3. Radioactive waste measurement

Radioactive Waste Measurement instruments use different technologies to quantify the radionuclide content or the mass of a radionuclide (or radionuclides) in waste.

ANTECH Radioactive Waste Measurement instruments cover a range of waste density and waste container sizes including small samples and small cans, drums of different sizes and large boxes and containers.

3.1 Gamma ray waste assay

Gamma ray waste assay systems include gross gamma based instruments to measure the total activity of low-density waste and gamma spectroscopy based instruments to measure specific radionuclide activity of medium density waste. Both types of instrument use density correction based on container weight. More sophisticated gamma spectroscopy segmented scanning instruments (including SGS and TGS) use gamma transmission sources for density correction and can measure more heterogeneous and higher density waste containers.

3.2 Neutron waste assay

Neutron waste assay systems measure the uranium or plutonium content of waste containers or objects. They can be either passive (measuring spontaneous fission neutrons) or active (measuring induced fission neutrons). Neutron counting technologies include: Total neutron counting (the total neutron count rate arising from a sample), Coincidence neutron counting (the rate of emission of two neutrons in coincidence) and Neutron multiplicity counting (the rate of emission of three neutrons in coincidence).

3.3 Calorimetry waste assay

Calorimeters perform waste assay by measuring the thermal energy generated by radioactive decay. Calorimeters are typically used to measure waste materials that produce significant amounts of heat by alpha particle decay (plutonium, americium), or beta particle decay (tritium).

3.4 Combined waste assay

Combined waste assay systems use multiple assay techniques to quantify waste and produce a complete assay result. It is common to combine a gamma system (to determine plutonium isotopic ratios) with a passive neutron coincidence system (to determine 240Pueffective mass). Analyzing the data in a combined technology assay instrument determines the individual mass of all of the plutonium isotopes and provides a complete assay result.