Tritium Bubbler -Reply

[FRAMEP@ORAU.GOV]

Travis Johnson wrote:

>I am looking for information on tritium sampling use the bubbler method
>for
>gaseous effluent streams.  Specifically looking for the optium
>configuration
>of the bubbler.

If my recent experience is valid (re. noble gas sampling), you have
already received a number of detailed replies that weren't distributed to
the list. So at the risk of being redundant here are a few thoughts that
might or might not be worth anything:

1. The bubblers will only collect HTO, not HT or other forms. I assume
you are only interested in HTO. If not, a catalytic heater will be needed
and that can be a pain.

2. To start out you probably want to run with three in series. Maybe later
you might reduce it down to two.  The ratio of activities can be used to
calculate collection efficiencies assuming the solutions haven't saturated.

3. My inclination would be to use Greenburg-Smith impingers rather than
fritted bubblers - I doubt efficiency will be a problem and they won't be
subject to the same plugging problems.

4. There is a difference of opinion as to whether to use deionized DW or
ethylene glycol.  The latter is less likely to be lost to the airstream, but it
saturates faster and can be more difficult to dispose of. 

5. Follow the bubblers with some sort of dry trap to prevent moisture
from reaching the flow meter and pump.

6.  Maybe run with 100 mls in each bubbler - the volumes can be
adjusted later.

7. The flow rates can also be adjusted later, but 0.5 lpm might be a good
start. 

8. See Osborne, R.V. Sampling for Tritiated water Vapor in Proceedings
of the 3rd International Congress, 9-4 Sept. Washington DC. IRPA CONF
730907-P2, 1428-1433, 1973.

Wood, M.J. et al Tritium Sampling and Measurement in Health physics
65(6):610-627, Dec 1993.

Unless I'm mistake, Mike? Wood, at Chalk River, used to be on Radsafe.
He'd certainly be worth talking to. I'd be interested in hearing what else
you learn.

Best wishes

Paul Frame
Professional Training Programs
ORISE
framep@orau.gov
www.orau.gov/ptp/ptp.htm