The
File
Radioactive Waste Worksheet
is provided to simplify the accounting of radioactive material in each waste form. The Worksheet is an Excel spreadsheet using information from the RADIOACTIVE MATERIAL RECEIPT AND USE RECORD. You may request a formatted copy to be sent via email from Environmental Health and Safety.
Contacts
Steve Stuckmeyer, Director of Environmental Health and Safety, Radiation Safety Officer
541-346-3197
Process
The Worksheet Date is entered as the date the Liquid Waste samples are counted to ascertain activity and is the date entered on the waste tags. The received activity is decay corrected to that date.
I. Nuclide: Enter the nuclide to be calculated. The form will account for multiple shipments received, but each nuclide requires a separate form. Enter the physical half-life in days. This allows the calculation of lambda (l) for the decay equation: A = A0e-lt.
II. Liquid Waste Accounting
A. Date: the Date for counting the Liquid Waste must be the same as the form is dated for decay purposes. Therefore, the date is filled in automatically once the form is dated.
B. 1 ml cpm: count a 1 milliliter sample from the liquid waste container with liquid scintillation cocktail in one of the LS counters to ensure the best efficiency.
C. Bkgd cpm: count a 1 milliliter sample of non-radioactive liquid similar in composition to the waste, i.e. water for an aqueous waste stream.
D. Efficiency: approximate efficiencies are posted for the various nuclides next to the Liquid Scintillation Counters. If there is significant differences in the H# for each sample, the counting efficiency may be different.
E. 1 ml dpm: calculated disintegrations per minute per milliliter
F. Volume (ml): enter the approximate milliliters in the waste bottle. The Nalgene bottle supplied by EH&S is 4000 ml, when filled to the shoulder of the container.
G. Liquid Activity (mCi): calculated activity contained in the waste bottle.
H. Liquid Waste Tag #: enter the waste tag number associated with the sample taken.
III. Solid Waste Disposal Activity: For best accuracy, calculate and dispose of solid waste on the same day as liquid waste.
A. Ship Code: enter the Ship Code for each shipment used since the previous waste collection.
B. Assay Date: enter the Assay Date from the RECEIPT AND USE RECORD.
C. # Days: calculated number of days from the assay date to the date the liquid waste is counted (date entered at the top ofthe form).
D. Activity Ordered (mCi): enter the activity from the RECEIPT AND USE RECORD, it is the quantity ordered from the vendor.
E. Decayed Activity: calculated total activity for the amount received from the vendor on the date entered on the form.
F. Volume Received: enter in milliliters.
G. Amount Remaining: enter the last entry in the Remaining column, which is the amount left in the stock vial. If the stock vial will also be discarded, the worksheet will add this amount to the solid waste disposal activity.
H. Fraction Used: calculated amount of the material used in experiments.
I. Activity Used (mCi): calculated activity used by the date the Liquid Waste was counted.
J. Remaining Activity: calculated activity remaining in the stock vial on form date. May be disposed in Solid Waste if less than 0.1 ml, indicate zero remaining on RECEIPT AND USE RECORD when disposed into waste container.
K. Total Activity Used: the sum of activity of each Ship Code used.
L. Sum of Non-Disposed Stock Vials: enter the sum of the Remaining Activity for each stock vial that will not be disposed with this waste collection.
M. Liquid Activity: carried forward activity from the Total Liquid Activity accounting.
N. Scintillation Vial Activity: enter activity estimated in liquid scintillation vials. When disposing of LSC vials enter at least 0.0001 mCi.
O. Disposal of stock vials: sum of stock vial activity disposed of in solid waste minus activity retained for future use.
P. Total Solid Activity: calculated activity disposed of in the solid waste container. Enter this activity on the waste tag.
Q. Waste Tag #: enter the waste tag number for the scintillation vial disposal and the solid waste tag.
IV. ASSISTANCE Please call 6-3197 or email Steve Stuckmeyer for assistance.