Sunday 22 April 2012

International collaboration to improve safety


International collaboration to improve safety



There is a great deal of international cooperation on nuclear safety issues, in particular the exchange of operating experience under the auspices of the World Association of Nuclear Operators (WANO) which was set up in 1989.  In practical terms this is the most effective international means of achieving very high levels of safety through its four major programs: peer reviews; operating experience; technical support and exchange; and professional and technical development. WANO peer reviews are the main proactive way of sharing experience and expertise, and by the end of 2009 every one of the world's commercial nuclear power plants had been peer-reviewed at least once.  Following the Fukushima accident these have been stepped up to one every four years at each plant, with follow-up visits in between, and the scope extended from operational safety to include plant design upgrades. Pre-startup reviews of new plants are being increased.  See also: paper on Cooperation in Nuclear Power Industry.

The IAEA Convention on Nuclear Safety  (CNS) was drawn up during a series of expert level meetings from 1992 to 1994 and was the result of considerable work by Governments, national nuclear safety authorities and the IAEA Secretariat. Its aim is to legally commit participating States operating land-based nuclear power plants to maintain a high level of safety by setting international benchmarks to which States would subscribe.

The obligations of the Parties are based to a large extent on the principles contained in the IAEA Safety Fundamentals document The Safety of Nuclear Installations. These obligations cover for instance, siting, design, construction, operation, the availability of adequate financial and human resources, the assessment and verification of safety, quality assurance and emergency preparedness.
The Convention is an incentive instrument. It is not designed to ensure fulfillment of obligations by Parties through control and sanction, but is based on their common interest to achieve higher levels of safety. These levels are defined by international benchmarks developed and promoted through regular meetings of the Parties. The Convention obliges Parties to report on the implementation of their obligations for international peer review. This mechanism is the main innovative and dynamic element of the Convention.  Under the Operational Safety Review Team (OSART) program dating from 1982 international teams of experts conduct in-depth reviews of operational safety performance at a nuclear power plant. They review emergency planning, safety culture, radiation protection, and other areas. OSART missions are on request from the government, and involve staff from regulators, in these respects differing from WANO peer reviews.

The Convention entered into force in October 1996. As of September 2009, there were 79 signatories to the Convention, 66 of which are contracting parties, including all countries with operating nuclear power plants.

The IAEA General Conference unanimously endorsed the Action Plan on Nuclear Safety that Ministers requested in June. The plan arises from intensive consultations with Member States but not with industry, and is described as both a rallying point and a blueprint for strengthening nuclear safety worldwide. It contains suggestions to make nuclear safety more robust and effective than before, without removing the responsibility from national bodies and governments. It aims to ensure "adequate responses based on scientific knowledge and full transparency". Apart from strengthened and more frequent IAEA peer reviews (including those of regulatory systems), most of the 12 recommended actions are to be undertaken by individual countries and are likely to be well in hand already.
 
In relation to Eastern Europe particularly, since the late 1980s a major international program of assistance was carried out by the OECD, IAEA and Commission of the European Communities to bring early Soviet-designed reactors up to near western safety standards, or at least to effect significant improvements to the plants and their operation. The European Union also brought pressure to bear, particularly in countries which aspired to EU membership.

Modifications were made to overcome deficiencies in the 11 RBMK reactors still operating in Russia. Among other things, these removed the danger of a positive void coefficient response. Automated inspection equipment has also been installed in these reactors. 

The other class of reactors which has been the focus of international attention for safety upgrades is the first-generation of pressurised water VVER-440 reactors. The V-230 model was designed before formal safety standards were issued in the Soviet Union and they lack many basic safety features. Four are still operating in Russia and one in Armenia, under close inspection.
Later Soviet-designed reactors are very much safer and have Western control systems or the equivalent, along with containment structures.





Sources : Safety of Nuclear Power Reactors, from website http://www.world-nuclear.org/info/inf06.html

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