Casey Zak's Mighty Blog

Oil has a higher specific heat than water. Hence when you fry food in oil, rather than boiling it in water, heat is transmitted more rapidly to whatever you are frying. This is one reason why fried food inevitably has a crispy exterior and juicy interior, while boiled food is homogeneously heated and boring.

Which brings me to my brainwave idea. Couldn’t you use liquid metal in place of water for sous vide cooking? Granted, liquid metals tend to be highly toxic, so you can’t just plop food into a pool of liquid metal to cook. But when food is cooked sous vide, it is first wrapped in airtight plastic before being dropped into a pool of evenly heated water. This wrapping would also prevent liquid metal from leaching into the food. And the high specific heat of liquid metal would allow ultra-rapid heat transfer to the food.

This would lower cooking times for sous vide food at standard temperatures. However, liquid metals also have a much higher boiling point than water (and higher smoke/ignition points than oil), so extremely high temperature cooking might become feasible. This could change the soft and flaccid (if marvelously tender) results of sous vide cooking into something closer to fried food.

There would be some novel mechanics to consider. For example, everything would float to the top of the liquid metal bath, so food would need to be anchored down. Still, the idea is so exciting that I’m sure someone will try it eventually.

Incidentally, the one prominent use of liquid metal baths in modern society is in cooling 3rd generation nuclear reactors. Liquid metal transmits heat so quickly that it could successfully cool down a nuclear core after a power failure (IE, Fukushima).

One of the things I keep hearing in the media lately is, “Fukushima is not nearly as bad as Chernobyl”. While this is true in a technical sense, I’m afraid it may not be true in a human sense.

From a technical perspective, Chernobyl was a criticality event, whereas Fukushima is presently just a partial meltdown event. The operators at Chernobyl could not insert control rods to stop the nuclear reaction and a runaway fission event led to a huge explosion and graphite fire that distributed radiation far and wide. In contrast, the fires of Fukushima are much less intense. Despite the presence of much more radioactive material at Fukushima, radioactive contamination is likely to be both less severe and less widespread.

But from the human perspective, the amount of radiation released or the size of the geographic area affected are not the most important issues. The key issue is how many humans are injured by radiation. The total number of radiation injuries (including low level exposures) from Chernobyl is estimated to be about 5.5 million. If you consider that Tokyo just advised people not to drink municipal tap water, we’re talking about 30 million or more people who are at risk of at least low level radiation poisoning.

I wish that the “experts” in the media would make this distinction when comparing Fukushima and Chernobyl.

He put a spell on you…. My favorite performance so far…

It’s now 3:30pm on Friday, 3/18/11.  Major problems continue at all 6 Fukushima reactors.

The largest threat of radiation release now seems to come from pools of spent fuel rods.  These pools contain much more radioactive material than the reactors themselves.  Some genius thought it would be a good idea to store these spent fuel rods in the same containment facility as the reactors.  When the reactors created hydrogen explosions that blew apart their outer containment structures, the explosions apparently cracked the pools holding the spent fuel rods.  Whoops.

Typically the pools hold enough water to cover the spent fuel by several meters.  Even if left uncooled, it would take weeks for enough water to boil off to uncover the spent fuel.  Hence the spent fuel pools were not a major concern in the inital stages of Fukushima.  However, enough water drained through the cracks in the pool that the spent fuel rods are at risk of being exposed to air.  This is very dangerous, as the spent fuel can ignite and spew plumes of radioactive material.  The spent fuel in reactor 4 is thought to be presently exposed to air.  Incidentally, reactor 4 holds most of the used fuel.

There is perhaps a subtle engineering lesson here.  Don’t store something which becomes terrifyingly dangerous if damaged IN THE SAME BUILDING as something that can explode and cause damage.  This is why I don’t keep fireworks in the gas tank of my car.

On the bright side, more and more resources keep arriving on site at Fukushima.  Power is being reconnected to the original cooling mechanisms of the reactors, and additional water is being directed at the fuel pools.  Despite all the doomsaying (here and elsewhere), it is still very possible that the situation could be stabilized.  That is, the amount of radiation emitted could be fixed at a tolerable level, and work could begin on reducing it.  On the down side, this could already be impossible due to reactor damage, or it could become impossible with a major radiation release from one of many potential sources on site. 

If this happens, the macabre option of “entombment” comes into play.  Essentially this just means dumping a whole bunch of inhibiting material on the site and then leaving the region alone for at least a few decades.  For now, let’s hope this is not necessary.

It’s now just past midnight on 3/15/11.  Four reactors at Fukushima have experienced fires and/or explosions.  Radiation exposure in some places is up to 400 millisieverts per hour, enough to induce vomiting from radiation sickness within a few hours.

Radiation is beginning to be detected in the Tokyo suburbs, anywhere between 4 and 33 times the normal background level.  The Nikkei was off 1,200 points at one time today.  Where tragedy and sorrow once hung in the air, a new sense of panic is growing.

There are 2 key developments today.  One is the elevated level of radiation, which is already to the point where anyone who works continuously at the site risks major health complications.  The second is the potential rupture of containment at reactor 2.  From what I can gather, this is not the rupture of the main steel structure surrounding the reactor.  Rather, it is rupture of an underlying mechanism which manages steam coming from the reactor.  TEPCO reports being unable to maintain both pressure and water levels in reactor 2.  This creates strong potential for so-called “full meltdown”, where molten uranium fuel pellets eat through the base of their steel confinement chamber and rupture it, creating a large explosion that widely distributes radioactive material.

Let’s hope that the workers on site are able to keep the reactors cool enough so that the worst does not happen.

It’s now 8:00pm EST on 3/12/11.  If you read through press accounts of the situation at Fukushima, you will find two trends.  First, credible outside experts (like Michio Kaku) are saying that a worst case scenario is unfolding or has already transpired.  Second, Japanese government officials are minimizing the problem.  This is the information profile of a disaster in progress.  The government denies everything (while evacuating a 20km radius), while outside experts make dire predictions.

I’m watching the situation with some concern because of the current prevailing winds.  There is much more nuclear material at Fukushima than there was at Chernobyl, and in the event of a large release, 10 times the radiation released by Chernobyl could be blown straight into downtown Tokyo (see this analysis from rt.com).  I’ve read plenty of judgments that this could never happen because the reactors are surrounded by 6 inches of steel plate.  But a nuclear reactor can easily get up above 5,000 degrees Fahreneit — more than hot enough to melt through steel.  And if this happens, the seawater that has been pumped through the reactor chamber would only help to vaporize and widely disperse radioactive material.

Everything I’ve read assures me that this is unlikely.  But if there’s even a 1% chance — would you want to be in Tokyo?  My thoughts are with everyone downwind of Fukushima right now.