Reactor safety

Nuclear Reactors. Nuclear power faciUties account for about 20% of the power generated in the United States. Although no new plants are plaimed in the United States, many other countries, particularly those that would otherwise rely heavily on imported fuel, continue to increase their nuclear plant generation capacity. Many industry observers predict that nuclear power may become more attractive in future years as the price of fossil fuels continues to rise and environmental regulations become more stringent. In addition, advanced passive-safety reactor designs may help allay concerns over potential safety issues. 

A system of the CRS type was adopted for a German-designed PWR and, ten years later, by Westinghouse for its advanced passive safety reactor AP 600. 

Obtain a copy of a fault tree analysis for a system and review the analysis and results. You might wish to look at one of the classic reports on nuclear power plant safety Reactor Safety Study An Assessment of Accident Risks in U.S. Commercial Nuclear Power Plants, Report WASH-1400, U.S. Nuclear Regulatory Commission, October 1975. (This report is also known as the Rasmussen report.)... 

Ardabyevsky A., Panov Y., Polunichev V. - KLT-40 Enhanced Safety Reactor Plant for Autonomous Energy Sources - Report to the Third Annual Scientific-Technical Conference of the Nuclear Society "Nuclear Technologies in Tomorrow s World". -St. Petersburg, October 14-18, 1992. 

The SSWS cools the Component Cooling Water System (CCWS) through the Component Cooling Water Heat Exchangers and rejects the heat to the ultimate heat sink during normal, transient, and accident conditions. The CCWS in turn provides cooling water to those safety-related components necessary to achieve a safe reactor shutdown, as well as to various non-safety reactor auxiliary components. 

MITENKOV F.M., et al., New generation medium power nuclear station with VPBER-600 passive safety reactor plant. Nuclear Engineering and Design, vol.173 (1997), p.99-108. 

Borms, L., et al.. Experiments MOL 7C/6 and MOL 7C/7 Results of Source Term Measurements, Proceedings of International Fast Reactor Safety Reactors - Snow-bird-USA, August 12-16,1990, Vol 1. 

The concept of a passive-safety reactor KAMADO (in Japanese a Japanese traditional kitchen range for cooking with firewood) was proposed in 2001 by the Central Research Institute of Electric Power Industry (CRIEPI), Japan. The KAMADO concept is based on a synthesis of the design approaches used in light water reactors, the heavy water reactor FUGEN [Xni-1] and pool type research reactors. 

Xni-2] MATSUMURA, T., et al.. New concept of a small passive-safety reactor with U02-Graphite-Water Core, Advanced Nuclear Power Plants (Proc. Int. Congress, Hollywood, FL. USA, June 9-13, 2002) ICAPP 02 (1038). 

Xin-3] MATSUMURA, T., et al.. Ability of new concept passive-safety reactor KAMADO - Safety, economy and hydrogen production, GENES4/ANP2003 (1092), Kyoto, Japan (2003),... 

Ronald L. Kathren, "Historical Development of Radiation Measurement and Protection" in CRC Handbook of Radiation Measurement and Protection, ed. Allen Brodsky, Section A, vol. 1 (West Palm Beach, Fla. CRC Press, 1978), pp. 43-50 T. J. Thompson, "Accidents and Destructive Tests," in The Technology of Nuclear Reactor Safety Reactor Physics and Control, ed. T. J. Thompson and J. G. Beckerley, 2 vols. (Cambridge MIT Press, 1964, 1973), 1 609-610 Barton C. Hacker, "Elements of Controversy A History of Radiation Safety in the... 

Many unique concepts of Increased safety reactors appeared In Russia In recent years but their development, however, did not always take decommissioning problem Into account. 

In the case of NPP, the qualification level of the adopted code and nodalisation affects the calculated NCP. Furthermore, in the case of new generation passive safety reactors 6 and 7, the emergency loops connected with the primary system are assumed to come into operation once the coolant draining process is initiated. 

The choice of reactor temperature depends on many factors. Generally, the higher the rate of reaction, the smaller the reactor volume. Practical upper limits are set by safety considerations, materials-of-construction limitations, or maximum operating temperature for the catalyst. Whether the reaction system involves single or multiple reactions, and whether the reactions are reversible, also affects the choice of reactor temperature, as we shall now discuss. 

Raw materials efficiency. In choosing the reactor, the overriding consideration is usually raw materials efficiency (bearing in mind materials of construction, safety, etc.). Raw material costs are usually the most important costs in the whole process. Also, any inefficiency in raw materials use is likely to create waste streams that become an environmental problem. The reactor creates inefficiency in the use of raw materials in the following ways ... 

Reactors in the overall process. It should be emphasized that many considerations other than those represented in Figs. 2.9, 2.10, and 2.11 also influence the decision on the choice of reactor. Safety considerations, operating pressure, materials of construction, etc. have a considerable effect on the outcome. 

Clearly, the potential hazard from runaway reactions is reduced by reducing the inventory of material in the reactor. Batch operation requires a larger inventory than the corresponding continuous reactor. Thus there may be a safety incentive to change from batch to continuous operation. Alternatively, the batch operation can be... 

Due to the many vibrations of the operating reactor, the RCCA rods are subject to wear, creating loss of material, mainly at guide cards height. This loss of material ean be the cause of important problems for the functioning and safety of the plant. 

Beryllium is added to copper to produce an alloy with greatly increased wear resistance it is used for current-carrying springs and non-sparking safety tools. It is also used as a neutron moderator and reflector in nuclear reactors. Much magnesium is used to prepare light nieial allo>s. other uses include the extraction of titanium (p. 370) and in the removal of oxygen and sulphur from steels calcium finds a similar use. 

Reppe s work also resulted in the high pressure route which was estabUshed by BASF at Ludwigshafen in 1956. In this process, acetylene, carbon monoxide, water, and a nickel catalyst react at about 200°C and 13.9 MPa (2016 psi) to give acryUc acid. Safety problems caused by handling of acetylene are alleviated by the use of tetrahydrofuran as an inert solvent. In this process, the catalyst is a mixture of nickel bromide with a cupric bromide promotor. The hquid reactor effluent is degassed and extracted. The acryUc acid is obtained by distillation of the extract and subsequendy esterified to the desked acryhc ester. The BASF process gives acryhc acid, whereas the Rohm and Haas process provides the esters dkecdy. 

Liquid metals, however, present several disadvantages. Their weights must be considered with regard to equipment design. Additionally, Hquid metals are difficult to contain and special pumps must be used for system safety. Alkali metals react violentiy with water and bum ia air. Liquid metals also may become radioactive whea used for cooling auclear reactors (qv). 

---