New Small Fission Reactor For Deep-space Missions Demonstrated 122
cylonlover writes "Exploring the regions of deep space beyond Mars means sending probes where solar power isn't practical. Since the 1960s, NASA has equipped its Apollo missions and unmanned explorers with Radioisotope Thermal Generators (RTGs). These have worked very well, but they run on plutonium 238, which is currently in short supply. Therefore, the Los Alamos National Laboratory is developing a new small nuclear reactor for spacecraft that uses uranium instead of plutonium to power Stirling engines and generate electricity. At the Nevada National Security Site's Device Assembly Facility near Las Vegas, engineers from Los Alamos, the NASA Glenn Research Center and National Security Technologies LLC conducted a Demonstration Using Flattop Fissions (DUFF) experiment that produced 24 watts of electricity using a pair of free-piston Stirling engines."
Re:What could possibly go wrong (Score:5, Interesting)
He had no health problems that could be attributed to radiation. Those of his friends and shipmates who were there also were the same. In every case when they suffered serious ill health it was due to smoking or drinking.
What I have noticed though is curious congenital conditions occasionally popping up in their children, about 1 child in 4 or 5, when there was no history of it previously. This may or may not be coincidence but while these conditions may be awkward for those that have them, no-one has died from one yet.
I myself have worked with radioactive materiels and while they creep the bejesus out of anyone who has anything to do with them the radiation is not overly dangerous at low levels except over long periods, say taking x-rays every day. Even spending six months in Nagasaki starting two weeks after they dropped a plutonium bomb on it didn't cause any problems among the people I know who did it.
When do we get them? (Score:2, Interesting)
When do we get them? Electric cars are all the rage... Imagine you had a non-stop range extender! Imagine your car just charges itself when parked anywhere. Better yet, imagine an RV powered by one of these... park out in the middle of nowhere, and still have a decent amount of power. Or in some cases where communities are isolated, how about end-of-the-block SRGs? The best thing about an EV/RV SRG is that the half-life is about 80 years, so just one will last you a couple lifetimes.
A number of years ago, I balparked the cost of RTGs, based on some unverified found info, and decided they were impractically expensive... But with SRGs dramatically improving the efficiency, the cost of the plutonium-238 to power one that'll be a usefully large (for range xextending EV's) would only run a bit over $100,000... a practical sum of money for a very large number of people. So when can we expect to see them on the market?
Re:Fission Reactor (Score:4, Interesting)
The reactor speed is controllable with a boron carbide control rod. If it was just nuclear decay then it would not be controllable. The "old" RTG's were just powergenerators running off decay energy.
By the way: how did you think a normal fission reactor works? It's just enhanced and controlled nuclear decay that heats up a bunch of water to form steam. This steam dives a turbine that drives a generator: He presto, power! (for a more detailed explanation: just ask. I don't know the details of the reactions but others here do.)
The main difference here is that they used Stirling engines and scaled it down big time. Sterling engines are probably used because they are incredibly reliable, despite being expensive and not very efficient. There is no way to fix a broken power supply in space, especially if you need to replace parts.
Re:What could possibly go wrong (Score:2, Interesting)
How do you get a sustained fission reaction without critical mass? Critical mass is defined as the mass required to sustain fission.
Re:What could possibly go wrong (Score:4, Interesting)
Yes, lots of people protested NASA's risky space launch of a nuclear reactor but failed to stop the launch. [cnn.com] The cops treated them just like they treated OWS. Sigh.
From the link:
The Cassini rocket will be powered by 72 pounds of plutonium -- the most ever rocketed into space. Protesters say that if the rocket explodes it could sprinkle deadly poison for hundreds of miles.
Winds can blow (plutonium) into Disney World, Universal City, into the citrus industry and destroy the economy of central Florida," said Michio Kaku, a protesting physics professor from New York. He claimed that casualties could run as high as a million people if there were an accident.
What? If you split it up into 1 million 30 milligram doses and had people directly inhale it or inject it into your blood, yeah that would do it. You could injest that much and survive (cancer risk goes up, but it is well under the LD50 of 500mg for ingestion [lbl.gov], cyanide is more lethal) But exploding it over the ocean where people are very unlikely to encounter any at all? Maybe that is the kind of science you get form a TV physicist. Make up a scary story to get yourself headlines.
As far as the OWS quip goes, some of these people did break into a secure facility by jumping the fence. Though they deserve to be arrested it is no reason for police brutality. However the article only says that there were only arrests.