Explanation of Terms
When completed correctly, the log will accurately show the undecayed activity remaining in the lab for each approval number. Waste tags and semi-annual inventory can be completed by transferring information directly from the appropriate column of this Use Log.
Approval Number:
When a shipment of radioactive material arrives at OSU, it is assigned an approval number by Radiation Safety. This number is used to track the receipt, use and disposal of each shipment of radioactive material while it is under OSU's radioactive materials license. Approval numbers are used on receipt records, semi-annual inventories, and waste tags.
Note: all orders for radioactive material must be pre-approved by calling Radiation Safety at 7-2227.
Total Volume &Concentration:
The volume (µl) and concentration (µCi/ml) of the original stock solution. These values are not provided by Radiation Safety. However, you MUST fill in these values if you are tracking isotope use by VOLUME (µl) instead of by activity (µCi or mCi).
Receipt Date:
Isotopes with short half-lives are usually shipped so they arrive with slightly more activity than was ordered. The Assay Date is the date when the isotope activity will decay to the value indicated in Ordered Activity, e.g. an order for 250 µCi of P-32 may arrive at OSU with a receipt activity of about 300 µCi. It will decay to the Ordered Activity of 250 µCi on the Assay Date. For long-lived isotopes such as C-14 and H-3, the ordered and receipt activities are the same.
Note: isotope inventories should be determined by subtracting disposals from the Ordered Activity, not the receipt activity, e.g. using the values in the example above, activity remaining in the lab would be determined by subtracting disposals from 250 µCi (not the receipt activity of 300 µCi). This method of inventory accounting was adopted as the easiest and most accurate method for keeping consistent inventory records.
Vial Wipe Test:
The removable activity found on the primary stock vial, in disintegrations/minute (dpm). This is determined by Radiation Safety by wiping the vial with a filter paper and measuring the removable activity with an appropriate instrument, such as a Geiger Counter. "0" indicates that no removable contamination was found above the detection limit for the instrument.
Vial Dose at Contact and at 1 foot:
The radiation field around the stock vial in mrem/hr, measured at contact (without geometry correction), and at 1 foot from the vial. This measurement is for an unopened vial. For beta emitters such as P-32, the contact dose rate may be as much as 1000 times greater for an opened vial, depending on the amount of shielding provided by the stock vial.
Date &User Name:
Date material was removed from stock vial or placed in waste, and initials of the person recording the transaction.
Use:
Amount of material removed from stock vial, recorded in units of activity such as mCi or µCi, or volume in µl. If you're using volume to track inventory, make sure Total Volume and Concentration (in µCi/ml) are entered at top of form.
The "Amt. Left" column indicates the activity or volume that remains in the stock vial. The value is determined by subtracting all the values in the Used column from the Ordered Activity.
Circle the unit for activity that is being used (mCi, µCi or µl).
Disposal:
Amount of material that is placed in the waste container. Record the activity or volume as instructed in "Use" above.Record the undecayed activity placed in each waste container (e.g. short-lived aqueous carboy, short-lived dry waste drum). If multiple containers are used for the same waste type, indicate which waste container was used (e.g. by location) in the Comments section.