Energy From Thorium Discussion Forum

It is currently Jul 21, 2018 6:23 pm

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 38 posts ]  Go to page Previous  1, 2, 3  Next
Author Message
PostPosted: Mar 19, 2015 5:10 pm 
Offline

Joined: Nov 14, 2013 7:47 pm
Posts: 568
Location: Iowa, USA
alexterrell wrote:
How do we sell MSRs on safety if we say that current reactors are safe enough?


Easy, MSRs will:

- Burn waste from past reactors, 4th generation reactors burn what was left over from generations 1, 2, and 3. Lots of so called "waste" already available for fuel.
- Burn fissile materials from nuclear weapons. If we wish to be rid of nuclear weapons (a stance I'm not totally on board with BTW) then that material would have to be disposed of somehow. Bonus in that the fissile weapon cores are perfect to jumpstart a LFTR, we may never have to enrich uranium again.
- Be safer, with fewer people. Do to inherent safety of MSRs we don't need an army of technicians to keep it running safely, or need an even larger reserve of people to be ready to respond to an accident. Nothing is perfectly safe, and we'd still need emergency response teams, but MSRs cannot fail spectacularly like solid fuel and/or water cooled reactors.
- Make it difficult to hide nuclear weapon manufacture under the guise of power production.
- Produce valuable medical and industrial isotopes and allow for economical removal of these isotopes from the spent fuel.

I believe that last point is worth repeating, MSRs produce valuable medical and industrial isotopes. That reason alone should be enough to convince people of the value of MSRs.

_________________
Disclaimer: I am an engineer but not a nuclear engineer, mechanical engineer, chemical engineer, or industrial engineer. My education included electrical, computer, and software engineering.


Top
 Profile  
 
PostPosted: Mar 19, 2015 5:57 pm 
Offline

Joined: Nov 14, 2013 7:47 pm
Posts: 568
Location: Iowa, USA
Kirk Sorensen wrote:
And they apparently know nothing of thermodynamics and believe that the 50% energy loss in generation can somehow be eliminated through "efficiency". If they knew the principles of the Carnot cycle then they would realize that such a goal is fundamentally impossible


When these same people are shown how inefficient wind, solar, and hydro are they will claim future enhancements will make them more efficient. But, why can't these future enhancements also bring about greater efficiency to nuclear power?

Another ploy is for the renewable energy advocates to use is that renewable energy is "free" and limitless. Right, solar power is "free". All you have to do is build a billion dollar solar collector, on land you had to buy, pay the salaries of a maintenance crew, and so forth to get this "free" energy. Had that money been spent on nuclear power we'd not only have cheaper power we'd get power during the night.

Oh my, these solar power advocates really hate it when it's pointed out to them that solar power does not work at night. They'll come up with all kinds of excuses. The sun is always shining somewhere, like in the middle of the ocean where running power lines are "free". We can put solar panels into orbit, as if getting a solar panel into orbit is also "free". We can store the solar energy in batteries, as if batteries are "free". That "free" energy sure sounds expensive.

I recall conversations I had with someone I worked with at the residence hall food service when I was in college. He was majoring in some humanities degree while I was in engineering. He'd go on and on about "reduce, reuse, recycle". He apparently didn't take chemistry from the same professor I had, the professor declared flat out how stupid it was to recycle plastics. He said we should just burn the plastic when we're done with it, and go make more. He had a convincing argument, we're wasting a lot of time, energy, and effort to recycle plastics. We'd be better off if we didn't.

I'll make myself clear, I do not propose burying plastics in a landfill as that is wasteful. Plastics are to be burned for their energy content when we're done with them. Recycling makes sense for things like metals and glass, not for plastics. What of reduce and reuse? Of course, when that also makes sense.

_________________
Disclaimer: I am an engineer but not a nuclear engineer, mechanical engineer, chemical engineer, or industrial engineer. My education included electrical, computer, and software engineering.


Top
 Profile  
 
PostPosted: Mar 19, 2015 7:16 pm 
Offline

Joined: Jun 19, 2013 11:49 am
Posts: 1525
Gassifiers followed by methanol production and MTO to make more plastics feedstocks.

Recycling without the massive amounts of manual labour and the huge amounts of plastic lying around in bails waiting to catch fire in gigantic and very messy fires.


Top
 Profile  
 
PostPosted: Mar 19, 2015 10:18 pm 
Offline

Joined: Aug 29, 2008 4:55 pm
Posts: 495
Location: Idaho Falls, Idaho
Nothing wrong with reducing and reusing. But I agree sometimes it just better to burn the stuff.

I live part time in Jackson Hole, Wyoming, where they have to haul their garbage 110 miles to the Idaho Falls(Bonneville county) landfill. So reducing and reusing and perhaps composting makes sense to them. but hauling plastic 500 miles makes no sense at all.


Top
 Profile  
 
PostPosted: Mar 21, 2015 4:20 am 
Offline

Joined: Sep 02, 2009 10:24 am
Posts: 511
E Ireland wrote:
Gassifiers followed by methanol production and MTO to make more plastics feedstocks.

Recycling without the massive amounts of manual labour and the huge amounts of plastic lying around in bails waiting to catch fire in gigantic and very messy fires.


I think the argument is that as long as we're burning oil products to make electricity, we might as well turn the oil into plastic bottles / toys / widgets first, use them, and then burn them.

The argument should also apply to wood > paper > energy.

That said, the benefit of re-use, recylce will vary case by case - having a religious aversion one way or the other is not logical. Where re-use is designed into the process, it works well. The British doorstep milk delivery system was a case in point. The glass bottles have now been replaced by plastic bottles in the UK (Germany is still fixed on tetra pak). But once the infrastructure is set up, these are fairly easy to recycle.


Top
 Profile  
 
PostPosted: Mar 21, 2015 7:35 am 
Offline

Joined: Jun 19, 2013 11:49 am
Posts: 1525
Really?
I still get deliveries from the milkman in glass bottles.
Indeed that is the bulk of the appeal of the service to many people.


Top
 Profile  
 
PostPosted: Mar 21, 2015 9:27 am 
Offline
User avatar

Joined: Nov 14, 2013 2:34 pm
Posts: 177
Location: Here and There
I used to heat with wood. Combustion of any sort must be handled carefully because it can put toxins and particulates into the environment.

Burning plastic can produce a lot of toxins.http://www.wecf.eu/cms/download/2004-2005/homeburning_plastics.pdf

If I remember garbage burners have to scrub for HCL, mercury and a lot of nasty stuff that you don't worry about as much with normal coal (dirt burning) plants. Garbage burners end up burning plastic. If you've ever burned any plastic such as styrofoam, you quickly see a lot of nasty smoke produced.

If the full cost of burning plastic is considered, perhaps recycling is the better option.


Top
 Profile  
 
PostPosted: Mar 21, 2015 10:24 am 
Offline

Joined: Jun 19, 2013 11:49 am
Posts: 1525
Most "recycled" plastic is near worthless because of all the cross contamination.
Gassification gets you a very rich syngas that can be used to make useful fresh plastic.


Top
 Profile  
 
PostPosted: Mar 21, 2015 10:42 am 
Offline
User avatar

Joined: Dec 29, 2011 10:14 am
Posts: 217
Reading the anti-nuclear crowd's propaganda is disappointing. Education is a powerful thing, but equally dangerous if the education is flawed and based on emotional miss-information. Bicycles are inherently unsafe, just ask any of thousands and thousands of small kids with broken arms. And, the sad stories of deaths due to bicycle accidents are tragic. Hmm, could it be there are more bicycle injuries than nuclear accidents? Silly comparison, I know, but an uninformed zealot is just hard to accept if you value logic.


Top
 Profile  
 
PostPosted: Apr 06, 2015 12:09 am 
Offline

Joined: Jun 05, 2011 6:59 pm
Posts: 1332
Location: NoOPWA
Cyril R wrote:
In terms of replying to the likes of GreenWar, Foes of the Earth, and the Silly Club,

Please, that's Greenfarce, Fiends of the Earth, and the Sierra Flub! ;)

_________________
DRJ : Engineer - NAVSEA : (Retired)


Top
 Profile  
 
PostPosted: Apr 08, 2015 3:06 am 
Offline

Joined: Jan 29, 2014 4:05 am
Posts: 269
Location: Vitoria-ES-Brazil
alexterrell wrote:
How do we sell MSRs on safety if we say that current reactors are safe enough?

MSRs promise better safety than PWR at far lower cost.
Current PWR fission half of the U-235 on loaded fuel, fission one Plutonium atom for each U-235 fissioned, leaving a lot of U-235 and Plutonium unfissioned on spent fuel.
A well designed Uranium DMSR reactor achieve close to 100% U-235 fission, while fissioning at 1-2 Plutonium atoms for each U-235 fissioned.
The resulting heat is higher temperature which leads to more efficient electricity production.

So its expected that a DMSR will cost around 25% of real life PWR costs, while producing just 1/6th of the nuclear waste per MWh of electricity produced.
A DMSR using Th+U fuel would lead to slightly higher efficiency, since Th-232->U-233 provides better fission than U-238->Pu-239 fission in the thermal spectrum. We could have DMSRs with 10x MWh of electricity per Kg of nuclear waste produced.
And then we have the LFTR which would result in another order of magnitude efficiency gain over a DMSR.

More safety at a lower cost than PWR is just one selling argument.
The real problem of PWR/BWR today is cost, not safety.

_________________
Looking for companies working to change the world.


Top
 Profile  
 
PostPosted: Apr 08, 2015 3:47 am 
Offline

Joined: Sep 02, 2009 10:24 am
Posts: 511
Making PWRs the safest form of large scale electricity generation is the reason they cost so much.


Top
 Profile  
 
PostPosted: Apr 08, 2015 11:04 pm 
Offline

Joined: Jan 29, 2014 4:05 am
Posts: 269
Location: Vitoria-ES-Brazil
alexterrell wrote:
Making PWRs the safest form of large scale electricity generation is the reason they cost so much.

A lot of the "safety" costs of PWRs don't actually contribute to safety. Does prevention from a problem that MIGHT happen once every thousand of years (with zero certainty it really could happen) might not increase the real safety of the reactor.
Billions of dollars will be spent to Fukushima proof nuclear reactors, regardless of the fact that existing reactors already had proper safegards to such instances. But the NRC doesn't care about facts too much, they care much more about perception, specially when it comes to further ratcheting nuclear regulations.
I wish the only response to Fukushima was to ensure at least two of three generators must be kept in a higher point in the reactor building and that tsunami walls would be mandated to be increased in height. Those are cost effective solutions. But go look at all of the solutions mandated, even to reactors that have zero tsunami or earthquake risk.

_________________
Looking for companies working to change the world.


Last edited by macpacheco on Apr 09, 2015 11:15 pm, edited 1 time in total.

Top
 Profile  
 
PostPosted: Apr 09, 2015 10:45 pm 
Offline

Joined: Nov 14, 2013 7:47 pm
Posts: 568
Location: Iowa, USA
macpacheco wrote:
Billions of dollars will be spent to Fukushima proof nuclear reactors, regardless of the fact that existing reactors already had proper safegards to such instances. But the NRC doesn't care about facts too much, they care much more about perception, specially when it comes to further ratcheting nuclear regulations.


What it takes to "Fukushima proof" reactors is just a change in policy. When the earthquake was detected an automated system shut down the reactor, putting it in a state where external power was required to restart the reactor and to cool it. When the wave hit and flooded the generators and took out the utility power lines all that was left to operate the facility was a backup battery.

I can only assume that the batteries could not provide the power needed to restart the reactor, there was damage to the turbines, or it was somehow decided that it would have been unsafe to restart any of the reactors. The earthquake and tsunami did not damage the reactor, it was the lack of cooling power. Had the reactor been put in a low power mode when the earthquake hit, instead of shut down to the point where criticality was lost, the power plant would have been able to operate until the utility lines were repaired. After the power plant was reconnected to the power grid they could have chosen a safe shut down or return the power plant to full power.

I suspect that had the reactors not been shut down by the automated systems it would have been shut down manually anyway. The damage to the backup power systems would likely have been sufficient that continued operation of the plant would have been deemed unsafe.

It just amazes me that we have nuclear reactors still in operation that are capable of melting down in such a spectacular fashion only because power was lost. One would think that a facility designed to produce power would never need to have power provided to it.

Getting back to the cost of power in the future I see a nuclear powered future as nearly inevitable.

The price of traditional sources of energy are only going to increase. More people are seeking utility electricity, and those that have it want more. The more we dig and drill the harder it becomes to find more coal, oil, and gas, that translates into higher costs. As we build up more wind, solar, geothermal, and hydro the surface area on the planet for that energy gets consumed, and land costs money. Nuclear power is so dense and plentiful that it is effectively infinite. The fuel needed for nuclear power is right now a byproduct of minerals we mine for other reasons, so it effectively costs nothing. Since nuclear reactors can be buried they take no effective space. They may even take what is effectively negative space as small modular reactors do not require the use of long transmission lines, switching and transformer yards, and other infrastructure to support large, gigawatt scale, power plants.

I see one of two outcomes. First, the price will increase until the threat of public unrest forces governments to allow nuclear power to be developed more freely. Second, the price of energy will inevitably and slowly increase until we reach a point where things like wind and solar become viable, which is about three times what energy costs now. After we consume all the easily available fossil fuels society would, for the most part, revert to the technology of an earlier age. We might not light our homes with whale oil, solar panels and batteries would do for that, but other things might be much like how things were done a century or even a millennia ago. Busses and automobiles would be replaced by streetcars, horses, and bicycles. We'd heat our buildings with wood and only the very wealthy could afford air conditioning.

Fossil fuels are a gift but one that can only last for so long. Once we use that up it is going to be very hard to get from a society powered by wood, wind, and water to one powered by nuclear power.

_________________
Disclaimer: I am an engineer but not a nuclear engineer, mechanical engineer, chemical engineer, or industrial engineer. My education included electrical, computer, and software engineering.


Top
 Profile  
 
PostPosted: Apr 10, 2015 7:58 am 
Offline

Joined: Jun 19, 2013 11:49 am
Posts: 1525
Even if the reactors had not been immediately shut down they would have had to SCRAM immediately because the tsunami destroyed the cooling water intakes for both the water-cooled generators and the main steam turbine sets.
Then you would have been in worse condition because the reactor would still have been at full decay power when cooling was lost, rather than having some time to decay.

The whole thing would have been fine if the backup generators had all been air cooled and positioned such that the cooling pump switchgear hadn't been taken out by the tsunami


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 38 posts ]  Go to page Previous  1, 2, 3  Next

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group