ALERT at North Anna ended

Dominion has announced the end of the alert status at North Anna after having started one reactor coolant pump at each of the two nuclear plants at that site.



1:45 PM Eastern Wednesday August 24, 2011

ATOMIC POWER REVIEW

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US Nuclear Plant SITREP

Here I will provide, as completely as possible, the situation at the US nuclear plants affected by yesterday's earthquake. I should say "affected," in quotes, because only North Anna had any effect whatsoever so far as is now known.



The reporting earlier on this site vis a vis North Anna holds; the two reactor plants are safely shut down, offsite power has been restored and the site is still in Alert status -- second lowest of the NRC notification levels. No evacuations occurred.



There are a slew of NRC notifications, exactly as I had indicated yesterday. I will summarize these below.



University of Maryland - TRIGA reactor - NOUE due to seismic event, and later the licensee exited the event.



NC State University - PULSTAR reactor - NOUE due to seismic event. Licensee terminated event status simultaneous with notification of NRC.



Peach Bottom 2 / Peach Bottom 3 - GE BWR/4 - Delta, Pennsylvania - NOUE due to seismic event. Declared at 1401 and cleared at 1750. NOUE data indicates receipt of .01G acceleration alarm which is short of the .05G operating basis earthquake alarm. Both units remain at power as before; no other trips or actions occurred.



Calvert Cliffs 1 / Calvert Cliffs 2 - CE PWR - Lusby, Maryland - NOUE due to seismic event. Both units maintained full power. Event cleared at 0005 hours.



Limerick 1 / Limerick 2 - GE BWR/4 - Limerick, Pennsylvania - NOUE due to seismic event. Both plants remain at 100% power. Event terminated at 1819 hours. No plant actions / trips occurred.



Susquehanna 1 / Susquehanna 2 - GE BWR/4 - Berwick, Pennsylvania - NOUE due to seismic event. Licensee terminated event at 2110 hours. No plant actions / trips occurred.



Palisades - CE PWR - Covert, Michigan - NOUE due to seismic event. Event status terminated at 1825 hours. No trips or actions.



Oyster Creek - GE BWR/2 - Forked River, New Jersey - NOUE due to seismic event. Event status terminated at 1801 hours. No trips or actions.



Surry 1 / Surry 2 - WE 3-loop PWR - Surry, Virginia - NOUE due to seismic event. Both units at 100% power, no trips or actions. Event terminated at 1752 hours.



Three Mile Island 1 - B&W PWR - Middletown, Pennsylvania - NOUE due to seismic event. Terminated at 1730 hours, with Unit 1 at 100% power with no trips or actions. Licensee also reported this for No. 2 plant, which is essentially in permanent SAFSTOR mode since the 1979 accident, is defueled and inoperative.



Salem 1 / Salem 2 - WE 4-loop PWR - Hancock Bridge, New Jersey - NOUE due to seismic event. No trips or effects; event cleared at 1941 hours. Licensee declared this event and the event for the following plant as the SAME NOUE event and cleared all at the same time:



Hope Creek - GE BWR/4 - Hancock Bridge, New Jersey (see above.)



Shearon Harris - WE 3-loop PWR - New Hill, North Carolina NOUE due to seismic event. Event cleared at 1757 hours with no plant effects or trips.



Cook 1 / Cook 2 - WE 4-loop PWR - Stevensville, Michigan - NOUE due to seismic event. Event cleared at 1723 hours. No plant effects or trips.



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The first two in the listing here are University training reactors, for those not familiar while the rest are power reactors from all four major reactor vendors. As noted yesterday, all have declared Notification Of Unusual Events and then cleared them except for North Anna.



Here is the text of the notification for North Anna, which does NOT include any relief valve lifting. While not particularly important, this is good from the standpoint that anti-nuclear folks like Michio Kaku have less to get hold of and misinterpret. The report:



ALERT DECLARED DUE TO AN EARTHQUAKE IN THE AREA AND A LOSS OF OFFSITE POWER



At 1403 hrs. EDT, North Anna Power Station declared an Alert due to significant seismic activity onsite. The Alert was declared under EAL HA6.1. Both units experienced automatic reactor trips from 100 % power and are currently stable in Mode 3. All offsite electrical power to the site was lost. All four emergency diesel generators (EDG) automatically started and loaded and provided power to the emergency buses.



While operating, the 2H EDG developed a coolant leak and was shutdown. As a result, the licensee added EAL SA1.1 to their declaration.



All control rods inserted into the core. Decay heat is being removed via the steam dumps to atmosphere. No personnel injuries were reported.



More details will be posted if necessary on earthquake related events. The nuclear industry will now be gearing up to face any effects of the approaching hurricane Irene heading for the east coast of the United States.



We might note the total non-event status which finally resulted from the flooding affecting Fort Calhoun and Cooper nuclear stations in the middle of the nation, and add to that a number of other non-events (tornado touchdown recently at Surry, and another in the switchyard at Browns Ferry, or perhaps the direct hit of Hurricane Andrew some time back on Turkey Point) which various sources predicted would be disasters but were not. It is in this light we look toward the approach of another hurricane, not ignoring the effects but knowing that the plants and operators stand prepared.



10:45 AM Eastern Wednesday August 24, 2011

ATOMIC POWER REVIEW

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US Earthquake Update: 4:40 AM Wednesday

Offsite power at North Anna Station has been restored, according to the Wall Street Journal site.



According to the report, the diesel generator that failed was shut down because of a coolant leak - but another was started, keeping four running at all times. This is in contrast to earlier reports. Thus, the plant never had three running at one time for very long at all.



The plant remains shut down and in alert status.



It might be interesting to note that Dominion's Bear Garden power station also shut down due to the quake -- and this is a conventional station. See here.



4:47 AM Eastern Wednesday August 24, 2011

ATOMIC POWER REVIEW



UPDATE: The WSJ story is taken from Dominion's press release, seen HERE.

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More Virginia Earthquake information

At this moment, we do not have any actual operational details from the North Anna Power Station other than that which we have reported. Briefly, those details can be consolidated as the following:



-Both reactors are shut down safely.

-Both reactors shut down when offsite power was lost.

-Offsite power was apparently lost as a result of an on-site switchyard fault.

-North Anna station is presently on diesel power.

-All four site diesels started normally. One stopped later on at some point.



We will likely have some better details from press releases and from reporting to the NRC tomorrow. For the moment, all we can do is speculate. Several further things are fairly clear;



-There will be a report to the NRC of an unusual event; the quake, and LOOP. The stoppage of one diesel may be a further event.

-Although not reported, hinted at, or speculated anywhere else, it should be noted in a prophylactic mode only that there may have been a lifting of either a primary or a secondary relief valve if the plants tripped from at or near full rated power. This is a common occurrence -- and by that we might just go ahead and say that we mean BOTH full reactor scrams and turbine trips from full rated power, and very brief lifting and reseating of relief valves when this happens on pressurized water plants. Many plants each year suffer turbine trips (a full load reject) from 100% power when inclement weather takes out the electrical network; for example, Surry had this exact thing happen this year and so did a number of others.



We report these two things here only because either or both would / will get press coverage and we want our readers to EXPECT them to be reported.



We might also at this point note that we're already aware of the declaration of an Unusual Event at at least six other nuclear plant sites. This is required to be declared as a result of the earthquake; this declaration is an acknowledgement of the earthquake being detected at the site or in the vicinity, and is NOT a declaration that anything unusual or problematic has occurred at the site. With the sole exception of North Anna, all of the plants that today declared UE's as a result of this earthquake have, as we understand it, cleared the conditional declaration. In point of fact none of the plants altered operation one bit, again except for North Anna.



One of the plant sites we understand declared, and then cleared, Unusual Event status is the Three Mile Island (Unit 1.) Do not be surprised when these UE reports hit the press tomorrow after appearing at the NRC site or in owner-operator press releases and then get legs.



Now, getting back to North Anna; I have some preliminary findings here, and some good solid data from the ANS Social Media List, on just what kind of quake the plants at North Anna are designed against and as soon as the USGS puts out some data in some form that people can understand (in other words, accelerations by location and not effects in Modified Mercalli scale, which is practically useless in comparing plant design data that's given in both accelerations in fractions or multiples of "g" or else in the old Richter scale) I will report on the comparison of those data here. For now, I might say it is too early to determine just what the acutal accelerations experienced on site were although it does appear that the plant was within seven to nine miles of the epicenter of a fairly shallow 5.9 Richter / VII Modified Mercalli quake. (Note that the VII region of damage as indicated graphically by the USGS for this quake is quite small, and on the latest USGS "Cities affected" list there is only one city/township in the VII range at all, the rest being less... but which oddly enough is the city North Anna Station is located in.)



Once some hard data comes in from the site's owner-operator we can make some further commentary on plant actions and conditions, but at this moment no news is good news and considering the plant capabilities (Westinghouse PWR) heat removal should be no problem. I will report again with any news, or any NRC posts, or owner-operator releases for the press as soon as I'm aware of them.



10:25 PM Eastern Tuesday August 23, 2011

ATOMIC POWER REVIEW

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US Earthquake information

According to the wires, and good inside information, there was only one nuclear power plant affected by today's earthquake: North Anna station, which comprises two nuclear power plants. No unsafe condition exists. The plants were shut down quickly and safely.



ANS NUCLEAR CAFE has a good update of the information regarding the quake.



Both reactors at North Anna, operated by Dominion Power and located about 40 miles northwest of Richmond, Virginia, are Westinghouse three-loop pressurized water reactors. Their construction was begun in 1971. The plants are shut down safely and are being supplied power by three of the four onsite diesels.



SEE HERE FOR ANS NUCLEAR CAFE STATUS REPORT.



More details as they're available; note the range of nuclear blog links on this site for further information. However, let's post this: NO severe situation exists at the plant at this time.



Below, both of North Anna's reactor containment buildings are visible in this shot provided by Dominion.







7:10 PM Eastern Tuesday August 23, 2011

ATOMIC POWER REVIEW



UPDATE: {8:50 PM Eastern Tuesday} Thanks to Dan Yurman, we are now aware that the shutdown at North Anna was automatic, due to LOOP (Loss Of Offsite Power) due to some problem in the electrical switchyard at the plant. Loss of external power triggers an automatic shutdown. At this time, approaching two hours after the first post and many since the quake, there are still no reports of any serious matters at the plant. Many of us are monitoring the situation and reports will appear here and at the fine sites linked at the right of this blog.

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