Inventory extension at the Nuclear Materials Storage Facility

The planned renovation of the Nuclear Material Storage Facility (NMSF) at Los Alamos National Laboratory will be a significant addition to the plutonium storage capacity of the nuclear weapons complex. However, the utility of the facility may be impaired by an overly conservative approach to performing inventories of material in storage. This report examines options for taking advantage of provisions in Department of Energy orders to extend the time between inventories. These extensions are based on a combination of modern surveillance technology, facility design features, and revised operational procedures. The report also addresses the possibility that NMSF could be the site of some form of international inspection as part of the US arms control and nonproliferation policy

Special nuclear materials cutoff exercise: Issues and lessons learned, Volume 2 of 3: Appendixes A - C

This document is the 2nd volume of the three volume set from the Special Nuclear Materials Cutoff Exercise held at Hanford in 1994. Volume 2 contains Appendices A-C, with Appendices A and B containing a discussion of the design of the PUREX process and Appendix C containing a discussion of the safeguards measures for the PUREX facility

Inventory extension considerations for long-term storage at the nuclear materials storage facility

Los Alamos National Laboratory is in the process of modifying its nuclear materials storage facility to a long-term storage configuration. In support of this effort, we examined technical and administrative means to extend periods between physical inventories. Both the frequency and sample size during a physical inventory could significantly impact required sizing of the non-destructive assay (NDA) laboratory as well as material handling capabilities. Several options are being considered, including (1) treating each storage location as a separate vault, (2) minimizing the number of items returned for quantitative analysis by optimizing the use of in situ confirmatory measurements, and (3) utilizing advanced monitoring technologies. Careful consideration of these parameters should allow us to achieve and demonstrate safe and secure storage while minimizing the impact on facility operations and without having to increase the size of the NDA laboratory beyond that required for anticipated shipping and receiving activities

Joint DOE-PNC research on the use of transparency in support of nuclear nonproliferation

PNC and LANL collaborated in research on the concept of transparency in nuclear nonproliferation. The research was based on the Action Sheet No. 21, which was signed in February 1996, ``The Joint Research on Transparency in Nuclear Nonproliferation`` under the ``Agreement between the Power Reactor and Nuclear Fuel Development Corporation of Japan (PNC) and the US Department of Energy (DOE) for Cooperation in Research and Development Concerning Nuclear Material Control and Accounting Measures for Safeguards and Nonproliferation``. The purpose of Action Sheet 21 is to provide a fundamental study on Transparency to clarify the means to improve worldwide acceptability for the nuclear energy from the nuclear nonproliferation point of view. This project consists of independent research and then joint discussion at workshops that address a series of topics and issues in transparency. The activities covered in Action Sheet 21 took place over a period of 18 months. Three workshops were held; the first and the third hosted by PNC in Tokyo, Japan and the second hosted by LANL in Los Alamos, New Mexico, US. The following is a summary of the three workshops. The first workshop addressed the policy environment of transparency. Each side presented its perspective on the following issues: (1) a definition of transparency, (2) reasons for transparency, (3) detailed goals of transparency and (4) obstacles to transparency. The topic of the second workshop was ``Development of Transparency Options.`` The activities accomplished were (1) identify type of facilities where transparency might be applied, (2) define criteria for applying transparency, and (3) delineate applicable transparency options. The goal of the third workshop, ``Technical Options for Transparency,`` was to (1) identify conceptual options for transparency system design; (2) identify instrumentation, measurement, data collection and data processing options; (3) identify data display options; and (4) identify technical options for reprocessing, enrichment, and MOX fuel fabrication facilities

Noble gas atmospheric monitoring at reprocessing facilities

The discovery in Iraq after the Gulf War of the existence of a large clandestine nuclear-weapon program has led to an across-the-board international effort, dubbed Programme 93+2, to improve the effectiveness and efficiency of International Atomic Energy Agency (IAEA) safeguards. One particularly significant potential change is the introduction of environmental monitoring (EM) techniques as an adjunct to traditional safeguards methods. Monitoring of stable noble gas (Kr, Xe) isotopic abundances at reprocessing plant stacks appears to be able to yield information on the burnup and type of the fuel being processed. To estimate the size of these signals, model calculations of the production of stable Kr, Xe nuclides in reactor fuel and the subsequent dilution of these nuclides in the plant stack are carried out for two case studies: reprocessing of PWR fuel with a burnup of 35 GWd/tU, and reprocessing of CAND fuel with a burnup of 1 GWd/tU. For each case, a maximum-likelihood analysis is used to determine the fuel burnup and type from the isotopic data

Joint DOE-PNC research on the use of transparency in support of nuclear nonproliferation

PNC and LANL collaborated in research on the concept of transparency in nuclear nonproliferation. The research was based on the Action Sheet No. 21, which was signed in February 1996, ``The Joint Research on Transparency in Nuclear Nonproliferation`` under the ``Agreement between the Power Reactor and Nuclear Fuel Development Corporation of Japan (PNC) and the US Department of Energy (DOE) for Cooperation in Research and Development Concerning Nuclear Material Control and Accounting Measures for Safeguards and Nonproliferation``. The purpose of Action Sheet 21 is to provide a fundamental study on Transparency to clarify the means to improve worldwide acceptability for the nuclear energy from the nuclear nonproliferation point of view. This project consists of independent research and then joint discussion at workshops that address a series of topics and issues in transparency. The activities covered in Action Sheet 21 took place over a period of 18 months. Three workshops were held; the first and the third hosted by PNC in Tokyo, Japan and the second hosted by LANL in Los Alamos, New Mexico, US. The following is a summary of the three workshops. The first workshop addressed the policy environment of transparency. Each side presented its perspective on the following issues: (1) a definition of transparency, (2) reasons for transparency, (3) detailed goals of transparency and (4) obstacles to transparency. The topic of the second workshop was ``Development of Transparency Options.`` The activities accomplished were (1) identify type of facilities where transparency might be applied, (2) define criteria for applying transparency, and (3) delineate applicable transparency options. The goal of the third workshop, ``Technical Options for Transparency,`` was to (1) identify conceptual options for transparency system design; (2) identify instrumentation, measurement, data collection and data processing options; (3) identify data display options; and (4) identify technical options for reprocessing, enrichment, and MOX fuel fabrication facilities

SEARCHING the GAMMA-RAY SKY for COUNTERPARTS to GRAVITATIONAL WAVE SOURCES: FERMI GAMMA-RAY BURST MONITO R and LARGE AREA TELESCOPE OBSERVATIONS of LVT151012 and GW151226

We present the Fermi Gamma-ray Burst Monitor (GBM) and Large Area Telescope (LAT) observations of the LIGO binary black hole merger event GW151226 and candidate LVT151012. At the time of the LIGO triggers on LVT151012 and GW151226, GBM was observing 68% and 83% of the localization regions, and LAT was observing 47% and 32%, respectively. No candidate electromagnetic counterparts were detected by either the GBM or LAT. We present a detailed analysis of the GBM and LAT data over a range of timescales from seconds to years, using automated pipelines and new techniques for characterizing the flux upper bounds across large areas of the sky. Due to the partial GBM and LAT coverage of the large LIGO localization regions at the trigger times for both events, differences in source distances and masses, as well as the uncertain degree to which emission from these sources could be beamed, these non-detections cannot be used to constrain the variety of theoretical models recently applied to explain the candidate GBM counterpart to GW150914

Supplement: "Localization and broadband follow-up of the gravitational-wave transient GW150914" (2016, ApJL, 826, L13)

This Supplement provides supporting material for Abbott et al. (2016a). We briefly summarize past electromagnetic (EM) follow-up efforts as well as the organization and policy of the current EM follow-up program. We compare the four probability sky maps produced for the gravitational-wave transient GW150914, and provide additional details of the EM follow-up observations that were performed in the different bands

Gravitational Waves and Gamma-Rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A

On 2017 August 17, the gravitational-wave event GW170817 was observed by the Advanced LIGO and Virgo detectors, and the gamma-ray burst (GRB) GRB170817A was observed independently by the Fermi Gamma-ray Burst Monitor, and the Anti-Coincidence Shield for the Spectrometer for the International Gamma-Ray Astrophysics Laboratory. The probability of the near-simultaneous temporal and spatial observation of GRB 170817A and GW170817 occurring by chance is 5.0 x 10(exp -8). We therefore confirm binary neutron star mergers as a progenitor of short GRBs. The association of GW170817 and GRB 170817A provides new insight into fundamental physics and the origin of short GRBs. We use the observed time delay of (+1.74 +/- 0.05) s between GRB170817A and GW170817 to: (i) constrain the difference between the speed of gravity and the speed of light to be between -3 x 10(exp-16) times the speed of light, (ii) place new bounds on the violation of Lorentz invariance, (iii) present a new test of the equivalence principle by constraining the Shapiro delay between gravitational and electromagnetic radiation. We also use the time delay to constrain the size and bulk Lorentz factor of the region emitting the gamma-rays. GRB170817A is the closest short GRB with a known distance, but is between 2 and 6 orders of magnitude less energetic than other bursts with measured redshift. A new generation of gamma-ray detectors, and subthreshold searches in existing detectors, will be essential to detect similar short bursts at greater distances. Finally, we predict a joint detection rate for the Fermi Gamma-ray Burst Monitor and the Advanced LIGO and Virgo detectors of 0.1 - 1.4 per year during the 2018--2019 observing run and 0.3 - 1.7 per year at design sensitivity

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta