Disposal Of Surplus Plutonium At The Waste Isolation Pilot Plant

Disposal of Surplus Plutonium at the Waste Isolation Pilot Plant: Interim Report evaluates the general viability of the U.S. Department of Energy's National Nuclear Security Administration's (DOE-NNSA's) conceptual plans for disposing of 34 metric tons (MT) of surplus plutonium in the Waste Isolation Pilot Plant (WIPP), a deep geologic repository near Carlsbad, New Mexico. This report evaluates DOE-NNSA's plans to ship, receive, and emplace surplus plutonium in WIPP and its understanding of the impacts of these plans on WIPP and WIPP-bound waste streams. This report, the first of two to be issued during this study, provides a preliminary assessment of the general viability of DOE-NNSA's conceptual plans, focusing on some of the barriers to their implementation.

In 2018, the National Academies of Sciences, Engineering, and Medicine issued an Interim Report evaluating the general viability of the U.S. Department of Energy's National Nuclear Security Administration's (DOE-NNSA's) conceptual plans for disposing of 34 metric tons (MT) of surplus plutonium in the Waste Isolation Pilot Plant (WIPP), a deep geologic repository near Carlsbad, New Mexico. It provided a preliminary assessment of the general viability of DOE-NNSA's conceptual plans, focused on some of the barriers to their implementation. This final report addresses the remaining issues and echoes the recommendations from the interim study.

The United States has pledged to dispose of 34 metric tons of surplus, weapons-grade plutonium. The current U.S. approach relies on disposing of the plutonium by irradiating it as MOX fuel-a mixture of plutonium and uranium oxides-in modified commercial nuclear reactors. Due to a significant rise in cost, DOE recently proposed terminating the MOX approach in favor of the dilute and dispose approach, which DOE stated may be less expensive. Under this approach, plutonium would be diluted with inert material and then disposed of in a geologic repository. GAO was asked to review DOE's planning for both the MOX and dilute and dispose approaches. This report examines: (1) the extent to which DOE's revised cost estimates for completing the construction of the MOX facility and for completing the overall Plutonium Disposition Program met best practices, (2) the status of NNSA's development of a life-cycle cost estimate for the dilute and dispose approach, and (3) the extent to which DOE has sufficient disposal space and statutory capacity at WIPP to dispose of all defense TRU waste, including waste from the dilute and dispose approach. GAO reviewed documents and interviewed DOE and NNSA officials, including officials from five major waste-generating sites.

This volume discusses the readiness of the U.S. Department of Energy's (DOE) Waste Isolation Pilot Plant (WIPP) facility near Carlsbad, New Mexico, to serve as a geological repository for transuranic radioactive waste. WIPP is located in a Permian-age bedded salt deposit 658 meters below the surface. The committee has long reviewed DOE's readiness efforts, now aimed at demonstrating compliance with U.S. Environmental Protection Agency regulations. Site characterization studies and performance assessment modeling are among the topics considered in this volume.

The National Research Council convened a committee of experts to advise the U.S. Department of Energy (DOE) on the operation of the Waste Isolation Pilot Plant (WIPP), a geologic repository for disposal of defense transuranic (TRU) waste near Carlsbad, New Mexico. The committee was asked to provide recommendations on the following two issues: (1) a research agenda to enhance confidence in the long-term performance of WIPP; and (2) increasing the throughput, efficiency, and cost-benefit without compromising safety of the National TRU Program for characterizing, certifying, packaging, and shipping waste to WIPP. The committee has written this interim report to provide DOE with recommendations on several issues that the committee believes merit immediate consideration and action. In developing this report, the committee has been guided by the principle of "reasonableness" with respect to risks, costs, and the ALARA (as low as reasonably achievable) principle. In the committee's judgment, implementing the recommendations contained in this report will contribute to the continued safe operation of WIPP.

PLUTONIUM DISPOSITION: Proposed Dilute and Dispose Approach Highlighs Need for More Work at the Waste Isolation Pilot Plant

The Waste Isolation Pilot Plant (WIPP) is a deep underground mined facility for the disposal of transuranic waste resulting from the nation's defense program. Transuranic waste is defined as waste contaminated with transuranic radionuclides with half-life greater than 20 years and activity greater than 100 nanocuries per gram. The waste mainly consists of contaminated protective clothing, rags, old tools and equipment, pieces of dismantled buildings, chemical residues, and scrap materials. The total activity of the waste expected to be disposed at the WIPP is estimated to be approximately 7 million curies, including 12,900 kilograms of plutonium distributed throughout the waste in very dilute form. The WIPP is located near the community of Carlsbad, in southeastern New Mexico. The geological setting is a 600-meter thick, 250 million-year-old saltbed, the Salado Formation, lying 660 meters below the surface. The National Research Council (NRC) has been providing the U.S. Department of Energy (DOE) scientific and technical evaluations of the WIPP since 1978. The committee's task is twofold: (1) to identify technical issues that can be addressed to enhance confidence in the safe and long-term performance of the repository and (2) to identify opportunities for improving the National Transuranic (TRU) Program for waste management, especially with regard to the safety of workers and the public. This is the first full NRC report issued following the certification of the facility by the U.S. Environmental Protection Agency (EPA) on May 18, 1998. An interim report was issued by the committee in April 2000 and is reproduced in this report. The main findings and recommendations from the interim report have been incorporated into the body of this report. The overarching finding and recommendation of this report is that the activity that would best enhance confidence in the safe and long-term performance of the repository is to monitor critical performance parameters during the long pre-closure phase of repository operations (35 to possibly 100 years). Indeed, in the first 50 to 100 years the rates of important processes such as salt creep, brine inflow (if any), and microbial activity are predicted to be the highest and will be less significant later. The committee recommends that the results of the on-site monitoring program be used to improve the performance assessment for recertification purposes. These results will determine whether the need for a new performance assessment is warranted. For the National TRU Program, the committee finds that the DOE is implementing many of the recommendations of its interim report. It is important that the DOE continue its efforts to improve the packaging, characterization, and transportation of the transuranic waste.

The U.S. Department of Energy (DOE) disposes of plutonium-contaminated debris from its 27 nuclear weapons facilities at the Waste Isolation Pilot Plant (WIPP), an underground repository in Carlsbad, New Mexico. After four years of operational experience, DOE has opportunities to make changes to the costly and time-consuming process of "characterizing" the waste to confirm that it is appropriate for shipment to and disposal at WIPP.  The report says that in order to make such changes, DOE should conduct and publish a systematic and quantitative assessment to show that the proposed changes would not affect the protection of workers, the public, or the environment.