An automatic programed scaler
Automatic programed scaler for measuring and processing data on radioactive materials
DATA PROCESSING↗
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Ageing of a neutron shielding used in transport/storage casks
In radioactive materials transport/storage casks, a mineral-filled vinylester composite is used for neutron shielding which relies on its hydrogen and boron atoms content. During cask service life, this composite is mainly subjected to three types of ageing: hydrothermal ageing, thermal oxidation and neutron irradiation. The aim of this study is to investigate the effect of hydrothermal ageing on the properties and chemical composition of this polymer composite. At high temperature (120 Degree-Sign C and 140 Degree-Sign C), the main consequence is the strong decrease of mechanical properties induced by the filler/matrix debonding.
36 MATERIALS SCIENCE↗
Regulatory Control of Sealed Sources in Germany including Regulations Regarding Spent and Disused Sources - 13176
Effective regulatory control is essential to ensure the safe and secure use of radioactive material and the appropriate management of radioactive waste. To ensure a sustainable control of high radioactive sources, the European Commission published the Council Directive 2003/122/EURATOM on the control of high-activity sealed radioactive sources and orphan sources, which had to be transferred into national legislation by all member states of the European Union. Major requirement of the Directive is a system to ensure traceability of high-activity sealed sources from 'cradle to grave' as well as the provision to take back disused sources by the supplier or manufacturer. With the Act on high-activity sealed radioactive sources Germany implemented the requirements of the Directive 2003/122/EURATOM and established a national registry of high-activity sealed sources in 2006. Currently, about 27.000 high-activity sealed sources are recorded in this national registry. (authors)
07 ISOTOPE AND RADIATION SOURCES↗
Designing Flexibility into the Authorized Radioactive Contents of the 9982 Shipping Package
The 9982 radioactive material shipping package, or the 9982, differs from the others by allowing a multitude of radionuclides instead of a single defined set. While allowing flexibility, this requires more justification on why these contents would be worthwhile and why they would not cause various safety hazards when shipped together. The latter was covered through mass limit calculations, and the potential uses for the package are shown through comparison with historical shipments. Here, the mass limits were already calculated[1] and used to show three example shipments are suitable for the 9982 as well. Plutonium stored in 3013 containers[2], training sources shipped in 9977 packages[3], and americium standards shipped in 9978 packages[4] were all analyzed. The mass of each radionuclide and the corresponding mass limit were used to first determine if the listed content could be shipped. If so, the maximum allowed mass of such contents is also calculated in order to see if the 200-gram fissile limit for the 9982 would be violated if additional material was packed. The sum-of-the-fractions method produces contents that do not violate the mass limits or exceed the 200-gram fissile limit. These sets also serve as realistic examples of what may be shipped in the 9982. Well-founded example contents will help the approval of the package by showing its compatibility with previously shipped material. Unfounded hypothetical contents would not show the usefulness of having a wide variety of allowed radionuclides. More contents may be developed in order to incorporate other radionuclides that were not present in these three examples. The light elements will also need to be evaluated due to their exclusion currently preventing some materials from being allowed in the 9982.
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A METHODOLOGY FOR DETERMINING THE DOSE RATE FOR BOUNDING MASS LIMITS IN A 9977 PACKAGING
The Small Gram Quantity (SGQ) concept is based on the understanding that the hazards associated with the shipment of a radioactive material are directly proportional to its mass. This study describes a methodology that estimates the acceptable masses for several neutron and gamma emitting isotopes that can be shipped in a 9977 Package compliant with the Title 10 of the Code of Federal Regulations, Part 71 (10CFR71) external radiation level limits. 10CFR71.33 states that a shipping application identifies the radioactive and fissile materials at their maximum quantity and provides an evaluation demonstrating compliance with the external radiation standards. Since rather small amounts of some isotopes emit sufficiently strong radiation to produce a large external dose rate, quantifying of the dose rate for a proposed content is a challenging issue for the SGQ approach. It is essential to quantify external radiation levels from several common gamma and neutron sources that can be safely placed in a specific packaging, to ensure compliance with federal regulations. A methodology was established for determining the dose rate for bounding mass limits for a set of isotopes in the Model 9977 Shipping Package. Calculations were performed to estimate external radiation levels using the MCNP radiation transport code to develop a set of response multipliers (Green's functions) for 'dose per source particle' for each neutron and photon spectral group. The source spectrum from one gram of each isotope was folded with the response multipliers to generate the dose rate per gram of each isotope in the 9977 shipping package and its associated shielded containers. The maximum amount of a single isotope that could be shipped within the regulatory limits for dose rate at the surface was determined. For a package containing a mixture of isotopes, the acceptability for shipment can be determined by a sum of fractions approach. Furthermore, the results of this analysis can be easily extended to additional radioisotopes by simply evaluating the neutron and/or photon spectra of those isotopes and folding the spectral data with the Green's functions provided.
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
Training on Transport Security of Nuclear/Radioactive Materials for Key Audiences - 16149
Beginning in 2013, the U.S. Department of Energy (DOE) Packaging Certification Program, Office of Packaging and Transportation, Office of Environmental Management has sponsored a series of three training courses on Security of Nuclear and Other Radioactive Materials during Transport. These courses were developed and hosted by Argonne National Laboratory staff with guest lecturers from both the U.S. and international organizations and agencies including the U.S. Nuclear Regulatory Commission, the Federal Bureau of Investigation, DOE, the National Nuclear Security Administration, DOE national laboratories, the International Atomic Energy Agency, the World Nuclear Transport Institute, and the World Institute for Nuclear Security. Each of the three courses held to date were one week in length. Significant lessons were learned, and have been used to improve the courses as time progressed, along with inclusion of new materials, new exercises, and the use of an advanced electronic voting system that greatly enhanced class interactions. Two options are being considered for adapting the training materials for key audiences in the future: A two-week university credit training course and customized courses for key audiences who may have specific training needs. This paper highlights the lessons learned in previous one-week courses, and discusses the options for university-credit and customized courses/workshops for key audiences. (authors)
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Estimating Public Dose Along Hypothetical Spent Nuclear Fuel Transportation Routes
In the future, it will be necessary to transport large quantities of spent nuclear fuel (SNF) from nuclear power plant sites to an interim storage facility (ISF) or a repository when such a facility is available. Because it is impossible to shield all of the radiation from this material, the general public will receive a very small, but quantifiable, dose from this transportation campaign. This paper describes the estimated collective effective radiation dose to the public due to SNF shipments under routine conditions and compares the estimated dose figures to the natural background radiation dose. To determine the estimated collective effective dose to the public, this analysis uses the US Department of Energy's (DOE) Stakeholder Tool for Assessing Radioactive Transportation (START), a geographic information system (GIS) routing tool, and a set of unit dose factors (UDFs) which were developed to calculate the estimated dose to the public along transportation routes. The estimated doses of radiation to which the public would be exposed during shipments of SNF is expected to be a consideration, along with many other factors, when making routing decisions. In all cases studied in this paper, estimated doses to the public will be orders of magnitude lower than the natural background radiation dose and will meet all US federal regulatory requirements for radiation dose/exposure to members of the public. The sample routes analyzed in this paper are expected to be representative of future SNF shipment routes in terms of length and mode of transportation, although they do not represent actual routes or destinations. This paper considers four routes from two shutdown reactor sites to two destinations. It must be noted that the specified origin sites are not necessarily the first sites under consideration for a de-inventory process. Further, the destination sites reviewed in this report are only to illustrate estimated dose figures along different routes and should not be taken as potential sites for an ISF or repository. For illustrative purposes only, the shortest distance rail route was found between each origin and destination point, and the collective effective dose to the public from the SNF cask was estimated along each route. This paper is not intended to make recommendations for routing decisions, but rather is intended to inform further discussion about the transportation of SNF and other radioactive materials.
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On-Site Oxy-Lance Size Reduction of South Texas Project Reactor Vessel Heads - 12324
On-Site Oxy-Lance size reduction of mildly radioactive large components has been accomplished at other operating plants. On-Site Oxy-Lance size reduction of more radioactive components like Reactor Vessel Heads had previously been limited to decommissioning projects. Building on past decommissioning and site experience, subcontractors for South Texas Project Nuclear Operating Company (STPNOC) developed an innovative integrated system to control smoke, radioactive contamination, worker dose, and worker safety. STP's innovative, easy to use CEDM containment that provided oxy lance access, smoke control, and spatter/contamination control was the key to successful segmentation for cost-effective and ALARA packaging and transport for disposal. Relative to CEDM milling, STP oxy-lance segmentation saved approximately 40 person- REM accrued during 9,000 hours logged into the radiological controlled area (RCA) during more than 3,800 separate entries. Furthermore there were no personnel contamination events or respiratory uptakes of radioactive material during the course of the entire project. (authors)
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Naturally elevated radionuclides encountered at environmental radiation remediation sites - 15224
Many FUSRAP sites contain contamination that is similar to naturally occurring radioactive material (NORM) which may lead to improper characterization of elevated material, resulting in additional effort and cost. Several instances of NORM or other non-FUSRAP related material present at cleanup locations are discussed herein. (authors)
54 ENVIRONMENTAL SCIENCES↗
Initial Evaluation of Processing Methods for an Epsilon Metal Waste Form
During irradiation of nuclear fuel in a reactor, the five metals, Mo, Pd, Rh, Ru, and Tc, migrate to the fuel grain boundaries and form small metal particles of an alloy known as epsilon metal (ε-metal). When the fuel is dissolved in a reprocessing plant, these metal particles remain behind with a residue - the undissolved solids (UDS). Some of these same metals that comprise this alloy that have not formed the alloy are dissolved into the aqueous stream. These metals limit the waste loading for a borosilicate glass that is being developed for the reprocessing wastes. Epsilon metal is being developed as a waste form for the noble metals from a number of waste streams in the aqueous reprocessing of used nuclear fuel (UNF) - (1) the ε-metal from the UDS, (2) soluble Tc (ion-exchanged), and (3) soluble noble metals (TRUEX raffinate). Separate immobilization of these metals has benefits other than allowing an increase in the glass waste loading. These materials are quite resistant to dissolution (corrosion) as evidenced by the fact that they survive the chemically aggressive conditions in the fuel dissolver. Remnants of ε-metal particles have survived in the geologically natural reactors found in Gabon, Africa, indicating that they have sufficient durability to survive for ≈ 2.5 billion years in a reducing geologic environment. Additionally, the ε-metal can be made without additives and incorporate sufficient foreign material (oxides) that are also present in the UDS. Although ε-metal is found in fuel and Gabon as small particles (≈10 µm in diameter) and has survived intact, an ideal waste form is one in which the surface area is minimized. Therefore, the main effort in developing ε-metal as a waste form is to develop a process to consolidate the particles into a monolith. Individually, these metals have high melting points (2617°C for Mo to 1552°C for Pd) and the alloy is expected to have a high melting point as well, perhaps exceeding 1500°C. The purpose of the work reported here is to find a potential commercial process with which ε-metal plus other components of UDS can be consolidated into a solid with minimum surface area and high strength Here, we report the results from the preliminary evaluation of spark-plasma sintering (SPS), hot-isostatic pressing (HIP), and microwave sintering (MS). Since bulk ε-metal is not available and companies could not handle radioactive materials, we prepared mixtures of the five individual metal powders (Mo, Ru, Rh, Pd, and Re) and baddeleyite (ZrO 2 ) to send the vendors of SPS, HIP, and MS. The processed samples were then evaluated at the Pacific Northwest National Laboratory (PNNL) for bulk density and phase assemblage with X-ray diffraction (XRD) and phase composition with scanning electron microscopy (SEM). Physical strength was evaluated qualitatively. Results of these scoping tests showed that fully dense cermet (ceramic-metal composite) materials with up to 35 mass% of ZrO 2 were produced with SPS and HIP. Bulk density of the SPS samples ranged from 87 to 98% of theoretical density, while HIP samples ranged from 96 to 100% of theoretical density. Microwave sintered samples containing ZrO 2 had low densities of 55 to 60% of theoretical density. Structurally, the cermet samples showed that the individual metals alloyed in to ε-phase - hexagonal-close-packed (HCP) alloy (4-95 mass %), the α-phase - face-centered-cubic (FCC) alloy structure (3-86 mass %), while ZrO 2 remained in the monoclinic structure of baddeleyite. Elementally, the samples appeared to have nearly uniform composition, but with some areas rich in Mo and Re, the two components with the highest melting points. The homogeneity in distribution of the elements in the alloy is significantly improved in the presence of ZrO 2 . However, ZrO 2 does not appear to react with the alloy, nor was Zr found in the alloy.
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
Bond Strength of Plasma Sprayed Zr Diffusion Barrier on U-Mo Fuels
The United States government is continually committed to strengthening nuclear security and nonproliferation for reducing the threat of radioactive materials acquisition by terrorists. To meet this important mission, the US Department of Energy and National Nuclear Security Agency's (NNSA) Office of Material Management and Minimization (M{sup 3}) Reactor Conversion Program (CONVERT) seeks to minimize the use of highly enriched uranium (HEU) in civilian applications through work with governments and facilities around the world to convert research reactors to the use of non-weapons-usable low enriched uranium (LEU) fuels. Each reactor converted not only eliminates the need for HEU at civilian sites, but also reduces the amount of HEU being manufactured, stored, and transported, where the nuclear material is most vulnerable. In instances where suitable LEU fuels do not exist for the conversion of particular reactors, CONVERT contributes to development of new LEU fuels. Currently, the CONVERT Program is committed to development of a high-density U-Mo fuel that will be able to convert high performance research reactors, while establishing an efficient and economic fabrication capability to manufacture the fuel. To that end, Los Alamos National Laboratory (LANL) has been tasked with development of a method to affix zirconium (Zr) metal fuel diffusion barrier via plasma spraying, which will prevent a reaction between the U-Mo fuel and the 6061 aluminum cladding. A successful diffusion barrier requires adequate Zr layer thickness, uniform coverage, sufficient bonding at the Zr/fuel and Zr/aluminum cladding interface, and maintenance of the original nuclear fuel properties i.e. physical dimensions, alloy composition and dispersion, crystallographic phase concentration, neutronics, etc. This work outlines development of the Zr plasma spray processing techniques, parameters affecting the diffusion barrier/nuclear fuel bond strength, and characterization of the Zr diffusion barrier. (authors)
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Intrinsic Radiation Source Generation with the ISC Package: Data Comparisons and Benchmarking
The characterization of radioactive emissions from unstable isotopes (intrinsic radiation) is necessary for shielding and radiological-dose calculations from radioactive materials. While most radiation transport codes, e.g., MCNP [X-5 Monte Carlo Team, 2003], provide the capability to input user prescribed source definitions, such as radioactive emissions, they do not provide the capability to calculate the correct radioactive-source definition given the material compositions. Special modifications to MCNP have been developed in the past to allow the user to specify an intrinsic source, but these modification have not been implemented into the primary source base [Estes et al., 1988]. To facilitate the description of the intrinsic radiation source from a material with a specific composition, the Intrinsic Source Constructor library (LIBISC) and MCNP Intrinsic Source Constructor (MISC) utility have been written. The combination of LIBISC and MISC will be herein referred to as the ISC package. LIBISC is a statically linkable C++ library that provides the necessary functionality to construct the intrinsic-radiation source generated by a material. Furthermore, LIBISC provides the ability use different particle-emission databases, radioactive-decay databases, and natural-abundance databases allowing the user flexibility in the specification of the source, if one database is preferred over others. LIBISC also provides functionality for aging materials and producing a thick-target bremsstrahlung photon source approximation from the electron emissions. The MISC utility links to LIBISC and facilitates the description of intrinsic-radiation sources into a format directly usable with the MCNP transport code. Through a series of input keywords and arguments the MISC user can specify the material, age the material if desired, and produce a source description of the radioactive emissions from the material in an MCNP readable format. Further details of using the MISC utility can be obtained from the user guide [Solomon, 2012]. The remainder of this report presents a discussion of the databases available to LIBISC and MISC, a discussion of the models employed by LIBISC, a comparison of the thick-target bremsstrahlung model employed, a benchmark comparison to plutonium and depleted-uranium spheres, and a comparison of the available particle-emission databases.
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
Occurrence of Radiological Contamination in Urban Parks Established over Former Landfill Sites - 19433
In 2005, the National Park Service was notified that elevated radiation levels were detected at Great Kills Park during a baseline radiological mapping effort conducted by the Counter Terrorism Bureau of the New York City Police Department and the United States Department of Energy. Great Kills Park is in the Staten Island Unit of Gateway National Recreation Area. A records search determined that approximately 1.1 x 10{sup 6} square meters (280 acres) of the park was established over an area in which the New York City Department of Sanitation placed approximately 1.2 x 10{sup 7} cubic meters (15.1 million cubic yards) of waste fill from 1944 to 1948. Since 2005, a series of response actions and investigations were conducted on behalf of the National Park Service to mitigate risk to human health and the environment and to determine the nature of radiological contamination at Great Kills Park. The findings support that radiological contamination is related to certain components of waste fill, including incinerator residue from both on and offsite incinerators, coal ash from the historical use of coal-fired boilers for heating, and incidental radiological artifacts in the waste fill due to their historical use and subsequent disposal. A majority of the radiological artifacts were determined to contain Ra-226 and included radioluminescent markers, radium buttons, radium paint containers, and brachytherapy devices. The National Park Service is currently performing a Remedial Investigation for the waste-filled area of Great Kills Park under the Comprehensive Environmental Response, Compensation and Liability Act. Several other Parks in Gateway National Recreation Area were established in areas with a similar history to Great Kills Park, and overlie waste fill historically placed during landfilling operations. Recently, radiological surveys were performed over limited portions of Spring Creek Park in the Jamaica Bay Unit of Gateway National Recreation Area. These surveys identified several locations with gamma radiation levels above the ambient level, several of which were attributable to radiological artifacts similar in nature to those recovered at Great Kills Park. Ongoing investigations at Great Kills Park and the recent findings at Spring Creek Park suggest that radiological contamination may be associated with historical landfilling practices that were common prior to the regulation and control of radioactive materials. (authors)
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ADAPTING A CERTIFIED SHIPPING PACKAGE FOR STORAGE APPLICATIONS
For years shipping packages have been used to store radioactive materials at many DOE sites. Recently, the K-Area Material Storage facility at the Savannah River Site became interested in and approved the Model 9977 Shipping Package for use as a storage package. In order to allow the 9977 to be stored in the facility, there were a number of evaluations and modifications that were required. There were additional suggested modifications to improve the performance of the package as a storage container that were discussed but not incorporated in the design that is currently in use. This paper will discuss the design being utilized for shipping and storage, suggested modifications that have improved the storage configuration but were not used, as well as modifications that have merit for future adaptations for both the 9977 and for other shipping packages to be used as storage packages.
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Introduction to Pits and Weapons Systems (U) [Slides]
A Nuclear Explosive Package includes the Primary, Secondary, Radiation Case and related components. This is the part of the weapon that produces nuclear yield and it converts mechanical energy into nuclear energy. The pit is composed of materials that allow mechanical energy to be converted to electromagnetic energy. Fabrication processes used are typical of any metal fabrication facility: casting, forming, machining and welding. Some of the materials used in pits include: Plutonium, Uranium, Stainless Steel, Beryllium, Titanium, and Aluminum. Gloveboxes are used for three reasons: (1) Protect workers and public from easily transported, finely divided plutonium oxides - (a) Plutonium is very reactive and produces very fine particulate oxides, (b) While not the 'Most dangerous material in the world' of Manhattan Project lore, plutonium is hazardous to health of workers if not properly controlled; (2) Protect plutonium from reactive materials - (a) Plutonium is extremely reactive at ambient conditions with several components found in air: oxygen, water, hydrogen, (b) As with most reactive metals, reactions with these materials may be violent and difficult to control, (c) As with most fabricated metal products, corrosion may significantly affect the mechanical, chemical, and physical properties of the product; and (3) Provide shielding from radioactive decay products: α, γ, and η are commonly associated with plutonium decay, as well as highly radioactive materials such as 241 Am and 238 Pu.
36 MATERIALS SCIENCE↗
The MacArthur Maze Fire and Roadway Collapse: Consequences for SNF Transportation - 12476
In 2007, a severe transportation accident occurred near Oakland, California, on a section of Interstate 880 known as the 'MacArthur Maze', involving a tractor trailer carrying gasoline which impacted an overpass support column and burst into flames. The subsequent fire caused the collapse of portions of the Interstate 580 overpass onto the remains of the tractor-trailer in less than 20 minutes, due to a reduction of strength in the structural steel exposed to the fire. The US Nuclear Regulatory Commission is in the process of examining the impacts of this accident on the performance of a spent nuclear fuel transportation package, using detailed analysis models, in order to determine the potential regulatory implications related to the safe transport of spent nuclear fuel in the United States. This paper will provide a summary of this effort and present results and conclusions. The detailed thermal models of the MacArthur Maze fire scenario with ANSYS and COBRASFS have produced preliminary results indicating that in a fire of this severity, the peak fuel cladding temperature would almost certainly exceed the short-term limit of 570 deg. C (1058 deg. F), and would likely exceed the Zircaloy burst temperature limit of 750 deg. C (1382 deg. F) assumed in previous transportation studies. Additional work is needed to refine and verify some of the details of these complex models, but the overall results are consistent with previous fire analyses with similar models, and with the results obtained for the HAC fire evaluations with these models. These results as well as future results produced by these models can therefore be considered as reliable estimates of the temperatures that would be experienced in fire conditions of the severity of the MacArthur Maze fire scenario. The structural analyses show that the GA-4 package is robust enough to withstand the impact of the overhead span without suffering major damage or deformation to the containment boundary. The greatest potential for local package damage in this scenario appears to be at the bolted closure end. The thermal expansion response of the closure bolts and impact limiter attachment bolts were evaluated in a separate analysis, and it was determined that both the lid and impact limiters are expected to remain in place. The response of the closure seal is currently being evaluated separately in the context of the accident's overall potential to release radioactive material in the environment. (authors)
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RCUT: A Non-Invasive Method for Detection, Location, and Quantification of Radiological Contaminants in Pipes and Ducts - 12514
Radiological Characterization Using Tracers (RCUT) is a minimally invasive method for detection and location of residual radiological contamination in pipes and ducts. The RCUT technology utilizes reactive gaseous tracers that dissociate when exposed to gamma and/or beta radiation emitting from a radiological contaminant in a pipe or duct. Sulfur hexafluoride (SF{sub 6}) was selected as a tracer for this radiological application, because it is a chemically inert gas that is both nonflammable, nontoxic, and breaks down when exposed to gamma radiation. Laboratory tests demonstrated that the tracer pair of SF{sub 6} and O{sub 2} formed SO{sub 2}F{sub 2} when exposed to a gamma or beta radioactive field, which indicated the presence of radiological contamination. Field application of RCUT involves first injecting the reactive tracers into the pipe to fill the pipe being inspected and allowing sufficient time for the tracer to interact with any contaminants present. This is followed by the injection of an inert gas at one end of the pipe to push the reactive tracer at a known or constant flow velocity along the pipe and then out the exit and sampling port at the end of the pipeline where its concentration is measured by a gas chromatograph. If a radiological contaminant is present in the pipe being tested, the presence of SO{sub 2}F{sub 2} will be detected. The time of arrival of the SO{sub 2}F{sub 2} can be used to locate the contaminant. If the pipe is free of radiological contamination, no SO{sub 2}F{sub 2} will be detected. RCUT and PCUT are both effective technologies that can be used to detect contamination within pipelines without the need for mechanical or human inspection. These methods can be used to detect, locate, and/or estimate the volume of a variety of radioactive materials and hazardous chemicals such as chlorinated solvents, petroleum products, and heavy metals. While further optimization is needed for RCUT, the key first step of identification of a tracer compound appropriate for the application of detecting radioactive pipeline contamination through the detection of decomposition products of SF{sub 6} has been demonstrated. Other tracer gases that will also undergo radiolysis will be considered in the future. The next step for the RCUT development process is conducting laboratory scale tests using short pipelines to define analytical requirements, establish performance boundaries, and develop strategies for lower exposure levels. Studies to identify additional analytical techniques using equipment that is more field rugged than a GC/MS would also be beneficial. (authors)
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Implementation of a spark plasma sintering facility in a hermetic glovebox for compaction of toxic, radiotoxic, and air sensitive materials
Spark plasma sintering (SPS) is a rapidly developing method for densification of powders into compacts. It belongs to the so-called “field assisted sintering techniques” that enable rapid sintering at much lower temperatures than the classical approaches of pressureless sintering of green pellets or hot isostatic pressing. In this paper, we report the successful integration of a SPS device into a hermetic glovebox for the handling of highly radioactive material containing radioisotopes of U, Th, Pu, Np, and Am. The glovebox implantation has been facilitated by the replacement of the hydraulic system to apply pressure with a compact electromechanical unit. The facility has been successfully tested using UO{sub 2} powder. Pellets with 97% of the theoretical density were obtained at 1000 °C for 5 min, significantly lower than the ∼1600 °C for 5-10 h used in conventional pellet sintering.
36 MATERIALS SCIENCE↗