Noble Gas grab sample size

[dandelion742]

Hello, I am a chemistry tech working at one of the nuke plants in Taiwan.

In our plant we grab Noble Gas at sampling skids where gaseous effluent are collected from releasing points.  

The sampling container we have used for years is a Marinelli-style 20 Liter plastic box with petcocks, and it is heavy and NOT easy-to-carry.

I always wanna change to the commercially avaliable 4L Marinelli gas-tight container.

But I wonder if 4L is big enough to meet regulatory required LLD,1 x 10-4 uCi/ml, when 40% germanium detector is used and counting time is limited to about 10 min ?

What do you use for Noble Gas sampling?

Thanks for your sharing information.

[Imaginos]

1 liter (1220 cc) Marinelli with Swagelok quick-disconnect fittings for the continuous release sample points; we can meet the LLDs with a 30 minute count time.

[SloGlo]

Yore problem is with mass or time? That counter's chamber should handle whatever volume sew aye am thinking the lab schedule is too tite two alter time frames. Oar is their a programing challenge?

[dandelion742]

Thank you for your reply.

Since our Lab have large sample loads with only two gamma spectroscopy systems and cannot tolerate counting time longer than 10 ~15min, we try to enlarge our sample mass as possible as we can.

[milo124]

A junior HP tech running around with an open bag to trap the gas?

[dandelion742]

  haha, I am a junior with open mind seeking for the best practice on grabing gas sample from you experienced senior.

[SloGlo]

But I wonder if 4L is big enough to meet regulatory required LLD,1 x 10-4 uCi/ml, when 40% germanium detector is used and counting time is limited to about 10 min ?

if your lld is regulated then you need to contact your instrument supplier for more sensitivity as lld is a measure of minimum counting to satistical acceptable efficiency.

[Ksheed]

if your lld is regulated then you need to contact your instrument supplier for more sensitivity as lld is a measure of minimum counting to satistical acceptable efficiency.

Only one misspelled word, and reading your post didn't make my head hurt. Did you use this? https://www.hookedonphonics.com/

[SloGlo]

Only one misspelled word, and reading your post didn't make my head hurt. Did you use this? https://www.hookedonphonics.com/

hail know! eye took a simplistic approach to onscreen persona. It was write after aye attended yet an udder educational enlightenment effort. Deepest apologies for that miss spelling, totally inadvertent. 

[MGH]

Dear Junior Tech...take clear plastic bag...the bigger the better...draw a propeller symbol on it...now open the top and run around the plant in the vicinity of where you think you need to take a sample...make five laps around the closest component...close bag and seal with J-seal. Post photos or video on line and provide the link...senior techs will provide the sample results...no further analysis needed. Thanks

[HydroDave63]

haha, I am a junior with open mind seeking for the best practice on grabing gas sample from you, experienced senior.

When sampling gas from an experienced senior, usually Depends with a tight duct tape seal along the legs and sample point works best! 

[SloGlo]

When sampling gas from an experienced senior, usually Depends with a tight duct tape seal along the legs and sample point works best! 

as opposed two sampling from an inexperienced senior oar an eager junior, when won uses an inserted inverted flexible sample container.