Half-Life Measurement of ¹²⁶Sn
Isolated from
Hanford Nuclear Defense Waste

S. A. Catlow, G. L. Troyer, and D. R. Hansen

Fluor Hanford · gary_l_troyer@rl.gov

Long term risk assessment of residual and disposed nuclear fuel reprocessing waste requires good knowledge of component isotopes with long half lives. For example, the accuracy of the accepted ¹²⁶Sn half life is insufficient for desired risk assessments. From modeling and sampling, ¹²⁶Sn is known to exist in Hanford nuclear waste. Excess portions of waste characterization samples were used to isolate ¹²⁶Sn for measurement of its half life. Isolation was performed with ion exchange resins. The resulting ¹²⁶Sn was gamma assayed with a hyperpure germanium spectrometer for decay photon identification and activity values. An inductively coupled plasma mass spectrometer (ICP/MS) was used to measure the atom quantity of the isolated ¹²⁶Sn. The separation chemistry, observed gamma energies and calculated half life are presented.