No abstract

A highly absorbent consumer-product, polyacrylate-polymer material tagged with carbon-14 (14C), was dosed to a standard on-site aerobic wastewater treatment plant which contained a settling chamber, an aeration chamber, and an effluent chamber. Operation of the test plant was essentially the same as that of a control plant even under exaggerated conditions. About 97% of the polymer material was retained in solids deposited in the primary and aeration chambers, and effluent releases were minimal. The use of a 14C tagging procedure proved to be a successful method for studying the behavior of these complex materials. It may be useful to conduct a further study on retained solids to determine whether microbial decomposition of the polymer material occurs while they remain in typical plants. Notation AC-aeration chamber BOD,-biochemical oxygen demand, S-day technique COD-chemical oxygen demand E-effluent LS-liquid scintillation mCi-millicurie MLSS-mixed liquor suspended solids NSF-national sanitation foundation PC-primary chamber pCi-picocurie SL-sludge SN-supernate SS-suspended solids VSS-volatile suspended solids 57-refers to plant 57, the test plant 58-refers to plant 58, the control plant

Determination of "Fe in reactor samples requires some care because of the low-energy x-rays emitted following decay by electron capture and the presence of "Fe and other possible y-ray emitting contaminants in radiochemical separations. This problem was dealt with by radiochemical separation of Fe followed by use of an intrinsic germanium detector operated at high amplifier gain to count the low-energy x-ray emissions to quantitate "Fe. Separation of this important nuclide in reactor samples was by solvent extraction using triisooctylamine in xylene. Low-energy photon counting was done with a high gain setting and a 3 ps shaping time, which provided accurate quantitation without interference of rVFe and other potential contaminants, which were either removed by separation or discriminated against by the counting procedure. Iron-59. either present in the sample or added as a spike, was used as a tracer for determining radiochemical yield, which was about 70%. The lower limit of detection was found to be 80 pCi/g based on a 10 g sample and a 5 min counting time.

WESKEM, LLC’s Environmental, Safety and Health (ES&H) Department had previously assessed that a lack of consistency, poor communication and use of antiquated communication tools could result in varying operating practices, as well as a failure to capture and disseminate appropriate Integrated Safety Management (ISM) information. To address these issues, the ES&H Department established an Activity Hazard Review (AHR)/Activity Hazard Analysis (AHA) process for systematically identifying, assessing, and controlling hazards associated with project work activities during work planning and execution. Depending on the scope of a project, information from field walkdowns and table-top meetings are collected on an AHR form. The AHA then documents the potential failure and consequence scenarios for a particular hazard. Also, the AHA recommends whether the type of mitigation appears appropriate or whether additional controls should be implemented. Since the application is web based, the information is captured into a single system and organized according to the ≥200 work activities already recorded in the database. Using the streamlined AHA method improved cycle time from over four hours to an average of one hour, allowing more time to analyze unique hazards and develop appropriate controls. Also, the enhanced configuration control created a readily available AHA library to research and utilize along with standardizing hazard analysis and control selection across four separate work sites located in Kentucky and Tennessee. The AHR/AHA system provides an applied example of how the ISM concept evolved into a standardized field-deployed tool yieling considerable efficiency gains in project planning and resource utilization. Employee safety is preserved through detailed planning that now requires only a portion of the time previously necessary. The available resources can then be applied to implementing appropriate engineering, administrative and personal protective equipment controls in the field.

This paper documents how utilizing available source term information, integrated safety management, and associated engineering, administrative and personal protective equipment (PPE) controls are used in concert to perform work safely. Two field projects consisting of 1) a room containing both hazardous (e.g., hydrofluoric acid) and radioactive constituents and 2) a former reaction vessel containing approximately 568 liters (150 gallons) of lime sludge and technetium-99 (Tc-99) were organized using the Department of Energy’s (DOE’s) Integrated Safety Management System (ISMS). This system allowed the project teams to control work-related decisions based on their knowledge, experience, expertise, and field observations. The information and experience gained from each project stage and rehearsals contributed to modifying subsequent entries, further emphasizing the importance of developing hold points and incorporating lessons learned. Furthermore, selecting the appropriate PPE is based on providing an adequate level of employee protection relative to the task-specific conditions and hazards. PPE is categorized into four ensembles based on the degree of protection afforded, e.g., Levels A (most restrictive), B, C, and D (least restrictive). What is often overlooked in preparing an ensemble is that the PPE itself can create significant worker hazards, i.e., the greater the level of PPE, the greater the associated risks. Furthermore, there is confusion as to whether a more “conservative approach” should always be taken since Level B provides the same level of respiratory protection as Level A but less skin protection. Additional information summarizes the Occupational Safety and Health Administration regulations addressing Level A versus Level B, and provides justification for selecting Level B over Level A without under-protecting the employee. The hazards and the chemical nature of hydrofluoric acid provide qualitative evidence to justify Level A. Once hydrofluoric acid is removed as a source term constituent, PPE performance is evaluated against the remaining chemical inventory. If chemical breakthrough from direct contact is not expected to occur and instrument readings confirm the absence of any hazardous vapors, additional skin protection afforded by wearing a vapor-tight, totally encapsulated suit is not required. Therefore, PPE performance and instrument data provide quantitative evidence to justify Level B. These projects exemplify that using guidance provided by DOE’s ISMS and the Occupational Safety and Health Administration (OSHA) demonstrates how a detailed and thorough planning process integrating safe work practices and commitment to teamwork can result in the safe and effective completion of very complex and highly hazardous projects.