[Federal Register Volume 76, Number 67 (Thursday, April 7, 2011)]
[Notices]
[Pages 19476-19488]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-8317]


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NUCLEAR REGULATORY COMMISSION

 [Docket Nos. 50-277 and 50-278; NRC-2010-0303]


Exelon Generation Company, LLC, Peach Bottom Atomic Power 
Station, Unit Nos. 2 and 3; Exemption

1.0 Background

    Exelon Generation Company, LLC (the licensee, Exelon) is the holder 
of Renewed Facility Operating License Nos. DPR-44 and DPR-56, which 
authorizes operation of the Peach Bottom Atomic Power Station (PBAPS), 
Units 2 and 3. 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 two boiling-water reactors located partly 
in Peach Bottom Township, York County, partly in Drumore Township, 
Lancaster County, and partly in Fulton Township, Lancaster County, in 
southeastern Pennsylvania.

2.0 Request/Action

    Title 10 of the Code of Federal Regulations (10 CFR), Part 50, 
Section 50.48(b), requires that nuclear power plants that were licensed 
before January 1, 1979, satisfy the requirements of 10 CFR Part 50, 
Appendix R, ``Fire Protection Program for Nuclear Power Facilities 
Operating Prior to January 1, 1979,'' Section III.G, ``Fire protection 
of safe shutdown capability.'' PBAPS, Units 2 and 3 were licensed to 
operate prior to January 1, 1979. As such, the licensee's Fire 
Protection Program (FPP) must provide the established level of 
protection as intended by Section III.G of 10 CFR Part 50, Appendix R.
    By letter dated March 6, 2009, ``Request for Exemption from 10 CFR 
50, Appendix R, Section III.G, `Fire Protection of Safe Shutdown 
Capability' '' available at Agencywide Documents Access and Management 
System (ADAMS), Accession No. ML090680141, and supplemented by letter 
dated February 12, 2010, ``Response to Request for Additional 
Information Request for Exemption from 10 CFR 50, Appendix R, Section 
III.G, `Fire Protection of Safe Shutdown Capability' '' (ADAMS 
Accession No. ML100470774), the licensee requested an exemption for 
PBAPS, Units 2 and 3, from certain technical requirements of 10 CFR 
Part 50, Appendix R, Section III.G.2 (III.G.2) for the use of operator 
manual actions (OMAs) in lieu of meeting the circuit separation and 
protection requirements contained in III.G.2 for Fire Areas 2, 6N, 6S, 
13N, 26, 30, 36, 37, 43, 50, and 58 at the plant.

3.0 Discussion

    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. The licensee has stated 
that special circumstances are present in that the application of the 
regulation in this particular circumstance is not necessary to achieve 
the underlying purpose of the rule, which is consistent with the 
language included in 10 CFR 50.12(a)(2)(ii).
    In letters dated March 6, 2009, and February 12, 2010, the licensee 
discussed financial implications associated with plant modifications 
that may be necessary to comply with the regulation. 10 CFR 
50.12(a)2(iii) states that if such costs have been shown to be 
significantly in excess of those contemplated at the time the 
regulation was adopted, or are significantly in excess of those 
incurred by others similarly situated, this may be considered a basis 
for considering an exemption request. However, financial implications 
were not considered in the regulatory review of the request since no 
substantiation was provided regarding such financial implications. Even 
though no financial substantiation was provided, the licensee did 
submit sufficient regulatory basis to support a technical review of the 
exemption request in that the application of the regulation in this 
particular circumstance is not necessary to achieve the underlying 
purpose of the rule.
    In accordance with 10 CFR 50.48(b), nuclear power plants licensed 
before January 1, 1979, are required to meet Section III.G, of 10 CFR 
Part 50, Appendix R. The underlying purpose of Section III.G of 10 CFR 
Part 50, Appendix R, is to ensure that the ability to achieve and 
maintain safe shutdown is preserved following a fire event. The 
regulation intends for licensees to accomplish this by extending the 
concept of defense-in-depth to:
    (1) Prevent fires from starting;
    (2) Rapidly detect, control, and extinguish promptly those fires 
that do occur;
    (3) 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 stated purpose of 10 CFR Part 50, Appendix R, Section III.G.2 
(III.G.2) is to ensure that one of the redundant trains necessary to 
achieve and maintain hot shutdown conditions remains free of fire 
damage in the event of a fire. III.G.2 requires one of the following 
means to ensure that a redundant train of safe shutdown cables and 
equipment is free of fire damage, where redundant trains are located in 
the same fire area outside of primary containment:
    a. Separation of cables and equipment by a fire barrier having a 3-
hour rating;

[[Page 19477]]

    b. Separation of cables and equipment by a horizontal distance of 
more than 20 feet with no intervening combustibles or fire hazards and 
with fire detectors and an automatic fire suppression system installed 
in the fire area; or
    c. Enclosure of cables and equipment of one redundant train in a 
fire barrier having a 1-hour rating and with fire detectors and an 
automatic fire suppression system installed in the fire area.
    Exelon has requested an exemption from the requirements of III.G.2 
for PBAPS, Units 2 and 3 to the extent that one of the redundant trains 
of systems necessary to achieve and maintain hot shutdown is not 
maintained free of fire damage in accordance with one of the required 
means, for a fire occurring in Fire Areas 2 (Radwaste Building), 6S 
(Unit 2 Reactor Building), 6N (Unit 2 Reactor Building, North side), 
13N (Unit 3 Reactor Building), 26 (Unit 3 Motor-Generator (MG) Set 
Ventilation Equipment Room), 30 (Unit 3 B/D Battery Room), 36 (E42 
Switchgear Room), 37 (E22 Switchgear Room), 43 (E-4 Emergency Diesel 
Generator Room), 50 (Turbine Building), and 58 (Unit 3 MG Set Room).
    In its submittals, the licensee described elements of the FPP that 
provide justification that the concept of defense-in-depth that is in 
place in the above fire areas is consistent with that intended by the 
regulation. To accomplish this, the licensee utilizes various 
protective measures. Specifically, the licensee stated that the purpose 
of its request was to credit the use of OMAs, in conjunction with other 
defense-in-depth features, in lieu of the separation and protective 
measures required by III.G.2 for a fire in the fire areas stated above.

3.1 Fire Prevention

    In its March 6, 2009, and February 12, 2010, letters, the licensee 
provided an analysis that described how fire prevention is addressed 
for each of the fire areas for which the OMAs may be required. Unless 
noted otherwise in Section 3.4 below, all of the fire areas included in 
this exemption have a combustible fuel load that is considered to be 
low with fuel sources consisting primarily of fire retardant cable 
insulation and limited floor-based combustibles. Unless noted 
otherwise, there are no high energy ignition sources located in the 
areas. The fire areas included in the exemption are not shop areas, so 
hot work activities are infrequent with administrative control programs 
(e.g., hot work permits, fire watch, and supervisory controls). The 
administrative control programs are described in the PBAPS FPP, which 
is incorporated into the Updated Final Safety Analysis Report.

3.2 Detection, Control and Extinguishment

    PBAPS has been divided into fire areas, as described in the PBAPS 
FPP. Three-hour fire barriers are normally used to provide fire 
resistive separation between adjacent fire areas. In some cases, 
barriers with a fire resistance rating of less than 3 hours are 
credited, but exemptions have been approved or engineering evaluations 
performed in accordance with Generic Letter 86-10, ``Implementation of 
Fire Protection Requirements,'' to demonstrate that the barriers are 
sufficient for the hazard. Walls separating rooms and zones within fire 
areas are typically constructed of concrete. In addition to these 
boundaries, the licensee provided a hazard analysis that described how 
detection, control, and extinguishment of fire are addressed for each 
of the fire areas for which the OMAs may be required.
    Unless noted otherwise below, fire areas are provided with 
ionization smoke detectors in various locations within a particular 
fire area. Although not installed in accordance with a recognized 
standard with regard to spacing, the detectors are located near 
equipment such that they are likely to adequately detect a fire. Upon 
detecting smoke, the detectors initiate an alarm in the Control Room 
enabling fire brigade response. The licensee stated that in most cases, 
no automatic fire suppression systems are provided in the areas 
included in this exemption but that fire suppression systems are 
installed in plant areas with significant fire hazards, such as lube 
oil. Suppression systems have also been installed in areas with 1-hour 
barrier walls and 1-hour rated electrical raceway encapsulation.
    The automatic suppression systems are not credited in reducing fire 
exposure to redundant equipment unless they are indicated as being 
full-area or specifically described as being effective for redundant 
equipment. Equipment operators are trained fire brigade members and 
would likely identify and manually suppress or extinguish a fire using 
the portable fire extinguishers and manual hose stations located 
throughout the fire areas.

3.3 Preservation of Safe Shutdown Capability

    Each OMA included in this review consists of a sequence of tasks 
that occur in various fire areas. The OMAs are initiated upon 
confirmation of a fire in a particular fire area. The licensee stated 
that the postulated fire events that may require the use of the OMAs 
would include multiple failures of various components or equipment. In 
most cases, it is considered highly unlikely that the sequence of 
events required to necessitate the OMAs would fully evolve because of 
the fire prevention, fire protection, and physical separation features 
in place. However, in the event that the sequence does evolve, the OMAs 
are available to provide assurance that safe shutdown can be achieved.
    This analysis postulates that OMAs may be needed to assure safe 
shutdown capability in addition to the traditional fire protection 
features described above. For each of the fire areas included in this 
exemption, the licensee evaluated the OMAs against the criteria of 
NUREG-1852, ``Demonstrating the Feasibility and Reliability of Operator 
Manual Actions in Response to Fire,'' October 2007, in the March 6, 
2009, submittal. A Fire Hazards Analysis was provided for each of the 
OMAs in the licensee's February 12, 2010, supplement.
3.3.1 Licensee's Bases for Establishing Feasibility and Reliability
    The licensee's analysis addresses factors such as environmental 
concerns, equipment functionality and accessibility, available 
indications, communications, portable equipment, personnel protection 
equipment, procedures and training, staffing and demonstrations.
    In its March 6, 2009, submittal, and further supported by its 
February 12, 2010, supplement, the licensee stated that environmental 
considerations such as radiological concerns, emergency lighting, 
temperature and humidity conditions and smoke and toxic gases were 
evaluated and found to not represent a negative impact on the 
operators' abilities to complete the OMA. The licensee stated that the 
dose limits contained in 10 CFR Part 20 are never challenged at any 
point along the travel path of any of the OMAs included in this 
exemption.
    The licensee confirmed that each of the OMA locations addressed by 
this exemption is provided with emergency lighting that illuminates 
both the location where the manual action is performed and the access 
route to the manual action location. Where travel is required to 
buildings outside of the power block, portable lights are staged in the 
fire safe shutdown equipment locker which is inventoried and maintained 
by performance of a periodic routine test. The emergency

[[Page 19478]]

lights are periodically checked for operation and aim at the target 
location.
    The licensee also confirmed that temperature and humidity 
conditions will not challenge the operators performing the OMAs. 
Additionally, the licensee indicated that heat and smoke or gas 
generation from a fire will not impact the operator performing the 
OMAs. This is further supported by the fact that the locations of the 
postulated fire events are in different fire areas than the locations 
for where the actions are performed. In most cases, the initiating fire 
area and manual action location fire area are in separate buildings and 
have separate ventilation systems. Other than smoke, CO<INF>2</INF> is 
another toxic gas that could present a hazard. However, all of the 
CO<INF>2</INF> fire suppression systems at PBAPS are manually actuated 
to prevent an inadvertent discharge of a system.
    The licensee stated that the equipment to be operated as part of 
the OMAs will be functional and maintained free of fire damage and will 
be accessible to the operators performing the action. Additionally, 
PBAPS maintains Transient Response Implementing Plan procedures and T-
300 Fire Guides. T-300 Fire Guides provide the operators with specific 
instructions in the event of a fire in a specific fire area. The T-300 
Fire Guides provide a list of the key protected instruments available 
for a fire in the fire area and list any ``prompt'' actions that are 
needed to restore an instrument for a fire in that area (i.e., those 
that need to be performed within 30 minutes). The applicable T-300 Fire 
Guide lists the ``prompt'' actions at the front of the document. In 
addition, the licensee stated that where specific indications may be 
lost due to a postulated event, the applicable T-300 Fire Guide for 
that fire area identifies which indications may be lost and how to 
recover the loss of that indication. Most required shutdown parameter 
indications are provided by multiple instruments; therefore, even with 
the loss of certain instruments or power supplies, redundant 
instruments are available to provide indications to assist operators.
    With regard to communications, the licensee stated that PBAPS has 
radios and phones available as part of the normal communications 
between the Control Room and the operators. Although the communication 
system is not specifically hardened for post-fire survivability, the 
radio and phone systems are robustly designed such that they will be 
available following most fire scenarios. In the event that the radio 
and phone systems are inoperable, face-to-face communication, and 
adequate time, is available to dispatch the safe shutdown operators 
from the Control Room to perform the tasks and return to the Control 
Room for reassignment when the task is complete. With the exception of 
Action H, none of the operator manual actions addressed by this 
exemption require immediate or concurrent coordination with the Control 
Room while performing the task.
    The licensee stated that if any keys, tools or equipment are 
required to perform the OMAs, the T-300 Fire Guides provide 
instructions on where to find them and how to use them. In addition, 
the licensee stated that operators are provided with standard personal 
protective equipment (PPE) (i.e., hardhat, safety glasses, hearing 
protection, gloves, etc.) and that additional PPE is not required for 
any of the OMAs, with the exception of actions that require that an 
electrical enclosure be opened to manipulate an insulated handle of a 
manual transfer switch. For these tasks, a PBAPS corporate safety 
procedure requires the use of additional electrical safety PPE when 
performing this task.
    The licensee stated that the T-300 Fire Guides provide in-depth 
safe shutdown direction for fires in specific fire areas and that the 
procedures included in the guides include specific instructions on 
assessing plant indications and events as well as instructions on how 
to perform each of the OMAs. The procedures are then used to train the 
operators on the OMAs, which consist primarily of activities that are 
considered to be similar to those performed as part of typical work 
activity and are considered straightforward with minimal training 
demands. In addition, the licensee stated that licensed operators are 
trained biennially on the use of the T-300 Fire Guides using simulator 
scenarios that start with a fire in a specific fire area.
    With regard to staffing, the licensee stated that PBAPS maintains a 
minimum of three operators on each shift to perform safe shutdown 
duties in the event of a fire, which may be comprised of equipment 
operators, reactor operators or senior reactor operators. Additionally, 
the licensee stated that PBAPS performed several demonstrations using 
what is considered to be the most challenging initiating fire area, the 
Turbine Building (Fire Area 50), because it encompasses both Unit 2 and 
Unit 3, includes an action that is a prompt action in other fire areas, 
and includes a number of OMAs to perform within the first 60 minutes.
3.3.2 NRC Staff Evaluation of Feasibility
    The NRC staff has determined that the licensee's analysis 
demonstrates that, for the expected scenarios, the OMAs can be 
diagnosed and executed within the amount of time necessary to complete 
them. The licensee's analysis also demonstrates that various factors, 
as discussed above, have been considered to address uncertainties in 
estimating the time available. Therefore, the NRC staff finds that the 
OMAs included in this review are feasible because there is adequate 
time available for the operator to perform the required OMAs to achieve 
and maintain hot shutdown following a postulated fire event. The 
following table summarizes the ``required'' verses ``allowable'' times 
for each OMA. Where a diagnosis time has been identified, it is 
included as part of the required time for a particular action. Where an 
action has multiple times or contingencies associated with the 
``allowable'' completion time, the lesser time is used. This approach 
is considered to represent a conservative approach to analyzing the 
timelines associated with each of the OMAs with regard to the 
feasibility and reliability of the actions included in this exemption. 
In some cases, the margin between the required time and allowable time 
is small. Specifically actions D, U, V, and X, have 20 percent or less 
margin. This limited margin is based on using the most limiting 
information from the licensee. For example, if the licensee postulated 
up to 30 minutes for diagnosis, the higher value of the required time 
range noted in the table below includes the time to complete the action 
plus the full 30 minutes.
    Finally, these numbers should not be considered without the 
understanding that the manual actions are a fall back in the unlikely 
event that the fire protection defense-in-depth features are 
insufficient. In most cases, there is no credible fire scenario that 
would necessitate the performance of these OMAs. The licensee provided 
a discussion of the times and circumstances associated with each of the 
actions in its March 6, 2009, and February 12, 2010, correspondence.

[[Page 19479]]



------------------------------------------------------------------------
                                                  Required    Allowable
   Fire area of fire origin          OMA         time (min)   time (min)
------------------------------------------------------------------------
Fire Area 2 (Radwaste          Action B.......      15--45*          120
 Building).
                               Action C.......           15        25 **
                               Action D.......      18--48*           60
Fire Area 6S (Unit 2 Reactor   Action G.......      14--44*           60
 Building).
Fire Area 6N (Unit 2 Reactor   Action H.......            7        25 **
 Building, North Side).
Fire Area 13N (Unit 3 Reactor  Action J.......      12--42*           60
 Building).
Fire Area 26 (Unit 3 MG Set    Action K.......      12--42*           60
 Ventilation Equipment Room).
Fire Area 30 (Unit 3 B/D       Action M.......       9--39*           60
 Battery Room).
Fire Area 36 (E42 Switchgear   Action R.......      12--42*           60
 Room).
Fire Area 37 (E22 Switchgear   Action S.......      12--42*           60
 Room).
Fire Area 43 (E-4 Emergency    Action T.......       9--39*           60
 Diesel Generator Room).
Fire Area 50 (Turbine          Action U.......      26--56*           60
 Building).
                               Action V.......      26--56*           60
                               Action X.......      24--54*           60
                               Action Y.......      15--45*          120
Fire Area 58 (Unit 3 MG Set    Action BB......      12--42*           60
 Room).
                               Action CC......           12         25**
------------------------------------------------------------------------
* The higher value of the required time range accounts for a generic 30-
  minute diagnosis time to assess the need for OMAs.
** Prompt actions are those having allowable completion times of 30
  minutes or less.

3.3.3 NRC Staff Evaluation of Reliability
    The completion times noted in the table above provide reasonable 
assurance that the OMAs can reliably be performed under a wide range of 
conceivable conditions by different plant crews. This is because the 
completion time, in conjunction with the time margins associated with 
each action and other installed fire protection features, account for 
sources of uncertainty such as variations in fire and plant conditions, 
factors unable to be recreated in demonstrations and human-centered 
factors. Therefore, the NRC staff finds that the OMAs included in this 
review are reliable because there is adequate time available to account 
for uncertainties not only in estimates of the time available, but also 
in estimates of how long it takes to diagnose a fire and execute the 
OMAs (i.e., as based, at least in part, on a plant demonstration of the 
actions under non-fire conditions).
    For each of the fire areas included in this exemption, the 
postulated fire scenarios and pertinent details are summarized in 
Section 3.4 below.

3.4 NRC Staff Fire Area Evaluations

3.4.1 Fire Area 2 (Radwaste Building)
Fire Prevention
    The licensee stated that the floor-based combustibles include 
health physics cleaning supplies, such as mops, vacuums and other Class 
A combustibles as well as several steel carts containing new resins in 
paper or plastic bags. The total weight of the plastic bags is 
estimated to be less than 5 pounds and empty resin bags are immediately 
removed.
Detection, Control, and Extinguishment
    The licensee stated that Fire Area 2 has fire suppression systems 
installed within the fire area but not within the rooms containing 
redundant cables. The licensee has further stated that the detection 
systems in the rooms containing redundant cables are not code compliant 
in terms of overall spacing in the fire area. However, a smoke detector 
is located within 5 feet of redundant cable ZA2B1021A. There is also a 
smoke detector located within 15 feet of both cables ZD3A1806A and 
ZD3A1321A. The licensee also stated that the Radwaste Control Room is 
located directly adjacent to these three rooms and that it is normally 
occupied by an equipment operator. Because of this, it is likely that 
any fire would be quickly identified by an operator in the area. 
Additionally, the licensee stated that a fully trained onsite fire 
brigade is provided, which is dispatched via plant page in the event of 
a fire. The fire brigade is composed of plant operators that are 
separate from operators assigned safe shutdown duties and are 
instructed to provide information about a fire event over the 
operations radio to assist in mitigating the event. Fire Area 2 is 
provided with manual fire fighting equipment such as portable fire 
extinguishers and manual hose stations throughout the area.
Preservation of Safe Shutdown Capability
    The licensee stated that Fire Area 2 is a large fire area 
containing a number of rooms on several elevations and that spatial 
separation of redundant cables is provided as discussed below.
OMAs Credited for a Fire in This Area
Action B
    The licensee stated that the redundant cables located in Fire Area 
2 (cables ZA2B1021A and ZD3B1321A or ZD3A1806A) are located a minimum 
of approximately 30 feet from each other and that no intervening 
combustibles are present between the two trains of cables. This 
physical separation with the available fire detection system will 
provide the site fire brigade an opportunity to extinguish the fire 
before redundant trains are damaged. The licensee also stated that the 
cables are located a minimum of approximately 9 feet above the floor 
and that they are enclosed in rigid conduit, such that transient fire 
exposures and self-ignited cable fires are unlikely to affect the 
circuits.
    In the unlikely event that both trains of cable are lost due to a 
fire in Fire Area 2, an OMA (Action B) is available to restore or 
maintain the necessary function to the effected equipment (SU-25 
Breaker). Action B directs an operator to transfer SU-25 breaker 
auxiliary equipment from the normal power source to its alternate power 
source, by operating manual transfer switch 00S306, which is located in 
the Unit 2 Startup Building. The Unit 2 Startup Building is located in 
the exterior yard area.
Action C
    The potential need to perform this action is low since this action 
is only needed if two of three offsite power sources are unavailable, 
power to the 2SU transformer tap changer is lost, and the tap changer 
is in the wrong position. The licensee stated that offsite power is 
provided to each of the 4kV Class 1E switchgear by two of three 
redundant

[[Page 19480]]

sources (2SU, 3SU, and 343SU) and that control cables for the sources 
have been physically separated by rerouting selected cables, such that 
one of the redundant sources remains free of fire damage for fires in 
most plant areas. In particular, the licensee stated that cables 
associated with the 2SU source have been relocated out of the Turbine 
Building (Fire Area 50), and portions of the Radwaste Building (Fire 
Areas 2 and 58).
    The licensee stated that balance of plant (BOP) cables are routed 
through Fire Area 2, but that the routing of the cables was not part of 
the analysis. In the licensee's February 12, 2010, supplement, the 
licensee described the circumstances that would determine the 
availability of the safe shutdown equipment located in this area; 
namely the 2SU power source, which includes a transformer tap changer 
that is powered by BOP power. Since the BOP cable routing was not part 
of the analysis, the loss of BOP power was assumed for a fire in these 
three fire areas. The licensee's analysis also assumed that the 
transformer tap changer, which is powered by the BOP and responsible 
for maintaining power to the 4kV Bus, was not in the correct position. 
When the tap changer is not in the correct position, the voltage could 
vary resulting in actuation of the 4kV trip relays.
    In the unlikely event that all of the conditions discussed above 
exist and fire damage occurs to the redundant cables, Action C can be 
utilized, which directs operators to pull the fuse blocks for the 
degraded voltage trip relays to ensure that the 4kV busses remain 
available. Action C is a ``prompt'' action, with an allowable 
completion time of 30 minutes or less, however, the licensee stated 
that its analysis assumed that the redundant cables were lost 
regardless of their location and that the tap changer was not in the 
correct position. The licensee stated that the loss of certain 
equipment in a fire area due to a fire will result in a Control Room 
alert. Off Normal procedure ON-114, ``Actual Fire Reported in the Power 
Block, Diesel Generator Building, Emergency Pump, Inner Screen or 
Emergency Cooling Tower Structures,'' is immediately entered upon 
confirmation of a fire condition. Procedure ON-114 directs immediate 
entry into the Fire Guide for the affected fire area. The licensee also 
stated that a note is provided in the applicable safe shutdown fire 
guide series (T-300 Fire Guides) providing guidance on how to determine 
whether the 2SU transformer tap changer has lost power using 
indications within the Control Room. Therefore, the Control Room will 
know immediately if this action is required and a generic diagnosis 
time is not necessary.
    The licensee's T-300 Fire Guides also provide the following 
guidance to assist operators in evaluating a postulated event, ``If 2SU 
is the only offsite power source available, and a loss of power to the 
2SU Transformer Tap Change has occurred, then perform the manual action 
to remove the fuses.'' Additionally, the 2SU transformer and associated 
auxiliaries are located in the yard area and would not be exposed by a 
fire in Fire Area 2. Lastly, the location of the OMA to remove the 
fuses in the 4kV Switchgear Rooms is in a separate fire area, with 
ventilation systems that are separate from Fire Area 2.
Action D
    The licensee stated that this action would only be required if the 
conduit containing cable, which is located above the suspended ceiling 
with the only exposing combustible being a tray with fire retardant 
cables, is damaged by fire. There is a lack of ignition sources and a 
relatively short length (approximately 6 feet) of cable that passes 
through Fire Area 2. In addition, there is a smoke detector located 
within 5 feet of the conduit containing the cable, which would result 
in rapid plant notification of an exposure fire.
    In the unlikely event that a fire in Fire Area 2 damages cable 
ZA2B1014A, normal power to the 2AD003 battery charger could be lost, 
which is needed to maintain long term DC power through the station 
batteries. A loss of ZA2B1014A would necessitate a manual action to 
transfer battery charger 2AD003 to an alternate power source within 60 
minutes since the batteries can operate for 60 minutes prior to the 
initiation of recharging. The alternate power source is routed in 
separate fire areas, so a single fire cannot damage both the normal and 
alternate power feed. Action D is available to transfer the alternate 
power supply to the battery charger 2AD003. The action entails closing 
a breaker located in the E13 4kV Switchgear Room (Fire Area 33) and 
then operating a manual transfer switch located in the E32 4kV 
Switchgear Room (Fire Area 38), both of which are separate fire areas 
from Fire Area 2.
NRC Staff Evaluation
    Given the limited amount of combustible materials and ignition 
sources, it is unlikely that a fire would occur and go undetected by 
the smoke detection system noted above or unsuppressed by personnel, 
and damage the safe shutdown equipment. Even if such circumstances 
exist, Actions B, C, and D are available to provide additional 
assurance that safe shutdown capability is maintained.
3.4.2 Fire Area 6S (Unit 2 Reactor Building)
Fire Prevention
    The licensee stated that conduits are routed primarily through a 
transient combustible-free zone where a permit and review are required 
prior to the placement of combustibles in this area.
Detection, Control, and Extinguishment
    The licensee stated that Fire Area 6S has ionization smoke 
detectors installed in the overhead area but that these smoke detectors 
do not have code compliant spacing due to ceiling height and beam 
pockets. However, there are three smoke detectors located above the 
general routing of the redundant cable conduits, which would be 
expected to activate in the event of a fire occurring in close 
proximity to the redundant cables. Additionally, the licensee stated 
that a fully trained onsite fire brigade is provided, which is 
dispatched via plant page in the event of a fire. The fire brigade is 
composed of plant operators that are separate from operators assigned 
safe shutdown duties and are instructed to provide information about a 
fire event over the operations radio to assist in mitigating the event.
Preservation of Safe Shutdown Capability
    The licensee stated that Room 403 in Fire Area 6S has a ceiling 
height of approximately 29' and an approximate floor area of 6,848 
square feet, so it is unlikely that smoke and heat would accumulate at 
the height of the safe shutdown equipment and cause a failure due to 
fire damage.
OMAs Credited for a Fire in This Area
Action G
    The licensee stated that recent plant experience with faults and 
malfunctions in similar load centers has been that even when energetic 
failures have occurred, its damage has been contained within the 
breaker cubicle, with some heat and smoke damage to immediately 
adjacent cubicles. Therefore, it is considered unlikely that the cables 
routed above the load centers would be affected by a fault within the 
load centers since there is not a credible fire scenario that would be 
capable of damaging the cables within the conduits.
    A fire in Fire Area 6S has the potential to damage cables 
ZA2B1014A, ZA2A1505A, and ZA2B1021A. The licensee stated that there are 
three 480V

[[Page 19481]]

load centers in the room containing the redundant cables and that the 
cables are routed to one of the load centers. As a result, each cable 
is routed over a 480V load center and in two cases the conduit passes 
over two load centers prior to entering the third load center. The 
conduits are located above the two adjacent load centers, which consist 
of a 4kv to 480v sealed gas cooled step-down transformer and a 480v 
switchgear.
    The loss of these cables could result in a loss of the normal power 
supply to the 2AD003 battery charger, which is needed to maintain long 
term DC power through the station batteries. A loss of ZA2B1014A, 
ZA2A1505A, and ZA2B1021A would necessitate a manual action to transfer 
battery charger 2AD003 to an alternate power source within 60 minutes 
since the batteries can operate for 60 minutes prior to the initiation 
of recharging. The alternate power source is routed in separate fire 
areas, so a single fire cannot damage both the normal and alternate 
power feed. Action G is available to transfer the alternate power 
supply to the battery charger 2AD003. The action entails closing a 
breaker located in the E13 4kV Switchgear Room (Fire Area 33) and then 
operating a manual transfer switch located in the E32 4kV Switchgear 
Room (Fire Area 38), both of which are separate fire areas from Fire 
Area 6S.
NRC Staff Evaluation
    Given the limited amount of combustible materials, ignition 
sources, and the large volume of the space, it is unlikely that a fire 
would occur and go undetected by the smoke detection system noted above 
or unsuppressed by personnel, and damage the safe shutdown equipment. 
Even if such circumstances exist, Action G is available to provide 
additional assurance that safe shutdown capability is maintained.
3.4.3 Fire Area 6N (Unit 2 Reactor Building, North side)
Fire Prevention
    The licensee stated that the only floor-based combustibles in this 
area are trash cans and cables. Trash can lids are designed to provide 
self-extinguishing capability to the trash cans. Cables in the area are 
qualified to the Institute of Electrical and Electronics Engineers, 
Inc. Standard-383, ``IEEE Standard For Qualifying Class 1E Electrical 
Cables And Field Splices for Nuclear Power Generating Stations'' (IEEE 
383), or equivalent.
Detection, Control, and Extinguishment
    The licensee stated that Fire Area 6N has a smoke detection system 
installed, but that the spacing is not in compliance with National Fire 
Protection Association Code 72, ``National Fire Alarm and Signaling 
Code'' (NFPA 72), due to deep beam pockets at the ceiling of this area. 
However, there is a smoke detector within the vicinity (approximately 
25 feet) of each of the cases where cable ZA2Q1280B and a ``B'' 
residual heat removal (RHR) cable intersect, which would be expected to 
activate in the event of a fire in close proximity to the redundant 
equipment. There is also an automatic water curtain on the west side of 
the Unit 2 Reactor Building that separates Fire Area 6N from Fire Area 
6S, thus reducing any anticipated exposure from Fire Area 6S. 
Additionally, the licensee stated that a fully trained onsite fire 
brigade is provided, which is dispatched via plant page in the event of 
a fire. The fire brigade is composed of plant operators that are 
separate from operators assigned safe shutdown duties and are 
instructed to provide information about a fire event over the 
operations radio to assist in mitigating the event.
Preservation of Safe Shutdown Capability
    The licensee stated that Fire Area 6N is the Unit 2 Reactor 
Building 135' elevation, north side, which is in a separate building 
from the Cable Spreading Room, Fire Area 25, which is the location of 
the OMA.
OMAs Credited for a Fire in This Area
Action H
    The licensee stated that the cables associated with ``B'' RHR are 
located in trays and in conduit and that cables for both ``A'' and 
``B'' RHR trains cross within 2 feet of each other. However, there are 
no high energy ignition sources where cable ZA2Q1280B and a ``B'' RHR 
train cable cross and only a small amount of combustibles in the area 
overall. Therefore, it is unlikely that a single fire could damage both 
the ``A'' train RHR cable and ``B'' RHR cables and necessitate the use 
of Action H. Action H, which requires coordination with the control 
room, directs an operator to insert a plug-in test switch into Panel 
20C032, located in the Cable Spreading Room (Fire Area 25), to bypass 
the reactor low pressure permissive for opening MO-2-025A.
    In the unlikely event that a fire does damage the pressure 
permissive instrumentation circuit for opening MO-2-025A, operators 
will be aware of the condition, either by electronic indications in the 
Control Room, a smoke detection alarm annunciation in the Control Room, 
or physical observation by operators, and will initiate Action H, which 
is the only OMA required to achieve hot shutdown for a fire in Fire 
Area 6N. Therefore, the Control Room will know immediately if this 
action is required and a generic diagnosis time is not necessary.
    A fire in Fire Area 6N has the potential to damage cable ZA2Q1280B. 
This cable is associated with the pressure permissive circuit needed to 
open valve MO-2-10-025A. This valve needs to open to permit injection 
of Low Pressure Core Injection (``A'' train RHR) following 
depressurization. Fire Area 6N also contains a number of cables 
associated with the ``B'' train of RHR. Any number of ``B'' RHR train 
cables could be damaged as a result of a fire in Fire Area 6N, so the 
licensee's analysis assumed that the ``B'' RHR was considered to be 
unavailable for a fire in Fire Area 6N.
NRC Staff Evaluation
    Given the limited amount of combustible materials and ignition 
sources, it is unlikely that a fire would occur and go unsuppressed by 
personnel, and damage the safe shutdown equipment. Even if such 
circumstances exist, Action H is available to provide additional 
assurance that safe shutdown capability is maintained.
3.4.4 Fire Area 13N (Unit 3 Reactor Building)
Fire Prevention
    The licensee stated that limited amounts of Class A combustible 
materials, including step-off pads, are present in this area. The three 
cables addressed in this area are routed such that they terminate at 
either a 480V load center or a motor control center (MCC) cabinet or 
both.
Detection, Control, and Extinguishment
    The licensee stated that both elevations containing redundant 
equipment within Fire Area 13N have smoke detection systems installed 
that produce an alarm in the Control Room, but that due to the room 
height and steel beams at the ceiling, the spacing of the smoke 
detectors on both elevations does not meet the spacing listed in NFPA 
72. Although not entirely compliant with NFPA 72, this system is 
considered to provide adequate coverage to detect a fire and alert 
operators of a fire. Additionally, the licensee stated that a fully 
trained onsite fire brigade is provided, which is dispatched via plant

[[Page 19482]]

page in the event of a fire. The fire brigade is composed of plant 
operators that are separate from operators assigned safe shutdown 
duties and are instructed to provide information about a fire event 
over the operations radio to assist in mitigating the event.
Preservation of Safe Shutdown Capability
    The licensee stated that the 135' elevation of Fire Area 13N has a 
ceiling height of approximately 29' and an approximate floor area of 
4,033 square feet and the 165' elevation has a ceiling height of 
approximately 29' and an approximate floor area of 6,848 square feet, 
so it is unlikely that smoke and heat would accumulate at the height of 
the safe shutdown equipment and cause a failure due to fire damage.
OMAs Credited for a Fire in This Area
Action J
    The licensee stated that while it is possible that any one of the 
three redundant cables located in Fire Area 13N could potentially be 
damaged as a result of a fault or failure within its associated 480V 
load center or MCC, the impact of a fire on the ability to perform this 
action is low since Fire Area 13N is in a separate building with a 
separate ventilation system from the E43 4kV Switchgear Room and ample 
time is available to complete the action. However, the other installed 
fire protection features such as the smoke detection system, cable 
conduit, and fire brigade response would likely minimize the impact of 
a fire on the cables themselves.
    A fire in Fire Area 13N has the potential to damage cables 
ZD3B1313A, ZD3A1806A, and ZD3B3983A. The loss of any of these cables 
could result in a loss of the normal power supply to the 3DD003 battery 
charger. A loss of ZD3B1313A, ZD3A1806A, or ZD3B3983A, would 
necessitate a manual action to transfer battery charger 3DD003 to an 
alternate power source to within 60 minutes since the batteries can 
operate for 60 minutes prior to the initiation of recharging. Battery 
charger 3DD003 can also be fed from an alternate power source, which is 
routed in separate fire areas, so a single fire cannot damage both the 
normal and alternate power feed. Action J is available to transfer the 
alternate power supply to the battery charger 3DD003. The action 
entails first closing a breaker and then operating a manual transfer 
switch. The breaker and manual transfer switch are located in the E43 
4kV Switchgear Room (Fire Area 34).
NRC Staff Evaluation
    Given the limited amount of combustible materials, ignition 
sources, and the large volume of the space, it is unlikely that a fire 
would occur and go undetected by the smoke detection system noted above 
or unsuppressed by personnel, and damage the safe shutdown equipment. 
Even if such circumstances exist, Action J is available to provide 
additional assurance that safe shutdown capability is maintained.
3.4.5 Fire Area 26 (Unit 3 MG Set Ventilation Equipment Room)
Fire Prevention
    The licensee stated that the primary combustible material in Fire 
Area 26 is fire retardant cable insulation and that there are no in 
situ ignition sources in the vicinity of the cables.
Detection, Control, and Extinguishment
    The licensee stated that in Fire Area 26, there are two ionization 
smoke detectors located in the portion of the room containing the 
cables of concern, but that the overall detector placement for the fire 
area as a whole does not comply with the layout and spacing 
requirements of NFPA 72; however, the two smoke detectors are located 
in the immediate vicinity of the cables and would provide an alarm of a 
fire condition. Additionally, the licensee stated that a fully trained 
onsite fire brigade is provided, which is dispatched via plant page in 
the event of a fire. The fire brigade is composed of plant operators 
that are separate from operators assigned safe shutdown duties and are 
instructed to provide information about a fire event over the 
operations radio to assist in mitigating the event.
Preservation of Safe Shutdown Capability
    The licensee stated that Fire Area 26 has a ceiling height of 
approximately 25' and an approximate floor area of 2,100 square feet, 
so it is unlikely that smoke and heat would accumulate at the height of 
the safe shutdown equipment and cause a failure due to fire damage.
OMAs Credited for a Fire in This Area
Action K
    The licensee stated that it is unlikely that Action K will be 
necessary because there is reasonable assurance that both of the cables 
would not be damaged in the event of a fire in Fire Area 26 since there 
are no in situ ignition sources in Fire Area 26 in the vicinity of the 
cables, there are no combustible materials, other than fire retardant 
cable insulation exposing the two cables, and there are two smoke 
detectors provided in the area to notify operators of a fire. In the 
event that the action is necessary, the impact of a fire on the ability 
to perform this action is low since Fire Area 26N is in a separate 
building with a separate ventilation system from the E43 4kV Switchgear 
Room and ample time is available to complete the action.
    A fire in Fire Area 26 has the potential to damage cables 
ZD3B1313A, ZD3A1806A, and ZD3B3983A. The loss of any of these cables 
could result in a loss of the normal power supply to the 3DD003 battery 
charger. A loss of ZD3B1313A, ZD3A1806A, or ZD3B3983A, would 
necessitate a manual action to transfer battery charger 3DD003 to an 
alternate power source within 60 minutes since the batteries can 
operate for 60 minutes prior to the initiation of recharging. Battery 
charger 3DD003 can also be fed from an alternate power source, which is 
routed in separate fire areas, so a single fire cannot damage both the 
normal and alternate power feed. Action K is available to transfer the 
alternate power supply to the battery charger 3DD003. The action 
entails first closing a breaker and then operating a manual transfer 
switch. The breaker and the manual transfer switch are located in the 
E43 4kV Switchgear Room (Fire Area 34).
NRC Staff Evaluation
    Given the limited amount of combustible materials, ignition 
sources, and the large volume of the space, it is unlikely that a fire 
would occur and go undetected by the smoke detection system noted above 
or unsuppressed by personnel, and damage the safe shutdown equipment. 
Even if such circumstances exist, Action K is available to provide 
additional assurance that safe shutdown capability is maintained.
3.4.6 Fire Area 30 (Unit 3 B/D Battery Room)
Fire Prevention
    The licensee stated that the combustible loading in this area is 
considered to be low with the primary combustible material in this area 
being liquid filled plastic battery cases and that there are no cables 
in trays in this fire area. Additionally, the potential for hydrogen 
buildup due to the battery charging process is mitigated by the 
ventilation system in the room. The ventilation system is monitored, 
alarmed, and programmatically controlled. The licensee also stated that 
there are no significant ignition sources in this area.

[[Page 19483]]

Detection, Control, and Extinguishment
    The licensee stated that for Fire Area 30 there are three smoke 
detectors located in the room and that the spacing of the detectors is 
compliant with NFPA 72 with regard to ceiling height, beam 
configuration and air flow. Additionally, two of the three smoke 
detectors are located directly above the encapsulated conduits that 
contain redundant cables. Additionally, the licensee stated that a 
fully trained onsite fire brigade is provided, which is dispatched via 
plant page in the event of a fire. The fire brigade is composed of 
plant operators that are separate from operators assigned safe shutdown 
duties and are instructed to provide information about a fire event 
over the operations radio to assist in mitigating the event.
Preservation of Safe Shutdown Capability
    The licensee stated that Fire Area 30 has a ceiling height of 
approximately 14' and an approximate floor area of 525 square feet, so 
it is unlikely that smoke and heat would accumulate at the height of 
the safe shutdown equipment and cause a failure due to fire damage.
OMAs Credited for a Fire in This Area
Action M
    The licensee stated that it is unlikely that both of the redundant 
cables located in Fire Area 30 would be damaged in the event of a fire 
in Fire Area 30 since the conduits containing cables ZA3B1014A and 
ZA3A1505A are both encapsulated in abandoned Thermo-Lag, the primary 
combustible material in the room is liquid filled plastic battery 
cases, there are no cable trays or high voltage components located in 
the fire area, there are three smoke detectors located in close 
proximity to the cables, and the potential for hydrogen release from 
the battery charging process is mitigated by the ventilation system 
that is monitored for operation and addressed by the Technical 
Requirements Manual.
    A fire in Fire Area 30 has the potential to damage cables ZA3B1014A 
and ZA3A1505A, which the licensee stated are located approximately 16 
inches from one another at their closest location. The loss of either 
of these cables could result in a loss of the normal power supply to 
the 3AD003 battery charger (located in Fire Area 32). A loss of 
ZA3B1014A or ZA3A1505A would necessitate a manual action to transfer 
battery charger 3AD003 to an alternate power source within 60 minutes 
since batteries can operate for 60 minutes prior to the initiation of 
recharging. Battery charger 3AD003 can also be fed from an alternate 
power source, which is routed in separate fire areas, so a single fire 
cannot damage both the normal and alternate power feed. Action M is 
available to transfer the alternate power supply to the battery charger 
3AD003. The action entails operating a manual transfer switch located 
in the E33 4kV Switchgear Room (located in a different fire area).
NRC Staff Evaluation
    Given the ventilation system located in the room, limited amount of 
combustible materials, lack of ignition sources, and the volume of the 
space, it is unlikely that a fire would occur and go undetected by the 
smoke detection system noted above or unsuppressed by personnel, and 
damage the safe shutdown equipment. Even if such circumstances exist, 
Action M is available to provide additional assurance that safe 
shutdown capability is maintained.
3.4.7 Fire Area 36 (E42 Switchgear Room)
Fire Prevention
    The licensee stated that the cables in this area are qualified to 
IEEE 383, or equivalent. The licensee also indicated that there are 
several sections of Thermo-Lag in the room. Thermo-Lag is a fire 
barrier material that is also considered a combustible. The licensee 
determined that this material does not create a credible fire exposure 
to the conduit and that the overall combustible material loading for 
the area is low. Additionally, Fire Area 36 contains 4kV switchgear 
which can create a high energy fault in the event of a failure and is 
considered an ignition source. However, the conduit containing the 
cables of concern is routed 4 feet horizontally from the front of the 
switchgear cabinet, not routed over the switchgear, and is not expected 
to be damaged in the event of a switchgear failure. Conduit containing 
four cables of concern is routed over two battery chargers, which 
convert 480 volt AC into 125 volt DC for the batteries. However, these 
chargers are not anticipated to provide a sustained fault current like 
a 4kV switchgear, but heat from a failure could expose the conduit and, 
therefore, represent an ignition source.
Detection, Control, and Extinguishment
    The licensee stated that Fire Area 36 has an NFPA 72-compliant 
smoke detection system installed, comprised of six smoke detectors, and 
that the room is also provided with a pre-action sprinkler system 
designed in accordance with NFPA Standard 13, ``Standard for the 
Installation of Sprinkler Systems'' (NFPA 13). Additionally, the 
licensee stated that a fully trained onsite fire brigade is provided, 
which is dispatched via plant page in the event of a fire. The fire 
brigade is composed of plant operators that are separate from operators 
assigned safe shutdown duties and are instructed to provide information 
about a fire event over the operations radio to assist in mitigating 
the event.
Preservation of Safe Shutdown Capability
    The licensee stated that Fire Area 36 has a ceiling height of 
approximately 14' and an approximate floor area of 525 square feet, so 
it is unlikely that smoke and heat would accumulate at the height of 
the safe shutdown equipment and cause a failure due to fire damage.
OMAs Credited for a Fire in This Area
Action R
    The licensee stated that while it is possible that the redundant 
cables located in Fire Area 36 could potentially be damaged by heat 
resulting from a battery charger failure, it is unlikely that the 
cables within the conduits would be damaged since Fire Area 36 has full 
area smoke detection and pre-action sprinkler systems, the conduit is 
not routed directly above the 4kV switchgear, the combustible loading 
in the room is low consisting primarily of fire retardant cable 
insulation and Thermo-Lag, and there are no cable trays routed below 
the conduit.
    A fire in Fire Area 36 has the potential to damage cables 
ZA2A1501E, ZA2A1501F, ZA2A1508E, and ZA2A1508F, which the licensee 
stated are routed together in a single conduit, located approximately 9 
feet above the floor, for their entire length in Fire Area 36. The loss 
of these cables could result in the loss of power to the E12 bus from 
the E1 Emergency Diesel Generator. Since Fire Area 36 is the E42 4kV 
Switchgear Room, the switchgear in this room is primarily associated 
with the B and D electrical trains. Therefore, a fire in this room is 
assumed to result in the loss of the components associated with the B 
and D trains. In the event that these are lost due to a fire in Fire 
Area 36, Action R is available, which directs an operator to enter the 
E12 Switchgear Room (located in Fire Area 39) and pull two fuse blocks, 
open two breakers by depressing the mechanical breaker trip button and 
taking a Main Control Room breaker control switch to ``Close.''

[[Page 19484]]

NRC Staff Evaluation
    Given the limited amount of combustible materials and the volume of 
the space, it is unlikely that a fire would occur and go undetected by 
the smoke detection system noted above or unsuppressed by personnel, 
and damage the safe shutdown equipment. Even if such circumstances 
exist, Action R is available to provide additional assurance that safe 
shutdown capability is maintained.
3.4.8 Fire Area 37 (E22 Switchgear Room)
Fire Prevention
    The licensee stated that the cables in this area are qualified to 
IEEE 383, or equivalent. Thermo-Lag is also present, but does not 
create a credible fire exposure to the conduit. The licensee determined 
that this material does not create a credible fire exposure to the 
conduit and that the overall combustible material loading for the area 
is low. Fire Area 37 also contains 4kV switchgear which can create a 
high energy fault in the event of a failure and is considered an 
ignition source. However, the conduit containing the cables of concern 
is routed 4 feet horizontally from the front of the switchgear cabinet, 
not routed over the switchgear, and is not expected to be damaged in 
the event of a switchgear failure. Additionally, a bank of 480V MCCs 
exposes conduit containing four cables of concern to an exposure hazard 
in the event that an MCC fails.
Detection, Control, and Extinguishment
    The licensee stated that Fire Area 37 has an NFPA 72-compliant 
smoke detection system installed, comprised of three smoke detectors, 
and that the room is also provided with a pre-action sprinkler system 
designed in accordance with NFPA 13. Additionally, the licensee stated 
that a fully trained onsite fire brigade is provided, which is 
dispatched via plant page in the event of a fire. The fire brigade is 
composed of plant operators that are separate from operators assigned 
safe shutdown duties and are instructed to provide information about a 
fire event over the operations radio to assist in mitigating the event.
Preservation of Safe Shutdown Capability
    The licensee stated that Fire Area 37 has a ceiling height of 
approximately 14' and an approximate floor area of 525 square feet, so 
it is unlikely that smoke and heat would accumulate at the height of 
the safe shutdown equipment and cause a failure due to fire damage.
OMAs Credited for a Fire in This Area
Action S
    The licensee stated that while it is possible that the redundant 
cables located in Fire Area 37 could potentially be damaged by failure 
of the bank of 480V MCCs located below the conduit, it is unlikely that 
the cables within the conduits would be damaged since Fire Area 37 has 
full area smoke detection and pre-action sprinkler systems, the conduit 
is not routed directly above the 4kV switchgear, the combustible 
loading in the room is low consisting primarily of fire retardant cable 
insulation and Thermo-Lag, and there are no cable trays routed below 
the conduit.
    A fire in Fire Area 37 has the potential to damage cables 
ZA2A1501E, ZA2A1501F, ZA2A1508E, and ZA2A1508F, which the licensee 
stated are routed together in a single conduit, located approximately 9 
feet above the floor, for their entire length in Fire Area 37. The loss 
of these cables could result in the loss of power to the E12 bus from 
the E1 Emergency Diesel Generator. Since Fire Area 37 is the E22 4kV 
Switchgear Room, the switchgear in this room is primarily associated 
with the B and D electrical trains, so a fire in this room is assumed 
to result in the loss of the components associated with the B and D 
trains. In the event that these are lost due to a fire in Fire Area 36, 
Action R is available, which directs an operator to enter the E12 
Switchgear Room (located in Fire Area 39) and pull two fuse blocks, 
open two breakers by depressing the mechanical breaker trip button and 
taking a Main Control Room breaker control switch to ``Close.''
NRC Staff Evaluation
    Given the limited amount of combustible materials and the volume of 
the space, it is unlikely that a fire would occur and go undetected by 
the smoke detection system noted above or unsuppressed by personnel, 
and damage the safe shutdown equipment. Even if such circumstances 
exist, Action S is available to provide additional assurance that safe 
shutdown capability is maintained.
3.4.9 Fire Area 43 (E-4 Emergency Diesel Generator Room)
Fire Prevention
    The licensee stated that other than the diesel fuel and lube oil in 
the EDG Rooms, the combustible material loading is considered to be 
low. The fuel oil day tank is located within the fire area, but in a 
separate room with heavy concrete walls and a 3-hour Underwriters 
Laboratory (UL)-listed fire door. Additionally, failure of an operating 
diesel generator represents a significant ignition source. There are 
also high voltage electrical components associated with the generator 
in the room. However, these ignition sources are only credible when the 
diesel is in operation. During routine diesel operations, an equipment 
operator is stationed in the room to monitor the diesel and would be 
available to immediately suppress any small fires that occurred, or to 
secure the diesel if a significant malfunction occurred.
Detection, Control, and Extinguishment
    The licensee stated that Fire Area 43 has eight heat detectors 
installed that annunciate an alarm in the Control Room and that the 
room also has a manually-actuated carbon dioxide (CO<INF>2</INF>) fire 
suppression system installed. Additionally, the licensee stated that a 
fully trained on-site fire brigade is provided, which is dispatched via 
plant page in the event of a fire. The fire brigade is composed of 
plant operators that are separate from operators assigned safe shutdown 
duties and are instructed to provide information about a fire event 
over the operations radio to assist in mitigating the event.
Preservation of Safe Shutdown Capability
    The licensee stated that the emergency diesel generator rooms are 
located in a separate building from the rest of the plant and that each 
of the emergency diesel generators are separated from one another with 
a three-hour rated fire barrier. Additionally, the OMA for this area is 
performed in the E42 Switchgear room, Fire Area 36, which is located in 
the turbine building.
OMAs Credited for a Fire in This Area
Action T
    The licensee stated that while it is possible that the redundant 
cables in Fire Area 43 could potentially be damaged by a lube or fuel 
oil fire, it is unlikely that the cables within the conduits would be 
damaged since they are located in conduit that is embedded in the floor 
slab for much of the length they are in Fire Area 43, and there would 
have to be a sufficient amount of oil present on the floor which then 
spreads across the floor to expose the control panels. Even if these 
two circumstances occur, a manually-actuated CO<INF>2</INF> fire 
suppression system is available to extinguish any fires in the area.
    A fire in Fire Area 43 has the potential to damage cables ZD2A1807E 
or ZD2A1807H, which the licensee stated are located in conduits 
embedded in the concrete floor slab, control

[[Page 19485]]

panels, and a junction box. Failure of these cables via a hot short 
could cause the Unit 2 emergency diesel generator breaker to close into 
the E42 bus, either out of phase or not running, which would cause a 
protective trip of the E42 bus. This could result in a loss of the 
normal power supply to the 2DD003 battery charger. The battery charger 
is needed to maintain long term DC power through the station batteries. 
The batteries can operate for 60 minutes prior to the initiation of 
recharging. Battery charger 2DD003 can also be fed from an alternate 
power source, which is routed in separate fire areas, so a single fire 
cannot damage both the normal and alternate power feed. Action T is 
available to transfer the alternate power supply to the battery charger 
2DD003 (located in Fire Area 36). The action entails operating a manual 
transfer switch located in the E42 4kV Switchgear Room which is a 
separate fire area in a separate building.
NRC Staff Evaluation
    Given the limited amount of combustible materials and monitoring of 
credible ignition sources in this area, it is unlikely that a fire 
would occur and go undetected by the heat detection system or 
unsuppressed by the suppression system noted above or by personnel, and 
damage the safe shutdown equipment. Even if such circumstances exist, 
Action T is available to provide additional assurance that safe 
shutdown capability is maintained.
3.4.10 Fire Area 50 (Turbine Building)
Fire Prevention
    The licensee stated that limited amounts of Thermo-Lag and various 
Class A combustible materials are present in the fire area. The 
licensee also stated that the room containing the cables of concern 
contains two rows of 13kV switchgear cabinets, which would be capable 
of exposing the cables in the event of a 13 kV switchgear failure.
Detection, Control, and Extinguishment
    The licensee stated that Fire Area 50 includes most of the Unit 2 
and Unit 3 Turbine Building and as such is a large fire area including 
several rooms located on multiple elevations. However, the cables of 
concern with regard to the associated OMA are only routed through Room 
126. This room contains a full room smoke detection system with spacing 
in accordance with NFPA 72. In addition, a full room pre-action 
sprinkler system is provided in Room 126 with sprinkler head placement 
in accordance with NFPA 13. There is also an automatic sprinkler system 
in the adjacent open areas of the Turbine Building. The remainder of 
the Turbine Building is separated from Room 126 by heavy concrete 
radiation barriers and a water curtain (which is part of the Room 126 
pre-action system) at the doorways. Additionally, the licensee stated 
that a fully trained onsite fire brigade is provided, which is 
dispatched via plant page in the event of a fire. The fire brigade is 
composed of plant operators that are separate from operators assigned 
safe shutdown duties and are instructed to provide information about a 
fire event over the operations radio to assist in mitigating the event.
Preservation of Safe Shutdown Capability
    The primary basis for preserving safe shutdown capability is 
included in the discussion of prevention, detection, suppression, and 
control above or included in the OMAs discussed below.
OMAs Credited for a Fire in This Area
Action U
    The licensee stated that while it is possible that one of the 
redundant cables located in Fire Area 50 could potentially be damaged 
by failure of the 13kV switchgear, it is unlikely that additional 
redundant cables would be damaged since the conduit containing cable 
ZD2A1807E runs above the 13kV switchgear, there is approximately 5 feet 
of separation between it and the next closest conduit which contains 
cable ZA2A1503E, and this conduit is not located above the 13kV 
switchgear. The area is also provided with a smoke detection system and 
a pre-action sprinkler system and the presence of abandoned, but 
intact, Thermo-Lag to protect the cables that are needed to ensure 
power to the ``A'' and ``C'' train switchgear to power credited 
shutdown components.
    There is a cable associated with each of the four 4kV busses routed 
through Fire Area 50. There is the potential for any of the four diesel 
generator output breakers to spuriously close, rendering the bus 
unavailable until the diesel generator breaker is opened and lockouts 
are reset. The four cables associated with the Unit 2 4kV busses are: 
Bus E12 breaker cable ZA2A1503E; bus E22 breaker cable ZB2A1606E; bus 
E32 breaker ZC2A1704E; and bus E42 breaker cable ZD2A1807E. Loss of any 
one of these cables will only affect the associated 4kV bus and all 
four cables are routed in separate conduits. Cables ZA2A2503E and 
ZC2A1704E are routed in conduits that remain encapsulated in abandoned 
Thermo-Lag for their entire routing through Fire Area 50 while cables 
ZB2A1606E and ZD2A1807E are routed in conduit that is not encapsulated. 
The conduit containing cable ZB2A1606E is located within 5 feet of the 
conduits containing cables ZA2B1503E and ZD2A1807E.
    Only cables ZA2A1503E and ZC2A1704E are necessary to power the 
busses credited for safe shutdown. However, Action U would restore 
power to all four busses. Only three of the four busses would require 
restoration within 60 minutes and only one bus is assumed to require 
restoration, since only one bus is assumed to spuriously operate. 
Nevertheless, a 26-minute performance time is credited for restoration 
of all four Unit 2 busses.
    In the unlikely event that a fire does occur and goes undetected by 
the smoke detection system or unsuppressed by the suppression system 
and damages multiple redundant cables, Action U is available to restore 
power to the busses, which entails tripping the breaker and pulling a 
fuse block for each of the busses. The location of Action U is in the 
associated Switchgear Room for each associated bus. Additionally, the 
Switchgear Rooms are separate fire areas from the Turbine Building and 
from each other and have separate ventilation systems from the Turbine 
Building. Therefore, a fire in Fire Area 50 would not impact the 
location of the action.
Action V
    Action V is the same as Action U above but for Unit 3. There is a 
cable associated with each of the four 4kV busses routed through Fire 
Area 50. There is the potential for any of the four diesel generator 
output breakers to spuriously close, rendering the bus unavailable 
until the diesel generator breaker is opened and lockouts are reset. 
The four cables associated with the Unit 3 4kV busses are: bus E13 
breaker cable ZA3A1503E; bus E23 breaker cable ZB3A1606E; bus E33 
breaker cable ZC3A1704E; and bus E43 breaker cable ZD3A1807E. Loss of 
any one of these cables will only affect the associated 4kV bus and all 
four cables are routed in separate conduits. Cables ZA3A1503E and 
ZC3A1704E are routed in conduits that remain encapsulated in abandoned 
Thermo-Lag for their entire routing through Fire Area 50 while cables 
ZB3A1606E and ZD3A1807E are routed in conduit that is not encapsulated. 
The conduit containing cable ZB3A1606E is located within 5 feet of the 
conduits containing cables ZA3A1503E and ZC3A1704E.
    Only cables ZA3A1503E and ZC3A1704E are necessary to power the 
busses credited for safe shutdown. However, Action V would restore 
power

[[Page 19486]]

to all four busses. Only three of the four busses would require 
restoration within 60 minutes and only one bus is assumed to require 
restoration, since only one bus is assumed to spuriously operate. 
Nevertheless, a 26-minute performance time is credited for restoration 
of all four Unit 3 busses. The licensee stated that while it is 
possible that one of the cables could potentially be damaged by failure 
of the 13kV switchgear since the conduit containing cable ZD2A1807E 
runs above the 13kV switchgear, there is approximately 5 feet of 
separation between it and the next closest conduit which contains cable 
ZA2A1503E, and this conduit is not located above the 13kV switchgear. 
Therefore, it is unlikely that the cables required for safe shut down 
would be damaged by a fire resulting from failure of the 13kV 
switchgear since the area is also provided with a smoke detection 
system and a pre-action sprinkler system and the presence of abandoned, 
but intact, Thermo-Lag to protect the cables that are needed to ensure 
power to the ``A'' and ``C'' train switchgear to power credited 
shutdown components.
    In the unlikely event that a fire does occur and goes undetected by 
the smoke detection system or unsuppressed by the suppression system 
and damages multiple redundant cables, Action V is available to restore 
power to the busses, which entails tripping the breaker and pulling a 
fuse block for each of the busses. The location of Action U is in the 
associated Switchgear Room for each associated bus. Additionally, the 
Switchgear Rooms are separate fire areas from the Turbine Building and 
from each other and have separate ventilation systems from the Turbine 
Building. Therefore, a fire in Fire Area 50 would not impact the 
location of the action.
Action X
    The potential need to perform this action is low since this action 
is only needed if two of three other offsite power sources are 
unavailable, power to the 2SU transformer tap changer is lost, and the 
tap changer is in the wrong position. The licensee stated that offsite 
power is provided to each of the 4kV Class 1E switchgear by two of 
three redundant sources (2SU, 3SU, and 343SU) and that control cables 
for the sources have been physically separated by rerouting selected 
cables, such that one of the redundant sources remains free of fire 
damage for fires in most plant areas. In particular, the licensee 
stated that cables associated with the 2SU source have been relocated 
out of the Turbine Building (Fire Area 50), and portions of the 
Radwaste Building (Fire Areas 2 and 58).
    The licensee stated that BOP cables are routed through Fire Area 50 
but that the routing of the cables was not part of its analysis. In its 
February 12, 2010, supplement, the licensee described the circumstances 
that would determine the availability of the safe shutdown equipment 
located in this area; namely the 2SU power source, which includes a 
transformer tap changer that is powered by BOP power. Since the BOP 
cable routing was not part of the analysis, the loss of BOP power was 
assumed for a fire in these three fire areas. The licensee's analysis 
also assumed that the transformer tap changer, which is powered by the 
BOP and responsible for maintaining power to the 4kV Bus 2SU, was not 
in the correct position. When the tap changer is not in the correct 
position, the voltage could vary resulting in 4kV trip relays 
actuating.
    In the unlikely event that all of the conditions discussed above 
exist and fire damage occurs to the redundant cables, Action X can be 
utilized, which directs operators to pull the fuse blocks for the 
degraded voltage trip relays to ensure that the 4kV busses remain 
available.
    The licensee's T-300 Fire Guides provide the following guidance to 
assist operators in evaluating a postulated event, ``If 2SU is the only 
offsite power source available, and a loss of power to the 2SU 
Transformer Tap Change has occurred, then perform the manual action to 
remove the fuses.''
    A note is also provided in the Fire Guide for this step providing 
guidance on how to determine if the 2SU transformer tap changer has 
lost power using indications within the Control Room. Therefore, the 
Control Room will know if this action is required. Additionally, the 
2SU transformer and associated auxiliaries are located in the yard area 
and would not be exposed by a fire in Fire Area 50. Lastly, the 
location of the OMA to remove the fuses in the 4kV Switchgear Rooms is 
in a separate fire area, with separate ventilation systems, from Fire 
Area 50.
Action Y
    The licensee stated that while it is possible that the redundant 
cables in Fire Area 50 could potentially be damaged by a fire resulting 
from a 13kV switchgear failure, it is unlikely that both of the cables 
within the conduits would be damaged since the conduit containing cable 
ZA2B1021B remains encapsulated in Thermo-Lag for the entire length 
above the 13kV switchgear, the cable ZA2B1021B is not located within 
the same conduit as cables ZD3B1321B and ZD3B1321D. In addition, the 
area is provided with a smoke detection system, as well as a pre-action 
sprinkler system.
    The licensee stated that the redundant cables located in Fire Area 
50 (cables ZA2B1021B and ZD3B1321B or ZD3A1321D) are located 
approximately 5 feet from each other and that no intervening 
combustibles are present between the two trains of cables. 
Additionally, the conduit containing cable ZA2B1021B remains 
encapsulated in abandoned Thermo-Lag for the entire routing through 
Fire Area 50. The licensee also stated that the conduits containing the 
cables associated with this OMA are routed directly above 
(approximately 5 feet) the 13kV switchgear cabinets in the room and 
that the conduits are assumed to be located within the anticipated heat 
plume in the event of a 13kV switchgear failure.
    In the unlikely event that a fire does occur and goes undetected by 
the smoke detection system or unsuppressed by the suppression system 
and both trains of cable are lost, an OMA (Action V) is available to 
restore or maintain the necessary function to the effected equipment 
(SU-25 Breaker). Action V directs an operator to transfer SU-25 breaker 
auxiliary equipment from the normal power source to its alternate power 
source, by operating manual transfer switch 00S306, which is located in 
the Unit 2 Startup Building, which is located in the exterior yard 
area.
NRC Staff Evaluation
    Given the limited amount of combustible materials and the volume of 
the space, it is unlikely that a fire would occur and go undetected by 
the smoke detection system noted above or unsuppressed by the 
suppression systems noted above or by personnel, and damage the safe 
shutdown equipment. Even if such circumstances exist, Actions U, V, X, 
and Y are available to provide additional assurance that safe shutdown 
capability is maintained.
3.4.11 Fire Area 58 (Unit 3 MG Set Room)
Fire Prevention
    The licensee stated that the combustible loading in Fire Area 58 is 
considered to be moderate and consists primarily of lube oil from the 
MG set. Other combustible materials in the area include fire retardant 
cable insulation and Thermo-Lag. Additionally, the MG set and the MCCs 
located in the room represent ignition sources.
Detection, Control, and Extinguishment
    The licensee stated that Fire Area 58 has a pre-action sprinkler 
system

[[Page 19487]]

installed that is designed to provide localized protection of the MG 
set with sprinkler heads located over the MG set itself and not at the 
ceiling. Although this is not considered to be an area-wide system and 
does not comply with NFPA 13, this system was an original plant 
installation designed to provide localized protection of the MG set. 
The pre-action system is actuated automatically by any one of the six 
smoke detectors in the room, which are also located directly above the 
MG set and not at the ceiling. Since the detectors are not located at 
the ceiling level, the smoke detection system does not comply with NFPA 
72, but still provides some smoke detection capability for the area as 
a whole and would be expected to alert operators of the credible fire 
scenarios for this area. Additionally, the licensee stated that a fully 
trained onsite fire brigade is provided, which is dispatched via plant 
page in the event of a fire. The fire brigade is composed of plant 
operators that are separate from operators assigned safe shutdown 
duties and are instructed to provide information about a fire event 
over the operations radio to assist in mitigating the event.
Preservation of Safe Shutdown Capability
    The licensee stated that Fire Area 58 has a ceiling height of 
approximately 29' and an approximate floor area of 3,525 square feet, 
so it is unlikely that smoke and heat would accumulate at the height of 
the safe shutdown equipment and cause a failure due to fire damage.
OMAs Credited for a Fire in This Area
Action BB
    The licensee stated that while it is possible that the two 
redundant cables in Fire Area 58 associated with the normal power 
supply to the 3DD003 battery charger could potentially be damaged by a 
lube oil or MG set fire, it is unlikely that the cables within the 
conduits would be damaged since the conduit containing cable ZD3B3983A 
is not located above the MG set. In addition, there is a smoke 
detection system provided in the area, as well as a pre-action 
sprinkler system located above the MG set. In the unlikely event that 
both cables are lost, the location of the action is in a different fire 
area from Fire Area 58.
    A fire in Fire Area 58 has the potential to damage cables ZD3A1806A 
and ZD3B3983A, which the licensee stated are located in conduits 
embedded in the concrete floor slab, control panels, and a junction 
box. The loss of either of these cables could result in a loss of the 
normal power supply to the 3DD003 battery charger. The battery charger 
is needed to maintain long term DC power through the station batteries. 
The batteries can operate for 60 minutes prior to the initiation of 
recharging. Battery charger 3DD003 can also be fed an alternate power 
source, which is routed in separate fire areas, so a single fire cannot 
damage both the normal and alternate power feed.
    In the unlikely event that a fire does occur and goes undetected by 
the smoke detection system or unsuppressed by the suppression system 
and the cables are damaged, Action BB is available to transfer the 
alternate power supply to battery charger 3DD003. The action entails 
closing a breaker and then operating a manual transfer switch, both 
located in the E43 4kV Switchgear Room (Fire Area 34), which is a 
separate fire area from Fire Area 58.
Action CC
    The potential need to perform this action is low since this action 
is only needed if two of three other offsite power sources are 
unavailable, power to the 2SU transformer tap changer lost, and the tap 
changer is in the wrong position. The licensee stated that offsite 
power is provided to each of the 4kV Class 1E switchgear by two of 
three redundant sources (2SU, 3SU, and 343SU) and that control cables 
for the sources have been physically separated by rerouting selected 
cables, such that one of the redundant sources remains free of fire 
damage for fires in most plant areas. In particular, the licensee 
stated that cables associated with the 2SU source have been relocated 
out of the Turbine Building (Fire Area 50), and portions of the 
Radwaste Building (Fire Areas 2 and 58).
    The licensee stated that BOP cables are routed through Fire Area 58 
but that the routing of the cables was not part of its analysis. In its 
February 12, 2010, supplement, the licensee described the circumstances 
that would determine the availability of the safe shutdown equipment 
located in this area; namely the 2SU power source, which includes a 
transformer tap changer that is powered by BOP power. Since the BOP 
cable routing was not part of the analysis, the loss of BOP was assumed 
for a fire in these three fire areas. The licensee's analysis also 
assumed that the transformer tap changer, which is powered by the BOP 
and responsible for maintaining power to the 4kV Bus 2SU, was not in 
the correct position. When the tap changer is not in the correct 
position, the voltage could vary resulting in the actuation of the 4kV 
trip relays.
    In the unlikely event that a fire does occur and goes undetected by 
the smoke detection system or unsuppressed by the suppression system 
and fire damage occurs to the redundant cables, Action CC can be 
utilized, which directs operators to pull the fuse blocks for the 
degraded voltage trip relays to ensure that the 4kV busses remain 
available.
    Action CC is a ``prompt'' action, however, the licensee stated that 
its analysis assumed that the redundant cables were lost regardless of 
their location and that the tap changer was not in the correct 
position. The licensee also stated that a note is provided in the 
applicable T-300 Fire Guide providing guidance on how to determine 
whether the 2SU transformer tap changer has lost power using 
indications within the Control Room. Therefore, the Control Room will 
know immediately if this action is required and a generic diagnosis 
time is not necessary.
    The licensee's T-300 Fire Guides also provide the following 
guidance to assist operators in evaluating a postulated event, ``If 2SU 
is the only offsite power source available and a loss of power to the 
2SU Transformer Tap Changer has occurred, then perform the manual 
action to remove the fuses.''
    Additionally, the 2SU transformer and associated auxiliaries are 
located in the yard area and would not be exposed by a fire in Fire 
Area 58. Lastly, the location of the OMA to remove the fuses in the 4kV 
Switchgear Rooms is in a separate fire area, with separate ventilation 
systems, from Fire Area 58.
NRC Staff Evaluation
    Given the moderate amount of combustible materials, ignition 
sources, and the large volume of the space, it is unlikely that a fire 
would occur and go undetected by the smoke detection system noted above 
or unsuppressed by the suppression system noted above or by personnel, 
and damage the safe shutdown equipment. Even if such circumstances 
exist, Actions BB and CC are available to provide additional assurance 
that safe shutdown capability is maintained.

3.5 Summary of Defense-in-Depth and Operator Manual Actions

    In summary, the NRC staff finds that the defense-in-depth concept 
for a fire in the fire areas discussed above provides a level of safety 
that results in the unlikely occurrence of fires, rapid detection, 
control and extinguishment of fires that do occur and the protection of 
structures, systems and components important to safety. As discussed 
above, the licensee has provided preventative and protective measures 
in addition to

[[Page 19488]]

feasible and reliable OMAs that together demonstrate the licensee's 
ability to preserve or maintain safe shutdown capability in the event 
of a fire in the analyzed fire areas.
Authorized by Law
    This exemption would allow PBAPS to rely on OMAs, in conjunction 
with the other installed fire protection features, to ensure that at 
least one means of achieving and maintaining hot shutdown remains 
available during and following a postulated fire event, as part of its 
FPP, in lieu of meeting the requirements specified in III.G.2 for a 
fire in the analyzed fire areas. As stated above, 10 CFR 50.12 allows 
the NRC to grant exemptions from the requirements of 10 CFR Part 50. 
The NRC staff has determined that granting of this exemption will not 
result in a violation of the Atomic Energy Act of 1954, as amended, or 
the Commission's regulations. Therefore, the exemption is authorized by 
law.
No Undue Risk to Public Health and Safety
    The underlying purpose of 10 CFR Part 50, Appendix R, Section III.G 
is to ensure that at least one means of achieving and maintaining hot 
shutdown remains available during and following a postulated fire 
event. Based on the above, no new accident precursors are created by 
the use of the specific OMAs, in conjunction with the other installed 
fire protection features, in response to a fire in the analyzed fire 
areas. Thus, the probability of postulated accidents is not increased. 
Also, based on the above, the consequences of postulated accidents are 
not increased. Therefore, there is no undue risk to public health and 
safety.
Consistent with Common Defense and Security
    The proposed exemption would allow PBAPS to credit the use of the 
specific OMAs, in conjunction with the other installed fire protection 
features, in response to a fire in the analyzed fire areas, discussed 
above, in lieu of meeting the requirements specified in III.G.2. This 
change, to the operation of the plant, has no relation to security 
issues. Therefore, the common defense and security is not diminished by 
this exemption.
Special Circumstances
    Pursuant to 10 CFR 50.12(a)(2)(ii) special circumstances are 
present whenever application of the regulation in the particular 
circumstances is not necessary to achieve the underlying purpose of the 
rule. The underlying purpose of 10 CFR Part 50, Appendix R, Section 
III.G is to ensure that at least one means of achieving and maintaining 
hot shutdown remains available during and following a postulated fire 
event. Therefore, since the underlying purpose of Appendix R, Section 
III.G is achieved, the special circumstances for granting an exemption 
from 10 CFR Part 50, Appendix R, Section III.G exist, as required by 10 
CFR 50.12(a)(2)(ii).

4.0 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 Exelon an exemption from the 
requirements of Section III.G.2 of Appendix R of 10 CFR Part 50, to 
utilize the OMAs discussed above at PBAPS.
    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 (75 FR 58445).
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 30th day of March 2011.

    For The Nuclear Regulatory Commission.
Joseph G. Giitter,
Director, Division of Operating Reactor Licensing, Office of Nuclear 
Reactor Regulation.
[FR Doc. 2011-8317 Filed 4-6-11; 8:45 am]
BILLING CODE 7590-01-P