Gamma Monitor

The Gamma Monitor System detects fuel element ruptures by continuously monitoring effluent water from each rear cross-header. A gamma sensitive Ion chamber la revolved past the respective continuous streams and measures the magnitude of the gamma emission. Vlstial fluid audible Alarms eumunclate if the trip points are exceeded. radiation profile of the crossheaders Is plotted on multipoint recorders. 

The totflJ. power level of the reactor is computed using toteil flow to the reflkctor from the 190 Building fluid the bulk outlet fluid Inlet temperatures, me total power level is recorded on a clrculflur chflurt fluid ]power deviation is recorded from a preset power level value. 

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Hence it was the Commission s view that a complete verification mission required access for verification purposes to the atolls of Mururoa and Fangataufa. Access was granted to Mururoa but the French authorities held the view that this invitation was solely for the purposes of information, not of verification. Access was denied to Fangataufa for reasons of defence security . Access was also denied to military premises at Faaa (Tahiti Airport) in which facilities for aerosol sampling and gamma monitoring are installed. While the last-mentioned facilities are of less importance because they duplicate similar facilities nearby, the denial of verification access at... 

The requirement to access cells for maintenance purposes and to transfer full product containers to the vitrified product store offers the potential for >1-Sv doses to operators under fault conditions. In order to prevent such incidents, entries to cells are controlled via inner and outer shield doors that are interlocked to gamma monitors. Additionally Operating Rules and Instructions place requirements on operators with regard to man entries to cells and prohibit the presence or introduction of active product containers to specified cells. Personal Alarmed Dosimeters are routinely worn during cell entries to provide an immediate indication of high dose rates. 

In line with the philosophy of monitoring the effluent for fuel element ruptures, the 107 Basin Effluent Monitor should be operated from the battery source. Ihls could serve as an alternative to having the Gamma Monitors battery-opeirated of the load from the Gamma Monitor is too large for the capacity of an inverter and a battery. 

Area radiological control technicians monitor the fixed radiation monitor systems and use portable hand held gamma monitors to verify that safe conditions exist at key points in the process. ... 

The filtered water makeup systems The Disassembly Basin filtration system The MB cutting saw stops The hand-hdd gamma monitors The MB oiticality bars used in the fuel bundling process The HBBS rack spacers and fuel blocking system The shipping cask blanks and cadmium separator plates The installed gamma monitors on the machine basin equipment... 

Stationary, automatic gamma monitoring system Energy-compensated GM counters Automatic alarm possible R id overview over wide areas Could be complex and costly Rq>resentative siting is criti- Height above background is an important parameter Differences in calibration... 

Beta/gamma monitoring GM, proportional or scintillation counters Not radionuclide-specific ... 

Bq/m ) or equivalent Beta/gamma monitoring GM, proportional, or scintillation counters Immediate results Not radionuclide-specific tance from surface to monitor... 

Answer Neutron and gamma monitoring devices have an almost ins tantaneous... 

Airborne contamination. Monitoring should be carried out by means of continuous on-line measurement or by sampling and off-line analysis. Whenever there is a potential for a significant release of airborne contamination, monitors should be installed in the workplaces and/or the ventilation system. Sometimes area gamma monitors are used at locations of interest to warn of increasing airborne contamination. In this case, care should be taken to distinguish between dose rates from airborne contamination and those from other possible sources. 

Liquid contamination. Monitoring may be carried out by continuous online measurement or by sampling and off-line analysis. Gamma monitors located close to pipes carrying liquids that may possibly be contaminated may be used to monitor contamination levels if the influences of other sources are known and can be taken into account. 

Nuclear instrumentation in the HRE-2. The purpose of the nuclear instrumentation in homogeneous reactors is to provide neutron-level measurement and the gamma monitoring of auxiliary process lines and control areas for the detection of radioactive leaks (see Article 7-4.8). 

Ten Minute Line Monitor Cooling Water Gamma Monitor... 

The multiplication trip circuit contains two interlocks one is in the safety rod power circuit, the other is in the control rod power circuit. The latter is superfluous as a multiplication trip. It does, however, provide a convenient interlock to insure a full insertion of the control rods with a gamma monitor of personnel-monitor trip. Without this interlock, a slight interruption of the gamma or personnel-monitor circuits would drop the control rods a small amount. This could occur unnoticed by the operator. Without the control rod power reset button (shown in Fig. 1.12), it would be impossible to regain control rod power until the background level had dropped to startup level. 

A model CD-I 79 gamma monitor is mounted on the top of the reactor console. This instrument is a sensitive DC current-measuring device with a trip circuit which operates a relay when the current exceeds a preset level. An audible alarm is then given. The CD-179 receives its input from a nitrogen-filled ion chamber lC-34, which is placed near the reactor tank. 

This chamber has a sensitivity of 10 Amp per R /hr. The range of the gamma monitor is from 0.001 to 10 R/hr. The instrument is calibrated and tested by means of an internal calibration circuit, which is also used to set the trip level of the instrument. The normal trip level of the instrument is set in the range from 2 to 3 mR/hr. 

Radioprotection Occupational area gamma monitor high A... 

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