[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Radon in LP Gas
I have just a little to add to what Franz and John have already posted.
I review of my available documents came up with the following:
European Commission - nuclear science and technology report (EUR17621)
Current practice of dealing with natural radioactivity from oil and gas
production in EU member states
"3.4 Radionuclides in gas treatment facilities.
Natural gas is processed to remove impurities and to recover the less
volatile hydrocarbons which seperate out naturally in pipelines or in
seperation plants by condensation. These so-called Natural Gas Liquids
(NGL) generally include ethane, propane and heavier fractions such as
butane. The heaviest fraction is indicated as condensate. Radionuclides in
gas treatment and transport equipment relates to the presence of Rn-222 in
the natural gas. The raadon appears to concentrate preferentially in the
ethane and propane stream relative to the natural gas output of the plant
(ref. 1). In addition condensate may contain Po-210 far in excess to its
grandparent Pb-210 which has led to the development of a condensate
treatment process to remove polonium (ref. 2). The potential has associated
with Rn-222 in natural gas and condensate is the deposition of the long
lived daughters Pb-210 and Po-210 in the processing and transport equipment
(as mentioned by Franz), in particular on the innner surfaces of pumps and
valves (ref. 3). These depositions do not pose any significant hazard from
external radiation but may require radiological protection measures when
disassembling and servicing equipment"
ref. 1 Gesell, T.F. Occupational radiation exposure due to Rn-222 in
natural gas and natural gas products, Health Physics, Vol. 29, 1975 pp.
681-687.
ref. 2 Bukkems, F.H.J., Sie, S.T., Beens, Van der Heijde, H.B., van
Klavern, J.A., Knaepen, W.A.L., A treating process for removing poloniu-210
from natural gas condensate at high temperature and pressure in a packed bed
reactor. AMOR.0013.78
ref. 3 Drummond, I., Boucher, P., Bradford, B., Evans, H., McLean, J.,
Reczek, E., Thunem., Occurances of Rn-222 progeny in natural gas processing
plants in western Canada, Health Physics, Vol. 59, pp 133-137, 1990
The same conclusions are given in an Introduction to Naturally Occuring
Radioactive Material by Philip Egidi - ORNL which was presented at the 42nd
Annual Meeting of the Health Physics Society June 30 1997 (available from
the DOE Public Information Bridge). It also indicates " Gas processing
equipment with the highest levels (exposure rates) include reflux pumps,
propane pumps, and tanks and lines. Median exposure rates were repotred to
be in the 30 to 70 microR/h range. For both oil and gas processing
equipment, a few measurements were observed to be in excess of 1 milliR/h."
Regards
Julian Ginniver
----- Original Message -----
From: "Franz Schoenhofer" <franz.schoenhofer@CHELLO.AT>
To: "Tad Blanchard" <Tad.M.Blanchard.1@gsfc.nasa.gov>;
<radsafe@list.vanderbilt.edu>
Sent: Friday, July 20, 2001 11:21 PM
Subject: Re: Radon in LP Gas
>
> -----Ursprüngliche Nachricht-----
> Von: Tad Blanchard <Tad.M.Blanchard.1@gsfc.nasa.gov>
> An: radsafe@list.vanderbilt.edu <radsafe@list.vanderbilt.edu>
> Datum: Freitag, 20. Juli 2001 22:49
> Betreff: Radon in LP Gas
>
>
> >Hello all,
> >
> >Someone called me this morning and I couldn't give them an answer to this
> question. They wanted to know if there was any significant amounts of
Radon
> in Liquid Propane Gas. If someone has information on this, please post a
> link on the radsafe list.
> >
> >I seem to recall seeing something about radon in "natural" gas but
nothing
> about LP gas.
>
>
> Tad,
>
> As a first information I can tell you the following:
>
> During production of LPG radon, which has a boiling point in the range
> of -50 C, is concentrated in the LPG. (Radon always accompanies natural
> gas.) Since LPG is usually not used right after production, but stored in
> tanks, the radon will decay (half life 3.8 d). Equipment like pumps and
the
> tanks themselves will be contaminated by the accumulated longlived decay
> products like Pb-210 and Po-210. These might pose a radiation hazard by
> inhaling them, when for instance pumps are taken apart and cleaned. The
> accumulation in tanks should not play a big role by external radiation,
> especially because of the shielding effect of steel.
>
> I remember some papers - (one of) the first might have been a paper by
> Howard Pritchard. I do not have them at hand - they are in my office, but
> they are of course not available on the web.
>
> If this information is not enough, please contact me and I would look on
> Monday into my literature collection.
>
> Best regards,
>
> Franz
>
>
>
> ************************************************************************
> You are currently subscribed to the Radsafe mailing list. To unsubscribe,
> send an e-mail to Majordomo@list.vanderbilt.edu Put the text "unsubscribe
> radsafe" (no quote marks) in the body of the e-mail, with no subject line.
>
>
************************************************************************
You are currently subscribed to the Radsafe mailing list. To unsubscribe,
send an e-mail to Majordomo@list.vanderbilt.edu Put the text "unsubscribe
radsafe" (no quote marks) in the body of the e-mail, with no subject line.