Production Of Nuclear Materials Research Articles

Estimating North Korea's nuclear capabilities: Insights from a study on tritium production in a 5MWe graphite-moderated reactor

This study explores the potential for tritium production in North Korea's 5MWe graphite-moderated reactor, a facility primarily associated with nuclear weapons material production. While existing research on these reactors has largely centered on plutonium, our focus shifts to tritium, a crucial element in boosted fission bombs. Utilizing the MCNP6 code for simulations, the results estimate that North Korea can possibly produce approximately 7–12 g of tritium annually. This translates to the potential production of 1–3 boosted fission bombs each year. By incorporating tritium production into assessments of North Korea's nuclear capabilities, our methodology provides insights into the dynamics of the country's nuclear force, revealing a more diversified and complex composition than previously assumed. The findings significantly aid policymakers, regulatory bodies, and researchers in comprehending potential proliferation risks associated with graphite-moderated reactors and in developing strategies to address the nuclear threat emanating from North Korea.

Utilizing a Metagenome Assembled Genome Approach Revealed Further Insights into Microbially Mediated Heavy-Metal Resistance in Soils from a Former Nuclear Materials Production Facility

Soils and sediments from the Savannah River Site (SRS), located in the USA are known to have a long history of co-contamination with radionuclides (mainly uranium) and heavy metals. To better understand the bacterial taxonomic and genomic characteristic of the SRS soil habitat, shotgun metagenomes were obtained from three different levels of contaminated soil—high, medium, and low. Sequences were then assembled and annotated to generate metagenome-assembled genomes (MAGs) using toolkits within the nf-core/mag. The initial analysis resulted in a total of 254 MAGs. After bin refinement and de-replication, 55 MAGs which met the quality standard with a completeness > 75% and contamination < 25%, accounting for 21.67% of all the MAGs, were reconstructed. Further refinement with completeness > 90% and contamination < 10% yielded 24 MAGs (18 from the winter season and 6 from the summer season) spanning 6 bacterial phyla, predominantly Actinomycetota, Proteobacteriota, Bacteroidota, and Cyanobacteria. Overall, the Arthrobacter MAG was found to be robust for further analysis, with over 1749 genes putatively involved in the crucial metabolism of elements viz. nitrogen, phosphorous, and sulfur, and 598 genes encoding enzymes for the resistance of metals including cadmium, zinc, chromium, arsenic, and copper. In summary, this project enhances our understanding of genes conferring resistance to heavy metals in uranium-contaminated soils.

AI and atoms: How artificial intelligence is revolutionizing nuclear material production

ABSTRACT The associability of artificial intelligence (AI) as a dual-use technology for nuclear material production (NMP) within the academic and practitioner communities remains widely neglected, and so a widening opportunity for AI to aid in illicit and covert non-peaceful applications exists. To address this emerging gap, this paper investigates the evolving and applicable uses of AI and finds broad evidence of its use to optimize performance, promote innovation, reduce costs, and enhance safety associated with the development and production of nuclear material. AI’s use in this arena will, thereby, facilitate broader accessibility of peaceful uses of nuclear science and technology, while at the same time cause concerns that said improvements can aid the illicit development of nuclear weapons. As such, this paper advocates for a three-dimensional solution to manage the evolving dual-use concern of AI that involves advancing states-centric monitoring and regulation, promoting intellectual exchange between the nonproliferation sector and the AI industry, and encouraging AI industrial contributions.

A probabilistic inverse prediction method for predicting plutonium processing conditions

In the past decade, nuclear chemists and physicists have been conducting studies to investigate the signatures associated with the production of special nuclear material (SNM). In particular, these studies aim to determine how various processing parameters impact the physical, chemical, and morphological properties of the resulting special nuclear material. By better understanding how these properties relate to the processing parameters, scientists can better contribute to nuclear forensics investigations by quantifying their results and ultimately shortening the forensic timeline. This paper aims to statistically analyze and quantify the relationships that exist between the processing conditions used in these experiments and the various properties of the nuclear end-product by invoking inverse methods. In particular, these methods make use of Bayesian Adaptive Spline Surface models in conjunction with Bayesian model calibration techniques to probabilistically determine processing conditions as an inverse function of morphological characteristics. Not only does the model presented in this paper allow for providing point estimates of a sample of special nuclear material, but it also incorporates uncertainty into these predictions. This model proves sufficient for predicting processing conditions within a standard deviation of the observed processing conditions, on average, provides a solid foundation for future work in predicting processing conditions of particles of special nuclear material using only their observed morphological characteristics, and is generalizable to the field of chemometrics for applicability across different materials.

Synthesis of Thorium Dioxide Nanocrystals by Pyrolysis of a Thorium‐based Metal‐organic Framework

AbstractA new method is demonstrated for synthesizing thorium dioxide (ThO2) nanoparticles (NPs) by thermal decomposition of an undiscovered thorium‐based metal‐organic framework (MOF). Upon heating at 520 °C, the thorium‐based MOF crystals, designated Th‐MTB, are converted completely to ThO2 NPs with an average size of 150 nm. The MOF‐derived ThO2 NPs are easily sintered to form ThO2 ceramics which have good thermal conductivity. The crystalline grains of ThO2 grow continuously during sintering.The method for the synthesis of ThO2 NPs could have potential applications in the production of nuclear materials.

Assessing Uranium Ore Processing Activities Using Satellite Imagery at Pyongsan in the Democratic People’s Republic of Korea

The Democratic People’s Republic of Korea (DPRK)’s only confirmed uranium mill is within the Pyongsan uranium mining complex. The ore processing pathway and the production capacity for uranium concentrate is analyzed, based on comprehensive satellite imagery analysis of this facility. This assessment of the Pyongsan facility indicates an ore processing capacity of ∼750–1,200 tonnes per day. One year of maximum production at Pyongsan would yield enough processed ore to fuel one load of the 5 MWe reactor in Yongbyon as well as ∼3,000 kg of LEU or ∼100 kg of HEU. The analysis suggests that the ore processing capacity at Pyongsan is not a constraint on the DPRK’s nuclear material production and that the available capacity at the Pyongsan milling facility strongly suggests that the DPRK has no need in another uranium milling facility of a comparable size. This report provides an improved understanding of the ore processing steps and production rates of the only confirmed uranium mill in the DPRK, enabling a more quantitative assessment of its nuclear materials production and inventories.

Literature survey to the materials used in laser-assisted additive manufacturing processes for the production of nuclear materials

Literature survey to the materials used in laser-assisted additive manufacturing processes for the production of nuclear materials

Consideration of Administrative Monetary Penalties in Nuclear Safety and Security

An Administrative Monetary Penalty (AMP) is a penalty imposed by the Canadian Nuclear Safety Commission (CNSC), without court involvement for a violation of a regulatory requirement. An AMP can be applied against any individual or corporation subject to the Nuclear Safety Control Act, which regulates the development, production and use of nuclear energy and the production, possession and use of nuclear and radioactive material. However, AMPs are not the same as criminal offences. They are civil sanctions which try to secure compliance through the application of monetary penalties for non-compliance with regulatory requirements. The AMP program was introduced in 2013 in Canada and to this date over 30 penalties have been issued. In all of these cases, the violations were related to handling and security of radioactive material. Based on these issued penalties investigations were conducted to discover pros and cons of the AMP system and to propose potential improvements for future implementation. This paper also addresses some of the complicated issues of the system, such as the economic aspect of the process, and the subjectivity and relative ease of issuing these penalties. In order to improve nuclear security in Canada, the regulator must be aware of possible violations of the Nuclear Safety Control Act and work on prevention of these violations. It is postulated that current AMP policy may not motivate individuals or corporations to report violations. The paper gives recommendations on modifications which could be implemented to motivate self – identification of violation, and give significant benefit to the AMP system. Other than the issued AMPs, the paper will analyze data obtained through the survey conducted on human readiness to self – identify violations in the nuclear industry under different circumstances. This confirms that the modified AMP policy would improve the body of knowledge and provide significant information on violations of the Nuclear Safety Control Act and improve nuclear security.

What to do with 177 giant tanks of radioactive sludge

It's a place of superlatives. Reporters have called it the most polluted place in the Western Hemisphere. It's also the location of one of the largest construction projects in the world. · At the Hanford Site in south-central Washington state, 177 giant tanks sit below the sandy soil, brimming with the radioactive remnants of 44 years of nuclear-materials production. From World War II through the Cold War, Hanford churned out plutonium for more than 60,000 nuclear weapons, including the atomic bomb that razed Nagasaki, Japan, in August 1945. The sprawling enterprise eventually contaminated the soil and groundwater and left behind 212 million liters of toxic waste-enough to fill 85 Olympic-size swimming pools. Decades after the site stopped producing plutonium, the U.S. government is still grappling with how to clean it all up. · Today the 1,500-square-kilometer site, roughly half the size of Rhode Island, is a quiet expanse of sagebrush and wispy grasses outside Richland, Wash. The underground steel-and-reinforced-concrete tanks are grouped in "farms" beneath a central plateau, while shuttered nuclear reactors stand like sentinels on the periphery. Scientists have identified some 1,800 contaminants inside the tanks, including plutonium, uranium, cesium, aluminum, iodine, and mercury. Watery liquids rest atop goop as thick as peanut butter and salt cakes resembling wet beach sand.

Legacy Contaminants in Aquatic Biota in a Stream Associated with Nuclear Weapons Material Production on the Savannah River Site.

Former nuclear weapons material production at the U.S. Department of Energy's Savannah River Site (SRS) has resulted in contamination of certain terrestrial and aquatic ecosystems on site with legacy wastes such as radiocesium (137Cs), tritium (3H), and metals. We collected fish and invertebrates from five beaver ponds (sites) above, adjacent, and downgradient of three SRS facilities (H-, F-, and C-Areas) to evaluate whether the accumulation of metals and radionuclides in biota were associated with specific facility operations and if the measured levels could pose risks to aquatic organisms. We compared concentrations of various metals, 137Cs, and 3H in fish, as well as in water (3H only), among sites along the stream gradient. Fish collected from sites adjacent to H-Area had significantly higher 137Cs concentrations compared to fish from other sites. Both biota and water samples indicated significantly greater levels of 3H in sites adjacent to and downstream of C-Area. Concentrations of zinc (Zn), copper (Cu), and mercury (Hg) in some samples exceeded effects levels reported for fish and may pose a risk to fish populations. This study reported fish tissue concentrations of 137Cs and 3H, which have not been documented extensively in ecotoxicological studies. Our results suggested that industrial operations such as nuclear material production at SRS could have long-lasting impact on the aquatic ecosystem via the release of radionuclides and metals, and long-term monitoring of physiological effects and population level impact in biota exposed to these contaminants are recommended.

Comparing multiple statistical methods for inverse prediction in nuclear forensics applications

Forensic science seeks to predict source characteristics using measured observables. Statistically, this objective can be thought of as an inverse problem where interest is in the unknown source characteristics or factors (X) of some underlying causal model producing the observables or responses (Y=g(X)+error). This paper reviews several statistical methods for use in inverse problems and demonstrates that comparing results from multiple methods can be used to assess predictive capability. Motivation for assessing inverse predictions comes from the desired application to historical and future experiments involving nuclear material production for forensics research in which inverse predictions, along with an assessment of predictive capability, are desired.Four methods are reviewed in this article. Two are forward modeling methods and two are direct inverse modeling methods. Forward modeling involves building a forward casual model of the responses (Y) as a function of the source characteristics (X) using content knowledge and data ideally obtained from a well-designed experiment. The model is then inverted to produce estimates of X given a new set of responses. Direct inverse modeling involves building prediction models of the source characteristics (X) as a function of the responses (Y) – subverting estimation of any underlying causal relationship. Through use of simulations and a data set from an actual plutonium production experiment, it is shown that agreement of predictions across methods is an indication of strong predictive capability, whereas disagreement indicates the current data are not conducive to making good predictions.

Nuclear energy and nuclear-weapon potential: A historical analysis of Japan in the 1960s

ABSTRACTThis article analyzes Japan's development of civilian nuclear energy and its potential for developing nuclear weapons in the late 1960s. First, it examines two technological studies of Japan's nuclear fissionable material production capability: one sponsored by the Japanese government and the other sponsored by the US government. A comparative analysis of them reveals that the Japanese study did not investigate the full range of feasible measures toward Japan's nuclear armament. Further scrutiny of Japanese nuclear-energy development in relation to its policy-making structure at that time draws out the following arguments: (1) Japan's civilian nuclear program clearly contributed to its acquisition of a latent nuclear weapon potential; (2) Japan had not deliberately developed the latent capability, which reflected the lack of coordination among political actors; (3) Japan increased its dependence on the United States in the nuclear-power field, making its pursuit of nuclear weapons politically more difficult. This case study of Japan illustrates not only the intricate relationship between the development of civilian nuclear power, the development of nuclear-weapon potential, and the proliferation of nuclear weapons, but also the effects of the state’s nuclear-policy-making structure on its nuclear posture.

Physicochemical study of extractants for extraction of rare earth element

In nuclear technology, the solvent extraction is an important step for recovery of rare earth materials, purification, radionuclide production, and preparation of nuclear reactor materials. Tributyl phosphate (TBP) and toluene are taken as extractant and diluent, respectively, for study of extraction efficiency for rare earth element like CeO2. In the present paper, idea of ultrasonic sound theory is intensively applied to study the physicochemical property of extractants and diluent pair. The experimental value of ultrasonic velocity, measured density, molar volume, and viscosity are used for computation of acoustical parameters and their excess values. The variations of physical and acoustical parameter are discussed in terms of molecular interactions. The prepared samples are treated for extraction of CeO2 by separating the organo-aqueous phase. The recovery of this reactor material with the help of this ultrasonic technique has been explained in terms of nature and extent of intermolecular interactions present in the binary mixture. The ultrasonic treatment for the recovery of this material provides an optimum value of the binary mixture for recovery of CeO2.

Joint U.S./Russian Studies of Population Exposures Resulting From Nuclear Production Activities in the Southern Urals

Beginning in 1948, the Soviet Union initiated a program for production of nuclear materials for a weapons program. The first facility for production of plutonium was constructed in the central portion of the country east of the southern Ural Mountains, about halfway between the major industrial cities of Ekaterinburg and Chelyabinsk. The facility, now known as the Mayak Production Association, and its associated town, now known as Ozersk, were built to irradiate uranium in reactors, separate the resulting plutonium in reprocessing plants, and prepare plutonium metal in the metallurgical plant. The rush to production, coupled with inexperience in handling radioactive materials, led to large radiation exposures, not only to the workers in the facilities, but also to the surrounding public. Fuel processing started with no controls on releases, and fuel dissolution and accidents in reactors resulted in release of ~37 PBq of I between 1948 and 1967. Designed disposals of low- and intermediate-level liquid radioactive wastes, and accidental releases via cooling water from tank farms of high-level liquid radioactive wastes into the small Techa River, caused significant contamination and exposures to residents of numerous small riverside villages downstream of the site. Discovery of the magnitude of the aquatic contamination in late 1951 caused revisions to the waste handling regimes, but not before over 200 PBq of radionuclides (with large contributions of Sr and Cs) were released. Liquid wastes were diverted to tiny Lake Karachay (which today holds over 4 EBq); cooling water was stopped in the tank farms. In 1957, one of the tanks in the tank farm overheated and exploded; over 70 PBq, disproportionately Sr, was blown over a large area to the northeast of the site. A large area was contaminated and many villages evacuated. This area today is known as the East Urals Radioactive Trace (EURT). Each of these releases was significant; together they have created a unique group of cohorts with their chronic, low dose-rate radiation exposure. The 26,000 workers at Mayak were highly exposed to external gamma and inhaled plutonium. A cohort of individuals raised as children in Ozersk is under evaluation for their exposures to radioiodine. The Techa River Cohort consists of over 30,000 people who were born before the start of exposure in 1949 and lived along the Techa River. The Techa River Offspring Cohort consists of ~21,000 persons born to one or more exposed parents of this group, many who also lived along the contaminated river. The EURT Cohort consists of ~18,000 people who were evacuated from the EURT soon after the 1957 explosion and another 8,000 who remained. These groups together are the focus of dose reconstruction and epidemiological studies funded by the United States, Russia, and the European Union to address the question, "Are doses delivered at low dose rates as effective in producing health effects as the same doses delivered at high dose rates?"Introduction of Joint U.S. and Russian Studies of Population Exposures (Video 2:13, http://links.lww.com/HP/A28).

Toxicodynamic modeling of 137Cs to estimate white-tailed deer background levels for the Department of Energy's Savannah River Site

The U.S. Department of Energy's (USDOE) Savannah River Site (SRS) is a former nuclear weapon material production and current research facility adjacent to the Savannah River in South Carolina, USA. The purpose of this study was to determine the background radiocesium ((137)Cs) body burden (e.g., from global fallout) for white-tailed deer (Odocoileus virginianus) inhabiting the SRS. To differentiate what the background burden is for the SRS versus (137)Cs obtained from SRS nuclear activities, data were analyzed spatially, temporally and compared to other off-site hunting areas near the SRS. The specific objectives of this study were: to compare SRS and offsite deer herds based on time and space; to interpret comparisons based on how data were collected as well as the effect of environmental and anthropogenic influences; to determine what the ecological half-life/decay rate is for (137)Cs in the SRS deer herd; and to give a recommendation to what should be considered the background (137)Cs level in the SRS deer herd. Based on the available information and analyses, it is recommended that the determination of what is considered background for the SRS deer herd be derived from data collected from the SRS deer herd itself and not offsite collections for a variety of reasons. Offsite data show extreme variability most likely due to environmental factors such as soil type and land-use patterns (e.g., forest, agriculture, residential activities). This can be seen from results where samples from offsite military bases (Fort Jackson and Fort Stewart) without anthropogenic (137)Cs sources were much higher than both the SRS and a nearby (Sandhills) study site. Moreover, deer from private hunting grounds have the potential to be baited with corn, thus artificially lowering their (137)Cs body burdens compared to other free-ranging deer. Additionally, sample size for offsite collections were not robust enough to calculate a temporal decay curve with an upper confidence level to determine if the herds are following predicted radioactive decay rates like the SRS or if the variability is due to those points described above. Using mean yearly values, the ecological half-life for (137)Cs body burdens for SRS white-tailed deer was determined to be 28.79 years--very close to the 30.2 years physical half-life.

Confronting the “Perpetual Menace to Human Security”

Nuclear weapon states historically have attached great secrecy to their nuclear weapon and fissile material production programs and stockpiles, despite warnings that this would fuel fears, handicap informed debate and decision making, and drive arms races. As evidenced by the “Action Plan on Nuclear Disarmament” agreed upon at the 2010 Treaty on the Non-Proliferation of Nuclear Weapons (NPT) Review Conference, however, the international community now sees greater transparency about nuclear weapon and fissile material stocks as necessary for enabling and monitoring progress toward nuclear disarmament. To support this effort, the International Panel on Fissile Materials has proposed a step-by-step program for weapon states to declare their inventories, production histories, and disposition of nuclear warheads and fissile materials, and to set up joint projects to develop methods for verifying these declarations. This openness initiative is described here, and could be adopted at the 2015 NPT Review Conference, laying a basis for negotiating verifiable deep reductions in nuclear arsenals and their eventual elimination.

Trophic dynamics of U, Ni, Hg and other contaminants of potential concern on the Department of Energy’s Savannah River Site

The Department of Energy's Savannah River Site is a former nuclear weapon material production and current research facility located in South Carolina, USA. Wastewater discharges from a fuel and nuclear reactor target manufacturing facility released depleted and natural U, as well as other metals into the Tims Branch-Steed Pond water system. We investigated the current dynamics of this system for the purposes of environmental monitoring and assessment by examining metal concentrations, bioavailability, and trophic transfer of contaminants in seven ponds. Biofilm, detritus, and Anuran and Anisopteran larvae were collected and analyzed for stable isotopes (δ (15)N, δ (13)C) and contaminants of potential concern (COPC) with a focus on Ni, U, and Hg, to examine metal mobility. Highest levels of Ni and U were found in biofilms U (147 and 332mgkg(-1) DW, respectively), while highest Hg levels were found in tadpoles (1.1mgkg(-1) DW). We found intraspecific biomagnification of COPCs as expressed through stable isotope analysis. Biofilms were the best indicators for contamination and Anuran larvae with the digestive tract removed were the best indicators of the specific bioavailability of the focal metals. Monitoring data showed that baseline δ (15)N values differed between ponds, but within a pond, values were stable throughout tadpole Gosner stage, strengthening the case to use this species for monitoring purposes. It is likely that there still is risk to ecosystem integrity as COPC metals are being assimilated into lower trophic organisms and even low levels of this mixture has shown to produce deleterious effects to some wildlife species.

ONE PERSPECTIVE ON STAKEHOLDER INVOLVEMENT AT HANFORD

The Hanford nuclear site in Washington State had a major role in the production of nuclear weapons materials during the Manhattan Project in World War II and during the Cold War that followed. The production of weapons-grade radionuclides produced a large amount of radioactive byproducts that have been stored since the mid-1900s at the Hanford Site. These by-product radionuclides have leaked from containment facilities into the groundwater, contaminated buildings used for radionuclide processing, and also contaminated the nuclear reactors used to produce weapons-grade uranium and plutonium. This issue has been a major concern to Hanford stakeholders for several decades, and the U.S. Department of Energy, the U.S. Environmental Protection Agency, and the Washington State Department of Ecology established a Tri-Party Agreement in 1989, at which time Hanford ceased production of nuclear weapons materials and began a major effort to clean up and remediate the Hanford Site's contaminated groundwater, soil, and facilities. This paper describes the concerns of stakeholders in the production of nuclear weapons, the secrecy of Hanford operations, and the potential impacts to public health and the environment from the unintended releases of weapons-grade materials and by-products associated with their production at the Hanford Site. It also describes the involvement of public stakeholders in the development and oversight by the Hanford Advisory Board of the steps that have been taken in cleanup activities at the Hanford Site that began as a major effort about two decades ago. The importance of involvement of the general public and public interest organizations in developing and implementing the Hanford cleanup strategy are described in detail.

Technology Breakthrough by Heavy Water Board in Material Support to Indian Nuclear Power Programme

Abstract Heavy Water Board (HWB) is the sole agency in the country for production and sustained supply of heavy water, nuclear grade solvents and enriched elemental boron which are the key input materials for Indian Nuclear Power Programme. DAE has ventured to develop heavy water technology indigenously starting from scratch. H2S-H2O bi-thermal process was developed starting from laboratory studies to pilot plant and breakthrough was achieved by setting up first industrial plant at Kota and double capacity plant at Manuguru. In early 1960‟s, NH3–H2 mono-thermal process was at nascent stage of development. The rich experience from first industrial plant set up at Baroda has led to success story in second generation plants at Thal and Hazira, totally with indigenous efforts. NH3-H2O front-end process had also been developed for ammonia based Heavy Water Plants (HWPs) making them independent of fertilizer plants. Performance indicators of operating HWPs have reached the zenith level. India is the largest global producer of heavy water and is the only country using multiple technologies. HWB is also fulfilling the global demand of high quality heavy water. HWB has diversified into other activities like industrial production of other nuclear materials and development of spin off technologies.

Hanford remediation at 20 years: A glass half‐empty

AbstractThe U.S. Department of Energy's (US DOE's) responsibilities for its former national nuclear weapons complex include remediation of the Hanford Site in Washington State. In 1989, the site's primary mission shifted from nuclear weapons material production to cleanup of the extensive radioactive and chemical contamination that represented the production legacy. Cleanup is governed by the Tri‐Party Agreement (TPA), between the US DOE, as responsible party, and the U.S. Environmental Protection Agency and Washington State Department of Ecology, as joint regulators. Nearly 20 years have passed since the TPA was signed, but the Hanford remediation is expected to require decades longer. This article covers the cleanup progress to date and challenges that remain, particularly from millions of gallons of highly radioactive liquid wastes and proposals to bring new wastes to Hanford. © 2008 Wiley Periodicals, Inc.