Document: NRC Regulatory Guide
Document ID: 5f67f910-de21-4629-9b03-b5a9f09c3c66
Document Type: regulatory_guide
Title: 
Source: NRC Regulatory Guide Division 4
Source URL: https://www.nrc.gov/docs/ML0037/ML003739544.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-4.6
CFR Part: 
CFR Title: 

Content:
techniques should be used in making these measurements. Some of the better high precision radiochemical procedures for low-level Sr-90 assay depend on counting the Y-90 daughter activity, rather than Sr-90 itself or the combined Sr-90 - Y-90 activities. There are several advantages of the former technique. The 64-hour half-life of Y-90 makes it convenient for following radioactive decay as a check on isotopic purity, and the single-component activity minimizes ambiguities in its measurement. Strontium-89 determinations are made by difference, i.e., by taking the difference between total strontium counts and the counts due to Sr-90 alone. The Sr-89 and Sr-90 radioanalytical procedures described in HASL 300 1 and SWRHL-1 1 have been in routine use for many years at their respective laboratories and have been shown to provide consistently good results in terms of both sensitivity and accuracy. C. REGULATORY POSITION The analytical procedures for Sr-89 and Sr-90 described in HASL 3001 and in SWRHL-1 1 2 are acceptable to the Regulatory staff as bases for meeting the analytical performance standards needed to assess accurately the Sr-89 and Sr-90 levels in biological and environmental media. ' "HASL Procedures Manual." Copies may be obtained from Health and Safety Laboratory, U.S. Atomic Energy Commission, 376 Hudson St., New York, N.Y. 10014. ' "Southwestern Radiological Health Laboratory Handbook of Radiochemical Analytical Methods," March 1973. Copies may be obtained from EPA National Environmental Research Center, Las Vegas, P.O. Box 15027, Las Vegas, Nevada 89114. 4.6-2