In a first, Kansai Electric Power Co. on Thursday applied for permission to use Japan’s oldest nuclear reactors for another 20 years after finding the units devoid of problems during special safety checks conducted at its Takahama nuclear plant in Fukui Prefecture.
The application to extend the use of Takahama reactors 1 and 2, both around 40 years old, was submitted to the Nuclear Regulation Authority. It is the first time permission has been sought to extend the life span of a reactor that is 40 years old or older.
Under the revised law on nuclear power plant regulations, the time limit for running a nuclear reactor is 40 years. This can be extended only once, by up to 20 years, if certain conditions are met.
At the Takahama plant, reactor 1 is more than 40 years old and reactor 2 will reach 40 in November. They are the oldest of the 43 viable commercial reactors in Japan. Both are idle.
Kepco has to meet the special conditions for extension by July 2016.
Before its request, Kepco started special tests on the reactors in December. After checking their pressure and containment vessels with ultrasonic and visual examinations, the company concluded the units could function beyond the 40-year limit.
According to Kansai Electric, the safety screenings for the extension will cover the pressure and containment vessels, pipes, buildings and emergency power generators of the two units, comprising about 3,100 items for reactor 1 and about 3,000 for reactor 2.
The NRA also will determine whether Kansai Electric’s special safety checks were satisfactory.
In March, Kansai Electric separately applied for NRA screening to restart the reactors under the new safety standards introduced in July 2013. If the extensions are approved, Kepco does not expect the two units to resume operations until November 2019, at the earliest, because further safety measures will need to be taken before restarting them.
Also on Thursday, Kepco told the Fukui Prefectural Government that it will likely launch special checks this month for reactor 3 at its Mihama plant. The reactor, which is also offline, will turn 40 in December 2016.