ML20246D822
| ML20246D822 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 12/31/1988 |
| From: | Whittier G Maine Yankee |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GDW-89-159, MN-89-66, NUDOCS 8905110058 | |
| Download: ML20246D822 (13) | |
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SUMMARY
OF DESIGN CHANGES COMPLETED IN 1988 t'
'EDCR-80-44 Hydrogen Purge Line Flow Indication EDCR-84-79 Steam Generator Blowdown Sample System
.EDCR-85-50 345kV Relay House Smoke Detection System EDCR-86-11 . Heat Tracing Alarm Circuit Improvements EDCR-86-16; Waste Gas Oxygen ~ Analyzer EDCR-86-18 Permanent Installation of LPSI Pressure Gages EDCR-87-03 Relocate MS-S-170 EDCR-87-05 ICI Cable Replacement EDCR-87 LP Turbine Retrofit EDCR-88-05 Reactor Coolant Pump Seal Upgrade-EDCR-88-08 P-2C Trip Logic Modifications .
EDCR-88-26-1 Primary Inventory Trend System Upgrade EDCR-88-26-2 Subcooled Margin Monitor Upgrade EDCR-88-28 Safety. Parameter. Display System Improvements-
'EDCR-88-31 Auxiliary Boiler System Modifications
.EDCR-88-36 Control Room Air Conditioning Cooling Water EDCR-88-37 NNS Battery Room Ventilation Upgrade
.EDCR-88-40 ll5kV Capacitor Bank EDCR-88-41 Water Treatment Plant Improvements EDCR-88-43 Fifth Point Drain Heater and Gland. Steam Condenser Replacement EDCR-88-44 #3 Feedline Modifications -
EDCR-88-45 -Containment Centrol Air Compressor System Improvements EDCR-88-51. Steam Generator Pressure Indication EDCR-88-52 PCC/ SCC Flow Monitoring EDCR-88-53 Steam Generator Level Indication EDCR-88-54 Containment Spray Flow Indication-
'EDCR-88-55 P-2C Input Modifications' to Computer Sequence of Events EDCR-88-504 480' Volt Circuit Breaker Upgrades 1
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EDCR-80-44 Hydrogen Purge Line Flow Indication This design modification changed the Containment Hydrogen Purge Flow j indicator to a lower range. The old 0-100 SCFM range indicator was difficult j to read at the low rates used for monthly surveillance tests (15-35 SCFM). A l 0-51.5 SCFM range indicator was installed.
This change enables better readability of the Containment Hydrogen Purge I Flow during monthly surveillance testing. This change did not increase the probability of occurrence or the consequences of an accident or malfunction of ]
3 equipment important to safety previously evaluated, create the possibility of j an accident or malfunction of a different. type than any evaluated previously in the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
EDCR-84-79 Steam Generator Blowdown Sample System A sodium leak detection unit, conductivity transmitter, pH meter and sample pump were installed on the Steam Generator Blowdown System. This system provides a continuous, accurate record of sodium concentration in the S/G Blowdown tank effluent to better monitor steam generator secondary side chemistry.
This change provides additional information for use in monitoring steam generator chemistry. This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
EDCR-85-50 345 kV Relay House Smoke Detection System A smoke detection and warning system was added to the 345 kV Switchyard Relay House. The system includes a local audio / visual alarm and a remote visual alarm (roof-mounted strobe light).
l This char.ge provides an early indication of a smoke or fire problem in the 345 kV Switchyard Relay House. This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
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EDCR-86-11 Heat Tracing Alarm Circuit Improvements Prior to this change, the contrci room indication of a heat tracing !
circuit alarm locked in if any heat tracing circuit was in alarm. To reactivate the control room alarm function (allow it to receive another alarm) !
a bypass was added at the local alarm panels. The bypass switch maintains the local alarm and deactivates the control room alarm so that the control room ;
may receive a subsequent heat tracing alarm.
This change enables the control room to be notified of new heat tracing i circuit alarms and reduces operator time to maintain status of these alarms.
This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated nreviously in tLe safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
EDCR-86-16 Waste Gas Oxygen Analyzer This modification added an oxygen analyzer to the Haste Gas Surge Drum, with alarms and indication to alert operators to the possibility of an explosive mix of hydrogen and oxygen in the Haste Gas System.
This addition of the oxygen analyzer to the Waste Gas System will enable operators to detect air in-leakage to this hydrogenated system which enables operators to take corrective action to preclude an explosive mixture. This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
EDCR-86-18 Permanent Installation of LPSI Pressure Gages This design change provided permanent installation of a pressure gauge in each of the three Low Pressure Safety Injection headers. The gauges are used during monthly surveillance testing to monitor system pressure prior to cycling system valves. Unusual system pressure conditions can be detected (i.e., check valve back leakage) prior to cycling valves, thus precluding inadvertently subjecting low pressure sections of the system to higher than normal pressures.
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' This change improves-the operator's ability to monitor system parameters to preclude subjecting low pressure portions of the safety injection system to inadvertent overpressure. This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment '
important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis or 'uce the margin of safety as defined in the basis for any Technical Specifica 1 The change did not present an unreviewed safety question as defined in CFR 50.59. ,
EDCR 87-03 Relocate MS-S-170 This change relocated a safety valve on the turbine steam inlet line of the Turbine Driven Auxiliary Feed Water Pump. The relocation minimized safety valve challenges due to normal pressure surges while ensuring overpressure protection for the turbine nozzle rings.
This change is intended to reduce spurious actuation of an equipment protective device. This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to sefety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis, or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present en unreviewed safety question as defined in 10 CFR 50.59.
EDCR 87-05 ICI Cable Replacement This modification replaced several In-Core-Instrument assemblies and cables with environmentally qualified assemblies. This is a continuation of Maine Yankee's effort to provide environmentally qualified core exit ,
temperature indication. l This modification increases the probability of this equipment performing its intended function during accident conditions. This change did not f increase the probability of occurrence or the consequences of an accident or !
malfunction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously.in the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
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i EDCR 87-08 LP Turbine Retrofit Maine Yankee's original low pressure turbine rotors were susceptible to, and had experienced, stress corrosion cracking. The rotors were replaced with 1
rotors of a different design, which reduces the likelihood of stress corrosion cracking. Modifications to the blade design, inlet first stage, and exhaust transition area produce increases in cycle efficiency of approximately 17.5 MWe.
This modification improves the design of the low pressure turbine rotors, ,
improves reliability and availability of the turbines, and improves secondary plant efficiency. This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification?. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
EDCR 88-05 Reactor Coolant Pump Seal Upgrade New Reactor Coolant Pump seals were installed and all experienced early failure. They were subsequently removed and replaced with the old seal design pending investigation of the cause of the failures.
The intent of the upgrade was to improve the seal reliability and thus l plant availability. This change did not increase the probability of i occurrence or the consequences of an accident or malfunction of equipment j important to safety previously evaluated, create the possibility of an )
accident or malfunction of a different type than any evaluated previously in the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
l EDCR 88-08 I P-2C Trip Logic Modifications The trip circuitry of the turbine-driven main feedwater pump was originally designed to trip the pump if a single parameter were out of j tolerance. The trip logic required only one signal to trip, and therefore, an l instrument failure could also trip the pump. Instrumentation was modified to I a two-out-of-two trip logic to enhance component reliability by reducing the j likelihood of spurious trips.
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This modification to the turbine-driven feed water 9 ump (P-2C) trip system improves plant safety and reliability by reducing the rotential for inadvertent pump trips. This change did not increase the probability of ,
occurrence or the consequences of an accident or malfunction of equipment I important to safety previously evaluated, create the possibility of an :
accident or malfunction of a different type than any evaluated previously in l I the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety i question as defined in 10 CFR 50.59. )
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EDCR 88-26-1 )
Primary Inventory Trend System Upgrade I 1
The Primary Inventory Trend System is intended to provide indication of l collapsed liquid level in the Reactor Vessel following a small break loss of coolant accident. This is accomplished by comparing the force exerted by the j height of water in the vessel to a fixed force from the reference leg. The i existing system was enhanced as follows: q Replaced overlapping indications with one full range scale - top of vessel to bottom.
Two separate, redundant trains of indication have been provided. -
Temperature compensation has been improved. j
- Instrumentation submergence qualification requirements have been !
satisfied.
This upgrade improves the accuracy, readability and reliability of an ,
instrument system installed for post accident monitoring. This change did not i increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
EDCR 88-26-2 Subcooled Margin-Monitor Upgrade This change provided train separation of core exit thermocouple input; to ;
the Saturation Margin Monitor (formerly the Subcooled Margin Monitor). A 1 second, separate, margin to saturation indicator and set of incore thermocouple readouts has been provided on the main control board.
This upgrade improves the reliability of an instrument system installed for post accident monitoring. This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in i the safety analysi: or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in-10 CFR 50.59.
- EDCR 88-28 Safety Parameter Display System Improvements The Safety Parameter Display System is used in conjunction with the Emergency Operating Procedures (E0Ps). Changes have been made to the SPDS hardware to correspond to changes to the E0Ps.
- Temperature inputs were replaced with environmentally qualified Class
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1E inputs.
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Containment High Range Radiation signals eere upgraded to Class 1E.
- Primary Vent Stack Fan indication is based on fan breaker position.
The Hide Range Log signals have been conditioned to imprend accuracy.
Engineered Safeguards Features Actuation (SIAS, CIS, CSAS) indication is based on actuation relay status.
This design change brings the Safety Parameter Display System in line with instrumentation requirements to support Emergency Operating Procedures. This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
EDCR 88-31 Auxiliary Boiler System Modifications The Fuel Oil system has been modified to allow burning waste oil. This codification involved the installation of equipment which allows waste oil to be pumped into the fuel line during boiler operation.
This change to a non-nuclear safety system provides an economical and safe means for disposing of waste lubricating oil. This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated, crfIte the possibility of an accident or malfunction of a different type than ans evaluated previously in the safety analysis or reduce the margin of s4. 'ety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
EDCR 88-36 Control Room Air Conditioning Cooling Hater
! Cooling water supplies to the Control Room and Computer Room Air Conditioning units have been realigned. The Control Room Air Conditioner (AC-18) is now cooled by Secondary Component Cooling Hater; the Computer Room Air Conditioner (AC-1A) is now cooled by Primary Component Cooling Water, i
Previously, a loss of electrical Bus 5 (and therefore loss of Motor Control Center MCC-7A) would cause a loss of power to AC-1A (Computer Room) and loss of PCC cooling to AC-18. This configuration would not have met single failure criteria.
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' This change will ensure that air conditioning capabilities will be
'. maintained to the Control Room in the event of a single electrical fault.
This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipmeLt important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
EDCR 88-37 NNS Battery Room Ventilation Upgrade Additional ventilation (fans, dampers, ducts) has been added to the NNS Battery Room. This additional ventilation is intended to maintain the room's temperature within limits recommended by the battery manufacturer.
This modification improves the long(vity of a non-nuclear safety system. '
This change did not increase the probability of occurrence or the consequences of an accident or malfur.ction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
EDCR 88-40 115 kV Capacitor Bank A capacitor bank was added to the 115 kV Switchyard. This additional
' capacitive load will be used, when necessary, to boost voltage being supplied through the reserve power transformers X-14 and X-16.
This modification increases the reliability of offsite power supply system voltage. This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59. ,
1 l EDCR 88-41 l Water Treatment Plant Improvements Resin traps have been installed in the outlet of the organic trap and in j the regenerant waste lines from the organic trap and the mixed bed i
demineralizers. These modifications are expected to assist in locating sources of resin loss before complete charges of resin are lost, as has happened in the past.
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This change improves the operation and reliability of the non-nuclear
'- safety-related water treatment plant. This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
EDCR 88-43 Fifth Point Drain Heater and Gland Steam Condenser Replacement Maine Yankee has maintained an aggressive program to minimize pitting corrosion in the steam generators. In a continuing effort to reduce the ingress of copper contaminants in the feedwater train and thus in the steam generators, the fifth point drain heaters and the gland steam condenser were replaced using copper free alloys. These changes additionally resulted in increases in thermal efficiency and reduced pressure drop at the feed pump suction.
These modifications to non-nuclear safety-related components enhance steam generator tuDe integrity by further reducing the ingress of contaminants and thereby increasing plant safety. This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specifi;ation. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
i EDCR 88-44
- 3 Feedline Modifications This alteration of Feedwater line support H-13 is intended to make the Feed line less rigid and better able to withstand the dynamic loadings due to water hammer and pressure transients. Damage to the line and supports has occurred in the past.
This modification improves the reliability of Feedwater System components. This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
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EDCR 88-45
- - Containment Control Air Compressor System Improvements Forced air cooling flow has been provided directly to the Containment Control Air Compressors, to reduce operating temperatures and increase reliability. The forced airflow has been provided by routing new duct work from the containment ventilation system duct work. l This modification improves the reliability of air supply to containment instruments and valves. This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type thar any evaluated previously in the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
EDCR 88-51 Steam Generator Pressure Indication The range of indication for Steam Generator Pressure on the Main Control Board was increased to satisfy Regulatory Guide 1.97, which requires indication from 0 to 201, above the lowest safety valve setting (985 psig).
The new range is 0-1185 psig.
This change provides a wider range of steam generator pressure indication to the operator. This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
EDCR 88-52 PCC/ SCC Flow Monitoring Regulatory Guide 1.97 requires monitoring of Component Cooling Hater flow for accident conditions. Ultrasonic flowmeters with a readout of 0-8000 gpm are used to monitor heat exchanger flow and are provided with readouts in the Control Room.
This change provides the operator with an indication of flows in the component cooling water systems (primary and secondary). This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
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.ED~CR 88 *. Steam Generator Level Indication The wide range level indication for all three steam generators has been upgraded to satisfy t; environmental qualification, electrical separation, and other Class lE and Regu h tory Guide 1.97 requirements.
This change provides better and more reliable steam generator level indication to the operator. Thi: change did not increase the probability of occurrence or the consequences of an accident or malfunction af equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis or reduce the margin of safety as defined in t'ne basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
EDCR 88-54 Containment Spray Flow Indication Instrumentation was added to the Containment Spray System to provide indication of flow through each spray line during accident conditions. This instrumentation is to satisfy Regulatory Guide 1.97 requirements.
This change will provide the operator with the ability to monitor flows in each of the containment spray headers in the event of activation of this system. This chacge did not increase the probability of occurrence or the consequences of ra accident or malfunction of equipment important to safety previously evalutted, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis or reduce the margin of safety as defined in the basis for any Technical l Specification. The change did not present an unreviewed safety question as I defined in 10 CFR 50.59.
EDCR 88-55
( P-2C Input Modifications to Computer Sequence of Events
! Sixteen Turbine Driven Feed Pump (P-2C) annunciator points have been added '
to the plant computer Sequence of Events recorder.
This modification provides more information from the plant computer for P-2C related parameters; this will enable better analysis of P-2C related trips. This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis or l reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety question as defined in 10 CFR 50.59.
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. EDCR 88-504 l *. 480 Volt Circuit Breaker Upgrades The General Electric 480 volt type AK-25 and AK-50 circuit breakers have required frequent maintenance and refurbishment and are difficult to calibrate. This comprehensive upgrade includes replacement of the overcurrent '
trip devices with solid state devices and a general overhaul.
This upgrade was implemented to ensure continued reliability of the electrical system. This change did not increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated, create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety i analysis or reduce the margin of safety as defined in the basis for any Technical Specification. The change did not present an unreviewed safety i question as defined in 10 CFR 50.59.
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c"' MaineYankee RELIABLE ELECTRICITY FOR MAINE SINCE 1972 EDISON DRIVE . AUGUSTA. MAINE 04330 .(207) 622-4868 May 3, 1989-MN-89-66 GDH-89 ~59 United States Nuclear Regulatory Commission Attention: Document Control Desk i Hashington, D. C. 20555 l l
References:
(a) License No. DPR-36 (Docket No. 50-309)
(b) MYAPCo Letter to USNRC dated March 11, 1981 (FMY-81-33)
Subject:
Annual Report of Facility Changes and Relief and Safety Valvo
-Failures and Challenges Gentlemen:
In accordance with 10 CFR 50.59, attached i' a report containing a brief description of the facility changes completed at the Maine Yar.S.ce Atomic Power t Station during 1988, and a summary of the safety evaluation for each.
1 In Reference (b), Maine Yankee committed to reporting any challenges i and/or failures of PORV and pressurizer safety valves. During 1988 there were ;
no such events. '
Very truly yours, 1
MAINE YANKEE 7
0).AA-Avh -
G. D. Whittier, Manager i Nuclear Engineering and Licensing GDH:BJP Enclosure c: Mr. Richard H. Hessman Mr. Hilliam T. Russell l Mr. Patrick H. Sears Mr. Cornelius F. Holden i l
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