NRA drafts tightened nuke plant safety rules

Kyodo

The Nuclear Regulation Authority presented a draft outline Monday of new safety measures to prevent or minimize the consequences of severe atomic plant crises.

Among other features, the NRA said utilities will be required to build a special safety facility housing a secondary control room for reactor operations to protect reactors against natural disasters and acts of terrorism, such as the intentional crashing of an aircraft into a nuclear plant.

The new safety standards are expected to come into force in July, replacing the current ones, which the triple-meltdown disaster that erupted in March 2011 at the Fukushima No. 1 plant proved were insufficient.

Adopting the new safety standards is a major precondition in order for utilities to apply for government permits to restart their idled reactors.

In the Fukushima crisis, triggered by a huge earthquake and tsunami on March 11, 2011, three reactors suffered core meltdowns because their key cooling systems failed due to complete station blackout.

A series of hydrogen explosions followed, resulting in massive radioactive fallout.

Before Fukushima, authorities left it up to each utility whether to take steps against the possibility of a major calamity, based on the assumption such disasters are extremely unlikely.

But new safety measures will become mandatory under the forthcoming standards.

The draft also calls for the installation of vents with filters that are able to reduce the amount of radioactive substances ejected in the event the reactors must undergo emergency venting. The Fukushima complex had venting systems but not with radiation-screening filters.

Utilities will also be told to prepare emergency power sources to ensure reactors stay cool, even during a prolonged blackout.

In addition to these new measures, the NRA is crafting new safety criteria to deal with natural disasters such as earthquakes and tsunami.

Requirements to be included in the new regulations are drawing attention because they could affect unpopular plans to restart the idled reactors.

Only two reactors are currently online, at Kansai Electric’s Oi power plant in Fukui Prefecture.