Radiation Safety Committee
Margaret Telfer Building K07
Telephone +61 2 9351 7722
Facsimile +61 2 9351 5868
File Reference: 2006/2525
email howarda@usyd.edu.au
30 July 2008
INFORMATION SHEET
No. 8
REMOVAL & DISPOSAL OF EQUIPMENT FROM
RADIOISOTOPE LABORATORIES
Introduction
This information sheet outlines the procedure required for the removal of
laboratory equipment from areas where radioisotopes have been used.
The removal may be either for disposal as general waste, or for relocation to
another laboratory.
The aim of this procedure is to ensure that equipment:
1. Does not contain unwanted radioactive material
2. Is not contaminated with radioactive isotopes,
Fridges and freezers are the most common items that fall into this category. In
most cases they have been used to store radioactive stock solutions or
contaminated research specimens.
Responsibilities
It is the responsibility of the chief investigator or laboratory manager to:

Ensure that contaminated items are decontaminated prior to their removal
from the radioisotope laboratory.

Make arrangements for any unwanted sources to be removed from the
equipment and appropriately stored or disposed of.
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Radiation Safety Committee
Margaret Telfer Building K07
Telephone +61 2 9351 7722
Facsimile +61 2 9351 5868
File Reference: 2006/2525
email howarda@usyd.edu.au
30 July 2008
1. Remaining Radioactive Sources
The chief investigator or laboratory manager must conduct a thorough visual
inspection of the inside of the fridge or freezer to confirm that no material is
present. Particular attention should be paid to door compartments and trays in
the bottom of the unit.
2. Contaminated Equipment
In order to conduct an accurate assessment of any contamination, all isotopes
previously used in the area must be known. List the isotopes used, their
activities and the date last used in Attachment 1.
After identifying what isotopes have been used in the area, select a suitable
radiation contamination meter to check if there is any residual contamination.
This direct monitoring method is appropriate for the detection of gamma emitting
isotopes such as I-125 or the higher energy beta emitting isotopes such as P32
and P-33. Lower energy S-35 & C-14 can also be detected by this method if the
monitor has the appropriate energy response.
This direct survey method is however not appropriate for low energy beta
emitting isotopes, such as tritium [H-3].
If H-3 has been used in the laboratory the equipment must be wipe-tested and
counted in a liquid scintillation counter.
If alpha emitting isotopes have been used contact the University Radiation Safety
Officer before proceeding.
 Measurements using a contamination meter.
Contamination measurements should be conducted at 10 mm above the
equipment’s external & internal surfaces [fridges & freezers].
This will give a reading in counts per second [CPS].
Details of monitor used, who conducted the survey, the date of the survey and
the CPS readings should be recorded on the Contamination Measurement
Results form in Attachment 2.
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Radiation Safety Committee
Margaret Telfer Building K07
Telephone +61 2 9351 7722
Facsimile +61 2 9351 5868
File Reference: 2006/2525
email howarda@usyd.edu.au
30 July 2008
 Wipe testing
Monitors will not detect low energy beta. The most commonly used low energy
beta source in the University is tritium [H-3].
The method used to confirm that there is no contamination on surfaces from
H-3, is to wipe the surface and count the sample in a liquid scintillation
counter.
The method is as follows:

Wipe surfaces for removable contamination by rubbing a moist 25
mm filter paper disc over approximately 100 cm 2 of the test area.

Use a grid of approximately 1 meter2.

Analyse wipe tests in a liquid scintillation counter [many counters will
count for both H-3 & C-14].

Attach printout from counter!
Remedial Action
1. Where radioactive sources are present they must be identified, and
removed from the equipment. Where possible they should be disposed of
through the waste system otherwise placed into long term storage.
2. Where surface contamination is detected the equipment must be
decontaminated. The goal is to remove all contamination. This may require
the monitoring/counting/decontamination process to be repeated several
times.
If detectable contamination remains after 3 such attempts, advice from the
University Radiation Safety Officer should be sought. Equipment that is
unable to be completely decontaminated may be able to be disposed of
through the Hazardous Waste service.
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Radiation Safety Committee
Margaret Telfer Building K07
Telephone +61 2 9351 7722
Facsimile +61 2 9351 5868
File Reference: 2006/2525
email howarda@usyd.edu.au
30 July 2008
Clearance
1. Radioactive Sources
The equipment was inspected and found:

Not to contain a radioactive source OR

Had any radioactive material removed
The equipment is safe to dispose of as general waste.
2. Contaminated Equipment.

Test Specification:
All accessible external & internal surfaces of the equipment were
monitored at 10 mm from surface using a contamination monitor OR
wipe tested and counted if low energy  sources were present.

Acceptance Specification:
Only equipment with no detectable surface activity is to be cleared
for disposal as general waste
There was no indication of any radioactive contamination by  or  emitting
isotopes on any external or internal surfaces of the equipment.
The equipment is safe to dispose of as general waste.
Chief Investigator/Laboratory Manager:
{insert name}
University Radiation Safety Officer:
Howard Ackland
Report Date:
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Radiation Safety Committee
Margaret Telfer Building K07
Telephone +61 2 9351 7722
Facsimile +61 2 9351 5868
File Reference: 2006/2525
email howarda@usyd.edu.au
30 July 2008
ATTACHMENT 1
RADIATION SOURCES USED IN THAT AREA
Laboratory:
Building:
EPA Registration Number:
The following isotopes were used in this laboratory.
Isotope
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Maximum Activity
[in MBq]
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Date last
used
Created on 13/11/2008 10:31:00
Radiation Safety Committee
Margaret Telfer Building K07
Telephone +61 2 9351 7722
Facsimile +61 2 9351 5868
File Reference: 2006/2525
email howarda@usyd.edu.au
30 July 2008
ATTACHMENT 2
CONTAMINATION MEASUREMENT RESULTS
Equipment:
Model No:
Serial No:
Surveyed by:
Date:
* POSITION MONITORED
Monitor[s] used:
CPS
Background:
..………. cps  ………... cps
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