Earthquake off Japan

[Edi]

Not sure if a new thread should be started, since we're discussing the Japanese earthquake and the nuclear power plant issues, but West Coast Americans should take a look at this:

California's Fukushima in Waiting?

A cascading nuclear disaster is underway in Japan. Could it happen here? You bet.

Consider Diablo Canyon, California's most earthquake-prone nuclear power plant. It was built — on the central coast near San Luis Obispo, half way between San Francisco and LA — to withstand a magnitude 7.5 earthquake. Which sounds reassuring — until you realize that Japan's Fukushima nuclear plant, now in partial meltdown, was engineered to stand up to a 7.9, only to be hit by a 8.9 quake.

(Don't be misled by the logarithmic Richter scale; those numbers are worlds apart: A 7.5 quake is the equivalent to the force of detonating 180,000 kilotons of TNT; a magnitude 8.9 quake: 22 million kilotons — 122 times greater.)

Scarier still, Diablo Canyon was built with the Hosgri Fault, 4.5 kilometers offshore, in mind. But in 2008, scientists discovered a second major fault — the Shoreline Fault — only 1 kilometer offshore from the nuclear plant.

The federal Nuclear Regulatory Commission and the plant's operator PG&E have both declared the second fault a non-issue. But a September 2010 presentation from the California Energy Commission raises troubling questions about the second fault, reporting that its "major characteristics...are largely unknown," including "whether an earthquake beginning on the Hosgri Fault could continue on the Shoreline Fault or vice versa, causing a larger quake than if either fault broke on its own." Most troubling of the unknowns? "Whether this fault or fault displays could extend under the plant." (Emphasis added here and below.)

The commission's presentation blasts PG&E for not investigating known risks, reporting that the fault geology is "not understood sufficiently to rule out [an] earthquake directly beneath the plant," and that the utility "has not assessed the expected ground motions and plant vulnerabilities from such an earthquake."

In light of the fact that the current disaster in Japan has resulted in both earthquake and tsunami damage, it's also troubling that the commission presentation calls on PG&E and the feds to update Diablo Canyon's "tsunami hazard assessment."

(Calls to PG&E, the NRC, and the California Energy Commission were not immediately returned.)

Take a look at the article. In light of what happened at Fukushima, the picture there is more illuminating than any words that could be used to describe it. Diablo Canyon - the place is aptly named...

[Erik von Nein]

Well, that didn't take long. I live near the plant, we've been hearing how terribly vulnerable it is (oh noes!) ever since anti-nuclear activists found out about the fault-line. Sure, it needs some more study, and up in the northern part of the county a completely different fault-line caused a 6.8 earthquake about 7-ish years ago, but we all know why Fukushima's failing today, and it wasn't directly because of the earthquake.

Now, granted, I won't defend PG&E too terribly much, since they've gotten complaints from their engineering staff about being overworked, but I can't see Fukushima happening here. Though they have been storing all their waste in dry-casks on site. But where else is it going to go?

[FSTargetDrone]

SDF Helicopters may be used to drop water on the scene:

Kitazawa: Studying dispatch of SDF helicopters

Defense Minister Toshimi Kitazawa says his ministry is considering a plan to dispatch Self-Defense Force helicopters to spray water on a fire at the No.3 reactor at the Fukushima Daiichi nuclear power plant.

Kitazawa made the remark at a news conference on Wednesday as plumes of white smoke appear to be rising from the reactor.
Wednesday, March 16, 2011 12:43 +0900 (JST)

[Shroom Man 777]

The workers have returned to the plant.

[Edi]

Well, that didn't take long. I live near the plant, we've been hearing how terribly vulnerable it is (oh noes!) ever since anti-nuclear activists found out about the fault-line. Sure, it needs some more study, and up in the northern part of the county a completely different fault-line caused a 6.8 earthquake about 7-ish years ago, but we all know why Fukushima's failing today, and it wasn't directly because of the earthquake.

Now, granted, I won't defend PG&E too terribly much, since they've gotten complaints from their engineering staff about being overworked, but I can't see Fukushima happening here. Though they have been storing all their waste in dry-casks on site. But where else is it going to go?

I won't pretend to know more about that site than you do, but if those are the backup power generation stations behind the main plant building there, they look pretty vulnerable to a tsunami. If there's more of them up on the hills, good.

[starslayer]

I won't pretend to know more about that site than you do, but if those are the backup power generation stations behind the main plant building there, they look pretty vulnerable to a tsunami. If there's more of them up on the hills, good.

I've never been closer to the plant than San Luis Obispo itself, but if those cliffs are anywhere near as tall as many of the others along the California coast, they're easily 15-20 meters high. I'm also wondering where the tsunami would come from; Californian earthquakes, IIRC, aren't generated by the right type of fault to make one on their own, but I'm not sure what the landslide potential of the seabed is around there.

[Sky Captain]

Why those reactors don't have any steam powered backup circulation pumps or steam powered generators? As I understand after shutdown there is still few MW of heat coming from core. Not enough to run main turbine but it should be more than enough to run small turbine able to generate few hundred kW of electricity to power the most essential plant ecquipment. Basically it would make the waste heat from enemy into an asset - as long as you have hot core you have onsite power. I'm sure nuclear engineers have thought about something like that.

[Chris OFarrell]

Funny enough, Chernobyl happened when they were conduting a test to try exactly that.

Albeit a test performed in an absurdly stupid and crazy way.

[Simon_Jester]

I won't pretend to know more about that site than you do, but if those are the backup power generation stations behind the main plant building there, they look pretty vulnerable to a tsunami. If there's more of them up on the hills, good.

I've never been closer to the plant than San Luis Obispo itself, but if those cliffs are anywhere near as tall as many of the others along the California coast, they're easily 15-20 meters high. I'm also wondering where the tsunami would come from; Californian earthquakes, IIRC, aren't generated by the right type of fault to make one on their own, but I'm not sure what the landslide potential of the seabed is around there.

Also, a lot of the fault lines are inland; you're far more likely to see a land-based earthquake than a sea-based one, and you won't get tsunamis from a quake that's centered inland. At least, probably not.

Where Japan has a long history of problems with tidal waves, California doesn't- or rather, doesn't have such a history of tidal waves from quakes along its own shoreline.

Why those reactors don't have any steam powered backup circulation pumps or steam powered generators? As I understand after shutdown there is still few MW of heat coming from core. Not enough to run main turbine but it should be more than enough to run small turbine able to generate few hundred kW of electricity to power the most essential plant ecquipment. Basically it would make the waste heat from enemy into an asset - as long as you have hot core you have onsite power. I'm sure nuclear engineers have thought about something like that.

Does anyone have that?

The problem that I can think of is that the ability of the reactor to make steam can easily be compromised by the measures taken to cool the reactor. Trying to generate steam from a reactor that's undergone a partial meltdown, or that's been doused in seawater, isn't necessarily going to work all that well.

[Thanas]

It's an easy thing to say what others should do when it's their lives on the line and not our own. We may proudly state we'd walk into a near-certain deathtrap, nobly upholding our high-minded morals without hesitation, bravely sacrificing ourselves for a greater good, but until we actually face the moment, words are meaningless. The idea that anyone here is offended because these workers evacuated (after being told to do so by their government, no less) after risking their health and quite probably their lives is grotesque.

They volunteered to go into that nightmare, and now we are bothered because they decided that they can endure no more after enduring so much? Why not, we ask? They are probably dead anyway, so why shouldn't they finish the job? What have they got to lose, right?

The idea that traumatic experience is special to people in these situations is utterly moronic. We're all human beings. Did I say I would nobly uphold high-minded morals, you shitwit? No. I said I'd flog myself into it, overcoming terror and fear by imagining a six year old girl dying in a hospital bed of leukemia because I didn't. You're damned right, high minded shits frequently run like hell. Fathers and mothers, on the other hand, and people with parental instincts in general, however, have plenty of biological impulses that can be manipulated to do the right thing. I have been through plenty in my life and have some idea of my limits. Anguish is a better motivator than idealism, and I'm withdrawing from this thread because my hatred for your shitty little nattering is indescribable. INNOCENT PEOPLE WILL DIE if they don't go in. That isn't idealism, that's a little girl's body destroying her from the inside out. I HATE YOU.

Calm the heck down. Flying off the handle is not going to help anything, and loudly screaming "I hate you" is not impressing anybody either, nor is it considered acceptable behaviour by me.

[Keevan_Colton]

SDF gives up on dousing No.3 reactor
Japan's Self-Defense Forces have postponed a mission to dump water by helicopter on the No.3 reactor at Fukushima Daiichi nuclear plant, because radiation above the facility has climbed too high for such work.

White plumes started rising from the reactor on Wednesday morning. Tokyo Electric Power Company says the vapor was steam caused by water evaporating from the reactor's storage pool for spent fuel rods, which is heating up.

In an effort to avert the fuel rods' exposure, a Self Defense Force CH47 helicopter took off from the Sendai base hauling a large container of water on Wednesday afternoon.

But the plan was aborted after radiation levels above the plant were found to have largely exceeded 50 millisieverts -- the maximum permissible for SDF personnel on a mission.

The Self-Defense Forces say it is ready to recommence work when radiation levels and other conditions allow.
Wednesday, March 16, 2011 19:06 +0900 (JST)

link

[Thanas]

The french nuclear company EDF is apparently preparing to send material and engineers to Japan.

[Keevan_Colton]

Just to clarify on the evacuation of staff front, from what I've read it was an evacuation of all but the absolute minimum staff rather than a complete abandoning of the site.

[Tribun]

This is how the reactor buildings look like at the moment:


Reactor buildings 3 and 4 look pretty much totaled, while the building of reactor 2 is surprisingly intact, but you can see the holes in the structure. That hints that the explosion that was reported indeed was not of the same type as the ones in 1 and 3.

[Zixinus]

After this, I hope we see a revision/worldwide-upgrade on emergency cooling of various reactors. This accident has caused way too much people and property for comfort.

[Sea Skimmer]

Water drops from helicopters will never work well; they are talking about using fire trucks at last. One fire truck will dump more water then a dozen Chinooks working together.

Just to clarify on the evacuation of staff front, from what I've read it was an evacuation of all but the absolute minimum staff rather than a complete abandoning of the site.

It sounds like the whole 50 man crew stayed on site, but took cover in some kind of building for 45 minutes. They only abandon the pumps.

[Keevan_Colton]

This particular type is a really lousy old design. You push the control rods up from underneath using hydraulic rams. Compare this with the current designs, which tend to use electromagnets holding the rods above the core. So that if the power goes poof, gravity does the work of getting them into the core. That also generally means that all you need to initiate the SCRAM is to trip a circuit breaker and the laws of physics take over.

Of course, a big problem seems to be that they simply arent able to get enough water to the site, and arent being as agressive with the use of neutron poison as they could be. Partly due to the use of neutron poisons in large amounts essentially destroying this style of reactor. The proposed 7 and 8 reactors were meant to be of a better design that would have been more tolerant to restoration, but they werent due to start construction until next year.

[bz249]

This particular type is a really lousy old design. You push the control rods up from underneath using hydraulic rams. Compare this with the current designs, which tend to use electromagnets holding the rods above the core. So that if the power goes poof, gravity does the work of getting them into the core. That also generally means that all you need to initiate the SCRAM is to trip a circuit breaker and the laws of physics take over.

Of course, a big problem seems to be that they simply arent able to get enough water to the site, and arent being as agressive with the use of neutron poison as they could be. Partly due to the use of neutron poisons in large amounts essentially destroying this style of reactor. The proposed 7 and 8 reactors were meant to be of a better design that would have been more tolerant to restoration, but they werent due to start construction until next year.

AFAIK only the PWR type reactors have their rods above the zone, the BWR is pushed from down (the upper half of the vessel is steam... I guess that could be the reason). However I do not really understood the problem with the reactor loss? Isn´t this plant meant to be scrapped soon anyway? Or only a part of it?

[Keevan_Colton]

They just got granted a 10 year extension to the life last month. Otherwise, yes, it was scheduled for decomission this year.

[Thanas]

A better picture of the destroyed buildings.

[Keevan_Colton]

AFAIK only the PWR type reactors have their rods above the zone, the BWR is pushed from down (the upper half of the vessel is steam... I guess that could be the reason). However I do not really understood the problem with the reactor loss? Isn´t this plant meant to be scrapped soon anyway? Or only a part of it?

That's one of the reasons that PWR's are the main type of reactor in the US and Europe while BWR's are in a distinct minority.

[Tribun]

Well, it now certaily got decomissioned, although in a rather destructive manner. However, I wonder how much bribery and/or extortion TEPCO did, to keep these ridiculously outdated reactors active.

[Broomstick]

After this, I hope we see a revision/worldwide-upgrade on emergency cooling of various reactors. This accident has caused way too much people and property for comfort.

From my own (admittedly layperson) research, it seems there HAVE been upgrades to cooling systems world wide in most locations already, at least in comparison to Fukushima. Safey-oriented modifications developed and installed after TMI in most GE reactors world wide were not retrofitted to Fukushima. Why, I don't know, they should have been and damn the cost (yes, I suspect cost was a factor there). They might not have prevented all problems, but may have made post-tsunami management of this situation easier and lesser of a mess.

Last night the Grundy county, Illinois officials were on TV. I'm sure most folks wouldn't be aware of it, but Grundy county has three of the Chicago area's nuke power plants. The reporter was fishing for hysteria, I think, but the county commissioner was very calmly discussing that the Grundy county plants, although also BWR's and PWR's, were actually engineer for an 8.3 quake with add safety margin, post-TMI upgrades had been done, there was no chance of a tsunami in Grundy county (we're several thousand kilometers from the ocean), there were independent watchdog groups keeping the plant under observation as well as the government... In all, a different situation, less chance of multiple disasters occurring at once, more advanced design, and no, we're not overly concerned about the matter.

Fukushima has some issues that other locations don't, that other reactors don't. I strongly suspect all the other nuclear power plants in Japan will undergo thorough reviews and maybe upgrades as well, possibly some re-jiggering of where back up power generators are located and various other contingency measures.

[Broomstick]

Well, it now certaily got decomissioned, although in a rather destructive manner. However, I wonder how much bribery and/or extortion TEPCO did, to keep these ridiculously outdated reactors active.

Likely none - it was probably just a matter of making a case it was more cost-effective to extend the run-time of the reactor than to decommission it at this time, plus an assurance that a major accident hadn't happened in Japan and nothing with that type of reactor since TMI, which posed no danger to the surrounding community. In hindsight we can see some major flaws, but that's post-accident.

Personally, I like the idea of using the laws of physics to enhance safety - a gravity operated failsafe to lower the control rods, what a great idea. Gravity has never been known to fail.

Of course, I'm sure there are engineering issues involved I'm not aware of, but it seems so obvious....

[Keevan_Colton]

Well, it now certaily got decomissioned, although in a rather destructive manner. However, I wonder how much bribery and/or extortion TEPCO did, to keep these ridiculously outdated reactors active.

Likely none - it was probably just a matter of making a case it was more cost-effective to extend the run-time of the reactor than to decommission it at this time, plus an assurance that a major accident hadn't happened in Japan and nothing with that type of reactor since TMI, which posed no danger to the surrounding community. In hindsight we can see some major flaws, but that's post-accident.

Personally, I like the idea of using the laws of physics to enhance safety - a gravity operated failsafe to lower the control rods, what a great idea. Gravity has never been known to fail.

Of course, I'm sure there are engineering issues involved I'm not aware of, but it seems so obvious....

As was said, it doesnt work so well for a BWR because of the physics of the design, it's used in PWR designs, which are the most common type. The other interesting difference between BWR and PWR is of course the fact that there is a secondary loop which acts as a heat sink for the primary loop. PWR's arent without their own issues, mostly related to the serious decay that the pressure and chemicals imposes on the coolant loops, but it's definetly one up when it comes to a passive scram option.