Underground Nuclear Detonations Research Articles

Speculative High-Level Nuclear Waste Processing Methods

With the exception of recent progress in Sweden and Finland, traditional and planned high-level nuclear waste processing disposal methods have yet to be successfully implemented on a commercial scale. Failure to solve the high-level waste issue is an impediment to the expansion of nuclear power production particularly in North America and Europe. Given these issues, this paper presents three speculative methods and an accelerator/reactor approach to process high-level nuclear waste. The first speculative approach explores the possibility of incorporating an underground nuclear detonation as a means to process the waste. A second method uses antiprotons and antineutrons to transmute the high-level waste. The third utilizes plasma to obliterate the isotopes comprising the radioactive waste. A somewhat less speculative approach involving nuclear waste transmutation using a reactor or accelerator is also presented. However, this approach has several issues to overcome and is not a likely a near-term solution to the waste disposal/processing issue.

Fission product isotope ratios as event characterization tools– Part II: Radioxenon isotopic activity ratios

Abstract Air sampling for radioxenon has been recommended as part of the verification system for a Comprehensive Nuclear-Test-Ban Treaty. Xenon isotopic activity ratios are used as a basis for confirming nuclear detonation, and discriminating between nuclear reactor accidental release and nuclear explosion. The primary purpose of this work is to use the available data on explosions, accidental reactor releases and laboratory experiments and simulations, in order to define the most probable scenarios for nuclear reactor accidental release, and for emission from underground nuclear detonations, to calculate the relevant radioxenon isotopic activity ratios in each scenario and to assess their use as event characterizing tools.

Adsorptive transport of noble gas tracers in porous media

The transport of noble gas radionuclides in porous media is relevant to the detection of underground nuclear detonations as well as the sequestration of reprocessing off-gases. However, in field tests releasing radioxenon underground, the quantity of radioxenon observed at the surface has fallen well below expectations.[Formula: see text] This study examined the diffusivity of noble gases (Kr and Xe) and the inert molecular gas sulfur hexafluoride (SF[Formula: see text] in porous media to observe any unexpected behavior. To replicate the transport of radiogenic noble gases in underground media, a two-bulb gaseous diffusion apparatus was constructed. The two bulbs were connected with a column of 10–30 Ottawa sand and ordinary atmosphere filled both the bulbs and pore spaces. The tracer gases were diluted in an isolated bulb to approximately 1000 ppm. Once released, the gases were allowed to diffuse through the column. Aliquots were withdrawn at regular time intervals from both bulbs and concentrations were quantified using a Shimadzu QP2010 SE gas chromatograph-mass spectrometer. The effective diffusivity was then calculated using a maximum likelihood estimate on the quasi-steady state model. The effective diffusivity of Xe in the silica sand was observed to be 135.2% that of SF[Formula: see text] whereas the effective diffusivity of Kr was observed to be 161.4% that of sulfur hexafluoride. These findings are consistent with the binary diffusivities in N[Formula: see text]: 132.6% and 161.7%, respectively. However, the apparent volume of the system was inconsistent amongst the species, with Xe converging at slightly lower gas-phase concentrations than Kr or SF[Formula: see text]. This apparent reduction in gas-phase concentration occurred within the first few measurements and is consistent with transient accumulation of an adsorbed phase. As the effective diffusivities in the silica sand were shown to be consistent with the binary diffusivities in N[Formula: see text], a porosity-tortuosity model appears to be sufficient when considering similar geological materials. However, with the observation of significant gas adsorption, consideration of adsorbed-phase accumulation is necessary when scaling to larger geological systems.

Radioxenon Production and Transport from an Underground Nuclear Detonation to Ground Surface

Radioxenon isotopes are considered as possible indicators for detecting and discriminating underground nuclear explosions. To monitor and sample the release of radioxenon isotopes, both independent and chain-reaction yields need to be considered together with multiphase transport in geological systems from the detonation point to the ground surface. For the sake of simplicity, modeling of radioxenon isotopic radioactivities has typically been focused either on chain reactions in a batch reactor without considering multiphase transport or on radionuclide transport with simplified reactions. Although numerical methods are available for integrating coupled differential equations of complex decay networks, the stiffness of ordinary differential equations due to greatly differing decay rates may require substantial additional effort to obtain solutions for the fully coupled system. For this reason, closed-form solutions for sequential reactions and numerical solutions for multiparent converging and multidaughter branching reactions were previously developed and used to simulate xenon isotopic radioactivities in the batch reactor mode. In this paper, we develop a fully coupled numerical model, which involves tracking 24 components (i.e., 22 radionuclide components plus air and water) in two phases to enhance model predictability of simultaneously simulating xenon isotopic transport and fully coupled chain reactions. To validate the numerical model and verify the corresponding computer code, we derived closed-form solutions for first-order xenon reactions in a batch reactor mode and for single-gas phase transport coupled with the xenon reactions in a one-dimensional column. Finally, cylindrical 3-D simulations of two-phase flow within a dual permeability fracture-matrix medium, simulating the geohydrologic regime of an underground nuclear explosion, indicate the existence of both a strong temporal and spatial dependence of xenon isotopic ratios sampled at the surface. In the example presented here, temporally evolving subsurface xenon isotopic ratios are found to migrate across the discrimination line delineating civilian nuclear activities from an underground nuclear explosion in the KALINOWSKI Multi-Isotope Ratio Chart.

Childhood Thyroid Radioiodine Exposure and Subsequent Infertility in the Intermountain Fallout Cohort

Background: Above-ground and underground nuclear weapon detonation at the Nevada Test Site (1951–1992) has resulted in radioiodine exposure for nearby populations. Although the long-term effect of environmental radioiodine exposure on thyroid disease has been well studied, little is known regarding the effect of childhood radioiodine exposure on subsequent fertility.Objectives: We investigated early childhood thyroid radiation exposure from nuclear testing fallout (supplied predominantly by radioactive isotopes of iodine) and self-reported lifetime incidence of male or female infertility or sterility.Methods: Participants were members of the 1965 Intermountain Fallout Cohort, schoolchildren at the time of exposure who were reexamined during two subsequent study phases to collect dietary and reproductive histories. Thyroid radiation exposure was calculated via an updated dosimetry model. We used multivariable logistic regression with robust sandwich estimators to estimate odds ratios for infertility, adjusted for potential confounders and (in separate models) for a medically confirmed history of thyroid disease.Results: Of 1,389 participants with dosimetry and known fertility history, 274 were classified as infertile, including 30 classified as sterile. Childhood thyroid radiation dose was possibly associated with infertility [adjusted odds ratio (AOR) = 1.17; 95% CI: 0.82, 1.67 and AOR = 1.35; 95% CI: 0.96, 1.90 for the middle and upper tertiles vs. the first tertile of exposure, respectively]. The odds ratios were attenuated (AOR = 1.08; 95% CI: 0.75, 1.55 and AOR = 1.29; 95% CI: 0.91, 1.83 for the middle and upper tertiles, respectively) after adjusting for thyroid disease. There was no association of childhood radiation dose and sterility.Conclusion: Our findings suggest that childhood radioiodine exposure from nuclear testing may be related to subsequent adult infertility. Further research is required to confirm this.

UTEX modeling of radioxenon isotopic fractionation resulting from subsurface transport

The underground transport of environmental xenon (UTEX) model is a finite-difference code that was developed at the University of Texas at Austin to simulate the transport of radioxenon from an underground nuclear detonation to the surface. UTEX handles a time dependent source term and includes the effects of radioactive decay to determine isotopic signatures of the various radioxenon species as a function of release time. The model shows that significant perturbations in the isotopic signatures are possible under some geologic conditions. Transport of radioxenon gas in UTEX is driven in large part by atmospheric pumping. A study was undertaken to characterize the dependence of resulting isotopic signatures on the various geologic and physical parameters that define the system model. Additionally, the model was used to roughly simulate isotopic measurements at various depths and position; the potential dependence of isotopic radioxenon fractionation on sampling depth and lateral position between fractures was examined.

Sensitivity to Formation Porosity of Contaminant Transport from Nevada Test Site to Yucca Mountain

This study quantified the sensitivity of advective contaminant arrival time to the porosity of hydrogeologic units (HGUs) for groundwater transport from the Nevada Test Site (NTS) to the Yucca Mountain (YM) area in the United States. Advective arrival time of contaminants associated with underground nuclear detonations was obtained by using particle tracking on the basis of flow velocities from the Death Valley Regional Groundwater Flow System (DVRFS) model and porosity information for the HGUs along the flowpaths. The objectives were to (1) determine which HGU’s porosity is influential in contaminant advective arrival time from the NTS to the YM, and (2) apportion uncertainties in contaminant advective arrival time to the uncertainty contributions from individual HGU porosity. Over 90% of the uncertainty in advective transport arrival time from the NTS to YM could be described by uncertainties in porosity values of two of the 27 HGUs present in the DVRFS model. The study was significant for optimizing re...

Groundwater transport of tritium and krypton 85 from a nuclear detonation cavity

Underground nuclear detonations at the Nevada Test Site provide a unique opportunity to study the hydrologic transport of radionuclides in the field. At the Cambric experiment a pumped well 91 m from the detonation cavity was sampled regularly over 16 years and recovered 94% of the tritium but only 42% of the expected 85Kr, both following decay correction. In addition, the elution curves were different for these two ideal tracers of groundwater movement. Modeling is used to determine the fate of the missing 85Kr based on the phenomenology of underground nuclear detonations and the specific hydrogeology of the Cambric site. At Cambric, large amounts of carbon dioxide created by the detonation caused the upward migration of 85Kr through the collapsing chimney and into the unsaturated zone. A numerical model simulated tritium and 85Kr transport to the pumped well using tritium data to determine regional anisotropy in hydraulic conductivity and reduced hydraulic conductivity in the cavity region. The calibrated model reproduces the 85Kr breakthrough data when emplacement of 85Kr by the upward migration of carbon dioxide is included. Nuclear detonations provide long‐term tracer tests in the subsurface, but knowledge of the spatial distribution of sources at this specific site is essential in understanding the transport of these two radionuclide tracers.

Aged nuclear explosive melt glass: Radiography and scanning electron microscope analyses documenting radionuclide distribution and glass alteration

Assessment of the long-term performance of nuclear melt glass under saturated conditions provides insight into factors controlling radionuclide release into groundwater. Melt glass samples were collected from an underground nuclear detonation cavity at the Nevada Test Site that was in contact with groundwater for more than 10 years. The samples were made into thin sections and the distribution of alpha-activity mapped using CR-39 plastic detectors. The melt glass is visually heterogeneous and the results of the alpha-track radiography indicate that the highest alpha-activity is associated with areas of dark colored glass. Analyses of the thin sections by alpha-spectrometry show the prominent actinide species to be 238Pu, 239,240Pu and 241Am. Scanning electron microprobe analysis of the bulk glass shows conspicuous alteration layers lining internal vesicle surfaces in the glass. X-ray diffraction patterns for the alteration phases are consistent with clay mineral compositions. Glass dissolution models indicate these layers are too thick to have formed at ambient temperatures over the 10 year period in which they remained in a saturated environment. This implies the alteration layers likely formed at temperatures higher than ambient during cooling of the cavity following the underground detonation. Mobilization of this clay alteration layer as colloidal particles in groundwater represents a potential source of actinide release into the environment.

Descriptive study of deaths from cancer associated with residential proximity to the site of underground nuclear detonations.

During the 1960s, two nuclear detonations were exploded in an underground salt dome in Lamar County, Mississippi. Citizens in this rural area expressed concern about excess cancer among the residents as a result of exposure to tritium. Researchers initiated an epidemiologic investigation in response to these concerns. Investigators identified 2251 deaths, of which 562 (25.7%) were cancer related. Observed cancer rates for the area of Mississippi were no different than those expected for the state as a whole. Investigators found no association between cancer mortality and distance from the center of detonation.

Residual Radioactivity in the Soil of the Semipalatinsk Nuclear Test Site in the Former USSR

This paper deals with our efforts to survey residual radioactivity in the soil sampled at the Semipalatinsk Nuclear Test Site and at off-site areas in Kazakhstan. The soil was sampled at the hypocenter where the first Soviet nuclear explosion was carried out on 29 August 1949, and at the bank of the crater called "Bolapan," which was formed by an underground nuclear detonation on 15 January 1965 along the Shagan River. As a comparison, other soil was also sampled in the cities of Kurchatov and Almaty. These data have allowed a preliminary evaluation of the contemporary radioactive contamination of the land in and around the test site. At the first nuclear explosion site and at Bolapan, higher than background levels of 239,240Pu with weapons-grade plutonium were detected together with fission and activation products such as 137Cs, 60Co, 152Eu, and 154Eu.

Decomposition of seismic moment tensors for underground nuclear explosions

Generally the decomposition of a seismic moment tensor is not unique. However, to favorably view the characteristics of a certain seismic source, one must decompose a seismic moment tensor into parts according to assumptions about the properties of the seismic source. Different from natural earthquakes in which the shear dislocation component plays a predominant role in the source process, and the seismic moment tensor can be separated into an isotropic component, a double couple, and a compensated linear vector dipole (CLVD), underground nuclear explosions have three major components in their source process, i.e., the explosion, the tensional spalling, and the tectonic strain release associated with the explosion. In such a situation the conventional moment tensor decomposition for earthquakes is not convenient to estimate the yield of the explosion and to characterize the tectonic strain release. In this paper, an alternative decomposition scheme is proposed to deal with the moment tensor of underground nuclear explosions, which might benefit the approach to study the tectonic strain release induced by underground nuclear detonations.

TELESEISMIC DISCRIMINATION OF EARTHQUAKES AND NUCLEAR DETONATIONS WITH FEATURES DERIVED FROM MAXIMUM ENTROPY POWER SPECTRAL ESTIMATES

This paper describes pattern recognition techniques for discriminating between earthquakes and underground nuclear detonations from teleseismic signals. The features investigated are obtained by Maximum Entropy Spectral Analysis techniques. Classification performance is evaluated on a seismic database recorded at the Large Aperture Seismic Array (LASA) in Montana. The events are randomly divided into design and test subsets. Several pattern recognition algorithms including Baye's quadratic classifier, the minimum distance classifier and the nearest neighbor rule are applied. The best results are obtained with spectral ratios from windows taken at regular intervals within the coda combined with bodywave magnitude. With the Baye's classifier, 85% correct classification was achieved for the test set events. For a reduced dataset containing only central Asian events, 96% was achieved.

Concentrations of krypton-85 near the Nevada Test Site

Since 1972, the Environmental Monitoring Systems Laboratory has operated a network of noble gas samplers around the Nevada Test Site (NTS). For 10 of those years, the network also included several samplers on the NTS. The network was established to measure the concentrations of noble gases released to the atmosphere by underground nuclear detonations, by post-test operations, and by seepage from the ground from previous underground tests. During this 12-year period, the concentrations of krypton-85 measured in samples collected around the NTS gradually increased with time from 16 pCi/m/sup 3/ in 1972 to 25 pCi/m/sup 3/ in 1983. This increase was not found to be due to nuclear testing activities at the NTS but to the world-wide use of nuclear technology, a trend that has been predicted by previous investigators. The observed trend of increasing concentration was considerably less than had been projected by other authors, being only one-eighth to one-fifth of that projected. It is suggested that the difference from predictions is due to a decrease in the rate of growth in the number of nuclear power plants and, more significantly, the slow growth of nuclear duel reprocessing activities.

Cancer Incidence in an Area of Radioactive Fallout Downwind From the Nevada Test Site

Exposures in southwestern Utah to radioactive fallout (1951 through 1962) from atmospheric nuclear detonations at the Nevada Test Site (NTS) were followed by smaller exposures (1962 through 1979) from venting of underground nuclear detonations. The cancer incidence in a 1951 cohort (4, 125) of Mormon families in southwestern Utah near the NTS was compared with that of all Utah Mormons (1967 through 1975). There were 109 more cases of cancer than expected (288[observed]/179[expected]). Leukemia was most prominent early (1958 through 1966), with 19 cases, five times more than expected (3.6). The excess of leukemia persisted into the later period (1972 through 1980), with 12 cases observed, 3.4 expected. There was an increase in lymphoma. Excess cases of thyroid cancer appeared early and a notable excess appeared later (14/1.7). An excess of breast cancer was noted later (27/14). There were more cancers of the gastrointestinal tract than expected. There was an excess of melanoma (12/4.5), bone cancer (8/0.7), and brain tumors (9/3.9). A subgroup with history of acute fallout effects had a higher cancer incidence. That these cases can be associated with radiation exposures is supported by a comparison between groups of the ratio of cancers of more radiosensitive organs with all other types of cancer.

Current Status of In-Situ Recovery From the Tar Sands of Alberta

Abstract A number of schemes have been proposed and tested for the in-situ. recovery of oil from the tar sands of the Athabasca, Cold Lake, Wabasca and Peace River areas of Alberta. The present paper reviews the field tests that have been conducted or are currently underway. An attempt is made to put together the available information on these field tests, in order to assess the technology of in-situ exploitation of tar sands. In particular, field tests of the combination steam injection process in the Athabasca and Peace River regions, of cyclic steam stimulation in the Cold Lake region and of in-situ combustion in the Athabasca region are critically reviewed, and the project statistics a:te analyzed in order to evaluate and compare these methods, The operational problems encountered are described, and it is shown that the conditions in the tar sands areas are such that a combination recovery method has the best chance of success, Several other in-situ, recovery methods that have been proposed including in-situ. hydrogenation and cracking, combined miscible and thermal methods, and underground nuclear detonations are briefly discussed and evaluated. Introduction THE TAR SANDS OF ALBERTA represent an enormous hydrocarbon deposit, covering some 19,000 square miles and totaling 895 billion barrels of bitumen, Table 1 gives a breakdown of this deposit, also indicating the volumes of the recoverable synthetic crude(l,2). It is seen that only 8.3 per cent of the deposits occur in the 0-150-ft overburden thickness range, which is currently considered to be the range within which surface mining and processing methods are applicable. These data are based on a cut-off bitumen saturation of 2 per cent by weight (3 per cent for Cold Lake). It is noteworthy that 69~9 per cent of the total deposits occur in the Athabasca region. Also, 15.1 per cent of the deposits occur under overburden 150-500 ft in thickness, and are currently deemed to be unexploitable (figure in full paper) by either surface mining or in-situ methods (exceptions will be noted below), Figure I, based on Reference (3), shows the distribution of overburden in the Athabasca region. This article reviews the results of some of the field tests conducted in the tar Bands formations. The discussion is based on published articles, news items and other public records, together with the author's calculations. At the present time, at least 11 experimental in-situ recovery projects are in operation in the tar sands area, and even a larger number is planned for the next two years. At least 23 projects have already been conducted and terminated for various reasons. Very little information derived from these tests has been published to date, Figure 2 shows the locations of some of the terminated and current in-situ projects. Other projects not shown include those of Cities Service, Tenneco, WECO, Numac and BP, which are in the planning stages. Although oil recovery from tar sands by surface mining methods has been adequately established, the in-situ operations are still experimental and account for a net production of about 2000 B/D.

Atmospheric HT and HTO: Major HT injections into the atmosphere 1973

Two major injections of tritium gas into the atmosphere occurred in late 1973. They appeared to originate from underground nuclear detonations, and were detected by our sampling stations at Fairbanks, Alaska; at Miami, Florida; and at Mauna Loa Observatory, Hawaii. Total injected amount is estimated at 80 g of tritium.

Survival of Rainbow Trout Eggs after Receiving Physical Shocks of Known Magnitude

Abstract Salmonid eggs are known to be sensitive to physical shock at certain stages of development. Survivability of the eggs is unknown when incubating under natural conditions and subjected to the seismic shock of underground nuclear detonations. Rainbow trout eggs were incubated to various stages of development (37.5, 75, 125 or 250 Temperature Units) in simulated redds and subjected to five sequential physical shocks of either 1, 2, 5 or 10 g. Eggs were then allowed to continue incubation to hatch or near hatch. Results indicated no significant difference in survival of eggs subjected to physical shocks of these four magnitudes at the various developmental stages when compared to eggs subjected to no shock. There was no significant difference in egg survival after shocking at 8.2 C (47 F) or at 11.1 C (52 F).

Calculating the response of emplacement structures subjected to ground shock from underground nuclear detonation : DEP. TECH. INF. SERV. UCRL-74055, 1972, 29P

Calculating the response of emplacement structures subjected to ground shock from underground nuclear detonation : DEP. TECH. INF. SERV. UCRL-74055, 1972, 29P

Release of tectonic strain by large underground nuclear detonation : Final report. Tabls, Refs DEP. NAT. TECH. INF. SERV. AD-755883, 1973, 44P

Abstract : The report describes an attempt to observe SH waves from several large underground nuclear explosions at first-zone distances (600 km) from each event. The data base was supplemented by seismograms from the World Wide Standard Station Network and Canadian Network. Good SH arrivals were observed at the shorter ranges (250 km) but not at ranges between 250 km and about 1800 km. In an effort to detect the arrival of any S waves (SV or SH) within this 'shadow zone', a flat-layered earth approximation was assumed (with hence critically refracted S-wave paths), and particle motion diagrams were then constructed. (The flat-layered earth hypothesis suggests small angles of incidence and, therefore, rectilinear particle motion). Such rectilinear motion was observed and in several 'shadow-zone' instances, arrival times were consistent with the model chosen.