钠冷快堆燃料破损及其探测方法

中国原子能科学研究院反应堆工程技术研究部,北京 102413

原子能技术; 钠冷快堆; 金属材料; 燃料包壳; 燃料破损探测; 裂变产物释放; 缓发中子先驱核; 缓发中子探测

Fuel failure and failed fuel detection methods for sodium cooled fast reactor
Pan Junyan, Ma Qiang, Wang Gang, and Zhang Hang

Pan Junyan, Ma Qiang, Wang Gang, and Zhang HangReactor Engineering Technology Research Division, China Institute of Atomic Energy, Beijing 102413, P.R.China

atomic energy technology; sodium cooled fast reactor; metallic material; fuel cladding; failed fuel detection; fission product release; delayed neutron precursor; delayed neutron detection

DOI: 10.3724/SP.J.1249.2016.04331

备注

结合钠冷快堆一回路冷却剂系统特点,系统阐述了燃料包壳在不同尺寸破口下的裂变产物释放机理. 燃料包壳在小气密性破损阶段会有气态裂变核素Kr和Xe释放到一回路覆盖气体中,当发展到燃料与冷却剂接触性破损阶段,短寿命的缓发中子先驱核会释放到钠冷却剂中. 钠冷快堆燃料破损在线监测系统由燃料破损覆盖气体监测系统和燃料破损缓发中子监测系统组成,分别监测不同性质的燃料破损. 基于国际快堆燃料破损在线监测系统设计方案对比分析,评述了不同的燃料破损探测方法和影响燃料破损探测灵敏度的相关因素.

The release mechanism of fission products in deterioration process of fuel failure is summarized according to the characteristics of primary coolant system in sodium cooled fast reactor(SFR). When fuel cladding has pinhole failure, the gaseous fission products Kr and Xe would escape to the cover gas. When fuel cladding is developed to the fuel-coolant contact failure, the delayed neutron precursor with short life would be released to the sodium coolant. The fuel failure online monitoring system in SFR is composed of the failed fuel cover gas monitoring subsystem and the failed fuel delayed neutron detection subsystem. They are designed to monitor failed fuel with different properties. The development of failed fuel detection methods and the factors of detection sensitivity are illustrated in detail on basis of a comparison analysis of the international design for failed fuel online monitoring system in SFR.