U.S. Nuclear Power Plants Weather the “Polar Vortex”

 Neil Sheehan
Public Affairs Officer
Region I

When the temperatures plunge into Arctic territory, there are few parts of the infrastructure not impacted in one way or another. Pipes can freeze, roads and bridges can quickly ice over and car batteries can go dormant.

Now, with what meteorologists are calling a “polar vortex” flooding much of the country with a blast of frigid air, precautions are being taken to guard against potential effects. Count U.S. nuclear power plants among those facilities gearing up for the coldweather2014 version of the Big Chill.

As of Monday afternoon, no plants were reporting any problems of note related to the frigid extremes, but ongoing checks will be in order to ensure that remains the case.

The NRC’s regional offices in the Midwest and Northeast are keeping an eye on plant owners’ responses to the unusually low temperatures. Plants in the affected areas have entered off-normal procedures that entail minimizing regular surveillance activities and increasing the frequency of checks and walkdowns (visual evaluations) of equipment that could be impacted by the temperatures.

NRC Resident Inspectors, who are assigned to specific sites, will continue to monitor the situation. The inspectors use an “Adverse Weather Protection” inspection procedure to guide their assessments of whether plants are ready for extreme temperatures, including the bitter cold. Those reviews are typically done at the start of the season.

“As applicable, verify cold weather protection features, such as heat tracing, space heaters, and weatherized enclosures are monitored sufficiently to ensure they support operability of the system, structure or component (SSC) they protect,” the procedure states in part.

It also instructs inspectors to perform walkdowns to verify the physical condition of weather-protection features.

The NRC has long recognized the need for nuclear plant owners to be on guard for extreme cold-related issues. Along those lines, the agency in January 1998 issued an Information Notice on “Nuclear Power Plant Cold Weather Problems and Protective Measures.” Although such notices do not require a specific action or written response, they do serve to make plant owners aware of possible concerns.

For example, the Information Notice discussed an ice plug that formed on Jan. 8, 1996, at the Millstone Unit 2 nuclear power plant in a service water strainer backwash drain line. Service water refers to water taken from a nearby source of water — be it the ocean, a lake or river — used for cooling purposes in the plant and then returned.

To prevent a recurrence of the problem, the plant owner changed an operating procedure to ensure closer monitoring when service water intake structure temperatures drop below 40 degrees Fahrenheit and to make use of portable heaters or go to manual operation of the strainers.

Nuclear power plants are designed to withstand weather extremes. Nevertheless, NRC inspectors will be on hand to keep a close watch on plant conditions during the “vortex” and beyond.

Update: Nebraska was not exempt from freezing temperatures. On Jan. 9, around 9 a.m. central time, operators shut down Fort Calhoun Station to repair one of six sluice gates after a plant worker discovered ice forming preventing it from closing. The gates, located at the intake structure, control the flow of water from the Missouri river into the plant. All six gates must be functional for the plant to be allowed to operate as part of the flood protection strategy. On Friday, Jan. 10, workers corrected the problem.

Early Sunday morning, during plant start up, operators had to manually shut down the reactor after a control rod would not move as required to due a faulty motor. Sunday, workers repaired the motor and OPPD is currently restarting the plant.

Lara Uselding
Public Affairs Officer
Region IV

Author: Moderator

Public Affairs Officer for the U.S. Nuclear Regulatory Commission

26 thoughts on “U.S. Nuclear Power Plants Weather the “Polar Vortex””

  1. Hey Neil,

    Seems your post wasn’t just promotional it was premature.
    See the Fort Calhoun LERs below the reactor is shutdown due to ice.
    Are you planning a retraction; a rewrite or an update?
    In the future, perhaps NRC can stick to regulating the nuclear
    reactors rather than lauding them.

    Jim Riccio

    To top of page
    Power Reactor Event Number: 49703
    Facility: FORT CALHOUN
    Region: 4 State: NE
    Unit: [1] [ ] [ ]
    RX Type: (1) CE
    NRC Notified By: SCOTT MOECK
    HQ OPS Officer: DAN LIVERMORE Notification Date: 01/09/2014
    Notification Time: 06:42 [ET]
    Event Date: 01/09/2014
    Event Time: 03:15 [CST]
    Last Update Date: 01/09/2014
    Emergency Class: NON EMERGENCY
    10 CFR Section:
    50.72(b)(3)(v)(B) – POT RHR INOP
    Person (Organization):

    Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
    1 N Y 99 Power Operation 96 Power Operation
    Event Text

    ” At 2230 CST on 1/8/14 during operator rounds it was self identified there was a block of ice formed on the shaft and top of one of the intake structure sluice gates. This has bent the sluice gate operating shaft. At 0315 CST on 1/9/14 it was verified this gate could not be closed.

    “There are six intake sluice gates that are required to be able to close to act as flood barriers. The other 5 sluice gates are not affected by this condition.”

    The licensee informed the NRC Resident Inspector.

    To top of page
    Power Reactor Event Number: 49704
    Facility: FORT CALHOUN
    Region: 4 State: NE
    Unit: [1] [ ] [ ]
    RX Type: (1) CE
    NRC Notified By: SCOTT MOECK
    HQ OPS Officer: DAN LIVERMORE Notification Date: 01/09/2014
    Notification Time: 06:42 [ET]
    Event Date: 01/09/2014
    Event Time: 05:18 [CST]
    Last Update Date: 01/09/2014
    Emergency Class: NON EMERGENCY
    10 CFR Section:
    50.72(b)(2)(i) – PLANT S/D REQD BY TS
    Person (Organization):

    Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
    1 N Y 99 Power Operation 0 Hot Shutdown
    Event Text

    “At 0315 CST T.S. 2.0.1 was entered for all four Raw Water pumps being declared inoperable. The pumps were declared inoperable due to inability to close one of the sluice gates. There are six sluice gates and one is not functional.

    “At 0518 the technical specification required shutdown commenced.”

    The licensee notified the NRC Resident Inspector.


    “At 0900 CST 1/9/14 Fort Calhoun Station Unit 1 was manually tripped and entered Mode 3. Reactor Coolant System (RCS) cooldown to less than 300 deg F was commenced at time 1030 CST 1/9/14. The RCS temperature was less than 300 deg F at time 1433 CST. A press release has been issued.”

    The licensee informed the NRC Resident Inspector.

    Notified R4DO [Hagar]

  2. Thank you for that! We try to be as liberal as possible in posting comments so we don’t disrupt an ongoing conversation!


  3. A big thank you to both moderators for patiently putting up with blasts and chilling comments that are not directly related to the weather or the polar vortex. I was an offender. I have looked at the open forum section of the NRC Blog and it appears that some of my remarks should have been placed there. It appears that there is much open discussion on this forum and I will consider using it as well in the future.
    Thanks for all the info that you really didn’t have to provide that you did anyway.

  4. Japan’s independent Fukushima investigation committee only refers to evacuation-related deaths, with no deaths caused by radiation:

    http://warp.da.ndl.go.jp/info:ndljp/pid/3856371/naiic.go.jp/wp-content/uploads/2012/09/NAIIC_report_lo_res10.pdf (page 19 of the executive summary PDF)

    http://warp.da.ndl.go.jp/info:ndljp/pid/3856371/naiic.go.jp/wp-content/uploads/2012/08/NAIIC_Eng_Chapter4_web.pdf (page 72 of the main report PDF says no reports of even acute radiation injury)

    Scott Burnell

  5. Williamson says “inspection program planned out years in advance”. Hmmmmm

    When I was a government inspector, I found that besides procedures and paperwork that required the contractor to at least look at the specifications, and it required them to lie if they wanted to “willfully” break the regulations. Besides that, what I found above and beyond all else in effectiveness, was surprise inspections. And what I mean is…I didn’t keep a set schedule of where I would be and what I would be looking at, just by varying daily routine.

    I wasn’t there to make friends and to “work with them”. I was there to keep them on their toes. I would go as far as to tell people I had a camping weekend coming up, and then I show up on Saturday and see what the heck they were trying to get away with. It often worked. They sharpened their act for sure. Even showing up 2 hours earlier than my normal shift.

    And surprise inspections on maintenance logs, after boning up on the requirements. Amazing what you can catch. They didn’t like me, but I wasn’t there to make friends. The system worked. Of course, like Jackzo, I was sacked on a job for actually trying to enforce the rules and specs.

  6. Hey, don’t get me wrong. I never said that NRC inspectors just sit around. What I meant to say is that NRC inspectors might as well sit around for all the good they do.
    Case in point: All the nuclear plants that have been placed under Chapter 0350, enhanced NRC inspection. They get that dubious honor when they screw up, not as a result of any NRC inspection activity. When plants are placed under 0350 they are forced to look hard at their operation. They find many program, process, equipment, and management problems when they do. None of these problems were detected earlier by the regular, routine inspection effort of the NRC. These problems are serious and typically have been in existence for a long time. Pardon my French, but where the hell was the NRC?! What could have the NRC done differently or better to prevent a nuclear plant from getting into such a seriously degraded condition? Have you even asked yourself the question? Or do you feel you have achieved regulatory perfection and have absolutely no culpability whatsoever?!

  7. I agree, and there has to be a wise and tested balance between the effort needed to learn the specific plant, and the inspectors getting to cozy in the typical small community they live in, thus making it less likely to regulate properly. i.e. inspectors have to relocate fairly often, methinks 2 years max.

  8. While these comments originally were related to the blog post on the impact of cold weather on U.S. nuclear power plants, they are now largely “off topic.” Please feel free to continue this dialogue on our Open Forum section of the blog.


  9. Additional NRC resources needed where the rubber meets the road
    The NRC has well over 3000 employees. However only about 6% of these employees are actually stationed at the nuclear plant sites they “regulate”. Over 2000 “work” inside the DC beltway. The remainder are scattered in four regional offices around the country. I know the NRC does other stuff besides oversee the nation’s nuclear plants but with nuclear plant after nuclear plant getting into trouble perhaps additional NRC resources should be allocated to where the rubber meets the road.

  10. Resident NRC Inspectors Really Unimportant
    So you say NRC “resident” inspectors need to be able to respond to the nuclear plant they are assigned within 2 to 8 hours in case of an unforeseen event. That is a far cry from designated plant folks that have to be at the site on shift work or within 30-60 minutes of the site in case they are needed. I guess NRC “resident” inspectors really don’t need to “reside” close to the plants they are assigned. Gives you a clear indication of how unimportant “resident” inspectors are relative to nuclear plant safety.

  11. Viktoria and Neil, I’m requesting you rethink or reconsider your choice of wording in these blogs, which are basically PR work. My reading, especially by looking at the comments, is that the choice of words is leading to a public perception that plants are safe only because your inspectors are on-site (as in “4WD vehicles should be mandatory). Viktoria specifically at January 7, 2014 at 4:46 pm, your statement “NRC inspectors make sure that spent fuel at Kewaunee is safe”. Nope, it’s safe because Kewaunee employees make sure it is safe; the NRC inspectors verify. This subtle wording difference can have a significant impact on a reader, e.g. without your inspectors on site things aren’t safe. My comment applies to several such blog posts over the years, hurricanes on the E coast, earthquakes in VA, flooding on the Mississippi, even labor disputes. Your selected choice of words definitely leads a reader to assume without your on site presence things are not safe; hopefully you do not believe that. Thanks for any consideration.

  12. You have no idea what you’re talking about. The resident inspectors and their counterparts from the regional offices at NOT just sitting around waiting for something to happen. There is an ongoing, invasive inspection program that’s planned out years in advance to cover all aspects of plant operation. I know…I live it every day. Go read some of the endless stream of inspection reports, and see for yourself the level of detail they cover. It’s easy to sit behind your keyboard making broad, hazy, and unfounded generalizations that fit your worldview. Get the facts before you pontificate.

  13. Completely wrong the FOIA emails releases shows 5 took lethal doses during the R3 prompt criticality

  14. NRC inspectors sometimes arrive in time to get in the way of those qualified folks who are trying to do their jobs!

  15. NRC inspectors make sure that spent fuel at Kewaunee is safe. Even though nuclear plants undergoing decommissioning do not have resident inspectors, NRC inspectors specializing in decommissioning focus on areas of importance given the current plant configuration. Since there is still has fuel in the pool, spent fuel pool cooling is an important focus area. There are approximately 280 Dominion employees still onsite.

    As for Palisades, the NRC requires nuclear plants to monitor weather conditions, evaluate potential impacts on the plant and take necessary steps to ensure safety. NRC resident inspectors assess the plant’s handling of such issues. At this time, there is no evidence of significant power lines icing at Palisades. However, even if such a condition occurs and causes the loss of offsite power, the plant would continue to operate safely using other sources of power. As the plant workers evaluate extreme weather conditions they take steps to make sure that the
    equipment needed to respond to an emergency situation is available. NRC resident inspectors at Palisades have been monitoring the weather conditions and the plant’s actions to ensure safety.

    Viktoria Mitlying
    Senior Public Affairs Officer
    Region III

  16. No one in Japan died or was harmed from radiation exposure in Fukushima. No one!


  17. Thanks for the reply. So I take it then that for a 3 day cold snap that at least 2 resident inspector go to the plant and stay there, and alternate 12 hours shifts? So they have living quarters at the plant?

    I am just speculating, but don’t see any other way this would work out.

  18. The NRC expects resident inspectors to reach a reactor within two to eight hours of an unforeseen event. If an unpredictable weather event such as a tornado occurs, the NRC will ensure residents are on-site as soon as conditions permit. For forecast weather events such as hurricanes or this severe cold snap, we make sure a site has enough residents to last through the event before the weather sets in. We also have the ability to ask the state police for transportation assistance.

    Neil Sheehan

  19. Nuclear plants are inherently unsafe. Agreed that talented and dedicated people are what have kept things kind of OK. But in this new world of Corporate/Banker control and capture of government, the dozens of recent near misses speak truth, that our lucky streak of only 101 nuclear accidents since 1941 is going to exponentially higher.

    Lots of good work in Dry Casking, lets get on it.

  20. The NRC has nothing to do with nuclear plant safety.
    These plants are safe due exclusively to the fine men and women who operate and maintain them.
    Why? Because the NRC finds nothing amiss through their inspection efforts. Only if a plant has an operational incident does the NRC react. They get all over the plant if they screw up. That, as they say, is “dog piling on the rabbit”. Getting after a plant after the cow is already out of the barn. Until and unless the NRC gets to be a pro-active regulator, finding real problems through their inspection efforts, they are just another useless, wasteful, federal agency.

  21. Thats not true, Fukushima is the worst accident in human history, and its continues its damage. Far greater than all oil tanker combined.

  22. So Capt by your logic no ship should ever go out to sea. We know that there has been more damage done to the environment due to oil tankers sinking or leaking than has been caused by nuclear power plants.

  23. If you want to be 100% safe from nature all of the time, then find another planet to live on.

  24. Weather/Nature can destroy any land based nuclear reactor, any place anytime 24/7 and even though the NRC hopes for the best, that is a fact which can turn any one of our NPP’s into a Trillion Dollar Eco-Disaster like Fukushima!

    Just because it has not happened yet is not guarantee that it will not happen in the future!
    Ask The Japanese, they thought they had everything under control before 03/11/11 and now they know better since they are trying to deal with not one but three reactor meltdowns!

    Seasoned sailors know that no ship is 100% safe from the Sea, yet the NRC tells us that NPP are 100% safe from Nature! N☢T

  25. How many inspectors and plant workers are looking after Kewaunee, that plant still has plenty of HOT used fuel cooling off?

    Also with Palisades perfectly situated for massive deep lake effect snow, and power line icing conditions that may take weeks to fix, I just wonder what specific contingencies Entergy has put in place, any ideas or links?

    Thanks for running a credible site!

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