Detection device UDPN-02 is intended is intended for monitoring of thermal neutron flux density in the channels of ionization chambers at reactor plant operation in the working range.
UDPN-02 ensures monitoring of density of thermal neutron flux within the range from 1.0·105 to 1.5·1010 cm-2·s-1 (neutr/(cm2·s)) at the dose rate of background gamma-radiation absorbed in the air at the place of detection unit location of not more than 1.0·104 Gy·h-1 (1.0·106 R·h-1) at nominal power of reactor plant (100 %).
UDPN-02 sensitivity for thermal neutrons is (1.0 ± 0.1) ·10-5 cm2 (pulses during 1 s at the flux density of 1 neutron via 1 cm2 during 1 s).
UDPN-02 sensitivity for background gamma-radiation at exposition dose rate up to 1.0·103 Gy·h-1 does not exceed 1.5·10-1 s-1/(Gy·h-1) (1.5·10-3 s-1/(R·h-1).
UDPN-02 consists of the following:
- Conversion unit BPH-02, implemented in the form of flat housing, inside of which the electromagnetic shield with electronic modules is located. BPH-02 is intended for conversion of current from BDPN-02 into succession of voltage pulses which frequency is proportional to neutron flux density.
- Detection unit BDPN-02, implemented in the form of casing (thin-wall cylinder made of stainless steel). BDPN-02 converts neutron radiation into current.
UDPN-02 is built-up on the basis of boron compensated ionization chamber KNK53M with thermo-radiation-stable cable with magnesia insulation KNM2S with direct input of BDPN-02 cable into BPH-02. Length of BDPN-02 cable is 14 meters.