Nuclear Plant That Eats Waste

[Star]

.

Molten salt nuclear reactor that eats radioactive waste gets funded

By Ryan Whitwam
August 15, 2014

<snip>

Reactors like the one proposed by Transatomic use salt mixed with the nuclear fuel to slow the reaction. When the temperature goes up, the salt expands and reduces the rate of fission. Since salt’s melting point is higher than the core temperature, even if power is lost and no one is around to fix things, the reaction will eventually stop on its own. This technology has been proposed before, but Transatomic says it can do it better with improved internal reactor geometry (PDF). This is what could allow it to fuel a reactor with nuclear waste or mined uranium at enrichment levels as low as 1.8 percent.

<snip>
.

 

[Shanty]

.

Molten salt nuclear reactor that eats radioactive waste gets funded

By Ryan Whitwam
August 15, 2014

<snip>

Reactors like the one proposed by Transatomic use salt mixed with the nuclear fuel to slow the reaction. When the temperature goes up, the salt expands and reduces the rate of fission. Since salt’s melting point is higher than the core temperature, even if power is lost and no one is around to fix things, the reaction will eventually stop on its own. This technology has been proposed before, but Transatomic says it can do it better with improved internal reactor geometry (PDF). This is what could allow it to fuel a reactor with nuclear waste or mined uranium at enrichment levels as low as 1.8 percent.

<snip>
.

I first heard of this possibility about 4 or 5 years ago. It sounds promising. I don't know the costs and feasibility.

 

[elektra]

who cares, our current pwr's have no problems,

 

[Shrimpbox]

What keeps the salt from absorbing the radioactivity and becoming a waste problem itself?

 

[TruthSeeker56]

Are you talking about SALT (sodium chloride) or liquid sodium? Liquid sodium test reactors were built and tested back in the 60s, and they failed miserably.

I thought Obama was in favor of building more nuclear power plants. So far, after almost 6 years, I haven't seen ONE new license granted to ANY utility to build even ONE new nuclear power plant.

 

[Star]

What keeps the salt from absorbing the radioactivity and becoming a waste problem itself?

Good question - according to...

...Leslie Dewan on CNN's Fareed Zakaria GPS
DEWAN: So each conventional nuclear power plant in the U.S. today produces about 20 metric tons of high-level waste that's radioactive for hundreds of thousands of years. And there isn't really a solution for it yet.

UNTIL NOW, PERHAPS... USING A DESIGN THAT WAS INVENTED 50 YEARS AGO, THEY CREATED THE WASTE ANNIHILATING MOLTEN SALT REACTOR– OR WAMSR. THE WAMSR USES MOLTEN SALT TO DISSOLVE NUCLEAR FUEL. THAT ULTIMATELY REDUCES BOTH THE RADIOACTIVITY AND AMOUNT OF THE WASTE. THEIR NEW REACTOR COULD CREATE ABOUT 10-20 KG OF LONG-LIVED WASTE PER YEAR INSTEAD OF THE 20 METRIC TONS PRODUCED BY TRADITIONAL COMMERCIAL PLANTS. 20 KG IS ABOUT THE SIZE OF A GRAPEFRUIT.

DEWAN: And the remaining waste that comes out, it's waste that's radioactive for just a few hundred years, so much shorter than the hundreds of thousands of years from other plants.

AND HERE'S ANOTHER BIG PLUS. AROUND THE WORLD TODAY, THERE EXISTS ABOUT 270,000 METRIC TONS OF HIGH LEVEL NUCLEAR WASTE. WAMSR COULD "EAT" THAT WASTE AND TURN IT INTO ELECTRICITY.
.

 

[TruthSeeker56]

There is a reason why the WAMSR design has been around for over 50 years, and has never been viable.

I happen to be a retired nuclear power plant engineer, so I believe I know what I am talking about.

Just another CNN fluff job to appease the tree huggers.

 

[Shrimpbox]

Thank you Starr. It would still be nice if someone could go into more detail about why the salt is so much less toxic, what chemical properties allow the radioactivity to be so much less potent. I am ignorant about these processes.

 

[Star]

Thank you Starr. It would still be nice if someone could go into more detail about why the salt is so much less toxic, what chemical properties allow the radioactivity to be so much less potent. I am ignorant about these processes.

Nuclear physics or anything nuclear for that matter is over my head too but-----but that said, this article from Forbes has some pretty good information about how thorium compares to Uranium and why/how it solves a lot of the problems associated with Uranium.
I C&Ped a couple of excerpts from Forbes but read the whole article -- very interesting.


The Thing About Thorium: Why The Better Nuclear Fuel May Not Get A Chance
Marin Katusa
2/16/2012

The Thing about Thorium

Thorium’s advantages start from the moment it is mined and purified, in that all but a trace of naturally occurring thorium is Th232, the isotope useful in nuclear reactors. That’s a heck of a lot better than the 3% to 5% of uranium that comes in the form we need.

Then there’s the safety side of thorium reactions. Unlike U235, thorium is not fissile. That means no matter how many thorium nuclei you pack together, they will not on their own start splitting apart and exploding. If you want to make thorium nuclei split apart, though, it’s easy: you simply start throwing neutrons at them. Then, when you need the reaction to stop, simply turn off the source of neutrons and the whole process shuts down, simple as pie.

Here’s how it works. When Th232 absorbs a neutron it becomes Th233, which is unstable and decays into protactinium-233 and then into U233. That’s the same uranium isotope we use in reactors now as a nuclear fuel, the one that is fissile all on its own. Thankfully, it is also relatively long lived, which means at this point in the cycle the irradiated fuel can be unloaded from the reactor and the U233 separated from the remaining thorium. The uranium is then fed into another reactor all on its own, to generate energy.
The U233 does its thing, splitting apart and releasing high-energy neutrons. But there isn’t a pile of U238 sitting by. Remember, with uranium reactors it’s the U238, turned into U239 by absorbing some of those high-flying neutrons, that produces all the highly radioactive waste products. With thorium, the U233 is isolated and the result is far fewer highly radioactive, long-lived byproducts. Thorium nuclear waste only stays radioactive for 500 years, instead of 10,000, and there is 1,000 to 10,000 times less of it to start with.

<snip>

The Bottom Line

Thorium is three times more abundant in nature than uranium. All but a trace of the world’s thorium exists as the useful isotope, which means it does not require enrichment. Thorium-based reactors are safer because the reaction can easily be stopped and because the operation does not have to take place under extreme pressures. Compared to uranium reactors, thorium reactors produce far less waste and the waste that is generated is much less radioactive and much shorter-lived.

To top it all off, thorium would also be the ideal solution for allowing countries like Iran or North Korea to have nuclear power without worrying whether their nuclear programs are a cover for developing weapons… a worry with which we are all too familiar at present.

So, should we run out and invest in thorium? Unfortunately, no. For one, there are very few investment vehicles. Most thorium research and development is conducted by national research groups. There is one publicly traded company working to develop thorium-based fuels, called Lightbridge Corp. Lightbridge has the advantage of being a first mover in the area, but on the flip side the scarcity of competitors is a good sign that it’s simply too early.

Had it not been for mankind’s seemingly insatiable desire to fight, thorium would have been the world’s nuclear fuel of choice. Unfortunately, the Cold War pushed nuclear research toward uranium, and the momentum gained in those years has kept uranium far ahead of its lighter, more controllable, more abundant brother to date. History is replete with examples of an inferior technology beating out a superior competitor for market share, whether because of marketing or geopolitics, and once that stage is set it is near impossible for the runner-up to make a comeback. Remember Beta VCRs, anyone? On the technical front they beat VHS hands down, but VHS’s marketing machine won the race and Beta slid into oblivion. Thorium reactors aren’t quite the Beta VCRs of the nuclear world, but the challenge they face is pretty similar: it’s damn hard to unseat the reigning champ.
.