United States Nuclear Regulatory Commission - Protecting People and the Environment

Explosive Detectors for Use at Airports

HPPOS-196 PDR-9111210326

See the memorandum from S. A. Treby to R. E. Cunningham dated April 17, 1987, and the memorandum from R. E. Cunningham to S. A. Treby dated March 19, 1987.

NRC has no direct authority to regulate neutron activated materials from byproduct sources such as californium-252. However, under 10 CFR 20.105 (a), NRC can require the licensee to consider radiation safety from all sources in unrestricted areas. Also see 10 CFR 51.20 (a). This health physics position applies to "new" 10 CFR 20.1301 (c).

Considerations by NMSS raised questions concerning the proposed use of neutron sources to detect explosives in baggage prior to loading onto aircraft. The device contains a Cf-252 source which meets the definition of byproduct material in 10 CFR 30.3 (d). The Cf-252 is used as a source of neutrons to excite nitrogen which is commonly found in explosives. The excited nitrogen-15 undergoes radioactive decay by emission of 10.8-MeV gamma rays. The gamma rays are detected and configured by an array of scintillation detectors on three sides of the baggage. A micro-computer warns a user of the device that the baggage is likely to contain explosives. During this process, some activation of materials both in the baggage and the baggage itself occurs.

The response of OGC to various questions are provided seriatim below:

  1. We find no direct statutory authority for NRC to exercise regulatory jurisdiction over material made radioactive though neutron activation where byproduct material is the neutron source. Such radionuclides would not be byproduct material as defined in AEA Section 11e. Apparently, activation using byproduct material was not contemplated by Congress when it defined byproduct material. NRC does have clear authority under AEA Section 81 to license and regulate the use of Cf-252 to protect the public health and safety from any radiological hazard present and associated with that use; and it remains the fact that the induced radiation created through the use of Cf-252 in the described manner creates a potential exposure of the public to radiation. NRC regulations require the licensee to consider radiation from all sources in radiation safety in unrestricted areas [10 CFR 20.105 (a) or 10 CFR 20.1301 (c)]. Because of this, it is our opinion that NRC has the authority to take into account all the potential radiation effects associated with the described use of licensed material.
  2. It is our understanding from talking with a staff member in NMSS, that the anticipated exposure levels will be far less than the thresholds of exposure addressed in 10 CFR Part 20. Since the anticipated material is not "byproduct" material, no regulatory action would be needed for its "possession" by travelers. This would not preclude placing appropriate licensing conditions on the use of Cf-252 so as to insure no harm to the public health and safety.
  3. Whether the public should be informed that materials within their baggage may be subject to activation because of exposure to the Cf-252 source appears to be more a public relations policy decision rather than a legal question. The desirability of fully informing the public may be offset by the possible unreasonable fear of "radiation exposure." Having said this, in our opinion open candor would be the preferred policy.
  4. Agreement States, having been given authority over licensing the use of byproduct material, would have the authority to license the roposed use.
  5. The proposed licensing action does not appear to fall within the categorical exclusion contained in 10 CFR 51.22; nor on its face does it appear to meet the criteria requiring an environmental impact statement as set out in 51.20 (b). Therefore, an environmental assessment must be made pursuant to 51.21 unless the Commission, in the exercise of its discretion, determines that the licensing action should be covered by an environmental impact statement [51.20 (a) (2)]. The environmental assessment would be made and further processed in accordance with 51.25, 51.30, etc.

Regulatory references: 10 CFR 20.105, 10 CFR 20.1301, 10 CFR 51.20, 10 CFR 51.22

Subject codes: 11.3, 11.5, 12.9

Applicability: Byproduct Material

Page Last Reviewed/Updated Tuesday, June 16, 2015