Updated safety documents for a ventilation tunnel at the Savannah River Site’s H Canyon facility are expected to be approved this summer and implemented in the fall, according to the Department of Energy.
The documents should reflect a different approach to how the 310-square-mile site will handle incidents at the facility during an earthquake or other emergency. Specifically, they should detail ways to prevent impacts from seismic events to the tunnel, rather than the current standard of mitigating the impacts once an incident occurs.
Currently, the tunnel is connected to sand filters that remove more than 99 percent of airborne contaminants from the processing facility. The filters are required to function during an earthquake to prevent material from spreading. But under the updated safety standards, workers would take more proactive measures, such as increased attention to piping to prevent leaks and ensuring tanks at H Canyon aren’t leaking material. “The function of the H Canyon exhaust air tunnel would not change. It would still direct H Canyon air to the sand filters, it would just not be relied upon to do this during an earthquake,” said SRS spokesperson Monte Volk.
There are no cost projections or infrastructure upgrades currently planned for the tunnel.
The H Canyon air tunnel is a large, 20-inch thick concrete ventilation duct connecting the facility to its air ventilation system. Concerns on the tunnel’s viability were first raised in a June 2017 report from the Defense Nuclear Facilities Safety Board. The board cited degradation of the tunnel wall and questioned its ability to withstand an earthquake.
In November 2017, the Energy Department approved a justification for continued operations, Volk said. That has allowed work to continue at H Canyon while regulators update the safety standards. The approval has enabled H Canyon, the site’s nuclear processing facility, to continue treating materials such as highly enriched uranium. Once the updated safety measures are approved, they will be implemented later this year, Volk said.
While processing continues, the Savannah River Site has been updating two key safety documents for the H Canyon air tunnel. The documented safety analysis evaluates potential hazards during design, construction, operation, and eventual cleanup. The technical safety requirements document covers standards that ensure facilities are operating properly and within acceptable limits.
To update the documents for the air tunnel, Volk said workers are recalculating H Canyon’s sustainability to provide a more realistic assessment of its ability to withstand the force on an earthquake. They are also working to prevent the hazardous release of radioactive materials during an accident, versus the current pathway of limiting how much of the material gets released.
Updated versions of the documents are not available. The Energy Department is expected to approve them this summer, though a firm date has not been set.
