Results 1 - 10 of 337
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[en] HVAC equipment, gloveboxes, and other types of enclosures are required to meet rigid well-defined leak rates when they are to be installed in a nuclear facility. This paper describes two implementations of an instrumentation system that is used to test leak rates on heating, ventilation, and air conditioning (HVAC) plenums, gloveboxes, and experimental chambers, etc. One of the implementations used a programmable logic controller (PLC). The other used what is probably a simpler system based on FlexNet reg-sign modules. The emphasis on both systems was on automatic data collection, automatic report generation, and validation of the test results to ERDA 76-21 and ASME-N510. The data are collected using input modules connected to the PLC in one case. In the other case the data are collected using the FlexNet reg-sign modules. In both cases, the data are stored and the reports are generated in a spreadsheet
[en] The paper highlights the ELF EMF radiation safety assessment performed at an overhead 275-kV High-Voltage Transmission Lines (HVTL). The study comprised of assessment performed at three (3) different transmission lines. The instrument setup and measurement protocols during the assessment were adopted from standard measurement method and procedures stipulated under the Institute of Electrical and Electronics Engineers (IEEE) Standard. The results were compared with the standards recommended in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. The results showed that the measured electric and magnetic field strengths were within the permissible exposure limit. Both the field strengths were found to drop significantly against distance from the transmission lines where closer distances showed higher field strengths. (author)
[en] Highlights: • The index allocation methodology of structure stability has been elaborated in SG facility. • The influence produced by thermal was eliminated by constant temperature with HVAC system and other local cool systems. • The system structural stability was improved significantly by improving the stiffness, increasing the damping ratio, and reducing the excitation power spectrum. • The beam shot precision was 26 μm RMS that was less than 30 μm RMS and satisfied the stability demand. - Abstract: The Shenguang-III laser facility is the largest high-power solid-state laser facility in Asia and provides 48 laser beams for laser fusion. To satisfy the demands of physics experiments, all the laser beams are required to be accurately positioned on the target and the positioning error of all the laser beams should not exceed 30 μm (root mean square). The formidable challenge in the facility design is how to minimize drift errors and structure vibrations and place the optical elements in their ideal locations. In the paper, we focus on the control strategy of structure stability for the Shenguang-III laser facility. Firstly, we present the methodology of stability index allocation to obtain the design parameter of structure stability for the laboratory platform and each optical element. Then we discuss the factors influencing stability of optical elements and the control methodology. Finally, we measure the beam pointing error to prove the feasibility of strategy. The results show that the maximum drift of all the laser beams is 26 μm (root mean square), which is less than 30 μm and satisfies the stability demand.
[en] US nuclear plants are implementing preventive maintenance (PM) tasks with little documented basis beyond fundamental vendor information to support the tasks or their intervals. The Preventive Maintenance Basis project provides utilities with the technical basis for PM tasks and task intervals associated with 40 specific components such as valves, electric motors, pumps, and HVAC equipment. This report provides an overview of the PM Basis project and describes use of the PM Basis database. Volume 21 of the report provides a program of PM tasks suitable for application to HVAC-Air Handling Equipment. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used, in conjunction with material from other sources, to develop a complete PM program or to improve an existing program. Users of this information will be utility managers, supervisors, craft technicians, and training instructors responsible for developing, optimizing, or fine-tuning PM programs
[en] In 1983, the Advisory Committee on Reactor Safeguards (ACRS) recommended that the US NRC develop a control room HVAC performance testing protocol. To date no such protocol has been forthcoming. Beginning in mid-1994, an effort was funded by NRC under a Small Business Innovation Research (SBIR) grant to develop several simplified test protocols based on the principles of tracer gas testing in order to measure the total unfiltered inleakage entering a CRE during emergency mode operation of the control room ventilation system. These would allow accurate assessment of unfiltered air inleakage as required in SRP 6.4. The continuing lack of a standard protocol is unfortunate since one of the significant parameters required to calculate operator dose is the amount of unfiltered air inleakage into the control room. Often it is assumed that, if the Control Room Envelope (CRE) is maintained at +1/8 in. w.g. differential pressure relative to the surroundings, no significant unfiltered inleakage can occur it is further assumed that inleakage due to door openings is the only source of unfiltered air. 23 refs., 13 figs., 2 tabs
[en] The HVAC systems for conventional facility of Proton Accelerator Research Center consist of 3 systems : accelerator building HVAC system, beam application building HVAC system and miscellaneous HVAC system. We designed accelerator building HVAC system and beam application research area HVAC system in the conventional facilities of Proton Accelerator research center. Accelerator building HVAC system is divided into accelerator tunnel area, klystron area, klystron gallery area, accelerator assembly area. Also, Beam application research area HVAC system is divided into those of beam experimental hall, accelerator control area, beam application research area and Ion beam application building. In this paper, We described system design requirements and explained system configuration for each systems. We presented operation scenario of HVAC system in the Conventional Facility of Proton Accelerator Research Center
[en] Modern building HVAC systems are complex and consist of a large number of interconnected sub-systems and components. In the event of a fault, it becomes very difficult for the operator to locate and isolate the faulty component in such large systems using conventional fault detection methods. In this study, transient pattern analysis is explored as a tool for fault detection and diagnosis of an HVAC system. Several tests involving different fault replications were conducted in an environmental chamber test facility. The results show that the evolution of fault residuals forms clear and distinct patterns that can be used to isolate faults. It was found that the time needed to reach steady state for a typical building HVAC system is at least 50-60 min. This means incorrect diagnosis of faults can happen during online monitoring if the transient pattern responses are not considered in the fault detection and diagnosis analysis
[en] Vehicle-mounted antennas used for wireless communications generally operate at a power level of three watts or less. These wireless antennas are typically mounted on the roof, trunk, or rear window of a particular vehicle. For this project the radio frequency radiation level from the vehicle-mounted antennas were conducted by using Spectrum Analyser SRM 3006 with the frequency range from 27 MHz-3 GHz. The monitoring is carried out on 10 selected vehicles based on 3 different radio channels with different frequency modulation. The data obtained were compared to the guideline set by the International Commission on Non-Ionizing Radiation Protection (ICNIRP 1998). (author)
[en] This engineering note documents three different options for upgrading the Dzero HVAC control system. All three options leave the current field hardware and field devices intact and upgrade the computer control hardware and software. Dzero will be heading into a physics run starting in 2000. This physics run could last several years. The Dzero HVAC system is an integral part of climate control and electronics cooling. The current HVAC control system is based upon a 1985 Johnson Controls System. In order to enter the next long-term physics run with a solid HVAC control system, the current control system needs to be upgraded. This proposal investigates three options: (1) Replacement to the next generation of Johnson Controls Hardware and Software with the Johnson Controls operator interface - FESS; (2) Replacement to the next generation of Johnson Controls Hardware and Software with the FIX32 Operator Interface - FESS/Dzero; and (3) Replacement with a commercially available Programmable Logic Controller (PLC) WITH THE FIX 32 Operator Interface - Dzero.
[en] The objective of this report is to study on the application of UV sterilization method on HVAC system in building. One type of commercial UV lamp was utilized during this research. It was 1,050 mm length, 24.5 mm diameter, 65 w lamp output, single ended lamp intended for insertion into al frame from inside. Twenty six lamps were mounted and operated in cross flow. They were allowed to operate for at least 30 minutes prior to beginning each test. The test rig was operated at 2.5 m/s and 20 .deg. C, and the relatively humidity 21.6 %RH. The effect of UV sterilization are investigated that as the general virus about 94 %, the mold microbe about 64 % and the bacillus about 86 %, respectively. Following this report will be used important data for the design and manufacture of the UV