Don't gut nuclear safety standards

The Nuclear Regulation Authority has disclosed an outline of new safety standards for nuclear power plants. They include obligatory measures to cope with a large-scale natural disaster and terrorist attacks.

Currently these measures are taken voluntarily by nuclear power plant operators. After listening to opinions from the public, the NRA will enforce the new standards from July. It is imperative that power companies strictly follow them.

It is deplorable that the power industry has already voiced complaints about the new standards. The industry objects to the large sums of money required over a long period of time to meet the standards. To prevent a catastrophe like the one at Tokyo Electric Power Co.’s Fukushima No. 1 plant, the NRA should reject any moves to weaken the new standards.

The Abe government, which appears in favor of reviving the traditional pro-nuclear power policy, should refrain from dropping the policy of ending the nation’s reliance on nuclear power in the 2030s as set by the Democratic Party of Japan government.

The characteristic of the new standards is that operators of nuclear power plants have to take measures to cope with such “severe accidents” as a strong earthquake, a tsunami, a terrorist attack and an airplane crash.

Operators will be required to multiply power sources to be used in cooling reactor cores, to set up a second control room to cool a reactor core by remote control in case the regular control room becomes inoperative as well as to establish an emergency command center with seismic isolation and radiation shielding functions, to install filters to remove radioactive substances when such substances have to be vented from a reactor containment vessel and to use fireproof electric cables.

The NRA will also assume a maximum height of a possible tsunami for each nuclear power plant and will require each plant to take necessary steps including installment of a seawall.

Currently operators of nuclear power plants are required to find out whether geological faults inside a plan site were active in the past 120,000 to 130,000 years. But the period for examination will be extended to the past 400,000 years if the operators cannot prove that no faults were active in the past 120,000 to 130,000 years.

Building reactor containment vessels and other important facilities above an active fault will be prohibited. NRA head Mr. Shunichi Tanaka should be praised for saying that the authority will not take into consideration the costs that power companies must bear in implementing the new safety standards.

Unfortunately, it seems that the NRA will likely allow a grace period for installing filters to remove radioactive substances at pressurized light water reactors on the grounds that hydrogen explosions are unlikely to occur in this type of reactor. There is also a possibility that the NRA will allow a grace period for the installation of a second control room and an emergency command center with seismic isolation and radiation filtering functions.

But can nuclear power plants that lack these facilities keep severe accidents under control and prevent them from spiraling into major disasters? The NRA should refrain from granting grace periods as they would only serve to gut the new safety standards.