AP1000

From Wikipedia, the free encyclopedia

Computer generated image of AP1000
Computer generated image of AP1000

Westinghouse Electric Company's AP1000 reactor design is the first Generation III+ reactor to receive final design approval from the NRC.[1] It is an evolutionary improvement on and essentially a larger version of the AP600[1] but with roughly the same size footprint.

In the spring of 2007 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.

Contents

[edit] Design Specifications

The AP1000 is a two-loop PWR which will produce a net 1117 MWe.[2][3] The safety systems apply passive protection, which is designed to yield such high degree of safety that there is no need for the usual diesel generators,[citation needed] which provide the equipment with power in the case of a loss of electrical supply. In the event of an accident 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 different types of systems are used and thus the effect of potential intrinsic failures can be avoided.

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 licensing will also help reduce the time and cost of construction.

In December 2005, the Nuclear Regulatory Commission approved the final design certification for the AP1000.[2] 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.[1]

Diagram of AP600/AP1000 passive safety systems
Diagram of AP600/AP1000 passive safety systems

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.

The safety systems in the AP1000 are passive, relying on things like gravity and natural recirculation rather than active systems such as pumps.[2] 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.[4]


[edit] Construction Plans

The Chinese units will be the first to be built.

[edit] China

Chinese undergoing training for the AP1000 reactor. The first four units will be built there.
Chinese undergoing training for the AP1000 reactor. The first four units will be built there.
  • The Sanmen Nuclear Power Plant will have 2 units, construction planned for 3/2008 and operation in 2013 to 2014
  • The Haiyang Nuclear Power Plant also has 2 units planned with construction to start on 9/2008 for operation in 2014 or 2015

[edit] USA

As of April 2008 three Combined Construction and Operating Licenses (COLs) have been filed for AP1000 reactors in the United States, two in Cherokee County, South Carolina, two for the Bellefonte Nuclear Generating Station in Alabama, and two for Vogtle in Georgia. [2]

Other sites expected to file a COL in the near future are:


On April 9, 2008, Georgia Power Company reached a contract agreement with Westinghouse and Shaw for two AP1000 reactors to be built at Plant Vogtle.[5] The contract represents the first agreement for new nuclear development since the Three Mile Island accident in 1979.[6] The COL for the Vogtle site will be based on the revision 16 to the AP1000 design, which has not been approved by the NRC.

[edit] References

  1. ^ a b AP 1000 Public Safety and Licensing (web). Westinghouse (September 13, 2004). Retrieved on 2008-01-21.
  2. ^ a b c T.L. Schulz. Westinghouse AP1000 advanced passive plant (web). Nuclear Engineering and Design; Volume 236, Issues 14-16, August 2006, Pages 1547-1557; 13th International Conference on Nuclear Energy, 13th International Conference on Nuclear Energy. ScienceDirect. Retrieved on January 21 ,2008.
  3. ^ Contact;Tom Murphy. New Reactor Designs (web). Article summarizes nuclear reactor designs that are either available or anticipated to become available in the United States by 2030. Energy Information Administration (EIA). Retrieved on January 21 ,2008.
  4. ^ R.A. and Worrall, A. “The AP1000 Reactor the Nuclear Renaissance Option.” Nuclear Energy 2004
  5. ^ Westinghouse wins first US nuclear deal in 30 years. Guardian News and Media Limited. Retrieved on 9-Apr-2008.
  6. ^ Georgia Power to Expand Nuclear Plant. Associated Press. Retrieved on 9-Apr-2008.

[edit] See also

[edit] External links