العربية
中国
Français
Deutsch
Ελληνική
हिन्दी
Italiano
日本語
Português
Русский
EspañolADVANCED PRESSURIZED WATER REACTOR
(Redirected from AP1000)
'Advanced Pressurized Water Reactor' is a type of nuclear reactor which is an improved version of existing Pressurized Water Reactor types. Examples include Westinghouse's AP600 and AP1000, Areva's EPR and Mitsubishi's APWR. Westinghouse of which Toshiba owns a 77% share, has obtained approval of two standard plant types; the AP600 and the AP1000, the latter of which is expected to see construction before 2010. An EPR is currently being constructed in Finland. Mitsubishi's US-APWR is in the pre-application stage of the licensing process of the Nuclear Regulatory Commission.
In this design the safety systems mainly apply passive protection, which are designed to yield such high degree of safety that there is no need for the usual diesel generators, which provide the equipment with power in the case of a loss of electrical supply (the EPR does not rely on passive systems). They require little intervention, which reduces the chance of human error and other failures. Safety enhancement is also achieved by using modern, reliable devices. The probability of failures is further decreased by applying the concept of diversity: several and different type of systems are used and thus the effect of potential intrinsic failures can be avoided.
In a standard PWR design, cooling requires elaborate pumps, while in an APWR it can be handled by simple gravity flow with natural circulation — cool water enters the bottom of the reactor, which heats it, causing it to rise because warm water is less dense. This process sets up a natural circulation driven only by gravity. Unlike pumps which can fail and are driven by electric power which may not always be available, gravity never stops working. It is referred to "passive stability," since no active measures by operators or by mechanical or electrical control systems are required.
The design is less expensive to build partly due to the fact that it uses existing technology. The expense is also reduced by rationalizing technology, which means decreasing not only the number of pipes, wires, and valves necessary, but reducing a number of other components, and therefore reducing cost. Standardization and type-related licencing will also help reduce the time and cost of construction.
The AP600 is a relatively small, 600 MWe plant that has passive safety features characteristic of the AP concept. The projected core damage frequency is nearly 1000 times less than today's NRC requirements, on par with plants currently being considered for construction.
NRC final design certification was received in 1999 but no orders were ever placed. A large reason Westinghouse entered development of the AP1000 was to improve the economies of scale that come with larger MWe plants.[1] The AP1000 was adapted to have a similar footprint but a taller containment and a power output of 1000 MWe or greater.
The AP1000 is a proposed pressurized water reactor utilizing passive safety features [1] designed and manufactured by Westinghouse Electric Company for nuclear power plants. This is considered a Generation III+ design. Each reactor is designed to generate 1117 net MWe.
China National Nuclear Corp. selected the Westinghouse/Shaw consortium to build four nuclear reactors for an estimated US$8 billion, the largest International nuclear contract in history. The 1117 MWe plants will use Westinghouse's advanced AP1000 design, which was given final design certification by the U.S. Nuclear Regulatory Commission in December 2005.
The AP1000 is an enlarged version of an earlier, lower-output proposed design, the AP600. However, the AP600 design failed to attract customers. This is primarily because the construction cost per megawatt output made the cost of power generation uncompetitive, particularly in the economic climate of lower natural gas prices in the 1990s. The AP1000 builds on the research for that plant, with the economies of scale of a larger plant reducing the cost per megawatt output.
In December 2005, the Nuclear Regulatory Commission approved the final design certification for the AP1000. This means that prospective builders can apply for a combined Construction and Operating License (COL) before construction starts, whose validity is conditional upon the plant being built as designed, and that each AP1000 should be virtually identical.
Probabilistic risk assessment was used in the design of the plants. This enabled minimization of risks, and calculation of the overall safety of the plant. (The Nuclear Regulatory Commission is preparing a new safety study, and believes that these plants will be orders of magnitude safer than the last study, NUREG-1150.) The AP1000 has a maximum core damage frequency of 5.09 x 10-7 per plant per year.[2]
The AP1000 will be manufactured in modules designed for rail or barge shipment. This will allow constructing many modules in parallel, and the plant is designed to have fuel load 36 months after concrete is first poured. This construction period is considerably shorter than earlier generation designs, and if achieved in practice will greatly decrease the overall capital cost of the plant. Such reductions would make the design much more economically competitive against other power sources than previous generation nuclear plants.
So far two AP1000s are slated for Cherokee County, South Carolina, and one or two for the Bellefonte Nuclear Generating Station in Alabama. Four AP1000s are to be built in China, with the first to begin operation by 2013. [3]
The safety systems in the AP1000 are passive, relying on things like gravity and natural recirculation instead of on active systems such as pumps. The Passive Core Cooling System (PCCS) is the AP1000's passive analogue to the Emergency Core Cooling System used in currently operating reactors. The PCCS is passive because none of the systems are reliant on AC power and the actuation for the safety systems is automatic. The valves required for alignment are usually fail-safe (requiring power to stay in their normal, closed positions) and are always powered by energy stored in batteries, springs, or compressed gas.[2]
Main articles: Mitsubishi APWR
The APWR is a generation III nuclear reactor developed by Mitsubishi Heavy Industries based on Pressurized Water Reactor technology. This model has had some success already by being selected for the next two units at the Tsuruga Nuclear Power Plant. It features several design enhancements including a neutron reflector, improved efficiency and improved safety systems. Though its safety systems are improved, it would generally not be considered passive.
★ Nuclear power
★ Nuclear safety in the U.S.
★ Economics of new nuclear power plants
★ Nuclear Power 2010 Program
★ ESBWR
★ European Pressurized Reactor
★ The AP600 advanced 600 MWe nuclear power plant
★ The AP1000 advanced 1000 MWe nuclear power plant
★ Advanced Pressurized Water Reactor (APWR) simulator
★ AP1000 design review documents
★ BrucePower Open House, see Appendix B2
1. http://www.uic.com.au/nip16.htm
2. R.A. and Worrall, A. “The AP1000 Reactor the Nuclear Renaissance Option.” Nuclear Energy 2004
'Advanced Pressurized Water Reactor' is a type of nuclear reactor which is an improved version of existing Pressurized Water Reactor types. Examples include Westinghouse's AP600 and AP1000, Areva's EPR and Mitsubishi's APWR. Westinghouse of which Toshiba owns a 77% share, has obtained approval of two standard plant types; the AP600 and the AP1000, the latter of which is expected to see construction before 2010. An EPR is currently being constructed in Finland. Mitsubishi's US-APWR is in the pre-application stage of the licensing process of the Nuclear Regulatory Commission.
| Contents |
| Design Innovations |
| AP600 |
| AP1000 |
| Mitsubishi APWR |
| See also |
| External links |
| References |
Design Innovations
In this design the safety systems mainly apply passive protection, which are designed to yield such high degree of safety that there is no need for the usual diesel generators, which provide the equipment with power in the case of a loss of electrical supply (the EPR does not rely on passive systems). They require little intervention, which reduces the chance of human error and other failures. Safety enhancement is also achieved by using modern, reliable devices. The probability of failures is further decreased by applying the concept of diversity: several and different type of systems are used and thus the effect of potential intrinsic failures can be avoided.
In a standard PWR design, cooling requires elaborate pumps, while in an APWR it can be handled by simple gravity flow with natural circulation — cool water enters the bottom of the reactor, which heats it, causing it to rise because warm water is less dense. This process sets up a natural circulation driven only by gravity. Unlike pumps which can fail and are driven by electric power which may not always be available, gravity never stops working. It is referred to "passive stability," since no active measures by operators or by mechanical or electrical control systems are required.
The design is less expensive to build partly due to the fact that it uses existing technology. The expense is also reduced by rationalizing technology, which means decreasing not only the number of pipes, wires, and valves necessary, but reducing a number of other components, and therefore reducing cost. Standardization and type-related licencing will also help reduce the time and cost of construction.
AP600
The AP600 is a relatively small, 600 MWe plant that has passive safety features characteristic of the AP concept. The projected core damage frequency is nearly 1000 times less than today's NRC requirements, on par with plants currently being considered for construction.
NRC final design certification was received in 1999 but no orders were ever placed. A large reason Westinghouse entered development of the AP1000 was to improve the economies of scale that come with larger MWe plants.[1] The AP1000 was adapted to have a similar footprint but a taller containment and a power output of 1000 MWe or greater.
AP1000
The AP1000 is a proposed pressurized water reactor utilizing passive safety features [1] designed and manufactured by Westinghouse Electric Company for nuclear power plants. This is considered a Generation III+ design. Each reactor is designed to generate 1117 net MWe.
China National Nuclear Corp. selected the Westinghouse/Shaw consortium to build four nuclear reactors for an estimated US$8 billion, the largest International nuclear contract in history. The 1117 MWe plants will use Westinghouse's advanced AP1000 design, which was given final design certification by the U.S. Nuclear Regulatory Commission in December 2005.
The AP1000 is an enlarged version of an earlier, lower-output proposed design, the AP600. However, the AP600 design failed to attract customers. This is primarily because the construction cost per megawatt output made the cost of power generation uncompetitive, particularly in the economic climate of lower natural gas prices in the 1990s. The AP1000 builds on the research for that plant, with the economies of scale of a larger plant reducing the cost per megawatt output.
In December 2005, the Nuclear Regulatory Commission approved the final design certification for the AP1000. This means that prospective builders can apply for a combined Construction and Operating License (COL) before construction starts, whose validity is conditional upon the plant being built as designed, and that each AP1000 should be virtually identical.
Probabilistic risk assessment was used in the design of the plants. This enabled minimization of risks, and calculation of the overall safety of the plant. (The Nuclear Regulatory Commission is preparing a new safety study, and believes that these plants will be orders of magnitude safer than the last study, NUREG-1150.) The AP1000 has a maximum core damage frequency of 5.09 x 10-7 per plant per year.[2]
The AP1000 will be manufactured in modules designed for rail or barge shipment. This will allow constructing many modules in parallel, and the plant is designed to have fuel load 36 months after concrete is first poured. This construction period is considerably shorter than earlier generation designs, and if achieved in practice will greatly decrease the overall capital cost of the plant. Such reductions would make the design much more economically competitive against other power sources than previous generation nuclear plants.
So far two AP1000s are slated for Cherokee County, South Carolina, and one or two for the Bellefonte Nuclear Generating Station in Alabama. Four AP1000s are to be built in China, with the first to begin operation by 2013. [3]
The safety systems in the AP1000 are passive, relying on things like gravity and natural recirculation instead of on active systems such as pumps. The Passive Core Cooling System (PCCS) is the AP1000's passive analogue to the Emergency Core Cooling System used in currently operating reactors. The PCCS is passive because none of the systems are reliant on AC power and the actuation for the safety systems is automatic. The valves required for alignment are usually fail-safe (requiring power to stay in their normal, closed positions) and are always powered by energy stored in batteries, springs, or compressed gas.[2]
Mitsubishi APWR
Main articles: Mitsubishi APWR
The APWR is a generation III nuclear reactor developed by Mitsubishi Heavy Industries based on Pressurized Water Reactor technology. This model has had some success already by being selected for the next two units at the Tsuruga Nuclear Power Plant. It features several design enhancements including a neutron reflector, improved efficiency and improved safety systems. Though its safety systems are improved, it would generally not be considered passive.
See also
★ Nuclear power
★ Nuclear safety in the U.S.
★ Economics of new nuclear power plants
★ Nuclear Power 2010 Program
★ ESBWR
★ European Pressurized Reactor
External links
★ The AP600 advanced 600 MWe nuclear power plant
★ The AP1000 advanced 1000 MWe nuclear power plant
★ Advanced Pressurized Water Reactor (APWR) simulator
★ AP1000 design review documents
★ BrucePower Open House, see Appendix B2
References
1. http://www.uic.com.au/nip16.htm
2. R.A. and Worrall, A. “The AP1000 Reactor the Nuclear Renaissance Option.” Nuclear Energy 2004
This article provided by Wikipedia. To edit the contents of this article, click here for original source.
psst.. try this: add to faves
