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Eurajoki, Finland

Teollisuuden Voima Oyj is a Finnish nuclear power company owned by a consortium of power and industrial companies. The biggest shareholders are Pohjolan Voima and Fortum. The company operates Olkiluoto Nuclear Power Plant, which consists of two BWRs , an EPR which is still under construction, and one half of a coal-fired power plant along with a wind farm.The third reactor at Olkiluoto was expected to be ready in 2009, but last estimate is 2018. TVO has filed compensation claim for delays.On 21 April 2010, the Government of Finland decided to grant a permit for construction of fourth reactor at Olkiluoto. The decision was approved by the Parliament on 1 July 2010.In January 2015 TVO announced plans to save around $17.7 million per year through 'efficiency-related structural changes' which are expected to cause up to 110 job cuts. The CEO of TVO, Jarmo Tanhua, explained the reasons as:The competitiveness of the electricity produced in Olkiluoto has declined during the recent years and the outlook of the future is uncertain. Electricity market price has dropped and there are no signs of improvement in the foreseeable future ... In addition, costs related to nuclear power production have increased and the delay of Olkiluoto 3 project has caused remarkable additional costs. Wikipedia.

Inkinen J.,Satakunta University of Applied Sciences | Kaunisto T.,Satakunta University of Applied Sciences | Kaunisto T.,Prizztech Ltd. WANDER Nordic Water and Materials Institute | Pursiainen A.,Finnish National Institute for Health and Welfare | And 6 more authors.
Water Research | Year: 2014

Complex interactions existing between water distribution systems' materials and water can cause a reduction in water quality and unwanted changes in materials, aging or corrosion of materials and formation of biofilms on surfaces. Substances leaching from pipe materials and water fittings, as well as the microbiological quality of water and formation of biofilms were evaluated by applying a Living Lab theme i.e. a research in a real life setting using a full scale system during its first year of operation. The study site was a real office building with one part of the building lined with copper pipes, the other with cross-linked polyethylene (PEX) pipes thus enabling material comparison; also differences within the cold and hot water systems were analysed. It was found that operational conditions, such as flow conditions and temperature affected the amounts of metals leaching from the pipe network. In particular, brass components were considered to be a source of leaching; e. g. the lead concentration was highest during the first few weeks after the commissioning of the pipe network when the water was allowed to stagnate. Assimilable organic carbon (AOC) and microbially available phosphorus (MAP) were found to leach from PEX pipelines with minor effects on biomass of the biofilm. Cultivable and viable biomass (heterotrophic plate count (HPC), and adenosine triphosphate (ATP)) levels in biofilms were higher in the cold than in the hot water system whereas total microbial biomass (total cell count (DAPI)) was similar with both systems. The type of pipeline material was not found to greatly affect the microbial biomass or Alpha-, Beta- and Gammaproteobacteria profiles (16s rRNA gene copies) after the first one year of operation. Also microbiological quality of water was found to deteriorate due to stagnation. © 2013 Elsevier Ltd.

Tuulensuu H.,Teollisuuden Voima Oy
PSAM 2014 - Probabilistic Safety Assessment and Management | Year: 2014

For Olkiluoto 1 (OL1) and Olkiluoto 2 (OL2) nuclear power plant units, planned outages are done annually. Every second year a refuelling outage (duration about 1 week) and every second year a maintenance outage (duration about 2-3 weeks) is performed. To ensure nuclear safety in such short outage times, well planned outage schedules are required. Because of this, a PRA application to support the outage schedule planning has been developed. The PRA application for outage risk management has six goals: (1) to support outage schedule planning, (2) to assess plant modifications during outage, (3) to estimate core damage and radioactive release frequencies of the outage, (4) to identify "weak points" of the outage, (5) to teach risk-informed thinking to the outage schedule coordinators and (6) to develop the outage PRA models. The PRA application is performed hour by hour throughout the whole outage. A risk profile for the outage as a function of time is the main result of the analysis. The assessment is updated when outage schedule is updated. Based on the results, the PRA application to support outage schedule planning is an efficient way to improve risk management during outages.

Himanen R.,Teollisuuden Voima Oy | Julin A.,Radiation and Nuclear Safety Authority | Jankala K.,Fortum Corporation | Holmberg J.-E.,VTT Technical Research Center of Finland | Virolainen R.,Radiation and Nuclear Safety Authority
Risk Analysis | Year: 2012

There are four operating nuclear power plant (NPP) units in Finland. The Teollisuuden Voima (TVO) power company has two 840 MWe BWR units supplied by Asea-Atom at the Olkiluoto site. The Fortum corporation (formerly IVO) has two 500 MWe VVER 440/213 units at the Loviisa site. In addition, a 1600 MWe European Pressurized Water Reactor supplied by AREVA NP (formerly the Framatome ANP-Siemens AG Consortium) is under construction at the Olkiluoto site. Recently, the Finnish Parliament ratified the government Decision in Principle that the utilities' applications to build two new NPP units are in line with the total good of the society. The Finnish utilities, Fenno power company, and TVO company are in progress of qualifying the type of the new nuclear builds. In Finland, risk-informed applications are formally integrated in the regulatory process of NPPs that are already in the early design phase and these are to run through the construction and operation phases all through the entire plant service time. A plant-specific full-scope probabilistic risk assessment (PRA) is required for each NPP. PRAs shall cover internal events, area events (fires, floods), and external events such as harsh weather conditions and seismic events in all operating modes. Special attention is devoted to the use of various risk-informed PRA applications in the licensing of Olkiluoto 3 NPP. © 2012 Society for Risk Analysis.

Tunturivuori L.,Teollisuuden Voima Oy
11th International Probabilistic Safety Assessment and Management Conference and the Annual European Safety and Reliability Conference 2012, PSAM11 ESREL 2012 | Year: 2012

The probabilistic fire risk assessment (fire PRA) of the Olkiluoto 1 and 2 NPP units has been updated in the beginning of the year 2011. In the updated version, the fire frequency of each component group is evaluated using a Bayesian approach with NUREG/CR-6850 data as a prior and using historical fire events at the NPP as evidence. The resulting total fire frequency estimate in the PRA model of the units is 10 % higher than the historical fire frequency of the NPP units. However, the fire frequency estimate for certain rooms changed by orders of magnitude due to the transition to the usage of component based fire frequencies. Especially, the fire frequency estimate of rooms housing components with exceptionally high fire frequency, like main feed water pumps, large amount of electric equipment, like relay rooms and rooms with hydrogen systems increased in the updated evaluation. In the analysis, the safety related components are mapped to their locations. Furthermore, the cable routing database is used in order to locate the power and control cables of the safety related components. Also the locations of cables transmitting measuring data to the reactor protection system are assessed. The resulting fire scenarios with similar consequences are grouped into tens of initial events using conservative assumptions. The update of the fire PRA increased the CDF by 16 %. After the update, the CDF originating from firerelated initiating events constitutes of 20 % of the total CDF. The fire PRA demonstrates that in a highredundant NPP unit, such as the Olkiluoto 1 and 2 NPP units, which has four redundant divisions, each of 50 % capacity, a fire affecting two redundancies increases the conditional core damage probability by a factor of ten compared to a scenario in which only one redundancy is affected by the fire, demonstrating the significance of physical separation between safety significant equipment and active fire suppression systems in rooms housing two redundancies.

Lemmetty M.,Teollisuuden Voima Oy
International Congress on Advances in Nuclear Power Plants 2010, ICAPP 2010 | Year: 2010

Most Nordic-type BWRs rely on sea water for the final heat sink. This paper discusses the situation where the both ends of the sea water inlet must be closed, which results in the loss of the final heat sink. We propose an accident mitigation strategy which guarantees that the rooms containing the most important safety-related pumps can be cooled. It is shown that the accident will not result in a large emission of radioactive substances.

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