SAFETY ANALYSIS APPROACH TO TANK 241-SY-101 REMEDIATION ACTIVITIES
An Unreviewed Safety Question was declared related to the unexplained waste surface level growth in high-level radioactive waste storage Tank 241-SY-101 at the Hanford Site in Richland, Washington. Because the waste surface level in Tank 241-SY-101 was growing in a manner inconsistent with previous behavior, the following issues of concern were recognized: (1) The continually rising surface level had the potential to reach physical encumbrances or limits within the tank (e.g., instrumentation, cameras, established Authorization Basis limits, and the double containment boundary) and the potential to significantly change the consequences of previously analyzed accidents (e.g., flammable gas deflagrations). (2) The presence of new hazards because of significant quantities of flammable gas retained in the crust (e.g., crust collapse gas-release events). (3) The potential to inhibit information gathering related to the existing hazards in the tank (e.g., unable to determine surface level to assess the potential for large gas releases). In response to this situation, a Contractor Project Team, which included Department of Energy representation, was formed to constructively address the issue. The team was responsible for developing and evaluating remediation options and executing the chosen option for remediating the surface level rise issue for Tank 241-SY-101. From an Authorization Basis perspective, the following important aspects will be discussed in this paper: (1) The integrated nature of the Project Team. The team consisted of all the organizations necessary to ensure that the time available to remediate Tank 241-SY-101 was effectively used. Most notable is the connectivity of the Nuclear Safety & Licensing organization with the Engineering, Design, and Operations organizations. (2) The ability of the safety analysis support to adjust to and address evolving Project Team goals and dynamic tank conditions. (3) Due to the urgency to mitigate this developing issue, supplemental controls to ensure safety during remediation operations and activities were developed and approved at the Contractor level with DOE cognizance through their participation as an integral part of the Project Team. This approach was selected as the most expedient to meet the aggressive project schedule and changing tank conditions. This project has been successful in meeting established goals because of the effectiveness of an integrated project team that included Nuclear Safety & Licensing at the start, the integral involvement of DOE during each phase of the project, and the ability of the Contractor to develop, approve, and implement the supplemental controls necessary to safely perform operations and activities.
- Research Organization:
- FDNW (US)
- Sponsoring Organization:
- USDOE Office of Environmental Management (EM) (US)
- DOE Contract Number:
- AC06-96RL13200
- OSTI ID:
- 820823
- Report Number(s):
- HNF-5650-FP, Rev.0; TRN: US0400626
- Resource Relation:
- Conference: Conference title not supplied, Conference location not supplied, Conference dates not supplied; Other Information: PBD: 22 Mar 2000
- Country of Publication:
- United States
- Language:
- English
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