Comparison of ASME Code NB-3200 and NB-3600 results for fatigue analysis of B31.1 branch nozzles
Fatigue analyses wre conducted on two reactor coolant system branch nozzles in an operating PWR designed to the B31.1 Code, for which no explicit fatigue analysis was required by the licensing basis. These analyses were performed as part of resolving issues connected with NRC`s Fatigue Action Plan to determine if the cumulative usage factor (CUF) for these nozzles, using the 1992 ASME Code and representative PWR transients, were comparable to nozzles designed and analyzed to the ASME Code. Both NB-3200 and NB-3600 ASME Code methods were used. NB-3200 analyses included the development of finite element models for each nozzle. Although detailed thermal transients were not available for the plant analyzed, representative transients from similar PWRs were applied in each method. CUFs calculated using NB-3200 methods were significantly less than using NB-3600. The paper points out differences in analysis methods and highlights difficulties and unknowns in performing more detailed analyses to reduce conservative assumptions.
- Research Organization:
- Lockheed Idaho Technologies Co., Idaho Falls, ID (United States)
- Sponsoring Organization:
- Nuclear Regulatory Commission, Washington, DC (United States)
- DOE Contract Number:
- AC07-94ID13223
- OSTI ID:
- 240454
- Report Number(s):
- INEL-96/00044; CONF-960706-11; ON: TI96009015; TRN: 96:012893
- Resource Relation:
- Conference: American Society of Mechanical Engineers (ASME) pressure vessels and piping conference, Montreal (Canada), 21-26 Jul 1996; Other Information: PBD: [1996]
- Country of Publication:
- United States
- Language:
- English
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