RE: Gas pipeline safety- Radon-222 dose vs. holdup in transit??

["Jonkers, Gert G SIC-ASA/4" <Gert.G.Jonkers@opc.shell.com>]

Group,

Some remarks/additions and queries wrt Rn-222 in Natural Gas:

   Most natural gas is stemming from pure natural gas wells. However, some
'gas' fields have high concentrations of higher alkanes (ethane, propane,
butane, etc.) as well. Under production conditions a mixture of the lower
alkanes (up to about octane) will be produced as liquid (so called natural
gas liquids - NGL). After fractionating Rn-222 mainly partions over the C2,
C3 and C4 products. Olefines like ethene, propene etc. never are found in
NGL. These compounds are only obtained after cracking of (higher) alkane
compounds. To my knowledge max. Rn-222 conc. reported in propane-fraction
900 Bq/L(liquid), leading to detectable (short-lived) external radiation
levels at the outside of installations and to (long-lived) contamination of
the inside of installations.

   Occupational doses from Rn-222 in NG in Gesell, Health Physics 29 (1975)
681, Public doses due to NG consumption in UNSCEAR  
1977 20 micro-sievert/annum.

   I was not aware (but am interested in) of cavern storage of these gases.
Do you have a (traceable) reference to cavern storage as referenced to in
your mail?

   I do not understand your expectation why radon levels may now be much
lower than in the 70's. Can you please explain on which arguments your
expectation is build?

   Radioactive contamination of bottom sludge found in LPG rail transport
cars (up to 30 Bq[Pb-210]/g[sludge]) have been reported. 

P.S. Please add your name and affiliation to future mails to the RADsafe
list.

Kind Regards, Gert Jonkers 
ASA - Amsterdam Services Analytical 'Special Projects'
Shell Research and Technology Centre, Amsterdam (SRTCA), 
http://www.srtca.shell.nl/welcome.html
PO Box 38000, NL-1030 BN Amsterdam, the Netherlands
tel.        +31 - 20 - 630 3424
fax        +31 - 20 - 630 2911
e-mail   Gert.G.Jonkers@OPC.Shell.COM

> ----------
> From: 	NSSIHOU@aol.com[SMTP:NSSIHOU@aol.com]
> Reply To: 	radsafe@romulus.ehs.uiuc.edu
> Sent: 	2000-08-22 15:56
> To: 	Multiple recipients of list
> Subject: 	Re: Gas pipeline safety- Radon-222 dose vs. holdup in
> transit?? 
> 
> In todays world, much of the countries natural gas is treated in proximity
> to 
> the point of production to remove the Butane, Propane, Propylene,
> Ethylene, 
> etc. for sale at a far higher value than what natural gas sells for. Many
> of 
> these gases distill in the same temperature range as Radon gas. As a
> result 
> much of the Radon ends up as a constituent in these gas streams. Some 
> refiners and producers of polethylene and polypropylene have built storage
> 
> systems such as underground storage caverns specifically to hold these
> gases 
> for at least 30 days to eliminate the Radon problem. Where such storage 
> caverns are not available, the decay may take place in the large storage 
> tanks at Propane distributors. 
> 
> If you locate the EPA document you are seeking, you should keep in mind
> that 
> the Radon may now be much lower than in the 70's. 
> 
> And don't be surprised at the levels you find on the Propane storage tanks
> at 
> your local distributor. 
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