US experts fear 'Chernobyl-like' crisis for Japan - an "act of desperation"

http://newsinfo.inquirer.net/breakingnews/world/view/20110313-325126/US-experts-fear-Chernobyl-like-crisis-for-Japan

US nuclear experts warned Saturday that pumping sea water to cool a quake-hit Japanese nuclear reactor was an "act of desperation" that may foreshadow a Chernobyl-like disaster.

Several experts, in a conference call with reporters, also predicted that regardless of the outcome at the Fukushima No. 1 atomic plant crisis, the accident will seriously damage the nuclear power renaissance.

"The situation has become desperate enough that they apparently don't have the capability to deliver fresh water or plain water to cool the reactor and stabilize it, and now, in an act of desperation, are having to resort to diverting and using sea water," said Robert Alvarez, who works on nuclear disarmament at the Institute for Policy Studies.

"I would describe this measure as a 'Hail Mary' pass," added Alvarez, using American football slang for a final effort to win the game as time expires.

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plain water for cooling purposes? Why is it desperation if it gets the job done?

and sea water is full of salts that will not react well with the reactor...could make the bad situation that much worse as it corrodes away the metal and concrete around the nuclear materials.

This means they have no options left to bring the reactor under control and bring it back online.

This reactor is dead.

seawater will ruin the reactor, whereas fresh water or coolant would not. Therefore, they would wait until either the reactor is already ruined or until it's the last shot to prevent a catastrophe.

will stop the fission process and cool it.

Nothing but the expiration by fission of all the fissile material will "stop" the fission process.

A nuclear reactor is forever....

And what happens when the boron is not added, because all the humans have died or fled for safety?

Nothing but the expiration by fission of all the fissile material will "stop" the fission process.
=========================

How do you think they shutdown the reactor to service / refuel it?

Ever hear of something called "control rods".

The fission process works via a chain reaction. Each fission has to trigger
exactly one more fission on average so the reactor operates.

However, if you put a rod of a material that absorbs neutrons without fissioning,
then you don't have continuity of the chain reaction and the fission chain dies out.

That was what happened as soon as the plant instruments detected the quake. The
control rods were dropped and fissioning stopped.

What needs to be cooled now is the heat produced by radioactivity, not fissions.

PamW

CALL CONGRESS RIGHT FUCKING NOW!!!1111

:rofl:

the fission will continue until all the radioactive material is reduced to lead or other non-radioactive material.

Fission is a natural process that cannot be stopped by any force known to Man or God. It can only expire by the exhaustion of the radioactive material through the process of self-destruction that fission is.

Sorry to get so technical--it is my engineering training.

Furthermore, there is a good possibility that the sustained reaction is not completely stopped by the control rods at this point, which were likely damaged, at least by now, considering what the reactor has experienced.

Reactors are dependent upon geometry, purity, and stability of the pile, none of which exists any longer in a partially-melted core flooded by seawater...

the fission will continue until all the radioactive material is reduced to lead or other non-radioactive material.
================

NOPE - it has to decay to lead in order for there to be no radioactivity.
That is different than fissions.

The fissions stop completely when none of the material is fissile - that doesn't
mean it has to go down to lead.

Although there may be occasional fissions - due to cosmic ray neutrons - a few
fissions here and there doesn't amount to any amount of energy on a macro scale.

Each fission gives you 200 MeV of energy. An MeV is about 10 to the -13-th Joules.
So one fission is about one hundred-billionth of a Joule - a miniscule amount
of energy.

In order to have any macroscopic amount of energy being generated, you have to have
LOTS and LOTS of fissions. You can get that in a reactor if you can sustain a chain
reaction.

However, when the control rods are dropped into the reactor, which happened the first
instant the plant detected the quake - there's enough neutron absorbing material in
those rods so that the plant can't sustain a chain reaction.

Additionally, by a phenomenon known as "Doppler broadening" the fact that the core is
overheating also results in parasitic neutron absorption.

So there no fission chain reaction going on.

What is providing the heat is radioactivity and not fission.

Try Google on "decay heat"

PamW

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My patience with this process is exhausted.

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but thanks. It's nice to banter with someone who can do so in logical thoughts and grammatical English.

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there are these rules, you see

You do know, I hope, that radioactivity is the product of fission? The fact that natural radiation is "only" a proton, neutron, electron and/or gamma ray shed by the atom, instead of a complete "splitting" of the atom, is insignificant?

ra·di·o·ac·tiv·i·ty
n.
1. Spontaneous emission of radiation, either directly from unstable atomic nuclei or as a consequence of a nuclear reaction.
2. The radiation, including alpha particles, nucleons, electrons, and gamma rays, emitted by a radioactive substance.

AND THEN THERE'S

nuclear fission
n.
(Physics / General Physics) the splitting of an atomic nucleus into approximately equal parts, either spontaneously or as a result of the impact of a particle usually with an associated release of energy. Sometimes shortened to fission

SINCE REACTORS DO NOT IRRADIATE THE FISSILE MATERIAL WITH OUTSIDE PARTICLES TO START THE FISSION PROCESS, AND SINCE THERE IS NO WAY TO VERIFY THAT THE CONTROL RODS ARE WORKING, I SUGGEST YOU CONCEDE THE POSSIBILITY THAT THINGS ARE GOING TO HELL IN A HANDBASKET FOR THE FORESEEABLE FUTURE, AND FURTHERMORE, THAT UNDER THE CIRCUMSTANCES, IT'S NOT LIKELY THAT ANYONE WILL BE ABLE TO "STOP" IT.

One involves an atom spontaneously giving off a subatomic particle, the other involves a collision between two atoms (or an atom and a subatomic particle).

Both are exothermic, but on very different levels.

You do know, I hope, that radioactivity is the product of fission? The fact that natural radiation is "only" a proton, neutron, electron and/or gamma ray shed by the atom, instead of a complete "splitting" of the atom, is insignificant?
===============================

You said that you had to go all the way down to lead in order for the fissions
to stop.

That is 100% wrong!!! All you have to have is a nuclide with a zero fission cross section.
That does NOT mean lead.

This is one of those "All humans are Greeks" vs "All Greeks are humans".

You are the one with the wrong set being the subset.

If you want all the nuclear reactions to stop including radioactive decay - then
you have to go down to lead.

But that wasn't the question. It wasn't how to stop all the nuclear reactions -
it was how to stop all the particular reaction of fission.

For that you do not need to go all the way down to lead.

PamW

Releasing a proton or neutron or even an alpha particle does not come anywhere close to splitting something with the atomic mass of uranium into "approximately equal parts."

There's a lot of decay heating going on there now, but no fission. None.

I operated nuclear plants for the Navy and went through their nuclear training pipeline. You weren't a Navy nuclear operator by any chance?

I operated nuclear plants for the Navy and went through their nuclear training pipeline. You weren't a Navy nuclear operator by any chance?
==================

No - I'm a nuclear physicist with one of DOE's national laboratories.

I used to design nuclear reactors though.

PamW

Just wanted to let you know that I appreciate your clear and concise explanations.

It has been twenty years since I worked in nuclear power, and your posts are very helpful.

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will stop the fission process and cool it.
========================

The fission process stopped the instant the plant sensed the earthquake
and dropped the control rods into the reactor.

We have no new fissions and no new fission energy.

The heat that must be removed from the reactor is due to radioactivity of
the fuel. It's not fission energy

PamW

It ensures that the core will not reattain criticality.

sorry to inform you

yup

Are you saying that the reactor has fission chain reactions
going on right now? WRONG!!!

There are no fission chain reactions going on right now.
There's no need to stop any fissioning - because none is
taking place.

The reason you add boron is so that you don't START a chain
reaction - not to stop one that is in progress.

Since water is a moderator, and can help start a chain reaction,
it's standard operating procedure to add boron to the water so
it has a net zero or negative reactivity effect.

Sorry to inform you that you don't understand what is going on
at all.

PamW

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The folks trying to stabilize that reactor don't know what they are doing

yup

:rofl:

An engineer's job, if done ethically, is to design a device to be fail-safe.

Otherwise, the liability lawyers nix it.

Or the board of directors does. Especially after several spectacular technical failures and massive liability lawsuit victories.

A scientist deals only with the theoretical and ideal. When things go pear-shaped, the scientist is long gone, and the techs and engineers and poor slobs chosen for their disposability are sent in to "clean it up".

But nuclear catastrophes cannot be cleaned up with current technology. CANNOT.

A nuclear accident, like a nuclear reactor, is forever. A permanent, polluting blot on the environment.

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Or... the electronics industry... or goodness, pretty much ANY industry?

Can you provide me a list of those "fail safe" devices?

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It goes to far to pretend that any failure (keep in mind... this is after a MAJOR earthquake.) means either a bad design or bad engineering.

For the record... scientists don't design reactors... engineers do.

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Take a look at what happened in Japan. Ignore the nuclear component and just look at all the minor little troubles they've had over the last couple days.

Was there some massive failure in engineering/design that should receive blame?

Of course not. The reality is that their advanced engineering (etc) saved incredible numbers of lives and great amounts of damage. Yes, a "biggest ever in Japan" event would pretty much define the meaning of the word "surprise". Unless things continue to get much worse with the reactors, the earthquake and tsunami are a MUCH bigger disaster.

I asked it elsewhere earlier. We have a super volcano sitting under the Yosemite National Park. It will blow some day. If we're still here when it happens, we're pretty much all dead. Is that a design failure?

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If there were a 8.9-9.1 earthquake near a major hydro-electric dam... what might happen?

Would that mean that there was something wrong with dams in general? That they were poorly designed?

You have a funny and very poor definition of surprise.

Really? "Something that has never happened before" isn't a "surprise"?

I guess that IS funny.

sufficed to say that
if I was to build a nuclear reactor on the side of a super
volcano that didn't have some magical protective shield around
it, then yeah, I'd think that might be a failure of engineering
and safety.

Really? Is it your opinion that things should be designed to withstand ANY POSSIBLE CATASTROPHE?

That's really what I was getting at with my first comment re: "failsafe".

I'm a huge fan of hydro power so let's use that example again. It absolutely CAN happen that a sizable meteorite could strike one and destroy it. In some cases that could kill hundreds of thousands of people downstream. How should their designs be changed?

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Is this your lame attempt to pretend like major earthquakes have never
happened in this region before. Maybe you're suggesting the science of Seismology doesn't exist?
Maybe geology doesn't?

You haven't by any chance noticed that they've had reactors there for a few decades too, have you?

Think it's any coincidence that reactor damage that they've never seen before coincides with natural disaster damage unlike what they've seen?

Any possible, no. Probable, yes, foreseeable, yes.

Sorry. It's amazing how many things become "probable" and "foreseeable" after they happen. That's why designs improve over the years. The reactors being built and designed today would not have left you with a point to debate. You would have just read that they shut down. These much older designs were before some potential issues were considered.

There were calls earlier today for admonition of the politicians who cut funding for advanced tsunami warning equipment for the West Coast.

It's amazing how "probable" and "foreseeable" this need suddenly became. Does it matter than the worst tsunami in West Coast history killed something like a dozen people?

If things can't be built to withstand the probable and
foreseeable, maybe they shouldn't be built at all.

Aaand that takes us right back to all those other examples that you hope to avoid. Bridges failed this week in Japan... as did dams and buildings and refineries and ships and cars and and and and. Why is it that your rule of thumb only really applies to something that you probably opposed before this week's events?

It's forseeable that a big tsunami will eventually hit the coast of Japan again. Think they won't build along the coast ever again?

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No double standard there.

does seismology and geology exist?
did anyone predict that it was possible to have major quake activity in this region, ever?


Of course. Do we never build things that could POSSIBLY fail and kill people?

Why is your answer "no", but you expect the answer to be so obviously "yes" when talking about a reactor?

unlike bridges and cars and
your ridiculous laundry list of collateral items... they generally don't linger around in
nasty pools of dangerousness for 1000s of years

And the issue you're ignoring is... neither do reactors - and what passes for those longstanding "nasty pools of dangerousness" are STILL not as dangerous as the other stuff that we elect to surround ourselves with every day.

They CAN cause large amounts of damage. That damage is not out of proportion to the benefits they provide or the costs/risks of other alternatives that provide the same services. Coal (to use yet another example that you'll ignore) kills large numbers of people all the time... AND it puts radiation into the environment all the time... AND it kills people with black lung and just plain old collapses all the time... AND it has a BIG impact on the environment that could trump all that we've talked about so far.

the ethical engineers were fired or forcibly retired. Now they are mostly in or of Japan (and that's irony for you!)

And as an electrical engineer, and daughter of one, (the whole family engineers in various specialties, actually), I can confirm that the same goes for the electronics industry.

Or is the concept of "the hollowing out of America" unfamiliar to you?

...have been sitting around sucking their thumbs for the last several decades?

Can you describe the last one you can remember?

And as an electrical engineer, and daughter of one

So... that begs the obvious question... what entirely failsafe devices have you or your parent built? :)

Or is the concept of "the hollowing out of America" unfamiliar to you?

Well... yeah... sure. But I always thought that part of that theory was that the tallent base had shifted to... wait for it... Japan. :-)

n/t

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