Southern Nuclear Operating Company; Joseph M. Farley Nuclear Power Plant, Unit 1; Exemption, 15770-15772 [E6-4586]

Agencies

• NUCLEAR REGULATORY COMMISSION

[Federal Register Volume 71, Number 60 (Wednesday, March 29, 2006)]
[Notices]
[Pages 15770-15772]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E6-4586]


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NUCLEAR REGULATORY COMMISSION

[Docket No. 50-348]


Southern Nuclear Operating Company; Joseph M. Farley Nuclear 
Power Plant, Unit 1; Exemption

1.0 Background

    The Southern Nuclear Operating Company (SNC, the licensee) is the 
holder of Renewed Facility Operating License No. NPF-2 which authorizes 
operation of Joseph M. Farley Nuclear Power Plant (FNP), Unit 1. 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 
Houston County, Alabama.

2.0 Request/Action

    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 
features required to satisfy General Design Criterion 3, ``Fire 
protection,'' of Appendix A to10 CFR Part 50 with respect to certain 
generic issues for nuclear power plants licensed to operate prior to 
January 1, 1979. FNP, Unit 1 was licensed to operate prior to January 
1, 1979. Therefore, FNP, Unit 1 is directly subject to Appendix R.
    By letter dated January 19, 2005, as supplemented by letters dated 
June 9 (two letters) and November 18, 2005, SNC, the licensee for FNP, 
Unit 1, submitted a request for a permanent exemption from 10 CFR 
Appendix R, Section III.G.2, pertaining to FNP, Unit 1 (SNC letters NL-
04-2357, NL-05-0937, NL-05-0960 and NL-05-1975, respectively). 
Specifically, 10 CFR Appendix R, Section III.G.2, would require the use 
of a 1-hour rated fire barrier for protection of certain safe shutdown 
control circuits located in Fire Areas 1-013 and 1-042. In lieu of 
providing such 1-hour rated fire barriers, the licensee proposes the 
use of fire-rated electrical cable produced by Meggitt Safety System, 
Inc., (previously known as Whittaker Electronic Resources Unit of 
Whittaker Electronic Systems) for several cables in Fire Areas 1-013 
and 1-042 associated with safe shutdown control circuits.

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. These special circumstances 
are described in 10 CFR 50.12(a)(2)(ii), in that the application of 
these regulations is not necessary to achieve the underlying purpose of 
the rule.
    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.

3.1 Overview of Approach Used by Licensee

    For this specific fire protection application, SNC proposes plant 
modifications to use 1-hour fire-rated electrical cable in lieu of a 1-
hour rated fire barrier as required by 10 CFR Part 50, Appendix R, 
Section III.G.2. Section III.G.2 of 10 CFR Part 50, Appendix R, 
provides fire protection requirements for electrical cables located 
within the same fire area whose failure could cause the maloperation of 
redundant trains of systems necessary to achieve and maintain hot 
shutdown conditions. These areas are required to have protection 
features such that one of the redundant trains will be free of fire 
damage in the event of a fire. One method, described in Section 
III.G.2, for ensuring compliance with this requirement is to enclose 
the cable and equipment and associated non-safety circuits of one 
redundant train in a 1-hour rated fire barrier. In addition, an area-
wide automatic fire suppression and detection system shall be installed 
in the fire area.
    A postulated fire in Fire Area 1-013 or 1-042 could cause loss of 
offsite power; both fire areas contain cable bus ducts from the startup 
transformers to both redundant trains of the 4 kilovolt (KV) Appendix R 
safe shutdown (SSD) busses. A postulated fire in either of these fire 
areas could also potentially impact the function of the Train B 4 KV 
Emergency Diesel Generator (EDG) 1B control circuitry. The majority of 
the Train A onsite electrical power system components required for 
Appendix R SSD are not located in Fire Area 1-013 or 1-042. The 
following Train A onsite power system related SSD circuits

[[Page 15771]]

located in Fire Areas 1-013 and 1-042 will be protected by a 1-hour 
fire-rated electrical cable along with area-wide automatic fire 
suppression and detection:
    1. Protection of control circuitry that could potentially disable 
the supply of the onsite power from the Train A 4KV EDGs 1-2A and 1-C, 
or disable supply of 7 Train A onsite power due to inadvertent loading 
of electronic switching system (ESS) loads onto EDG 1-C:

    (a) The control interlocks for the automatic alignment of the 
Train A Swing EDG 1C Incoming Breaker 1-DH07 or 2-DH07 to provide 
onsite AC power due to loss of offsite power to the shutdown buses.
    (b) The control interlocks for the automatic alignment of the 
Train A Swing EDG 1-2A Incoming Breaker 1-DF08 or 2-DF08 to provide 
onsite AC power due to loss of offsite power to the shutdown buses.
    (c) The control interlocks for the automatic alignment of Unit 1 
600V Load Center 1D Breaker 1-ED13 or Unit 2 600V Load Center 2D 
Breaker 2-ED13 to MCC 1S (power to the Train A Swing EDG 1-2A 
auxiliaries) so that the MCC is aligned to the same DG 1-2A.
    (d) The control interlocks from Unit 2 ESS Sequencer that blocks 
Unit 1 ESS Sequencer on a Unit 2 safety injection actuation signal 
(This signal is to prevent inadvertent loading of ESS loads on 
smaller DG 1C).
    (e) The control interlock from Unit 1 ESS Sequencer that blocks 
Unit 2 ESS Sequencer on a Unit 1 safety injection actuation signal 
(This signal is to prevent inadvertent loading of ESS loads on 
smaller DG 1C).

    2. Protection of the control circuitry that could potentially 
disable the operation of the 4KV power supply breakers to the Train A 
Component Cooling Water Pump 1C, Train A Charging Pump 1A, and Train A 
Motor-Driven Auxiliary Feed-Water Pump 1A.
    3. Protection of the control circuitry that could potentially 
disable the operation of the 600V load center power supply breaker to 
Train A Pressurizer Heater Group 1A.
    A 1-hour rated fire barrier as described in Section III.G.2 of 10 
CFR Part 50, Appendix R is not provided. Instead, these credited Train 
A components will utilize fire-rated electrical cables (Mineral 
Insulated (MI) cables). This fire-rated electrical cable has been 
tested in accordance with American Society for Testing Materials (ASTM) 
E-119, ``Standard Test Methods for Fire Tests of Building Construction 
Materials.''

3.2 Technical Evaluation

3.2.1 Test Results
    The NRC staff reviewed this issue with respect to determining that 
the fire-rated electrical cables would be capable of providing an 
equivalent level of protection as would be provided by a 1-hour rated 
fire barrier as required by 10 CFR part 50, Appendix R, Section 
III.G.2.
    The licensee provided copies of the test report, ``Appendix R, One-
Hour Fire Resistive Control Cable Test,'' dated August 11, 2004, in its 
submittal. The cables in Farley, Unit 1 are used as control circuit 
applications and are rated at 125 volts direct-current (VDC). The 
licensee's report, listed above, includes the fire test performance 
results for 8 Conductor 12 AWG Meggitt Safety Systems 
electrical cable with factory splices and several support systems and 
attachment methods, when exposed to the ASTM E-119 time-temperature 
heating curve for a period of 1 hour.
3.2.2 Megger Testing
    The fire-rated electrical cables at FNP were tested for use in low 
voltage control circuits. Megger Testing was conducted at 500 VDC, to 
obtain conductor-to-conductor and conductor-to-ground insulation 
resistance values, before the fire test, during the fire test, and 
after the hose stream test. To ensure that the conductor-to-conductor 
and conductor-to-ground insulation resistance (IR) readings were 
obtained for all conductor combinations at the peak ASTM E-119 1-hour 
test temperature, the first test was extended for an additional 38 
minutes and 12 seconds with the furnace temperature held as close as 
possible to 1700 degrees Farenheit until all IR values were recorded. 
Obtaining insulation resistance values during the fire test by the test 
method applied provided conservative test results that meet the fire 
Megger Testing requirements of GL 86-10, Supplement 1, for the FNP 
specific 1-hour rated control cable application. The NRC staff finds, 
based on the Megger Testing, that the insulation resistance values are 
acceptable for the specific application at FNP, Unit 1.
3.2.3 Minimum Insulation Resistance Value
    The licensee completed a plant circuit-specific analysis and 
concluded that the control circuit protective devices will not trip 
during a fire event with an IR value of 5.7 mega-ohms/foot (M'[Omega]/
ft). The minimum IR value recorded during the fire test was 0.8 
M'[Omega], and with 24.176 feet of cable inside the furnace, that 
equated to 19.3 M'[Omega]/ft. This far exceeds the FNP-specific minimum 
acceptance value of 5.7 M'[Omega]/ft.
    The NRC staff concludes that, based on the information provided, 
the minimum IR value recorded during testing is acceptable for the 
specific application at FNP, Unit 1.
3.2.4 Mechanical Damage Protection
    Rated 1-hour electrical cable raceway fire barriers are tested in a 
furnace and subject to a hose stream test that ensures the raceway and 
the barriers will stay in place following a fire exposure. The fire-
rated electrical cables were tested in a furnace and subjected to a 
hose stream. Since the fire-rated electrical cables themselves are the 
barriers, any mechanical damage that occurs to the cables may cause the 
cables to fail. The licensee's letter dated June 9, 2005, stated that 
the areas where the fire-rated electrical cables are routed are 
protected with area-wide automatic fire suppression and detection 
systems, as required by Appendix R Section III.G.2.c. In addition, the 
routing for each fire-rated electrical cable was established by plant 
walk-downs to protect against potential physical hazards. The licensee 
stated that the fire-rated electrical cables are also safety-related 
and will be installed to meet the FNP routing requirements for Class 1E 
cable protection from physical hazards. The fire-rated electrical 
cables are only routed in safety-related Class 1 structures, and all 
safety-related and nonsafety-related equipment and components in these 
structures are seismically supported.
    The NRC staff concludes, based on the information provided, that 
there is adequate protection from mechanical damage to demonstrate 
equivalence to a raceway fire barrier system for the specific 
application at FNP, Unit 1.
3.2.5 Galvanized Supports
    When in contact with galvanized supports, fire-resistive electrical 
cable produced by Meggitt Safety Systems, Inc. has been reported to 
experience degradation due to liquid metal embrittlement. This 
degradation occurs at the positions where the galvanized supports are 
in direct contact with the stainless steel cable jacket. Section 4, 
subsection j of Meggitt Safety Systems engineering document, 
``Unpacking, Inspection, Installation and Standard Practices for 8/C 
12 AWG Si 2400 Fire-Rated Cable For J.M. Farley Nuclear Plant, 
Revision D,'' states that ``Si Fire Cable may be routed in cable trays; 
Stainless steel trays are recommended. Cable should not be installed in 
galvanized trays and should NOT be in direct contact with galvanized or 
aluminum trays or structures.''
    The NRC staff concludes, based on the information provided in the 
engineering document, that the installation standard

[[Page 15772]]

will adequately address the concern with galvanized supports for the 
specific application at FNP, Unit 1.
3.2.6 Defense-in-Depth
    The following are the fire protection defense-in-depth objectives: 
(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 licensee stated that Fire Areas 1-013 and 1-042 are provided with 
area-wide automatic fire suppression and detection systems. The use of 
fire-rated electrical cables is a substitute for 1-hour rated fire 
barriers that are required by 10 CFR Part 50, Appendix R, and supports 
the third defense-in-depth objective. For this specific application, 
the licensee has demonstrated that the fire-rated electrical cables 
used are a suitable alternative to the 1-hour rated fire barrier as 
required by 10 CFR part 50, Appendix R.

4.0 Conclusion

    The NRC staff concludes that, on the bases of the discussions in 
the sections above, for the specific application of this material, the 
licensee has adequately demonstrated that this fire-rated electrical 
cable will perform in an equivalent manner when compared to a rated 
barrier for this use. The NRC staff also concludes that the use of the 
MI cable for these purposes, meets the underlying purpose of Appendix R 
and, that, therefore special circumstances are present. 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. Therefore, the Commission hereby grants Southern Nuclear 
Operating Company an exemption from the requirements to 10 CFR Part 50, 
Appendix R, Section III.G.2, to the extent that it requires protection 
of cables of one redundant train of safe shutdown equipment by a 1-hour 
rated fire barrier, for Fire Areas 1-013 and 1-042. The fire-rated 
electrical cables provide an equivalent level of protection necessary 
to achieve the underlying purpose of the rule for Joseph M. Farley 
Nuclear Plant, Unit 1.
    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 (71 FR 12219, March 9, 2006).
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 22nd day of March 2006.

    For the Nuclear Regulatory Commission.
Edwin M. Hackett,
Acting Director, Division of Operating Reactor Licensing, Office of 
Nuclear Reactor Regulation.
 [FR Doc. E6-4586 Filed 3-28-06; 8:45 am]
BILLING CODE 7590-01-P