Gov’t Memo: “One or more of the building explosions ejected radioactive material around the site” at Fukushima

Published: March 7th, 2012 at 8:00 am ET
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Blue Ribbon Commission on America’s Nuclear Future (BRC)
BRC MEMORANDUM
Date: May 10, 2011

Memorandum for: Commissioners
From: BRC Staff
Subject: Overview of the Accident at the Fukushima-Daiichi Nuclear Complex

Link: http://brc.gov/sites/default/files/meetings/presentations/brc_staff_memo_re_fukushima_5-10-11.pdf
Emphasis Added
h/t Enformable

[...]

The Unit 1 isolation condenser boiled dry at 4:36 pm on March 11, leading to the loss of ability to cool the reactor. Subsequently the Unit 3 RCIC failed at 5:10a on March 13, and the Unit 2 RCIC at 1:25p on March 14.

With the loss of the backup cooling systems, the water in the reactors heated up and ultimately boiled off in amounts sufficient to uncover at least part of the fuel in the reactor cores in Units 1, 2 and 3. This caused the pressure inside the reactor’s steel primary containment vessel to build up from the generation of steam and hydrogen gas. To control the pressure in the primary containments, operators were required to vent some gases. For an unknown reason, flammable gases from the venting, which should have been directed out through the plant stacks, instead accumulated in reactor buildings and subsequently exploded, damaging the reactor buildings at Units 1 and 3. Unit 2 also suffered a hydrogen explosion (“deflagration”) in its primary containment building, but the extent of the damage to its secondary containment was much less than at the other three units.

Unit 4, which was shutdown and defueled at the time of the tsunami, also suffered an explosion that severely damages its reactor building. The flammable gas that exploded in Unit 4 came from an unknown source. It may have been generated by fuel in the storage pool which might have become uncovered, but this has not been confirmed.

Ultimately, the damage to fuel in the Unit 1, 2 and 3 reactors was stopped by actions to connect portable pumps (fire trucks) to inject seawater into the reactor vessels to provide cooling. The action to initiate seawater injection took 27 hours to complete after Unit 1 lost backup cooling, and approximately 7 hours after Unit 2 and Unit 3 lost cooling. There is still considerable uncertainty regarding the precise cause and progress of events leading to explosions and radionuclide releases, in part because instrumentation was not available to measure key plant safety parameters such as water inventories in spent fuel pools and reactor and turbine building sumps.

As of late April 2011, the status of the reactors at the Fukushima Daiichi station is believed to be the following:

The reactor cores in Units 1, 2, and 3 have been severely damaged. Tokyo Electric Power Company (TEPCO) estimates that the cores have sustained damage (i.e., melting of the fuel elements) ranging from 55 percent (Unit 1) to 35 and 30 percent for Units 2 and 3. For purposes of comparison, the reactor meltdown at Three Mile Island was between 50 and 75 percent.

The cores also have extensive buildup of salt as the result of emergency injection of seawater into them in an effort to cool the reactors. Fresh water is now being used to cool the reactors, so no new salt is being added. Nitrogen is also being injected to reduce the potential for additional explosions. The initial addition of salt water is expected to accelerate corrosion processes, and will be one factor complicating long-term management of the accident.

High radiation levels have been detected in the containment buildings and around the reactor site. It is believed one or more of the building explosions ejected radioactive material around the site. Radiation readings in the buildings and around the site have been trending downward but are still hampering efforts to stabilize the site and begin mitigation efforts.

At Unit 4, as noted earlier, the reactor core had been unloaded about three months before the earthquake and tsunami occurred. The cooling system of the spent fuel pool at Unit 4 ceased to function, and makeup water needed to be added to the pool using a truck normally used for pumping concrete. Water continues to be added periodically to all the units’ spent fuel pools, most extensively at the Unit 4 pool.5 Recent video taken inside the Unit 4 pool shows that the fuel is in intact and largely or completely undamaged condition (Figure 1).

Units 5 and 6 at Fukushima Daiichi were shut down at the time and spent fuel pool cooling is functional at both units. These units are believed to be relatively undamaged.

There is separate central shared spent fuel pool at the plant site that contains 6,375 spent fuel assemblies, some 60 percent of the spent fuel on-site. That facility appears to have suffered little if any significant damage.

The plant also has nine dry storage casks containing 408 older spent fuel assemblies; initial reports indicate no significant damage has occurred to these casks.

The building housing the casks was flooded during the tsunami.

A great deal of attention has been paid to the spent fuel stored at the Fukushima Daiichi plant and the current state of that fuel. The following table shows the location, types (new or spent), and numbers of fuel assemblies, in the Fukushima Daiichi reactors, spent fuel pools, shared pool, and dry storage facility.

Please note that we have seen discrepancies in reports of the plant’s actual fuel storage inventories and capacities, so the numbers provided below must be considered preliminary at this time.

[...]

The reactor spent fuel pools have high density racking are relatively full, with 5,042 assemblies out of a total capacity of 8,310 assemblies.

The freshly offloaded fuel in the Unit 4 pool was apparently closely packed, rather than being distributed in a “checkerboard” pattern intermingled with older fuel as is required in the United States. The central storage facility at the site, which seems to have escaped serious damage, is nearly full—it only has additional space for some 465 assemblies, only a fraction of the assemblies in the reactor pools that will need to be removed. 408 assemblies are stored in dry casks.

The entire core of Unit 4—548 assemblies—had been unloaded into its spent fuel pool for reactor maintenance about three months before March 11th. There is no mixed oxide (MOX) fuel in any pools, although some had been loaded in the Unit 3 core. The pools’ inventory may have been relatively high in part because TEPCO had planned to ship SNF from this and other reactor sites to the Recyclable Fuel Storage Center in Mutsu beginning in 2012.13

Radiation releases

The accident at Fukushima has already released far more radioactivity than was released at Three Mile Island (and an estimated ten percent of what was released during the Chernobyl accident), but the amounts and effects are still being assessed. Not surprisingly, workers at the site received the greatest radiation exposures, and will continue to be exposed as cleanup efforts continue. 22 workers have received doses over 100 milliseiverts (10 rem or 10,000 millirem), but to date none have reportedly reached 250 milliseiverts (25 rem, or 250,000 milllirem), the limit recently set for emergency workers.

An acute lethal dose is on the order of 5000 to 10000 miliseiverts. Three workers were killed at the site as a result of the earthquake and tsunami (not by radioactivity).

Following the hydrogen explosions, radioactive cesium and iodine were detected in the vicinity of the plant, a clear indication of fuel damage. These had been released via venting of gases from the reactors, including an apparent rupture of the suppression chamber at Unit 2.

The population within a 20-kilometer (12.4 mile) radius of the plant has been evacuated; this evacuation was made mandatory on April 21st. Residents in the 20-30 kilometer 12.4-18.6 mile) radius have been told to prepare to shelter in place or evacuate, depending on developments.15 Food grown in the region was banned from sale soon after the event, although restrictions on some products have since been lifted following extensive sampling. Rice in the evacuation and evacuation preparation zones will not be cultivated in 2011.16 France’s nuclear safety agency IRSN estimates the maximum external doses to people living around the plant are unlikely to exceed 30 milliseiverts (3 rem, or 3,000 millirem) in the first year. This is based on airborne measurements taken to date, and has not been confirmed by any other agency. Natural background levels between 2-3 milliseiverts (0.2-3 rem, or 200-300 millirem) would normally be expected in the region.

Gamma radiation measurements onsite close to the reactors decreased greatly when the Unit 3 fuel pool was replenished with water on March 19th. Some buildings continue to have very high radiation readings inside, which have been measured remotely using robots. TEPCO is continuing to remove radioactive rubble from the plant site using remotely-controlled equipment, and these efforts are reducing radiation levels at the plant.

Published: March 7th, 2012 at 8:00 am ET
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40 comments

40 comments to Gov’t Memo: “One or more of the building explosions ejected radioactive material around the site” at Fukushima

    • Whoopie Whoopie

      Good one IP. "In an exclusive interview for BURN: An Energy Journal, Carl said he remains traumatized by the events to this day and has spent the last year trying to move past it"
      I feel bad for him, I really do. PTSD more than likely. :( TY


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    • oscar419

      oh gawd… Right there is a man who has experienced the genuine terror of realizing he may not survive… What a clip. oh gawd


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  • InfoPest InfoPest

    Propaganda Alert! "The lesson that the world needs to take away from Fukushima is that it is okay to build hundreds or thousands of new nuclear power stations and to place them quite close to the backyards of millions of people."

    http://atomicinsights.com/2012/03/least-informed-piece-on-fukushima-yet.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+AtomicInsights+%28Atomic+Insights%29


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  • lam335 lam335

    re: "For an unknown reason, flammable gases from the venting, which should have been directed out through the plant stacks, instead accumulated in reactor buildings and subsequently exploded, damaging the reactor buildings at Units 1 and 3."

    They say the stacks failed "for an unknown reason." Didn't Arnie Gundersen say early this summer that the plant stacks required electricity to vent properly–which is brilliant when one of the biggest dangers for a nuke plant is loss of off-site power.

    It would be nice if we could say the GE brainiacs thought of everything, but it appears that they scarcely thought of anything at all.


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    • oscar419

      …."For an unknown reason"….. love it, I think maybe the earthquake and ensuing tsunami may have had a little to do with it.

      @ lam335.. I thought I remember Arnie saying those need no power to vent, I thought ut relied on the pressure of the steam it is relasing. Oh more than likely I am wrong but for some odd reason that is the way I remember it.


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      • goathead goathead

        Hmmmmmm if the stacks did need power to vent but weren't getting it and that this issue may of had nothing to do with said earthquake, then maybe that old theory of the stuxnet virus comes back into play???


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    • HoTaters HoTaters

      And this one,

      Unit 4, which was shutdown and defueled at the time of the tsunami, also suffered an explosion that severely damages its reactor building

      If Unit 4 was defueled, why was there an explosion? Dry SPF?


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      • StPaulScout StPaulScout

        If it was a hydrogen explosion then we know that happens when the fuel rods are explosed to air and the zirconium tubes holding the fuel pelets burn off creating hydrogen in the process. It could have only come from the SFP. Unless of course there was fuel in the reactor and it went dry. That is the problem with TEPCO, they lie so much it's hard to figure out what all to believe.


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      • Uh, hydrogen from three, went out through a common stack, and then came back down into 4, filled it to the point of explosiveness, and then BOOM.

        Seriously, that is their claim.


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    • gottagetoffthegrid

      "…instead accumulated in reactor buildings…"
      the venting, at least in reactor 1 was not controlled as noted by Arnie G.

      http://enenews.com/fairewinds-nuclear-expert-believes-top-lifted-off-reactor-no-1-containment-before-explosion-video

      "One possible reason for the lower containment pressure is that the containment vent was open. But that had not happened yet. So what made the pressure drop down? One possibility I believe to be the case, is something that happened 40 years ago at a plant called the Brunswick Plant in North Carolina. Now the nuclear industry in the U.S., the IAEA, the Japanese, are all aware of this, but they are all ignoring this test and pretending that it did not happen.

      What happened 40 years ago was this: When a containment was pressurized, it was pressurized to just about 100 pounds [per square inch] and then something really strange and unexpected happened. The top, the head of the containment, began to lift off of the bottom of the containment. [...]

      "


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    • fireguyjeff fireguyjeff

      @Iam
      I am compelled to offer some clarification.

      Yes, I am essentially in full agreement with you.

      However, having spent the last 30 years on the design side of "engineering" (weak signal comm systems and chip design) what I can say with certainty is that what a GE Mark 1 reactor IS and what the designers wanted or designed are likely worlds apart.

      Many projects like a NPP can wind up getting designed "by committee".
      And the latter scenario is so often technical people who are in management roles (regardless of the reason why….they don't always get a choice in it) who forget a lot about "how things work" and put their MBA hats on and start looking at how to save money.
      And the original designers get kept out of the decision/information loop.
      I will save the rant about overly simplistic/delusional/absurd "cost-benefit analysis".
      So a committee asks very loaded questions about whether the project will still work if item X and backup system Y and function Z are removed or never implemented.
      If the answer is yes, then do without items X,Y and Z.
      Hence, the idea of jamming the SFP to overload in order to save space and money.
      Or the insanity of ever even thinking of ever building a nuclear reactor.


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  • lam335 lam335

    re: "Gamma radiation measurements onsite close to the reactors decreased greatly when the Unit 3 fuel pool was replenished with water on March 19th."

    Do they mean Unit 4 here?


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  • chrisk9

    Lack of vision and imagination was the killer here. The engineers designed systems with multiple backups and assured everyone that all these systems could not fail at the same time. Any disagreement was stifled because the bottom line was that GE (Westinghouse and B+W) were in it to make money. That is their only goal. Don't rock the boat or create problems, or you will need to go away. I did once and was not rehired until I threatened them with action.

    But almost everyone at GE believed in their product and it's safety because it had so many back up systems that could never all fail. This tragedy was similar to Challenger, BP, and other disasters. People build something that is very dangerous, are entrusted with it's safety, but in the end must protect the bottom line most of all. To make it worse we have so many politicians and people arguing that we have too much regulation, and we end up with the NRC, which promotes much more than it seriously regulates. Remember GE built it, but the NRC and our governments signed off on all of it.


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    • James2

      It doesn't really matter how many backups it has.

      Build 100 more backups and it's still not safe.

      The fundamental problem is that we have built a device that fails catastrophically when it fails.

      And unlike almost every other device I've ever seen that fails catastrophically – Challenger is a good example – It doesn't just kill a few unlucky people when it fails – it kills an entire nation. It kills millions of people. It has the potential to wipe out life on earth.

      So even if the plant can be kept 99.9999% safe – the risk of catastrophic failure is still too high to justify the use of it.

      Make it so it's just as safe and it only kills 100 people or 1000 people when it burns to the ground – then we'll talk about it. until then – no way.


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  • aigeezer aigeezer

    "Blue Ribbon Commission" means a whitewash. Example:

    "TEPCO is continuing to remove radioactive rubble from the plant site using remotely-controlled equipment, and these efforts are reducing radiation levels at the plant."

    Noble, gallant Tepco… and they all lived happily ever after, except, um, how much are the radiation levels at the plant reduced, how much remains, and, um, where are they putting the radioactive rubble that they remove from the plant? It is still radioactive rubble, is it not?

    This document is classic bureauspeak, with almost every sentence written in passive voice, adjectives when quantities are important, quantities when the information is trivial, feel-good spin, and never – never – ever any accountability.

    "…to date none have reportedly reached 250 milliseiverts (25 rem, or 250,000 milllirem)."

    Oopsie – our bad – we're a nuclear blue ribbon commission, not math majors or spelling buffs. An intern must be sacrificed.


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  • HoTaters HoTaters

    I can't even read articles at FluffPost. The authors of the piece you posted on keep repeating the mantra, "one of the world's worst nuclear accidents" and saying Chernobyl was the worst.
    (Reporting on "The Fukushima accident's legacy one year later."

    Liars, liars, pants on fire!

    Glad you posting retorts to all of this drivel.

    As some brilliant person here said, "Synaptic drivel spews forth."

    Same goes for what the "Blue Ribbon Panel" says on this report. Am in agreement with Aigeezer. 'Just love how they gloss over things like the explosion at #4.

    In yesterday's article on the NRC reporting and SPF #3 (link I found on another report), all the SPF's were thought possibly compromised except #1. That's in addition to whatever was going on inside the reactors.


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  • HoTaters HoTaters

    An acute lethal dose is on the order of 5000 to 10000 miliseiverts. Three workers were killed at the site as a result of the earthquake and tsunami (not by radioactivity).

    They even lied about the lethal dose in this report, 2,000 to 5,000 mSv (2 to 5 sieverts, usually 2 to 4 causing death within a few days);


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    • HoTaters HoTaters

      And we also know from reports in the public domain at least five (5) workers were said to have received lethal doses of radiation within the first couple of days of the accident.


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      • HoTaters HoTaters

        http://www.brc.gov

        The Blue Ribbon Commission on America’s Nuclear Future
        The BRC was established in accordance with the provisions of the Federal Advisory Committee Act (FACA), as amended, 5 U.S.C. App. 2, and as directed by the President’s Memorandum for the Secretary of Energy dated January 29, 2010: Blue Ribbon Commission on America’s Nuclear Future. This charter establishes the Commission under the authority of the U.S. Department of Energy (DOE).

        And this:

        http://brc.gov/sites/default/files/documents/potus_ltr_121211.pdf

        Funds for the disposal of spent nuclear fuel from commercial power reactors are collected regularly through the assessment of a nuclear waste fee on nuclear‐generated electricity as a quid pro quo payment in exchange for the federal government’s contractual commitment to begin accepting commercial spent fuel for disposal beginning by January 31, 1998. These fee payments, which total approximately $750 million per year, go to the government’s Nuclear Waste Fund, which was established for the sole purpose of covering the cost of disposing of civilian nuclear waste and ensuring that the waste program would not have to compete with other funding priorities.
        As we have learned through our investigation, the Nuclear Waste Fund does not work as intended. A series of Executive Branch and Congressional actions has made annual fee revenues and the unspent $26 billion balance in the Fund effectively inaccessible to the nuclear waste management program. Instead, the waste program must compete for federal funding each year and is therefore subject to exactly the budget constraints and uncertainties that the Fund was created to avoid. This situation must be remedied to allow the program to succeed.

        Note the use of the phrase, "disposing of the civilian nuclear waste." Right. We all pushed for this filthy technology and the technology of nuclear weapons. Now it's our waste and we must pay for its disposal. The money isn't being spent for its…


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  • or-well or-well

    It's time to head for
    radiation-filled hills!
    With their motion-sensors
    and nightvision cameras
    and CCTV eyes up in the trees,
    watched 24/7 by compromised grunts
    who by degrees lost the ability
    to pass, run or punt, and now
    only surf surveillance inputs
    and scratch their rumps.
    Oh, and don't forget satellite eyes
    on land that is owned by someone -
    Surprise! The Gov't or some Corporation
    or if by a citizen it matters not,
    Eminent Domain can take what they've got.
    Better to head for the Halls of Power,
    all aglow with contamination – the Horror!
    of lobbyist cash and profit cartels,
    pushing, among other things, more nuclear hell.
    The Rule of Law smashed
    to the ringing of bells – time to vote!
    Corporations are human!
    As once was said
    by Alfred E. Neuman -
    "What me worry?" if nuke plants go wild,
    someone will fix it – or so I've been told.


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    • Heart of the Rose Heart of the Rose

      @or-well..lol..That human hunting machine looks a little weak in the kness…
      Just hoping….


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      • or-well or-well

        @Heart, was hoping you'd catch it,
        something you said got me thinking
        and then stuck in my head
        so off or-well went running
        while I was ruminating,
        little "o"'s on a mission
        of nuke-Terminating -
        strike low and hard
        and never stop fighting
        and when it gets desparate
        there's kicking and biting -
        well, I'm gonna do lunch
        with my little pal,
        so I say see ya later and
        or-well says "ciao".


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  • jackassrig

    TEPCO can not understand why hydrogen built up in the building. The vent piping goes through the building. The vent piping failed during the Eq. IMHO.


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  • gottagetoffthegrid

    what a fantastic memo. looks like they watched a CNN piece and took notes.

    "The reactor cores in Units 1, 2, and 3 have been severely damaged. Tokyo Electric Power Company (TEPCO) estimates that the cores have sustained damage (i.e., melting of the fuel elements) ranging from 55 percent (Unit 1) to 35 and 30 percent for Units 2 and 3. For purposes of comparison, the reactor meltdown at Three Mile Island was between 50 and 75 percent"

    this was the crap talking point that TEPCO stuck to until just a few months ago when they admited that they had full melts in at least 2 of the 3 RPVs. why didnt these BRC staffers ask for a independent assessment from, say the NRC guys, who, as we have been reading, knew as early as MARCH 20th that there were full melts in SPF 3 and 4 and full melts in all 3 of the RPVs?

    sheesh. I wish I could get away with sh!t work like that and not get canned.


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  • StPaulScout StPaulScout

    "The reactor cores in Units 1, 2, and 3 have been severely damaged. Tokyo Electric Power Company (TEPCO) estimates that the cores have sustained damage (i.e., melting of the fuel elements) ranging from 55 percent (Unit 1) to 35 and 30 percent for Units 2 and 3."

    Of course we all know now that those cores have gone ex-vessel since. Some by melting, some by explosive ejection.


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  • We know for a fact that a serious amount of uranium was launched in the explosions. EPA RADNET data and my calculation to turn density in air into mass prove it.

    If you haven't checked it out, do so now. It will take you 10 minutes to understand it, then you will understand beyond a shadow of a doubt, that we been dosed, and we been lied to. And we need to get angry and effective.

    They knew, we KNOW

    http://nukeproffesional.blogspot.com/p/uranium-aerosolized-into-atmosphere.html


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  • Dr. Anne Lee Tomlinson Maziar anne

    No nuclear energy under any circumstances!!!!!!!!

    I really find the above comment
    “Make it so it's just as safe and it only kills 100 people or 1000 people when it burns to the ground – then we'll talk about it”

    to be unethical and calling for mass extinction of all life forms on earth. Solar and wind energies are inexpensive and don’t accept any deaths.

    Accepting one death leads to an exponential progression:
    10^0 =1, 10^2=100, 10^3 =1000, etc.

    Spreading 4000 nuclear reactors across the US times 1000 deaths each = 4,000,000 deaths and renders the whole US uninhabitable for millions of years and the rest of the population dead as well and the radiation would spread around the world and render the rest of the world uninhabitable.

    Any nuclear energy = death and mass extinction for the whole earth.

    NO RADIATION IS SAFE.


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  • jackassrig

    TEPCO can not understand why hydrogen built up in the building. The vent piping goes through the building. The vent piping failed during the Eq.

    The reactor is equipped with safety relief valves to protect against overpressure. I don't know the number of valves but maybe (2) to (3). The discharge piping of the safety valves would connect to the vent pipe to the stack.

    When the core melted down, excessive pressure from hydrogen and steam builtup in the reactor and was relieved by the safety valves into the vent pipe. The vent pipe was leaking and the hydrogen and steam vented into the building.

    The safety valves can only handle a certain volume. When the relieving capacity is exceeded the pressure in the reactor would continue to rise until an explosion. The heat from the corium would create too much volume for the valves to release. IMHO


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