Merged nuclear power safe?

[Rasmus]

Not at all. Japan has a significant quake risk,

Yes. And the plant has been build to withstand the quakes it was likely to discover and many quakes it was even very unlikely to discover. The Wikipedia page had just one other earthquake of the same magnitude - and that did not occur in Japan. It is not like they ignored earthquakes or anything.

it is the second biggest economy in the world, the cost of the risk occurring is huge, new designs that are much safer are available for a cost much less than the risk.

The potential cost of the risk would be huge, yes. But you need to factor in the likelihood of the risk materializing.

Engineers from the time say some of those risks were identified back then, but not addressed.

Right. Were they more specific than that in any way? I can easily imagine that nobody did much about a 20.0 quake, e.g.

 

[a_unique_person]

Yes. And the plant has been build to withstand the quakes it was likely to discover and many quakes it was even very unlikely to discover. The Wikipedia page had just one other earthquake of the same magnitude - and that did not occur in Japan. It is not like they ignored earthquakes or anything.



The potential cost of the risk would be huge, yes. But you need to factor in the likelihood of the risk materializing.

In the world, a quake that big happens every year, on known major fault lines. Japan sits right on top of one. It's not like it's the whole world that is at risk, the areas at risk are confined to particular areas. They could also afford the new designs.

 

[Aepervius]

In the world, a quake that big happens every year, on known major fault lines. Japan sits right on top of one. It's not like it's the whole world that is at risk, the areas at risk are confined to particular areas. They could also afford the new designs.

Again it is NOT the quake that did them in. It was the tsunami. And even Japan do not have Tsunami that large that often. And before you cite large tsunami of 100 m, be aware of the circumstance and the concept of funneling.

 

[BenBurch]

In the world, a quake that big happens every year, on known major fault lines. ...

Not even close to true.

 

[Belz...]

Not at all. Japan has a significant quake risk, it is the second biggest economy in the world, the cost of the risk occurring is huge, new designs that are much safer are available for a cost much less than the risk.

Engineers from the time say some of those risks were identified back then, but not addressed.

I don't think it's reasonable to expect them to dismantle things when something better is developped. Those plants had an operational lifespan. It's easy to say they should've replaced it when you would never personally have had to finance that operation.

 

[Java Man]

Again it is NOT the quake that did them in. It was the tsunami. And even Japan do not have Tsunami that large that often. And before you cite large tsunami of 100 m, be aware of the circumstance and the concept of funneling.

While the concept of funneling is true and leads to increases in the wave height. The wall was only 20 feet (a little over 6 m tall)

Take a look at this picture:

http://www.andaman.org/mapstsunami/SriLankatsunami.jpg

And see how much the wave heights change in a short span of distances. And this is Sri Lanka which is at the other side of the ocean from the epicenter.

In the image you see variations ranging from two to three times bigger than in other areas. Not to mention that the sea structures around the plant could lead to funneling and increased wave height at some point.

Then there is also the concern that the wall could be broken by something big being carried by the water either coming in or going out.

Back to the point. As long as prevention is thought of as things we have to stop things rather than things we need to keep safe regardless of, then we'll have issues.

If we turn to keeping the generators water tight in a structure capable of supporting 20m-30m water pressure (not very hard to accomplish). If we think of designs capable of plugin aux power from mobile generator units. Two simple things that can't cost too much would have prevented so much trouble.

 

[Java Man]

It's easy to say they should've replaced it when you would never personally have had to finance that operation.

Which operation? The remodeling operation? The cleanup operation? or the rebuilding operation that will now be required anyway?

 

[Java Man]

You can come up with any hypothetical that will take out a plant or a plane or anything. You are doing a post hoc analysis by elevating all the accident scenarios—everything looks like a failure under that type of analysis. You keep assuming that it is possible to design for everything failing—that is not possible. If you actually try to do that, we would never build any plant or drive a car or fly any plane or actually walk out of the front door. I suggest you look up PRA.

Am I assuming it is possible to design for everything failing? I'm not saying you can counter all failures, but you can at least anticipate them. I'm saying you should ask "what happens if this fails or is not enough". As was the case with the wall. You can't build an infinitely tall wall, but you can have a backup in case it is not enough. In this case it was not enough. You can have a better design for the spent fuel ponds that anticipate failure in the cooling. Be prepared to bring mobile generators to anywhere in Japan within 24 hrs.

A great deal of trouble would have been mitigated if some things were looked into deeper instead of just saying, "oh we have the backup generators", "oh we have the wall". I get the feeling they just ran through a checklist to see if they had it, but not to see if they would have it during a crisis and what would be the backup then.

"No plan of operations extends with certainty beyond the first encounter with the enemy's main strength" ((no plan survives contact with the enemy), Helmuth von Moltke) As we've seen here the plans failed because once in contact with the real life scenario of a crisis things quickly became uncertain and the plan was designed around a series of events and not a series of failures. If there is a earthquake, if there is a tsunami, if there is a power outage. Rather than if the wall fails, if the generators fail, if power isn't restored in a week, etc.

 

[Belz...]

Which operation? The remodeling operation? The cleanup operation? or the rebuilding operation that will now be required anyway?

That's ridiculous. Of COURSE the plant will have to be replaced at some point. But replacing it years in advance means you're paying for the re-construction more often. Did you even follow the conversation ?

 

[Java Man]

But replacing it years in advance means you're paying for the re-construction more often. Did you even follow the conversation ?

That's quite obvious and no need to follow the conversation to know that. If you have to replace an installation because there is a new safer model you have to pay for it. That's a no brainer. If you do it before the expected life of the installation you're doing it more often than expected. That's another "duh" moment you're trying to push to us as some revealing fact.

I'm not asking the plant be replaced five years after being commissioned, but 40 years? Give me a break.

What you're trying to sell us is that we are all victims of fate. That we can not upgrade a power plant 25 or 30 years into its lifetime because a new safer model was designed 20 years after it was built. Thirty years sounds reasonable. Why wait until the last, specially knowing it has serious design deficiencies.

You're trying to convince us that we should put profit ahead of security. And I don't mean some profit, but more profit. Excess profit which will probably go in the cleanup unless of course they're clever enough to bill the government and the Japanese population.

Please don't take this as an anti-capitalist stance. But rather a pursue of security and good business practices. You've already made a statement that this was a very improbable scenario and yet it happened. Improbable as it is it happened and still you propose we delay upgrades of other similar designs because it "costs too much". What chance do other power plants of similar design have if Japan fell victim to an event that according to you "wasn't supposed to happen". From such an angle it makes perfect sense to replace 30 or 40 year old plants as soon as possible even if they're perfectly well.

 

[Bill Thompson]

Does the accident at the nuclear power plant in Japan mean nuclear power is unsafe or does it mean that earthquakes are unsafe?

 

[Belz...]

That's quite obvious and no need to follow the conversation to know that. If you have to replace an installation because there is a new safer model you have to pay for it. That's a no brainer. If you do it before the expected life of the installation you're doing it more often than expected. That's another "duh" moment you're trying to push to us as some revealing fact.

It seemed to escape you.

I'm not asking the plant be replaced five years after being commissioned, but 40 years? Give me a break.

40 years isn't such a huge amount of time when you consider how much time it takes to build these damn things.

That we can not upgrade a power plant 25 or 30 years into its lifetime because a new safer model was designed 20 years after it was built.

I never said nor implied such a thing. But in hindsight, of COURSE they should've replaced it. But they didn't have the benefit of that hindsight three weeks ago.

Thirty years sounds reasonable.

Okay. Let's say we're in 2001 and the exact same event occurs; tell me you wouldn't be saying the exact same thing, but replacing "thirty" with "twenty" ? That's the core of what I was saying. The benefit of hindsight is blinding you.

You're trying to convince us that we should put profit ahead of security.

Again, you're not very good at following the conversation. I'm not saying we _should_. I'm saying we _do_.

You've already made a statement that this was a very improbable scenario and yet it happened.

Yes. **** happens and there's little to do to stop it, and there's always going to be a bigger disaster that manages to knock all your backup plans down.

 

[BenBurch]

Does the accident at the nuclear power plant in Japan mean nuclear power is unsafe or does it mean that earthquakes are unsafe?

The latter, obviously.

 

[a_unique_person]

I don't think it's reasonable to expect them to dismantle things when something better is developped. Those plants had an operational lifespan. It's easy to say they should've replaced it when you would never personally have had to finance that operation.

The operational lifespan for something with known defects was well and truly over. We are talking about very early nuclear technology designed in the 1960's. If state of the art reactors don't incorporate much better cooling systems, then why did they bother with them? There is a reason reactors have been designed with fully self contained passive cooling systems so they can better cope with quakes, which cause power outages.

Japan trains it's citizens from early ages to cope with major quakes, they have a strict building code to cope with major quakes, they shut down their trains in the even tof a major quake. It's a given in Japan that there will be major quakes. Tsunamis are a part of major quakes. Every time there is a major quake near a shore, the first question is, is there a Tsunami coming.

 

[Java Man]

Okay. Let's say we're in 2001 and the exact same event occurs; tell me you wouldn't be saying the exact same thing, but replacing "thirty" with "twenty" ? That's the core of what I was saying. The benefit of hindsight is blinding you.

No I wouldn't because they wouldn't have existed by then. Generation III reactors are a recent thing and came into service in Japan in the second half of the 90's. So expecting them to be replaced overnight and ready by 2001 is ludicrous. But move ahead 15 or 16 years and still no change is just negligent action trying to maximize profit from and outdated design. Notice that Gen III designs (http://www.world-nuclear.org/info/inf08.html)

• a standardised design for each type to expedite licensing, reduce capital cost and reduce construction time,
• a simpler and more rugged design, making them easier to operate and less vulnerable to operational upsets,
• higher availability and longer operating life - typically 60 years,
• further reduced possibility of core melt accidents,*
• resistance to serious damage that would allow radiological release from an aircraft impact,
• higher burn-up to reduce fuel use and the amount of waste,
• burnable absorbers ("poisons") to extend fuel life.

The benefits are right there, including the added lifespan and reduces upfront cost.

If this had happened in the first half of the 00's and work was underway to build the new replacement reactors, well it would say it was bad luck. It's hard to get a new design in the same decade as you roll out a replacement for all units. But a little over two decades later (from early 90s to early 10's) and they're just getting started on seeing when they'll start disassembling it, mmhhhh. Just plain negligent.

 

[timhau]

In the world, a quake that big happens every year, on known major fault lines.

This was a 9.0 magnitude earthquake. Including this one, history knows a total of 5 earthquakes that were measured at 9.0 or above, and Wikipedia lists 4 others from further back in history that, according to estimates, might be 9 or bigger. So that's not only wrong, it's really wrong.

 

[r-j]

This is starting to remind me of a scene from Jurassic Park.

 

[qarnos]

No I wouldn't because they wouldn't have existed by then. Generation III reactors are a recent thing and came into service in Japan in the second half of the 90's. So expecting them to be replaced overnight and ready by 2001 is ludicrous. But move ahead 15 or 16 years and still no change is just negligent action trying to maximize profit from and outdated design.

...

The benefits are right there, including the added lifespan and reduces upfront cost.

The added life-span will only reduce costs if the reactors are allowed to remain in service for their full life-span. Yet, here you are arguing that the previous generation should not have been allowed to remain in service for their prescribed life-span because something better had come along.

 

[BenBurch]

Something better always comes along.

The first real public railroad, the Stockton and Darlington, there was a fatal accident with a person on the tracks the very first day. (And the person was an important politician, too.)

Locomotives back then did not have brakes. The tender did, but the braking action was fairly minimal. It was simply impossible to stop a locomotive quickly. Westinghouse's air brakes were 50 years in the future.

Should the S&D have been closed, or reverted to horse running until the air brake?

And that air brake? Not the last word in train stopping. It has been improved over the years so that we now have electronically-controlled air brakes that can apply brakes in the whole train at once rather than wait for the brake pipe pressure reduction to propagate back to the end of the train (a long time on a 10,000 foot train) and we have locomotive dynamic braking and we have mid-train power to apply locomotive braking mid-train.

Maybe railroads should have been put off 180 years?

Think of the tens of thousands of lives you would have saved!

 

[Toke]

This is starting to remind me of a scene from Jurassic Park.

I am reminded of what I think is a Ray Bradbury story.
It is realised that a runaway reaction in the nuclear reactor would ignite the whole atmosphere, they decide not to tell the operators on the control rod handle as they are stressed enough as it is.

I kind of hope the worst possible case here is only a limited area contaminated for centuries.