Nuclear Reactor Design Caused GE Scientist To Quit In Protest

This is why Japan should have chosen the Canadian CANDU reactor design
over the USA GE design:
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Mark 1 Nuclear Reactor Design Caused GE Scientist To Quit In Protest
Damaged Japanese Nuclear Plant Has Five Mark 1 Reactors
Thirty-five years ago, Dale G. Bridenbaugh and two of his colleagues at
General Electric resigned from their jobs after becoming increasingly
convinced that the nuclear reactor design they were reviewing -- the
Mark 1 -- was so flawed it could lead to a devastating accident.
Questions persisted for decades about the ability of the Mark 1 to
handle the immense pressures that would result if the reactor lost
cooling power, and today that design is being put to the ultimate test
in Japan. Five of the six reactors at the Fukushima Daiichi plant, which
has been wracked since Friday's earthquake with explosions and radiation
leaks, are Mark 1's.
"The problems we identified in 1975 were that, in doing the design of
the containment, they did not take into account the dynamic loads that
could be experienced with a loss of coolant," Bridenbaugh told ABC News
in an interview. "The impact loads the containment would receive by this
very rapid release of energy could tear the containment apart and create
an uncontrolled release."
The situation on the ground at the Fukushima Daiichi plant is so fluid,
and the details of what is unfolding are so murky, that it may be days
or even weeks before anyone knows how the Mark 1 containment system
performed in the face of a devastating combination of natural disasters.
But the ability of the containment to withstand the events that have
cascaded from what nuclear experts call a "station blackout" -- where
the loss of power has crippled the reactor's cooling system -- will be a
crucial question as policy makers re-examine the safety issues that
surround nuclear power, and specifically the continued use of what is
now one of the oldest types of nuclear reactors still operating.
GE told ABC News the reactors have "a proven track record of performing
reliably and safely for more than 40 years" and "performed as designed,"
even after the shock of a 9.0 earthquake.
Still, concerns about the Mark 1 design have resurfaced occasionally in
the years since Bridenbaugh came forward. In 1986, for instance, Harold
Denton, then the director of NRC's Office of Nuclear Reactor Regulation,
spoke critically about the design during an industry conference.
"I don't have the same warm feeling about GE containment that I do about
the larger dry containments,'' he said, according to a report at the
time that was referenced Tuesday in The Washington Post.
"There is a wide spectrum of ability to cope with severe accidents at GE
plants,'' Denton said. "And I urge you to think seriously about the
ability to cope with such an event if it occurred at your plant.''
Bridenbaugh told ABC News that he believes the design flaws that
prompted his resignation from GE were eventually addressed at the
Fukushima Daiichi plant. Bridenbaugh said GE agreed to a series of
retrofits at Mark 1 reactors around the globe. He compared the retooling
to the bolstering of highway bridges in California to better withstand
"Like with seismic refitting, they went back and re-analyzed the loads
the structures might receive and beefed up the ability of the
containment to handle greater loads," he said.
When asked if that was sufficient, he paused. "What I would say is, the
Mark 1 is still a little more susceptible to an accident that would
result in a loss of containment."
ABC News asked GE for more detail about how the company responded to
critiques of its Mark 1 design. GE spokesman Michael Tetuan said in an
email that, over the past 40 years, the company has made several
modifications to its Mark 1 reactors in the U.S., including installing
"quenchers" and fortifying the steel structures "to accommodate the
loads that were generated." He said that GE's responses to modifications
ordered by the Nuclear Regulatory Commission were also shared with the
Japanese nuclear industry.
Bridenbaugh told ABC News that he is watching the events in Japan with a
mix of anxiety and deep reflection. Many years have passed since he and
fellow GE colleagues Gregory C Minor and Richard B. Hubbard publicly
resigned, joined the anti-nuclear movement, and became known as the "GE
Undoubtedly, he said, the containment structures at that Fukushima
Daiichi plant are facing significant amounts of pressure -- and testing
the very questions he was studying on paper more than three decades
earlier. While he knew then that the Mark 1 had design limits, he said,
no one knows now whether those limits will be surpassed.
Reply to
Home Guy
Structural integrity aside, it sounds like there was not enough cooling system redundancy, in the first place. Isn't all this containment breakdown due to overheating of the reactors?
Reply to
Which they are reporting this morning was caused by *human error*. The knucklehead in charge of keeping the generator running got distracted and it ran out of deisel. Generator stops. . . pumps stop. . .
You can build them to withstand earthquakes., tornados, and attack-- but that guy with a broom will screw you every time.
Reply to
Jim Elbrecht
Also everything we've heard so far has nothing to do with the reactor vessels being under designed for containment and having failed. Evertyhing I've seen and heard says the reactor vessels themselves appear to be intact.
As always, until we have a full accident investigation it's foolish to start speculating about what might have happened.
Reply to
... There's no indication the containments have failed at any of the units last I saw...
While I can't read Japanese and so can't read the actual SAR (Safety Analysis Report) file to the equivalent of the NRC to find out the design basis earthquake (DBE) specifically for these units, the failure(s) seem entirely to be the result of the tsunami after the tremblor.
I've heard no discussion about what the design basis for the tsunami was, if any.
Also, in general the containment design is a site-specific design and would not be in the actual design area of the reactor vendor (GE) other than for analysis of a given design for any particular plant. The "balance of plant" design is virtually always the purview of the AE (architect-engineer) and subject to the site-specific requirements of the appropriate licensing bodies.
Typically (in the US, anyway, I don't know the Japanese licensing process altho I'd presume it has much in common w/ US) the vendor then does the safety analyses to determine the effects of the postulated DBE(vents) such as large and small LOCA, etc., etc., etc., that include that specific design for each plant.
Reply to
Which is why these puppies have to be designed so that coolant shutoff can only occur through the failure of four or five redundant systems. Hell, with all the heat generated, you can have a steam powered pump that runs without need for external electricity, generators or batteries. It's obvious that the cooling systems just aren't robust enough or properly designed to be fail-safe. If these reactors meltdown right on the oceanside, the Japanese economy could fail. They depend on the ocean for much of their diet. Buy stock in companies making radiation detection devices. Every home in Japan is going to need one. Maybe Alaska, too.
-- Bobby G.
Reply to
Robert Green
In article ,
It is a little early, but if I may hazard a guess, it looks like this, like most other major disasters, will be more a failure of imagination than anything else. It looks like most of the containment stuff worked through the earthquake, but nobody imagined what might happen if a Tsunami hit at the same time. Disaster planners and generals both tend to fight the last war and may be late making needed adjustments to this one. No one imagined, pre-9/11 what might happen if hijackers decided to do something other than fly to Havana. Before Katrina, nobody imagined what might happen if the people who rode out the storm in the Superdome had no longer term shelters to go to afterward per the hurricane plan.
Reply to
Kurt Ullman
Seems really hard to get good information on what happened and what is going on.
Best I have seen is that all the reactors in Japan automatically shut down, as intended, when the earthquake hit. You then need outside power or emergency generator power to continue the cooling water circulation. At the problem plant the tsunami flooded the emergency generator. A sea wall was supposed to protect the generator from a tsunami. The tsunami was bigger than anticipated. One report said the generator was in a basement - doesn't sound like a good idea. real close to the ocean.
First it was reported there were 3 reactors, then 4, and now it has been reported there are 6. I think I heard 7 once. 1, 2 and 3 were running. 4, 5 and 6 were shut down for maintenance.
The biggest radiation hazard as of last night was at reactor 4 in the spent rod pool. The spent rod pool is outside the primary containment vessel and inside the secondary containment building. Apparently the water level dropped, rods overheated, and some fuel rod casings oxidized. The high level radioactive byproducts in spent rods can then boil/evaporate into the atmosphere. particularly cesium. Secondary containment has holes in it. Everyone reports fires. Nobody reports what is burning. Apparently it is too radioactive to get near enough to find out?
There was question whether there was some breach in primary containment for reactor 2. The 3rd explosion was inside the primary containment. The 1st and 2nd explosions blew up the secondary containment buildings for reactors 1 and 3.
They are (were?) pumping sea water into reactors 1, 2, 3 (primary containment) and venting the resulting steam which is a little radioactive.
There is some atrocious reporting by people who do not understand the science or have to fill the air-time. The best reports I have seen are by (the dreaded) Rachel Maddow on (the dreaded) MSNBC. She tries real hard to get the science right, and interviews nuclear experts. Experts seem to have information that is not making it out in interviews with people that are not nuclear experts.
Someone in newsgroups was involved in the TMI incident. Was that you?
Reply to
I've heard similar w/o enough detail confirming to be at all clear how much is actually so...
Your description of spent fuel pools is correct geometry, it is certainly unclear what is burning; perhaps generating enough H2 from the cladding to be self-sustaining but that's purely conjecture.
On consulting basis re: incore instrumentation interpretation and computer alarm systems and such, yes...had several in office whose specialty was more specific to the balance of plant issues that were on site after about 2nd day...
Reply to
Except one that is thought to have a crack now, going from the inside to the outside.
Reply to
Yes, that was a stupid comment.
Even moreso when you consider that tsunami is a Japanese word.
Reply to
Home Guy
In article ,
Besides, given the placement, it was imminently possible to have a tsunami at the plant even if the quake occurred elsewhere. They should have imagined both happening as independent events. The two happening together shouldn't make any difference.
Reply to
Kurt Ullman

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