CAJ | 학술논문

COSINE软件包堆芯物理分析程序采用节块展开法（NEM ）进行中子扩散方程的求解，NEM 以节块均匀化理论为基础。在A P1000堆芯核设计过程中，由于燃料组件的多种轴向材料分区方式、定位格架分布及控制棒插入均会引起节块轴向材料不均匀，需进行再均匀化处理。由于再均匀化过程基于一些假设，给NEM计算带来了一定误差。这种误差最为直接的表现形式为控制棒的尖端效应。本文采用了子网格技术来处理轴向材料不均匀性的问题，并给出了初步验证结果，计算了控制棒的微分价值曲线。计算结果表明，子网格的应用有效地缓解了控制棒尖端效应的影响。
COSINE연건포퇴심물리분석정서채용절괴전개법（NEM ）진행중자확산방정적구해，NEM 이절괴균균화이론위기출。재A P1000퇴심핵설계과정중，유우연료조건적다충축향재료분구방식、정위격가분포급공제봉삽입균회인기절괴축향재료불균균，수진행재균균화처리。유우재균균화과정기우일사가설，급NEM계산대래료일정오차。저충오차최위직접적표현형식위공제봉적첨단효응。본문채용료자망격기술래처리축향재료불균균성적문제，병급출료초보험증결과，계산료공제봉적미분개치곡선。계산결과표명，자망격적응용유효지완해료공제봉첨단효응적영향。
The core code of COSINE package uses NEM to solve diffusion equation and NEM is based on the node homogenization theory .In the AP1000 core design process , there are some reasons w hich cause material heterogeneity in the axial direction ,such as the fuel assembly dividing into several areas with different enrichments , the arrangement of spacer grid and the insertion of control rod , and it is needed to be rehomogenization .The re-homogenization can bring error into NEM calculation result because of some hypothesis . The directive phenomenon of the error is control rod cusping effect .Sub-node technology was proposed to solve the material heterogeneity in the axial direction problem in this paper ,and the differential worth of control rod was calculated .The results show that the control rod cusping effect greatly reduces because of the sub-node technology .