Heating Help

Japan Nuke plants

 Having worked in a nuclear power plant on the turbine deck, and containment area this is scary times, and sad. 

  The power of steam to drive the turbines is amazing, and damaging. I have witnessed during outages what steam has done to 16" dia. stainless steel pipes at elbows eroding the steel away like some one took a torch to it on the inside.  Erode turbine blades. This is all anticipated, and the reason for outages to perform inspection, and maintenance from such occurrences.

 The complexity of these nuclear plants is awe inspiring to say the least. The Byron facility close to me had to replace a steam vessel in the containment that was suppose to last 30 years in 15 years. In order to do this they had to build a containment attached to the containment to exchange the new vessel for the old. The old radioactive vessel being left in the new containment addition. First time something like that had been done.

   Japans power plant dilemma is going to be a set back to nuclear oriented power generation to say the least which I find to be saddening. Things happen. Engineers try to design for the worst case scenario. Sometimes things get missed or events are more devastating than could be imagined. I just hope things can be controlled to prevent a melt down, and Japan can be seen as a pillar in the nuclear generation community on how they handled catastrophic events successfully with as little impact to the environment, and human element possible.


 Gordy


 

Worst case scenario.

The Japanese had some of the most advanced warning and controls systems possible. They knew they were building reactors in areas that were prone to quakes and Tsunamis. They had a back up plan to their back up plan, and unfortunately, they all failed.

If a quake was detected, the plant was to trip off line, and emergency generators were supposed to kick in and allow them to shut the reactor cored down correctly and safely. If the generators should fail, they had a battery back up to keep the pumps running to cool the reactor and buy some time for a plan C.

Plan C in this case is to dump/pump sea water into the reactor in an attempt to cool it down.

Scary stuff here. And I am certain that many lessons will be learned, and the results of those lessons shared with the nuclear world.

I am a firm believer that nuclear energy will eventually power the majority of the world.

ME

On YouTube

"RussiaToday" was comparing this situation to the Chernobyl disaster. Their latest one is here:

http://www.youtube.com/watch?v=7Vpg8eleaeM

But the GE reactor (yes, our very own GE) at Fukushima-1 at least has a containment building, just like the Babcock & Wilcox one did at Three Mile Island, whereas the RBMK-1000 did not.

The problem is that even after a reactor is shut down it still needs to be cooled. This is one thing that makes nuclear such an unforgiving technology. The smallest breakdown can pyramid into disaster. At TMI, a control system malfunction and operator error resulted in a loss of cooling which led to a partial meltdown.

Cooling

   The byron facilty requires 50,000 gpm to cool its reactors. Thats a lot of pumping  to run on batteries for a long period of time.

   I do not know how long an emergency shut down takes.  Shut downs for planned outages take weeks to keep from damaging components outside the reactor itself. But these planned ouages take place near the end of the fuel rods life span. 

   Example being the turbine which rides on a high pressure film of oil during full operation. Ramping it down it goes to a turning gear after it slows to so many rpms then it turns on the turning gear slowly for days until it stops to prevent damage to the turbine shaft.

  The generator at the end of it all is about 500,000 pounds, and the size of a two car garage.  When you look at all the complexity in the end its all done just to turn this generator.  All so you can get up in the middle of the night to take a leak, and not be in the dark.  As one old timer I worked with put it.

BWR or PWR ?

Gordy, is Byron a PWR or BWR plant?
My guess as to why it takes so long to shut down the steam plant is to minimize the amount of positive reactivity to prevent the fuel from going critical with the cooler water. This is done to minimize the amount of time required to perform the the core maintenance and fuel shuffle.  The refueling floor work is typically the critical path maintenance.
 
Also a slower cooldown minimizes thermal stresses on the steam side components.

Pwr

2300 MW Pressurized light water reactor.  there are 2 reactors at Byron Larry
I suppose in an emergency scenario the infrastructure for the drive line components are sacrificial to prevent a catastrophic failure of the reactor. But I do not believe the reactor can be shut down in the time frame of the quake tsunami double wham happened. We really do not know what actually happened for sure was it the quake that caused the initial failure or the tsunami? Does anybody know the time span from initial quake to tsunami actually over taking the plant?

Basically Japan is going to have three monoliths, and counting.  I'm sure the world will question the remaining plants operation, and the design build of a new plant in that country.......Depending on the outcome of this tragedy, not looking favorable as things unfold.

If interested

www.eia.doe.gov/cneaf/nuclear/state_profiles/illinois

This link is interesting. Illinois gets 50% of its electricity from Nuclear Energy.

Not looking too good.....

I am by no means an expert in explosive forces, but when I see the amount of material that you can see in this video suspended in mid air, it would indicate to me that there is a lot of concrete being lifted into the air, as in concrete containment structure.

In the chemical manufacuring business, they intentionally build the buildings to allow them to blow apart in case of an explosion, and that is what appeared to happen in the first reactor explosion, but this one looked completely different. Substantial lift, then a lot of heavy debris falling back to Earth.

Now they are saying that the spent fuel rod facility for #4 was allowed to be exposed, and subsequently caught on fire, and that they suspect the radiation in suspension probably came from that fire. The fire is out for now, but they are struggling to keep the rods covered with water.

God bless the brave nuclear warriors who have stayed on site in an effort to get this situation under control. Scary stuff here...

This makes the oil spill of last summer pale by comparison...

http://www.youtube.com/watch?v=pIZKlaEZMLY

What could POSSIBLY go wrong next !?

ME

What could POSSIBLY go wrong next !?

When I first started as a student at a prestigeous engineering school, I was introduced to Murphy's laws. I later learned, in the scholarly journal, Mad Magazine, that Mr. Murphy's first name was Edsel.

In any case, the first tree laws were:

1.) If anything can go wrong, it will.
2.) If several things can go wrong, they will all go wrong, all at once.
3.) The amount you learn from this is proportional to the cost of equipment destroyed.

The next three went:

4.) You can't win.
5.) Wou can't break even.
6.) You can't get out of the game.

Cutaway reactor drawing

Mark, you bring up a good point. The initial explosion seemed to only blow off the light metal construction at the top of the reactor building, while the last explosion seemed to involve some of the heavier concrete below hat level.

Sequence of events

Here is the best description I have found of the Japanese nuclear accident, without all the media hype.

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

With everything that has gone wrong, its amazing that so far the result is not worse.

I am less worried about the containment...

... than I worry about the spent fuel rods in the storage pools. These are outside of the containment, but must nevertheless be cooled.  Presumably there is failure in this cooling because the hydrogen that has been exploding is probably due to the zirconium of the cladding around the fuel getting so hot as to grab the oxygen from the water, leaving free hydrogen to explode once it finds some air. Now that the roof has been blown off some of these reactors, if that stuff catches fire, it becomes a major calamity. And they did have a fire there in unit 4 that took them about 2 hours to put out.

And their using sea water to replace the coolant, even with boric acid in it, is very corrosive as those here who got a little in their boilers can attest. Probably worse in the reactor and storage pool if the circulation is too low and the temperatures exceed 2000F.

Looks like it's getting worse

http://www.nytimes.com/2011/03/17/world/asia/17nuclear.html?_r=1&hp

Not over for months

   No one has said when these reactors were fueled.  Usually they will run 9 months freshly fueled with CONTROLLED reaction. Usually reactors are fueled in such an order that while one is down for maintenance, and refueling the others are operational. How they are staggered depends on how many reactors are on the site.  Most plants here in Illinois have 2 reactors. Some are PWR some are BWR. Japans site has 6 much more of a complex of a site to maintain.

 Looking at the size of the explosion in Marks youtube link I would say they had some Containment damage. 

 With that being said a freshly fueled reactor will take longer to keep under control which appears to be a struggle now. They need an end to come to this soon being operating in emergency mode, and the Hail Mary sea water boric acid pass to absorb neutrons, and slow the reaction.  These workers are going to get dosed in a hurry, and new ones will need to be rotated. Time, shielding, and radiation level all come in to play here.

    Gordy

Dump GE

 If you own any stock. Their Mark 1 reactors have been known to be troubled. This will be litigation heaven.  I hope the workers are getting rotated according to the latest news.  I can't believe our satellites are not monitoring the radiation. Time for outside sources to step in if not to late. Japan has way to many things going on right now to handle this also.

Probably too late.

If you go here,

http://bigcharts.marketwatch.com/interchart/interchart.asp?symb=ge&insttype=&time=&freq=

And set Chart Range to 5 days, and Chart Frequency to 1 minute, you will see quite a dip; it dropped $2 this morning, about 10%.

Well, at least

they weren't Babcock & Wilcox!

GE mark 1 reactor problems

DEVASTATION IN JAPAN

Warning was issued in ’70s on GE-designed reactors
By Tom Zeller Jr. New York Times / March 16, 2011

NEW YORK — The warnings were stark and issued repeatedly as
far back as 1972: If the cooling systems ever failed at a
Mark 1 nuclear reactor, the primary containment vessel
surrounding the reactor would probably burst as the fuel
rods inside overheated. Dangerous radiation would spew into
the environment.

Now, with one Mark 1 containment vessel damaged at the
embattled Fukushima Daiichi nuclear plant and other vessels
there under severe strain, the weaknesses of the design —
developed in the 1960s by General Electric — could be
contributing to the unfolding catastrophe in Japan.

When the ability to cool a reactor is compromised, the
containment vessel is the last line of defense. Typically
made of steel and concrete, it is designed to prevent — for
a time — melting fuel rods from spewing radiation into the
environment if cooling efforts fail.

In some reactors, known as pressurized water reactors, the
system is sealed inside a thick steel-and-cement tomb. Most
nuclear reactors around the world are of this type.

But the type of containment vessel and pressure suppression
system used in the failing reactors at the Fukushima Daiichi
plant is physically less robust, and it has long been
thought to be more susceptible to failure in an emergency
than competing designs. In the United States, 23 reactors at
16 locations use the Mark 1 design, including Pilgrim 1 in
Plymouth, Mass.; Vermont Yankee in Vernon, Vt., and the
Oyster Creek plant in central New Jersey.

GE began making the Mark 1 boiling-water reactors in the
1960s, marketing them as cheaper and easier to build — in
part because they used a comparatively smaller and less
expensive containment structure.

US regulators began identifying weaknesses very early on.

In 1972, Stephen Hanauer, then a safety official with the
Atomic Energy Commission, recommended that the Mark 1 system
be discontinued because it presented unacceptable safety
risks. Among the concerns cited was the smaller containment
design, which was more susceptible to explosion and rupture
from a buildup in hydrogen — a situation that may have
unfolded at the Fukushima Daiichi plant.

Later that same year, Joseph Hendrie, who would later
become chairman of the Nuclear Regulatory Commission, a
successor agency to the atomic commission, said the idea of
a ban on such systems was attractive. But the technology had
been so widely accepted by the industry and regulatory
officials, he said, that “reversal of this hallowed policy,
particularly at this time, could well be the end of nuclear
power.’’

In an e-mail yesterday, David Lochbaum, director of the
Nuclear Safety Program at the Union for Concerned
Scientists, said those words seemed ironic now, given the
potential global ripples from the Japanese accident.

“Not banning them might be the end of nuclear
power,’’ said Lochbaum, a nuclear engineer who spent 17
years working in nuclear facilities, including three that
used the GE design.

Questions about the design escalated in the mid-1980s, when
Harold Denton, an official with the NRC, asserted that Mark
1 reactors had a 90 percent probability of bursting should
the fuel rods overheat and melt in an accident.

Industry officials disputed that assessment, saying the
chance of failure was only about 10 percent.

Michael Tetuan, a spokesman for GE’s water and power
division, staunchly defended the technology this week,
calling it “the industry’s workhorse with a proven track
record of safety and reliability for more than 40 years.’’

Tetuan said there are currently 32 Mark 1 boiling-water
reactors operating safely. “There has never been a breach of
a Mark 1 containment system,’’ he said.

Several utilities and plant operators also threatened to
sue GE in the late 1980s after the disclosure of internal
company documents dating to 1975 that suggested the
containment vessel designs were either insufficiently tested
or had flaws that could compromise safety.

The Mark 1 reactors in the United States have undergone
modifications since the initial concerns were raised. Among
these, according to Lochbaum, were changes to the
doughnut-shaped torus — a water-filled vessel encircling the
primary containment vessel that is used to reduce pressure
in the reactor.

Oyster Creek...

"In the United States, 23 reactors at

16 locations use the Mark 1 design, including Pilgrim 1 in

Plymouth, Mass.; Vermont Yankee in Vernon, Vt., and the

Oyster Creek plant in central New Jersey."

Oh! Poo! I live less than 40 miles from that one.

You're Lucky

I live 70 miles from BOTH of the other 2

20/20 Hindsight

My guess at a fundemental flaw at the Japan plants, is the same one that bit us in Katrina.  The emergency generators and switchgear are located on or below the ground.  Any significant flooding and you are at the bottom of the pool.  The shaking did not cause the failures, it was the lack of emergency power from the flooding that did them in. 
Unfortunately it is expensive to fix, and we are still stuck with millions of industrial, commercial, and residential locations worldwide with this same issue.
 
20/20 hindsight.

Be careful what you read.

I read that it was not the flooding that took up the emergency generators. They were never tested properly, but just for a short time under low load conditions. When the emergency came, they started up. One quit after about an hour with a broken crankshaft. The other two did the same a little later.

I have no evidence that what I just typed is true or not. But likewise, I have no evidence that the tsunami took them out either. The problem of inadequate reporting, nervous bureaucrats covering up, and a government trying to avoid panicing the citizens, make it impossible to know what is going on.

generator failures

 
Running diesel engines under a light load will result in 'wet stacking'.  That is when unburnt fuel collects in the exhaust system.  When the engine is fully loaded for an extended amount of time, the exhaust system heats up and the unburnt fuel is ignited.  Now you have a chimney fire plus the full load of exhaust.  It is an impressive sight, albeit a bit scary.
 
Running the generators with a full load should not lead to a crankshaft failure.  If the units where undersized, the engine would bog down and run slower, the alternator would overheat, but a catastrophic mechanical failure should not occur.
 
My speculation is that the generator's engine sucked in sea water thru the air intakes, hydrolocked, and THAT's what broke the crankshaft.  1500 rpm to zero in milliseconds.  Yeah, that is a little outside the design specs.

hydrolocked

"My speculation is that the generator's engine sucked in sea water thru
the air intakes, hydrolocked, and THAT's what broke the crankshaft. 
1500 rpm to zero in milliseconds.  Yeah, that is a little outside the
design specs."

I like that explanation because there could be truth both in the report I read and the more common report that the water did it. Now how would those things run for an hour with water in them? I would assume that water would take out either the crankshaft, or the connecting rods in about one revolution of the engine. (I know from second-hand experience that that is what happens when a sports car runs through too deep a puddle.) That would accord more with slowly rising water than a sudden 500 mph tsunami. But perhaps the water in the genreator rooms did rise slowly.

Why the delay?

Now how would those things run for an hour with water in them?
 
They did not.  The water took an hour to flood the facility after the quake.  That is why the generators were running for an hour before they failed.

Site development

 If anyone has looked closely at the close up photos/videos released lately.  I think you will find that it will be a miracle to get the systems up, and running even with newly supplied power.  Electrical, piping,controls and pumping infrastructure needs to be operable in all facets. any broken link in the chain to get water where it needs to be is complete failure.

 The mass of broken concrete, re bar, and structural steel is a sign of the magnitude of the explosions. The damage that has been done to the structure is a leading indicator of the possible damage to the cooling components of the reactors, and spent rod pools. A much more fragile mass of components in my opinion.

  If you look at the site landscape you will see why generators were flooded. The whole chain of reactors were built in a man made basin with the side to the ocean open to ground elevation. There are a number of reasons for this. Maybe to contain a radioactive spill to the site not allowing spillage to go in land, but out to sea.  Conceal the site from the in land landscape. 

  Bottom line there were plenty of areas to keep the generators high, and dry.  But were probably installed where they are for ease of maintenance, Close proximity to the power needs, and where fuel could be stored for the generators.

Gordy

I suspect you're right Gordy...

I think anything they do at this point in time is hand waving to appease the masses. THe human masses, because their other mass (nuclear) is beyond critical mass. I hope I am completely wrong, but for pipes, valves and fittings to be able to withstand the forces that the explosions displaced would be nothing short of a miracle in my estimation.

I heard today that they are strategizing how to bury the pools/reactor in a dirt/sand fill. Sounds like a cat trying to cover their tracks to me...

And to think, that these explosions WERE supposedly controllable, but due to lack of electrical power, their hydrogen flare igniters would not work.... Maybe we need to send Timmie Mc over there to teach them the basic of controlled combustion. I will donate the spark ignition modules.

I think it is going to get worse before it gets better.

In watching the videos, they are trying to pump water into the buildings from the ground using airplane fire fighting equipment. Why don't they send someone up those smoke stacks behind the reactor with a hose and nozzle and let them drop water IN to the hole, instead of throwing water AT the hole blindly, like they've been doing.

Desperate measures...

Pray for quick resolution.

ME

Try to

 Plan for the worst, and hope for the best. Many design flaws in all facets of construction which are only revealed after catastrophic events of inconceivable proportions.

 Their use to be a show on T.V. called failure analysis I think. I enjoyed watching what can be learned from failures.  Some things are discovered through an event failure analysis like during construction a 1 1/2" re bar spacer was used instead of a 1" which was determined to cause a failure. No one could probably believe that 1/2" difference in re bar clearance could make so much of a structural difference.


 What designer would ever consider a direct hit from a passenger airliner at near Mach speed to a building let alone 2 minutes apart to separate buildings in close proximity to one another would really happen. But they did with the World Trade Center buildings. Never thought about the amount of damage the burning fuel would cause only the impact.


 The events in Japan are three catastrophes at once. Any one of them would be bad enough on its own. Let alone a quake, Tsunami, and A nuclear reactor failure do to the Tsunami.  At the time of the Nuclear Plants design 70's there was not the information known today about how quakes, and Tsunamis fault line locations etc.  are events tied to one another as we come to know today.  So I'm sure the designers banked on one event happening, and not another.  But the Tsunami event alone would have done the same damage to redundant cooling systems which is really the whole issue here, and that is the ability to move cooling water to the reactors, and fuel storage ponds.



  At any rate it will be a learning experience for the world.  I see the NG, and coal advertisements taking off right now on the TV.


  The CEO of Exelon Corporation which operates nuclear power plants even says that nuclear is cost prohibitive today. The best play is solar/ wind with NG/ Coal as the balance to the lack of wind, or night time demands.

  The problem with that is the technology to capture solar is very inefficient. do we cover the planet with todays inefficient sloar panel designs to only replace them in 10 years with designs that have 30% or 40% conversion efficiencies compared to maybe 20% efficiency of todays designs. Where is the greeness, and economics in that? 

Upgrade to level 5 ???

 Same as TMI. Uhmm okay  TMI sure did not look like that mess. US War Ships 200 miles off the coast pick up radiation?

Measuring radiation

We can measure levels of radiation that are magnitudes below levels that can cause significant biological effects.  I personally been measured by ultra sensitive radiation detectors that were shielded with pre WW II steel because any steel made after 1945 contained isotopes from the nuclear weapons explosions.
 
Just my SPECULATION, but I would make a wager that the occupants of Denver, ID, AZ, TN, and NH will recieve more radiation from their environment than anybody on the west coast will receive from Japan.

Larry

 You make a good point with all the atomic weapons testing that has been done in the past above ground below ground, and out to sea. It makes this look like a smudge pot.  Its almost ironic to see the anti nuclear activists plea not in my back yard after all the testing that has been done in so many countries for 30 years post WWII isn't it.

Gordy

Gordy

Gordy, did you ever run into an old fitter around Byron named Brian Beatty ?
bob

Bob

   No I don't recall him.  There were a lot of crews that just worked the outage circuit going from plant to plant.  When I was down there the few times I worked for Westinghouse, and Blount bros. 

  I was really appalled by the amount of unprofessional craftsmenship when I worked during plant construction back in the mid 80's. Not so much the quality of work, but more how it was carried out.  The parking lot was littered with beer bottles, and fifths everywhere. The work was way over manned, and the men did not work. Seemed everything was TM.  The plants budget went up 3 fold if I remember correctly.Those were different times.  No wonder I pay 12 cents a kilowatt.

  The few times I worked in the plant I came to notice while going in, and leaving the plant not a single bird to be found ANYWHERE on the site.  Sort of an eerie feeling in my mind.  Maybe it was nothing, maybe there is deliberate animal control on the site to avoid fowling systems excuse the pun.  The eagles love the open water for food on the river though.


 Gordy

 

Bury It

Bury the darn thing...Problem solved!!!! How long would that take a week or so. Did it in Russia in about a week 20 years ago. I'm getting sick and tired of hearing the news agencies now questioning if America's plant are safe. This was a natural disaster for sakes. Should we be planning to make us safe for the next ice age...Nope. We'll find someone to blame for that too.

Got this from Perry on the 14th

"Things are getting worse - and at least 3 of the
reactors are done for life - and have partial meltdowns; but,
containment is holding (as of last reports) so there will not be
anything approaching Chernobyl.  The question is can they save the
other 4 (and those have not yet hit the news).
A
key item is that the plants were designed for either 7.9 or 8.2
earthquake and they got hit with a 8.9   The difference between 7.9 and
8.9 is a factor of 10 (its a logarithmic scale).
Overall I'd say the plants have stood up well given what they were hit with.
As
far as the US reactors.   We have about 30 similar reactors here (GE
Boiling Water Reactors - BWR) - and many with the same vintage
containment.    Key is that very few of these are on an ocean where
they could be hit with a tsunami an hour after the earthquake (and it
was the tsunami that took out the diesel generators).
The
other 70+ reactors are Pressurized Water Reactors - and I believe that
design is inherently more capable of dealing with a total loss of power
than a BWR.
The new Generation III reactors
(for example the AP-1000 which will start construction later this year
in the US) are designed to handle a total loss of power - and have
enough passive cooling to prevent a meltdown."

I haven't heard anything in the last couple days because they are in the middle of refueling the plant he works in. ...makes him a wee bit busy.

The difference between PWR, and BWR

The real difference

 Is a PWR uses a HX for steam production, and a BWR the steam is a direct output from the water in the reactor. A PWR reactor is not as dirty (radioactive) as a BWR.

DP

Showing the vulnerable components

BWR cut away

In the picture Gordy posted labeled "Showing the vunerable components", the spent fuel pool is the pool on the upper left side.  The pool on the upper right side is where the moisture seperator parts are placed when the reactor top is removed.
 
During a refueling outage, the concrete blocks that the people are standing on in this diagram are removed and placed elsewhere on the floor.  The top of the containment vessel is removed, followed by the top of the pressure vessel.  The space between the two pools is filled up with water.  The steam drum and moisture separators are moved over to the far pool to sit during the duration of the outage.  The small red platform to the left of the drawing is used to remove the fuel bundles and place them in the spent fuel pool.  Various maintenance tasks are performed and the new and used fuel bundles are reloaded. All of the bits and pieces are reassembled and away we go.
 
Domestically, in all of the plants I have worked at, the refueling floor walls have sheet metal blow out panels that open at some low pressure (1 psi ??) in case of a steam explosion.
 
Someone brought up the concern about the pumps and piping being destroyed in the aftermath.  I doubt it.  Most of the piping and pumps would be in the lower and middle levels of the concrete reinforced structure.  I believe the primary issue is the lack of power to operate the pumps.
 
I hope this helps.

Still believe

 That the systems in 3,4 and possibly 1 will actually be able to cool once power is connected?

What the Radiation readings really mean

Radiation's biological effect on a person's body is commonly measured in microsieverts.
At one point today, Japan's stricken Fukushima reactor No. 2 was reported to have been emitting up to 8217 microsieverts of radiation.
As a comparison, a person can expect to be exposed to 20 microsieverts from a single chest x-ray, 240 microsieverts from the food they eat every year, 350 microsieverts annually from radiation that comes in through the Earth's atmosphere from space, and around 3000 microsieverts from a single CT scan.
The International Atomic Energy Agency says an average person can expect to be exposed to around 2400 microsieverts per year.
To get ill from a sudden dose of radiation, you would need to be exposed to around 1 million microsieverts (or 1 sievert). Four million will drop your chances of survival to 50 percent.
Six to seven million microsieverts will kill you.

Radiation Chart

another way to explain it graphically.

Light water reactor poor choice?

Out of options
A surprising culprit in the nuclear crisis
By Leon Neyfakh

March 20, 2011

As the nuclear crisis in Japan unfolded last week, experts scrambled to understand why things were going so horribly wrong. While no one was surprised that a 9.0 earthquake and a massive tsunami had caused severe and complicated problems, critics charged that various aspects of the Fukushima Daiichi plant’s design had made the catastrophe more perilous than it had to be. Some considered the particulars: Why had the cooling system’s backup generators been installed in a way that left them vulnerable to the tsunami? Why did the reactors use a cost-saving containment vessel whose disaster-worthiness had been repeatedly questioned by scientists? Why had the pool of spent fuel rods overheated?
   
For those taking a longer view, however, there is a larger question looming over the disaster: Why was Japan, a nation at high risk for earthquakes and natural disasters, using a type of reactor that needed such active cooling to stay safe? And the answer to that doesn’t lie with Japan, or the way the plant was built. The problem lies deeper, and concerns the entire nuclear industry.

Japan’s reactors are “light water” reactors, whose safety depends on an uninterrupted power supply to circulate water quickly around the hot core. A light water system is not the only way to design a nuclear reactor. But because of the way the commercial nuclear power industry developed in its early years, it’s virtually the only type of reactor used in nuclear power plants today. Even though there might be better technologies out there, light water is the one that utility companies know how to build, and that governments have historically been willing to fund.

Economists call this problem “technological lock-in”: The term refers to the process by which one new technology can prevail over another for no good reason other than circumstance and inertia. The best-known example of technological lock-in comes from the 1970s, when VHS and Betamax, two different kinds of videotape, competed in the market until VHS gained a slight lead and then leveraged it to total domination. Whether the VHS format was actually superior to Betamax didn’t matter. After the lock-in, consumers no longer had a choice.

Much more is at stake in nuclear power. Some reactor designs are safer than others in an accident; some are more efficient than others in their use of fuel and produce less nuclear waste. The fact that the industry settled on light water over any number of alternatives was determined in the years after World War II, when the US Atomic Energy Commission and Navy Admiral Hyman Rickover made a series of hasty decisions that irreversibly set the course for how nuclear power plants around the world are built today.

“There were lots and lots of ideas floating around, and they essentially lost when light water came to dominate,” said Robin Cowan, a professor at the University of Strasbourg and the University of Maastricht who wrote a 1990 paper in The Journal of Economic History about the nuclear industry’s technological stagnation. “The market tends to choose a dominant design before it’s optimal, and it tends to under-explore.”

The fact that light water was used in the first American nuclear power plant in 1957 made it that much more likely that subsequent nuclear plants in the United States and around the world would use it, too, as utility companies decided, one after another, that it was in their best interest to use a well-established reactor technology instead of trying something more experimental. The result was that many potentially viable proposals — including plants that, in an emergency, wouldn’t have depended on the diesel generators that failed at Fukushima — were stifled before anyone could properly evaluate them.

Lately, concerns about fossil fuels have brought new enthusiasm for nuclear power, and led scientists back to the task of inventing new and better types of reactors. But even as innovators succeed at securing funding and attention for their research, the power of technological lock-in still hovers over the practical questions of who will design and build them. As the catastrophe in Japan inspires a new reckoning with the benefits and perils of nuclear energy, the industry’s lock-in will need to be part of the discussion.

When nuclear fission was initially harnessed for energy, its first successful use was not in power plants, but in submarines. After the conclusion of World War II, the Navy wanted a submarine fleet that could stay underwater for long periods of time without having to come up for fuel. The key would be nuclear energy. In 1946, Rickover was put in charge of figuring out what kind of reactor should be used in these submarines.

Rickover had several kinds of reactor designs to choose from besides light water, which at the time was the exclusive domain of the American manufacturing giants Westinghouse and General Electric. The most significant differences among them had to do with the materials used to cool their cores and to moderate the fission process. The so-called heavy water reactor, developed in Canada, used a coolant based on a different isotope of hydrogen from that in normal water. (Light water is just normal H2O.) Gas-cooled reactors, meanwhile, which had their origins in Great Britain, did not use liquid coolant at all. The breeder reactor, developed by General Electric, relied on liquid sodium as a coolant.

Each one had its advantages. The sodium-cooled breeder reactors were more economically efficient; the gas-cooled reactors took longer to get hot, and would probably not melt down as quickly if their power failed. But Rickover’s choice ultimately came down to size. “He needed a reactor that would fit inside his submarine,” said Charles Forsberg, executive director of the MIT Nuclear Fuel Cycle Project. Because reactors built with light water technology could be much smaller than any other kind, Rickover decided they were the Navy’s best bet.
At that point, the nuclear power industry was still anyone’s game. Though Rickover’s decision certainly gave Westinghouse reason to be optimistic about the future of its light water technology, it did not discourage the Canadians from pursuing heavy water nor the British from pursuing their gas-cooled systems. In fact, there was a brief window when it looked like the British had a big win on their hands with the completion of the world’s first commercial nuclear power plant in August 1956. But as it happened, the Americans were right behind them: A little over a year later, the first US nuclear plant went live in the town of Shippingport, Pa. It was a light water plant.

It had not been a foregone conclusion that Shippingport would be powered by light water technology. In fact, according to Cowan, some of the nuclear physicists on the US government’s payroll at the time insisted that they had not done enough research on light water to conclusively declare it was the best option available. But a few factors tipped the scale. First of all, Rickover was in charge of overseeing its construction. And the US government considered it a matter of national security to get the plant built as quickly as possible, in order to send a swift signal to the Soviet Union and the rest of the world about America’s technological supremacy. Light water was familiar, domestic, and the most likely to work immediately.

“We were competing with the rest of the world, trying to become leaders in nuclear technology, and we wanted to quickly, without straining the budget, build some demonstrations,” said Ashley Finan, a PhD candidate at MIT’s department of nuclear science and engineering who has been studying the history of innovation in nuclear technology since World War II. “The reactors that were most available were the light water reactors, so that’s what we used.”
It was after Shippingport that light water truly took off, as both Westinghouse and General Electric — which had focused all of its resources on developing water reactors after some early experiments with breeders — made an aggressive push on behalf of the United States for dominance of the global market. “They knew there were other technologies in the wings that might be better,” said Cowan, whose paper on the rise of light water technology was recently featured on the economics blog Marginal Revolution.

By 1970, according to Cowan’s research, light water had been adopted by every major consumer of nuclear power in the world except for Canada and Great Britain, who were at that point still trying to make a go of heavy water and gas-cooled, respectively. According to Finan, the federal regulations in the United States essentially assumed that plants would use light water technology, making it extremely difficult for any other type of plant to get clearance at all.

By 1986, more than 80 percent of all nuclear reactors in the works around the world — excluding the Soviet Union — were of the light water variety. Japan’s reactors were built in the 1970s based on light water designs by General Electric, Toshiba, and Hitachi. Today, the vast majority of all nuclear power plants around the world — and all 104 operating commercial reactors in the United States including the Vermont Yankee plant and the Pilgrim Nuclear Station in Mass. — use light water technology.

Light water may have been — and may still be — the best option available. Certainly the technology has been refined since its early days, and newer reactor designs have advanced safety features that partly address the cooling problems suffered in Japan. But the trouble with technological lock-in is that you never really know: With only one choice, it’s impossible to tell whether you might have been better off with one of the early alternatives.

“Once the bandwagon gets rolling and starts to accrue advantage, it tends to get more advantage,” said W. Brian Arthur, the economist at the Santa Fe Institute who introduced and coined the concept of technological lock-in in the early 1980s. “Even if it’s not the best to start with, if it just gets ahead by chance, then it tends to get further ahead because of all the advantages.”

As soon as one technology gets a significant leg up in the competition, it becomes extremely difficult for rivals to derail it. Apart from the VHS-Betamax competition, the effects of lock-in can be seen in the dominance of the QWERTY configuration of keyboard letters, and in the victory of internal-combustion automobiles over Stanley Steamers in the early 20th century.

In the nuclear industry, more experimental approaches were decisively frozen out before their merits could be properly tested. A good example of this happened in the mid-’70s, when an American company called General Atomics tried to break into the market with a type of “high temperature” gas-cooled reactor that could cool itself in an emergency using the natural circulation of air instead of relying on motor-powered pumps and valves. One might have thought this cooling system would be seen as a major achievement — and certainly, a useful option for sites like Japan, where there’s a high risk of natural disasters knocking out a power supply. But of the seven high temperature graphite-gas-based power plants that General Atomics had been contracted to build by 1976, all but one ended up being canceled.

“One of the, let’s say, challenges in nuclear technology is that the plants are expensive and owners are usually risk-averse,” said Mujid Kazimi, director of MIT’s Center for Advanced Nuclear Energy Systems. “Part of it, also, is that it takes a long time to get a license for a new reactor concept. If you have a new idea and you want to eventually get it into the market, you need a license, and that can take years.”

Ultimately, experts say, overcoming technological lock-in requires the deliberate participation of the federal government, at least by partnering with private companies and university researchers trying to introduce new ideas. Trying to disrupt a locked-in technology is an extremely risky proposition, and in most cases, it’s too tall an order for a single company to take on alone. As Arthur put it, “If everybody’s clapping to one beat and you try to start clapping to a different one, it’s a little hard to take over. It can be done, but you need a whole bunch of people and it needs to be loud.”

There are signs that that’s starting to happen. Over the past decade or so, concerns about climate change and fossil fuel dependence have led to something of a renaissance for the nuclear industry, which has started to look into new ideas that don’t involve light water, and some that do. In 2002, the US government unveiled an initiative aimed at helping private companies develop and bring to market new nuclear technologies. And according to Finan, the federal regulations that are used to license new nuclear technology in the United States are in the process of being rewritten so that they don’t favor light water reactors as heavily as they used to.

Meanwhile, a number of promising projects are underway around the world. Toshiba is working on a sodium-based breeder reactor. The Department of Energy is working with General Atomics and Westinghouse on a high-temperature gas-cooled one. In India, there are plans for a reactor that uses thorium and molten salt. Meanwhile, several manufacturers are exploring designs for so-called modular reactors that could radically change the industry — and make it friendlier to innovation — by allowing utilities to build small plants and expand them as necessary instead of going all in with a multibillion dollar investment right away.

Whether any of these ideas catches on will depend in part on the industry’s willingness to take risks. It will also depend on circumstances, though, just as it did back in the 1940s when light water first emerged. As the nuclear industry comes to grips with the tragedy in Japan, experts hope that one effect will be to encourage a rare, concerted push that forces a locked-in market to open up again.
“There are certainly innovative reactors available to be developed that have safety features we would value,” said Finan. “I hope we’ll see a more open-minded approach.”

Leon Neyfakh is the staff writer for Ideas. E-mail lneyfakh@globe.com.
© Copyright 2011 Globe Newspaper Company.

Interesting article

  Its interesting to note that mums the word until something happens. Then everyone has an opinion the shoulda,coulda, woulda syndrome.

  As far as the "technology lock in" cliche.  Sometimes you have to pick something that does work, and go with it.  It happens all around us. Take the automotive industry. We would not be driving anything if we were to wait for the ultimate fuel efficient, environmentally safe, passenger safe car to drive. the technology evolves to the needs, and desires of those facets.

  The fact of the matter is that these designs are all over the world, and no one made other countries use the PWR/BWR designs.

  The thing with nuclear reactors is this. Once built you just do not tear it down, and build the next evolution in technology on the same site. There are some that have been operating for 40 plus years.  I look at as what they have done to save the amount of CO2 in the atmosphere.  The waste though more concentrated goes back where it came from. 


 If you take all the pollution from all the CO2 emitting power plants, vehicles, ships, etc I think you will find that out weights the amount of radioactive pollution power plants, and nuclear ships have contributed to the environment

 People will always be afraid of what they do not fully understand.  We as society associate nuclear energy with the "bomb", and its after effects. Which is a very different facet. But yet most people do not think twice about the radioctivity they are around day to day with radon gas, the sun, xrays, ct scans etc. 

   They do not realise that the co2 in the atmosphere we produce hangs around just as radioactivity does. How much petroleum thats been spilled all over the earth since its discovery. Radioactive waste is a drop in the bucket.

  I myself think nuclear is the "technology lock in" today because solar, and wind requires much larger footprints to achieve the same outputs in electricity. These solar, and wind technologies are another example of "technology lock ins".

 Mark Eatherton if you happen to read this post. There was a thread sometime ago you posted about these small modular reactors that could be used for say a community, or even a home. I could not think of how it was brought up to do a search.  I always thought that would be the way to go.

 In the end I hope Japan gets these reactors under control, and it is determined that the amount of spill was not that bad compared to the damage done. I think it will prove the containments robustness even with the lack of cooling. But I think the big issue will be how to manage the spent rods better which in the end has been the real problem this far in to the game......that we know of.


Gordy

Public perceptions

People are paranoid about accidental radiation releases from nuclear power plants, but don't realize that coal fired plants release more radiation into the environment than all the nuclear plants and past accidents combined.

http://www.scientificamerican.com/article.cfm?id=coal-ash-is-more-radioactive-than-nuclear-waste

Exacly Mike

  What about all the glow in the dark radium watch dials.  Lots of ladies in the factory painting the dials were getting mouth cancer from always licking the brush to keep a point.
  God only knows what we deem safe today will be unhealthy in 10 years.

Might be a light at the end of the tunnel

I meant to state that the PWR type of reactor might have been a poor choice for seismically active areas near the ocean. Of course we have to deal with what we have not what we wish we had.

I think this disaster will make people look at what might be required to retrofit these older designs so they can be made safer in the event of power to the cooling systems being cutoff for extended periods.

All industries get blind sided by disasters like this, you can't protect against any conceivable event and still remain practical. From what I've read today in the WIKI article I think they are pretty much on the road to getting the cooling pond problem under control. Next they have to figure out how to control that one reactors cooling and then there is the question about entombing the destroyed reactors and finding a rational way to handle the nuclear waste (we in the US are guilty on that front).

As you stated, hopefully this can be done without any large scale release of radioactive material.

Bob

Nuke thing is so yesterday

This week we have a new war and as a bonus this week.....another leak in the gulf http://www.examiner.com/environmental-news-in-tallahassee/potential-new-deep-water-oil-spill-gulf-of-mexico-100-mile-sheen-reported
Try to stay focused guys lol

In the words of Don Henley

 The bubble headed bleach blonde comes on at 5.  Its interesting when people die give us dirty laundry. 

  The media never had so much to talk about their pissing their pants wondering what alert to put in the ticker next.  Focus people. LOL