New nuclear safety standards

The Nuclear Regulation Authority on June 19 approved new safety standards for reactors. It will put them into force beginning July 8. Four power companies are expected to apply for safety screening by the NRA in July to restart up to 12 reactors at six nuclear power plants.

NRA Chairman Shunichi Tanaka said that his organization will not take power companies’ business conditions into consideration. The NRA should stick to this principle and carry out the screening in a transparent manner and reject any political pressure.

Although the Abe administration and the power industry are eager to restart nuclear power plants, they should not view the new safety standards as a procedural tool for the restart. Power companies must understand that if reactors fail to meet the requirements under the new standards, the companies must start a concrete process of decommissioning them.

The essence of the new standards is that they require power companies to take measures to cope with a severe accident as happened at Tokyo Electric Power Co.’s Fukushima No. 1 nuclear power plant. Such measures include construction of sea walls that will protect individual nuclear power plants from the largest tsunami that could conceivably hit them and installation of filters to remove radioactive substances if such substances are vented from reactor cores into the atmosphere during an emergency.

Before the Fukushima nuclear crisis, authorities had left the decision on whether to adopt those measures up to power companies by virtually refusing to consider the possibility that a severe accident could happen. But under the new safety standards, a grace period of five years will be allowed for the installation of filters in pressurized light-water reactors, since hydrogen explosions are unlikely in them. There is no grace period for installing filters in boiling-water reactors.

A grace period of the same length will be allowed for the installation of a second control room that is capable of independently controlling and cooling reactors in the event of a natural disaster or a terrorist attack.

Before the Fukushima nuclear fiasco, operators of nuclear power plants were required to find out whether geological faults inside a plan site were active in the past 120,000 to 130,000 years. The period to be examined will now be extended to the past 400,000 years if the operators are unable to prove that faults have not been active in the past 120,000 to 130,000 years. Important facilities of a nuclear power plant must not be built near an active fault.

The new standards are based on the idea of backfitting: making changes to existing nuclear power plants to reflect the latest knowledge and findings related to safety. The NRA should quickly incorporate such knowledge and findings into the standards.

The government, for its part, should adopt a policy to speedily reduce Japan’s reliance on nuclear power and to eventually abolish it. It also should help create new industries in areas now hosting nuclear power plants.