BS IEC 60951-2:2009

What is BS IEC 60951-2 - Radioactivity monitoring equipment in nuclear power plants about? 

BS IEC 60951 is an international standard that discusses instrumentation important to safety of nuclear power plants. The main purpose of the IEC 60951 series is to provide guidance on post-accident radiation monitors, to maintain safety and integrity of nuclear power plants. 

BS IEC 60951-2 is the second part of the BS IEC 60951 series that provides general guidance on the design principles and performance criteria for equipment for continuous off-line monitoring of radioactivity in gaseous effluents and ventilation air used in nuclear power plants for accident and post-accident conditions. 

General requirements for technical characteristics, test procedures, radiation characteristics, electrical, mechanical, and environmental characteristics are given in BS IEC 60951-1. These requirements are applicable in this part unless otherwise stated. 

BS IEC 60951-2 is applicable to: 

• Noble gas activity monitors intended to measure the volumetric activity of radioactive noble gases in gaseous effluents at the discharge point and the variation of volumetric activity with time during the accident and post-accident conditions. The monitor may also be used the determination of the total discharge of noble gas activity over a given period 
• Noble gas, aerosol, and specific nuclide (commonly iodine, in its different forms: inorganic iodine, organic iodine, and iodine sticking on dust) monitors intended to measure the volumetric activity in air or gas systems (control room ventilation, reactor leakage collection, drywell ventilation exhaust, fuel handling building ventilation exhaust, reactor building ventilation purge exhaust) and detect any significant increase of radioactivity during or after an accident 

BS IEC 60951-2 is only applicable to continuous off-line measurement, i.e. monitors whose detector measures a representative proportion of the main effluent or ventilation stream at some remote location (sampling assembly). It does not apply to monitors with the detector positioned in or adjacent to the effluent or ventilation stream, which are within the scope of 

BS IEC 60951-4. 

Who is BS IEC 60951-2 - Radioactivity monitoring equipment in nuclear power plants for? 

BS IEC 60951-2 on radiation monitoring equipment for nuclear power plants is useful for: 

• Nuclear power stations 
• Atomic energy agencies 
• Atomic research organizations 
• Nuclear power plants electrical systems and equipment manufacturers 
• Operators of NPP, systems evaluators, and licensors 
• Nuclear safety authorities 
• Regulatory authorities 

Why should you use BS IEC 60951-2 - Radioactivity monitoring equipment in nuclear power plants ? 

BS IEC 60951-2 specifically focuses on radiation monitoring systems used for accident and post-accident operations. It is intended for use by purchasers in developing specifications for their plant specific radiation monitoring systems and by manufacturers to identify needed product characteristics when developing systems for accident monitoring conditions. Some specific instrument characteristics such as measurement range, required energy response, and ambient environment requirements will depend upon the specific application. 

BS IEC 60951-2 provides you with the design principles for the equipment, compliance to which can ensure the efficient provision of the measure of activity discharged to the environment or detection and quantification of leakage in containment barriers, and any useful information on the behaviour of the plant, which causes or allows the activity release. 

Guidance on functional testing is also covered in BS IEC 60951-2. 

Overall, adopting BS IEC 60951-2 can ensure monitors are capable of detecting and measuring gaseous effluent radioactivity, to keep plant operators aware of current radiological conditions, for control purposes and/or initiation of protective actions.