LIQUID RADIOACTIVE WASTE SYSTEM

To borate the reactor coolant system, the operator sets the makeup control system to automatically add a preset amount of boric acid by fully diverting the three-way valve in the pump suction line to the boric acid storage tank, with delivered flow measured at the discharge of the makeup pumps. Dilution operates in a similar feshion. In either case, if the pressuriser level exceeds its control point, the letdown path to the liquid radioactive waste system holdup tanks is automatically opened by the protection and safety monitoring system. 

The concentration of lithium-7 in the reactor coolant system varies according to a pH control curve as a function of the boric acid concentration of the reactor coolant system. If the concentration exceeds the proper value, as it may during the early stages of core life when lithium-7 is produced in the core at a relatively high rate, the cation bed demineraliser is used in the letdown path in series with the mixed bed demineraliser to lower the lithium-7 concentration. Since the build up of lithium is slow, the cation bed demineraliser is used only intermittently. When letdown is being diverted to the liquid radioactive waste system, the purification flow is... 

The reactor coolant drain tank in the liquid radioactive waste system. 

The liquid radioactive waste system is designed to collect, process, store and dispose of liquid radioactive waste generated as the result of normal operation, including anticipated operational occurrences such as reactor coolant system level reduction for refuelling. Nonradioactive secondary system waste is not processed by the liquid radioactive waste system however, if significant radioactivity is detected in secondary-side systems, blowdown or a portion of the blowdown may be diverted to the liquid radwaste system for processing and disposal. 

The liquid radioactive waste system includes tanks, pumps, ion exchangers and filters. The liquid radioactive waste system is designed either to process liquid radioactively contaminated liquid waste, or to store for processing by mobile equipment. The liquid waste is in four major categories ... 

The following design requirements for the liquid radioactive waste system support safe operation of the plant under normal conditions ... 

The liquid radioactive waste system must collect and process liquid waste collected from the reactor coolant system and connected systems, and then discharge the processed hquid to the environment in a controlled marmer. 

The levels of radiation released from the liquid radioactive waste system after treatment must be within the allowed discharge limits. 

The liquid radioactive waste system must be capable of being isolated by the containment isolation system. 

The liquid radioactive waste system is appropriately sized to handle the predicted waste arising. The two effluent hold-up tanks have a combined total capacity of 212 m (see Table 11.2-2 of Reference 6.1). This is significantly greater than the volume of liquid expected to arise, which are of the order of 10 m per day (see Table 11.2-6 of Reference 6.1). 

Prior to the collection of liquid samples either in the laboratory or in the grab sampling unit, the lines are purged with source liquid to provide representative samples. The purging flow returns to the effluent holdup tank of the liquid radioactive waste system. 

The radioactive waste drain system transfers collected waste to the liquid radioactive waste system. The contents of the sump are pumped to the liquid radioactive waste system tanks. Drainage lines from the negative pressure boundary areas of the auxiliary, radwaste, and armex... 

All the NPPs have their own systems for managing the solid and liquid radioactive waste generated at the site. The very low level waste (VLLW) and the low and intermediate level short lived radioactive waste (L IL SL) waste is eonditioned in accordance with the waste acceptance criteria for the landfill type and the SFR repository respectively. Standard techniques are used processing liquid and solid waste. Cement and bitumen are used as matrix for conditioning. 

From the above table it follows that major works in different areas are to be performed in Gremikha including -management of SNF of Nuclear Submarines (NSs) with Liquid-Metal Coolant (LMC) reactors and WER -management of Solid and Liquid Radioactive Waste (SRW and LRW) -removal of SNF and Spent Removable Units (SRUs) to Mayak for reprocessing -rehabilitation of buildings, constructions, terrestrial and aquatic systems. 

They reported the distribution ratios (Dm) of lanthanide and actinide ions and compared the Dm values with that of Am " in the extraction system of 1 M HNO3 and 0.1 M TODGA/ M-dodecane as shown in Table 18.11. The order of extractability of actinide ions from 1 M HNO3 is An, An > An02 > An02. The TODGA has an ability of co-extraction of trivalent actinide ions and lanthanide ions from high-level liquid radioactive waste. 

A reduction in the volume of solid and liquid radioactive waste due to the use of leak-tight equipment and systems and the increases in the service life of the main replaceable equipment (steam generator pipe systems, MCP replaceable elements, etc.), resulting in a reduced maintenance costs ... 

N-1 1301-N Liquid radioactive waste disposal system for N Reactor. Effluents from reactor coolant system, spent fuel storage basin, periphery coolant systems, and various radioactiv e drain systems in the reactor facility. Also disposal area for various laboratory chemicals. Historical average high flow rate of 2.100 gal/min. Crib and trench. 

The treatment systems for gaseous and liquid radioactive waste result in authorised discharges to atmosphere and controlled waters. Progressive reductions in discharges consistent with the UK National Strategy are expected as the AP 1000 is operated over time by applying plant operational experience and lessons learned from the individual AP 1000 plants, AP 1000 plants as an operating... 

Liquid Radioactive Wastes - the Environment Report, section 3.3 of the Environment Report, (reference 15.6) summarises the sources of liquid radioactive waste, the liquid radwaste system (WES), and a BAT assessment for the chosen design options. 

III-28. Examples of accidents that may occur in auxiliary systems are pipe breaks in the auxiliary systems, the ignition of filters or absorbers, explosions in storage tanks, spilling of liquid radioactive wastes, and fires in radioactive waste systems. Their consequences may be as severe as those described in the preceding sections. The consequences will depend upon the design features of the systems concerned, for which there are significant differences in different designs of reactor. For this reason, the assumptions to be chosen for the purposes of accident analysis need to be made on a case by case basis. 

Solid radioactive waste results from the operation and maintenance of the nuclear power plant and its associated processing systems for gaseous and liquid radioactive waste. The nature of such waste varies considerably from plant to plant, as do the associated levels of activity. Sohd radioactive waste may consist of spent ion exchange resins (both bead and powder) cartridge filters and pre-coat filter cake particulate filters from ventilation systems charcoal beds tools contaminated metal scrap core components debris from fuel assemblies or in-reactor components and contaminated rags, clothing, paper and plastic. 

Radioactive waste system failures RAPS (Radioactive argon processing system ) /CAPS (Cell atmosphere processing system) valve leaks RAPS surge tank failure Cover gas diversion to CAPS Liquid metal tank leaks. 

Unit I standard liquid radioactive waste (LRH) treatment systems... 

Y. S. Tang. Ph.D has more than 35 years of experience in the field of thermal and fluid flow. His research interests have covered aspects of thermal hydraulics that are related to conventional and nonconventional power generation systems, with an emphasis on nuclear reactor design and analysis that focuses on liquld-meta -cooled reactors. Dr. Tang is co-author of Radioactive Waste Management published by Taylor 8 Francis, and Thermal Analysis of Liquid Metal Fast Breeder Reactors, He received a B5. from National Central University In China and an MS. in mechanical engineering from the University of Wisconsin. He earned his Ph.D. 

Nuclear Waste. NRC defines high level radioactive waste to include (/) irradiated (spent) reactor fuel (2) liquid waste resulting from the operation of the first cycle solvent extraction system, and the concentrated wastes from subsequent extraction cycles, in a facility for reprocessing irradiated reactor fuel and (3) solids into which such liquid wastes have been converted. Approximately 23,000 metric tons of spent nuclear fuel has been stored at commercial nuclear reactors as of 1991. This amount is expected to double by the year 2001. 

Exempt Radioactive Wastes. The radioactive waste classification system in the United States does not include a general class of exempt waste (see Table 1.1). Rather, many products and materials that contain small amounts of radionuclides (e.g., specified consumer products, liquid scintillation counters containing 3H and 14C) have been exempted from requirements for use or disposal as radioactive material on a case-by-case basis. The various exemption levels are intended to correspond to low doses to the public, especially compared with dose limits in radiation protection standards for the public or doses due to natural background radiation. However, the exemption levels are not based on a particular dose, and potential doses to the public resulting from use or disposal of the exempt products and materials vary widely. 

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