EXPEDITED SHIPMENT OF HIGH-WATTAGE CH-TRU WASTE FROM LOS ALAMOS NATIONAL LABORATORY

The Los Alamos National Laboratory (LANL) is currently storing approximately 9,100 cubic meters (43,700 55-gallon drum equivalents) of contact-handled transuranic waste at Technical Area 54 (TA-54). The Cerro Grande fire in summer 2000, and the events of September 11, 2001, led to an evaluation of the risk associated with the waste inventory stored at TA-54. Results of the analysis indicate that the amount of dispersible plutonium stored above ground at TA-54 is a credible hazard. A key finding is approximately 60% of the dispersible high activity waste at risk is packaged in 5% (2,000 55-gallon drum equivalents) of the total inventory. The accelerated shipment of these 2,000 containers to the Waste Isolation Pilot Plant (WIPP) would significantly reduce the hazard associated with their continued storage at TA-54. This paper presents the methodology proposed for the expedited shipment of the 2,000 containers from LANL to WIPP in the Transuranic Package Transporter-II (TRUPACT-II), in compliance with all governing requirements. A methodology to mitigate the concerns associated with flammable gas generation is proposed, allowing these containers to be shipped in compliance with the 5% limit (by volume) on hydrogen concentration. The methodology, which is specific only to the TRUPACT-II shipment of the 2,000 containers, consists of the following elements: • Applying a vacuum to remove hydrogen that may have accumulated in the containers during storage • Backfilling the TRUPACT-II inner containment vessel with an inert gas as an additional margin of safety (i.e., no credit is taken for inerting in the compliance demonstration) • Imposing a shorter shipping period (five days) to minimize hydrogen accumulation during transportation • Defining controls to ensure that the five-day shipping period is not exceeded and that the maximum normal operating pressure for the payload is well below the TRUPACT-II design pressure. The methodology must be approved mmm by the U.S. Nuclear Regulatory Commission as an amendment to the TRUPACT-II Authorized Methods for Payload Control (TRAMPAC). Specific details of the proposed methodology are presented. This paper also discusses public involvement and stakeholder participation.