DNFSB’s “H-Canyon Justification for Continued Operation” – letter dated September 7, 2018 and attached report linked here
>>> The question begs: Should H-Canyon be closed until there is full resolution of this safety matter?
The problem is it’s unknown if the deterioration in the H-Canyon Exhaust (HCAEX) Tunnel will impact safe operation and if the measures put in place under the interim “justification for continued operation” (JCO) are adequate.
“Conclusion. SRNS implemented a JCO in February 2018 because the ability of the HCAEX Tunnel to perform its safety class safety function is indeterminate. The JCO includes new administrative compensatory measures, elevates the functional classification of existing controls, and allows for H-Canyon to receive and process certain spent nuclear fuel. One of the new administrative compensatory measures, the Transfer Protocol, is credited to mitigate the radiological dose consequence for the co-located worker and MOI as a result of a seismicinduced failure of the HCAEX Tunnel and process piping. The Board’s staff reviewed the new control set and identified several issues. SRNS has not properly implemented the Transfer Protocol compensatory measure, and has not demonstrated it to be reliable. Additionally, SRNS has not designated the portable air compressor supporting the Seismically Qualified Vessel Air Purge Response as a safety class SSC, despite the fact that it serves a safety class function. The staff team concludes these safety issues should be resolved to ensure the continued safe operation of H-Canyon while the HCAEX Tunnel’s ability to perform its safety class function is indeterminate.”