Tag Archives: nuclear accident

Day 68: Video of work at Fukushima and a encouraging PDF

TEPCO has released a video that shows work being done at the Fukushima plant. Very interesting to watch.

One gets a real sense for the devastation the tsunami inflicted while watching that clip.

TEPCO also recently released this PDF file that gives an overview of work being done. I will add some pictures from it:

In the above picture one can see how they plan to rig up the new heat exchangers for reactor 1. Within the reactor building, but outside the containment, they will put a water to water heat exchanger. They will pump water from within the containment through this heat exchanger, where it transfers the heat to a secondary circuit that in turn flows to a heat exchanger outside of the reactor building that dumps the heat to the air. This is the original plan TEPCO had before they realized the full extend of the damage to the number 1 core and containment, so it is not sure they will progress as described. But the secondary heat exchanger and its piping is already being built.

Tepco also shows the above picture on how they plan to reuse leaking water from the containment as cooling for the reactor. It is not clear how the two plans are connected to each other. I would assume the second plan is the one that is going to be used instead of the first plan. Instead of taking water directly out of the containment they will use the existing leakage paths, purify the water and pump it back into the reactor.

For the number 2 reactor shown above the main problem is to stop the leakage from the suppression pool. They plan to excavate the reactor building in order to access the room where the suppression pool is housed and then fill the entire volume with grout. Considering that (probably) the suppression pool is leaking at number one as well then maby this plan will be implemented there as well (just my speculation).

Both in unit 2 and 3 are they planning to reuse the leaking water in the same manner as in unit 1.

In the rest of the document they give some basic information on how they plan to clean the massive amounts of contaminated water that exists on the site, some details on the protective building they want to build around the reactors and how to prevent more contamination of soil, water etc. Well worth scrolling through, massive work is certainly ongoing at the site and it seems TEPCO has a solid plan that they are implementing.  Of course more surprises will without a doubt pop up during work, but it looks promising. We are still waiting for more in depth information on the situation of the number 2 and 3 reactors.

English blogs:
All Things Nuclear TEPCO Says Core of Unit 1 Melted
Atomic Power Review Fukushima Daiichi update, Weds. morning 5/18

English News:
New York Times Venting Failure in the Nuclear Reactors at Fukushima Daiichi
Reuters UK nuclear power gets green light

/Johan

 

Day 67: Complete meltdown of the number 1 core

During the last days a lot of news has been released by TEPCO. TEPCO has released this presentation that gives more details of the events that took place in the number 1 reactor from the beginning of the earthquake up until now. To summarize the content of the presentation.

  • The water level gauge has been giving wrong readings, the reading has been stating that the water level is about 1.7 meters below the top of the fuel assemblies. In reality the water level has been 8 meters below the top of the fuel assemblies, this means the entire length of the fuel has been uncovered completely.
  • TEPCO now assumes the RCIC system failed after the tsunami (another news release indicates it was manually shut down!!)
  • 16 hours after the earthquake the entire core had suffered a meltdown and all of it dropped down to the lower part of the pressure vessel.
  • The temperature readings on the vessel indicate that the core is still mostly within the vessel and adequately cooled.
  • Some parts of the core is suspected to have melted small holes in the bottom of the containment, which explains why they could not increase water level despite increasing pump rate.

They don't mention the reading of the pressure gauge that indicates the vessel pressure is about 14 atmospheres. I was personally fooled by this reading and assumed the number 1 vessel is in better shape than the number 2 and 3 reactors. The question is what readings can be trusted at all.

Due to this new information on the status of the reactor TEPCO has decided to scrap the original plan to flood the containment up to the level of the fuel assemblies. Since all the fuel is now located at the bottom of the vessel there is no need to flood the containment that high.  The containment is also confirmed to be breached and water leaking out of the it like in the case with reactor number 2.

Another theory for the explosion in the number 4 reactor building has appeared. The videos from the pool show that it is largely intact and no major fuel damage can be seen. That means it seems unlikely hydrogen from a zircalloy+water reaction in the spent fuel pool can be the cause of the explosion. Instead TEPCO now believes hydrogen leaked into the number 4 building from a shared ventilation system with the number 3 reactor.

TEPCO is going to do more complete analysis of the status of reactor 2 and 3 and the information will be released within days. It will be interesting to see if the RCIC system (see this blog post for a description of the system) worked in the other 2 reactors and, if it did, to what extent it mitigated the consequences of the station blackout.

Work is progressing on all fronts to build a enclosure around the number 1 reactor, to build a water processing plant, create more redundancy in the electricity supply, clear the area of debris and to pump away the junk water from the turbine halls and trenches. IAEA as usual reports the release of radioactive material and dose rates.

The Fukushima accident has unfortunately seen its first death with a 60 year old worker that lost consciousness  while working on a drainage system to the radioactive waste storage. He was brought to a hospital but could not be revived. So far there is no report that the death was related to radiation.

 

News English:
WNN Fukushima fuel melt confirmed
WNN Theory for Fukushima Daiichi 4 explosion
WNN Revisions to Fukushima restoration roadmap

Blogs English:
Depleted Cranium Worker Dies at Fukushima Nuclear Plant
Atomic Power Review Core totally demolished at Fukushima Daiichi No. 1

Blogs Swedish:
TEM funderingar <Är kärnkraft förnybart?
Den blinde Argus Kärnkraft och rädsla
Supermiljöbloggen IPCC: Förnybart kan ersätta fossila bränslen
Fourfact Blinkar jätten?
Skattepolitik och samhällsfilosofi Inga elbilar i Sverige om Tyskland stänger kärnkraften?
Ann-Kristine Johansson Kärnkraftsdiskussion
Nina Drakfors Japan, kärnkraftshaveriet fortsätter och kräver strålningsdödstal
Supermiljöbloggen Amerikansk kärnkraft dåligt rustad för katastrofer

/Johan

"Mummy, mummy, there's a nuclear monster!"

One of the frustrating parts about being a proponent of nuclear power is when people rag at you for showing them facts that nuclear accidents aren't that big a deal. After all... "everyone knows" that a nuclear accident is a catastrophe unlike all others and that a "meltdown" means instant death to thousands of people, cancer to millions and huge tracts of land made uninhabitable for centuries... as told by various groups out there.

So when you point out to them that the TMI meltdown had zero casualties, that the Fukushima triple meltdown and explosion/fire in a fuel pool is presently holding the zero and that the prognosis is slowly starting to look hopeful, and that the current death toll from Chernobyl correspond to the number of people killed in US motor vehicle accidents in one day, people tend to take great offense at you questioning the supposed "truth" about nuclear power. I have been called quite a few unflattering things for this heinous crime of not being upset about nuclear accidents and - even more blasphemous - trying to calm other people about them as well.

Therefore it was with a great sense of recognition I read Lewis Page's piece "Mummy, mummy, there's a nuclear monster!" in "The Register today. I won't steal his glory but I will point out two core pieces and quote them:

This is the problem that everyone faces, who describes nuclear incidents as they really are – that is: insignificant. You are accused of being heartless, of failing to care about or empathise with people who are terribly frightened. You have committed the same sin as bracingly telling a toddler that there is no monster under his bed and that he should go back to sleep.

Part of the problem here is that in the case of nuclear dangers it is rather as though the toddler had a mentally troubled aunt or uncle who, in addition to telling the kid fairytales at story time, insists that the monsters in the stories are real.

The people in charge of story time here are the media, and like many of us finding ourselves troubled by bizarro in-laws, the media fails – seldom really even tries, often enough – to prevent the mad aunt telling the kids rubbish.

[....]

Some of us at least are getting a bit sick of the idea that you simply aren't allowed to tell frightened people quite bluntly to act their age – and we're getting more than just a bit sick of irrational or unscrupulous fairytale-spinners making them frightened in the first place.

That is pretty much it: you are considered a villain for telling people "Oh stop whining you baby, it's just a nuclear accident!". You're being painted as an arsehole for not playing along with paranoia and prejudice. They are calling you foul names and questioning your moral character for trying to make people less scared.

It's one of those things that makes me want to bang my head against the desk and tell people to go overdose on their stress- and angst-hormones if they are so much in love with them. It feels like getting yelled at by a drunk relative for taking his/her bottle away. Why would I bother?

Well... I must, because it's the right thing to do. If I didn't, then I'd be an arsehole for real, wouldn't I? If I firmly believe that someone is wrong in their actions and beliefs, and that they are hurting because of these beliefs, would you suggest I play along? Or should do as I would to the same human being if they had been 25-75 years years younger, by telling them that there is no monster waiting to eat their toes?

The worst part is - of course - that some people have a very strong self-interest in keeping others scared of the nuclear monster under the bed. Let me show you another example...

With "information" like that, is it any wonder that people are frightened? Those who made that video are the ones that should be called heartless, for using and abusing people's fears simply to advance their position and get more influence.

But good news are no news. It's easier to sell a story of Doom & Destruction than telling people that things are actually not very bad at all. You're considered the weird one for not being a paranoid alarmist professing the impending end of life as we know it.

What can we do to break the trend? How can we make people stop being scared of things that are not scary, and focus on the real dangers out there, such as fossil fuels that are killing literary millions of people every year?

Facts... keep speaking the facts... that's how you eradicate fear, prejudice and misconceptions. I have so far not met a single person who have learned the facts about nuclear power and who has since remained genuinely scared of it! Keep pushing the facts...

Let me close up this post with a video of a fellow swede that has opened up many people's eyes and minds by showing the cold hard facts in a very funny and interesting manner: Hans Rosling. Enjoy... I did. 🙂

EDIT: as commented below... there is more on www.gapminder.org. 😉

Thirty years after Harrisburg, time to let go.

Thirty years ago to the day of this article, the so far worst nuclear accident in a power plant the world had ever seen took place. Unit number 2 at the Three Mile Island Nuclear Generating Station near Harrisburg, Pennsylvania, suffered a loss of coolant accident. This led to that most infamous of nuclear failure modes: a core meltdown.

But despite that "everyone knows" a meltdown supposedly is the worst that could ever happen, with millions of dead and entire states rendered uninhabitable forever and ever, the effects of the TMI-2 accident are well documented with no deaths, no injuries, no cancers. The only casualty that came from accident was said by nuclear physicist Edward Teller to be his heart attack, caused by the stress of seeing Jane Fonda using the event to unjustly trashtalk nuclear power. With this in mind, maybe it's time we had a little reality check when it comes to our nuclear fears, wouldn't you say?

Don't get us wrong, a nuclear meltdown still is no laughing matter. Having a vital energy producing unit that is supplying hundreds of thousands of citizens with electricity unexpectedly becoming permanently disabled is of course not good. But there is a huge different between "not good", and "the end of normal life as we know it".

Deriders of nuclear energy try to abuse the event by saying "They said it couldn't happen, and yet it did". This is simply not true. Noone ever said a nuclear accident cannot happen. The proof of this is in the accident itself, or rather its non-existing harmful effects. How can such a serious nuclear meltdown not harm anyone? The answer is simple: because we expected it might happen and prepared for it.

The promise that was made was not that an accident wouldn't happen, but that nuclear power would not harm anyone in the public. This promise has been kept for 55 years all throughout the world in all places except one, Chernobyl, for reasons obvious: the Soviet Union did everything wrong in ways that would have been considered appalling and shocking to the entire world, even before the accident, had we but known about them. Everywhere else, nuclear power has not harmed a single individual in the general public by cause of radioactive release. And in the thirty years that has passed since the accident, we have only become better at enforcing this promise.

It is definitely time to let go of the past and Harrisburg. The lessons have been learned. We are moving on towards creating a sustainable future for ourselves and the next generations where all forms of clean energy has their given place in the energy mix. With each coal plant we exchange for a nuclear fission reactor, we save approximately 15 000 human lives over the course of the reactor's lifetime.  Nuclear power has never been safer and cleaner that it is today. Of course we shall stop being afraid of using it, instead having a healthy amount of respect for it,  especially if the only reason we have for worrying is a thirty year old accident that didn't harm anyone.