Safety research program of LWR fuels and materials using the Japan materials testing reactor

Power up-rates, burn-up extension and long term operation enable us to utilize Light Water Reactors efficiently. This will have the fuels and structural materials exposed to severe operational condition for a longer period, which can affect their integrity. Continuous researches for solving irradiation-related issues on the fuels for high-duty uses and the plant aging are essential in order to realize the up-graded uses of LWR safely. Japanese regulator has decided to install new irradiation test facilities in the Japan Material Testing Reactor (JMTR) at the Japan Atomic Energy Agency (JAEA). For the fuels tests, transient tests facility is being constructed for the power transient tests of new design BWR fuels. For the materials tests, the irradiation test loops under well controlled environment simulating BWR water chemistry condition and a large irradiation capsule, which can accommodate 1 inch-thickness compact tension specimens in an inert gas environment, are being prepared for the researches on stress corrosion cracking and irradiation embrittlement, respectively. These fuels and materials irradiation tests will be started in 2011 after refurbishment of JMTR. (author)