RBG-21451, Final Deficiency Rept DR-298 Re Possible Failure of Air Start Check Valves KE-008-000 for Tdi Standby Diesel Generators.Initially Reported on 850703.Replacement Valves Installed & Loose Particle Exam Performed

Final Deficiency Rept DR-298 Re Possible Failure of Air Start Check Valves KE-008-000 for Tdi Standby Diesel Generators.Initially Reported on 850703.Replacement Valves Installed & Loose Particle Exam Performed

ML20132G741
Person / Time
Site:	River Bend
Issue date:	07/05/1985
From:	Booker J GULF STATES UTILITIES CO.
To:	Martin R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
DR-298, RBG-21451, NUDOCS 8507190451
Download: ML20132G741 (2)

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.g GULF STATES UTILITIES COMPANY RNER BEND STATION POST OFFICE BOX 220 ST. FRANCISVILLE. LOUISIANA 70775 AREA CODE 504 635-6094 346 8651 July 5, 1985 RBG- 21451 File Nos. G9.5, G9.25.1.1 Mr. Robert D. Martin, Regional Administrator U.S. Nuclear Regulatory Cmmission Region IV 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011

Dear Mr. Martin:

River Bend Station - Unit 1 Docket No. 50-458 Final Report /DR-298 On July 3,1985, GSU notified Region IV by telet t ane that it had deter-mined DR-298 concerning air start check valves for standby diesel genera-tors supplied by Transamerica Delaval, Incorporated to be reportable under 10CFR50.55 (e) . The attachment to this letter is GSU's final 30-day written report pursuant to 10CFR50.55(e) (3) with regard to this deficiency.

Sincerely,

. F. W J. E. Booker

['4 Manager-Engineering, Nuclear Fuels & Licensing River Bend Nuclear Group hfr0 JEB/PJD/amg cc: Director of Inspection & Enforcanent Qi, U. S. Nuclear Regulatory Cmmission

+ Washington, D. C. 20555 NRC Resident Inspector-Site %ggggg p' INFO JUL l U 1985 ;

u if 8507190451 850705 PDR ADOCK 05000458 S PDR

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• 1 A'ITACHMENT July 5, 1985 RBG- 21451 DR-298/ AIR START OIECK VALVES Background and Description of the Problem The deficiency concerns air start check valves supplied by the Williams Gauge Co. (now Clow Corporation) for standby diesel generators manufactured by Transamerica Delaval, Incorporated ('IDI) . TDI in its letter dated March 12, 1985, described how flames emanating from an air start assably were noticed during diesel operation at another facility. Upon examination, it was found that two of these four air check valves installed by 'IDI were broken and/or cracked. The remaining two were undamaged. The cause of the probl m is not known at this time. Failure of these valves has been known to occur only after 900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br /> of operation.

The valves for the River Bend Station (RBS) diesels are identified with 'IDI Part No. KE-008-000. The diesels at RBS to date have run for approximately 330 hours0.00382 days <br />0.0917 hours <br />5.456349e-4 weeks <br />1.25565e-4 months <br />.

A similar problem has not occurred at RBS; however, steps were taken to detentu.ne whether a similar deficiency might exist.

Safety Implication While there is no physical evidence which indicates the existing valves at RBS are deficient, GSU conservatively assumes that the valves could have failed. Failure of the check valves could seriously degrade the diesel's performance to a condition where it would fail to start, or because of cmpression leakage during the firing stroke could result in external flam-ing with unplanned diesel shutdown. The safe operations of the plant could therefore be adversely affected by this condition.

Corrective Action

'IDI's recmmendation is to disassemble each of the two check valves / engine on RBS engine R-48 type for nondestructive examination.

In lieu of this procedure, replacment units were obtained from a different manufacture under 'IDI Warranty Order No. W-39258 for both diesels. Noncon-formance and Disposition Report No. 12,209 has been initiated to remove the potentially deficient valves, to perform loose particle examination and return the existing valves to TDI, and to install the replacement valves.