[ RadSafe ] off-line liquid effluent monitors
cejjr56 at gmail.com
Wed Dec 21 11:34:55 CST 2011
I don't know of any off-the-shelf systems currently on the market, and
obviously Sargent Lundy doesn't have one either or you wouldn't be asking.
In most cases an off-the-shelf system would have to be tailored to address
the specific sampling needs of the particular site anyway (e.g.,
radionuclides, their geochemical state, representative flow rates, etc.).
Years ago, however, as the junior environmental HP at the Knolls Atomic
Power Laboratory (KAPL). I was responsible for the automated sample
collection, analysis, and reporting of an effluent at the Knolls Site in
Niskayuna, New York that combined secondary- and sometimes tertiary-treated
sewage with runoff and groundwater that was diverted and collected from
across the site. The effluent passed through a weir and Parshall flume and
was discharged to the Mohawk River. The sewage was generally
uncontaminated, but the groundwater constituent was primarily contaminated
with low levels of highly soluble Sr-90 and much less soluble Cs-137 that
were leaching from contaminated soils on the site, mostly from an old
underground tank farm that stored processed liquid wastes from lab
operations in the 1950s and 60s, including the R&D/pilot project for what
ultimately became the PUREX process. The tanks might have been deactivated
and removed by now, as the old separations facilities have been/are
undergoing remediation (D&D).
The effluent sampling system was sheltered in a small enclosure and was
custom designed and fabricated in-house. It included a sodium iodide
detector permanently inserted into the effluent stream that monitored real
time gamma emissions from the cesium and any other gamma-emitting nuclides
that would be entrained in the flow. This monitor incorporated an alarm
system and its real purpose was to alert us of any unexpected high levels
of contaminants in the effluent resulting from accidental releases either
in the sewage from lab operations, or from a new surge of ground
contaminants that could occur from unusually high groundwater events, such
as a rain causing a major snow melt or heavy spring/summer rains, flushing
fresh contaminants from soil areas that weren't normal contributors to our
effluent. Upon alarm, we would attempt to collect event-specific samples
to identify and report the off-normal discharge.
The system also included a sampling pump energized by a timer that operated
at regular frequencies throughout a 24-hour period in order to provide a
sample that was as representative as possible. The captured sample was
dumped into a collection bottle that was regularly retrieved for analysis
(can't recall if it was weekly or monthly). Thus, we calculated and
reported results that reflected mean concentrations over a period of time.
The effluent flow rate was typically such that some groundwater sediment
was entrained, so that we could capture both dissolved cesium and cesium
that was adsorbed onto sediment particles. Cesium, of course, has a high
adsorption coefficient for the clay silts that typified the glacial till
near-surface geology of that region of upstate New York.
Without going into detail, suffice to say that the sample analyses included
a suite that would cover all the bases, as pure beta emitters (other than
Sr-90) and transuranic alpha emitters were also potential effluent
I've described this example to point out that great consideration must be
given to your client's specific monitoring, sampling, analysis, and
reporting objectives, which are radionuclide, hydrologically, and
geochemically-dependent, as well as dictated by their in-house and
regulatory dictated monitoring and reporting requirements. I don't know if
KAPL still operates their system or if they have a new and improved
version, but if you cannot find any off-the-shelf systems that can be
customized for your client, you might try to contact the environmental
folks at KAPL who could provide the design and operations details of their
system. IF THERE ARE ANY KAPL-ites READING THIS, and Naval Reactors allows
it, you might want to contact John Rich at 312-269-3768 and help him out.
Good luck, John.
Carl Ed Johnson
Albuqerque, New Mexico
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
> You are currently subscribed to the RadSafe mailing list
> Before posting a message to RadSafe be sure to have read and understood
> the RadSafe rules. These can be found at:
> For information on how to subscribe or unsubscribe and other settings
> visit: http://health.phys.iit.edu
More information about the RadSafe