[en] This report presented the experimental characterization of the PbWO₄ crystals that we will be used for the photon detector of the Compton polarimeter at the Jefferson laboratory. We could draw 3 main features from this study. The transmission rate of the crystals is about 60 % in the scintillation wavelength region. From the decay time analysis, we deduced 3 decay components of the PbWO₄, predicted by other measurements: τ₁∼5 ns, τ₂∼20 ns, τ₃∼100 ns, taking respectively 26 %, 30 % and 4 % of the total light amplitude emitted by the crystals. Moreover, we showed the existence of a fourth decay constant (τ₄∼1μs) taking 40 % of the total quantity of light which is responsible for the bad precision on the third constant determination. We could not characterize this component accurately because of the limited time range of the recordings. To improve the determination of the super-slow component, we need to perform the measurements again on a longer time scale, on the order of a few microseconds. We eventually measured the light yield of the PbWO₄ crystals. With a first analysis, we found about 3.5 photoelectrons per MeV whereas the constructors note gave about 10. We then reduced the light loss in the experimental set up by wrapping the last open end of the crystal. The results were slightly improved. Eventually, we increased the recording time, to take account the super-low decay, and found that the crystals yield about 6 photoelectrons per MeV which is still less than predicted. (author)

[en] The Keystone Center began its work with the Environmental Management Science Program (EMSP) in May, 1996, when The Center agreed to design, organize, and facilitate stakeholder meetings at two DOE sites: Savannah River and Hanford. These meetings were held June 24--25, 1996 for the purpose of discussing the role of EMSP in constructing a site-specific basic research agenda that maps site cleanup needs to basic science areas. Summaries of the discussions from these meetings as well as lists of the stakeholders who were invited are included as Attachment 1. In August/September 1996, the Keystone Center was asked to convene two additional site meetings using funds that remained in their contract. These meetings were held in October 1996 at Oak Ridge and Idaho National Engineering Laboratory. Summaries from these meetings and participant lists are included as Attachment 2

[en] This project is designed to establish the utility of a novel centrifugal membrane filtration technology for the remediation of liquid mixed waste streams at US Department of Energy (DOE) facilities in support of the DOE Environmental Management (EM) program. The Energy and Environmental Research Center (EERC) has teamed with SpinTek Membrane Systems, Inc., a small business and owner of the novel centrifugal membrane filtration technology, to establish the applicability of the technology to DOE site remediation and the commercial viability of the technology for liquid mixed waste stream remediation. The technology is a uniquely configured process that makes use of ultrafiltration and centrifugal force to separate suspended and dissolved solids from liquid waste streams, producing a filtered water stream and a low-volume contaminated concentrate stream. This technology has the potential for effective and efficient waste volume minimization, the treatment of liquid tank wastes, the remediation of contaminated groundwater plumes, and the treatment of secondary liquid waste streams from other remediation processes, as well as the liquid waste stream generated during decontamination and decommissioning activities

[en] The purpose of this document is to provide an overview of the Nye County FY92 Nuclear Waste Repository Program (Program). Funds to pay for Program costs will come from the Federal Nuclear Waste Fund, which was established under the Nuclear Waste Policy Act of 1982 (NWPA). In early 1983, the Yucca Mountain was identified as a potentially suitable site for the nation's first geologic repository for spent reactor fuel and high-level radioactive waste. Later that year, the Nye County Board of County Commissioners (Board) established the capability to monitor the Federal effort to implement the NWPA and evaluate the potential impacts of repository-related activities on Nye County. Over the last eight years, the County's program has grown in complexity and cost in order to address DOE's evolving site characterization studies, and prepare for the potential for facility construction and operation. Changes were necessary as well, in response to Congress's redirection of the repository program specified in the amendments, to the NWPA approved in 1987. In early FY 1991, the County formally established a project office to plan and implement its program of work. The Repository Project Office's (RPO) mission and functions are provided in Section 2.0. The RPO organization structure is described in Section 3.0

[en] This report consists of two separate papers: Fernley Basin studies; and Influence of sediment supply and climate change on late Quaternary eolian accumulation patterns in the Mojave Desert. The first study involved geologic mapping of late Quaternary sediments and lacustrine features combined with precise control of elevations and descriptions of sediments for each of the major sedimentary units. The second paper documents the response of a major eolian sediment transport system in the east-central Mojave Desert: that which feeds the Kelso Dune field. Information from geomorphic, stratigraphic, and sedimentologic studies of eolian deposits and landforms is combined with luminescence dating of these deposits to develop a chronology of periods of eolian deposition. Both studies are related to site characterization studies of Yucca Mountain and the forecasting of rainfall patterns possible for the high-level radioactive waste repository lifetime

[en] A new method for determining the density of neutrals near the X-point of a diverted plasma is described. Code calculations have predicted that the neutral density peaks poloidally near the X-point and there is evidence that neutrals play a role in the L-H transition and in damping the plasma rotation. The new method uses D_α data from a tangentially-viewing video camera calibrated by a vertically-viewing photomultiplier. These data, combined with electron temperature and density measurements from the divertor Thomson scattering (DTS) system, provide sufficient information to determine the neutral density in the X-point region of DIII-D. Preliminary results show neutral densities above the X-point are order 10¹⁰--10¹¹ atoms cm³. The diagnostics used to determine these neutral densities, the data analysis method, and preliminary results are described in this paper

[en] The document reproduces the texts of the notes verbales received by the Director General of the IAEA on 1 December 1997, from the Permanent Missions to the IAEA of Belgium, China, Germany, Japan, the Russian Federation, Switzerland, the United Kingdom of Great Britain and Northern Ireland and the United States of America, and of the note verbale dated 28 November 1997, from the Permanent Mission of France to the IAEA. The purpose of these notes verbales is to provide information on the policies which these governments have decided to adopt in the management of plutonium. These policies are set out in the notes verbales and are specified in the document 'Guidelines for the Management of Plutonium' which is attached to each of the notes verbales

[en] The methods applicable to determining fracture mechanics characteristics of the threshold toughness, published in various recommendations and draft standards, are compared and evaluated. The methods are put to the test and comparatively analysed using compact tensile specimens (CT), standardized three-point bending specimens (TPB), and TPB specimens with short cracks. It is shown that only the physical crack initiation value J_i yields results that can be applied for comparative evaluations. (orig./CB)

[en] Safety assessment of reactor components has to encompass the nozzles, as in the event of a LOCA, the nozzle areas are subject to heavy thermal stresses due to the low temperature there of the cooling agent. The paper refers to three-dimensional, elasto-plastic FEM analyses of the integer RPV and calculations of the J-integral for various crack locations and geometries, for derivation of realistic transients. The J-integral and K values calculated with FEM have been compared with stress intensity factors determined by means of enhanced analytical methods. Calculations for description of the integer nozzle yield plastifications in the cladded and the ferritic areas, so that the K concept of linear-elastic fracture mechanics is restricted in applicability. For postulated cracks beneath the integer cladding, J-integral values are determined which are below the initiating value J₁ of the material used, which excludes crack initiation. For the largest postulated, 20 mm deep surface crack and through-cladding damage, a crack growth of 0.1 mm is derived according to the crack resistance curve. The analytical method for calculating the stress intensity factors has been expanded to also include application to evaluation of nozzle edge cracks under the cladding. (orig./CB)

[en] ENDEF, an initiative of the European Commission, DG XVII (Energy) was well supported by the European industrial institutions working in assistance with nuclear industrial organisations in the CEEC's (Central and Eastern European Countries) and NIS's (New Independent States). This Forum provides effectively a platform for open discussion between representatives of industrial actors active in the NDE (Non Destructive Examination)/ISI (In Service Inspection) field with the purpose to establish a co-operation pattern between qualified representatives of the EU (European Union) industry to offer a better co-ordinated and well defined assistance to the CEEC's and NIS in the field of NDE/ISI, and to lay the ground for further industrial co-operation. ENDEF developed a strategy to follow for the establishment of co-operation projects. This strategy is now used to understand the extent of past or present assistance projects and to identify the areas where more co-operation is needed. ENDEF encourages the creation in the NIS's and CEEC's of similar forums in order to increase the co-operation and co-ordination. ENDEF is also working in perfect agreement with the European Network ENIQ, piloted by the European plant operators. This identity of views lead to the leadership by the ENDEF co-ordinator of the ENIQ Task 3 involving Applications of the European Methodology for ISI qualification in the CEEC's and NIS's and presently fully integrated in ENDEF. (orig.)