Fast intermittent transport has been observed in the scrape-off layer (SOL) of major tokamaks including Alcator C-Mod, DIII-D, and NSTX. This kind of transport is not diffusive but rather convective. It strongly increases plasma flux to the chamber walls and enhances the recycling of neutral particles in the main chamber. We discuss anomalous cross-field convection (ACFC) model for impurity and main plasma ions and its relation to intermittent transport events, i.e. plasma density blobs and holes in the SOL. Along with plasma diffusivity coefficients, our transport model introduces time-independent anomalous cross-field convective velocity. In the discharge modelling, diffusivity coefficients and ACFC velocity profiles are adjusted to match a set of representative experimental data. We use this model in the edge plasma physics code UEDGE to simulate the multi-fluid two-dimensional transport for these three tokamaks. We present simulation results suggesting the dominance of anomalous convection in the far SOL transport. These results are consistent with the hypothesis that the chamber wall is an important source of impurities and that different impurity charge states have different directions of anomalous convective velocity.

A hydrogen safety sensor is presented which provides high sensitivity and fast response time when operated in air. The target application for the sensor is external deployment near systems using or producing high concentrations of hydrogen. The sensor is composed of a catalytically active metal-oxide sensing electrode and a noble metal reference electrode attached to an yttria-stabilized zirconia (YSZ) electrolyte. The sensing approach is based on the difference in oxidation rate of hydrogen on the different electrode materials. Results will be presented for a sensor using a sensing electrode of tin-doped indium oxide (ITO). Response to H{sub 2}, and cross-sensitivity to hydrocarbon and H{sub 2}O are discussed.

We present the longitudinal coherence measurement of the transient inversion collisional x-ray laser for the first time. The Ni-like Pd x-ray laser at 14.68 nm is generated by the LLNL COMET laser facility and is operating in the gain-saturated regime. Interference fringes are produced using a Michelson interferometer setup in which a thin multilayer-coated membrane is used as a beam splitter. The longitudinal coherence length for the picosecond duration 4d{sup 1}S{sub 0} {yields} 4p{sup 1}P{sub 1} lasing transition is determined to be {approx}400 {micro}m (1/e HW) by adjusting the length of one interferometer arm and measuring the resultant variation in fringe visibility. This is four times improved coherence than previous measurements on quasi-steady state schemes largely as a result of the narrower line profile in the lower temperature plasma. The inferred gain-narrowed linewidth of {approx}0.29 pm is also substantially narrower than previous measurements on quasi-steady state x-ray laser schemes. This study shows that the coherence of the x-ray laser beam can be improved by changing the laser pumping conditions. The x-ray laser is operating at 4 - 5 times the transform-limited pulse.

We have developed and characterized a mixer to study the reaction kinetics of protein folding on a microsecond timescale. The mixer uses hydrodynamic focusing of pressure-driven flow in a microfluidic channel to reduce diffusion times as first demonstrated by Knight et al.[1]. Features of the mixer include 1 {micro}s mixing times, sample consumptions of order 1 nl/s, loading sample volumes on the order of microliters, and the ability to manufacture in fused silica for compatibility with most spectroscopic methods.

d on 25 Feb 2003 (v1), last revised 10 Apr 2003 (this version, v2))We estimate the Coulomb energy of static quarks from a Monte Carlo calculation of the correlator of timelike link variables in Coulomb gauge. We find, in agreement with Cucchieri and Zwanziger, that this energy grows linearly with distance at large quark separations. The corresponding string tension, however, is several times greater than the accepted asymptotic string tension, indicating that a state containing only static sources, with no constituent gluons, is not the lowest energy flux tube state. The Coulomb energy is also measured on thermalized lattices with center vortices removed by the de Forcrand-D'Elia procedure. We find that when vortices are removed, the Coulomb string tension vanishes.

Explicit supersymmetry breaking is studied in higher dimensional theories by having boundaries respect only a subgroup of the bulk symmetry. If the boundary symmetry is the maximal subgroup allowed by the boundary conditions imposed on the fields, then the symmetry can be consistently gauged; otherwise gauging leads to an inconsistent theory. In a warped fifth dimension, an explicit breaking of all bulk supersymmetries by the boundaries is found to be inconsistent with gauging; unlike the case of flat 5D, complete supersymmetry breaking by boundary conditions is not consistent with supergravity. Despite this result, the low energy effective theory resulting from boundary supersymmetry breaking becomes consistent in the limit where gravity decouples, and such models are explored in the hope that some way of successfully incorporating gravity can be found. A warped constrained standard model leads to a theory with one Higgs boson with mass expected close to the experimental limit. A unified theory in a warped fifth dimension is studied with boundary breaking of both SU(5) gauge symmetry and supersymmetry. The usual supersymmetric predictionfor gauge coupling unification holds even though the TeV spectrum is quite unlike the MSSM. Such a theory may unify matter and Higgs in the same SU(5) …

As requirements for surface slope error quality of grazing incidence optics approach the 100 nanoradian level, it is necessary to improve the performance of the measuring instruments to achieve accurate and repeatable results at this level. We have identified a number of internal error sources in the Long Trace Profiler (LTP) that affect measurement quality at this level. The LTP is sensitive to phase shifts produced within the millimeter diameter of the pencil beam probe by optical path irregularities with scale lengths of a fraction of a millimeter. We examine the effects of mirror surface ''macroroughness'' and internal glass homogeneity on the accuracy of the LTP through experiment and theoretical modeling. We will place limits on the allowable surface ''macroroughness'' and glass homogeneity required to achieve accurate measurements in the nanoradian range.

Motivation. The power of multi-sequence comparison forbiological discovery is well established and sequence data from a growinglist of organisms is becoming available. Thus, a need exists forcomputational strategies to visually compare multiple aligned sequencesto support conservation analysis across various species. To be efficientthese visualization algorithms require the ability to universally handlea wide range of evolutionary distances while taking into accountphylogeny Results. We have developed Phylo-VISTA, an interactive tool foranalyzing multiple alignments by visualizing the similarity of DNAsequences among multiple species while considering their phylogenicrelationships. Features include a broad spectrum of resolution parametersfor examining the alignment and the ability to easily compare any subtreeof sequences within a complete alignment dataset. Phylo-VISTA uses VISTAconcepts that have been successfully applied previously to a wide rangeof comparative genomics data analysis problems. Availability Phylo-VISTAis an interactive java applet available for downloading athttp://graphics.cs.ucdavis.edu/~;nyshah/Phylo-VISTA. It is also availableon-line at http://www-gsd.lbl.gov/phylovista and is integrated with theglobal alignment program LAGAN athttp://lagan.stanford.edu.Contactphylovista@lbl.gov

We utilize ultrafast terahertz pulses to monitor the carrierdynamics in the high-TC superconductor Bi2Sr2CaCu2O8+delta. Thetemperature, density and timedependence distinctly exposes a bimolecularrecombination process of quasiparticles which underlies formation ofCooper pairs.

A more urgent need now exists since 9/11 to protect vital assets at nuclear plants from physical security threats. Any approach to successful defense must result in the best possible risk profile , while also performing this defense against credible threats within the context of limited personnel and materiel resources. Engineered solutions need to be well thought out, and take advantage of each plant's available organic strengths and opportunities. A robust, well trained/equipped highly motivated protective force will help reduce concerns where there are weaknesses making the plant vulnerable to threats. A thorough risk assessment takes into account the proper combination of both deterministic and probabilistic application of resources as a most advantageous approach; this is postulated to be development of integrated protection methods and plans, which blend solid engineering design with the highest caliber of protection forces. By setting a clear and ambitious objective to shield the nuclear assets with this type of dynamic full spectrum defense in depth, the risk of harm-breach or likelihood of any opponent's threat being realized should be reduced to the lowest practicable levels.

Today, each utility or country operating nuclear power plants can select between two long-term spent fuel management policies: either, spent fuel is considered as waste to dispose of through direct disposal or, spent fuel is considered a resource of valuable material through reprocessing-recycling. Reading and listening to what is said in the nuclear community, we understand that most people consider that the choice of policy is, actually, a choice among two technical paths to handle spent fuel: direct disposal versus reprocessing. This very simple situation has been recently challenged by analysis coming from countries where both policies are on survey. For example, ONDRAF of Belgium published an interesting study showing that, economically speaking for final disposal, it is worth treating spent fuel rather than dispose of it as a whole, even if there is no possibility to recycle the valuable part of it. So, the question is raised: is there such a one-to-one link between long term spent fuel management political option and industrial option? The purpose of the presentation is to discuss the potential advantages and drawbacks of spent fuel treatment as an implementation of the policy that considers spent fuel as waste to dispose of. Based on technical …

With several military base closures resulting in property transfer to public use and the decommissioning of many legacy waste facilities, the opportunity for remediation of older buildings is increasing. Along with these projects, come several problems that could give the potential remediator some surprises. During the preconstruction and planning phases of the original construction activities, several generations of drawings were most likely produced for approval and permit submittal. Over the years, buildings may undergo several renovations with or without the full characterization or remediation that should be done when radioactive materials are used on a site. New walls or floors may be built over the original construction materials. Contamination in and around the building may have resulted from processes that were accepted at the time or from inadvertent activities that may have been covered up, including accidental spills. Many buildings contain hidden rooms or accesses that over time became useless and have been closed up or over, these areas may not be very obvious. When characterizing a building the effluents of the building are usually forgotten, sewer lines are important areas to investigate. All these items could cause a remediator to overlook a potentially highly contaminated area. With more of …

The U.S. Environmental Protection Agency (EPA) recently developed a searchable database and website for the Environmental Radiation Ambient Monitoring System (ERAMS) data. This site contains nationwide radiation monitoring data for air particulates, precipitation, drinking water, surface water and pasteurized milk. This site provides location-specific as well as national information on environmental radioactivity across several media. It provides high quality data for assessing public exposure and environmental impacts resulting from nuclear emergencies and provides baseline data during routine conditions. The database and website are accessible at www.epa.gov/enviro/. This site contains (1) a query for the general public which is easy to use--limits the amount of information provided, but includes the ability to graph the data with risk benchmarks and (2) a query for a more technical user which allows access to all of the data in the database, (3) background information on ER AMS.

In this study, we describe a new laundry system to wash clothes, including those contaminated with radionuclides, without using detergent. The main part of this system is electrolytic cell that consists of a cathode with a special coating of nickel, an anode of nickel, and a cation exchange membrane between the two electrodes. The electrolyte is supplied to the anode and the tap-water to the cathode. When an electricity of 5 volts and 25 amperes is applied to the electrodes, the processed water is produced from the cathode. This processed water containing no detergent was investigated experimentally with regard to its decontamination efficiency of radionuclides and detergency of soil as compared to the conventional washing using detergent. It was found that the processed water from this system has an ability to simultaneously remove radionuclides and soil from the cloth with good efficiency.

To meet the requirements of the State of Tennessee's Department of Environment and Conservation Commissioner's Order for treatment of mixed low level wastes, Oak Ridge has utilized commercial treatment companies to treat and dispose mixed waste. Over the past year, Oak Ridge has shipped organic-contaminated mixed waste for treatment to meet milestones under the Site Treatment Plan. Oak Ridge has established contracts with commercial treatment companies accessible by all DOE sites for treatment of a wide range of mixed wastes. The paper will describe and summarize the activities involved in treating and disposing of organic-contaminated mixed waste utilizing DOE complex-wide contracts and the treatment and disposal activities required. This paper will describe the case history of treatment of several organic-contaminated mixed wastes from the Oak Ridge Reservation requiring treatment prior to disposal. The paper will include waste category information, implementation activities, and contract access. The paper will discuss the specifics of the mixed waste treatment including waste characteristics, treatment process and equipment utilized, and treatment results. Additional information will be provided on task order development, waste profiling, treatment pricing, and the disposal process.

Studsvik has completed over four years of operation at its Erwin, TN facility. During this time period Studsvik processed over 3.3 million pounds (1.5 million kgs) of radioactive ion exchange bead resin, powdered filter media, and activated carbon, which comprised a cumulative total activity of 18,852.5 Ci (6.98E+08 MBq). To date, the highest radiation level for an incoming resin container has been 395 R/hr (3.95 Sv/h). The Studsvik Processing Facility (SPF) has the capability to safely and efficiently receive and process a wide variety of solid and liquid Low Level Radioactive Waste (LLRW) streams including: Ion Exchange Resins (IER), activated carbon (charcoal), graphite, oils, solvents, and cleaning solutions with contact radiation levels of up to 400 R/hr (4.0 Sv/h). The licensed and heavily shielded SPF can receive and process liquid and solid LLRWs with high water and/or organic content. This paper provides an overview of the last four years of commercial operations processing radioactive LLRW from commercial nuclear power plants. Process improvements and lessons learned will be discussed.

The United States Department of Energy's Carlsbad Field Office (CBFO) is responsible for the successful management of transuranic radioactive waste (TRUW) in the United States. TRUW is a long-lived radioactive waste/material (LLRM). CBFO's responsibilities includes the operation of the Waste Isolation Pilot Plant (WIPP), which is a deep geologic repository for the safe disposal of U.S. defense-related TRUW and is located 42 kilometers (km) east of Carlsbad, New Mexico. WIPP is the only deep-geological disposal site for LLRM that is operating in the world today. CBFO also manages the National Transuranic Waste Program (NTP), which oversees TRU waste management from generation to disposal. As of February 2003, approximately 1500 shipments of waste have been safely transported to the WIPP, which has been operating since March 1999.

Problematic radioactive wastes were generated during various activities of both industrial facilities and research institutions usually in relative small amounts. These can be spent ion exchange resins, inorganic absorbents, wastes from research nuclear reactors, irradiated graphite, mixed, organic or chlorine-containing radioactive waste, contaminated soils, un-burnable heavily surface-contaminated materials, etc. Conventional treatment methods encounter serious problems concerning processing efficiency of such waste, e.g. complete destruction of organic molecules and avoiding of possible emissions of radionuclides, heavy metals and chemically hazardous species. Some contaminations cannot be removed from surface using common decontamination methods. Conditioning of ash residues obtained after treatment of solid radioactive waste including ashes received from treating problematic wastes also is a complicated task. Moreover due to relative small volume of specific type radioactive waste the development of target treatment procedures and facilities to conduct technological processes and their deployment could be economically unexpedient and ecologically no justified. Thermochemical processing technologies are used for treating and conditioning problematic radioactive wastes. The thermochemical processing uses powdered metal fuels (PMF) that are specifically formulated for the waste composition and react chemically with the waste components. The composition of the PMF is designed in such a way as to minimize the release of …

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This presentation describes the status of recent initiatives undertaken by the United Kingdom Government to address the long-standing problems confronting it with regards to discharge of public sector civil nuclear liabilities. It describes the enabling steps taken thus far in the creation of a Liabilities Management Unit (LMU) to prepare the ground for this important work, with specific reference to some of the more technically challenging problems which must be resolved in order to make progress towards cleaning up the UK's nuclear legacy facilities and waste materials. Finally, it addresses some of the approaches proposed by the LMU as it seeks to establish a robust, permanent entity to meet the challenges.

Decontamination projects are typically undertaken in the interest of reducing disposal costs. This goal can be achieved because decontamination concentrates the contaminant into a smaller volume or changes its form so that a lower cost disposal technology becomes available. Less frequently, decontamination adds value back to the fouled structure or contaminated piece of equipment. This removal of dioxins from a gas turbine generator set is one of the latter cases. A multi-million dollar piece of equipment could have been destined for the scrap pile. Instead, an innovative, non-destructive decontamination technology, developed under EPA and DOE demonstration programs has was employed so that the set could repaired and put back into service. The TechXtractchemical decontamination technology reduced surface dioxin / furan concentrations from as high as 24,000 ng / m2 to less than 25 ng / m2 and below detection limits.

The staff of the Spent Fuel Project Office at the U.S. Nuclear Regulatory Commission undertook the investigation and thermal analysis of the Baltimore tunnel fire event. This event occurred in the Howard Street tunnel, in Baltimore, Maryland, on July 18, 2001. The staff was tasked with assessing the consequences of this event on the transportation of spent nuclear fuel. This paper describes the staff's coordination with the following government and laboratory organizations: the National Transportation Safety Board (NTSB), to determine the details of the train derailment and fire; the National Institute of Standards and Technology (NIST), to quantify the thermal conditions within the tunnel; the Center for Nuclear Waste Regulatory Analysis (CNWRA), to validate the NIST evaluations, and the Pacific Northwest National Laboratory (PNNL), to assist in the thermal analysis. The results of the staff's review and analysis efforts are also discussed. The staff has concluded that had the spent fuel transportation cask analyzed, a design approved under 10 CFR Part 71, been subjected to the Howard Street tunnel fire, no release of radioactive materials would have resulted from this postulated event, and the health and safety of the public would have been maintained.

The U.S. Nuclear Regulatory Commission (NRC) does not currently require full-scale physical testing of shipping casks as part of its certification process. Stakeholders have long urged NRC to require full-scale testing as part of certification. NRC is currently preparing a full-scale casktesting proposal as part of the Package Performance Study (PPS) that grew out of the NRC reexamination of the Modal Study. The State of Nevada and Clark County remain committed to the position that demonstration testing would not be an acceptable substitute for a combination of full-scale testing, scale-model tests, and computer simulation of each new cask design prior to certification. Based on previous analyses of cask testing issues, and on preliminary findings regarding the July 2001 Baltimore rail tunnel fire, the authors recommend that NRC prioritize extra-regulatory thermal testing of a large rail cask and the GA-4 truck cask under the PPS. The specific fire conditions and other aspects of the full-scale extra-regulatory tests recommended for the PPS are yet to be determined. NRC, in consultation with stakeholders, must consider past real-world accidents and computer simulations to establish temperature failure thresholds for cask containment and fuel cladding. The cost of extra-regulatory thermal testing is yet to be determined. …

This paper reviews issues that have been raised concerning radiological risks and safety of the public exposed to shipments of spent nuclear fuel and high-level radioactive waste to a Yucca Mountain repository. It presents and analyzes the contrasting viewpoints of opponents and proponents, presents facts about radiological exposures and risks, and provides perspective from which to observe the degree of risk that would devolve from the shipments. The paper concludes that the risks to the public's health and safety from being exposed to radiation from the shipments will not be discernable.