Management of
Radioisotope Laboratory
and Use Area
I.
Laboratory
and Radioactive Materials Use Areas Security:
Radioisotope sources and radioactive wastes must be stored in a secure
area. Therefore, it is required that radioactive material
laboratory and use areas' doors must be closed all the time, and locked
when no one is in the laboratory. Failure to do so constitutes a
violation of the University's NRC License, and may result in a hold on
radioactive materials purchases and possible permit close out.
II.
Shielding of Radioactive Sources:
 Appropriate shielding must be provided so
that radiation exposure rate from radioisotope sources is less than 2.5
mR/hour in any controlled area and less than 0.25 mR/hour in any
uncontrolled area. Radiation exposure rates must be maintained as low
as is reasonably achievable within these limits. 3-sided Lucite shields
are available for P-32 short half-life solid waste containers from RPD.
To order a Lucite shield for your lab, or for more information on
available shielding materials and techniques, contact the Radiation
Protection division at 612-625-1682.
III.
Radioisotope Laboratory/Storage Areas Posting:
| All areas where
radioactive materials are stored or used including refrigerators,
freezers, hoods etc, must be labeled with a Radioactive Materials
Caution Label (see picture to the side), to inform others of
radiation hazard within the laboratory. To request a "Caution
Label" for your laboratory or equipment, contact our office at
7273, or by email at ehso@d.umn.edu.
Click image to view a larger size version
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IV.
Record Keeping and Inventory:
An inventory of all radioactive
materials under the use permit must be submitted to the RPD at the end
of each calendar quarter. This inventory must include the total, decay
corrected activity of each radioisotope in stock form as of the end of
the quarter, plus the total decay corrected activity of each
radioisotope in waste form as of the end of the quarter
- In order to maintain accurate
radioisotope inventory records, All users of radioactive materials are
required to keep on file radioactive waste inventory records,
quarterly report records and employee training records.
The RPD staff and the NRC audit these records annually and during
inspection of the University NRC license.
- Use the Radioactive Waste Inventory Form to generate
and maintain an accurate waste inventory. The use of this form will aid
in tracking small amounts of radioactive stock material from the vial
to ultimate disposal in a waste container. Once full, form should be
used to determine total activity of each radioisotope in any individual
waste container.
- Use the quarterly report form to generate accurate
quarterly reports and records.
- Use the employee training form to maintain accurate employee training records.
V.
Laboratory and Use Area Surveys:
Contamination survey results, and in
some cases exposure rate survey results, must be submitted with the
Quarterly Report. All radioisotope use areas for which the permit
holder is responsible must be accounted for on the Quarterly Report. A
diagram of your areas, showing where smears were taken, must also be
included with the survey results. Identify the area by using both the
building name and room number(s).
A. Frequency of Surveys
- All active, radioisotope areas that
are classified as "Low Risk", must have contamination surveys completed
each month, and the results submitted with the Quarterly Report. Refer
to your copy of the radioisotope use permit for the risk classification
of your areas.
- All restricted areas where there
was no handling of radioactive materials during the entire calendar
quarter must have one survey completed during that quarter. This survey
should be taken in the vicinity of any stored radioisotopes (e.g.,
refrigerator, freezer, cold room shelf, etc.), or radioactive waste
containers.
B. Survey Information Requirements
- Surface contamination smear surveys
are required for all restricted radioisotope areas. The surveys should
be conducted using dry filter paper and analyzed with the appropriate
counting instrument (liquid scintillation or auto-gamma counter). All
results must be reported in disintegrations per minute (DPM).
- Record on the survey form which
radioisotopes were used in the area.
- Record what counting efficiency was
used in determining DPM.
- Record the make and model of the
counting instrument.
- Number the smears and indicate on
the survey map where these smears were taken.
- Describe their locations in the
SMEAR SURVEY DATA column. Locations should include those where
radioactive materials are stored, handled, and/or discarded. For
example (work station bench top or fume hood working surface floor in
front of work station, refrigerator/freezer shelves and handles, floor
in front of refrigerator/freezer etc.)
- Record the DPM per 100 square
centimeters for each smear. (DPM = [smear CPM - background
CPM]/[fractional counting efficiency].
For more information on smear surveys
consult the Quarterly Report Instructions
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