Video of reactor 1 at Fukushima plant • Hacker News Board

Re: Video of reactor 1 at Fukushima plant

#31

Post by craigmccaskill » Sat, Mar 12, 2011, 10:34 AM UTC

koski wrote: post #25

what I understand now is that the blast at the nuclear plant may have been caused by a hydrogen explosion (pressure) or If nuclear fuel rods overheat and then come into contact with water, this produces a large amount of highly-flammable hydrogen gas which can then ignite. Right? Can anyone with more knowledge and experience of this confirm?

That's certainly possible, theoretically. However, I'm not sure if those conditions can actually be met (rods should not ever come into contact with water and nothing should be able to ignite the gas, especially not at higher pressure levels).

Re: Video of reactor 1 at Fukushima plant

#32

Post by hartror » Sat, Mar 12, 2011, 10:36 AM UTC

brg wrote: post #26

Can someone provide background information on the type of reactor at Fukusima, it's age, and it's failsafe mechanism. I was under the impression that no modern reactor would sustain criticality in the event of a failure.

From wikipedia: "Fukushima I – 1 BWR First criticality: March 26, 1971". So it isn't a "modern" reactor, not sure what the fail safes are but I have read from some sources all the fail safes are older generations which require power.

Re: Video of reactor 1 at Fukushima plant

#33

Post by jensnockert » Sat, Mar 12, 2011, 10:38 AM UTC

[deleted] wrote: post #19

[deleted]

As I understood it (when discussing it with someone in the know), was that it was likely caused by zirconium in the fuel-rods reacting with water.

This hydrogen should be taken care of, but without (enough?) electrical power levels of hydrogen gas builds up.

This does not mean that containment is broken, or that there is an imminent danger to outsiders. But it is a very serious situation, especially since there seems to be at least two more reactors in similar situations at Fukushima Daiichi.

(http://www.world-nuclear-news.org/RS_Battle_to_stabilise_ear... also refers to a problem at Fukushima Daini.)

Re: Video of reactor 1 at Fukushima plant

#34

Post by wazoox » Sat, Mar 12, 2011, 10:38 AM UTC

koski wrote: post #22

ck2 wrote: post #8

http://news.google.com/news/more?ncl=d_LFixACgsQEvVMNHMag3MA... There is almost guaranteed significant radiation release. quote from slashdot: The outer walls of the Reactor 1 building have partially blown off, leaving only what looks like a steel frame. NHK is saying that a sensor within 5km of the plant is detecting radiation levels approaching 1015 microsieverts - that is apparently a year's worth of radiation exp…

"This is starting to look a lot like Chernobyl" Walt Patterson, an associate fellow with Chatham House, has told the BBC after seeing pictures of the explosion at the Fukushima-Daiichi nuclear plant. "The nuclear agency says that they have detected caesium and iodine outside the unit, which certainly indicates fuel melting at the very least," he says. "Once you have melting fuel coming into contact with water, that w…

This is quite different from Chernobyl, which didn't even have a proper confinement wall. It's unlikely that it can get as bad as Chernobyl was.

Re: Video of reactor 1 at Fukushima plant

#35

Post by koski » Sat, Mar 12, 2011, 10:38 AM UTC

ck2 wrote: post #8

http://news.google.com/news/more?ncl=d_LFixACgsQEvVMNHMag3MA... There is almost guaranteed significant radiation release. quote from slashdot: The outer walls of the Reactor 1 building have partially blown off, leaving only what looks like a steel frame. NHK is saying that a sensor within 5km of the plant is detecting radiation levels approaching 1015 microsieverts - that is apparently a year's worth of radiation exp…

Japanese authorities are extending the evacuation zone around the two Fukushima nuclear plants from 10km to 20km, according to local media.

Re: Video of reactor 1 at Fukushima plant

#36

Post by brg » Sat, Mar 12, 2011, 10:39 AM UTC

brg wrote: post #26

Can someone provide background information on the type of reactor at Fukusima, it's age, and it's failsafe mechanism. I was under the impression that no modern reactor would sustain criticality in the event of a failure.

To answer my own question, Fukushima is a first generation bwr:

http://en.wikipedia.org/wiki/Boiling_Water_Reactor

It lacks the safety mechanisms of an abwr. Namely even after the control rods are deployed, heat can continue to build up. Hence the plant requires forced cooling, in this case provided by diesel and electric pumps. After the earthquake the diesel pumps failed and cooling was effected by battery power. While the government rushed in new diesel generators, they were not installed in time to prevent the build up of pressure resulting in this explosion.

Re: Video of reactor 1 at Fukushima plant

#37

Post by rwmj » Sat, Mar 12, 2011, 10:40 AM UTC

koski wrote: post #22

ck2 wrote: post #8

http://news.google.com/news/more?ncl=d_LFixACgsQEvVMNHMag3MA... There is almost guaranteed significant radiation release. quote from slashdot: The outer walls of the Reactor 1 building have partially blown off, leaving only what looks like a steel frame. NHK is saying that a sensor within 5km of the plant is detecting radiation levels approaching 1015 microsieverts - that is apparently a year's worth of radiation exp…

"This is starting to look a lot like Chernobyl" Walt Patterson, an associate fellow with Chatham House, has told the BBC after seeing pictures of the explosion at the Fukushima-Daiichi nuclear plant. "The nuclear agency says that they have detected caesium and iodine outside the unit, which certainly indicates fuel melting at the very least," he says. "Once you have melting fuel coming into contact with water, that w…

Walt Patterson:

http://www.waltpatterson.org/nuclearpower.htm

http://www.chathamhouse.org.uk/about/directory/view/-/id/34/

Re: Video of reactor 1 at Fukushima plant

#38

Post by po » Sat, Mar 12, 2011, 10:40 AM UTC

uvdiv wrote: post #18

uxp wrote: post #15

Earlier quoted context omitted.

This picture just appeared on Wikipedia, of which I am guessing is the building that may or may not be the one that possibly exploded. Maybe someone more knowledgable than myself can identify what the building is used for. The 2011 Sendai earthquake article says " the outer structure of reactor number 1's containment building had blown off, releasing a large cloud of dust and vapour." http://en.wikipedia.org/wiki/Fil…

I have no clue what's going on (and I Am Not An Engineer), but I'm fairly sure that in this photo http://upload.wikimedia.org/wikipedia/commons/e/e8/Fukushima... The longer, rectangular buildings on the seaside are the turbine halls, and the square buildings next to them (in the inland direction) are the containment buildings.

That's correct. Of the four, it's the small building on the right that is reactor number one: the one that is melting down.

Re: Video of reactor 1 at Fukushima plant

#39

Post by ajb » Sat, Mar 12, 2011, 10:41 AM UTC

Any opinions on what the thing rising up very quickly during the explosion is? I initially thought it was the roof, but I'm wondering now if it isn't actually a flame from burning hydrogen. Ideas?

Re: Video of reactor 1 at Fukushima plant

#40

Post by brg » Sat, Mar 12, 2011, 10:45 AM UTC

hartror wrote: post #32

brg wrote: post #26

Can someone provide background information on the type of reactor at Fukusima, it's age, and it's failsafe mechanism. I was under the impression that no modern reactor would sustain criticality in the event of a failure.

From wikipedia: "Fukushima I – 1 BWR First criticality: March 26, 1971". So it isn't a "modern" reactor, not sure what the fail safes are but I have read from some sources all the fail safes are older generations which require power.

Thanks, wiki continues to provide detailed information in the deep links on the page. It seems we are witnessing a case of failure upon failure. Truly a horrific tragedy for the country and the world.