Evaluation of P-T Limit Curves According to Alternative Fracture Toughness Requirements

Abstract:

During the heat-up and cool-down processes of nuclear power plants, temperature and pressure histories are to be maintained below the P-T limit curve to prevent the non-ductile failure of the RPV(Reactor Pressure Vessel). The ASME Code Sec. XI, App. G describe the detailed procedure for generating the P-T limit curve. The evaluation procedure is containing the evaluation methods of RT_NDT using 10CFR50.61. However, recently, Alternative fracture toughness requirements were released 10CFR50.61a. Therefore, in this study, RT_NDT of RPV according to the 10CFR50.61a was calculated and used for evaluation of P-T limit curve of a typical RPV under cool-down condition. As a result, it was proven that the P-T curve obtained from 10CFR50.61 is conservative because RT_NDT value obtained from the alternative fracture toughness requirements are significantly low.

• Periodical: Advanced Materials Research (Volume 1051)
• Pages: 896-901
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1051.896
• Online since: October 2014
• Authors: Sin Ae Lee, Sung Jun Lee, Sang Hwan Lee, Yoon Suk Chang*
• Keywords: Cool-Down Condition, Pressurized Thermal Shock, P-T Limit Curve, Stress Intensity Factor

References

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DOI: 10.12989/sem.2002.14.2.191

[2] The American Society of Mechanical Engineering, Fracture toughness criteria for protection against failure, Appendix G, (2007).

[3] USNRC, Alternate fracture toughness requirements for protection against pressurized thermal shock events, 10CFR50. 61a, (2010).

[4] USNRC, Fracture toughness requirements for protection against pressurized thermal shock events, 10CFR50. 61, (1985).

[5] ABAQUS version 6. 10, ABAQUS standard/user's manual, Simulia Inc. (2010).