ML17228B368

Responds to Violations Noted in Insp Repts 50-335/95-20 & 50-389/95-20.Corrective Actions:Multidiscipline Team Established to Perform Comprehensive Review of Nuclear safety-related Relief Valve Lift & Blowdown Settings

ML17228B368
Person / Time
Site:	Saint Lucie
Issue date:	12/19/1995
From:	Goldberg J FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-95-333, NUDOCS 9512260055
Download: ML17228B368 (7)

See also: IR 05000335/1995020

Text

LXA M AXE A (ACCELERATED

RIDS PROCESSIiC

REGULATORY

INFORMATION

DISTRIBUTION

SYSTEM (RIDS)CESSION NBR: 9512260055

DOC.DATE: 95/12/19 NOTARIZED:

NO FACIL:50-335

St.Lucie Plant, Unit 1, Florida Power&Light Co.50-389 St.Lucie Plant, Unit 2, Florida Power&Light Co.AUTH.NAME AUTHOR AFFILIATION

GOLDBERG,J.H.

Florida Power&Light Co.RECIP.NAME

RECIPIENT AFFILIATION

Document Control Branch (Document Control Desk)SUBJECT: Responds to violations

noted in insp repts 50-335/95-20

50-389/95-20.Corrective

actions:multidiscipline

team established

to perform comprehensive

review of nuclear safety-related

relief valve lift&blowdown settings.DISTRIEDTION

CODE: IEOID COPIES RECEIVED:LTR

I ENCL g SIZE: TITLE: General (50 Dkt)-Insp Rept/Notice

of VioTation Response NOTES: DOCKET 05000335 05000389 RECIPIENT ID CODE/NAME PD2-1 PD INTERNAL: ACRS AEOD/SPD/RAB

DEDRO NRR/DISP/PIPB

NRR/DRPM/PECB

NUDOCS-ABSTRACT

OGC/HDS3 EXTERNAL: LITCO BRYCE,J H'RC PDR COPIES LTTR ENCL 1 1 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 RECIPIENT ID CODE/NAME NORRIS,J AEOD/DEIB AEO TC LE C ER N CTP/HHFB NRR/DRPM/PERB

OE DIR RGN2 FILE 01 NOAC COPIES LTTR ENCL 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 VOTE TO ALL"RIDS" RECIP IEY'TS: PLEASE HELP US TO REDUCE iVASTE!COYTACTTHE

DOCL'ifEYT

COYTROL DESK.ROOM Pl-37 (EXT.504.2083)TO ELI XII iATE 5'OI.'R iAiIE FROil DISTRIBUTIOY

LISTS I'OR DOCI.'MEi'I'S

YOU DOi"I'ELIDI OTAL NUMBER OF COPIES REQUIRED: LTTR 20 ENCL 20

Florida Power 5 Light Company, P.O.Box 128, Fort Pierce, FL 34954-0128

FPL DEC 19 1995 L-95-333 10 CFR 2.201 U.S.Nuclear Regulatory

Commission

Attn: Document Control Desk Washington, D.'.20555 Re: St.Lucie Units 1 and 2 Docket No.50-335 and 50-389 Reply to Notice of Violation In inR-2-EA-222 Florida Power and Light Company (FPL)has reviewed the subject, notice of violation issued on November 28, 1995.Pursuant to 10 CFR 2.201, the response is attached.On December 1, 1995, the NRC senior resident inspector for St.Lucie notified FPL that the response to this notice of violation was not required to be submitted under oath or affirmation

as originally

requested'by the notice of violation.

Very truly yours, J.H.oldberg President-Nuclear Division JHG/GRM Attachment

cc: Stewart D.Ebneter, Regional Administrator, USNRC Region II Senior Resident Inspector, USNRC, St.Lucie Plant Q f>P;~r Vi t~r 9512260055

951219 PDR ADDCK 05000335 9 PDR an FPL Group company

Re: St.Lucie Units 1 and 2 Docket No.50-335 and 50-389 Reply to Notice of Violation Ins eci n Re-20 Violation EA 5-222 10 CFR 50, Appendix B, Criterion XVI,"Corrective

Actions," requires, in part, that measures be established

to assure that conditions

adverse to quality are promptly identified

and corrected.

Contrary to the above, conditions

adverse to quality, involving relief valve setpoint and blowdown values, identified

on February 20, March 2, and March 10, 1995, did not receive prompt corrective

actions and led to a repeat of previously

identified

problems on August 10, 1995, when Unit 1 relief valve V-3439 lifted and failed to reseat without operator intervention.

The subject event resulted in approximately

4000 gallons of reactor coolant accumulating

in the Unit 1 pipe tunnel.Evaluations

performed after this event revealed the need to replace, or establish new setpoints for, several relief valves in safety systems in both units.This is a Severity Level IV violation (Supplement

I).FPLR n e 1.The reason for the violation:

The series of relief valve events that occurred in early 1995 took place in different plant systems and involved both St.Lucie Unit 1 and Unit 2.Initial plant efforts to correct these individual

plant events were focused on solving the plant system control problems that led to the pressure transients

causing the series of relief valve actuation.

Briefly, these events are discussed below: The causes of the Unit 1 and Unit 2 letdown events (between January 23, 1995 and July 8, 1995)were associated

with letdown pressure control problems.The corrective

actions were focused on the letdown pressure control valve performance.

The cause of the Unit 2 component cooling water relief valve actuation event (February 17, 1995)was a test configuration

problem.At the time of the NRC inspection

for the subject inspection

report, a system transient test was being developed to evaluate the configuration

problem.

l

The cause of the Unit 1 shutdown cooling suction relief event (February 27, 1995)was a flow initiated pressure transient.

The corrective

action was the implementation

of a procedure change which mitigates the potential for pressure transients

while placing shutdown cooling in service.Long term corrective

actions are discussed in paragraph 2.D.The cause of the Unit 1 shutdown cooling discharge relief (V3439)event (August 10, 1995)was identified

as a design lift and blowdown setpoint problem.Once the relief lifted, it did not reseat without operator intervention

to isolate the affected portion of the system.The corrective

actions were to replace the valve V3439 and to increase the relief valve lift setpoint and to reduce the blowdown setting thereby providing additional

operating margin.These individual

events did not appear to share a common root cause and corrective

actions to resolve these individual

problems were promptly initiated by plant management.

A generic relief valve setpoint concern was identified

by the Operations

Supervisor

on March 2, 1995 (following

the February 27, 1995 event), and was assigned to Mechanical

Maintenance

for resolution.

Between March and August of 1995, Maintenance

focused on developing

three corrective

actions: 1)a new relief valve test bench, 2)revisions to valve test procedures, and 3)improved maintenance

training.Maintenance

had not considered

a design problem with relief valve setpoints and, therefore, efforts were directed toward verifying that the relief valves could be set in accordance

with plant design.The underlying

root cause for the series of relief valve events-lack of design integration

between system operating pressures and relief valve reseat pressures-was not evident until the St.Lucie Unit 1 shutdown cooling discharge relief event (August 10, 1995).At that time, the Engineering

Department

established

a multi-disciplined

team to investigate

safety-related

relief valve lift and reseat settings.The St.Lucie Action Request (STAR)process was a contributing

factor to the delay in finding the underlying

root cause of the events.The STAR process relied on series assignments

for actions and did not lend itself to parallel investigations

or corrective

actions.The corrective

steps that have or will be taken and the results achieved: A.The corrective

actions taken to address the specific problem of safety related relief valve lift and blowdown settings and control of relief valve design information

were provided in the Unit 1 Licensee Event Report (LED)95-06, and at the pre-decisional

enforcement

conference

on November 14, 1995.

B.In August 1995, a multi-discipline

team was established

to perform a comprehensive

review of the St.Lucie Unit 1 and Unit 2 nuclear safety related relief valve lift and blowdown settings.The team was composed of personnel from Maintenance, Operations, Plant System Ec Component Engineering, and Nuclear Engineering.

A total of 114 relief valves were reviewed (53 for Unit 1 and 61 for Unit 2)and their design settings were evaluated relative to system operating and transient pressures.

Seventeen of these valves required additional

analysis.Corrective

actions, except as noted in 2.D below, have been taken to increase the margin between system operating pressures and the lift/reseat

setting, where appropriate.

C.Unit 1 relief valve modifications, with the exception of the shutdown cooling suction overpressure

relief valves, V3468 and V3483, were implemented

prior to the October 1995 startup, following the shutdown related to Hurricane Erin.D.Unit 1 shutdown cooling suction overpressure

relief valves, V3468 and V3483, lift settings were adjusted to improve the lift margin prior to the October 1995 startup.With these revised lift settings, shutdown cooling can be initiated without challenging

these relief valves.The lift and blowdown settings will be further modified during the Spring 1996 refueling outage.E.Unit 2 relief valve modifications

were implemented

during the Fall 1995 refueling outage.3.The corrective

steps taken or planned to avoid further violations:

~A.FPL Maintenance

Specification

SPEC-M-038, Safety Related Relief Valve Setpoints St.Lucie Units 1 and 2, was issued in November 1995 to institutionalize

the results of the relief valve design review team.B.The STAR process was modified to facilitate

parallel department

assignments

for the evaluation

and correction

of deficiencies.

4.The date when full compliance

will be achieved: A.The STAR process procedure was modified in October 1995.B.Full compliance

for the relief valve settings will be achieved during the Spring 1996 refueling outage.