Nuclear power plant pressurizer

N.N. Alekseenko, A.D. Amaev, I. Gorynin, V.A. Nikolaev, Radiation Damage in Nuclear Power Plants Pressure Vessel Steels, ANS Russian Materials Monograph Series, American Nuclear Society, Grange Park, IL, 1997. 

Nuclear Power Plant in this model of a nuclear power plant, pressurized water is heated by fission of uranium-235. This water is circulated to a steam generator. The steam drives a turbine to produce electricity. Cool water from a lake or river is then used to condense the steam into water. The warm water from the condenser may be cooled in cooling towers before being reused or returned to the lake or river. 

Fig. 1. Pressurized water reactor (PWR) coolant system having U-tube steam generators typical of the 3—4 loops in nuclear power plants. PWR plants having once-through steam generators contain two reactor coolant pump-steam generator loops. CVCS = chemical and volume-control system.

If the containment holds, nuclear power plants present no risk to the public. Overpressurization of the containment is the failure mode that could allow direct release of radioactivity to the public. Design a risk reduction investigation of the benefits of releasing the gas pressure through an offgas processing system that removes the particulates. 

Selby, D, L. et al., Pressurized Thermal Shock Evaluation of H. B, Robinson Unit 2 Nuclear Power Plant, September 1985... 

Sacks, 1. J. et al., 1983, Systems Interaction Results from the Digraph Matrix Analysis of the Watts Bar Nuclear Power Plant High Pressure Safety Injection Systems, LLNL UCRI..-53467, December. 

Taking into account the possibility of highly directional blast effects, Eichler and Napadensky (1977) recommend the use of a safe and conservative value for TNT equivalency, namely, between 20% and 40%, for the determination of safe standoff distances between transportation routes and nuclear power plants. This value is based on energy it should be applied to the total amount of hydrocarbon in the largest single, pressurized storage tank being transported. 

The Electric Power Research Institute (EPRI 1981) conducted a survey of transuranic radionuclides in the terrestrial environs of nuclear power plants in the United States in 1978-1979. The plants included two pressurized water reactors (PWRs) and two BWRs that were of modem design and had been in operation at least 3 years. The 241 Am air concentrations around all of the power plants were extremely low and indistinguishable from fallout background... 

Boiler and Pressure Vessel Code, Section II, Materials (Part A, Ferrous Material Specifications, and Part D, Properties ), Section ID, Rules for Construction of Nuclear Power Plant Components, and Section VIII, Pressure Vessels, Divisions 1 and 2. Code for Pressure Piping, ASME/ANSI B31.3, Chemical Plant and Petroleum Refinery Piping ... 

Two accidents of vastly differing severity have occurred at nuclear power plants. On 28 March 1979, an accident occurred in the nuclear power plant at Three Mile Island, Pennsylvania, USA. The radiation was contained and the small amount released had negligible effects on the health of individuals at the plant. On 26 April 1986 an accident occurred in the nuclear power plant 10 miles from the city of Chernobyl, then part of the Soviet Union. The chain reaction in the radioactive core of one of the four reactors became uncontrolled. Steam pressure rose to dangerous levels there were several explosions and a subsequent fire took several hours to extinguish. Large amounts of radioactive material were scattered over a wide area and into the atmosphere (later descending in a dilute form in rain all over the world). 

Direct fired pressure vessels Nuclear power plants Heating boilers Unfired pressure vessels... 

Armenia is particularly sensitive to its energy security because it faced a crippling energy crisis between 1992 and 1995 as a result of the collapse of former markets in the Soviet Union. The severity of the crisis was compounded by a decision in March of 1989 to shut down the Armenian nuclear power plant due to pressure from environmental groups and safety concerns following the 1988 earthquake. Instability in the power grid resulted in over utilization of hydro resources, particularly Lake Sevan. 

France owns a major nuclear power plant program for electricity production (more than 70% of total production). Both reactors for civil and defence programs are pressurized water reactors, with similar fissile materials. 

Radioactive waste treatment applications have been reported [3-9] for the laundry wastes from nuclear power plants and mixed laboratory wastes. Another interesting application of reverse osmosis process is in decontamination of boric acid wastes from pressurized heavy water reactors (PHWRs), which allows for the recovery of boric acid, by using the fact that the latter is relatively undissociated and hence wdl pass with water through the membrane while most of the radioactivity is retained [10]. Reverse osmosis was evaluated for treating fuel storage pool water, and for low-level liquid effluents from reprocessing plants. 

Nuclear power plants in the United States use light water moderated nuclear reactors (LWR) that produce the steam to generate electricity. The fuel elements for boiling water reactors and pressurized water reactors (PWR) are nearly the same. The fuel is uranium dioxide enriched with 3 % and this produces a nearly uniform spent fuel, which would be the feed for domestic fuel reprocessing. 

Figure 1.8 Schematic of pressurized-water nuclear power plant.

In part III of Fig. 1.11, the 160 short tons of UgOg consumed per year corresponds to a daily feed rate of 341 kg natural uranium. As this pressurized-water nuclear power plant has a thermal efficiency of 32.5 percent, the fraction of the natural uranium feed converted to energy is... 

It has been proposed that some of the natural uranium needed to fuel a pressurized-water nuclear power plant be obtained by extracting uranium from seawater used to cool the plant. If the seawater temperature rise is lO C and the reactor and fuel-cycle conditions are as given in Frg. 3.31, how many kilograms of uranium per year could be recovered at 80 percent yield from cooling water What fraction is this of the armual fuel requirement of the reactor ... 

Several plate and frame MF units have been installed in Japanese nuclear power plants. The units operate with automatic periodic backwash using accumulated filtrate. Typically, the units backwash every 3 hours at a back pressure twice that of the final forward pressure. The backwashed crud is removed from the system as concentrated RAD wastes. In this sense, these back-wash systems are not dissimilar to cross-flow units using MF or UF-membranes. In either case, a reject stream containing concentrated crud must be disposed of. 

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