Comprehensive review and critical evaluation of the half-life of tritium

Abstract

As part of the preparation and calibration of three new National Institute of Standards and Technology (NIST) tritiated-water radioactivity Standard Reference Materials (SRMs), we have performed a comprehensive review and critical evaluation of the half-life of tritium (hydrogen-3). Twenty three experimentally-determined values of the half-life of tritium, reported between 1936 and 2000, were found. Six of these values were updated by later values. Two values were limits. Two values were deemed to be outliers. The 13 remaining values were evaluated in several ways. The results are compared with the results of other recent evaluations and all are found to be in good agreement. Our final recommended value for the half-life of tritium is the average of the adopted values from the four most recent evaluations, (4500 ± 8) d, where 8 d corresponds to one standard uncertainty.

Isotopic composition of precipitation in Ljubljana (Slovenia)

“…Tritium decays by β-decay with a half-life of 12.32 years (LUCAS & UNTERWEGER, 2000). The atmospheric concentration of tritium prior to 1953 was about 3-5 TU.…”

Reconstruction and Optimization of Tritium Time Series in Precipitation of Beijing, China

“…Edmunds 2009;Bretzler et al 2011). Tritium is a radioactive isotope of hydrogen with a half-life of 12.32 yr (Lucas and Unterweger 2000) produced naturally in the upper atmosphere by cosmic rays (Kaufman and Libby 1954;Clark and Fritz 1997). However, most of the tritium found in the environment was introduced during nuclear testing in the atmosphere since the early 1960s (Michel 2005).…”

A Geochemical Approach to Determine Sources and Movement of Saline Groundwater in a Coastal Aquifer

“…Sr and 87 Sr/ 86 Sr analyses were done in the USGS Yucca Mountain Project Branch Strontium Isotope Laboratory (now located in the Crustal Geophysics and Geochemistry Science Center in Denver, Colorado). Sr samples were analyzed using methods described by Garbarino (1999) (Lucas and Unterweger 2000). Because of its short half-life, tritium is useful for identifying water that has been in the hydrologic cycle more or less than about 60 years (Clark and Fritz 1997).…”