HPGe gamma spectrum of spent nuclear fuel from Chernobyl

This area is for discussions involving any fusion related radiation metrology issues. Neutrons are the key signature of fusion, but other radiations are of interest to the amateur fusioneer as well.
bionerd23
Posts: 53
Joined: Sat Jun 12, 2010 8:52 am
Real name:
Contact:

HPGe gamma spectrum of spent nuclear fuel from Chernobyl

Post by bionerd23 » Sun Apr 15, 2012 8:06 pm

Hey folks!

I managed to recover Carl's fuel fragment which he found near Chernobyl during his visit (thanks again, Carl!!).
No, no - of course I did not take the whole piece, as that would've got me into big trouble indeed (as it would have certainly been detected).

I simply took an invisibly small swipe on 2x2mm fine sandpaper (piece of cardboard nail file actually), which - according to Ba-133 point source calibration - contains a mere 200 Bq of Cs-137 (the main source of activity). The rest of the fuel fragment is back where I've found it.

After measuring the piece for just 1200 seconds, a clean Am-241 peak comes up along with the Cs-137 peak. There are also some other peaks which may or may not be "something", but this requires long-term measurement (which is in the works as I write this).

The Cs-137 is also visible on a small piece of moss from Pripyat, but the Am-241 is not. Pu's daughter - at least in this much activity % - seems unique to Carl's little jewel.

Here are the 1200s measurements of both... More to follow.
Attachments
moss 1200s.jpg
moss 1200s.jpg (79.71 KiB) Viewed 3709 times
fuel 1200s.jpg
fuel 1200s.jpg (66.63 KiB) Viewed 3709 times

User avatar
Richard Hull
Moderator
Posts: 11473
Joined: Fri Jun 15, 2001 1:44 pm
Real name: Richard Hull

Re: HPGe gamma spectrum of spent nuclear fuel from Chernobyl

Post by Richard Hull » Mon Apr 16, 2012 2:10 pm

Thanks for sharing Illy. That is real a tiny sample! You had a nice instrument at your disposal. Trinitite reads similarly but with a decent instrument you see all the other fission debris isotopes. Your sample is so small, you probably couldn't detect those which surely must be in there.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

bionerd23
Posts: 53
Joined: Sat Jun 12, 2010 8:52 am
Real name:
Contact:

Re: HPGe gamma spectrum of spent nuclear fuel from Chernobyl

Post by bionerd23 » Mon Apr 16, 2012 4:52 pm

Hey Richard,

well, you're probably right... the sample *is* indeed very small. Maybe I should've been a little more daring... Hmmm. Nothing that can be done now - except give it some TIME.
Here's the next attempt, with 12000s this time...
Attachments

[The extension txt has been deactivated and can no longer be displayed.]

[The extension txt has been deactivated and can no longer be displayed.]

[The extension txt has been deactivated and can no longer be displayed.]

fuel 12000s.GIF
fuel 12000s.GIF (15.9 KiB) Viewed 3709 times

User avatar
Richard Hull
Moderator
Posts: 11473
Joined: Fri Jun 15, 2001 1:44 pm
Real name: Richard Hull

Re: HPGe gamma spectrum of spent nuclear fuel from Chernobyl

Post by Richard Hull » Tue Apr 17, 2012 2:17 pm

Looks like you nailed all thsoe other isotopes! Good work

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

User avatar
Carl Willis
Posts: 2841
Joined: Thu Jul 26, 2001 11:33 pm
Real name: Carl Willis
Location: Albuquerque, New Mexico, USA
Contact:

Re: HPGe gamma spectrum of spent nuclear fuel from Chernobyl

Post by Carl Willis » Wed Apr 18, 2012 6:37 am

Awesome.

I successfully transported this pinhead-sized fuel flake from where I dug it up, near Reactor No. 5 at ChNPP, past the dysfunctional scintillator checkpoint at Lelev, to our hotel in Chornobyl. That's where I made some measurements and a YouTube video about the piece. But I would have been busted trying to move it out of the Zone...or so I thought (reality is we could have taken it out unawares from the Semikhody train station due to certain administrative policies at that checkpoint). So I left it behind at the Firefighters' Memorial near Chornobyl, hoping some other visitor would be able to enjoy it.

And that is precisely what has happened. It's like getting a postcard from an old friend.

The HPGe spectrum is a nice new piece of data. The Eu-154 and Am-241 are fun to see. The HPGe is blind to Sr-90 (except for its broad-spectrum x-rays), but that is undoubtedly the second major contribution to activity after Cs-137.

I'm attaching a photo of the fuel flake as I knew it in the summer of last year. I hope to meet it again someday!

-Carl
Attachments
P1020040_l_2_circled.png
P1020040_l_2_circled.png (568.05 KiB) Viewed 3709 times
Carl Willis
http://carlwillis.wordpress.com/
TEL: +1-505-412-3277

bionerd23
Posts: 53
Joined: Sat Jun 12, 2010 8:52 am
Real name:
Contact:

Re: HPGe gamma spectrum of spent nuclear fuel from Chernobyl

Post by bionerd23 » Wed Apr 18, 2012 4:10 pm

Hey Carl,

here's more from your "old friend"...

1. Close-up photo. Bottom right: Radiation strikes CCD, leaves pink streak.
2. Intentional dark exposure with streaks from ionizing radiation on the CCD.
3. Absurd dose rate on a totally overflowing GM-tube. Voltage is dropping massively; screen is flickering and faint, thus the numbers are appearing grey instead of pitch black.
Attachments
IMG_1801.JPG
IMG_1801.JPG (147.56 KiB) Viewed 3709 times
IMG_17783.JPG
IMG_17783.JPG (116.48 KiB) Viewed 3709 times
IMG_17713.jpg
IMG_17713.jpg (162.13 KiB) Viewed 3709 times

bionerd23
Posts: 53
Joined: Sat Jun 12, 2010 8:52 am
Real name:
Contact:

Re: HPGe gamma spectrum of spent nuclear fuel from Chernobyl

Post by bionerd23 » Sun Apr 22, 2012 1:43 pm

68000s, linear scale, skipping the large Cs-137 peak.
Peak analysis obviously not accurate due to half life of some of the identified nuclides, interpret with caution.
Attachments

[The extension txt has been deactivated and can no longer be displayed.]

nuklide 68000s 3.gif
nuklide 68000s 3.gif (12.27 KiB) Viewed 3709 times
nuklide 68000s 2.gif
nuklide 68000s 2.gif (14.15 KiB) Viewed 3709 times
nuklide 68000s 1.gif
nuklide 68000s 1.gif (13.89 KiB) Viewed 3709 times

RandM
Posts: 2
Joined: Tue Jun 25, 2019 3:19 pm
Real name: Randy Mitter

Re: HPGe gamma spectrum of spent nuclear fuel from Chernobyl

Post by RandM » Tue Jun 25, 2019 3:53 pm

Hello, in the wake of HBO's Chernobyl, lots of ppl, like me have become interested in radioactivity, & reading up on the work of other enthusiasts. The youtube videos concerning this particular fuel fragment are now in the millions of views range.

Whereas in the series, we see firemen following neutron bombardment becoming radioactive themselves and irradiating visitors, on this thread &
( on youtube), we see its safe handling of nuclear fuel on bare hands.

I dont want to intrude, but am trying to reconcile what i saw in the series with what I am seeing here: are the ppl mentioned (bionerd23 / Willis) who handled the fragment ok ? thanks,
Randy




fuel fragment link
https://www.youtube.com/watch?v=ejZyDvtX85Y

User avatar
Richard Hull
Moderator
Posts: 11473
Joined: Fri Jun 15, 2001 1:44 pm
Real name: Richard Hull

Re: HPGe gamma spectrum of spent nuclear fuel from Chernobyl

Post by Richard Hull » Wed Jun 26, 2019 8:26 am

Randy, Of course, Carl and bionerd are OK. Both are smart cookies and know the rules. Rules, which no one else seems to know. These Know-nothing folks will forever remain frightened to the "sissy" level about radiation.

The tiny spec seen here is probably a tiny used fuel fragment, as noted and shown by gamma spec investigation. This is not fissioning now, and thus, there are zero neutrons. Only neutrons can make normal materials radioactive and then only under special conditions. This specimen will emit a small amount of alpha and a lot of beta and Gamma radiation, only.

What keeps Carl and Bionerd safe

They are rad-wise and follow these rules.

1. The inverse square law: A well known and understood tenet in physics. This is always is a life saver when faced with genuine deadly sources of radiation, but observed even for the weakest of radioactive sources. If you don't know the law, you will forever remain a rad sissy. Rad-wise people know what is nasty due to a good deal of instrumentation demanded and used by them, and a fore knowledge of what they have in front of them. This is because they are very cautious, ever curious and know the rules. They are never blindly frightened by the mere word radioactivity or radiation signs if armed with knowledge and good instrumentation.

2. Acute versus Chronic radiation doses: As for touching with the bare hands, again, no problem. why? The tiny spec is a rather low activity radiation source, (compared to a seriously dangerous radioactive specimen), coupled with almost no exposure time, (seconds), followed by a full washing of the hands until no radiation is detected beyond background. In such cases, you receive a harmless acute dose versus a nasty chronic dosing i.e., attaching it next to your bare skin and body for 10 full days...no let up.

3. Time of exposure: This tiny spec is properly stored 99.9999% of the time in a suitable lead container owned by such rad-wise folks. the time spent near a source of radiation be it deadly or a very low level source is always kept to a bare minimum. Can you live if exposed to a deadly radiation source? Yes! The instant you know it is deadly, run away and you will live, no problem. With good instrumentation, you will know it is deadly long before you get anywhere near to it.

For its size, yes, this little spec is extremely hot, but not deadly or even dangerous to the rad-wise.

Would I handle it by hand? Yes, but with latex gloves (just a very smart precaution...not due to the radiation, as you get the same acute dose with or without the gloves.) The gloves avoid any skin contamination and avoid perhaps a tedious scrub up with multiple washings needed to clean the skin to background levels later.

It would be stupid to expose oneself to a chronic dose of even moderate radiation levels. Number 3 above avoids that and all rad-wise folks see to this.

1. There are fraidy-cats (ignorant public types) these represent 99% of all humans on the planet constantly wringing their hands in fear.
2. There are Rad-wise learned people who know and follow the rules. There are very few people in this category less than 0.5 %, perhaps.
3. There are careless idiots loaded with bravado who think "radiation is just a big hoax...It won't hurt me", again, about 0.5%. Fortunately, most all of this type will never die due to radiation.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

RandM
Posts: 2
Joined: Tue Jun 25, 2019 3:19 pm
Real name: Randy Mitter

Re: HPGe gamma spectrum of spent nuclear fuel from Chernobyl

Post by RandM » Wed Jun 26, 2019 9:31 pm

thanks Richard for the detailed information. I will keep the rules in mind. I can imagine that radiation hysteria makes life difficult for the enthusiast, legislation, restrictions, possibly even stigma?

Bionerds youtube views are in the magnitude of millions per video, she has become the defacto radioactivity ambassador to the youtube audience. After watching the HBO series, millions of people are looking up radiation on youtube, they come across her videos, and see as you said that radioactivity doesnt have to be dangerous/scary & no longer feel threatened.

Then they realize she hasnt posted in over a year & from the hundreds of recent comments , the consensus appears to be that
that Chernobyl has claimed another victim, that not even scientists armed with multiple instruments can deal with radioactivity unscathed.

Post Reply