지원사업
학술연구/단체지원/교육 등 연구자 활동을 지속하도록 DBpia가 지원하고 있어요.
커뮤니티
연구자들이 자신의 연구와 전문성을 널리 알리고, 새로운 협력의 기회를 만들 수 있는 네트워킹 공간이에요.
이용수
초록· 키워드
오류제보하기
In ports and airports, radiation portal monitors (RPM) are deployed to detect illicitradioactive materials. Detected gamma rays in a RPM include background radiation and radiationfrom a freight. As a vehicle moves through the RPM, the vehicle causes the fluctuations in thenatural background radiation signal, which ranges of up to 30%. The fluctuation increases theuncertainty of detection signal and can be a cause of RPM false alarm. Therefore, it is importantto evaluate background radiation as well as radiation from a container. In this paper, a naturalbackground radiation model was developed to evaluate RPM. To develop natural backgroundradiation model, a Monte Carlo simulation was performed and compared with experimentalmeasurements from a RPM for 40K, 232Th series, and 235U series, which are major sources ofnatural background radiation. For a natural radiation source, we considered a cylindrical soilvolume with 300 m radius and 1 m depth, which was estimated as the maximum range affectingthe RPM by MCNP6 simulation. The volume source model was converted to surface source byusing MCNP SSW card for computational efficiency. The computational efficiency of the surfacesource model was improved to approximately 200 times better than that of the volume sourcemodel. The surface source model is composed of a hemisphere with 20 m radius in which the RPMand container are modelled. The natural radiation spectrum from the simulation was best fitted tothe experimental measurement when portions of 40K, 232Th series, and 235U series were 0.75, 0.0636,and 0.0552 Bq·g-1, respectively. For gross counting results, the difference between simulation andexperiment was around 5%. The background radiation model was used to evaluate backgroundsuppression from a 40 ft container with 7.2 m·s-1 speed. In further study, background modelsand freight models for RPM in real container ports will be developed and applied to optimize theoperating system of port security.
목차
등록된 정보가 없습니다.
참고문헌 (16)
참고문헌 신청
김정훈 / 2009 / 한국토양 내 천연 방사성핵종에 의한 거주민의 방사선피폭평가 / 방사선기술과학 32(2):219~224
이병수 / 2013 / 공항만 방사선감시기 설치운영 효율화 방안 연구
Burr T / 2008 / Signatures for several types of naturally occurring radioactive materials / Appl. Radiat. Isotopes 66:1250~1261
Burr T / 2009 / Effects of background suppression of gamma counts on signal estimation / Appl. Radiat. Isotopes 67:1729~1737
Burr T / 2007 / Alarm criteria in radiation portal monitoring / Appl. Radiat. Isotopes 65:569~580
이병수 / 2013 / 공항만 방사선감시기 설치운영 효율화 방안 연구
Burr T / 2008 / Signatures for several types of naturally occurring radioactive materials / Appl. Radiat. Isotopes 66:1250~1261
Burr T / 2009 / Effects of background suppression of gamma counts on signal estimation / Appl. Radiat. Isotopes 67:1729~1737
Burr T / 2007 / Alarm criteria in radiation portal monitoring / Appl. Radiat. Isotopes 65:569~580
이 논문의 저자 정보
최근 본 자료
댓글(0)
0