Coolant sampling system

Reactor coolant pump seal water injection system Steam generator blowdown system Sampling system... 

Generic Safety Issue (GSI) II.B.3 in NUREG-0933 (Reference 1), addresses the TMI requirements of 10 CFR 50.34(f) and guidance identified in NUREG-0737 (References 2 and 3, respectively). Basically, plants must install a post-accident sampling system to sample reactor coolant and containment atmosphere. 

The reactor coolant and containment atmosphere sampling systems used for post-accident sampling conditions shall permit sampling of the reactor coolant and containment atmosphere without personnel exceeding their individual dose limits. The systems shall permit analyses for radioactive noble gases, iodine, cesium and nonvolatile isotopes, and also boron and chlorides. 

Primary coolant samples for analysis can be taken at various locations by means of the nuclear sampling system. Downstream of the sample line coolers, the liquid is depressurized and transported over the lines to the sampling points the most important one of these sampling stations is located in the chemical laboratory. This provides convenient access, but it results in a considerable length of the line from the primary circuit to the sampling station. 

Figure 4.22. Flow scheme of a sampling system for both high-temperature and ambient-temperature sampling of coolant (Roesmer, 1985)...

The sample is positioned in a temperature-control chamber which contains a radiant heater and a coolant distribution system. The radiant heater provides precise and accurate control of sample temperature. The coolant distribution system uses cold nitrogen gas for smooth, controlled sub-ambient operation and for quench cooling at the start or end of a run. Both the radiant heater and the coolant accessory are controlled automatically by the 983 system to ensure reproducible temperature programming. An adjustable thermocouple, mounted close to the sample, provides precise feedback information to the temperature controller, as well as a readout of sample temperature. 

During plant operation, the purification and aftercooling system is activated depending on the results of coolant sampling in the primary circuit. The system is deactivated after coolant quality recovery. Sampling of the primary circuit coolant is carried out quarterly. 

Back-up batteries and battery charging equipment Condensate chemical dosing equipment Various tanks for storing chemicals Component cooling water pumps and heat exchangers Power supply for each reactor coolant piunp s variable-speed drive Secondary sampling system Annex Building... 

The reactor coolant system interfaces with a number of auxiliary systems, principally the ehemical and volume control system, the normal residual heat removal system, the steam generators, the primary sampling system, the liquid radwaste system and the eomponent cooling water system. 

Borated reactor-grade waste water collected from the reactor coolant system effluents received through the chemical and volume control system, the primary sampling system sink drains and equipment leak offs and drains. 

The primary sampling system is a manually operated system. It eolleets representative samples of fluids Ifom the reactor coolant system and various primary auxiliary system process streams for analysis by the plant operating staff. This sampling process is performed during normal plant operations. 

The primary sampling system must maintain the integrity of the primary coolant botmdary. 

The primary sampling system must be able to provide a representative sample of the primary coolant, whilst minimising operator doses to levels that are ALARP. 

The primary sampling system collects representative samples of primary coolant..During normal operation, the primary sampling system collects representative samples of fluids in the following reactor coolant system and auxiliary primary systems process streams ... 

Because the motive force during normal operations is the system pressure, the sampling system is designed to reactor coolant system pressure. If system pressure is not available, an eductor supplies the motive force for sample collection. 

Primary sampling system liquid sample radiation monitor. The monitor s primary function is to indicate elevated reactor coolant sample radiation levels following a design basis event or severe accident. It may also be used to provide early indication of a possible fuel cladding breach. The monitor isolates the sample flow and initiates an alarm in the main control room and locally. 

HR-ICP-MS EEEMENT-2 (Pinnigan MAT, Germany) equipped with a standard introduction system (quartz water-cooled spray chamber, concentric nebulizer, torch with 1.5 mm i.d. injector and nickel cones) was used for measurements. The following operating conditions were used RP power 1150 W, coolant gas flow rate 16 1 min k auxiliary gas flow rate 0.85 1 min nebulizer gas flow rate 1.2 1 min k Sample uptake rate was 0.8-1 ml min k Measurements were performed with low and middle resolutions. Rh was used as an internal standard. Por calibration working standard solutions were prepared by diluting the multielemental stock solutions CPMS (SPEX, USA) with water to concentration range from 5 ng to 5 p.g I k... 

Coolant systems are an integral part of container formation and serve to cool the molds and, if applicable, the parison clamp assembly. Coolant, although not in direct contact with product pathways, is in close proximity to the containers, and maintenance should be carried out to prevent leakage. Coolant systems are prone to microbiological contamination and should be routinely treated to keep the bioburden imder eontrol. They should be regularly sampled and tested for bioburden to ensure continuous compliance to a predefined specification. 

Many types of vacuum adsorption apparatus have been developed and no doubt every laboratory where serious adsorption measurements are made has equipment with certain unique features. The number of variations are limited only by the need and ingenuity of the users. However, all vacuum adsorption systems have certain essential features, including a vacuum pump, two gas supplies, a sample container, a calibrated volume, manometer and a coolant. 

As shown previously (Section 14.7), thermal transpiration or thermomole-cular flow arises when gas is contained in two vessels at equal pressures but different temperatures and a connection is made between the vessels. A vacuum microbalance represents just such a system. The long tube surrounding the hang-down wire separates the sample, immersed in the coolant bath from the warm upper portion of the apparatus. With vacuum microbalances the effects of thermal transpiration are further exacerbated by the temperature gradient along the hang-down wire. 

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