155 research outputs found
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Visual examinations of K east fuel elements
Selected fuel elements stored in both ``good fuel`` and ``bad fuel`` canisters in K East Basin were extracted and visually examined full length for damage. Lower end damage in the ``bad fuel`` canisters was found to be more severe than expected based on top end appearances. Lower end damage for the ``good fuel`` canisters, however, was less than expected based on top end observations. Since about half of the fuel in K East Basin is contained in ``good fuel`` canisters based on top end assessments, the fraction of fuel projected to be intact with respect to IPS processing considerations remains at 50% based on these examination results
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Visual examinations of K west fuel elements
Over 250 fuel assemblies stored in sealed canisters in the K West Basin were extracted and visually examined for damage. Substantial damage was expected based on high cesium levels previously measured in water samples taken from these canisters. About 11% of the inner elements and 45% of the outer elements were found to be failed in these examinations. Canisters that had cesium levels of I curie or more generally had multiple instances of major fuel damage
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Acceptance testing of the eddy current probes for measurement of aluminum hydroxide coating thickness on K West Basin fuel elements
During a recent visual inspection campaign of fuel elements stored in the K West Basin, it was noted that fuel elements contained in sealed aluminum canisters had a heavy translucent type coating on their surfaces (Pitner 1997a). Subsequent sampling of this coating in a hot cell (Pitner 1997b) and analysis of the material identified it as aluminum hydroxide. Because of the relatively high water content of this material, safety related concerns are raised with respect to long term storage of this fuel in Multi-Canister Overpacks (MCOs). A campaign in the basin is planned to demonstrate whether this coating can be removed by mechanical brushing (Bridges 1998). Part of this campaign involves before-and-after measurements of the coating thickness to determine the effectiveness of coating removal by the brushing machine. Measurements of the as-deposited coating thickness on multiple fuel elements are also expected to provide total coating inventory information needed for MCO safety evaluations. The measurement technique must be capable of measuring coating thicknesses on the order of several mils, with a measurement accuracy of 0.5 mil. Several different methods for quantitatively measuring these thin coatings were considered in selecting the most promising approach. Ultrasonic measurement was investigated, but it was determined that due to the thin coating depth and the high water content of the material, the signal would likely pass directly through to the cladding without ever sensing the coating surface. X-ray fluorescence was also identified as a candidate technique, but would not work because the high gamma background from the irradiated fuel would swamp out the low energy aluminum signal. Laser interferometry could possibly be applied, but considerable development would be required and it was considered to be high risk on a short term basis. The consensus reached was that standard eddy current techniques for coating thickness measurement had the best chance for success in this endeavor. If proper placement and alignment of the eddy current measurement probe on the coating could be achieved, the thickness of this non-conductive coating over the conductive fuel cladding (Zircaloy 2) should be measurable based on magnetic stand-off aspects. Eddy current devices are routinely used to measure paint coating thicknesses on metal surfaces in this regard. The purpose of this report is to document the development and acceptance testing of the eddy current system conducted to qualify its use for the measurement of aluminum hydroxide coating thicknesses on fuel stored in the K West Basin
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Canister choices for sampling of fuel and sludge from K West basin canisters (second characterization campaign)
The Characterization of Spent Nuclear Fuel in the sealed K West canisters involves four steps, (1) sampling of gas/liquid, (2) ``Lift-and-Look`` visual examinations of fuel elements, (3) sampling of canister sludge, and (4) retrieving fuel for hot cell examinations. This document indicates the choices of particular canisters that were examined during the second characterization campaign in the Hanford K West Basin
Does it look safe? An eye tracking study into the visual aspects of fear of crime
Studies of fear of crime often focus on demographic and social factors, but these can be difficult to change. Studies of visual aspects have suggested that features reflecting incivilities, such as litter, graffiti, and vandalism increase fear of crime, but methods often rely on participants actively mentioning such aspects, and more subtle, less conscious aspects may be overlooked. To address these concerns, the present study examined peopleâs eye movements while they judged scenes for safety. Forty current and former university students were asked to rate images of day-time and
night-time scenes of Lincoln, UK (where they studied) and Egham, UK (unfamiliar location) for safety, maintenance and familiarity, while their eye movements were recorded. Another twenty-five observers not from Lincoln or Egham rated the same images in an internet survey. Ratings showed a strong association between safety and maintenance and lower safety ratings for night-time scenes for both groups, in agreement with earlier findings. Eye movements of the Lincoln participants showed increased dwell times on buildings, houses, and vehicles during safety judgments, and increased dwell times on streets, pavements, and markers of incivilities for maintenance.
Results confirm that maintenance plays an important role in perceptions of safety, but eye movements suggest that observers also look for indicators of current or recent presence of people
CTCs-derived xenograft development in a Triple Negative breast cancer case
Triple-negative breast cancer (TNBC) is characterized by high rates of metastasis and no available molecular targets. CTCs derived xenografts (CDX) have demonstrated to be a promising tool for understanding cancer biology. In our study, a CDX from a TNBC patient was developed for the first time. After CDX characterization, WNT signaling was found as the main mechanism related with this tumor biology and potential CTCs markers were identified and subsequently validated in TNBC patients. In this cohort high levels of MELK expression were associated with poorer survival rates. Overall, our study demonstrates that CTCs from TNBC are tumorigenic and CDXs are a useful model to obtain valuable information about the tumor
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