D3S - results of qualification measurements of a wearable RIID for homeland security
Paper presented at INMM 2019, 60th Annual Meeting Institute of Nuclear Materials Management, July 14-18, 2019, Palm Desert, California, USA
A testing facility for qualification tests of measurement devices for radioactive and nuclear material was established at the Fraunhofer INT. This was done in the framework of the Illicit Trafficking Radiation Detection Assessment Program + 10 (ITRAP+10). The test methods were developed in the program based on ANSI and IEC standards. After the completion of the setup of the facilities, they are now used for the testing of various devices. This paper deals with tests in accordance with the ITRAP test procedures and the corresponding results obtained for the D3S detector from Kromek. The device is designed to be used as radiation isotope identifier (RIID) as well as personal radiation dosimeter (PRD). Therefore tests referring to both test methods were performed. The device contains a cesium iodine gamma as well as a non-helium-3 neutron detector and both kinds of sources were used for the device qualification. The tests are divided in tests of general requirements, radiological tests, and radionuclide identification tests. The tests of general requirements include for example tests of the user interface, battery requirements, documentation or audible and vibrational alarm. The radiological tests comprise tests concerning false identification rate, time to alarm, accuracy tests for photons, over range and gamma response of the neutron detector. The quality of the nuclide identification results is part of the radionuclide tests. Partly the requirements for PRDs and RIIDs are identical, partly not. For example the time to alarm value in which an alarm after the device is exposed to the source shall be created is 2 s for PRDs and 3 s for RIIDs. The D3S passed many tests, but also failed some. The tests also showed the limits of such test procedures. They are standard tests under fixed conditions whereas in reality different situations occur in which the obtained results may not turn out as well as the tests indicate. The paper gives results of the qualification tests done with the D3S as well as a suggestion for an additional close to reality test.