DOE time basically counts the same as power plant time. The distinction is not based on where you worked, but what you did. If you were only required to count air samples as a part of your duties as a chemistry tech, that time wouldn't count at all. But if you are a chem tech who gets transferred to RP during outages, you can count all of that time. Likewise, if you worked in an Anti-C laundering facility and spent most of your time sorting, washing and folding, and some of your time doing routine surveys of the facility - then only the time doing surveys counts.
You don't have to keep a log or anything. Just figure what percentage of your time is devoted toward Health Physics and use that to determine the total time.
There are some exceptions to this, at least I've experienced and seen some exceptions when it comes to individual plant qualification criteria - some plants will give you 1 for 1 as far as counting DOE HP towards commercial time, some - not many. Most work it this way, and remember this is just a general "rule", at least from what I have observed in trying to staff them.
18.1 sites will generally grant 1 for 1 up to 12 total months DOE experience to count towards commercial time, that 12 mo's plus 12 mo's of commercial time will generally make a tech qualified to be an 18.1 SHP at those sites.
3.1 sites will generally grant 1 for 1 up to 24 mo's exp DOE to count towards commercial HP time, so that plus 12 mo's commercial will allow a tech to work as a 3.1 at those sites.
However I have staffed 18.1 sites that will grant up to 24 mo's DOE exp. towards commercial and 3.1 sites that will grant 36 mo's DOE exp. towards commercial. Like wise I have staffed sites that wont count DOE time or will only take minimal time, 18.1 sites giving up to 6 mo's and 3.1 sites giving up to 12 mo's credit.
Overall the set standard of qualifying resumes falls to the minimum of the ANSI standards, then to the Plant standards. For example I have sites that I staff that won't consider you a "Senior" unless you have 5 years experience. Its all case by case, plant by plant ranging from the standard ANSI quals to "stricter" quals based on the individual plants program.
Sorry if I made it more confusing, but thats the nature of the beast.
Eric