NPR Story on the Future of Nuclear Power 353
deeptrace writes "The Living on Earth show on NPR recently had a segment on the future of Nuclear Energy. The nearly hour long show is available as an mp3 and in transcript form. It talks about hot fusion, cold fusion, and Pebble Bed Reactors. It provides a well balanced and informative overview of progress towards their use for future nuclear power generation. Most interestingly, they talk with Dr. Pamela Boss and Dr. Stanislaw Szpak at the Space and Naval Warfare Systems Center in San Diego. Dr. Szpak says of their cold fusion experiments: 'We have 100 percent reproducible results'."
Crystal or Sonic? (Score:4, Informative)
Re:Pebble Bed reactors (Score:5, Informative)
Re:Converting to fusion later? (Score:5, Informative)
Very impractical. The principles are totally different; all they have in common is the word 'nuclear'.
Think about what it would take to refit a coal-fired power plant into a gas-fired power plant. You'd have to rip out and replace the entire furnace. Same with fission to fusion; you might be able to keep the boiler and turbines and so forth, but the heat source - the actual power core - would have to be totally replaced.
Re:Errrr... (Score:5, Informative)
In a nuclear reactor, heat is cheap.
What you're doing with these things is using the heat from the nuclear reaction to boil water, then using the steam to spin turbines and thus turn dynamos to generate electricity. It's a giant steam engine.
Now, if you want to desalinate salt water, one way to do it is to boil the stuff. The salt is left behind, and once the steam condenses you have fresh water. So. Use your nuclear furnace to boil off some salt water from the sea. Direct the hot steam through your turbines. Generate electricity. Then condense the steam in your cooling towers and output fresh water.
There'll be some tricky engineering to be done to make sure you don't get salt deposits clogging up your plumbing, but in principle the idea is pretty sound.
Some reading (Score:1, Informative)
http://en.wikipedia.org/wiki/Pebble_bed_reactor [wikipedia.org]
Other useful stuff:
http://en.wikipedia.org/wiki/Synroc [wikipedia.org]
http://en.wikipedia.org/wiki/Vitrification [wikipedia.org]
http://en.wikipedia.org/wiki/Nuclear_waste [wikipedia.org]
http://en.wikipedia.org/wiki/Aneutronic_fusion [wikipedia.org]
Suffice to say, these articles cover alot of ground.
Re:Pebble Bed reactors (Score:3, Informative)
I guess you haven't been to Chernobyl lately. The down sides to any nuclear power is its nuclear. It could blow and take a whole lot with it.
When was the last nuclear power plant accident that happened while its operators were following all prescribed safety procedures? Nuclear power is extremely safe, even more so than traditional coal plants. As long as the operators are trained properly, they perform maintenance as required, etc. there isn't much of a problem.
Name me one nuclear power plant accident and I guarantee it was caused by plant operators not doing what they were supposed to. Sure, this is part of the overall risk. However, it is no different than any other method of producing power. A negligent coal plant operator could cause an explosion or a really big, dirty fire.
Re:Errrr... (Score:3, Informative)
Instead of water, it uses pyrolytic graphite as the neutron moderator, and an inert or semi-inert gas such as helium, nitrogen or carbon dioxide as the coolant, at very high temperature, to drive a turbine directly.
From this Wikipedia Article: http://en.wikipedia.org/wiki/Pebble_bed_reactor/ [wikipedia.org]
Re:Pebble Bed reactors (Score:4, Informative)
"We" never made that claim about Soviet reactors. Cherbobyl didn't "blow sky high" anyways. It simply burned.
Re:Pebble Bed reactors (Score:4, Informative)
I cannot describe in words how assine this statement is. Plutonium might not be the worlds most lethal substance, but it's a danm sight more dangerous than everyday toilet bleach. Just ask Harry Daghlian and Louis Slotin. Well, you could have asked them if they hadn't been killed in plutonium accidents.
Re:Pebble Bed reactors (Score:2, Informative)
As far as a danger to the public, we are closer to death every time we get in a car--especially if some idiot is using a cell-phone. Your chances of dying quadruple every time you use that cell phone. You'd be better off driving drunk (.08).
TMI was a public relations disaster, and not much else.
Re:Errrr... (Score:4, Informative)
What's generally done in nuclear reactors is that the core cooling is done through a sealed loop; the material which flows through the core never actually goes near the steam turbines. It goes out of the core, into a heat exchanger, and then back into the core. That's it. Barring some sort of disaster, it never leaves this closed loop.
This gives you a lot of additional flexibility in terms of what kind of coolant you want to use, too. It doesn't have to be water -- it can be liquid metal (IIRC the French use or used liquid NaK in their breeder reactors) or even some sort of pressurized gas or something more exotic.
Having an open-loop core cooling system just doesn't strike me as a particularly good idea; I do like the concept of using the waste heat from power generation for some actual purpose though, be it desalination or H2 production or whatever, but I think there are lots of ways to do this without opening up the core to the environment.
Re:Pebble Bed reactors (Score:4, Informative)
Actually, it did blow "sky high". The boiler overpressurized and exploded. That's why old-style pressurized-boiler systems aren't liked. They have a tendency to explode suddenly. Those same boilers were responsible for quite a few industrial accidents in the 19th and early 20th centuries.
The nuclear fuel, however, never exploded. It was merely scattered by the boiler explosion. Had the Chernobyl reactor bunker been properly designed to withstand such an explosion, the mess could have been completely contained. Instead it spread across several miles of nearby area and found its way into the water table. Some of it was carried by winds, but this really wasn't anything different than the hundreds of nuclear bomb tests that had been done in decades past.
One way or another, Chernobyl was a stupid, stupid design. The reactor had insufficient safeguards, the personnel were not fully trained, they performed a fail-safe test by actively overriding the fail-safes themselves (!?), and the fail-safe test was done with no qualified overseerers present. Put it all together, and it spells a recipe for disaster.
can't use drinking water as primary coolant (Score:3, Informative)
You could still heat exchange from an inert gas to water, however, and most likely have more than enough heat to boil it or "crack" it.
Re:Pebble Bed reactors (Score:2, Informative)
By the way, if you are terrified of plutonium, you might want to read up on exactly what comes out of the stacks at a coal fired power plant. 12,000 tons of thorium and 5,000 tons of uranium worldwide in 2000 alone.
Re:NPR (Score:5, Informative)
And as the sibling said, if you think NPR is leftist, your 'left-right' spectrum is way out of whack.
While I personally don't get cable anymore, anyone who does pays for Fox News, whether they like it or not. The only way to not pay for Fox News is to not have cable or satellite, which is a minority of the US.
Re:Pebble Bed reactors (Score:5, Informative)
Simple sanity check: How's a coal powerplant smokestack filter going to catch thorium oxide if it's not stopping carbon dioxide? The size of the molecules is not significantly different. Additionally, if it is catching those many tons of thorium and uranium, where are all the nuclear waste disposal people dealing with the spent smokestack filters that by onw are surely clogged with tons of radioactive metal compounds?
Don't kid yourself. Nuclear is clean and safe.
Hydrogen power, on the other hand, is idiotic. Releasing CO2 into the atmosphere is fine as long as it comes from a carbon neutral source. If you were producing methanol from plants and burning that in cars (not farfetched, seeing as several racing leagues use it), it would not matter that CO2 was released, because each molecule of CO2 would be one that was taken out of the atmosphere a few months prior to grow the plant feedstock in the first place. The lack of a carbon in H2 is not an advantage. The very real disadvantages of H2, such as difficult of containment and poor energy/volume, still stand.
Re:NPR (Score:5, Informative)
Couldn't find any info on an NPR hiring scandal (unless you mean the recent Bush CPB scandal?) Care to provide a link? Or is this a 20-year old canard that you are still holding onto like Chappaquiddick? Also couldn't find anything on a funding scandal so a source there would be helpful as well.
I don't believe Fox is publicly owned.. or did you mean Fox as the 'government-controlled' media source?
Re:Candu (Score:3, Informative)
Re:Pebble Bed reactors (Score:5, Informative)
You have no idea what you are talking about. None. What carries radiation in pure H2O? What is it's half life? (Admiral Nimitz [wikipedia.org] once drank reactor water to prove it safe - and still these myths.) The water in most modern reactors never turns to steam - it's used as a heat source to turn a secondary water system to steam to drive turbines and other useful equipment - through heat exchangers - look it up. The reactor water, safe as it is, is never dumped anywhere. It lasts the life of the system.
Here is a nice picture to explain the heat exchange cycle of a presurized water reactor [tva.gov] for you.
Re:Pebble Bed reactors (Score:4, Informative)
What do you mean by "explode"? Are you thinking "turn into a nuclear bomb" explode? If so, yah, I agree, but that's mainly because reactors aren't built to be a bomb. Chernobyl did blow up - the boiler definitely exploded. Blew the roof off of the building. Several other things blew up, too. Heck, there was a seismic event recorded near Chernobyl at the same time, so I think it's safe to say there was an explosion.
Three Mile Island was an explosion, too. The core became exposed, boiled away a ton of water (and split it into hydrogen and oxygen), and detonated the resulting hydrogen as well.
If you're trying to say that nuclear reactors don't turn into a nuclear bomb, I'd agree with you. But all reactors that burn things and boil liquid into gas under lots of pressure for electricity can explode.
Now, it's perfectly possible to contain that explosion (using a containment building) but saying "oh, nuclear reactors are safe, they can't explode" is a little false. They can explode, and they would spew a lot of radioactivity. It's just that there are a lot of safeguards built in. Forgetting this means you could end up with a situation like Chernobyl, where the system was built with only partial containment. With a coal reactor, you might be able to get away with that, although it would still make a giant mess. With a nuclear reactor, you absolutely cannot.
Re:Pebble Bed reactors (Score:3, Informative)
Wait a minute. There are several different issues here.
1: It was impossible for them to explode like a nuclear bomb. Several anti-nuclear groups were saying that nuclear power plants could explode like a nuclear weapon. This sort of explosion is impossible for a number of reasons. The enrichment of the fuel (3% vs 90+%), the modulator that is present in the reactor is not in the bomb, the explosives that trigger the bomb are not present in the reactor, the reactor dependence on thermal vs fast neutrons, etc, etc, etc.
2: The much maligned Rasmussen report (WASH-1400) never said that a nuclear accident was impossible. It calculated the odds of various forms of accidents happening. The worst case had odds of 1 in a billion per reactor per year. But what about Three Mile Island? Worst case had 45 thousand people immediately dead and over a million suffering cancer over the next 10 years. Unless there has been a fantastic government coverup, that has not happened at TMI. But here is the fun part. Read the Kermey report on TMI (the presidential commission report). According to the Kermey report THE RASMUSSEN REPORT PREDICTED THREE MILE ISLAND. From memory, a TMI style accident had a 30% chance of happening by the year 1980, and there was a 75% chance that it would be in a Babcock and Wilcox designed reactor, which it was. The accident was predicted, but no one was looking at it because they were all looking at the big accident!
3: Chernobyl: for years the Russians said that the fact that the west had containment buildings and the Soviets did not was a testiment to the superiority of the communist system. Funny how they no longer make that claim. But here is an inditement against the Soviet reactor design. There is an arrangement of the control rods and coolent that would make the reactor prompt neutron critical instead of thermal neutron critical. In fission reactions there are two kinds of neutrons that come out: prompt and thermal. Prompt neutrons come out in microseconds. Thermal ones come out over a period of several seconds. To make a reactor controllable, you rely on thermal neutrons because no machine in the world is fast enough to control based on prompt neutrons. The russian system, in a certain configuration, was prompt neutron critical, and that is what they did during the testing that night. Once that happpened, no control system in the world could shut that thing down.
4: now to pebble reactors. Pebble reactors are designed using what is known as passively safe. This means a terrorist could blow apart the pumps, the control rods, and even the containment vessel, the damn thing isn't melting. Why? They figured out the maximum amount of heat the pebbles could produce, and then designed the ceramic coating to melt at a higher temperature.
Re:NPR (Score:3, Informative)
Indeed. Listen to a my hometown radio station KPFA [kpfa.org] in Berkeley, Ca. for a few hours then you will know what real leftist radio sounds like.
Probably not subduction zone disposal . . . (Score:5, Informative)
Of course, many countries have banned dumping radioactive waste into the sea under the London Convention [londonconvention.org]. The United States signed it in 1998, but it hasn't been ratified yet.
Re:The idea of re-using the heat appeals, but worr (Score:2, Informative)
A 2002 Economist article [economist.com] looked at the pebble bed reactors, they described the process as
Re:Pebble Bed reactors (Score:4, Informative)
Actually, people living in Bavaria (West Germany) and Czech Republic are supposed to have any mushrooms they pick in the forest tested for radioactivity. There are offices in most small towns that will do this service for free (or a small cost).
Here is my supporting research:
http://www.racerocks.com/fungi/fungrad.htm [racerocks.com]
http://www.chernobyl.info/index.php?userhash=1155
Re:Pebble Bed reactors (Score:3, Informative)
Re: the leukemia sufferers around the Irish sea, your last argument was that radioactive material could not possibly be the cause of cancer around coal plants, and leukemia is a cancer. You can't have your cake and eat it too.
For an "obsessive maths geek", you should know better than to throw around figures like 90% efficiency. Assuming a cold sink temperature of 25 C (298 K) for said hydrogen engine, the combustion temperature would need to be 2980 K (carnot eff. = 1 - Tl/Th), or 4900 degrees Fahrenheit, assuming your hydrogen engine was a Carnot heat engine, which it's not. I didn't say a thing about using fossil fuels; I agree that using non-carbon neutral sources like fossil fuels is idiotic for a variety of reasons. I was simply supplying one example of the many possible carbon neutral fuels that make far more sense from a practical standpoint (as opposed to the standpoint of a stoned hippie), such as plant-matter derived alcohols, and biodiesel.
Re:Pebble Bed reactors (Score:4, Informative)
Exactly. Containment structures have saved our collective arses, so to speak, so many times in the US that the concept of building without one seems outright foolish. They work amazingly well. Three Mile Island wouldn't have been a Chernobyl without its containment structure, but it could have been a Chazhma Bay or Windscale sized disaster.
That's why I don't support pebble beds. Their idea is to work economic voodoo thanks to the lack of a containment structure, insisting that their reactor is safe simply because it has a negative void coefficient (produces less power as it gets hotter). Pardon me to all of the people who bring this fact up in every discussion of PBMRs, but whoop-di-doo.
Plus, PBMRs use *graphite* as a moderator. Even if you believe that nuclear grade graphite only erodes instead of burning (even though the Soviets were insistant that it was burning graphite that spread the radioactive plume from Chernobyl), the erosion of a few percent would be bad enough. But it gets worse. Not only is air (with oxygen) the "backup coolant" in the event of a helium leak, but in most designs I've seen, there's water/steam near the main loop, either as a secondary coolant or for hydrogen generation. Steam + graphite = hot h2 = explosion.
I instead would like to see more money being put on reactors that aren't the current buzz - liquid metal breeders, esp. lead and lead-bismuth breeders. As breeders, you recover a hundred times as much energy and leave a small fraction of the waste from a given amount of fuel. Your fuel is automatically entombed in case something goes wrong. Often, the reactor is underground, so the ground acts as extra neutron shielding. The metal typically can circulate through natural convection if necessary. In general, while they have high capital costs, their operation is quite simple. And without needing much fuel or waste disposal, quite cheap to run in general. While China is really pushing for new PBMRs, Russia is pushing for liquid metal breeders.
Re:Pebble Bed reactors (Score:3, Informative)
Not much plutonium is mined. About 0% in fact.
Any that was created in stars has long ago decayed. All the plutonium we have now was made in fission reactors. (The first generation of reactors was built specificaly for plutonium manufacture - any electricty was a side product.)
Re:Great! (Score:2, Informative)
Re:NPR (Score:1, Informative)
I can't see the inherant bias on NPR's side if they use a term that the GAO uses:/ undocres.htm [uscis.gov]
http://www.gao.gov/new.items/d04472.pdf [gao.gov]
Or the DOJ/INS:
http://uscis.gov/graphics/publicaffairs/summaries
Please do your research before spouting off about something you know nothing about. You only prove your own bias and obscure the argument with unfounded speculation.
Re:But the uranium! (Score:3, Informative)