FOR IMMEDIATE RELEASE – 05/28/2012
NEWS AND COMMENTARY
NEC COMMENTARY: It is so often-the simple things that bring down complicated mechanisms.
In a May 24th report, Entergy VY discovered a missing conduit seal – opening below-grade electrical switch rooms to flooding via an exterior manhole chamber. It is likely that the missing seal was discovered during an examination of VY flooding vulnerabilities, recently ordered by NRC in response to lessons from Fukushima. Otherwise, the missing seal might not have been discovered until flood-induced failure of the safety related components listed in the report.
There is some indication from news reports of the Fukushima site accident response that flooding of electrical components in below-grade structures contributed to power loss to vital safety systems.
NRC has issued numerous warnings to its licensees that flooding of electrical equipment (cables, switches, relays, etc.) not designed for submerged duty can lead to, in the worst case, station blackout and loss of accident mitigation systems. However, on the day before the Fukushima disaster, March 10, 2011, the US Nuclear Regulatory Commission turned down New England Coalition’s final contention regarding Entergy Vermont Yankee’s License Renewal Application – that Entergy had inadequate aging management plans for non-qualified electrical components vulnerable to submersion. Two weeks later, despite the pleas of the Vermont Congressional team to sort out the Fukushima accident first, NRC went ahead to issue the renewed VY license.
New England Coalition recently objected that NRC’s 2011 Annual Assessment Letter for VY should not, based on the scope of its annual inspections, claim that the overall plant was operated in a manner to protect the public health and safety. NRC typically inspects only 5 to 10% of licensee activities; and systems, structures, and components (even on paper). In this case the safety significant seal was among the 90 to 95 percent uninspected post-Fukushima and, likely as not, for many years before.
Just so we can stop laughing about tsunamis on the Connecticut River, the concern here is simple flooding; not monster waves. In May 2010, NRC reported that Entergy VY had found several electrical cable vaults (manholes) flooded, exposing non-qualified electrical cables to submergence. NRC permitted the issue to be buried in Entergy’s Corrective Action Program, the activities of which are not reflected in public documents; darkness once again falling on the Vernon shores of the Connecticut.
New England Coalition
- Submitted by NUCBIZ on May 25, 2012 – 15:32
10 CFR Section:
50.72(b)(3)(v)(A) – POT UNABLE TO SAFE SD [potentially unable to safely shutdown]
50.72(b)(3)(v)(B) – POT RHR INOP [potentially residual heat removal inoperable]
50.72(b)(3)(v)(C) – POT UNCNTRL RAD REL [potential uncontrolled radiation release]
50.72(b)(3)(v)(D) – ACCIDENT MITIGATION [ potential to interfere with accident mitigation]