Establishment of Voluntary Consensus Codes and the Role of Code Engineers—Example of Creating the Environmental Fatigue Evaluation Method for Light Water Reactors—

Abstract

The design and construction codes for nuclear power plants worldwide have been established based on ASME Boiler and Pressure Vessel code Section III. Since the requirements for fatigue evaluation were first introduced in the ASME codes in 1963, fatigue evaluation methods have been used with few changes. In 2006, the world's first consensus codes describing a method for environmental fatigue evaluation have been established by the JSME. These codes incorporate the results of international research projects, led mainly by Japan, regarding environmental fatigue, that is, the reduced fatigue life of components subjected to a high-temperature reactor coolant environment. This effort exemplifies the international collaboration of engineers with expertise in the field of codes/standards. The Japanese team was a key contributor to the creation of these new international consensus codes for environmental fatigue evaluation. This paper describes the activities leading to the establishment of these codes, the development of the environmental fatigue evaluation method, the roles of code engineers during this process, and the remaining technical issues to be addressed.

KEYWORDS:

• ASME Section III codes
• codes and standards
• code engineer
• environmental fatigue
• fatigue evaluation
• JSME codes
• low-cycle fatigue
• Plant Life Management
• voluntary consensus code