Early safety assessment for Oskarshamn 2

22 December 2014

Sweden's nuclear regulator has instructed operator OKG to submit its next safety assessment for Oskarshamn 2 in 2017, three years earlier than scheduled, because of shortcomings in its previous submission.  

Oskarshamn 2 (Image: OKG)

Swedish nuclear plant licensees are required to submit an assessment of a plant's radiation safety at least once every ten years. The licensee must assess how they meet radiation safety requirements, as well as checking that they have embraced scientific and technological developments to ensure that safety gains can continue to be made. However, the Swedish Radiation Safety Authority (Strålsäkerhetsmyndigheten, or SSM), has ruled that OKG's 2010 assessment for Oskarshamn 2 contains deficiencies that warrant an earlier reassessment.

Although the SSM's review found that OKG's assessment identified the majority of existing requirements and set out clear positions on regulatory compliance, the regulator was particularly dissatisfied with the information supplied on how scientific and technological developments would be implemented. Information supplied on OKG's operating methods was also deemed to be lacking. SSM says it has set timescales for such deficiencies to be addressed.

Under the SSM's injunction, OKG must submit its next overall assessment of Oskarshamn 2 by the end of 2017, only seven years after the previous assessment. An implementation plan for the assessment must be submitted by 30 September 2015.

Furthermore, the regulator has decided that OKG has not performed the necessary analyses and measures to manage the transition to long-term operation. Skånberg said the regulator saw no "immediate risks" from this, but the regulator has instructed OKG to address the gaps. By the end of June 2015, OKG must submit to the regulator the results of any analyses that need to be implemented, plus risk assessments and schedules for analyses yet to be completed.

Oskarshamn 2 is undergoing extensive modernization work and has been off line since June 2013. The SSM noted in its supervision the shortcomings in the assessment have already been identified and are being addressed in the course of the work already under way. None of the deficiencies have been deemed to be significant enough to warrant immediate action. Oskarshamn's two other BWR units are currently operational, but the plant has been operating under special regulatory supervision since 2011, when the SSM identified issues with safety culture. Since late 2012 OKG has been required to submit six-monthly progress reports. In its most recent review of operations at the site earlier this month, the SSM said that OKG is on track with measures to improve the safety culture.

Oskarshamn 2 is not expected to return to service until mid-2015.

Researched and written
by World Nuclear News