10CFR20.2207 Appx E

[Boilermaker]

Hey guys,
In appendix E, list thresholds for nationally tracked sources.  This is a dumb question, but what is the differences btw category 1 and category 2?  I mean, the obvious difference is the range in the activity, but why give me a range?  If it's a threshold table, then why give me 2 sets of numbers?  Which category is the threshold you observe by? 

[cincinnatinuke]

I dont see a range??  You have Cat 1 which is listed in TBq and Curies and then you have Cat 2 which is listed in TBq and Curies also.  These are different units for the same thing, Activity.

[Boilermaker]

Category 1 gives me a higher threshold than category 2.  Why?  Why are there 2 different thresholds for the same nuclide?  Is this table saying, "if you have something over the amount listed in category 2 than it is considered a nationally tracked source"?  If that's the case, why give me a higher limit in Category 1??

[cincinnatinuke]

I am assuming you are a Radiation Safety Officer or your name is on a materials license.  My understanding, and keep in mind I have been away from this type of work (sealed sources) for 6 months now, is that Nationally tracked sources will be implemented in phases.  First Cateogry 1, then 2, and so on.  Actually, I believe a Cat 2 is a NTS as is a Cat 1, but each category dictated when you had to report your inventories to the NRC.  I believe the intention is to finally one day have every source tracked no matter the size/activity.  I also believe in Canada and most every where else internationally they have already accepted this as pretty common practice. 

Do an ADAMS search on the NRC page for  "ML051100240"

or

go to this link:

http://adamswebsearch.nrc.gov/scripts/rwisapi.dll/@pip1.env?CQ_SESSION_KEY=KDVZVDCILVXU&CQ_QUERY_HANDLE=127114&CQQNUM=2&CQ_CUR_DOCUMENT=21&CQ_RESULTS=YES

and hit the pdf link on item 38. 

[cincinnatinuke]

It seems my link expired... so just do a search on the NRC's ADAMS webpage...or I can just email you the attachment

[RAD-GHOST]

Actually there are three categories: 1, 2 & 3.  The two columns listed for each category, (1 & 2), are simply the conversion from TBq to Curies, (1 TBq = 27.27 Curies).  They aren't ranges; they are threshold values for that category, (at, or above).  Category 3, a US NRC thingy, is established at 10% of cat 2 threshold.  The reasoning, the more you glow the more they want to know!  Tracability and accountability! 

[spentfuel]

(h) Each licensee that possesses Category 1 nationally tracked sources shall report its initial inventory of Category 1 nationally tracked sources to the National Source Tracking System by November 15, 2007. Each licensee that possesses Category 2 nationally tracked sources shall report its initial inventory of Category 2 nationally tracked sources to the National Source Tracking System by November 30, 2007. The information may be submitted by using any of the methods identified by paragraph (f)(1) through (f)(4) of this section. The initial inventory report must include the following information:

Cat 1 sources are more radiotoxic than cat 2 and so on.  Also if your a state licensee you should look at your equivilant regs.  The catagories also have conditions associated with source storage and personel background checks etc. for state licensee's cat 1 sources have a higher level of control and access then to cat 2.

I all has to do with dirty bomb stuff and IAEA harmonization.  If you google Radioactive Sources of Concern you can find many explainations about it for example

http://www.crcpd.org/AnnualMeeting-04/Posters/Poster14_Holahan.pdf

kinda puts it in a nutshell

hope that helps

sf

[cincinnatinuke]

All good answers, but you never did mention how this applies to your current situation.  It is pretty uncommon to have sources this large in activity. 

If I were to ponder a guess, Boilermaker means you are an avid Purdue fan or you do a lot of radiography shots.