The Advanced Boiling Water Reactor (ABWR) is a Generation III

Generation III reactor

A generation III reactor is a development of any of the generation II nuclear reactor designs incorporating evolutionary improvements in design developed during the lifetime of the generation II reactor designs...

 boiling water reactor

Boiling water reactor

The boiling water reactor 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 , also a type of light water nuclear reactor...

. The ABWR is currently offered by GE Hitachi Nuclear Energy

GE Hitachi Nuclear Energy

GE Hitachi Nuclear Energy 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...

 (GEH) and Toshiba

Toshiba

is a multinational electronics and electrical equipment corporation headquartered in Tokyo, Japan. It is a diversified manufacturer and marketer of electrical products, spanning information & communications equipment and systems, Internet-based solutions and services, electronic components and...

. 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.

Boiling water reactors (BWRs) are the second most common form of light water reactor

Light water reactor

The light water reactor is a type of thermal reactor that uses normal water as its coolant and neutron moderator. Thermal reactors are the most common type of nuclear reactor, and light water reactors are the most common type of thermal reactor...

 with a direct cycle design that uses fewer large steam supply components than the pressurized water reactor

Pressurized water reactor

Pressurized water reactors constitute a large majority of all western nuclear power plants and are one of three types of light water reactor , the other types being boiling water reactors and supercritical water reactors...

 (PWR), which employs an indirect cycle.