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in creator/contributor: "Lum, B Y"

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Evaluation of permanently charged electrofibrous filters

These studies showed that loading the permanently charged filters with captured aerosols will lead to a neutralization of the filter charge. The transfer from the captured aerosol to the fiber surface and the subsequent neutralization of fiber charge. The increased efficiency is due to the additional mechanical capture by the particle deposits. The minimum efficiency obtained during the loading of solid aerosols is determined by the aerosol charge, with highly charged aerosols producing a lower… more

Date: October 18, 1982

Creator: Biermann, A. H.; Lum, B. Y. & Bergman, W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Photolytic destruction of oxalate in aqueous mixed waste

In aqueous plutonium processing, residual oxalic acid can be destroyed (oxalate kill) by UV light with hydrogen peroxide (H{sub 2}O{sub 2}) in 1 M HCl solutions. By controlling the amount of H{sub 2}O{sub 2}, the oxalate kill process will not affect the chloride concentration. In nitric acid solutions, UV light alone can destroy the oxalic acid. However, with H{sub 2}O{sub 2}, the rate of destruction is faster. After the destruction of oxalic acid, the acidic solutions may be reusable without f… more

Date: March 1, 1995

Creator: Wang, F. T. & Lum, B. Y.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Field evaluation of prototype electrofibrous filters

New prototype electrofibrous filters were designed, built and evaluated in laboratory tests and in field installations. Two prototypes were designed for use in nuclear ventilation ducts as prefilters to HEPA filters. One prototype is designed to be a permanent component of the ventilation system while the other is a disposable unit. The disposable electrofibrous prefilter was installed in the exhaust stream of a glove box in which barrels of uranium turnings are burned. Preliminary tests show t… more

Date: September 30, 1982

Creator: Kuhl, W. D.; Bergman, W.; Biermann, A. H. & Lum, B. Y.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Effect of environmental variables on localized corrosion of high-performance container materials

Electrochemical cyclic potentiodynamic polarization (CPP) experiments were performed on several candidate high-performance waste package container materials to evaluate their susceptibility to localized corrosion in aqueous environments relevant to the potential underground high-level nuclear waste repository. This paper presents the results of this study showing the effects of chloride ion (Cl) concentrations, pH, temperature, and electrochemical potential scan rate on the pitting corrosion be… more

Date: January 1, 1997

Creator: Roy, A. K.; Fleming, D. L. & Lum, B. Y.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Electrostatic air filters generated by electric fields

This paper presents theoretical and experimental findings on fibrous filters converted to electrostatic operation by a nonionizing electric field. Compared to a conventional fibrous filter, the electrostatic filter has a higher efficiency and a longer, useful life. The increased efficiency is attributed to a time independent attraction between polarized fibers and charged, polarized particles and a time dependent attraction between charged fibers and charged, polarized particles. The charge on … more

Date: January 27, 1981

Creator: Bergman, W.; Biermann, A. H.; Hebard, H. D.; Lum, B. Y. & Kuhl, W. D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Effect of controlled potential on SCC of nuclear waste package container materials

The slow-strain-rate (SSR) test technique was used to evaluate the susceptibility of Titanium (Ti) Gr-7 (UNS R52400) and Ti Gr-12 (UNS R53400) to stress corrosion cracking (SCC). Ti Gr-7 and Ti Gr-12 are two candidate container materials for the multi-barrier package for nuclear waste. The tests were done in a deaerated 90 C acidic brine (pH {approx} 2.7) containing 5 weight percent (wt%) sodium chloride (NaCl) using a strain rate of 3.3 x 10{sup -6} sec{sup -1}. Before being tested in the acid… more

Date: August 1, 1999

Creator: Lum, B Y; Roy, A K & Spragge, M K

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Galvanic corrosion-effect of environmental and experimental variables

Galvanic corrosion behavior of A 516 steel coupled to alloy C-22 and Ti Gr-12, respectively was evaluated in an acidic brine (pH {approx} 2.75) at 30 C, 60 C and 80 C using zero resistance ammeter method. A limited number of experiments were also performed in a neutral brine involving A 516 steel/alloy C-22 couple. The steady-state galvanic current and galvanic potential were measured as functions of anode-to-cathode (A/C) area ratio and electrode distance. Results indicate that the galvanic cu… more

Date: November 1, 1998

Creator: Fleming, D. L.; Lum, B. Y. & Roy, A. K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Evaluation of Prototype Electrofibrous Filters for Nuclear-Ventilation Ducts

Two prototypes electrofibrous filters were designed, built and evaluated in laboratory tests and in field installations. These prototypes were designed for use in nuclear ventilation ducts as prefilters to HEPA filters. One prototype is designed to be a permanent component of the ventilation system while the other is a disposable unit. The disposable electrofibrous prefilter was installed in the exhaust stream of a glove box in which barrels of uranium turnings are burned. Preliminary tests sho… more

Date: December 2, 1982

Creator: Bergman, W.; Kuhl, W. D.; Biermann, A. H.; Johnson, J. S. & Lum, B. Y.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Electrochemical and metallographic evaluation of alloys C-22 and 625

Electrochemical cyclic potentiodynamic polarization (CPP) experiments were performed on Alloys C-22 and 625 to evaluate their susceptibility to localized corrosion in acidic brines of various salt content at 90{degrees}C. The microstructures of both tested and untested specimen`s were evaluated by optical microscopy. This paper presents the results showing the effect of chloride ion concentration on the pitting and crevice corrosion behavior of these alloys, and the relationship of the observed… more

Date: May 1, 1997

Creator: Roy, A. K.; Fleming, D. L. & Lum, B. Y.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Localized corrosion of candidate container materials in ferric chloride solutions

Localized corrosion behavior of candidate inner and outer container materials of currently-designed nuclear waste package was evaluated in aqueous solutions of various concentrations of ferric chloride (FeCl{sub 3}) at 30 C, 60 C and 90 C using the electrochemical cyclic potentiodynamic polarization (CPP) technique. Materials tested include A 5 16 carbon steel and high-performance alloys 825, G-3, G-30, C-4, 625. C-22, and Ti Gr-12. A 516 steel suffered from severe general and localized attack … more

Date: October 1, 1998

Creator: Fleming, D. L.; Lum, B. Y. & Roy, A. K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Stress corrosion cracking of Fe-Ni-Cr-Mo, Ni-Cr-Mo and Ti alloys in 90{degrees}C acidic brince

Susceptibility to stress corrosion cracking (SCC) of candidate materials for the inner container of the multi-barrier nuclear waste package was evaluated by using wedge-loaded precracked double- cantilever-beam (DCB) specimens in deaerated acidic brine (pH at 2.70) at 90{degrees}C. Materials tested include Alloys 825, G-30, C-4, 625 and C-22; and Ti Grade- 12. Duplicate specimen of each material was loaded at different initial stress intensity factor (K) values ranging between 23 and 46 ksi/in.… more

Date: November 1, 1997

Creator: Roy, A. K.; Fleming, D. L. & Lum, B. Y.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Electrofibrous prefilters for use in the nuclear industry

High efficiency particulate air (HEPA) filters are used in the nuclear industry to remove radioactive aerosols. Although these HEPA filters are effective and practical devices, they generate a large volume of radioactive waste and are costly to purchase and operate. In an effort to reduce the HEPA's operational cost and volume of radioactive waste, the Department of Energy (DOE) has contracted with LLNL to develop electrofibrous prefilters to extend the service life of HEPA filters. A comprehen… more

Date: January 1, 1980

Creator: Bergman, W.; Taylor, R. D.; Hebard, H. D.; Lum, B. Y.; Kuhl, W. D.; Boling, R. M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Enhanced filtration program at LLL. A progress report.

As part of Lawrence Livermore Laboratory's Enhanced Filtration Program, we are investigating the use of an externally applied electric field to improve the performance of fibrous filters. Our objective in this program is to develop filtration systems for the nuclear industry that will reduce the cost and volume of nuclear waste associated with present systems. We have developed a new theory of the electrostatic filter that is consistent with experimental tests made during transient and steady-s… more

Date: July 28, 1978

Creator: Bergman, W.; Taylor, R. D.; Miller, H. H.; Bierman, A. H.; Hebard, H. D.; daRoza, R. A. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

SCC evaluation of candidate container alloys by DCB method

The authors use a solid mechanics approach to investigate hydride formation and cracking in zirconium-niobium alloys used in the pressure tubes of CANDU nuclear reactors. In this approach, the forming hydride is assumed to be purely elastic and its volume dilation is accommodated by elasto-plastic deformation of the surrounding matrix material. The energetics of the hydride formation is revisited and the terminal solid solubility of hydrogen in solution is defined on the basis of the total elas… more

Date: September 24, 1999

Creator: Roy, A. K.; Freeman, D. C.; Lum, B. Y. & Spragge, M. K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Operating manual for the electrostatic glove-box prefilter installed inside the filter glove box No. 046 at Rocky Flats, Building 776

Objective of the evaluation is to evaluate the effectiveness of the electrostatic prefilter in prolonging the life of HEPA (high-efficiency particulate-air) filters. The theory of the electrostatic filter is reviewed, and Glove Box Number 046 is described in detail, followed by a description of the electrostatic prefilter used in the present application. Engineering drawings of the electrostatic prefilter are included. The procedure for evaluating the electrostatic prefilter includes the steps … more

Date: May 11, 1979

Creator: Bergman, W.; Kaifer, R. C.; Hebard, H. D.; Taylor, R. D.; Lum, B. Y.; Buttedahl, O. I. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Electrofibrous prefilters for use in nuclear ventilation systems

We have established a comprehensive program for the US Department of Energy to develop electrofibrous prefilters to extend the life of High Efficiency Particulate Air (HEPA) filters that are used in the nuclear industry. We have selected the electrofibrous filter because, compared to the mechanical fibrous filter, it has a higher efficiency and longer lifetime. Two different electrofibrous filters have been developed for use in nuclear ventilation systems. One prototype is a stationary prefilte… more

Date: February 19, 1981

Creator: Bergman, W.; Kuhl, W. D.; Russell, W. L.; Taylor, R. D.; Hebard, H. D.; Biermann, A. H. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department