The European Commission and the European Nuclear Safety Regulators’ Group (ENSREG) – made up of 27 independent national nuclear safety authorities – announced yesterday that they had agreed on the criteria for safety reviews of the 143 nuclear power reactors in the European Union and on how these will be conducted. The reviews, which the EU called for 25 March to draw lessons from the Fukushima disaster, are due to begin on 1 June. The EU wants reactors that fail the stress tests to be upgraded or shutdown permanently.
Agreement had been stalled by opposition from regulators in some countries, including France and the UK, to including terrorist attacks on plants, using explosives or aircraft as missiles. The European Commission conceded by agreeing to leave out discussion of security-related aspects of preparedness and countermeasures for terrorists attacks, but says that the tests should nonetheless study the effect of an accidental aircraft impact or explosion, and so equivalent ground will be covered.
The tests will include three phases, with reactor operators replying to a questionnaire, and submitting supporting documentation to national regulators, who will produce national reports. These will then be peer reviewed by seven-person multinational EU teams, each including one European Commission expert. The teams will also have powers to carry out plant inspections. The commission will present a preliminary report to the EU’s heads of state in December, and a final report in June 2012.
This peer-review aspect could be critical to helping ensure that operators come clean. The stress tests are largely being carried out by operators and national regulators who in some sense are being asked to justify their own past decisions and practices as to what they considered reactors could withstand – the European Commission has few powers when it comes to nuclear safety as this remains a national prerogative. The commission also lacks powers to force countries to take action on reactors that fail the tests, so it hopes that the fact that the national reports and peer review will be made public will mean that public pressure will force governments and plant operators to act.
The focus of the tests will be on how well designed power plants are to withstand earthquakes, floods, and other events, such as blackouts, that could prompt a loss of safety functions, and how well plants are prepared to handle and contain accidents such as a loss of core coolant were this to occur. The tests won’t deal with the emergency responses of police, firefighters, or health services.
The tests will also explore a plant’s robustness against events greater than what they have been designed for. Operators must furnish seismic and other studies to support their design basis, and to show what severity of earthquake or flood would cause inevitable damage to safety systems and fuel. The reviews will also emphasise how long a plant could survive loss of external and backup power, and what measures are available to quickly bring in new power sources.
One clear lesson from Fukushima that will be taken on board in the tests is that an adverse event wil be presumed to affect all reactors and spent fuel ponds at the same time. Accident management issues that will be looked at include emergency procedures to vent pressure from the reactors, without incurring the hydrogen explosions that were so devastating in the Fukushima accident.
Today, the European Union also called on all countries worldwide with nuclear plants to carry out similar reviews, Reuters reports, and said it will raise the issue at the G8 summit taking place today and tomorrow in Deauville, France.
Image: Forsmark nuclear power plant in Sweden courtesy of Arenamontanus via Flickr under Creative Commons.