中性子個人被曝管理および中性子個人被曝線量計校正方法の現状と今後の課題

Abstract

The present situation of personnel neutron monitoring is summarized in the facilities where the neutron exposure really happens, such as reactor, accelerator and nuclear fuel handling facilities, and the actual calibration method using a phantom is described for personnel neutron dosimeters (film badge, albedo TLD, solid state track detector) of practical use in these facilities.The calibration method of neutron dosimeters is not standardized at present, and it is usually carried out using 252Cf and 241Am-Be neutron sources. Neither the energy spectra of these neutron sources are similar to those of actual neutron fields in the facilities nor are the energy responses of these neutron dosimeters coincident with the fluence-to-dose equivalent conversion factor defined by ICRP; it is thus difficult to evaluate the neutron dose equivalent from the measured data. Here, we refer to some typical neutron spectral fields and propose to use the moderating radioactive neutron source field, which has a similar spectrum to that of the actual field, for calibration of personnel neutron dosimeter.