Massive Quake Hits NE Japan

[Barnabas]

That is what everybody fears, if this happens in Japan, then the rest of the countries with nuclear plants would be super screwed were they to suffer a similar earthquake

[kittenOFchaos]

Ogie this is nothing on the scale of Chernobyl, it shouldn't even be mentioned in the same sentence as difference in degree is so vast.

[kittenOFchaos]

That is what everybody fears, if this happens in Japan, then the rest of the countries with nuclear plants would be super screwed were they to suffer a similar earthquake

Earthquakes don't happen without a reason. You build your nuclear power plants this close to a subduction zone, you make sure they can cope with significant seismic activity. In Britain or France...the risk is minute.

[Ogie Oglethorpe]

Can't speak to Japanese codes or specific seismic design criteria for Japan. Don't even know if the quake took out the diesels or if that was a function of the tsunami and proximity to the coast. All is supposition at this point.

[Ogie Oglethorpe]

@guy

Probably a kernel of truth with respect to commercial and residential construction. Wrt nukes they are required to withstand Design basis seismic events depending somewhat on seismic surveys.

http://www.world-nuclear.org/info/inf18.html

Remember the seismic numbers given in design
basis are for an epicenter at the site proper.

[Ogie Oglethorpe]

Ogie this is nothing on the scale of Chernobyl, it shouldn't even be mentioned in the same sentence as difference in degree is so vast.

As I indicated the severity of the accident all depends on the dispersion of radioactive nuclides and the population density affected. In any event catastrophic failure of containment and what I interpret as concerns over loss of fuel cladding means that it all depends on how well the reactor held together upon the explosion.

[Docfeelgood]

Who else works in the industry on these forums? Would like to compare notes. Have been traveling the last few days so am missing details. Never would have imagined catastrophic loss of containment.

Thank the maker! finally, someone who knows what they are talking about.

[Jon Miller]

I heard that the plants were set up to handle 8.25 earthquakes and that the diesel generators were taken out by the tsunami.

JM

[Docfeelgood]

olgie, they are talking about more than one reactor, would this be a super mettdown should more than one ?

[Ogie Oglethorpe]

Thanks JM. I suspected the wave did the bulk of the damage.

[Docfeelgood]

On ABC that Jap/American physicist said they were 40 years old and they were only made for a 7 something.

[Docfeelgood]

I'm starting to get the impression the Gov is handing out a lot of BS!
One news agency is saying that the dose of radiation is a full years dose every hour.

Japanese officials confirmed a radiation leak at the Fukushima Daiichi nuclear power plant -- one of two such plants........Japan's nuclear agency said serious damage to a reactor at the plant was "unlikely,"................A nuclear expert said a meltdown may not pose widespread danger........Government officials were reportedly handing out iodine to protect Japanese citizens from radioactive exposure....Japan has declared states of emergency for five nuclear reactors at two power plants after the units lost cooling ability.......A "meltdown" is not a technical term. Rather, it is an informal way of referring to a very serious collapse of a power plant's systems and its ability to manage temperatures

[Ogie Oglethorpe]

At Doc

Likely same scenario in other reactors. Tsunami took out backup power to run coolant and or Emergency core cooling system pumps. They are off the grid and can't power the essential safety equipment. Even though they likely scrammed (killed the reaction) they have no means to dissipate the residual heat of the reactor. They are attempting back up means to put in coolant but may have no reliable means to do so. Eventually the steam pressure become too great and things fail explosively so. It becomes especially dangerous if the fuel becomes uncovered as the residual heat can cause the fuel to exceed safety limits. Bad things like steam reaction with zircaloy cladding starts to happen thus causing additional heat and fuel damage.

Backup power and safety systems are required to be available upon criminal penalty. This design consideration of loss of safety essential equipment, power is it would appear be beyond design basis.

[germanos]

The bastards are right though Doc. An aircraft crashing in the ocean MAY not prove to be fatal for it's passengers. lone survivor

Whether that means you shouldn't worry if your plane goes down is another story .

[Ogie Oglethorpe]

If this is true this is good news. Reactor remains intact.

http://www.bbc.co.uk/news/world-asia-pacific-12720219