Control of Radioactively Contaminated Material
See IE Circular No. 81-07 entitled as above and dated May 14, 1981.
This document specifies that the monitoring of items and materials removed from a restricted area should be done with instruments and techniques capable of detecting 5000 dpm/100 cm2 total and 1000 dpm/100 cm2 removable beta / gamma contamination.
IE Information Notice No. 80-22 described events at nuclear power reactor facilities regarding the release of radioactive contamination to unrestricted areas by trash disposal and the sale of scrap material. These releases were caused by a breakdown in the contamination control program including inadequate survey techniques, untrained personnel performing surveys, and inappropriate material release limits.
The recurring problems associated with minute levels of contamination indicated that specific guidance was needed by NRC nuclear power reactor licensees for evaluating potential radioactive contamination and determining appropriate methods of control. Thus, IE Circular No. 81-07 provides guidance on the control of radioactive contamination. Because of the limitations of the technical analysis supporting this guidance, it is only applicable to nuclear power reactor facilities.
Contaminated or radioactive items and materials must be controlled, contained, handled, used, and transferred in accordance with applicable regulations. Items and materials should not be removed from restricted areas until they have been surveyed or evaluated for radioactive contamination by a qualified individual. (A qualified individual is defined as a person meeting the radiation protection technician qualifications of RG 1.8, Rev. 1.) The only exceptions are hand-carried personal effects (e.g., notebooks and flashlights) that are subject to the same survey requirements as the individual possessing them.
Contamination monitoring with portable survey instruments or laboratory measurements should be performed with instruments and techniques (survey scanning speed, counting times, background radiation levels) that are capable of detecting 5000 dpm/100 cm2 total and 1000 dpm/100 cm2 removable beta / gamma contamination. Instruments should be calibrated with radiation sources that have energy spectrum and instrument response characteristics consistent with the radionuclides being measured.
If alpha contamination is suspected, appropriate surveys and/or laboratory measurements capable of detecting 100 dpm/100 cm2 fixed and 20 dpm/100 cm2 removable alpha activity should be performed.
In evaluating the radioactivity of inaccessible surfaces (e.g., pipes, drain lines, etc.), measurements at accessible points may be used. However, this method can be used only if the contamination at accessible points is representative of contamination at inaccessible locations. If this can not be demonstrated, the items should not be released for unrestricted use.
Draft ANSI Standard 13.12 provides useful guidance for evaluating radioactive contamination and should be considered when establishing a contamination control and radiation survey program. [Editorial Note: Draft ANSI Standard 13.12 was never issued in final form and it is no longer considered to be a source of useful guidance.]
Regulatory references: 10 CFR 20.201, 10 CFR 20.301, 10 CFR 20.1501, 10 CFR 20.2001
Subject codes: 7.6, 9.7