교육용 모사 HPGe 검출기 스펙트럼 개발

이모성,서경원 대한방사선방어학회 2007 방사선방어학회지 Vol.32 No.1

원통형 용기에 담긴 액체 혼합선원의 HPGe 검출기 교정용 스펙트럼으로부터 스펙트럼 분석 교육을 위한 모사 스펙트럼을 개발하였다. 모사 스펙트럼은 측정된 스펙트럼으로부터 피크를 분리한 후, 채널별 계수들의 변동이 제거된 스펙트럼을 결합한 것이다. 모사 스펙트럼의 통계적 변동은 Box-Muller 함수로 만들었다. 이 스펙트럼은 18개의 피크를 포함하고 있다. 각 피크의 중심 위치 및 면적 등은 정확하게 정의되었다. 개발된 스펙트럼은 교정용 스펙트럼, 시료 스펙트럼, 백그라운드 스펙트럼 그리고 기하학적 및 동시합성 보정을 위한 스펙트럼이다.

^(152)EU에서 동시합성 효과 보정 방정식의 유도

이모성 청주대학교 산업과학연구소 2007 産業科學硏究 Vol.24 No.2

In this study, we studied about a loss of a peak area by coincidence summing of gamma rays emitting in 152^(Eu). The loss of the peak area by the effect is related with each emission rate of the coincidence summing gamma rays as well as their peaks and total efficiencies. The emission rates can be derived from the decay scheme of the nuclide. Then we analyzed the decay schemes of 152^(Eu), calculated the coincidence summing probability of gamma rays that are emulated from the nuclide, proposed the equations to correct the peak areas by the effect.

공기 중 방사능 측정을 위한 공기 채집시 라돈붕괴 생성물의 영향

이모성 청주대학교 2009 産業科學硏究 Vol.26 No.2

One of the main issues in monitoring of airborne radioactivity is a reliable subtraction of natural background and then a clear understanding of the impact of these details is essential. Sampling and detection of airborne particulates is a dynamical process and depends on the detailed characteristics of monitoring instruments. In radiation monitoring of our country, airborne particulate samples are collected by means of low-volume, constant-flow, air samplers, the samples are analyzed for gross alpha and gross beta concentrations after 5 hours to allow for decay of radon and thoron decay products. In this paper the gross alpha and beta activities in airborne particulates were calculated by solving Bateman equation and compared with measurement values.

고리원자력발전소 주변 환경 방사선 조사

이모성 청주대학교 산업과학연구소 2004 産業科學硏究 Vol.21 No.2

The gamma energy spectra using 3"×3" Nal detector around Kori nuclear power plant were measured, evaluated man-made radiation exposure by Energy Band Method and Total Energy Method. The Energy Band Method for Nal spectrum calculates only the exposure rate due to natural radiation but the Total Energy Method calculates the exposure rate due to man-made radiation. Then the exposure rate calculated by the Total Energy Method is apparently the exposure rate due to man-made radiation We found that the exposure rates calculated by those two methods are equal within the statistical variation of ±0 3μR·h^(-1) Consequently, no other man-made radiation was detected in this study.

NaI(Tl) 검출기 스펙트럼으로부터 조사 선량율의 계산

이모성 청주대학교 산업과학연구소 1997 産業科學硏究 Vol.15 No.2

Both total energy method and energy band method can used to calculate exposure rate directly from gamma ray spectrum with some parameters. In this study, the parameters were determined by using the relationship between the exposure rates and the gamma ray spectra obtained by 3" × 3" NaI(T1) detector at many different places. Exposure rates measured by ionization chamber were in good agreement with the calculated values within the error range of 10%. Also daily variation of the calculated exposure rate agrees with the reported daily variation of radon concentration in the air. With energy band method and the parameters, total exposure rate as well as individual exposure rates by (40)^K, (238)^U and (232)^Th series can be determined from environmental gamma ray spectrum without any information about the distribution of radionuclides in soil.

환경 방사선의 일변화

이모성 청주대학교 산업과학연구소 1999 産業科學硏究 Vol.17 No.1

In order to obtain data concerning the diurnal variation of environmental radiation, in situ spectrometry of a NaI(T1) detector, pressurized ion chamber measurement and continuous radon monitoring in free air have been carried out. On the whole, the exposure rates from ^(40)K and ^(232)Th series among environmental radiation were constant during a day, but the exposure rate from ^(238)U series varied as the sine function of time of the day. The maximum and the minimum exposure rate in the diurnal variation were appeared at about 7:00 and 6:00 PM respectively. The difference between the maximum and the minimum was about 0.1 μR/h. This pattern of the diurnal variation was identical with that of the radon concentration in free air.

NaI 스펙트럼으로부터 인공방사선 조사선량의 계산

이모성,Lee, M.S. 대한방사선방어학회 2001 방사선방어학회지 Vol.26 No.2

NaI 스펙트럼으로부터 조사선량을 계산하는 에너지대 방법은 $1300{\sim}3000keV$ 영역의 에너지 스펙트럼을 사용하여 조사선량을 계산하기 때문에 자연방사선만의 조사선량이 계산되어지지만, 총에너지 방법은 $150{\sim}3400keV$ 영역의 에너지 스펙트럼을 사용하기 때문에 인공방사선의 조사선량도 포함하여 계산한다. 따라서 총에너지 방법에 의한 조사선량과 에너지대 방법에 의한 조사선량의 차이는 인공방사선에 의한 조사선량이 될 것이다. 본 연구에서는 인공방사선이 없는 지역에서 단지 기상요인에 의해서 조사선량 변동이 심한 기간동안 NaI 검출기로 스펙트럼을 측정하였다. 이와 같이 측정한 스펙트럼에 대해서 두 방법으로 계산한 조사선량률들은 통계적 변동 ${\pm}0.3{\mu}R\;h^{-1}$ 이내에서 잘 일치하였다. 결과적으로 두 방법에 의해 계산된 조사선량값이 차이가 있다면 그것은 인공방사선에 의한 조사선량으로 해석할 수 있을 것이다. The energy band method for NaI spectrum calculates only the exposure rate due to natural radiation because it calculates exposure rate using energy spectrum of $1300{\sim}3000keV$. However, the total energy method includes in its calculation the exposure rate due to man-made radiation because it uses the energy spectrum of $150{\sim}3400keV$. Therefore, the resulting difference of extracting the exposure rate calculated by the energy band method from the exposure rate calculated by the total energy method is apparently the exposure rate due to man-made radiation. In this study, we measured the NaI spectrum during the period of significant changes of the exposure rate in the area without a man-made radiation. As the results, we found the exposure rates calculated by those two methods are equal within the statistical variation of ${\pm}0.3{\mu}R\;h^{-1}$. Consequently, if the difference between the exposure rates calculated by the two methods exists, it may be due to the man-made radiation exposure rate.

동해 방사성폐기물 투기영향 - 한$\cdot$러$\cdot$일 3국 공동조사 결과와 내용

이모성 한국원자력산업회의 1995 원자력산업 Vol.15 No.9

옛소련 및 러시아의 방사성폐기물 동해투기와 관련하여 당사국인 한국$\cdot$러시아$\cdot$일본 등 3국은 공동조사단을 구성하여, 지난해 3월 18일$\~$4월 16일까지 30일 동안 방사성폐기물 투기해역의 7개 정점에 대한 방사능오염도를 조사했다. 조사결과 투기해역의 해수$\cdot$해저퇴적물$\cdot$해양생물 중의 $^{137}Cs, ^{90}Sr, ^{239, 240}Pu$ 함량은 방사능낙진 정도의 수준으로 나타나 아직까지는 뚜렷한 방사능오염이 없는 것으로 밝혀졌다. 다음은 그 조사결과의 내용이다.

원자력 발전소 주변환경 방사선 조사 지침에 관한 연구

이모성 청주대학교 산업과학연구소 2000 産業科學硏究 Vol.18 No.1

As a result of adoption of 1990 Recommendations of the International Commission on Radiological Protection in atomic law, the radiation assessment standard was changed due to the permissible concentration determined from the exemption level, exposure limit, and etc. It affected the environmental investigation guide around nuclear power plant. The base limit for the radioactivity detection method in the guide is lower than the exemption level of radioactivity. Thus a new method for analysis of radioactivity is not nessary However, in the exposure assessment done from the environmental samples, changes in the dose conversion factor are needed.

환경 방사선의 강우에 의한 영향 연구

이모성 청주대학교 산업과학연구소 2001 産業科學硏究 Vol.19 No.1

By analyzing the spectra measured by NaI detector in rainy weather, variation characteristics of individual exposure rates due to ^(40)K, ^(238)U and ^(232)Th series were investigated The exposure rates by ^(40)K and ^(232)Th series were varied to about 02 μR/h due to cover of their radiations by water in sell Because of the wash out of radon daughters from the air to the ground surface by precipitation in rainy weather, the exposure rate of ^(238)U series was increased to about 2 μR/h