Ghazi N, Haj Hassan H, Hainoun A
Department of Nuclear Engineering, Atomic Energy Commission, Damascus, Syria.
Appl Radiat Isot. 2009 Oct;67(10):1919-24. doi: 10.1016/j.apradiso.2009.06.003. Epub 2009 Jun 21.
A comprehensive analysis has been performed to investigate the conversion of the Syrian MNSR (miniature neutron source reactor) from current HEU fuel to selected alternatives LEU and MEU fuels. For this purposes the core design calculations related to design and engineering of LEU and MEU fuels have been carried out using the codes WIMSD/4 and BORGES-part of the MTR-PC and the code CITATION. Aiming at reducing the fuel enrichment by maintaining reactor power, thermal neutron flux and excess reactivity in the same range of the current MNSR design, two fuel alternatives of LEU (UO(2)-Mg) and MEU (U(3)Si(x)-Al) have been investigated. The results indicate that the first type (UO(2)-Mg) realizes the criticality conditions with low enrichment of 20% using the similar overall design of the present HEU fuel pins, whereas the second type (U(3)Si-Al) requires increasing the enrichment up to 33%. For the purpose of reactor core lifetime extension the possibility of mixing the burnable poisons Gd(157) and Cd(113) in the fresh core has been also explored. Thus, the calculation results indicate that the long-term control effect of Cd(113) on the excess reactivity is more homogeneous over the time due to the lower burn up rate of this burnable poison.
已进行了全面分析，以研究叙利亚微型中子源反应堆从当前高浓铀燃料转换为选定的低浓铀和中浓铀替代燃料的情况。为此，使用WIMSD/4和BORGES（MTR-PC的一部分）代码以及CITATION代码，对与低浓铀和中浓铀燃料的设计和工程相关的堆芯设计进行了计算。为了在维持反应堆功率、热中子通量和过剩反应性处于当前微型中子源反应堆设计相同范围内的同时降低燃料富集度，研究了两种低浓铀（UO₂-Mg）和中浓铀（U₃Si-Al）燃料替代方案。结果表明，第一种类型（UO₂-Mg）使用与当前高浓铀燃料棒类似的总体设计，在20%的低富集度下实现了临界条件，而第二种类型（U₃Si-Al）则需要将富集度提高到33%。为了延长反应堆堆芯寿命，还探索了在新堆芯中混合可燃毒物钆-157和镉-113的可能性。因此，计算结果表明，由于这种可燃毒物的燃耗率较低，镉-113对过剩反应性的长期控制效果在时间上更为均匀。
