RADIATION AND CONTAMINATION MONITORING UNDER ACCIDENT CONDITIONS

RADIATION AND CONTAMINATION MONITORING UNDER ACCIDENT CONDITIONS 

Means should be provided so that the operator is aware of the performance of the radiation monitoring systems under the environmental conditions that occur as a result of an accident. The most onerous design requirements are associated with the radiation measurement systems that are within or close to the reactor containment. The design of the systems for sampling and the direct measurement of activity in gaseous effluents is also complex. 

The operability of measurement systems should be maintained under specified environmental conditions following accidents. The operational ranges of temperature, pressure, humidity, vibration and ambient radiation fields at least should be specified. 

For design basis accidents, the emergency power supply to the continuous radiation monitoring systems should comply with the single failure criterion. 

The radiation measurement data under accident conditions should be available in the main control room and in those locations, such as the emergency control room, where personnel would be implementing measures to manage the accident. Suitable communications systems should be provided to enable information and instructions to be transmitted between different locations and to provide external communication with such other organizations as may be required. Provision should be made for the direct transfer of relevant data to the emergency response centre. 

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