United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 94-28: Potential Problems with Fire-Barrierpenetration Seals


April 5, 1994



All holders of operating licenses or construction permits for nuclear power


The U.S. Nuclear Regulatory Commission (NRC) is issuing this information
notice to alert addressees to potential problems in installed fire-barrier
penetration seals that may have gone undetected as a result of inadequate
surveillance inspection procedures and inadequate acceptance criteria.  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

Description of Circumstances

Nine Mile Point Nuclear Station, Unit 1, (NMP 1)

On April 25, 1988, Niagara Mohawk Power Corporation, the licensee for NMP 1,
reported (licensee event report [LER] 88-009) that on March 26, 1988, it had
determined that some existing fire barriers were inoperable because the
barriers contained potentially nonfunctional penetrations through the
fire-barrier.  Initially, the licensee verified fire detection on one side of
the affected penetrations, established a fire-watch patrol, and walked down
additional potentially inoperable fire barriers.  When these walkdowns
revealed additional potentially nonfunctional fire-barrier penetrations, the
licensee took additional corrective actions that included performing a
100-percent visual reinspection of the penetration seals, performing an
engineering evaluation of each penetration that did not meet accepted design
configurations, and upgrading its surveillance inspection procedure.
Supplements 1 and 2 to LER 88-009 (June 8 and August 16, 1990, respectively)
attributed the root cause of the event to personnel error due to a lack of
understanding of the fire-barrier commitments; a contributing cause was a
lack of required documentation and inadequate surveillance procedures.
Additional documentation of this event can be found in NRC Region I
Inspection Reports 50-220/88-15 and 50-220/89-33 (June 2, 1988, and March 8,
1990, respectively).

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James A. FitzPatrick Nuclear Power Plant (FitzPatrick)

During the performance of fire-barrier penetration surveillance inspections by
the licensee at FitzPatrick between May and November 1990, inspectors
documented numerous nonconforming conditions.  One predominant condition was
the lack of adequate damming material.  In August 1990, the licensee Quality
Assurance group forwarded an adverse quality condition report describing these
nonconforming conditions to the Site Engineering group for evaluation.  Site
Engineering determined that the barriers were acceptable pending further
evaluation by the Corporate Engineering group.  No compensatory fire watches
were established at that time.  In December 1990, after additional condition
reports were submitted to Site Engineering documenting these nonconforming
conditions, an operability determination was performed and 2-hour fire patrols
were established.  In December 1990, the NRC reviewed the licensee activities
(Region I Inspection Report 50-333/90-09, March 1, 1991) and concluded that
licensee control of the fire-barrier penetration seals was inadequate because:
(1) the licensee had not documented determinations of the ability of the
nonconforming penetrations to perform as fire barriers for 3 hours; (2) there
was no documented justification for establishing 2-hour fire patrols when the
Technical Specifications required continuous compensatory fire watches; and
(3) the inspection criteria used by the licensee were inadequate because the
criteria did not provide the information necessary to allow inspectors to
determine that the seals were not in conformance with the as-built design.

In October 1991 a NRC diagnostic evaluation team noted problems regarding the
implementation of the fire-protection program and Appendix R regulations at
FitzPatrick.  As a result, a special NRC fire-protection review was conducted
at FitzPatrick in March 1992 (Region I Inspection Report 50-333/92-80,
April 8, 1992).  The special NRC fire-protection review team conducted a
walkdown of fire barriers and reviewed the corrective actions initiated by the
licensee as a result of the concerns identified in Region I Inspection Report
50-333/90-09 and the findings in the licensee July 1991 triennial
fire-protection audit.  The team noted that some of the existing penetration
seals in fire-barrier walls were made of a combustible urethane foam and
fiberglass. In addition, several silicone foam seals were degraded or were
not well maintained.  The licensee initiated a corrective action program that
included: (1) reverifying the location of the 10 CFR Part 50, Appendix R,
required fire barriers in the plant; (2) performing a baseline inspection of
all fire-barrier penetration seals associated with Appendix R and the
fire-protection license condition in the plant license; and (3) evaluating
the deficiencies, making operability determinations, and completing repairs
as required. Vermont Yankee Nuclear Power Station (Vermont Yankee)

On January 15, 1993, Vermont Yankee Nuclear Power Corporation, the licensee
for Vermont Yankee, reported (LER 93-001) that on December 17, 1992, an
insulated pipe-penetration seal was identified as potentially not in .
IN 94-28                                         April 5, 1994
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compliance with design requirements.  The seal was only partially filled with
the expected fire-barrier material because it was partially filled with
insulation.  A second similar insulated pipe penetration seal was identified
on December 22, 1992.  The following day the licensee declared all similar
insulated pipe penetrations inoperable and compensatory measures were
instituted.  The licensee stated that these conditions had probably existed
since the fire-barrier penetration seals were upgraded by a 1979/1980
fire-barrier modification.  Supplement 1 to LER 93-001 (March 5, 1993)
indicated that certain noninsulated penetrations and the boot-seal design for
lines with large displacements were also of concern.  The licensee assigned
the following root causes:  (1) inadequate documentation of assumptions
during the 1979 effort to scope the penetration sealing effort, (2)
inadequate procedures, (3) inattention to detail, (4) failure to follow
procedures, and (5) an inadequate surveillance procedure.  Additional
documentation of this event can be found in NRC Region I Inspection Reports
50-271/92-24 and 50-271/93-05 (February 1 and April 1, 1993, respectively).


This notice alerts addressees to the possibility that some installed
fire-barrier penetration seals may contain nonconforming conditions that have
not been identified because of inadequate acceptance criteria and inadequate
surveillance inspection procedures.  Additionally, nonconforming conditions
may go undetected if the surface of the seal is covered by thermal insulation
or damming material.

NRC requirements and guidelines for fire-barrier penetration seals are
contained in various documents, including 10 CFR Part 50, Appendix R, "Fire
Protection Program for Nuclear Power Facilities Operating Prior to January 1,
1979;" Branch Technical Position APCSB 9.5-1, Appendix A, "Guidelines for Fire
Protection for Nuclear Power Plants Docketed Prior to July 1, 1976;" and
NUREG-0800, "Standard Review Plan."  The extent to which these requirements or
guidelines are applicable to a specific nuclear power plant depends on plant
age, commitments established by the licensee in developing the fire protection
plan, the staff safety evaluation reports and supplements, and the license
conditions pertaining to fire protection.

The goal of these requirements and guidelines is to ensure that fire-barrier
penetration seals will remain in place and retain their integrity when exposed
to a fire.  By so doing, there is reasonable assurance that the effects of a
fire will be limited to discrete fire areas and that one division of
safe-shutdown-related systems will remain free of fire damage.

Related Generic Communications

The NRC has issued other generic communications that have discussed
requirements, guidance, and potential problems with fire-barrier penetration
seals.  For example:
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(1)On April 24, 1986, the NRC issued Generic Letter 86-10, "Implementation
of Fire Protection Requirements," to provide information concerning the
interpretation and implementation of NRC fire-protection requirements.

(2)On February 5, 1988, the NRC issued Information Notice (IN) 88-04,
"Inadequate Qualification and Documentation of Fire Barrier Penetration
Seals," to alert addressees that some installed fire-barrier penetration
seal designs may not be adequately qualified for the design rating of
the penetrated fire barrier.  This IN discussed an NRC staff review
which identified some instances where installed fire-barrier penetration
seal configurations were not qualified by adequate testing or were not
supported by adequate qualification documentation.

(3)On August 4, 1988, the NRC issued IN 88-56, "Potential Problems With
Silicone Foam Fire Barrier Penetration Seals," to alert addressees to
potential problems in their installed fire-barrier penetration seals
that could result in the reduction of fire-resistive capabilities for
protection of safety-related redundant equipment and electrical power
and control circuits.  The IN discussed a vendor report (10 CFR Part 21,
"Reporting of Defects and Noncompliance") which identified the potential
for nonconforming conditions, such as splits, gaps, voids, and lack of
fill in the sealing material not being detected during routine
inspections because the surface of the seal material is typically
covered by damming material.

(4)On August 9, 1988, the NRC issued IN 88-04, Supplement 1, "Inadequate
Qualification and Documentation of Fire Barrier Penetration Seals," to
alert addressees to problems caused by potential misapplication of
silicone foam material used in penetration openings at nuclear power

This information notice requires no specific action or written response.  If
you have any questions about the information in this notice, please contact
one of the technical contacts listed below or the appropriate Office of
Nuclear Reactor Regulation (NRR) project manager.

                                       original signed by

                        Brian K. Grimes, Director
                        Division of Operating Reactor Support
                        Office of Nuclear Reactor Regulation

Technical contacts:  Fred L. Bower, III, RI
               (610) 337-5328

               Jeff Holmes, NRR
               (301) 504-2280

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