[ RadSafe ] Re: Costs of "rad protection"?

[John R Johnson]

Radsafers

Julian says "quoted activity is just for Ra-226 as the daughter isotopes
could (if I recall correctly) multiply the total activity present by a
factor of 6 if the Radium is contained inside a sealed capsule."  But if it
isn't in a sealed capsule then risk from Rn-222 needs to be taken into
account.

I think that an ALARA calculation is needed if the interest is in saving
lives, and not "political".

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-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl]On
Behalf Of JGinniver at aol.com
Sent: October 24, 2005 4:32 PM
To: didi at tgi-sci.com
Cc: radsafe at radlab.nl
Subject: Re: [ RadSafe ] Re: Costs of "rad protection"?



In a message dated 24/10/2005 22:12:56 GMT Standard Time, didi at tgi-sci.com
writes:

While I  don't really know how radioactive these conductors are (my guess is
the  activity is negligible),


According to the IAEA Tecdoc 1357 on the " Management of  disused
long lived sealed radioactive sources (LLSRS)"

SNIP>In the past 226Ra and 241Am were used in lightning rods, which have
mostly been removed and collected. Their activity is usually in the order of
40
to 70 MBq. In few cases an activity in the range of GBq had been  used.<SNIP

which if at least obe was mounted on 1000 buildings would give 40 to 70 GBq
is not insignificant.  It also depends whether the quoted activity is just
for Ra-226 as the daughter isotopes could (if I recall correctly) multiply
the
total activity present by a factor of 6 if the Radium is contained inside a
sealed capsule.

Must of the emphasis on the protection of long lived sources is to prevent
their acquistion by terrorists in so called 'dirty bombs', however I do feel
that they would be little chance that someone could obtain a significant
number
 of these without their loss being detected.  I believe the real concern is
the long term management of items such as these that may not be properly
controlled and disposed of leading to the potential that the public could
unwittingly come into contact with these items, or more likely that they
could  be
accidentally re-cycled in scrap metal leading to a release from the
recycling
plant the need for expensive decontamination of the furnace.

Perhaps the question should be whether the Government in Singapore should
have required the removal of these, resulting in a one off cost, or instead
opted to have instituted a regulatory framework for the long term management
which could have resulted in higher costs of the remaining lifetime of the
lightning conduction systems?

Personally I suspect that it's cheaper to remove these items on masse and
arrange for direct disposal, the IAEA has provide quite simple guidelines in
the
 past for direct disposal of Radium to deep boreholes which should be quite
cheap  to achive.

Regards,
        Julian
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