Radiation Protection Program Update: The Details. July 2010. Update Topics. Changes mandated by Title 10, Code of Federal Regulations, Part 835, Occupational Radiation Protection ( 10 CFR 835 ) How changes affect your work / dose Resources Code of Federal Regulations Federal Registers
Equivalent dose (HT) - the product of average absorbed dose in a tissue or organ and a radiation weighting factor (WR). For external dose, the equivalent dose to the whole body is assessed at a depth of 1 cm in tissue; the equivalent dose to the lens of the eye is assessed at a depth of 0.3 cm in tissue, and the equivalent dose to the extremity and skin is assessed at a depth of 0.007 cm in tissue.
Committed equivalent dose (HT,50)- the equivalent dose received by a tissue or organ over a 50-year period after the intake of a radionuclide into the body. It does not include contributions from radiation sources external to the body.
Committed effective dose (E50)- the sum of the committed equivalent doses to various tissues or organs in the body multiplied by the appropriate tissue weighting factor
E50 = ΣWTHT,50 + wRemainderHRemainder,50
Where WRemainderis the tissue weighting factor assigned to the remainder organs and tissues and HRemainder,50 is the committed equivalent dose to the remainder organs and tissues.
Effective dose (E)
The summation of the products of the equivalent dose received by specified tissues or organs of the body and the appropriate tissue weighting factor (WT)
E = Σ WTHT
Includes the dose from radiation sources internal and/or external to the body. For purposes of compliance with this part, equivalent dose to the whole body may be used as effective dose for external exposures.
Total effective dose (TED)
The sum of the effective dose (for external exposures) and the committed effective dose.
Cumulative total effective dose
The sum of all total effective dose values recorded for an individual plus, for occupational exposures received before the implementation date of this amendment, the cumulative total effective dose equivalent (as defined in the November 4, 1998 amendment to this rule) values recorded for an individual, where available, for each year occupational dose was received, beginning January 1, 1989.
4 E−11 μCi/mL
2 E−13 μCi/mL
In addition to the updates needed to be in compliance with 10 CFR 835, additional updates improve the rigor and quality of the Radiation Protection Program.
Pocket ion chambers (PICs) are prohibited for supplemental dosimetry because of calibration requirements.
Do not use a PIC when radiological controls specify the use of supplemental dosimetry (i.e. entering a high radiation area).
Sealed source training is dependent on the radionuclide, activity, and exposure rates. The training requirements are listed in the table below. In addition, sealed source custodians must be appointed by their supervisor. This can be accomplished by completing a form memo and sending to RPD. Contact RPD x4299 for details.
How this affects you
If you are a sealed source custodian:
Have your supervisor appoint you if you have not done so already.
Brief users on the new training requirements when issuing sources.
If you are a sealed source user:
Check with your custodian or RPD to verify you have the appropriate training.
Notify Radiation Protection at ext. 4299 prior to bringing any radioactive material onsite such as