ML19323E426
| ML19323E426 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 05/19/1980 |
| From: | Mary Johnson SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | |
| References | |
| NUDOCS 8005230534 | |
| Download: ML19323E426 (3) | |
Text
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Sora CAnouNA El.EOTRIC & GAS CCMPANY
- C+T G P F'C r 9 3 s 78t*
Co'.uwsiA. Scuta CnouN A 232ts M. C. Jousou n a eus as..wo s. -. cism.:
May 19, 1930 n u... o. a......>..:......
". S. Nuclear Regulatory Coraission Attn:
Mr.
ames P. O'Reilly Director Region II 101 Mariatta Street, '4 Atlanta, Georgia 30303
Subject:
V. C. Suc=er ':uclear Station Unit al Licease CPRP-91, R2 portable Ite in Accordance with 10CFR30.33(e),
tu!R Valve Failure Cantleten:
On April 22, 1930, the Re:; ion II Resident Inspector, Jack Skolds, was natified of a reportable item regarding the f ailute. of the A Train Residual
- iea t Removal (RfiR) IIeat Enchanger Discharpe Flov Ccntrol Valve to the closed p;sition when its failure nede is open for safety considerations.
'!ature of Condition During heatup of the Reactor Coolant Systen (ACS) for cold hydro, the Flia system tras being used to control the heatup rate.
During the course of this evolution, the A Train RHR Heat Exchanger Flo: Control Valve went closed.
Investigation by Nuclear Operations Start-up personnel revealed that the scem connector had separated which allowed the actuator sten and operator sten to disengage and thus the valve went closed.
Cause The reason the stam connector had separated was due to excessive penetratien of the stud bolt into the stem connector. The stud bolt provides nechanical f eedback to the va'.ve positioner.
Excessive pene-tration of the stud bolt prevanted the female threads of the stem connector frcn conpletely engaging the male threads of the actuator and cperators stens. The cause of the excessive stud belt penetration seas attributed to annufacture of replacement pieces on Site by persons unknoten uithout censideratica of desi2n or OA prc2ran recuirenents for the manufacture and use of items for safety related conponents. No 36/'l s
)I g
THIS DOCUMENT CONTAINS O
POOR QUAllTY PAGES 8005230 4
- Mr. Janas P. O'Reilly Page'2 May 19, 1980 i
documentation existad to establish when or how the replacement pieces were made, but physical examination of the pieces in the failed valve i
indicated they uere not of vendor origin. Further investigations into the program violation aspects of the condition could not establish who i
performed the work outside the QA program.
Safety Inclications i
j The safety implication of the condition reported is that during l
postulated accident conditions (i.e. design LOCA with single active i
failure in the 3 Train RHR systet0 the RER system would hava been inoperable and the ability to keep the reactor core covered co=procrised.
i Actions o Correct conditions I
Since the specific cause of the condition was indeterminate, actions were takan to inspect four similar valves that were suspect since they were capable of having the same non-progra:matic ::odifications performed.
j Two valves are Flia Heat Exchanger bypass valves and two are in the Thermal Regeneration Systen. L'pon inspection, similar conditions were i
not discovered in thase valves. Additionally, the operator stem is being replaced on the failed valve since it was damaged during the failure, and j
new stud bolts ara being procurred for installation in the A & B valves in this system.
1 Corrective Actions to Pravent Racurrence No specific corrective actions have been taken to prevent recurrence of-this condition. The condition is believed to be an isolated case of' l
working outside the QA program. Since appropriate Nuclear Operations Start-up and Maintenance personnel and supervisors were involved with Nuclear Engineering in investigating and correcting the condition, SCE&G j
believes the emphasis of program controls has been delineated to the extent necessary to prevent recurrence considering the indeterminate nature of specific perpetrators.
I SCEEG believes actions outlinad above will adequately resolve problems encountered with the valve failure.
Since all necessary actions have been identi-fled and are in the process of being implemented, we consider this a final report.
All actions taken will be available at the Site for NRC review. Should further information be required, please centact us.
Very truly yours, Sn
.: w.
y;.uA3 W
c.et/MCJ/jls cc: Page 3
- Mr. James P. O'Railly Page 3 May 19, l'330 cc:
C. J. Frit:
G. C. Meet::e p fice of Director Inapection & Enforcement Washington, DC 20555
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