ML18113A276

LER 1977-005-00 for St. Lucie Unit 1, Two Main Feed Pump Discharge Valves Could Reopen After Closing on a Main Steam Isolation Signal

ML18113A276
Person / Time
Site:	Saint Lucie
Issue date:	02/25/1977
From:	Schmidt A Florida Power & Light Co
To:	Moseley N NRC/IE, NRC/RGN-II
References
PRN-LI-77-43 LER 1977-005-00
Download: ML18113A276 (9)

Text

FOR,'ACTION/INFO RMATIO BRANCH CHIEF:

V 3 CYS FOR ACTION LICo ASSTo:

H CYS ACRS I CYS ~%:.K S INTERNAL D IST RI BUTION REG FI PDR I&E (2 HIPC SCHROEDER/IPPOLITO

'OUSTON NOVAK/CHECK GRIMES CASE BUTLER HANAUER TEDESCO/HACCARY EISENHUT SHAO VOLLNER/BUNCH KREGER/J COLLINS EXTERNAL DISTRIBUTION CONTROL NUMBER LPDR:

TIC:

NSIC+

NAG FOAM 196 (2.76)

C NRC FOIr~ 195 U.S. NUCLFAR REGULATORY COMMISSION DOCKET NUMBER r

/'RC I2. 76) r DISTRIBUTION FOR PART 50 DOCKET MATERIAL FILE NUMOER 50-335 TO: FROM: DATE OF DOCUMENT Florida Power 6 Light Company 2/25/77 Mr."Norman C. Moseley Miami, Florida DATE RECEIVED A. D. Schmidt 3/le/77 JgLETTE R ONOTORI2ED PROP INPUT FORM NUMBER OF COPIES RECEIVED

@OR IGINAL IF IE D OCOPY gifUNC LASS One Sl ~d.

DESCRIPTION ENCLOSU RE F+tr. trans the following: Licensee Event Report (RO 50-935-77-5) on l/25/77. concerning the two MFP'ischarge valves not reopening after..closing on a gain Steam Isolation Signa)......

PLANT NAME:

(-l-P-)-(-2-P) IlkCKNOgrggD<@>

St. Lucie Unit No. l DO gOT REMOVE RJL SAFETY FOR ACTION/INFORMATION ASSIGNED AD:

0 EC7 %ANNA PROJECT MANAGER L C ASST LIC ASST IN TE R MAL D I ST R I BUT ION REG FXLE SYSTEMS"SAFETY PLANT. SYSTEMS- S SAFE NRC PDR HEINEMAN TEDESCO

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OELD r,r'PPOLXTO GOSSICK & STAFF ENGINEERXNG MIPC MACARR ERNST CASE BOSNAK BALLARD HANAUER SIHWEXL OPERATING REACTORS YOUNGBLOOD HARLESS PAW ICK 'STELLO SITE TECH PROJECT MANAGEMENT REACTOR SAFETY OPERATING TECH GAMIfILL BOYD EXSENHUT . STEPP ROSS PE COLLINS NOVAK HULMAN HOUSTON ROSZTOCZY PETERSON CHECK BUTLE SITE ANALYSIS MELTZ VOLLMER HELTEMES AT6c I BUNCH SKOVHOLT SALTZMAN J ~ COLLINS RUTBERG KREGER EXTERNAL DISTRIBUTION CONTROL NUMBER LPDR'IC:

NAT LAB REG V IE ULR KSON OR NSXC: LA PDR ~ ~

ASLB:

ACRS CYS HOLDING/ E T CONSULTANTS:

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FLORIDA POWER 8L LIGHT COMPANY February 25, 1977 PRN-LI-77-43 Mr.'Norman C. Moseley, Director, Region Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 230 Peachtree Street, N.W., Suite 1217 Atlanta, Georgia 30303 MAR1 4 190~

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Dear Mr. Moseley:

tglhllSSIOg t SccII REPORTABLE OCCURRENCE 335-77 ST. LUCIE UNIT 1 A DATE OF OCCURRENCE: JANUARY 25, 1977 MSIS CIRCUIT The attached Licensee Event Report is being submitted in accordance with Technical Specification 6.9 to provide 30-day notification of the subject occurrence.

Very truly yours, A. . Schmidt Vice President Power Resources MAS/cmp Attachment cc: Robert Lowenstein, Esquire Director, Office of Inspection and Enforcement (30)

Director, Office of Management Information and Program Control (3) 8689 a>o>sowed'EI.PING 8UILD FLOR IDA

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CONTROL BLOCK:

LICENSEE EVENT REPORT

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[PLEASE PRINT ALL REQUIRED INFORMATION) 1 tICENSEEI'AME UCENSE EVENT UCENSE NUMBER TYPE TYPE

[OD1] F L S L S 1 0 0 0 0 .01 0 0 0 0 4 1 1 1 1

~03 89

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7 I15 25 26 30 31 32 REPORT REPORT CATEGORY TYPE SOURCE OOCKET NUMBER EVENT OATE REPORT OATE ICD1] coNT ~L 0 5 0 0 3 3 5 0 ] 2 5 7 7 0 2 2 5 7 7 7 8 57 58 59 60 61 68 69 74 75 80r EVENT OESCRIPTION Jog During a review of the Main Feed Pump'(MFP) control circuitry which had been undertaken 89 80 m due to spurious pump trips, it was determined that the two MFP discharge valves could 7 8 9 80 lOS] reo en c cle after closin on a Main Steam Isolation Signal (MSIS) under the fol low-7 8 9 80

~05 ing conditions: (1) MFP continues to run, (2) a Safety Injection Actuation Signal 7 8 9 80 Jog NOT .reachin ful 1 o en the valves would close if a MSIS were 7 8 9 PRME 60 SYSTEM CAUSE COMPONENT COMPONENT COOE COOE COMPONENT CODE MANUF~IAEA Qojz ~co ~e z z z z z z Z 9 9 9 N 7 8 9 10 11 12 17 47 48 CAUSE OESCRIPTION

~08 The as-built control circuitry did not'fully meet the design intent. On January 25, 7 8 9 80 Qpg 1977, after Plant Facility Review Group and Company Nuclear Review Board approval, a 7 8 9 80

~10 control circuit lead was lifted for each valve to ensure that the valves would remain 7 89 FACIUTY METHOO OF STATUS 5 POWER OTHER STATUS OISCOVERY OISCOVEAY OESCRIPTION 9 ~os o NA c NA 7 8 9 10 12 13 44 45 46 60 FOAM OF ACTIVITY COIIITENT RELEASED OF RELEASE AMOUNT OF ACTIVITY LOCATION OF RELEASE IIIOI ~z ~z NA NA 7 9 9 10 11 44 45 9

PERSONNEL EXPOSURES NUMBER TYPE OESCAIPTION P~g ~oo o ~z NA 7 8 9 11 12 13 80 PERS'ONNEL INJURIES NA 7 89 11 12 80 PROBABLE CONSEQUENCES Q1g Since these valves are redundant backups to the Main, Feed Block Valves and since a Main 7 8 9 80 LOSS OR OAMAGE TO FACILITY TYPE 0ESCAIPTION 7 8 9'0 z

PUBLICITY 80 NA 7 8 9 ~ 80 AOOITIONAL FACTORS

~18 See Page 2 for continuation of Event Description, Cause Description, and Probable 7 89 80 Q~ 9 Conse uences.

7 89 80 M. A. Schoppman PHONE'5/552-3779 GF0 681 057

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REPORTABLE OCCURRENCE 335-77-5 LICENSEE EVENT REPORT PAGE TWO Event Descr,i tion (continued) still present. This was the second occurrence of this type involving a safeguards (ESFAS) design problem (see LER 335"76-3 dated March 18, 1976), however, the first occurrence involved ESFAS response on loss of power, and the two events are not considered to be generically related. (335-77-5) ~

Cause Descri tion (continued) closed when required. This interim fix was determined not to involve an unreviewed safety question per 10 CFR 50.59 as it implemented the original design intent of the Final Safety Analysis Report and did not affect any other accident analysis. Final corrective action was to permanently modify the circuits in accordance with 10 CFR 50.59 to meet the design intent. (335-77-5)

Probable Conse uences (continued)

Steam line rupture would most likely initiate SIAS as well as HSIS, the probability of the valves not remaining closed was low.

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