Reactor boiling water

To prevent such release, off gases are treated in Charcoal Delay Systems, which delay the release of xenon and krypton, and other radioactive gases, such as iodine and methyl iodide, until sufficient time has elapsed for the short-Hved radioactivity to decay. The delay time is increased by increasing the mass of adsorbent and by lowering the temperature and humidity for a boiling water reactor (BWR), a typical system containing 211 of activated carbon operated at 255 K, at 500 K dewpoint, and 101 kPa (15 psia) would provide about 42 days holdup for xenon and 1.8 days holdup for krypton (88). Humidity reduction is typically provided by a combination of a cooler-condenser and a molecular sieve adsorbent bed. 

A variety of nuclear reactor designs is possible using different combinations of components and process features for different purposes (see Nuclear REACTORS, reactor types). Two versions of the lightwater reactors were favored the pressurized water reactor (PWR) and the boiling water reactor (BWR). Each requites enrichment of uranium in U. To assure safety, careful control of coolant conditions is requited (see Nuclearreactors, water CHEMISTRY OF LIGHTWATER REACTORS NuCLEAR REACTORS, SAFETY IN NUCLEAR FACILITIES). 

As of 1994 there were 105 operating commercial nuclear power stations in the United States (1) (see Power generation). AH of these faciUties were light, ie, hydrogen—water reactors. Seventy-one were pressurized water reactors (PWRs) the remainder were boiling water reactors (BWRs). 

By contrast, uranium fuels for lightwater reactors fall between these extremes. A typical pressurized water reactor (PWR) fuel element begins life at an enrichment of about 3.2% and is discharged at a bum-up of about 30 x 10 MW-d/t, at which time it contains about 0.8 wt % and about 1.0 wt % total plutonium. Boiling water reactor (BWR) fuel is lower in both initial enrichment and bum-up. The uranium in LWR fuel is present as oxide pellets, clad in zirconium alloy tubes about 4.6 m long. The tubes are assembled in arrays that are held in place by spacers and end-fittings. 

Most nuclear reactors use a heat exchanger to transfer heat from a primary coolant loop through the reactor core to a secondary loop that suppHes steam (qv) to a turbine (see HeaT-EXCHANGETECHNOLOGy). The pressurized water reactor is the most common example. The boiling water reactor, however, generates steam in the core. 

Herein reactors are described in their most prominent appHcation, that of electric power. Eive distinctly different reactors, ie, pressurized water reactors, boiling water reactors, heavy water reactors, graphite reactors, and fast breeder reactors, are emphasized. A variety of other appHcations and types of reactors also exist. Whereas space does not permit identification of all of the reactors that have been built over the years, each contributed experience of processes and knowledge about the performance of materials, components, and systems. 

The mathematical formulation of forced convection heat transfer from fuel rods is well described in the Hterature. Notable are the Dittus-Boelter correlation (26,31) for pressurized water reactors (PWRs) and gases, and the Jens-Lottes correlation (32) for boiling water reactors (BWRs) in nucleate boiling. 

The General Electric simplified boiling-water reactor (SBWR) of lower (600 MWe) power features natural ckculation of the coolant rather than the usual forced ckculation. Use is made of a water reservok and pools for emergency cooling of the reactor and the containment building ak. 

A. W. Kramer, Boiling Water Reactors, Addison-Wesley Publishing Co., Inc., Reading, Mass., 1958. 

The EBWR Experimental Boiling Water Reactor, ANL-5607, Argonne National Laboratory, U.S. Atomic Energy Commission, Washington, D.C., 1957. 

BWRf 6 General Description of a Boiling Water Reactor, General Electric Co., Nuclear Energy Group, San Jose, California, 1980. 

The 1,356 MWe Advanced Boiling Water Reactor was jointly developed by General Electric, Hitachi, and Toshiba and BWR suppliers based on world experience with the previous BWRs. Tokyo Electric Power operates two ABWRs as units 6 and 7 of the Kashiwazaki-Kariwa Nuclear Power Station. Features of the ABWR are (Wilkins, 19921 ... 

The 600 MWe Simplified Boiling Water Reactor was designed by an international team consisting of EPRI, General Electric, Bechtel, Bums and Roe, Foster Wheeler, Southern Company, Massachusetts Institute of Technology, University of California (Berkeley), other U.S. utilities. 

Four boiling water reactor (BWR), and 15 pressurized water reactor (PWR) li acknowledged plant vulnerabilities. Some BWR vulnerabilities are failure of ... 

BWR - Boiling Water Reactor (GE reactor having no steam generator separate from the reacior). BWST - Borated Water Storage Tank. 

SBWR - Simplified Boiling Water Reactor - second generation reactor. 

Wilkins, D. R. and J. Chang, 1992, GE Advanced Boiling Water Reactors and Plant System Designs. 8th Pacific Basin Nuclear Conference, Taiwan, April. 

For nuclear plants reactor type BWR for Boiling Water reactor, PWR for pressurized water reactor... 

Corporation beginning in 1959, used a pressurized-water reactor instead of a boiling-water reactor, and required a heavy government operating subsidy. 

Much of the recent research on stress-corrosion cracking of austenitic stainless steels has been stimulated by their use in nuclear reactor coolant circuits. The occurrence of stress-corrosion cracking in boiling water reactors (BWR) has been documented by Fox . A major cause for concern was the pipe cracking that occurred in the sensitised HAZ of the Type 304 pipework, which is reported to have been responsible for about 3% of all outages of more than 100 h from the period January 1971 to June 1977. 

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. 

AVT Barg BD BDHR BF BOF BOOM BOP BS W BSI BTA Btu/lb BW BWR BX CA CANDUR CDI CFH CFR CHA CHF CHZ Cl CIP CMC CMC CMC COC All-Volatile treatment bar (pressure), gravity blowdown blowdown and heat recovery system blast furnace basic oxygen furnace boiler build, own, operate, maintain balance of plant basic sediment and water British Standards Institution benzotriazole British thermal unit(s) per pound boiler water boiling water reactor base-exchange water softener cellulose acetate Canadian deuterium reactor continuous deionization critical heat flux Code of Federal Regulations cyclohexylamine critical heat-flux carbohydrazide cast iron boiler clean-in-place carboxymethylcellulose (sodium) carboxy-methylcellulose critical miscelle concentration cycle of concentration... 

C6. Cook, W. H., Fuel cycle program. A boiling water reactor research and development program, 1st Quart, rept., Aug. 1960-Sept. 1960, GEAP-3558 (1960). 

The relative activity of americium isotopes for a typical pressurized-water reactor (PWR) fuel assembly are 1,700, 11, and 13 Ci for241 Am, 242Am, and 243Am (DOE 1999). The respective activity ratios for a typical boiling water reactor (BWR) are 680, 4.6, and 4.9 Ci. There are 78 PWR and 41 BWR reactors in the United States, several of which have ceased operation. Total projected inventories of these three radionuclides for all reactors are 2.3x10s, 1.4xl06, and 1.7xl06 Ci, respectively. The post irradiation americium content of typical PWR and BWR reactor fuel assemblies are 600 g (0.09%) and 220 g (0.07%), respectively. 

Up front capital costs are a critical issue, particularly in our emerging deregulated electricity sector. In Japan, TEPCO reduced the construction time on its newest Advanced Boiling Water Reactor - Unit 7 of the Kashiwazaki Kaariwa Nuclear Power Station - to 51 months. 

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