The jury’s out on that question. the Defense Nuclear Facilities Safety Board (DNFSB) thankfully continues to monitor the status of the aging H-Canyon’s radioactive air discharge tunnel
DNFSB weekly report for November 23, 2018 linked here
“H-Canyon: Two existing issues call into question the ability of the H-Canyon Exhaust (HCAEX) System to perform its safety class function of protecting the public from a radiological release caused by several events initiated by a design basis earthquake (DBE). The first issue is the HCAEX Tunnel’s ability to withstand a DBE is indeterminate, which is the subject of the December 16, 2015 is Board Letter to DOE and the declaration of a positive unreviewed safety question (USQ) in June 2017 (see 6/30/17 report). The second issue is the more recent identification that the HCAEX System does not meet the single point failure criteria during and after a DBE for safety class components (see 11/2/18 report). SRNS personnel submitted a safety basis strategy to DOE-SR with a proposed revision to the H-Canyon post-seismic control strategy such that it would not rely on the HCAEX System to protect the public during and after a DBE. Several of the proposed control changes were discussed in the 10/19/18 weekly report. The safety basis strategy requests DOE-SR’s concurrence by November 30. SRNS expects to have the H-Canyon safety basis revised and submitted to DOE-SR in June 2019.”