Charges on Hot Particles

[RDTroja]

Sometimes I wish it were a mere 38!   

Only 3?  I'm also glad the flea problem had not hit the boards when we were doin some major plugging (10 ea x 5)!  And not even one recordable contamination incident.

I'm not talking about 3 charges in the tubes -- I am talking about them loose in the bottom of the bowl. The equivalent of a full stick of dynamite just laying in the bottom after they fell out of the tubes. We blew a bolted-on steel blast cover across the S/G bay. When I went in to investigate and grab an air sample, my brother told me I disappeared in to the cloud that was rolling out of the channel head. Fun stuff.

No contaminations on that one, either. Of course, that was back in the 'tape-up-the-respirator' days.

[OldHP]

I'm not talking about 3 charges in the tubes

I forgot about that incident!

[Starkist]

came across this article, seems to be aligned to what you guys are discussing.

http://www.anl.gov/Media_Center/News/2010/news100225.html 

[HydroDave63]

came across this article, seems to be aligned to what you guys are discussing.

http://www.anl.gov/Media_Center/News/2010/news100225.html 

Only if the workers are soaked in water and cesium...

[Starkist]

Only if the workers are soaked in water and cesium...

Nah, just meaning the general idea of attracting charged radioisotopes. I thought it was neat anyway, not really implying its use (or lack thereof) in a nuclear plant setting.

[HydroDave63]

The conundrum would be that any combination of blown ionized air strong enough to remove the DRPs is also going to have safety warnings of  'avoid face and eyes, avoid bare skin' etc. Assuming the IH folks agree with the precautions, some of these babies could do the trick:


http://www.ccsteven.com/Static_Control/Ionizing_Blowers/ionizing_blowers.html

or

http://www.esdproducts.biz/Ionization/IonizingGuns/ionizingguns.html

[Safety Matt]

Only if the workers are soaked in water and cesium...

How could that ever happen? 

[peteshonkwiler]

Would this deionizing air knife installed above the passage way prior to the RCA exit point reduce PCEs?

I am pretty sure that using both or either of these items at the CA exit of containment would give the station CHP a cardiac condition.  I don't ever remember being told to send a hot particle airborne as a matter of decontamination.  I do remember that we were taught to tightly contain and control said particles. 

[retired nuke]

I am pretty sure that using both or either of these items at the CA exit of containment would give the station CHP a cardiac condition.  I don't ever remember being told to send a hot particle airborne as a matter of decontamination.  I do remember that we were taught to tightly contain and control said particles. 

Well.... having it inhaled will contain and control it....

[spentfuel]

I'm just glad we didn't know about DRPs when we set off the three explosive charges in the bottom of the SG Bowl at a certain New York power plant and blew the blast cover off. I can only imagine the fun we would have had collecting them all...

Jeez you are older than dirt 

From what I recall one of the plugs fell out of the tube and landed on the blast bag prior to detonation.... oops

IMHO that was prior to the invention of DRP's but that certain plant was known for having pieces of fuel lodged in various valves like a certain 800+ R/hr drain on a letdown heat exchanger.

I think DRP's actually became more prominent in the industry when our regulators started requiring utilities to fully offload the core for fuel inspections instead of just replacing the spent and doing incore reshuffles but again IMHO.

To the actual question the charges are positive and I have never seen any of the electrostatic devices work worth a hoot.  A massillen or a tacky mat roller is what Ive seen most effective.

Ill also add I have never seen one on an air sample so I would guess that instead of being blown out by an open door, the the fleas are carried out by workers and perhaps moved around a bit by airflow during PC removal.

My two cents
sf

[RDTroja]

Jeez you are older than dirt 

From what I recall one of the plugs fell out of the tube and landed on the blast bag prior to detonation.... oops

IMHO that was prior to the invention of DRP's but that certain plant was known for having pieces of fuel lodged in various valves like a certain 800+ R/hr drain on a letdown heat exchanger.

I think DRP's actually became more prominent in the industry when our regulators started requiring utilities to fully offload the core for fuel inspections instead of just replacing the spent and doing incore reshuffles but again IMHO.

To the actual question the charges are positive and I have never seen any of the electrostatic devices work worth a hoot.  A massillen or a tacky mat roller is what Ive seen most effective.

Ill also add I have never seen one on an air sample so I would guess that instead of being blown out by an open door, the the fleas are carried out by workers and perhaps moved around a bit by airflow during PC removal.

My two cents
sf

Actually, as I stated before, all three fell out (the boilermaker didn't understand what an over-center cam lock was) and the 'blast bag' was a HEPA Hose attached to a steel collar bolted to the manway. The whole thing was blown off the S/G, toward the S/G bay wall and down to the floor. Very loud. That was how we knew something was wrong before we looked. Everyone was wearing a Full Face Respirator and all you could see in the facepieces were eyes. Fairly comical looking back on it... not so much at the time.

I agree that moving the fuel around extraneously probably contributed to the DRP problem, but I also think longer fuel cycles didn't help either.

BTW, I am only older than some dirt.