Finite element analysis of the PWR control rod absorber thermal evaluation

Conference · Fri Jul 01 04:00:00 EDT 2016

OSTI ID:22764054

Zhang, Bin; Deng, Yongjun; Wang, Yang ^[1]; Jin, Xin ^[2]

---

1. China Nuclear Power Technology Research Institute Co., Ltd. Chengdu, Sichuan (China)
2. China Nuclear Power Technology Research Institute Co., Ltd. Shenzhen, Guangdong (China)

The RCCAs (Rod Cluster Control Assembly) are part of the reactor control systems and are designed to adjust the reactivity by neutron absorption. In PWR, a RCCA is composed of a spider holding 24 control rods. During operation, the absorber stacks are heated up by neutron and γ-ray radiation. This paper describes the PWR control rod absorber temperature analysis model in details, derives the theoretical equations, and presents a FEA model for control rod absorber thermal evaluation. The FEA model is based on finite element analysis and on 3 major assumptions: 1) steady-state condition, 2) the thermal conductivities of absorber, cladding and gas are assumed to be constant, and 3) thermal expansion and radiation are neglected. The control rod of an AFA 3G fuel assembly in Ningde NPP unit 1 and 2 in steady state on condition I operation was used as a case to qualify the FEA method. A special software named CRABE, designed and qualified by AREVA, was used to do the same analysis for comparison. Several conclusions can be drawn. First, compared with traditional methods, FEA is more convenient with higher accuracy and can greatly simplify the calculation process. In addition, the FEA software is always ease to use, with a friendly interface and a more intuitive display of results. Secondly, the FEA model was qualified though a practical case calculated in different ways. Thirdly, when it comes to a special structure such as an eccentric absorber or an oval cladding, the FEA model has a great applicability, while traditional methods are difficult to use.

• Research Organization: American Nuclear Society - ANS, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
• OSTI ID: 22764054
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
42 ENGINEERING
C CODES
CLADDING
COMPARATIVE EVALUATIONS
CONTROL ELEMENTS
FINITE ELEMENT METHOD
FUEL ASSEMBLIES
GAMMA RADIATION
NEUTRON ABSORBERS
NEUTRONS
NINGDE-1 REACTOR
NINGDE-2 REACTOR
REACTIVITY
REACTOR CONTROL SYSTEMS
REACTOR DESIGN
STEADY-STATE CONDITIONS
THERMAL CONDUCTIVITY
THERMAL EXPANSION