AU’s are responsible for ensuring that monitoring is performed both during and after each use of radioactive materials. The type of monitoring and surveys shall be appropriate for detecting the radionuclide in use. The area covered by the survey shall be sufficient to assure that radioactive material remains controlled and within the radionuclide work or storage area.
All surveys shall include
- Measurement of surface contamination with the appropriate instrument,
- Measurement of removable contamination by swipes.
WHEN TO DOCUMENT A SURVEY
Although routine surveys shall be performed during and after every use of radioactive materials, not all surveys need to be documented. Surveys shall be documented at least on the frequency given in Table 1. Surveys shall also be documented every time contamination or radiation action levels are found, either by routine survey or as the result of a spill; refer to Table 2 and Table 3 below for survey levels and required accompanying actions.
INSTRUMENTATION
As of October 1, 2022, MU EHS RSS no longer provides calibration services for detection equipment as required by 10 CFR 20.1501 and 10 CFR 35.61. Both handheld and benchtop detectors must be calibrated annually or upon repair. The AU is responsible for coordinating calibrations and replacing batteries. More information on the calibration process can be found on the Meter Calibrations page. For additional information on using survey meters and swipe counters, see instructions detailed on Surveying the Lab for Contamination.
Table 1.
When do I need to document a survey? (Use or storage of potentially uncontained materials) | |||
|---|---|---|---|
| Action Required | Daily | Weekly | Monthly |
| Instrument survey and Removable Contamination survey | Greater than 5 mCi of activity handled or in use at any one time | Greater than 1 mCi of activity handled or in use at any one time | Active Authorization |
- Monitoring shall be performed after each use of uncontained radioactive materials and in the case of spills. Such surveys document the event and the effectiveness of corrective action or cleanup.
- Surveys shall be documented on at least the frequency indicated above.
- Surveys shall also be documented in the case of contamination or radiation levels in excess of action levels listed in Tables 2 and 3 (including documentation of corrective actions and results).
- Instrument surveys are not required for tritium (H-3) or as stated in Special Conditions specifically approved for the authorization.
- If active Authorization does not possess radioactive material, then monthly documented survey shall document that the survey meter(s) and LSC (or other swipe counters) are calibrated and functioning properly.
Table 2.
Removable Contamination Survey Levels and Actions for Beta and Gamma Emitters (Swipes in dpm/100 cm2) | ||||
|---|---|---|---|---|
| Contamination of | Less Than 200 (or Less Than 20 for Alpha Emitters*) | Greater Than 200 and Less Than 2000 | Greater Than 2000 and Less Than 20000 | Greater Than or Equal to 20000 |
| Personnel and/or clothing; areas outside restricted areas | ALARA | Control and Report immediately | Control and Report immediately | Control and Report immediately |
| Floor in restricted area; areas outside of Radioisotope Work Area | ALARA | Decontaminate, document, and report by next work day | Control and Report immediately | Control and Report immediately |
| Designated Radioisotope Work Area | ALARA | ALARA | Decontaminate and Document | Decontaminate, Document, and Report by next work day |
| Labeled Equipment, Apparatus, or Appliances | ALARA | ALARA | ALARA | Decontaminate, Document, and if greater than 200,000, report by next day |
*Isotopes with alpha emissions must have removable contamination limits of less than 20 DPM to remain ALARA. Anything greater shall be decontaminated and documented.
Note: Report any spill involving greater than 1 microcurie (2,200,000 dpm) immediately!
Table 3.
| Instrument Survey Levels and Actions | ||
|---|---|---|
| Action | Instrument Surface Contamination Survey | Instrument - Area Radiation Level Survey |
| Decontaminate or shield, and document | Greater than or equal to 0.3 mR/hr @ 1 cm from surface | Greater than or equal to 0.2 mR/hr @ 30 cm |
| Control and Report Immediately | Greater than or equal to 3.0 mR/hr @ 1 cm from surface | Greater than or equal to 2.0 mR/hr @ 30 cm |
Page last updated on August 31, 2022.