ML20207K142
| ML20207K142 | |
| Person / Time | |
|---|---|
| Site: | Washington Public Power Supply System |
| Issue date: | 09/22/1988 |
| From: | Sorensen G WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| REF-PT21-88 GO1-88-0058, GO1-88-58, NUDOCS 8809280260 | |
| Download: ML20207K142 (2) | |
Text
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- l} e Cs WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968 = 3000 George \\%'ashington 11'ay
- Richland 1%'ashington 99352 September 22, 1988 Respond To: N/A G01-88-0058 Response Required:
N/A Docket No. 50-460 Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Connission Mail Station P1-137 Washington D. C.
20555
Subject:
NUCLEAR PROJECT NO. 1 POTENTIALLY REPORTABLE CONDITION 10CFR50.55(E)
EERGENCY DIESEL GENERATOR CALCON CONTROL DEVICES
References:
A) Telecon, T.J. Houchins (Supply System) to Bill Wagner (NRC),
August 30, 1988, same subject.
- 8) GCI-88-0004, 10CFR Part 21, IMO Delaval to NRC, dated 4/29/88.
C) GCI-88-0005, same subject, dated 5/12/88.
In Reference A, the Supply System informed your office of a potentially reportable deficiency under 10CFR50.55(e).
The attached provides a statement of the identified condition and a brief description of our planned actions to correct the identified deficiency. Based on the current construction status at WNP-1, the Supply System will not be able to issue a final report at this tirr.e.
An update will be provided at construction restart.
If you have any questions or desire further information, please advise.
l d:s n G. C.'Sorensen Mgr. Regulatory Programs (280)
GCS/LC0/11w Attachrnent ec: OC Leonard, UE&C (898)
E. Revell, SPA (399)
JB Martin, NRC Region V l
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ATTACHMENT 00cket No. 50-460 Potentially Reportable Condition Per 10CFR50.55(e)
Emergency Diesel Generator Calcon Control Devices Description of Deficiency The Supply System's WNP-1 Project utilizes two emergency diesel generators from IMO Delaval, formerly Transamerica Delaval (TDI), as its emergency power supply source.
IMO recently issued a 10CFR Part 21 report concerning a potential problem with engine control devices manufactured by California Controls (Calcon).
The specif >; control devices are the air start valve, low lube oil trip switch, high temperature jacket water trip switch, and the high pressure crank case trip switch.
These control devices have had a significant number of failures.
Analysis of Safety Implic'ttion Failure of any cf these components could affect the availability of the emergency diesci generators by not allowing a start or by shutting the engine down.
Cause of Deficiency Based on the number of reported failures, IMO Delaval performed an audit of Calcon's manufacturing facility. A failure in the implementation of their Quality Assurance program was identified in that no objective evidence of product testing was available.
Due to the number of failures and the deficiency in the QA program IMO Delaval has questioned the reliability of the components.
In a subsequent investigation, IMO Delaval identified an additional problem on the lube oil trip switch (Calcon P/N B4400).
Addi+1onal testing and examinations conducted by the manufacturer of this component (California Controls Company -
Calcon) have now identified that because of a tolerance stack-up the diaphragm (Calcon P/N 283) can be held solid against the pressure head (Calcon P/N 4370),
thus creating a smaller surface area.
This smaller surf &ce area would require a much higher pressure to activate the valve. On a newly assembled unit this would not show up on test because the diaphragm has not had a chance to stretch and seat itself against the pressure head.
Several hours are needed between tests for the unit to fail.
Corrective Action IMO Delaval does not recommend removal of any of the items except the lube oil pressure switch.
For tho3e items not removed, a surveillance plan will be developed at restart to nonitor performance.
This action is based on IMO Delaval's recomendation and the fact that the WNP-1 engine controls were shipped prior to the recent QA audit deficiency.
IMO Delaval will also perform a source inspection on all safety related components prior to shipment until such time that a reaudit confirms full QA program implementation. Root causes for multiple field failures will also continue to be investigated by IMO Delaval.
The lube oil pressure trip switch will be removed no later than restart and returned to the vendor. Corrective action for this device is to add an additional 1-1/8" diameter with.030" deep counterbore in the pressure head (Calcon P/N 4370).
This will always provide a positive gap between the head and diaphragm.
The devices will be remachined, inspected and tested by the manufacturer (Calcon) and identified with the stamping "B4400B" to record the new configuration.
Action to Prevent Recurrence Following completion of the above described activities no further action is deemed necessary.