Ten more years for Bugey 4

Wednesday, 31 July 2013

Bugey 4 has successfully completed a major periodic safety review, making it the fifth reactor that French nuclear safety regulators have approved for operation to the age of 40.

Bugey is home to four operating PWRs (Image: EDF)

The Nuclear Safety Authority (Autorité de Sûreté Nucléaire, ASN) has notified operator EDF of additional measures that must be taken to enhance safety levels at the plant to ensure they are brought in line with the latest practices. The regulator noted that these are broadly similar to those it required at Bugey 2, which is of a similar design to unit 4, plus some measures that are specific to unit 4. All the work will be subject to verification by the regulator.

Rather than issuing an operating licence for a set period of time, French law requires that the operator of a reactor performs a review of the level of safety at the unit every ten years. This involves a compliance review, which ensures that the plant complies with applicable safety rules, and a security review. The process also makes sure the plant incorporates the latest safety practices and sets new operating conditions. It also verifies that any phenomena associated with plant ageing will be manageable for a minimum of ten years.

The ASN says its decision on Bugey 4 takes into account first lessons learned from the Fukushima nuclear accident of 2011. The regulator notes that its requirements for Bugey 4 may be amended or supplemented as more feedback from Fukushima emerges over the next decade.

The safety inspections at Bugey 4 were carried out between February and June 2011, while the unit was out of service. During that time, the ASN supervised four inspections including hydraulic requalification of the unit's primary circuit.

Bugey 4 is a 880 MWe pressurized water reactor that started operation in 1979. It now joins Bugey 2, Tricastin 1 and Fessenheim 1 and 2 in the list of French reactors to complete their third ten-yearly assessment and regulatory review. ASN approved Bugey 2's continued operation in June 2012, while Bugey 3 is currently undergoing its third decennial inspection.

Researched and written
by World Nuclear News