A Nuclear Engineer on Fukushima And The Future Of The Industry


Radiation At Fukushima Twice As High As Reported Immediately After Disaster

I was sitting on the deck talking to a young nuclear engineer, J, who suggested that the Fukushima disaster may actually be good for the nuclear industry. He remembers reading about an staunch anti-nuke environmentalist's conversion to being pro-nuke, and paraphrases:

Here you've got forty year old technology that wasn't maintained properly, beyond design basis accident, beyond design basis earthquake, beyond design basis tsunami, and it still managed to shut down, it bought them a few days before they had to start venting...

From Wikipedia: The reactor core (1) consists of fuel rods and moderator rods (39) which are moved in and out by the device (31). Around the pressure vessel (8), there is an outer containment (19) which is closed by an concrete plug (2). When fuel rods are moved in or out, the crane (26) will move this plug to the pool for facilities (3). Steam from the dry well (11) can move to the wet well (24) through jet nozzles (14) to condense there (18). In the spent fuel pool (5), the used fuel rods (27) are stored. .

(That would be George Monbiot, who wrote:

A crappy old plant with inadequate safety features was hit by a monster earthquake and a vast tsunami. The electricity supply failed, knocking out the cooling system. The reactors began to explode and melt down. The disaster exposed a familiar legacy of poor design and corner-cutting. Yet, as far as we know, no one has yet received a lethal dose of radiation.)

I interject "but they didn't make the right decisions, they closed the venting..."

No, that's not how it works, here is the problem. You want to maximize the time between your loss of cooling and when you start to vent in order to give your very high activity radionucleides time to decay inside containment. You will have radioactive noble gases that are fission products that have very short half-lives. When they decay, the decay along the periodic table, and sometimes those noble gases will become solid particulates that will fall instead of being vented out. You want to maximize the time and then you want to have a controlled, monitored release path and rate.


Ongoing Crisis at Japan's Fukushima I Nuclear Power Plant

I mentioned that from an architectural point of view, it was a dumb design, to put the spent fuel bays way up in the air, having all that mass so high in an earthquake zone. J. suggested another reason they should have designed it so that the spent fuel was lower:

I would designed it differently, and put them at the ground level. As you recall, One of the biggest problems was was with restoring cooling water to the spent fuel pools, they were way up in the air and the pumps didn't work. You should do it by gravity, it never fails.

LA: if they had been lower, would than not have a worse problem, flooding them and spreading radioactivity in the water?

J. No, that is what you want. Inside the spent fuel pool, ideally you don't have any failed fuel. If the cladding is intact, it is fine as long as you can keep the pool wet under water. It doesn't matter what kind of water you put in there. If there had been a gravity flow you just have to keep the water moving, you don't need that head pressure to get it up to the pool.

J. explained why new reactor designs are so much safer.

With more modern technologies and the iterative design process, designs that have fewer valves, that have passive safety systems, that are easier to maintain, that rely on gravity for cooling, and have much lower accident frequencies than 40 year old designs.


In Light of Fukushima, Switzerland and Germany Say No More Nuclear

LA: What is the consensus in the industry, do you think that there is a future in the nuclear industry or will cheap fracked gas and the current environment in the states where they say climate change is a hoax, not to mention Fukushima, all of that militates against more nukes. Not to mention even the worldwide protests against the industry.

J. All good things come to an end. Cheap fossil fuels will only last so long, we have bought a little time as far as I am concerned. I think nuclear has to be part of the energy mix, and it has to be a pretty big part of the mix, to continue generating base load power because that is what it is best at. Renewables will come into their own as part of the base load with better storage systems.

Nuclear demands respect but if people understand the real hazard, compared to the alternatives, if people really understood the nature of nuclear power and radiation risk, they would accept it.

Not a view that I think most TreeHugger readers share, but thanks, J.

We did a poll on this, Has the Fukushima Reactor Crisis Changed Your View of Nuclear Power?

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Tags: Canada | Japan | Nuclear Power

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