Cell Phone Contamination

[kp88]

The radiation detectors in the contamination monitors at my plant are incapable of detecting radiation emitted through cell phone and pager cases.  A pen that is used in a radiological controlled space, carried in a pants pocket, is not subject to this radiation shielding effect.

Cloth, leather, and vinyl materials, such as pager and cell phone cases, are not commonly used as radiation shielding materials.

Can someone explain to me what type of radiation is detected by a tool monitor that is not detected by a personnel monitor?

Why can't this technology be developed to detect contamination on actual people?  I tend to care about people more than wrenches.   

[retired nuke]

The tool monitor detects gamma radiation. It is electromagnetic radiation emitted from the nucleus of an atom, and has great penetrating power relative to it's energy. It can penetrate metal. It does not have a charge, and thus, is not as likely to interact with matter.

The personnel monitor detects beta radiation. It is particulate radiation from the nucleus or an atom. It has a charge of -1 (sometimes +1) and interacts readily with matter. It can be stopped by lightweight materials like plastic and aluminum.

The second personnel monitor (at most plants) is also a gamma detector. This ensures that radioactive material is detected on personnel, including items in pockest, stuck on shoes, seams of clothes, etc.

Many plants now are using an "empty pockets rule" where ALL items that can be put in a tool monitor, will be monitored that way.

Hope this helps.

[kp88]

"The tool monitor detects gamma radiation.
The personnel monitor detects beta radiation.
The second personnel monitor (at most plants) is also a gamma detector."

Ok, I agree.

However, you are telling me that personnel contamination monitors are incapable of detecting gamma radiation, if it is emitted through commonly used clothing materials.  I hoped that I had already said that.

[HydroDave63]

"The tool monitor detects gamma radiation.
The personnel monitor detects beta radiation.
The second personnel monitor (at most plants) is also a gamma detector."

Ok, I agree.

However, you are telling me that personnel contamination monitors are incapable of detecting gamma radiation, if it is emitted through commonly used clothing materials.  I hoped that I had already said that.

It's more a function that the cell phone has lots of nooks and crannies where alpha and beta emitters can hide out and not be detected by the SAM or personnel monitor, or the person and pocket being monitored would shield it from detection.

[dinutt]

  Are we starting to see this as a major issue at the sites ? alot of personnel take their cell phones into RCA..haven't heard much about this yet til now? interesting 

[retired nuke]

"The tool monitor detects gamma radiation.
The personnel monitor detects beta radiation.
The second personnel monitor (at most plants) is also a gamma detector."

Ok, I agree.

However, you are telling me that personnel contamination monitors are incapable of detecting gamma radiation, if it is emitted through commonly used clothing materials.  I hoped that I had already said that.

Personnel contamination monitors - commonly called "portal monitors" detect gamma - plants have them at the RCA line, just after the beta monitors (the ones you have to turn around in) and usually at the security gatehouse going out. They are a walk through type monitor.

[kp88]

Personnel contamination monitors - commonly called "portal monitors" detect gamma - plants have them at the RCA line, just after the beta monitors (the ones you have to turn around in) and usually at the security gatehouse going out. They are a walk through type monitor.

Again, tool monitors detect gamma radiation emitted by contamination on cell phones.  Personnel monitors are effectively shielded from this gamma radiation by commonly used fabrics.

Don't be condescending.

[nowhereman]

I am not intending to drift on this subject but, there are a number of workers who balk/hesitant about placing their small electronics into the S.A.M. for fear of damage to the electronics.  sad to say but the list also includes some Jr hp's AND some Sr hp's.

[kp88]

Are we starting to see this as a major issue at the sites ? alot of personnel take their cell phones into RCA..haven't heard much about this yet til now? interesting 

I think that this started at Palo Verde.

[kp88]

I am not intending to drift on this subject but, there are a number of workers who balk/hesitant about placing their small electronics into the S.A.M. for fear of damage to the electronics.  sad to say but the list also includes some Jr hp's AND some Sr hp's.

Tool Monitors are harmless to electronics.  Radiation detectors detect radiation.  They don't emit radiation.  It kind of defeats the purpose.
Feel free to PM me if you drift too far off the subject.

[grantime]

Again, tool monitors detect gamma radiation emitted by contamination on cell phones.  Personnel monitors are effectively shielded from this gamma radiation by commonly used fabrics.

Don't be condescending.

Not to be condescending--- but what kind of commonly used fabrics are good Gamma shields? Besides Pb aprons?  Lots of fabrics are pretty fair beta shields however.

On a different subject the use of radio transmitters(like cell phones) in at least my plant is controlled and limited to where the are supposed to be used.  I'm not saying that everyone abides by those rules but I do know that you can trip plant if radio transmitter used in wrong area.  I don't want to be the one that proves that it can be done with a cell phone. 

[kp88]

Just to swerve back on to my question for a minute.

Radiation Protection Technicians are telling me that the two personal contamination monitors I just passed through, do not detect gamma rays emitted from contamination on my cell phone.

The tool monitor does have this ability.

(I feel stupid that I have to defend this.)

[grantime]

OK all kidding aside .   

The gas flow PCM type monitors in use at many plants will detect gamma radiation.  However at much lower efficiencies than it will for Beta radiation.  That is just the nature of the beast.  The scintillation type(SAM-9) Tool monitor is only sensitive to gamma radiation.  If your isotope mixture has a high amounts of  isotopes that are predominately beta emitters with little gamma component then the tool monitor may miss it.  IF you have contamination inside your shoes or inside a pocket the PCM will find it only if it is a relatively high amount.  That is why most plants have put in walk through gamma detectors.  More chance to find the contamination. If you neglect the gamma efficiencies for the gas flow type detectors(PCM) then these can be thought of as a way of monitoring the external surface of person or thing and the gamma sensitive scintillators can be thought of a a volume monitor.  They are not equivalent but are complimentary.

[SloGlo]

all dose peeps wit da cells in da plants.... are they all non-camera type phones?

[kp88]

OK all kidding aside .   

The gas flow PCM type monitors in use at many plants will detect gamma radiation.  However at much lower efficiencies than it will for Beta radiation.  That is just the nature of the beast.  The scintillation type(SAM-9) Tool monitor is only sensitive to only to gamma radiation.  If your isotope mixture has a high amounts of  isotopes that are predominately beta emitters with little gamma component then the tool monitor may miss it.  IF you have contamination inside your shoes or inside a pocket the PCM will find it only if it is a relatively high amount.  That is why most plants have put in walk through gamma detectors.  More chance to find the contamination. If you neglect the gamma efficiencies for the gas flow type detectors(PCM) then these can be thought of as a way of monitoring the external surface of person or thing and the gamma sensitive scintillators can be thought of a a volume monitor.  They are not equivalent but are complimentary.

My cell phone needs to go through the tool monitor, but my lanyard, security badge, and dosimeters do not.  I disagree, but I'll accept and move on.

[Melrose]

Just to swerve back on to my question for a minute.

Radiation Protection Technicians are telling me that the two personal contamination monitors I just passed through, do not detect gamma rays emitted from contamination on my cell phone.

The tool monitor does have this ability.

(I feel stupid that I have to defend this.)

Wow, didn't know where to start here.  You received alot of informative replies.... though like stated, a little off track.
First, your statement above.  The techs are wrong, the PCM and Portal will both detect gamma emitted from your cell phone.  IF the origin is such that it can be detected i.e. how directional is the source, what's the energy of the source, and whether or not the phone is shielding it.

Everyone remembers stories of workers clearing the PCM with a particle or two on their person and getting caught at the portals.  These particles are places and are directional in manner the these places (crevices) aide in shielding.  (Under the arm pits, under the folds of 'extra' skin etc.
Clothing has nothing to do with the shielding.  Directional attributes, energy and location together help.

Here's an idea.... since you and others that can't live without the feeling of that cool gadget on your hip don't have reception in the building anyway, leave the phone in your locker.

Serioulsly, most plants have a hand carried rule.  If it's a hand carried item, like a clipboard, cell phone, radio, ruler, pen, paper, not pad, gloves and not a "tool" used for working in the plant, then it goes in the SAM.  You don't hand carry your lanyard and badge.  The idea is that the hand carried item could have been and probably was laid down somewhere, and may have picked up some lost and wondering contamination, therefore it gets to be put in the SAM.

Don't sweat it,
leave the phone outside

[kp88]

Wow, didn't know where to start here.  You received alot of informative replies.... though like stated, a little off track.
First, your statement above.  The techs are wrong, the PCM and Portal will both detect gamma emitted from your cell phone.  IF the origin is such that it can be detected i.e. how directional is the source, what's the energy of the source, and whether or not the phone is shielding it.

Everyone remembers stories of workers clearing the PCM with a particle or two on their person and getting caught at the portals.  These particles are places and are directional in manner the these places (crevices) aide in shielding.  (Under the arm pits, under the folds of 'extra' skin etc.
Clothing has nothing to do with the shielding.  Directional attributes, energy and location together help.

Here's an idea.... since you and others that can't live without the feeling of that cool gadget on your hip don't have reception in the building anyway, leave the phone in your locker.

Serioulsly, most plants have a hand carried rule.  If it's a hand carried item, like a clipboard, cell phone, radio, ruler, pen, paper, not pad, gloves and not a "tool" used for working in the plant, then it goes in the SAM.  You don't hand carry your lanyard and badge.  The idea is that the hand carried item could have been and probably was laid down somewhere, and may have picked up some lost and wondering contamination, therefore it gets to be put in the SAM.

Don't sweat it,
leave the phone outside

For the record, I hate cell phones.
To swerve completely off topic, one nanocurie of Co-58 on my cell phone must be stopped at the power plant boundary.  A gazillion curies of tritium discharged into the environment is okay.  Illinois Power launched the whole groundwate protection initiative.
I believe that the term is "below regulatory concern", I just don't agree with the NRC's concern level.

[SloGlo]

h3?  yer worryed about h3??  den stay outta containment.

[JsonD13]

kp,
  you have to remember that curies, activity, bq, and etc. just refer to the rate of change of that particular radioactive substance based off of its mass.  The actual difference in treating those two isotopes is in the risk of exposure to the public. 

Tritium yields a low energy beta (~5.7keV), where drinking water at the normal estimation out of that old antiquated EPA report, contaminated at 60,900 pCi/L tritium, will give a yearly dose of 4mrem.

Co-58 yields a higher energy beta (~201 keV), along with xrays.  Just seeing the difference in energies should give you an idea that there would be wayyyyy more dose with Co-58, thus limiting more on how much you can release.

Jason

[Smart People]

Serioulsly, most plants have a hand carried rule.  If it's a hand carried item, like a clipboard, cell phone, radio, ruler, pen, paper, not pad, gloves and not a "tool" used for working in the plant, then it goes in the SAM.  You don't hand carry your lanyard and badge.  The idea is that the hand carried item could have been and probably was laid down somewhere, and may have picked up some lost and wondering contamination, therefore it gets to be put in the SAM.

Don't sweat it,
leave the phone outside

I've been to some plants recently that have gone to the practice of samming lanyards.

[dinutt]

 we have a hand carried item policy but alot of people are taking cells inside with them and they find the reception and they do wear them all the time and talk on them during exit process thru  monitors so I agree with you Melrose not to take them in with you but is this a  can of worms we want to open or is it a big look ahead item and do they want to start enforcing this at more  sites to have them monitor thru the SAM .It could make for a angry bunch of folks that don't have that communication with them ........interesting.....Karma to you grantime for explaining........

Di

[grantime]

 dinutt, thanks for the karma.  Its been too long since you worked Farley. You need to come back down here sometime.

One thing I try to remind people is that they shouldn't take anything into a RCA that they would mind seeing buried in a waste site-- be that nice watches, fancy jewelry or in this case -cell phones. 

[dinutt]

  grantime it has been a very long time since I  have been to Farley but since I joined the house side I don't travel anymore much unless I support our sister plants or if  its a benchmark maybe they will let me come that way one day to benchmark...always had a good outage there and fun......I too try the waste story but they don't believe it , as it still continues, if need just try to  take their boots wow!! ( another story )

Di

[snowman]

Radiation Protection Technicians are telling me that the two personal contamination monitors I just passed through, do not detect gamma rays emitted from contamination on my cell phone.

That's what you get for hiring HP's from McDonald's. Time your plant found some new HP's or a better training department.