Comment on the paper 'Post-Shutdown decay power and radio- nudide inventories in the discharged fuels of HEU and potential LEU miniature neutron source reactors'

摘要

We would like to comment on the article titled, "Post-shutdown decay power and radionuclide inventories in the discharged fuels of HEU and potential LEU miniature neutron source reactors" by Mirza et al. published on pages 701-706 in Volume 37 of Annals of Nuclear Energy, 2010. In this article an assessment of fission product and actinide content along with the time variation of decay power of discharged fuels of both HEU and LEU cores of MNSRs have been carried out for once-through cycle using the OR1GEN2 computer code. In their method, they have assumed once-through cycle for preparing the input file for the ORIGEN2 code. According to the Miniature Neutron Source Reactor instruction manual, an MNSR can operate at its rated power (30 kW) 2 h per day, 5 days per week, and 50 weeks per year. Therefore, refueling time of the reactor is 10 years. The total time of reactor operation (in continuous mode) is 200 days. Calculation of the fuel burn-up can be performed using the once-through method but radioactivity calculation depends on the half-life of radionuclides which are in the core. Xe-135 is one of the most important nuclides that affects the efficiency and operation mode of the reactor. In this letter we want to prove that the radioactivity assessment in once-through method is incorrect.