Robert X Cringely Predicts More Mininuke Plants 430
LandGator writes "PC pundit Robert X Cringely had a life before writing 'Triumph of the Nerds' for PBS: He covered the atomics industry and reported on Three Mile Island. In this blog post, he analyzes the Fukushima reactor failures, and suggests the end result will be a rapid growth in small, sealed 'package' nuclear reactors such as the Toshiba 4S generator considered for Galena, Alaska. He thinks Japan may have little choice, and with rolling blackouts scheduled, he may be right."
Re:NO.. just NO. STUPID IDEA. (Score:4, Informative)
until you factor in the earthquake and tsunami. water + sodium = BIG BOOM.
You fail sir. The 4S reactor is placed 30m underground in a concrete and steel containment vessel. The sodium is encased inside the reactor and cannot come into contact with anything outside the vessel. It's a sealed unit. There is a transfer loop that you pump water in and get steam out. The earthquake would shake it. The tsunami would damage the above ground equipment. And the reactor would be fine, sitting in its containment. I believe (and I'd have to go look to be sure) the Toshiba 4S uses a neutron reflector ring that's coupled with fusible links to the control rods. If it overheats the links melt, the reflector drops to the bottom of the vessel, and the reaction stops. Of course, now you're sitting on a dead reactor that you'd have to send back to Toshiba for refurbishment. Yes, the thing is designed (in principle) to be recycled and refueled at a Toshiba factory.
Much Ado About Nothing (Score:3, Informative)
The Toshiba 4S is a reactor with a 10 MW capacity. The peak summer load in New England is 28,130 MW (see link below). So you would need 2,813 of these reactors. Get 50% of New England's power from nukes and thats still 1406.5. Whats the cost to protect them by the way?
Sure, its the next best thing for Galena Alaska. For national energy policy, this is completely irrelevant.
http://www.ferc.gov/market-oversight/mkt-electric/new-england.asp#gen [ferc.gov]
Re:I'd be open to it, but good luck with everyone (Score:4, Informative)
Your sarcasm is well placed. The BWR design with a pressure-supression pool was designed so that a weaker containment system could be built as a, you guessed it, cost cutting measure. This design was been questioned in 1972 by S.H. Hanauer. [nytimes.com] Of course, because of the weaker design and the requirement for many valves and backup valves (which are notoriously unreliable), Hanauer concluded that costs are probably about the same as the safer dry containment system.
Re:I'd be open to it, but good luck with everyone (Score:4, Informative)
The nuclear reactors in Fukushima are boiling water reactors. It uses water for coolant, which boils as it flows through the reactor chamber, goes through a heat exchanger, and is recirculated. Since the coolant systems are not functioning properly, they are dumping saltwater into the coolant lines, letting it boil off, and vent out into the atmosphere through pressure release valves. This is releasing radiation, however it is a small amount, and containing elements with short half-lives that will decay rapidly and cease to be a danger. This has been happening for several days
This steam release is very energetic. It is so energetic that the water is spontaneously disassociating to hydrogen and oxygen. When you get large volumes of hydrogen and oxygen, along with a high temperature source, you're going to have an explosion. There is no way around that, but it is not an indicator that the containment vessel has breached and the core is exposed.
The reports of a breach in reactor #2 appear to be part of the coolant system. The suppression chamber has developed a crack, which lead to an uncontrolled release of coolant, as the system depressurized to atmospheric. This resulted in a large venting of radiation as it depressurized, but now, the situation is no different than at the controlled steam releases at the other reactors. The containment vessel is still intact. Corium is not flowing out of the containment vessel. There is not currently any risk of it being released and contaminating the ground water.
Re:I'd be open to it, but good luck with everyone (Score:4, Informative)
nat geo: small town nukes
http://ngm.nationalgeographic.com/big-idea/08/mini-nukes [nationalgeographic.com]
i have the magazine somewhere, but cant seem to find the article at a glance and dont remember if the print article was any longer.
Re:I'd be open to it, but good luck with everyone (Score:5, Informative)
ask any Victorian about their willingness to live near Hazelwood (note: Moe is near there...)
That's Victoria, Australia folks. Home of the meanest belching brown-coal moonscape and Pink-Floyd nightmare of a 1950's power station. And Moe (pronounced "mowie") is a Township, not a Stooge. Or was, anyhow. Just in case you needed more detail. Bad idea to leave your clothes out on the line for any length of time.
Re:I'd be open to it, but good luck with everyone (Score:5, Informative)
First off, the fuel pellets in these boiling water reactors are made of uranium dioxide [wikipedia.org] -- a ceramic which has a melting point of 2,865 degrees Celsius and the zircaloy cladding melts somewhere in the range of 1,850 to 1,975 degrees Celsius (depends on which alloy they are using). I could not even find a combustion temperature for either material. That doesn't matter, though, because the temperature of the spent fuel in the pool would be somewhere around 200 degrees Celsius, depending on how long it had been taken out of the reactor.
So it is unreasonable to speculate that the fuel rods have `caught fire`.
Secondly, Tokyo Electric Power Co. said that an oil leak in a cooling water pump at Unit 4 was the cause of [cachefly.net] the fire the media keeps talking about.
I would strongly suggest anybody interested in following this event watch that web page and/or this one [world-nuclear-news.org] for accurate, knowledgeable, non-scaremongering reporting. I've heard too many news reports totally screw the facts up. (Like when they reported there was a 3rd explosion when really it was the 2nd explosion that happened in the #3 reactor building.)
Re:I'd be open to it, but good luck with everyone (Score:4, Informative)
The ash from coal plants is radioactive. Coal has low concentrations of radioactive elements in it. When you burn the coal the radioactive elements are among the ash and are at a higher concentration of the ash than they are of the source coal.
http://www.epa.gov/rpdweb00/tenorm/coalandcoalash.html [epa.gov]
http://pubs.usgs.gov/fs/1997/fs163-97/FS-163-97.html [usgs.gov]
A lot of the commentary about radioactivity and coal plants come from this Scientific American article:
http://www.scientificamerican.com/article.cfm?id=coal-ash-is-more-radioactive-than-nuclear-waste [scientificamerican.com]
Many people read the headline of that article and didn't really bother to read the article. The argument that Scientific American makes is that a coal plant puts more radiation into the surrounding environment than a nuclear plant. The nuclear waste is still obviously more radioactive than the ash. However, the nuclear plant carefully controls their waste and materials.
In both cases the radiation released is low and not a health risk.
Re:I'd be open to it, but good luck with everyone (Score:4, Informative)
Water [engineeringtoolbox.com] has a specific heat of 4.187 kJ/kgK and a heat of vaporization of 2,270 kJ/kg.
Liquid nitrogen [uigi.com] has a specific heat of 2.042 kJ/kgK and a heat of vaporization of 199.1 kJ/kgK, and a specific heat of 1.04 kJ/kgK when gas.
So putting in 1 kg of water at 20 C and extracting it as steam at 100 C removes (4.187)*80 + 2270 = 2605 kJ of heat energy from the reactor.
Putting in 1 kg of liquid nitrogen at -200 C and extracting it at 100 C removes (2.042)*4 + 199.1 + (1.04)*296 = 515 kJ of heat energy from the reactor.
Per kg, water removes over 5x more heat energy than liquid nitrogen. The only reason to use liquid nitrogen is if you wanted to drop the temperature below the boiling point of water. AFAIK radioactive decay is not influenced by temperature, so there would be no benefit to doing that here.
If I had to guess, the Soviets had to encase an active pile in-situ with concrete. Concrete tends to be very temperature-sensitive when curing - too hot and it'll crack. So they probably used liquid nitrogen to drop the temperature to where the concrete which initially contacted the pile could cure without cracking.