Facility & Company Information > Canada
CANDU & H3
Sun Dog:
--- Quote from: stormgoalie on Aug 30, 2010, 02:14 ---Here we use a negative pressure, half mask, air purifying respirator with a specific cartridge that is wetted prior to use to absorb H3 present in atmosphere. This is only used at lower levels as ~50% of your H3 exposure is through the skin, at high levels we use an air supplied plastic suit with a hood...
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Please have patience with me. I am ignorant about the ways of commercial power north of the border.
What is the filter media in this "special cartridge"? Did the manufacturer designed the cartridge to be wetted? What is it wetted with? Do you assign a PF for this respirator/cartridge combo? If you do, how do you account for the evaporation of the wetting agent, and the reduced effectiveness of the cartridge? Do you have a bioassay program to assess tritium intake/exposure? Why the half-face? Why not a FF (since by your estimate 50% of tritium exposure is by skin absorption)? What other protective equipment is required (gloves, coveralls, etc.)?
Already Gone:
--- Quote from: Sun Dog on Aug 30, 2010, 03:39 ---Please have patience with me. I am ignorant about the ways of commercial power north of the border.
What is the filter media in this "special cartridge"? Did the manufacturer designed the cartridge to be wetted? What is it wetted with? Do you assign a PF for this respirator/cartridge combo? If you do, how do you account for the evaporation of the wetting agent, and the reduced effectiveness of the cartridge? Do you have a bioassay program to assess tritium intake/exposure? Why the half-face? Why not a FF (since by your estimate 50% of tritium exposure is by skin absorption)? What other protective equipment is required (gloves, coveralls, etc.)?
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I don't remember what the medium was, but I seem to remember PF of 2. I do not recall ever wetting the cartridge, but it came in a sealed foil package and was only good for about 4 hours. The bioassay was what you might expect. It was a bin full of plastic bottles in every washroom. If your REP required it, you would go once a day, scan the barcode on your TLD, take the barcode sticker from the scanner and put it on the lid of a new plastic bottle, provide about 100ml of last night's Labbatt's, and leave the labeled bottle in the rack. Then someone from Health Physics (separate from Rad Protection) would collect all the trolleys of bottles to the lab and LSC your dose for the day.
FF was not really an option. Unless the H3 levels were really low or the trip really short, we wore the air-fed suit. Considering heat stress, it was a better option.
I don't know how much things have changed since I left, but some areas could be entered in tyveks over street clothes. The use of an air suit, or work in certain areas required that you strip, put on plant-supplied socks, underwear, coveralls, yellow workboots -- all that BEFORE dressing out. On the way out, you passed through about 6 different monitors, stripped, showered, put on your own clothes and shoes, and went through two more monitors to get to the clean zone. You had two lockers -- one for your yellow boots and dirty side stuff, and the other for your street clothes.
CANDU plants are very low dose, low contamination (other than Tritium) and definitely different from a LWR. 98% of my dose was from H3.
http://www.nukeworker.com/study/hp/CANDU_RP_study_info.pdf
Rennhack:
If you would like to read more about the US DOE approach, read this:
DOE HDBK-1105-2002 Radiological Training for Tritium Facilities
mostlyharmless:
Here at srs, at one of the few tritium factories in the country,plastic suites are the norm. If not then street clothes are good. Lots and lots of bioasseys. The hazard is low compared to most that we encounter. The tritium good practice handbook Renhack suggests is good. If you really want to know I will contact folks who deal with tritium,both elemental and oxide( it makes all the difference) every day and get back with you.
retread:
SunDog, why did you change your avatar? The cute pug was the only reason you had any positive karma. You're in for it now!! :P :P
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