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Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - The Impact of 234U α-emission Induced Radiolysis on UF6 Storage Composition for Non-destructive Verification via Passive Neutron Counting
AU - Byrne, S.
AU - Favalli, A.
AU - Croft, S.
PY - 2024/6/10
Y1 - 2024/6/10
N2 - The mass of 235 U present in storage cylinders containing low enriched uranium (LEU) in the form of uranium hexafluoride (UF 6) may be verified nondestructively using a combination of gamma-ray based enrichment meter and passive neutron counting techniques. A hypothetical concern is that the (α,n) production rate in aged bulk UF 6 might differ from that of fresh material if the chemical composition changes over time, the thought being that this could be initiated by the self-induced radiation field, the process known as radiolysis. To support the physics-based interpretation of the observations Croft et al. measured, in 2020, for the specific 234 U-driven (α,n)-yield in UF 6, this work reviews available literature to quantify the possible impact of radiolysis on (α,n) production rate. Building on the review, a radiochemical yield value, G = 0.5 molecules of F 2 per 100 eV is selected, to calculate the impact of UF5 production – via radiolysis – on the (α,n)-yield. Calculations demonstrate a negligible impact on bulk UF 6 concentration and respective neutron yield.
AB - The mass of 235 U present in storage cylinders containing low enriched uranium (LEU) in the form of uranium hexafluoride (UF 6) may be verified nondestructively using a combination of gamma-ray based enrichment meter and passive neutron counting techniques. A hypothetical concern is that the (α,n) production rate in aged bulk UF 6 might differ from that of fresh material if the chemical composition changes over time, the thought being that this could be initiated by the self-induced radiation field, the process known as radiolysis. To support the physics-based interpretation of the observations Croft et al. measured, in 2020, for the specific 234 U-driven (α,n)-yield in UF 6, this work reviews available literature to quantify the possible impact of radiolysis on (α,n) production rate. Building on the review, a radiochemical yield value, G = 0.5 molecules of F 2 per 100 eV is selected, to calculate the impact of UF5 production – via radiolysis – on the (α,n)-yield. Calculations demonstrate a negligible impact on bulk UF 6 concentration and respective neutron yield.
KW - UF radiolysis
KW - UF verification
KW - non-destructive assay
KW - nuclear safeguards
U2 - 10.3011/ESARDA.IJNSNP.2024.3
DO - 10.3011/ESARDA.IJNSNP.2024.3
M3 - Journal article
VL - 66
SP - 28
EP - 34
JO - ESARDA Bulletin
JF - ESARDA Bulletin
SN - 0392-3029
ER -