Raw water system

Evaluate alternatives to upgrade the raw water system valve bos and piping... 

A spurious primary coolant system dump during equilibrium power operation is a credible but unlikely Incident. The primary loop has been designed to withstand the thermal and vibrational shock of at least six dump transients. The Incident is chosen for aiscusslon because it represents the most severe of a class of incidents Involving rapid depressurization of the system and reliance on the emergency once-throuc raw water system without a preceding major line falliure. 

The demineralised water treatment system receives water from the raw water system, processes this water to remove ionic impurities and provides demineralised watertothe demineralised water transfer and storage system. The system consists of two reverse osmosis feed piunps, two 100-percent reverse osmosis units normally operating in series for primary demineralization and one electrode ionization imit for secondary demineralisation. 

Circulating Raw Water System Operation During Reactor Outages... 

During reactor operation, the secondary system is operated as a steam condensate system to transfer heat removed from the primary loop to the circulating raw water system. Heat transfer from the primary loop results in boiling on the secondary side of the ten main heat exchangers. This steam then flows to the main 46 steam header atop the 109 Building. Sufficient steam to drive the six drive turbines and to supply auxiliary areas uses flows to the turbine supply header the remainder is condensed in the dump condensers, completing the heat transfer to the circulating raw water system. Secondary coolant pressures, flow rates and Inventory are directly controlled coolant temperatures are dependent variables. 

Reactor generated heat is transferred to the circulating raw water system in the dump condensers for ultimate dissipation in the Columbia River. About 400,000 gpm of untreated Columbia River water will be pumped from the river, through the tube side of the diimp condensers and turbine condensers, and back to the river. Flow control is exercised primarily through the number of circulating raw water pumps online however, trimming adjustments are possible at each of the condensers. Since the drives for these pumps do not Incorporate speed control, fluctuations in river level will also effect the flow rates in this loop. 

Circulating Raw Water System Operation During Reactor Outages Operation of the circulating raw water system will be required... 

Primary pump drive pony motors will normally not be used during an outage however, some units may be placed on electric drives to conserve steam Automatic actuation will normally be effective if the loop la on recirculation since drive unit speeds will be in excess of 900 rpm Shortly after a nuclear shutdown residual heat generation rates will be low and the emergency raw water system may be bypassed and moved from service to minimise the chance of raw water Introduction Into the primary system. Manual actuation will provide backup If normal cooling la lost and fuel overheating la approached. 

Waste from steam systems. If steam is used as a hot utility, then inefficiencies in the steam system itself cause utility waste. Figure 10.9 shows a schematic representation of a steam system. Raw water from a river or other source is fed to the steam system. This is... 

A fourth mechanism is called sweep flocculation. It is used primarily in very low soflds systems such as raw water clarification. Addition of an inorganic salt produces a metal hydroxide precipitate which entrains fine particles of other suspended soflds as it settles. A variation of this mechanism is sometimes employed for suspensions that do not respond to polymeric flocculants. A soHd material such as clay is deUberately added to the suspension and then flocculated with a high molecular weight polymer. The original suspended matter is entrained in the clay floes formed by the bridging mechanism and is removed with the clay. 

The defoamer formulations mentioned so far consist of fairly inexpensive raw materials, but several more cosdy defoaming materials have come into use in paper mills. Hydrophobicized siUca particles are useful in some emulsion formulations. SiUcone solutions and emulsions are very effective in eliminating foam in paper machine water systems. The siUca- or siUcone-based defoamers have higher activity, which somewhat compensates for the higher cost, but care must be taken to prevent ovemse. 

Alkalinity Reduction. Treatment by lime precipitation reduces alkalinity. However, if the raw water alkalinity exceeds the total hardness, sodium bicarbonate alkalinity is present. In such cases, it is usually necessary to reduce treated water alkalinity in order to reduce condensate system corrosion or permit increased cycles of concentration. 

High sodium, raw water, existing 2-bed system, low leakage required... 

The RO system removes 90-95 % of the dissolved solids in the raw water, together with suspended matter (including colloidal and organic materials). The exact percent of product purity, product recovery and reject water depends on the amount of dissolved solids in the feedwater and the temperature at which the system operates. 

At present, chlorine dioxide is primarily used as a bleaching chemical in the pulp and paper industry. It is also used in large amounts by the textile industry, as well as for the aching of flour, fats, oils, and waxes. In treating drinking water, chlorine dioxide is used in this country for taste and odor control, decolorization, disinfection, provision of residual disinfectant in water distribution systems, and oxidation of iron, manganese, and organics. The principal use of chlorine dioxide in the United States is for the removal of taste and odor caused by phenolic compounds in raw water supplies. 

Improved service water reliability by elimination of rubber expansion joints in the recirculated cooling water system and minimization of their use in the raw service water systems... 

Piping system Main steam Process steam Feedwater Raw water Treated water Potable water Aux. cooling system Firefighting system Clarified water Filtered water Water-intake system Circulating-water system Chemical dosing Station drains Fuel oil Fuel gas... 

Fan-cooled radiators (as seen in Figure 15.29) or the system shown in Figure 15.30 are typical. As an alternative to the cooling tower, when a good source of raw water is available (such as from a river) this can be used on one side of the heat exchanger. 

Raw water MU may be used, although in areas where the hardness exceeds 200 mg/1 as CaC03 and MU exceeds 1% of system capacity per week, a supplementary dispersant should be used. 

Chen et al. [24] provide a good review of Al techniques used for modeling environmental systems. Pongracz et al. [25] presents the application of a fuzzy-rule based modeling technique to predict regional drought. Artificial neural networks model have been applied for mountainous water-resources management in Cyprus [26] and to forecast raw-water quality parameters for the North Saskatchewan River [27]. 

The microbial ecology of water is of great importance in the pharmaceutical industry due to its multiple uses as a constituent of maity products as well as for various washing and cooling processes. Two main aspects are involved the quality of the raw water and any processing it receives and the distribution system. Both should be taken into consideration when reviewing the hazaids to the finished product and aity critical control points. 

Krofta, M., Wang, L.K., Barns, D., and Janas, J., Treatment of Pittsfield Raw Water for Drinking Water Production by Innovative Process Systems, U.S. Department of Commerce, National Technical Information Service, Springfield, VA, Report No. P1382118795, 87pp., February 1981. 

Figure 23.2 shows a schematic representation of a boiler feedwater treatment system. Raw water from a reservoir, river, lake, borehole or a seawater desalination plant is fed to the steam system. However, it needs to be treated before it can be used for steam generation. The treatment required depends both on the quality of the raw water and the requirements of the utility system. The principal problems with raw water are1,2 ... 

---