[Federal Register Volume 62, Number 213 (Tuesday, November 4, 1997)]
[Notices]
[Pages 59750-59752]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-29140]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-302]
Florida Power Corporation; Crystal River Nuclear Generating Plant
Unit 3, Exemption
I.
Florida Power Corporation (the licensee) is the holder of Facility
Operating License No. DPR-72, which authorizes operation of the Crystal
River Nuclear Generating Plant Unit 3 (CR3). The license provides,
among other things, that the licensee is subject to all rules,
regulations, and orders of the Commission now or hereafter in effect.
The facility is of a pressurized water reactor type and is located
in Citrus County, Florida.
II.
In its letter dated June 21, as supplemented November 22, 1996, the
licensee requested an exemption from the Commission's regulations.
Title 10 of the Code of Federal Regulations, part 50, Appendix A,
``General Design Criteria for Nuclear Power Plants,'' Criterion 3,
``Fire Protection,'' specifies that ``Structures, systems, and
components important to safety shall be designed and located to
minimize, consistent with other safety requirements, the probability
and effect of fires and explosions.'' 10 CFR part 50, Appendix R sets
forth the fire protection features required to satisfy the general
design Criterion 3 of the Commission's regulations. Pursuant to 10 CFR
part 50, Appendix R, Section III, Paragraph G, design features shall be
established that are capable of limiting fire damage so that one train
of systems necessary to achieve and maintain hot shutdown conditions is
free of fire damage. Specifically, 10 CFR part 50, Appendix R,
Paragraph III.G.2.c requires (if Paragraphs III.G.2.a or b are not
applicable) enclosure of cable and equipment and associated non-safety
circuits of one redundant train in a fire barrier having a 1-hour
rating; in addition, fire detectors and an automatic fire suppression
system shall be installed in the fire area.
The current CR3 design includes Thermo-Lag fire barriers which do
not provide the level of fire resistance required by NRC regulations.
As part of its program for resolving Thermo-Lag issues, the licensee
has determined that the Thermo-Lag material used as a fire barrier for
the protection of certain safe shutdown cables located in certain
elevations of the auxiliary and intermediate buildings does not qualify
as 1-hour fire rated barriers. In lieu of upgrading the existing
Thermo-Lag fire barriers to satisfy the 1-hour fire rating requirement,
the licensee proposes to implement an enhanced automatic fire
suppression system coverage for these specific fire zones. The licensee
indicates that its proposed enhanced automatic fire suppression system
coverage coupled with the existing Thermo-Lag barriers and other
defense-in-depth features will ensure that one train of equipment
necessary to achieve hot shutdown remains free of fire damage. An
exemption from 10 CFR Part 50, Appendix R, Section III, Paragraph
G.2.c., is required to allow the use of the existing Thermo-Lag
material that has less than a 1-hour fire rating, for the specific
cables and equipment located in certain elevations of the auxiliary and
intermediate buildings. By letter dated June 21, as supplemented
November 22, 1996, the licensee submitted the exemption request.
This exemption does not address the licensee's request relating to
the requirements for battery powered lighting in areas for the
operation of safe shutdown equipment.
III.
Discussion
The exemption request is for the following fire zones: auxiliary
building fire area AB-95-3B and G, AB-119-6A (elevations 95 and 119)
and the intermediate building fire area IB-119-201A (elevation 119).
Automatic sprinkler protection and automatic fire detection designed
and installed in accordance with the applicable National Fire
Protection Association (NFPA) codes and standards are provided in these
fire zones. The licensee, in its response to the U.S. Nuclear
Regulatory Commission (NRC) staff's request for additional information
(RAI) dated September 24, 1996, identified no significant deviations
from the applicable NFPA codes and standards that would adversely
affect system performance. The licensee has proposed upgrading the
existing automatic sprinkler protection in each of these zones to
compensate for the existing Thermo-Lag fire barriers. The licensee has
determined that the existing Thermo-Lag fire barriers, coupled with the
enhanced sprinkler protection and administrative controls, provide an
adequate level of fire protection. The staff's evaluation of the
licensee's exemption request is discussed below.
[[Page 59751]]
Auxiliary Building Hallway AB-95-3BA
This zone is the main east/west corridor for this elevation of the
auxiliary building. The corridor is approximately 9 feet wide and the
ceiling is approximately 26 feet above the floor level. An open
stairway at the east end of this fire zone leads up to elevation 119 of
the auxiliary building (AB 119-6A) and is open to adjacent fire zones
at each end. The remainder of the zone is bounded by 3-hour fire walls
on the north, east, and west. The ceiling and floor are also 3-hour
fire rated barriers. The south wall is a non-fire rated concrete
barrier with unsealed penetrations. The fire hazards in this zone
include cables, electrical cabinets and an air conditioning unit. The
safe shutdown circuits located in this zone are associated with the
makeup system and battery charging. The unprotected redundant circuits
are within 5 feet of the Thermo-Lag protected cables. The fire
protection features provided for this zone include a wet pipe sprinkler
system, hose station, and smoke detection. The licensee has performed
an engineering evaluation that concluded that the Thermo-Lag fire
barriers in this zone have an equivalent fire rating of 23 to 48
minutes.
Auxiliary Building Hallway AB-95-3G
This is a north/south corridor providing access to the make-up pump
cubicles. This zone is enclosed by non-fire rated concrete walls
ranging from 24 to 36 inches thick. The floor and ceiling are 3-hour
rated fire barriers. The fire hazards in this zone include cables and
electrical cabinets. The safe shutdown circuits located in this zone
are associated with the makeup system and battery charging. The
unprotected redundant circuits are within 1 foot of the Thermo-Lag
protected cables. The fire protection features provided for this zone
include a wet pipe sprinkler system, hose station, and smoke detection.
The licensee has performed an engineering evaluation that concluded
that the Thermo-Lag fire barriers in this zone have an equivalent fire
rating of 23 to 48 minutes.
Auxiliary Building Hallway AB-95-3G
This zone is the main east/west corridor for this elevation of the
auxiliary building. The corridor is approximately 9 feet wide and 40
feet high. An open stairway at the east end of this fire zone leads
down to elevation 95 of the auxiliary building (AB-95-3B) and is open
to adjacent fire zones at each end. The remainder of the zone is
enclosed by 3-hour fire walls on the north, east and west side, a 3-
hour fire rated floor and a 36-inch thick concrete non-fire rated
ceiling and south wall. The fire hazards in this zone include cables
and fan motors. The safe shutdown circuits located in this area are
associated with the makeup system, heating ventilation and air
conditioning (HVAC), instrumentation, battery charging and essential
power supplies. The unprotected redundant circuits are greater than 20
feet from the Thermo-Lag protected cables; however, intervening
combustibles are present. The fire protection features provided for
this zone include a wet pipe sprinkler system, hose station, and smoke
detection. The licensee has performed an engineering evaluation that
concluded that the Thermo-Lag fire barriers in this zone have an
equivalent fire rating of 23 to 39 minutes.
Intermediate Building Industrial Cooler Room IB-119-201A
This zone connects the industrial room cooler to the auxiliary
building and is located between the turbine building and the reactor
building. The corridor is a narrow hallway with a ceiling approximately
26 feet high. This zone is separated from the turbine building by a 3-
hour rated wall. The zone is also separated from the reactor building
by a non-fire rated concrete wall approximately 42 inches thick. The
east side of this zone is adjacent to fire zone IB-119-201B, separated
by a ``jailbar'' door. The fire hazards in this zone include cables and
electrical cabinets. The safe shutdown circuits located in this zone
are associated with instrumentation. The unprotected redundant circuits
are within 3 feet of the Thermo-Lag protected cables. The fire
protection features provided for this zone include a wet pipe sprinkler
system, hose station, and smoke detection. The licensee has performed
an engineering evaluation that concluded that the Thermo-Lag fire
barriers in this zone have an equivalent fire rating of 22 to 36
minutes.
Intermediate Building Personnel Hatch IB-119-201B
This zone connects the industrial cooler room with the auxiliary
building. The floor area is approximately 1100 square feet. The north,
east and part of the south wall have a 3-hour fire rating. The
remaining portion of the south wall is the reactor building non-fire
rated concrete wall approximately 42 inches thick. The fire hazards in
this zone are cables and protective clothing storage. The safe shutdown
circuits located in this zone are associated with instrumentation. The
unprotected redundant circuits are within 20 feet of the Thermo-Lag
protected cables. The fire protection features provided for this zone
include a wet pipe sprinkler system, hose station, and smoke detection.
The licensee has performed an engineering evaluation that concluded
that the Thermo-Lag fire barriers in this zone have an equivalent fire
rating of 22 to 36 minutes.
IV.
Evaluation
A fire on the 95 or 119 elevations of the auxiliary building could
cause the loss of the redundant divisions of the makeup system, HVAC,
instrumentation, battery charging or essential power supplies. A fire
on the 119 elevation of the intermediate building could cause the loss
of redundant divisions of instrumentation needed to achieve and
maintain safe shutdown following a fire.
The licensee has committed to upgrade the existing sprinkler
protection on elevations 95 and 119 of the auxiliary building and on
elevation 119 of the intermediate building in the vicinity of the
Thermo-Lag fire barriers that are the subject of this exemption
request. The additional sprinkler protection, coupled with the existing
automatic detection and suppression, and manual fire suppression
capability provided in these fire zones, would provide reasonable
assurance that an exposure fire from in situ or transient combustible
materials in the vicinity of the Thermo-Lag fire barriers will not
challenge the barriers, such that damage to redundant divisions of
systems and instrumentation needed to achieve and maintain safe
shutdown following a fire will not occur. Due to variations in the
important parameters of the installed Thermo-Lag barriers from the
tested barriers, and deviations in the conduct of the industry-
sponsored fire endurance tests from the guidance provided in Supplement
1 to Generic Letter 86-10, the equivalent fire resistance rating of the
Thermo-Lag fire barriers at Crystal River Unit 3, that are the subject
of this exemption request, is indeterminate. However, based on data
obtained from industry-sponsored fire test programs, the staff
estimates that the existing Thermo-Lag barriers would provide a minimum
of 20 minutes of fire resistance. The licensee has committed to
maintain the Thermo-Lag fire barriers that are the subject of this
request in place. Automatic wet pipe sprinkler protection that is
designed, installed and maintained in accordance with NFPA 13,
``Installation of Sprinkler Systems,'' have historically
[[Page 59752]]
demonstrated a high reliability in controlling fires during the
incipient stage, thereby limiting fire damage and propagation until
extinguishment can be achieved through manual actions. The licensee has
stated that an upgrade of the existing Thermo-Lag fire barriers to
achieve literal compliance with the regulation is not feasible due to
the locations of the raceways; however, the protection provided by the
existing Thermo-Lag and supplemented with fire suppression capability
by the additional sprinkler heads would protect one train of safe
shutdown cables and satisfy the underlying purpose of the rule. On the
basis of its review and evaluation of the technical information
provided in the licensee's exemption request and the licensee's
response to the request for additional information, the NRC staff
concludes that the licensee's proposed alternative means of protection
coupling the existing barriers with enhanced suppression capability
provides a level of safety equivalent to that prescribed by the
regulation.
V.
Pursuant to 10 CFR 50.12, the Commission may, upon application by
any interested person or upon its own initiative, grant exemptions from
the requirements of 10 CFR part 50 when (1) the exemptions are
authorized by law, will not present an undue risk to public health or
safety, and are consistent with the common defense and security; and
(2) when special circumstances are present. Special circumstances are
present whenever, according to 10 CFR 50.12(a)(2)(ii), ``Application of
the regulation in the particular circumstances would not serve the
underlying purpose of the rule or is not necessary to achieve the
underlying purpose of the rule.''
The underlying purpose of 10 CFR part 50, Appendix R, Section
III.G, Fire Protection of Safe Shutdown Capability, is to ensure the
capability to achieve and maintain safe shutdown conditions during and
after any postulated fire in the plant. The staff has concluded that
the licensee's proposed alternative means of protection, as described
in its request for exemption from the technical requirements of Section
III.G.2.c for auxiliary building fire area AB-95-3B and G, AB-119-6A
(elevations 95 and 119) and the intermediate building fire area IB-119-
201A (elevation 119), would provide reasonable assurance that a level
of safety equivalent to that specified by the regulation would be met.
Therefore, application of the one hour barrier requirement under the
above circumstances is not necessary to achieve the underlying purpose
of the rule.
VI.
In consideration of the foregoing, the NRC staff has concluded that
the licensee's proposed use of an enhanced automatic fire suppression
system coverage for these specific areas in lieu of upgrading the
existing Thermo-Lag fire barriers to satisfy the 1-hour fire rating
requirement, is authorized by law, will not present an undue risk to
public health and safety and is consistent with the common defense and
security. The NRC staff has determined that there are special
circumstances present, as specified in 10 CFR 50.12(a)(2)(ii), in that
application of 10 CFR 50, Appendix R, Section III G.2.c, is not
necessary in order to achieve the underlying purpose of this
regulation.
Accordingly, the Commission hereby grants, pursuant to 10 CFR
50.12(a), the requested exemption. The granting of this exemption is
contingent upon (1) the installation of the enhanced fire suppression
capability as described in the licensee's request, and (2) maintaining
in place the existing fire barriers that are the subject of this
exemption.
Pursuant to 10 CFR 51.32, the Commission has determined that the
granting of this exemption will not have a significant effect on the
quality of the human environment (62 FR 56207).
This exemption is effective upon issuance.
Dated at Rockville, Maryland, this 29th day of October 1997.
For the Nuclear Regulatory Commission.
Samuel J. Collins,
Director, Office of Nuclear Reactor Regulation.
[FR Doc. 97-29140 Filed 11-3-97; 8:45 am]
BILLING CODE 7590-01-P
