[ RadSafe ] Sr-90 in milk (re-named)

[Brennan, Mike (DOH)]

Hi, Franz.

While I would not expect more than trace amounts of staple Sr or Y in
the fuel to start with, it would build up over time.  Both Sr-88 and
Y-89 are, at least on my chart of the nuclides, shown as stable and
fission products.  We just never think about the stable fission products
because, well, they are stable.  I don't think I've ever even considered
them, or their activation products, which generally will be isotopes
that are themselves fission products.  

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of
franz.schoenhofer at chello.at
Sent: Tuesday, June 07, 2011 7:50 AM
To: The International Radiation Protection (Health Physics) MailingList;
Edmond Baratta; The International Radiation Protection (Health Physics)
MailingList
Cc: Glenn R. Marshall
Subject: Re: [ RadSafe ] Sr-90 in milk (re-named)

Thanks, Edmond. 

My reasoning is based on the well known curve (we call it the double
camel hump). According to this the concentrations of Sr-90 and Sr-89
must be initially (almost) equal. Of course there will be a difference
when a nuclear reactor has operated for a while because of the different
half lives. Nuclear explosions are not so much different. What I know
for sure from the Chernobyl accident is, that the activity
concentrations we found in precipitation, aerosols etc. was initially
about equal. I described the problems to discern Sr-89 and Sr-90. I
would expect that Sr-89 might be less from emissions after weeks or
months after the NPP was shut down. I know that some "experts" take this
and claimed I-131 emissions as a proof that there is still a chain
reaction going on in the reactor.

To my knowledge there is no stable Strontium or Yttrium in a reactor. So
what should be the source?

Thanks for some years of reasonable discussion at RADSAFE and a few
personal meetings!

Best regards,

Franz