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Confinement of airborne radioactivity. Progress report, January--December 1974

Description: Several commercial activated carbons, marketed for iodine removal in reactor off-gas cleanup systems, were evaluated for iodine penetration at elevated temperatures (4 hr at 180$sup 0$C), and the penetration data varied widely. Subsequent chemical analysis of the samples indicated a strong correlation between the atom ratio of iodine to potassium (I/K) in the carbon and the high-temperature performance data. Iodine penetration tests were also performed on several carbons in an intense gamma radiation field (greater than 10$sup 7$ rads/hr). Test data show that carbons intentionally exposed to high concentrations of DOP aerosol performed as well as unexposed carbons. Studies of the rate of evaporation of elemental iodine from aqueous solutions indicated that significant quantities of I$sub 2$ might be expected to become airborne within a short period of time (5 hr) after release to open ponds. Addition of sodium thiosulfate to the solution substantially reduced the evaporative loss of iodine; however, the effects of high-intensity radiation fields on iodine-thiosulfate solutions remain to be evaluated. Small HEPA filters containing filter media of the type used in the Savannah River confinement system were exposed to reactor building air and a high-intensity radiation field. Following this exposure, they were tested for flow performance under simulated accident conditions. Radiation exposure slightly impaired the performance of new filters and improved the performance of service-aged filters. Service aging effects on filter performance were far more significant than radiation effects. (auth)
Date: January 1, 1974
Creator: Dexter, A.H.; Evans, A.G. & Jones, L.R.
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

Air cleaning systems analysis and HEPA filter response to simulated tornado loadings. [TVENT]

Description: A computer code, TVENT, for predicting tornado-induced depressurization in air cleaning systems is described. TVENT easily fits on many computers with input/output formats that are familiar to most analysts and HVAC designers. Applications of TVENT to several nuclear facilities in Idaho, New York, and New Mexico are described. Flow-resistance data of HEPA filters for use in TVENT are also described. At low flow resistance appears to be mainly caused by a diffusion mechanism, while at high flow the resistance seems to be caused by the mechanism of momentum exchange.
Date: January 1, 1978
Creator: Gregory, W.S.; Andrae, R.W.; Duerre, K.H.; Horak, H.L.; Smith, P.R.; Ricketts, C.I. et al.
Partner: UNT Libraries Government Documents Department

Demonstration of an Emergency Containment System. [Tritium containment]

Description: A system called an Emergency Containment System (ECS) to be used for tertiary containment of tritium was reported at the 13th Air Cleaning Conference. This system was part of the Tritium Effluent Control Laboratory then under construction at Mound Facility. A series of experiments has recently been conducted to evaluate the performance of an ECS in capturing tritium accidentally released into an operating laboratory. The ECS is an automatically actuated laboratory air detritiation system utilizing a catalytic oxidation reactor and presaturated oxide adsorption/exchange columns. In the event of an accidental release of tritium into the laboratory, the ECS is automatically activated, and quick-acting pneumatic dampers divert the laboratory air supply and exhaust through the ECS until room concentrations are returned to safe operating levels. The results of the experiments have shown that a tertiary containment of tritium is feasible. In the event of a catastrophic accident, the ECS is capable of preventing the release of a large quantity of tritium to the environment.
Date: January 1, 1978
Creator: Flanagan, T.M.; Rogers, M.L. & Wilkes, W.R.
Partner: UNT Libraries Government Documents Department

Progress in standards for nuclear air and gas treatment

Description: Standardization in nuclear air and gas treatment spans a period of more than 25 years, starting with military specifications for HEPA filters and filter media, and now progressing to the development of a formal code analogous to the ASME Boiler and Pressure Vessel Code. Whereas the current standard for components and installation of nuclear air cleaning systems is limited to safety related facilities for nuclear power plants, the proposed code will cover all types of critical ventilation and air and gas treatment installations for all types of nuclear facilities.
Date: January 1, 1978
Creator: Burchsted, C.A.
Partner: UNT Libraries Government Documents Department

Recent aerosol tests in the Containment Systems Test Facility

Description: The Containment Systems Test Facility (CSTF) is a 20-meter high, 850m/sup 3/ model containment vessel in which various sodium fire aerosol air cleaning tests are studied for purposes of developing and proof testing air cleaning techniques. The first series of tests was designed to study the properties of sodium fire aerosols without any air cleaning and to provide a data base for model verification using large-scale experiments. To date, three such tests (two pool fire and one spray fire) have been completed and are being analyzed. These tests will be discussed, as will plans for the air cleaning tests to follow.
Date: October 1, 1978
Creator: McCormack, J.D.; Hilliard, R.K. & Postma, A.K.
Partner: UNT Libraries Government Documents Department

Tritium monitoring at the Sandia Tritium Research Laboratory

Description: Sandia Laboratories at Livermore, California, is presently beginning operation of a Tritium Research Laboratory (TRL). The laboratory incorporates containment and cleanup facilities such that any unscheduled tritium release is captured rather than vented to the atmosphere. A sophisticated tritium monitoring system is in use at the TRL to protect operating personnel and the environment, as well as ensure the safe and effective operation of the TRL decontamination systems. Each monitoring system has, in addition to a local display, a display in a centralized control room which, when coupled room which, when coupled with the TRL control computer, automatically provides an immediate assessment of the status of the entire facility. The computer controls a complex alarm array status of the entire facility. The computer controls a complex alarm array and integrates and records all operational and unscheduled tritium releases.
Date: October 1, 1978
Creator: Devlin, T.K.
Partner: UNT Libraries Government Documents Department

Confinement of airborne radioactivity. Progress report, January--December 1977

Description: Iodine penetration and ignition temperature data obtained from carbon that was removed from the Savannah River Plant (SRP) confinement system show that Type GX-176 carbon has a useful life of at least 30 months. Development studies on new halogen adsorbers showed that coal- and petroleum-base carbons can be treated in the laboratory to retain methyl iodide as well as, or better than, commercial coconut-base carbons. Radiation stability tests for iodine-loaded, silver-exchanged zeolite (AgX) showed that some internal migration of iodine occurs in the AgX under dynamic flow conditions in a high intensity radiation environment. The tests also showed that the distribution of iodine in the test bed is more affected by the inlet air concentration than by exposure to gamma radiation.
Date: January 1, 1979
Creator: Evans, A.G.
Partner: UNT Libraries Government Documents Department

Containment air cleaning for LMFBRs

Description: A variety of air cleaning concepts was evaluated for potential use in future sodium-cooled breeder reactors. A 3-stage aqueous scrubber system was selected for large-scale demonstration testing under conditions similar to those postulated for containment venting and purging during reactor melt-through accidents. Two tests were performed in the Containment Systems Test Facility using a quench tank, a jet venturi scrubber and a high efficiency fibrous scrubber in series. The results of two tests with Na/sub 2/0/sub 2/ and Na0H aerosol and NaI vapor are presented showing >99.9% removal of Na/sub 2/0/sub 2/ and Na0H and >99.7% for NaI.
Date: January 1, 1979
Creator: Hilliard, R. K.; McCormack, J. D.; Postma, A. K. & Owen, R. K.
Partner: UNT Libraries Government Documents Department

Proceedings of the fifteenth DOE nuclear air cleaning conference

Description: Papers presented are grouped under the following topics: air cleaning; waste volume reduction and preparation for storage; tritium, carbon-14, ozone; containment of accidental releases; adsorbents and absorbents; and off-gas treatment. A separate abstract was prepared for each paper.
Date: February 1, 1979
Creator: First, M.W. (ed.)
Partner: UNT Libraries Government Documents Department

Experimental investigation of acoustic agglomeration systems for fine particle control. Final report

Description: The feasibility of using an acoustic agglomerator (AA) as a preconditioner in the upstream of conventional devices such as an electrostatic precipitator, a scrubber, a filter, or a cyclone are investigated. The objective is to agglomerate all finer particles into coarser ones in an acoustic agglomerator and then remove them more effectively by one of the conventional devices. Laboratory-scale experiments were performed using NH/sub 4/Cl and fly ash redispersed aerosols. Turbulence caused by intensive sound fields under standing-wave condition has been found to be extremely effective for aerosol agglomeration. The nature and the energy dissipation rate of the acoustic turbulence are determined by using hot-film (or hot-wire) anemometry and Fast Fourier Transform (FFT) data processing equipment. The root-mean-square turbulent velocity, which is directly proportional to acoustic agglomeration rate, is experimentally found to have a I/sup 1/2/(I: acoustic intensity) dependence, but is relatively independent of the acoustic frequency. The results obtained from this program show that acoustic agglomeration is effective as a particle pre-conditioner which can increase approximately one order of magnitude in mean particle diameter (2..mu..m ..-->.. 20..mu..m). As a flow-through standing wave device, it can be used to facilitate the removal of dust particles in a subsequent inertia base separation device.
Date: October 1, 1979
Creator: Shaw, D.T.; Lee, P.; Wegrzyn, J.; Chou, K.H.; Cheng, M.T. & Patel, S.
Partner: UNT Libraries Government Documents Department

Experimental evaluation of acoustic agglomerators as an air cleaning system concept for emergency use in LMFBR plants. Final report

Description: In the development of the Liquid Metal Fast Breeder Reactor, a major safety problem concerns the suppression of the sodium oxides aerosol particles produced during a hypothetical core disruptive accident. Some theoretical calculations are presented concerning sonic agglomeration rates of such a system in terms of acoustic frequency, intensity and particles. The information is useful in providing some guidelines for the evaluation and design of sonic systems for LMFBR emergency applications.
Date: November 1, 1979
Creator: Shaw, D T & Wegrzyn, J
Partner: UNT Libraries Government Documents Department

Comparison of HEPA filter test methods in corrosive environments

Description: The in-plant testing of process off-gas high efficiency particular air (HEPA) filters is an important quality control activity of the ALARA (As Low As Reasonably Achievable) policy at nuclear facilities. Imprecise and irreproducible data were recorded during DOP testing at the Atmospheric Protection System (APS) of the Idaho Chemical Processing Plant (ICPP). The tests at the APS are performed in an environment that has high humidity, high temperatures and has NO/sub x/ present. An evaluation of three HEPA filter test methods in corrosive environments was conducted: the dioctyl phthalate (DOP) method (US Standard Method ANSI N-101.1-1979) the sodium chloride method (British Standard 3928:1969), and the soda-fluorescein or uranine method (French Standard AFNOR STD NFX 44-011). The effects of high humidity, temperature, and oxides of nitrogen (NO/sub x/) on each method was examined. The effects of each variable and any interaction between variables on the test methods were examined. Recommendations for changes in the standard methods to reduce erratic on-line results are presented.
Date: January 1, 1980
Creator: Murphy, L.P.; Fernandez, S.J. & Motes, B.G.
Partner: UNT Libraries Government Documents Department

Filtered-vented containment systems. [PWR; BWR]

Description: The potential benefits of filtered-vented containment systems as a means for mitigating the effects of severe accidents are analyzed. Studies so far have focused upon two operating reactor plants in the United States, a large-containment pressurized water reactor and a Mark I containment boiling water reactor. Design options that could be retrofitted to these plants are described including single-component once-through venting systems, multiple-component systems with vent and recirculation capabilities, and totally contained venting systems. A variety of venting strategies are also described which include simple low-volume containment pressure relief strategies and more complicated, high-volume venting strategies that require anticipatory actions. The latter type of strategy is intended for accidents that produce containment-threatening pressure spikes.
Date: January 1, 1980
Creator: Benjamin, A.S.; Walling, H.C.; Cybulskis, P. & DiSalvo, R.
Partner: UNT Libraries Government Documents Department

In-place testing of off-gas iodine filters

Description: At the Idaho National Engineering Laboratory, both charcoal and silver zeolite (AgX) filters are used for radioactive iodine off-gas cleanup of reactor systems. These filters are used in facilities which are conducting research in the areas of reactor fuel failure, reactor fuel inspection, and loss of fluids from reactor vessels. Iodine retention efficiency testing of these filters is dictated by prudent safety practices and regulatory guidelines. A procedure for determining iodine off-gas filter efficiency in-place has been developed and tested on both AgX and charcoal filters. The procedure involves establishing sample points upstream and downstream of the filter to be tested. A step-by-step approach for filter efficiency testing is presented.
Date: January 1, 1980
Creator: Duce, S.W.; Tkachyk, J.W. & Motes, B.G.
Partner: UNT Libraries Government Documents Department

In-place testing of tandem HEPA filter stages using fluorescent aerosols

Description: Fluorescent test aerosols were used in field testing of large multiple-stage HEPA filter systems. The technique excluded interference from non-fluorescent background particles known to leak into the plenum or ducting between the filters and the downstream sampling probe. This technique solved the problem of measuring extremely low concentrations of the test aerosol in the presence of background aerosol. The upstream fluorescent test aerosol was diluted with clean air and drawn into a single particle aerosol spectrometer capable of counting, sizing, and detecting fluorescence of each particle. The particle sizing function was performed on light scattered by the particle passing through the beam of a helium-cadmium laser. Concurrently the fluorescence excited by the laser illumination was detected at a longer wavelength. Since spectrometer response in the fluorescent mode was <2% of naturally occurring aerosols, background aerosols were insignificant as an interference to the downstream concentration measurement. Decontamination factors (DF) on the order of 10/sup 8/ were measured in the field studies on >9.4 m/sup 3//s (20,000 cfm) systems. Additional generator capacity and acceptably lower test aerosol to background aerosol concentraion ratios could be used to extend this capability to measure DF greater than 10/sup 8/. Dye-tagged DOP aerosols were generated either by gas-thermal or sonic nozzle generators. Experiments with the gas-thermal generator showed only 20% of fluorescence from the dye was degraded by the vaporization process. A single sonic nozzle was shown to aerosolize 0.7 to 1.0 L/h of dye-tagged DOP aerosol in the proper size range for HEPA filter testing. A multiple sonic nozzle generator is a practical consideration to provide greater capacity.
Date: January 1, 1980
Creator: Elder, J.C.; Kyle, T.G.; Tillery, M.I. & Ettinger, H.J.
Partner: UNT Libraries Government Documents Department

Investigation of air cleaning system response to accident conditions

Description: Air cleaning system response to the stress of accident conditions are being investigated. A program overview and hghlight recent results of our investigation are presented. The program includes both analytical and experimental investigations. Computer codes for predicting effects of tornados, explosions, fires, and material transport are described. The test facilities used to obtain supportive experimental data to define structural integrity and confinement effectiveness of ventilation system components are described. Examples of experimental results for code verification, blower response to tornado transients, and filter response to tornado and explosion transients are reported.
Date: January 1, 1980
Creator: Andrae, R.W.; Bolstad, J.W.; Foster, R.D.; Gregory, W.S.; Horak, H.L.; Idar, E.S. et al.
Partner: UNT Libraries Government Documents Department

Large-scale tests of aqueous scrubber systems for LMFBR vented containment

Description: Six large-scale air cleaning tests performed in the Containment Systems Test Facility (CSTF) are described. The test conditions simulated those postulated for hypothetical accidents in an LMFBR involving containment venting to control hydrogen concentration and containment overpressure. Sodium aerosols were generated by continously spraying sodium into air and adding steam and/or carbon dioxide to create the desired Na/sub 2/O/sub 2/, Na/sub 2/CO/sub 3/ or NaOH aerosol. Two air cleaning systems were tested: (a) spray quench chamber, educator venturi scrubber and high efficiency fibrous scrubber in series; and (b) the same except with the spray quench chamber eliminated. The gas flow rates ranged up to 0.8 m/sup 3//s (1700 acfm) at temperatures to 313/sup 0/C (600/sup 0/F). Quantities of aerosol removed from the gas stream ranged up to 700 kg per test. The systems performed very satisfactorily with overall aerosol mass removal efficiencies exceeding 99.9% in each test.
Date: January 1, 1980
Creator: McCormack, J.D.; Hilliard, R.K. & Postma, A.K.
Partner: UNT Libraries Government Documents Department

Development of a passive self-cleaning scrubber for containment venting applications

Description: A novel air cleaning concept is being developed for potential use in venting reactor containment buildings. The two-stage system employs a pre-scrubber (a submerged gravel scrubber) and a fibrous scrubber to obtain high removal efficiencies for particulate contaminants. The submerged gravel scrubber is unique in that water flow is induced by the gas flow, eliminating the need for an active liquid pump. In addition, design gas velocities through the gravel bed are 10 to 20 times higher than for a conventional sand bed filter. A series of development tests have been performed on an engineering scale model with a gravel bed area of 0.07 m/sup 2/. Hydraulic tests indicate that the scrubber can be designed to operate at a superficial gas velocity of 0.50 m/s. Aerosol tests were performed with a variety of sodium fire aerosols. The aerosol mass removal efficiency for the pre-scrubber was 99.8% and the efficiency for the system exceeded 99.99%. The test results show that the aerosol removal efficiency is not a strong function of the gas velocity. Scale-up tests were made to evaluate gas distribution on a larger bed. The results demonstrated that the self-cleaning gravel bed can be scaled-up to the sizes required for full-scale containment applications.
Date: April 1, 1980
Creator: Owen, R.K. & Postma, A.K.
Partner: UNT Libraries Government Documents Department