Comments on: May 3, 2023 Quick space links

By: Jeff Wright

Jeff Wright — Fri, 12 May 2023 20:45:30 +0000

Some quotes:

“NASA / DOD are producing Plutonium 238.
It’s a different isotope, great for RTGs, useless for nuclear reactors.”

“Plutonium 239
Great for nuclear reactors, useless for RTGs.”
https://thebulletin.org/2020/04/britain-has-139-tons-of-plutonium-thats-a-real-problem/

By: Lee S

Lee S — Sat, 06 May 2023 10:24:20 +0000

@Jay, Thanks for the info and the link back to Bob’s post.

On a tangential note, it’s funny how as we all get older, over 5 years becomes “a couple of years” !! ;-)

By: Jay

Jay — Fri, 05 May 2023 15:34:27 +0000

Lee, Good questions. The half-life of the Pu-238 is about 88 years. This isotope is not weapons grade material, that is Pu-239. We are back to producing it at INL (Idaho National Laboratories), just not a great quantities. We also purchased Pu-238 from the Russians a few times. To answer your question about medicine, they quit using the same material in pacemakers a few decades ago. They use Lithium batteries now, starting in the early 80's. Bob did talk about this shortage a couple years ago in this article.

By: Robert Zimmerman

Robert Zimmerman — Thu, 04 May 2023 17:22:41 +0000

In reply to Lee S. Lee S: Link added. Sorry about that.

By: Lee S

Lee S — Thu, 04 May 2023 16:50:14 +0000

Haven’t NASA been complaining about this for decades? I’m sure I had a conversation on some forum ( here? ) Regarding the particular isotope that nasa uses, the lack of it, and the fact no one is producing it any more. It was long ago, and my memory is woozy, but I believe it is the same isotope used for medical practice. I am pretty sure since then we have had New horizons, and 2 Mars rovers at least powered by plutonium. That seems a long time to keep something with a relatively short half life in storage.

I’m also sure that someone here can refresh my memory with more details please… I find the very notion that the same element can have very different properties absolutely fascinating, even though I understand the physics.

( Bob, you didn’t include the link..)

On an absolute side note… My daughter today got the result that she aced an A+ on her biology exam… I just hope she doesn’t become a serial underachiever like Father… If not, she is destined to certainly become a scientist in one branch or another… I couldn’t be more proud :-)