Headspace gas and vapor characterization summary for the 43 vapor program suspect tanks

Huckaby, J.L.; Bratzel, D.R.

doi:10.2172/273290

Cited by 11 publications

(13 citation statements)

References 2 publications

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“…The probability of such exposures, however, and the accidental release rates are difficult to predict. 1,13 At the time of this survey, the CHG workforce was not routinely monitored for potential chemical hazards, should they be exposed from an accidental release of tank vapors. Since the NIOSH site visit, there have been substantial changes in the Health and Safety program including additional exposure monitoring.…”

Section: Discussionmentioning

confidence: 99%

“…There are adequate data and scientific technology to characterize the compounds within the tanks, but the concentrations in the head space vapors are subject to change. 12,13 2. Exposure data for individual workers are limited in quantity and quality and are not kept in an easily-accessible data base.…”

Section: Discussionmentioning

confidence: 99%

“…In 1995 and 1996, evaluations of the tank contents were conducted by the Westinghouse Hanford Company (WHC) under contracts from DOE. 12,13 Based on the results of these evaluations, WHC considered the tank constituents to be characterized and the tank vapor exposures to be controlled, so the requirement for supplied air respirators was discontinued. Subsequently, CHG required respiratory protection only for certain types of work activities and locations on the tank farms.…”

Section: Respiratory Protectionmentioning

confidence: 99%

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Health hazard evaluation report: HETA 2004-0145-2941, CH2M Hill Hanford Group, Inc. and United States Department of Energy, Office of River Protection, Richland, Washington.

2004

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This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports ii PREFACEThe Hazard Evaluation and Technical Assistance Branch (HETAB) of the National Institute for Occupational Safety and Health (NIOSH) conducts field investigations of possible health hazards in the workplace. These investigations are conducted under the authority of Section 20(a)(6) of the Occupational Safety and Health (OSHA) Act of 1970, 29 U.S.C. 669(a)(6) which authorizes the Secretary of Health and Human Services, following a written request from any employers or authorized representative of employees, to determine whether any substance normally found in the place of employment has potentially toxic effects in such concentrations as used or found.HETAB also provides, upon request, technical and consultative assistance to federal, state, and local agencies; labor; industry; and other groups or individuals to control occupational health hazards and to prevent related trauma and disease. Mention of company names or products does not constitute endorsement by NIOSH. ACKNOWLEDGMENTS AND AVAILABILITY OF REPORTThis report was prepared by Dr. Yvonne Boudreau, Dr. John Cardarelli and Mr. Gregory Burr of HETAB, Division of Surveillance, Hazard Evaluations and Field Studies (DSHEFS). Desktop publishing, review and preparation for printing were performed by Lisa Maestas and Ellen Blythe.Copies of this report have been sent to employee and management representatives at CH 2 M Hill Hanford Group, Inc., DOE, and the OSHA Regional Office. This report is not copyrighted and may be freely reproduced. The report may be viewed and printed from the following internet address: http://www.cdc.gov/niosh/hhe. Single copies of this report will be available for a period of three years from the date of this report. To expedite your request, include a self-addressed mailing label along with your written request to: NIOSH Publications Office 4676 Columbia Parkway Cincinnati, Ohio 45226 800-356-4674After this time, copies may be purchased from the National Technical Information Service (NTIS) at 5825 Port Royal Road, Springfield, Virginia 22161, http://www.ntis.gov/ordering.htm. Information regarding the NTIS stock number may be obtained from the NIOSH Publications Office at the Cincinnati address.For the purpose of informing affected employees, c...

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Respiratory Protectionmentioning

confidence: 99%

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Health hazard evaluation report: HETA 2004-0145-2941, CH2M Hill Hanford Group, Inc. and United States Department of Energy, Office of River Protection, Richland, Washington.

2004

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“…Barefield et al (1995Barefield et al ( , 1996 found small concentrations of nitriles in long-term studies of decomposition pathways of HEDTA in simulated wastes. Simple aliphatic nitriles with more than four carbon atoms have been detected in the dome space of several Hanford tanks (Huckaby et al 1995). Although these substances are apparently derived from normal paraffinic hydrocarbons, their existence in the waste provides an excellent precedent for the formation of other nitriles from the nonvolatile complexants.…”

Section: Ammonia From Nitrilesmentioning

confidence: 99%

Chemical pathways for the formation of ammonia in Hanford wastes

Stock¹,

Pederson²

1997

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This report reviews chemical reactions leading to the formation of ammonia in Hanford wastes. The general features of the chemistry of the organic compounds in the Hanford wastes are briefly outlined. The radiolytic and thermal free radical reactions that are responsible for the initiation and propagation of the oxidative degradation reactions of the nitrogen-containing complexants, trisodium HEDTA and tetrasodium EDTA, are outlined. In addition, the roles played by three different ionic reaction pathways for the oxidation of the same compounds and their degradation products are described as a prelude to the discussion of the formation of ammonia. The reaction pathways postulated for its formation are based on tank observations, laboratory studies with simulated and actual wastes, and the review of the scientific literature. Ammonia derives from the reduction of nitrite ion (most important), from the conversion of organic nitrogen in the complexants and their degradation products, and from radiolytic reactions of nitrous oxide and nitrogen (least important).Reduction of nitrite ions is believed to be the most important source of ammonia. Whether by radiolytic or thermal routes, nitrite reduction reactions proceed through nitrogen dioxide, nitric oxide, the nitrosyl anion, and the hyponitrite anion. Nitrite ion is also converted into hydroxylamine, another important intermediate on the pathway to form ammonia. These reaction pathways additionally result in the formation of nitrous oxide and molecular nitrogen, whereas hydrogen formation is produced in a separate reaction sequence.The oxidative degradation of trisodium EDTA and tetrasodium HEDTA also yields ammonia and other nitrogenous gases. The complexants react with nitric oxide and nitrogen dioxide to produce oxidized compounds that subsequently undergo hydrolysis, eventually liberating ammonia. Amides and nitriles are intermediates in these long reaction sequences. , The direct reaction of hydrogen with nitrous oxide and nitrogen can account for only negligible quantities of ammonia in Hanford tanks. Thermal reactions require high temperatures (AOOOC), high pressures, and the presence of catalysts, to proceed at significant rates. Similarly, radiolytic yields for direct reactions of hydrogen with nitrogen and nitrous oxide under tank conditions are expected to be very small.Oxygen can substantially alter the yields of nitrogenous gases. Two principal pathways have been identified. Oxygen intercepts radicals produced in thermal and radiolytic reactions that would otherwise eventually result in the formation of nitrogen, nitrous oxide and ammonia. Oxygen also reacts directly with complexants and intermediates to yield oxalate ion. The hydrogen yield is often increased in the presence of oxygen.

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“…The 39 tank air samples and 2 ambient air control samples collected are listed in Table 2-1 by analytical laboratoty. A general description of vapor sampling and sample analysis methods is given by Huckaby and Babad (1995). The sampling equipment, sample collection sequence, sorbent trap sample air flow rates and flow times, chain of custody information, and a discussion ofthe sampling event itself are given in WHC (1995b).…”

mentioning

confidence: 99%

Headspace gas and vapor characterization summary for the 43 vapor program suspect tanks

Cited by 11 publications

References 2 publications

Health hazard evaluation report: HETA 2004-0145-2941, CH2M Hill Hanford Group, Inc. and United States Department of Energy, Office of River Protection, Richland, Washington.

Health hazard evaluation report: HETA 2004-0145-2941, CH2M Hill Hanford Group, Inc. and United States Department of Energy, Office of River Protection, Richland, Washington.

Chemical pathways for the formation of ammonia in Hanford wastes

Tank 241-C-109 headspace gas and vapor characterization results for samples collected in August 1994. Revision 2

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