Thermally driven advection for radioxenon transport from an underground nuclear explosion

Journal Article · Wed May 11 00:00:00 EDT 2016 · Geophysical Research Letters

DOI:https://doi.org/10.1002/2016GL068290· OSTI ID:1402235

Sun, Yunwei ^[1]; Carrigan, Charles R. ^[1]

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1. Lawrence Livermore National Laboratory Livermore California USA

Abstract Barometric pumping is a ubiquitous process resulting in migration of gases in the subsurface that has been studied as the primary mechanism for noble gas transport from an underground nuclear explosion (UNE). However, at early times following a UNE, advection driven by explosion residual heat is relevant to noble gas transport. A rigorous measure is needed for demonstrating how, when, and where advection is important. In this paper three physical processes of uncertain magnitude (oscillatory advection, matrix diffusion, and thermally driven advection) are parameterized by using boundary conditions, system properties, and source term strength. Sobol' sensitivity analysis is conducted to evaluate the importance of all physical processes influencing the xenon signals. This study indicates that thermally driven advection plays a more important role in producing xenon signals than oscillatory advection and matrix diffusion at early times following a UNE, and xenon isotopic ratios are observed to have both time and spatial dependence.

• Sponsoring Organization: USDOE
• OSTI ID: 1402235
• Journal Information: Geophysical Research Letters, Journal Name: Geophysical Research Letters Vol. 43 Journal Issue: 9; ISSN 0094-8276
• Publisher: American Geophysical Union (AGU)
• Country of Publication: United States
• Language: English