FirstEnergy Nuclear Operating Company, Davis-Besse Nuclear Power Station, Unit 1; Exemption, 43719-43721 [E5-4012]

Agencies

• NUCLEAR REGULATORY COMMISSION

[Federal Register Volume 70, Number 144 (Thursday, July 28, 2005)]
[Notices]
[Pages 43719-43721]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E5-4012]


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NUCLEAR REGULATORY COMMISSION

[Docket No. 50-346]


FirstEnergy Nuclear Operating Company, Davis-Besse Nuclear Power 
Station, Unit 1; Exemption

1.0 Background

    The FirstEnergy Nuclear Operating Company (FENOC or the licensee) 
is the holder of Facility Operating License No. NPF-3, which authorizes 
operation of the Davis-Besse Nuclear Power Station, Unit 1 (DBNPS). The 
license provides, among other things, that the facility is subject to 
all rules, regulations, and orders of the Nuclear Regulatory Commission 
(NRC, the Commission) now or hereafter in effect.
    The facility consists of a pressurized-water reactor located in 
Ottawa County, Ohio.

2.0 Request

    Title 10 of the Code of Federal Regulations (10 CFR), part 50, 
appendix R, ``Fire Protection Program for Nuclear Power Facilities 
Operating Prior to January 1, 1979,'' establishes fire protection 
requirements to satisfy 10 CFR part 50, appendix A, General Design 
Criterion No. 3, ``Fire Protection.'' By letter dated January 20, 2004 
(ADAMS ML040220470), as supplemented by letters dated September 3, 2004 
(ADAMS ML042520326), and February 25, 2005 (ADAMS ML050610249), FENOC 
requested an exemption from Appendix R, Section III.G.3, ``Fire 
Protection of Safe Shutdown Capability.''
    The licensee is requesting an exemption from the requirements of 
Section III.G.3 to provide area-wide fire detection and fixed fire 
suppression in Fire Area HH. Control room emergency ventilation systems 
are routed through Fire Area HH in the auxiliary building. Fire Area HH 
is equipped with a fire detection system (covering approximately 96 
percent of Fire Area HH), but no fixed suppression system is installed.
    In summary, FENOC has requested an exemption from the 10 CFR Part 
50, Appendix R, Section III.G.3 requirement for a fixed fire 
suppression system in Fire Area HH and for fire detection in the 
approximately 4 percent of Fire Area HH not equipped with a fire 
detection system.

3.0 Discussion

    Pursuant to 10 CFR 50.12(a), 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. These special circumstances 
are described in 10 CFR 50.12(a)(2)(ii), in that the application of 
these regulations in this circumstance is not necessary to achieve the 
underlying purpose of the regulations.
    The underlying purpose of appendix R, section III.G, is to provide 
features capable of limiting fire damage so that: (1) One train of 
systems necessary to achieve and maintain hot shutdown conditions from 
either the control room or emergency control station(s) is free of fire 
damage; and (2) systems necessary to achieve and maintain cold shutdown 
from either the control room or emergency control station(s) can be 
repaired within 72 hours.
    Fire Area HH consists of the Air Conditioning (A/C) Equipment Room 
(Room 603), the Records and Storage Area (Room 603A), and Vestibule 
(Room 603B). Room 603 consists of approximately 3,150 square feet of 
floor area, with an in situ combustible loading consisting of cable 
insulation; heating, ventilation and air conditioning (HVAC) duct 
insulation; and small quantities of grease, lube oil, and miscellaneous 
combustibles. Combustibles are located throughout the room, and in 
proximity to the cables of interest. Rooms 603A and 603B do not contain 
combustibles or equipment.
    Existing fire protection capability in the area consists of a fire 
detection system that protects the A/C Equipment Room (Room 603) and 
manual (not fixed) fire suppression capability consisting of portable 
fire extinguishers and standpipe hose stations for the protection of 
the entire area. Rooms 603A and 603B are not equipped with detection. 
Room 603A is separated from Room 603 by a 12-inch thick concrete 
masonry unit wall and a Underwriters Laboratory Class B fire door with 
a louvered opening. Room 603A is no longer used as a records storage 
area. The louvered opening is equipped with a fire damper held open by 
a fusible link. The door is normally locked and placarded with a sign 
that states, ``Storage of Any Kind is Forbidden'' and ``Door Must 
Remain Locked.'' Room 603B is a vestibule separated from Room 603 by a 
2-hour rated barrier.
    Fire Area HH has 3-hour rated fire barriers on the walls and 
floors. The fire barrier between Room 603 and the stairwell and 
elevator, Fire Area UU, is 2-hour rated. All cables are within

[[Page 43720]]

conduit or cabinets. There are no cable trays in Area HH.
    Fire damage to the circuits for the Control Room Emergency 
Ventilation System (CREVS) in Fire Area HH could disable the Control 
Room HVAC.
    The installed ionization smoke detection system will alert the 
Control Room operators to summon the fire brigade to respond and 
manually extinguish the fire. Standpipe hose stations are available to 
the fire brigade. No combustibles are stored in Rooms 603A and 603B, 
and these rooms are separated from Room 603, therefore a fire in Room 
603A or 603B is not expected to damage the cables of interest.
    FENOC performed an analysis to determine the impact of a fire in 
Fire Area HH. For example, assuming a 500kW fire in Room 603, the room 
would not exceed 250 [deg]F for at least 20 minutes. Even with this 
relatively large fire size for the equipment in the room, the room 
temperature would not be high enough to cause area-wide cable damage. 
Also, 20 minutes would provide time for the fire brigade to respond to 
the fire alarm that would annunciate in the control room. The 20-minute 
response time allows 5 minutes for the detection system to actuate and 
15 minutes for the fire brigade to respond.
    FENOC verified that a number of the motor control centers in Room 
603 were remote from the cables of interest and therefore, would not be 
expected to impact them. Other combustible sources were considered to 
cause damage to the cables of interest and are discussed in the risk 
analysis.
    A floor drain is provided in Room 603. Based on the configuration 
of the room, it is expected that if any of the combustible liquids leak 
from their enclosures the liquids would flow to the floor drain and not 
flow to below the circuits of interest, where if ignited, could cause a 
fire that would impact the cables of interest.
    Loss of the Control Room HVAC is not expected to have an immediate 
effect on the ability to shutdown the plant from the Control Room. With 
no reduction in Control Room heat load, FENOC calculated that it will 
take 30 minutes before the Control Room will reach a temperature of 105 
[deg]F. Although procedural guidance to mitigate a temporary loss of 
HVAC is provided (i.e., by reducing the Control Room heat load), the 
operators may need to or choose to abandon the Control Room due to high 
temperatures.
    FENOC has identified a few pinch points where a single fire could 
potentially fail both trains of CREVS circuits. These pinch points are 
in the area near the C6714 and C6715 cabinets, around C6705 cabinet, 
and a transient fire affecting the CREVS controls and compressors 
located in Room 603. Since the room configuration does not assure that 
safe shutdown will not be challenged, the licensee has performed a risk 
analysis to determine the probability that the existing configuration 
will challenge safe shutdown as discussed below.
    Alternate shutdown capability can be provided by evacuating the 
Control Room and shutting down the plant from the Auxiliary Shutdown 
Panel. Plant procedures include instructions for these manual operator 
actions if Control Room cooling is disabled.
    The licensee performed a risk analysis of Room 603, and determined 
that the fire frequency of fires that could impact the CREVS is 8.25E-
5/year. The risk analysis also estimates the likelihood that the 
Control Room operators would fail to take actions to shed Control Room 
heating loads in order to keep the Control Room habitable. This 
conditional probability of failure to shed control room heat loads was 
evaluated as 0.05 (5E-2). The risk analysis also estimates the 
likelihood that safe shutdown would fail if a fire affecting the CREVS 
required control room evacuation. This conditional probability was 
calculated to be 0.079 (7.9E-2). Therefore, the probability that both 
the CREVS cables would be damaged by a fire and the mitigation from 
outside the control room would fail would be:

----------------------------------------------------------------------------------------------------------------
                                                                                Fail to
                                                         Fail to shed        shutdown from
                  Fire frequency                    x     heat loads     x   alt. shutdown    =       Total
                                                                                 panel
----------------------------------------------------------------------------------------------------------------
8.25E-5/year.....................................  ..            5E-2   ..          7.9E-2   ..    3.3.E-7/year
----------------------------------------------------------------------------------------------------------------

    This value is the frequency that a fire in the area may challenge 
safe shutdown. The value may be smaller (for example, this value does 
not take credit for manual suppression). FENOC also provides the 
overall core-damage frequency for DBNPS as 1.2E-5/year.
    The NRC staff examined the licensee's submittals to determine if 
the configuration in Fire Area HH would meet the underlying purpose of 
the rule, 10 CFR part 50, appendix R. The NRC staff has compared the 
configuration to the three defense-in-depth elements described in 10 
CFR part 50, appendix R:
    1. To prevent fires from starting,
    2. To detect rapidly, control, and extinguish promptly those fires 
that do occur, and
    3. To provide protection for structures, systems and components 
important to safety so that a fire that is not promptly extinguished by 
the fire suppression activities will not prevent the safe shutdown of 
the plant.
    The combustibles and ignition sources in Fire Area HH are limited 
to those expected in an area of this type. The licensee has control 
over transient combustibles and hot work performed in this area. 
Combustible liquids are installed within equipment, and cables are 
installed within cabinets and conduits; no cable trays are installed in 
the area. According to the licensee's analysis, if the combustible 
liquids were to escape their enclosure, they would flow to the floor 
drain and not to an area of Room 603 where, if ignited, could affect 
the cables of interest. There is substantial separation (2-hour rated 
barriers) between this area and other exposing fire areas.
    Room 603 is equipped with an ionization smoke detection system 
which annunciates to the control room for rapid plant response. The 
other rooms, 603A and 603B, do not contain combustibles and are 
separated from Room 603, and therefore are not considered to be an 
ignition source that could damage the cables of interest. In the 
unusual event that a fire did occur in either Room 603A or 603B, it is 
expected that the fire detectors in Room 603 would actuate. Fire 
suppression equipment (hose stations and fire extinguishers) are 
available for suppression of a fire were it to occur.
    Based on the room size and expected fire types, a fire creating a 
hot layer that causes area wide damage is not expected.
    The licensee identified combustibles and pinch points in Fire Area 
HH. These may be subjected to fires in the area, which could challenge 
safe shutdown. FENOC states that there are only a few pinch points and 
only a few

[[Page 43721]]

fire hazards that could affect the pinch points. Although it is 
unlikely that a fire will affect the pinch points, if such damage were 
to occur and the CREVS was to be made inoperable, means to achieve safe 
shutdown remain available. First, the operators could shed loads to 
reduce the heat load in the Control Room so that Control Room 
abandonment is not required. Secondly, if Control Room abandonment is 
required, the alternate shutdown panel is available to shutdown the 
plant. The licensee performed a risk analysis of these configurations 
which is described above.
    The risk analysis in the February 25, 2005, submittal is generally 
consistent with the NRC's fire protection significance determination 
process (Inspection Manual Chapter 0609, Appendix F). The results of 
the analysis are consistent with a change that would be acceptable when 
compared to the acceptance criteria described in Regulatory Guide 
1.174, ``An Approach for Using Probabilistic Risk Assessment in Risk-
Informed Decisions on Plant-Specific Changes to the Licensing Basis,'' 
Revision 1.
    The evaluation that FENOC prepared assesses the impact of the 
change. This evaluation uses a combination of risk-insights and 
deterministic methods to show that sufficient safety margins are 
maintained.
    The NRC staff examined the licensee's rationale to support the 
exemption request and concluded that adequate defense-in-depth and 
safety margins exist. Although fixed suppression is not installed in 
the area, the configuration of the area makes it unlikely that the 
cables of interest will be damaged by a fire in the area. Also, if the 
cables of interest are damaged, adequate assurance remains to 
demonstrate that the plant can be brought to a safe shutdown condition.
    Based upon the above, the NRC staff concludes that application of 
the regulation is not necessary to achieve the underlying purpose of 
the rule. Therefore, the NRC staff concludes that pursuant to 10 CFR 
50.12(a)(2)(ii), the requested exemption is acceptable.

5.0 Conclusion

    Accordingly, the Commission has determined that, pursuant to 10 CFR 
50.12(a), the exemption is authorized by law, will not present an undue 
risk to the public health and safety, and is consistent with the common 
defense and security. Also, special circumstances are present. 
Therefore, the Commission hereby grants FENOC an exemption from the 
requirements of 10 CFR part 50, appendix R, section III.G.3 to install 
a fixed fire suppression system in Fire Area HH for DBNPS and to 
install fire detection in the approximately 4 percent of Fire Area HH 
(i.e., Rooms 603A and 603B) not currently covered by a fire detection 
system. This exemption is based on the limited combustibles located in 
the fire area (including no storage of combustibles in Rooms 603A and 
603B), the limited ignition sources in the fire area, administrative 
controls on both transient combustibles and hot work, the configuration 
of Room 603 that avoids in-situ combustible liquids from affecting the 
cables of interest, the fire detection and manual suppression 
capability available, and the availability of alternate means to 
achieve shutdown if a fire were to occur and cause damage to the cables 
of interest.
    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 (70 FR 42112).
    This exemption is effective upon issuance.

    Dated in Rockville, Maryland, this 21 day of July 2005.

    For the Nuclear Regulatory Commission
Ledyard B. Marsh,
Director, Division of Licensing Project Management, Office of Nuclear 
Reactor Regulation.
[FR Doc. E5-4012 Filed 7-27-05; 8:45 am]
BILLING CODE 7590-01-P