Overestimation of Radioactivity Concentration of Difficult-To-Measure Radionuclides in Scaling Factor Methodology

• 발행기관: 한국방사성폐기물학회
• 저자명: Junghwan Park Tae-Hyeong Kim Jeongmook Lee Junhyuck Kim Jong-Yun Kim Sang Ho Lim
• 간행물 정보: 『Journal of Nuclear Fuel Cycle and Waste Technology (JNFCWT)』Vol.19 No.3, 367~386쪽, 전체 20쪽
• 주제분류: 공학 > 공학일반
• 파일형태: PDF
• 발행일자: 2021.09.30

국문 초록

The overestimation and underestimation of the radioactivity concentration of difficult-to-measure radionuclides can occur during the implementation of the scaling factor (SF) method because of the uncertainties associated with sampling, radiochemical analysis, and application of SFs. Strict regulations ensure that the SF method as an indirect method does not underestimate the radioactivity of nuclear wastes; however, there are no clear regulatory guidelines regarding the overestimation. This has been leading to the misuse of the SF methodology by stakeholders such as waste disposal licensees and regulatory bodies. Previous studies have reported instances of overestimation in statistical implementation of the SF methodology. The analysis of the two most popular linear models of the SF methodology showed that severe overestimation may occur and radioactivity concentration data must be dealt with care. Since one major source of overestimation is the use of minimum detectable activity (MDA) values as true activity values, a comparative study of instrumental techniques that could reduce the MDAs was also conducted. Thermal ionization mass spectrometry was recommended as a suitable candidate for the trace level analysis of long-lived beta-emitters such as iodine-129. Additionally, the current status of the United States and Korea was reviewed from the perspective of overestimation.

키워드

Scaling factor Overestimation Radioactivity concentration Minimum detectable activity