ML20049A930
| ML20049A930 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 09/25/1981 |
| From: | Curtis N PENNSYLVANIA POWER & LIGHT CO. |
| To: | Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8110020382 | |
| Download: ML20049A930 (2) | |
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[E3 Pennsylvania Power & Light Company Two North Ninth Street
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>;}-;ii Norman W. Curtis Vice President-Engineering & Construction-Nuclear 215 / 770-5381 O
9 September 25, 1981
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Mr. R. C. Haynes A
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Director, Region I OC7 y
U. S. Nuclear Regulatory Commission u,,'
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- .,JSQUEHANNA STEAM ELECTRIC STATION INTERIM REPORT OF A POTENTAILLY REPORTABLE DEFICIENCY INVOLVING SAFETY RELIEF VALVE SOLENOIDS ERs 100450/100508 FILES 821-10/840-4 PLA-936
Dear Mr. Haynes:
This letter serves to provide the Commission with an interim report of a potentially reportable deficiency involving the inability of Crosby safety relief valve solenoids to actuate at reducedD.C. voltages. The solenoids and thus the Automatic Depressurization System (ADS) may not operate at the reduced D.C.
system bus voltages that might exist during a Loss of Coolant Accident (LOCA).
General Electric haa reported this condition under the provisions
<>f 10 CFR 21 in their letter o' August 13, 1981; G. G. Sherwood to V. Stello, Jr. (See attachment).
Mr. A. Sabol of PP&L advised Mr. L. Narrow of NRC Region I in a telephone conversation on August 21, 1981 that PP&L was evaluating the condition under than provisions of 10 CFR 50.55(e). Therefore, this report is submitted pursuant to the requirements of 10 CFR 50.55(e).
The described condition is a potentially significant deficiency in final design that could possibly have adversely affected the safety of operations of the nuclear power plant.
PP&L has been informed that General Electric is working on a modification program for the solenoid valves. This program will include testing to insure that I
the modified valves meet LOCA environment performance specifications. Modified solenoid valves would then be installeci in all Susquehanna ADS safety relief valves prior to fuel load,
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8110020382 810925 PDR ADOCK 05000387 S
Mr. R. C. !!aynes September 25, 1981 A final report describing the details of the corrective action plan will be provided in December, 1981. We trust the Commission will be satisfied with this information.
Very truly yours, N. W. Curtis Vice President-Engineering & Construction-Nuclear FLW sah Attachment cc:
Mr. Victor Stello (15)
Director-Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. G. Mcdonald, Director (1)
Office of Management Information & Program Control U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. Gary Rhoads U. S. Nuclear Regulatory Commission P.O. Box 52 Shickshinny, PA 18655
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G E N ER ALM. E LECTRIC
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nuctaan cowan sysvams civision GENERAt ELECTR!C COA 4*ANY,175 CURThER AVE SAN.)CSE. CALTORNIA 95125 f / - Gff _. ()f)d MC 682, (4C8) 925-5040
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Office of Inspectica and Enforcement US Nuclear Regulatory Ceciaission
$p-Mt Washington, DC 20555 g_qq Attenticn:
Victer Stallo, Jr., Director
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M,3 Gentlemen:
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SUBJECT:
REPCRTABLE C0!?DITION CROSBY. SRY SOLF.NOIDS This lettar is to advise the HRC cf a reportsbie condition per 10CFR -
Part 21 as reported to your office by C. A. Came-on, Manager, Safety Evaluation Pro; rams on At gust u,1981. The condition is an incompatt-bility which exists between the capability of the Crosby 6x10 and 8x10 SEY 551EB01 E in DE att E;.cu cutiris a 340*f LOCP. cancitisn end the wct-t case minimum plant availd21e power supply vcitage. The condition was f
jt @ reportable on Augu.st 11, 1981.
Attached is the report of the condition including the corrective actions to be taken. General Electric tsf11 inform the utilities that are affected by the defect and will advise them of the corrective actions to be taken.
The scheduled corrective action completion dates have not yet been established. The NRC will be ondvised of these dates when they are established.
Very truly yours, 7
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ne ager Nuclear Safety and Licensing Operation GGS: hec /SLP515 Attachment cc:
R. T. Carlsen, HRC Region I J. P. O'Reilly, MRC Region II J. G. Keppler, MRC Region III V. Potapovs. NRC Region IV R. H. Engelken, NRC Region V V. Stallo, Jr., NRC (2 extra copies)
.J F. McAllister, General Electric L. S. Gifford, General Electric
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7 R-s CROSBY SRV $0'90I0 PILOT VALVE ASSENSLY I.
Description of the Condition An environmental qualification test was performed at Wyle Laboratories under GE contract en a Crosby SRV actuator t.nd solenoid assembly to demonstrate compliance with IEEE-323-1974. The test identified that during the simulated 340*F,105
' condition, the solenoids required 130 VDC power'psig steam LCG to be actuated. A septrate Wyle evaluation done for LaSalle showeci that at least 125 Vtc are required to actuate the solenoid valves for ADS appli-cation under LaSalle environmental and operating conditions. A review of the applicable GE plant D.C. power supply specification for LaSalle and other plants utilizing the Crosby SRV solenoids in question specifies that the systas voltage at the bus should be between 110 VDC and 135 VDC normally with an extreme low of 105 VDC durirg peak loading or at the end of discharge during an emergency.
Therefore, the minimum voltage available to actuate the solenoid is 105 VDC urder worst case conditions, not the required 125 VDC.
This incompatibility is applicable to all Crosby SRV's on the fol'iowing plants:
Hanford 2 Zimmer 1 Susquehanna 1 TVA X-17 i
LaSalle 1/2
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There are no Crosby valves in domestic operating plants. This
,7 condition is reportable under Part 21 because these valves had n
already been shipped to sites before the defect was found.
II. Safety Inclications 4
The safety implication of this condition is quita clear.
If-,
during the extremely unlikely event that a $8A LOCA is followed by e
loss of off-site power and the ADS signal is received due to HPCS/HPCI failure and th2 ADS fails due to low voltage, then serious degradation of the core cooling capability results.
III. Corrective Actions.
Recent tests performed by General Electric at Crosby Valve and Gage Company have identified the necessary criteria to assure. solenoid l
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operation at a 340*F LOCA condition with a 105 VDC power supply source applied. All assemblies manufactured and/or in the field '
will be inspected using the stricter acceptance criteria. Those assemblies which do not meet the acceptance critaria will be replaced.
R$8:rn:hac/857 7/16/81-l 1
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