United States Nuclear Regulatory Commission - Protecting People and the Environment

U.S. Nuclear Regulatory Commission

Explosive Detectors for Use at Airports

HPPOS-196 PDR-9111210326

Title: Explosive Detectors for Use at Airports

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


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 proposed 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 Thursday, March 29, 2012