ML20098G287
| ML20098G287 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 09/04/1984 |
| From: | Kemper J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| CON-#484-744 120, OL, NUDOCS 8410040299 | |
| Download: ML20098G287 (4) | |
Text
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SE? O41984 c
Dr. Thcznas E. Murley, Director g,ggg United States Nuclear Regulatory Co. mission cy., e.,,, si r q
. S 3 5,3 O C Office of Inspection and Enforcement, Region I r
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631 Park Avenue King of Prussia, PA 19406
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Sitbject:
Significant Deficiency Report #120 Final Report on Paul Munroe Electric-HydratilicSEP 10 All :35 Valve Actuator Deficiency Limerick Generating Station, Units 1 and 2 NRC Construction Permit Nos. CPPR 106 and.107;_
Reference:
1)
Telecon Record J. P. Evans and ~
R. B. Atkinson (PECO) to W. Baunack, (USNRC), dated 11/22/83 2)
Interim Report, dated 12/22/83 File:
QUAL 2-10-2 (SDR #120 and 147)
Dear Dr. Murley:
In empliance with 10CFR50.55(e) we are sutrnitting our Final Significant Deficiency Report concerning the Paul Munroe Electric-Hydraulic Valve Actuator Deficiency.
Interim Report (Reference 2) was previously sutruitted to your office.
We trust that this satisfactorily resolves this itm. If further information is required, please do not hestitate to contact us.
Sincerely,
[
MTM/ndb/08298401 Copy *to: Director of Inspection and Enforement United States Fuclear Regulatory Catrission Washington DC 20555 o
J. Wiggins, Resident NRC Inspector (Limerick) 8410040299 840904 PDR ADOCK 05000352 S
cci Judge Lawrrnce Brenner (w/rnclosure)
- ~
Judge Peter A. Morris (w/cnclosure)
Judg3 Richard F. Cole (w/ enclosure)
Judge Christine M. Kohl (w/ enclosure)
Judge Gary J. Edles (w/ enclosure)
Judge Reginald L. Gotchy (w/ enclosure)
Troy B. Conner, Jr., Esq.
(w/ enclosure)
Ann P. Hodgdon, Esq.
(w/ enclosure)
Mr. Frank R. Romano (w/ enclosure)
Mr. Robert L. Anthony (w/ enclosure)
Ms. Maureen Mulligan (w/ enclosure)
Charles W. Elliott, Esq.
(w/ enclosure)
Zori G. Ferkin, Esq.
(w/ enclosure)
Mr. Thomas Gerusky (w/ enclosure)
Director, Penna. Emergency (w/ enclosure)
Management Agency Angus Iove, Esq.
(w/ enclosure)
David Wersan, Esq.
(w/ enclosure)
Robert J. Sugarman, Esq.
(w/ enclosure)
Martha W. Bush, Esq.
(w/ enclosure)
Spence W. Perry, Esq.
(w/ enclosure)
Jay M. Gutierrez, Esq.
(w/ enclosure)
Atomic Safety & Licensing Appeal Board (w/ enclosure)
Atomic Safety & Licensing Board Panel (w/ enclosure)
Docket & Service Section (w/ enclosure - 3 copies))
James Wiggins (w/ enclosure)
Timothy R. S. Campbell (w/ enclosure)
+
Significant Deficiency Report-SDR'#120 Paul-Munroe Electric-Hydraulic Valve Actuator Deficiency Limerick Generating Station-Unit 162 NRC Construction Pennit Nos. CPPR 106 C 107 Description of Deficiency 1
The Limerick Generating Station has twenty-eight (28) HVAC valve e
actuators manufactured by PfH; Unit 1 and Conmon have eighteen (18) and Unit 2 has ten (10). As repnrted by reference 2, eighteen (18)
Unit I and Conmon valve actuators were sent back to Pfti for a complete overhaul as a result of contaminated hydraulic fluid and 4
concern about depletion of seal life during the extended storage 3
period..This overhaul which has been conpleted, included 'se'ai replacement and repair and/or replacement of damaged components.
Reference 2 also stated that proper operation of the Unit I and Connon systems with these overhauled valve actuators will be verified duraing the pre-operational testing activities.
During the pre-operational testing however, an additional problem was discovered with the valve actuators. The hydraulic-oil purp on many of the valve actuators was cycling more frequently to recharge the accunulator than specified by the PPfl Service Manual. Analysis by PPN, through inspection of severa! disassent>1ed valve actuators in their shop and at the Limerick Jcbsite, determined that the punp cycling was a result of the hydraulic pressure being reduced as a result of leakage occuring in various components; the solenoid valve, accunulator, i
and Flo-Tork.
14 of 18 valve actuators were found to have at least one of the leaking components. Hydraulic fluid contamination was not believed to be the cause of these leaking components.
Corrective Action The corrective action established to correct the leaking components causing the puro cycling problems is as follows:
A.
Accunulators - Four accutulatnrs (HV-76-012A, 012B, 010A and 1
010t0 were found to be leaking as a result of porosity on k
i the inside of the accurulator barrels. These accunulators i
will be replaced with new ores. Other accurulators are
[
being monitored and will be replaced if leaks develop.
B.
Flo-Torks - Hydraulic fluid was found to be leaking past the piston seal on ten Flo-Torks (HV-76-012A, 012B, 013A and 0138 and HV-78-010A, 010B, 020C, 020D, 184A and 184B). The cause of this leakage appeared to be a result of Plti switching from a unqualified seal to a qualified seal. With existing piston to cylinder wall clearances, this new seal could not prevent hydraulic fluid leakage under operating conditions.
l These leaking Flo-Torks are being repaired by PPtf by re-bronzing
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the pistons and re-honing the cylinder barrel walls. Other-l Flo-Torks are being monitored and will be repaired if leaks develop.
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C.
Keane Solenoid Valves - Ten solenoid valves were found to be leaking and are being replaced with new or repaired valves.
To date, solenoid valves on six valve actuators (HV-76-110, 109, 013A and 1848 and HV-78-010A and 020C) have been replaced, with replacement still scheduled for four valve actuators (HV-76-012A and 012B and HV-78-020A and 0208).
Each actuator system had the ten micron filter replaced with a two micron filter to insure more positive filtration of stray contaminants.
This leakage occured as a result of the solenoid valve seating surfaces being scored during fabrication or from previous fluid contamination.
Other solenoid valves are being monitored and will be repaired and/or replaced if leaks develop.
All valve actuators that have the hydraulic-oil puro cycling problem will have the leaking components replaced or repafred and all Unit 1 and Conmon systems with the valve actuators will have been tested to assure proper operat ton by Septenter 14, 1984. None of the Unit 2 valve actuators will be overhauled at this time pending 43~
resolution of the Unit 2 status.
Safety Irrp1 Icat ton Leakage of hydraulic fluid could have resulted in improper operation of the actuator since the actuator is driven by hydraulic fluid from the purp.-
Sufficient hydraulic pressure may not have been available to the actuator for its normal and safety modes of operation.
If it had gone uncorrected, leakage of hydraulle fluid could have had an adverse effect on the safe operation of the plant.
MJM/m'b/08298402
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