[en] The Savannah River Site''s (SRS) Defense Waste Processing Facility (DWPF) near Aiken, SC is the nation''s first and world''s largest high level waste vitrification facility. DWPF began, operations in March 1996 to process radioactive waste, consisting of a matrixed predominantly ¹³⁷Cs precipitate and a predominately ⁹⁰Sr and alpha emitting sludge, into boro-silicate glass for long term storage. Presently, DWPF is processing only sludge waste and is preparing to process a combination of sludge and precipitate waste. During precipitate operations, canister dose rates are expected to exceed 10 Sv hr^-1 (1000 rem hr^-1). In sludge-only operations, canister contact gamma dose rates are approximately 15 mSv hr^-1 (1500 mrem hr^-1). Transferable contamination levels have been greater than 10 mSv hr^-1 (100 cm²) ^-1 for beta-gamma emitters and into the millions of Bq (100 cm²)^-1 for the alpha emitting radionuclides. This paper presents an evaluation of the radiological maintenance areas and their ability to support radiological work

[en] The lead waste inventory throughout the US Department of Energy (DOE) complex has been estimated between 17 million and 24 million kilograms. Decontamination of at least a portion of the lead is viable but at a substantial cost. Because of various problems with decontamination and its limited applicability and the lack of a treatment and disposal method, the current practice is indefinite storage, which is costly and often unacceptable to regulators. Macroencapsulation is an approved immobilization technology used to treat radioactively contaminated lead solids and mixed waste debris. (Mixed waste is waste materials containing both radioactive and hazardous components). DOE has funded development of a polyethylene extrusion macroencapsulation process at Brookhaven National Laboratory (BNL) that produces a durable, leach-resistant waste form. This innovative macroencapsulation technology uses commercially available single-crew extruders to melt, convey, and extrude molten polyethylene into a waste container in which mixed waste lead and debris are suspended or supported. After cooling to room temperature, the polyethylene forms a low-permeability barrier between the waste and the leaching media

[en] Low wall losses and low wakefields inherent in superconducting radiofrequency (srf) cavities make them attractive candidates for accelerators that operate efficiently at high continuous-wave (cw) gradients. Such accelerators are desirable for free-electron lasers (FELs) that extract high-power cw light from a high-average-current electron beam, or that produce ultrashort-wavelength light from a high-energy electron beam. Efficiency is a prime consideration in the former case, while high electron-beam quality is a prime consideration in the latter case. This paper summarizes the status of FEL projects involving srf accelerators. It also introduces Jefferson Lab's srf FEL and surveys its design because it is a new machine, with commissioning having commenced in October 1997. Once commissioning is complete, this FEL should produce tunable, cw, kW-level light at 3-6 μm wavelength

[en] In 1992-93, Los Alamos National Laboratory collaborated with the U.S. Geological Survey in an effort to characterize radionuclide concentrations in bed sediment and fish tissue within the Rio Grande drainage basin from Colorado to Texas. Bed sediment was sampled from 18 locations for cesium (¹³⁷Cs), tritium (³H), strontium (⁹⁰Sr), plutonium (²³⁸Pu and ²³⁹Pu), americium (²⁴¹Am), total uranium (^totU) and alpha, beta, and gamma activity. Fish tissue was sampled from 12 locations for ¹³⁷Cs, ⁹⁰Sr, ²³⁸Pu, ²³⁹Pu and ^totU

[en] The purpose of the Old Hydrofracture Facility (OHF) Tanks Contents Removal Project is to remove the liquid low-level waste from the five underground storage tanks located at OHF and transfer the resulting slurry to the Melton Valley Storage Tanks facility for treatment and disposal. Among the technical objectives for the OHF Project, there is a specific provision to maintain personnel exposures as low as reasonably achievable (ALARA) during each activity of the project and to protect human health and the environment. The estimated doses and anticipated conditions for accomplishing this project are such that an ALARA Plan is necessary to facilitate formal radiological review of the campaign. This ALARA Plan describes the operational steps necessary for accomplishing the job together with the associated radiological impacts and planned controls. Individual and collective dose estimates are also provided for the various tasks. Any significant changes to this plan (i.e., planned exposures that are greater than 10% of original dose estimates) will require formal revision and concurrence from all parties listed on the approval page. Deviations from this plan (i.e., work outside the scope covered by this plan) also require the preparation of a task-specific ALARA Review that will be amended to this plan with concurrence from all parties listed on the approval page

[en] Results from a regional-scale ground-water flow model of the Fennoscandian shield suggest that ground-water flow is strongly affected by surface conditions associated with climatic change and glaciation. The model was used to run a series of numerical simulations of variable-density ground-water flow in a 1500-km-long and approximately 10-km-deep cross-section that passes through southern Sweden. Ground-water flow and shield brine transport in the cross-sectional model are controlled by an assumed time evolution of surface conditions over the next 140 ka. The simulation results suggest that vertical movement of deep shield brines induced by the next few glacial cycles should not increase the concentration of dissolved solids significantly above present-day levels. However, the concentration of dissolved solids should decrease significantly at depths of up to several kilometers during periods of glacial melt water recharge. The melt water may reside in the subsurface for periods exceeding 10 ka and may bring oxygenated conditions to an otherwise reducing chemical environment

[en] We analyze spin correlations between top quark and anti-top quark produced at polarized e⁺ e^- and γγ colliders. We consider a generic spin basis to find a strong spin correlation. Optimal spin decompositions for top quark pair are presented for e⁺e^- and γγ colliders. We show the cross- section in these bases and discuss the characteristics of results

[en] This report describes the results from three studies of source spectra, attenuation, and site effects of central and eastern United States earthquakes. In the first study source parameter estimates taken from 27 previous studies were combined to test the assumption that the earthquake stress drop is roughly a constant, independent of earthquake size. 200 estimates of stress drop and seismic moment from eastern North American earthquakes were combined. It was found that the estimated stress drop from the 27 studies increases approximately as the square-root of the seismic moment, from about 3 bars at 10²⁰ dyne-cm to 690 bars at 10²⁵ dyne-cm. These results do not support the assumption of a constant stress drop when estimating ground motion parameters from eastern North American earthquakes. In the second study, broadband seismograms recorded by the United States National Seismograph Network and cooperating stations have been analysed to determine Q_Lg as a function of frequency in five regions: the northeastern US, southeastern US, central US, northern Basin and Range, and California and western Nevada. In the third study, using spectral analysis, estimates have been made for the anelastic attenuation of four regional phases, and estimates have been made for the source parameters of 27 earthquakes, including the M_b 5.6, 14 April, 1995, West Texas earthquake

[en] In the report, the results of a joint research project carried out in 1991-1997 by the Finnish Radiation and Nuclear Safety Authority (STUK) and the Electromagnetics Laboratory of the Helsinki University of Technology are presented. The main purpose was to create computational models for electric potential responses when the medium is anisotropic and is bounded by a perfect magnetic conductor, a perfect electric conductor, and an anisotropic impedance surface. Furthermore, the geometry of two anisotropic half spaces and a layered medium were considered. The solutions of the problems were made using image theory. For modeling the electric potential in anisotropic medium with inhomogeneities, an integral equation was formulated. Also a wedge structure was treated as an extension to the traditional two parallel plate model of fracture geometry. The equivalentization of fracturing with anisotropy is a research area that still continues that still continues

[en] It is shown that unlike a gas plasma or an electron plasma in a metal, an ionized cluster material (open-quotes cluster plasmaclose quotes) permits propagation below the plasma cut-off of electromagnetic (EM) waves whose phase velocity is close to but below the speed of light. Its unique properties allow a variety of applications, including direct acceleration of particles with its EM fields and the phase matching of waves of high harmonic generation (HHG)