Development of criteria for assessment of reactor vessels with low upper shelf fracture toughness. Part 1: Development of criteria and analysis methods

Journal Article · Mon Jul 01 04:00:00 EDT 1996 · Bulletin - Welding Research Council

OSTI ID:445396

The question of an adequate Charpy upper-shelf energy for operation of nuclear reactor pressure vessel materials has been considered and studied for a number of years. The Federal Register contains a minimum upper-shelf Charpy requirement of 50 ft-lb. If the upper-shelf energy falls below the requirement, three actions are required: 1. Perform a volumetric examination of the belt-line region covering the material of concern and characterize any indications found, per Section XI of the ASME Boiler and Pressure Vessel Code. 2. Obtain additional evidence of the material fracture toughness. 3. Perform a safety analysis demonstrating the adequate margin for continued safe operation. In 1982, the NRC published proposed procedures for the analyses required by 10CFR50 for operating reactor vessels, as NUREG-0744, and this led to further discussions on the issue. Many comments were received, and these were also published in revision 1 of NUREG-0744. Concurrently, the NRC officially requested the ASME Code to recommend criteria for the evaluation of reactor vessels that do not meet the Charpy upper-shelf requirements. This request was accepted by the Code and assigned to the Working Group on Flaw Evaluation of Section XI. This report presents the results of that effort.

• OSTI ID: 445396
• Journal Information: Bulletin - Welding Research Council, Journal Name: Bulletin - Welding Research Council Journal Issue: 413; ISSN 0043-2326; ISSN WRCBA2
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
CALCULATION METHODS
EVALUATION
FRACTURE PROPERTIES
PRESSURE VESSELS
PROBABILISTIC ESTIMATION
REACTOR MATERIALS
REACTORS
STANDARDS