OT: Massive 8.9 quake in northern Japan

[lazydawg]

ORIGINAL: khyberbill

I have been trying to refrain from posting until I have all the facts about what went wrong in Fukushima-but I suspect that wont be available for awhile. I have actually been to the Fukushima site on business in 1998 but my reactor expertise was with PWRs and not BWRs. I did spend a year removing highly radioactive components from the spent fuel pools of two American BWRa and can say that the building structure above spent fuel pools in PWRs and BWRs are not designed to contain a hydrogen explosion-or most any other type. As some recall, there was a hydrogen explosion at Three Mile Island although it was in the containment.

I'm a nuclear engineer with both PWR and BWR experience. In every plant where I have worked, the emergency procedures will direct the operators to run a fire hose to the spent fuel pool (if the spent fuel pool cooling system is lost). When I heard about the Fukushima accident, the first thought that entered my mind was "I hope they ran the red rubber hoses to the spent fuel pools". I'm wondering why they didn't do this at Fukushima. My speculations:

• They ignored their emergency procedures, or
• They got a bad case of tunnel vision & their only concern was reestablishing safety injection to the reactor vessels, or
• All of their portable generators were being used for water injection into the reactor vessels & none were available to pump water into the spent fuel pools

I wonder how the industry is going to address the problem going forward? In the high radiation flux inside the reactor, water is broken down into H and O. O being very reactive is not desirable (it causes rust and rust gets to become very radioactive Mn54, Co60 etc) and so H is added to reactor water to recombine the free O into H2O. This explosive potential will exist as long as water is used as a coolant. CO2 and sodium have been briefly used but discarded. I imagine these hydrogen explosions will be a weapon for the anti-nukes in any future licensing effort-at least here in the US. I know I am interested in how current or future designs mitigate the problem.

Actually, during an accident the majority of the hydrogen production isn't from the disassociation of water, it's caused by the "zirc-water" reaction between the zircalloy cladding of the fuel rods and water (or steam). When the zircalloy cladding reaches approximately 2200 deg-F, it undergoes an exothermic reaction with water creating zirconium dioxide and hydrogen. Due to the hydrogen explosion inside the containment at Three Mile Island, all U.S. PWRs (and maybe the newer BWRs ?) have been required to install hydrogen recombiners or hydrogen burners inside containment. For the older BWRs with the "light-bulb and torus" type containments, hydrogen recombiners are not required. These older BWRs have a hardened & filtered vent that runs between the wetwell region of the containment & the plant stack. My guess is that the hydrogen explosions seen at Fukushima were due to zirc-water reactions in the spent fuel pools (this is definitely what happened at Fukushima 4, since there was no fuel in the number 4 reactor).

[witpqs]

ORIGINAL: ncdawg

My speculations:

• All of their portable generators were being used for water injection into the reactor vessels & none were available to pump water into the spent fuel pools

Obviously I can't say with any certainty, but I have the impression that once the tsunami went through they had zero sources of electricity. On top of that I presume that when they additional (read = dry) portable stuff in there they had the issue of how to approach the radioactive area of the pools. I am assuming that because of transportation difficulties and the widespread nature of the devastation that it was a while before they got any working portables in there.

Commenting on an earlier post, I've also wondered why standpipes weren't available, or maybe the last bit of that chain is the fire hoses that you are talking about?

Due to the hydrogen explosion inside the containment at Three Mile Island, all U.S. PWRs (and maybe the newer BWRs ?) have been required to install hydrogen recombiners or hydrogen burners inside containment.

Thanks - I was wondering about that.

[Cap Mandrake]

ORIGINAL: JWE

ORIGINAL: Cap Mandrake
Speaking of San Onofre, I heard yesterday the seawall there for tsunamis is 30 ft whereas the one at Fukushima is only 12ft. The greatest risk at Old Man's is getting the crap beat out of you for not showing proper deference to a local.

Oh, c'mon, we weren't that bad. Always found the San Onofre poeple to be gracious and helpful (admit I'm a longboarder and folks down there do longboards).

Never noticed a seawall that high. Nice to know it's there, but never saw it. Been around the offshore bouy a gazillion times, till Homeland Security shut it down. Actually, way back when, that little bobber was maybe 0.75 - 1.1 miles off the beach. Never knew they had a tall wall. Sea floor is way deep till maybe a mile, then it goes to a 100 --> 60 foot ledge. So nothing but swell, till the last little bit. Cool; bet a surfer (or a sailor) had some input on that design.

Been 40 years since I had to do any chemistry. Wonder what the solubility of cobalt, or other nasty unstable elements, is in water.

Maybe the top of the seawall is 30 ft above seal level because the base is not right on the sand? My brother-in-law tells me the surfing stories. Perhaps he is embellishing. [:D]

[Cap Mandrake]

ORIGINAL: ncdawg

Actually, during an accident the majority of the hydrogen production isn't from the disassociation of water, it's caused by the "zirc-water" reaction between the zircalloy cladding of the fuel rods and water (or steam). When the zircalloy cladding reaches approximately 2200 deg-F, it undergoes an exothermic reaction with water creating zirconium dioxide and hydrogen. Due to the hydrogen explosion inside the containment at Three Mile Island, all U.S. PWRs (and maybe the newer BWRs ?) have been required to install hydrogen recombiners or hydrogen burners inside containment. For the older BWRs with the "light-bulb and torus" type containments, hydrogen recombiners are not required. These older BWRs have a hardened & filtered vent that runs between the wetwell region of the containment & the plant stack. My guess is that the hydrogen explosions seen at Fukushima were due to zirc-water reactions in the spent fuel pools (this is definitely what happened at Fukushima 4, since there was no fuel in the number 4 reactor).

That (the reaction between the fuel rod zircalloy and the steam) is the explanation given at the MIT site. Certainly, as the pools are not pressurized, doesn't the presence of that much hydrogen prove that the spent fuel rods were at least partly uncovered and hot as hell? How else could it reach 2200 deg F?

As for pumping water to the SFR pools, we were told the backup diesels were wrecked by the tsunami and the battery backup gave up at about 8 hrs.

[herwin]

ORIGINAL: khyberbill

I've been reading Polmar and Moore, Cold War Submarines. The Soviet Navy had a lot of nasty reactor accidents! There was even a melt-down in 1979.

The war up north was cold only in temperature. Lots of action between NATO and Soviets. I have read that the life expectancy of many of the sailors on early Soviet nuclear subs was very short due to high radiation exposure.

I was told they glowed in the dark... The HEN boats had lots of problems.

[herwin]

ORIGINAL: JWE

ORIGINAL: Cap Mandrake
Speaking of San Onofre, I heard yesterday the seawall there for tsunamis is 30 ft whereas the one at Fukushima is only 12ft. The greatest risk at Old Man's is getting the crap beat out of you for not showing proper deference to a local.

Oh, c'mon, we weren't that bad. Always found the San Onofre poeple to be gracious and helpful (admit I'm a longboarder and folks down there do longboards).

Never noticed a seawall that high. Nice to know it's there, but never saw it. Been around the offshore bouy a gazillion times, till Homeland Security shut it down. Actually, way back when, that little bobber was maybe 0.75 - 1.1 miles off the beach. Never knew they had a tall wall. Sea floor is way deep till maybe a mile, then it goes to a 100 --> 60 foot ledge. So nothing but swell, till the last little bit. Cool; bet a surfer (or a sailor) had some input on that design.

Been 40 years since I had to do any chemistry. Wonder what the solubility of cobalt, or other nasty unstable elements, is in water.

I did most of my surfing in La Jolla. Initially body surfing. Spent every summer there from the age of 13. My family moved there when I was 18. Eventually a friend taught me to board surf one winter in return for tutoring in calculus.

[lazydawg]

ORIGINAL: witpqs

ORIGINAL: ncdawg

My speculations:

• All of their portable generators were being used for water injection into the reactor vessels & none were available to pump water into the spent fuel pools

Obviously I can't say with any certainty, but I have the impression that once the tsunami went through they had zero sources of electricity. On top of that I presume that when they additional (read = dry) portable stuff in there they had the issue of how to approach the radioactive area of the pools. I am assuming that because of transportation difficulties and the widespread nature of the devastation that it was a while before they got any working portables in there.

Commenting on an earlier post, I've also wondered why standpipes weren't available, or maybe the last bit of that chain is the fire hoses that you are talking about?

Due to the hydrogen explosion inside the containment at Three Mile Island, all U.S. PWRs (and maybe the newer BWRs ?) have been required to install hydrogen recombiners or hydrogen burners inside containment.

Thanks - I was wondering about that.

You are correct, the tsunami wiped out their diesel fuel tanks so they were unable to run their backup diesels. The battery backup power isn't intended for running pumps. It supplies power to monitoring instumentation & it allows for the operation of certain critical valves. However, they acting quickly & had portable diesels onsite & were injecting seawater into at least one of the reactors by the next day. They could easily airlift the portable diesels onto the site; however, keeping the portable diesels fueled was probably a much bigger problem.

Standpipes for the spent fuel pools aren't required because it is assumed that power will be available before they have boiled down & uncovered the fuel. A set of "time-to-boil" curves is maintained for the spent fuel pools so that the operators know how long they have to act before the pools start boiling (in the event of a loss of power). Usually the time-to-boil is measured in days. This seems to be the case for the units at Fukushima. The spent fuel pools at Fukushima Units 5 & 6 were heating up by approximately 0.5 to 1.5 deg-C per day. Unit 4 heated up more quickly; however, on Monday (after three days), the spent fuel pool was still at 84 deg-C. There shouldn't have been an unacceptable amount of radiation in the area of the Unit 4 spent fuel pool until a significant portion of the water had boiled away. However, it was probably hot as hades in the area (thermal heat, not radiation). Working in anti-C's along with a respirator in the area of the pool would not have been pleasant.

[lazydawg]

ORIGINAL: Cap Mandrake

ORIGINAL: ncdawg

Actually, during an accident the majority of the hydrogen production isn't from the disassociation of water, it's caused by the "zirc-water" reaction between the zircalloy cladding of the fuel rods and water (or steam). When the zircalloy cladding reaches approximately 2200 deg-F, it undergoes an exothermic reaction with water creating zirconium dioxide and hydrogen. Due to the hydrogen explosion inside the containment at Three Mile Island, all U.S. PWRs (and maybe the newer BWRs ?) have been required to install hydrogen recombiners or hydrogen burners inside containment. For the older BWRs with the "light-bulb and torus" type containments, hydrogen recombiners are not required. These older BWRs have a hardened & filtered vent that runs between the wetwell region of the containment & the plant stack. My guess is that the hydrogen explosions seen at Fukushima were due to zirc-water reactions in the spent fuel pools (this is definitely what happened at Fukushima 4, since there was no fuel in the number 4 reactor).

That (the reaction between the fuel rod zircalloy and the steam) is the explanation given at the MIT site. Certainly, as the pools are not pressurized, doesn't the presence of that much hydrogen prove that the spent fuel rods were at least partly uncovered and hot as hell? How else could it reach 2200 deg F?

As for pumping water to the SFR pools, we were told the backup diesels were wrecked by the tsunami and the battery backup gave up at about 8 hrs.

Since there was no fuel in the Unit 4 reactor, the hydrogen had to come from the Unit 4 spent fuel pool. So yes, the fuel in the Unit 4 spent fuel pool must have been uncovered.

The link listed below gives updates on the status of the Fukushima reactors updated several times daily. I have found this link to be the best source of information (the reports from the news media have been utterly useless). Even better, this site is in English (sort of)!

http://www.jaif.or.jp/english/

[rtrapasso]

ORIGINAL: ncdawg

ORIGINAL: Cap Mandrake

ORIGINAL: ncdawg

Actually, during an accident the majority of the hydrogen production isn't from the disassociation of water, it's caused by the "zirc-water" reaction between the zircalloy cladding of the fuel rods and water (or steam). When the zircalloy cladding reaches approximately 2200 deg-F, it undergoes an exothermic reaction with water creating zirconium dioxide and hydrogen. Due to the hydrogen explosion inside the containment at Three Mile Island, all U.S. PWRs (and maybe the newer BWRs ?) have been required to install hydrogen recombiners or hydrogen burners inside containment. For the older BWRs with the "light-bulb and torus" type containments, hydrogen recombiners are not required. These older BWRs have a hardened & filtered vent that runs between the wetwell region of the containment & the plant stack. My guess is that the hydrogen explosions seen at Fukushima were due to zirc-water reactions in the spent fuel pools (this is definitely what happened at Fukushima 4, since there was no fuel in the number 4 reactor).

That (the reaction between the fuel rod zircalloy and the steam) is the explanation given at the MIT site. Certainly, as the pools are not pressurized, doesn't the presence of that much hydrogen prove that the spent fuel rods were at least partly uncovered and hot as hell? How else could it reach 2200 deg F?

As for pumping water to the SFR pools, we were told the backup diesels were wrecked by the tsunami and the battery backup gave up at about 8 hrs.

Since there was no fuel in the Unit 4 reactor, the hydrogen had to come from the Unit 4 spent fuel pool. So yes, the fuel in the Unit 4 spent fuel pool must have been uncovered.

The link listed below gives updates on the status of the Fukushima reactors updated several times daily. I have found this link to be the best source of information (the reports from the news media have been utterly useless). Even better, this site is in English (sort of)!

http://www.jaif.or.jp/english/

This is the whole rationale of them using the fire hose cannons and air drops on no. 4 reactor: the cooling pool is essentially empty, and they are trying to refill it from above. Per prior posts, the fuel rods had been reported as "glowing red" from satellite, so they are visible from above.

Of course, since the pool has essentially been ruptured, they can only attempt to cool down the rods by continually dumping water on them. Eventually, if they are going to prevent a meltdown of the spent fuel rods in the cooling pools, they are going to have to either fix the leaks (good luck), move the rods, or entomb them in something that won't run out. IIRC, the Russians used a mixture of sand and boric acid dumped into burning radioactive material to damp down the reaction. Maybe something similar could be used.

[morganbj]

deleted

[Cap Mandrake]

At this point it appears a regional catastrophe has been avoided but I have to believe the whole complex will be shut down permanently from a production standpoint. I doubt the locals will go along with the "concrete sarcophagus" idea, which means a TMI style clean-up.

What a mess. Good place to try out new robot technology.

Check this out. "Nuclear lava" or Corium from Chernobyl. [X(]

[Canoerebel]

What does this mean for the nuclear industry in America (and the rest of the world)? Here, nuclear plants generate about 20% of our power. I heard some political commentary on the radio late last week that the situation in Japan means dire things for the industry in the USA, but I don't believe it. Despite perceived safety and environmental concerns, I don't think there's any going back. There's been a recent push for more nuclear power in the U.S., with two new generators being built at Plant Vogtle in eastern Georgia. Will this trend continue or will it be thwarted by Japan?

[USSAmerica]

Just my impression, but I think expansion of nuclear power in the US will be slowed by this tragedy, but not stopped.

[pad152]

Any one find it surprising, with all of the nuclear regulatory agency's that's there is no nuclear response team with equipment (remote controlled camera's, fire trucks, bulldozers, cement trucks, etc). Japan didn't have one, neither does Europe, US, or Russia.

[hunchback77]

ORIGINAL: pad152

Any one find it surprising, with all of the nuclear regulatory agency's that's there is no nuclear response team with equipment (remote controlled camera's, fire trucks, bulldozers, cement trucks, etc). Japan didn't have one, neither does Europe, US, or Russia.

Yeah PAd, their over confidence lead to the disaster. They never prepared for this type of disaster all they kept repeating is nuclear power is safe and nothing can go wrong. I bet their not prepared for a serious terrorist attack or conventional bombing of their Nuclear plants either.

[khyberbill]

Just my impression, but I think expansion of nuclear power in the US will be slowed by this tragedy, but not stopped

I agree. Also, nuclear plants are still very expensive to build and the problems at Fukushima wont make them cheaper. Once the plants are up and running they are like an ATM machine for the utility-however the expense of getting to that point might weaken the desire of US utilities. In addition, natural gas is becoming even more popular in the US now that new ways are being used to extract it (and perhaps poison groundwater in the process).

What is an interesting perspective of human nature is that houses will be built on or near the beaches in all the communities that were destroyed by the tsunami with probably 30,000+ people dead and missing before one nuclear power plant will be built (with none reported dead at Fukushima). People perceive risks in strange ways.

[JWE]

ORIGINAL: Canoerebel
What does this mean for the nuclear industry in America (and the rest of the world)?

Who knows. Once hysteria rears its ugly head, next thing you know we'll be burning ugly women as witches in Salem, Mass.

I have always wondered what would have happened if all the bailout bucks to the banks, auto industry and subsidies to "alternative" fuels went instead to Larry Liverbreath, CalTech, the Tute, etc .. for fusion development. It's clean, safe, requires only Boron for fuel (making Borohydride is a no-brainer), has an intrinsic auto-shutdown, no spent fuel issues, very small amounts of radiation products in obsoleted equipment, yadda, yadda, yadda.

I mean, we could relegate oil to it's most useful and efficient product - petrochemical based, long chain, hydrocarbon plastics, glues, epoxys, wood substitutes, woof !! (bye-bye Middle East) All we do now is burn the crap. Damn! fusion! What an idea. Woof!

[ed] sorry. silly me. got carried away.

[Canoerebel]

JWE, to a non-power generation/non-nuclear layman like me, you're talking Greek, though it sounds awfully enticing. In fact, it almost sounds like perpetual motion or alchemy. Oh, if only possible! So, why isn't it being pursued vigorously now and what are its prospects for the future?

[JWE]

ORIGINAL: Canoerebel
JWE, to a non-power generation/non-nuclear layman like me, you're talking Greek, though it sounds awfully enticing. In fact, it almost sounds like perpetual motion or alchemy. Oh, if only possible! So, why isn't it being pursued vigorously now and what are its prospects for the future?

Yeah, well, it's semi-Greek to me too. I'm an optical physicist. I like reading about the optical and magnetic containment possibilities, but the rest is more like serious P-Chem. Only personal contact I have had with the fusion industry is doing patent and corporate work for some people at UCI who developed a very interesting Boro-alkyl ring compound as a fuel (sorta like a Phenol). Learned a lot about fusion and fusion fuels, but only as a tyro.

These guys did this with $3.4 M in funding. Why isn't it being pursued? I'm just as perplexed as you and everyone in the field. Prospects? If you talk to these people, it's like talking to the original apostles. Technically, on paper, sure, works great. But there's some engineering burps that have to get solved. If somebody did a Manhatten Project push on it, we would likely have fusion in our lifetimes (if not in five to seven years). But oh, well. Windmills, yeah, that's the ticket, windmills.

[khyberbill]

It's clean, safe, requires only Boron for fuel

I admit to being ignorant on this source of fuel. From what little I have read, it takes 10 times as much energy for a hydrogen-boron fuel to fuse as it does for classic deuterium-tritium fusion. And we haven't made that work in over 40 years of experiments and billions of dollars. With those kind of temperatures straining to get loose, I would rather live near a fission reactor than a fusion reactor.