Category Archives: Japan

Roadmap towards Restoration from the Accident at Fukushima Daiichi Nuclear Power Station

TEPCO’s briefing slides are available here. My speculation that they would flood the PCV appears to be correct:

Countermeasure [9]: Flood the PCV up to the top of active fuel.

If they achieve their objectives in 9 months I will be impressed and relieved. My understanding is that TEPCO knows little about the actual state of the machinery inside the buildings. And they have no experience of doing such construction in a hot environment – with or without robots.

I hope we can assume that every other OECD nuclear power will be contributing every resource they can muster.

Fukushima: more encouraging TEPCO robot news

It’s much easier to catch these Kyodo News bulletins since I’ve rigged up a full text RSS feed for the Kyodo “nuclear crisis” (open feed, no subscriber password required). The full text XML looks like the following:

Like Instapaper, this is another brilliant free service, just insert the ‘’ into any RSS feed that only publishes summaries.

U.S. offers unmanned chopper to help remove Fukushima spent fuel

This looks a bit encouraging – Kyodo News:

(…) The U.S. government has told Japan that it can use a U.S. unmanned cargo transport helicopter to set up cranes to remove spent fuel rods from storage pools at the crippled Fukushima nuclear power plant, Japanese and U.S. sources close to the matter said Saturday.

The K-MAX helicopter, developed jointly by Lockheed Martin Corp. and KAMAN Aerospace Group of the United States, is being considered to set up the huge cranes.

Wikipedia, and Kaman Aerospace.

Fukushima: new TEPCO cooling strategy?

Will Davis at Atomic Power Review has two new posts outlining what I speculate will be an important change in TEPCO’s strategy toward reestablishing recirculation cooling of R1, R2, R3. We have been concerned about the complexity and labor-intensity of repairing the original plumbing to support circulatory cooling. Possibly TEPCO has similar concerns, if it is true that their new approach is evidently to construct new primary and secondary cooling, condensing circuits. Here’s Will on 16 April:

(…) The most interesting news of the day is the still developing story that TEPCO has ordered a large number of special heat exchangers, planned for a new external cooling system that it will construct for each reactor plant. This is a novel approach, and probably the best idea TEPCO has had yet. According to the Kyodo story, TEPCO will use several heat exchangers for each plant, and will connect them to the existing external emergency connections that it’s been using prior to this for core injection. Apparently TEPCO will use electric pumps, and two core connections to establish recirculating cooling flow and then use hoses to bring in and return seawater, if we understand the plan correctly. No timeline is given on this plan — but given the mounting complications of the water in the buildings and in the ground, I would have to say that this plan should be given top priority.

And an update today from Will on 17 April:

I’ve just read the first concrete piece of evidence about how the new systems TEPCO is planning to install will work. Apparently, the idea is to obtain the feed for the pumps from, according to the article, “the reactor containment buildings.” This still isn’t clear, but it does seem to indicate that TEPCO acknowledges the leakage and intends to recycle water in a sort of non-sealed, but closed loop fashion for the primary cooling… the heat from which will be transferred to sea water.

Right now, without any further information, it might be assumed that TEPCO will be taking the water directly from the dry wells or the suppression pools. Important to note is that the primary side of this system will become highly radioactively contaminated, so that the equipment will need to be shielded or else access controlled as the rad level around the equipment will be very high.

My speculation is they will try to flood and circulate the PCV including drywell and wetwell. Any thoughts, comments on this idea?

UPDATE: Kyodo News has a new bulletin that touches on Will’s perspective:

(…) Meanwhile, the utility is considering installing circulating water cooling systems for reactors and spent fuel storage pools outside the reactor buildings at the plant in a bid to bring it under control, sources familiar with the matter said.

The new systems would cool nuclear fuel inside the reactors and spent fuel pools in a stable manner. They would involve heat exchangers and circulation pumps to drain reactor coolant water from the containment buildings, cooling it with seawater and then sending it back to the reactors, the sources said.

TEPCO appears to have already placed orders for dozens of gasketed plate heat exchangers — each measuring 3 meters high, 1 meter wide and 2 meters long — for such systems, the sources said.

The existing circulating water cooling systems at the plant were crippled by the March 11 earthquake and ensuing tsunami.

(…) Radiation levels inside the containment buildings remain high. TEPCO plans to utilize the pipes that it has been using to pump water into the reactors in the new circulating water cooling loops, so it can minimize the need for work inside the dangerous buildings.

There are more details at Kyodo News. Evidently the TEPCO chairman will make an announcement today at 3PM. I will report back…

Energy Supply Implications of Japan’s Nuclear Crisis

Thanks to Roger Pielke Jr. for this perspective. Please read Roger’s post for the analysis and links to several important resources (click the thumbnail for full size image). I’ll just cherry pick a couple of key points:

1. A total of 4 nuclear complexes felt the effects of the earthquake and the tsunami, including flooding. Of those, 3 survived with no problems. Obviously, a 75% success rate is not good enough, but it does indicate that reactor complexes can be designed to successfully survive such an event.

2. Far more fossil energy was knocked out by the event than nuclear energy. (…)

Fukushima: who has changed their mind on nuclear

Barry Brook is running a thread surveying prominent people who have shifted their public position on nuclear power. Contributions are still flowing in, so the listing is dynamic. The reported position shifts are not restricted to post-Fukushima time. A related smart comment (I thought) was posted today by Huw Jones, who stated my view very crisply:

(…) I’m starting to find the whole concept of ‘anti-nuclear’ absurd. In fact, being opposed to any technology is absurd. I don’t consider myself particularly in favour of burning coal to generate energy, but I can conceive of a technological change to the technology which would bring me to a state of support for it, e.g. in situ gasification, CSS.

Rather than be 100% opposed to nuclear power, and campaigning against its use, why not campaign to make it safer/cheaper/more sustainable? If a nuclear power opponent can not admit that there is some technological change which could be make it acceptable, then they must also admit that they are believing in nothing more than a religious faith.

Next time you speak to someone ‘against’ nuclear power, ask them this.

It’s the worst; it’s also not so bad

Babbage at the Economist concludes a sensible article on Fukushima with this:

None of this makes Fukushima trivial; it is a grave crisis. Things are still scarily un-locked-down—an earthquake on April 11th interrupted the cooling pumps again, though only briefly. The psychological stress has been intense, and the long-term bill for cleanup will be massive. But in terms of hazard the situation appears to be improving, if in fits and starts. It has been big, yes, perhaps a lot bigger than industry experts originally expected or were willing to admit. But it does not seem, in public health terms, to have turned out too bad.

New Provisional INES Rating + A Chernobyl Primer

MIT NSE Nuclear Information Hub has a bulletin to help people understand what the INES 7 uprating means. I don’t think they offer much useful perspective, but they do have a concise summary of Chernobyl:

(…) Because the rating is now the same as that assigned to the Chernobyl accident, the blog has received a number of questions about how the events at Fukushima differ from it. We present a sequence of events at Chernobyl, along with links to some denser technical matter for interested readers, and an IAEA report on the human costs of the disaster. For comparison, it’s been estimated that the radiation released by the Fukushima reactors is 1/10th that released to the environment at Chernobyl.