NukeWorker Forum
Reference, Questions and Help => Nuke Q&A => Lessons Learned => Topic started by: LaFeet on Mar 19, 2006, 02:32
-
Having spoke to several divers, I have been told that there is a plant that does not include the head as part of the Whole Body.
Did I miss a change to the CFRs or NukeRegs? Am I amiss in that the head is part of the whole body?
Is it Thursday yet?
-
Only for management. In workers, the head contains a vital organ.
-
Only for management. In workers, the head contains a vital organ.
Well put, however... I really think this might be an issue
-
I have worked with diver's on several occasions. In every instance, we had a TLD and one of the SAIC probes inside the diver's helmet. The diver's had finger rings (2), toe rings (2) TLD's on each shoulder(2), one on the chest, and one in the helmet for a total of 8 TLDs. Sometimes, depending on the type of job and what position they are working in, they might also have TLD's placed on their thighs.
-
Having spoke to several divers, I have been told that there is a plant that does not include the head as part of the Whole Body.
Did I miss a change to the CFRs or NukeRegs? Am I amiss in that the head is part of the whole body?
Is it Thursday yet?
At this particular plant their heads seem to be extremities, due to not using the vital organ (in the head) the brain to think with. Extremites are defined as: from the elbow down including the fingers and from the knees down including the feet.
-
I have worked with diver's on several occasions. In every instance, we had a TLD and one of the SAIC probes inside the diver's helmet. The diver's had finger rings (2), toe rings (2) TLD's on each shoulder(2), one on the chest, and one in the helmet for a total of 8 TLDs. Sometimes, depending on the type of job and what position they are working in, they might also have TLD's placed on their thighs.
I agree, however the head is still part of the "Whole Body".
-
The divers most likely came from San Onofre's ICI thimble replacement project. SCE used a new, NRC-approved way of tracking whole-body exposure when working in non-uniform fields. The methods are outlined in ANSI N13.41. Assuming I have this all right, it works like this:
Instead of using the highest-reading whole body dosimeter for recording the exposure to the whole body, each section of the whole body is given "compartment factors". The dosimeter reading for each of these "compartments" is multiplied by a weighting factor. Each of these "compartment doses" are then added together for the assigned whole body exposure.
Chest = 0.88 (thorax, abdomen, pelvis)
Head and neck = 0.10
Upper Arm = 0.005 (each arm)
Thigh = 0.005 (each thigh)
Based on what I saw with the divers' doses during this project, this does result in a lower assigned whole-body dose (relative to this project, anyway).
I'm still trying to wrap my head around this "new" way of dealing with non-uniform field exposures, but it seems to work and appears to be a more realistic assignment of dose. I guess we'll just have to wait and see what the NRC decides to do relative to the rest of the industry.
-
The divers most likely came from San Onofre's ICI thimble replacement project. SCE used a new, NRC-approved way of tracking whole-body exposure when working in non-uniform fields. The methods are outlined in ANSI N13.41. Assuming I have this all right, it works like this:
Instead of using the highest-reading whole body dosimeter for recording the exposure to the whole body, each section of the whole body is given "compartment factors". The dosimeter reading for each of these "compartments" is multiplied by a weighting factor. Each of these "compartment doses" are then added together for the assigned whole body exposure.
Chest = 0.88 (thorax, abdomen, pelvis)
Head and neck = 0.10
Upper Arm = 0.005 (each arm)
Thigh = 0.005 (each thigh)
Based on what I saw with the divers' doses during this project, this does result in a lower assigned whole-body dose (relative to this project, anyway).
I'm still trying to wrap my head around this "new" way of dealing with non-uniform field exposures, but it seems to work and appears to be a more realistic assignment of dose. I guess we'll just have to wait and see what the NRC decides to do relative to the rest of the industry.
Yup... looks like ya read and copied everything correctly. Good work.
-
it looks like they're using an approach similar to what we use in calculating CEDE, which is considered a whole body exposure
-
Thanks for the help all.
-
A little dated, but it seems the NRC has addressed this before
http://www.nrc.gov/reading-rm/doc-collections/enforcement/actions/materials/ea97207o.html
may be they changed their minds
-
I don't see it as changing their minds. In the link, they do allow the use of weighting factors, but only if you get them approved first. If the process and weighting factors Chimera gave us were blessed prior to use, that would be consistant with the link.
Has anybody seen this done for people working in SG handholes or any other situations?
-
I don't see it as changing their minds. In the link, they do allow the use of weighting factors, but only if you get them approved first. If the process and weighting factors Chimera gave us were blessed prior to use, that would be consistant with the link.
Has anybody seen this done for people working in SG handholes or any other situations?
not with weighting factors, but i have had inspectors blessings for dosing different extremities to the max permitted at different times during an evolution.
-
Good catch.... I will call some friends and see if they can help.
-
not with weighting factors, but i have had inspectors blessings for dosing different extremities to the max permitted at different times during an evolution.
in the early 90's, at Maine Yankee (rest in peace) our procedure for handhole work required us to assign staytimes. We wanted to calculate separate stay times for the left and right hands based on their different doses, but the NRC wouldn't let us, saying that there is only one whole body dose and we had to use it to calculate and assign stay times. In other words, if you get 300 left and 150 right today, then you have 300 whole body. If you get 120 left and 400 right tomorrow, you now have 700 whole body. Didn't seem right to me.
-
in the early 90's, at Maine Yankee (rest in peace) our procedure for handhole work required us to assign staytimes. We wanted to calculate separate stay times for the left and right hands based on their different doses, but the NRC wouldn't let us, saying that there is only one whole body dose and we had to use it to calculate and assign stay times. In other words, if you get 300 left and 150 right today, then you have 300 whole body. If you get 120 left and 400 right tomorrow, you now have 700 whole body. Didn't seem right to me.
weird. in the late 80s i had a discussion with an inspector regarding this and if we used separate tlds for each extremity, we could max each, as long as we didn't overun. but i don't recall being able to badge more'n one head, or else'n we'da badged the heads on the beers after work 'n got the job done cheap.