Explosives Searches at Protected Area Portals (Generic Letter 91-10)

				               UNITED STATES
                        NUCLEAR REGULATORY COMMISSION
                           WASHINGTON, D. C. 20555

                                        July 8, 1991


TO ALL FUEL CYCLE FACILITY LICENSEES WHO POSSESS, USE, IMPORT, OR EXPORT 
FORMULA QUANTITIES OF STRATEGIC SPECIAL NUCLEAR MATERIAL


Gentlemen:

SUBJECT:  EXPLOSIVES SEARCHES AT PROTECTED AREA PORTALS
          (GENERIC LETTER 91-10)

This generic letter is being issued to advise you of the results of a 
recently completed study conducted by Sandia National Laboritories (SNL) for 
the Nuclear Regulatory Commission (NRC).  The classified study is entitled 
"Personnel and Package Screening Using a Walk-Through Type Explosives 
Detector."

Under 10 CFR 73.46, licensees are required to conduct explosives searches of 
personnel and hand-carried packages prior to entry into the protected area.  
It is common practice for personnel to bring hand-carried packages into 
walk-through or portal explosives detectors.  This enables a licensee to 
meet the personnel and package explosives search requirements concurrently.  
This procedure is acceptable to the NRC in meeting the explosives search 
requirements of paragraph 73.46.  packages of a questionable nature are 
typically searched with a hand-held explosives detector or via a "hands-on" 
search.

Results of the SNL study indicate an improved search methodology can be 
achieved by directing personnel passing into an explosives detection portal 
to hold hand-carried packages (1) in front of them, (2) a few inches from 
the body, (3) at waist level, and (4) opened.

Furthermore, for the specific portal explosives detection equipment 
installed at fuel cycle facilities using or possessing a formula quantity of 
strategic special nuclear material, improved equipment performance over that 
acceptable to the NRC may be achieved by operating the equipment in the 
"high sensitivity" mode as opposed to the "fast" mode (current practice).  
Alternatively, supplemental monitoring of the detector output voltage signal 
during the "fast" mode also has the potential for achieving improved 
equipment performance.

Addressees may wish to review their procedures for conducting protected area 
explosives searches in view of this guidance.

No specifc actions or written responses are required by this generic letter.  
If you have any questions about this matter, please contact P. Dwyer, 
(301) 492-0478

                                   Sincerely,


                                        Robert F. Burnett, Director
                                        Division of Safeguards
                                          and Transportation, NMSS