a This cylinder was first thought to contain a gas but was found to hold a liquid. As a liquid in its original container, no radiological contamination was suspected and the item could be shipped without further preparation.

Beyond the inventory of cylinders disposed of in the course of this project, a backlog of cylinders of compressed gas exists at the ORR which have not yet officially been declared as surplus. These undeclared cylinders will likely require disposition as soon as funding is provided to apply a proven technology.

The entire operation to process the 21 cylinders was completed in 5 d once the system was approved for operation. The system worked well and should now prove useful for processing the potentially thousands of additional cylinders not yet declared as surplus. The cylinders processed during this demonstration project fell into two general categories, based on whether or not there was an operable valve which required notably different approaches for processing. The logic used in processing the cylinders is depicted graphically in Fig. 1.

For cylinders with operable valves, it was possible to sample and analyze their contents to either identify (previously unknown) or verify (previously known) their contents. In cases where neutralization was suitable, the contents of the cylinder were treated to accomplish this goal. In those for which neutralization was not a viable option, the cylinder's contents were transferred to a new cylinder by using nitrogen, a compressor system, and a simple manifold.

Cylinders with inoperable valves were either penetrated or revalved. For cylinders known to contain liquefied gases, the containers could be revalved at temperatures low enough such as to freeze the contents. For cylinders with contents that were either unsuitable for freezing (e.g., compressed gases) or unknown, it was necessary to cut the cylinder and analyze its contents. At this point, the contents were neutralized, if feasible, or else recontainerized.

Although the actual processing of cylinders spanned only a few days, our preparing the way for the project required months of work. The project had to comply with an extensive list of federal, state, and site-based regulations and standards. Dozens of agencies and site organizations were required to sign off on the plans before operation could begin. Managers of the project used a self-assessment process (a) to ensure that the TCGRS was ready for safe startup and operation and (b) to coordinate the environmental, safety, and health documentation necessary to satisfy stringent DOE, Tennessee Department of Environment and Conservation (TDEC), and company requirements. The self-assessment process is built upon a readiness self-assessment checklist that tracks numerous aspects of the acquisition and operation of the TCGRS on site. The 6-page checklist breaks the process down into dozens of discrete tasks, from the inception of the contract with the vendor to the shutdown and storage of the system. The checklist also supplies start and finish dates, durations, prerequisite tasks, and a status indicator for each task.

The self-assessment checklist seeks to address every issue associated with the process from the perspective of all regulations and procedures that might apply [e.g., Occupational Safety and Health Administration (OSHA), Clean Water and Clean Air acts, National Environmental Policy Act (NEPA), RCRA, site health and safety (H&S) procedures, TDEC regulations, and applicable DOE standards and procedures].

There were two levels of compliance to the self-assessment process: site-level and division-level. Site-level compliance encompassed the following elements:

• Facility safety
• Radiation control (RADCON)-radiation control officer (RCO)
• OSHA/industrial safety
• Industrial hygiene
• Transportation safety
• RCRA
• Clean Air Act
• Clean Water Act
• NEPA
• Hazardous materials information system (HMIS)
• LLW
• Satellite storage area (SSA)
• Sanitary waste
• Spill control
• Safeguards

Division-level compliance encompassed the following elements:

• Conduct of operations
• Configuration management
• Quality assurance (QA)
• H&S
• Environmental compliance
• Training
• Waste tracking

As an example of the depth and scope of each element evaluated, the training element of the self-assessment is further explored in Table II. This example provides the requirements for division-level compliance.

Those persons responsible for overseeing compliance with each of these regulations and standards were required to evaluate the project plans and preparations and the documentation relevant to their responsibilities. Some conducted on-site inspections or walk-downs to inspect equipment, records, and site preparation. If the inspectors were not satisfied with their findings, the project managers were notified of what must be done to obtain approval. Once satisfied, the inspectors signed off on their respective areas. The project could begin operation only after all the signatures were obtained showing that all issues were addressed satisfactorily.

Disposition of these gas cylinders was challenging, primarily because of the hazards and uncertainties which tended to exacerbate the risks posed by those hazards. The H&S requirements, in combination with these risks, led to a number of hurdles which had to be overcome and issues which had to be resolved. Table III summarizes the hurdles and issues encountered in the course of this project. The checklist used for the self-assessment was the key instrument in identifying hurdles and issues.

One very interesting event occurred during the course of this demonstration project, which emphasizes the effectiveness of the TCGRS unit and the importance of this capability. During a walk-through of one area where cylinders are stored, the plant manager noticed a faint scent, which he recognized as being characteristic of fluorine gas. Upon further investigation, a cylinder in the area was indeed found to be leaking. Using the TCGRS, this problem was confirmed and resolved on the very same day, and the cylinder and its contents were then properly dispatched.

Schedule and cost for the project are summarized in Tables IV and V. The actual processing and disposition of the cylinders occurred over the course of only 5 d. Yet, the history of the project can be seen to extend over several years (Table IV). The project idea was first conceived in 1988 at a conference held at Los Alamos National Laboratory (LANL). A few years later (1992), MWFA and LANL initiated project activities in Albuquerque. In 1995, LMES began to get involved in Oak Ridge. Several months of preparation, coordinated by the Chemical Technology Division at ORNL, culminated in the processing operation spanning 5 d in which the 21 gas cylinders were examined, treated, and disposed.

Costs for the project are summarized in Table V. Not surprisingly, equipment costs were the largest item, accounting for 57% of the overall project cost of $1.24 million. Vendor costs were much less, amounting to 15%. Project coordination and other support used up 28% of the overall project costs. Future gas-cylinder disposition campaigns may be expected to be much less expensive because of (a) the sophisticated equipment which already exists and (b) the benefit of the experience gained in this demonstration project.

The project to treat 21 cylinders was completed with great success. The self-assessment approach used was effective in ensuring a safe and an effective operation, environmental protection, and regulatory compliance. Although the assessment was very thorough in its scope and significant effort was required to address all the H&S issues, the checklist method was an effective tool for organizing and streamlining the self-assessment process. The cost to this stage of the technology development has been notable. For this project, the cost of over $1 million may seem expensive. However, incremental costs and schedules for processing additional cylinders are expected to be significantly reduced.

The way is now open for wider application of the TCGRS technology. Once the documentation has been revised to address additional cylinders, the equipment can be used to process the approximately 1,000 cylinders at the ORR as they become surplus. Beyond the ORR, there are many other DOE sites at which gas-cylinder disposition is a problem. At Oak Ridge, the solution to this problem now exists in the form of the TCGRS-the only proven, safe alternative for repackaging, recontainerization, or neutralization of cylinders.

1. ORR Site Treatment Plan issued by the State of Tennessee's Department of Environment and Conservation pursuant to Sect. 3021(b) of Resource Conservation and Recovery Act, 42 U.S.C. 6936(c), as amended by the Federal Facility Compliance Act, and Tennessee Code Annotated Sect. 68-212-111.

The submitted manuscript has been authored by a contractor of the U.S. government under contract DE-AC05-96OR22464. Accordingly, the U.S. government retains a nonexclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for U.S. government purposes.

Prepared by the Oak Ridge National Laboratory, Oak Ridge, Tennessee

Managed by Lockheed Martin Energy Research Corporation for the U. S. Department of Energy under contract DE-AC05-96OR22464

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