Recent modelling studies for analysing the partial-defect detection capability of the Digital Cherenkov Vieweing Device
2014 (English)In: Esarda Bulletin, ISSN 0392-3029, no 51, 3-8 p.Article in journal (Refereed) Published
Strong sources of radioactivity, such as spent nuclear fuel stored in water pools, give rise to Cherenkov light. This light originates from particles, in this case electrons released from gamma-ray interactions, which travel faster than the speed of light in the water. In nuclear safeguards, detection of the Cherenkov light intensity is used as a means for verifying gross and partial defect of irradiated fuel assemblies in wet storage.
For spent nuclear fuel, the magnitude of the Cherenkov light emission depends on the initial fuel enrichment (IE), the power history (in particular the total fuel burnup (BU)) and the cooling time (CT). This paper presents recent results on the expected Cherenkov light emission intensity obtained from modelling a full 8x8 BWR fuel assembly with varying values of IE, BU and CT. These results are part of a larger effort to also investigate the Cherenkov light emission for fuels with varying irradiation history and other fuel geometries in order to increase the capability to predict the light intensity and thus lower the detection limits for the Digital Cherenkov Viewing Device (DCVD).
The results show that there is a strong dependence of the Cherenkov light intensity on BU and CT, in accordance with previous studies. However, the dependences demonstrated previously are not fully repeated; the current study indicates a less steep decrease of the intensity with increasing CT. Accordingly, it is suggested to perform dedicated experimental studies on fuel with different BU and CT to resolve the differences and to enhance future predictive capability. In addition to this, the dependence of the Cherenkov light intensity on the IE has been investigated. Furthermore, the modelling of the Cherenkov light emission has been extended to CTs shorter than one year. The results indicate that high-accuracy predictions for short-cooled fuel may require more detailed information on the irradiation history.
Place, publisher, year, edition, pages
Ispra, 2014. no 51, 3-8 p.
DCVD, Cherenkov light emission, partial defects, initial enrichment, burnup, cooling time, Geant4
Research subject Physics with specialization in Nuclear Physics
IdentifiersURN: urn:nbn:se:uu:diva-243258OAI: oai:DiVA.org:uu-243258DiVA: diva2:786715