IAEA concludes operational safety review at Bulgaria’s Kozloduy Nuclear Power Plant

An International Atomic Energy Agency (IAEA) team of experts today completed a review of the long-term operational safety of Unit 6 at the Kozloduy Nuclear Power Plant (NPP) in Bulgaria.

The Pre-SALTO (Safety Aspects of Long Term Operation) review mission was requested by the Kozloduy NPP. The 11-member team, whose review began on 19 June, focused on aspects essential to the safe Long-Term Operation (LTO) of Unit 6, which went into commercial operation in 1991. The plant operator is preparing a license renewal application to the Bulgarian Nuclear Regulatory Authority to extend the operating lifetime of Unit 6.

The SALTO team reviewed preparedness, organization, and programmes related to LTO against IAEA safety standards.

The team observed progress in the field of aging management and preparedness for safe LTO. It said the plant's management demonstrated a commitment to making further progress towards LTO, and that the LTO project addresses many topics recommended by IAEA safety standards. The team found plant staff to be professional, open and receptive to suggestions for improvement.

The team - comprising experts from Armenia, Canada, Finland, Mexico, the Netherlands, Romania, South Africa, Sweden and Ukraine as well as two IAEA staff members - identified several good performances that will be shared with the nuclear industry globally, including:

• The PLEX Navigator software developed by the plant for LTO flowcharts links to relevant documentation in a single application.
• The plant has an extensive aging management programme for buried water pipelines.
• Two independent teams inspect civil structures in the plant.

The team also provided several recommendations for further enhancing LTO safety, including:

• The plant should ensure that the methodology for determining the scope of LTO includes all relevant systems, structures, and components.
• The plant should fully implement the aging management review and programmes.
• The plant should complete the identification of aging effects and degradation mechanisms.

The plant management said it was committed to implementing the recommendations and requested that the IAEA schedule a SALTO mission in 2020.

The team provided a draft report to the plant management at the end of the mission. The plant manager and the Bulgarian Nuclear Regulatory Authority will have an opportunity to make factual comments on the draft. A final report will be submitted to the plant management, the regulatory authority, and the Bulgarian Government within three months.