After over 50 years in service delivering electricity in the United Kingdom, ten Magnox nuclear power plant sites will be decommissioned by Magnox Limited, UK. This major decommissioning programme underwent a five-year international peer review organized by the IAEA.
The review process, which started in 2008, included a preliminary site visit, a review of project documentation, and two meetings held at the at the Bradwell Nuclear Power Plant.
The IAEA set up a review team of six international experts from Canada, Germany, France, Spain, Switzerland and the United States. The IAEA Departments of Nuclear Energy and Nuclear Safety and Security jointly coordinated the review and contributed with their expertise.
Such reviews, always organized by the IAEA upon the request of the Member State (or organization) itself, enables the country to obtain independent expert opinion and advice on its proposed programmes and their implementation. The reviews also contribute to stakeholder confidence and enhancing international trust in the activities of the country, an increasingly important issue.
Key Findings and Recommendations of the Peer Review
The international peer review found that Magnox Limited has adopted a well-coordinated, corporate-wide approach to decommissioning projects, using accelerated entry into 'care and maintenance' at the Bradwell and Trawsfynydd nuclear power plants as models for the decommissioning of their remaining sites. 'Care and maintenance' means that the building is made safe and secure and placed under a routine surveillance schedule until the final stage of decommissioning commences. Currently, Magnox Limited's policy foresees a 'care and maintenance' period lasting 85 years or more to take advantage of the natural radioactive decay of the materials in the nuclear power plants. It also allows for sufficient time to establish disposal facilities for long-lived radioactive waste.
Magnox Limited plans to implement future major projects by moving teams from site to site, making the best use of experience gained at sites decommissioned earlier. This approach reflects good practices according to the expert reviewers, since it maximizes the efficient use of the available workforce and may be expected to substantially reduce overall project costs. Magnox Limited expects that the site teams will demonstrate and apply a number of alternative decommissioning technologies, whose benefits can be utilized at other decommissioning sites.
The review team recommended that a near-term solution for graphite disposal should be actively sought, and all reasonable attempts be made to establish a disposal option for long-lived intermediate level waste, in order to remove these barriers to achieving final site clearance as soon as possible.
Contaminated areas, particularly those near site boundaries, should be accurately characterised to determine their extent and the conditions that could result in any migration of contamination. If the results of the characterisation differ from current expectations, Magnox Limited should carefully reconsider its planning assumption that contaminated land will remain in situ until final clearance of the site.
The summary report of The Decommissioning Programme of Magnox Limited, United Kingdom, with Bradwell as the Reference Site [pdf] details all findings and recommendations of the international peer review. It was issued to Magnox Limited on 28 February 2012 at the IAEA.
Pioneer Design
Magnox nuclear reactors are a gas-cooled design, using pressurized carbon dioxide rather than water to remove heat from the nuclear reactors.
The first Magnox Nuclear Power Station, located at Calder Hall, UK, is also the world's first nuclear power plant to generate electrical power on an industrial scale. The reactor design is named after the "magnesium non-oxidising", or magnox, alloy used to clad the fuel rods inside the reactor.
Background
Magnox Limited is the nuclear site licensee responsible for 10 nuclear sites and operator of one hydroelectric plant in the UK.
IAEA Peer Review Services: Upon Member States request, the IAEA selects teams of internationally recognized specialists and leads reviews according to mutually agreed terms of reference.
The main objectives of international peer reviews are to provide - on the basis of international safety standards - an independent assessment of the safety of an activity or facility and to assist Member States in improving their performance in the area or operation under review. The requesting Member State (or organization) obtains independent expert opinion and advice on their proposed programmes and actions and their implementation. The review also informs a Member State whether its programme is consistent with good practice in other national programmes.
In the area of radioactive waste management, decommissioning and remediation, Member States have requested reviews and appraisals in many different areas, e.g. planning, developing and operating waste management facilities, decommissioning nuclear facilities and environmental remediation of contaminated lands.