ML18151A690

Proposed Tech Specs Re Circulating & Svc Water Sys & Intake Canal

ML18151A690
Person / Time
Site:	Surry
Issue date:	03/27/1989
From:	VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML18151A691	List: ML18151A690 ML18153B667
References
NUDOCS 8904030364
Download: ML18151A690 (52)

Text

• ATTACHMENT 1 PROPOSED TECHNICAL SPECIFICATION CHANGE --------------

---qo:327 *

• 890 403036c~ i 50 00200

• pDR ADO r, PNU

• p hl34-WDC-12142-4 SURRY VE&PCo Application for Amend to Licenses DPR-32 DPR-37 & Rec'd w/ltr dtd 03/27/89 ... 8904030350 -NOTICE-THE A TI ACHED FILES ARE OFFICIAL CORDS OF THE RECORDS & REPORTS MANAGEMENT BRANCH. THEY HAVE BEEN CHARGED TO YOU FOR A LIMITED TIME PERIOD AND MUST BE RETURNED TO THE RECORDS & ARCHIVES SERVICES SECTION P1-122 WHITE FLINT. PLEASE DO NOT SEND DOCUMENTS CHARGED OUT THROUGH THE MAIL. REMOVAL OF ANY PAGE(S) FROM DOCUMENT FOR DUCTION MUST BE REFERRED TO FILE PERSONNEL. -NOTICE-TS 3.14-1. 3.14 CIRCULATING AND SERVICE WATER SYSTEMS Applicability Applies to the operational status of the Circulating and Service Water Systems. Objective To define those limiting conditions of the Circulating and Service Water Systems necessary to assure safe station operation.

Specification A. The Reactor Coolant System temperature or pressure of a reactor unit shall not exceed 350°F or 450 psig, respectively, or the reactor shall not be critical unless: 1. The high level intake canal is filled to at least elevation

+23.0 feet at the high level intake structure.

2. Unit subsystems, including piping and valves, shall be operable to the extent of being able to establish the following:

a. Flow to and from one bearing cooling water heat exchanger.

b. Fl ow to and from the component coo 1 i ng heat exchangers required by Specification 3.13. 3. At least two circulating water pumps are operating or are operable.

4. Three emergency service water pumps are operable; these I pumps will service both units simultaneously.

• TS 3.14-2 5. Two service water flowpaths to the charging pump service water subsystem are operable.

6. Two service water flowpaths to the recirculation spray subsystems are operable.

B. The requirements of Specification 3.14.A.4 may be modified to a 11 ow one Emergency Service Water pump to remain i noperab 1 e for a period not to exceed 7 days. If this pump is not operable in 7-days, then place both units in Hot Shutdown within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and Cold Shutdown within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. The requirements of 3.14.A.4 may be modified to have two Emergency Service Water pumps operable with one unit in Cold Shutdown with combined Spent Fue 1 pit and shutdown unit decay heat 1 oads of 25 mi 11 ion BTU/HR or less. One of the two remaining pumps may be inoperable for a period not to exceed I 7 days. If this pump is not operable in 7 days, then place the operating unit in Hot Shutdown within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and Cold Shutdown within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. C. There shall be an operating service water flow path to and from one operating main control and emergency switchgear rooms air J j conditioning condenser and at least one operable service water fl ow path to and from at 1 east one operable main cont ro 1 and emergency switchgear rooms air conditioning condenser whenever fue 1 is 1 oaded in reactor core. Refer to Section 3. 23. C for air conditioning system operability requirements above cold shutdown.

D. The requirements of Specifications A-5 and A-6 may be modified to allow unit operation with only one operable flow path to the charging pump service water subsystem and to the recirculation spray subsystems.

If the affected systems are not restored to the requirements of Specifications A-5 and A-6 within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />,

,,

• TS 3 .14-3 the reactor shall be placed in a hot shutdown condition.

If the requirements of Specifications A-5 and A-6 are not met within an additional 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, the reactor shall be pl aced in a cold shutdown condition.

The Circulating and Service Water System are designed for the removal of heat resulting from the operation of various systems and components of either or both of the units. Untreated water, supplied from the James River and stored in the high level intake canal is circulated by gravity through the recirculating spray coolers and the bearing cooling water heat exchangers and to the charging pumps lubricating oil cooler service water pumps which supply service water to the charging pump lube oil coolers. In addition, the Circulating and Service Water Systems supply cooling water to the component cooling water heat exchangers and to the main control and emergency switchgear rooms air conditioning condensers~*

The Component Cooling heat exchangers are used during normal plant operations to cool various station components and when in shutdown to remove residual heat from the reactor. Component Cooling is not required on the accident unit during a loss-of-coolant accident.

If the loss-of-coolant accident is coincident with a loss of off-site power, the nonaccident unit wil 1 be maintained at Hot Shutdown with the ability to reach Cold Shutdown.

The long term Service Water requirement for a loss-of-coolant accident in one unit with simultaneous loss-of-station power and the second unit being brought to Hot Shutdown is greater than 15,000 gpm. Additional Service Water is necessary to bring the nonaccident unit to Cold Shutdown.

Three diesel driven Emergency Service Water pumps with a design capacity of 15,000 gpm each, are provided to supply water to the High Level Intake canal during a loss-of-station power incident.

Thus, considering the single active failure of one pump, three Emergency Service Water pumps are required to be operable.

The allowed outage time of 7 days provides operational flexibility to allow for repairs up to and

• • TS 3.14-4 including replacement of an Emergency Service Water pump without forcing dual unit outages, yet 1 imits the amount of operating time without the specified number of pumps. When one Unit is in Cold Shutdown and the heat 1 oad from the shutdown unit and spent fuel pool drops to less than 25 million BTU/HR, then one Emergency Service Water pump may be removed from service for the subsequent time that the unit remains in Cold Shutdown due to the reduced residual heat removal and hence component cooling requirements.

A minimum level of +17.2 feet in the High Level Intake canal is required to provide design flow of Service Water through the Recirculation Spray heat exchangers during a loss-of-coolant accident for the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. If the water level falls below +23'6", signals are generated to trip both unit's turbines and to close the nonessential Circulating and Service Water valves. A High Level Intake canal level of +23'6" ensures actuation prior to canal level falling to elevation

+23'. The Circulating Water and Service Water isolation valves which are required to close to conserve Intake Canal inventory are periodically verified to limit total leakage flow out of the Intake Canal. In addition, passive vacuum breakers are installed on the Circulating Water pump discharge lines to assure that a reverse siphon is not continued for canal levels less than +23 feet when Circulating Water pumps are de-energized.

The remaining six feet of canal level is provided coincident with ESW pump operation as the required source of Service Water for heat loads following the Design Basis Accident.

References:

FSAR Section 9.9 FSAR Section 10.3.4 FSAR Section 14.5 Service Water System Circulating Water System Loss-of-Coolant Accidents, Including the Design Basis Accident

• TS 3.7-9b control room . The supply lines installed from the containment penetrations to the hydrogen analyzers have Category I Cl ass IE heat tracing applied. The heat tracing system receives the same transferable emergency power as is provided to the containment hydrogen analyzers.

The heat trace system is de-energized during normal system operation.

Upon receipt of a safety injection signal (Train A or Train B), the system is automatically started, after a preset time delay, to bring the piping process temperature to 250°F +/- l0°F within 20 minutes. Each heat trace circuit is equipped with an RTD to provide individual circuit readout, over temperature alarm and cycles the circuit to maintain the process temperatures via the solid state control modules. The hydrogen analyzer heat trace system is equipped with high temperature, loss of D.C. power, loss of A.C. power, loss of control power and failure of automatic initiation alarms. Control Room Chlorine Detection System The operability of the chlorine detection system ensures that sufficient capability is available to promptly detect and automatically initiate protective action in the event of an accidental chlorine release. This capability is required to protect control room personnel, and is consistent with the recommendations of Regulatory Guide 1.95, "Protection of Nuclear Power Plant Control Room Operators Against an Accidental Chlorine Release," February 1975. Non-Essential Service Water Isolation System The operability of this functional system ensures that adequate intake canal inventory can be maintained by the emergency service water pumps. Adequate intake canal inventory provides design service water flow to the recirculation spray heat exchangers and other essential loads (e.g., control room area chillers, charging pump lube oil coolers) following a design basis loss of coolant accident with a coincident loss of offsite power. This system is common to both units in that each of the two trains will actuate equipment on each unit.

• -3.7-2

• ENGINEERED SAFEGUARIB ACTION INSTRUMENT OPERATING CX>NDITIONS 1 2 3 4 DffiREE OPERA'IDR ACTION IF MIN. OF CX>NDITIONS OF CX>IIJMN 1 OPERABIB REDJN-PERMISSIBIB BYPASS OR 2 EXCEPI' AS CX>NDITIONED FUNCTIONAL UNIT aJANNEIS D.1\NCY CX>NDITIONS BY CX>IIJMN 3 CANNOI' BE MITT' d. station Blackout 2 0 Restore inoperable channel start Motor Driven Purrp within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> or be in hot shutdown within next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in cold shutdown within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. e. Trip of Main Feedwater 1/Purrp 1/Purrp Restore inoperable channel Pl.mps within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> or be in hot start Motor Pl.mps shutdown within next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in cold shutdown within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. 4. LOSS OF :rowER a. 4.16 "1W Ercergency 2/Bus 1/Bus Place inoperable channel in Bus Undezvoltage tripped condition within (loss of Voltage) one hour. b. 4.16 "1W Emergency 2/Bus 1/Bus Place inoperable channel in Bus Undezvoltage tripped condition within (Grid Degraded Voltage) one hour. 5. NON-ESSENTIAL SERVICE WATER ISOIATION

a. I.ow Intake canal level 3 1 One train may be Place inoperable channel(s) blocked for a period in tripped condition with-not to exceed two in one hour. w hours for the pur-. ....J pose of logic testing. I .... O'l 3.7-4 ENGINEERED SAFEl'Y FEA'IURE SYSTEM INITIATION LIMl'I'S INSTRUMENT SEITING NO. FUNCTIONAL UNIT CliANNEL ACTION SEITING LIMIT 6. AUXILIARY FEEI:WATER.

a. Steam Generator Water level LJ:M-lrM Aux. Feedwater Initiation 5% narrow range S/G Blowdown Isolation

b. RCP un:Iei:voltage Aux. Feedwater Initiation 70% nominal c. Safety Injection Aux. Feedwater Initiation All S.I. setpoints

d. station Blackout Aux. Feedwater Initiation 46.7% naminal e. Main Feedwater Pl.nnp Trip Aux. Feedwater Initiation N.A. 7. I..OSS OF :i:mER a. 4 .16 ro/ Emergency Bus Emergency Bus 75~i% volts with a Undei:voltage Separation an:l (loss of Voltage) Diesel start 2+5, -0.1 seoorxi time delay b. 4.16 ro/ Emergency Bus Emergency Bus 90~i:g% volts with a Undei:voltage Separation and (I'.legraded Voltage) Diesel start 60 3.0 seco:rrl time delay (Non CIS, Non SI) 7+. 35 second time delay (CIS or SI Co:rrlitions)

8. NON-ESSENTIAL SERVICE WATER ISOIATION {.,J a. IJ::::M Intake canal level Isolation of Sei:vice 23 feet-6 inches . water flow to non-I t-' essential loads U)

I I

• TABIE 4.1-1 MINIMUM FREX)UENCIFS FOR CHECK, CALIBRATIONS, AND TEST OF INSTRUMENT OIANNELS Channel Description 33

• loss of Power 34. a. 4.16 1W Einergency Bus voltage (loss of Voltage) b. 4.16 1W Energency Bus voltage (Degraded Voltage) Control Roam Clll.orine Detectors

35. Manual Reactor Trip 36. Reactor Trip Bypass Breaker 37. safety Injection Input from FSF 38. Reactor Coolant Pump Breaker Position Trip Check N.A. N.A. s. N.A. N.A. N.A. N.A. calibrate R R R N.A. N.A. N.A. N.A. Test M M M R M(l), R(2) R R Remarks 'Ihe test shall irrlependently verify the operability of the urnei:voltage and shunt trip attachments for the manual reactor trip function.

'Ihe test shall also verify the bility of the bypass breaker trip circuit. (1) IDcal manual urnei:voltage trip prior to placing breaker in service. (2) Automatic shunt trip. u5 ,i::,. . t--' I O:> PJ Channel Description

39. Steam/Feedwater Flow and low S/G Water Level T 4.1-1 MINIMUM FREQUENCIES FOR CHECK, CALIBRATIONS, AND TEST OF INSTRUJ.VIENT CHANNEIS s calibrate R M 40. Intake canal I.ow {See Footnote 1) D R M{l), Q{2) s -Each Shift M -Monthly

• Remarks {l) Logic Test (2) Channel Electronics Test D N.A. Q -Daily -Not Applicable P -Prior to each startup if not done within the previous week R -Each Refueling Shutdown -Evecy 90 effective full power days

• See Specification 4.1.D Footnote 1: calibration Consists of verifying for an indicated intake canal level greater than 23'-6" that all four low level sensor channel alanns are not in an alann state. Consists of uncovering the level sensor and measuring the time response and voltage signals for the immersed and dcy conditions.

It also verifies proper action of instnnnent channel from sensor to electronics to channel output .relays and annunciator.

Only the two available sensors on the shutdown unit would be tested. Test (1) The logic test verifies the three out of four logic development for each train by using the channel test switches for that train. (2) Channel electronics test verifies that electronics module responds properly to a superimposed differential millivolt signal which is equivalent to the sensor detecting a "dl:y" condition.

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DFSCRIPI'ION 14a. Service Water System Valves in Line SUpplying lation Spray Heat Exchangers

b. Sezvice Water System Valves Isolating Flow to essential loads on Intake canal IDw level Isolation

15. Control Room Ventilation System 16. Reactor Vessel OVe:pressure Mitigating System ( except backup air supply) 17. Reactor Vessel OVe:pressure Mitigating System Backup Air SUpply TABI.E 4 ** (CONTINUED)

MINIMUM ~CY FOR ~IMENT TESTS Functional Functional

• Ability to maintain positive sure for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> using a volurre of air equivalent to or less than stored in the bottled air supply Functional Setpoint FRE@ENCY F.ach refueling Refueling F.ach refueling intel:val (approx. every 12-18 months) Prior to decreasing RCS temperature below 350 _F and monthly while the RCS is 350 F and the Reactor Vessel Head is bolted Refueling

• FSAR SECTION REFERENCE 9.9 9.9 9.13 None None

• EVALUATION OF SORRY INTAKE CANAL INVENTORY TECHNICAL SPECIFICATION CHANGES 10 CFR 50.92 REVIEW The Virginia Electric and Power Company requests an amendment in the form of a change to the Technical Specifications to Operating Licenses DPR-32 and DPR-37 for Surry Power Station Units 1&2, respectively.

This change will: 1) raise the minimum Circulating and Service Water Intake Canal level from eighteen feet to twenty-three feet, 2) increase the requirement from two to three Emergency Service Water pumps to be operable with provision for limited duration maintenance outages, and 3) provide operability and surveillance requirements for the new safety-related canal level actuation system. Virginia Electric and Power Company has reviewed the proposed changes against the criteria of 10 CFR 50.92 and has concluded that the changes do not pose a significant safety hazards consideration as defined therein. Specifically, operation of Surry Power Station with the proposed amendment will not: 1. Involve a significant increase in the probability of occurrence or consequences of any accident or malfunction of equipment which is important to safety and which has been previously evaluated in the UFSAR. h134-WDC-12142-10 These Technical Specification changes are accompanied by changes to the physical plant which will include new vacuum breakers to prevent reverse siphoning at the new, higher canal level, addition of a safety-related canal low level actuation system, repowering the Circulating Water valves to assure isolation in the event of an Emergency Diesel Generator failure, installation of manual vacuum breaker valves on the Discharge Tunnel to break prime and hence conserve inventory, and installation of Component Cooling heat exchanger Service Water flow instrumentation to allow throttling during a Design Basis Accident.

Changes to the Emergency Operating procedures have also been developed which will require operator actions to verify specific Circulating and Service Water valves are closed to limit canal inventory depletion during accident conditions, the Emergency Service Water pumps are started when required, the discharge tunnel vacuum breakers are opened, the CCHX's are throttled and the Residual Heat Removal System is placed in service. New Periodic Tests will ensure the operability

• of the safety-related canal level actuation system, verify Component Cooling Water heat exchanger operability, and verify Circulating and Service Water valve leakage flow rates. Changes to the Technical Specifications will raise canal level to provide more working inventory, require additional Emergency Service Water pumping capacity during a Design Basis Accident and impose surveillance requirements on the new canal low level actuation system. A review has been made of the containment analysis, Main Steamline Break, large break LOCA analysis and other UFSAR Chapter 14 accidents.

These changes do not affect the probability of any accident.

The effect of the changes will be to improve the reliability of and to ensure Emergency Service Water supply under abnormal and accident conditions.

The current UFSAR accident analysis results and conclusions, therefore, are not affected by the proposed changes. 2. Create the possibility of a new or different type of accident from those previously evaluated in the safety analysis report. The enhancements to the reliability and performance of the Service Water supply system have no impact on the range of initiating events previously assessed.

These proposed changes address and will eliminate or reduce the probability of several of the potential safety system failure modes identified in the Service Water design basis review. 3. Involve a significant reduction in a margin of safety. h134-WDC-12142-ll Although operational requirements and plant systems have been modified to conform to the reconstituted design basis and assumptions, the Service Water system function is maintained, thereby ensuring the present safety analysis remains bounding.

Specifically, increasing the canal inventory, requiring additional Emergency Service Water pumping capacity, addressing Component Cooling Water heat exchanger Service Water flow, providing time for operators to isolate specific Circulating and Service Water valves and limiting leakage flows ensures that the system function to provide adequate Service Water is maintained.

Since the system function is being maintained, the results of th_e UFSAR accident analyses remain bounding, and therefore, the safety margins are not impacted .

• A"l-rACHMENT 2 EVALUATION OF SURRY INTAKE CANAL INVENTORY AND COMPONENT COOLING BEAT EXCHANGER OPERABILITY I. INTRODUCTION II. IDENTIFICATION OF ISSUES III. DESIGN MODIFICATIONS IV. TECHNICAL SPECIFICATION CHANGES

V. PROCEDURE

S AND TRAINING VI. CANAL INVENTORY DESIGN BASIS UPDATE VII.

SUMMARY

h134-WDC-12142-13 I

• *

• I. ATTACHMENT 2* EVALUATION OF SURRY INTAKE CANAL INVENTORY AND COMPONENT COOLING HEAT EXCHANGER OPERABILITY INTRODUCTION For the past several months, Virginia Electric and Power Company has been reviewing, in conjunction with a NRC Safety System Functional Inspection (SSFI), the design basis of the Surry Power Station Service Water System. Our letter (Serial No.88-689) of October 19, 1988, identified several areas which required investigation and corrective action prior to plant restart. One of these areas was the Intake Canal inventory control and management during and following a postulated Design Basis Accident.

As a result, an integrated program of Design Changes, Technical Specifications changes, Periodic Test procedure changes and Emergency Operating Procedure changes was developed to address these deficiencies.

Integral with these solutions was the need to address Component Cooling heat exchanger operability.

The associated design and procedure changes are discussed in some detail, so that the Technical Specifications Changes may be seen in the context of the overall canal inventory management program. The purpose of this evaluation is therefore to present an assessment of the integrated solutions to various issues identified in reviewing the Surry Power Station Intake Canal inventory and Component Cooling heat exchanger operability.

The evaluation will first describe each of the issues which were developed from the NRC Safety System Functional Inspection and independently by Virginia Electric and Power Company. Each of these issues will be addressed by some combination of Design Changes, Station Procedure changes and Technical Specification changes. These changes are identified on the following page in a resolution matrix which will serve as a guide to discussion of the resolutions.

A summary of the Intake Canal inventory design basis reconstitution is then presented.

The conclusion of this report is that the proposed changes do not pose a significant safety hazards consideration.

In fact, the Technical Specification changes described herein represent an imposition of new and more conservative means of meeting the design basis requirements

• h134-WDC-12142-14

• ISSUES SECTION MATRIX OF CANAL INVENTORY ISSUES The following sections address Identification of Issues, Design Changes, Technical Specification Changes and Procedure Changes, in that order. The matrix shown below helps to correlate these various solutions to their source issues. The integrated solution is then evaluated in the final sections (Sections VI and VII) of this report. ISSUE DESIGN CHANGE TECHNICAL SPECIFICATION CHANGE PROCEDURE CHANGE II.A.l. LOCA/LOOP with ESWP Failure Section V.A New EOP Steps II.A.2. LOCA/LOOP with EDG Failure II.A.3. LOCA/LOOP or Low Canal Level with SW or CW valve failure Section III. A Repower CW valvesSection III.A Repower CW valves II.B. Nonsafety-Related Canal Isolation -Section III.B Safety Grade Level Actuation II.D. II.E. II.F.

• DEA with RHR on Nonaccident Unit Reverse Siphon of CW Lines Appendix 'R' Vacuum Breakers Component Cooling Water Heat Exchanger Operability hl34-WDC-12142-15 Section III.C Passive Vacuum BreakersSection III.D Waterbox Vacuum BreakersSection III.E. Discharge Tunnel Vacuum BreakersSection III. F. CCHx Flow & Delta P mentation Section IV.A New Canal Level Section V.A New EOP StepsSection IV.C Section V.B New Surveillance New Periodic Requirements TestsSection IV.B 3 ESWPs Operable Section V.A New EOP StepsSection V.B New Periodic Tests II. IDENTIFICATION OF ISSUES As a result of NRC and Virginia Electric and Power Company review of the Circulating and Service Water System, the following issues were identified as needing resolution.

The related Station Deviations are identified in this report. The report provides information concerning the modifications and procedure changes made to address these Station Deviations. (See Addendum #1). A brief statement concerning the proposed resolution for each issue is presented.

Further details on these resolutions are provided in subsequent sections.

A. Intake Canal Level Drawdown During a Design Basis Accident Due to Single Failure. (Station Deviations 88-0921, 88-1170) 1. Loss of Coolant Accident (LOCA) and Loss of Off-site Power (LOOP) with Emergency Service Water Pump (ESWP) Failure. The first postulated event is a loss of coolant accident in one unit with a concurrent loss of off-site power. The scenario assumes four Recirculation Spray heat exchangers and pumps on the affected unit actuate per the Engineered Safeguards design and only one diesel-driven Emergency Service Water pump operates (Technical Specification 3.14.A.4 currently requires two Emergency Service Water pumps operable for a unit to be above 350° F/450 psig or critical; in the scenario, one of these pumps is assumed to fail). The Emergency Service Water pump has a design capacity of 15,000 gpm. The Recirculation Spray system will initially draw approximately 25,000 gpm. Thus a canal drawdown of at least 10,000 gpm could result, leading to eventual loss of adequate canal inventory (i.e., less than 17 feet). RESOLUTION:

Revise the Emergency Operating Procedures for operation of Emergency Service Water pumps and Recirculation Spray heat exchangers to manage canal inventory losses. 2. LOCA and LOOP With Nonaccident Unit's Emergency Diesel Generator Failure The second postulated event is a loss of coolant accident in one unit with a concurrent loss of off-site power to the Station. This scenario assumes a failure of the Emergency Diesel Generator on the nonaccident unit with the other two Emergency Diesel Generators aligned to the accident unit. In this case, no power is available to close the Circulating .Water valves on the nonaccident unit resulting in a canal draw down of at least 880,000 gpm, and subsequent loss of adequate canal inventory.

At some point, the swing diesel could be transferred to the nonaccident unit, but the associated design penalty in additional required canal level was unacceptable.

RESOLUTION:

Repower the Circulating Water valves, as required, to ensure that emergency power is available to at hl34-WDC-12142-16

• least one inlet or outlet Circulating Water valve for each waterbox.

In this way, a loss of a single Emergency Diesel Generator does not prevent isolation of Circulating Water. 3. LOCA & LOOP or Low Canal Level With a Failure of Circulating Water (CW), Bearing Cooling (BC), Component Cooling (CC) or Service Water (SW) Supply Valve Isolation The third postulated event also starts on a loss of coolant accident in one unit with a concurrent loss of off-site power to the Station or a low canal level. This scenario assumes a power feed failure or mechanical failure to close any one of the Bearing Cooling, Component Cooling (Unit 1) or other Service Water supply (Unit 2) valves. Component Cooling, Bearing Cooling and Turbine Building Service Water Supply valves do not have a redundant MOV downstream.

As such, a single failure of a valve will leave the line open thereby reducing canal inventory.

During a LOOP/LOCA, one half of the Circulating Water valves on the nonaccident unit will not have power available.

This would result in an open Circulating Water line should one of the remaining valves with power fail to close. RESOLUTION:

a.) Repower the Circulating Water valves as discussed in A.2 above. b.) Revise the Emergency Operating Procedures to require manual confirmation/action for closing specific Service Water isolation valves under accident or abnormal operating conditions.

c.) Revise the Technical Specifications to raise the minimum Intake Canal level from 18'0" to 23'0". This will allow sufficient time for required operator actions and still ensure Recirculation Spray heat exchanger operability throughout the event. B. Nonsafety-Related Grade Condenser and Service Water Isolation Signals (Station Deviations 88-0759, 88-0921) 1. Low intake canal level (18' -0") detection by nonsafety-related Unit 1 and Unit 2 sensors with no provision for single failure closes both Unit 1 and Unit 2 Circulating Water main condenser inlet and outlet valves via the nonsafety-related turbine trip circuitry.

2. MOV-SW-lOls, 102s, 201s and 202s respond to the same signals as noted above. These valves serve to isolate the Bearing Cooling, Component Cooling and nonessential Service Water subsystems.

h134-WDC-12142-17 RESOLUTION:

a.) Install safety-related canal low level actuation circuitry for these valves and upgrade the canal level indication.

• b.) Revise the Technical Specifications to add new operability and surveillance ments for this safety-related tation. C. Potentia1 for Inadequate Emergency Service Water Supp1y During a Design Basis Accident with Cooldown or Residua1 Heat Residual (RHR) Operation on the Nonaccident Unit (Station Deviation 88-0921, 89-0256) D. As discussed in 'A.l' above, Technical Specification 3.14.A.4 requires operability of two Emergency Service Water pumps. In the event of a Loss of Coolant Accident with a loss of off-site power with cooldown required on the nonaccident unit, or if that unit's RHR system is operating, three Emergency Service Water pumps should be operable as stated in UFSAR Section 9.9.1.2. RESOLUTION:

Revise the Technical Specifications to require three Emergency Service Water pumps to be operable with two units at power. Potentia1 for the Circulating Water Pump Discharge Lines to Siphon Back to the James River on a Loss of Power to the Circulating Water Pumps (Station Deviation 88-0962) The Circulation Water pumps, lines and air operated vacuum breakers are non-safety grade equipment located at the Low Level Intake Structure.

Failure of the vacuum breakers must be assumed and as a result, a reverse siphon could be established following a power loss to the Circulating Water pumps. The existing design includes a passive vacuum breaker element in that the discharge piping is uncovered starting at canal levels of approximately 19 feet. By the time level drops to 18 feet sufficient air flow is established to break the vacuum. This scenario becomes a problem only when canal inventory must be maintained at elevations above 18 feet. Because the resolution to the problems stated in A through C above required canal levels to be held greater than 18 feet, then this issue must be addressed.

RESOLUTION:

Install passive vacuum breakers on the Circulating Water Pump discharge lines to assure a reverse siphon will not be present for canal levels less than or equal to 23 feet. h134-WDC-12142-18

• E. Circulating Water Valves Not Required to Operate During an Appendix R Event (Station Deviation 88-1169) The current Appendix R analysis allows for failur~ of the Circulating Water valves to close followed by Operator action. The failure of the valves would cause Intake Canal level to drop to the bottom row of condenser tubes. At this elevation suction conditions for the Charging Pump Service Water pumps and Control Room Chiller Condenser Service Water pumps would remain satisfactory throughout the event. A method for breaking Condenser waterbox vacuum under full flow conditions is not addressed in the current plant design. RESOLUTION:

a.) Install vacuum breakers on the Condenser waterboxes with pneumatic remote and local actuation capability.

F. Component Cooling Water Heat Exchanger Operability in a Degraded Condition (Station Deviation 89-0256) The Service Water side of the heat exchangers is subject to significant microfouling and macrofouling phenomena.

The reduced performance of the heat exchangers must be accounted for in the design basis by application of appropriate fouling factors to both the Service Water and Component Cooling Water sides of the heat exchanger.

RESOLUTION:

a.) Install flow and differential pressure instrumentation on the Service Water side of the heat exchangers.

hl34-WDC-12142-19 b.) Install Discharge Tunnel vacuum breakers to conserve Intake Canal inventory for use in the Component Cooling heat exchangers.

c.) Implement a periodic test to measure combined Circulating and Service Water isolation valve leakage. Implement a periodic test to measure Component Cooling Water heat exchanger operability.

d.) Revise the EOP's to include operator actions for establishing throttled flow of the Component Cooling heat exchangers and opening the Discharge Tunnel vacuum breaker valves .

• III. DESIGN MODIFICATIONS The modifications identified in the previous section are described in more detail in this section. Note that each modification is referenced to its related issue. A. Repower Circulating Water valves (Refer to Section II.A.2 and II.A.3) The design modification to repower the Circulating Water valves will ensure that power is available to close enough valves to isolate the Condenser waterboxes assuming a Design Basis Accident (DBA) coincident with a failure of any Emergency Diesel Generator (EDG)

• The modification involves repowering the "purple" lJ and 2J Motor Operated Valves (MOV's) from Motor Control Center (MCC) lJl-lA located in Emergency Diesel Generator Room No. 3. This MCC is typically supplied from MCC lJl-1, but will automatically align (by sensing voltage) to either 480V Bus lJl-1 or MCC 2Jl-l depending upon which bus, lJ or 2J, that EDG 3 aligns to. Under this design both the inlet and outlet valves on each waterbox receive power. This ensures that a single EDG failure during a design basis accident will not prevent isolation of the Condenser waterboxes and will conserve canal inventory.

In addition, this scheme ensures that the inlet and outlet valves receive power if the three EDG's operate properly and, therefore, a postulated single failure of an inlet or outlet valve will not result in loss of canal inventory.

B. Safety-Related Canal Level Actuation (Refer to Section II.B) A new Intake Canal low level isolation actuation system has been installed as a safety-related system. The four canal level sensors are installed in separate High Level Intake screen bays between the screens and the bar racks. The level sensors are made of titanium, have a teflon coating, and have a welded construction to resist the effects of brackish water and marine growth. Each sensor is seismically mounted at a fixed elevation (23'6") to initiate canal isolation at a level which will maintain the canal level above the Technical Specification limit of 23 feet. The sensor's remote electronics enclosures are located on the north wall of the High Level Intake structures.

The enclosures and the interconnecting conduit are missile protected from the sensor to the underground cable duct bank. Each sensor and remote electronics module forms an independent instrument channel which has its own independent vital bus power supply, separate raceway routing, and separate channel relay panel. The four independent instrument channels are used to develop two independent trains of 3-out-of-4 logic for canal low level isolation actuation.

Each logic train has its own independent power supply, located in separate areas (Unit 1 Cable Vault and Unit 2 Instrument Rack room), is continuously monitored for loss of power, and can be tested independently of the other train. hl34-WDC-12142-20

• Each logic train develops signals to initiate a turbine trip (both units) and send valve closure signals to the Circulating Water valves (MOV-CW-lOOA-D, 106A-D, 200A-D, 206A-D) and Service Water valves (MOV-SW-101A&B, 102A&B, 201A&B, 202A&B) upon reaching the canal low level isolation setpoint.

Annunciation in the main control room will be provided for the following conditions:

each level channel power failure, low level condition, sensor failure, or channel testing; each logic train power failure or testing; and "first out" alarms for Unit 1 and Unit 2 turbine trips caused by Intake Canal low level. The existing Intake Canal level indicating system is improved by upgrading the electrical portion of the system to safety-related.

A new safety-related level instrument channel is being installed in each unit's instrument racks which are powered from separate vital buses. Each level channel will develop the following signals: high and low level alarms (existing), channel test alarm (new), P250 computer input (existing), control room indication (existing), and Emergency Response Facility computer input (new). A new cable will be installed and routed in the channel raceway for the instrument rack to the level transmitter at each unit's screenwell.

When these changes are implemented, the level indication system will be an independent and diverse system from the canal low level isolation actuation system. It will not, however, include a safety-related air supply to the bubbler. A long term modification to install a complete safety-related canal level continuous indication system is also being pursued, but is dependent on qualification of an indication transmitter for use in the Surry Intake Canal environmental conditions.

C. Passive Vacuum Breakers (Refer to Section II.D) A passive vacuum breaker is being installed which consists of an open nozzle in the down sloping leg of the Circulating Water discharge pipe. The passive vacuum breaker will conserve Intake Canal water inventory in the event of a failure of the existing nonsafety grade, air operated vacuum breaker(s) concurrent with the associated Circulating Water pump being de-energized and canal level falling to elevation 23 feet. The location of the new Circulating Water discharge pipe nozzle is just above the proposed Technical Specification canal level of 23 feet. If the canal water level falls below the elevation of the discharge pipe nozzle, a means of temporarily plugging the nozzle is provided to evacuate the discharge pipe prior to energizing a Circulating Water pump. After the Circulating Water pump is energized and the normal siphon assist established, Station.procedures will require removal of the plug to assure the integrity of the passive vacuum breaker . h134-WDC-12142-21

• D. Waterbox Vacuum Breakers {Refer to Section II.E) The proposed resolution for breaking vacuum on the Condenser waterbox involves the installation of manually operated, pneumatically actuated butterfly valves on each of the four (4) Condenser waterboxes per unit. The valves are being furnished with local as well as a remote means of actuation.

Each Unit's remote control station is located in a fire area that is separated from the Turbine Building by a fire wall. The remote control stations are required in the event of an Appendix 'R' fire in the Turbine Building.

For this reason, the valve actuation system is entirely pneumatic.

E. Discharge Tunnel Vacuum Breakers {Refer to Section II.F) In order to conserve Intake Canal inventory in the event of a Design Basis Accident {DBA), the self-priming action of the Discharge Tunnel must be broken before 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> have elapsed since the start of the accident.

The discharge tunnels (2) for Surry have manhole accesses in the Radiologically Controlled Area {RCA) in the North yard near each of the two (2) Vacuum Priming houses *. A seismic, safety-related valve will be installed in each manhole pit. The valves will be manually operated and missile protected.

In all likelihood, Discharge Tunnel priming will not be maintained in the event of a DBA. The valve is provided to ensure that prime is broken and canal inventory is conserved.

F. Component Cooling Heat Exchanger SW Instrumentation

{Refer to Section II. F.) Service Water flow through the Component Cooling heat exchangers must be controlled to remove heat loads and minimize canal inventory usage. Determining Component Cooling heat exchanger operability requires the installation of both Service Water flow and differential pressure instrumentation.

The flow device will be a stainless steel annubar mounted on the inlet side of the heat exchanger.

This device will be permanently installed and periodically removed for cleaning.

The initial calibration will be achieved by performing a series of Pitot traverses at different flow points for each heat exchanger.

Flow will be read at local gauges. The differential pressure instruments will also be locally read and valved into service only when readings are required.

The combination of gauges will be used to periodically verify the operability of the heat exchangers during normal operations, and to allow throttling of the heat exchangers during a DBA. The throttled flow value conserves canal inventory while allowing sufficient flow to a heat exchanger for removal of plant heat loads. hl34-WDC-12142-22 IV. * * ---~ .. h134-~ TECHNICAL SPECIFICATION CHANGES There are three separate technical specification (TS) changes included in this section. The first and second revise TS 3.14 on Circulating and Service Water Systems. They correspond to issues II.A.3., and II.C .. One issue will require raising intake canal level to support Recirculation Spray heat exchanger flow by allowing for automatic and operator action times to isolate nonessential Service Water flowpaths.

The other issue requires three operable Emergency Service Water pumps for long term accident mitigation.

The third technical specification change revises both TS 3.7 and TS 4.1 to add surveillance requirements for the new safety-related canal level actuation system. This change corresponds to issue II.B. A. Revised Intake Canal Level (Refer to Section II.A.3) The minimum Intake Canal Level Technical Specification 3.14.A.l will be modified to be consistent with the Intake Canal design basis. The Specification is being revised as noted in Attachment

1. The proposed changes are based on an analysis of canal inventory depletion and makeup for various accident scenarios.

This calculational design basis is explained in detail in Section VI of the report. The additional level provides adequate Service Water flow inventory to all essential equipment throughout the DBA. The additional level works in conjunction with the Emergency Service Water pumps to supply these needs for the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. After 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> canal level will stabilize based on isolating the third Recirculation Spray heat exchanger.

B. Revised Emergency Service Water Pump Operability Requirements (Refer to Section II.C) An additional revision to Technical Specification 3.14 is being proposed which enhances the performance of the Emergency Service Water system. Specifically, Specification 3.14.A.4, 3.14.B.1 and 3.14.B.2 are being revised as noted in Attachment

1. The current specification (3.14.A.4) requires two Emergency Service Water pumps (ESWPs) to be operable for a unit to exceed. 350° For 450 psig. Requiring an additional ESWP will ensure adequate service water inventory for both units in the event of a Design Basis Accident (DBA) in one unit coincident with or followed by a loss of off-site power. Analyses have shown that, even with a single active failure of an Emergency Service Water pump, the inventory in the Intake Canal combined with the makeup capability of the two remaining Emergency Service Water pumps is adequate to provide an ultimate heat sink for the following loads: Component Cooling to the Spent Fuel Pool coolers and the Residual Heat Removal system for a shutdown unit.

• Cooling to the inside and outside Recirculation Spray heat exchangers for the accident unit (operator action is required to remove heat exchangers from service as containment heat loads drop.) Cooling to the Control Room, Emergency Switchgear Room and Relay Room Chillers and Charging pumps Up to one hour of excess flow to non-required loads (e.g., Component Cooling, Bearing Cooling) which would require manual operator action for isolation during the event. Continuous leakage flow through Circulating and Service Water isolation valves up to 5000 gpm total for the Station (Leakage flow is reduced to 1000 gpm total when T.S.3.14.B.2 is in effect. The analyses show that the minimum canal level reached during the limiting scenario remains above that required to guarantee design Service Water flow rate to the required loads. (See Section VI). The allowed outage time of 7 days provides operational flexibility to allow for repairs up to and including replacement of an Emergency Service Water pump without forcing a dual unit outage, yet limits the amount of operating time without the third pump operable.

Operation for a limited time without the third pump operable is acceptable based on the low probability of a design basis loss of coolant accident with a loss of off-site power and the likelihood that the two operable Emergency Service Water pumps will start and run on-demand.

When one unit is in cold shutdown and spent fuel pool plus the shutdown unit's heat loads drop to less than 25 million BTU/HR, then one Emergency Service Water pump may be removed from service for the subsequent time that the unit remains in cold shutdown.

In this case, a second ESWP can be inoperable for 7 days for the same reasons as stated above. C. Intake Canal Level Instrumentation and Low Level Isolation Actuation Circuitry (Refer to Section II.B) Technical Specifications 3.7 and 4.1 are being modified in order to specify the operability and surveillance requirements of the four new channels of safety-related canal level instrumentation and two new trains of low level isolation actuation circuitry.

The setting limit for the low level isolation actuation was set for elevation 23 feet -6 inches in order to ensure Intake Canal isolation prior to reaching the safety analysis limit of elevation 23 feet during a maximum canal drawdown event and taking into account the time response of the level sensor . The actual changes to the Technical Specifications are noted in Attachment

1. hl34-WDC-12142-24

• *

V. PROCEDURE

S AND TRAINING The design and Technical Specification changes for the upgraded Service Water inventory control program are being augmented with enhancements to training and to station procedures.

These are designed to enhance the control room operators' awareness of the consequences of and readiness to cope with losses or potential losses of Intake Canal inventory during normal and accident conditions.

The three important aspects of this program which are discussed here are the associated upgrades to emergency operating procedures (EOPs), addition of periodic tests and general background training on canal inventory issues. A. Emergency Operating Procedure Upgrades II.A.l, II.A.3, & II.F) (Refer to Sections New guidance is being added to the existing EOPs used in response to reactor trip/safety injection and loss of reactor or secondary coolant. The operator will be directed to confirm canal level above the required minimum. If the level drops below the requirement, direction will be given for confirming isolation of nonessential Service Water loads to both units and for starting available Emergency Service Water pumps. Steps are being added to the loss of coolant procedure which provide guidance on reducing Service Water requirements to the Recirculation Spray system after the initial phases of containment depressurization have been accomplished

• The effectiveness of this approach is being validated by training exercises with two shifts of licensed operators.

These exercises are used to confirm the conservatism of various operator response times assumed in the design basis canal inventory calculations for activities required within the first two hours of the DBA. These calculations analyzed the various failure scenarios and established the minimum canal level Technical Specification requirement (see Section VI). The operator response times pertain to isolation of nonessential Service Water loads which may require manual action due to postulated valve failures or loss of emergency power; to initiation of Emergency Service Water pump operation as required; and to reduction of service water flow to the Recirculation Spray system based on observation and assessment of containment conditions during the course of the event. Additional steps are being verified and added to the EOP's for activities which are not required in the first two hours of the accident.

These steps will cover opening of the Discharge Tunnel vacuum breakers and throttling of the Component Cooling heat exchangers.

These activities must be completed within the first four hours of the initiation of the accident.

In addition, Residual Heat Removal should be deferred on the nonaccident unit for at least 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to allow for the maximum cooldown possible on Auxiliary Feedwater.

hl34-WDC-12142-25

• Actions for ensuring canal inventory (isolate an additional Recirc. Spray heat exchanger, restore inoperable Service Water pumps and/or restore off-site power and start a Circulating Water pump, etc.) for long term accident recovery are also being inserted.

Similar steps are being added to other supporting procedures (e.g., annunciator procedures, Fire Contingency Actions, abnormal operating procedures) to provide a comprehensive operator awareness of canal inventory.

While the steps required within the first two hours are being validated by the approach outlined above, changes to the Station procedures based on Canal Inventory issues will undergo a documented verification program. B. Periodic Test Procedures (Refer to Sections II.Band II.F) There are three periodic tests to be added to the Station's periodic testing program as a result of the Canal Inventory issues. 1. A set of periodic tests will be added to verify the operability of the canal low level actuation circuitry.

The specific tests will be prepared in accordance with the new Technical Specification requirements in Sections 3.7 and 4.1 as noted in Attachment

1. 2. A periodic test will be prepared to verify Circulating and Service Water isolation valve leakage remains less than the allowable as established in the reconstituted design basis. Specifically, a.) For all modes of operation, the allowable total Station leakage flow must be less than 5000 gpm, except for the following case; b.) When one unit is in operation and one unit is in Cold Shutdown with Spent Fuel Pool and Residual Heat Removgl heat loads for the shutdown unit less than 25Xl0 BTU/HR and it is desired to remove one Emergency Service Water pump from service, then the total Station leakage flow must be less than 1000 gpm. Establishing these leakage flow requirements on a Refueling frequency ensures adequate inventory and Emergency Service Water pump flow are available to serve all Service Water flow requirements during the design basis accidents.

3. A periodic test will be prepared to verify operability of Component Cooling Water heat exchangers.

Various plant operating modes were considered, but the limiting case is a h134-WDC-12142-26 Design Basis Accident with a loss of offsite power to the Station. An operable heat exchanger can meet the limiting case heat removal requirements while in a quantifiable, partially degraded (i.e., flow blockage) condition.

The periodic test will be used to determine that the heat exchanger remains operable for the limiting heat removal condition.

Due to the seasonal variations in heat exchanger fouling, the period for this test must be established by first setting a fairly high testing frequency until a reduction in that frequency can be substantiated.

C. General Training Enhancement The control room operator training programs are being enhanced to provide additional background information regarding the role of the Intake Canal level as an indicator of availability of the ultimate heat sink for the plant during shutdown and accident conditions.

Topics to be discussed will include the basis for the minimum level, assumptions made in the design basis analyses, the new EOP enhancements and manual actions which may be required to mitigate excessive canal drawdown under abnormal and accident conditions.

The various design enhancements, periodic tests and Technical Specifications changes presented in this report are being incorporated into the training program and will be discussed in terms of their interrelationship with the procedures in comprising a comprehensive program for upgraded canal inventory management.

hl34-WDC-12142-27

• VI. CANAL INVENTORY DESIGN BASIS UPDATE The design basis of the Intake Canal Technical Specification has been updated as a result of a review of the Service Water system operational requirements under a design basis event with loss of site power. Items reviewed for this update are the various single failure modes, operator actions and response times, and analysis conservatisms.

This review has resulted in a redefinition of the limiting case and associated final results. These are explained as separate items below. A. Single Failure Modes Single failure modes considered are the failure of an isolation valve on the Bearing Cooling heat exchangers (BCHX), or the Component Cooling heat exchangers (CCHX), or the Condenser waterbox.

The failure of a single Emergency Service Water (ESW) pump and the failure of any single Emergency Diesel Generator (EDG) are also considered.

The failure of an Emergency Diesel Generator has been covered by repowering the Circulating Water isolation valves. (See Section III.A). Therefore, failure of four Circulating Water lines to isolate was not further considered.

Failure of an EDG will result in a failure of a BCHX and CCHX isolation valve to close, however. The normal flow of the CCHX is less than that of the BCHX, therefore a failure of a CCHX isolation valve is bounded by the failure of a single BCHX isolation valve. The failure of an isolation valve on the waterbox was analyzed and was demonstrated to require a higher initial Intake Canal level than the BCHX isolation valve or ESWP failure; but the design change identified in Section III.A which places the inlet and outlet waterbox isolation valves on separate Emergency Diesel Generator powered buses has eliminated this as a condition requiring analysis.

Since both the inlet and outlet valves will close upon the appropriate emergency signal, the waterbox will be isolated even with a single valve failure of one of its isolation valves or of an emergency power source. With each of the failure modes two initial operating cases were considered

1) two units initially operating, 2) one unit operating and one unit in refueling (on RHR). While other failure modes were reviewed as identified above, the summary of analyzed failure modes consists of only the two most limiting cases as follows: 1. I-Bearing Cooling heat exchanger isolation valve 2. 1-Emergency Service Water pump hl34-WDC-12142-28

• B. Identification of Required Operator Action With each failure mode, operator actions are required to ensure that the Intake Canal inventory is maintained while providing adequate water to required Service Water loads. The essential nature of these actions is related to the verification and closure of any valves that are required to be isolated within a set period of time, to ensuring that the ESW pumps are operating within the appropriate time, to opening the Discharge Tunnel vacuum breaker valves and to throttling the Component Cooling heat exchangers. (See Section V.A for further details.)

The necessary nonessential Service Water isolation valves are assumed to be closed or verified closed within the first 60 minutes of the initiation of a DBA or Loss of Off-Site Power. These valves along with the Circulating Water isolation valves are assumed to meet specific leakage flow limits as verified by Periodic Tests. The isolation of one train of Recirculation Spray heat exchangers is dependent on reaching subatmospheric conditions in the containment.

This is conservatively assumed to be within 60 minutes of the initiation of the Design Basis Accident.

Isolation of one train of heat exchangers (2 total) is assumed rather than one heat exchanger from each train as this allows a lower, yet acceptable Service Water flow without the need for throttling the flow. Excess Service Water flow results when only one heat exchanger is in service per train. The necessary ESW pumps are to be verified as operating within 120 minutes from the initiation of a DEA or Loss of Off-Site Power event. As discussed in Section V, these response times have been demonstrated to be conservative by standard emergency operating procedure validation techniques, including simulator exercises and plant walkdowns.

Additional operator actions are required within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of the initiating event. The discharge tunnel is required to be in an unprimed condition in order to conserve canal inventory.

An operator will open the Discharge Tunnel vacuum breakers to insure that any residual self-priming is broken. An operator must also go to the Component Cooling heat exchangers and throttle Service Water flow to the heat exchangers within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of the initiating event. The local readout for Service Water Flow and the manually operated discharge valves will be used to establish the desired flowrate.

For the case where two units are initially at power, the nonaccident unit is assumed to be put on Residual Heat Removal (RHR) no sooner than eight hours after the initiating event. Auxiliary Feedwater will provide Reactor Coolant System cooling for the first eight hours. This is required due to the limited equipment available for an RHR cooldown (i.e., one RHR heat exchanger and pump, one Component Cooling pump and one throttled Component Cooling heat exchanger.)

hl34-WDC-12142-29 The operator actions as outlined in this section will be incorporated into the appropriate procedures and documented verification established including analysis of anticipated doses where applicable and expected durations of each activity.

C. Ana1ytical Conservatism and Assumptions Certain conservative assumptions were used in the development of the revised Technical Specifications.

These are itemized below: 1. The valves which receive a closure signal at the start of an event are considered to flow fully over the entire closure sequence of 70 seconds. This is conservative with respect to inventory.

2. The ESW pumps are designed for a flow rate of 15000 gpm. The analysis considered a flow at the ASME XI-IWP alert level of 94% of design or 14100 gpm. Additionally, a reduction in flow is taken due to the requirement for the Emergency Service Water Pumps to be shutdown for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> out of every 16 for diesel oiling. 3. The discharge tunnel is considered to be initially primed. This is conservative with respect to inventory.

The discharge tunnels must be vented to atmospheric pressure within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of the start of the event. (Recirc Spray heat exchanger performance is based on unprimed tunnels throughout the event). 4. The flow equations modelling the various heat exchangers (RS, BC, CC, Condenser) neglected the associated piping resistances.

This is conservative with respect to inventory.

5. Control Room Chillers and Charging Pump Lube Oil Coolers loads remain in service throughout the scenario.

6. Component Cooling heat exchanger shell side temperatures are allowed to reach 140°F at the inlet for control of Reactor Coolant System heat rejection.

7. One Component Cooling pump is operating at the initiation of the event. 8. Total leakage flow from the Circulating Water and Service Water isolation valves is 5000 gpm. (1000 gpm for the scenario with one unit operating and one unit on RHR and Spent ;uel Pool and shutdown unit heat loads less than 25 xlO BTU/HR). 9. The DBA and Loss of Offsite Power start with canal level at +23.0 feet. 10. The final Technical Specification Intake Canal level includes additional margin for any potential undefined flows. h134-WDC-12142-30

• D. Description of the Limiting Case The limiting failure mechanism is the loss of an ESW pump. This is true for either of the two initial conditions considered, i.e., whether two units are operating or for one unit in refueling with the other unit operating.

For the initial condition where one unit is in refuel!ng (assumed core and Spent Fuel Pool heat loads less than 25 x 10 BTU/HR), after two hours, 1 of 3 ESW pumps is expected to be started, (2 pumps are required to be operable, allowing for a single failure of 1 pump). For the initial condition where two units are operating, after two hours, 2 of 3 ESW pumps are expected to be started. (3 pumps are required to be operable, allowing for a single failure of 1 pump). Note that the limiting case assumes an increase over current Technical Specification requirements in the number of operable Emergency Service Water pumps in order to satisfactorily provide for long term flow requirements (See Section IV.B). With a DBA or Loss of Off-Site power, the 3 Emergency Diesel Generators (EDG) are signaled to start-up. (Note: The Circulating Water lines are assumed to isolate within 70 seconds of the initiating event based on the design modifications identified in Section III.A.) Assuming Unit 2 as the accident unit, the swing EDG aligns to Unit 2, leaving Unit 1 with only a single EDG. The design of the BC and CCHX isolation valves provides for parallel flow paths to these heat exchangers.

The two parallel isolation valves for the BC and CCHX's are powered from separate electrical buses which are powered by separate EDG's. With only one EDG available for Unit 1, one set of isolation valves will always remain open as a flow path even before a single failure is taken, requiring operator action to isolate the open valves to conserve inventory.

Initially, 4-Recirc.

Spray HXs, 4-CCHXs, 3-BCHXs, 2 sets of Control Room, Switchgear Room and Relay Room Chillers, and 2 units of charging pump lube oil coolers are considered to receive continued Service Water flow after the initial closure of the normal flow paths. This alignment is considered to exist for one hour to allow time for operator action to isolate the 3-BCHXs and 3 CCHXs. One CCHX is left in service and after four hours, it is set to a throttled flow rate to support the nonaccident unit. Service Water flow to the Recirc. Spray heat exchangers is isolated as follows: One train (2 heat exchangers) at one hour once containment has been returned to subatmospheric conditions and a third heat exchanger at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> into the event. The Discharge Tunnel is initially primed, but is confirmed to be at atmospheric pressure by opening the Discharge Tunnel vacuum breaker valves within four hours. With two units initially at power, RHR on the nonaccident unit is assumed to be established at 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> into the event. With one hl34-WDC-12142-31 unit initially at cold shutdown, RHR is assumed to be in service from the beginning of the event. The initial Intake Canal level necessary to support these scenarios was found analytically to be less than +23 feet. Additional conservatism was added to account for miscellaneous leakage and isolation system uncertainties and response times. The resulting canal level Technical Specification minimum limit is +23 feet. The minimum Intake Canal level reached by this analysis is greater than +17.2 feet at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> into the event. Once the third Recirc. Spray heat exchanger is isolated, Intake Canal level stabilizes.

hl34-WDC-12142-32

• VII.

SUMMARY

-EVALUATION OF PROGRAM From an original set of issues related to Intake Canal inventory, a comprehensive set of solutions has been developed which also encompasses Component Cooling heat exchanger operability.

Design Changes have been described which repower the Circulating Water valves, install a new safety-related canal low level actuation system for isolation of nonessential Circulating and Service Water lines plus turbine trip, upgrade the existing canal level indication circuitry, install passive vacuum breakers on the Circulating Water pump discharge lines, install vacuum breakers on the Condenser waterboxes, install vacuum breaker valves on the Discharge Tunnel and provide Component Cooling heat exchanger flow and differential pressure instrumentation.

Technical Specification changes have been described which raise the canal level lower limit to +23 feet, require three Emergency Service Water pumps to be operable and impose operability surveillance requirements on the new safety-related canal low level actuation system. Emergency Operating Procedure changes have been described which require specific operator actions to ensure isolation of nonessential Service Water lines, operation of Emergency Service Water pumps, operation of Recirc. Spray heat exchangers, throttling of Component Cooling heat exchangers, opening Discharge Tunnel vacuum breakers, and establishing Residual Heat Removal. New Periodic Tests will be incorporated to verify Circulating and Service Water isolation valve leakages, to establish operability of the Component Cooling heat exchangers and to confirm operability of the canal low level actuation system. The design bases for canal inventory and Component Cooling heat exchanger operability have been evaluated and serve as the foundation for the changes described above. h134-WDC-12142-33

• AT'l'ACHMENT 3 EVALUATION OF EMERGENCY SERVICE WATER PUMP MODIFICATIONS I. INTRODUCTION . II. IDENTIFICATION OF ISSUES III. DESIGN MODIFICATIONS IV. SPECIAL TESTS V. CONCLUSIONS hl34-WDC-12142-34

• ATTACHMENT 3 EVALUATION OF EMERGENCY SERVICE WATER PUMP MODIFICATIONS I. INTRODUCTION The following report will examine the Emergency Service Water (ESW) Pumps by introducing the basic system function and design and then describing the various issues, modifications and special tests that are being performed.

The previous attachments reviewed Intake Canal. inventory and Component Cooling heat exchanger operability which are very closely interrelated.

This separate section describes the ESW pumps and the diverse issues raised during the Safety System Functional Inspection.

This will complete the review of Intake Canal inventory management and its related systems. The Emergency Service Water subsystem provides makeup water from the James River to the Intake Canal at the Low Level Intake Structure in the event of a loss of offsite power or other events that would render the Circulating Water Pumps inoperable.

The subsystem consists of three safety-related ESW Pumps, associated diesel drivers and a fuel oil system which is housed in a missile protected, seismic structure.

The ESW Pumps (1-SW-P-lA, B, & C) are vertical pumps which take suction from within the screenwells of three Circulating Water Pumps and discharge through individual 24 inch lines. The discharge lines are buried beneath the Low Level Intake service road and Intake Canal berm and emerge open ended at the edge of the Intake Canal above the maximum water level. Each pump is designed to provide 15,000 gpm at a total head of 45 feet. The ESW Pumps are driven by individual, dedicated diesel engines. The "A" pump also has an electric motor drive for use when offsite power is available.

Each diesel has an electric start and control system which is powered by its own 24 volt battery system (two 12 volt batteries wired in series). Battery chargers, fed from normal station power, are used to maintain the batteries in a fully charged condition.

Combustion air for the diesels is drawn from within the ESW Pumphouse.

To provide for both the diesels' combustion air needs and normal room ventilation, the Pumphouse is equipped with five motor operated dampers, four of which are mounted on the wall and one which is mounted in the ceiling. The dampers are designed to be closed when powered and open when power is interrupted.

The power is interrupted whenever any of the diesels are started or when a roo~ thermostat senses 'a temperature of greater than 75°F. In cold weather, the ESW Pumphouse room temperature is maintained at 70°F by electric space heaters. These heaters are fed by normal station power. The next sections of the report define each of the issues identified during the review process and refer to a discussion of the design modification work that resulted.

Changes to Station procedures and the need for Special Tests have also been identified and are discussed in the following sections.

h134-WDC-12142-35

• All three Emergency Service Water pumps are undergoing extensive refurbishment at the manufacturer's facility including an increase in impeller size and performance.

The design analysis presented in Attachment 2 uses 15,000 gpm per pump as a basis. The increased impeller size should provide additional margin beyond 15,000 gpm. The adequacy of the entire diesel driven pump unit will be confirmed in consideration of the increased flow delivery of the pump. The testing described in this section is dependent on the return to service of the pumps. h134-WDC-12142-36

• II. IDENTIFICATION OF ISSUES 1. ESW Pump Diesel Starting Batteries (Station Deviation 88-0998) 2. No seismic qualification documentation could be found for the ESW Pump diesel starting batteries.

The batteries have been purchased in the past as commercial grade, non-safety-related, non-lE equipment and they were not identified on the Q-List. No calculation or test data was available to document the sizing of the batteries other than the vendor statement in the diesel purchase specification that the batteries were designed for "4 to 5 diesel starts at standard temperature conditions".

The effects of the small, but continuous load imposed on the batteries by the diesel control system was apparently not considered in the initial battery sizing (the diesel had no alternator).

Operability of the batteries at extremes within the postulated range of room ambient conditions was indeterminate since, as stated above, the batteries were sized for standard temperature conditions.

Finally, surveillance testing performed to verify battery operability did not take into consideration the battery manufacturer's recommendations.

Resolution Calculations were prepared to seismically qualify the ESW Pump diesel batteries and to establish the sizing criteria for the ESW Pump diesel batteries.

The batteries have been replaced with larger capacity batteries and each diesel has been fitted with an alternator to carry running loads and recharge the batteries during diesel operation.

Battery replacement and surveillance procedures will be revised to incorporate the manufacturer's recommendations for testing. Refer to the section on Emergency Service Water Pump Electrical Modifications.

Battery Charger Not Safety Related or Seismically Qualified (Service Deviation 88-0098) Failure of the ESW pump diesel battery charger by short-circuiting could discharge the batteries and prevent a diesel start. Although seismically mounted, the non-safety-related charger is not seismically qualified.

Resolution Safety-related blocking diodes have been installed between the battery chargers and the batteries to prevent discharging the batteries due to a failure in the charger. Refer to the section on Emergency Service Water Pump Electrical Modifications.

3. Pump Surveillance Testing Does Not Verify the Required Discharge Flow No flow instrumentation was originally installed for the ESW Pumps. To facilitate some form of flow verification testing, a pass/fail "benchmark" test was developed for the Periodic Test Program. Although the ESW Pumps were designed to provide 15,000 gpm at a total head of 45 feet, the calculation which designed the benchmark h134-WDC-12142-37

---

-incorrectly assumed that only 12,000 GPM was required from each pump. Additionally, the pump suction conditions are not considered during the performance of the Periodic Test. The current benchmark test method for measuring pump flow is not appropriate for an operability demonstration or ASME Section XI, IWP testing. Resolution Annubar flow elements have been installed in the 24 inch discharge line of each ESW Pump to obtain pump flow measurements.

Refer to the section on Emergency Service Water Pump Instrumentation.

Each ESW pump will have been refurbished prior to restart. Performance tests will be conducted on each of the refurbished pumps prior to returning them to service to verify that design flow rates are met and to establish the baseline performance for the ASME Section XI IWP program. Refer to the section on Special Test ST-231. 4. Ambient Temperature Effects on Diesel Engine Operability (Station Deviation 88-0998) Failure of the electric space heaters in the ESW Pumphouse could expose the diesels to temperatures of less than 40°F. At temperatures below approximately 45°F, the diesel manufacturer recommends that starting aids be installed on the engine. No such starting aids are installed.

Additionally, based on calculations performed during the SSFI, Pumphouse temperatures of up to 185°F are possible in the summer in the worst case. condition where 3 pumps (2 diesel driven/ 1 motor driven) are operating.

Resolution In the interim, to ensure that the temperature in the ESW Pumphouse remains above 45°F under normal conditions, a temperature watch has been established in the building whenever outdoor temperature falls below 50°F. Portable space heating equipment is available to maintain the room temperatures in the event of a failure of the electric space heaters. The temperature watch will continue to be used until a modification is implemented to provide Control Room indication of the ESW Pumphouse temperature.

Low ambient temperatures experienced during single diesel operation may also occur. Since this is postulated to occur during a loss of offsite power and because the diesel must be stopped for oiling for one hour every sixteen hours, the portable space heating equipment will be required to keep room temperatures above 45°F during diesel operations as well. A reevaluation of the maximum expected average pumphouse room temperature has been performed by Engineering.

Temperature and air flow data taken during the performance of Special Test ST-231 was used to predict the maximum average room temperatures.

The operation of the electric motor driver in combination with any diesel was not considered since under a loss of offsite power condition, the motor would not be available.

With all three diesels operating, the maximum daily average temperatures would be hl34-WDC-12142-38

• less than 125°F. At this temperature, the diesel batteries have a minimum service life of 39.2 days if they are replaced annually.

Electrical Maintenance Procedures are being revised to require replacement of the batteries every 12 months. The other concern associated with elevated temperatures in the ESW Pumphouse is the derating of the diesel output due to the reduced density of combustion air. At a power reduction of 1 horsepower per 10 degree rise above the base 60°F, a maximum derating of 7 horsepower would be expected.

Using derated values, the diesels still have sufficient reserve capacity to supply the pumps' needs under all suction conditions.

5. Replenishment of Diesel Lubricating Oil During Operation At the lube oil consumption rates published by the manufacturer, the diesel would run out of lube oil in approximately 88 hours0.00102 days <br />0.0244 hours <br />1.455026e-4 weeks <br />3.3484e-5 months <br />. The pumps could be needed for longer periods after an accident.

No procedure exists for checking oil levels during operation.

Resolution Operating procedures are being revised to require that a diesel that has been operated continuously for 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> be shut down for one hour for checking and replenishment of lube oil. At the manufacturer's published oil consumption rate of 1/2 pint/hr., approximately 20% of the diesel's total oil capacity of 22 quarts would have been consumed by this time. By using 20% consumption as the basis for the shutdown interval, it is assured that no excessive heating and thinning of the lube oil will occur. The oil consumption rate measured on the "A" Pump during the performance of ST-231 was slightly more than half of the manufacturer's published rate (2.5 qts in 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />). The test results confirm that the manufacturer's expected consumption rate is conservative.

6. Seismic Support of the Diesel Exhaust Piping (Station Deviation 88-0998) Calculations could not be found which document the seismic adequacy of the diesel exhaust piping. The installed supports did not appear to be adequate as the location of the baseplate anchor bolts appeared to be too close to the edge of the concrete.

Resolution A calculation of the diesel exhaust piping performed during the SSFI showed that DBE pipe stress levels are acceptable, even if the two ceiling mounted supports were not i'nstalled.

However, the resulting exhaust manifold nozzle loading has not been verified as acceptable by the diesel manufacturer.

To eliminate the concern for nozzle loads, the diesel exhaust pipe supports are being replaced.

The new support system substantially reduces the seismic loads on the exhaust manifold nozzles. Refer to the section on Emergency Service Water Pump Supports.

h134-WDC-12142-39

• 7

• ESW Pumps Have No Control Room Indication For Clutch Position Without indication of clutch position in the Control Room, the diesel could be remotely started and run uncoupied from the pump. Resolution As a result of the electrical modifications which have been performed, only local operation of the ESW Pumps is now possible.

The operator can therefore reengage the clutch if it is inadvertently left in the disengaged position prior to starting the diesel. A prestart check of the clutch position is being included in the ESW Pump Operating Procedures.

8. Maintenance And Operation Of The Diesels, Pumps And Batteries Not In Accordance With Vendor Recommendations Existing maintenance and operations procedures in some cases do not take into consideration the equipment manufacturer's recommendations (i.e., warm up and shutdown of the diesels, electrolyte testing of batteries, etc.). No documented evaluations could be found to justify why the vendors recommendations need not be followed.

Resolution A complete overhaul of each of the ESW Pumps is being performed at the equipment manufacturers' facilities.

Additionally, a review of the maintenance and operating procedures for the diesels, pumps, batteries and related equipment are being performed by Station personnel to ensure that manufacturers' recommendations are followed.

Technical justification is being provided and documented where it has been determined that manufacturers recommendations need not be followed.

Vendor recommendations for activation, pre-installation testing and periodic testing of the diesel batteries is being incorporated in Periodic Test and Electrical Maintenance Procedures.

9. Low Level Intake Equipment Status Indication In Control Room Control and status indication of Low Level Intake Structure equipment, including the ESW Pumps, is provided in the Main Control Room through the General Electric Telemetering And Control (GETAC) system. The GETAC system is not safety-related.

A failure in the system could produce false indications of diesel status or cause one or more operating ESW Pumps to shut down inadvertently.

Resolution The ESW Pump diesel control circuit has been disconnected from the GETAC system. Operation of the ESW Pump diesels is now only possible from the local panel in the ESW Pumphouse.

Refer to the section on Emergency Service Water Pump Electrical Modifications.

h134-WDC-12142-40

.... *

• 10. 11. Pump Suction Strainer Clogging The ESW Pump suction strainers have a history of clogging.

A clogged pump suction strainer could result in pump starvation.

Resolution The suction strainers are being removed from the ESW Pumps, since adequate protection for the pumps is provided by the existing screenwell trash racks. To prevent clogging of the diesel and gearbox lube oil coolers, duplex strainers are being installed in the 3 inch cooling water lines. Refer to the section on Emergency Service Water Pump Strainers.

During the performance of the 48-hour test (ST-231) on the "A" Pump, the newly installed strainer was periodically checked and cleaned. Once, small amounts of seaweed and a small fish (approximately 5" long) were found in the strainer when opened. All of the other inspections revealed clean strainer baskets. ESW Pump Operating Procedures are being revised to require switching and cleaning of the strainers based on diesel coolant temperatures.

ESW Pump Room Ventilation Dampers The ESW Pumphouse ventilation dampers (4 wall mounted, 1 ceiling mounted) are assumed open upon a loss of power or the operation of any diesel. It was not known how the dampers were wired or how they change position on a loss of power. Operability of the dampers should be demonstrated.

Additionally, during a hurricane, the four wall mounted dampers are covered to prevent water from entering the building.

If the only remaining damper failed to open, there might not be sufficient combustion air to operate the diesels. Finally, no documentation of the seismic qualification of the dampers was found. Resolution An as-built drawing of the ventilation damper circuitry has been prepared.

A review of this drawing and discussions with the manufacturer of the Honeywell Modutrol Model M-955Cl014 damper positioners have confirmed that the dampers are held closed against the force of an internal spring when power is supplied to them. When power is interrupted, the spring force opens the dampers. The operation of the dampers is verified during the quarterly Periodic Testing of the ESW Pumps. In order to ensure that combustion air is available during a hurricane when the wall dampers are covered, instructions and tools (a ladder and pliers) are being provided for the Operator to enable him to disconnect the positioner on the ceiling damper and to block the dampers open to preclude any possibility of the damper failing closed. The instructions are being included in the revised ESW Pump Operating Procedures.

The necessary tools will be stored in the ESW Pumphouse and administratively controlled.

A calculation was performed to analyze the seismic adequacy of the dampers. The calculation concluded that the dampers are seismically qualified.

h134-WDC-12142-41

..

• 12. Wiring of Diesel Control Circuits 13. Station drawing 11448-ESK-llL and diesel vendor drawings apparently do not match and hence, wiring of the diesel control system is uncertain.

The diesel control system running loads supplied by the batteries need to be identified and considered in their sizing. Resolution As-built drawings have been prepared for the wiring for the ESW Pump diesels. These drawings will be issued and maintained as Controlled Station Drawings.

Similarly, a corrected copy of drawing 11448-ESK-llL will be used to update the original Controlled Station Drawing. The components powered by the diesel batteries were identified from the as-built drawings.

Manufacturers' power consumption data for each component was included in the battery sizing calculation.

The actual total load on the batteries was verified on the "C" ESW Pump by Special Test ST-228 and on the "A" ESW Pump by Special Test ST-231. The results of the tests confirmed that the manufacturers' data was conservative.

Pump Operability At Extremely Low Tides The potential exists for cavitating the ESW Pumps if the river water level becomes extremely low. Procedures for management of the Intake Canal inventory are required under these conditions.

Resolution The minimum submergence required to prevent cavitation of the ESW Pumps equates to a river water level of -4.8 ft MSL. The weather conditions that would be necessary to reduce the river level to below this elevation would only occur during a hurricane.

Station response to the threat of a hurricane and in particular, the ability of the Service Water system to meet the requirements of General Design Criterion 2 is currently under review by Virginia Power and NRR. This item remains open pending completion of that evaluation.

14. Q-List Documentation A review of the ESW Pumps and associated safety-related equipment should be performed to verify that they are properly identified on the Q-List. Resolution Equipment required for operation of the ESW Pumps has been reviewed and compared with the Q-List. While the pumps and diesels were included on the Q-List, several pieces of equipment required to support the operation of the pumps were not. These included the diesel batteries, diesel control panels and ventilation dampers. These items have been assigned mark numbers and will be added to the Q-List. Recently added safety-related equipment (i.e., h134-WDC-12142-42

• strainers, alternators and diodes) will also be included in the Q-List . 15. New Impellers on the ESW Pumps (Station Deviation 89-0579) The 'A' ESW pump did not meet the 15,000 gpm flow requirement during the 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> test run after refurbishment by the pump manufacturer.

The pumps have no excess capacity to compensate for even the slightest wear. The 'B' Emergency Service Water pump has an oversize impeller and therefore passed the flow test. Resolution The ESW Pumps, as originally supplied by Bingham Pump Company (now Sulzer-Bingham), contain impellers which were trimmed from the standard full-size of 20 1/4 inches to 18 3/4 inches in order to meet the flow and total developed head requirements of NUS 144 -Specification for Screen Wash and Emergency Service Water Pumps. By replacing the trimmed impellers with full-size impellers, a substantial increase in flow can be achieved.

The entire pumping unit including the diesel driver and auxiliaries, will be reviewed to ensure that the increased horsepower requirements of the modified pumps can be achieved.

Preliminary discussion with the diesel drivers' manufacturer indicates that the diesel will require only the installation of new fuel injectors.

h134-WDC-12142-43 III. DESIGN MODIFICATIONS A. Emergency Service Water Pump Supports An Engineering Work Request package was prepared to document.

The reviews and evaluations performed to verify that safety-related equipment in the ESW Pumphouse is seismically qualified and supported.

Additionally, non-safety equipment that could be dislodged and become missiles during a seismic event were evaluated.

As a result of these evaluations, it was determined that modifications were necessary to the supports for the ESW Pump diesel exhaust piping and the electric space heaters mounted on the ceiling. These modifications will be completed prior to restart. B. Emergency Service Water Pump Electrical Modifications An Engineering Work Request evaluated the qualification of the electrical equipment required to start, operate and monitor the ESW Pumps and specifies the modifications required to upgrade equipment where necessary.

Included in the review were: ESW Pump diesel batteries Chargers for the diesel batteries Diesel control panels Ventilation damper control panel 1. ESW Pumps Diesel Batteries The ESW Pump diesel batteries provide the power required to start and shut down the diesel and to monitor diesel status. Because their operation is essential to the operation of the diesels, the EWR concludes that the batteries should be classified as safety-related, seismic, class lE equipment.

No documents could be found, other than the specification sheet for the diesel, to justify the sizing of the batteries.

Therefore, a calculation was generated to reestablish the design basis. The calculation considers the effects of temperature variations in the ESW Pumphouse and the continuous load imposed by the diesel control circuit on the batteries.

The calculation concludes that the Exide D-8D batteries currently installed should be replaced with higher capacity Exide COM 8D-P batteries.

Additionally, it was concluded that the diesels should be equipped with alternators to supply the running electrical loads and maintain the battery charge during extended operation of the diesels. The battery replacements and alternator additions are documented in the EWR. Both the old and the new batteries were seismically qualified using methodology developed by the Seismic Qualification Utility Group (SQUG). The analyses are documented in calculations for the old and new batteries.

2. Battery Chargers The non-safety-related battery chargers are powered from normal station power. No documentation could be found to indicate that the chargers were seismically qualified.

The chargers are, h134-WDC-12142-44 however, seismically supported.

Safety related diodes are being installed in the wiring between the non-safety-related chargers and the batteries to prevent discharge of the batteries should a charger fail (short circuit).

Installation of the diodes is documented under the EWR. 3. Diesel Control Panels It was determined during the SSFI that Controlled Station Drawing 11448-ESK-llL was inconsistent with the vendor drawings for the diesel control system. A walkdown was performed and as-built drawings of the control system were developed.

These drawings are included in the EWR and will be issued as Controlled Station Drawings upon completion of the EWR. It was recognized following the walkdown, that the safety-related diesel control system was directly connected to the related Low Level Intake Structure Supervisory Panel. The Supervisory Panel is part of the General Electric Telemetering And Control (GETAC) system which provides control and indication of Low Level Intake equipment in the Main Control Room. To eliminate the potential of a loss of diesel control in the event of failures in the GETAC system, the ESW Pump control system has been disconnected from the Supervisory Panel. This modification is documented in the EWR. As a result of this modification, it is no longer possible to operate the ESW Pump diesels from the Main Control Room. Intake Canal inventory calculations have therefore included a two hour delay in initiating ESW Pump operation after a loss of offsite power to allow sufficient time for an operator to travel to the ESW Pumphouse and start the diesels from the local panels. 4. Ventilation Damper Control Panel In response to several questions raised during the SSFI about the operation of the ESW Pumphouse ventilation dampers, a review was conducted of the Controlled Station Drawings to find a drawing of the damper control circuit. No wiring diagrams of the damper control system were found. A walkdown was therefore conducted and an as-built drawing was generated.

The drawing has been included in the EWR and will be issued as a Controlled Station Drawing upon completion of the EWR. C. Emergency Service Water Pump Strainers The ESW Pumps were originally supplied with suction strainers on the inlet bell. These consisted of an expanded metal strainer elements with approximately 1/4 inch openings supported by steel frames. At some time during the operation of the plant, the original strainers were removed and replaced, presumably because they frequently clogged. The replacement strainers were constructed of a lattice of stainless steel bars. The lattice openings measure approximately 4 inches square on the bottom and 4 x 9 1/2 inches on the side. Since the openings in the trash racks across the face of the screenwells are only 3 1/2 inches wide, the current strainers do not provide any additional protection for the pumps. h134-WDC-12142-45

(

• D. However, seaweed and sea grasses still collect on the strainers and impede flow into the pumps. Therefore, to eliminate the potential for clogging and starvation of the pumps, the normally inaccessible ESW Pump suction strainers have been removed. Accessible duplex strainers have been installed in the 3 inch coolirig water lines to the diesel and angle drive lube oil coolers to prevent clogging of these coolers. These strainers are physically located within the ESW Pumphouse.

Operating procedures are being revised to require the Operator to check the diesel coolant temperature periodically for evidence of strainer clogging.

Emergency Service Water Pump Instrumentation An Engineering Work Request documents the installation of an annubar flow element in the 24 inch discharge line of each ESW Pump. The flow element was used during the performance of Special Test ST-231 to provide baseline flow data for the refurbished pumps as required by ASME Section XI. Temporary tubing and gauges were used during the baseline testing and will be used for the Periodic Testing of the pumps until permanent tubing and instrumentation is installed.

Permanent tubing and local flow indicators will be installed as previously committed as part of the Inservice Testing Program. (Refer to our letter Serial No. 88-024A dated September 30, 1988) Additionally, an EWR installs vent valves in the sensing lines to the local pump discharge pressure indicators.

This is required to vent air from the sensing line which normally drains when the pump is shut down. E. ESW Pumphouse Damper Modifications Although the UFSAR states that covers would be installed over the wall mounted ventilation dampers in the ESW Pumphouse during a hurricane, no covers specifically identified for this purpose were found onsite. Additionally, no design for such covers was found. This EWR provides for the design and fabrication of the necessary covers. These covers would be installed on the outside of the building prior to the arrival of the hurricane.

In order to ensure that combustion air is available during a hurricane when the wall dampers are covered, this EWR provides the basis for procedural instructions to direct an Operator to disconnect the positioner on the ceiling damper and to block the damper open should the single positioner motor fail. Such instructions are being included in Operating Procedures.

A ladder and pliers will be available and administratively controlled in the ESW Pumphouse to implement the procedure.

This is a temporary measure until a design for manually operated dampers is developed and installed.

The design process for the installation of manual operators for the dampers will begin after restart of the Units. This EWR also documents the findings of the calculation which verifies the seismic adequacy of the ventilation dampers. hl34-WDC-12142-46 l

r F. ESW Pump Uprating Modifications Full size impellers are being installed in each of the ESW pumps to replace the trimmed impellers originally provided by the manufacturer.

The replacement impellers will enable the pumps to provide significantly more flow than the originally specified 15,000 GPM at 45 feet TDH. To accommodate the increased horsepower requirements of the modified pump, the diesel drivers will be modified by installing larger fuel injectors.

The capabilities of the modified diesel-pump combination will be verified by Special Test prior to restart of either Unit. h134-WDC-12142-47 r 1**

• IV. SPECIAL TESTS ST-228 This Special Test was performed on the "C" ESW Pump to verify the diesel starter cranking amps and to determine the actual running load imposed on the battery by the diesel control system. The test verified that the actual loads were within the manufacturer's published power consumption values which were used in the battery sizing calculation.

ST-231 This Special Test was performed on the ESW Pumps to obtain data necessary to support design assumptions concerning room temperature profiles, lube and fuel oil consumption and electrical loading of the diesel batteries and to obtain baseline performance data for the refurbished pumps. The test consists of four parts; a 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> instrumented run of one pump and independent, short duration baseline performance runs on all three pumps. 48 Hour Test During the 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> test, the following parameters were periodically measured:

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. Pump discharge flow (includes 3 inch diesel and gearbox cooling line) Pump discharge pressure Screenwell water level Pump RPM Pumphouse room temperatures (includes an array of RTD's throughout the building)

Outdoor psychrometric conditions Outdoor wind speed and direction Diesel engine coolant temperature Diesel battery voltage and current Number and duration of diesel start sequences Fuel oil consumption Lube oil consumption Pump vibration Diesel air intake flow and temperature Room exhaust air flow Battery temperature Diesel exhaust stack surface temperature The test pump was shut down every 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> to perform checks of the lube oil level and cooling water strainer condition.

Additionally, the other 2 pumps were started and run until room temperature stabilized to provide data on 3-pump operation.

Flow Test Independent tests will be performed on each of the ESW Pumps, prior to restart, to measure discharge flow and pressure, screenwell water level (suction condition), pump RPM and vibration.

This series of tests will h134-WDC-12142-48 be used to verify that the design flow requirements of the pumps can be achieved and to obtain the baseline performance data for the pumps as required for the Periodic Test Program. The test was successfully completed on the "B" pump. Data collected from this pump test verified that pump performance was considerably better than required to satisfy the design flow assumptions for Intake Canal inventory calculations.

ST-256 This Special Test will provide verification that the ESW Pumps and diesel drivers can perform satisfactorily following the replacement (upsizing) of the pump impellers and diesel fuel injectors.

The pump will be operated at various screenwell water levels (suction conditions) to develop performance curves for the as-installed pump/ diesel combination.

V. CONCLUSIONS The Emergency Service Water pumps will be completely refurbished prior to restart. Design modifications have been made for piping and equipment supports, diesel batteries, battery chargers, control panel wiring, ventilation damper controls, pump strainers, pump instrumentation and ventilation dampers. Special Tests have been described for diesel cranking amps *and pump performance tests. Station procedure changes will be incorporated to cover pump maintenance and operation.

Taken together, these activities provide assurance for the continued reliability and performance of the Emergency Service Water Pumps. h134-WDC-12142-49

,.\ . Deviation 88-0759 88-0921 88-0962 88-0998 88-1169 88-1170 89-0256 89-0579

• h134-WDC-12142-50 ADDENDUM fl

SUMMARY

OF SURRY INTAKE CANAL INVENTORY STATION DEVIATIONS Date Filed 7-25-88 9-9-88 9-19-88 9-29-88 10-19-88 10-19-88 02-01-89 03-07-89 Subject Nonsafety-related canal level instrumentation Service Water Operability a.) Canal Drawdown with one emergency Service Water pump and four Recirculation Spray heat exchangers.

b.) Nonsafety-related canal level instrumentation.

c.) Canal drawdown with one unit on Residual Heat Removal and a Design Basis Accident on the other unit. Reverse siphon on Circulating Water pump discharge lines. Indeterminate Operability of Emergency Service Water Pumps. Appendix R -Failure to break condenser waterbox vacuum. Failure of the nonaccident unit's Emergency Diesel Generator as relates to Intake Canal inventory.

Potential inability to achieve a 30 hour3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> cooldown to Cold Shutdown in accordance with the current design basis. Oversize Impeller on the 'B' Emergency Service Water Pump *