ITER. In addition, a small auxiliary program has been written to interface with the ONEDANT/TWODANT neutral particle transport codes. This allows RACC-Pulse to utilize the same spatial mesh, geometric model and spatial neutron flux as in the transport codes. Though the RACC-Pulse code is quite flexible in its modeling of irradiation histories, the user of the code should be cautioned that the run time of the code can be quite excessive for a realistic, full size computational model of the facility. The CPU time is a function of the number of zones modeled and the number of transmutation generations treated. Indications are that run times on the order of hours can be expected when performing a detailed 1-D calculation having many zones, several hundred mesh intervals, and treating 3 transmutation generations. There are several reasons for this: (1) the basic calculational philosophy of the code, (2) the complexity of the pulsing structure, and (3) the version of the code provided to our group for modification which is an older version that has been optimized for IBM computers of the late 70's. Based on the above observation, though the results are accurate, the use of the RACC-Pulse code for routine design calculations should be reconsidered.