NFA-01.03: Multichannel Radiation Monitor

Ionizing nuclear radiations (alpha, beta, gamma and neutron) cannot be detected by human senses, but it can cause biological damage both from genetic and somatic point of view, so radiation monitoring system has to be applied in nuclear practice. The most important function of the radiation monitoring systems is to provide direct information about the radiological environment of the reactor or other nuclear facility. For this purpose fixed and portable (measuring) instruments are used to determine radiation level where personnel may be working.

Area monitoring systems detect and measure ambient gamma or X-ray radiation. The NFA-01.03 Multichannel Radiation Monitor achieves this in and around nuclear reactors, accelerators, hot cells, irradiators and other facilities where radiation-emitting materials are handled or processed. Typically, an area monitoring system will utilize a detector in any location where personnel might possibly be exposed to an adverse amount of radiation. For reactor facilities, these areas consist of the following: inside and outside the containment, fuel storage and handling areas, reactor beam ports, hold-up tanks, coolant loops, normal working areas such as labs, hallways and control rooms.

Monitoring of pulsed beams and residual radiation is required around accelerator and irradiator facilities, which means that the detector must respond properly to both pulsed, and steady state radiation.

Radiochemistry labs should have at least one detector in each room of normal size and several strategically located in larger open areas. The read-out console itself including the alarm set controls should be located in areas under supervisory control. In addition to issuing a warning of increasing and high radiation levels, the alarm trips can be used to actuate interlock devices or other safety features.


  • Highly reliable detection of criticality incidents
  • Low maintenance and high availability
  • Very low spurious alarm rate
  • Modular system can be configured for large or small facilities
  • Simple gamma detectors allow cost effective wide area coverage
  • Meets the European and USA standards for criticality detection
  • Seismic tested and proven rugged
  • Individual power supplies allow independent operation of every channel
  • Eight decade display plus choice of any three consecutive decades from 0.1 to 10' mR/hr
  • Completely interchangeable detectors
  • Fixed fast response on all ranges