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SSINS No.: 6835
IN 86-83
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C. 20555
September 19, 1986
Information Notice No. 86-83: UNDERGROUND PATHWAYS INTO PROTECTED
AREAS,
VITAL AREAS, MATERIAL ACCESS AREAS, AND
CONTROLLED ACCESS AREAS
Addressees:
All nuclear power reactor facilities holding an operating license or
construction permit and fuel fabrication and processing facilities using or
possessing formula quantities of special nuclear material.
Purpose:
This notice is to advise licensees of the potential for undetected,
unauthorized access to controlled areas on the site through unprotected,
underground pathways. The existence of any unprotected underground pathway
of the type described below may be considered a violation and may be
reportable to the NRC in accordance with the appropriate sections of 10 CFR
Part 73.
It is expected that the recipients of this notice will review the
information for applicability to their facilities and consider actions, if
appropriate, to preclude similar problems from occurring at their
facilities. However, suggestions contained in this information notice do not
constitute NRC requirements; therefore, no specific action or written
response is required at this time.
Description of Circumstances:
There have been a number of recent discoveries by licensees and NRC
inspectors of underground pathways into protected areas (PAs), vital areas
(VAs), material access areas (MAAs), and controlled access areas (CAAs).
These pathways are normally some form of tunnel, pipe, or other design
feature for which no protection had been installed or from which the
protective features have been removed. (Protective features must provide a
nonremovable physical obstacle to attempted entry to, or exit from, the
tunnel.) Because these penetrations are often underground, traditional
intrusion detection systems are ineffective for monitoring unauthorized
attempts at entry, and the existence of such a pathway simultaneously
defeats both the barrier and monitoring elements of access control.
8609170346
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IN 86-83
September 19, 1986
Page 2 of 3
The following examples were discovered at various sites during recent
inspections:
1. Large piping used as part of the storm drain system led from outside
the PA to inside the PA where numerous unsecured manhole covers were
located.
2. Personnel restraint bars which were required by design had not been
installed in a 20-inch drain line penetrating a vital area barrier.
3. Personnel restraint features installed in a heating, ventilating, and
air conditioning system had only bolted covers which failed to meet the
standards for physical barriers, thereby reducing the overall level of
security.
4. Two large storm drains penetrated the VA barrier and could be accessed
by as many as 30 unsecured manholes and other openings inside the PA.
One of the drain outfalls was covered by a grate that was secured by
four bolts into the concrete, but bolts had not been welded or peened
over and were accessible for easy removal by a hand wrench. The other
could be accessed through two manholes secured only with a metal strap
and brass shackled locks.
5. A drainage pipe extended from outside the PA into the PA. The manhole
cover intended to seal the opening inside the PA had originally been
welded closed, but traffic over the grate had broken the weld.
Discussion:
Improperly secured underground pathways into PAs and VAs pose a potentially
significant threat to site security because they allow unauthorized and
undetected access. The seriousness of the threat is determined by the
physical characteristics of the pathway, which include the type of entry as
well as impediments to entry.
Vital area barriers are expected to completely enclose vital equipment to
prevent the introduction of objects and materials useful in sabotage as well
as to preclude unauthorized access by individuals. Therefore, any opening
that reduces effectiveness of the barrier would be unacceptable.
Any breach of a PA barrier that exceeds the industry standards of 96 square
inches with at least one dimension greater than 6 inches (as referenced in
NUREG-0908 and ANSI 3.3) is considered to be sufficient to allow the
unauthorized entry of an individual. Therefore, openings into or out of
tunnels that cross PA physical barriers may not exceed the 96-square-inch
standard. Openings include the open ends of the tunnel, removable grates and
manholes, and gaps in the grates and manholes.
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IN 86-83
September 19, 1986
Page 3 of 3
However, the 96-square-inch standard applies only to two-dimensional
openings and may not apply to large pipes and tunnels. Tunnels may be
slightly larger than 96 square inches cross-section (11.04-inch diameter)
and still preclude passage to a controlled area because its length and
circuitous route may make it impossible for an intruder to move along the
interior of the tunnel in such a small area.
It is suggested that licensees review their physical barriers for suspected
penetrations to assure that they conform to existing requirements. It is
advisable that any variation from the 96-square-inch standard be documented
and appended to the physical security plan (PSP). It is suggested that these
situations be evaluated and that a determination be made as to whether
operational or physical impediments to entry should be installed.
Continuous operational impediments to entry include such things as
continuous flushing, high pressure areas, or other activity that would
prevent a person from using the tunnel. Discontinuous or random operational
impediments cannot adequately preclude unauthorized entry.
Physical impediments to entry can include bars installed in the tunnel to
reduce the size of the opening; grates or covers that are locked and
alarmed, welded, or permanently installed in a way that precludes the entry
of a person; bottlenecks in the tunnel; pipe bundles installed inside the
tunnel; or other devices that form a barrier between the areas. Note that
physical impediments must have penetration resistance equivalent to that
specified in 10 CFR 73.2 for physical barriers.
No written response to this information notice is required. If you need
additional information about this matter, please contact the Regional
Administrator of the appropriate NRC regional office or the technical
contact listed below.
Edward L. Jordan, Director
Division of Emergency Preparedness
and Engineering Response
Office of Inspection and Enforcement
Technical Contact: Dick Rosano, IE
(301) 492-4006
Attachment: List of Recently Issued IE Information Notices
Page Last Reviewed/Updated Thursday, March 29, 2012

