Answer to Question #7193 Submitted to "Ask the Experts"

Category: Radioactive Waste Disposal — Disposal

The following question was answered by an expert in the appropriate field:


Can you please let me know about the Nuclear Regulatory Commission (NRC) action levels for air sampler calibration in a radioactive waste area for long-lived radionuclides? Is it more specific for various filters like paper, charcoal, etc.?


Thank you for your question pertaining to air sampler calibration.

If your question is about the calibration of the flow meter of the air sampler, then NRC Regulatory Guide 8.25 and NUREG-1400, both titled "Air Sampling in the Workplace," address this issue. Section 5.2 of Regulatory Guide 8.25 states that flow-rate meters for air samplers should be calibrated annually and after repairs or modifications to the flow rate meter. NUREG-1400 section 5.2.4 specifically addresses the calibration of rotometers and offers an in-depth discussion into the methods and provides references for this calibration. So there is no threshold at which calibration should be performed for flow-rate meters. Like all other instruments used for radiation measurements, they should be calibrated before use for the range of expected conditions.

There is a threshold for when air sampling should be performed, and if using fixed-head air samplers, when air sampling needs to be representative. Table 1 and Table 2 of Regulatory Guide 8.25 provide these criteria, with greater in-depth discussion in NUREG-1400.

Eric W. Abelquist, PhD, CHP

Answer posted on 11 March 2008. The information posted on this web page is intended as general reference information only. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. To the best of our knowledge, answers are correct at the time they are posted. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society.