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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 199 records · Page 11
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Physical cryptographic verification of nuclear warheads

Significance We provide a method for potentially solving one of the central problems in arms control: proving the authenticity of a nuclear warhead without revealing information about its construction. The proposal is the first, to our knowledge, to be proof-theoretically sound (i.e., unspoofable) and information-theoretically secure. The method uses a tomography technique which can resolve the spatial distribution of mass with isotopic specificity. The soundness and security emerge from an integral-geometric transform that is able to uniquely map 3D geometries from zero-dimensional point measurements.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2015

Nuclear Warhead Verification: A Review of Attribute and Template Systems

Verification of current nuclear arms control treaties between United States and Russia relies primarily on the verification of delivery vehicles. Warheads are counted indirectly via the delivery vehicles that they are associated with. As states move to lower numbers of nuclear weapons in their arsenals, verification will likely pose complex challenges. Most importantly, future nuclear disarmament treaties may place limits on the total number of nuclear weapons in the arsenals. Their verification would require inspections of individual nuclear warheads without revealing secret information. By confirming the authenticity of nuclear warheads and perhaps also of warhead components we show the verification challenge for future reductions in the nuclear arsenals. Our paper provides an overview of the development of verification systems, and highlights the challenges and the opportunities for future research in this area.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2019

A Cryptographic Escrow for Treaty Declarations and Step-by-Step Verification

The verification of arms-control and disarmament agreements requires states to provide declarations, including information on sensitive military sites and assets. There are important cases, however, where negotiations of these agreements are impeded because states are reluctant to provide any such data, because of concerns about prematurely handing over militarily significant information. To address this challenge, we present a cryptographic escrow that allows a state to make a complete declaration of sites and assets at the outset and commit to its content, but only reveal the sensitive information therein sequentially. Combined with an inspection regime, our escrow allows for step-by-step verification of the correctness and completeness of the initial declaration so that the information release and inspections keep pace with parallel diplomatic and political processes. We apply this approach to the possible denuclearization of North Korea. Such approaches can be applied, however, to any agreement requiring the sharing of sensitive information.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2022

Document-Based Nuclear Archaeology

Deeper reductions in the nuclear arsenals will require better understanding of historic fissile material management and production. The concept of “nuclear archaeology” has been considered since the 1990s to provide the tools and methods to develop independent production estimates, primarily based on nuclear forensic techniques. Here, we propose to add a framework for reconstructing the history of a nuclear program that complements traditional nuclear archaeology techniques by examining the role of operating records to support such an effort. As a test case, we use the JEEP II reactor, a 2 MW civilian research reactor at Norway’s Institute for Energy Technology (IFE), in operation for more than fifty years, however, recently shut down permanently. We have collected, analyzed, and started to preserve the reactor’s operating records, which exist on both analog and digital media, and to simulate parts of its history using OpenMC/ONIX neutronics calculations. Here, a particular focus of this project has been on digital data curation and preservation to confirm and maintain the integrity, authenticity, and provenance of these records. In developing guidelines for best practices that conform to existing standards for long-term digital preservation and curation, we hope this project can help lay the basis for future nuclear archaeology efforts to support nuclear arms control and disarmament.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2023

Ceci N’est Pas Une Bombe: Lessons from a Field Experiment Using Neutron and Gamma Measurements to Confirm the Absence of Nuclear Weapons

In March 2023, the UN Institute for Disarmament Research held a verification experiment that included a mockup onsite inspection at a former military facility in the municipality of Menzingen, Switzerland. The experiment included a visit to the site by an inspection team, accompanied by the host team. Among other activities, radiation measurements were used to confirm the non-nuclear nature of selected items stored onsite. In this paper, we discuss the neutron and gamma measurement systems used during the experiment and the inspection protocols followed to confirm the absence of nuclear weapons. Furthermore, results from the experiment and a laboratory reproduction are presented, before concluding with lessons learned for how absence-confirmation measurements can help support verification of future arms control agreements.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2016

The history and outlook for seismic monitoring of nuclear explosions in the context of the Comprehensive Nuclear-Test-Ban Treaty

Modern methods of nuclear-explosion monitoring are vastly more capable than they were when underground nuclear testing began in the late 1950s, in part because a cycle of improvements in explosion monitoring in the 1960–80 period led to improvements in monitoring for earthquakes and other phenomena, which then led to a general growth in monitoring assets that in turn has been applied back to explosion monitoring. Practical experiences in nuclear-explosion monitoring, acquired during the era of active testing prior to finalization of the CTBT text in 1996, laid the basis for monitoring in support of this arms-control initiative. This article elaborates on the future of nuclear-test-monitoring technology, which can build upon an additional and remarkable growth of general monitoring assets that began in the 1990s, largely unrelated to the specifics of nuclear-test monitoring. A new cycle of improvements in earthquake monitoring is likely to improve monitoring for explosions. While it is not easy to quantify the degree of monitoring improvement afforded by such new assets, an example from North Korea indicates the improvement can be substantial.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2019

Deferred Verification: The Role of New Verification Technologies and Approaches

Researchers at UNIDIR have recently proposed a fundamentally new approach to nuclear arms control verification, dubbed "deferred verification." The concept forgoes inspections at sensitive nuclear sites and inspections of nuclear materials or components in classified form. To implement this concept, a state first divides its territory into a closed segment and an open segment. The total fissile material inventory in the closed segment, which includes the weapon complex, is known and declared with very high accuracy. Essentially no inspections take place in the closed segment. Yet, inspectors have access to the open segment, which includes in particular the civilian nuclear sector. The fissile material inventory in the open segment is known with less accuracy, but uncertainties can be reduced over time using methods of nuclear archaeology. Deferred verification relies primarily on established safeguards techniques and avoids many unresolved verification challenges, including for example the need for information barriers for warhead confirmation measurements. At the same time, deferred verification faces some unique challenges. In this work, we explore some of these challenges and offer possible solutions while maintaining the strengths of the concept; to do so, we examine possible noncompliance strategies in which a state would seek to withhold a higher-than-declared inventory.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2021

Neutron-Resonance Transmission Analysis with a Compact Deuterium-Tritium Neutron Generator

Neutron Resonance Transmission Analysis (NRTA) is a spectroscopic technique which uses the resonant absorption of neutrons in the epithermal range to infer the isotopic composition of an object. This spectroscopic technique has relevance in many traditional fields of science and nuclear security. NRTA in the past made use of large, expensive accelerator facilities to achieve precise neutron beams, significantly limiting its applicability. Here, we describe a series of NRTA experiments where we use a compact, low-cost deuterium-tritium (DT) neutron generator to produce short neutron beams (2.6 m) along with a 6 Li-glass neutron detector. The time-of-flight spectral data from five elements – silver, cadmium, tungsten, indium, and 238 U – clearly show the corresponding absorption lines in the 1-30 eV range. The experiments show the applicability of NRTA in this simplified configuration, and prove the feasibility of this compact and low-cost approach. This could significantly broaden the applicability of NRTA, and make it practical and applicable in many fields, such as material science, nuclear engineering, and arms control.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2020

Colloquium : Neutrino detectors as tools for nuclear security

For over 40 years, physicists have discussed possible uses for neutrino detectors in nuclear nonproliferation, arms control, and fissile materials security. Neutrinos are an attractive fission signature because they readily pass through matter. The same property makes neutrinos challenging to detect in systems that would be practical for nuclear security applications. This Colloquium presents a broad overview of several potential neutrino applications, including the near-field monitoring of known reactors, far-field monitoring of known or discovery of undeclared reactors, detection of reactor waste streams, and detection of nuclear explosions. Recent detector advances have made near-field monitoring feasible, whereas farther-field reactor detection and waste stream detection monitoring may be possible in some cases with further research and development. Very long-range reactor monitoring and nuclear explosion detection do not seem feasible for the foreseeable future due to considerable physical and/or practical constraints.

42 ENGINEERING↗
DOE OSTI2019

Randomized prospective phase III trial of 68 Ga-PSMA-11 PET/CT molecular imaging for prostate cancer salvage radiotherapy planning [PSMA-SRT]

Salvage radiotherapy (SRT) for prostate cancer (PCa) recurrence after prostatectomy offers long-term biochemical control in about 50–60% of patients. SRT is commonly initiated in patients with serum PSA levels < 1 ng/mL, a threshold at which standard-of-care imaging is insensitive for detecting recurrence. As such, SRT target volumes are usually drawn in the absence of radiographically visible disease. 68 Ga-PSMA-11 (PSMA) PET/CT molecular imaging is highly sensitive and may offer anatomic localization of PCa biochemical recurrence. However, it is unclear if incorporation of PSMA PET/CT imaging into the planning of SRT could improve its likelihood of success. The purpose of this trial is to evaluate the success rate of SRT for recurrence of PCa after prostatectomy with and without planning based on PSMA PET/CT. Methods We will randomize 193 patients to proceed with standard SRT (control arm 1, n = 90) or undergo a PSMA PET/CT scan (free of charge for patients) prior to SRT planning (investigational arm 2, n = 103). The primary endpoint is the success rate of SRT measured as biochemical progression-free survival (BPFS) after initiation of SRT. Biochemical progression is defined by PSA ≥ 0.2 ng/mL and rising. The randomization ratio of 1:1.13 is based on the assumption that approximately 13% of subjects randomized to Arm 2 will not be treated with SRT because of PSMA-positive extra-pelvic metastases. These patients will not be included in the primary endpoint analysis but will still be followed. The choice of treating the prostate bed alone vs prostate bed and pelvic lymph nodes, with or without androgen deprivation therapy (ADT), is selected by the treating radiation oncologist. The radiation oncologist may change the radiation plan depending on the findings of the PSMA PET/CT scan. Any other imaging is allowed for SRT planning in both arms if done per routine care. Patients will be followed until either one of the following conditions occur: 5 years after the date of initiation of randomization, biochemical progression, diagnosis of metastatic disease, initiation of any additional salvage therapy, death. Discussion This is the first randomized phase 3 prospective trial designed to determine whether PSMA PET/CT molecular imaging can improve outcomes in patients with PCa early BCR following radical prostatectomy.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Development of an ideal observer that incorporates nuisance parameters and processes list-mode data

Observer models were developed to process data in list-mode format in order to perform binary discrimination tasks for use in an arms-control-treaty context. Data used in this study was generated using GEANT4 Monte Carlo simulations for photons using custom models of plutonium inspection objects and a radiation imaging system. We evaluated observer model performance and then presented using the area under the receiver operating characteristic curve. Lastly, we studied the ideal observer under both signal-known-exactly conditions and in the presence of unknowns such as object orientation and absolute count-rate variability; when these additional sources of randomness were present, their incorporation into the observer yielded superior performance.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2015

Proliferation Persuasion. Coercive Bargaining with Nuclear Technology

Why do states wait for prolonged periods of time with the technical capacity to produce nuclear weapons? Only a handful of countries have ever acquired the sensitive nuclear fuel cycle technology needed to produce fissile material for nuclear weapons. Yet the enduring trend over the last five decades is for these states to delay or forgo exercising the nuclear weapons option provided by uranium enrichment or plutonium reprocessing capabilities. I show that states pause at this threshold stage because they use nuclear technology to bargain for concessions from both allies and adversaries. But when does nuclear latency offer bargaining benefits? My central argument is that challengers must surmount a dilemma to make coercive diplomacy work: the more they threaten to proliferate, the harder it becomes to reassure others that compliance will be rewarded with nuclear restraint. I identify a range of mechanisms able to solve this credibility problem, from arms control over breakout capacity to third party mediation and confidence building measures. Since each step towards the bomb raises the costs of implementing these policies, a state hits a sweet spot when it first acquires enrichment and/or reprocessing (ENR) technology. Subsequent increases in proliferation capability generate diminishing returns at the bargaining table for two reasons: the state must go to greater lengths to make a credible nonproliferation promise, and nuclear programs exhibit considerable path dependency as they mature over time. Contrary to the conventional wisdom about power in world politics, less nuclear latency thereby yields more coercive threat advantages. I marshal new primary source evidence from archives and interviews to identify episodes in the historical record when states made clear decisions to use ENR technology as a bargaining chip, and employ this theory of proliferation persuasion to explain how Japan, North Korea, and Iran succeeded and failed to barter concessions from the United States. By clarifying when countries are able to leverage steps towards the bomb for international political gain, my work advances our understanding of proliferation and coercive diplomacy.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2016

Oak Ridge National Laboratory Office of International Nuclear Safeguards: Human Capital Development Activity in FY16

In 2007, the U.S. Department of Energy National Nuclear Security Administration (DOE NNSA) Office of Nonproliferation and Arms Control (NPAC) completed a comprehensive review of the current and potential future challenges facing the international safeguards system. One of the report’s key recommendations was for DOE NNSA to launch a major new program to revitalize the international safeguards technology and human resource base. In 2007, at the International Atomic Energy Agency (IAEA) General Conference, then Secretary of Energy Samuel W. Bodman announced the newly created Next Generation Safeguards Initiative (NGSI). NGSI consists of five program elements: policy development and outreach, concepts and approaches, technology and analytical methodologies, human capital development (HCD), and infrastructure development. This report addresses the HCD component of NGSI. The goal of the HCD component as defined in the NNSA Program Plan is “to revitalize and expand the international safeguards human capital base by attracting and training a new generation of talent.” The major objectives listed in the HCD goal include education and training, outreach to universities and professional societies, postdoctoral appointments, and summer internships at national laboratories.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2016

Report on July 2015 Additional Protocol Coordinators Best Practices Workshop

After 10 years of implementation experience, the Office of Nonproliferation and Arms Control (NPAC) within the Department of Energy/National Nuclear Security Administration (DOE/NNSA) conducted the Additional Protocol (AP) Coordinators Best Practices Workshop at Oak Ridge National Laboratory from July 29-30, 2015. The goal of this workshop was to identify implementation best practices, lessons learned, and compliance challenges from the various Additional Protocol Coordinators (APCs) at each laboratory in the DOE/NNSA complex and associated sites. The workshop provided the opportunity for participants to share their insights and establish networks that APCs can utilize to continue to discuss challenges (new and old), identify best practices, and enhance communication and coordination for reporting multi-lab research projects during review activities. Workshop participants included DOE/NNSA HQ, laboratory and site APCs, seasoned experts, members of the original implementation outreach team, and Field Element and site security representatives.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2015

Gary Laughlin IHNS Intro to 2015 HPC Annual Report

The International, Homeland, and Nuclear Security (IHNS) Program Management Unit (PMU) oversees a broad portfolio of Sandia’s programs in areas ranging from global nuclear security to critical asset protection. We use science and technology, innovative research, and global engagement to counter threats, reduce dangers, and respond to disasters. The PMU draws on the skills of scientists and engineers from across Sandia. Our programs focus on protecting US government installations, safeguarding nuclear weapons and materials, facilitating nonproliferation activities, securing infrastructures, countering chemical and biological dangers, and reducing the risk of terrorist threats. We conduct research in risk and threat analysis, monitoring and detection, decontamination and recovery, and situational awareness. We develop technologies for verifying arms control agreements, neutralizing dangerous materials, detecting intruders, and strengthening resiliency. Our programs use Sandia’s High-Performance Computing resources for predictive modeling and simulation of interdependent systems, for modeling dynamic threats and forecasting adaptive behavior, and for enabling decision support and processing large cyber data streams. In this report, we highlight four advanced computation projects that illustrate the breadth of the IHNS mission space.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2017

Delayed Gamma-ray Spectroscopy for Safeguards Applications

The delayed gamma-ray assay technique utilizes an external neutron source (D-D, D-T, or electron accelerator-driven), and high-resolution gamma-ray spectrometers to perform characterization of SNM materials behind shielding and in complex configurations such as a nuclear fuel assembly. High-energy delayed gamma-rays (2.5 MeV and above) observed following the active interrogation, provide a signature for identification of specific fissionable isotopes in a mixed sample, and determine their relative content. Potential safeguards applications of this method are: 1) characterization of fresh and spent nuclear fuel assemblies in wet or dry storage; 2) analysis of uranium enrichment in shielded or non-characterized containers or in the presence of a strong radioactive background and plutonium contamination; 3) characterization of bulk and waste and product streams at SNM processing plants. Extended applications can include warhead confirmation and warhead dismantlement confirmation in the arms control area, as well as SNM diagnostics for the emergency response needs. In FY16 and prior years, the project has demonstrated the delayed gamma-ray measurement technique as a robust SNM assay concept. A series of empirical and modeling studies were conducted to characterize its response sensitivity, develop analysis methodologies, and analyze applications. Extensive experimental tests involving weapons-grade Pu, HEU and depleted uranium samples were completed at the Idaho Accelerator Center and LLNL Dome facilities for various interrogation time regimes and effects of the neutron source parameters. A dedicated delayed gamma-ray response modeling technique was developed and its elements were benchmarked in representative experimental studies, including highresolution gamma-ray measurements of spent fuel at the CLAB facility in Sweden. The objective of the R&D effort in FY17 is to experimentally demonstrate the feasibility of the delayed gamma-ray interrogation of shielded SNM samples with portable neutron sources suitable for field applications.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2017

Rethinking Approaches to Strategic Stability in the 21st Century

Lawrence Livermore National Laboratory (LLNL) hosted a two-day conference on rethinking approaches to strategic stability in the 21st century on October 20-21, 2016 in Livermore, CA. The conference was jointly convened by Lawrence Livermore, Los Alamos, and Sandia National Laboratories, and was held in partnership with the United States Department of State’s Bureau of Arms Control, Verification and Compliance. The conference took place at LLNL’s Center for Global Security Research (CGSR) and included a range of representatives from U.S. government, academic, and private institutions, as well as representatives from U.S. allies in Europe and Asia.The following summary covers topics and discussions from each of the panels. It is not intended to capture every point in detail, but seeks to outline the range of views on these complex and inter-related issues while providing a general overview of the panel topics and discussions that took place. The conference was held under the Chatham House rule and does not attribute any remarks to any specific individual or institution. The views reflected in this report do not represent the United States Government, Department of State, or the national laboratories.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2017

FPGA Authentication Methods.

One of the greatest challenges facing designers of equipment to be used in a nuclear arms control treaty is how to convince the other party in the treaty to trust its results and functionality. Whether the host provides equipment meant to prove treaty obligations and the inspector needs to gain that trust (commonly referred to as authentication), or the inspector provides this equipment and the host needs to gain this trust (commonly considered to be included in certification), one party generally has higher confidence in the equipment at the start of a treaty regime and the other party needs to gain that confidence prior to use. While we focus on authentication in this document—that is, the inspector gaining confidence in host-provided equipment—our conclusions will likely apply to host certification of inspector-provided equipment.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗