SBK-L-18195, Submittal of Changes to the Seabrook Station Technical Specification Bases

Submittal of Changes to the Seabrook Station Technical Specification Bases

ML18352B109
Person / Time
Site:	Seabrook
Issue date:	12/18/2018
From:	Browne K NextEra Energy Seabrook
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
SBK-L-18195
Download: ML18352B109 (8)

Text

NEXTera ENERGY ~

SEABROOK December 18, 2018 Docket No. 50-443 SBK-L-18195 U.S. Nuclear Regulatory Commission Attn.: Document Control Desk Washington, DC 20555-0001 Seabrook Station Submittal of Changes to the Seabrook Station Technical Specification Bases NextEra Energy Seabrook, LLC submits the enclosed changes to the Seabrook Station Technical Specification Bases. The changes were made in accordance with Technical Specification 6.7.6.j.,

"Technical Specification (TS) Bases Control Program." Please update the Technical Specification Bases as follows:

REMOVE INSERT B2-7 B 2-7 B 3/4 8-20 B 3/4 8-20 Bases index ii Bases index ii B 3/4 8-18 B3/48-18 B3/48-18a B 3/4 8-21 B 3/4 8-21 Should you have any questions concerning this submittal, please contact me at (603) 773-7932.

Sincerely, owne Licensing Manager cc: D. Lew, NRC Region I Administrator J. Poole, NRC Project Manager, Project Directorate I-2 P. Cataldo, NRC Senior Resident Inspector NextEra Energy Seabrook, LLC PO Box 300, Seabrook, NH 03874

Enclosure to SBK-L-18195 LIMITING SAFETY SYSTEM SETTINGS BASES 2.2.1 REACTOR TRIP SYSTEM INSTRUMENTATION SETPOINTS (Continued)

Undervoltaqe and Underfrequency - Reactor Coolant Pump Susses The Undervoltage and Underfrequency Reactor Coolant Pump Bus trips provide core protection against DNB as a result of complete loss of forced coolant flow.

The specified Setpoints assure a Reactor trip signal is generated before the Low Flow Trip Setpoint is reached. Time delays are incorporated in the Underfrequency and Undervoltage trips to prevent spurious Reactor trips from momentary electrical power transients. For undervoltage, the delay is set so that the total delay between the time the bus supply voltage on two or more reactor coolant pump bus circuits is lost and the time the control rods are free and begin to fall into the core shall not exceed 2.25 seconds. For underfrequency, the delay is set so that the time required for a signal to reach the Reactor trip breakers after the Underfrequency Trip Setpoint is reached shall not exceed 0.6 second.

On decreasing power the Undervoltage and Underfrequency Reactor Coolant Pump Bus trips are automatically blocked by P-7 (a power level of approximately 10% of RATED THERMAL POWER with a turbine impulse chamber pressure at approximately 10% of full power equivalent); and on increasing power, the Undervoltage and Underfrequency Reactor Coolant Pump Bus trips are reinstated automatically by P-7.

Turbine Trip A Turbine trip initiates a Reactor trip. On decreasing power, the Reactor trip from the Turbine trip is automatically blocked by P-9 (a power level of approximately 45% of RATED THERMAL POWER); and on increasing power, the Reactor trip from the Turbine trip is reinstated automatically by P-9.

Safety Injection Input from ESF If a Reactor trip has not already been generated by the Reactor Trip System instrumentation, the ESF automatic actuation logic channels will initiate a Reactor trip upon any signal which initiates a Safety Injection. The ESF instrumentation channels that initiate a Safety Injection signal are shown in Table 3.3-3.

Reactor Trip System Interlocks The Reactor Trip System interlocks perform the following functions:

P-6 On increasing power, P-6 allows the manual block of the Source Range trip (i.e., prevents premature block of Source Range trip). On decreasing power, Source Range Level trips are automatically reactivated and high voltage is restored.

SEABROOK - UNIT 1 B 2-7 Amendment No. 34, 70, BC 00-04, 18-01

ELECTRICAL POWER SYSTEMS BASES 3/4.8.3 ONSITE POWER DISTRIBUTION (continued) emergency DG supplies power to the 4.16 kV emergency buses. Control power for the 4.16 kV breakers is supplied from the Class 1E batteries.

Although not explicitly contained in TS 3.8.3.1 and 3.8.3.2, the MCCs that support the design function of the on-site AC power system must be energized to permit the functioning of structures, systems, and components important to safety under all normal and accident conditions. The AC distribution system ensures the safety functions of the Reactor Coolant Makeup, Residual Heat Removal, Emergency Core Cooling, Containment Heat Removal, Containment Atmosphere Cleanup, and the Cooling Water Systems can be accomplished. The accident analyses assume that the ESF systems are operable, which includes the availability of necessary power.

Consequently, the MCCS that support these functions are required to be energized to maintain operability of the associated ESF systems and components.

No bus ties exist between redundant buses; however, manual bus tie breakers provide the capability to interconnect load center buses within a single train. Bus ties may be used when a unit substation transformer is out of service for maintenance or repair. Bus ties are provided only for operational flexibility. The unit substations are not designed to supply the total load of both buses when bus ties are used. When a bus tie breaker is used, loading on each unit substation will be administratively controlled to be within the rating of the unit substation transformer.

The 120V Vital Instrumentation and Control Power System consists of the uninterruptible power supply (UPS) units and the 120-volt vital instrument panels arranged in two trains. Two vital UPS units that provide power to two NSSS instrumentation channels (Channels Ill & IV) are powered from either the 480V system or 125V DC system depending on the available 480V bus voltage.

Two vital UPS units that provide redundant power supplies to the balance-of-plant train A and train B vital instrument panels and two Vital UPS units that provide power to Channels I and II NSSS instrumentation are normally powered from the 480V system and can also convert 125V DC power from the station batteries to 120V AC power. These UPS units feed six electrically independent 120-volt AC vital instrument panels which serve as instrument and control power supplies.

The DC electrical power distribution system for each train consists of two 125-volt DC buses.

APPLICABLE SAFETY ANALYSES The initial conditions of Design Basis Accident (OBA) and transient SAFETY analyses in the UFSAR assume Engineered Safety Features (ESF) systems are OPERABLE. The AC, DC, and DC vital bus electrical power distribution systems are designed to provide sufficient capacity, capability, redundancy, and reliability to ensure the availability of necessary power to ESF systems so that the fuel, Reactor Coolant System, and containment design limits are not exceeded.

The OPERABILITY of the AC, DC, and AC vital bus electrical power distribution systems in MODES 1 through 4 is consistent with the initial assumptions of the accident analyses and is based upon meeting the design basis of the unit. This includes maintaining power distribution systems OPERABLE during accident conditions in the event of:

SEABROOK- UNIT 1 B 3/4 8-20 BC 04 15, 14 02, 17 02, 18-03

INDEX BASES SECTION PAGE TABLE B 3/4.4-1 (THIS TABLE NUMBER IS NOT USED) ............................................. B 3/4 4-22 3/4.4.10 (THIS SPECIFICATION NUMBER IS NOT USED).............................................. B 3/4 4-31 3/4.4.11 REACTOR COOLANT SYSTEM VENTS............................................................... B 3/4 4-32 3/4.5 EMERGENCY CORE COOLING SYSTEMS 3/4.5.1 ACCUMULATORS ..................................................................................................... B 3/4 5-1 3/4.5.2 and 3/4.5.3 ECCS SUBSYSTEMS ............................................................................ B 3/4 5-1 3/4.5.4 REFUELING WATER STORAGE TANK B 3/4 5-4 3/4.6 CONTAINMENT SYSTEMS 3/4.6.1 PRIMARY CONTAINMENT...................................................................................... B 3/4 6-1 3/4.6.2 DEPRESSURIZATION AND COOLING SYSTEMS............................................. B 3/4 6-3 3/4.6.3 CONTAINMENT ISOLATION VALVES .................................................................. B 3/4 6-3c 3/4.6.4 COMBUSTIBLE GAS CONTROL............................................................................ B 3/4 6-4 3/4.6.5 CONTAINMENT ENCLOSURE BUILDING ........................................................... B 3/4 6-5 3/4.7 PLANT SYSTEMS 3/4.7.1 TURBINE CYCLE....................................................................................................... B 3/4 7-1 3/4.7.2 STEAM GENERATOR PRESSURE/TEMPERATURE LIMITATION ................ B 3/4 7-9 3/4.7.3 PRIMARY COMPONENT COOLING WATER SYSTEM..................................... B 3/4 7-9 3/4.7.4 SERVICE WATER SYSTEM I ULTIMATE HEAT SINK ...................................... B 3/4 7-10 3/4.7.5 (THIS SPECIFICATION NUMBER IS NOT USED).............................................. B 3/4 7-12 3/4.7.6 CONTROL ROOM SUBSYSTEMS ......................................................................... B 3/4 7-12 3/4.7.7 SNUBBERS................................................................................................................. B 3/4 7-13 3/4.7.8 SEALED SOURCE CONTAMINATION .................................................................. B 3/4 7-15 3/4.7.9 (THIS SPECIFICATION NUMBER IS NOT USED).............................................. B 3/4 7-15 3/4.7.10 (THIS SPECIFICATION NUMBER IS NOT USED).............................................. B 3/4 7-15 3/4.8 ELECTRICAL POWER SYSTEMS 3/4.8.1 A. C SOURCES.......................................................................................................... B 3/4 8-1 3/4.8.2 D.C. SOURCES.......................................................................................................... B 3/4 8-18 3/4.8.3 ONSITE POWER DISTRIBUTION.......................................................................... B 3/4 8-20 3/4.8.4 ELECTRICAL EQUIPMENT PROTECTIVE DEVICES........................................ B 3/4 8-23 3/4.9 REFUELING OPERATIONS 3/4.9.1 BORON CONCENTRATION.................................................................................... B 3/4 9-1 3/4.9.2 INSTRUMENTATION ................................................................................................ B 3/4 9-2a 3/4.9.3 DECAY TIME .............................................................................................................. B 3/4 9-2c 3/4.9.4 CONTAINMENT BUILDING PENETRATIONS ..................................................... B 3/4 9-2d 3/4.9.5 (THIS SPECIFICATION NUMBER IS NOT USED).............................................. B 3/4 9-3 3/4.9.6 (THIS SPECIFICATION NUMBER IS NOT USED).............................................. B 3/4 9-3 3/4.9.7 (THIS SPECIFICATION NUMBER IS NOT USED).............................................. B 3/4 9-3 SEABROOK - UNIT 1 ii BCR No. 00 02, BC 04 01, 07 01, 11 05,

&--02:, 18-02

ELECTRICAL POWER SYSTEMS BASES 3/4.8.1 AC SOURCES (Continued)

SURVEILLANCE REQUIREMENTS (SR) (continued)

REFERENCES

1. 10 CFR 50, Appendix A, GDC 17.

2. UFSAR, Chapter 8.

3. Regulatory Guide 1.9, Rev. 3. *

4. UFSAR, Chapter 6.

5. UFSAR, Chapter 15.

6. Regulatory Guide 1.93, Rev. 0, December 1974.

7. Generic Letter 84-15, "Proposed Staff ACTIONs to Improve and Maintain Diesel Generator Reliability," July 2, 1984.

8. 10 CFR 50, Appendix A, GDC 18.

9. Regulatory Guide 1.108, Rev. 1, August 1977.*

10. Regulatory Guide 1.137, Rev. 1, October 1979. *

11. ANSI Std. C84.1

12. IEEE Std. 387-1984**

13. Generic Letter 91-04, April 1991.

14. Regulatory Guide 1.182, May 2000.

3/4.8.2 DC SOURCES The safety-related portion of the DC power system shown consists of four 125-volt batteries, chargers and DC buses. During normal operation, the DC power system is powered from the battery chargers with the batteries floating on the system. In the event of a loss of normal power to the battery charger, the DC buses are automatically powered from the station batteries.

Two DC electrical trains are required to be OPERABLE in Modes 1 through 4 to supply the inverters for redundant vital instrument buses, distribution panels for power to the Class 1E direct current loads, power for control and operation of the Class 1E systems for Engineered Safety Features, and power for selected non-Class 1 E loads. The system is normally operated with each battery aligned to its own charger and DC bus. In this configuration, each battery supplying a DC bus must be OPERABLE. However, each battery has 100% capability of supplying the full load requirements of both Class 1E DC buses within its associated electrical train. Consequently, a DC electrical train is OPERABLE when one battery and the two associated battery chargers are aligned to power both Class 1E DC buses in the train.

• Seabrook Station is only committed to demonstrating the OPERABILITY of the diesel generators in accordance with the recommendations of Regulatory Guides 1.9, "Selection of Diesel Generator Set Capacity for Standby Power Supplies," Revision 2, December 1979; 1.108, "Periodic Testing of Diesel Generator Units Used as Onsite Electric Power Systems at Nuclear Power Plants," Revision 1, August 1977, Errata September 1977; and 1.137, "Fuel-Oil Systems for Standby Generators." Revision 1, October 1979. Exceptions to these Regulatory Guides are noted in the UFSAR.

• • Seabrook Station is only committed to IEEE Std. 387-1972 and 1977.

SEABROOK - UNIT 1 B 3/4 8-18 BC 03 03, 04 07, Amendment No. 97, BC Q4..4.e, 18-02

ELECTRICAL POWER SYSTEMS BASES 3/4.8.2 DC SOURCES (Continued)

In the event that a battery bank supplying one or both DC electrical buses becomes inoperable, the Action provides two hours to restore the inoperable battery to OPERABLE status. Each DC bus must be aligned to an OPERABLE battery; therefore, restoring the inoperable battery to OPERABLE status or aligning the affected DC buses to an alternate, OPERABLE battery, will restore compliance with the limiting condition for operation.

The OPERABILITY of the minimum D.C. power sources during shutdown and refueling ensures that: (1) the facility can be maintained in the shutdown or refueling condition for extended time periods and (2) sufficient instrumentation and control capability is available for monitoring and maintaining the unit status.

With less than the minimum required DC power sources, the action statement requires immediately suspending core alternations, positive reactivity changes, or movement of irradiated fuel. With respect to suspending positive reactivity changes, operations that individually add limited, positive reactivity are acceptable when, combined with other actions that add negative reactivity, the overall net reactivity addition is zero or negative. For example, a positive reactivity addition caused by temperature fluctuations from inventory addition or temperature control fluctuations is acceptable if it is combined with a negative reactivity addition such that the overall, net reactivity addition is zero or negative. Refer to TS Bases 3/4.9.1, Boron Concentration, for limits on boron concentration and water temperature for MODE 6 action statements involving suspension of positive reactivity changes.

SEABROOK - UNIT 1 B 3/4 8-18a BC 18-02

ELECTRICAL POWER SYSTEMS BASES 3/4.8.3 ONSITE POWER DISTRIBUTION (continued)

1. An assumed loss of all offsite power or all onsite AC electrical power, and

2. A worst case single failure.

The OPERABILITY of the minimum AC, DC, and AC vital bus electrical power distribution subsystems during MODES 5 and 6 ensures that:

1. The unit can be maintained in the shutdown or refueling condition for extended periods,

2. Sufficient instrumentation and control capability is available for monitoring and maintaining the unit status, and

3. Adequate power is provided to mitigate events postulated during shutdown.

The AC and DC electrical power distribution systems satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).

LCO The power distribution subsystems required to be OPERABLE in MODES 1 through 4 ensure the availability of AC, DC, and AC vital bus electrical power for the systems required to shut down the reactor and maintain it in a safe condition after an anticipated operational occurrence (AOO) or a postulated design basis accident (OBA). Maintaining the Train A and Train B AC, DC, and AC vital bus electrical power distribution subsystems OPERABLE ensures that the redundancy incorporated into the design of ESF is not defeated. Therefore, a single failure within any system or within the electrical power distribution subsystems will not prevent safe shutdown of the reactor.

In MODES 5 and 6, various subsystems, equipment, and components are required OPERABLE by other LCOs. Implicit in those requirements via the definition of OPERABILITY is the requirement for availability of necessary electrical power. Maintaining the minimum required onsite power distribution system OPERABLE in MODES 5 and 6 ensures the availability of sufficient power to operate the unit in a safe manner to mitigate the consequences of postulated events during shutdown (e.g., fuel handling accidents).

OPERABLE electrical power distribution subsystems require correct breaker alignments and indicated voltage on the required buses. In addition, OPERABLE DC electrical power distribution subsystems require that the 125-volt DC buses be energized from a vital battery in the same train.

OPERABLE 120-volt vital instrument panels are required to be energized from the associated inverter connected to its DC bus.

The DC electrical system is normally operated with each battery aligned to its own charger and DC bus. In this configuration, each battery supplying a DC bus must be OPERABLE. However, each battery has 100% capability of supplying the full load requirements of both Class 1E DC buses within its associated electrical train. Consequently, a DC electrical train is OPERABLE when one battery and the two associated battery chargers are aligned to power both Class 1E DC buses in the train.

SEABROOK - UNIT 1 B 3/4 8-21 BC G4--%, 18-02