Cavity-melt partitioning of refractory radionuclides and implications for detecting underground nuclear explosions

Carrigan, Charles R.; Sun, Yunwei; Pili, Éric; Antoun, T.

doi:10.1016/j.jenvrad.2020.106269

Cited by 10 publications

(27 citation statements)

References 25 publications

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“…In contrast to using simplified source terms, full decay and ingrowth networks were modeled assuming radionuclide evolution in a closed and well-mixed (i.e., batch-mode) detonation cavity (Kalinowski et al 2010(Kalinowski et al , 2011Yamba et al 2016). However, more realistic and detailed models considering the post-detonation state of the cavity and its effect on xenon isotopic evolution do not retain the idealized batch mode (Kalinowski and Liao 2014;De Geer 2013;Carrigan et al 2020b) and closed-system assumptions (Carrigan et al 2020b) of these isotopic evolutionary models. Similarly, the analytical models developed here do not depend on the batch-mode or closed-system assumptions by following the model development of Carrigan et al (2020b).…”

Section: Introductionmentioning

confidence: 99%

“…However, more realistic and detailed models considering the post-detonation state of the cavity and its effect on xenon isotopic evolution do not retain the idealized batch mode (Kalinowski and Liao 2014;De Geer 2013;Carrigan et al 2020b) and closed-system assumptions (Carrigan et al 2020b) of these isotopic evolutionary models. Similarly, the analytical models developed here do not depend on the batch-mode or closed-system assumptions by following the model development of Carrigan et al (2020b). In the cavity-melt partitioning model of Carrigan et al (2020b), xenon production and transport from a UNE are described using partial differential equations (PDEs) governing multiphase flow and transport and ordinary differential equations (ODEs) governing radioactive decay and ingrowth (Carrigan and Sun 2014;Carrigan 2014, 2016;Lowrey et al 2015;Sun et al 2015;Jordan et al 2015;Sloan et al 2016;Bourret et al 2019;Harp et al 2019;Carrigan et al 2020a).…”

Section: Introductionmentioning

confidence: 99%

“…Similarly, the analytical models developed here do not depend on the batch-mode or closed-system assumptions by following the model development of Carrigan et al (2020b). In the cavity-melt partitioning model of Carrigan et al (2020b), xenon production and transport from a UNE are described using partial differential equations (PDEs) governing multiphase flow and transport and ordinary differential equations (ODEs) governing radioactive decay and ingrowth (Carrigan and Sun 2014;Carrigan 2014, 2016;Lowrey et al 2015;Sun et al 2015;Jordan et al 2015;Sloan et al 2016;Bourret et al 2019;Harp et al 2019;Carrigan et al 2020a). To mitigate the difficulty and high computational expense of solving the coupled PDEs and ODEs of transport and the complex decay/ingrowth networks necessary in evaluating details of the linkage between the physical and chemical evolution of the cavity, closedform solutions may be developed.…”

Section: Introductionmentioning

confidence: 99%

“…In the context of our cavity-melt partitioning model (Carrigan et al 2020b), the detonation cavity following a UNE is composed of several interacting subsystems or compartments (e.g., cavity, rock-melt puddle, and host rock, as shown in Fig. 1).…”

Section: Introductionmentioning

confidence: 99%

“…2a, c, and e) has been further used to calculate a multi-isotope ratio chart (MIRC, Kalinowski et al 2010). In reality, this singlebatch model is unable to address nuclide redistribution among subsystems or its effect on xenon isotopic evolution in the gas phase of the post-detonation cavity (De Geer 2013;Carrigan et al 2020b). The initial fraction of radionuclide inventory is partitioned between the cavity and rock-melt phase constituting the puddle (Carrigan et al 2020b).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

A Closed-form Solution for Source-term Emission of Xenon Isotopes from Underground Nuclear Explosions

et al. 2021

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Isotopic ratios of radioactive xenons sampled in the subsurface and atmosphere can be used to detect underground nuclear explosions (UNEs) and civilian nuclear reactors. Disparities in the half-lives of the radioactive decay chains are principally responsible for time-dependent concentrations of xenon isotopes. Contrasting timescales, combined with modern detection capabilities, make the xenon isotopic family a desirable surrogate for UNE detection. However, without including the physical details of post-detonation cavity changes that affect radioxenon evolution and subsurface transport, a UNE is treated as an idealized system that is both closed and well mixed for estimating xenon isotopic ratios and their correlations so that the spatially dependent behavior of xenon production, cavity leakage, and transport are overlooked. In this paper, we developed a multi-compartment model with radioactive decay and interactions between compartments. The model does not require the detailed domain geometry and parameterization that is normally needed by high-fidelity computer simulations, but can represent nuclide evolution within a compartment and migration among compartments under certain conditions. The closed-form solution to all nuclides in the series 131–136 is derived using analytical singular-value decomposition. The solution is further used to express xenon ratios as functions of time and compartment position.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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A Closed-form Solution for Source-term Emission of Xenon Isotopes from Underground Nuclear Explosions

et al. 2021

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Implications of Underground Nuclear Explosion Cavity Evolution for Radioxenon Isotopic Composition

Sun

Carrigan²,

Pili

et al. 2022

Pure Appl. Geophys.

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Isotopic ratios of radioxenons sampled in the atmosphere or subsurface can be used to verify the occurrence of an underground nuclear explosion (UNE). Differences in the half-lives of radioactive xenon precursors and their decay-chain networks produce different time-dependent concentration profiles of xenon isotopes allowing isotopic ratios to be used for tracking UNE histories including estimating the time of detonation. In this study, we explore the potential effects of post-detonation cavity processes: precipitation of iodine precursors, gas seepage, and prompt venting on radioxenon isotopic evolution which influences UNE histories. Simplified analytical models and closed-form solutions yielding a potentially idealized radioactive decay/ingrowth chain in a closed and well-mixed system typically have limited application by not including the partitioning of the radionuclide inventory between a gas phase and rock melt created by the detonation and by ignoring gas transport from the cavity to host rock or ground surface. In reality, either subsurface transport or prompt release that is principally responsible for gas signatures violates the closed-system (or batch-mode) assumption. A closed-form solution representing time-dependent source-term activities is extended by considering the cavity partitioning process, slow seepage, and/or prompt release of gases from the cavity and applied to realistic systems.

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Characterization of CTBT-Relevant Radioxenon Detections at IMS Stations Using Isotopic Activity Ratio Analysis

Boxue¹,

Kalinowski²,

Sun

et al. 2023

Pure Appl. Geophys.

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Radioxenon isotopes measured at radionuclide stations of the Comprehensive Nuclear-Test-Ban Treaty’s (CTBT) International Monitoring System (IMS) may indicate releases from underground nuclear explosions (UNEs) but are often caused by emissions from nuclear facilities. Characterization of CTBT-relevant nuclear events may use the evolution of isotopic activity ratios over time, which goes from the release of an assumed UNE, through atmospheric transport, to sample collections and measurements. A mathematical approach is presented to discuss the characterization of the spatial and temporal relationships between a nuclear explosion and radioxenon measurements. On the one hand, activity concentrations at an IMS station are estimated by using the assumed release scenario regarding a UNE and atmospheric transport modelling. On the other hand, the activities collected in the samples are determined by spectral analysis first and the activity concentrations in the air passing over the IMS station are estimated under an assumption of constant concentration during sampling. The isotopic ratios of activities released from the UNE are related to the isotopic ratios of activity concentrations in the plume of air crossing the IMS station, resulting in a function of the isotopic activity ratio over the time from detonation to sample measurement. The latter is used for discrimination of a nuclear test and estimation of the time of detonation, such as a four radioxenon plot of the activity ratio relationship of 135Xe/133Xe versus 133mXe/131mXe.

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Cavity-melt partitioning of refractory radionuclides and implications for detecting underground nuclear explosions

Cited by 10 publications

References 25 publications

A Closed-form Solution for Source-term Emission of Xenon Isotopes from Underground Nuclear Explosions

A Closed-form Solution for Source-term Emission of Xenon Isotopes from Underground Nuclear Explosions

Implications of Underground Nuclear Explosion Cavity Evolution for Radioxenon Isotopic Composition

Characterization of CTBT-Relevant Radioxenon Detections at IMS Stations Using Isotopic Activity Ratio Analysis

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