The federal government’s nuclear health-and-safety watchdog has raised concerns about whether an exhaust tunnel at the Savannah River Site’s nuclear materials processing facility can withstand the impact of an earthquake.
The concern is related to two ongoing issues at the facility that have not yet been remedied, the Defense Nuclear Facilities Safety Board (DNFSB) said in a recently released Nov. 23 site report for the Department of Energy facility in South Carolina. One involves degradation in a duct tunnel and the other questions about sustaining power to the ventilation system.
H Canyon is used to convert materials such as highly enriched uranium (HEU) into diluted forms that can be repurposed as an energy source. The canyon first began operations in 1955 and is suffering degradation in various areas, SRS management and operations contractor Savannah River Nuclear Solutions (SRNS) explained in a recent email. Company spokeswoman Barbara Smoak said a 2017 inspection showed that the H Canyon exhaust tunnel, a large concrete ventilation duct connecting the facility to its air ventilation system, is either eroding or corroding.
Smoak said about 2 inches of the 20-inch thick duct walls had either “eroded from the constant flow of air over its 65 years of service, or corroded since the air contains low levels of nitric acid.” Either way, the issue now has the contractor and DNFSB wondering if the duct could withstand a catastrophic event, such as an earthquake.
“Complex structural analysis calculations to evaluate this condition are in progress and are scheduled to be completed in mid-year 2019.” Smoak said. The site is looking into how to fix the problem. There are no current cost projections for the work at this time.
The second issue raised by the safety board stems from a recent Energy Department review of H Canyon. The facility has two diesel trains that are expected to serve as a backup power source for the ventilation system in the event of an earthquake. But the DOE review concluded that assuming both of the generators would remain operable “is not consistent with the DOE safety analysis guidance,” Smoak said.
As a result, SRNS is looking into how the system would function if one of the generators was unusable during an earthquake. The issues are not expected to slow work, and there are no planned infrastructure upgrades at H Canyon at this time.
