Underwater Testing of Detectors and Electronics Hardware for Spent Fuel Measurements
2015 (English)Conference paper (Other academic)
Underwater gamma and neutron spent fuel measurement techniques are being researched to meet thecombined needs of the international safeguards community and the Swedish Nuclear Fuel and WasteManagement Company (SKB), which is responsible for fuel encapsulation and repository operation inSweden. Both SKB and the involved regulators anticipate measuring each spent fuel assemblyindividually before encapsulation; such a measurement plan presents a real challenge for the performanceand long-term behavior of detectors and electronics hardware. The reliability and radiation hardness of theelectronics and detectors are a big challenge for users of this technology. For instance, the gammadetectors and electronics may have to operate at count rates up to few million counts per second whilemaintaining good spectral resolution to detect lines from 137Cs, 134Cs, and 152Eu. If the 10B proportionalcounters are to replace the difficult-to-transport 235U fission chambers, they must tolerate a gamma doserate of many thousand R/h (many tens of Sv/h) without gain changes due to space charge effects or long-term degradation of the gas mixture. To address these challenges, a special underwater enclosure wasdeveloped for testing these detectors and electronics in parallel with the design and deployment ofnondestructive assay options for characterization of the spent fuel. In this paper we describe the hardwareand modeling components of the testing setup.
Place, publisher, year, edition, pages
spent fuel, underwater measurements, passive gamma spectroscopy, high counting rate, U-235 fission chambers, B-10 detectors, scintillation detectors, radiation resistance, front-end electronics, collimator modeling
IdentifiersURN: urn:nbn:se:uu:diva-253273OAI: oai:DiVA.org:uu-253273DiVA: diva2:813878
ESARDA Symposium 20015