Description and modelling of a standard low level environmental radionuclide calibration facility

The objective of this paper is the development of a much needed facility to calibrate environmental radiation field measuring devices. A well characterised standard low-level radiation field facility can provide the basis for instrument calibrations and dispute resolution. The experimental facility which was installed underground in a large low radiation scatter room, will be described. The facility was approached using multidimensional Monte Carlo program (MCNP-Monte Carlo N-Particle code) which models the detector/source to estimate detector efficiencies. This work is the outcome of the close cooperation between the Ionizing Radiation Division of NIST, USA and Nuclear Engineering Laboratory of Democritus University of Thrace, Greece.