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radiological conditions
wlrun3@aol.com:
...are these radiological conditions standard in the industry...
Cavity Decon (50 OW - 5 CW) 4 = 180 mrad/hr/100 cm^2
SG Channel Head 10 rem/hr GA / 1 hr/60 min = 16.7 mrem/min
Protected Area Yard = 10 urem/hr
retired nuke:
I don't know about standard, but none of them would raise my eyebrows if I was to encounter them at an appropriate time.
First S/G I went into was about 3x that hot...
Depending upon the cavity, SFP water chemistry and fuel conditions, I've seen worse in a cavity, seen better...
Seen PA yard from 7-30, depending how close you were to the Turbine....
But those numbers are in a normal range.... :)
Bonds 25:
While 10 micro rem/hr is very low in general, it seems a little high for a PWR (no turbine shine). I would say 10 rem/hr at the channel head is a little high for today's standards (of course Ive seen a lot higher) 120 mrad/100cm2 seems about right as far as pre-cavity decon levels go.
Already Gone:
--- Quote from: Bonds 25 on Mar 07, 2009, 01:51 ---That explains 11 Rem/hr contact being the hottest CRD pulled while I was covering changeout under vessel. My very next outage was Quad Cities, 400 Rem/hr. I did take my hottest smear ever while at Fermi though, RWCU valve inside the steam tunnel....80 Rad/hr/100cm2. Valve looked like part of a sewer line.
--- End quote ---
Have I been out of the tech business too long,. or have they come up with a new meter? The last open window instrument I ever used only went up to 50 R/hr. How could you get 80 Rad/hr?
Already Gone:
--- Quote from: wlrun3 on Mar 07, 2009, 08:55 ---
...are these radiological conditions standard in the industry...
Cavity Decon (50 OW - 5 CW) 4 = 180 mrad/hr/100 cm^2
SG Channel Head 10 rem/hr GA / 1 hr/60 min = 16.7 mrem/min
Protected Area Yard = 10 urem/hr
--- End quote ---
Bill, most of the time that 50 OW would be 50 mRad/100cm2 since it is not common to BCF a smear. So, based on my fading memory, this is s pretty clean cavity post refuel. The channel head dose rate is at the low end of the range (considering that they were 50 - 100 R/hr back when I started the business, and 500mR/minute was considered relatively low.)
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