CRDIAC: Coupled Reactor Depletion Instrument with Automated Control

Steven K. Logan

关键词: BERYLLIUM;    CROSS SECTIONS;    GOLD;    NUCLEAR FUELS;    NUCLEAR PHYSICS;    NUCLEAR REACTIONS;    PLATES;    POST-IRRADIATION EXAMINATION;    REACTION KINETICS;    REACTORS;    SIMULATION;    TESTING;    TRANSMUTATION;    ISOTOPES AFIP-3;    Depletion;    MCNP;    Monte Carlo;    MRTAU;    Python;   

DOI  :  10.2172/1048406
RP-ID  :  INL/EXT-12-26804
PID  :  OSTI ID: 1048406
Others  :  TRN: US1204262

美国|英语

来源: SciTech Connect

【 摘 要 】

When modeling the behavior of a nuclear reactor over time, it is important to understand how the isotopes in the reactor will change, or transmute, over that time. This is especially important in the reactor fuel itself. Many nuclear physics modeling codes model how particles interact in the system, but do not model this over time. Thus, another code is used in conjunction with the nuclear physics code to accomplish this. In our code, Monte Carlo N-Particle (MCNP) codes and the Multi Reactor Transmutation Analysis Utility (MRTAU) were chosen as the codes to use. In this way, MCNP would produce the reaction rates in the different isotopes present and MRTAU would use cross sections generated from these reaction rates to determine how the mass of each isotope is lost or gained. Between these two codes, the information must be altered and edited for use. For this, a Python 2.7 script was developed to aid the user in getting the information in the correct forms. This newly developed methodology was called the Coupled Reactor Depletion Instrument with Automated Controls (CRDIAC). As is the case in any newly developed methodology for modeling of physical phenomena, CRDIAC needed to be verified against similar methodology and validated against data taken from an experiment, in our case AFIP-3. AFIP-3 was a reduced enrichment plate type fuel tested in the ATR. We verified our methodology against the MCNP Coupled with ORIGEN2 (MCWO) method and validated our work against the Post Irradiation Examination (PIE) data. When compared to MCWO, the difference in concentration of U-235 throughout Cycle 144A was about 1%. When compared to the PIE data, the average bias for end of life U-235 concentration was about 2%. These results from CRDIAC therefore agree with the MCWO and PIE data, validating and verifying CRDIAC. CRDIAC provides an alternative to using ORIGEN-based methodology, which is useful because CRDIAC's depletion code, MRTAU, uses every available isotope in its depletion, unlike ORIGEN, which only depletes the isotopes specified by the user. This means that depletions done by MRTAU more accurately reflect reality. MRTAU also allows the user to build new isotope data sets, which means any isotope with nuclear data could be depleted, something that would help predict the outcomes of nuclear reaction testing in materials other than fuel, like beryllium or gold.