NukeWorker Forum
Career Path => Radiation Safety => Topic started by: Rain Man on Nov 09, 2014, 05:26
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Been a while since I logged in. But I have a question on H3 release criteria. My CRS mode is in gear and can't remember what Mound used but 50K dpm/100 cm2 sticks in my head. NUREG 1757 Volume 1, Revision 1, Consolidated Decommissioning Guidance, Appendix B, Table B.1, Acceptable License Termination Screening Values of Common Radionuclides for Building-Surface Contamination (Attachment 8), states in part:
"an acceptable screening level for unrestricted release for tritium is 120,000,000 dpm/100 cm2. The screening level is based upon a total effective dose equivalent (TEDE) of 25 millirem (mrem) per year."
That seems a bit high to me but it's been some time since dealing with H3. Some input on what release criteria you are currently using or have used in the past would be appreciated.
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Read deeper in 1757 and you will discover there are other criteria which must be facts in place to allow use of the screening values,...
Tritium does have a relatively high release value as an individual nuclide,...
Place tritium into a multiple nuclide distribution, factor in exposure pathways, and the tritium value you will see at DnD projects et al, begins to correspond with your experience on the tritium value allowed,...
Tritium is typically surrogated, albeit we can monitor for tritium as an individual nuclide in certain medias with appropriate protocols and instrumentation,...
does that help?!?!?
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I'm no expert but this is what little I know:
10 CFR Part 50 Appendix I has 3 mRem ALARA objective for Power Plant Effluent
10 CFR 20.1301(e) 25 mRem standard for Nuclear Plants.
10 CFR 20.1301(a)(1) 100 mRem for everywhere that's not a power plant.
I recommend reading DOE-HDBK-1129-2008 DOE HANDBOOK TRITIUM HANDLING AND SAFE STORAGE: (http://energy.gov/sites/prod/files/2013/06/f1/DOE-HDBK-1129-2008.pdf)
10 CFR 835: The surface contamination value for removable tritium is 10,000 dpm/100 cm2.
ANSI/HPS Standard N13.12-1999, Surface and Volume Radioactivity Standards for Clearance, gives the screening level for unrestricted used items with residual levels of tritium on the surface of 600,000 dpm/100 cm, of which no more than 20% or 120,000 dpm/100 cm should be removable (volume screening value of 3,000 pCi/g). These values are currently not endorsed by DOE.
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Look at 10 CFR 30 Appendix B or Part B. A lot of people including regulators are not aware that an "Exit" sign has 23 curies of tritium.
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Look at 10 CFR 30 Appendix B or Part B. A lot of people including regulators are not aware that an "Exit" sign has 23 curies of tritium.
2008 was a watershed year for regulatory sensitivity to tritium outside of the usual suspects (aka commercial nuke power, DOD & DOE),....
courtesy of WalMart, Nebraska and Colorado,...
http://pbadupws.nrc.gov/docs/ML0903/ML090330489.pdf
almost forgot,....
ETD & GR!!!!! ;D