Primary purification system

The design and the operation of the primary purification system shall be described in detail, including the procedures for resin exchange and the shielding used to protect persons during this operation. This may be described in this section, or reference may be made to Chapter A. 10 (Auxiliary Systems). 

The design and performance characteristics of the main components (pumps, valves, filters, resins, piping) should be tabulated. A flow and instrumentation diagram should be included, as well as drawings of the main components. The materials of which the components are made should be specified. The means for monitoring the performance and for renewing the system s ability to purify the coolant should be described. 

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A. 1005. All water systems of the facility that have not been described previously shall be discussed in this section. These may include the primary purification system, the service water system, the cooling system for reactor auxiliaries and the primary coolant make-up system. In each case, the information provided should include the design bases, a system description, flow and instrumentation diagrams, a safety evaluation, if required, testing and inspection requirements, and instrumentation requirements. 

Fig. 38. Caustic purification system a, 50% caustic feed tank b, 50% caustic feed pumps c, caustic feed preheater d, amonia feed pumps e, ammonia feed preheater f, extractor g, trim heater h, ammonia subcooler i, stripper condenser j, anhydrous ammonia storage tank k, primary flash tank 1, evaporator reboiler m, evaporator n, caustic product transfer pumps o, purified caustic product cooler p, purified caustic storage tank q, ammonia stripper r, purified caustic transfer pumps t, overheads condenser u, evaporator v, evaporator vacuum pump w, aqueous storage ammonia tank x, ammonia scmbber y, scmbber condenser 2, ammonia recirculating pump aa, ammonia recycle pump. CW stands for chilled water.

Commercial VPO of propane—butane mixtures was in operation at Celanese Chemical Co. plants in Texas and/or Canada from the 1940s to the 1970s. The principal primary products were acetaldehyde, formaldehyde, methanol, and acetone. The process was mn at low hydrocarbon conversion (3—10%) and a pressure in excess of 790 kPa (7.8 atm). These operations were discontinued because of various economic factors, mainly the energy-intensive purification system required to separate the complex product streams. 

The primary water specifications for a PWR are given in Table 1 (4). Rigid controls are appHed to the primary water makeup to minimise contaminant ingress into the system. In addition, a bypass stream of reactor coolant is processed continuously through a purification system to maintain primary coolant chemistry specifications. This system provides for removal of impurities plus fission and activated products from the primary coolant by a combination of filtration (qv) and ion exchange (qv). The bypass stream also is used both to reduce the primary coolant boron as fuel consumption progresses, and to control the Li concentrations. 

RCCS air ducts 26 - primary coolant purification system 27 - helium transportation and storage system ... 

Figure 2.6 schematically illustrates sections of a typical semiconductor ultrapure water (UPW) production process in a semiconductor plant. The water circuit consists of two main sections (1) makeup (or central) system and (2) polishing loop, which provides water at the point of use. There are multiple locations in such a water process where membrane degassing could be needed as shown in the figure. Reverse osmosis is mostly used in makeup line as the primary purification means in such processes. In the past, large and inflexible vacuum towers were frequently used after RO to remove dissolved gases, such as O2, N2, and CO2. Membrane contactors are the norm today for replacement or supplement to vacuum towers in makeup lines, as shown in Figure 2.6. 

All of the aforementioned HPLC purification systems employ detectors other than mass spectrometers as the selection criteria by which peaks are collected. With these systems, however, mass spectrometry is generally employed as a primary structural validation tool. More recently, systems have been described whereby a mass spectrometer has been added to preparative HPLC format to detect compounds of interest for collection. A recent review by Kassel [9] discusses the relative merits of employing MW-triggered versus UV-triggered fraction collection in various environments for the purification of combinatorial libraries. 

Possibilities of reducing the permeation streams are the formation of oxide layers (in-situ or pre-coated) or, as active measures, an improved design of the gas purification system or even die construction of an intermediate circuit between the primary and secondary circuit to serve as a sink for both hydrogen and tritium. 

Considerable radioactivity is induced in the sodium in the primary cooling circuit of a liquid metal cooled fast breeder reactor (LMFBR) Na(n,y) Na, Na(n,p) Ne, etc. Na has a IS h r, and emits energetic y s. The primary cooling loop must therefore be well shielded. Its activity is a nuisance only in case of repair work in the primary system, requiring considerable waiting time before the loop can be approached. The sodium dissolves many of the corrosion and fission products eventually released. To remove these the primary loop is provided with cold trap purification systems. 

Locations in the reactor system, in addition to the reactor pressure vessel, that are primary concerns for thermal shock include the pressurizer spray line and the purification system. 

Primary Sodium and Irradiated Fuel Storage Drum Sodium Purification Systems... 

The most serious leak occured in the primary sodium purification system pipeline on October 7, 1993. The volume of the spilled sodium was about 1000 litres but owing to sufficiently effective performanceof the leak suppression system the release of radioactivity outside the plantwas only 10 Ci. The increased exposure of the plant and public did not occur. 

Primary sodium purification system Electric heaters, radioactive aerosol monitoring Insufficient selfcompensation of pipelines 1000 kg... 

In order to make measurements of caesium-137 activity, special device containing graphite pellet was installed in the loop connected in parallel to the primary sodium purification system. Just after the event of January 21, 1987, some decrease of the system indications was observed. Further, indications of the system came back to the previous level, however, some feature in caesium behaviour was noticed. While in the period preceding described events the decrease of the system indications in case of the reactor shutdown and sodium temperature reduction down to 250°C was 30-40%, later this decrease became as large as 10-12 times. After full power of the reactor had been reached, sodium temperature being as high as 530-540T, indications of caesium activity measurement system returned to the rated level. 

Two types of FP traps have been installed in JOYO. One is a cesium trap installed in the primary coolant sodium purification system to capture cesium released from failed fuels. An open pore, foam-like glassy carbon that consists of thin struts of Reticulated Vitreous Carbon (RVC) is used as a material for collecting cesium. The capacity of this trap is designed to be 7.4E+12 Bq. The other trap is a Cover Gas Clean-up System (CGCS) to collect and store the noble fission gas released from failed fuels. Although it is planned that only one failed fuel pin will be in the core at any time, the CGCS is designed to handle the releases of up to twelve failed fuel pins. 

Cold filter-trap of the primary circuit purification system ... 

The system for sodium purification in the cold filter-traps is intended for purification of primary circuit sodium from oxides, hydrates, carbonates and other impurities. The sodium purification system comprises five cold filter-traps with connection to charge and discharge pipelines Purification system is connected to loops No 2 and 3 of primary circuit. The sodium purification scheme can be seen in Fig. 7. 

Sodium flows out of the pressure head leg of DU500 main (second or third loop) to the pressure header of primary circuit sodium purification system and then flows to operable cold filter-trap. Here sodium is purified from soluble impurities owing to its cooling to the impurity setting-out and trapping temperature. After purification sodium is returned to (second or third loop) to the pump suction pipeline. 

These can be retained by intact coating layers, then these are released from failed particles. Noble gases exist in the gas phase and can be removed by primary coolant purification system. Though some of them have condensable daughter FPs, this effect is not large at failure fraction of HTGR fuel. 

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