NRA approves Takahama 1 and 2 safety standards

25 February 2016

Units 1 and 2 of Kansai Electric Power Company's Takahama nuclear power plant in Fukui prefecture meet Japan's new safety regulations, the country's nuclear regulator has decided. Both units have already operated beyond their 40-year licence period.

Takahama 460  (NRA)
Kansai's Takahama plant (Image: NRA)

The Nuclear Regulation Authority (NRA) disclosed yesterday that the two units meet safety standards introduced in July 2013 following the March 2011 accident at the Fukushima Daiichi plant. Kansai requested in March 2015 that the NRA carry out inspections of the units to check their compatibility with the revised standards.

According to the Japan Atomic Industrial Forum, the NRA's approval of Takahama 1 and 2's safety standards will formally be approved after hearings by the Japan Atomic Energy Commission and the Ministry of Economy, Trade and Industry. In addition, a public invitation for scientific and technological comments will also be called.

Takahama units 1 and 2 are the oldest reactors so far to be deemed to meet Japan's new safety standards.

Under Japanese previous regulations, nuclear power plant operators received a licence that lasts for 40 years, subject to a review every ten years in which the NRA checked the operator's maintenance plan for the unit.

The NRA approved a ten-year life extension for unit 1 of the Takahama plant in November 2014. The 780 MWe (net) pressurized water reactor (PWR) began operating in November 1974. Takahama 2 - also a 780 MWe PWR - was granted a ten-year life extension in April 2015. That unit started up a year after unit 1.

Under the revised regulations, reactors have a nominal lifespan of 40 years. However, extensions can be granted once only and limited to a maximum of 20 years, contingent on exacting safety requirements.

To extend the operating lives of Takahama 1 and 2, Kansai must receive NRA approval by July - the mandatory deadline - on three outstanding issues: safety measures, detailed designs and extension of operations. The company applied to the NRA in April 2015 to extend the operation of each reactor by 20 years.

Takahama 4 set to restart

Kansai said today that it plans to start up unit 4 of the Takahama plant tomorrow and that the unit should reach criticality the following day. It will become the fourth Japanese reactor to be restarted.

The 870 MWe PWR will start "power control operation" on 29 February, Kansai said. This is the final stage of the periodic outage inspection following various types of tests. Takahama 4 is scheduled to resume full operation at the end of March, the company said.

Units 3 and 4 of the Takahama plant had remained offline since being shut for periodic inspections in February 2012 and July 2011, respectively. Takahama 3 was restarted on 29 January.

Unit 1 of Kyushu Electric Power Company's Sendai plant in Kagoshima prefecture was the first of Japan's operable reactors to resume operation since September 2013 when it restarted last August. The restart of unit 2 followed in October.

Another 20 reactors are moving through the restart process, which has been prioritised to bring on the most-needed reactors first, in the localities and prefectures more supportive of restart.

Researched and written
by World Nuclear News