10 Dec (NucNet): The single-unit Borssele nuclear power station in the Netherlands continues to operate as one of the top 25% water-cooled and water-moderated power reactors in the EU, the US and Canada, a committee established to evaluate the facility has concluded.
The Borssele benchmark committee said in its latest report, released on 7 December, that the results of a benchmarking exercise indicate that from the design point of view, Borssele remains well within the top 25% safest reactors.
The committee said the facility’s favourable score is the result of “prudent original design, but even more because of continuous safety improvement programmes that have taken place since 1986, in particular due to periodic safety reviews”.
The five-person independent committee carried out its last review of Borssele, owned and operated by EPZ, in 2013. Reviews are every five years with the next one scheduled for 2023.
The purpose of the reviews is to determine whether EPZ is ensuring that Borssele, a 482-MW pressurised water reactor unit that began commercial operation in October 1973, continues to be among the top 25% of nuclear reactors surveyed.
The reviews are part of an agreement not to close the plant in 2013 – as was politically intended – but to allow it, in principle, to continue operation until 31 December 2033, if safety requirements are met.
The latest review also says Borssele’s safety performance in reactor operations, maintenance, and safety management compares well to that of the 25% best-performing reactors.
The facility’s ageing management programme was benchmarked against a peer group of five water-cooled and water-moderated reactors and was found to be “comparable to that of its peers”.
The committee noted, however, that safety culture cannot be benchmarked in the same way as other aspects of performance.
Safety culture often reflects the attitudes, values, beliefs and behaviour that employees share in relation to safety and how management influences this behaviour, the committee said. “Attitudes, values and beliefs do not easily lend themselves to measurement. However, attributes can be identified that shape or influence safety culture.”
In June 2006, the Dutch government and EPZ and its shareholders agreed to end Borssele’s operating life no later than 31 December 2033 if a number of conditions are met. One of those conditions is that EPZ meets the top 25% target.
The committee compared Borssele, designed by Siemens/KWU, to 236 similar reactor units that were in commercial operation as of 31 December 2016. According to the International Atomic Energy Agency there are 454 reactors in commercial operation globally.
The committee developed its own methodology, noting that there are no internationally harmonised evaluations available for all safety aspects of a nuclear power reactor that express the safety “in one well-defined number”. Requirements for nuclear safety are established in most countries in line with IAEA safety standards and, within the EU, with guidelines set by the Western European Nuclear Regulators Association and the European Nuclear Safety Regulators Group.
However, the responsibility lies with the national regulatory authorities and despite the efforts of the international organisations to harmonise these requirements, national differences remain, and the importance attached to various safety aspects is not necessarily uniform, the committee said.
The committee said the new report reflects three recent developments in the industry: post-Fukushima studies, the wider use of IAEA long-term operation review missions, and “the increased worldwide consciousness about the importance of safety culture”.