Development of Wall Thinning Management Codes in Japan

Author : Hideki Masui
                

Company : Tokyo Electric Power Company
                   Nuclear Asset Management Department
    
Country : Japan

Topic :

Wall thinning management

ABSTRACT :

It has been integral part of nuclear power plant management in Japan to properly control wall thinning of piping system. The Japan Society of Mechanical Engineers (JSME) established codes on wall thinning management in 2006. This initiative was triggered by the fatal accident caused by piping rupture in secondary system at Mihama 3 in 2004. The regulator, NISA (Nuclear and Industry Safety Agency), endorsed those codes in 2008 and all nuclear power plants implement the wall thinning management program accordingly.

One of the characteristics of those codes is "two-tier" structure consisting of common performance-based code and specification codes. The former states the responsibilities of the plant manager and requirements for the guideline that the plant manager has to formulate. The latter states specific technical requirements and is categorized into three types: thermal power plant, PWR and BWR.

This presentation mainly focuses on technical requirements of the BWR code. These include planning process, screening of testing scope, testing practice and evaluation methodology.

Although those practices have been in place, some technical challenges remain to be tackled. This presentation also shows those technical challenges and some examples of associated research and development program currently conducted by Japanese utilities.

Speaker Biographical Information

Mr. Hideki Masui graduated from Kyoto University in 1989 with bachelor's degree of environmental engineering and joined Tokyo Electric Power Company (TEPCO). He started his professional career at Fukushima Daiichi Nuclear Power Station. At that time, he was in charge of chemical control and involved in Japan's first-ever pilot test of Hydrogen Water Chemistry program. 

From 1994 to 1996, he pursued mater's degree of nuclear engineering at Massachusetts Institute of Technology. During his stay in the U.S., his main academic interest was probabilistic risk assessment. After returning to TEPCO corporate office, he was involved in nuclear fuel cycle issues and became a prominent professional in the field of radioactive waste disposal. In 2005, he took new position of the engineering manager at Kashiwazaki Kariwa Nuclear Power Station. His responsibilities were diverse, including designing new facility, performing periodical safety review, developing IT system and encouraging use of operational experience. It was during his tenure in 2007  when a massive earthquake hit the power station. As a member of emergency management team, he was in charge of information gathering and analysis in the aftermath of the earthquake. Then, supporting post-quake restoration work became one of his missions.

The current position, codes and standards manager at corporate office, was assigned to him in 2009. Since then, he has been responsible for development of codes and standards and an active member of standard developing organizations such as The Japan Society of Mechanical Engineers (JSME) and Japan Electric Association (JEA).

France has been always his preferred destination. He has made many personal and duty trips to France.