Abstract: In this paper, we present an approach for on-site calibration of stationary neutron dose instruments, which enables us not necessary to disassemble the probe and to accomplish the calibration of the neutron probe in the state of online monitoring.

The on-site calibration system of stationary neutron dose instrument is mainly comprised of a small controllable neutron source and a reference neutron dose instrument. According to the principle of “relative calibration method”, a small controllable neutron source continuously emits neutrons at the calibration site to construct a neutron radiation field. The calibration factor (*N~B~*) can be obtained by comparing the response numbers from two instrument, the instrument to be calibrated and the reference instrument, which are symmetrically placed in the neutron radiation field. In order to complete the transmission of the ambient dose equivalent calibration coefficients of the reference instrument from National Metrology Center (^252^Cf Standard radiation field) to nuclear facility site, the calibration coefficient needs to be modified, that is, multiplied by the "energy correction factor". Energy response correction factor includes: (1) “Instrument Energy Response Correction Factor” *k~ε~* for instrument neutron counting to neutron fluence, (2) "Conversion Correction Factor" *k~Φ~* for neutron fluence to neutron ambient dose equivalent.

Tests have shown that the ambient dose equivalent rate error without energy correction is 17.2%, the ambient dose equivalent rate error for energy correction is 2.3%. It can be seen that the necessity of energy correction during the on-site calibration process of the ambient dose equivalent rate measuring instrument around the neutron.

Key words: Neutron dose; Energy correction; Radiation measurement; on site calibration


Study on On-Site Calibration Method of Stationary Neutron Dosimeter

Division / Sponsors: 
Power Division & Nuclear Engineering Division (NED)

Power Conference
Paper Proceedings: https://asmedigitalcollection.asme.org/POWER/POWER2020/volume/83747

International Conference on Nuclear Engineering
Paper Proceedings: https://asmedigitalcollection.asme.org/ICONE/ICONE2020/volume/83761

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