NEUTRONDETEKTOR

The detector system comprises longitudinal housings each contg. a number of detectors. The housings are made from a material having a low neutron-moderating ability and a low neutron capture cross-section (pref. Zr,Nb,Al,Mo,Ti,Cr or their alloys). The neutron detection are fixed at different levels in channels; whilst the neutron detector can be lowered and hoisted along the channel to record the neutron flux along the whole height of the reactor. The detector housing is dimensioned in such a manner that it nearly completely displaces the liq. moderator from the space between the nuclear fuel elements and the neutron detectors. Thus there is practically no neutron moderation in this space and the detectors monitor the neutron flux as it is in the vicinity of the nuclear fuel elements.