US metric study mission to the United Kingdom and the Federal Republic of Germany: Report of the NASA representative (Full Report)
For abstract, see preceding accession.
Vlannes, P. N.↗
SEARCH · Engineering Papers
Results for “UNITED KINGDOM”
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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United Kingdom participation in the Middle Atmosphere Programme
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Thomas, L.↗
Optical identifications of radio sources with accurate positions using the United Kingdom Schmidt Telescope (UKST) IIIa-J plates
Several programs are making use of UKST Sky Survey plates to identify southern radio sources. The fine-grain modern plates and accurate radio positions give a much improved identification rate. It seems that it will very soon be possible to determine whether or not there is a quasar redshift cut-off at z of about 4. There is an urgent need for more accurate fundamental reference star positions in the South.
Savage, A.↗
The Southern Hemisphere lower stratosphere during August and September 1987 - Analyses based on the United Kingdom Meteorological Office Global Model
This paper presents a series of meteorological analyses used to aid the interpretation of the in situ Airborne Antarctic Ozone Experiment (AAOE) observations obtained aboard the ER-2 and DC-8 aircraft and examines the basis and accuracy of the analytical procedure. Maps and sections of meteorological variables derived from the UK Meteorological Office Global Model are presented for ER-2 and DC-8 flight days. It is found that analyzed temperatures and winds are generally in good agreement with AAOE observations at all levels; minor discrepancies were evident only at DC-8 altitudes. Maps of potential vorticity presented on the 428-K potential temperature surface show that the vortex is essentially circumpolar, although there are periods when major distortions are apparent.
Mckenna, D. S.↗
Use of Nuclear Divers in Decommissioning of Spent Fuel Pools/Ponds in the United Kingdom - 17431
Magnox Ltd. (Operated by the Cavendish Fluor Partnership) has initiated decommissioning of spent fuel pools/ponds utilizing divers. This decommissioning technique is being employed to disassemble and size reduce underwater equipment and furniture, as well as the collection of sludge and debris prior to draining of the pool. This technique has proven to be highly effective at reducing the radiological exposure to the workforce over previously implemented methods and is expected to significantly reduce overall decommissioning durations and costs. The decommissioning of the UK Nuclear Decommissioning Authority's (NDA) Dungeness A power station spent fuel ponds was initiated in 2015 to eliminate the mobile hazards and prepare the facilities for entry into a Care and Maintenance period. This dual reactor site has two spent fuel ponds each containing 1000 m{sup 3} of water, with the fuel removed since April 2012, which will utilize divers to remove solid wastes from the ponds prior to drain down. This technique has overcome many challenges to implementation including regulatory approval and high airborne contamination. The use of divers for decommissioning was a new technique for the Magnox Sites and required early engagement with the UK Office for Nuclear Regulation (ONR) and the Health and Safety Executive (HSE). The use of plasma arc cutting underwater required the pond area to be classified as an airborne contamination area. The implementation of local ventilation has controlled this hazard. The initial demonstration dives at Dungeness A were completed in April 2016 and the decommissioning dives are expected to be completed in March 2017. This is a substantial improvement to the project schedule and will allow the project completion 5 1/2 years ahead of the Licence Condition milestone. This technique is planned to be implemented at two further NDA Magnox power stations over the next three years. This paper provides the accomplishments and lessons learned to date. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Panel Session 19: Developments in the Clean-up Mission of Sellafield
This panel focused on the progress towards closure of the legacy ponds and silos on the Sellafield Site. The discussion included progressive learning, technical challenges, safety, and regulatory flexibility required to achieve cleanup. The panel included NDA, regulators and Sellafield Ltd. Presentations proposed include: 1 - Developments in the Cleanup of Sellafield: An Owners Perspective (Adrian Simper, Nuclear Decommissioning Authority UK (United Kingdom)); 2 - Sellafield Ltd (Lee Peck, Sellafield Ltd. (United Kingdom)); 3 - Developments in the Clean-up Mission at Sellafield (Ian Dallas, Office for Nuclear Regulation (United Kingdom)); 4 - Developments in the Clean-up Mission of Sellafield, UK (Steven Thomson, National Nuclear Laboratory (United Kingdom))
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Recent Developments in Space Debris Mitigation Policy and Practices
In recent years, emphasis has shifted from national efforts to control the space debris population to international ones. Here, too, great progress has been made, most notably by the Inter-Agency Space Debris Coordination Committee (IADC) and the Committee on the Peaceful Uses of Outer Space (COPUOS) of the United Nations. Today, a firm international consensus is rapidly building on the principal space debris mitigation measures. The IADC is an association of the space agencies of ten countries (China, France, Germany, India, Italy, Japan, Russia, Ukraine, the United Kingdom, and the United States) and the European Space Agency, representing 17 countries of which four (France, Germany, Italy, and the United Kingdom) are also full IADC members. At the 17th meeting of the IADC in October 1999, a new Action Item (AI 17.2) was adopted to develop a set of consensus space debris mitigation guidelines. The purpose of the activity was to identify the most valuable space debris mitigation measures and to reach an international agreement on common directives. The IADC Space Debris Mitigation Guidelines (www.iadc-online.org/index.cgi?item=docs_pub) were formally adopted in October 2002 during the Second World Space Congress in Houston, Texas. Two years later a companion document, entitled Support to the IADC Space Debris Mitigation Guidelines, was completed to provide background and clarification for the guidelines.
Johnson, Nicholas L.↗
A review of collaborative studies between the NSTX/-U and MAST/-U spherical tokamaks
The National Spherical Torus Experiment (NSTX) at the Princeton Plasma Physics Laboratory in the United States, and the mega ampere spherical tokamak (MAST) at the United Kingdom Atomic Energy Authority in the United Kingdom, and their respective upgrades (NSTX-U and MAST-U) are two MAST fusion devices that have operated roughly over the past two decades. Both devices have made significant contributions to understanding spherical tokamak (ST) plasma physics, and fusion plasmas in general, and both have contributed data to multi-machine database studies. Several diagnostics have been physically moved from one machine to the other by diagnostic teams working on both devices. Collaboration has benefited both research teams in the areas of operational expertise, scenario development, and equilibrium reconstruction techniques. More focused comparative studies between the two devices have been pursued over the years in many areas as well, including stability calculations, disruption characterization, pedestal and edge localized mode stability, confinement and transport, energetic particles, and heating and current drive modelling. Together NSTX/-U and MAST/-U set the stage for the future of STs, which is entering the phase of design of demonstration power plant devices.
70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
Determination of the 161 Tb half-life
There is significant interest in the use of terbium radioisotopes for applications in cancer therapy and diagnosis. Of these, 161 Tb, a medium energy beta- and prolific auger emitter, is being investigated as a potential alternative to 177 Lu. The higher proportion of conversion electron and Auger electron emissions, and variety of low-energy gammas make 161 Tb an attractive targeted theranostic. As a product of nuclear fission, 161 Tb is also of importance to nuclear forensics. The current evaluated half-life of 6.89(2) d has a standard uncertainty that contributes significantly to the standard uncertainty of decay calculated activity determination. Furthermore, the accuracy of this evaluated half-life has been called into question by measurements reported recently at the Institute of Radiation Physics (IRP), Switzerland. In this work, the half-life of 161 Tb was measured at three independent laboratories located in the United Kingdom and United States of America for a total of five determinations using three independent measurement techniques. In conclusion, the half-life determined for 161 Tb of 6.9637(29) d confirms the observed 1 % relative increase observed by IRP, though the reported half-lives in this work and at IRP are significantly different (ζ-score = 3.1).
half-life↗
XXVIIth International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY 2019) (Final Report)
Supersymmetry (SUSY) is one of most elegant extensions of the Standard Model (SM) and explains the puzzles of the SM by providing a candidate to explain the dark matter content of the universe, allowing scientists to understand the origin of the electroweak scale requiring the top mass to be around 170 GeV and leading to the unification of forces at a grand unified scale. Further the minimal supersymmetric standard model (MSSM) predicts the Higgs boson mass to be less than 135 GeV. The discovery of the Higgs Boson with mass around 125 GeV at the LHC has provided a major support to SUSY ideas. Searches for SUSY are ongoing at the Large Hadron Collider (LHC). Direct and indirect dark matter experiments are searching for a particle dark matter candidate which arises most naturally in SUSY models. Proton decay predicted by SUSY grand unified theories is being searched for at deep underground experiments. In addition, recent advances in neutrino and dark matter physics, observational astrophysics, precision cosmology and the promising new window into the cosmos opened by the direct detection of gravitational waves, have brought new ideas on the potential connections between new fundamental particles and our understanding of their impact on the early universe and its evolution. At present, the major questions include: Is SUSY still the best candidate for models beyond the SM? Do we have any well motivated alternative to SUSY? Have we exhausted all possibilities to search for new physics at high and low energy scales? XXVIIth International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY 2019), hosted by Texas A&M University – Corpus Christi during May 20-24, 2019, provided a unique venue to discus and understand the status of SUSY, connection between particle physics and cosmology, supersymmetry and its alternative, Higgs sector, neutrino sector, flavor sector, dark matter, electroweak phase transition, astroparticle physics, gravitational waves and string theory. Discussion of results from the LHC, recent neutrino experiments and observations, direct and indirect dark matter detection experiments, detection of gravitational waves, data from particle colliders, as well as measurements of the CMB and Large Scale Structure were an integral part of SUSY 2019. To ensure the younger participants will benefit from the conference the most, the conference was preceded by the 4 day long pre-SUSY summer school for graduate students and postdocs. The invited speakers were leading scientists in the fields of SUSY interest. The school took place on Texas A&M University – Corpus Christi campus during the week prior the SUSY 2019 conference (May 15 – 18, 2019). Since its inception in 1993, SUSY has become one of the most important and widely attended international meetings in high energy physics, devoted to new ideas in fundamental particle physics. SUSY 2019 brought together approximately 250 scientists, theorists, phenomenologists, experimentalists and cosmologists, (including over 60 graduate students and 70 postdocs) representing 22 nations: Australia, Belgium, Canada, Chile, China, Colombia, France, Germany, India, Italy, Japan, Mexico, Peru, Portugal, Romania, South Korea, Spain, Sweden, Switzerland, Taiwan, United Kingdom and United States. SUSY 2019 provided a stimulating venue for the exchange of scientific ideas among experts in dark matter, neutrino physics, particle physics, astrophysics and cosmology. The following scientific topics were delivered during SUSY 2019 in form of 44 plenary talks and over 200 parallel talks: Unification of Forces; Electroweak, Top and Higgs Physics; Precision Calculations and MC tools; BSM in Flavor Physics; Neutrino Masses: Models and Phenomenology; Cosmology and Gravitational Waves; Dark Matter, Astroparticle Physics; Formal Field Theory and Strings; Alternatives to Supersymmetry; Quantum Information: Machine Learning/Big Data. 28 talks were given during the pre-SUSY program related to the following topics: Neutrino Physics; Big Data; Collider Physics & SUSY; String Phenomenology; Cosmology; Dark Matter; SUSY Models and Phenomenology
43 PARTICLE ACCELERATORS↗
Results of international Dobson spectrophotometer calibrations at Arosa, Switzerland, 1990
An international comparison of Dobson ozone spectrophotometers, organized and partially funded by the World Meteorological Organization (WMO), was held at the Lichtklimatisches Observatorium (LKO) in Arosa, Switzerland, July-August 1990. Countries participating with a total of 18 Dobson instruments were Belgium, Czechoslovakia, Denmark, Germany, Greece, Hungary, Iceland, Norway, Poland, Portugal, Rumania, Spain, Switzerland, the United Kingdom, the United States, and the United Soviet Socialist Republics. The reference standard instrument for the comparison was U.S.A. Secondary Standard Dobson Spectrophotometer 65 maintained by the NOAA Climate and Monitoring and Diagnostics Laboratory, Boulder, Colorado. The mean difference in ozone obtained with the Dobson instruments relative to Dobson instrument 65, calculated from ADDSGQP observations in the air mass range 1.15-3.2, was minus 1.0 plus or minus 1.2 (1 sigma) percent. The WMO Standard Brewer Spectrometer 39 also participated. In the mean, the Brewer instrument measured 0.6 plus or minus 0.2 (1 sigma) percent more ozone than did Dobson instrument 65. Results are presented, also, of ozone vertical profile measurements made with the Dobson instruments, two Brewer spectrometers, a LIDAR, a balloon ozonesonde flown from Hohenpeissenberg, Germany, and balloon ozonesondes flown from Payerne, Switzerland.
Grass, R. D.↗
Design and testing of a combined neutron and gamma assay system for measuring fissile material in fuel and waste items - 15340
A combined neutron and gamma ray assay system for the measurement of fissile material in both fuel and waste items has been designed, modelled, developed and tested. The purpose of the system is to measure and characterize a wide range of fissile materials including uranium, plutonium, americium and mixed oxide fuel arising from a variety of processes and facilities across the United Kingdom. Dounreay Site Restoration Limited at Dounreay currently stores these items form the United Kingdom Nuclear Decommissioning Authority's un-irradiated fuel inventory. This inventory comprises historic materials from ex-United Kingdom Atomic Energy Authority nuclear fuel projects and experiments together with fast reactor fuel materials and some commercial fuel items as delivered to Dounreay for recovery. The combined assay system has been designed and constructed to support the operation of a fuel processing facility, which will be operated at Dounreay to treat these historic legacy fuel materials, making them suitable for long term storage. Appropriate characterization of the fissile material is required for safety, criticality control and nuclear materials safeguards purposes prior to final disposition. The system consists of both gamma ray and neutron measurement components. The results of a neutron measurement are combined with the gamma ray isotopic ratio measurement results to generate the assay result for the fissile material being characterized. The gamma ray component of the system employs a safeguards quality high purity Germanium detector with electro-mechanical cooling and the measurements of fissile material containers are made in a shielded chamber with a tin and copper graded lining. Containers of fissile material are rotated during the gamma ray measurement and a variable automatic steel collimator aperture mechanism is employed to adjust the measured count rate to control detector dead time. Gamma ray spectra are analysed using the plutonium and uranium isotopic ratio code PC/FRAM. The gamma ray system can also be configured to perform a direct assay of small quantities of uranium bearing material. For this assay measurement a series of cadmium filters can be positioned in front of the detector to reduce the contribution from 59 keV gamma rays from Am-241. In addition to gamma ray isotopic measurements, both active and passive neutron assay is performed by the system. The neutron-measuring component consists of a thick walled cylindrical polyethylene chamber, which provides neutron moderation for 30 one-inch diameter He-3 detector tubes located in re-entrant channels in the polyethylene moderator. Two removable polyethylene-inserts incorporating lower plug assemblies are provided, one with and one without a cadmium lining. Also two top plug units are provided, again one with cadmium and one without a cadmium liner. The Neutron Subsystem can be operated both as a passive and as an active neutron coincidence counter. In both fast and thermal active neutron mode, the neutron component employs two americium-beryllium (Am-Be) alpha-n neutron sources, one positioned in the top and the other in the bottom plug unit. The neutron sources are removed when the counter is operated in passive mode. Passive neutron detection efficiency and active neutron performance has been modelled using the MCNP Monte Carlo computer simulation code as part of the design process. In the absence of fissile samples, operation of the gamma ray component of the system has been tested initially using calibrated Eu-152 and Ba-133 gamma ray sources and the use of archived spectra from fissile material measurements. Initial testing of the neutron system has employed a calibrated Cf-252 spontaneous fission neutron source. Neutron testing has been confirmed using further MCNP simulations. The results of test measurements with the system are presented and compared with the results of MCNP measurement simulations. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
The AMPTE CCE Spacecraft
The flight segment of the Active Magnetospheric Particle Tracer Explorers (AMPTE) Program consisted of three separate spacecraft which were launched 'piggyback' into orbit aboard a Delta 3924 launch vehicle, from Cape Canaveral, FL, on August 16, 1984. The three spacecaft are the Charge Composition Explorer (CCE), built for NASA by the Applied Physics Laboratory of the Johns Hopkins University (APL/JHU); the Ion Release Module (IRM), built in the Federal Republic of Germany; and the United Kingdom Subsatellite (UKS), built in the United Kingdom. This paper describes the CCE Spacecraft design, development, and early performance in orbit.
Dassoulas, J.↗
Evaluation of radiographers’ mammography screen-reading accuracy in Australia
This study aimed to evaluate the accuracy of radiographers’ screen-reading mammograms. Currently, radiologist workforce shortages may be compromising the BreastScreen Australia screening program goal to detect early breast cancer. The solution to a similar problem in the United Kingdom has successfully encouraged radiographers to take on the role as one of two screen-readers. Prior to consideration of this strategy in Australia, educational and experiential differences between radiographers in the United Kingdom and Australia emphasise the need for an investigation of Australian radiographers’ screen-reading accuracy. Ten radiographers employed by the Westmead Breast Cancer Institute with a range of radiographic (median = 28 years), mammographic (median = 13 years) and BreastScreen (median = 8 years) experience were recruited to blindly and independently screen-read an image test set of 500 mammograms, without formal training. The radiographers indicated the presence of an abnormality using BI-RADS®. Accuracy was determined by comparison with the gold standard of known outcomes of pathology results, interval matching and client 6-year follow-up. Individual sensitivity and specificity levels ranged between 76.0% and 92.0%, and 74.8% and 96.2% respectively. Pooled screen-reader accuracy across the radiographers estimated sensitivity as 82.2% and specificity as 89.5%. Areas under the reading operating characteristic curve ranged between 0.842 and 0.923. This sample of radiographers in an Australian setting have adequate accuracy levels when screen-reading mammograms. It is expected that with formal screen-reading training, accuracy levels will improve, and with support, radiographers have the potential to be one of the two screen-readers in the BreastScreen Australia program, contributing to timeliness and improved program outcomes.
62 RADIOLOGY AND NUCLEAR MEDICINE↗
Clean Energy Manufacturing: Renewable Energy Technology Benchmarks
The manufacturing of clean energy technologies has become a global enterprise. An analysis of four clean energy technology manufacturing processes—wind turbine components, crystalline silicon solar photovoltaic modules, light-duty vehicle lithium-ion battery cells, and light-emitting diodes—was conducted to provide a reference point for comparison over time as this sector evolves. The manufacturing supply chain analysis included processing of raw materials, making required subcomponents, and assembling final products, using benchmarks that crossed 12 economies: Brazil, Canada, China, Germany, India, Japan, Malaysia, Mexico, South Korea, Republic of China (Taiwan), the United Kingdom, and the United States. Larger economies, with extensive manufacturing supply chains and high prevailing wages, tend to retain more value added from clean energy manufacturing than small economies. Manufacturing of clean energy technologies drives extensive trade among economies to support the widely distributed supply chain links. Production of wind turbine components and photovoltaic modules is more centralized than production of light-emitting diodes and lithium-ion battery cells. Across the four clean energy technologies evaluated, there was generally an excess of manufacturing capacity relative to global supply.
benchmarks↗
39th Lauriston S. Taylor Lecture
Since the early days of the Manhattan Engineer District, Oak Ridge National Laboratory (ORNL) has served to advance the dosimetry models used to set protection standards for radionuclides taken into the body. Throughout the years, this effort benefited significantly from ORNL staff's active participation in national and international scientific bodies. The first such interaction was in 1946 with the National Committee on Radiation Protection (NCRP), chaired by L.S. Taylor, which led to the 1949 to 1953 series of tripartite conferences of experts from Canada, the United Kingdom, and the United States. These conferences addressed the need for standardization of dosimetry models and led to the establishment of an anatomic and physiologic model called “Standard Man,” a precursor of the reference worker defined in Publication 23 of the International Commission on Radiological Protection (ICRP). Standard Man was used in setting the maximum permissible concentrations in air and water published in NBS Handbook 52 and subsequent reports by NCRP and ICRP. K.Z. Morgan, then director of the Health Physics Division at ORNL, participated in the tripartite conferences and subsequently established ORNL as a modeling and computational resource for development of radiation protection standards. ORNL’s role expanded with participation in the work of the Medical Internal Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine. Results of interactions with the MIRD Committee are evident in the radiation protection guidance for internal emitters in ICRP Publication 30. The annual limit on intake and derived air concentration values tabulated in Publication 30 were computed by an ORNL-based task group of ICRP Committee 2. A few years after the appearance of Publication 30, the Chernobyl nuclear reactor accident made clear the need to develop standard dosimetry models for pre-adult ages as members of the public. In the late 1980s, ICRP began an effort to extend its reference worker concept to a reference family and develop dosimetric models for application to intake of radionuclides by members of the public. However, the modeling approach underlying the ICRP Publication 30 computational framework was not amenable to age and gender considerations. With support of U.S. federal agencies, ORNL had begun efforts in the early 1980s to develop age- and gender-specific dosimetric models, including physiologically informed biokinetic models and age-specific dosimetric phantoms. ORNL’s models and methods became the starting point for the ICRP’s series of reports on dose coefficients for radionuclide intake by the public. Currently ICRP Committee 2 is overseeing development of a second generation of post-Chernobyl models and methods, with updates of Publications 30 and 68 soon to appear and new models for members of the public in preparation. The goal of this Lauriston S. Taylor Lecture is to chronicle advancements in the dosimetry of internal emitters with some discussion of models and methods but with due deference to decisions within scientific bodies and stimulated by radiological events.
61 RADIATION PROTECTION AND DOSIMETRY↗
International Outdoor Experiments and Models for Outdoor Radiological Dispersal Devices
With the advent of nuclear reactors and the technology to produce radioactive materials in large quantities, concern arose about the use of radioactivity as a poison in warfare, and hence, consideration was given to defensive measures (Smyth 1945). Approximately forty years later, the interest in the environmental- and health effects caused by a deliberate dispersal was renewed, but this time, from the perspective of a malevolent act of radiological terrorism in an urban area. For many years there has been international collaboration in scientific research to understand the range of effects that might result from a device that could be constructed by a sub-national group. In this paper, scientists from government laboratories in Australia, Canada, the United Kingdom, and the United States collectively have conducted a myriad of experiments to understand and detail the phenomenology of an explosive radiological dispersal device.
98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗