The Nuclear Power Thread

[russ_watters]

My father once did a back of the envilope calculation on solar power, and determined that to supply the US with power BACK IN THE 60'S, even if we could collect solar power 100% efficiently, we would have to turn the state of Arizona into a solar collector. (I would love to see one of you actually crunch those numbers and verify his results, remember that you need to include gas usage, not just electric) It won't work... give it up... Solar isn't the solution, we need Nuclear.

Welcome to PF.

I agree with pretty much everything you said. I believe that nuclear is going to make a dramatic comeback in the next 20 years because there simply is no other option (the fact that it is the best option, unfortunatly, isn't enough for today).

There may be a thread around here somewhere about it, but a few years ago, I did some calculations about solar and concluded that with good solar panels, we'd nee to cover an area of about 300 miles square - similar to your father's calculation of the entire state of Arizona.

Strictly speaking, area isn't the issue - money is. Right now, the per-watt cost of solar is far too high to make it viable. If it can drop by an order of magnitude, then it could be a real solution.

 

[vanesch]

Certainly 100 yrs. There is limited production of Pu, which essentially absent in nature due to it's relatively short (geologically speaking) half-life.

Nuclear energy is produced primarily from the fission of U-235, with fissioning of some Pu which is produced through transmutation reactions involving U-238 in the UO₂-based fuel. Converting more U-238 to Pu-239/240/241 could extend the U-resources, and then there is Th-232, which can be transmuted to U-233, which is fissionable.

So there is potentially hundreds of years of energy resources based on fission.

One key issue is where to put all the fission products, which must be isolated from the biosphere.

I would like to add to this. Current thermal-spectrum reactors use MAINLY U-235 in the power production. U-235 is 0.7% of the natural content of uranium on earth. In fact, at high burnup, SOME U-238 (the 99.3% remaining if we neglect some traces) is converted into Pu-239 and is burned up ; about 30% of the energy that is extracted in a reactor comes from this Pu-burning, and 70% comes from the original U-235 burning.

So that means that currently, we use effectively ONE PERCENT of the energetic content of the uranium that has been extracted.

In a fast reactor, we can use ALL of it, because U-238, through conversion in Pu-239, can become a nuclear fuel. We can use all the U-238 that we already DUG UP, and partially discarded (in the "enrichment" of uranium, which is nothing else but removing 3/4 of the U-238 from the original ore), and MOST of the "burned fuel" which consists mainly of passive U-238.

So, by switching to fast breeders, we can extract in principle ONE HUNDRED TIMES MORE ENERGY from the EXISTING waste than we already extracted. In principle without any more uranium input. Just by using the "waste" correctly.

If some powerplants have been working for 30 years, this means, in principle, that we can extract the same power for another 3000 years, just by using its "waste".

 

[vanesch]

On the other hand...

Given that it is inevitable, the question is, what should we do about it? My work is in Decision Theory, and I believe that the probability of a nuclear accident associated with Nuclear power is low... unfortunately the cost is high. Utility is the product of the probability * the cost. There is a good reason to be cautious about Nuclear power. I think that we need a balanced middle of the road approach. The "it's ok, there are no risks" or "the risks are so small" thing is not necessarily the best response. But the argument that the risks are lower than those of coal (as so many of you have nicely made) works better.

The point really is that the risks ARE already really small in the West. The objective risk (as you point out: risk = probability x cost(lives, land...) ) of nuclear activities is about a million times lower than driving cars, and even lower than making shoes (just by comparing the number of yearly dead). The "maximum disaster" is Chernobyl, which is a serious catastrophe, but much less so than many accidents in other branches of human activity (for instance, the Chernobyl disaster is way less terrible than the Bhopal disaster, and a Chernobyl accident in the west is way way way less likely - for fundamental reasons - than another Bhopal).

Furthermore research is needed to make those risks smaller. Thus it is my belief that research into safer Nuclear energy is the solution. We need to spend the bucks, and get it done. This research needs to focus on making the process safer and on dealing with the waste. We have done a lot on the first one, but can do more.

There are good solutions for the waste. It is not as catastrophic as eco wackos want us to believe. There are in fact 3 timescales in nuclear waste:

- fission products: about harmless after 300 years
- minor actinides: about harmless after 10 000 years
- plutonium: about harmless after 100 000 years.

Now, reprocessing can remove the plutonium (to be re-used as fuel!), and there's a lot of work going on - and prototype processes such as DIAMEX have been set up - to remove also the minor actinides. This leaves us with the main ash from nuclear power: the inevitable fission products. Well, there life time is of the order of 300 years.
That's not the "millions of years" that is usually talked about.

The minor actinides can be considered as waste, but they can also be burned in fast reactors. There are experiments under way to burn them in subcritical accelerator-driven reactors, but I think that this is overkill. Even considering them as waste is not such a problem, because geological storage can be made secure for 10 000 years with high reliability. Also, if there's a leak after, say, 1000 years, that's not a major disaster. There will be a minor polution of a relatively local area, much less of a danger than most waste storages of today.

I truly believe that we can also do much better on the second one. We can find better ways of dealing with the waste that we have. Some have been discussed above but there are others. There is energy in that waste. Decays=energy... perhaps not very much, especially in the stuff that takes forever to decay, but it is in there, and there should be good ways of getting it out and making it useful instead of a scourge. Next we can find better ways of reprocessing (I know proliferation rears its ugly head) but there are ways of reprocessing that can be internationally monitored and where the reprocessed materials can be used immediately... or something... so we aren't stockpiling weapons grade materials. That's the point of research, we don't know what solutions will be found, but we should look for them. Finally we can produce reactors that produce less waste.

Most of this is already well-studied. There have been 18 fast breeder reactors active in the world ; only two of them are still working, most of them were closed down for political reasons. So this is not a dream on paper. Prototypes have been build and made working. One just needs to improve a bit on the engineering to optimise the design. There are no known difficulties of principle. This stuff has been working before.

These are the research areas. Some solutions already exist in these areas, but we just can't use them for political reasons etc. Some better solutions are in the works, and some even better solutions are sure to come out of some good investments in research.

In fact, France has the ambition to put its first Gen-IV reactor, with closed fuel cycle, up and running by about 2020. If the green party didn't ask for drilling a hole in the reactor vessel of super-phenix in 1998 or so, it would probably already be up and running.

 

[Astronuc]

Re: Fast Reactors - this would be of interest.

The status of Fast Reactors programme in France in 2005
http://www-ist.cea.fr/publicea/exl-doc/200600003924.pdf

I attended a lecture by the program manager of the US fast reactor program 25 years ago. At the time, he had just dismissed 300 people from the program! He likened a fast reactor to building a supersonic aircraft out of balsa wood. My colleagues and I were rather shocked at the statement.

Fast reactor technology has been rather problematic, not so much from the standpoint of the nuclear physics and fuel design, but from the aspect of balance of plant and operational issues. FR's are complicated because the fuel handling has to be done under liquid sodium. Traditionally, electrical generation has been accomplished by large steam turbines, but the problem there would be the basic incompatibility of water and sodium.

Superphenix was plagued with problems, and the Japanese MONJU had its own set of problems, including some deficiencies in design.

Perhaps the better alternative is a gas-cooled fast reactor.

I'm not arguing that fast reactor technology is impossible, but rather, it is not so easy.

 

[vanesch]

I attended a lecture by the program manager of the US fast reactor program 25 years ago. At the time, he had just dismissed 300 people from the program! He likened a fast reactor to building a supersonic aircraft out of balsa wood. My colleagues and I were rather shocked at the statement.

This is more kind of emotional rethoric than based upon any technological assessment. I attended a lot of seminars in Karlsruhe a few months ago, and had the opportunity to have a dinner with one of the CEA responsibles for the former Superphenix programme, which seemed to claim exactly the opposite: that liquid sodium cooling is technologically mastered and that the closedown of it was purely political. It is true that Superphenix had a lot of problems in its first years, but in its last years it ran without many troubles, and it was also a prototype: you expect difficulties in a prototype.
Let's not forget that Phenix has been running for over 30 years without problems.
So according to him, one can always improve upon robustness and one can always improve upon engineering, but there wasn't any fundamental objective technological obstacle to building liquid sodium cooled reactors.

Fast reactor technology has been rather problematic, not so much from the standpoint of the nuclear physics and fuel design, but from the aspect of balance of plant and operational issues. FR's are complicated because the fuel handling has to be done under liquid sodium. Traditionally, electrical generation has been accomplished by large steam turbines, but the problem there would be the basic incompatibility of water and sodium.

Nobody will deny that a FR is a bit more complicated than a LWR, but that's more because a LWR is *extremely simple*. The problem with steam turbines - in as much as that is a problem - is the low Carnot efficiency, because you cannot use steam much above 400 degrees Celcius (critical point of water). It would of course be dangerous to have a direct Sodium/water heat exchanger, but nothing stops you from having an intermediate fluid which is compatible with both.

Superphenix was plagued with problems, and the Japanese MONJU had its own set of problems, including some deficiencies in design.

Sure, but these are prototypes, exactly to learn from. If one would have built a few tens of prototypes, the experience gathered would make this technology probably just as robust as LWR are now.

Perhaps the better alternative is a gas-cooled fast reactor.

I'm not arguing that fast reactor technology is impossible, but rather, it is not so easy.

There are essentially 4 types of fast reactors:
- liquid sodium
- liquid lead
- gas
- salt

Sodium makes people nervous because of its reactivity with water, but all the other properties of sodium are OK, which makes it less of a problem than people think. For instance, a liquid sodium reactor is NOT under pressure, which relieves a lot of safety, materials and mechanics issues. In that respect, a liquid sodium reactor is "easier" than a LWR which is under high pressure. Also, one can, as with the IFR, use a "buffer bath" of sodium to make the reactor entirely passively safe. The only true engineering challenge is to keep the water out in all circumstances.

Liquid lead seems to address this, but is actually worse. Yes, liquid lead is less reactive towards water, but: 1) it is very corrosive, which puts a strong materials engineering challenge - which isn't the case for sodium and 2) you generate radioisotopes such as polonium.

Gas cooled reactors seem better in this respect, but, again, they are under pressure, and they are difficult to make passively safe. A loss of pressure for instance means a big challenge to restore the cooling.

Salt cooled reactors seem to address many issues, and are very promising. Only difficulty: almost no experience with it!

So, everything in a row, technologically, sodium cooled reactors are "closest to operational commercially". If we are serious in installing MANY production FR by 2030, we better start with a technology where experience exists.

 

[Astronuc]

With respect to fast reactor technology, this might be of interest -

Fast Reactors and Accelerator Driven Systems Knowledge Base
Working Materials of the Technical Working Group on Fast Reactors
http://www.iaea.org/inisnkm/nkm/aws/fnss/twgfr/working_materials.html

and - http://www.iaea.org/inisnkm/nkm/aws/frdb/index.html


Phenix has had its problems - e.g. shutdown between 1998 to 2003, which is similar to long shutdowns seen at some US LWRs. I think the problems with Superphenix were related to scaling up the technology. The fact that Phenix was shutdown for upgrades didn't help the cause.

French nuclear safety authority has granted permission to restart the Phenix breeder reactor. Phenix, a 250 MW fast reactor using liquid sodium as coolant, has been idle since 1998 for inspection, repairs and safety upgrades. All work is expected to be completed by March, 2003 when the reactor is scheduled for restart.

In addition to its work as a prototype fast reactor, Phenix is also to be instrumental for study on the potential for transmutation of nuclear wastes. Phenix first started up in 1973.

Last year, I attended a conference on Gen VI materials, and I'll be involved with the next one coming up next year. While there has been much research with a broad range of materials, and there are some promising ones, none of the presentations and literature addressed the performance of these materials in a radiation environment nor for any time close to intended service life. I'm not cynical (except in a few cases such as molten lead systems), just very cautious when it comes to claims regarding nuclear energy and technology.

BTW, there is a concept for a superheated water reactor.

 

[daveb]

Salt cooled reactors seem to address many issues, and are very promising. Only difficulty: almost no experience with it!

In our reactor design class ( a team based design course) we continued work that the previous classes had done with regards to the lquid fluoride reactor (using a 2 salt FLiBe material) originally developed by ORNL. I imagine the next several years' classes will build upon our work, so maybe in several years' time there may be some experience.

 

[Astronuc]

One of the former ANS presidents recommended this site for topics on Nuclear Energy and Power Systems.

http://www.atomicinsights.com/AEI_Topics.html

 

[gdsandkes]

The Duke Energy plant near Charlotte NC was in trouble during the recent drought due to unprecedented low water levels, and came very close to shutting down because of a lack of cooling water from the intake pipe. The sun is available with no lingering waste or pollution. Thermal solar
can be scaled to work with current mature technology large scale turbine generators and water can be split effeciently with this MIT catalyst.

http://web.mit.edu/newsoffice/2008/oxygen-0731.html

If we are to go nuclear we need to have a plan to deal with the 55,000 tons of radioactive material already on hand. We currently use only 5 percent of the energy available in the stored material. Let's reprocess the available material, as the French do, and use 95 percent of the available energy.

 

[vanesch]

The Duke Energy plant near Charlotte NC was in trouble during the recent drought due to unprecedented low water levels, and came very close to shutting down because of a lack of cooling water from the intake pipe. The sun is available with no lingering waste or pollution. Thermal solar ...

Every thermal-to-electricity conversion will need external cooling, that's Carnot who dictates that. So there's no point in pointing out "lack of cooling" with a nuclear power plant, and propose any other thermal process in its place (thermal solar, biofuels, coal, gas,...) They all need a heat sink in the environment. It's elementary thermodynamics.

It is only wind, hydro, photovoltaic, and tidal sources that don't need any thermal dump.

If we are to go nuclear we need to have a plan to deal with the 55,000 tons of radioactive material already on hand. We currently use only 5 percent of the energy available in the stored material. Let's reprocess the available material, as the French do, and use 95 percent of the available energy.

There is a simple plan to deal with the waste. Compare 55 000 tons (world-wide some 170 000 tons I think) of waste accumulated over 30 years or more with the 2.8 MILLION tons of coal a single 1 GWe coal fired plant needs in one year, and you will see the smallness of the actual amount of waste. I'm not talking about its toxicity, I'm talking about its amount. If it is possible to mine tens of millions of tons of coal, then it is also possible to burry 55 000 tons of high level waste, which looses its "high level" status after a few centuries. We can also sit on it for as long as we want to as the total quantity is small. If we need to keep it as of yet some 50 more years to find out whether really there is not any problem with burying it, then that's no big deal. It is a few acres of land storage for the waste of a whole continent, for several decades. To bury it deeply under the surface is very feasible, given the smallness of the quantity compared to what one digs up from deep within the earth. So really, the waste is a non-issue. It is a small amount, and one knows what to do with it, and it is feasible.

Reprocessing is also a good idea as it separates the inert and useful (U and to a lesser extend, Pu) from the radioactive (fission products and minor actinides). The active part only represents 5% of the total spend fuel, so as a matter of volume (but not of activity and toxicity) it is a good idea to reprocess. It diminishes the volume of the waste to be buried and hence optimizes the use of the final repository.

However, it is a misunderstanding that - right at this moment - one can re-use the inert part. In thermal reactors such as light-water reactors, the plutonium can only be re-used once (MOX), because it gets a worse and worse isotopic composition, and the conversion of uranium into plutonium is only marginal. What is really needed, are fast (breeder) reactors, which can use *all* the plutonium, which can convert *all* the uranium and which can even burn all the minor actinides and don't produce many of them.

While it is true that LWR currently burn about 5% of the *enriched* uranium, that corresponds to about 0.5% of the natural uranium from which this enriched uranium was made. So overall, we only use about 0.5% of the energetic potential of natural uranium. With fast reactors, this can be in principle 100% (although in practice probably lower). That means a gain of about 50-100 in fuel efficiency.

Or, put differently: if you have the "waste" of 30 years of LWR operation, you can re-use this for about 1500 - 3000 years of equivalent energy output with fast reactors. Without any new natural uranium. Just by reprocessing the current waste and using the depleted uranium.

But all this is only possible in fast reactors. Not in LWR.

 

[Astronuc]

U.S. Decides One Nuclear Dump Is Enough
http://www.nytimes.com/2008/11/07/washington/07yucca.html
By MATTHEW L. WALD

WASHINGTON — The Bush administration will recommend that Congress give up the idea of a second nuclear waste dump, dropping a grand bargain struck in the 1980s, and instead vote to enlarge the repository now proposed in Nevada, the director of the Energy Department’s civilian radioactive waste management program said on Thursday.

The director, Edward F. Sproat III, who is in charge of work on the proposed repository at Yucca Mountain, 100 miles northwest of Las Vegas, said that the process of trying to open one repository had been so slow and expensive that this was not a good time to start looking for another.

The future of the entire repository program may be in flux anyway because President-elect Barack Obama has called for finding another solution. But Mr. Sproat noted that the law called for his department to pursue the opening of the Yucca site.

Originally, the government promised utility companies that it would begin accepting nuclear waste in 1998 and began accepting payments from them of one-tenth of a cent per kilowatt-hour generated at their reactors. The government now predicts that a waste repository will open by 2020 at the earliest, and clearing the backlog could take many decades. Because of the delay, the government will owe commercial damages to the utilities of $11 billion or more.

When Congress sent the Energy Department to look for places to bury waste from civilian reactors and the nuclear weapons program in the 1980s, the idea was for two repositories, one in the West and one in the East, and the Energy Department listed a dozen sites in seven states, ranging from Maine to Minnesota and Mississippi. Congress eventually ordered the department to focus on Yucca Mountain, but set a limit of 70,000 metric tons of uranium and plutonium wastes, and to report back if another was needed.

Mr. Sproat, who spoke Thursday at a conference on nuclear waste held by the Center for Strategic and International Studies here, said that the inventory of waste would reach 70,000 tons by 2010.

. . . .

It certainly keeps changing.

 

[Astronuc]

FYI,

https://inlportal.inl.gov/portal/server.pt?open=514&objID=3052&parentname=CommunityPage&parentid=25&mode=2&in_hi_userid=200&cached=true

https://inlportal.inl.gov/portal/server.pt/gateway/PTARGS_0_200_3005_257_2460_43/http%3B/inlpublisher%3B7087/publishedcontent/publish/communities/inl_gov/newsroom/publicationsarchive/ebr_ii.pdf (link to pdf - use 'save target as')

 

[Astronuc]

Can Nuclear Power Compete?
http://www.sciam.com/article.cfm?id=can-nuclear-power-compete
Newly approved reactor designs could reduce global warming and fossil-fuel dependence, but utilities are grappling with whether better nukes make market sense
By Matthew L. Wald (Science Writer at NYTimes)

. . . . Wallace announced that his company, UniStar Nuclear Energy, a partnership between Constellation Energy and the European nuclear consortium Areva, was looking to build a new kind of nuclear power plant in the U.S. and elsewhere. “I’m pleased to say I played a role in the last round of nuclear power plant development, and I’m really pleased to be involved,” the chairman said, calling to mind a graying astronaut who walked on the moon years ago and now wanted to do it again.

That was in 2006. Since then, Wallace has intermittently made new announcements about incremental progress toward building a new reactor about 45 miles south of Washington, which could be the first U.S. nuclear plant put on order and built since 1973. Wallace’s original feat was leading the start-up of two of the nation’s last big nuclear plants, completed in 1987 in Illinois. Like another moon shot, the launch of new reactors after a 35-year hiatus in orders is certainly possible, though not a sure bet. It would be easier this time, the experts say, because of technological progress over the intervening decades. But as with a project as large as a moon landing, there is another question: Would it be worthwhile?

A variety of companies, including Wallace’s, say the answer may be yes. Manufacturers have submitted new designs to the Nuclear Regulatory Commission’s safety engineers, and that agency has already approved some as ready for construction, if they are built on a previously approved site. Utilities, reactor manufacturers and architecture/engineering firms have formed partnerships to build plants, pending final approvals. Swarms of students are enrolling in college-level nuclear engineering programs. And rosy *projections from industry and government predict a surge in construction.

. . . .

Sciam produced several articles on the current and future trends of nuclear power.
http://www.sciam.com/report.cfm?id=nuclear-future

 

[Sriram.S]

Is it possible to recreate the happenings on the sun on earth? Well, what is happening in the sun is fusion and there still isn't a solution to controlled fusion, but why not uncontrolled fusion by supplying extremely little fuel(i.e, what is going to fuse, for example hydrogen and helium in the sun).

Sriram

 

[Vals509]

i feel that people shoul install breeder nuclear reactors as they can re use fuel instead of the conventional reactors. i know that congress has banned/blocked the building of such a source but believe that it is a viable alternative and that it should be brought up again.

another thing is that the only thing scaring people to death about nuclear reactors are accidents like chernobyl. what needs to be done is informing people of the latest safety features of current reactors and we must remember is that chernobyl occurred because of several stupid mistakes. sure stupid mistakes can still happed but we are a lot more educated to respond to such accidents.

finally research into fusion rather than fission reactors must be accelerated. i know that it is still taking place but more attention must be given to it. also reactors need to be built in areas with a cordoned off area of whatever kilometeres needed and people around should be trained to respond in emergency.

or the simplest solution is to invest into other sources of energy like solar and wind??

 

[Vals509]

Is it possible to recreate the happenings on the sun on earth? Well, what is happening in the sun is fusion and there still isn't a solution to controlled fusion, but why not uncontrolled fusion by supplying extremely little fuel(i.e, what is going to fuse, for example hydrogen and helium in the sun).

Sriram

well fusion reactions can take place and they are controlled but however they are theoretically possible. examples like the TOKAMAK have i believe achieved fusion but are financially bad.

 

[Astronuc]

The Westinghouse AP-1000 is one of the modern Gen 3+ plants that are proposed near future NPPs.

http://www.ne.doe.gov/pdfFiles/AP1000_Plant_Description.pdf

Other plants under consideration:

US APWR - Mitsubishi
AP600 - Westinghouse
System 80+ - Westinghouse
AP600 - Westinghouse
EPR - AREVA

ABWR - GE/Hitachi
ESBWR - GE

GT-MHR - General Atomics
ACR - AECL
PMBR - Westinghouse/ESKOM
4S - Toshiba
IRIS - Westinghouse


EPRI has established the Advanced Nuclear Technology program regarding the new NPP designs.
www.epri.com/ant[/URL]

 

[Astronuc]

The Future of Nuclear Power - An interdisciplinary study by MIT.

http://web.mit.edu/nuclearpower/

The original study was completed in 2003, and the situation has changed. There is a large (~29 MB pdf file).

There is an update for 2009.

 

[sloughter]

I met a nuclear physicist/engineer who was the go to guy for Army Intelligcnce when Chernoble went south. He was asked to give his opinion of impending casualties. He told the Army brass, "You are going to lose some firefighers and some of the helicopter pilots who flew through the radioactive plume. That should be about 35-40 people. That's it" A recent World Health Organization Report came out indicating 23 years later that 40 people had died because of Chernoble, just as the nuclear expert predicted.

What is not appreciated in the American public is that equating American Nuclear Plants to Chernoble is comparable to comparing the safety features of a Lexus to a Model T. Chernoble consisted of vertical concrete walls 2-3 feet thick with a tarpaper roof. We have reactor domes over a foot thick with rebar.

When the radioactive cloud took off, the vertical walls acted like a chimney and the cloud rose vertically, traveled about 30 miles and then descended into an unpopulated area. Unfortunately, the Russian Government forgot to tell the peasants not to drink milk from cows eating grass tainted with radioactive iodine (Only the volatiles, radioactive cesium and iodine were released when the reactor burned, and some of the peasants came down with thyroid cancer---they also used graphite as a moderator which also burns).

Don't eat striped bass from the Hudson River unless you like the taste of PCB's. Don't eat predatory fish from the Atlantic three times a day, unless you like mercury-induced insanity. Don't drink milk from cows eating radioactive grass. Duh.

The studies relating low levels of exposure to radiation used to predict thousands of casualites at Chernoble are based on bogus extrapolation of high doses of radiation to low doses (I was exposed to more radiation digging for pyrite nodules in black shales than most Cheronobleites were exposed to from the radioactive cloud.)

If I eat 1000 aspirin at once and die, does this mean if 1,000,000 people eat one aspirin/day for a year that 1000 will die of aspirin poisoning? This is great science if you want to start a new industry getting radon out of the basements of people's homes, but it is low quality science. Greenpeace and the Union of Concerned Scientists are little more than scare mongers. If they wished to do something useful, they should try to get kids not to start smoking or drinking and driving, they'd save a lot more lives, but it is not nearly as exciting as being in an organization going after those big bad nuclear power plants.

As far as nuclear research, check out the websites by George S. Stanford and Charles E. Till on the Integral Fast Reactor. It promises to provide clean, safe, proliferation-resistant, weapons-incompatible fast breeder technology. It was shut down by Senator John Kerry in 1994 presumably because it competed with MIT's hot fusion program (The research was about to be completed within three years; completing the research cost no more than shutting it down. Commercial viability was inevitable and MIT stood to lose billions of dollars in research grants if the program was completed.

I'd like to start a discussion/debate of nuclear power for the purpose of informing people about it. I am participating in a thread in another forum http://www.badastronomy.com/phpBB/viewtopic.php?t=9370 where we are discussing an article about Germany planning to phase out nuclear power. I am STRONGLY against this. It is bad for scientific, economic, political, and environmental reasons.

In the course of discussions of the nuclear power issue, it seems to me that the arguements against nuclear power are based primarily on ignorance and emotion. I'm all for open scientific debate, but on this particular subject, I tend to take the approach of educating, not strictly debating. If that comes off as arrogant, I apologize, but this is a remarkably straightforward issue when you get down to the science of it.

So, to start off, a few facts:
-The US has roughly 98 million kW of nuclear generation capacity in roughly 100 plants and runs at about 90% load.
-For comparison, the US has about 4 thousand kW of wind capacity and that doubles about every other year.
-Virtually all new generation capacity in the US is from oil.
-The US has not started construction on a single nuclear plant since Three Mile Island about 20 years ago.
-According to the WHO, air pollution kills 70,000 people in the US every year and affects virtually everyone.
-electric power generation is the leading producer of air pollution in the US.
-HALF of the electricity in the US comes from COAL.
-No civilian has ever been killed as a result of nuclear power in the US (TMI was the worst accident and a long term study produced no statistically significant increase in cancer rates).
-Chernobyl killed roughly 50 people and injured/sickened maybe 1000, including long-after cancers (I had no idea it was that low, so http://www.vanderbilt.edu/radsafe/9604/msg00651.html is where I found that).

To me, the evidence is so enormously strong in favor of re-activating our nuclear power program, it should be self-evident. Clearly however, nuclear power is all but dead in the US and indeed much of the world.

I'd also like to discuss research. There has been nuclear power research done over the past 20 years (though not much because of TMI). Pebble-bed reactors for example have potential to be both easy to service and virtually melt-down proof. I'd like to hear of other technologies.

 

[sloughter]

Financially bad is an understatement. If you consider Inertial Confinement Fusion at the Lawrence Livermore National Laboratory, you are probably talking electricity at over $10/kWh. Here's why. For openers, we are told that they must detonate at least the equivalent of one gallon of gasoline/sec. with a repetition rate of one repetition/sec i.e. not over multiple chambers (as presented in a cartoon on Charlie Gibson).

Let me get this straight hmm 100,000,000 degrees C (The temperature of implosion fusion by lasers) going to -260 degrees C in less than one second (the temperature of a deuterium/tritium sand grain). Sounds realistic doesn't it?

Let's take that measly one gallon of gasoline/sec. For openers, a big coal fired plant may need as much as 17,000 tons of coal/day. That works out to 400 pounds/sec. Sounds like a lot more energy than a gallon of gasoline, so that gallon of gasoline/sec. is a pretty small base load plant. As for the gallon of gasoline: One pound of gasoline has the explosive equivalent of 15 pounds of dynamite. So a gallon of gasoline going off every second is the explosive equivalent of 100 pounds of dynamite going off every second.

How do we capture the explosive power of 100 pounds of dynamite going off every second? Here are the steps: 1)Input, 2)Compression, 3)Ignition, 4)Exhaust. Doesn't this sound like an internal combusion engine?

Now for the engineering details conveniently omitted by the LLNL people. How do you isolate the lasers from the force of a 100 pound stick of dynamite going off a few feet away? Suppose the laser zigs when it should zag and the implosion front of the pellet is all screwed up. One second it is a 100 pound stick of dynamite, the next a 10 pound stick of dynamite. This would require going to some kind of 1000 ton + flywheel to even out the detonations just like on a John Deere tractor.

The next thing that is required is that you will need Star Wars in a bottle. How do you get a particle the size of a sand grain into the chamber, then lock onto a moving target and detonate it with 196 lasers simultaneously? We can't even hit something as big as a missile yet we can lock onto a moving sand grain and hit it synchronously with 196 lasers!

Each chamber will need at least a minute to cool off and the need to damp the lasers motion, so that the sand grain doesn't vaporize upon entering the chamber. This means that there will need to be at least 60 times the numbers of lasers and chambers suggested by LLNL.

Toroidal fusion will never be practical because it requires enormously expensive, incredibly complicated machinery (Murphy's Law considerations) that requires fuel so expensive that it is cheaper to burn one carat diamonds in the reactor with enormous numbers of cooling towers. This competes with simple, rapidly improving technology with free fuel and no cooling towers (Wind, solar and geothermal---bio fuels are cheap and the Integral Fast Reactor is far more competitive).

After 30 years, they can barely sustain the plasma and they still haven't reached break ever when the energy of the magnets is considered. News Flash! They don't know how to deal with the exhaust from the plasma fusion products!

Did the Department Of Energy do a Draft Environmental Impact Statement and a Final Environmental Impact Statement when they decided to fund the hot fusion program at MIT as required by the National Environmental Policy Act of 1969?

Who wanted the hot fusion program? As a geologist, I'd love to spend billions of dollars putting a geothermal system in every single family residence having over 1/2 acre. This would put a whole lot of geologists to work. If I was a chemist, I'd like to build better batteries, more fuel efficient cars, better insulation, high temperature superconductivity and such things as better insulators, semiconductors, etc. If I was a biologist, I'd love to build cellulose bio fuel plants all over the US and have thousands of ponds producing hydrogen-producing algae. If I was an atmospheric scientist, I'd love to put wind mills everywhere.

Did the DOE get input from other branches of the sciences when they decided to fund the hot fusion program at MIT?

So why do we have a hot fusion program? Because the gool 'ole boys network at DOE decided to provide the underfunded physicists at MIT with a gravy train lasting 35 years with another 35 years in the offing (Ask any hot fusion scientist when hot fusion will be commericially viable, it is always, "Thirty years from now."

well fusion reactions can take place and they are controlled but however they are theoretically possible. examples like the TOKAMAK have i believe achieved fusion but are financially bad.

 

[Astronuc]

Archive of Previous Symposia
http://www.world-nuclear.org/sym/subindex.htm

The papers are fairly general and deal with the industry, trends, fuel cycle issues, waste and other related topics.

 

[Astronuc]

If one is studying nuclear engineering, or is planning to do so, or planning a career in nuclear engineering, then this is relevant.

http://www.ne.doe.gov/pdfFiles/rpt_NEFutureRequiredRDCapabilities_Sep2008.pdf

Lot's of other good reports here - http://www.ne.doe.gov/


An overview of new and proposed NPPs
http://www.world-nuclear.org/info/inf08.html

 

[oldsloguy]

I would like to add to this. Current thermal-spectrum reactors use MAINLY U-235 in the power production. U-235 is 0.7% of the natural content of uranium on earth. In fact, at high burnup, SOME U-238 (the 99.3% remaining if we neglect some traces) is converted into Pu-239 and is burned up ; about 30% of the energy that is extracted in a reactor comes from this Pu-burning, and 70% comes from the original U-235 burning.

So that means that currently, we use effectively ONE PERCENT of the energetic content of the uranium that has been extracted.

In a fast reactor, we can use ALL of it, because U-238, through conversion in Pu-239, can become a nuclear fuel. We can use all the U-238 that we already DUG UP, and partially discarded (in the "enrichment" of uranium, which is nothing else but removing 3/4 of the U-238 from the original ore), and MOST of the "burned fuel" which consists mainly of passive U-238.

So, by switching to fast breeders, we can extract in principle ONE HUNDRED TIMES MORE ENERGY from the EXISTING waste than we already extracted. In principle without any more uranium input. Just by using the "waste" correctly.

If some powerplants have been working for 30 years, this means, in principle, that we can extract the same power for another 3000 years, just by using its "waste".

Yes, and you have not even mentioned thorium which I understand is 3 to 5 times more plentiful in the Earth's crust than uranium. Is there some reason that you did not mention thorium or were you just addressing uranium issues only!

 

[oldsloguy]

Sodium makes people nervous because of its reactivity with water, but all the other properties of sodium are OK, which makes it less of a problem than people think. For instance, a liquid sodium reactor is NOT under pressure, which relieves a lot of safety, materials and mechanics issues. In that respect, a liquid sodium reactor is "easier" than a LWR which is under high pressure. Also, one can, as with the IFR, use a "buffer bath" of sodium to make the reactor entirely passively safe. The only true engineering challenge is to keep the water out in all circumstances.

I’m not very familiar with hot liquid sodium, but you seem really comfortable with the idea of handling hot liquid sodium in and accident which might expose it to air. Does it not burn very vigorously or is it easily controlled?

 

[oldsloguy]

I believe that the probability of a nuclear accident associated with Nuclear power is low... unfortunately the cost is high. Utility is the product of the probability * the cost. There is a good reason to be cautious about Nuclear power.

I remember reading somewhere in the past that the cost of cleaning and decommissioning TMI was about 900 million dollars and that the initial construction cost was about 4 billion dollars. I'm not sure if those cost were adjusted for inflation over the intervening time differential between them or not, but I don't think it really matters for the purposes of this discussion.

It seems to me that TMI is about the worst possible accident that can happen to a modern LWR. Am I correct in that or can anyone reasonably postulate a worse accident?

If so, agreed that the risk is low, but when you have over 100 commercial plants operating 30+ years each and the worst case accident, which occurs only once over that period, is ¼ the value of one plant, how can you argue that “unfortunately the cost is high”?

 

[joelupchurch]

I remember reading somewhere in the past that the cost of cleaning and decommissioning TMI was about 900 million dollars and that the initial construction cost was about 4 billion dollars. I'm not sure if those cost were adjusted for inflation over the intervening time differential between them or not, but I don't think it really matters for the purposes of this discussion.

It seems to me that TMI is about the worst possible accident that can happen to a modern LWR. Am I correct in that or can anyone reasonably postulate a worse accident?

If so, agreed that the risk is low, but when you have over 100 commercial plants operating 30+ years each and the worst case accident, which occurs only once over that period, is ¼ the value of one plant, how can you argue that “unfortunately the cost is high”?

The construction cost on TMI-2 was 800 million in 1978, which is 2.5 billion in 2007 dollars. Here is a table with construction costs of various reactors adjusted to 2007 dollars:
http://depletedcranium.com/why-i-hate-the-nrc/#more-2748"

Also you should note that the Probabilistic Risk Assessment on the new Westinghouse Ap1000 is hundred times less likely to have a core meltdown than a 2nd generation plant.
http://www.asmeconferences.org/ICONE16/pdfs/NewPlantsBeBuilt.pdf"
The PRA starts on page 23.

 

[oldsloguy]

The construction cost on TMI-2 was 800 million in 1978, which is 2.5 billion in 2007 dollars. Here is a table with construction costs of various reactors adjusted to 2007 dollars:
http://depletedcranium.com/why-i-hate-the-nrc/#more-2748"

Also you should note that the Probabilistic Risk Assessment on the new Westinghouse Ap1000 is hundred times less likely to have a core meltdown than a 2nd generation plant.
http://www.asmeconferences.org/ICONE16/pdfs/NewPlantsBeBuilt.pdf"
The PRA starts on page 23.

Thanks, that is an interesting. TMI-I cost the 400 million dollars and TMI-2 800 million dollars. So, doing the correction more accurately would yield:

Assumptions, using 2007 $:
Cost TMI-2 = 2544 million $
Cost of clean up = $973, over 12 years, use 1985 for adjustment
http://www.ans.org/pi/resources/sptopics/tmi/cleanup.html
Inflation adjustment from 1985 = 1.93
http://www.usinflationcalculator.com/

Clean-up of TMI-2 as a fraction of plant cost = 973*1.93/2544 = 0.74

So, restating my earlier post:

If so, agreed that the risk is low, but when you have over 100 commercial plants operating 30+ years each and the worst case accident, which occurs only once over that period, is 3/4 the value of one plant, how can you argue that “unfortunately the cost is high”?

And as you point out, and my gut feeling is, even that small overhead loss is way over stated.

 

[vanesch]

I’m not very familiar with hot liquid sodium, but you seem really comfortable with the idea of handling hot liquid sodium in and accident which might expose it to air. Does it not burn very vigorously or is it easily controlled?

I think it is the main worry: the confinement has to be double. In a thermal reactor, you want the stuff not to get out in any case, and in a sodium-cooled reactor, on top of that, you don't want water or air to get in in any case. That's why people look into other types of coolant such as liquid lead or gas. But most experience is nevertheless with sodium (and yes, there have been minor problems with it). I think it is the main challenge in the design of a fast reactor. But it is not necessarily so terribly more difficult than a PWR, because there's no pressure.

 

[mheslep]

Special section on in the Sept 8 edition titled "The New Nukes"
http://online.wsj.com/wsjgate?subURI=%2Farticle%2FSB10001424052970204409904574350342705855178-email.html&nonsubURI=%2Farticle_email%2FSB10001424052970204409904574350342705855178-lMyQjAxMDA5MDAwODEwNDgyWj.html"

The article is lengthy, covering many of the topics up thread. To start, I wanted to summarize the various cost figures cited through the article:

• Gen III plants in general, i.e. all designs: $4k to $6.5k per kw
• Small, modular nuclear, i.e. Hyperion or B&W: $3.5k to $5k per kw, add $50 to $100m licensing costs per site.
• Gen IV Ge-Hatachi Prism design: $10k per kw (small size ~300 MW)

Summary of experts quoted in the article:
Revis James, EPRI
Ronaldo Szilard, Idaho National labs
Amir Shakarami, Exelon VP
Tom Cochrane, NRDC

 

[joelupchurch]

Special section on in the Sept 8 edition titled "The New Nukes"
http://online.wsj.com/wsjgate?subURI=%2Farticle%2FSB10001424052970204409904574350342705855178-email.html&nonsubURI=%2Farticle_email%2FSB10001424052970204409904574350342705855178-lMyQjAxMDA5MDAwODEwNDgyWj.html"

The article is lengthy, covering many of the topics up thread. To start, I wanted to summarize the various cost figures cited through the article:

• Gen III plants in general, i.e. all designs: $4k to $6.5k per kw
• Small, modular nuclear, i.e. Hyperion or B&W: $3.5k to $5k per kw, add $50 to $100m licensing costs per site.
• Gen IV Ge-Hatachi Prism design: $10k per kw (small size ~300 MW)

Summary of experts quoted in the article:
Revis James, EPRI
Ronaldo Szilard, Idaho National labs
Amir Shakarami, Exelon VP
Tom Cochrane, NRDC

I read the article and it was pretty good except for the comments by Tom Cochrane. My biggest disagreement would be with implicit assumption that US construction costs are facts of nature rather than products of our regulatory environment. The Chinese are building AP1000 reactors for about $2K per KWh. The World Nuclear Association has better information. http://www.world-nuclear.org/info/inf02.html"

I have been very pleased with the construction updates I've seen from Sanmen. I was inclined to write off the modular design stuff as Westinghouse marketing hype, but the actual results are impressive. As I recall, one of the pictures I saw was the whole control room being lifted in place as a single module. By the time we start building our AP1000s, we will be dealing with a proven design and not have to deal with FOAK issues.

 

[Astronuc]

I read the article and it was pretty good except for the comments by Tom Cochrane. My biggest disagreement would be with implicit assumption that US construction costs are facts of nature rather than products of our regulatory environment. The Chinese are building AP1000 reactors for about $2K per KWh. The World Nuclear Association has better information. http://www.world-nuclear.org/info/inf02.html"

The Chinese didn't have to pay the development costs that Westinghouse did. Westinghouse sold an essentially off-the-shelf design at a relatively huge discount. The Chinese did however buy the first 4 which are now under various stages of construction.

I have been very pleased with the construction updates I've seen from Sanmen. I was inclined to write off the modular design stuff as Westinghouse marketing hype, but the actual results are impressive. As I recall, one of the pictures I saw was the whole control room being lifted in place as a single module. By the time we start building our AP1000s, we will be dealing with a proven design and not have to deal with FOAK issues.

Modular construction is relatively new. Designs like the AP1000 were on the drawing boards before modular construction techniques has matured.

The cost of concrete and steel is a big factor in current capital costs, as well as labor, as is interest. The Chinese government would certainly be more inclined to subsidize NPPs than would the US government.

 

[mheslep]

The Chinese didn't have to pay the development costs that Westinghouse did. Westinghouse sold an essentially off-the-shelf design at a relatively huge discount...

Any idea why Westinghouse would do that? To what end? Are you suggesting that the several AP1000 sites on the NRC proposal list would enjoy Chinese construction costs?

 

[Astronuc]

Any idea why Westinghouse would do that? To what end? Are you suggesting that the several AP1000 sites on the NRC proposal list would enjoy Chinese construction costs?

Money. Short term gain. After W assumed CBS, the nuclear (WN) part got sold to BNFL, who in turn sold WN to a partnership with Toshiba (majority) and Shaw (minority), and some others, IIRC.

The nuclear industry is very competitive, but it is very expensive and the margins are often thin.

 

[mheslep]

Money. Short term gain. ...

I'm referring to your statement "at a relatively huge discount", implying they did it for any other reason but short term money. So 1. Why the huge discount? 2. Can the US get the same deal?

 

[Astronuc]

I'm referring to your statement "at a relatively huge discount", implying they did it for any other reason but short term money. So 1. Why the huge discount? 2. Can the US get the same deal?

From a relative who negotiates gas contracts in China, the Chinese are tough negotiators - and the market is competitive. W competes with AREVA and others in the Chinese market. The W deal also involved technology transfer.

The US market is different. I don't see the same deals being done in the US, because W, AREVA and Mitsuibishi are the primary PWR suppliers - and they can't afford to lose money here.

Besides the US DOE (Uncle Sam) is supposed to kick in some subsidies (direct and indirect).

 

[joelupchurch]

The cost of concrete and steel is a big factor in current capital costs, as well as labor, as is interest. The Chinese government would certainly be more inclined to subsidize NPPs than would the US government.

Actually Westinghouse is also claiming the AP1000 uses a lot less concrete and steel than other designs also. They are claiming 100,000 cubic meters of concrete compared to 520,000 for the Sizewell B reactor. I assume Sizewell B must be a bad design, but they are showing a very small footprint even compared to their own 2nd generation plants. (Page 30-31)

http://amgroupes.fr/admin/compte_rendus/195_compte_rendu.pdf"

The reason that the Chinese got a good deal on the AP1000 is that they ordered a 100 of them. The most any US utility company ordered is 2. I've suggested on my blog that Congress change the charter of the TVA so they can build nuclear power plants anywhere in the United States. Maybe they could get some economies of scale also.

BTW on the question of what government is providing loan guarantees for these reactors, the answer is the United States.

"[URL
/info/inf63.html [/URL]

The US, French and Russian governments were reported to be giving firm support as finance and support arrangements were put in place. The US Export-Import bank approved $5 billion in loan guarantees for the Westinghouse bid

 

[mheslep]

Actually Westinghouse is also claiming the AP1000 uses a lot less concrete and steel than other designs also. They are claiming 100,000 cubic meters of concrete compared to 520,000 for the Sizewell B reactor. I assume Sizewell B must be a bad design, but they are showing a very small footprint even compared to their own 2nd generation plants. (Page 30-31)

http://amgroupes.fr/admin/compte_rendus/195_compte_rendu.pdf"

The reason that the Chinese got a good deal on the AP1000 is that they ordered a 100 of them. The most any US utility company ordered is 2.

I don't think 'ordered' is the correct word, as the implies a contract to build, and I'm unaware of a final go ahead on any US nuclear units. Design and services contracts have no doubt been placed.

Where did you get the number 100 for China?

 

[Astronuc]

The reason that the Chinese got a good deal on the AP1000 is that they ordered a 100 of them. The most any US utility company ordered is 2. I've suggested on my blog that Congress change the charter of the TVA so they can build nuclear power plants anywhere in the United States. Maybe they could get some economies of scale also.

Please cite sources. Checking the World Nuclear link - China has plans for about 100 1 GWe units - not all of which are AP1000. And China negotiated a technology transfer program, so after the first 4, CNNC (and perhaps CGNPC and China Power Investment Corporation (CPI)) will likely build most of them. They are also contemplating CPR-1000 and EPRs.

Sizewell B was based on standard 4-loop Westinghouse design like Wolf Creek or Callaway. The essentially used the requirements of the time, given the limited experience (less than 20 years.) Now with 40+ years experience, the plant and reactor designs can be optimized.

 

[joelupchurch]

I don't think 'ordered' is the correct word, as the implies a contract to build, and I'm unaware of a final go ahead on any US nuclear units. Design and services contracts have no doubt been placed.

Where did you get the number 100 for China?

That is what it says in Wikipedia. http://en.wikipedia.org/wiki/AP1000"

I checked the reference and the Westinghouse CEO did say that:
http://www.pittsburghlive.com/x/pittsburghtrib/s_575073.html"

I also found an article repeating what Wikipedia said about the AP1000 being the standard for Inland nuclear power plants.
http://www.neimagazine.com/story.asp?storyCode=2053048"

I would interpret that to mean that they will use something else for plants that don't require a cooling tower.

US AP1000 Orders.

http://www.nucpros.com/?q=node/4313"
http://www.world-nuclear-news.org/newsarticle.aspx?id=24250"

 

[Astronuc]

The AP-1000 is a simplified design with a simplified ECCS. It will require cooling towers in some areas where the site would not have adequate river or ocean volumes.

See also
Westinghouse, Shaw to provide four reactors to China
http://www.neimagazine.com/story.asp?storyCode=2046380

from the Candris article:

Last year the company beat out French rival Areva to win a $5.3 billion contract to build four AP1000s in China. Although Westinghouse will transfer the technology to Chinese licensees over the next few years, Candris said, it will build several additional plants with partner The Shaw Group, of Baton Rouge, La.

http://www.pittsburghlive.com/x/pittsburghtrib/s_575073.html

The AP1000 has a core size of 157 17x17 assemblies with a 14-ft (4.27 m) active fuel length (core height) with a thermal output of ~3400 MWt, which is about the same thermal output from a standard 4-loop 193-assembly core with a core height of 12 ft (3.66 m) before they were uprated. The fuel rods in the AP-1000 uses a 9.5 mm cladding OD.

 

[mheslep]

I checked the reference and the Westinghouse CEO did say that:
http://www.pittsburghlive.com/x/pittsburghtrib/s_575073.html" ..

I only check this reference - it says China wants 100, not bought. I've never gotten a volume discount for wanting anything (so far)

Regards the US plants, even Vogle in Georgia is bit early to call an order. The utility and the state utility commission have given the go ahead, but the NRC doesn't give final signoff until 2011, if then. So ground breaking is several years away, if if happens.
http://www.nrc.gov/reactors/new-reactors/col/vogtle/review-schedule.html
I hope it does go ahead, but I expect this administration won't let it happen - not in 2011 anyway.

 

[joelupchurch]

I only check this reference - it says China wants 100, not bought. I've never gotten a volume discount for wanting anything (so far)

Regards the US plants, even Vogle in Georgia is bit early to call an order. The utility and the state utility commission have given the go ahead, but the NRC doesn't give final signoff until 2011, if then. So ground breaking is several years away, if if happens.
http://www.nrc.gov/reactors/new-reactors/col/vogtle/review-schedule.html
I hope it does go ahead, but I expect this administration won't let it happen - not in 2011 anyway.

If the Chinese build 100 AP1000 plants, I'm not sure if Westinghouse cares if they see much money from them. There is a whole international supply chain being built for the AP1000. This gives them a lot of leverage when they are bidding against Areva and GE. That's assuming that Westinghouse only licensed the design for construction in China.

The second point is probably valid. The NRC just announced a delay in licensing the AP1000 because Westinghouse hadn't answered all their questions about the sump design.

http://greeninc.blogs.nytimes.com/2009/09/09/a-nuclear-renaissance-stumbles-forward/"

 

[Equate]

Am I Reading This Right?

DOE Has $40M for Design and Development of Next Gen Nuclear Plants

The $40 million funding announcement made today will support phase one activities including the development of cost-shared conceptual designs, cost and schedule estimates and a business plan for integrating Phase 2 activities. The data gathered in Phase 1 will be used to determine if Phase 2 should continue. Applications for receiving funds from the $40 million are due by November 16 and the DOE expects to make two awards in February 2010 with each supporting a unique reactor concept.

A demonstration plant is expected to be produced by 2021.

Source: http://www.dailytech.com/article.aspx?newsid=16304

$40 million to be split in half for two separate research projects? They are spending billions to bail out dubious investors and then they are giving out jump change for the development of NGNPs?

That's a slap in the face...

 

[tmyer2107]

I was wondering what everyone's thoughts were on gas turbine modular helium reactors (GT-MHR). I recently came across the technology and found it very interesting but wasn't able to find many details on it. Some details can be found here, http://gt-mhr.ga.com/" . How does this technology compare to AP1000 reactors?

 

[Astronuc]

Some info on GA's MHR.

http://web.gat.com/pubs-ext/MISCONF06/A25381.pdf


Some info on GT-MHR:
http://ocw.mit.edu/NR/rdonlyres/0863E2E6-0F70-4843-B2C0-541EC6CD8F59/0/gtmhr.pdf

http://www.world-nuclear.org/sym/1997/labar.htm

http://txspace.tamu.edu/bitstream/handle/1969/1531/etd-tamu-2004C-NUEN-Cocheme.pdf?sequence=1 (particulars on core and fuel are on pages 38-46)


Operational Parameters on the Gen IV Gas-Cooled Fast Reactor

Reactor power                      600 MWth
Net plant efficiency               48% (direct cycle helium)
                                    
Coolant inlet/outlet temperature   490°C/850°C
  and pressure                     90 bar
Average power density              100 MWth/m3
Reference fuel compound            UPuC/SiC (70/30%)
                                    with about 20% Pu content
Volume fraction,Fuel/Gas/SiC       50/40/10%
Conversion ratio                   Self-sufficient
Burnup, Damage                     5% FIMA; 60 dpa

Ref: http://gif.inel.gov/roadmap/pdfs/gen_iv_roadmap.pdf
5% FIMA is about 51-52 GWd/tHM, which is comparable to discharge burnups in modern LWRs.

Fast reactors can achieve much higher burnup ~100 GWd/tHM, or about 10% FIMA.

The GT-MHR unit would produce 288 MWe based on 0.48 * 600 MWt.


In contrast, the AP-1000 produces ~3400 MWt (~1100 MWe) using 157 fuel assemblies. The fuel is a 14-ft (4.27 m) 17x17 fuel design, which is typical of STNP or French REP1300 or N4 reactor fuel designs.

The AP-1000 produces approximately the same power (~3411 MWt, without uprate) as a standard Westinghouse 4-loop 17x17 plant with a 12-ft core of 193 assemblies.

 

[mheslep]

I was wondering what everyone's thoughts were on gas turbine modular helium reactors (GT-MHR). I recently came across the technology and found it very interesting but wasn't able to find many details on it. Some details can be found here, http://gt-mhr.ga.com/" . How does this technology compare to AP1000 reactors?

Reading the GA material suggests the major difference is simply the He cooling instead of water, which provides:
o high temperature operation and a Brayton cycle
o no corrosion potential from the coolant
o no phase change (water - steam - water) complications, reducing the size/cost of the balance of plant.
I can't find a reference, but I expect the fuel is still enriched U. Graphite encased.

 

[mike232]

Just to add this, I don't know if it is true but I heard that France was working on a way to reactivate, and reuse the nuclear waste that is produced by the nclear plants.

 

[mheslep]

Just to add this, I don't know if it is true but I heard that France was working on a way to reactivate, and reuse the nuclear waste that is produced by the nclear plants.

Not working-on, but have-been-doing - as a major operation, the largest in the world since 1976.
http://en.wikipedia.org/wiki/COGEMA_La_Hague_site

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

 

[Astronuc]

Forbes - Where The Jobs Are: Nuclear Plant Work

Atomic power is coming back, and so are the jobs to make it happen.

http://www.forbes.com/2010/02/12/nuclear-power-jobs-leadership-careers-employment.html

America hasn't built a new nuclear plant in three decades. That's about to change. With 28 license applications pending at the Nuclear Regulatory Commission and construction likely to begin on at least four plants within the next five years, companies like Westinghouse, General Electric, Bechtel, Areva, URS and the Shaw Group are staffing up, according to Edward Quinn, a past president of the American Nuclear Society, a nuclear power industry group.

The jobs aren't just for nuclear engineers. In fact, only 5% to 10% of the employees who work on a plant hold a nuclear engineering degree, says Quinn. Those specialists work on the core, which uses nuclear technology. There are plenty of other types of engineers employed at nuclear plants and the companies that service, design and construct them, including civil, mechanical and electrical engineers. Beyond engineers, there are a slew of jobs for workers in the construction trades, from welders to grinders. There's also plenty to do for electricians, pipe fitters, iron workers, carpenters and boiler makers.

. . . .

 

[mheslep]

Forbes - Where The Jobs Are: Nuclear Plant Work

Atomic power is coming back, and so are the jobs to make it happen.

http://www.forbes.com/2010/02/12/nuclear-power-jobs-leadership-careers-employment.html

Yes pending at the Nuclear Regulatory Commission, for several years now, and pending, and pending. I've yet to see anything indicating the NRC's Jaczko is going to actually give a go ahead on any of them.