Joe Perez

iTrader: (8)

I'll be putting on my JasonC hat today and simply posting a link to a mainstream media source, rather than articulating my own opinions.

http://www.telegraph.co.uk/finance/c...r-thorium.html

Damned interesting, really. I've always thought of thorium as one of the more boring of the radioactive metals. You mix it with tungsten to make TIG welding electrodes, and coat the filaments of high-power vacuum tubes with it to extend their life.

I do have to question the scientific accuracy of the article, though admittedly as a layperson rather than a nuclear engineer. Specifically that "Thorium-fluoride reactors can operate at atmospheric temperature." Isn't the whole point of a nuclear reactor to make heat?

Braineack

iTrader: (62)

So in 3-5 years we are going FORCE all "wealthy" (I'm sorry but a 250K year salary i not someone who is 'rich') Americans pay to 90% of their income to pay to convert all cars/trucks in the world to nuclear reactor power?

I do agree the idea behind this thorium power source to be interesting, I just hope we naturally evolve to it and it's not forced "innovation"

im sure you remember my position on florescent light bulbs...

TurboTim

iTrader: (9)

wait...my tig electrodes are radioactive?! ****...

hustler

iTrader: (6)

So we need to invest billions of dollars into research on something that's certain? That makes sense.

mgeoffriau

iTrader: (7)

But the planet is dying. Think of the children. (You bastard.)

Splitime

iTrader: (24)

Lol, please tell me you already knew that? Grinding them should be done with a mask on....

cardriverx

iTrader: (12)

yeah I dunno what they mean when they said there is no pressurized water, because a nuclear reactor is made to heat water to create electricity...

Eaither way, there are some HUGE claims in that article...

Braineack

iTrader: (62)

but we can completely be free of gasoline driven cars in 5 years from today.

mgeoffriau

iTrader: (7)

Regarding the "atmospheric temperature" confusion in the article, I think what the writer was trying to explain that thorium reactors (while operating at high temperatures) don't produce the high vapor pressure that requires the level of containment systems necessary in typical nuclear reactors.

http://en.wikipedia.org/wiki/Molten_salt_reactor

Joe Perez

iTrader: (8)

Maybe not, but consider a broader point of view:

Roughly 75% of all electricity in the US is produced from fossil fuels, which includes both coal and petroleum-based fuels.

Transportation (which includes, but is not limited to cars and trucks) accounts for only 28% of total energy consumption in the US. Electric power generation accounts for 40%.

If 100% of electric power generation which is currently fossil-fuel based were transitioned to nuclear (plus other renewables), then two things would happen:

1: The annual production of CO2 and other "greenhouse products" would be radically reduced, which would decrease pressure on the automotive sector to constantly reduce emissions.

2: The petroleum-based fuels currently going into power generation could be eliminated, thus decreasing net imports of petroleum, possibly to the point where domestic production alone would satisfy demand.

So, no, it wouldn't get us totally off of oil. But it would be a huge step towards the broader goal of "energy independence."




Well, no pressurized water in the primary loop maybe, which is where all the nasty **** lives. You still need pressurized water in the secondary or you can't spin a turbine.

Braineack

iTrader: (62)

here's all I care about: cost & efficiency.

I simply want energy that is cheaper and easier to produce and i DO NOT want the government involved, the market should evolve naturally.

I don't want to see a large number of unutilized nuclear reactors that cost 100s of millions to maintain per year that look like this: http://www.foxnews.com/us/2010/08/31...ous-buildings/

redfred18t

iTrader: (1)

Wow, I dont think I ever heard about thorium outside of my high school chemistry class.

Hopefully it can work but I it wouldn't surprise me if the lobbyists of coal, oil, etc will try to prevent it from happening.

Braineack

iTrader: (62)

they have every right to lobby against the gov't intervening in the marketplace where they have little to no authority.

JasonC SBB

I forwarded the link to a physicist friend.

If it's such a pot of gold, why doesn't industry invest in it? That public money is always needed for large projects that have an ROI is a bit silly. If there's no ROI why should public money be spent on it?

Re: nuclear costs - how much of it is due to badly written gov't regulations?

ScottFW

iTrader: (4)

Nuclear power is the way to go IMO, and we'd be using a lot more of it today if not for that little Three Mile Island thing. That scared people enough that nobody wants anything to do with nuclear power happening in their back yard, so we haven't approved a new reactor in ~30 years.

You know how we don't like the French? I don't mean the individual people, who can be rude and who don't shower as frequently as I'd like them to, but the nation as a whole. We generally don't like them because they don't very much support our recent wars. The reason they don't have to is because after the oil crisis in 1973 they decided to build 50-something nuclear reactors so today they get 80% of their power from nuclear energy. Their energy independence enables their foreign policy to not be as oil-driven as ours has to be because we're living in the technological stone age. When oil & gas prices spiked a few years ago, you know what the French did? They commissioned another nuclear reactor. We need to wake up and get on board with that ****.

Cliffs:
1. Build more nuke plants.
2. Drill for our own oil.
3. Give middle finger to middle east.
4. ?????
5. Profit.

JasonC SBB

3 Mile Island was a demo that the engineers designed it right. It failed safe despite the crew's best efforts. Greenies turned it around and said "nuclear, bad!".

b0ne

I like it. Let's do it! Seriously.

redfred18t

iTrader: (1)

I never mentioned anything about the government though. Let's say this was totally privately funded (which I highly doubt), they would probably lobby against it regardless because it will hurt them in the long run.

Joe Perez

iTrader: (8)

In the US? Probably > 75%. I'm not sure I'd condemn the whole NRC as "bad", but it's definitely a hell of a bureaucracy.

Back when nuclear power was first being talked about, it was supposed to be "Too cheap to meter" (Lewis L. Strauss, chairman U.S. Atomic Energy Commission, September 16, 1954)

Trouble is, I think ole' Louey was only looking at the technical aspect of the problem, and not the political one. What if nuclear reactors in the 250-500MWe range were built in a mass-production environment and type certified rather than site certified? My guess is that while electrical power might still merit metering, the end-user cost would be a fraction of what it is today. And that doesn't even account for the secondary and tertiary costs of not having nuclear power; environmental impact from fossil fuels (and the money spent on it), dependence on foreign energy supplies (and the costs, both direct and military of that), R&D spent on blue-sky renewables that will never be economically viable, etc.




Well, it didn't help that the film "The China Syndrome" had opened in theaters just 12 days prior, and that in it, Jane Fonda noted that an accident of the exact sort which did happen at TMI would "render an area the size of Pennsylvania permanently uninhabitable." (TMI, for those who don't know, is in fact located in Pennsylvania.)

So I don't really blame the greenies, at least not for the immediate hysteria. I blame Hollywood.


Chernobyl didn't help either. That one genuinely was a catastrophe, and again, mostly the fault of poor reactor design.




Well, yes and no.

Good engineering is what prevented a major accident from turning into an outright disaster after it had happened. The reactor vessel remained intact and containment was not breeched.

OTOH, bad engineering is what allowed the meltdown to occur in the first place. Here's a very brief summary of what happened:

1: Some dipshit maintenance worker cross-connected a high pressure water line to the plant's process air system, presumably by accident. (Bad engineering: both the service water system and the safety-critical process air system used the same physical connectors.)

2: Said water started working its way down the air lines until it hit the flow control valves on the secondary cooling system (secondary meaning the loop that transfers heat from the boiler to the turbine, not implying that it was secondary in importance.) When this occurred, the valves failed shut. (Bad engineering: the valves should have failed in their last-known state, not shut.)

3: When the valves slammed shut, the turbine automatically tripped (good) and the reactor scrammed (good) however the resultant water-hammer ruptured the **** out of the secondary loop. Think about compressor surge when you slam the throttle shut with no BOV, only with tens of thousands of gallons of very hot water and steam. For reference, the secondary loop is the principal method for removing heat from the reactor. So at this point, there is no longer heat being drawn out of the reactor, and it is no officially becoming a very bad day, though the situation is not unsalvegable.

4: As a result of #3, temperature and pressure in the primary loop starts to skyrocket. (For reference, the primary loop is the one that flows through the core itself, carrying heat to the boilers where it is exchanged with the secondary loop. The primary loop is radioactive.) A relief valve, called the PORV, on top of the pressurizer (the highest point in the primary loop) opens to vent steam into a collection tank, which is inside the containment building, in order to prevent the primary loop from rupturing. (good) Unfortunately, this particular valve was known to be a shitty design that tended to stick open from time to time. It did, and continued to vent and vent and vent, overflowing out of the tank and onto the floor of the containment building. (Bad engineering: if you know that a particular part is a piece of ****, replace it with one that isn't.)

5: There is, inside the control room, a big-*** light which indicates the status of this valve. At least, that's what the operators thought it indicated. It actually indicated the commanded status of the valve, meaning what the valve had been told to do, not what it was actually doing. So, the big-*** light goes out, the operators think the valve is closed even though it isn't. (Bad engineering: if a $5 part is capable of causing a meltdown, at least instrument the damn thing properly.)

6: Because of this valve, steam continued to vent inside containment, lowering the pressure in the primary loop below the boiling point, which caused the water inside the core to start to boil off. (This is the beginning of the meltdown proper.)

7: The Emergency Core Cooling System automatically switched on, to directly flood the core with cool water. Unfortunately, all of the service valves on the ECCS were closed, presumably as a result of some maintenance work that had been done in the weeks prior. This was a violation of operating procedure, but the automatic control system was not designed to detect this unsafe condition. (Bad engineering: the reactor should not have been permitted to operate with the ECCS inoperative. The valves were monitored, but only by small indicator lights on the panel which the operators didn't notice. The reactor's control system should have been interlocked to these valves, causing an auto-shutdown any time all of them were closed.)

8: The operator's only indication of the water level in the primary system (including the water level in the reactor itself) was the water level in the pressurizer, which is basically a holding tank near the top of the primary loop. (The same as mentioned in #4.) Because water was boiling in the core, the water level in the pressurizer went UP, despite the fact that they were loosing tons of coolant through the PORV, none was coming in from the ECCS, and the water level in the core was dropping. So, the operators not only shut down the ECCS pumps, but also started draining water directly out of the primary. (Bad engineering: there was no way for the operators to know that water level in the core was falling, only that the water level in the pressurizer was rising. This led them to take the wrong actions.)

9: The primary coolant pumps (which are massive bus-sized electric motors) start going overspeed and vibrating like hell as they begin picking up the steam that's being produced inside the core. The operators shut those down as well, to prevent them from rupturing. Their training tells them that convection will cool the reactor, however it can't because steam bubbles are blocking the pipes. And remember: they still think the core is full of water.

10: At this point, the reactor really starts to go apeshit. With all flow stopped, coolant is now explosively boiling in the core, and still pouring out of the PORV. This is when the fuel rods become uncovered, and subsequently melt. As they do, the zirconia cladding of the rods reacts with the steam to form hydrogen gas, which subsequently boils out through the open valve, into containment. (Bad engineering: try to make your fuel rods out of something that doesn't create an explosive gas when it breaks down.) TMI2 is now officially down for the count.

11: Finally, one of the operators, going through the board methodically, discovers that the ECCS valves are shut. He opens them and re-starts the pumps. It's too late to save the plant, but fortunately, the molten fuel stopped at the bottom of the reactor vessel and didn't escape, so no China Syndrome. (Good engineering? Who knows what would have happened if they hadn't finally restarted ECCS.) The core begins to re-fill (although they have no way of knowing it) but they still have zero pressure and uncontrolled boiling.

12: Shift change. Fresh operators arrive in the control room.

13: One of the new operators, looking at the situation with a clear head, realizes that nothing makes sense, and at least some of the instruments have to be lying to them. Noting that both temperature and pressure inside containment are higher than they ought to be even under the circumstances, he checks a temperature sensor in the blowoff line after the PORV, finds it off-scale high, and surmises that the PORV has failed open. He closes an aux valve, which stops the venting. Pressure begins to stabilize, collapsing all of the steam bubbles that have been forming.

14: All of the hydrogen gas that got formed in #10, and has just been hanging around inside the containment building, explodes. The containment building does not rupture (good engineering), however the operators decide that in order to bring the pressure in containment under control and prevent a rupture, to vent some of the pressure from inside it directly to the atmosphere. This is the only release of radiation that occurs.

15: After much jury-rigging, the primary system is finally purged of all steam and the primary loop pumps are re-started, dumping their heat into a secondary secondary system. (No, that's not a double-negative.) The crisis is now over.



So yeah, good containment engineering saved the day. Shitty process control engineering caused the whole mess in the first place.

NA6C-Guy

iTrader: (1)

They will sweep it under a rug.