Results 1 - 10 of 20196
Results 1 - 10 of 20196. Search took: 0.038 seconds
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[en] This project has been focused on the experimental and numerical investigations of the water-cooled and air-cooled Reactor Cavity Cooling System (RCCS) designs. At this aim, we have leveraged an existing experimental facility at the University of Wisconsin-Madison (UW), and we have designed and built a separate effect test facility at the University of Michigan. The experimental facility at UW has underwent several upgrades, including the installation of advanced instrumentation (i.e. wire-mesh sensors) built at the University of Michigan. These provides high resolution time-resolved measurements of the void-fraction distribution in the risers of the water-cooled RCCS facility. A phenomenological model has been developed to assess the water cooled RCCS system stability and determine the root cause behind the oscillatory behavior that occurs under normal two-phase operation. Testing under various perturbations to the water-cooled RCCS facility have resulted in changes in the stability of the integral system. In particular, the effects on stability of inlet orifices, water tank volume have and system pressure been investigated. MELCOR was used as a predictive tool when performing inlet orificing tests and was able to capture the Density Wave Oscillations (DWOs) that occurred upon reaching saturation in the risers. The experimental and numerical results have then been used to provide RCCS design recommendations. The experimental facility built at the University of Michigan was aimed at the investigation of mixing in the upper plenum of the air-cooled RCCS design. The facility has been equipped with state-of-the art high-resolution instrumentation to achieve so-called CFD grade experiments, that can be used for the validation of Computational Fluid Dynanmics (CFD) models, both RANS (Reynold-Averaged) and LES (Large Eddy Simulations). The effect of risers penetration in the upper plenum has been investigated as well.
[en] Mechanical filters are very important to ensure smooth operation of the secondary cooling system. The present condition of the mechanical filter treatment duration of PA-02 BT001 is increasing compared to other mechanical filters (PA-01 BT001 and PA-03 BT001). Seeing these conditions, it is very important to conduct an evaluation / study to find the cause and resolution through operating data starting in 2010 - 2017, collection of maintenance data starting from 2010 - 2017. After evaluation and review it can be concluded that the mechanical filter causes (PA-02 BT001) maintenance is most often compared to other mechanical filters, this is due to the location of the mechanical filter (PA-02 BT001) located on the side of the pipe straight at the far end so that dirt and lichen will be carried to the section. Besides this, PA-02 BT001 also serves cooling towers on the outside so that the growth of moss is more than the others. Based on these results, it is very important to review the mechanical filter operating schedule, maintenance scheme and the use of anti-moss in secondary cooling system water. (author)
[en] Has been calculated the cooling installation performance of Decy-13 cyclotron. The cooling installation is analysed based on the technical specifications of each cooling component to proof the results of the design and implementation of installations meet the cooling requirement. Analysis of loss of pressure and flow rate in the piping installation is done empirically using Hazen-Williams equation while the analysis of heat transfer processes in the cooling tower is done using the help of psychometric charts that available. Cooling component consists of a condenser and associated piping systems with cooling towers and equipped with a pump to push the circulation of cooling. The calculations show that the installation of the condenser cooler uses the cooling tower LiangChi LBC-30 with a booster pump Grundfos 4 kW NF30-36T powered 47kW able to transfer heat with the coolant flow rate 136 lpm, input to output coolant pressure difference 2.1atm and the cooling temperature difference 5 °C. Conclusion of the calculation is the technical specifications of cooling components and installation already meets the needs of the cooling expected. (author)
[en] An outcome of the Joint Review Panel that evaluated the proposal by Ontario Power Generation (OPG) for the Darlington New Nuclear Project was that OPG must undertake a formal quantitative cost-benefit analysis for cooling tower versus once-through condenser cooling water systems. While OPG's analysis concluded the preference for the once-through condenser approach, the possibility for using cooling towers remains. This paper presents an analysis of the different cooling tower designs that could be used for a potential CANDU new build at the Darlington Site. The work was completed in partial fulfilment of the requirements of a capstone design project by a group of nuclear engineering students. The project considered the various cooling tower designs used in similar applications for both nuclear and thermal power plants, and identified the preferred option based on criteria such as: energy penalty, cost, thermal/aquatic effects, social acceptance and land use. (author)
[en] The purpose of the Technical Meeting is to provide a platform for detailed presentations and technical discussions on recent progress in R&D activities on in-vessel melt retention (IVMR) and ex-vessel corium cooling (EVCC) during severe accidents at water-cooled reactors (WCRs).
[en] A heater tank is designed and developed at the Malaysian Nuclear Agency whereby the setup allows investigation of the heat transfer between heater rods and fluids in a tank. The heater tank is a physical simulation of an array of nuclear fuel rods within a nuclear fuel assembly. In this paper, we introduce the tank, heating rod, and electrical control, with a focus on design. The heater tank shall be used as an educational unit to study convective cooling and for tomographic inspection. (author)
[en] The paper presents a press-pack package integrated with a microchannel cooling system, which is a new thermal solution for power devices, e.g. diodes. In comparison with conventional solutions enforcing the use of either an air cooling system or a liquid one, the novel package is characterised by considerably smaller dimensions, lower weight and significantly higher thermal performance. The conducted measurements of the manufactured model showed that a thermal resistance of 0.0182 K/W can be obtained for an allowable pressure drop for electronic applications.
[en] The U.S. Nuclear Regulatory Commission (NRC) is currently preparing for the possible near-term submittal of design certification applications for light-water, small modular reactors (SMRs). This paper discusses the NRC's activities with respect to preparations for SMR applications, the status of reviews, and the expected review timelines. Also discussed are the policy and technical challenges specific to SMRs, such as emergency planning and control room staffing, and how the NRC plans to address these during its reviews of applications. In addition to positioning itself for the receipt of light-water SMR applications, the NRC is strategically considering how it would approach the review of applications for non-light-water reactor designs in the future. For example, with respect to non-light water reactors, the NRC has recently participated in several activities that will help to lay the groundwork for future application reviews including participating in a joint initiative with the U.S. Department of Energy to develop possible General Design Criteria for non-light water designs. An overview of the NRC's current activities and important positions related to light-water SMR and non-LWR designs are presented in this paper. (author)