The shop should have policies and procedures in place to limit exposure to employees or workers in the area that are not performing radiography. Check with their Radiation Safety Officer if you have concerns with the way they are doing things. I do believe the Nuclear Regulatory Commision as well as OSHA provide rules and regulations for this type of work. Dont quote me on this but the allowable exposure at the barricade is 2 Millirems if I remember correctly and this can and should be monitored by the technician or helper.
This shop is in China and I am not sure that there is a Radiation Safety Officer ...
I do have concern in the way that i have no knowledge at all in the field of radiation exposure. I have been told the limit per year of exposure is 20 milli vs ... not even knowing what does that unit refers to. It s more the lack of information from the RT team itself that is a worry.
When it comes to being exposed to radiation during a whole shift, I worry for my safety and the one of the people who are working on the job i am inspecting.
Im still trying to find more information on that matter, but thanks for your input already.
here in the states, if you're not bein monitored daily with dosimetry, your dosage is zero. You can try to get a pocket dosimeter whitch you can use to tell how much exsposure you picked up during the day. Are you dealing with millirems like we do in the state, or microsevents? I think 10 micros is equal to a millirem. US laws say that radiation workers are allowed 5000 millirem annually but most of the utilities will limit the workers to 1-2000 MR annually. Anything more than that has to have special permission. If you're not being monitored for exsposure tho, its still zero no matter what. Usually when they do x-rays here, they make everybody except the techs get atleast 100 feet away depending on how mush of the source they have to exspose. Plus they check the levels while doing the shot to see what actually is given off at certain areas for safety.
Thanks a lot for that answer. I understand that without the monitor, i can't claim anything as no exposure amount has been recorded ...
I am dealing with microsevents i guess (micro sv it says on the meter) and was definitely more than 100 feet away (id say 200 to 300 feet - 60 to 100m away, depending on the vessels radiograhed).
The only answer i got from the factory management so far is an extract from the GB code (kind of chinese version of ASME) that states that it is safe up to 40 microsevents/hour.
I hope someone who performs RT can elaborate on or verify what I say but if you do the conversion from Millirems to microvents hopefully 2 Mr =< 40 Mv ...... I am not an RT tech and have only been exposed to the method marginally. However the technicians should have some clue as to the strength of their source as well as type of source and exposure times ETC...... as well as the safe distance for others. I would hope that they barricaded an area for the safety of others. I dont know that a construction code would give you safe exposure levels but I am not familiar with the code you referenced. Hopefully a more knowledgeable person will help you here but good for you for addressing the safety concern for your sake as well as the others in the shop. Radiation is NO JOKE!!
Ok. I looked up the conversion and it's 1 millirem=10 micro sieverts. I don't think that any dose is safe if you're not being monitored for how much you acquire over time. Yes, we all pick up natural background dose but any more than that and you're increasing your chances although really small doses might increase your chance of something by like .00001%. If the code allows 40 microsieverts/hr (4 MR/hr), that means you could pick up 320 MicroSV (32MR) per day for an 8 hr day. If that's the case, you would end up with .01 SV (1 REM) of exposure in a little more than a month. That's usually where the nuke plants here will make you leave for the year. That code is extremely lax over there! You could possibly pick up more than the NRC allows us for a year in less than 6 months. The distance away from the area they're working at is gonna be the best precaution to take. If you was that far away you prolly didn't pick up anything and if you did, it wasn't hardly anything. I'd just say to make sure all workers are as far away as you were when they are doing all the shots, even if it means shutting down some production for an hour. Radiation isn't something to be taken very lightly as nobody really knows what all the long term effects are yet.
I have worked with live source type and X-ray tube radiography in the US. The NRC requires that the exposure outside your barrier is 2 mR per hour or less. Determining how much radiation you are being exposed to is based on a lot of variables including the strength of the source, how long it is active, the amount of shielding it has (collimator), and your distance from it. The inverse square law is your best friend. The farther away you are from the source the weaker the radiation, link here: http://hyperphysics.phy-astr.gsu.edu/HBASE/forces/isq.html
And for $39.95 you can get a pocket dosimeter to get a general idea of how much radiation you are exposed to. This set comes with the charger and two dosimeters so you can place one nearer to the radiation source to make sure it works.