글로벌 삼중수소 순환 모델을 이용한 삼중수소 환경 방사능 추정

Estimation of Tritium Concentration in the Environment based upon Global Tritium Cycling Model

  • 발행 : 2003.03.30

초록

원자력 발전소에 대한 주기적 안전성 평가에서는 발전소 주변 환경감시 프로그램 적절성의 확보를 요구한다. 이를 위하여 고리 원자력발전소 주변에 대하여 과거에 측정된 삼중수소의 환경방사능 자료를 분석하고, 새로이 시료를 채취하여 농도를 측정하였다. 분석결과 고리 원자력 발전소 주변에서의 삼중수소 농도가 국내 자연 환경 방사능 농도와 유사하였다 국내 삼중수소 환경방사능 변화를 모델링을 통하여 추정하였다. 이 모델링에서는 NCRP 62에서 권고한 7격실 글로벌 삼중수소 순환 모델 중 지구 전체에 대한 것과 북반구에 대한 것을 비교하였다. 이들 모델식에 대한 수치해는 AMBER 프로그램을 이용하여 구하였으며, 대기 중으로 방출되는 삼중수소의 선원항으로 4가지 경우를 고려하였다. 계산결과, 지표수의 삼중수소 농도가 해수나 지하수의 농도보다 놀게 나타났고, 우주선에 의한 삼중수소 발생이 가장 중요한 삼중수소 발생원 이었으며, 핵실험에 의해 발생된 삼중수소는 많이 감소하였다.

The periodic safety review of operational nuclear power plants requires that the plants should keep a well organized environmental monitoring program. The past records of environment monitoring data were analyzed. and the tritium concentrations of the samples in the surface and ground water around Kori site were measured. It was shown that the tritium concentrations around the Kori site were slightly higher than that of natural background. The change of background tritium concentration was estimated through a numerical modeling. Two different versions of 7 compartments model - the world and the northern hemisphere - defined in NCRP-62 were modeled for the global tritium cycling. The numerical solution of the model was obtained using a computer program, AMBER. The four cases of tritium source-terms into the atmosphere were considered. The results showed that the tritium concentration in the surface soil water was higher than that in sea water or surface stream water. Also, it was shown that the tritium produced by the interaction between cosmic rays and the gases were the major source of tritium, and the tritium produced by nuclear weapon test decreased considerably.

키워드

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