Excore power level detector assembly for neutron flux monitoring system

摘要

An excore neutron flux power level detector assembly includes a neutron flux detector subassembly (40) and a moderator subassembly (52) having the form of a dual-wall canister (54) of annular cross-section for receiving the detector subassembly (40) in coaxial and telescoping relationship therein and having moderator material (56), preferably high density polyethylene, in the annular space between the dual-walls thereof for converting epithermal neutrons in leakage flux from a nuclear reactor to thermal neutrons having a power level detectable by the flux detector subassembly. Insulating spacer elements affixed concentrically about and axially displaced along the surface of the cylindrical housing of the detector (40) provide lateral, structural support and spacing therebetween and electrical insulation of the detector subassembly (40) from the moderator subassembly.