Nuclear Power Thoughts with Fukushima in Mind

I am pro nuclear power, with a few caveats. The Fukushima situation has strengthened most of my opinions about nuclear and anti-nuclear activists.

Activists for the most part are driven by their agenda and have little use for facts or fact checking. There are exceptions of course, but not that many really. They will quote any source that gives them ammunition for their crusade no matter how outdated or wrong it may be. The activists have been out in full force with Fukushima, but this time it seems their zeal, despite evidence, has bit them in the ass.

George Monboit, a left wing type blogger picked up on the lack of facts thing. Why Does It Matter, he is focused on the facts for a change after being duped for quite some time. Why he has suddenly started to use logic and reason is a bit of a puzzle. The non-sense has been out there for a long time, all he had to do was question the logic, i.e. build a bullshit detector. His revelation may be past due, but it has come.

I had mentioned a few passionate activists spreading lies without having a clue they were just pawns of other bullshitters. The Penn and Teller Di-hydrogen Monoxide video is a way of life for many of the activists. Some though are the bullshit originators. As the Japanese radiation situation unfolded, one activist posted a radiation map. The data is supposedly real time updated daily by SPEEDI, whoever they are. The original posting of the map mentioned that the data for Fukushima and a neighboring prefecture were not posted and insinuated that a possible Japanese Government cover-up was involved. Well, the real time data from SPEEDI stopped 17 days ago and the little anti-government note is missing. No, I do not believe government censorship was involved, more like the situation was getting better which went against his agenda. By the way, data for Fukushima prefecture and the neighboring prefecture were available from very early on at the MEXT website. It is in PDF form so the concerned activist would have actually had to look.

There will be more quotes available for activist use soon as the legal process for Fukushima begins. Expert witnesses can be found to testify for or against anything. So the misinformation hasn't even started. It will be interesting to find if the Japanese legal system is bullshit tolerant, for there will be plenty of bullshit to spread. All of this will confuse the real issues which I had hoped would finally be addressed. My main one is the degree of safety of light water reactor designs.

The basic light water reactor design is very safe though not terribly efficient. Using regular water as a coolant and moderator makes these reactors self regulating. Maximum chain reactions requires the water moderator. Should the water over heat, air bubbles slow the reaction. If all the water disappears the reaction nearly stops. It really is a very safe design. The problem with Fukushima and Three Mile Island is the size of the reactors. While they still have the inherent safety of the design, the mass of fuel and the residual temperature of that mass is enough to cause fuel damage, i.e. melting, in a loss of coolant event.

Because of the fuel damage, imaginations run wild. The China Syndrome comes to mind and people forget that it is a fantasy, a movie, not the real world. Once people start with the theoretical, it is Katey bar the door, anything goes. The designs, even the old General Electric Mark I without recommended modifications, will never produce a China Syndrome event. Much of the radiation released in Japan is due to attempts to save the population from something that cannot happen, a China Syndrome.

While imaginative use of the theoretical can convince people that doom is on its way, the real physics behind the design shows there is very little probability of a total meltdown burning through the reactor pressure vessel much less the concrete containment building. Unfortunately, this design feature has never been fully tested, so the theoretical can be brought into play by activists.

Smaller light water reactors eliminate even the theoretical possibility of a catastrophic meltdown. A few hours after the control rods are placed to stop the reaction, the energy of the reactor mass drops to about 1.5% of its maximum operating energy. The Fukushima reactors where rated for about 750 megawatts with roughly a 33% efficiency. The maximum power of the reactors allowing for efficiency is 2250 megawatts, 1.5% of that is 33.75 megawatts or 33,750 Kilowatts. That is enough energy to cause melting of the fuel rod cladding and some melting of the fuel oxide which has a higher melting point. That is enough energy to melt some of the way through the massive bottom of the reactor pressure vessel, but not enough to penetrate en mass. A smaller light water reactor designed for say 200 megawatts at the same efficiency would have a maximum energy of about 600 megawatts and a few hours after shut down, a residual energy of 9 megawatts. This amount of energy could cause some melting of the fuel cladding, but is unlikely to cause melting of the fuel oxide, so there is little chance of a major fuel damage scenario. That means the accident would be just that, a accident that is fairly easily corrected and the reactor could quite possibly be placed back into service. There is a huge potential cost difference between the design scales.

An even smarter design is 50 Megawatts, then with 150 megawatts maximum energy reduced to 1.5% you have 2.25 megawatts residual energy. That is 2,250 kilowatts which is not enough to reliably provide power to the average US household (Correction: that should be neighborhood not household, an average household is about 20 kilowatts). It is unlikely that there would be any damage at all to the reactor core with a loss of coolant accident.

These smaller designs also do something very interesting, by eliminating the theoretical dooms day scenario, they can actually be evaluated by insurance actuaries so that they can be insured by the utility instead of the government. They can even be used in destructive testing to "prove" what would happen in a realistic worst case accident. Eliminating the bizarre fantasies of the theoretical with realism is a good thing.

A less than realistic destructive test, one where say the reactor is run full bore without coolant, would cause some meltdown, which would damage the pressure vessel and core controls to the point that the reactor is unusable, but even that would not produce a very impressive accident. Then you could assume that Homer Simpson's less intelligent cousin was in charge and tried to cool the reactor with just enough water to produce maximum steam, therefore maximum radioactive fallout, kinda like at Fukushima, which would produce nearly a Three Mile Island event. In other words, small modular light water reactors are damn near idiot proof! (Added: Here is another view of small modular reactors from safety and security standpoints.)

Small modular reactors in the range of 50 to 150 megawatts each, used for a nuclear power parks, can produce equivalent power output at a more reasonable cost with much greater safety. That makes way too much sense though, I mean realistic regulations might even become part of life if we lose the theoretical.

Since facts are not much use in the activist world, we can always go with man powered treadle devices to recharge our electric cars in a few days. Then, there is no real need to think, is there?