ML18025A659
| ML18025A659 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 04/17/1978 |
| From: | Curtis N Pennsylvania Power & Light Co |
| To: | Grier B NRC Region 1 |
| References | |
| Download: ML18025A659 (6) | |
Text
REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
DISTR IBUTIOh)
FOR INCOMING MATERIAL 50-3
-88 REC:
GPIER B
H
'NRC QRG:
CURTIS N
W
'P'A 'PWR 8( LIGHT DQCOATE: 04/ 17/78 DATE RCVD: 05/04/7-DOCTYPE:
LETTER NOTARIZED:
NO COPIES RECEIVED
SUBJECT:
LTR 1
ENCL 0 FURNISHING INFO RE CONSTRUCTION DEFICIENCY REPT CONCERNING WESTINGHOUSE SUPPLIED MEDIUM VOLTAGES METAL CLAD SWITCHGEAR WHICH MAY NOT BE FULLY CAPABLE OF WITHSTANDING THE POSTULATED SEISMIC EVENT FOR SUBJECT FACILITY...ADVISING REQUIRED DEFINITIVE REPT WI PLANT NAME:SUSQUEHANNA UNIT 1
SUSQUEHANNA UNIT 2 REVIEWER INITIAL:
XJM DISTRIBUTER INITIAL:~~
DISTRIBUTION OF THIS MATERIAL IS AS FOLLOWS
'CO¹ TRUCT"I"Oil
< i"OCFR50. '55'<'E ).
(DISTRIBUTION CODE 3004 FOR ACTION:
INTERNAL:
EXTERNAL:
ASST DIR VASSALLO++LTR ONLY(l>
PR J~MGR~M INER R ONLY< 1 )
Eg~
E~LTR Oh(LY< 1)
- 8. E~~L ORL GOSSICK.
8c STAFF++LTR ONLY< 1)
BOYD++LTR ONLY(1)
HELTEMES++LTR ONLY< 1)
KNIGHT>+LTR ONLY(1 TEDESCO++LTR ONLY<i)
STANDARDS DEV. ++LTR ONLY(i>
LPDR S WILKES BARREr PA+<LTR ONLY< 1 )
TIC++LTR 'ONLY(1 NSIC++LTR ONLY(i)
FERD DREHER/IE++LTR ONLY(1)
ACRS CAT B++LTR ONLY<ib)
BR CHIEF PARR++LTR ONLY(1>
LIC ASST RUSHBROOK<+LTR ONLY<i~
NRC PDR+4LTR ONLY<i)
OELD++LTR ONLY(i>
MIPC4+LTR ONLY< 1)
DEYOUNG++LTR ONLY(i)
R.
MATTSON++LTR ONLY<i)
ROSS>+LTR ONLY(1>
EISENHUT++LTR QhlLY< 1 )
K SEYFRIT/IE++LTR ONLY(i >
DISTRIBUTION:
2P THE END CONTROL NBR:
781240 31
J
TWO NORTH NINTH STREET, ALLENTOWN, PA.
18101 PHONE:
(215) 821-5151 NORMAN W CURTIS Vice President. Engineering 8 Construction 821.5881 April 17, 1978 Mr. Boyce H. Grier Director, Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406 yr) c it i ~ i Lr V) r
~C C7 SUSQUEHANNA STEAM ELECTRIC STATION
,'TNTERZM~BEPORT OF.PZPORTABLE
.DEFICIENCY
'REGARDING POTENTIAL TRANSFORMERS ON 4.16KV SWZTCHGEAR DOCKET NOS:
50-387, 50-388 LICENSE NOS: CPPR-101, CPPR-102, ERs 100450/100508 gILE 840-4 PLA-246
Dear M. Gr'r:
This relates to a eportable deficiency, under: the provision of 10CFR 50.55(e),
which was.. identified to Mr. A. Toth, NRC, Region I by Mr. A. R. Sabol, PPtt'L during a telephone conversation on 3/31/78.
The deficiency involves Westing-house supplied medium voltage, metal, clad switchgear which may not be fully capable of withstanding the postulated seismic event for the Susquehanna plant..
Specifically, Westinghouse has advised that the potential transformer secondary disconnecting contact assemblies on ecuipment similar to that supplied for Susquehanna have failed-.to withstandrecent..seismic, tests.
Westinghouse further stated. that, under seismic conditions, it is possible that the secondary contacts could be dislodged from their normal positions causing open circuiting or shorting of the secondary circuits.
It has been established that eight of the sixteen units, purchased for use in safety related applications>
have been shipped to the SSES plant site.
To preclude installation of this ecuipment, Bechtel has identified (3/16/78) these eight units in a QA Stop Work Report (No. 78-06) as being nonconforming.
As
2514) and each switchgear unit has had a "Hold Tag" attached.
Bechtel Engineering has reviewed the system design and they have concluded that the worst condition exists with the loss, on each switchgear bus, of the potential transformers on both incoming feeders coupled with the loss of one, or both, of the bus voltage monitoring transformers.
781240031 PENNSYLVANIA POWER rL LIGHT COMPANY
Mr. Boyce P., Grier
'y'r April 17, 1978 Under this "condition, the incoming bus feeders 'from the safeguard transformers would be automatically disconnected and the diesel generator power source connected restoring power to the bus.
The feeder breakers supplying power to the shutdown loads are normally open.
A LOCA occurring during or after the postulated seismic event would initiate a closing signal to the motor feeder breakers of the shutdown loads, i.e.
RHR and Core Spray Pumps.
These feeder breakers would close and immediately trip due to the false undervoltage indication as sensed by the undervoltage xelay.
The circuit breakex's would be unable to close again because of 'the permanent undervoltage trip signal imposed on them.
The above analysis assumes that the failures concuxrently occur on all'x'edundant
"'sw'itch'gearbu'ses.
Bechtel Engineering has further concluded that this loss of capability to supply power to shutdown equipment under a LOCA constitutes a safety hazard to the operation of the plant and represents a deficiency in final design.
As proposed remedial action, Westinghouse has advised that modification kits are available. which, when installed, would eliminate the faulty secondary dis-connecting assemblies from the. circuit..
This is accomplished by hard wi ing
'the secondary to the load circuits..
Bechtel Engineering's considering the use of these modification kits pending assurance from Westinghouse that this modi-fication will meet all the reauirements of the technical specification.
We anticipate submittal of the required definitive report of the deficiency by 7/31/78.
Very truly yours, N.
W. Curtis Vice President-Engineering
& Construction WHG/ARS:mcb cc:
Ms. M. C.
Mr. N.
W.
Mr. R. L.
Mr. J.
W.
Mr. J.
D.
Mr. H. L.
Mr. J. T; Barto Curtis Emery Geiling Green Harris.
Kauffman N4 N4 N4 N5 SSES SSES TW16 Mr. H. F. L'ligh Mr. E. M. Mead Mr. M. R. Muir Mr. J.
R. Schmiedel Mr. R. J. Shovlin SPGE Correspondence File Susquehanna Letter File Bechtel SSES NS Bechtel SFHO Bechtel SFHO N4 N3 N3 C
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