NASA Running Out of Plutonium

PRB_Ohio takes us to Space.com for a story about NASA's plutonium shortage, and how it may affect future missions to the far reaches of the solar system. The U.S. hasn't produced plutonium since 1988, instead preferring to purchase it from Russia. We discussed the U.S. government's plans to resume production in 2005, but those plans ended up being shelved. If NASA is unable to find an additional source, it could limit missions that take spacecraft too far from the Sun. Quoting: "Alan Stern, NASA associate administrator for science, ... said he believed the United States had sufficient plutonium-238 on hand or on order to fuel next year's Mars Science Lab, an outer planets flagship mission targeted for 2017 and a Discovery-class mission slated to fly a couple years earlier to test a more efficient radioisotope power system NASA and the Energy Department have in development. To help ensure there is enough plutonium-238 for those missions, NASA notified scientists in January that its next New Frontiers solicitation, due out in June, will seek only missions that do not require a nuclear power source."

Comments

WTF?

[Scrameustache]

The U.S. hasn't produced plutonium since 1988, instead preferring to purchase it from Russia. Whaaaaaa?

Re:WTF?

[AKAImBatman]

The official position of the US Government is that breeder reactors are a potential threat. Bad Guys(TM) might get ahold of fissible materials bound for reprocessing, and THEN where would we be, hmm?

Never mind the fact that it's about 1000x simpler to create a gun-type bomb with Uranium rather than creating an uber-complex implosion device. All terrorists obviously have access to the advanced nuclear engineering and simulation capabilities necessary to create a plutonium implosion device.

...

Despite the fact that they can't refine Uranium...

Re:WTF?

[ISoldat53]

The West has been buying Russian plutonium from old weapons and from surplus stockpiles under the idea that it's better to use it as fuel in a power plant than in a weapon.

Re:WTF?

[AKAImBatman]

The catch-22 is that they come from the same type of breeder reactor and have to separated by processing. Ergo, lack of breeder reactors == lack of PU-238. You follow?

Re:WTF?

[NeverVotedBush]

Not entirely true. You operate the reactors and process the fuel rods differently, and I would assume load the fuel rods differently, depending on the isotope you want to make.

If you read the Global Security link I added, you will see. If you want to make predominately Pu239, you go with short run cycles so you don't get buildup of other, more radioactive isotopes, that make handling the fuel rods more problematic. You also want to use more U238 in the rods.

I would guess (as I don't know) that based on the Global Security article, if you want to make Pu238, you would start with more U235 in the rods and maybe run longer between reprocessing cycles.

It's interesting stuff.

Re:WTF?

[NeverVotedBush]

Also, though a breeder may be more efficient at making them (I don't know), it isn't required. Plutonium was first made in the X-10 graphite reactor at Oak Ridge. All rectors that use uranium as fuel will produce plutonium. If you read the Wikipedia articles on breeder reactors, all light water reactors gradually transition from predominately burning their starting fuel to predominately burning the new isotopes that get bred into the fuel rods.

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

Re:Plan B

[edwardpickman]

In all seriousness N Korea would probably be thrilled to trade us Plutonium for wheat. That is a deal where everyone wins.

Re:simple solution: ionic propulsion

[zippthorne]

Yeah, until they hit round about Mars orbit. Then, due to the dropoff in insolation, it starts to make sense to switch to internal power supplies. Especially if you require propulsion-level power supply.

Plutonium RTGs will run for a very long time, and your electric propulsion doesn't care where the electricity comes from. Why not use both? Solar panels for the inner solar system, and explosive bolts for when the the panels' mass causes "drag" on a decay-dominated power source?

NASA is weak

[CopaceticOpus]

NASA states that for their next mission they will only consider missions without a nuclear power source. This is a sad thing to hear, because it shows just how short-sighted and unambitious they have become. I've had enough with sending tiny robots to various places to look for traces of water. Some of those missions have been awesome, but we're now reaching the point that they're not going to teach us much more or help us to move forward.

The greatest promise for truly advancing space exploration is nuclear power. We're not even willing to produce plutonium for providing a little power to deep space missions. We're nowhere near actively considering the use of nuclear reactors for propulsion. Nuclear has the potential to increase by one or two orders of magnitude the size and weight we can send into space, which would radically change what we can do in space. However, it would require a huge investment in R&D as well as a big change of mindset, and the United States is not willing. Here's hoping another country will pick up the slack.

Re:We're just plain running out.

[MacColossus]

We have plenty of plutonium 238 in country. All the spent nuclear fuel rods sitting at power plants have plutonium 238. The states won't allow them to ship it to processing centers. So it sits in water or structures in storage at each individual power plant.

Well...

[jd]

....they COULD have bought plutonium easily enough from the British (their reprocessing plant produces a fair amount of extractable plutonium) and probably from the French. Possibly even from the Israelis. Buying from Russia makes no real sense, due to the security issues in the region, politics and the problems of safe transport. The British would seem to be the best bet, as they probably generate the most, have extensive experience in transporting nuclear material, and have a special relationship with the US. Except for the fact that the special relationship doesn't seem to include giving the British very much. For that matter, there's probably enough plutonium of the right isotope on the bed of the Irish Sea, due to questionable BNFL dumping practices and accidents at Sellafield. The sea is shallow and it shouldn't be hard for NASA to rig up some extraction system or other. Even if it were rocket science, they ARE rocket scientists.

They should make us an offer.

[Oktober Sunset]

We have 100 tons of the damn stuff we want to get rid of over here in the UK. They were even thinking of building a new reactor to use it all up cos there's no where suitable to keep it all. I'm sure the US and UK could strike a good deal, and I'm sure all those grouchy old cold war rememberers would prefer buying from the UK than Russia.

We have a ready supply of domestic plutonium

[MSTCrow5429]

Spent fuel rods are 95 percent U-238. Plutonium can be produced form U-238. If we recycled our spent fuel rods, there would be a ready supply of domestic plutonium available. Why aren't we recycling our fuel rods? In 1977, President Jimmy Carter outlawed nuclear recycling, out of fear foreign nations would somehow steal plutonium to make nuclear bombs. This fear never came to pass, and nations have simply produced plutonium from their own reactors, or enriched uranium, a la Iran. It is time to discard baseless fears about the dangers of nuclear recycling, and produce our own plutonium. Canada, Britain, France and Russia all recycle their nuclear fuel, and France, which produces 80% of its electricity from nuclear energy, stores all of its waste inside of a single room. Recycling our nuclear fuel would render Yucca Mountain obsolete, and vastly decrease the time, energy and space that would need to be spent to handle spent nuclear fuel.

Source: http://www.hillsdale.edu/news/imprimis.asp

More efficient usage

[NMajik]

NASA has thus far used radioisotope thermoelectric generators (RTGs) to produce the electricity from the heat of the decaying plutonium. They are now moving forward with its plans to use Stirling engines to produce the electricity. Stirling engines are much more effective in this regard, requiring only one-fourth the amount of plutonium to produce and equivalent amount of power and have the added benefit of weighing about half as much as the current RTGs.