ML20041E494

Part 21 Deficiency Rept Re RHR Design Documentation Error. Diameter Orifice in Discharge Line to Containment Pressure Suppression Pool Was Listed Smaller than Required.Error Discovered Before Fabrication

ML20041E494
Person / Time
Site:	Hartsville
Issue date:	03/02/1982
From:	Sherwood G GENERAL ELECTRIC CO.
To:	Deyoung R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
References
REF-PT21-82-582-000 10CFR-50.55E, CAC-19-82, MFN-028-82, MFN-28-82, PT21-82-582, PT21-82-582-000, NUDOCS 8203110008
Download: ML20041E494 (3)

Text

o NUCLEAR POWER SYSTEMS DIVISION GENERAL ELECTRIC COMPANY.175 CURTNER AVE.. SAN JOSE, CALIFORNIA 95125 MC 682, (408) 925-5040 l MFN 028-82 CAC 19 82 March 2,1982

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11ECEivgp U.S. Nuclear Regulatory Commission UI98.?* $  !

Office of Inspection and Enforcement Washington, DC 20555 V

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sN Attention: Richard C. DeYoung 4 /

ro-Gentlemen:

SUBJECT:

10CFR PART 21, REPORTABLE CONDITION RHR DESIGN DOCUMENTATION ERROR This letter advises the NRC of a reportable defect per 10CFR Part 21 as reported to W. Mills of your office by Charles A. Cameron, Manager of Safety Evaluation Programs on March 2, 1981. Attached is the report of the defect, which is an error found in a document released by GE to the utility for fabrication. The affected plant is Hartsville A1.

l General Electric has infortred the Tennessee Valley Authority of the l

defect and has advised them of the appropriate corrective action taken by GE.

Very truly yours, Glenn G. Sherwood, Manager Nuclear Safety and Licensing Operation GGS:rf/102N3 Attachment cc: R. C. DeYoung, NRC (two extra cop es)

J. P. O'Reilly, NRC Region II U. Potapovs, NRC Region IV L. S. Gifford, General Electric

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8203110008 820302 5I \

PDR PT21 ENVCENE 82 PDR

REPORTABLE CONDITION RHR DESIGN DOCUMEliTATION ERROR .

I. Description of Deficiency The reportable defect is an error found and corrected in a document released for fabrication for Hartsville A1, a TVA Project. The error is the statement of a 0.63" diameter orifice requirement in the fabrication specification, instead of the actual required diameter of 6.31". It was found while performing a normal ongoing review of the containment design to assure its conformance with GE containment requirements. The error was discovered and corrected cfter the drawing was released for fabrication, but before the hardware was fabricated and installed in the plant.

II. Analysis of Safety Implication The system affected by this error is the RHR discharge line to the containment pressure suppression pool. The purpose of the orifice-is to create the correct flow and velocity from the RHR discharge line to promote circulation and mixing.

1 In the unlikely event of a LOCA,the consequence of this error, had it not been detected by the Design Review or in preoperation test, could have been the overpressurization of the containment. The use of a 0.63" diameter orifice in the discharge line would cause a severe reduction in the RHR heat removal capability from the suppression pool. In fact, if the orifice had been fabricated with the incorrect orifice diameter, it would have been detected immediately during preoperation testing. Therefore, the potential overpressurization of the containment could not have happened.

This type of defect is reportable when it is found in a basic component after the component has been accepted by the purchaser, and the defect could cause a substantial safety hazard. Specifically the erroneous specification had been accepted for fabrication. Although the likelihood for such an error to go undetected is very small, it is reportable under 10CFR Part 21.

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