Radionuclide in Soil Reference Materials

Consequence management of a radiological incident requires rapid information about the nuclides, amount, dispersion, and speciation for the determination of sheltering-in-place, evacuation, food safety, population safety/monitoring, access to commerce/critical infrastructure.

Consequence management measurements of nuclides dispersed by radiological incidences need to be of the highest certainty because life saving, commerce restoration, and access to critical infrastructure decisions are based on them.  The sheer volumes of radionuclide measurements that will need to be done in a very short period of time (hundreds of thousands over a few months) require rapid analytical methods that do not require much human intervention (fatigue factor).  Additionally, field measurements have the advantage of being conducted at high need sites.  Evaluation and validation of semi-automatic field instrumentation by NIST reference materials will provide the confidence to depend on its capability when needed.

The U.S. Air Force evaluated the efficacy of using a semi-automatic radiochemical separation instrument (ARS-IIe) in the field for rapid intelligence gathering from radiological incidents.  The capabilities of the ARS-IIe needed to be evaluated and validated prior to field use, and NIST collaborated in the effort by developing the radionuclide in soil reference materials for instrument testing.  The soils were spiked with NIST SRMs (e.g., ⁹⁰Sr, ²³⁹Pu, ^natU, ²⁴¹Am, ²³⁰Th), and the spiking process was verified by gamma-ray tracing.  These soil reference materials were spiked with yield tracers and carriers, fused with lithium metaborate, dissolved, the radionuclides separated by the ARS-IIe, and the purified nuclide fractions were counted and compared with the NIST certified values.  The operational protocol for the ARS-IIe was optimized for accuracy, speed, and operational efficiency and readied for field use for the U.S. Air Force.