Dose Evaluation of Neutron within Containment Building of a CE type Nuclear Power Plant

CE형 원전의 격납건물내 중성자선량 평가

From measured results of the neutron fields at some principal places within the containment building in a CE type nuclear power plant in operation, the radiation exposure of a worker to the neutron at there was evaluated and the equivalent dose reflecting new recommendation (ICRP 60) was compared with that doing the old one (ICRP 26). The measured neutron field was also compared with calibration neutron field. From the analysis, the following conclusion was obtained: the average neutron radiation weighting factor according to new recommendation is 2.41 to 2.71 times higher than the old one. The average neutorn radiation weighting factor at the measured place was similar to that at calibration neutron field. The average neutron energy at measured place was between 42 and 158 keV and higher than that of calibration field of 500 keV. So, the measured equivalent dose in nuclear power plant could be overestimated compared to the real equivalent dose.

CE형 원자력발전소를 대상으로 운전중 격납건물내 주요지점의 중성자장을 측정하여 작업자가 받을 수 있는 예상 방사선 피폭선량 등을 평가하고, 국제방사선방호위원회의 구권고(ICRP-26) 및 신권고(ICRP-60)에 따른 방사선 피폭선량 비교 및 교정 중성자장과 실제 중성자장의 방사선가중치 등을 분석해보았다. 분석결과 신권고에 따른 중성자가중치는 구권고에 의한 값보다 $2.42\~2.71$ 배 높은 것으로 나타났으며 , 측정지점의 중성자 방사선가중치 평균은 교정 중성자장의 평균과 비슷하였다. 중성자 평균에너지는 $42~158 keV$로 교정 중성자장의 평균에너지 500 keV보다 낮아 이럴 경우 각 측정지점에 대한 측정값은 실제 등가선량보다 보수적으로 평가될 수 있음을 알 수 있었다