Tank Waste (2020 DOE transition)
| Book 2 - Issue Papers
|
|---|
| Entire 2020 DOE Transition book As of October 2020 |
The Office of Environmental Management (EM) has made significant progress in addressing waste generated from past spent nuclear fuel reprocessing activities and other plutonium production activities. This “tank waste” is EM’s biggest technical and budgetary challenge.
Summary
EM is responsible for the safe and effective management, including treatment and disposal, of radioactive waste from past reprocessing and other plutonium production activities. This waste, stored in aging underground tanks at three EM sites, poses a significant financial liability to the government.
This tank waste is being conservatively managed as high-level waste (HLW). HLW, as defined in the Atomic Energy Act (AEA) and the Nuclear Waste Policy Act (NWPA), requires disposal in a deep geological repository. In 2019, the Department of Energy (DOE) issued an interpretation of the definition of HLW to increase options for disposing of waste that could be properly and radiologically classified as something other than HLW.
At the Savannah River Site (SRS) in South Carolina, EM has completed the major components of the tank waste treatment system. The last major component was the Salt Waste Processing Facility (SWPF), which began hot operations in October 2020. The SWPF will process the majority of the site’s remaining tank waste inventory by separating the highly radioactive waste from the less radioactive salt solution.
The Idaho Cleanup Project, at the Idaho National Laboratory, is in the final stages of preparing the Integrated Waste Treatment Unit (IWTU) to treat the remaining sodium bearing tank waste. The IWTU is expected to begin operations in 2021. The Idaho Cleanup Project is also responsible for 4,400 cubic meters of solid radioactive waste called “calcine” that was generated from the reprocessing of spent nuclear fuel. There is not yet a defined path forward for treatment of this material, which is being safely stored on-site.
At the Hanford Site in Washington state, EM is constructing the Waste Treatment and Immobilization Plant (WTP), which is intended to vitrify (convert into borosilicate glass) a large portion of the tank waste stored in underground tanks. The WTP is the largest, most complex, and most expensive construction project in the entire Department. The components of the WTP that will treat low-activity tank waste through the Direct Feed Low Activity Waste Approach are expected to begin operations by the end of 2023.
The West Valley Demonstration Project (WVDP) in New York State is the first and only DOE site to construct, operate, and demolish a vitrification facility used to treat high level radioactive tank waste. All 600,000 gallons of the tank waste have been vitrified, and the glass canisters are in storage at the site pending disposal.
Issue(s)
EM is still working to finalize the approaches and capabilities for treating tank waste at Hanford and Idaho, and is working to ensure sufficient funding to allow for full utilization of the tank waste treatment system at Savannah River. With the Department’s interpretation of the term HLW, there are opportunities to make meaningful progress on dispositioning waste that has been historically managed as HLW but does not have a high radioactive content.
Status
HLW Interpretation
- In June 2019, DOE issued its interpretation of the AEA and NWPA definition for HLW, which allows waste to be classified and disposed according to its radiological characteristics (risk-based), rather than solely according to its origin (source-based).
- In August 2020, DOE issued the Environmental Assessment and Finding of No Significant Impact concluding that SRS Defense Waste Processing Facility (DWPF) recycle wastewater can be safely stabilized and disposed of as low-level radioactive waste (LLW).
- This first application of the HLW interpretation was completed September 22, 2020, with 8 gallons of DWPF recycle wastewater shipped to the Waste Control Specialists, LLC (WCS) LLW disposal facility in Texas for treatment and disposal.
- In FY21, EM will evaluate potential next waste stream(s) under the HLW interpretation, and, if appropriate, will initiate the required environmental evaluations, and technical and safety analyses.
SWPF
Salt Waste Processing Facility (SWPF) received Critical Decision-4 (CD-4) and Authorization to Operate in August 2020, and began “hot” or radioactive operations in October 2020.
IWTU/Calcine
- The Sodium Bearing Waste Treatment Facility (IWTU) is in final commissioning in preparation for radiological operations. Construction of the facility was completed in 2011.
- Delays in commencing IWTU “hot” operations have caused the Department to miss a site treatment plan milestone corresponding to an Idaho Settlement Agreement milestone, resulting in fines of $6,000 per day (since 2012). However, the Department has performed supplemental environmental projects in lieu of paying the fine.
- DOE is in the process of analyzing potential alternatives for the treatment of the calcine material.
WTP
- Since 2013, EM has been pursuing the Direct Feed Low Activity Waste (DFLAW) approach to begin the treatment of low activity tank waste by the end of 2023. Construction of all facilities needed for DFLAW operation should occur in 2021.
- The Department is conducting a comprehensive Analysis of Alternatives to evaluate options for the treatment of Hanford’s high level waste.
- DOE and the U.S. Department of Justice are engaged in holistic negotiations with the State of Washington and the U.S. Environmental Protection Agency (EPA) regarding the Hanford cleanup mission.
Milestone(s)
SWPF
The first transfer of 4,000 gallons of salt waste from one of Savannah River’s underground waste tanks to SWPF is scheduled for Q1 FY21.
IWTU
Final IWTU facility modifications in preparation for the start of radiological operations are scheduled to be completed in early 2021. The start of radiological operations is currently targeted for 2021.
WTP
EM currently expects to meet a milestone to complete hot commissioning of the WTP Low Activity Waste (LAW) Facility, part of the DFLAW approach, by December 31, 2023.
Major Decisions/Events
- Aspects of the Hanford cleanup mission are the subject of negotiations with the State of Washington and EPA.
- Decisions will be needed as a result of the Analyses of Alternatives for both WTP and Idaho’s calcine waste.
Background
SWPF
The waste in Savannah River’s tanks is a mixture of solids and liquids. After the liquid is evaporated the result is sludge-like material and crystalline salts. The crystalline material is commonly referred to as salt waste. Removing salt waste, which fills over 90 percent of tank space in the SRS tank farms, is a major step toward emptying and closing the Savannah River Site’s 43 remaining tanks. In 2002, Parsons Corporation was selected to design, build, commission, and operate for the SWPF one year, which will process salt waste at a rate eight times faster than recent waste treatment operations. Construction was completed in the spring of 2016, eight months ahead of the revised baseline schedule and $60 million under budget.
IWTU and Calcine
The IWTU will treat the remaining sodium bearing radioactive liquid tank waste at the Idaho National Laboratory using a steam reforming process. The tank waste is stored in three underground stainless steel tanks with a total volume to of approximately 850,000 gallons. This process will convert the liquid waste into a dry granular solid, which will be stored onsite in stainless steel canisters within concrete vaults until disposal.
Calcine material generated from the reprocessing of spent nuclear fuel is also stored at the Idaho National Laboratory. The calcine material is a dry granular solid stored in six Calcine Solids Storage Facilities onsite.
WTP
The WTP is intended to treat radioactive waste stored in 177 underground storage tanks, some of which have leaked. Originally, all of the components of the WTP would have been commissioned at the same time, with tank waste fed directly into the Pretreatment (PT) Facility, where it would be separated into high level radioactive and a low level radioactive waste streams, and subsequently fed to the HLW facility LAW facilities, respectively, for vitrification. Vitrified material from the LAW facility would be disposed of on-site in the Integrated Disposal Facility, while the vitrified HLW would be stored until disposal in an geologic repository.
The HLW stream constitutes roughly 10 percent of the expected volume, but represents roughly 90 percent of the radioactivity. Under current plans, the WTP is designed to treat all HLW in the Hanford wastes, but only one-third to one-half of the LAW. The Department has not yet identified the approach to treat the remaining LAW in the tanks, commonly referred to as the “supplemental LAW.”
In the summer of 2012, the Department directed the contractor, Bechtel National, Inc., to suspend production engineering and construction on the PT and HLW facilities due to unresolved technical challenges. To keep the mission moving forward, DOE developed an alternative approach intended to begin low activity waste treatment as soon as practicable while simultaneously completing resolution of the remaining technical issues associated with the PT and, to a lesser degree, HLW facilities.
WVDP
In 2018, EM and its cleanup contractor safely completed the demolition of the 50-foot-tall, 10,000-square-foot Vitrification Facility at the West Valley Demonstration Project (WVDP). The 278 canisters of vitrified waste produced at the facility are currently stored in casks on-site that have a design life of at least 50 years.