BOiling water ReActor experiment

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 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 ... 

In the United States, experiments at Argonne National Laboratory in Illinois indicate that a new generation of breeder reactors can be developed that will be inherently safer than the pressurized boiling-water reactors now in use. This research also shows that these reactors can be cost-competitive with coal-... 

Smith, J. M., and R. S. Gilbert Tritium Experience in Boiling Water Reactors, Proc. EPA Tritium Symp. Aug. 1971. 

A small Boiling Water Reactor (BWR) design concept has been developed at GE which maximizes the use of BWR design, technology and operating experience. Modest innovations are included to simplify the performance of safety functions. These, as well as other system simplifications, and a reduced power rating less than 600 MW(e) can reduce total costs and speed construction. 

Eickelpasch, N., Seepolt, R., Mullauer, J., Spalthoff, W. Operational experience with and post-irradiation examinations on boiling water reactor control rods. Nucl. Technology... 

Smith, J. M., Gilbert, R. S. Tritium experience in boiling water reactors. Trans. Am. Nucl. Soc. 14, 160-161 (1971)... 

Asakura, Y, Uchida, S., Ohsumi, K., Shindo, T., Aizawa, M., Usui, N., Amano, O., Yoshi-kawa, S., Otoha, K. Current operating experience with water chemistry in crud concentration suppressed boiling water reactors. Proc. 5. BNES Conf. Water Chemistry of Nuclear Reactor Systems. Bournemouth, UK, 1989, Vol. 1, p. 115-122 Asay, D. Radiation-field buildup at the Monticello BWR with hydrogen water chemistry. Report EPRI NP-7520 (1991)... 

Duce, S. W. Effectiveness and safety aspects of selected decontamination methods for LWRs - Recontamination experience 1988 . Nucl. Engng. and Design 118, 487-496 (1990) Eickelpasch, N., Steiner, H., Fischer, A. Pilot dismantling of the KRB A boiling water reactor. Proc. CEC 3. Internat. Conf. on Decommisioning of Nuclear Installations, Luxembourg 1994, p. 40—52... 

Experiences from damage to welded pipes made from the steel SAE 304 (1.4301) in boiling water reactors were summarised in [105]. Under the practical operating conditions in high purity water with 0.2-0.3 mg/1 oxygen, < 0.1 mg/1 chloride and at... 

Plant operating experience has shown that pressurized water reactors and boiling water reactors are susceptible to a variety of abnormal events during shutdown conditions. 

Void coefficient is usually associated with a boiling water reactor because of the bulk in-core boiling, but research reactor can experience void effects during transients as the result of insertion of experiments into the core. 

Experience of the Th -U cycle was first obtained in the Indian Point boiling water reactor, where the first core, loaded in 1962, contained pellets of urania-thoria mixture. The main interest, however, has centered on its use in the high-temperature gas-cooled reactor (HTGR), and thorium has been employed as fertile material both in the prismatic fuel elements of the Dragon reactor in the United Kingdom and the Peach Bottom reactor in the United States, and in the spherical elements of the pebble-bed AVR in West Germany. There is also a possibility of adopting the thorium cycle in the... 

Knowledge of the void coefficient is also important during the initial design and everyday operation of reactors, such as the boiling water reactor. For those reactors in which the void coefficient will be an important consideration in either the hazards or operation analysis, the coefficient is first calculated by theory and perhaps checked by experiment in a critical facility. When the reactor is completed, void coefficient measurements are often early on the agenda. ... 

In Advanced Gas Cooled (AGR), Pressurised Water (PWR) and Boiling Water (BWR) reactors, and in the Russian RMBK, the fuel is U02. Experiments in the UK and USA, reviewed by Farmer Beattie (1976), showed less than 1% release of fission product iodine and caesium from punctured U02 fuel cans at about 1000°C in air or steam, rising to 10-50% release at 1800°C. At 2800°C, the U02 melted and there was nearly complete release of volatile nuclides (I, Te, Cs, Ru) but only small release of refractory alkaline earth and rare earth nuclides. 

Kinetics studies were conducted at 55°C in a jacketed batch reactor. Shredded wastepaper (10 g / L) was added to 500 mL or 1L of citrate buffer, pH 4.8, and heated to the assay temperature. A specified quantity of either soluble or immobilized cellulase was added to the reactor to initiate hydrolysis. Samples were collected at regular intervals over 30-60 min, and centrifuged to separate solids. The DNS assay (4) was used to detect sugars formed during hydrolysis experiments. The supernatant from the centrifuge tube and the DNS solution were mixed and cooked for exactly 5 min in boiling water. Finally, the sample was transferred to a methacrylate cuvet, and its absorbance was measured at 540 nm. 

A thermal explosion is entirely different. This can be modeled by boiling water in a elosed container (WARNING Do not try this experiment, it may lead to serious injury.) After enough heat was absorbed by the container, formation of steam results in such a high presstrre irtside that cannot be borne by the walls. To avoid this, all elosed systems eontain safety valves that open at a pre-set pressme limit that is deemed safe and release exeess steam to the envirorunent and prevent the explosion from happening. The first explosion in Chernobyl was of this type because of the cooling water present in the reactor (the water circrrlation was intentionally stopped because of an experiment ). 

An experimental program was carried out in the Czech Republic, where Boiling crisis and Critical Heat Flux (CHF) were measured on the facilities that simulated the fuel assemblies of the former Soviet s Pressurised Water Reactors (PWR) WWER-440 and WWER-1000. The large part of experiments related to the CHF was performed at Skoda Plzen Ltd, Nuclear Machinery Plant. The NRI started a complex of research activities in this field at the end of seventies. 

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