Information Notice No. 84-43: Storage and Handling of Ophthalmic Beta Radiation Applicators
SSINS No.: 6835
IN 84-43
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C. 20555
June 7, 1984
Information Notice No. 84-43: STORAGE AND HANDLING OF OPHTHALMIC BETA
RADIATION APPLICATORS
Addressees:
All medical licensees.
Purpose:
This Information Notice is provided as notification to licensees of recent
findings where strontium-90 eye applicators were stored with radiation
levels in excess of regulatory requirements and possibly unnecessarily
exposed the public to radiation. Recipients are expected to review the
information for applicability to their facilities and consider actions, if
appropriate, to preclude similar problems occurring at their facilities.
However, suggestions contained in this information notice do not constitute
NRC requirements and no specific action is required.
Description of Circumstances:
During the past 2 years, Nuclear Regulatory Commission (NRC) inspectors have
observed several beta applicators in closed storage containers with surface
dose rates (from bremsstrahlung) in the range of 40-95 millirems/hour. Some
of these boxes housing stronium-90 were stored so that radiation levels in
unrestricted areas could exceed the requirements of 10 CFR 20.105(b).
Measured dose rates were found to be greater than 0.6 millirem/hour at 18
inches from area boundaries. Therefore, if persons were continuously present
in the area for 7 consecutive days, doses might exceed 100 millirems.
The primary reason that the radiation levels are above 0.6 millirems/hour at
18 inches from boxed applicators is that the loose pieces of aluminum placed
inside the boxes on the bottoms and sides by the manufacturer are often
discarded by the recipients of the eye applicators. The aluminum pieces
(called "donuts") provide the necessary shielding to prevent excessive
bremsstrahlung radiation.
Discussion:
The following three alternative actions have previously been found to
provide appropriate levels of protection:
1. Radiation surveys of the applicator in its closed storage container
demonstrating the maximum radiation levels at 12 inches from each
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IN 84-43
June 5, 1984
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of the container surfaces in accordance with the license terms and 10
CFR 20.201. Any reading exceeding 5 millirems/hour at 12 inches from
the container surfaces, requires posting the room or area as required
by 10 CFR 20.203(e). Storage and handling procedures must ensure that
persons in unrestricted areas are not exposed to radiation levels in
excess of the limits specified in 10 CFR 20.105(b). Some instances of
high radiation levels have been the result of missing aluminum donuts
from the boxes.
2. Shielding such as aluminum, wood, lucite, etc. which reduces the
readings in unrestricted areas to less than 0.6 millirem/hour at 18
inches from the shielding.
3. Storage of the applicator and container in a secured area that is
accessible only to the authorized applicator user and that limits the
dose rate to the public to less than 0.6 millirems/hour at 18 inches
from accessible surfaces of the storage area.
No written response to this information notice is required. If you need
additional information regarding this matter, please contact the Regional
Administrator of the appropriate NRC regional office or this office.
J. Nelson Grace, Director
Division of Quality Assurance, Safeguards,
and Inspection Programs
Office of Inspection and Enforcement
Technical Contact: Jack Metzger, IE
(301) 492-4947
Attachment:
List of Recently Issued IE Information Notices
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