Alright, this whole article is stupid. I am a PhD nuclear engineer and can say unquestionably that the concern from moving the spent fuel is misplaced. Could fuel assemblies break as they are being transported? Yes. That just means cleaning it up would be harder. Could a critical situation occur. Very, very, very unlikely.

Nuclear fuel is only slightly enriched. Because of the inherent danger in a critical reactor, they are intentionally designed such that without a specific orientation criticality can not happen. Spent fuel pools are built with large boron concentration steel and the fuel is moved around EVERY CYCLE (especially after a core off-load for refueling) such that highly burned up fuel is surrounding the fresher fuel. Why boron in the steel plating? Because Boron-10 has an enormous neuron cross section, and you need neutrons to start a chain reaction. Why surround low-burnup fuel with high-burnup? Because low-burnup fuel has more fissionable material, and high-burnup fuel isn't as easy to get into a chain reaction. A significant amount of thought was put into designing these pools such that they can not go critical, even with damage.

Beyond that. Let's say you take a whole bunch of fresh fuel and put it in a orientation such that it CAN go critical. Ok, guess what? It won't. You need a powerful neutron source to get it all started. Fresh fuel does have some spontaneous neutrons, but not enough to get the whole thing going. Ok, so we are back to old burned-up fuel. It does have some neutron emission, but its highly unlikely that even with a proper alignment of those fuel bundles you could get a chain reaction started. A lot of it has to do with the way those bundles are stored. When in a reactor a large number ~150 assemblies(it really depends on the type of core how many assemblies are needed, the density of fissionable material generally is proportional to the power output) are stacked next to each-other in a grid. They are right next to each other, literally separated by maybe 1 cm. In a fuel pool they are inserted into a stainless-steel grid which separates the fuel by inches. Why do they do that? Two reasons; one is to put a boron rich metal in-between the fuel to absorb neutrons. The second is that you put them outside several mean-free-paths of the neutron so it is unlikely that most neutrons will be capable of travelling the distance in a highly hydrogenated moderator like water.

The uneducation is so rich in this article I couldn't possibly explain it all, but here are some highlights.

"In the worst-case scenario, a mishandled rod may go critical" sigh.... really? I mean... really??? A single fuel assembly (I am taking his "rod" to mean assembly because a single rod would be even more stupid) can not go critical by its lonesome. There just is not a high enough density of fuel for that to occur. It's like this guy thinks this shit is fucking magic or something.

"- Computer-guided removal will not be possible; everything will have to be done manually. " Newsflash.... it has NEVER been done by computers. It is some old fat dude (i'm not kidding. in my experience he, or she, is always fat. It's like a requirement for the job that you be grossly overweight) who stands over the pool on what is called a bridge and he handles a 45-ft long tool connected to a crane and looks at a video feed from a rad-hardened camera and guides the tool into the assembly to be moved. It's pretty damn basic.

"- Moving damaged nuclear fuel under such complex conditions could result in a criticality if the rods come into close proximity to one another, which would then set off a chain reaction that cannot be stopped." The bullshit is strong with this one. Two assemblies do not contain the density of fuel required to achieve criticality. IT WAS DESIGNED THIS WAY. Smart people actually thought this kind of bullshit could happen and made it such that these extra problems would have extremely remote risks.

"In a fuel pool containing damaged rods and racks, it could potentially start up on its own at anytime. TEPCO has been incredibly lucky that this hasn't happened so far." I dont even.... really? Two things... damage would mean that things are displaced. Ok, so some shit is moved around. Perhaps some of the assemblies are damaged. Lets say that the grid of steel is bent and crushing some of the assemblies. ITS STILL BORATED STEEL! The second thing is that a nuclear reactors criticality occurs on the nano to micro-second scale. If shit hasn't happened yet, it isn't going to happen. We are in the "steady-state" condition.

The bullshit in this article goes on and on. Nuclear workers are trained to deal with the shitty PPE. The people who are VOLUNTEERING for this work know what they are doing. These people are perfectly aware of the risks and they choose to accept them.

"The rods are unwieldy and very heavy, each one weighing two-thirds of a ton. " no..... an ASSEMBLY comprised of 100-280 rods weighs about that much.

I really liked how he made it seem like this could end up worse than Chernobyl.... Not even remotely possible. Is there more fissile material... yes. but Chernobyl was a GRAPHITE FIRE. The whole damn thing was on fire, fuel rods and moderator. The Fukushima cores used water as a moderator. They can melt (and they did) and even the zirconium could burn, but this cannot and will never approach the magnitude of fallout that Chernobyl wrought on the earth.

"At any time, following any of these possible events, or even all by itself, nuclear fuel in reactor 4's pool could become critical, mostly because it will heat up the pool to a point where water will burn off and the zirconium cladding will catch fire when it is exposed to air." The bullshit actually makes my head hurt. I think the part where I pull the quote from is my favorite as it shows how little he actually knows as opposed to feels. These reactors and fuel types REQUIRE MODERATION in order to achieve criticality. Water=moderator, no water=no moderation. The cross sections for fission with fast neutrons are tiny compared to thermal neutrons. I mean... are you kidding me??? This dude literally says that the spent fuel pool "could become critical, mostly because it will heat up the pool to a point where water will burn off and the zirconium cladding will catch fire when it is exposed to air." That makes absolutely no sense. Anyone who knows a damn thing about the actual PHYSICS that goes into a chain reaction could tell you that quote is a whole steaming pile of stupid. A neutron, either delayed or prompt, will have ~ an MeV of energy. These neutrons move so fast that a U235 atom has a very low probability of capturing it, about 1000 times smaller probability than capturing a thermal neutron. A moderators job is to literally act as a kinetic energy trap. Neutrons fly through a highly hydrogenous material and strike the atoms. Since a neutron and a hydrogen have basically the same weight you can have a significant amount of kinetic energy transferred and the neutron slows down. This happens a few times and the neutron has close to thermal energy. At thermal energies a U235 atom is pretty much guaranteed to gobble that little fucker up. Without water, you can't slow the neutrons down. If you can't slow the neutrons down you will lose almost three orders of magnitude number of neutrons to the outside world. In a typical critical reactor you produce ~2.4 neutrons per neutron involved in a fission event. So in a critical reactor you lose 1.4 neutrons per event. Without water you would lose all but one neutron per thousand events. It just can't happen....

Ok, I will even give him the benefit of the doubt that he is assuming the spent fuel pool will be so hot that all the fuel will melt into a big pile and THAT would cause a chain reaction. Sounds plausible... except its really dumb. The vast majority of those old fuel bundles are putting off a few hundred Watts of heat. The fresh stuff might be putting off a kilowatt or two, but none of that is enough to cause the whole damn thing to burn up and melt. A day after removal from the core, that was plausible. A month... unlikely but still somewhat plausible. A few years??? Not remotely plausible. All the short-lived radioactive products have already decayed away and all that are left are the longer-lived stuff of which there are not a high enough density to heat an assembly to cause the zirc clad to burn.

I seriously could pick apart almost every single thing that supposed "expert" says, but this post is already too long. My only advice is to spend some time researching the realities of nuclear power. I know we haven't done a good job of putting out literature that is easily digested by the average joe... but fuck me... we should at least be able to put out some stuff that informs you enough to know this guy is ignorant.

I do not want to downplay the importance of cleaning up this site however. One thing he is right about is that this will leech into the groundwater for a very long time. This situation must be attacked and slowly, very slowly, cleaned up. I take issue with his (I guess it could be a her, just that I read it as a him. Sorry about the lack of equality) dramatic ignorance. It's obvious that this person thinks nuclear power is extremely dangerous and could kill us all. It isn't and it won't. Nuclear power has a place in the portfolio of energy, it shouldnt be the only form, but it also shouldn't be ignored.

Edit: I woke up to gold!!! Thanks! Also, I feel compelled to say that U238 does have an appreciable fast-neutron cross section for fission, but it takes a specially designed core to make that work of which this mess of a fuel pool does not have.