Simultaneous Exposure of Rad . Source in a Single area

By swsweld (****)

Date 02-16-2014 16:56

umbhai,
ALARA=As low as reasonably achievable.
Time-Distance-Shielding.

To minimize radiation exposure you practice ALARA by limiting the time spent near the source of radiation, increasing the distance from the source and yes, using shielding when necessary and practical.

If other options exist, asking people to pick up higher doses of radiation is unacceptable. Can the RT crew(s) set up simutaneously and exit the area, then make the shots at the same time? Then both crews enter together to move to the next set up.

If you rely on just lead shielding to be the total ALARA practice and there is ONE mishap, the exposed individual's health could be adversely affected forever. I know (knew) a man that was unintentionally exposed to a source while performing RT. He was in the boiler and the RT crew didn't clear the boiler before making the shot and he turned around and was facing the 'pill'. (through a hand hole)

Lead is an excellent barrier to radiation but if the individual isn't fully behind the barrier, the results could be fatal.
We don't know the atmosphere (layout) of the area but if you were able to set lead shielding in place and record the radiation, if any, on the opposite side of the lead while making a shot, then you would know how much, if any, radiation the individuals would recieve. Basically, perform a mock-up.

Is UT, instead of RT, not an option?

By umbhai Date 02-17-2014 06:00

Thank you SWS weld.
Your reply addresses much of concerns. I can make out that idea I mentioned ( Simultaneous working of two crews in the vicinity seperated by a lead shield) is not at all any best and to have an alternative inspection method is the best idea . As you mentioned we would explore possibility of UT, TOFD or Phased array.

Regards,
Murshid

By 46.00

Date 02-17-2014 06:13

umbhai, I have been on similar jobs with the need to xray many pigtails sets, we used the system described with good results.

By umbhai Date 02-24-2014 04:39

Dear 46,
Nice to hear you had a similar situation.Could you elaborate on how technique used for inspection.

Regards.

By 46.00

Date 03-12-2014 06:56 Edited 03-12-2014 07:04

You use more people simultaneity?

I don't know the size of piping you are using on the pigtails, most of my experience, the pigtails are small bore 2" OD or less. Most of the time they are stainless steel of one grade or another, sometime inconell alloy. UT is not really feasible. But that is just my experience.

By thirdeye (***)

Date 03-16-2014 17:50

Sorry for the delayed response, but my reply might help someone in the future in a similar situation. I have worked many RT jobs like this with multiple sources. Our solution was to set-up the cameras in the same general area, and coordinate the exposures being careful of the direction of the primary beams. Meaning both crews would position film, return to a common safe area and crank out both cameras. When both exposures were complete the process was repeated. The only additional shielding used was to either a) to reduce back-scatter from adjacent tubes or a wall, or b) shield one cassette from the secondary source.

By the way, what was your solution and how did it work out?

By 46.00

Date 03-16-2014 23:38

Are you asking Me? Basically the same I think, I'm not an RT tech so I don't know all the details but they worked it all out and had it done pretty easy. which was good because we were sure it going to present us with a pretty big problem. Sounds like much the way you lads did it! We all tend to see the tree's thru the wood's eventually!

By thirdeye (***)

Date 03-17-2014 03:09

46.00, actually I was replying to umbhai's post.... but my reply was generally in response to the question of how multiple RT crews in the same vicinity can work safely by coordinating their exposures.