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Inspectors Warn Faulty Valves In New-Generation EPR Nuclear Reactor Pose Meltdown Risk

Posted by samzenpus on from the go-boom dept.

Bruce66423 writes: Valves for the new generation of French reactors being built now have raised substantial safety concerns on top of the existing issues about the quality of the steel used for the containment vessel. Similar to the Three Mile Island nuclear accident, France’s nuclear safety watchdog found “multiple” malfunctioning valves in the Flamanville EPR that could cause its meltdown. The Telegraph reports: "The watchdog reportedly cited 'multiple failure modes' that could have 'grave consequences' on the safety relief valves, which play a key role in regulating pressure in the reactor. Owned by state-controlled French utilities giant EDF, Flamanville lies close to the British Channel Islands and about 150 miles from the southern English coast. Designed to be the safest reactors in the world and among the most energy-efficient, the €9 billion (£6.5 billion) EPR has suffered huge delays in models under construction in France, Finland and China. It is now due to enter service in 2017, five years later than originally planned."

27 of 126 comments (clear)

  1. ...Valves...Nuclear Reactor... by Anonymous Coward · · Score: 3, Funny

    Half-Life 3 confirmed!

  2. Hack piece by Mr+D+from+63 · · Score: 5, Insightful

    Valves don't cause meltdowns. Multiple faulty valves could inhibit the mitigation of an even that could lead to a meltdown.

    In this case, valves did not pass the required tests so they can't be used in the plant when it is built. The testing process is there for a purpose.

    1. Re:Hack piece by AmiMoJo · · Score: 2, Interesting

      It shows that the engineers designing and building these reactors are still unable to correctly predict and specify the needed hardware for it to be safe. All the claims about such reactors being safe and it being impossible for them to fail catastrophically are therefore questionable, because even now they can't get it right and have to rely on checks catching these faults.

      It's hardly the only screw-up either. The reactor vessel itself is compromised. It's probably fine, but the point is that the claims about safety don't match the reality.

      --
      const int one = 65536; (Silvermoon, Texture.cs)
      SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
    2. Re:Hack piece by dfenstrate · · Score: 3, Informative

      I'm more concerned about the vessel steel problems mentioned in the article. If faulty, the vessel head could be replaced (at great expense), and the reactor vessel itself can be replaced during the construction phase (at even greater expense). I would hate to see the project put at risk over the issue.

      Unfortunately, the articles are either vague or alarmist, so it's hard to be sure how serious of a problem it is. Being familiar with the nuclear industry, the 'problem' might be something like this:

      1) Carbon content for the steel has been analyzed and tested as satisfactory between 0.50% and 1.25%.
      2) Inspection reveals the carbon content at these two spots is 1.26%, outside the analyzed range.
      3) New analysis and coupon testing is necessary to determine if 1.26% is safe.

      It could even be general engineering knowledge that the steel is sufficient up to 2.00%, but since the properly documented analysis and tests haven't been done to that level, it doesn't count.

      (I am not a metallurgist and my numbers are entirely made up)

      --
      Alcohol, Tobacco and Firearms should be the name of a store, not a government agency.
    3. Re:Hack piece by Mr+D+from+63 · · Score: 2

      No, it shows that things happen, and processes need to be in place to ensure safety.

    4. Re:Hack piece by Mr+D+from+63 · · Score: 3, Informative

      Then what happened in Fukushima?

      The plant was deluged by a tsunami, it was never designed to handle that, and that was the central flaw. Cooling systems were not available, a necessity for this plant design. However, the melted fuel is still generally contained, but there are releases of contaminated coolant which is unacceptable, an outcome of placing a plant in the path of a tsunami when it is not designed to handle it, thus disabling the features that mitigate the things you discussed.

      But, left completely with no mitigation, you are right in that the containment of older designs alone may not be enough to guarantee complete retainment under all circumstances, and newer passive designs or ones with core catching features are addressing this aspect.

    5. Re:Hack piece by Zalbik · · Score: 5, Insightful

      It shows that the engineers designing and building these reactors are still unable to correctly predict and specify the needed hardware for it to be safe

      How do you figure? The valves are faulty. Not designed incorrectly, but actually malfunctioning.

      This indicates possible errors in the manufacturing/supply process. It says nothing about the design.

      have to rely on checks catching these faults.

      Like every other manufacturing process EVER.

      Surprisingly, humans aren't perfect. Inspections are done specifically to ensure that mistakes are caught.

      As far as I can tell, the process is working correctly...nothing to see here.

    6. Re:Hack piece by ChumpusRex2003 · · Score: 3, Informative

      There was a big change in design philosophy. Early reactor designs were intended to prevent meltdown and had limited mitigation. More recent designs now include substantial mitigation as well as more robust prevention strategies.

      E.g. The fukushima accident occurred because of a "common cause" failure of multiple safety critical systems - the redundant diesel generators. This failure led to a "cliff edge" cascading failure of numerous safety systems, effectively meaning that core melt was inevitable. (This is in addition to the incorrect site risk assessment, where an incorrect tsunami risk was used when assessing the suitability of the site for a nuclear power plant, and the additional failure to mitigate that risk when the tsunami risk was recognised in the 1980s).

      Most modern reactor designs (the EPR excepted) do not class their diesel generators as "safety critical", because they are not necessary to place the plant in a safe state and initiate adequate reactor cooling. In addition, nuclear regulators (Japan excepted) around the world started carefully investigating "cliff edge" scenarios following the 9/11 attacks, to see if deliberate sabotage could result in disproportionate failure of safety features. In the US, the NRC started mandating that "safety critical" diesel generators be heavily hardened against beyond design-basis natural events and other methods of attack, even if not originally conceived at design stage; that UPS batteries be upgraded to provide up to 24 hours of safety, in order to allow emergency assistance to be called in, and/or that additional electrical power sources (e.g. gas turbines) be installed in fortified near-site (to mitigate against local site damage) installations.

      A similar set of upgraded mitigations have also been in place for a while - hydrogen catalytic recombiners (these are basically catalytic converters similar to those in a car exhaust which react hydrogen and oxygen at a low temperature and low hydrogen concentration, well below the minimum ignition level. Heat generated from the recombination is used to cause natural circulation of air through the combiner to accelerate hydrogen removal and stir up the air to ensure that hydrogen cannot pool away from the recombiners) have been installed in-containment, and in buildings close to hydrogen vent pipes. In Fukushima, no hydrogen recombiners were used, instead the main containment building was inerted with nitrogen. As a result, hydrogen (and steam) built up in the containment pressurising the building. In order to reduce pressure to prevent rupture, the containment building was vented into the main reactor building, where the hydrogen mixed with air and later ignited. More modern designs vent directly outside through filters, or vent through hydrogen recombiners.

      The other complicating issue is that at Fukushima unit 1, the reactor core appears to have completely melted through the reactor vessel into the containment building, severely contaminating the water in the containment building which was being used for cooling (and also leaked through minor damage to the containment). Again, modern designs try to mitigate this. The AP1000 design fills the bottom of the reactor vessel with low-melting point, sacrificial material into which molten core material will melt, resulting in dilution, prevention of re criticality, and spreading of the decay heat. Then by flooding the containment building and submerging the reactor with water, "melt through" is prevented because of combination of external cooling water and the diluted core material, as a result the containment building itself is not contaminated. The EPR instead, has a special chamber beneath the reactor intended to spread and retain molten core material, in such a way that it would not contaminate the containment building.

    7. Re:Hack piece by drinkypoo · · Score: 2

      This indicates possible errors in the manufacturing/supply process. It says nothing about the design.

      Actually, from where we're sitting, we don't know what it tells us. Was the design shit to begin with? Were specified tolerances inadequate? This armchair engineering stuff is fun, but if you get the right answer, it will be a coincidence.

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
  3. Isn't that the point of inspections? by tomhath · · Score: 2

    They're verifying everything works as it should. If the valves have a problem it's good that the problem is identified and fixed.

    1. Re:Isn't that the point of inspections? by asylumx · · Score: 2

      With the project already billions over budget and years behind schedule ... You probably wouldn't get on a plane these guys designed

      Well if they were spending that time making sure their plane wouldn't fall apart in the air, then sure I would. One of the trends of today's society is that we aren't willing to wait for things. Especially when it comes to new tech and something as risky as a nuclear reactor, I want them to take their time and get it right. Hopefully that will mean the second one they build is put up much more quickly and safely.

      Kudos to them for finding their flaws now, and not after a meltdown happens.

    2. Re:Isn't that the point of inspections? by Mr+D+from+63 · · Score: 2

      You probably wouldn't get on a plane these guys designed, but a nuclear reactor, that's just something to ignore with the wave of a hand?

      What was ignored? The processes in place to find such problems found the problem.

      This is most likely a valve manufacturing problem, not a design problem, but we don't have the details.

    3. Re:Isn't that the point of inspections? by LWATCDR · · Score: 2

      Frankly I feel the opposite.
      Any project as large and complex as a nuclear reactor, airliner, or launch vehicle that passes inspection I think one thing. They did not look hard enough.

      --
      See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
    4. Re:Isn't that the point of inspections? by tao · · Score: 3, Interesting

      I'm gonna go out on a limb and assume that you won't intend to ever flying on the Boeing 787 Dreamliner, considering that they even had several issues that made it *past* testing? I seem to recall Airbus also having some issues. Furthermore I'm guessing you won't use any Apple, Dell, Sony, or Lenovo -- those are the ones I remember, I bet there are more -- laptops either. Their exploding batteries made it past testing.

      All projects have issues. That's why you have reviews, testing, redesign, more reviews, more testing, and for anything that needs high reliability, lots and lots of fail-safes. For some products, where liability is low, companies don't care too much about this. Not so here though. The test process worked properly; the fact that the valves either weren't according to spec, or that the spec wasn't resilient enough, was identified. The problem will be fixed, things will be reviewed and tested again, against the new spec or component.

      A nuclear power plant that gets delayed because of safety-related improvements feels a lot better than one that's finished on time. In one case you know that they at least took the safety issues seriously. In the other case you're left wondering whether everything was perfect to begin with, or if they just ignored possible issues.

    5. Re:Isn't that the point of inspections? by Maury+Markowitz · · Score: 2

      > All projects have issues

      Of course! But at some point the issues cost more than the project. And then you're supposed to *give up on the project*.

      Surely you've worked on a project at some point in your life that you just stop working on because it's no longer worth it?

      How many problems does EPR have to have before you reach that point? It's always WAY over budget, and at this point there is no way it could ever pay for itself. It appears highly unlikely Hinkley will use one, if anything ever gets built there, and everyone else is backed away. It's CANDU all over again. At some point you have to realize that no amount of extra money thrown at it will suddenly make it profitable.

    6. Re:Isn't that the point of inspections? by Mr+D+from+63 · · Score: 2

      That is being ignored? Seems like the problems are well covered. Delays are mostly due to non-technical reasons, but the few technical items that have arisen get tremendous attention.

  4. Re:Typical Frogs by monkeyzoo · · Score: 3, Insightful

    Flamanville lies close to the British Channel Islands and about 150 miles from the southern English coast

    I'm curious why the article says this at all. They could just as accurately have said: Flamanville lies ZERO miles from the French coast (ha ha) and is equidistant from Paris and London. That seems the more relevant information in terms of potential catastrophic impact on population centers.

    Seems like the author is maybe British and fear-mongering for the local audience?

  5. Re:Typical Frogs by Xiaran · · Score: 4, Informative

    The article is from the British newspaper The Telegraph so it is directed at a British audience.

  6. 5 years late by Orgasmatron · · Score: 4, Informative

    What is the importance of being 5 years late?

    Costs Of Nuclear Power Plants - What Went Wrong?

    --
    See that "Preview" button?
  7. Re:Beyond comprehension by fnj · · Score: 3, Interesting

    It's because government owns it, and government is building it. Government is concerned with one thing and one thing only: steering as much money as possible to their own pockets. They do it by cheaping out on critical safety valves.

    I have to smile at how much more apropos that statement is if you s/government/corporation/g. Any corporation by its very raison d'être is like a corrupt government. At least with a government you get a chance.

  8. Re:Ban ALL NUKES NOW!!!! by Guildor · · Score: 2

    You've got to be foolish to believe this. Because we're going to need batteries the size of mountains to stabilise the supply / demand of power from solar and wind alone. We require a more stable solution we can fire up or shut down at any given moment. You can't ask the national grid to hang on for the next breath of wind, or the sun to poke out from behind the cloud, especially at night!

    As much as I agree that Nukes are not a good solution, and the risks far out-weigh the benefits, I also accept that we have to look for much better solutions that work with tidal power perhaps, or a safer reaction (if it's ever developed) such as Thorium. I suspect the energy companies already have much better solutions available, but have no interest in bringing them online until they're forced to. That, or the military are forced to shake their tree, and see what falls out. I'm sure their black budget billions have turned up some awesome alternatives and advancements.

  9. Re:Typical Frogs by serviscope_minor · · Score: 5, Insightful

    Powerstations are usually placed near sources of cooling water, either large rivers or the sea. Such geographical features are also often borders. So, are they clustered closer than one would expect to borders given the cooling requirements?

    --
    SJW n. One who posts facts.
  10. Re:Beyond comprehension by fustakrakich · · Score: 2

    ...the fucking critical coolant valves don't fucking work when brand fucking new? WTF?????

    I dunno. My dad bought a Lincoln Continental once and the power windows didn't work and the electric convertable top got stuck when he tried to put it down. Shit happens I guess.

    --
    “He’s not deformed, he’s just drunk!”
  11. Re:Beyond comprehension by fnj · · Score: 2

    A corporation has no accountability to customers. It is accountable to the shareholders. See "fiduciary duties". A corporation taking maximum advantage of its customers is WORKING AS INTENDED.

    A government's duty, the reason it exists, is to serve the people. Yes, corruption and poor performance happens, but they are DEFECTS.

  12. Re:Univ Pittsburg report: a must read by Uecker · · Score: 2

    "What has all this bought in the way of safety? One point of view often expressed privately by those involved in design and construction is that it has bought nothing."

    Factual data. Haha.

  13. Re:On a related note. by koan · · Score: 2

    Well that's why it was posted as a question, I know that sea water evaporates and creates rain.

    But lets look at your point

    Evaporation famously does not tend to carry heavy metals

    Do you think ocean currents can move heavy metals from Japan to the West Cost?

    I ask because when the news points out hundreds of gallons of radioactive water leaking from the plant, they never specify whether it is a "cesium suspension" (particles of cesium in water) or if it's the water its self that is radioactive (if even possible).
    So if cesium can be suspended (or is soluble) in water long enough to travel to the US, why can't it be picked up by storms and rained down?

    Caesium-137 (137
    55Cs, Cs-137), cesium-137, or radiocaesium, is a radioactive isotope of caesium which is formed as one of the more common fission products by the nuclear fission of uranium-235 and other fissionable isotopes in nuclear reactors and nuclear weapons. It is among the most problematic of the short-to-medium-lifetime fission products because it easily moves and spreads in nature due to the high water solubility of caesium's most common chemical compounds, which are salts.

    http://en.wikipedia.org/wiki/C...

    --
    "If any question why we died, Tell them because our fathers lied."
  14. Actual numbers: 0.30% content vs required 0.22% by niceworkthere · · Score: 2
    "Areva carried out mechanical tests in representative zones, giving impact resistance1 values of between 36 J and 64 J, with an average of 52 J, which is lower than the regulation limit (60 J) [ie. by up to 40%, as the other reply to you mentions].

    Areva also measured the carbon content of a central core sample taken from this vessel head, which revealed a higher than expected carbon content (0.30% as opposed to a target value of 0.22%)."

    From the report on the French regulator's own website: http://www.french-nuclear-safe...