ML20090D215
| ML20090D215 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 09/02/1975 |
| From: | Carroll J, Sullivan J JERSEY CENTRAL POWER & LIGHT CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML20090D214 | List: |
| References | |
| AO-75-24, NUDOCS 8302240175 | |
| Download: ML20090D215 (5) | |
Text
8 ///&WLM IniU al Telephone Date of
- / Itcport Ddo:
kug. inst 29, 1975 Occurren August 29, 1975
~
Initial uritten Tine of Report Dctc; September 2, 1975-
' Occurren~cc:
1400 OYSTER CREEK NUCLEAR GENERATING STATION
, FORKED RIVER, NEW JEltSEY 08731
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Abnormal Occurrence Report No. 50-219/75/ 24 IDENTIFICATION Violation of the Technical Specifications, paragraph 2.3.4, ^.
OF OCCURRENCE:
Electromatic Relief Valve Pressure Switches, 1A83C and 1A83D, were found to trip at pressures in excess of the maximum allowable value of 1070 psig.
'Jhis event is considered to be an abnormal occurrence as de-fined in the Technical Specifications, paragraph 1.15A CONDITIONS PRIOR TO OCCURRENCE:
Steady State Power X Routinc Shutdown llot Standby Operation Cold Shutdown Load Changes During Refueling Shutdown Routive Power Operation Routine Startup Other (Specify)
Operation The Reactor Mode Switch was in the refuel position with the Reaetor Coolant temperature less than 212 F DESCRIPTION OF OCCURRENCE:
On Friday, August 29, 1975, while performing surveillance on the five Electromatic Relief Valve Pressure Switches, it was found the IA83C.and 1AS3D tripped at 1080 and 1084 psig, respectively.
These
-values are in excess of the maximum allowable trip points of 1077 and 1082 respectively, which are derived by adding appropriate head correction fcctors to the Technical Specification Limit ~ f 1070 psig.
It is noted o
here that switches 1A83C and 1AS3D are associated with valves NR108C and NR108D, respectively.
The "As Found" 6 "As Left" settings were:
"As Found" "As Left" Switch
, VALVE Setting Setting 1A83A NR108A 1073 1079 1A83B NR108B 1071 1084 1AS3C NR108C 1080 1077 1A83D NR108D 1084 1082 1A83E NR10SE 1082 1082 8302240175 750908 PDR ADOCK O'500021
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SOPY SENT REGION
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kcpart No. 50I219/75/ 24' n,O -
O, APPAREEf'CAUSE Design Pr:cedure 0F' OCCURRENCE':
Manufacture Unusual Service Condition Installation /
Inc. Environmental Construction Component Failure Operator X
Other (Specify)
Instrument setpoint dri f t s
is identified as the cause of this occurence.
ANALYSIS OF The relief valves are provided to remove sufficient energy OCCURRENCE: from the primary system to prevent the safety valves from lifting during a transient.
The limiting pressure transient is that which is produced upon a turbine trip from rated design power with a failure of the bypass system to function.
Under these conditions, the five relief valves are required to operate in order to prevent reaching the lowest set point of the primary system safety valves.
It should be noted that a 25 psig margin oxists between the resulting peak pressure and the lowest safety valve set point as added assurance that the safety valves will not lift during this transient.
With vlaves NR108C and NR108D actuating at 3 psig and 2
- psig, respectively, above the maximum allowable trip point of 1070 psig,and c.ssuming the most limiting pressure transient had occured, the lowest set point safety valve or valves may have been required to actuate in order to-limit the pressure transient.
Since the safety valve capacity provides sufficient vessel over-pressure protection again'st failure of all pressure release devices in addition to a failure of the reactor to scram, over-pressurization of the vessel would not have 6ccurred.
CORRECTIVE ACTION:
The involved pressure switches, 1A83C and 1A83D, were immediately reset to trip at allowable pressure levels.
There are continuing efforts to resolve the incompatibilities between the Technical Specification sotpoint limits and the sensor performance' limits.
It is felt that the conservative design margins associated with the derivation of the plant safety limits will permit a change in the Technical Specifications to be made which will take into account the expected sensor performance variations.
This will climinate instances of abnormal occurrence reports caused by the normal variation in a sensor setpoint within the design margins of the plant safety limits, ikILURE DATA: Manufacturer data pertinent to these switches are as follows:
Manufacturer -- Dresser Type 1539VX Serial Nos.
-- BK3340 (1A83C)
G BK3338 (1A03D)
Previous abnormal occurrence reports:
Abnormal Occurrence Report No. 50-219/74-28 Abnormal Occurrence Report No. 50-219/74-39 Abnormal Occurrence Report No. 50-219/75-16 l
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Date:
September 2, 1975 Prepared by:
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.initYat Telephouc Date of tcport D2c:
August 29, 1975 Occurrence:
August 29 1975
-1 Initial tfritten Time of Report Dcte:
_ September 2, 1975 Occurrencc:
1400 e
OYSTER CREEK NUCLEAR GENERATING STATION FORKED RIVER, HElf JERSEY 08731 Abnom! Occurrepec l
Report No, 50-219/75/ 24 IDENTIFICATION OF OCCURRRsCE:
Violation of the Technical Speci fications, paragraph 2. 3. 4 Electronatic Relief Valve Pressure Switches, IAG3C '
and 1A83D, wore found to trip at pressures in excess of the maximun allowabic value of 1070 psig.
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- Ihis event is considered to be an abnornal occurrence as de-fined in the Technical Specifications, paragraph _1.15 A CONDITION'S PRIOR TQ OCCURnusCE:
Steady State Power X Routine Shutdown
~
Ilot Standby Operation Cold Shutdotm Refueling Shutdown Load Changes During Routive Power Operation Routine Startup Other (Specify)
Operation The Reactor Node Switc8 was in the refuel than 212,ition with pos the Reactor Coolant tenperature less DESCRIPTION F
OF OCCURRENCE:
On Friday, August 29, 1975, while performing surveillance on the five Electromatic Relief Valve Pressure Switches, it was found the IA83C and 1AS3D tripped at 10C0 and 1084 psig, respectively.
These -
t values are in excess of the maxinum allowable trip points of 1077 and 1038 respectively. which are derived by adding appropriate head correction fac. tors to the Technical Specification Limit of 1070 psig.
It is noted here that switches IA83C and 1A33D are associated with valves NR108C a g R108D, respectively.
The "As Found" G "As Left" settings were:
"As Found" SiritW VALVE "As Left" Settin" Setting 1A83A NR108A 1073 1079 1A83B NR108B 1071 1084 1A83C NR108C 1080 1077 1A83D NR108D 1084 1082 IA83E NR108E 1082 1082 i
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tort No. 50-219/7S/ E
'ARuiT CAUSE Desidn Procedurc OCCURRENCE:
Manufacture Unusual Service Conditio.
Installation /
,Inc. Envirt r ; ental Construction Component raslure Operator x Other (Specify)
Instruncat setw4 ne di i h is ident'ified as the cause of this '
occurence.
d.YSIS OF The relief valves are provide'd to renove sufficient energy lURRENCE: from the primary system to prevent the safety valves fron lifting
]
ring a transient.
Tho liuiting pressure transient is that which is producet on a turbine trip from rated design power with a failure of the bypass,
sten to function.
Under thosc conditions, the five relief valves are quired to operate in order to prevent reaching the lowest set point of the 2S psig margin inary systen safety valves.
It should be noted that a 5sts between the resulting peak pressure and the lowest safety valve t point as added assurance that the safety valves will not lift during is transient.
With vlaves NRIOSC and NRIDED actuating at 3 psig and 2
?, g, respectively, above the maxinun allowabic trip point of 1070 psig,and assuming the cost limiting pressure transient had occured, the lowest set j int safety valve or valves may have been required to actuate in order to nit the pressure transient.
Since the safety valve capacity provides fficient vessel over-pressure protection against failure of all pressure lease devices in addition to a failure of the reactor to scran, over-
~
rssurization of the vessel would not have occurred.
A switches %
RECTIVE 1.83C and 1A83D, were inmediately
- ION:
The involved pressure set to trip at allowcbic pressure levels.
There are continuing efforts resolve the incompatibilities between the Technical Specific tion point 11 nits and the sensor performance' linits.
It is felt that the
..servative design narnins associated with the derivation of the plant
!EtyJIiMts will pernit a change in the Technical Specifications.to be e which will take into account the expected sensor performance variations.
s will clininate instancos of abnormal occurrence reports caused by nornal variation in a sensor setpoint within the design nargins of the at safety limits.
3 AIRE DATA:
Manufacturer data pertinent to these switches are as follows:
Manufacturer -- Dresser 1539VI Type BK3340 (IA83C) 6 DK3338 (IA83D)
Serial Nos.
vious abnormal occurrence reports:
Abnormal Occurrence Report No. 50-219/74-28 Abnornal Occurrence Report No. 50-219/74-39 Abnormal Occurrence Report No. 50-219/75-16 a
Date:
September 2.
1975 (A
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pared by:
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James P. O'Reilly Directorate of Regulatory Operations Region I 631 Park Avenue King of Prussia, Pennsylvania 19406 FRON:
Jersey Central Power G Light Co=pany Oyster Creek Nuclear Cencrating Station Docket #50-2
' Forked River, New Jersey 08731 a
SURJECT:
Abnormal Occurrence Report No. 50-219/75/ 24 The following is a preliminary report being subai,tted in compliance with the Technical Specifications, paragraph 6.6.2.
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Preliminary App'roval:
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5 J. T. Carroll, Date CC: Mr. A. Giaz.busso f
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