DCL-85-237, Annual Rept of Facility Changes,Oct 1983 - Sept 1984

Annual Rept of Facility Changes,Oct 1983 - Sept 1984

ML20134B810
Person / Time
Site:	Diablo Canyon
Issue date:	09/30/1984
From:	Shiffer J PACIFIC GAS & ELECTRIC CO.
To:	Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
CON-#385-852 DCL-85-237, OL, NUDOCS 8508160085
Download: ML20134B810 (10)

Text

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, PGandE Lstter No.: DCL-85-237 ENCLOSURE-DIABLO CANYON UNIT 1 DOCKET NO. 50-275 ANNUAL REPORT OF FACILITY CHANGES OCTOBER 1,1983 - SEPTEMBER 30, 1984 Pacific Gas and Electric Company P

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Diablo Canyon Unit 1 Docket No. 50-275 SINMARY OF FACILITY CHANGES FOR ANNUAL REPORT OCTOBER 1,1983 - SEPTEMBER 30, 1984 No. Change Identification Description  !

1 DCl-0E-293R1 Main Steam Line Isolation Monitor Light Box 2 DCl-EE-ll40 125Ydc Batteries and 250 Vdc Swi.tchgear Relocation 3 DC1-EE-1196 Station Battery 4 DCl-EC-1250 Station Battery 5 DCl-EC-1362R1 Extend ASW Pump Ventilation Shaft 6 DCO-GE-2659 Electrical Splicing Details at the Penetration Outside Containment 7 DCl-EE-3041 Instrument AC 7 SKYA Inverters 8 DCl-EM-3174R1 Emergency Borate System 9 DCl-EE-3182 Diesel Generator Tach Pack Power Supply 10 DCl-EC-3328 Auxiliary Saltwater System Vacuum Breakers 11 DCl-EH-5528R8 480Vac Switchgear Room Ventilation System 12 DCl-EM-7148 Component Cooling Water System 13 DCl-EH-7948 Mechanical Equipment Room HVAC 14 DCO-EE-9732R1 RTV Silicone Fire Sealant 15 DC1-94-11437 RCP Motor Lower Bearing 011 Coolcr 16 DCl-EH-ll877R2 Cable Spreading Room Ventilation System 17 DCl-EE-13620 Reactor Protection System ,

18 DCl-EE-13853 Pipe Break Isolation System 19 DC1-EJ-17548 Residual Heat Removal System 20 DCl-EE-19564 Auxiliary Building Ventilation System 21 DCO-(N-110R2 Diesel Fuel Oil Storage Tank Vents 22 DCO-EM-1048R1 Main Steamline Radiation Monitor l 1

23 DCl-EE-1057R1 Main Control Board Recorders ,

24 DCl-EE-1240 416KY Bus F, G, and H Relay Settings 25 DC0-04-1289 Mechanical Panel Moisture Seals i 0332S/0034K 1

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DESCRIPTION OF FACILITY CHANGES WHICH AFFECT THE PLANT AS DESCRIBED IN THE SAFETY ANALYSIS REPORT

1. DC1-0E-293R1, Main Steam Line Isolation Monitor Light Box i This change improves the operation of monitor light box D to alert the control room operator to a main steam isolation signal by sealing in alarm windows regardless of the duration of the isolation signal. i Safety Evaluation Summary This change improves the display of plant conditions for control room i personnel . The change does not affect operation of the Main Steam Isolation Valves (MSIVs) or other safety related equipnent.

2 DC1-EE-1140, Non-Vital 125/250 Ydc System This change provides a new non-vital 125/250 Yde system. Two of the a existing three 125 Vdc batteries and the 250V switchgear were relocated to the turbine building. The existing de intertie between Unit 1 and Unit 2 was removed.

I Safety Evaluation Summary

! The removal of non-safety related loads from the Class IE de power supply enhances the reliability of the Class IE de system. The reliability'of the non-vital 125/250 Yde system is unchanged.

j 3. DC1-EE-1196, Station Battery This change replaces some battery cells, modifies the battery racks to fit the smaller cells, and modifies the vital de system to establish a new non-vital 125/250 Vdc system in conjunetton with reported item 2 (DC1-E-E-ll40).

l Safety Evaluation Summary The RC approved revisions to Technical Specification 3/4.8.3 to reflect

changes in the Class 1E 125 Vdc system and 125/250 Vdc non-vital system.

Removal of non-safety related loads from the Class 1E de power supply i

enhances the reliability of the Class 1E de system.

4 DC1-EC-1250, Station Battery 4 This change provides a battery room in the turbine building for the batteries which supply non-class 1E 125/250 Yde loads. Ventilation is provided to limit hydrogen concentration to less than 2 percent by volume at any location within the area. Class 1E annunciation is to be provided  ;

i on a loss of ventilation.

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Safety Evaluation Summary The battery room was designed to protect adjacent safety equipment from I the potential buildup of hydrogen gas while recharging the batteries.

5. DC1-EC-1362R1, Extend ASW Pump Ventilation Shaft This design change increases the height of the Auxiliary Salt Water (ASW) ptrip ventilation shaft to mitigate the cosined effect of a Tsunami, high tide, storm waves, and damage to the breakwater on the intake structure.

Safety Evaluation Summary This change improves the capability of the ASW system to perform its intended function during a Tsunami or other flood condition.

6 DCO-GE-2659, Electrical Splicing Details at the Penetration Outside Containment This change revises the splice and sleeve procedure for multiconductor signal and control cables at the penetration to eliminate the requirement for the break-out boot from the outer side of the containment penetration.

, Safety Evaluation Summary Class 1E cable electrical penetrations located outside containment at the penetration are made using LOCAA4SLB qualified in-line cable splice

assemblies which provide adequate protection for any postulated accident such as High Energy Line Break. Use of the break-out boot outside containment can be discontinued without reducing the margin of safety.

7. DCl-EE-3041, Instrument AC 7.5 KVA Inverters This change provides additional capacity for present and future loads including 1MI instruments in the existing instrument ac system by installing two new instrument ac inverters.

Safety Evaluation Summary Electrical design of this installation is in accordance with FSAR design criteria. The total nuder of instrument inverters is increased, reducing the load on existing inverters. The consequences of an inverter failure causing a plant trip are reduced by powering fewer plant components with each inverter.

8. DC1-94-3174R1, Emergency Borate System This change adds two valves and piping to the emergency borate system to improve heat tracing and to provide an alternate emergency borate path, and the ability to calibrate FT-113 without flow to the charging pump suction.

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( Safety Evaluation Summary I

This change increases the flexibility of the emergency borate system with t

respect to operation and maintenance. ,

i l 9. DC1-EE-3182, Diesel Generator Tach Pack Power Supply i

This DCN changes the diesel tachometer power supply from 120Vac to 120Vdc.

i Safety Evaluation Summa'ry The manufacturer recommended this change to improve diesel generator reliability by eliminating dependence on 120Vac from the instrument ae i inverters and by providing isolation between 120Vdc and the tach pack.

i j 10. DC1-EC-3328 Auxiliary Saltwater System Vacuts Breakers l The design provides for the installation of vacuum breakers in the ASW

system to protect system piping from damage due to water hammer. See Licensee Event Report 82-009.

Safety Evaluation Summary

Installation of the vacuum breakers will prevent water hamer and reduce the potential of piping damage. System performance will not be  !

l a ffected.  !

11.- DC1-EH-5528R8, 480Vac Switchgear Room Ventilation System This change wereases the capacity of the Auxiliary Building, Area H ventilation supply fans and adds exhaust fans to control _ area maximum temperatures due to identified increased heat loads.

Safety Evaluation Sumary l This modification upgrades the ventilation system capability to maintain anbient temperatures for satisfactory operation of the Class 1E ,

! electrical equipment inside the areas served by the system.

l 12. DC1-EM-7148, Component Cooling Water System t

This change isolates the Component Cooling Water System from the Post-LOCA Sampling System by installing an isolation valve. l l Safety Evaluation Summary -

l l l The integrity of the CCW system is improved by ensuring that breaks in  !

the Post-LOCA Sampling System do not disable the vital CCW System. The. .

possibility for an accident or malfunction is reduced by this change. '

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13. DC0-EH-7948, Mechanical Equipment Room HVAC This change reduces the air quantity supplied to the control room and adds a ventilation supply to the mechanical equipment room.

Safety Evaluation Sumary This modification assures that Class 1E equipment in the mechanical equipment room will be maintained below 104 , while maintaining proper ventilation supply to the control room.

14. DCO-EE-9732R1, RTV Silicone Fire Sealant This change permits the use of RTV Silicone Fire Sealant for separation of electrical devices and circuits.

Safety Evaluation Summary This sealant will provide the circuits with the required physical separation to meet single failure criteria. .Its use is consistent with FSAR statements on fire protection of Class lE circuits.

15 DCl-EM-ll437, RCP Motor Lower Bearing 011 Cooler This change modifies the RCP motor lower bearing oil cooler supports.

Safety Evaluation Summary _

This modification increases the seismic integrity of the RCP motor oil cooler heat exchanger. This will seismically qualify the component cooling water header C pressure boundary.

16 DCl-EH-ll877R2, Cable Spreading Room Ventilation System This change revises the ventilation ductwork in Area H of the Auxiliary Building to control maximum temperatures due to increased heat loads.

Safety Evaluation Summary l

This modification assures that safety-related equipment in the cable i spreading room is provided with sufficient ventilation to perform its intended function.

17. DCl-EE-13620, Reactor Protection System l

This change provides an undervoltage trip signal to the shunt trip of the reactor trip breakers.. ,

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l Safety Evaluation Summary This change was made in response to EC Generic Letter 83-28, " Salem ATWS". The change increases plant safety by providing an automatic trip

via the shunt trip coil for greater assurance of proper system operation.  !

l' 18. DC1-EE-13853, Pipe Break Isolation System i .This change detects and isolates a High Energy Line Break in the I

, auxiliary building.

! Safety Evaluation Summary l~

This change significantly reduces the probability of a harsh environment being created in the auxiliary building, allowing instrumentation to perform its intended safety function without being qualified for a harsh environment.

i 1 19. DCl-EJ-17548, Residual Heat Removal System i

This change adds a low flow alarm and annunciator to the RHR pump miniflow recirculation control circuit. This DCN prompted by RC

SSERs 13 and 21.  ;

i Safety Evaluation Summary The low flow alarm increases the reliability of the RE system and

! prevents damage to the-pumps by warning the operators if no flow exists

while a pump is running. Plant safety will be improved by having operators more accurately informed of RHR system status.

4 i l 20. DCl-EE-19564, Auxiliary Building Ventilation System i i

This change revises the control logic for damper M-12 to meet the system flow distribution design.

4 Safety Eyaluation Summary i

This change fufills the primary function of the auxiliary building i ventilation system by maintaining the temperature of ESF pump motors within acceptable limits during their operation.

$ 21. - DCO-04-110R2, Diesel Fuel Oil Storage Tank Vents l This change reroutes the diesel fuel oil storage tank vents, provides 1

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cathodic protection, and physical protection by covering the vents in a l concrete box.

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Safety Evaluation Summary This change will prevent corrosion without interfering with venting of the tank.

22. DC0-EM-1048R1, Main Steamline Radiation Monitor This change provides for the installation of the Main Steamline Radiation Monitor System and the addition of inputs to the' Nuclear Measurement System.

Safety Evaluation Summary Monitoring of noble gas discharges through the Steam Dump Valves is required by NUREG-0737. Addition of this monitoring system does not adversely affect any safety aspect of the plant since it is not connected to any safety-related system or systems important to safety.

23. DC1-EE-1057R1, Main Control Board Recorders

-i This change provides for the installation of a synchronizing transformer for each of four (4) Leeds and Northrup recorders on the main control board to stabilize the recorder chart drive speed to the station line frequency.

Safety Evaluation Sumary The installation of these transformers will increase the accuracy and readability of the recorder charts and does not affect the performance of systems described in the FSAR.

24. DC1-EE-1240, 4.16KV Bus F, G, and H Relay Settings This design change modifies the setpoints for Diesel Generators 1-1,1-2,

, and 1-3 overcurrent trip, Auxiliary Saltwater Pump and Auxiliary Feedwater Pump overcurrent trips and the 4KV bus differential relay trip.

Safety Evaluation Summary ,

The overcurrent trip setpoints are designed for.125 per cent overcurrent capability to protect the motors and/or diesel ' generators while permitting them to perform their intended function. The differential relay trip setpoints allow detection of fault conditions while preventing spurious trips. ,

25. DCO-84 -1289, MechanicIl Panel Moisture Seal's This change removes the requirement for. moisture seals to be placed on mechanical panels for protection against the,. effects of Moderate Energy Line Breaks.

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Safety Evaluation Summary The installation of moisture seals on identified mechanical panels is unncessary as the devices being protected are presently qualified to operate in a submerged (LOCA) environment.

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.' 1 AECEIVED NRC PACIFIC GAS ' '

AND E LE C T RI C C O M PANY '

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PGandE Letter No.: DCL-85-237 4

Mr. John B. Martin, Regional Administrator U. S. Nuclear Regulatory Commission, Region Y 1450 Maria Lane, Suite 210 Walnut Creek, CA 94596-5368 Re: Docket No. 50-275, OL-DPR-80 Diablo Canyon Unit 1 >

Annual Report of Facility Changes

_ October 1,1983 - September 30, 1984

Dear Mr. Martin:

Pursuant to 10 CFR 50.59, enclosed is the Annual Report of Facility Changes submitted for the Diablo Canyon Power Plant Unit 1. All of these changes have been reviewed by the Plant Staff Review Committee as required by the PGandE Technical Specifications and none of these changes involve an unreviewed safety question. None of these changes >(1) increase the probability or consequences of an accident or malfunction of equipment important to safety as previously analyzed in the Final Safety Analysis Report (FSAR); (2) create the possibility _of an accident or malfunction of equipment not previously analyzed in the FSAR; or (3) reduce the margin of safety as defined in the bases of the Teenical Specifications.

I Kindly acknowledge receipt of this material on the enclosed copy of this letter and return it in the enclosed addressed envelope.

Sincerely,

.D i ffer Enclosures >

cc: G. W. Knighton '

H.~ E. Schierling i J. M. Tay1or Service List c 1 1

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