The commitment by Westinghouse Savannah River Company (WSRC) to bring safety analysis and risk management codes into compliance with national and sitewide quality assurance requirements necessitated a systematic, structured approach. As a part of this effort, WSRC, in cooperation with the Westinghouse Hanford Company, has developed and implemented a certification process for the development and control of computer software. Safety analysis and risk management computer codes pertinent to reactor analyses were selected for inclusion in the certification process. As a first step, documented plans were developed for implementing verification and validation of the codes, and establishing configuration control. User qualification guidelines were determined. The plans were followed with an extensive assessment of the codes with respect to certification status. Detailed schedules and work plans were thus determined for completing certification of the codes considered. Although the software certification process discussed is specific to the application described, it is sufficiently general to provide useful insights and guidance for certification of other software.

Spattered carbon films are widely used as protective overcoats for thin film disk media. Raman spectroscopy is nondestructive and relatively rapid and is well suited for the characterization of carbon films. Specific features in the Raman spectra are empirically correlated with the rates of specific types of mechanical wear for both hydrogenated and unhydrogenated films. This observation is interpreted in terms of a random covalent network, in which the mechanical performance of the film is determined by the nature of the bonding that links sp{sup 2}-bonded domains.

Spattered carbon films are widely used as protective overcoats for thin film disk media. Raman spectroscopy is nondestructive and relatively rapid and is well suited for the characterization of carbon films. Specific features in the Raman spectra are empirically correlated with the rates of specific types of mechanical wear for both hydrogenated and unhydrogenated films. This observation is interpreted in terms of a random covalent network, in which the mechanical performance of the film is determined by the nature of the bonding that links sp{sup 2}-bonded domains.

Structural ceramic materials, like metals, will require lubrication if they are to be used extensively for tribological applications. The use of thin soft metallic coatings (specifically Ag) as a boundary film during mineral oil lubrication of silicon nitride (Si{sub 3}N{sub 4}) and zirconia (ZrO{sub 2}) ceramic materials was investigated in this study. With a pin-on-flat contact configuration in reciprocating sliding, the steady friction coefficient was reduced by a factor of 2 (0.14 {minus}0.16 vs. 0.06--0.07) when the flats were coated with Ag. Also, with Ag coatings the wear of pins was reduced to an unmeasurable level, whereas, in the absence of Ag coatings specific wear rates of {approx}2 {times} 10{sup {minus}9} -- 4 {times} 10{sup {minus}8} mm{sup 3}/Nm and {approx}7 {times} 10{sup {minus}8} -- 2 {times} 10{sup {minus}7} mm{sup 3}/Nm were measured for Si{sub 3}N{sub 4} and ZrO{sub 2} pins respectively. In addition to preventing direct contact between pins and flats, thereby reducing wear, the Ag coatings also act as a solid lubricant, help dissipate flash heating, and accelerate modification of the {lambda} ratio.

Structural ceramic materials, like metals, will require lubrication if they are to be used extensively for tribological applications. The use of thin soft metallic coatings (specifically Ag) as a boundary film during mineral oil lubrication of silicon nitride (Si[sub 3]N[sub 4]) and zirconia (ZrO[sub 2]) ceramic materials was investigated in this study. With a pin-on-flat contact configuration in reciprocating sliding, the steady friction coefficient was reduced by a factor of 2 (0.14 [minus]0.16 vs. 0.06--0.07) when the flats were coated with Ag. Also, with Ag coatings the wear of pins was reduced to an unmeasurable level, whereas, in the absence of Ag coatings specific wear rates of [approx]2 [times] 10[sup [minus]9] -- 4 [times] 10[sup [minus]8] mm[sup 3]/Nm and [approx]7 [times] 10[sup [minus]8] -- 2 [times] 10[sup [minus]7] mm[sup 3]/Nm were measured for Si[sub 3]N[sub 4] and ZrO[sub 2] pins respectively. In addition to preventing direct contact between pins and flats, thereby reducing wear, the Ag coatings also act as a solid lubricant, help dissipate flash heating, and accelerate modification of the [lambda] ratio.

Reliable power supplies for use in transportation and remote systems will be an important part of space exploration terrestrial activities. A potential power source is available in the rare earth metal, thulium. Fuel sources can be produced by activating Tm-169 targets in the space station reactor. The resulting Tm-170 heat sources can be used in thermoelectric generators to power instrumentation and telecommunications located at remote sites such as weather stations. As the heat source in a dynamic Sterling or Brayton cycle system, the heat source can provide a lightweight power source for rovers or other terrestrial transportation systems.

Control rods in the Savannah River Site`s K-reactor are contained within housings composed of seven channels (`septifoils`). Each septifoil is suspended from the top of the reactor and is normally seated on an upflow pin that channels coolant to the septifoil. Forced flow to the septifoil would be eliminated in the unlikely event of a septifoil misseated upon installation, i.e., if the septifoil is not aligned with its upflow pin. If this event were not detected, control rod melting and the interaction of molten metal with water might occur. This paper describes a methodology used to address the issues of steam explosions that might arise by this mechanism. The probability of occurrence of a damaging steam explosion given a misseated septifoil was found to be extremely low. The primary reasons are: (1) the high probability that melting will not occur, (2) the possibility of material holdup by contact with the outer septifoil housing, (3) the relative shallowness of the pool of water into which molten material might fall, (4) the probable absence of a trigger, and (5) the relatively large energy release required to damage a nearby fuel assembly. The methodology is based upon the specification of conditions prevailing within …

Experiment 791 at Fermilab`s Tagged Photon Laboratory has just accumulated a high statistics charm sample by recording 20 billion events on 24000 8mm tapes. A 500 GeV/c {pi}{sup {minus}} beam was used with a fixed target and a magnetic spectrometer which now includes 23 silicon microstrip planes for vertex reconstruction. A new data acquisition system read out 9000 events/sec during the part of the Tevatron cycle that delivered beam. Digitization and readout took 50 {mu}S per event. Data was buffered in eight large FIFO memories to allow continuous event building and continuous tape writing to a wall of 42 Exabytes at 9.6 MB/sec. The 50 terabytes of data buffered to tape is now being filtered on RISC CPUs. Preliminary results show D{sup 0} {yields} K{sup {minus}}{pi}{sup +} and D{sup +} {yields} K{sup {minus}}{pi}{pi}{sup +} decays. Rarer decays will be pursued.

Experiment 791 at Fermilab's Tagged Photon Laboratory has just accumulated a high statistics charm sample by recording 20 billion events on 24000 8mm tapes. A 500 GeV/c [pi][sup [minus]] beam was used with a fixed target and a magnetic spectrometer which now includes 23 silicon microstrip planes for vertex reconstruction. A new data acquisition system read out 9000 events/sec during the part of the Tevatron cycle that delivered beam. Digitization and readout took 50 [mu]S per event. Data was buffered in eight large FIFO memories to allow continuous event building and continuous tape writing to a wall of 42 Exabytes at 9.6 MB/sec. The 50 terabytes of data buffered to tape is now being filtered on RISC CPUs. Preliminary results show D[sup 0] [yields] K[sup [minus]][pi][sup +] and D[sup +] [yields] K[sup [minus]][pi][pi][sup +] decays. Rarer decays will be pursued.

This paper summarizes a system integration approach to residential heating, cooling, and ventilation, embodied in a tight building envelope with precooling and dehumidification of forced ventilation air, and with ducts in the conditioned space.

An important aspect of the qualification of safety related systems, is the assessment of the possibility and consequences of seismic or vibration induced relay chatter. The current rules, contained in ANSI/IEEE C37.98 and the SQUG GIP, consider as seismic induced ``failure`` of a relay, a chatter contact in excess of 2 milliseconds. While this rule is clear in defining ``failure`` of single relay, the definition of ``failure`` becomes more problematic when we consider the alignment of an assembly of relays in series or parallel, and the effects of chatter on the function of the system in which the relays are mounted. In this paper, we report a method, based on system test and probabilities analysis, used to assess ``failure`` by relay chatter in an assembly of relays which control an electric motor. 2 refs.

The deflagration-to-detonation (DDT) phenomenon has been studied for many years. However, no comprehensive model of the DDT process is available. It is important to understand the mechanism by which an explosive will detonate when the source of ignition is a weak shock or flame, and to able to predict this response. We have identified several key areas of the DDT problem which need to be understood before any such prediction can be made, and have established a modest program to obtain a more fundamental understanding of the behavior of explosive under the conditions that can lead to DDT.

Triplets composed of superconducting quadrupoles have been built and installed as the final focusing element for the high-energy positron and electron beams of the SLAC Linear Collider. Special features include independent alignment to 100-micron tolerance inside a common cryostat; non-magnetic materials to allow operation inside the detector`s solenoid field; a continuous-flow helium-only system using 50-meter-long flexible transfer lines; and complete operation of the system before installation. The mechanical design and cryogenic operation experience are presented.

Triplets composed of superconducting quadrupoles have been built and installed as the final focusing element for the high-energy positron and electron beams of the SLAC Linear Collider. Special features include independent alignment to 100-micron tolerance inside a common cryostat; non-magnetic materials to allow operation inside the detector's solenoid field; a continuous-flow helium-only system using 50-meter-long flexible transfer lines; and complete operation of the system before installation. The mechanical design and cryogenic operation experience are presented.

A task group has revised the dosimetric model of the respiratory tract used to calculate annual limits on intake of radionuclides. The revised model can be used to project respiratory tract doses for workers and members of the public from airborne radionuclides and to assess past exposures. Doses calculated for specific extrathoracic and thoracic tissues can be adjusted to account for differences in radiosensitivity and summed to yield two values of dose for the respiratory tract that are applicable to the ICRP tissue weighted dosimetry system.

A task group has revised the dosimetric model of the respiratory tract used to calculate annual limits on intake of radionuclides. The revised model can be used to project respiratory tract doses for workers and members of the public from airborne radionuclides and to assess past exposures. Doses calculated for specific extrathoracic and thoracic tissues can be adjusted to account for differences in radiosensitivity and summed to yield two values of dose for the respiratory tract that are applicable to the ICRP tissue weighted dosimetry system.

Several perovskite-type oxides that contain transition metals on the B-site show mixed (electronic/ionic) conductivity. These mixed conducting oxides are promising materials for oxygen permeating membranes that can operate without the need of electrodes or external electrical circuitry. SrCo[sub 0.8]Fe[sub 0.2]O[sub x] perovskite is known to exhibit very high oxygen permeabilities and one could use this material for producing value added products by direct conversion of methane, the most abundant component of natural gas. This paper deals with the processing and fabrication by plastic extrusion of long lengths ([approx]30 cm) of hollow SrCo[sub 0.8]Fe[sub 0.2]O[sub x] ceramic tubes. These tubes are characterized by scanning electron microscopy, X-ray diffraction (XRD) and their thermodynamic stability is evaluated using room temperature XRD on samples equilibrated at high temperatures in different gas environment.

Several perovskite-type oxides that contain transition metals on the B-site show mixed (electronic/ionic) conductivity. These mixed conducting oxides are promising materials for oxygen permeating membranes that can operate without the need of electrodes or external electrical circuitry. SrCo{sub 0.8}Fe{sub 0.2}O{sub x} perovskite is known to exhibit very high oxygen permeabilities and one could use this material for producing value added products by direct conversion of methane, the most abundant component of natural gas. This paper deals with the processing and fabrication by plastic extrusion of long lengths ({approx}30 cm) of hollow SrCo{sub 0.8}Fe{sub 0.2}O{sub x} ceramic tubes. These tubes are characterized by scanning electron microscopy, X-ray diffraction (XRD) and their thermodynamic stability is evaluated using room temperature XRD on samples equilibrated at high temperatures in different gas environment.

This paper describes the combined analytical, computational, and experimental program developed for identifying operating strategies for mobilization and retrieval of radioactive waste stored in double-shell tanks at Hanford. Sludge mobilization, slurry uniformity, and slurry retrieval investigations will produce guidelines for mixer pump and retrieval pump operation based on the physical properties of the waste and the geometric properties of the system (number of operating pumps and pump design and placement).

This paper describes the combined analytical, computational, and experimental program developed for identifying operating strategies for mobilization and retrieval of radioactive waste stored in double-shell tanks at Hanford. Sludge mobilization, slurry uniformity, and slurry retrieval investigations will produce guidelines for mixer pump and retrieval pump operation based on the physical properties of the waste and the geometric properties of the system (number of operating pumps and pump design and placement).

Research activities being conducted as part of this project include: (1) fundamental studies of electrochemical processes occurring at surfaces and interfaces in fuel cells, and (2) development of novel materials synthesis and processing methodologies for fossil energy conversion applications. Complex impedance and dc polarization studies of the electrocatalytic activity at the cathode have allowed intrinsic materials properties to be separated from extrinsic properties related to morphology. Mixed conduction in cathode materials was shown to dramatically enhance electrocatalytic activity with this approach. Combustion synthesis methods were used to prepare multicomponent perovskite catalysts in the La{sub 1-x}Sr{sub x}Co{sub 1-y}Fe{sub y}O{sub 3} system. Electronic properties of these catalysts can be altered by adjusting the composition, which affects both catalytic activity and selectivity. Inverse micelles have been utilized to prepare nanosized nickel sulfide particles, which show promise as hydrodesulfurization catalysts for liquefied coal. Self-assembling organic monolayers and derivatized inorganic surfaces have been used to control nucleation and crystal morphology of inorganic phases.

Research activities being conducted as part of this project include: (1) fundamental studies of electrochemical processes occurring at surfaces and interfaces in fuel cells, and (2) development of novel materials synthesis and processing methodologies for fossil energy conversion applications. Complex impedance and dc polarization studies of the electrocatalytic activity at the cathode have allowed intrinsic materials properties to be separated from extrinsic properties related to morphology. Mixed conduction in cathode materials was shown to dramatically enhance electrocatalytic activity with this approach. Combustion synthesis methods were used to prepare multicomponent perovskite catalysts in the La{sub 1-x}Sr{sub x}Co{sub 1-y}Fe{sub y}O{sub 3} system. Electronic properties of these catalysts can be altered by adjusting the composition, which affects both catalytic activity and selectivity. Inverse micelles have been utilized to prepare nanosized nickel sulfide particles, which show promise as hydrodesulfurization catalysts for liquefied coal. Self-assembling organic monolayers and derivatized inorganic surfaces have been used to control nucleation and crystal morphology of inorganic phases.

From its beginning in 1943, Los Alamos National Laboratory (Los Alamos) has traditionally used science and technology to fine creative, but practical solutions to complex problems. Los Alamos National Laboratory is operated by the University of California, under contact to the Department of Energy. We are a Government Owned-contractor Operated (GOCO) facility, and a Federally-funded research and Development Center (FFRDC). At Los Alamos, our mission is to apply science and engineering capabilities to problems of national security. Recently our mission has been broadened to include technology transfer to ensure the scientific and technical solutions are available to the marketplace. We are, in staff and technical capabilities, one of the worlds largest multidisciplinary, multiprogram laboratories. We conduct extensive research in energy, nuclear safeguards and security, biomedical science, conventional defense technologies, space science, computational science, environmental protection and cleanup, materials science, and other basic sciences. Since 1980, by a series of laws and executive orders, the resources of the federal laboratories have been made increasingly available to private industry via technology transfer efforts. Los Alamos National Laboratory uses a variety of technology transfer methods including laboratory visits, cooperative research, licensing, contract research, user facility access, personnel exchanges, consulting, publications, and workshops, seminars …

Human error in execution of critical functions and tasks can be costly. The Three Mile Island and the Chernobyl Accidents are examples of results from human error in the nuclear industry. There are similar errors that could no doubt be cited from other industries. This paper discusses a strategy to minimize common mode human error in the execution of critical functions and tasks. The strategy consists of the use of human redundancy, and also diversity in human cognitive behavior: skill-, rule-, and knowledge-based behavior. The authors contend that the use of diversity in human cognitive behavior is possible, and it minimizes common mode error.