NukeWorker Forum
Reference, Questions and Help => Nuke Q&A => Lessons Learned => Topic started by: Kernwerker on Jul 21, 2006, 04:19
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Hi folks
I have a rather tricky question. Here in our BWR unit the initial entree of the containment is carried on by personal from HP and the fire department (O2 metering).
The HP person besides wearing full respiratory protection (due to Nitrogen) must carry a teletector, a 20 pound transformer and an air sampler weighing another 20 pounds to carry out the initial rad measurements inside the containment
My question is, are their any battery portable air samplers with an air flow of around 1m³/min (35cfm) on the market.
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He should also have a 20 pound neutron meter, just in case ops lied. I wonder what the necessity of a 35 cfm is. All you need is a volume of air consistent with the MDC you want to be able to see. A 15 min 3 lpm lapel would be just as good and only weighs in at a half a pound. I would also be concerned about any sparking in a potential Hydrogen/explosive atmosphere. There are battery operated radecos but they run about 20 cfm. Call Radeco or check them out on line. First, look into other BWR initial entry procedures to see if you can steal one that provides an easier entry. People Safety first! Nuclear 2nd, radiological 3rd.
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my concerns too... why would you need such a high flow on an airsampler.. breathing rates should be approximated.... sounds like an unsafe situation all around as far as human factors go.. something out of the 1970's
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He should also have a 20 pound neutron meter, just in case ops lied. I wonder what the necessity of a 35 cfm is. All you need is a volume of air consistent with the MDC you want to be able to see. A 15 min 3 lpm lapel would be just as good and only weighs in at a half a pound. I would also be concerned about any sparking in a potential Hydrogen/explosive atmosphere. There are battery operated radecos but they run about 20 cfm. Call Radeco or check them out on line. First, look into other BWR initial entry procedures to see if you can steal one that provides an easier entry. People Safety first! Nuclear 2nd, radiological 3rd.
The high flowrates are needed for a representative amount of air. the probe then is measured on a proportional gas flow thru counter. Of course we have built in Instrumentation for Iodine, aerosol and noblegas measuring. But it is common practice here in Germany in BWR's taking "hand samples" in addition to fixed monitoring.
Under normal cirumstances we dont have any conditions that involve high explosive gases like Hydrogen.
The initial entree takes place only when the reactor is undercritical and the pressure is below 17 bar and the neutron doserate is comparibly low against gamma.
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my concerns too... why would you need such a high flow on an airsampler.. breathing rates should be approximated.... sounds like an unsafe situation all around as far as human factors go.. something out of the 1970's
Unsafe is relative. Our containment is flooded with Nitrogen during a cycle (fire prevention etc). At the beginning of the outage the containment is vented with air to flush the nitrogen out. The full respiratory is just pure precaution. And both of our units have one of lowest collective dose amounts for the outage personal in the world! *brags* ;)
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not talking about the intrinsic safety of the equipment, talkin about all the stuff (human factors) that the tech has to deal with- the human factors portion... a teletector, a transformer, a high volume sampler not to mention his or her obligation to ensure rad and industrial safety, survey documentation, crew control... walking up or down a stair requires one hand on the rail to ensure safe passage.. is his focus on the equipment or the people and so on.. is he in an SCBA... physical and mental stress due to use of a SCBA or any reaspirator, time limits...too many factors to mention. Often situations like these are neglected or assumed safe because its always been done this way and no one has gotten hurt so far.. this does not mean the situation is safe, just lucky.
The full respirator is just pure precation!!!! That is a red flag statement. Is the atmosphere IDLH, contaminated or not.. does he have an escape bottle...Relative to the scenario presented- its unsafe as far as human factors go.
Just the perspective from a safety professional and site safety officer.
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not talking about the intrinsic safety of the equipment, talkin about all the stuff (human factors) that the tech has to deal with- the human factors portion... a teletector, a transformer, a high volume sampler not to mention his or her obligation to ensure rad and industrial safety, survey documentation, crew control... walking up or down a stair requires one hand on the rail to ensure safe passage.. is his focus on the equipment or the people and so on.. is he in an SCBA... physical and mental stress due to use of a SCBA or any reaspirator, time limits...too many factors to mention. Often situations like these are neglected or assumed safe because its always been done this way and no one has gotten hurt so far.. this does not mean the situation is safe, just lucky.
The full respirator is just pure precation!!!! That is a red flag statement. Is the atmosphere IDLH, contaminated or not.. does he have an escape bottle...Relative to the scenario presented- its unsafe as far as human factors go.
Just the perspective from a safety professional and site safety officer.
Ok you have a point there pertaining to the fact someone going up the stairs carrying all that stuff.. Thats one of the reasons we are looking for a portable hand sampler so we can skip the transformer (which ironically is used for safety reasons). Well I have done that trip a few times and the safety officer occompaning me usually gives a hand carrying some of the stuff. But it is still quite a few to carry especially wearing another weight in form of a bottle on your back.
But then again someone has to go in eventually. And our safety standards are just as well very strict.
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good to see you are thinking this thru... as a technician from the past, i remember those days of having a rem ball, air sampler, ion chamber, clip board, package of swipes, hanging off me while climbing up a ladder to do a survey.. i look back at that now and wonder how we all survived. (some didnt) we did it because we were expected too and were inexperienced.. lucky to live and tell others...
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The high flowrates are needed for a representative amount of air. the probe then is measured on a proportional gas flow thru counter. Of course we have built in Instrumentation for Iodine, aerosol and noblegas measuring. But it is common practice here in Germany in BWR's taking "hand samples" in addition to fixed monitoring.
Under normal cirumstances we dont have any conditions that involve high explosive gases like Hydrogen.
The initial entree takes place only when the reactor is undercritical and the pressure is below 17 bar and the neutron doserate is comparibly low against gamma.
Are you taking multiple air samples as in one sample per site with numerous sites visited on the initial entry, or are you taking one sample at multiple sites with the same sample media exposed during multiple on/off cycles? It would seem to me that it would be easier to carry an a/c air sampler, change out the filter media and plug it in at the various sites to be sampled.
That said, a quick surf picked up this site which may be of use to you.
http://www.laurussystems.com/products/air_samplers.htm
Maybe the H809C is what you are seeking?
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yer crakeen me up! 809c? wit dat battery? yinz gotta be rilly taleen hymn two higher a junyer too kerry alla dat! da battery ways 30 sum elbees!
try looking at the h810.
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good to see you are thinking this thru... as a technician from the past, i remember those days of having a rem ball, air sampler, ion chamber, clip board, package of swipes, hanging off me while climbing up a ladder to do a survey.. i look back at that now and wonder how we all survived. (some didnt) we did it because we were expected too and were inexperienced.. lucky to live and tell others...
Well "luckily" we had "only" two accidents in German nukes resulting in death. In both cases they were nonradiological in nature. And yes I know how it is making compromises when it comes to work related safety.
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Are you taking multiple air samples as in one sample per site with numerous sites visited on the initial entry, or are you taking one sample at multiple sites with the same sample media exposed during multiple on/off cycles? It would seem to me that it would be easier to carry an a/c air sampler, change out the filter media and plug it in at the various sites to be sampled.
That said, a quick surf picked up this site which may be of use to you.
http://www.laurussystems.com/products/air_samplers.htm
Maybe the H809C is what you are seeking?
No we usually take more one the one sample at specific area locations depending on our standard operation procedures. During the initial entree of the containment in our BWR unit we actually take only one probe or sample in this area. This probe is taken in a time frame around 5 minutes which equates to about 175 cf. So thats why we need a device with a capable air flow of around 35cfm.
Thanks for the info and the link to that site. Ill try contacting the company for further details.