NEEDS AND PERFORMANCE REQUIREMENTS FOR NEUTRON MONITORING IN THE NUCLEAR-POWER INDUSTRY

Neutrons do not contribute greatly to the collective occupational dose at Ontario Hydro's nuclear generating stations. Nonetheless, there is a need to monitor workers' exposure to neutrons in some locations. At present, neutron area surveys and personal dosimetry are both perform ed using integrating rem meters (of the Andersson-Braun design), which workers take with them when they will be working in an area where neu trons are known to be present This is not a satisfactory method for ne utron monitoring or dosimetry, both because of the inconvenience of ca rrying around a large, heavy instrument, and because rem meters are kn own to be inaccurate in many situations. There is a further problem as sociated with the calibration of the rem meters, which is done in a fa st neutron field quite unlike the neutron fields found in nuclear gene rating stations. However, rem meters continue to be used, owing to the lack of suitable alternatives and also to the low priority neutron do simetry has traditionally received in the company. The properties of a n ideal neutron dosemeter and of an ideal survey meter for use in nucl ear generating stations are described. These properties are compared w ith those of currently available dosemeters and instruments, and it is shown where changes and improvements are needed. The need for a calib ration field that is more representative of the energy spectra to be m easured in practice is also discussed.