NOC-AE-02001270, Technical Specification Bases Changes, Enhancements to Ecw Discharge Self-Cleaning Strainer & Emergency Transformer & Associated Bases

Technical Specification Bases Changes, Enhancements to Ecw Discharge Self-Cleaning Strainer & Emergency Transformer & Associated Bases

ML020650305
Person / Time
Site:	South Texas
Issue date:	02/18/2002
From:	Head S South Texas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NOC-AE-02001270
Download: ML020650305 (5)

Text

Nuclear Operating Company South Texas Proect Electric GeneratigStation P.. Box 289Y Wdsworth, Texas 77483 /-vA/--

February 18, 2002 NOC-AE-02001270 File No.: G20.02.02 G21.02.02 IOCFR50.59 STI: 31407570 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 South Texas Project Units 1 and 2 Docket Nos. STN 50-498, STN 50-499 Technical Specification Bases Change South Texas Project Technical Specification Bases pages B 3/4 7-3a, and B 3/4 8-2 are attached for your information and updating of the NRC copy of the Technical Specification Bases. These changes are enhancements to the Technical Specification Bases with information regarding:

0 the ECW discharge self-cleaning strainer, and 0 the emergency transformer and its associated bus If there are any questions, please contact me at (361) 972-7136.

Scott M. Head Manager, Licensing mkj

Attachment:

Revised Technical Specification Bases Pages B 3/4 7-3a and B 3/4 8-2 O:\QUALITYANDLICENS1NG\TSB\AMENDMENT\02\NOC- AE-02001270

NOC-AE-02001270 Page 2 cc:

Ellis W. Merschoff Jon C. Wood Regional Administrator, Region IV Matthews & Branscomb U.S. Nuclear Regulatory Commission 112 East Pecan, Suite 1100 611 Ryan Plaza Drive, Suite 400 San Antonio, Texas 78205-3692 Arlington, Texas 76011-8064 Mohan C. Thadani Institute of Nuclear Power Project Manager Operations - Records Center U. S. Nuclear Regulatory Commission 700 Galleria Parkway 1 White Flint North, Mail Stop: O-7D1 Atlanta, GA 30339-5957 11555 Rockville Place Rockville, MD 20852-2738 Richard A. Ratliff Bureau of Radiation Control Cornelius F. O'Keefe Texas Department of Health U. S. Nuclear Regulatory Commission 1100 West 49th Street P. 0. Box 289, Mail Code MN1 16 Austin, TX 78756-3189 Wadsworth, TX 77483 R. L. Balcom/D. G. Tees A. H. Gutterman, Esquire Reliant Energy, Inc.

Morgan, Lewis & Bockius P. 0. Box 1700 1111 Pennsylvania Avenue, NW Houston, TX 77251 Washington, DC 20004 C. A. Johnson/A. C. Bakken, III M. T. Hardt/W. C. Gunst AEP - Central Power and Light Company City Public Service P. 0. Box 289, Mail Code: N5022 P. 0. Box 1771 Wadsworth, TX 77483 San Antonio, TX 78296 U. S. Nuclear Regulatory Commission A. Ramirez/C. M. Canady Attention: Document Control Desk City of Austin Washington, D.C. 20555-0001 Electric Utility Department 721 Barton Springs Road Austin, TX 78704 O:\QUALITYANDLICENSING\TSB\AMENDMENTk02\NOC-AE-02001270

ATTACHMENT REVISED BASES PAGE

PLANT SYSTEMS BASES B 3/4.7.4 ESSENTIAL COOLING WATER SYSTEM The OPERABILITY of the Essential Cooling Water System ensures that sufficient cooling capacity is available for continued operation of safety-related equipment during normal and accident conditions. The ECW self-cleaning strainer must be in service and functional in order for the respective ECW train to be OPERABLE. The redundant cooling capacity of this system, assuming a single failure, is consistent with the assumptions used in the safety analyses.

When a risk-important system or component (for example Essential Cooling Water) is taken out of service, it is important to assure that the impact on plant risk of this and other equipment simultaneously taken out of service can be assessed. The Configuration Risk Management Program evaluates the impact on plant risk of equipment out of service. A brief description of the Configuration Risk Management Program is in Section 6.8.3 (administration section) of the Technical Specification.

SURVEILLANCE REQUIREMENTS SR 4.7.4.a Verifying the correct alignment for manual, power operated, and automatic valves in the ECW flow path provides assurance that the proper flow paths exist for ECW operation. This SR applies to valves that assure ECW flow to required safety related equipment (to CCW heat exchangers, Standby Diesel Generators, Essential Chillers, and CCW Pump Supplemental Coolers). This SR does not apply to valves that are locked, sealed, or otherwise secured in position, since they are verified to be in the correct position prior to being locked, sealed, or secured. This SR does not require any testing or valve manipulation; rather, it involves verification that those valves capable of being mispositioned are in the correct position. This SR does not apply to valves that cannot be inadvertently misaligned, such as check valves.

The 31 day Frequency is based on engineering judgment, is consistent with the procedural controls governing valve operation, and ensures correct valve positions.

SR 4.7.4.b.1 This SR verifies proper automatic operation of the ECW valves on an actual or simulated actuation signal. The relevant signals for the surveillance are safety-injection and loss of offsite power. The ECW is a normally operating system that cannot be fully actuated as part of normal testing. This SR applies to valves that assure ECW flow to required safety related equipment (to CCW heat exchangers, Standby Diesel Generators, Essential Chillers, and CCW Pump Supplemental Coolers). This Surveillance is not required for valves that are locked, sealed, or otherwise secured in the required position under administrative controls. The 18 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a unit outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power. Operating experience has shown that these components usually pass the Surveillance when performed at the 18 month Frequency. Therefore, the Frequency is acceptable from a reliability standpoint.

SOUTH TEXAS - UNITS 1 & 2 B 3/4 7-3a Unit 1 - Amendment No. 85-, 114,126 Unit 2 - Amendment No. 72,!02,!1!5 97-908

ELECTRICAL POWER SYSTEMS BASES A.C. SOURCES, D.C. SOURCES and ONSITE POWER DISTRIBUTION (Continued) manually transferred to the unit's auxiliary transformer or to the standby transformers.

In the event of a loss of preferred power, the ESF electrical loads are automatically connected to the DGs in sufficient time to provide for safe reactor shutdown and to mitigate the consequences of a Design Basis Accident (DBA) such as a loss of coolant accident (LOCA).

Ratings for Train A, Train B and Train C DGs satisfy the requirements of Regulatory Guide 1.108. The continuous service rating of each DG is 5500 kW with 10% overload permissible for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> in any 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period.

Refer to UFSAR Chapter 8 for a more complete description.

APPLICABLE SAFETY ANALYSES The initial conditions of DBA and transient analyses in the FSAR, Chapter 6 and Chapter 15, assume ESF systems are OPERABLE. The AC electrical power sources 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 (RCS), and containment design limits are not exceeded.

The OPERABILITY of the AC electrical power sources is consistent with the initial assumptions of the Accident analyses and is based upon meeting the design basis of the unit.

In Modes 1, 2, 3, and 4 this results in maintaining at least two trains of the onsite or one train of the offsite AC sources OPERABLE during Accident conditions in the event of:

a. An assumed loss of all offsite power or all onsite AC power; and

b. A worst case single failure.

The AC sources satisfy Criterion 3 of NRC Policy Statement.

A single train onsite AC source can effectively mitigate all but the most severe events with operator action in some cases. The events that cannot be mitigated by a single train onsite AC source are highly unlikely. When a risk-important system or component (for example a Standby Diesel Generator) is taken out of service, it is important to assure that the impact on plant risk of this and other equipment simultaneously taken out of service can be assessed. The Configuration Risk Management Program evaluates the impact on plant risk of equipment out of service. A brief description of the Configuration Risk Management Program is in Section 6.8.3 (administration section) of the Technical Specification.

LCO Two qualified circuits between the offsite transmission network and the onsite Class 1 E Electrical Power System and separate and independent DGs for each train ensure availability of the required power to shut down the reactor and maintain in a safe shutdown condition after an anticipated operational occurrence (AOO) or a postulated DBA.

The 138 kV emergency transformer and its associated 13.8 kV bus cannot be used as a source of offsite power for meeting an LCO in any Mode of operation. The 138 kV line from Blessing that feeds the emergency transformer physically crosses under several 345 kV transmission lines and thus fails the independence test for an off site power source.

Qualified offsite circuits are those that are described in the FSAR and are part of the licensing basis for the unit.

SOUTH TEXAS - UNITS 1 & 2 B 3/4 8-2 Unit 1 -Amendment No. 68, 85 Unit 2 - Amendment No. 57, 72 0O0!335!,97-908