The advanced boiling water reactor (ABWR) is a Generation III boiling water reactor. The ABWR is currently offered by GE Hitachi Nuclear Energy (GEH) and Toshiba. The ABWR generates electrical power by using steam to power a turbine connected to a generator; the steam is boiled from water using heat generated by fission reactions within nuclear fuel. Kashiwazaki-Kariwa unit 6 is considered the first Generation III reactor in the world.
A Generation III reactor is a development of Generation II nuclear reactor designs incorporating evolutionary improvements in design developed during the lifetime of the Generation II reactor designs. These include improved fuel technology, superior thermal efficiency, significantly enhanced safety systems, and standardized designs for reduced maintenance and capital costs. The first Generation III reactor to begin operation was Kashiwazaki 6 in 1996.
A boiling water reactor (BWR) is a type of light water nuclear reactor used for the generation of electrical power. It is the second most common type of electricity-generating nuclear reactor after the pressurized water reactor (PWR), which is also a type of light water nuclear reactor. The main difference between a BWR and PWR is that in a BWR, the reactor core heats water, which turns to steam and then drives a steam turbine. In a PWR, the reactor core heats water, which does not boil. This hot water then exchanges heat with a lower pressure water system, which turns to steam and drives the turbine. The BWR was developed by the Argonne National Laboratory and General Electric (GE) in the mid-1950s. The main present manufacturer is GE Hitachi Nuclear Energy, which specializes in the design and construction of this type of reactor.
GE Hitachi Nuclear Energy (GEH) is a provider of advanced reactors and nuclear services. It is located in Wilmington, N.C. Established in June 2007, GEH is a global nuclear alliance created by General Electric and Hitachi. In Japan, the alliance is Hitachi-GE Nuclear Energy, Ltd. In November 2015, Jay Wileman was appointed CEO.
Boiling water reactors (BWRs) are the second most common [ citation needed ], and is the first Generation III reactor design to be fully built[ citation needed ], with several reactors complete and operating.[ citation needed ] The first reactors were built on time and under budget in Japan, with others under construction there and in Taiwan. ABWRs were on order in the United States, including two reactors at the South Texas Project site (although the project is currently halted ). The projects in both Taiwan and US are both reported over-budgeted.form of light water reactor with a direct cycle design that uses fewer large steam supply components than the pressurized water reactor (PWR), which employs an indirect cycle. The ABWR is the present state of the art in boiling water reactors
Pressurized water reactors (PWRs) constitute the large majority of the world's nuclear power plants and are one of three types of light water reactor (LWR), the other types being boiling water reactors (BWRs) and supercritical water reactors (SCWRs). In a PWR, the primary coolant (water) is pumped under high pressure to the reactor core where it is heated by the energy released by the fission of atoms. The heated water then flows to a steam generator where it transfers its thermal energy to a secondary system where steam is generated and flows to turbines which, in turn, spin an electric generator. In contrast to a boiling water reactor, pressure in the primary coolant loop prevents the water from boiling within the reactor. All LWRs use ordinary water as both coolant and neutron moderator.
State-of-the-art refers to the highest level of general development, as of a device, technique, or scientific field achieved at a particular time. It also refers to such a level of development reached at any particular time as a result of the common methodologies employed at the time.
The standard ABWR plant design has a net electrical output of about GW , generated from about 1.35 MW of thermal power. 3926
The ABWR represents an evolutionary route for the BWR family, with numerous changes and improvements to previous BWR designs.
Major areas of improvement include:
Control rods are used in nuclear reactors to control the fission rate of uranium and plutonium. They are composed of chemical elements such as boron, silver, indium and cadmium that are capable of absorbing many neutrons without themselves fissioning. Because these elements have different capture cross sections for neutrons of varying energies, the composition of the control rods must be designed for the reactor's neutron spectrum. Boiling water reactors (BWR), pressurized water reactors (PWR) and heavy water reactors (HWR) operate with thermal neutrons, while breeder reactors operate with fast neutrons.
Basalt fiber is a material made from extremely fine fibers of basalt, which is composed of the minerals plagioclase, pyroxene, and olivine. It is similar to fiberglass, having better physicomechanical properties than fiberglass, but being significantly cheaper than carbon fiber. It is used as a fireproof textile in the aerospace and automotive industries and can also be used as a composite to produce products such as camera tripods.
Reinforced concrete (RC) (also called reinforced cement concrete or RCC) is a composite material in which concrete's relatively low tensile strength and ductility are counteracted by the inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel reinforcing bars (rebar) and is usually embedded passively in the concrete before the concrete sets. Reinforcing schemes are generally designed to resist tensile stresses in particular regions of the concrete that might cause unacceptable cracking and/or structural failure. Modern reinforced concrete can contain varied reinforcing materials made of steel, polymers or alternate composite material in conjunction with rebar or not. Reinforced concrete may also be permanently stressed, so as to improve the behaviour of the final structure under working loads. In the United States, the most common methods of doing this are known as pre-tensioning and post-tensioning.
The RPV and Nuclear Steam Supply System (NSSS) have significant improvements, such as the substitution of RIPs, eliminating conventional external recirculation piping loops and pumps in the containment that in turn drive jet pumps producing forced flow in the RPV. RIPs provide significant improvements related to reliability, performance and maintenance, including a reduction in occupational radiation exposure related to containment activities during maintenance outages. These pumps are powered by wet-rotor motors with the housings connected to the bottom of the RPV and eliminating large diameter external recirculation pipes that are possible leakage paths. The 10 internal recirculation pumps are located at the bottom of the annulus downcomer region (i.e., between the core shroud and the inside surface of the RPV). Consequently, internal recirculation pumps eliminate all of the jet pumps in the RPV, all of the large external recirculation loop pumps and piping, the isolation valves and the large diameter nozzles that penetrated the RPV and needed to suction water from and return it to the RPV. This design therefore reduces the worst leak below the core region to effectively equivalent to a 2-inch-diameter (51 mm) leak. The conventional BWR3-BWR6 product line has an analogous potential leak of 24 or more inches in diameter. A major benefit of this design is that it greatly reduces the flow capacity required of the ECCS.
The first reactors to use internal recirculation pumps were designed by ASEA-Atom (now Westinghouse Electric Company by way of mergers and buyouts, which is owned by Toshiba) and built in Sweden. These plants have operated very successfully for many years.
Westinghouse Electric Company LLC is a US based nuclear power company formed in 1998 from the nuclear power division of the original Westinghouse Electric Corporation. It offers nuclear products and services to utilities internationally, including nuclear fuel, service and maintenance, instrumentation, control and design of nuclear power plants. Westinghouse's world headquarters are located in the Pittsburgh suburb of Cranberry Township, Pennsylvania. Brookfield Business Partners is the majority owner of Westinghouse.
Toshiba Corporation is a Japanese multinational conglomerate headquartered in Tokyo, Japan. Its diversified products and services include information technology and communications equipment and systems, electronic components and materials, power systems, industrial and social infrastructure systems, consumer electronics, household appliances, medical equipment, office equipment, as well as lighting and logistics.
Sweden, officially the Kingdom of Sweden, is a Scandinavian Nordic country in Northern Europe. It borders Norway to the west and north and Finland to the east, and is connected to Denmark in the southwest by a bridge-tunnel across the Öresund, a strait at the Swedish-Danish border. At 450,295 square kilometres (173,860 sq mi), Sweden is the largest country in Northern Europe, the third-largest country in the European Union and the fifth largest country in Europe by area. Sweden has a total population of 10.2 million of which 2.5 million has a foreign background. It has a low population density of 22 inhabitants per square kilometre (57/sq mi). The highest concentration is in the southern half of the country.
The internal pumps reduce the required pumping power for the same flow to about half that required with the jet pump system with external recirculation loops. Thus, in addition to the safety and cost improvements due to eliminating the piping, the overall plant thermal efficiency is increased. Eliminating the external recirculation piping also reduces occupational radiation exposure to personnel during maintenance.
An operational feature in the ABWR design is electric fine motion control rod drives, first used in the BWRs of AEG (later Kraftwerk Union AG, now AREVA). Older BWRs use a hydraulic locking piston system to move the control rods in six-inch increments. The electric fine motion control rod design greatly enhances positive actual control rod position and similarly reduces the risk of a control rod drive accident to the point that no velocity limiter is required at the base of the cruciform control rod blades.
Slightly different versions of the ABWR are offered by GE-Hitachi, Hitachi-GE and Toshiba.
In 1997 the GE-Hitachi U.S. ABWR design was certified as a final design in final form by the U.S. Nuclear Regulatory Commission, meaning that its performance, efficiency, output, and safety have already been verified, making it bureaucratically easier to build it rather than a non-certified design.
In 2013, following its purchase of Horizon Nuclear Power, Hitachi began the process of generic design assessment of the Hitachi-GE ABWR with the UK Office for Nuclear Regulation.This was completed in December 2017.
In July 2016 Toshiba withdrew the U.S. design certification renewal for the ABWR because "it has become increasingly clear that energy price declines in the US prevent Toshiba from expecting additional opportunities for ABWR construction projects".
The ABWR is licensed to operate in Japan, the United States and Taiwan, although most of the construction projects have been halted or shelved.
As of December 2006 [update] , four ABWRs were in operation in Japan: Kashiwazaki-Kariwa units 6 and 7, which opened in 1996 and 1997, Hamaoka unit 5, opened 2004 having started construction in 2000, and Shika 2 commenced commercial operations on March 15, 2006. Another two partially constructed reactors are in Lungmen in Taiwan, and one more (Shimane Nuclear Power Plant 3) in Japan. Work on Lungmen halted in 2014. Work on Shimane halted after the 2011 earthquake
On June 19, 2006 NRG Energy filed a Letter Of Intent with the Nuclear Regulatory Commission to build two 1358 MWe ABWRs at the South Texas Project site. On September 25, 2007, NRG Energy and CPS Energy submitted a Construction and Operations License (COL) request for these plants with the NRC. NRG Energy is a merchant generator and CPS Energy is the nation's largest municipally owned utility. The COL was approved by the NRC on February 9, 2016.Due to market conditions, these two planned units may never be built and do not have a planned construction date.
Horizon Nuclear Power had plans to build Hitachi-GE ABWRs at Wylfa in Walesand Oldbury in England. Both projects were paused in March 2012 by the shareholders at the time (RWE and E-ON) to put Horizon up for sale, with Hitachi becoming the new owner. The 'Development Consent Order' for Wylfa was accepted in June 2018 and in August Bechtel were appointed as project managers. The first reactor was expected online in the mid 2020s with construction at Oldbury expected to start a few years after this. However, on January 17, 2019, Horizon Nuclear Power announced the suspension of both these projects for financial reasons.
In comparison with comparable designs, the four ABWRs in operation are often shut down due to technical problems.The International Atomic Energy Agency documents this with the 'operating factor' (the time with electricity feed-in relative to the total time since commercial operation start). The first two plants in Kashiwazaki-Kariwa (block 6 & 7) reach total life operating factors of 70%, meaning that about 30% of the time, since commissioning, they were not producing electricity. For example, in 2010 Kashiwazaki-Kariwa 6 had an operating capacity of 80.9%, and an operating capacity of 93% in 2011. However, in 2008 it did not produce any power as the installation was offline for maintenance, and therefore had an operating capacity of 0% for that year. In contrast other modern nuclear power plants like the Korean OPR-1000 or the German Konvoi show operating factors of about 90%.
The output power of the two new ABWRs at the Hamaoka and Shika power plant had to be lowered because of technical problems in the power plants steam turbine section.After throttling both power plants down, they still have a heightened downtime and show a lifetime operating factor under 50%.
|Reactor block||Net output power |
(planned net output power)
|Commercial operation |
|Operating Factor since commissioning start |
|HAMAOKA-5||1212 MW (1325 MW)||18.01.2005||46,7%|
|KASHIWAZAKI KARIWA-6||1315 MW||07.11.1996||72%|
|KASHIWAZAKI KARIWA-7||1315 MW||02.07.1996||68,5%|
|SHIKA-2||1108 MW (1304 MW)||15.03.2006||47,1%|
|Plant Name||Number of Reactors||Rated Capacity||Location||Operator||Construction Started||Year Completed (First criticality)||Cost (USD)||Notes|
|Kashiwazaki-Kariwa Nuclear Power Plant||2||MW1356||Kashiwazaki, Japan||TEPCO||1992,1993||1996,1996||First Installation.After the March 11, 2011 earthquake, all restarted units were shut down and safety improvements are being carried out. As of October 2017 [update] , no units have been restarted, and the earliest proposed restart date is in April 2019 (for reactors 6 and 7 that using ABWR).|
|Shika Nuclear Power Plant||1||MW1358||Shika, Japan||Hokuriku Electric Power Company||2001||2005||The plant is currently not producing electricity in the wake of the 2011 Fukushima Daiichi nuclear disaster.|
|Hamaoka Nuclear Power Plant||1||MW1267||Omaezaki, Japan||Chuden||2000||2005||On May 14, 2011 Hamaoka 5 was shut down by the request of the Japanese government.|
|Shimane Nuclear Power Plant Reactor 3||1||MW1373||Matsue, Japan||Chugoku Electric Power Company||2007||Construction suspended in 2011|
|Longmen Nuclear Power Plant||2||MW1350||Gongliao Township, Republic of China||Taiwan Power Company||1997||After 2017||$9.2 Billion||Construction halted in 2014|
|Higashidōri Nuclear Power Plant||3||MW1385||Higashidōri, Japan||Tohoku Electric Power and TEPCO||No firm plans|
|Ōma Nuclear Power Plant||1||MW1383||Ōma, Japan||J-Power||2010||After 2021||In December 2014 J-Power applied for safety checks at the Oma nuclear plant, slated for startup in 2021.|
|South Texas Project||2||MW1358||Bay City, Texas, United States||NRG Energy, TEPCO and CPS Energy||$14 billion||License granted 2016, construction is currently not scheduled|
A number of design variants have been considered, with power outputs varying from 600 to 1800 MWe.The most developed design variant is the ABWR-II, started in 1991, an enlarged 1718 MWe ABWR, intended to make nuclear power generation more competitive in the late 2010s. None of these designs have been deployed.
The new designs hoped to achieve 20% reductions in operating costs, 30% reduction in capital costs, and tight planned construction schedule of 30 months. The design would allow for more flexibility in choices of nuclear fuels.
A nuclear meltdown is a severe nuclear reactor accident that results in core damage from overheating. The term nuclear meltdown is not officially defined by the International Atomic Energy Agency or by the Nuclear Regulatory Commission. However, it has been defined to mean the accidental melting of the core of a nuclear reactor, and is in common usage a reference to the core's either complete or partial collapse.
The RBMK is a class of graphite-moderated nuclear power reactor designed and built by the Soviet Union.
The light-water reactor (LWR) is a type of thermal-neutron reactor that uses normal water, as opposed to heavy water, as both its coolant and neutron moderator – furthermore a solid form of fissile elements is used as fuel. Thermal-neutron reactors are the most common type of nuclear reactor, and light-water reactors are the most common type of thermal-neutron reactor.
Passive nuclear safety is a design approach for safety features, implemented in a nuclear reactor, that does not require any active intervention on the part of the operator or electrical/electronic feedback in order to bring the reactor to a safe shutdown state, in the event of a particular type of emergency. Such design features tend to rely on the engineering of components such that their predicted behaviour would slow down, rather than accelerate the deterioration of the reactor state; they typically take advantage of natural forces or phenomena such as gravity, buoyancy, pressure differences, conduction or natural heat convection to accomplish safety functions without requiring an active power source. Many older common reactor designs use passive safety systems to a limited extent, rather, relying on active safety systems such as diesel powered motors. Some newer reactor designs feature more passive systems; the motivation being that they are highly reliable and reduce the cost associated with the installation and maintenance of systems that would otherwise require multiple trains of equipment and redundant safety class power supplies in order the achieve the same level of reliability. However, weak driving forces that power many passive safety features can pose significant challenges to effectiveness of a passive system, particularly in the short term following an accident.
Wylfa Nuclear Power Station is a former Magnox power station situated west of Cemaes Bay on the island of Anglesey, North Wales. Construction of the two 490 MW nuclear reactors, known as "Reactor 1" and "Reactor 2", began in 1963. They became operational in 1971. Wylfa was located on the coast because seawater was used as a coolant.
The "Nuclear Power 2010 Program" was launched in 2002 by President George W. Bush in order to restart orders for nuclear power reactors in the U.S. by providing subsidies for a handful of Generation III+ demonstration plants. The expectation was that these plants would come online by 2010, but it was not met.
A containment building, in its most common usage, is a reinforced steel or lead structure enclosing a nuclear reactor. It is designed, in any emergency, to contain the escape of radioactive steam or gas to a maximum pressure in the range of 275 to 550 kPa. The containment is the fourth and final barrier to radioactive release, the first being the fuel ceramic itself, the second being the metal fuel cladding tubes, the third being the reactor vessel and coolant system.
The supercritical water reactor (SCWR) is a concept Generation IV reactor, mostly designed as light water reactor (LWR) that operates at supercritical pressure. The term critical in this context refers to the critical point of water, and must not be confused with the concept of criticality of the nuclear reactor.
The Economic Simplified Boiling Water Reactor (ESBWR) is a passively safe generation III+ reactor design derived from its predecessor, the Simplified Boiling Water Reactor (SBWR) and from the Advanced Boiling Water Reactor (ABWR). All are designs by GE Hitachi Nuclear Energy (GEH), and are based on previous Boiling Water Reactor designs.
The Lungmen Nuclear Power Plant, located nearby Fulong Beach, Gongliao District, New Taipei City, is Taiwan's fourth nuclear power plant, consisting of two ABWRs each of 1,300 MWe net. It is owned by Taiwan Power Company (Taipower). It was intended to be the first of these advanced Generation III reactors built outside Japan. In 2014 construction of the plant was deferred.
Oldbury nuclear power station is a closed nuclear power station located on the south bank of the River Severn close to the village of Oldbury-on-Severn in South Gloucestershire, England. It was operated by Magnox Limited on behalf of the Nuclear Decommissioning Authority (NDA). Oldbury is one of four stations located close to the mouth of the River Severn and the Bristol Channel, the others being Berkeley, Hinkley Point A, and Hinkley Point B.
International Reactor Innovative and Secure (IRIS) is a Generation IV reactor design made by an international team of companies, laboratories, and universities and coordinated by Westinghouse. IRIS is hoped to open up new markets for nuclear power and make a bridge from Generation III reactor to Generation IV reactor technology. The design is not yet specific to reactor power output. Notably, a 335 MW output has been proposed, but it could be tweaked to be as low as a 100 MW unit.
The Kashiwazaki-Kariwa Nuclear Power Plant is a large, modern nuclear power plant on a 4.2-square-kilometer site including land in the towns of Kashiwazaki and Kariwa in Niigata Prefecture, Japan on the coast of the Sea of Japan, from where it gets cooling water. The plant is owned and operated by Tokyo Electric Power Company (TEPCO).
The three primary objectives of nuclear reactor safety systems as defined by the U.S. Nuclear Regulatory Commission are to shut down the reactor, maintain it in a shutdown condition and prevent the release of radioactive material.
The B&W mPower was a proposed small modular reactor designed by Babcock & Wilcox, and to be built by Generation mPower LLC, a joint venture of Babcock & Wilcox and Bechtel. It was a Generation III+ integral pressurized water reactor concept.
Horizon Nuclear Power is a British energy company that is expected to build new nuclear power stations in the United Kingdom. It was established in 2009, with its head office in Gloucester, and is now owned by Hitachi.
Boiling water reactor safety systems are nuclear safety systems constructed within boiling water reactors in order to prevent or mitigate environmental and health hazards in the event of accident or natural disaster.
General Electric's BWR product line of Boiling Water Reactors represents the designs of a large percentage of the commercial fission reactors around the world.