Embedded fission source approach to analyze external source effect in a subcritical reactor

作者：Zafar Zafar Iqbal; Kim Myung Hyun^*

来源：Nuclear Engineering and Design, 2018, 327: 238-247.

DOI：10.1016/j.nucengdes.2017.11.039

• External source
• MCNPX
• TRU
• ADSR
• Fusion hybrid
• Transmutation

A simple modification of the fission source spectrum is proposed for the Monte Carlo calculation for externally driven subcritical reactors. Embedded fission source (EFS) approach replaces the fission spectrum with the collective spectrum of the external source and fission working in a small region near to external source only. This model provides eigenvalue search with external source contribution resulting in direct connection with isotope depletion calculation within Monte Carlo simulation. MCNPX 2.6.0 is modified for EFS and tested for three kinds of reactor problems; critical fast reactor driven subcritical reactor, accelerator driven subcritical reactor and fusion-fission hybrid reactor. The effectiveness of the external sources is determined by the extra amount of the TRU isotopes burnt and increase in the core multiplication level. The tests were performed for two subcritical cases; k(eff) similar to 0.986 and k(eff) similar to 0.959, with initial TRU loading of 188.8 kg and 183.2 kg, respectively. The EFS approach is validated by simulating a fission source driven system which gave the multiplication factor comparable to the original MCNPX within one standard deviation (32 pcm). The difference in TRU burn-up for both subcritical cases is of the order of 0.1% for each driving neutron source option. The study showed that the EFS can be a simple and a reliable approximation for the external source analysis.

• 出版日期2018-2