摘要
医用同位素生产水溶液堆(Medical Isotope Production aqueous Reactor,MIPR)具有尺寸小、功率低和固有安全性高等优点,是^(99)Mo和其他医用同位素生产的较佳候选堆型之一。本文重点研究低富集铀启堆模式下的提取方式以及处理能力对MIPR生产^(99)Mo效率的影响。采用SCALE6.1蒙特卡罗程序、ENDF/B-Ⅶ238群数据库进行计算。首先,根据已有的实验数据对MIPR中子学计算方法进行了验证,并对堆芯设计进行了中子学优化。然后,根据优化的堆芯模型对不同提取方式以及处理能力下的^(99)Mo生产效率进行了研究,确定了可实现临界的铀浓度与富集度范围。结果表明:在不同富集度下存在最小临界质量,且随235U富集度的增加,最小临界铀质量时的铀浓度减小;有效倍增因子随硝酸浓度增加线性减小,相应的硝酸反应性系数约为-1.400×10^(-2)L·mol^(-1);随着铀浓度的增加,空泡和温度反应性系数减小,对应反应性系数分别约在(-100~-250)×10-3℃^(−1)和(-18~-30)×10-5℃^(−1)范围。MIPR生产^(99)Mo的效率在线提取方式略高于离线批处理方式,5 d生产周期下,生产效率提高约16%。后处理能力对在线提取方式的生产效率影响较大,5 d生产周期下,后处理速率提高5倍,生产效率提高约113%。
[Background]The medical isotope production aqueous reactor(MIPR)has advantages of small size,low power,and high inherent safety,hence is one of better candidate reactor types for the production of^(99)Mo and other medical isotopes.[Purpose]This study aims at the effects of extraction methods and reprocessing capacity on the production efficiency of^(99)Mo based on low-enriched uranium MIPR designed with neutronic optimization.[Methods]First,the calculation method was verified according to existing experimental data,and the neutronic optimization of the MIPR was performed for core design by using SCALE6.1 code and ENDF/B-VII database with 238 groups.Then,the^(99)Mo production efficiency under different extraction methods as well as processing capacities was investigated based on the optimized core structure.The range of achievable critical uranium concentration and enrichment was determined.[Results]There is a minimum critical mass under different enrichment,and with the increase of 235U enrichment,the uranium concentration at the minimum critical uranium mass decreases.The effective multiplication factor decreases linearly with an increase in nitric acid concentration,and the corresponding nitric acid reactivity coefficient is approximately−1.400×10^(-2)L·mol^(-1).With an increase in uranium concentration,the void and temperature reactivity coefficients decrease,and the corresponding reactivity coefficients are approximately(−100~−250)×10−3℃^(−1)and(−18~−30)×10−5℃^(−1).[Conclusion]The production efficiency of the MIPR production of the^(99)Mo online extraction method is slightly greater than that of the offline batch processing method with an increment of about 16%under a five-day production cycle.The reprocessing capability has a greater impact on the production efficiency of the online extraction method.If the reprocessing rate is increased five times,the increment of production efficiency is about 113%under a five-day production cycle.
作者
郁长清
朱贵凤
严睿
邹杨
YU Changqing;ZHU Guifeng;YAN Rui;ZOU Yang(Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《核技术》
CAS
CSCD
北大核心
2023年第9期125-134,共10页
Nuclear Techniques
基金
国家自然科学基金(No.12005290)
中国科学院青年创新促进会(No.2020261)
中国科学院上海分院"基础研究特区计划"(No.JCYJ-SHFY-2021-003)资助。
