Answer to Question #656 Submitted to "Ask the Experts"

Q

As we know, 10 CFR 20.1301 gives dose limits to the general public. However the wording says it excludes exposure from individuals treated and released in accordance with 35.75. What is the regulatory guidance, for example, in the case of a patient readmitted after receiving a therapeutic dose? Is it 2 mrem in any one hour? 1301 seems to only address new construction or process management. All comments are appreciated. Thank you.

A

10 CFR 35.75 allows a licensee to release from its control any individual who has been administered radiopharmaceuticals or permanent implants containing radioactive material if the total effective dose equivalent to any other individual from exposure to the released individual is not likely to exceed 5 millisieverts (0.5 rem). Table 1 of Regulatory Guide 8.39, "Release of Patients Administered Radioactive Materials," gives quantities that allow release based on conservative assumptions. However, the licensee also has the option of doing a case-specific calculation. The question concerning readmission is similar to a question raised in the statements of consideration (SOC) for 10 CFR 35.75 (62 FR 4120): Comment. One commenter asked whether a patient who was releasable but was still hospitalized for other reasons would still be considered under the licensee's control. Response. Once a licensee has authorized the release of the patient, there is no need to keep the patient under licensee control for radiation protection purposes if the patient remains hospitalized for other reasons. However, good health physics practice would be to continue to make efforts to maintain doses to people at the facility as low as reasonably achievable. This same response would hold true if the patient had been released in accordance with 10 CFR 35.75 and subsequently readmitted. The SOC goes on to clarify that licensees who know about special circumstances may need to factor those circumstances into their calculations to determine the releasability of that particular patient: Comment. One commenter said that its facility treated many foreign patients . . . [who] may leave the hospital and immediately board a plane. . . . Response. In special circumstances, such as when a released patient would immediately board an airplane and would therefore be in close contact with one or more individuals, it may be necessary to base the release on a more realistic case-specific calculation. . . . Thus, if a licensee knows in advance that a treated patient is likely to be readmitted, and the licensee is opting to do a case-specific calculation to determine releasability, the licensee may need to factor this special circumstance into its calculation. R. Joseph DelMedico U.S. Nuclear Regulatory Agency