关键词: 核素, 半衰期, GB 18871—2002, 同质异能素

Abstract: The "Basic Standards for Protection against Ionizing Radiation and Safety of Radiation Sources" (GB 18871—2002) plays a guiding role in China′s radiation protection and safety efforts. Addressing the updates in nuclear physics data over the more than twenty years since the standard′s implementation, as well as the rigor of certain expressions within the standard text, this paper conducts a systematic theoretical review and data comparison. First, the expression of "two half-lives" for a single radionuclide in the standard is discussed in conjunction with the decay mechanisms and classification logic of isomers, clarifying the relationship between radionuclide definition and half-life. Second, based on the latest authoritative nuclear databases, a comprehensive verification of the radionuclide half-life data in Appendix B of the standard was performed. The study found that with the improvement of measurement precision, the recommended half-life values for certain radionuclides have changed significantly. Notably, the latest half-life data for long-lived radionuclides such as ⁶⁰Fe and ⁷⁹Se show deviations of orders of magnitude compared to the current values in the standard. Based on these analyses, this paper proposes revision suggestions for relevant expressions and a list of half-life data urgently needing updates in GB 18871—2002, aiming to further enhance the scientific rigor and currency of the standard.

Key words: nuclide, half-life, GB 18871—2002, isomer