What is a wipe test in nuclear medicine?
Routine wipe tests is a test to check working surfaces for contamination that might end up on a person’s clothes, hands or food. When performed regularly, these tests assure that any sloppy behavior will be detected early so that it can be corrected.
How do you do a wipe test in nuclear medicine?
- Use cotton swab to take several samples from different areas within the lab.
- At least one wipe in storage area.
- Place samples in separate vial or envelope.
- Label each vial or envelope noting the location of the sample.
- Fill out “Laboratory Wipe Test Report”
How often should wipe tests be performed?
Wipe tests are to be performed bi-monthly in general radiation laboratories, three-monthly in counting rooms and more frequently wherever risks may be higher.
What is the surface contamination limit for a wipe test?
220 dpm/cm2
If wipe test results indicate that removable contamination levels exceed 220 dpm/cm2, Health Physics shall be notified immediately.
What does a wipe test counter do?
A wipe test counter is a device used to measure for possible radioactive contamination in a variety of environments. When using radioactive materials it is necessary to test for accidental contamination, whether from use of liquid unsealed sources or to check for leaking sealed sources.
What is the limit of a radioactive package wipe test?
10CFR Part 20 requires that all packages containing radioactive material except exclusive gaseous and Special Form shipments must be wipe tested on the exterior of the package to check for removable contamination. The limit is 22 dpm/cm2 over 300 cm2 or 6600 dpm/300 cm2. This includes limited quantity packages.
How frequently do sealed radioactive sources need to be leak tested?
(1) Each sealed source (except an energy compensation source (ECS)) must be tested at intervals not to exceed 6 months. In the absence of a certificate from a transferor that a test has been made within the 6 months before the transfer, the sealed source may not be used until tested.
What type of detector is a well counter?
sodium iodide crystal detector
A well counter is a device used for measuring radioactivity in small samples. It usually employs a sodium iodide crystal detector. It was invented in 1951 by Hal Anger, who is also well known for inventing the scintillation camera.
What is the external contamination package limit?
10CFR Part 20 requires that all packages containing radioactive material except exclusive gaseous and Special Form shipments must be wipe tested on the exterior of the package to check for removable contamination. The limit is 22 dpm/cm2 over 300 cm2 or 6600 dpm/300 cm2.
What is a leak test for radiation?
The use of the smear test for detecting leaks in radioactive sources is based on the assumption that some of the radioactive material in a source can pass through a leak hole and be deposited on the outer surfaces of the source where it can be detected as transferable activity.
Why is wipe sampling important in radiation protection?
The wipe sampling is an important tool in controlling the quality of the workplace in nuclear and radioactive facilities. Although radioprotection regulations establish quantitative limits, the practice in the radiation protection routine is to use wipe sampling as a qualitative measurement.
What are the requirements for a wipe test?
The wipe sample must be analyzed for radioactive contamination. The analysis must be capable of detecting the presence of 185 Bq [0.005 microcuries] of radioactive material on the test sample and must be performed by a person approved by the Commission or an Agreement State to perform the analysis.
What are the NRC requirements for a wipe test counter?
Licensees must, at a minimum, choose a measurement system with an MDA equal to, or less than, that required by applicable NRC regulations. Licensees may either develop their own procedure or follow the manufacturer’s instructions for the calibration of the wipe test counter and the check of the MDA.
How are wipe tests used to detect contamination?
Wipe tests uses a disc of an absorbent material like paper, cloth, glass fiber filter etc, which are wiped with firm pressure over the contaminated surface to be monitored, removes part of the contaminant that is subsequently assayed by an appropriate method. The contaminants can then be identified and then concentrations determined.