IAEA reviews long-term safety of South African plant

Construction of the Koeberg plant began in 1976, with unit 1 entering commercial operation in 1984 and unit 2 in 1985. With a total capacity of 1860 MWe Koeberg's two pressurised water reactors can supply the equivalent of about 5.6% of South Africa's national energy needs, and currently about half of the energy demand of the Western Cape. Utility Eskom is planning to extend the operation of the units by 20 years to 60 years each. The plant is undergoing a periodic safety review to identify safety improvements for the long-term operation (LTO) period.

A SALTO peer review is a comprehensive safety review addressing strategy and key elements for the safe LTO of nuclear power plants. SALTO missions complement IAEA Operational Safety Review Team (OSART) missions which are designed as a review of programmes and activities essential to operational safety. SALTO peer reviews can be carried out at any time during the lifetime of a nuclear power plant, although according to the IAEA the most suitable time lies within the last 10 years of the plant's originally foreseen operating period. SALTO and OSART reviews are carried out at the request of the IAEA member country in which the review is to take place.

A Pre-SALTO review mission - requested by South Africa's Department of Energy - was conducted between 3-11 September.

The 12-member team - comprising experts from Belgium, Brazil, Czech Republic, France, Japan, Romania, Sweden, the UK and the USA, plus two IAEA staff members - identified good practices and performances that will be shared with the nuclear industry globally. These included the fact that a water chemistry programme had been implemented in line with IAEA safety standards, supporting ageing management for LTO. Also, the plant had launched a surveillance programme to monitor reactor embrittlement under operation for all relevant plant conditions, including LTO. Koeberg also uses a simulator of mechanical, electrical, chemical and radiation protection processes to improve staff performance and plant safety in these areas.

"We observed that, despite many challenges and delays, the plant has made progress in ageing management activities and preparation for safe LTO since the first Pre-SALTO mission in 2015," said team leader Robert Krivanek, a senior nuclear safety officer at the IAEA. "The SALTO team encourages Eskom and the plant management to address findings made by the SALTO team and to implement all remaining activities for safe LTO."

The team provided recommendations for further enhancing preparations for LTO safety, including that Eskom: empowers plant management and staff with all necessary mandates and processes, including adequate resources to achieve safe LTO in a timely manner; adequately plan and implement impressed current cathodic protection of the reactor containment, including tests with a mock-up to further improve corrosion prevention; and, develop and implement a knowledge management programme.

The team provided a draft report to the plant management at the end of the mission. A final report will be submitted to the plant, the South African nuclear regulator and the government within three months.

The plant management said it was committed to implementing the recommendations and requested that the IAEA schedule a SALTO follow-up mission to Koeberg in September 2021.

"We appreciate IAEA support of our plant in ageing management and preparation for safe LTO," said Riedewaan Bakardien, Eskom's chief nuclear officer. "The LTO of Koeberg NPP up to 2045 is a vital part of Eskom's energy planning strategy. The results of this mission will help us to finalise our activities for safe LTO in alignment with IAEA safety standards."