The U.S. Energy Department does not have a clear strategy to combat rising costs and delays for the Integrated Waste Treatment Unit (IWTU) at the Idaho National Laboratory, the Government Accountability Office (GAO) said Monday.
In the report, GAO says the Energy Department has not followed best practices that dictate cost estimates be “comprehensive, accurate, well-documented, and credible.”
Officials at the DOE Office of Environmental Management told congressional auditors they don’t yet have a cost estimate for re-engineering the IWTU to handle all the targeted waste. Instead, the nuclear cleanup office develops its cost estimates in phases. The first two of four re-engineering phases cost $150 million, and the agency lacks an estimate for phases three and four.
The Government Accountability Office best practices guide recommends “an exhaustive and structured accounting” of the potential expenses for developing and running a project over time. The Environmental Management office also fails to account for potential schedule slippage and, as a result, past timelines have been overly optimistic, the report says.
Decades of defense-related work at INL left behind two types of material treated as high-level radioactive waste (HLW) by the Energy Department: 900,000 gallons of sodium-bearing waste, as well as 1.2 million gallons of highly radioactive granular calcine waste.
Under an agreement with the state, DOE’s Office of Environmental Management must treat the material and ship it out of the state by 2035. The unit will convert liquid sodium-bearing waste into a solid via steam reforming – a process that involves using superheated steam and other gases inside a fluidized bed reactor.
But development of the IWTU, which would treat both types of waste, has been difficult. Although the facility was essentially finished in 2012 for $571 million, it has never worked as planned due to design problems, the GAO said in the report. The DOE nuclear cleanup office has worked since then to re-engineer the facility.
As of February, total construction and re-engineering costs amounted to $1 billion.
Energy Department officials in Idaho say the IWTU’s final trial run for sodium waste, this time using actual radioactive waste rather than a simulant, will start in early 2020. But Environmental Management and facility contractor Fluor Idaho have yet to decide if an extensive maintenance period to implement other tweaks is needed before the final test, the GAO said.
Treatment of the calcine waste requires construction of new equipment and is not expected to start until early 2024. The Energy Department plans to procure a contract for construction of the facilities this month and then start building the calcine treatment equipment in September 2020.
Waste from Treatment Unit Lacks a Clear Disposal Pathway
More challenges are ahead. For example, the Energy Department’s Waste Isolation Pilot Plant (WIPP) in New Mexico, the agency’s preferred disposal site for the Idaho sodium waste, is not currently authorized to take the material.
The state permit for WIPP currently prohibits disposal of sodium-bearing waste; federal law prohibits the underground salt mine from taking high-level waste; and there are also questions about existing capacity limitations, the GAO said.
High-level waste must be disposed of in a deep geologic repository such as Yucca Mountain unless the U.S. Nuclear Regulatory Commission approves an alternative disposal site, the report notes.
The Energy Department hopes its June reinterpretation of the definition of high-level waste could enable WIPP to take the material, the GAO said. Prior experience suggests any proposal to send HLW to WIPP would meet with public opposition.
If the agency uses its June reinterpretation to treat the sodium-bearing waste as non-HLW for disposal at WIPP, there is an increased risk of litigation, according to the GAO.
The principal deputy assistant energy secretary for Environmental Management, Todd Shrader, said Wednesday he has not reviewed the GAO report. He declined to say if DOE will seek to treat the sodium-bearing waste as something other than high-level waste once it goes through the IWTU.
The Energy Department is studying the possibility of treating 10,000 gallons of grouted wastewater from the Savannah River Site in South Carolina as low-level waste for disposal purposes. That is the agency’s current focus, Shrader said Wednesday at the DOE’s National Cleanup Workshop in Alexandria, Va.
In 2013, the Energy Department filed a request with New Mexico to modify WIPP’s state hazardous waste permit. The revision sought to allow sodium waste to be sent to the facility if DOE deemed the material “waste incidental to reprocessing,” which would clear the way for it to be treated as low-level waste. But the request was tabled after an underground radiation leak at WIPP in February 2014, which kept the facility offline for about three years.
In December 2018, New Mexico’s Environment Department approved a modification to the WIPP permit—sought by DOE and its site management contractor that will change the way waste volume is calculated to exclude empty space inside waste packing. According to DOE officials, this means that additional waste can be disposed of at WIPP under the existing statutory limit, GAO noted. The report also indicated the waste volume decision has been appealed, and is currently the subject of mediation.
The GAO report did not go into detail on the design problems at the IWTU, although the Energy Department has previously acknowledged problems with the primary reaction vessel for the sodium waste, dubbed the denitration mineralization reformer.
When it comes to calcine waste disposal, DOE is testing options for removing the waste from its storage bins, a precursor to treating or packaging the waste for disposal. But the agency lacks “a strategy or timeline for determining its next steps” in treatment and disposal, the GAO said. Without a strategy, DOE’s chances of getting the waste out by Dec. 31, 2035, said the government watchdog.
