The Hanford Advisory Board again stressed its concerns about leaking tanks in two pieces of written advice sent to the U.S. Department of Energy on Thursday.
In the second day of a virtual meeting, the board voted to tell DOE that it wants the feds to prioritize removal of 3.37 million gallons of liquid wastes from 149 single-shell underground tanks.
Central Hanford is host to 56 million gallons of highly radioactive waste in 149 old single-shell tanks and 28 newer, but still old, double-shell tanks. Sixty-eight single-shell tanks and one double-shell tank are suspected or confirmed leakers. The waste — byproducts of three different plutonium purification processes used during World War II and the Cold War — consists of fluids, thick sludges and chunks.
Most of the liquid wastes have been pumped to the double-shell tanks to await solidification into glass-like cylinders: a process scheduled to begin in late 2023 with lower-level radioactive waste and last until 2066. However, 3.37 million gallons of fluids remain in the single-shell tanks.
The latest new leak was made public in April 2021 in single-shell tank B-109.
“More (single-shell tanks) are certain to leak during the next four decades. Allowing them to leak unabated while they await their turn for retrieval is inconsistent with the values and expectations of all Hanford stakeholders as well as the Hanford Advisory Board [HAB],” said the HAB advice document approved Thursday. “The Board believes as a policy that a more organized, consistent, and timely approach to identifying and proactively abating leaking single-shell tanks is critical.”
The HAB document called for the 3.37 million gallons of fluids in the single-shell tanks to be removed as soon as possible. It also recommended that DOE develop a comprehensive plan to detect leaks in single-shell tanks, and how to analyze and fix them.
Future leaks should be analyzed so that DOE can understand the extent of the leaks, the chemical composition of the leaking wastes, the speed that the fluids are expected to reach the aquifer and then the Columbia River and the risks to human health, the HAB said.
Meanwhile, the HAB also approved a second advice document Thursday, which recommended cleanup priorities for Hanford. The board split those priorities into two categories, with top priorities dubbed “critical” and the second priorities called “important.”
The HAB said “critical” priorities include:
- Handling leaks from the single-shell tanks.
- Finish upgrading the Waste Encapsulation Storage Facility and to move underwater cesium canisters from wet storage to dry storage at the facility.
- Upgrade and expand pump-and-treat stations for the site’s heavily contaminated groundwater.
- Conduct soil remediation so that that clean fill is not required to support operation of central Hanford’s huge contaminated waste landfill.
- Finish cleanup of the 324 Building site — a former radioactive materials lab — nestled next to northern Richland.
- Ensure enough funding is in the pipeline to operate Hanford’s first low-activity-waste vitrification plant — due to go online in late 2023 — and to keep other major cleanup activities on their legally binding schedules.
- Ensure worker safety and training meet top standards, and to ensure older employees reaching retirement are replaced by trained younger employees.
The board classified other priorities as “important:”
- Building new double-shell tanks before more double-shell tanks spring leaks.
- Ensure Hanford’s shipments to the Waste Isolation Pilot Plant in New Mexico remain on schedule.
- Ensure all secondary wastes from cleanup projects have plans to be treated and disposed of.
