Smoke Alarms and radiation from them

  • #1
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Smoke Alarms and radiation from them
Why are smoke detectors with Americium exempt from leak testing when there are ones in older houses maybe 30 years old and one needs to open them up to change the battery. Surely the Americium could leak out over time from the ionisation chamber?
 

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  • #2
sophiecentaur
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"surely"??
The Americium wouldn't be in the form of a powder. Afaik, most sources are encapsulated in matrix of glass or ceramic which would stay intact for thousands of years if it were not roasted or dissolved income strong acid.
 
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  • #3
anorlunda
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Summary:: Smoke Alarms and radiation from them

Why are smoke detectors with Americium exempt from leak testing when there are ones in older houses maybe 30 years old and one needs to open them up to change the battery. Surely the Americium could leak out over time from the ionisation chamber?
It is not in the form of a gas or a powder.
https://hps.org/publicinformation/ate/q7445.html
Please be aware that there is a very small amount of 241Am, ~33.3 kBq in a smoke detector. This form of 241Am is embedded (fused) onto a layer of foil and does not pose any danger to you or your family; it cannot be wiped off, nor can it leach off. This is one of the reasons NRC originally authorized its use in the 1970s.
 
  • #4
Why then do smoke detectors need leaked tested in schools as radiation sources and also solid sealed sources need leak tested in labs?
 
  • #7
No I don't think my previous thread addressed how or why they could leak?
 
  • #8
berkeman
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No I don't think my previous thread addressed how or why they could leak?
We may end up merging your two threads. The Mentors are discussing it now...
 
  • #9
russ_watters
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Why then do smoke detectors need leaked tested in schools as radiation sources and also solid sealed sources need leak tested in labs?
Do you have a source for this requirement? I'm not familiar with it.
 
  • #10
Yes, in England all schools must leak test sealed sources including smoke detectors used in Physics experiments
 
  • #11
russ_watters
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Yes, in England all schools must leak test sealed sources including smoke detectors used in Physics experiments
No, a source. A link to a description of the requirement.

...also, if you already know the test protocol I don't understand why you would be asking about test instruments in the other thread.
 
  • #12
I know they need tested, but I dont know the how you actually do it part
 
  • #13
russ_watters
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I know they need tested, but I dont know the how you actually do it part
Well, since you said the UK I was able to find this (but you should really be doing your own homework here):
http://science.cleapss.org.uk/Resou...active-Substances-in-Schools-and-Colleges.pdf

I don't have time right now to dive into it, but the testing requirement and protocol are in there. But as a starting point, since this is the source of your concern it should be what frames your investigation.
 
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  • #14
davenn
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Yes, in England all schools must leak test sealed sources including smoke detectors used in Physics experiments

Well, since you said the UK I was able to find this (but you should really be doing your own homework here):
http://science.cleapss.org.uk/Resou...active-Substances-in-Schools-and-Colleges.pdf


excellent info, but I didnt seen any mention of smoke detectors in there

reading through this thread, I continue to wonder if the OP has some misunderstanding on what is being referred to.
@Happy Days2021 you still havent given an information source relating specifically to testing smoke detectors.
And since radioactive source smoke detectors have been made obsolete in most 1st world countries, I still cant help but wonder
why you are so fixated with them ??

Dave
 
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  • #15
russ_watters
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excellent info, but I didnt seen any mention of smoke detectors in there
Page 32, but more broadly the entire document is about radiation sources used in school labs. If there were an unspecified one, the requirements would still apply.
And since smoke detectors have been made obsolete in most 1st world countries...
What??!?!??!!
 
  • #16
davenn
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Page 32, but more broadly the entire document is about radiation sources used in school labs. If there were an unspecified one, the requirements would still apply.

Thanks for finding the bit about smoke detectors on page 31, I missed that :smile:

What??!?!??!!

yup, here and in NZ at least ..... the fire service will actively replace all radioactive source smoke detectors with the newer type
They called around home around 8 months ago and replaced our two, free of charge, and disposed of the radioactive source ones
in a safe manner.
Sorry of you Americans are behind the times :wink:

Dave
 
  • #17
russ_watters
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yup, here and in NZ at least ..... the fire service will actively replace all radioactive source smoke detectors with the newer type
They called around home around 8 months ago and replaced our two, free of charge, and disposed of the radioactive source ones
in a safe manner.
Sorry of you Americans are behind the times :wink:
Ok, you're talking about the radioactive type, not smoke detectors in general. That's not what you said. :wink:
 
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  • #18
davenn
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Awesome list
have several of them ( as ticked) always looking for more sources for the collection
Most of my sources are radioactive rocks, currently have ~ 15 samples with various mineral compositions

Cruising the old "op shops" ( second hand and antique shops) with my Geiger counter, which I need to do again,
been a while, brings up watches, clocks, occasional cup or plate.
The "hottest " natural source I used to be able to get to see what a thumb sized hunk of pitchblende
in the geology dept. where I did my studies. Even through the 1" think lead crucible it was still detectable


radioactive sources1.JPG



my 2 current detectors are these ......

one of these ( from China) ......

CAJOE Geiger counter.jpg




and 2 of these (from the Ukraine - sold like hotcakes during the Chernobyl chaos)

Bella Dosimeter.jpg


cheers
Dave
 
  • #19
davenn
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Ok, you're talking about the radioactive type, not smoke detectors in general. That's not what you said. :wink:


I said radioactive type :wink: :smile:

edit, ohhh maybe you were referring to post #14 .... I will edit
 
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  • #20
berkeman
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They called around home around 8 months ago and replaced our two, free of charge, and disposed of the radioactive source ones
in a safe manner.
I read somewhere that they actually donated them to school science labs...

:wink:

Well, to schools in other countries of course...
 
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  • #21
russ_watters
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The standard for UK schools it says this:
The residual risk is low with the control measures in place.
Note: these control measures are not required for smoke alarms when used in the home, as
they are extremely unlikely to suffer damage in the normal position, fixed to the ceiling.
So they are basically saying that they don't leak in normal use, but you never know what might happen if you let school kids abuse them.
 
  • #22
Vanadium 50
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but you never know what might happen if you let school kids abuse them.
I'm imagining the old American Tourister ads.

And since smoke detectors have been made obsolete in most 1st world countries
What??!?!??!!
You didn't hear? Building fires have been banned.


And since radioactive source smoke detectors have been made obsolete in most 1st world countries

The US is, last I checked, the 1st world. You can even get Vegemite if you know where to look. Not sure why anyone would want to.

According to Home Depot, ionization (they never say "radioactive source") detectors are the most popular. I'm not surprised. They are safe, inexpensive and effective.

They used to be uniformly superior to photocell detectors. Photocells are getting better, thanks to two developments: cheap computation, and blue LEDs. Photodetectors were less accurate - less sensitive at the same threshold, or if you lowered the threshold, more prone to false alarms. Shorter wavelengths help, comparing responses at different wavelengths helps, looking at the time profile helps, and tiny little DSP chips put it all together. And while in principle CO detection is independent of smoke sensor type, if you already are going to put some intelligence on your smoke detector, you can combine the information from the smoke detection with CO and do a better job on both fronts.
 
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  • #23
davenn
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Vegemite if you know where to look. Not sure why anyone would want to.


It's very yummy :smile:
 
  • #24
sophiecentaur
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It's very yummy :smile:
Nothing like as nice as the sharper taste of Marmite. I feel sorry for Aussies, in that respect. They seem to think that the poor relative is as good.
 

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