Document: NUREG-0800
Document ID: 6b7eddf4-f7ce-4821-9f11-e37070221e57
Document Type: srp
Title: DYNAMIC TESTING AND ANALYSIS OF SYSTEMS, STRUCTURES, AND
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1613/ML16133A418.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.2
CFR Part: 
CFR Title: 

Content:
results from a finite element analysis are typically used in the fatigue evaluation of fillet welded connections. Acceptable approaches depend on the local geometric complexity and the level of model refinement at the fillet welded connection. Two acceptable methods for determining the maximum stress for use in a fatigue evaluation are described in RG 1.20, Revision 4, Section C.2.1.3.2.c. The applicant/licensee should demonstrate the conservatism of the method employed to determine the maximum local stress at the weld, for use in the fatigue evaluation. (iv) Vibration and stress limits should be documented and substantiated. Acceptance criteria should be established for allowable responses and for the location of vibration sensors during startup testing. Such criteria relate to the code-allowable stresses, strains, and limits of deflection established to preclude loss of function of the reactor internals or generation of loose parts. Any deviations from commonly accepted standards, such as ASME BPV Code on fatigue limits, should be justified. Additional factors of safety imposed on fatigue limits should be consistent with previously accepted levels. For example, remote monitoring of steam dryer alternating stress via MSL strain gage array measurements commonly needs an added factor of safety of 2. For additional guidance on allowable limits, see RG 1.20, Revision 4, Section C.2.1.3.3. D. Calculated structural and hydroacoustic response estimates for preoperational and initial startup testing conditions as well as for normal operation should be made available, along with plans for subsequent comparisons to test data during power ascension. Any adjustments to calculated response during the ITAAC process to address differences between as-designed and as-built conditions should be documented, particularly changes in welds, materials, wall thicknesses, and any other parameter which affects structural response significantly. Choice of testing locations need to be based