[tpurves]

For anyone else wondering why Pu-238 is dwindling, from the linked wikipedia:

“The United States stopped producing bulk Pu-238 with the closure of the Savannah River Site reactors in 1988.[12][13][14]

Since 1993, all of the Pu-238 used in American spacecraft has been purchased from Russia. In total, 16.5 kilograms (36 lb) has been purchased but Russia is no longer producing Pu-238 and their own supply is reportedly running low.[15][16]”

Interestinly, it looks like Canada (Ontario, Darlington) are starting set up operations to make some in the near future.

[cptaj]

Here's an episode of Space Policy from Planetary Radio. They go very in depth on the issue of pu-238, the efforts to restart production and why it is so complicated.

http://www.planetary.org/multimedia/planetary-radio/show/201...

[Manglano]

US production has resumed, according to Wikipedia, as Cobalt 60 is coproduced and useful for medical sterilization.

As an aside: There are some people who are very skeptical of both atoms and space exploration. I'm not sure what their motives are but given the amount of steel necessary to produce wind turbines, I'm unconvinced that "renewable" is actually "greener."

[lloyd-christmas]

"over 20 years, a three-megawatt wind turbine can deliver 80 times more energy than is used in its production and maintenance." [0]

Beyond that, Steel is 100% recyclable^, and that accounts for over 65% of US steel production. Recycled steel can be done in arc furnaces, requiring no coal coke. [1]

Info like this is at the tip of your fingers.

[0] https://www.worldsteel.org/en/dam/jcr:f07b864c-908e-4229-9f9...

[1] https://seekingalpha.com/article/3785906-metallurgical-coal-...

^ This rate is never achieved. Global average is ~90%, as some countries aren't efficient: http://www.steel.org/sustainability/steel-recycling.aspx

[Manglano]

Okay!

Downvote me if you like but our fuel mix in this country is still ~40% combustion and the calculations on wind power say that at current power requirements civilization will harvest enough energy from the air currents to change the climate again. Maybe it stops hurricanes, I have no idea.

Also, steel, like atomic fuel, is toxic to produce and reprocess!

I know it is much-despised by but I am curious as to the lifetime energy footprint of a fission reactor facility with onsite fuel-reprocessing and waste transmutation. And then? Tokamak. Won't even need a turbine!!

Parts of that system don't even exist yet but me I believe one day there will be clean atoms, fission or fusion, and they will require even less energy to produce and maintain than the wind and solar grid.

But then, I have lived among the fission reactors my entire life. Perhaps I am "mad from the rads" ;)

[sbierwagen]

> the calculations on wind power say that at current power requirements civilization will harvest enough energy from the air currents to change the climate again

?

Wind doesn't circulate through the atmosphere forever with perfect efficiency, it eventually dumps its energy into the ground via friction.

There's no difference between slowing wind down with a wind turbine and slowing it down with a tree, they both end up as heat eventually.

[pault]

When I lived in Seattle I was sitting at a cafe one day and a government motorcade came down the street with an 18 wheel truck carrying a dumbell-shaped canister with a giant yellow nuclear symbol on the side. I've never been able to figure out what they were transporting. Does anybody here know what it might have been? It was post 9/11 so I was surprised they were still moving radioactive material on the surface streets of a major city.

[jhayward]

An RH-72B[1] cask is a container for shipping trans-uranic nuclear waste, probably to the WIPP site.

[1] http://www.wipp.energy.gov/WIPPCommunityRelations/images/pho...

[pault]

That's the one! I can finally put that mystery to rest. :)

[Manglano]

To some extent we are radioactive material on the surface streets of the major cities, because we have consumed soil!! Even our steel tools can be somewhat radioactive, refinement concentrates point sources.

However, containment vessels like that are usually for refined ores, which end up in reactors, smoke detectors, medical devices, radiotherapy machines, you name it. Too expensive and possibly hazardous to airlift.

As far as I know, production of atomic weapons has stopped in this country and we're not even sure if they still work (half-lives--they rot). Could've been materiel for a stewardship program at the Hanford Site, or waste being evacuated from the Hanford Site.

Generally speaking, the remaining atoms transported and transmuted are for peace. That's why Russia brokers Uranium to the States, and why people in Kazakhstan and elsewhere continue to mine fissile ore.

If you were to shut down the remaining fission plants of Planet Earth, civilization as we know it, would end almost immediately, such is our need for these fuels. It would not be pretty--consider the amount of electric heat, the number of electric stoves with 50+ year duty lifetimes. That's why Japan recycles spent fuel at the French reactor.

[willismichael]

Waste from the Hanford Site? Why would it be necessary to transport it through the most populous area of WA state? (I'm asking as somebody who has lived near Hanford as well as in the Seattle metro area)

[seanmcdirmid]

Eh, it also doesn’t make sense since Hanford is a waste storage site...where else could the waste be going, and even if it’s high grade, why does that involve the Pacific Ocean rather than a trip to Utah or neveda in the other direction? I’ll assume that whatever it was, it was unrelated to Hanford, more likely something to do with nuclear submarines or the training reactor they had at UW.

[RosanaAnaDana]

Waste from Hanford would either stay at Hanford or go through Portland. Seattle is way out of the way. Portland much closer.

[acidburnNSA]

Could be related to all the Navy nuclear stuff around town like the shipyard at Bremerton or the Bangor sub base

[52-6F-62]

This was my very first question. Thanks for pulling the basics out. I've been loosely following the proliferation of nuclear power in Ontario for a little while now, it is interesting to learn they'll be starting production nearby.

In light of the current geopolitical climate, it's probably better that NASA's (et al) plutonium should come from Canada vs. Russia.