|Cutaway of an EPR. (1) reactor vessel, (2) the steam generators,(3) the pressurizer, (4) reactor coolant pumps, (5) inner prestressed concrete housing, (6) metallic liner and outer reinforced concrete shell, (7) special area for collection and cooling of escaping molten core, (8, 9) backup diesel generators, (10) turbine building. Click to enlarge. Larger detailed cutaway here.|
AREVA and China Guangdong Nuclear Power COrporation (CGNPC) signed a record contract worth €8 billion (US$11.9 billion)—the biggest ever in the history of nuclear power—and entered into a long-term commitment.
Through a series of agreements, AREVA, in conjunction with CGNPC, will build two new generation EPR reactors and will provide all the materials and services required to operate them. Following Finland and France, China will be home to the third and fourth EPR to be built in the world. The EPR will be built in Taishan in Guangdong province.
The EPR is a Generation III+ pressurized water reactor (PWR) which generates about 1,600 MWe of electric power and features enhanced safety and simplified operations and maintenance. It has a projected service life of 60 years, compared with a 40-year service life for other power reactors. AREVA offers two third-generation reactor models: the EPR and the SWR 1000, a boiling water reactor (BWR) that can generate 1,000-1,250 MWe.
|Pressurized water reactor. Click to enlarge.|
In a Pressurized Water Reactor (PWR) like the EPR, water removes the heat produced inside the reactor core by nuclear fission. (See diagram at right.) This water also moderates neutrons to sustain the nuclear chain reaction (neutrons have to be moderated to be able to break down the fissile atom nuclei).
The heat produced inside the reactor core is transferred to the turbine through the steam generators. Only heat is exchanged between the reactor cooling circuit (primary circuit) and the steam circuit used to feed the turbine (secondary circuit). No exchange of cooling water takes place. The primary water is pumped through the reactor core and the primary side of the steam generators, in four parallel closed loops, by coolant pumps powered by electric motors.
The EPR was developed by Framatome and Siemens KWU (the nuclear division of Siemens), whose nuclear activities were combined in January 2001 to form Framatome ANP, now AREVA NP. The French electricity utility EDF (Electricité de France), together with the major German utilities, played an active role in the project.
As a new-generation reactor, the EPR affords economic and technical progress over its predecessors, according to AREVA: enhanced safety level, reduced volumes of long-lived waste, considerable reduction in the doses received by operating and maintenance personnel, and reduced electricity production costs (better use of fuel, improved availability, higher operating flexibility, and fewer maintenance constraints).
Better use is made of fuel in the EPR—17% less uranium is required to generate the same amount of electricity, thereby, reducing the volume of waste. Costs are therefore lower for the entire fuel cycle from enrichment to reprocessing. The general layout of the equipment is designed to provide easier access and simplify maintenance operations that are consequently carried out more rapidly. Routine maintenance of safety-related systems can be carried out without shutting down the plant. The length of the scheduled refueling outage has been shortened to allow an increase of reactor availability to more than 90%.
In line with the requirements of the French and German safety authorities, the initial designs of the EPR made allowance for a military aircraft impact scenario. In the September 11 context, the call for bids launched in 2002 by Finland for its fifth reactor demanded that candidate models must be capable of withstanding an impact by a commercial aircraft. The EPR designs were, therefore, upgraded with extra thickness and provided scope for these modifications without any effect on the fundamental design of the EPR.
In the event of core damage and the occurrence of a core melt, the molten core (“corium”), after melting through the reactor vessel wall, would be contained in a dedicated spreading compartment. This compartment is then cooled to remove the residual heat.
In the USA, AREVA will submit its US EPR Design Certification (DC) application by mid-December 2007 to the Nuclear Regulatory Commission with an anticipated validation by 2010. Validation by 2010 would enable that a US EPR to be licensed and ready for operation in 2015.
In the United Kingdom, on September 10, 2007, AREVA and EDF launched a joint website that presents the details of the EPR nuclear reactor. These details have been submitted to the UK regulators for design assessment.
Concurrent with the AREVA-GNPC contract, an agreement has been signed between China and France opening the way to industrial cooperation in the back end of the nuclear fuel cycle. Under this agreement, CNNC (China National Nuclear Corporation) and Areva have agreed to undertake feasibility studies related to the construction of a spent fuel reprocessing-recycling plant in China. They have also created a joint venture in the area of zirconium.
|China’s nuclear plants. Click to enlarge.|
In 2007, China has an installed nuclear capacity of 9 GWe with 11 nuclear power plants in operation, generating 2% of China's electricity production. Nuclear power stations are located in the south and south-east of the country where there is most economic growth and no coal or dams. China has selected a range of different technologies for its nuclear program, some of which have been developed by Chinese companies, while others are being imported from France, Canada, and Russia.
In May 2007, the government and the National Development and Reform Commission planned to increase nuclear capacity to 40 GWe by 2020, and to 120-160 GWe by 2030.