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In-place HEPA filter penetration test

Description: We have demonstrated the feasibility of conducting penetration tests on high efficiency particulate air (HEPA) filters as installed in nuclear ventilation systems. The in-place penetration test, which is designed to yield equivalent penetration measurements as the standard DOP efficiency test, is based on measuring the aerosol penetration of the filter installation as a function of particle size using a portable laser particle counter. This in-place penetration test is compared to the current in-place leak test using light scattering photometers for single HEPA filter installations and for HEPA filter plenums using the shroud method. Test results show the in-place penetration test is more sensitive than the in-place leak test, has a similar operating procedure, but takes longer to conduct. Additional tests are required to confirm that the in-place penetration test yields identical results as the standard dioctyl phthalate (DOP) penetration test for HEPA filters with controlled leaks in the filter and gasket and duct by-pass leaks. Further development of the procedure is also required to reduce the test time before the in- place penetration test is practical.
Date: January 1, 1997
Creator: Bergman, W.; Wilson, kK.; Elliott, J.; Bettencourt, B. & Slawski, J.W.
Partner: UNT Libraries Government Documents Department

Potential for Hepa filter damage from water spray systems in filter plenums

Description: The water spray systems in high efficiency particulate air (HEPA) filter plenums that are used in nearly all Department of Energy (DOE) facilities for protection against fire was designed under the assumption that the HEPA filters would not be damaged by the water sprays. The most likely scenario for filter damage involves filter plugging by the water spray, followed by the fan blowing out the filter medium. A number of controlled laboratory tests that were previously conducted in the late 1980s are reviewed in this paper to provide a technical basis for the potential HEPA filter damage by the water spray system in HEPA filter plenums. In addition to the laboratory tests, the scenario for HEPA filter damage during fires has also occurred in the field. Afire in a four-stage, HEPA filter plenum at Rocky Flats in 1980 caused the first three stages of HEPA filters to blow out of their housing and the fourth stage to severely bow. Details of this recently declassified fire are presented in this paper. Although these previous findings suggest serious potential problems exist with the current water spray system in filter plenum , additional studies are required to confirm unequivocally that DOE`s critical facilities are at risk.
Date: January 1, 1997
Creator: Bergman, W.; Fretthold, J.K. & Slawsld, J.W.
Partner: UNT Libraries Government Documents Department

DOE standard: Filter test facility quality program plan

Description: This standard was developed primarily for application in US Department of Energy programs. It contains specific direction for HEPA filter testing performed at a DOE-accepted HEPA Filter Test Facility (FTF). Beneficial comments (recommendations, additions, deletions) and any pertinent data that may improve this document should be sent to the Office of Nuclear Safety Policy and Standards (EH-31), US Department of Energy, Washington, DC 20585, by letter or by using the self-addressed Document Improvement Proposal form (DOE F 1300.3) appearing at the end of this document.
Date: February 1, 1999
Partner: UNT Libraries Government Documents Department


Description: Alternative air cleaning concepts were evaluated for possible application to FFTF containment margins. For evaluation purposes, it was assumed that the air cleaning system must process 3.07 m{sup 3}/s (6500 ACFM) of gas containing sodium compound aerosols (mainly NaOH) at temperatures up to 4070C (7000 F) and pressures up to 0.184 MPa (26.4 psia) and accommodate 5450 kg (12,000 lb) of aerosol material. Three systems designed for 90% efficient removal (a venturi scrubber, a submerged gravel scrubber and a spray scrubber) were compared. The submerged gravel scrubber and the venturi scrubber were rated as prime candidates. Four systems designed for 99% removal efficiency (the two optimum scrubbers chosen for 90% removal efficiency fitted with fibrous elements, a sand and gravel filter and a HEPA filter bank) were compared. The tI~ scrubbers were again rated as prime candidates. Both the sand and gravel filter and the HEPA filter bank were found to be excessively large and costly. Considerable experience supports the use of the optimum scrubber systems and it is concluded that their use is technically feasible for the FFTF containment margins application.
Date: August 1, 1980
Creator: POSTMA, A K. & HILLIARD, R K.
Partner: UNT Libraries Government Documents Department


Description: Development of a metal media standard (FI) for ASME AG-1 (Code on Nuclear Air and Gas Treatment) has been under way for almost ten years. This paper will provide a brief history of the development process of this section and a detailed overview of its current content/status. There have been at least two points when dramatic changes have been made in the scope of the document due to feedback from the full Committee on Nuclear Air and Gas Treatment (CONAGT). Development of the proposed section has required resolving several difficult issues associated with scope; namely, filtering efficiency, operating conditions (media velocity, pressure drop, etc.), qualification testing, and quality control/acceptance testing. A proposed version of Section FI is currently undergoing final revisions prior to being submitted for balloting. The section covers metal media filters of filtering efficiencies ranging from medium (less than 99.97%) to high (99.97% and greater). Two different types of high efficiency filters are addressed; those units intended to be a direct replacement of Section FC fibrous glass HEPA filters and those that will be placed into newly designed systems capable of supporting greater static pressures and differential pressures across the filter elements. Direct replacements of FC HEPA filters in existing systems will be required to meet equivalent qualification and testing requirements to those contained in Section FC. A series of qualification and quality assurance test methods have been identified for the range of filtering efficiencies covered by this proposed standard. Performance characteristics of sintered metal powder vs. sintered metal fiber media are dramatically different with respect to parameters like differential pressures and rigidity of the media. Wide latitude will be allowed for owner specification of performance criteria for filtration units that will be placed into newly designed systems. Such allowances will permit use of the most appropriate metal ...
Date: December 9, 2008
Creator: Adamson, D & Charles A. Waggoner, C
Partner: UNT Libraries Government Documents Department

DOE standard: Quality assurance inspection and testing of HEPA filters

Description: This standard establishes essential elements for the quality assurance inspection and testing of HEPA filters by US Department of Energy (DOE)-accepted Filter Test Facilities (FTF). The standard specifies HEPA filter quality assurance inspection and testing practices established in DOE-STD-3022-98, DOE HEPA Filter Test Program, and provides a basis for the preparation of written operating procedures for primary FTF functions.
Date: February 1, 1999
Partner: UNT Libraries Government Documents Department

Specification for HEPA filters used by DOE contractors

Description: This standard establishes specification and testing requirements for High Efficiency Particulate Air (HEPA) filters procured to provide personnel and environmental protection when installed in DOE nuclear facilities. The standard specifies minimum requirements to be included in contractor specifications.
Date: January 1, 1997
Partner: UNT Libraries Government Documents Department

Further development of the cleanable steel HEPA filter, cost/benefit analysis, and comparison with competing technologies

Description: We have made further progress in developing a cleanable steel fiber HEPA filter. We fabricated a pleated cylindrical cartridge using commercially available steel fiber media that is made with 1 {mu}m stainless steel fibers and sintered into a sheet form. Test results at the Department of Energy (DOE) Filter Test Station at Oak Ridge show the prototype filter cartridge has 99.99% efficiency for 0.3 {mu}m dioctyl phthalate (DOP) aerosols and a pressure drop of 1.5 inches. Filter loading and cleaning tests using AC Fine dust showed the filter could be repeatedly cleaned using reverse air pulses. Our analysis of commercially optimized filters suggest that cleanable steel HEPA filters need to be made from steel fibers less than 1 {mu}m, and preferably 0.5 {mu}m, to meet the standard HEPA filter requirements in production units. We have demonstrated that 0.5 {mu}m steel fibers can be produced using the fiber bundling and drawing process. The 0.5 {mu}m steel fibers are then sintered into small filter samples and tested for efficiency and pressure drop. Test results on the sample showed a penetration of 0.0015% at 0.3 {mu}m and a pressure drop of 1.15 inches at 6.9 ft/min (3.5 cm/s) velocity. Based on these results, steel fiber media can easily meet the requirements of 0.03% penetration and 1.0 inch of pressure drop by using less fibers in the media. A cost analysis of the cleanable steel HEPA filter shows that, although the steel HEPA filter costs much more than the standard glass fiber HEPA filter, it has the potential to be very cost effective because of the high disposal costs of contaminated HEPA filters. We estimate that the steel HEPA filter will save an average of $16,000 over its 30 year life. The additional savings from the clean-up costs resulting from ruptured glass HEPA filters ...
Date: January 1, 1997
Creator: Bergman, W.; Larsen, G.; Lopez, R.; Wilson, K.; Witherell, C. & McGregor, M.
Partner: UNT Libraries Government Documents Department

Resource Conservation and Recovery Act permit modifications and the functional equivalency demonstration: a case study

Description: Hazardous waste operating permits issued under the Resource Conservation and Recovery Act (RCRA) often impose requirements that specific components and equipment be used. Consequently, changing these items, may first require that the owner/operator request a potentially time-consuming and costly permit modification. However, the owner/operator may demonstrate that a modification is not required because the planned changes are ``functionally equivalent.`` The Controlled-Air Incinerator at Los Alamos National Laboratory is scheduled for maintenance and improvements. The incinerator`s carbon adsorption unit/high efficiency particulate air filtration system, was redesigned to improve reliability and minimize maintenance. A study was performed to determine whether the redesigned unit would qualify as functionally equivalent to the original component. In performing this study, the following steps were taken: (a) the key performance factors were identified; (b) performance data describing the existing unit were obtained; (c) performance of both the existing and redesigned units was simulated; and (d) the performance data were compared to ascertain whether the components could qualify as functionally equivalent. In this case, the key performance data included gas residence time and distribution of flow over the activated carbon. Because both units were custom designed and fabricated, a simple comparison of manufacturers` specifications was impossible. Therefore, numerical simulation of each unit design was performed using the TEMPEST thermal-hydraulic computer code to model isothermal hydrodynamic performance under steady-state conditions. The results of residence time calculations from the model were coupled with flow proportion and sampled using a Monte Carlo-style simulation to derive distributions that describe the predicted residence times.
Date: February 1, 1996
Creator: Elsberry, K.; Garcia, P.; Carnes, R.; Kinker, J.; Loehr, C & Lyon, W.
Partner: UNT Libraries Government Documents Department

Criteria for calculating the efficiency of HEPA filters during and after design basis accidents

Description: We have reviewed the literature on the performance of high efficiency particulate air (HEPA) filters under normal and abnormal conditions to establish criteria for calculating the efficiency of HEPA filters in a DOE nonreactor nuclear facility during and after a Design Basis Accident (DBA). The literature review included the performance of new filters and parameters that may cause deterioration in the filter performance such as filter age, radiation, corrosive chemicals, seismic and rough handling, high temperature, moisture, particle clogging, high air flow and pressure pulses. The deterioration of the filter efficiency depends on the exposure parameters; in severe exposure conditions the filter will be structurally damaged and have a residual efficiency of 0%. Despite the many studies on HEPA filter performance under adverse conditions, there are large gaps and limitations in the data that introduce significant error in the estimates of HEPA filter efficiencies under DBA conditions. Because of this limitation, conservative values of filter efficiency were chosen when there was insufficient data.
Date: December 1994
Creator: Bergman, W.; First, M. W.; Anderson, W. L.; Gilbert, H. & Jacox, J. W.
Partner: UNT Libraries Government Documents Department

Performance evaluation of cleanroom environmental systems

Description: This paper presents in-situ measurement results for energy and environmental performance of thirteen cleanroom systems located in the USA, including key metrics for evaluating cleanroom air system performance and overall electric power intensity. Comparisons with the IEST Recommended Practice (IEST-RP-CC012.1) are made to examine the performance of cleanroom air systems. Based upon the results, the paper discusses likely opportunities for improving cleanroom energy efficiency while maintaining effective contamination control. The paper concludes that there are wide variations in energy performance of cleanroom environmental systems, and that performance benchmarking can serve as a vehicle to identify energy efficient cleanroom design practices and to highlight important issues in cleanroom operation and maintenance.
Date: July 7, 2003
Creator: Xu, Tengfang
Partner: UNT Libraries Government Documents Department

Energy Performance of Cleanroom Environmental Systems

Description: By developing metrics for evaluating cleanroom air system performance and overall load intensity, this paper provides energy benchmarking results for thirteen cleanroom environmental system performance, and identifies opportunities for improving cleanroom energy efficiency while maintaining or improving cleanroom contamination control. Comparisons with IEST Recommended Practice are made to examine the performance of cleanroom air systems. These results can serve as a vehicle to identify energy efficient cleanroom design practices and to highlight important issues in cleanroom operation and maintenance. Results from this study confirm that there are opportunities in improving energy efficiency of cleanroom environmental systems while maintaining effective contamination control.
Date: November 1, 2001
Creator: Xu, Tengfang & Tschudi, William F.
Partner: UNT Libraries Government Documents Department

ATI TDA 5A aerosol generator evaluation

Description: Oil based aerosol ``Smoke`` commonly used for testing the efficiency and penetration of High Efficiency Particulate Air filters (HEPA) and HEPA systems can produce flammability hazards that may not have been previously considered. A combustion incident involving an aerosol generator has caused an investigation into the hazards of the aerosol used to test HEPA systems at Hanford.
Date: July 27, 1998
Creator: Gilles, D. A.
Partner: UNT Libraries Government Documents Department

Ventilation systems analysis during tornado conditions. Progress report, January--June 1975

Description: The principal concern of this investigation is to develop the capability to simulate the dynamic effects of a tornado depressurization on a ventilation system. The basic formulation and solution of the two-zone series model ventilation subsystem is based on lumped parameter component response equations, the isothermal compression of air, and the conservation of mass. Solutions based on these assumptions are also presented for the two-zone series model with natural bypass, the two-zone series model with recirculation, and the natural branching model. A parameter study is presented comparing the effects of changes in system resistance, system capacitance, and variable tornado depressurization rates. The adaptability of the basic formulation to adiabatic compression of air and the addition of duct resistance is examined. A quasi-steady formulation is introduced and preliminary considerations of the importance of inertia are presented. Preliminary conclusions in this area indicate that inertial effects can be neglected. For relatively long ducts slow shock development appears possible. Work on the effect of tornado depressurization rates as related to shock development and on the importance of inertia effects is continuing. (auth)
Date: November 1, 1975
Creator: Bennett, G.A.; Gregory, W.S. & Smith, P.R.
Partner: UNT Libraries Government Documents Department

Saving energy and improving IAQ through application of advanced air cleaning technologies

Description: In the future, we may be able use air cleaning systems and reduce rates of ventilation (i.e., reduce rates of outdoor air supply) to save energy, with indoor air quality (IAQ) remaining constant or even improved. The opportunity is greatest for commercial buildings because they usually have a narrower range of indoor pollutant sources than homes. This article describes the types of air cleaning systems that will be needed in commercial buildings.
Date: March 1, 2011
Creator: Fisk, W.J; Destaillats, H. & Sidheswaran, M.A.
Partner: UNT Libraries Government Documents Department

Evaluation of Ultra-Violet Photocatalytic Oxidation for Indoor AirApplications

Description: Acceptable indoor air quality in office buildings may be achieved with less energy by combining effective air cleaning systems for volatile organic compounds (VOCs) with particle filtration then by relying solely on ventilation. For such applications, ultraviolet photocatalytic oxidation (UVPCO) systems are being developed for VOC destruction. An experimental evaluation of a UVPCO system is reported. The evaluation was unique in that it employed complex mixtures of VOCs commonly found in office buildings at realistically low concentrations. VOC conversion efficiencies varied over a broad range, usually exceeded 20%, and were as high as {approx}80%. Conversion efficiency generally diminished with increased air flow rate. Significant amounts of formaldehyde and acetaldehyde were produced due to incomplete mineralization. The results indicate that formaldehyde and acetaldehyde production rates may need to be reduced before such UVPCO systems can be deployed safely in occupied buildings.
Date: February 1, 2006
Creator: Hodgson, A.T.; Sullivan, D.P. & Fisk, W.J.
Partner: UNT Libraries Government Documents Department

Sorbent-Based Gas Phase Air Cleaning for VOCs in CommercialBuildings

Description: This paper provides a review of current knowledge about the suitability of sorbent-based air cleaning for removing volatile organic compounds (VOCs) from the air in commercial buildings as needed to enable reductions in ventilation rates and associated energy savings. The fundamental principles of sorbent air cleaning are introduced, criteria are suggested for sorbent systems that can counteract indoor VOC concentration increases from reduced ventilation, major findings from research on sorbent performance for this application are summarized, novel sorbent technologies are described, and related priority research needs are identified. Major conclusions include: sorbent systems can remove a broad range of VOCs with moderate to high efficiency, sorbent technologies perform effectively when challenged with VOCs at the low concentrations present indoors, and there is a large uncertainty about the lifetime and associated costs of sorbent air cleaning systems when used in commercial buildings for indoor VOC control. Suggested priority research includes: experiments to determine sorbent system VOC removal efficiencies and lifetimes considering the broad range and low concentration of VOCs indoors; evaluations of in-situ regeneration of sorbents; and an updated analysis of the cost of sorbent air cleaning relative to the cost of ventilation.
Date: May 1, 2006
Creator: Fisk, William J.
Partner: UNT Libraries Government Documents Department

Control of Respirable Particles in Indoor Air with Portable AirCleaners

Description: Eleven portable air cleaning devices have been evaluated for control of indoor concentrations of respirable particles using in situ chamber decay tests. Following injection of cigarette smoke in a room-size chamber, decay rates for particle concentrations were obtained for total number concentration and for number concentration by particle size with and without air cleaner operation. The size distribution of the tobacco smoke particles was log normal with a count median diameter of 0.15 {micro}m and a geometric standard deviation of 2.0. Without air cleaner operation, the natural mass-averaged surface deposition rate of particles was observed to be 0.1 h{sup -1}. Air cleaning rates for particles were found to be negligible for several small panel-filter devices, a residential-sized ion-generator, and a pair of mixing fans. Electrostatic precipitators and extended surface filters removed particles at substantial rates, and a HEPA-type filter was the most efficient air cleaner studied.
Date: October 1, 1984
Creator: Offermann, F.J.; Sextro, R.G.; Fisk, W.J.; Grimsrud, D.T.; Nazaroff, W.W.; Nero, A.V. et al.
Partner: UNT Libraries Government Documents Department

New Air Cleaning Strategies for Reduced Commercial Building Ventilation Energy

Description: Approximately ten percent of the energy consumed in U.S. commercial buildings is used by HVAC systems to condition outdoor ventilation air. Reducing ventilation rates would be a simple and broadly-applicable energy retrofit option, if practical counter measures were available that maintained acceptable concentrations of indoor-generated air pollutants. The two general categories of countermeasures are: 1) indoor pollutant source control, and 2) air cleaning. Although pollutant source control should be used to the degree possible, source control is complicated by the large number and changing nature of indoor pollutant sources. Particle air cleaning is already routinely applied in commercial buildings. Previous calculations indicate that particle filtration consumes only 10percent to 25percent of the energy that would otherwise be required to achieve an equivalent amount of particle removal with ventilation. If cost-effective air cleaning technologies for volatile organic compounds (VOCs) were also available, outdoor air ventilation rates could be reduced substantially and broadly in the commercial building stock to save energy. The research carried out in this project focuses on developing novel VOC air cleaning technologies needed to enable energy-saving reductions in ventilation rates. The minimum required VOC removal efficiency to counteract a 50percent reduction in ventilation rate for air cleaning systems installed in the HVAC supply airstream is modest (generally 20percent or less).
Date: October 27, 2010
Creator: Sidheswaran, Meera; Destaillats, Hugo; Sullivan, Douglas P. & Fisk, William J.
Partner: UNT Libraries Government Documents Department

Operational evaluation of the high flow alternative filter test system

Description: An alternative to the current filter test system (Q107) used to test Size 4 (500 cubic feet per min rated flow) and larger nuclear grade high efficiency particulate air (HEPA) filters at DOE Filter Test Facilities (FTFs) has been developed. This new test system, called the High Flow Alternative Filter Test System (HFATS), has undergone a long-term operational evaluation at the Oak Ridge FTF (ORFTF) for: comparison between HEPA filter penetration measurements made with the HFATS and with the Q107; assessment of the HFATS' long-term routine operational performance in the FTF environment; and determination of the potential operational impacts of the HFATS on the FTFs. Data for the operational evaluation were collected by the Oak Ridge staff using both test systems. These data were analyzed and interpreted by Los Alamos staff. A total of 849 filters were tested in the evaluation. The data provided by the HFATS easily permits filter penetration to be reported in terms of: penetration at the size of maximum penetration; number, surface area, or mass penetration; or penetration at 0.3 ..mu..m for reference to historical data. Results of the penetration measurement comparisons show that the HFATS measurements at about 0.3 ..mu..m aerosol diameter do not differ significantly from the Q107 measurements. Analysis of the HFATS penetration data indicates that for the 100% flow tests maximum penetration most frequently occurs at an aerosol diameter of about 0.15 ..mu..m as measured by a laser aerosol spectrometer (LAS). The 0.15 ..mu..m HFATS measurements at 100% test flow were markedly higher than the corresponding Q107 measurements. These measurements resulted in over 18% of the filters being rejected by the HFATS only, compared to no filters being rejected only by the Q107 and approximately 0.2% being rejected by both systems.
Date: January 1, 1986
Creator: Scripsick, R.C.; Smitherman, R.L. & McNabb, S.A.
Partner: UNT Libraries Government Documents Department

Letter report: Evaluation of LFCM off-gas system technologies for the HWVP

Description: Radioactive high-level liquid waste (HLLW), a byproduct of defense nuclear fuel reprocessing activities, is currently being stored in underground tanks at several US sites. Because its mobility poses significant environmental risks, HLLW is not a suitable waste form for long-term storage. Thus, high-temperature processes for solidifying and isolating the radioactive components of HLLW have been developed and demonstrated by the US Department of Energy (DOE) and its contractors. Vitrification using liquidfed ceramic melters (LFCMs) is the reference process for converting US HLLW into a borosilicate glass. Two vitrification plants are currently under construction in the United States: the West Valley Demonstration Plant (WVDP) being built at the former West Valley Nuclear Fuels Services site in West Valley, New York; and the Defense Waste Processing Facility (DWPF), which is currently 85% complete at DOE`s Savannah River Plant (SRP). A third facility, the Hanford Waste Vitrification Plant (HWVP), is being designed at DOE`s Hanford Site.
Date: March 1, 1996
Creator: Goles, R.W.; Mishima, J. & Schmidt, A.J.
Partner: UNT Libraries Government Documents Department

Filtration theory using computer simulations

Description: We have used commercially available fluid dynamics codes based on Navier-Stokes theory and the Langevin particle equation of motion to compute the particle capture efficiency and pressure drop through selected two- and three- dimensional fiber arrays. The approach we used was to first compute the air velocity vector field throughout a defined region containing the fiber matrix. The particle capture in the fiber matrix is then computed by superimposing the Langevin particle equation of motion over the flow velocity field. Using the Langevin equation combines the particle Brownian motion, inertia and interception mechanisms in a single equation. In contrast, most previous investigations treat the different capture mechanisms separately. We have computed the particle capture efficiency and the pressure drop through one, 2-D and two, 3-D fiber matrix elements.
Date: January 1997
Creator: Bergman, W. & Corey, I.
Partner: UNT Libraries Government Documents Department

Twenty-third DOE/NRC Nuclear Air Cleaning and Treatment Conference

Description: This paper presents the details of the Nuclear Air Cleaning and Treatment Conference held in Buffalo, New York during July 1994. Topics discussed include: nuclear air cleaning codes and standards; waste disposal; particulate filter developments; sampling and monitoring of process and effluent streams; off-gasses from fuel reprocessing; adsorbents and adsorption; accident control and analysis; revised source terms for power plant accidents; and the highlight of the conference concerned operations at the West Valley DOE facility where construction is underway to solidify radioactive wastes.
Date: March 24, 1995
Creator: Bellamy, R. R.; Hayes, J. J. & First, M. W.
Partner: UNT Libraries Government Documents Department