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Wednesday, August 24, 2011

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

2 comments:

  1. I'm still blown away that these plants aren't even provided the option of running/cooling off their own generated power.

    James Greenidge

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  2. @jimwg: Well, they are provided that capability in the sense that all of the other plant cooling systems can run off the diesels. In pressurized water plants, though, you need offsite power to run the main coolant pumps (also called reactor coolant pumps - depends on vendor which term you use.) As we see today in the Dominion press release the plant was being cooled by what we call "NC" or Natural Circulation, where the water in the primary flows by simple convection -- no pumps -- to the steam generators and back. You can then take the heat out of the secondary side water in the steam generators. You would need, by the way, a lot more standby power to run main coolant pumps -- on the largest and highest capacity PWR plants each main coolant pump develops roughly 12,000 horsepower... and on a four loop plant you'd have four of them.

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