As the previous responses, show, this is a complicated topic. Let me provide my own lessons learned on this. I assume that you're a NRC licensee, i.e., either a nuclear power plant or a material licensee in a non-agreement state. If that's the case, 10 CFR 20 does not allow the release of any licensed material, except as an effluent, as allowed in your license, or by transfer to another licensee, such as a radwaste disposal facility. Some states, such as TN, do have release limits.
A common misconception is that if you have an "exempt quantity," or an "exempt concentration," as defined in 10 CFR 30, you can free release that. That's not true. If you read 10 CFR 30, there's really no such thing as an exempt quantity or exempt concentration, only exempt "persons," i.e. a person (a licensee is a "person") can possess an exempt quantity without a license. However, if you have a license, then all of your licensed material is subject to regulation. Some sources, such as smoke detectors, luminous materials, and static eliminators exempt the end user (not the manufacturer or distributor) from 10 CFR 20 requirements. These sources can be free released by the end user. The key is exemption from 10 CFR 20. Exemptions from 10 CFR 30 is not good enough.
Clearly, zero is not a practical release limit. This is translated into "nothing detectable." The question then becomes, "How hard do you have to look?" For surface contaminated materials, the generally accepted answer is a good frisk with a standard frisker, for beta emitters. For bulk contaminated items, such a liquids, sand, etc., the generally accepted answer, as expressed in a "Health Physics Position Statement," is that you have to test such materials to the LLD's generally required for a reactor's environmental monitoring program. These are sometimes difficult to meet, especially for I-131 and tritium.
Another practical concern, if the material is going to a landfill or scrap yard, is that many of these facilities have installed portal monitors with very low setpoints. If your material alarms the monitor, it will generally not be accepted.
All of this emphasizes the importance of waste minimization and controlling what goes into your restricted area.
doctorbill