25 July 2012 – Eskom’s Koeberg nuclear power station (surrounded by a 3,000 ha private game reserve owned by the utility) near Cape Town boasts the largest turbine generators in the southern hemisphere and is the most southerly-situated nuclear power station in the world. Low and intermediate waste from Koeberg is transported by road in steel and corporate containers to a remote disposal site in the Kalahari Desert.
The nuclear power station ranks amongst the safest of the world’s top ranking pressure water reactors (PWRs) of its vintage and is the most reliable Eskom power station. Johannes Kotze, project director: strategic nuclear projects at Eskom says, “The licence to operate Koeberg has no specified term and operation is subject to periodic reviews and risk-based assessments. It is accepted, however, that the Koeberg design in conjunction with the initiative contained in the station life of plant plans, currently supports an operational life of 40 to 50 years.
By 2014, unit 1 will have been in operation for 30 years, with unit 2 reaching the equivalent operational age by 2015. This is typically the point at which nuclear power plant operators purposely evaluate their long-term asset management strategies and, where applicable, either initiate processes for the approval and implementation of justifiable plant life extension initiatives or prepare for decommissioning.” Worldwide, there is an increasing trend amongst nuclear power plant utilities to opt for life extension, rather than decommissioning. There are life extension initiatives currently in progress at South Korean, Swedish, Soviet, Swiss, US and French utilities.
“In line with these international approaches, Koeberg has commissioned a long term asset management project with the purpose of facilitating the decision on optimum plant life of Koeberg units 1 and 2, while taking into account the merits and demerits of current and future project strategies for major component and system refurbishments,” Kotze says. After an internationally accepted approach, Eskom conducted a feasibility assessment which highlighted the technical challenges that impact the operational lifespan of Koeberg. “The general conclusion is that, when benchmarked against comparable utilities, no prohibitive technical challenges have been identified which would preclude a plant life extension of up to 60 years.”
Kotze adds that the most significant financial hurdle identified is the replacement of the steam generators at the power station. “In line with international trends, Koeberg is considering using the margins provided through steam generator replacement to optimise the generating capacity of the units by increasing their thermal power.”
Eskom performed an economic assessment on the generators which analysed the impact of life extension on capital requirements, future financial considerations and levelised electricity generation costs. “Based on the analyses, it is apparent that the economic modelling favours plant life extension to 60 years, together with the earlier implementation of the replacement project and concurrent power update,” Kotze concludes.
Kotze will be one of the guest speakers at this year’s Physical Asset Management Conference presented by Pragma, which takes place from 13th to 15th August 2012. Kotze will be speaking on Koeberg’s long term asset management project.