100% chance of reactor core damage if floodwaters went above 1010 ft. at Ft. Calhoun nuke plant, NRC said in 2010 — River now around 1,007 ft. and expected to rise

Published: June 27th, 2011 at 2:36 pm ET


The NRC in Action at Fort Calhoun, Monthly Review by Dave Lochbaum, June 27, 2011:

[…] During their routine inspections of weather protection readiness in 2010 […] NRC estimated there was a 100% chance of reactor core damage caused by a flood rising above 1010 feet.  The table at the top of Figure 1 provides the NRC’s assessment of the flooding risk while the table at the bottom provides the results from the risk assessment by Fort Calhoun Station (FCS).  The company contested the NRC’s estimate.  Its calculations showed that the chance of core meltdown was merely 19% for floods above 1010 feet and up to and including 1010.8 feet and only 23.9% for floods above 1010.8 feet to 1014 feet. […]

UCS cannot say that these NRC actions already prevented an accident at Fort Calhoun or that they will prevent one should the flood waters continue to rise.  However, the NRC did its job last year.  The NRC’s inspectors found that Fort Calhoun was supposed to be protected against floods rising to 1014 feet, but was not.  The NRC’s risk analysts determined that this deficiency was not academic — floods above 1010 feet had a 100 percent chance of core meltdown.  And the NRC’s managers used the agency’s enforcement process to compel the plant’s owner to remedy the shortcomings rather than merely debate their risk. […]

A Nuclear Plant’s Flood Defenses Trigger a Yearlong Regulatory Confrontation, New York Times, June 24, 2011:

[The water level at Ft. Calhoun nuclear plant] reached a height of nearly 1,007 feet above sea level at the plant yesterday. […]

Hydrograph, Missouri River near Blair, NE, Weather.gov, June 27, 2011:

Published: June 27th, 2011 at 2:36 pm ET


Related Posts

  1. Top Ft. Calhoun nuke plant official: To get to a disaster level floodwater would have to rise 3.5 feet above current levels — No one has a model of what river is going to do, says NWS hydrologist June 18, 2011
  2. NRC in 2010: Major flood could cause core damage at Ft. Calhoun nuke plant– Cited for second most serious category of violation June 21, 2011
  3. Two-thirds of hot nuclear fuel remains in reactor core at Calhoun plant even though media claims it was ‘shut down’ for refueling and maintenance June 17, 2011
  4. NRC says it is “closely monitoring” Missouri River as floodwaters rise at Cooper and Fort Calhoun nuclear plants June 22, 2011
  5. 2,000 ft berm holding back floodwater has collapsed at Ft. Calhoun nuke plant — River now surrounding two buildings June 26, 2011

49 comments to 100% chance of reactor core damage if floodwaters went above 1010 ft. at Ft. Calhoun nuke plant, NRC said in 2010 — River now around 1,007 ft. and expected to rise

  • AkDave AkDave

    3 feet game over, It was a good try tho.

  • AkDave AkDave

    Dang! With snow loads of 140% still not looking good.

  • radegan

    I’m guessing if anywhere near a three feet rise was predicted, you’d see evacuations. That does NOT take into account an earthen dam failure and there is at least one taking a lot of stress right now.

    • risabee risabee

      A stack of mud between us and what might be left of history. I’m having a hard time focusing on my firewooding and pasture work, gotta admit.

      • ocifferdave

        Well said. Mud wall between us and history. Wow.

      • CaliMom

        I’m sorry, Risabee. The days at hand are not turning out quite the way we thought they would, right? These past many weeks have forced me to live more in the moment with my family and friends. To paraphrase a biblical phrase, ‘who among us can gain one second in life by worrying?’. Praying for some miracles for this country.

      • Net

        Sorry. Hope things get better. I agree with Calimom. The media won’t tell the truth. Everyone I know is oblivious about what’s going on around the USA. Lots of bad things happening with Floods, Fires , and bad weather. Not to mention the fallout from Fukishima. I feel alone because my husband thinks I am crazy. I bought lots of water and powdered milk and he refuses to believe there is a problem. He says why worry about it because it is already in the system for years to come. Get used to it.This is a nice website with lots of information from a variety of sources. Hang in there Risabee 🙂

    • sorry charlie

      You are never going to see evacuations! People have to take action and choose to leave. Evacuations in nuclear events ALWAYS happen after people have already been endagered…..if I’m wrong please tell me about an evacuation that was arranged in advance of danger.
      3mile island?
      Fukushima?….The explotion happened days after the damage to the reactor…there was plenty of time to organize an evacution….IT WON’T HAPPEN!
      Use your own judgement!

      • Noah

        No Evac Orders (Repost from June 18, 2011)

        Norbu, in Japan, as well as in the US, large scale nuclear events are treated differently from what you might now imagine.

        Large populations will not and can not be evacuated.

        The concept for large populations is “quarantine in place”. Which means that action plans are followed to prevent large en-mass population migration in case of nuclear disaster.

        There will be no evacuation order given, but rather an effort to contain the populace in place. Evacuations on a smaller scale are different.

        Information Control

        The news black out/control is an important part of controlling the populace of a disaster zone, and is the first tool used to prevent migration.

        This is not a theory.

        Examine the evidence. The practice of the protocol is playing out in Japan right now.

        That is why, as my adviser once said, “when in doubt, get out”.

        Situational Awareness & Escape Routing

        Each individual family must decide as they see things trending, what to do before an apex event.

        • Noah

          No EVAC continued…

          The most concise way I can say it is…

          Don’t depend on the government to tell you to get out, use your knowledge and awareness of the situation to tell you to evacuate.

          In large scale nuclear, that order can not and therefore will not come.

          But, I think you know that already.

          But for those who are unfamiliar and new to this type of preparation and survival tactics, I thought I would offer it.

Large scale nuclear events involving 30 to 100 million people within multiple fallout plumes would be very different from the smaller scale biological events.

          Say a global war that crosses the nuclear threshold, involving attacks on the nations major cities. (Or multiple reactor meltdowns due to National Power Grid Failure or both.

          Compared to a biological event, great difference in scale.

          How do you evac a population of that size? You don’t, you seal borders and prevent migration. No one out. They are practicing for that scenario right now. Strategically known as “pre-positioning”.

          No country can handle millions of immigrants at one time.

          Instead of an evac order, the goal will be to induce “stay in place”, “radiation is at safe levels”. Very similar to how the situation is being handled in Tokyo.

        • arclight arclight

          good points… if the rest of the public knew about this strategy, it would not bode so well for the nuclear groups!!

      • mff

        You are never going to see evacuations!

        Sadly it will be day late dollar short if or when it comes! ??? The powers that be are so hell bent on keeping the money rolling what the heck are they going to do when the eastern sea board is no more?? Life comes first no matter the cost..$$$ what a place.

    • milk and cheese milk and cheese

      You assume that the authorities care about the people living there?
      Why, that would ‘panic’ them. It will be the same as in Fukushima. Or New Orleans. We are still so naive.

  • gatoralsoccer

    Remind me again of the engineering brilliance in site choices for this one & the Cooper plant down stream!

  • Terranigma1 Terranigma1

    I hate to be the bearer of bad news —


    People should have been told to at least stay inside with their windows and doors closed! Unbelievable!

    • Whoopie Whoopie

      Wow! I must have missed that one! That’s incredible. Posted at HP Nuclear thread.

    • sandman

      Ok, things are very bad, but people, this guy is a “doctor” of oriental medicine and an acupuncturist. Please.

  • Novamind

    How high is the water moma? I say its
    1,007 feet and risin..3 foot shy of Crisis.

  • Whoopie Whoopie

    They turned on the Blue Pixels on this Cam now:
    Trying to hide something? The other one they play with the colors all the time. Now this one??

  • TraderGreg

    Maybe I am reading this article wrong, but the difference was between 1,010 ft and 1,014 ft, and it says that FCS fixed the problem to comply with NRS – which is protection up to 1,014ft.

    That said – I think these ‘nuclear geniuses’ have found the way to screw up. They seem to do nothing right. Homer Simpson has huge family, both in USA and in Japan.

  • tony wilson

    the delusional comments of a ft calhoun nuclear engineer..

    named justin.

    Mary, the river is at the level it should be for the summer. On June 18th when Gary Howard made that comment, there is absolutely no information that I can find that says the river is going to rise another 4-5 ft. : )

    @ Mary, it takes years of education to understand nuclear physics thermodynamics, chemistry, radiation, electrical theory, mechanical theory, how those work together to make a power plant, and how to recognize morons. Unfortunately it only takes seconds to copy and paste un-necessary, un-researched, completely biased, and sensationalist claims to the internet. I’ll stick with the first route, you stick to the second and I’ll be sure to check back in with you in four to five months.

    the quotes above are the reasons millions will die these lunatics cannot except any kind of reality.the building is dry even when feet are wet…

  • flatsville

    According to this article–


    they have back-up generators located 22 ft. above the worse-case design standard.

    However, a lot of systems related issues could go wrong rendered the back-ups to the back-up generators inaccessible or inoperable or tying into the direct overhead lines.


    New problems could start in the 1,010- to 1,012-foot range.

    At around 1,010 feet, water would overflow an earthen levee protecting the electrical switchyard, based on the levee’s current height.

    The switchyard is important because it transfers electricity to the plant from the power grid. Even though the reactor is shut down, electricity is crucial for operating pumps and other equipment that circulate water to cool both the fuel in the nuclear reactor and the plant’s spent fuel pool.

    Bannister, OPPD’s chief nuclear officer, said equipment inside the switchyard is further protected by sandbags to a height of about 1,011 feet. The utility is in the process of raising the earthen levee around the switchyard because that type of levee remains strongest if water does not reach the top few feet.

    Should enough water get into the switchyard to damage the electrical equipment, the plant could lose power from the grid, and OPPD would again fire up its two primary backup generators. That’s what the company did Sunday, when water got into a different area of the plant.

    Bannister said the generators have weeks of fuel on site. The generators are protected against flooding to 1,014 feet above sea level, which means they should be able to provide energy to the plant if the river rises 7.5 feet above its current level.

    At another location on the plant site, a temporary levee has been built around the storage area where casks containing older and cooler used nuclear fuel are kept. At some point above 1,014 feet, the Missouri River would overflow that berm, according to OPPD. Hanson said the 88-ton casks are anchored and will not float.

    Also at 1,014, floodwater would incapacitate OPPD’s backup generators if they were still being used. The utility has developed plans for tying directly into the transmission lines above the plant, if necessary, Bannister said. It also could shift to secondary backup generators, which are stationed about 22 feet above the worst-case design standard — at an elevation of 1,036 feet, Bannister said.

    Water would have to rise to 1,038.5 feet above sea level to reach the spent fuel pool, a water-filled pool that holds the plant’s most recently used uranium fuel.

    If floodwater made it to the reactor, Bannister said, it couldn’t get inside. That’s because the reactor is itself a watertight vessel that holds nuclear fuel in its own deep pool of water.

  • ocifferdave

    In case the worst case happens and a US nuke plant goes down here’s a wind map of the USA showing the last few hours animated:


  • blackmoon

    Latest from dutchsinse. Says Large storm brewing in the GOM.

    “6/27/2011 — Giant storm forming off Mexico heading north — Florida severe ACROSS entire state”


  • transport barge carries new steam generators, a pressurizer, and
    the reactor vessel head (not shown) to the Fort Calhoun nuclear
    plant in Nebraska. The components were manufactured by Mitsubishi
    Heavy Industries in Kobe, Japan.


    In addition to refueling the
    plant’s 478-MWe Combustion Engineering
    pressurized water reactor, jobs included installing
    a new reactor vessel head and two
    steam generators, and new low-pressure
    turbines, a pressurizer, and a main output