The Materials Characterization Center (MCC) at Pacific Northwest Laboratory (PNL) provides well-characterized spent fuel from light-water reactors (LWRs) for use in laboratory tests relevant to nuclear waste disposal in the proposed Yucca Mountain repository. Interpretation of results from tests on spent fuel oxidation, dissolution, and cladding degradation requires information on the inventory and distribution of radionuclides in the initial test materials. The MCC is obtaining this information from examinations of Approved Testing Materials (ATMs), which include spent fuel with burnups from 17 to 50 MWd/kgM and fission gas releases (FGR) from 0.2 to 18%. The concentration and distribution of activation products and the release of volatile fission products to the pellet-cladding gap and rod plenum are of particular interest because these characteristics are not well understood. This paper summarizes results that help define the {sup 14}C inventory and distribution in cladding, the ``gap and grain boundary`` inventory of radionuclides in fuels with different FGRs, and the structure and radionuclide inventory of the fuel rim region within a few hundred micrometers from the fuel edge. 6 refs., 5 figs., 1 tab.

A workshop on applications and enhancements of the TOUGH/MULKOM family of multiphase fluid and heat flow simulation programs was held at Lawrence Berkeley Laboratory on September 13--14, 1990. The workshop was attended by 62 scientists from seven countries with interests in geothermal reservoir engineering, nuclear waste isolation, unsaturated zone hydrology, environmental problems, and laboratory and field experimentation. The meeting featured 21 technical presentations, extended abstracts of which are reproduced in the present volume in unedited form. Simulator applications included processes on a broad range of space scales, from centimeters to kilometers, with transient times from seconds to geologic time scales. A number of code enhancements were reported that increased execution speeds for large 3-D problems by factors of order 20, reduced memory requirements, and improved user-friendliness. The workshop closed with an open discussion session that focussed on future needs and means for interaction in the TOUGH user community. Input from participants was gathered by means of a questionnaire that is reproduced in the appendix. 171 refs., 91 figs., 16 tabs.

The announcement of the location of the SSC at the site near Waxahachie, Texas was made in January, 1989. Since then a great many important steps have been taken toward the start of the new Laboratory. Some 900 people have been brought to the site as the starting nucleus of the staff that will ultimate number about 2200. A design baseline has been completed that includes a conceptual design for the accelerator, and the detectors. Also, the process has begun to determine the configuration of detectors that will be built for the SSC. This process has several steps, and now the first of these has been taken: The detector collaborations have submitted the Expression of Interest to the Laboratory. These were reviewed by Laboratory management and the Physics Advisory Committee in July, 1990 and recommendations were made to the collaborations. Decisions were deferred for all of the detectors. But perhaps the most significant recommendation was the request to reduce the size and cost of the general purpose detectors. The detector collaborations are now reviewing their initial designs to prepare for the Letters of Intent, the next step in the detector planning process. This is clearly a difficult and crucial step …

The standing-wave free-electron laser (FEL) differs from a conventional linear-wiggler microwave FEL in using irises along the wiggler to form a series of standing-wave cavities and in reaccelerating the beam between cavities to maintain the average energy. The device has been proposed for use in a two-beam accelerator (TBA) because microwave power can be extracted more effectively than from a traveling-wave FEL. The standing-wave FEL is modeled in the continuum limit by a set of equations describing the coupling of a one-dimensional beam to a TE{sub 01} rectangular-waveguide mode. Analytic calculations and numerical simulations are used to determine the time variation of the reacceleration field and the prebunching required so that the final microwave energy is the same in all cavities. The microwave energy and phase are found to be insensitive to modest spreads in the beam energy and phase and to errors in the reacceleration field and the beam current, but the output phase appears sensitive to beam-energy errors and to timing jitter.

A modular, multichannel current regulator system has been developed to power the low current correction and focusing magnets used for beam transport. The basic module consists of a relay rack housing four card crates with eight regulators per crate. The rack also contains a utility chassis and common power supplies. Each regulator card includes a communications microprocessor and a temperature controlled analog circuit block containing precision reference, serial DAC, shunt resistor and error amplifier. The regulators are linear, bipolar units capable of furnishing up to 10 amps at 20 volts with less than 0.01% ripple and drift.

The high power portion of the CEBAF RF system utilizes 340 5kW klystrons providing 339 separately controlled outputs. Modulating anodes have been included in the klystron design to provide for economically efficient operation. The design includes shunt regulator-type modulating anode power supplies running from the cathode power supply, and switching filament power supplies. Remotely programmable filament voltage allows maximum cathode life to be realized. Klystron operating setpoint and fast klystron protection logic are provided by individual external CEBAF RF control modules. A single cathode power supply powers a block of eight klystrons. The design includes circulators and custom extrusion and hybrid waveguide components which have allowed reduced physical size and lower cost in the design of the WR-650 waveguide transmission system.

The RF control system for the CEBAF accelerator uses calibration tables to calibrate and linearize critical components in the RF control modules. This includes compensation for temperature drifts. Calibration data are stored in nonvolatile RAM on the CPU board in the control module. Algorithms for calibration of components like the vector modulator for the phase reference and the gradient detector are described. The calibration will be performed in a dedicated test stand which will be completely automated. The microprocessor in the control modules allows running of complex algorithms to achieve phase lock and optimize system gains for minimum residual errors for different gradients and beam loading.

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The status of hadronic and electromagnetic excitation of light quark (u, d) baryon states is reviewed and confronted with results of calculations within the framework of microscopic model of the baryon structure and the photon - baryon coupling. Prospects for a qualitative improvement of our knowledge in this sector using photon and electron beams at the new, intermediate energy cw electron machines are discussed.

The CEBAF accelerator includes a linac section which accelerates multiple beams with different energies. Problems arise when performing orbit correction, due to the fact that correction of higher energy passes disturb lower energy trajectories. Therefore, a perfect orbit correction cannot be obtained for all energy beams at the same time.\nWe present methods and performance (using simulation results) for performing orbit corrections in such a system. Limitations to the correction methods are also addressed.\n

Recent B-factory proposals taht use a linac beam colliding with the beam from a storage ring to achieve high luminosities (L > 10^34 cm^-2 sec^-1) result in very high disruption of the linac beam.The effects of such high disruption have been studied using the relativistic, 3-D code SWARM.We discuss the assumptions, parameters, and results of a series of runs that model such collisions.Regimes of high beam loss and methods to avoid them are also discussed.

Because of the high power in the CEBAF beam, equipment must be protected in the event of beam loss. The policy that has been adopted is to require a positive permissive signal from each of several inputs in order to operate the gun that starts the beam. If the permissive is removed, the gun shuts off within 20 micro-seconds. \nThe inputs that are not monitored include (1) radiation monitors that detect beam loss directly, (2) vacuum monitors (which also observe the status of various in-line valves), and (3) general input from the rf system, which combines detection of klystron failure, arcs, and rf window high temperature. The system is expandable, so other fault detectors can be added if experience shows their necessity.

Major trends of the physics program related to the study of hadron structure and hadron spectroscopy at the new high current, high duty cycle electron machines are discussed. It is concluded that planned experiments at these machines may have important impact on our understanding of the strong interaction by studying the internal structure and spectroscopy of the nucleon and lower mass hyperon states.

The effects of quench propagation are modeled in 40mm and 50mm diameter collider dipole magnet designs. A comparative study of the cold diode (passive) and quench heater (active) protection schemes will be presented. The SSCQ modeling program accurately simulates the axial quench velocity and uses phenomenological time delays for turn-to-turn transverse propagation. The axial quench velocity is field dependent and consequently, each conductor's quench profile is tracked separately. No symmetry constraints are employed and the distribution of the temperatures along the conductor differs from the adiabatic approximation. A single magnet has a wide margin of self protection which suggests that passive protection schemes must be considered. 6 refs., 3 figs., 1 tab.

A summary of the cable produced for the 1990 40 mm Dipole Program is presented. The cable design parameters for the 50 mm Dipole Program are discussed, as well as portions of the SSC specification draft. Considerations leading to the final cable configuration and the results of preliminary trials are included. The first iteration of a strand mapping program to automate cable strand maps is introduced. 7 refs., 2 figs., 1 tab.

We have developed instrumentation capable of measuring optical absorption spectra over a wavelength range of 200--1200 nm and a temperature range of 20--100{degree}C. This fiber-optic based spectrometer generates data which allow the computation of metal-ligand equilibrium constants. Studies at five temperatures have been completed using praseodymium-diglycolate as a model system. Fundamental thermodynamic values (free energies, enthalpies, entropies) were obtained from the experimentally-determined stability constants. Thermodynamic data pertinent to the interactions of actinides and long-lived fission products with groundwater, waste package components, and geologic media are critical input to modeling programs. 9 refs., 1 fig., 2 tabs.

A 40 mm bore quadrupole magnet design, called QC'', has been made for the SSC with the following parameters: 208 T/m gradient at 6500A, 2-layer cos 2 {theta}'' winding arrangement with 30 strand cable and one spacer wedge per coil. Structural support is provided by self-supporting interlocking collars; two types of symmetrical laminations are pre-assembled into collar packs for ease of assembly. This paper will describe the design of a prototype quadrupole magnet for the SSC and preliminary tests results on 1 m models. 7 refs., 6 figs., 2 tabs.

Several designs for the Superconducting Super Collider dipole magnet have been analyzed. This note discusses the mechanical and electromagnetic features of each design. Electromagnetic and Mechanical analyses were performed using hand, computer programs and finite element techniques to evaluate the design. 10 refs., 6 figs., 3 tabs.

Late in 1988, a prototype high speed cable machine was built by industry and delivered in FY88 for the Superconducting Super Collider (SSC), and delivered to New England Electric Wire Corp. for the fabrication of SSC cable. This cabling machine has produced the majority of the cable needed for the SSC Dipole Program. During the past year and a half we have experienced several cabling difficulties that were not seen previously. These difficulties were due to new techniques and equipment relating to the high speed production of cable meeting SSC specifications. These difficulties included mandrel alignment, Turk's-head roller alignment, and Turk's-head drive equipment. The solution to these problems are discussed with the SSC specification in detail. 2 refs., 6 figs.

A vexing problem associated with detection of Schottky signals from a bunched beam is the presence of the coherent signal, which can be 10 or more orders of magnitude greater than the Schottky signal. To overcome this difficulty, we have constructed a Schottky detector for the Tevatron collider in the form of a high-Q ({approx}5000) resonant cavity which operates at roughly 2 GHz, well above the frequency at which the single-bunch frequency spectrum begins to roll off ({approx}200--300 MHz for the Tevatron). The detector is capable of sensing independently the vertical and horizontal particle motions. The 2 GHz Schottky signals are down-converted to frequencies below 100 kHz to permit relatively rapid high-resolution analysis using a FFT spectrum analyzer. The initial installation consists of a single cavity; a second detector will be built which employs a pair of phased cavities to permit discrimination between p's and {bar p}'s. Details of the design of both the cavity and the associated electronics are presented. Spectra obtained from the detector show clearly observable Schottky betatron lines, free of coherent contaminants; also seen are the common-mode'' longitudinal signals due to the offset of the beam from the detector center. The latter signals indicate that at …

Several models and theories are reviewed that incorporate the idea of radiation-induced lesions (repairable and/or irreparable) that can be related to molecular lesions in the DNA molecule. Usually the DNA double-strand or chromatin break is suggested as the critical lesion. In the models, the shoulder on the low-LET survival curve is hypothesized as being due to one (or more) of the following three mechanisms: (1) interaction'' of lesions produced by statistically independent particle tracks; (2) nonlinear (i.e., linear-quadratic) increase in the yield of initial lesions, and (3) saturation of repair processes at high dose. Comparisons are made between the various approaches. Several significant advances in model development are discussed; in particular, a description of the matrix formulation of the Markov versions of the RMR and LPL models is given. The more advanced theories have incorporated statistical fluctuations in various aspects of the energy-loss and lesion-formation process. An important direction is the inclusion of physical and chemical processes into the formulations by incorporating relevant track structure theory (Monte Carlo track simulations) and chemical reactions of radiation-induced radicals. At the biological end, identification of repair genes and how they operate as well as a better understanding of how DNA misjoinings lead to …

This paper describes actual experiences in designing system level test cases for a large on-line transaction system which keeps track of work orders and payroll for a complex of machine shops. These system tests were designed after the software had been written and the system was about to undergo user acceptance testing. It was an effort independent of the development, intended to improve the overall quality of the delivered system. Although accepted software engineering methods had been used extensively during the development, at the time of these system tests, up-to-date documentation was limited to the user manual. Knowledgeable persons were mostly unavailable, busy with completion of the system. Nevertheless, in this real world situation, the system test cases were needed in a timely fashion. After more conventional tests were designed and run yielding no bugs, a new approach was taken. This involved identifying a major section of the software as an object and then developing a state model for it based on the implementation and availability of certain process information in the database such as: track flags, status, and time stamps. A flow graph was derived from the state transition diagram. Application of basis path testing to a simplified version …

The influence of ion-implanted Y, Hf, Zr and Cr on the oxidation behavior of a Ni-25 wt % CR alloy at 1000{degrees}C has been investigated. The implantation dosage was 5 {times} 10{sup 16} ions/cm{sup 2}. Two methods of implantation have been used. One was to implant ions directly into a clean alloy surface; the other was to implant into an approximately 0.6 {mu}m thick Cr{sub 2}O{sub 3} layer formed at 1000{degrees}C on the alloy. In neither case did the Cr implantation show any beneficial effects. Implantations of Y, Hf and Zr produced all the reactive element effects, i.e. reduction in oxidation rate, elimination of base metal oxide formation and improvement in scale adhesion, only if the ions were initially implanted in the alloy. When the ions were implanted in a preformed oxide, the subsequent oxidation process was altered to the same degree as before, but the scale adhesion was not affected. Implications of these results to the mechanism of the reactive element effect are discussed. 10 refs., 4 figs.

The Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) will be the first production facility in the United States for the immobilization of high-level nuclear waste. Production of DWPF canistered wasteforms will begin prior to repository licensing, so decisions on facility startup will have to be made before the final decisions on repository design are made. The Department of Energy's Office of Civilian Radioactive Waste Management (RW) has addressed this discrepancy by defining a Waste Acceptance Process. This process provides assurance that the borosilicate-glass wasteform, in a stainless-steel canister, produced by the DWPF will be acceptable for permanent storage in a federal repository. As part of this process, detailed technical specifications have been developed for the DWPF product. SRS has developed detailed strategies for demonstrating compliance with each of the Waste Acceptance Process specifications. An important part of the compliance is the testing which will be carried out in the DWPF. In this paper, the bases for each of the tests to be performed in the DWPF to establish compliance with the specifications are described, and the tests are detailed. The results of initial tests relating to characterization of sealed canisters are reported.