KOEBERG | REPAIR AND MAINTENANCE


Left: Koeberg power plant in South Africa


With the chance that the reactor may returned to the


service later than the planned-for June 2022 and the severe impact on consumers and businesses if that was the case, a decision was taken to delay the steam generator element of the refurbishment until the following refuelling outage. This is currently planned for August 2023. Eskom insists that these deferred tasks in no way affect the safe operations of the plant as the steam generators undergo a full series of inspections and integrity tests as part of the standard refuelling outage. As Riedewaan Barkadien, Eskom’s Chief Nuclear Officer, later explained: “We have moved the replacement of the generators into a window that suits Eskom better”. While the first phase of the current outage proceeded


as planned, including replacement of fuel and scheduled maintenance, the latest delay to the project is the second to be recently announced. Eskom laid the delays at the door of the global pandemic, which hampered the ability of the company to get resources to the site. Work on Unit 2 had initially been set for completion by mid-June. CEO André de Ruyter has said the work would now be finalised by the end of July, as NEI goes to press. Unit 2 had produced electricity for 454 days without interruption ahead of the January refuelling and maintenance shutdown. Each weighing about 380 tonnes and some 20 metres long, the steam generator replacement is an important part of a US$1.2bn longer-term programme to extend the operational life of the plant’s reactors by 20 years each. The original generators feature U-tubes that are susceptible to cracking. Once removed they will temporarily stored on-site, before final disposal at the Vaalputs radioactive waste storage facility in the Northern Cape “as complete and sealed units”. It has been reported that the on-site facilities to store the old steam generators are not ready, which is one of the reasons for the changing schedule. While the delay will not materially impact the life


extension plan it does narrow the available window to complete the work. Koeberg’s current operating licences expire in 2024 for Unit 1 and 2025 for Unit 2. Steam generator replacement at both units is one of the upgrades required by the National Nuclear Regulator (NNR) to grant an extension to the operating licence. The Koeberg Long-


Term Operation (LTO) plan is a series of activities that will enable Koeberg to operate to 2045. The plans are to be submitted along with supporting documentation to the NNR for evaluation and Eskom had planned to submit the required supporting documentation by June 2022. As part of the review of the Koeberg LTO programme, an


International Atomic Energy Agency (IAEA) 10-person team carried out a safety aspects of the LTO (SALTO) review during March 2022. “We observed that despite many challenges 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 Gabor Petofi, a Senior Nuclear Safety Officer at the IAEA. Koeberg management has also requested the IAEA schedule a follow-up mission to Koeberg during 2024. “Eskom has incorporated some IAEA standards and


guides into its policies and procedures, with a robust framework having been put in place for the life extension,” said Barkadien. In a statement Katse Maphoto, Chief Director: Nuclear


Safety and Technology of the Department of Minerals and Energy in South Africa, emphasised the importance of Koeberg LTO from national energy security and grid balancing perspective: “The government remains optimistic that the LTO project will benefit a lot from the IAEA mission recommendations for the power station to achieve the highest level of safety.” The South African government has previously indicated a strong commitment to the future of nuclear energy. Alongside the Koeberg LTO in October 2019 the country outlined plans to build 1 GW of new nuclear capacity by 2030. Koeberg unit 1 is currently scheduled to shut down for its


annual refuel and maintenance programme in September and the steam generator replacement on this unit will proceed as planned from October 2022. This is after the winter peak and is planned as a similar 155-day outage. Its reactor pressure vessel head had already been replaced several years ago. Areva was the original equipment manufacturer (OEM)


for Koeberg and in August 2014, Eskom awarded Areva the steam generator replacement contract in a ZAR 4.3bn (US$258m) contract that was later challenged in court by U


www.neimagazine.com | August 2022 | 27


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