Determination of neutron spectra in a MOX plant for the qualification of the BD-PND bubble detector.

Abstract

As a result of the introduction of the ICRP 60 recommendations and the increasing contribution of the neutron dose to the total dose of the personnel at the Belgonucleaire Mox fuel fabrication plant, the BD-PND bubble detector manufactured by Bubble Technology industries was introduced as a new, reliable personal neutron dosimeter. In the framework of the evaluation program of the bubble detector, measurements and calculations of the neutron spectra in the installations of the fuel fabrication plant were performed. The measurements were carried out with a ROSPEC neutron spectrometer, and the calculations were performed by means of the Monte Carlo code MCNP 4A. Comparison between measurements and calculations revealed good agreement. On the basis of the obtained neutron spectra, a correction factor was determined to take into account the new ICRP 60 recommendations and the difference between the calibration spectrum of the bubble detectors and the observed neutron spectra at the plant. This correction factor was applied to the calibration factor provided by Bubble Technology Industries.