Port-A-Nuke

Roland Piquepaille writes "Researchers at the U.S. Department of Energy (DOE) are designing a self-contained, tamper-resistant nuclear reactor that can be transported and installed anywhere in the world. In 'US plans portable nuclear power plants,' New Scientist writes that the sealed reactors would last 30 years and deliver between 10 and 100 megawatts. The largest version would be about 15 meters high and 3 meters wide, with a weight of about 500 tons, allowing for transportation by ships or very large trucks. The DOE thinks that this kind of nuclear reactor -- named SSTAR for 'small, sealed, transportable, autonomous reactor' -- would help to deliver nuclear energy to developing countries while significantly reducing the risk of nuclear proliferation associated with the use of nuclear power. What do you think of this idea? Is it a good one or a crazy one? Leaving a nuclear reactor in a developing country which can potentially become unstable during the 30 years of service of the reactor doesn't seem to be terribly safe. Read more before deciding. Anyway, there will be no prototypes before 2015."

Sounds familiar...

[flabbergast]

I knew this sounded familiar. Its even at New Scientist.

Mini nuclear reactor could power apartment blocks [newscientist.com]

With that said, I don't know how similar these two technologies are. But, smaller reactors seem to be an active area of research.

Re:Location, location

[Tazzy531]

This was the original idea back in the 1950s for the future of nuclear power. People would buy their own power stations to put in their yards to generate power. But power companies were against this [no money to make] and people were in an uproar about safety issues

We've been seeing a lot of this "safe" nukes stuff

[ahfoo]

What is being called safe is the cooling systems and other issues involved with a properly functioning system. What none of these are addressing is that a proplerly functioning nuclear fission plant produces wastes that need to be disposed of and those disposal costs are not being calculated in these reportedly cheap price tags.
This is a very serious accounting issue and a firm that tries to play this kind of accounting game deserves to be busted for fraud.

The ultimate hardware hack

[immel]

Notice they said "tamper-resistant" not "tamper-proof".This is just like in armor manufacturing, where there is no such thing as a "bulletproof" vest or a "bulletproof" door; there are bullet resistant things, but nothing can be entirely "proofed" from bullets or tampering.

If a seemingly "unupgradable" and unassuming iMac can be overclocked, then the cask can be broken.
If a supposedly "rock-solid" DRM can be defeated by depressing the shift key, then the alarms can be neutralized.
If the entire east coast of North America's power can be shut off by a single local power outage, then the coolant can be blocked.

Steam? Well...

[irokitt]

Be pretty hard to generate electricity without steam. Whether the reactor is a pebble-bed helium-moderated design or a "traditional" pressurized water-moderated design, the only purpose of a nuclear reactor is to generate heat, heating water to produce steam, which then turns a turbine to generate electricity. Either design you mention requires steam.

Perhaps your confused about how the primary loop-the water that comes into contact with the fuel elements-works. That water is under pressure, and does not turn into steam. There is a secondary loop, which passes through a heat exchanger with the primary loop, and it is this secondary loop that is converted to steam to turn the turbine. The secondary loop is not radioactive.

Pebble-bed reactors are promising because they have a potential to solve a lot of the problems that a PWR reactor has. But both reactors require steam.

Re:I've got mine on pre-order.

[aelbric]

Check out the new spiral ones in Home Depot or Lowes. They satisfy all three of your requirements. and fit in a standard incandescent light bulb socket.

I replaced every light bulb in my house with these. They are more expensive up front but they last forever (4 years and counting) and my electric bill has dropped by about 40%.

DEFINITELY worthwhile.

Re:It's not the CRT

[Anonymous Coward]

You seem utterly clueless.

The power rating of the PSU is how much power it *can deliver*, not how much it will drain from the grid just because you plug it in.

And fans draw practically no power at all, maybe one or two watts, so I don't see why you drag them into the discussion...

Re:Steam? Well...

[RsG]

Actually, in one pebble bed reactor design, a non-reactive gas is used in the heat exchangers only, steam is limited to the turbines themselves (easy to maintain that way - there is little or no corrosion among the radioactive parts). It is also possible to use recycled helium in the turbines, although IIRC it is less effecient. The advantage to a helium-only model is that He4 cannot be rendered radioactive via neutron bombardment, whereas water can (therefor there should be no liquid or gaseous waste products in a He4 design).

Re:Steam? Well...

[TheSync]

pretty hard to generate electricity without steam

Nope, high pressure gas turbines work fine [uic.com.au]:

JAERI is developing the Gas Turbine High Temperature Reactor (GTHTR) of up to 600 MW thermal per module. It uses improved HTTR fuel elements with 14% enriched uranium achieving high burn-up (112 GWd/t). Helium at 850C drives a horizontal turbine at 47% efficiency to produce up to 300 MWe. The core consists of 90 hexagonal fuel columns 8 metres high arranged in a ring, with reflectors. Each column consists of eight one-metre high elements 0.4 m across and holding 57 fuel pins made up of fuel particles with 0.55 mm diameter kernels and 0.14 mm buffer layer. In each 2-yearly refuelling, alternate layers of elements are replaced so that each remains for 4 years.

A US design, the Gas Turbine - Modular Helium Reactor (GT-MHR), will be built as modules of 285 MWe each directly driving a gas turbine at 48% thermal efficiency. The cylindrical core consists of 102 hexagonal fuel element columns of graphite blocks with channels for helium and control rods. Graphite reflector blocks are both inside and around the core. Half the core is replaced every 18 months. Burn-up is about 100 GWd/t, and coolant outlet temperature is 850C with a target of 1000C. It is being developed by General Atomics in partnership with Russia's Minatom, supported by Fuji (Japan). Initially it will be used to burn pure ex-weapons plutonium at Tomsk in Russia.

A smaller version of this, the Remote-Site Modular Helium Reactor (RS-MHR) of 10-25 MWe has been proposed by General Atomics. The fuel would be 20% enriched and refuelling interval would be 6-8 years.

A third full-size HTR design is Areva's Very High Temperature Reactor (VHTR) being put forward by Framatome ANP. It is based on the GT-MHR and has also involved Fuji. Reference design is 600 MW (thermal) with prismatic block fuel like the GT-MHR. Target core outlet temperature is 1000C and it uses and indirect cycle, possibly with a helium-nitrogen mix in the secondary system. This removes the possibility of contaminating the generation or hydrogen production plant with radionuclides from the reactor core.

HTRs can potentially use thorium-based fuels, such as HEU with Th, U-233 with Th, and Pu with Th. Most of the experience with thorium fuels has been in HTRs.

Re:I hope

[code shady]

Just an addendum:

The wired article talking about pebble bed reactors (in particular a type developed by the chinese to be modular, easy to produce, and apparently cluster) can be found online at http://www.wired.com/wired/archive/12.09/china.htm l

Um, no.

[tgd]

10 megawatts is 13,410.2209 horsepower. 1 million pounds. 0.0134 hp per lbs.

The 250hp engine in my truck weighs about 450lbs. Thats 186,425 watts, or .55 hp per lbs.

I'm not sure why the post was moderated as Interesting, since I assume it was a joke, but a lot of people don't realize a modern car engine puts out a hundred or more kilowatts peak.

Re:I've got mine on pre-order.

[Zaiff Urgulbunger]

The only problem I can think of is that you can't (as far as I know) use them with a dimmer switch. I do think they're great and I make a point of using them in places where the light is often on for hours and hours, e.g. the kitchen.

it is critical, somewhat

[rebelcool]

Its a slow fission system that uses a neutron reflecting shield that gradually (over 30 years) descends via gravity over the material. The neutrons bounce back into the fissile material thus creating fission. The shield descends at the rate it takes to consume the fuel (a long time)

The benefit of this is if for some reason the shield stops moving, the worse that would happen is fission would cease entirely at some point, rather than run away.

Or so my understanding goes.

Re:No boom, you will just scorch the paint

[morcheeba]

I'll second that. There were big chunks of the truck from the Murrah building still intact -- I'm sure they'll build a containment vessel stronger than a frame rail or a differential when exposed to a bomb.

Q. Were you also informed that a portion of the <I>frame rail was
found on top of a building approximately a block and a half to
two blocks away</I> from the Murrah Building?
A. Yes. I was.
Q. And what did that tell you about the size of the device or
the power of the device?
A. Again, it was a big bomb for a piece of -- it was smaller
than that this -- but for a piece of frame rail to have been
projected from the seat of the explosion in N.W. 5th Street
over these buildings to land on a roof on 6th Street.
Q. And here we have Government's Exhibit 713. Did you examine
that?
A. Yes, I did.
Q. And do you recall where that was recovered at the crime
scene?
A. Yes. That -- this fragment originated from part of the
rear axle, part of the differential housing from the rear axle,
so it would have been the back of the truck. And we said that
the -- we established that the rear axle had come to rest
outside the Regency Tower. That piece of metal had gone
further than that in the same general direction, I think
approximately 800 feet.
Q. And did that tell you something about the size or the power
of the bomb?
A. Yes. It was a big bomb.

Re:Sounds familiar...

[EvilTwinSkippy]

They've been using sealed reactors like this in Antarctica for decades.

Little blurb on little reactors around the world. [uic.com.au]

Re:I've got mine on pre-order.

[FooAtWFU]

I believe our current state reflects an inability of american society to realize that conservation is worthwhile and necessary.

The thing is that conservation is not worthwhile to the average American, from an economic perspective. Conservation and power efficiency in home devices and appliances often require a larger up-front cost, and only pay out their savings over an extended period of time. If energy became more expensive, things would change, but right now, it's worth it for average Joe to use his power-sucking appliances. Any damage to the environment or stuff to that effect is an externality [wikipedia.org] which he is not feling at the moment.

Re:As a former nuclear navy reactor operator

[Animats]

I can tell you that US Navy subs have had few catastophic disasters, and perhaps none at all for a long time.

USS Thresher and USS Scorpion were lost at sea. USS Guitarro sank alongside a pier during construction for reasons that can only be described as Really Dumb, but was refloated and repaired.

No US subs have been lost since the 1970s, though.

Re:No boom, you will just scorch the paint

[Marxist Hacker 42]

Which is why the reactor plans call for a GPS unit that phones home if tampered with. RTFA.

Chinese pebble reactor, safe due to physics, beats

[Anonymous Coward]

The Chinese pebble design, reported on a day or two ago, sounds safer. This seems to be the conventional design which can overheat and partially self destruct. The pebble design OTOH cools rapidly enough you can turn cooling off catastrophically and the fuel elements do not melt. (When moderator geometry is disturbed, the reaction stops in either case, but the pebble design has enough surface area that the melting point of the fuel is not reached. Current US designs OTOH melt leaving a mess. Actually I hope the pebble design replaces many of our existing power plants. It produces no carbon dioxide, and one of the side effects is it splits considerable water into hydrogen and oxygen, giving a very nice source of the latter.

RE: power consumption

[King_TJ]

As a matter of fact, I already *do* make liberal use of comapct flourescent replacements for regular lightbulbs - but they're not always viable. The biggest problem I have with them is they don't seem to be designed to stand up to the levels of heat they put out. They're not recommended for use in enclosed fixtures. (I tried it once anyway, in a couple ceiling lights in my kitchen. After only a few weeks, one of the flourescent bulbs started turning itself on and off every 30 seconds or so. I took it out and found its white plastic case had turned brownish - and it was obviously failing from the heat. A second one started exhibiting the same symptoms shortly afterwards, so I went back to regular 60 watt bulbs.)

The "100 watt + vs. 30 watt LCD monitor" suggestion isn't that sensible either, really. If you have a good CRT (like my Sony Trinitron 21"), where's the sense in disposing of it to save some watts of power? You're creating a big waste disposal issue from the lead in the glass and paying a big price premium for LCD technology that will take longer to recoup in energy savings than the panel is likely to last.

Honestly, attempts to guilt computer users into putting up with slower CPU speeds or twisting their arms to purchase specific technologies are not going to solve our country's power problems.

Most modern systems have all sorts of power savings/management features built into them already - including "sleep" and "suspend" modes, processors that step down to slower CPU speeds whenever they're idle, and so on.

glakes/Orlando/Ballston spa 1975-77

[Cryofan]

Hated it, BTW.

My website url above gives some of my thoughts about the nuke boats.

Re:I've got mine on pre-order.

[Frostalicious]

The reason I haven't converted my bedroom is that the compact floresent bulbs do have a 1 to 2 second startup delay

The latest generation of florescents have no warm up delay. Much less annoying. Sylvania, among others, make such bulbs.

bulb info [colorado.edu]