[ RadSafe ] off-line liquid effluent monitors

[Ed Johnson]

P.S.  John,

Sorry, I realized that you might not be looking to replace the client's
system, but only improve it.  To clarify, if excessive silt is a problem
and the concern is not getting a representative sample of it and/or that it
and the bio material are fouling the pump, one solution is to create a
diversion channel from the main effluent flow without reducing the
turbulence (which keeps the sediments suspended) and filter the sediments
upstream of the sample pump.  Both the filter and the collected water
sample would then be analyzed to get total concentrations and the results
scaled up to the total effluent flow rate.

Regarding the sample size, from your post it seems that the sample pump
itself has a high flow rate, perhaps collecting a sample volume that is
too large for practical collection and analysis (?).  To be analyzed, large
sample volumes can be boiled down to a manageable size, but you have to
ensure that you are still capturing volatiles in your analysis (labor
intensive and not fun).  Instead, the system may need modification to
divert a portion of the effluent stream, the key consideration being that
the diverted flow is representative of the total.  At KAPL, the collected
samples were composited for analysis.  If you use that approach,* *I
believe you need to apply the right statistical tools to correctly report
deviation from the mean in order to capture the inherent errors not only
from the analyses, but also from the compositing process.

Again, the folks at KAPL might be able to help, even though they are
"competitors."  After all, we worked in support of the same nuclear Navy,
right?!  Back at you :)

Carl Ed Johnson
Health Physicist/Consultant
Albuqerque, New Mexico
505-463-6685
cejjr56 at gmail.com


On Wed, Dec 21, 2011 at 7:42 AM, <JOHN.RICH at sargentlundy.com> wrote:

> Hi all,
>
> We're working with a client that has had (is having) problems with the off
> line liquid effluent monitor.  These are the usual issues with final
> effluent water, it has some silt, organic material (bio-fouling), and it's
> a high flow system that makes it difficult to get a representative sample.
>
> So, the questions are:
> 1. Does anybody have some good ideas on how to cope with this sample
> (e.g., high flow sample pump and then take a sample of a sample)?
> 2.How do you cope with these off line sample problems?
> 3. Has anybody gone to composite raw sampler followed by lab analysis?
>
> Thanx in advance  - -jmr
>
>
> John Rich
> 312-269-3768
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