Nuclear stress tests - Commission Interim Report

27 November 2011
by eub2 -- last modified 27 November 2011

Following the nuclear accident in Fukushima, the EU reacted swiftly and agreed on voluntary tests for all of its 143 nuclear power plants based on a set of common criteria. In its Communication published on 24 November, the Commission looks at first findings of these stress tests and points to some policy areas where the new EU nuclear safety framework can be strengthened through common standards.

What are nuclear stress tests?

The "stress tests" are a set of comparative criteria drawn up in the light of the nuclear accident in Fukushima. These EU wide tests will be in addition to existing the framework already applied at national level. Their aim is to assess whether the safety margins used in the licensing of nuclear power plants were sufficient to cover also extreme unexpected events.

The aim is to learn from what happened in Japan and help prevent that a similar accident can happen in Europe. One of the most important lessons to be drawn is that the extreme situations such as two natural disasters can hit at the same time and knock out the electrical power supply system completely. In Japan, the power plant withstood the earthquake but the tsunami interrupted the power supply which is necessary to cool down fuel elements. If they are not cooled down, there is a risk of a core meltdown with leakage of radioactivity and radiation getting into the soil and the water.

What is being assessed in the stress tests?

It is assessed whether the nuclear power plant can withstand the effects of the following events:

1. Natural disasters: earthquakes, flooding, extreme cold, extreme heat, snow, ice, storms, tornadoes, heavy rain and other extreme natural conditions.

2. Man-made failures and actions. These accidents can be: air plane crashes and explosions close to nuclear power plants, whether caused by a gas container or an oil tanker approaching the plant, fire or damaging effects from terrorist attacks.

What is the state of play of the stress tests?

Comprehensive risk and safety assessments ("stress tests"), based on commonly agreed criteria, started in all EU Member States that operate nuclear power plants before 1 June.

By mid August, nuclear plant operators carried out part of their self-assessment and sent national regulators their first interim report. By 15 September, the national regulatory authorities checked these first self-assessments and compiled national progress reports. All 14 Member States that operate nuclear power plants (Belgium, Bulgaria, Czech Republic, Finland, France, Germany, Hungary, the Netherlands, Romania, Slovak Republic, Slovenia, Spain, Sweden and United Kingdom) plus Lithuania, which is currently decommissioning its nuclear power producing units, submitted these progress reports to the Commission by 15 September. Similar reports were received from Switzerland and Ukraine, which accepted to take part in the exercise as neighbouring countries.

When will the EU present the results of the stress tests?

The national regulator will have to submit their final report by 31 st December. This will be followed by peer reviews which will be completed in April 2012. Safety experts from all EU Member States, including those who do not operate nuclear power plants, and Commission experts in nuclear safety will participate in peer review teams. National regulators under review should give the peer review team access not only to all necessary information but also to nuclear power plants.

The Commission will present its final report on the stress tests to the European Council of 28-29 June 2012.

What are Commission's initial impressions based on the national reports?

Subject to confirmation by the final national reports, the interim report recognises that in general nuclear operators follow and implement the agreed methodology. However, the format, content and level of detail of the reports vary substantially and the Commission's preliminary analysis indicates that the national regulators have different approaches to safety and use varying criteria to define safety improvements. For example, seismic risks are dealt with very differently and they seem to be evaluated independently of the actual seismicity of the regions concerned.

How can the results be compared if the reports are different from each other?

The Commission wants to enhance the coherence and comparability of the final national reports. To this end, it has agreed, together with the national regulators, a detailed common structure, which final national reports will have to follow.

The central element of this structure is the evaluation of safety margins for earthquakes, flooding, extreme weather conditions, loss of electrical power (including back-up and off-site supply) and loss of cooling capacity. It also contains a detailed chapter on severe accident management (measures to cope with major accidents, such as serious damage to the fuel or even the core meltdown and loss of containment capacity, resulting in important radioactive releases).

How about man-made risks, such as terrorist attacks?

There is no nuclear safety without security. Nuclear security aims at preventing intentional acts that might damage a nuclear facility or result in the theft or dispersion of nuclear materials. In the EU, only few of the national safety regulators have specific responsibility for the security of nuclear power plants. Moreover, security competencies in the Member States are spread among different bodies.

Security issues are an important part of the overall assessment process. Member States, assisted by the Commission, are directly in charge of assessing nuclear security. To that end, the Council set up the Ad-hoc Group on Nuclear Security (AHGNS). Its report is annexed to the Commission interim report.

The final results of the Group's work will be published in its final report by June 2012.

Switzerland and Ukraine are participating in the stress tests? What about other EU neighbours?

The Commission has involved in a common assessment process those EU neighbours that operate or own nuclear power plants or have clear plans for the development of nuclear power. Two of these countries – Switzerland and Ukraine – participate fully in the EU stress test process and have provided their progress reports. The Russian Federation stated that they had already performed safety re-assessments for their own nuclear power plants but they are interested to participate in the EU peer reviews.

The Commission aims to further enhance its cooperation with the International Atomic Energy Agency. It advocates improvements in the global legal framework for nuclear safety, especially the Nuclear Safety Convention, with the aim of increasing its effectiveness, governance and enforceability.

Are the results of the reports public?

Yes. All reports, including national reports and peer reviews, are or will be available at www.ensreg.eu .

Are there already conclusions available?

At this stage of the assessment process, any conclusions on overall stress tests results for a particular Member State or on plant-specific results would be premature. Therefore, the interim report contains only preliminary suggestions, which will be further elaborated in the light of the final outcome of the stress tests. The Commission will outline EU legislative initiatives in its final report to the European Council in June 2012.

Does the Commission propose any concrete follow-up actions?

In parallel, on the basis of initial findings, the European Commission is reviewing the EU nuclear safety legislation and envisaging ways for improvement.

In particular the Commission is considering:

    Minimum technical safety requirements . Today different Member States apply different safety margins in nuclear power plants. EU-level technical criteria in the areas of siting, plant design, construction and operation could be created. For instance, the criteria could establish a minimum distance of the plant from the sea. These criteria should be a reference point when licensing or checking the operations of the plants.

    Licensing and checks . National regulatory authorities are responsible for issuing licenses for new nuclear power plants and controlling the operation of the existing ones. To do this effectively they need to be completely independent. Their decisions and the reasoning behind them should be made available for the public.

    Cross-border emergency response . A possible radiological emergency would not stop at national borders. Therefore cross-border emergency plans should be put in place. These plans should foresee sharing and the availability of healthcare and response equipment, such as back-up generators in the event of loss of power in the plant.

    European liability schemes . Different Member States apply different liability regimes. For example, some countries require unlimited liability in terms of compensation to victims while in others only limited amounts are available. Victim protection should not depend on the nationality of the victims, therefore some minimum requirements should be put in place at EU level.

Source: European Commission