Decommissioning Costs of Wwer-440 Nuclear Power Plants

Fortum Power and Heat Ltd. has revised the decommissioning plan for the Loviisa Nuclear Power Plant (Loviisa1 and Loviisa 2) at the end of the year 1998 [4-1]. The plan is based on immediate dismantlement after shutdownof the power plant. Experienced plant personnel will still be available to lead the decommissioning work. Onlythe radioactive plant systems, components and structures will be dismantled and disposed of. The electric power of the power plant has been increased to 2 x 510 MW(e) in 1998, and the lifetime is plannedto be extended to 45 years in the decommissioning plan. The decommissioning of the power plant is planned to begin in 2022 and will be finished in 2048. The reason forthis long time is that the spent fuel will be stored at the plant for 20 years after shutdown of the power plant.Later, the spent fuel wil be transported from the site to the encapsulation plant, and to final disposal. The large and heavy reactor components, e.g., pressure vessels and steam generators, will be disposed of as such,without cutting into smaller parts. This will save time and radiation doses. These large components will be usedas packagings (barriers) for smaller equipment. Decommissioning wastes will be disposed in the undergroundrepository situated at the site at a depth of about 110 m. This repository is already used for wastes from the powerplant, and it will be enlarged to accommodate the wastes from decommissioning as well. The total volume of decommissioning wastes is 14,800m, when packaged in boxes. The manpower needed forthe decommissioning operations is about 2,800 man.years. The collective radiation dose for personnel isestimated to be about 9.2 man.Sv. The cost estimate for the decommissioning is about 1,117 million FIM or 220million USD (disposal of decommissioning wastes included). 1. GeneralThe Loviisa NPP consists of two WWER-440 type PWR units. The first unit (Loviisa 1) wastaken into commercial operation in 5/1977 and the second (Loviisa 2) in 1/1981. Each unit hasoperated well with high availability, high load factors and low personnel doses. The LoviisaNPP is owned and operated by Fortum Power and Heat Ltd. The electric power of the powerplant has been increased to 2 x 510 MW(e) in 1998, and the life time is planned to beextended to 45 years.The principal legislation regulating nuclear activities in Finland is the Nuclear Energy Act andDecree of 1988. They define the responsibilities and the principles for financingdecommissioning projects. The licensing procedures for decommissioning are not yet definedin detail.The licensees (e.g., utilities) are responsible for the implementation of decommissioning (andthey are also responsible for the management and disposal of all types of waste: spent fuel,operational and decommissioning wastes). In the event that the licensee is incapable of doingso, the state has the secondary responsibility. In this case, the costs are covered by assetscollected beforehand in the Nuclear Waste Management Fund and by securities provided bythe licensee.According to a governmental policy decision of 1983, the licensees are obliged to update theirdecommissioning plans every five years. These plans aim at ensuring that decommissioningcan be appropriately performed when needed and that the estimates for decommissioningcosts are realistic. The latest updates of decommissioning plans were published at the end of1998 [4-1], and the earlier plans were published in 1982, 1987 and 1993.In the past, spent fuel from the Loviisa NPP was transported to the former SovietUnion/Russian Federation with no return of reprocessing wastes. However, plans for spent