We all watched in somewhat lurid fascination the events yesterday when a 6.0 earthquake occurred within 4 miles of the two reactors at North Anna in north-central Virginia. In addition to causing those reactors to undergo emergency scrams, buildings from Richmond through Baltimore and D.C. to New York City were evacuated due to the eastern U.S. geology that propagates seismic events to great distances through bedrock. The quake was felt from Toronto to Charleston, and west to western Ohio. And two nuclear plants in Michigan were among the 10 that reported "unusual event" notifications to the NRC, the first level of incident indicating a possible compromise of safety systems.
Keeping track of news and official reports yesterday well into the evening hours and catching up this morning, I noticed several odd discrepancies and informational twists I thought ought to be compiled for posterity while they're fresh.
North Anna
Ah, North Anna. When my hubby got out of the Navy in early 1975 and started looking for work in the midst of a deep recession, VEPCO was hiring its initial health physics crew for the first of their four planned reactors in the beautiful Virginia countryside, even though it would be three more years before the first unit was completed and brought on line. The pay was decent, so he hired on and my brother came to live with us on a 700-acre farm in Orange County, worked construction while studying the Argon National Labs HP course for certification.
All that existed of what would eventually become two PWR reactor plants (the other two were eventually cancelled) at the time was a nice new visitor's center on a bluff overlooking a gigantic hole in the ground - the 'pit' for the unit 1 reactor and containment. Seems the brilliant siting team from VEPCO and its NRC pocket[book] protectors had managed to place not just one, but all four planned reactors smack dab on top of a 15-foot wide geological fault that wasn't discovered until they started blasting into the bedrock for the pit. Now, you or I would probably have gone back to the drawing board and moved the plants over 30 feet or so, so they wouldn't be right on top of the darned thing in a fairly active earthquake zone. I mean, they really hadn't started yet, it wouldn't have been that hard.
But noooo… as with all things civilian nuclear, the sub-geniuses decided they could keep things just as they were (since they already had approval), right smack dab on top of the fault. The NRC pocket[book] protectors instead okayed a not-so brilliant plan to wire the earth together in the pit with some 'extra' rebar they figured would keep the fault from moving in the event of a quake. I recall vividly standing on the observation platform outside the visitor's center over the pit watching ant-like construction crews setting all that 'extra' rebar into the base where concrete would be poured. And I remember laughing to myself loudly enough to draw some confused glances from others on the deck, about how painfully stupid the idea was. It was my very first realization of how the civilian nuclear industry is nothing like Rickover's Navy.
Shortly following yesterday's quake under North Anna's nukes, the Richmond Times-Dispatch issued a news update which included this information:
Dominion Virginia Power shut down its two North Anna reactors as a result of the earthquake, according to the company.
"The earthquake was felt at the North Anna Power Station and the reactor operators, following procedures, shut down the reactors," said company spokesman Jim Norvelle. "It was a manual shutdown."
The update makes it clear that Dominion had already made its emergency declaration to the NRC, and included some statements by an NRC spokesperson as well about response. But [my] bolded part of the above quote is from the Dominion "company spokesman," and unequivocally states that the operators shut down the reactors manually when off-site power was lost.
I noted that because it tends to suggest that when the power went out, the circuit for automatic scram within seconds of the event may have been cut off as well. Which would present a significant safety issue for any PWR plant anywhere that experienced a station blackout. Unlike BWRs (like Fukushima's), these plants have control rods that enter the core from above rather than below. And while control rod drives have been required since TMI-2 for these reactors, if drive power is lost the rods can still be inserted by gravity by mechanically releasing them to fall if need be.
Because North Anna failed several points in its post-Fukushima inspection just a few months ago, I'm pretty sure the operators have been paying close attention. A good thing, because not all the identified problems were fixed yet. Including an emergency diesel generator that was inoperable. Anyway, no big deal, they scrammed.
But within an hour or two the story strangely changed. The Wall Street Journal reported something else entirely from a different NRC spokesman:
The North Anna Power Station, which has two nuclear reactors, is now using four diesel generators to maintain cooling operations. The plant automatically shut down in the wake of the earthquake.
"As far as we know, everything is safe," said Nuclear Regulatory Commission spokesman David McIntyre.
From this point forward the "Official Story" is that the North Anna reactors automatically scrammed, as opposed to having been manually scrammed by the operators as the utility's own on-site spokesman reported. There's a reason for this discrepancy, but it's one that is technical and I won't get into it here because there's more fun stuff below. Just keep it in mind, it may come up again in the very near future.
On a side note to this, the NRC today has been busy-busy assigning new resident inspectors to some plants down south. In each of the news releases it is noted that:
"At least two NRC resident inspectors are assigned to each U.S. commercial nuclear plant."
But North Anna apparently didn't have two resident inspectors yesterday. And hadn't had two resident inspectors for some time, since the new one wasn't announced to be replacing anyone. [NRC News 11-050.ii]
Two more inspectors were assigned, as announced in NRC News releases 11-409.ii and 11-051.ii at the Robinson plant near Hartsville, SC and the Summer plant near Columbia, SC. Interestingly, neither of these South Carolina nuclear plants issued "Unusual Event" notifications to the NRC yesterday after the quake, as did so many other plants from North Carolina to New York to Michigan. I mention these notifications because it appears to me that the NRC is trying to quickly cover its regulatory ass for not bothering to follow its own procedures per number of on-site inspectors THEY require to be at operating nuclear plants in this country. Keep this activity in mind as well, since it may also come up again in the near future.
There is also an odd discrepancy about the off-site power that North Anna lost during the earthquake yesterday which led to the emergency scrams. I haven't been able to track the details of this one yet, but I'm sure there will be articles in coming days from which to glean a few of those details. That first Richmond Times-Dispatch update didn't specify anything specific about the off-site power supply other than that it was lost during the earthquake. The early WSJ article linked above also didn't specify specifics about the power loss.
The later NRC statement [11-153] - the one that contradicted Dominion's information that the scrams were manual rather than automatic - did include a previously missing detail. It said:
North Anna declared its Alert, the second-lowest of the NRC's four emergency classifications, when the plant lost electricity from the grid following the quake just before 2 p.m.
North Anna got its off-site power supply from the grid? That would be a bit unusual, given the requisite power needs for two multi-megawatt reactors that use far, far more electricity than is available from the standard grid supplying power to the small towns, villages and farms in the region and managed in 'grid' blocks throughout the eastern United States. Especially since according to all reports yesterday, the grid never went down. Typical reports were like this one from TriCities.com in Bristol, Tennessee:
No casualties, damage or significant power outages after earthquake.
There were a few downed house-size lines here and there, power quickly restored in the usual manner. The picture below was taken inside Louisa County High School just minutes after the earthquake -
Notice if you will that the lights are ON. As they remained ON in downtown Mineral, the rest of the county, and everywhere else on the east coast that felt and responded to the quake.
Power lines coming into a reactor complex are quite like the power lines going out. Those big T-scaffold mega-lines carrying huge amounts of electricity. For most plants this isn't regular grid power, it's dedicated lines from some other big power plant somewhere else - like, say, Surry (in this instance). But Surry remained operating at 100% during and after the earthquake even though it did file the requisite "Unusual Event" notification to NRC. We've heard nothing of whether any big coal plants were taken out by the earthquake, and I presume we would have if that had occurred. Heck, if that had occurred, then portions of the actual grid really would have gone out.
There was a momentary interruption in Richmond when North Anna went down, as the plant is one of its main suppliers. It was quickly switched to a different grid source and there were no reports of significant outage in that city. Thus I am left to wonder why it took many hours for off-site power to be restored to North Anna so it could go off its 3/4 supply of diesel generators. Will do some more research when I have time to try and track down where their off-site power originates and why it was interrupted. I'm just saying here that it wasn't the grid serving this region of Virginia.
This is too long already, though there's more interesting factoids piling up I'll deal with at another time. Just wished to take note of some highly suspicious statements and actions by the NRC in response to this situation. They've been caught lying down on the regulatory job before, and today's actions per inspectors at North Anna and the two South Carolina plants speak to some scrambling they hope nobody notices. I presume they also figured no one would notice their contradiction of the utility itself on the scrams, or on the reason for the station blackout.
This diary is to document that I noticed.