Resources

1. Environmental monitoring

Radiation Detection and Environmental Monitoring instruments determine radioactivity in the environment by gamma ray measurement. ANTECH Radiation Detection and Environmental Monitoring systems include:

Contamination vehicle and pedestrian portal monitors
The RadSearch gamma camera
Mobile environmental laboratories
Technology for in-field soil measurements

1. Gamma ray measurements

Most radionuclides decay by gamma ray emission. Gamma ray measurement is the most common and widely used method for measuring nuclear material. It can be used to determine three different qualities of a sample:

Total dose rate (commonly used for medical purposes)
Ratio of the constituents of the sample
Total radionuclide content of a source, either in terms of activity of the mass of a particular radionuclide

The gamma ray measurement process can be passive or active. In PASSIVE measurement the gamma rays emitted form radioactive decay are measured by appropriate detectors and counting electronics. In ACTIVE measurement gamma rays are used to interrogate samples and the attenuation of these interrogating gamma rays is measured. This is used to determine the ability for transmission through samples and thus the degree of attenuation in the sample material and the matrix in which it is contained.

ANTECH instruments perform gross gamma counting using ion chambers and plastic scintillators, and spectroscopy using low-resolution spectrometers (sodium iodide scintillators) or medium and high-resolution spectrometers (LaBr³scintillators and high purity germanium detectors). ANTECH instruments are configured to perform far field measurements to view entire objects, and segmented and tomographic gamma scanning for more complex samples.

1. Homeland security

ANTECH Homeland Security systems are sensitive dual technology measurement instruments (neutron and gamma ray measurement technologies). They are designed to detect:

Illegal and contraband radioactive sources
Improvised radioactive weapons (dirty bombs)

2. Homeland security

ANTECH Homeland Security systems are sensitive dual technology measurement instruments (neutron and gamma ray measurement technologies). They are designed to detect:

Illegal and contraband radioactive sources
Improvised radioactive weapons (dirty bombs)

2. Neutron measurements

Neutrons are emitted by the decay of Special Nuclear Materials (SNM) and transuranic elements. Neutron measurement is the process of counting the neutrons emitted in nuclear fission. It is normally used to quantify uranium and plutonium. It is a sensitive technique that can be used to measure large or small quantities. The neutron measurement process can be passive or active. In PASSIVE measurement neutron emissions from the sample are measured by the detector and counting system. In ACTIVEmeasurement the sample is interrogated with neutrons from a neutron source or a neutron generator. The neutrons emitted from this induced fission are measured by the detector and counting system. ANTECH neutron counting electronics record the three different rates of neutron emission.

Singles: the total neutron count rate arising from a sample (neutron totals counting)
Pairs: the rate of emission of two neutrons in coincidence (neutron coincidence counting)
Triples: the rate of emission of three neutrons in coincidence (neutron multiplicity counting)

ANTECH neutron instruments employ neutron detectors including fission chambers, boron proportional counters and helium-3 (He³) detectors.

2. Safeguards

Nuclear Safeguards instruments employ gamma ray, neutron and calorimetry measurement technologies to verify and quantify the presence of Special Nuclear Materials (SNM). Safeguards instruments either verify the radioactive fingerprint or signature of SNM and fission products (for example in spent nuclear fuel), or quantify SNM in bulk form (for example in unused nuclear fuel for verification purposes).

Safeguards instruments are sometimes used for nuclear materials assay for inventory and materials quantification purposes as well as for safeguards, for example in a nuclear fuel production plant.

3. Calorimetry measurements

Calorimetry measures the thermal energy released from a sample. It is applied in two areas:

The measurement of plutonium in relatively large quantities. Thermal energy is generated through alpha particle decay.
The measurement of tritium in relatively large quantities. Thermal energy is generated through beta particle decay.

Alpha and beta particles have a relatively short range inside the sample materials so the bulk of the energy released in the decay process is deposited locally in the sample. ANTECH calorimeters determine the rate of energy release by the samples through these decay processes.

Calorimeters are configured as single instruments, unlike gamma ray and neutron instruments in which the detector and counting electronics can be separated. The thermal element (or detector component) uses temperature sensitive materials such a nickel wire or thermocouples as a means of measuring temperature. It uses electrical heating elements as a means of depositing thermal energy for temperature control. The electronic coupling components are similar to electrical voltage and current measuring devices.

ANTECH employs two different calorimeter technologies: Isothermal calorimeters employ the power replacement method and achieving adequate measurement precision. Twin-cell heat-flow calorimeters are applied where high accuracy and precision measurement are required.

3. Integrated measurement

ANTECH integrated measurement solutions provide a complete measurement solution for Safeguards and Waste Assay applications. These systems include various combinations of gamma ray, neutron and calorimetry measurement technologies to provide integrated measurement results.

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 ²⁴⁰Pu_effective 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.

4. Combined technology measurements

ANTECH instruments often combine different measurement technologies to provide an optional measurement solution.

These combined instruments usually include neutron and gamma measurements in a single system for waste assay and nuclear safeguards measurement applications.