Underwater Rad Detection

[whaley]

Any recommendations, suggestions, or products to avoid for a high range underwater dose rate meter?

[retired nuke]

Use;

AMP-100, sleeved, long cable, on long handled tool, you can dip the detector into liquid tape to seal the water out should you breach the sleeving,....


Avoid;

RO-7, old, cumbersome, seals on the stainless capsule always develop leaks,....

I've found out that you can get 1 (just 1) underwater reading with a telepole that has a rubber glove over the probe.....

[UncaBuffalo]

Use;

AMP-100, sleeved, long cable, on long handled tool, you can dip the detector into liquid tape to seal the water out should you breach the sleeving,....


Avoid;

RO-7, old, cumbersome, seals on the stainless capsule always develop leaks,....

I don't mind the R0-7, if that is what is available.  I never had problems with the U/W housing leaking & it was rugged enough to live thru the punishment we put it thru on various refuel bridges & work platforms.  One issue that always comes up with the RO-7 is how to read the digital display, as the units (R/hr?  kR/hr?) change depending on which probe is attached.  Make sure you play with the probe you will be using to ensure you understand the resulting response.

I have used the AMP-100 & AMP-200 with good results.  I don't like sleeving them...the sleeving always leaks...  

On one project, we used the Dosimeter Model 3090-3 (commonly used as an ARM on refuel floors) after 'hot dipping' the probe & U/W connections.  It had a good range for the SFP we were in & we never had problems with the 'hot dip' leaking.  I will ask some of the old group for info on who manufactured the 'hot dip'.


Note:  ALL UNDERWATER INTRUMENTS HAVE GEOMETRY PROBLEMS, SO DO NOT TRUST THE UNDERWATER READING YOU OBTAIN.  IF THE ITEM YOU ARE SURVEYING MUST BE REMOVED FROM THE POOL, MONITOR THE DOSE RATES ABOVE THE WATER & IN THE WORKER'S AREA AS THE ITEM APPROACHES THE SURFACE.  OBTAIN ACCURATE GAMMA and  BETA DOSE RATES AFTER THE ITEM HAS BEEN REMOVED FROM THE WATER.  (IF you NEED accurate readings...don't waste dose to get a meaningless number...DO PROTECT YOURSELF & YOUR WORK GROUP.)

[UncaBuffalo]

I'm hearing ya, but UncaBuffalo is recognized industry wide as an awesome field tech who is one with his meters, his work environment and his karmic place in health physics,.....

All us other poor slobs hate that dam RO-7 dinosaur,.....

http://www.nukeworker.com/forum/index.php/topic,23507.0.html

http://www.nukeworker.com/forum/index.php/topic,23506.0.html

[stormgoalie]

Now now I too like the RO-7.  Though we built special PVC probe housings because the crappy metal ones leaked constantly.  Figured with the dose rates we were looking for any shielding that the steel housing provided was negligible at best so the difference in density didn't matter as far as we were concerned.

+1 on being uber cautious of stuff coming out of the bay!!

[UncaBuffalo]

All us other poor slobs hate that dam RO-7 dinosaur,.....

I guess maybe I am the dinosaur...'cuz, if I'm doing an area survey, I'd still pick a beat-up old RO2 over any of these 'State-of-the-Art' dose rate meters, too... 

[Marlin]

I guess maybe I am the dinosaur...'cuz, if I'm doing an area survey, I'd still pick a beat-up old RO2 over any of these 'State-of-the-Art' dose rate meters, too...  

Put in a plastic bag and hand it to the diver

[mostlyharmless]

I used an ro-7 quite a bit. Went through four in seven months oh heavy use. Had a learning curve for the first two. Then learned how to make the housings a little more water tight, and rig the probes to the wire so the elec. cable would not break. Once I figured it out the ro-7 worked well. True you cant be too carefull. A lot of dose can ride or be carried up by a diver. Got the HP scared out of me when I saw the mid range peg with a diver in the water. The diver had placed the probe on a pile of bolts. Fuel pools deserve respect.  
Recently switched to a digital rem ball, would rather have the analog. Ever used a digital teletechtor? Spend a lot of dose waiting on the numbers to settle.

[Already Gone]

I liked the AMP-100, even though I normally hate digital meters.  If you use the method one spot = one reading, you can do okay.  It just isn't very good if you're going hunting.  For one thing, the probe is very light, so you can't move it through the water very easily.  Even with no tri-nuc's or pumps running, it will drift around in the thermal currents.  You also have to be careful about weighing it down.  You can lose the weight somewhere in the depths of the reactor vessel.

My favorite underwater survey was the time the "Green Men" at Pickering A had to survey part of the Irradiated Fuel Bay.  (They were Millwrights and Boilemakers qualified to do rad coverage, while I was an HP employed to cut up stuff with the LPRM cutter)  They put Siemens electronic dosimeters into double bags and hung a dozen or so by strings in a grid pattern.  Then they read the histograms to see the highest reading on each.  It worked, and none of the dosimeters was damaged.  Later that day, I showed their boss the Eberline website.  He was amazed that you could buy underwater probes for the meters that the operators carried around in their back pocket all the time.  I guess they had never needed to do underwater surveys for the first few decades of their existence.?.?

[stormgoalie]

I liked the AMP-100, even though I normally hate digital meters.  If you use the method one spot = one reading, you can do okay.  It just isn't very good if you're going hunting.  For one thing, the probe is very light, so you can't move it through the water very easily.  Even with no tri-nuc's or pumps running, it will drift around in the thermal currents.  You also have to be careful about weighing it down.  You can lose the weight somewhere in the depths of the reactor vessel.

My favorite underwater survey was the time the "Green Men" at Pickering A had to survey part of the Irradiated Fuel Bay.  (They were Millwrights and Boilemakers qualified to do rad coverage, while I was an HP employed to cut up stuff with the LPRM cutter)  They put Siemens electronic dosimeters into double bags and hung a dozen or so by strings in a grid pattern.  Then they read the histograms to see the highest reading on each.  It worked, and none of the dosimeters was damaged.  Later that day, I showed their boss the Eberline website.  He was amazed that you could buy underwater probes for the meters that the operators carried around in their back pocket all the time.  I guess they had never needed to do underwater surveys for the first few decades of their existence.?.?

Beings that I work in Pickering B's IFB a bunch now, work for the Dry Fuel Storage operations deptartment, we use underwater probes with the IAEA all the time to "fingerprint" fuel bundles prior to loading them into a Dry Storage Cask.  Very interesting stuff.  Handling fuel is providing me with some fun stuff to think about.  Even though my job title changed from RP Supervisor to Senior Tech. Engineer I find that they really rely on me for RP "advice" so not out of the family completely.  Troy, you should come back up and visit some time

[Brett LaVigne]

I work the lack of fuel pool every day at Humboldt Bay. We are characterizing everything. The AMP 100/200 works well and has not failed us but only one time (bad cord), other than that it's all good.

We don't sleeve the cord, we just wrap the probe with a rubber electrical tape that bonds to it self and makes a water tight enclosure. I think it's the same tape that electricians use to wrap leads. Because we use it on a daily basis, we leave it in the water or at least bagged in the area. When we reach the cal. due date, we replace the meter and "86" the cord.

Other than that...I will go along with anything UncaBuffalo says! If the RO7 is for him, I'm in!

[Already Gone]

Beings that I work in Pickering B's IFB a bunch now, work for the Dry Fuel Storage operations deptartment, we use underwater probes with the IAEA all the time to "fingerprint" fuel bundles prior to loading them into a Dry Storage Cask.  Very interesting stuff.  Handling fuel is providing me with some fun stuff to think about.  Even though my job title changed from RP Supervisor to Senior Tech. Engineer I find that they really rely on me for RP "advice" so not out of the family completely.  Troy, you should come back up and visit some time

I'd love to.  Maybe someday.  My job was to clean out the disintegrated fuel pencils from the east elevator at Unit 2 and the transfer tunnel between U2 and the IFB.  We also chopped up a bunch of the rods that they used to make the Cobalt sources with.  They told us that there was a hot spot somewhere in the tube that they wanted us to get rid of.  I asked the Rad Engineer how hot it was, and she told me, "We don't know.  We just tell people to go by it really fast."
I'm thinking that they have moved forward in the technology since then.
But we all had fun playing in that pool.
Does the IAEA still have cameras watching every thing you do there?
Say hello to Hash for me.

[stormgoalie]

I'd love to.  Maybe someday.  My job was to clean out the disintegrated fuel pencils from the east elevator at Unit 2 and the transfer tunnel between U2 and the IFB.  We also chopped up a bunch of the rods that they used to make the Cobalt sources with.  They told us that there was a hot spot somewhere in the tube that they wanted us to get rid of.  I asked the Rad Engineer how hot it was, and she told me, "We don't know.  We just tell people to go by it really fast."
I'm thinking that they have moved forward in the technology since then.
But we all had fun playing in that pool.
Does the IAEA still have cameras watching every thing you do there?
Say hello to Hash for me.

They use that job as a success story all the time here! Yep the IAEA have their blue cameras EVERYWHERE in the IFB's and our Processing shop.  Am going to be talking to Hasher today and will pass on the message.  If you do decide to stop in for a visit let me know. First round is on me

[grantime]

I am a big fan of the AMP-100 .  there is no use sleeving them.  They decon easy .

[UncaBuffalo]

On one project, we used the Dosimeter Model 3090-3 (commonly used as an ARM on refuel floors) after 'hot dipping' the probe & U/W connections.  It had a good range for the SFP we were in & we never had problems with the 'hot dip' leaking.  I will ask some of the old group for info on who manufactured the 'hot dip'.

Okay, I was told it was 'cold dip', not 'hot dip'...brand name 'Plasti-Dip'...available at Home Depot, etc.

Other suggestions were liquid electrical tape...and heat shrink w/ silicone RTV.

Hope this helps someone...sorry for the delay in posting!

[Already Gone]

Are the FHZ 312 / 302 set-ups for the Eberline FH 40 comparable to the AMP?

AHA!  Thanks for the memory-aid.  This is the setup I was talking about.  There were hundreds of guys walking around Pickering with an FH40G (they called it a FAG Meter) in their back pockets.  Yet, they were seemingly unaware that you could buy the probes to attach to them for underwater surveys.

[thenukeman]

The Identifinder for covert operations.  May not be so good in reactor and pool use!!!

[stormgoalie]

The Identifinder for covert operations.  May not be so good in reactor and pool use!!!

Their telepole version also uses the underwater housing, just for those moments where distance matters

[UncaBuffalo]

AMP-100, sleeved, long cable, on long handled tool, you can dip the detector into liquid tape to seal the water out should you breach the sleeving,....

We've been having good luck with some AMP-100s we Ray-Chem'd...

[HousePuke]

I guess maybe I am the dinosaur...'cuz, if I'm doing an area survey, I'd still pick a beat-up old RO2 over any of these 'State-of-the-Art' dose rate meters, too... 

Then count me as a dinosaur cause I'm with you on this one!

[namlive]

I think the amp-100 is the inductry standard. Before that we used an RM-16 with a peanut probe we would staple to a diver.

[RealityCheck]

I wouldn't recommend sticking poles in the water unless they are flooded...that's one sure way of removing the shield (water)...it does make for an interesting source