Protecting People and the EnvironmentUNITED STATES NUCLEAR REGULATORY COMMISSION
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555-0001
February 27, 1997
NRC INFORMATION NOTICE 97-05: OFFSITE NOTIFICATION CAPABILITIES
Addressees
All holders of operating licenses or construction permits for nuclear power
reactors and test and research reactors.
Purpose
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information
notice to inform addressees of the potential for severe natural events to
disrupt communication systems that the addressees would use to inform offsite
governmental authorities of emergency conditions. The NRC is also issuing
this information notice to inform addressees of measures that some power
reactor licensees have adopted to ensure that offsite communication
capabilities remain reliable during and after severe natural events to which
their sites are susceptible. It is expected that recipients will review the
information for applicability to their facilities and consider actions, as
appropriate, to avoid similar problems. However, suggestions contained in
this information notice are not NRC requirements; therefore, no specific
action or written response is required.
Background
On August 24, 1992, Hurricane Andrew struck south Florida and caused extensive
onsite and offsite damage near the Turkey Point site. An NRC/industry team
reviewed the damage that the hurricane caused the nuclear units and the
utility's actions to prepare for the storm and recover from it. The team also
developed lessons learned that might benefit other nuclear reactor facilities.
The findings of this team were compiled in NUREG-1474, "Effect of Hurricane
Andrew on the Turkey Point Nuclear Generating Station from August 20-30,
1992," (Reference 1).
As part of an NRC task action plan to resolve the generic issues identified in
the NRC/industry team report, the NRC staff reviewed the existing requirements
and guidance pertaining to normal and backup offsite communication system
design capabilities for hurricanes. The objectives of this review were to
consider the adequacy of the guidance for other external events and to issue
any revised guidance or requirements that might be needed. The staff
concluded that the existing requirements and guidance were adequate for
licensees to maintain reliable communication capabilities.
The staff also obtained information on the reliability of offsite
communication systems at selected sites. The NRC developed Temporary
Instruction (TI) 2515/131, "Licensee Offsite
9702240071. IN 97-05
February 27, 1997
Page 2 of 4
Communication Capabilities" (Reference 2), which contained questions to be
asked by inspectors about the capabilities of the offsite notification systems
to survive severe natural events.
Description of Circumstances
NRC inspectors implemented the TI at 17 separate reactor sites in all 4
regions. The sites varied in the particular external events to which they
were prone. Consequently, they varied in the systems used to minimize their
vulnerability to these events. The inspectors noted two conditions at a
number of plants that could result in a sustained loss of communications after
a severe natural event. These conditions are described below:
Communication Circuit Routing
Of the 17 sites inspected, 9 had wiring schemes that routed more than one
communication circuit through common conduits or equipment rooms that were not
designed to withstand all possible external (or internal) hazards. At some of
the sites, cabling arrangements were such that a single communication room on
site contained necessary components for all of the external communication
circuits.
Communication Contingency Procedures
The NRC asked licensees whether they had contingency procedures for rapidly
restoring the capability to communicate with offsite agencies after its loss
as a result of a catastrophic natural disaster. At 7 of the 17 sites
inspected, no formally written contingency procedures existed. At the other
10 sites, procedures or plans varied widely in their level of detail. These
ranged from callout lists for communication technicians to formal letters of
agreement with local communication companies that were contained in full-blown
disaster recovery plans.
Discussion
Communication Circuit Routing
The routing of all or most of the communication circuits through common
conduits or equipment rooms raises the possibility of those circuits being
lost in the event of a single failure within those conduits or rooms.
Appendix A to Part 50 of Title 10 of the Code of Federal Regulations requires
independence and diversity of systems important to safety, but these criteria
are not applied to communication systems that do not interface with the
reactor plant. It is possible, therefore, to have offsite communication
systems that meet the regulatory requirements but that could not survive
natural or man-made hazards. If these circuits were all located in a single
room or building that was destroyed by fire, hurricane, tornado, or
earthquake, it would be possible to lose all offsite communication capability.
If the offsite termini of these systems were similarly configured, such an
event at these locations would also interrupt all emergency messages
transmitted over these circuits.. IN 97-05
February 27, 1997
Page 3 of 4
At least one licensee viewed this condition as serious enough to consider
obtaining a self-contained microwave antenna communication system that would
be independent of its other
communication systems and therefore not be susceptible to common mode failure.
This portable system would be used to transmit emergency messages to an
adjacent power reactor site for relay to the offsite authorities in the event
all other systems were disabled.
Several licensees have obtained satellite communication equipment that enables
them to maintain communication capabilities after severe natural events such
as hurricanes, tornados, and floods. Such systems do not rely on ground-based
transmission, but instead orbiting satellites are used to relay messages to
remote networks. They will likely be one of the only systems that would be
operational immediately after a severe event such as a major hurricane or
earthquake. Some satellite systems are highly portable and self-contained, so
that they can be deployed from a secure location for immediate use.
Communication Contingency Procedures
It is highly probable that a severe disaster that directly affects a reactor
site, as Hurricane Andrew did at Turkey Point, will disable all offsite
communication capability for some finite period of time. One lesson learned
from the Hurricane Andrew disaster was the need to be able to restore this
capability as quickly as possible.
As mentioned above, the contingency procedures adopted by the plants ranged
from callout lists for communication technicians to formal disaster recovery
plans. For plants relying on callout procedures for communication
technicians, a suitable method for notifying those technicians is required in
case electronic communication capability is completely lost. These plans or
procedures are of greatest value when they have been validated under
conditions likely to exist after a severe natural event. For example, if
personnel likely to be available on site during and after such an event are
trained on the plans or procedures, they can implement them quickly.
Part of the ability to quickly restore lost communication capability involves
the stocking of spare parts on site for replacement of storm-, wind-, or
water-damaged equipment. Although it is clearly not feasible for the licensee
to be able to repair damaged commercial telephone systems anywhere along the
transmission lines, damaged radio or microwave systems can be repaired almost
wholly on site. The TI results showed that at seven of the sites, spare
antennae and cabling were available to repair radio or microwave systems. At
some of these seven sites, these parts were stored in structures that were not
qualified to withstand the external events that could be encountered. If
these spare parts could be stored in qualified structures and installed by
knowledgeable personnel who are already on site, the downtime for these
systems could be minimized.
Related Generic Communication
NRC Information Notice 93-53, "Effect of Hurricane Andrew on Turkey Point
Nuclear Generating Station and Lessons Learned," July 20, 1993.. IN 97-05
February 27, 1997
Page 4 of 4
This information notice requires no specific action or written response. If
you have any questions about the information in this notice, please contact
the technical contact listed below or the appropriate Office of Nuclear
Reactor Regulation (NRR) project manager.
signed by
Thomas T. Martin, Director
Division of Reactor Program Management
Office of Nuclear Reactor Regulation
References
1. NUREG-1474, "Effect of Hurricane Andrew
on the Turkey Point Nuclear Generating
Station from August 20-30, 1992," March 1993.
2. Temporary Instruction 2515/131, "Licensee Offsite
Communication Capabilities," January 18, 1996.
Technical contact: William A. Maier, NRR
(301) 415-2926
E-mail: [email protected]
