Information Notice No. 82-33: Control of Radiation Levels in Unrestricted Areas Adjacent to Brachytherapy Patients
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C. 20555
August 20, 1982
Information Notice No. 82-33: CONTROL OF RADIATION LEVELS IN
UNRESTRICTED AREAS ADJACENT TO
All Medical Institutions.
During the course of several inspections NRC inspectors have found radiation
levels exceeding regulatory limits in unrestricted areas adjacent to brachy
therapy patients. This notice discusses the applicable regulatory limits and
associated requirements. It is expected that recipients of this Information
Notice will review the information for applicability to their facilities. No
specific response to this notice is required.
Radiation levels in unrestricted areas may not exceed the limits as
specified in 10 CFR 20.105(b)(1) and (2) unless the licensee has been
granted an exemption by demonstrating at the time of applying for a license
or amendment that the requirements of paragraph 20.105(a) will be met. This
exemption must be stated as a specific condition of the license.
Treatment of patients with brachytherapy sources may result in a situation
where the public may be exposed to unnecessary radiation. Insufficient
distance between the restricted and unrestricted areas and a lack of
shielding material in brachytherapy rooms has, in some cases, resulted in
the existence of levels of radiation greater than the permissible limits
specified in 10 CFR 20.105(b)(1) and (2). "Adjacent areas" may include
adjacent rooms and hallways as well as areas on floors above and below the
brachytherapy patient's room,.
The regulations require that, unless an exemption under paragraph 20.105(a)
has been granted, radiation levels may not exist in unrestricted areas so
that, if an individual were continuously present in the area, it could
result in that individual receiving a dose in-excess of 2 millirem in any
one hour or 100 millirem in any seven consecutive days. It is important to
note that compliance must be established with both paragraph 20.105(b)(1)
and (2). As an example, if a hospital treated a sufficient number of
brachytherapy patients to maintain continuous occupancy in one room and
radiation levels in adjacent unrestricted areas were greater than 0.6
millirem/hour, the facility would be in violation of paragraph 20.105(b)(2).
Specifically, a situation would exist where an individual who continuously
occupied the unrestricted area might receive more than 100 millirems in
seven consecutive days.
August 20, 1982
Page 2 of 2
In establishing compliance with paragraph 20.105(b)(1) and (2), it is
necessary to conduct a survey as required by paragraphs 20.201(a) and (b).
An evaluation of the radiation hazard must be made that, if appropriate,
would include measurements of the levels of radiation. In the event that
radiation levels greater than permissible levels are encountered, action
must be taken to reduce the level. Action might include increasing the
distance between the patient and the unrestricted area or the use of
portable shields. After employing such methods, a survey must again be
performed to assure that radiation levels in adjacent areas are below the
permissible limits. Records of these surveys must be maintained as required
by paragraph 20.401(b).
No written response to this information notice is required. If you need
additional information regarding this subject, you should contact the
Regional Administrator of the appropriate regional office.
L. I. Cobb, Director
Division of Fuel Facilities, Materials
and Safeguards, IE
Technical Contact: C. Yaczko
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