Nuclear power reactors light water reactor

Item facility. Power reactors (Light Water Reactor (LWR), On-load Reactor (OLR)), Research Reactor (Material Testing Reactor (MTR), Fast Breeder Reactor (FBR), (TRIGA) and Critical Assemblies, Nuclear Material Storage (dry and wet). 

United States Atomic Energy Commission, The Safety of Nuclear Power Reactors Light Water Cooled) and Related Facilities, USAEC Report WASH-1250, USAEC, Washington, D.C. 

The Reactor Safety Study was prompted in part by a request from Senator John Pastore for a comprehensive assessment of reactor safety. The AEC s first response to this request was the WASH-1250 report entitled The Reactor Safety Study of Nuclear Power Reactors (Light Water-Cooled) and Related Facilities, which was published in final form in July 1973. However, WASH-1250 did not provide a probabilistic assessment of risk as requested in Senator Pastore s letter. At the time, relevant probabilistic estimates were quite limited in scope and/or highly subjective. For example, in a policy paper dated November 15, 1971, to the commissioners proposing an approach to the preparation of environmental reports, the regulatory staff estimated that the probability of accidents leading to substantial core meltdown was 10 per reactor-year. In retrospect, this was a highly optimistic estimate, but it typifies the degree to which meltdown accidents were considered "not credible."... 

Plutonium will very likely play an important role in future power generation by nuclear reactors. Light-water reactors (LWR) already produce and burn Pu future LWR recycle and breeder options will place greater emphasis on Pu fuel cycles in nuclear technologies (2.). As a fuel, Pu is a valuable commodity thus it will be meticulously recovered for reuse, and only a small quantity will likely be released to aquatic and terrestrial environments. 

Source American Nuclear Society Standards Committee Working Group ANS-5.1, American National Standard for Decay Heat Power in Light Water Reactors, Standard ANSI/ANS-5.1, American Nuclear Society, La Grange Park, III., 1979. With permission of the publisher, the American Nuclear Society. 

Schrock, V.E. 1979. A revised ANS standard for decay heat from fission products. Nucl. Technol. 46 323, and ANSI/ANS-5.1-1979. 1979. Decay Heat Power in Light Water Reactors. Hindsdale, IL American Nuclear Society. 

Anon., 2005. Decay Heat Power in Light Water Reactors, vANSI/ANS-5.1-2005, LaGrange, IL American Nuclear Society. 

Characteristics of Pipe System Failures in Light Water Reactors Nuclear Approximately 100 records of pipe failure rates in a wide variety of failure modes Nuclear Power Plant Piping 114. 

There are various types of nuclear power reactors, including boiling water reactors (BWR) and pressurized water reactors (PLWR or LWR), which are both light-water reactor (LWR) designs and are cooled and moderated by water. There also are pressurized heavy-water reactor (PHWR or HWR) designs. 

The nuclear plants now operating in the U.S. are light water reactors, which use water as both a moderator and coolant. These are sometimes called Generation II reactors. In these Generation II Pressurized Water Reactors, the water circulates through the core where it is heated by the nuclear chain reaction. The hot water is turned into steam at a steam generator and the steam is used by a turbine generator to produce electric power. 

All over the world, 432 nuclear power reactors are under operation and more than 36 GW of electricity could be produced as of December 31, 2001. There are several types of reactors such as boiling water reactor (BWR), pressurized water reactor (PWR), Canada deuterium uranium (CANDU), and others. In these reactors, light water is normally used not only as a coolant, but also as a moderator. On the contrary, in CANDU reactors, heavy water is taken. It is widely known that the quality control of coolant water, the so-called water chemistry, is inevitably important for keeping the integrity of the plant. 

The basic design of most nuclear reactors is similar, but several types of reactors are used throughout the world. In the United States most reactors use plain water as the coolant. Reactors using ordinary water are called light water reactors. Light water reactors can be pressurized to approximately 150 atmospheres to keep the primary coolant in the liquid phase at temperatures of approximately 300°C. The heat from the pressurized water is used to heat secondary water to generate steam. In a boiling water reactor, water in the core is allowed to boil. The steam produced powers the turbines directly. Heavy water reactors use water in... 

Although there have been comparatively few gas-cooled reactors installed for generating commercial nuclear electric power, the concept has a number of operating advantages over light-water reactors and could play an important role in the reactor designs for the next century. 

FIGURE 17.26 The reactor core of a typical light-water reactor (LWR) nuclear power plant is immersed in... 

Steam production. Light water reactors produce steam. The power plant may operate as a conventional nuclear plant where all the steam is used to produce electricity. Alternatively, electricity and some of the steam may be diverted to hydrogen production. 

Spent fuel from light water reactors contains about 1 % of plutonium. According to Oi (1998) the IAEA estimates that in 1997 about 10,500 tonnes of spent fuel were discharged from nuclear power reactors world-wide this amount contains about 75 tonnes of plutonium. It is estimated that the annual production figure will remain more or less the same until 2010. The cumulative amount of plutonium in spent fuel from nuclear power reactors worldwide is predicted to increase to about 1700 tonnes by 2010. 

Nuclear reactors use the heat from a controlled nuclear fission reaction to produce power. The three important types of reactors are light water reactors, heavy water reactors, and breeder reactors. 

---