[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] Various analyses have been performed recently to estimate the performance of the air conditioning (HVAC) system planned for the Undulator Hall. This reports summarizes the results and provides an upgrade plan to be used if new requirements are needed in the future. The estimates predict that with the planned loads the tunnel air temperature will be well within the allowed tolerance during normal operation.

[en] A draft Method of Test (MOT) has been proposed for packaged, air-to-air, desiccant-based dehumidifier systems that incorporate a thermally-regenerated desiccant material for dehumidification. This MOT is intended to function as the ''system'' testing and rating compliment to the desiccant ''component'' (desiccant wheels and/or cassettes) MOT (ASHRAE 1998) and rating standard (ARI 1998) already adopted by industry. This draft standard applies to ''packaged systems'' that: Use desiccants for dehumidification of conditioned air for buildings; Use heated air for regeneration of the desiccant material; Include fans for moving process and regeneration air; May include other system components for filtering, pre-cooling, post-cooling, or heating conditioned air; and May include other components for humidification of conditioned air. The proposed draft applies to four different system operating modes depending on whether outdoor or indoor air is used for process air and regeneration air streams . Only the ''ventilation'' mode which uses outdoor air for both process and regeneration inlets is evaluated in this paper. Performance of the dehumidification system is presented in terms that would be most familiar and useful to designers of building HVAC systems to facilitate integration of desiccant equipment with more conventional hardware. Parametric performance results from a modified, commercial desiccant dehumidifier undergoing laboratory testing were used as data input to evaluate the draft standard. Performance results calculated from this experimental input, results from an error-checking/heat-balance verification test built into the standard, and estimated comparisons between desiccant and similarly performing conventional dehumidification equipment are calculated and presented. Some variations in test procedures are suggested to aid in analytical assessment of individual component performance

[en] This guide compares emerging diagnostic software tools that aid detection and diagnosis of operational problems for large HVAC systems. We have evaluated six tools for use with energy management control system (EMCS) or other monitoring data. The diagnostic tools summarize relevant performance metrics, display plots for manual analysis, and perform automated diagnostic procedures. Our comparative analysis presents nine summary tables with supporting explanatory text and includes sample diagnostic screens for each tool

[en] A small-scale directly gas-fired integrated HVAC system is being investigated. The main principle is to use the waste heat of a CHP plant, possibly in conjunction with solar energy, for dehumidification of ambient air. Driving a small-scale absorption chiller is not feasible because of the high waste heat temperature required and the high cost of an absorption chiller. The required cooling capacity of the mechanically / electrically driven compression-type chiller is reduced drastically since no further dehumidification by condensation is necessary. In contrast to Desiccant Cooling Systems no water is required. (author)

[en] Prior to the sluicing of Tank 241-C-106, the 296-P-16 ventilation system will be shutdown and the 296-C-006 ventilation system operation will be initiated. The 296-C-006 system has a low once through flow with an additional recirculation flow in the tank dome space. A minimum dome pressure of -3 in W.G. is necessary for safe operation. An evaluation of the system has been performed. The results of the study show that adequate dome space vacuum can be achieved if the pump pits in Tank 241-C-106 are sealed

[en] This represents a preoperational test report for Vent Building Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides Heating, Ventilation, and Air Conditioning (HVAC) for the W-030 Ventilation Building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System

[en] The Workshop on results of the Project Kosmomyikrofyizika - (Astroparticle Physics) of the National Academy of Sciences of Ukraine (NASU) 'Astrophysical and cosmological problems of invisible mass and dark energy in the Universe' was held on November 21-22, 2012 in the Institute for Nuclear Research, Kyiv, Ukraine. This Project was carried out during three years (2010-2012) by scientists from various Universities and Institutes of the NASU; it was a logical continuation of the previous scientific program of the NASU 'Researches of structure and composition of the Universe, hidden mass and dark energy (Kosmomyikrofyizika-2) in 2007-2009. These programs were devoted to theoretical and experimental investigation in astronomy, astrophysics, cosmology, physics of atomic nuclei and particle physics, which are related with the problems of dark matter and dark energy in the Universe

[en] The Pacific Northwest Laboratory (PNL), under contract to the U.S. Nuclear Regulatory Commission (NRC), has conducted an assessment of the values (benefits) and impacts (costs) associated with potential resolutions to Generic Issue 143, open-quotes Availability of Heating, Ventilation, and Air Conditioning (HVAC) and Chilled Water Systems.close quotes This assessment was conducted to identify vulnerabilities related to failure of HVAC, chilled water and room cooling systems and develop estimates of the core damage frequencies and public risks associated with failures of these systems. This information was used to develop proposed resolution strategies to this generic issue and perform a value/impact assessment to determine their cost-effectiveness. Probabilistic risk assessments (PRAs) for four representative plants from the basis for the core damage frequency and public risk calculations. Internally-initiated core damage sequences as well as external events were considered. Three proposed resolution strategies were developed for this safety issue and it was determined that all three were not cost-effective. Additional evaluations were performed to develop open-quotes genericclose quotes insights on potential design-related vulnerabilities and potential high-frequency accident sequences that involve failures of HVAC/room cooling functions

[en] The paper gives the general introduction of the contents and requirements of the safety analysis of HVAC systems designed in nuclear power plant. A typical ESF HVAC system is referenced as an example to show the main items in the safety analysis report reviewing of HVAC systems in Generation Ⅱ-Modified NPPs. (authors)