【作者】 刘晓晓； 曹建主； 张立国；

【Author】 LIU Xiao-xiao;CAO Jian-zhu;ZHANG Li-guo;Institute of Nuclear and New Energy Technology,Tsinghua University;

【机构】 清华大学核能与新能源技术研究院；

【摘要】 高温气冷堆(HTGR)走向国际市场将对核燃料(球形燃料元件)监督与核查提出更高要求,其中包括采用不同方法及装置对入堆前的球形元件进行计数和鉴别。目前,高温气冷堆仅统计进入燃料循环的新元件数量,未对新元件的类别进行判别。本文利用球形元件对γ射线的阻挡作用,初步设计了一套鉴别新元件类别的装置,并采用Geant4对上述装置进行建模分析,讨论了将不同密度的石墨球与含不同铀装量的燃料球进行鉴别的可行性,给出在较高置信度下鉴别两类元件的约束参数区间。该方法与装置为高温气冷堆核材料监管提供了一种可选手段。更多还原

【Abstract】 When high-temperature gas-cooled reactor(HTGR) is going to enter the international market,higher requirements from nuclear material(spherical fuel element for HTGR,known as fuel pebble) control and verification shall be met.One aspect may be to identify the type and number of fresh elements using different methods and devices before the pebbles are charged into the reactor.While only the number of fresh elements are counted without type-dicriminating in current fuel circulation.In this paper,a method and corresponding conceptual device is presented to identify type and count the number based on the fact that different type of fresh elements blocks gama rays by a quite different fraction.The feasibility of the new mothod to distinguish graphite pebbles with different density from fuel pebbles is analyzed by modeling the device and the gamma ray detection process using Geant4.Then key parametric constraint is discussed if high confidence distinguishing is ensured.The proposed method in the paper may provide a candidate manner for the supervision of nuclear materials for HTGR.更多还原