Nuclear power in Canada
The importance of nuclear energy in Canada is very different in the various provinces. Viewed National 2007, approximately 60 % of electricity was generated by hydropower, 20% in fossil power plants, and 14% in nuclear power plants. The use of nuclear energy is confined almost exclusively to the province of Ontario, where in 2007 50 % of electricity produced in nuclear power reactors 15, another reactor is also operated in New Brunswick (23 % of electricity ).
Development of an independent nuclear industry
Canada / Ontario built after the Second World War to its own nuclear industry and developed its own reactor design ( CANDU ) reactor, which took into account the existing industrial facilities in the country. Canada decreed in 1945 for lack of a military nuclear program neither uranium enrichment facilities nor a heavy industry that could produce large pressure vessel. Developed CANDU reactor is therefore operated with unangereichertem natural uranium and uses a plurality of pressure tubes, rather than a large pressure vessel. Because of the tendency for neutron absorption can be used as host not (light ) water, but it must be resorted to heavy water. The severity of this water is used for both cooling of the fuel as well as in a separate almost unpressurized tank, the Calandria as moderator. As in Canada are CANDU reactors in operation, the profitability of Canada's nuclear power plant operator is closely connected to the reactor design.
Economically arising from the use of heavy water, natural uranium and the pressure tubes three disadvantages: on the one hand, the fuel must be placed at greater distances than light water pressurized reactors; This reduces the power density in the core and resulting in reverse at the same power to larger reactor core dimensions and thus higher construction costs for the building structure. As a second aspect, the cost of providing the heavy water for the moderator tank and the primary circuit should be mentioned. Thirdly, a plurality of individual pressure tube during operation to monitor and check for inspection. The pressure tubes and the tubes of the moderator tank are exposed by their position between the fuel a very strong neutron bombardment and high temperatures. This makes replacement of pressure tubes in the course of a power plant life required. During the overhaul of the reactor core no power production can be done and there are high levels of investment during the operating life of the power plant necessary.
Expansion of power generation capacity
The nuclear research in Canada began 1940. ZEEP By 1945 took the first experimental reactor at the Chalk River Laboratories to operate on, the second reactor NRX was made available for scientific purposes in 1947.
Commercial use of nuclear energy in Canada largely drove the regional utility Ontario Hydro ahead - as part of an industry politically motivated contract came in the development of reactors and their construction also mainly companies from Ontario to train.
Until the 1990s, was a rapid expansion of production capacity, the following plants were connected to the grid:
Reactor types
See: CANDU reactor
Economic Situation
The electricity generation costs of nuclear power plants are, so primarily determined by construction costs and their financing costs and on the other side of the electricity generated from the power plant operating reliability. In the case of CANDU reactors used in Canada, the cost of at least an overhaul of the reactor core or added during the lifetime. In Ontario, there were on the cost and on the revenue side problems. The nuclear power plants in Ontario were never completed in time and on budget, the actual NPP construction costs amounted to an average of 250 % of the planned cost. By late commissioning of individual reactors also increased financing costs, this can account for over a third of during the operation to be repaid loan amount.
Due to technical problems also were produced electricity volumes fell short of expectations. In 1993, the reactors were throttled in Bruce because of possible non- mastery of a loss of coolant accident on 60% of its nominal power. As a result of retrofitting this limitation was raised later to 90%. Furthermore, several reactors have been decommissioned. After a first reactor block shutdown due to material problems in Bruce A 1995 Ontario Hydro had to temporarily shut down in late 1997 for failure retrofits on Notabschaltesystem and insufficient maintenance and repair efforts, the four reactors at Pickering A. For economic reasons, the remaining three reactors at the Bruce A nuclear power plant was put into operation arrest. Many other reactors are increased with increasing age for maintenance silent and consequently decreases their financial performance.
1998 were the costs for electricity from nuclear power stations of Ontario Hydro 7.7 Canadian cents / kWh higher than the average sale price of 6.4 Canadian cents / kWh. The losses from the operation of nuclear power plants (cents / kWh 4.3 kanad. ) Were prepared by hydro power plants ( 1.1 kanad cents / kWh. ) And fossil power plants offset - a pay off the loans for the power stations was due to its unreachable. Then Ontario Hydro was split into five separate companies in 1999 who grew -running debt of 19.4 billion Canadian dollars (more than 75% of them from the core of power plant construction and operation) were transferred to the State Ontario Electricity Financial Corporation. These are to be repaid until 2018 by a general consumption tax on electricity and income from the other parts of the former Ontario Hydro - where the forecast has shifted further to the time of redemption in the last 10 years continuously in the future.
After the split of Ontario Hydro four persisting in the stoppage of reactors have been modernized and put into operation, with two reactors, the works are still ongoing. Also reactors outside of Ontario had to be overhauled. All renovations exceeded thereby turn the scheduled time and on budget. You can not close on the profitability of the CANDU reactor to also derived from the financial problems of Canada's largest nuclear power plant operator Ontario Hydro and its successor companies. Going abroad is not built in Ontario CANDU reactor -6 was exported, they show at least during their usually relatively young operating life high reliability.