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:
nduct surveys of levels of radiation or concentrations of radioactive material as necessary for compliance with AEC regulations in 10 CFR Part 20. Paragraph 20.1(c) of 10 CFR Part 20 states that every reasonable effort should be made by AEC licensees to maintain radiation exposures, and releases of radioactive materials in effluents to unrestricted areas, as far below the limits specified in Part 20 as practicable; i.e., as low as is practicably achievable, taking into account the state of technology and the economics of improvements in relation to benefits to the public health and safety and in relation to the utilization of atomic energy in the public interest. This guide describes radioanalytical procedures acceptable to the Regulatory staff for implementing these requirements with respect to the determination of Sr-89 and Sr-90 in the environment. B. DISCUSSION Radioisotopes of strontium, principally Sr-90 and Sr-89, are fission products, of concern because they are chemically similar to calcium and deposit in bone. The literature lists a large number of procedures for conducting Sr-90 and Sr-89 analyses, and a wide range of analytical sensitivities may be obtained depending on the procedure used; no single procedure, however, is applicable to all situations. This guide is intended to provide a selection of radioanalytical procedures which have the required performance standards of sensitivity and accuracy for the determination of Sr-89 and Sr-90 in various media. The levels of Sr-90 and Sr-89 in environmental media are normally quite low, Sr-89 being measurable only for relatively short periods after its release to the environment. Large sample sizes and low-background beta counters are usually required in analyzing for Sr-90 and Sr-89. Although procedures have been developed for analyzing a medium such as milk without prior ashing or concentration of the sample, most methods for analyzing biological and environmental samples require some degree of sample