ML20094N321

Fifth Interim Rept,Item 41 Re Potentially Significant Failure of Reactor Protection Sys Following High Energy Line Rupture.Initially Reported on 800707.Steam Generator Ref Legs Will Be Insulated.Final Rept to Be Issued 841002

ML20094N321
Person / Time
Site:	Harris
Issue date:	07/30/1984
From:	Parsons R CAROLINA POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
CON-NRC-250 41, NUDOCS 8408160168
Download: ML20094N321 (4)

Text

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, 0 CP&L Carolina Power & Li Company

,, o i-P.O. Box 101, New Hill, N.C. 27562 July 30, 1984 Mr. James P. O'Reilly NRC-250 United States Nuclear Regulatory Commission Region II 101 Marietta Street, Northwest (Suite 2900)

Atlanta, Georgia 30323 CAROLINA POWER & LIGHT COMPANY SilEARON liARRIS NUCLEAR POWER PLANT 1986 - 900,000 KW - UNIT 1 POTENTIALLY SIGNIFICANT FAILURE OF Tile REACTOR PROTECTION SYSTEM FOLLOWING A SECONDARY HIGil ENERGY LINE RUPTURE (STEAM GENERATOR REFERENCE LEG llEATUP) - ITEM 41 Dear Mr. O'Reilly Attached is our fifth interim report on the subject item which wes deemed reportable per the provisions of 10CFR50.55(e) on July 7, 1980. CP&L is pursuing this matter, and it is currently projected -

that corrective action and submission of the final report will be accomplished by October 2, 1984.

Thank you for your consideration in this matter.

Yours very truly,

"??f M R. M. Parsons Project General Manager Shearon liarris Nuclear Power Plant RMP/ jam Attachment cc: Messrs. G. Maxwell /R. Prevatte (NRC-SilNPP)

Mr. R. C. DeYoung (NRC)

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CAROLINA POWER & LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT u

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< FIFIR INTERIM REPORT POTENTIAL SIGNIFICANT FAILURE OF THE REACTOR PROTECTION SYSTEM FOLLOWING A SECONDARY HICH ENERGY LINE RUPTURE (STEAM CENERATOR REFERENCE LEG HEATUP)'

ITEM 41 l.

4 JULY 31, 1984 REPORTABLE UNDER 10CFR50.55(e) s.

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SUBJECT:

-10CFR50.55(e) Reportable Item

.Shearon Harris Nuclear Power Plant Potential Significant Failure of the Reactor Protection System Following a Secondary High Energy Line Break (Steam Generator Reference Leg Heatup)

ITEM: Steam Generator Level. Measurement- for SHNPP Unit il SUPPLIED Bj[: Westinghouse Water Reactor Division

' NATURE OF DEFICIENCY: Westinghouse notified the NRC under 10CFR21 in June 1979 of a potentially significant failure of the reactor protection system following a secondary high energy line break. Such a break within containment could result in the heatup of the steam generator level measurement reference leg. A heatup of the reference leg sould result in severe density changes which:would give erronecas indication of steam generator water level.

DATE PROBLEM WAS CONFIRMED Tjl EXIST: Westinghouse Letter CQL-5801 dated Parch 20,fl980, received March 28, 1980.

PROBLEM REPORTED: N.J. Chiangi notified the NRC (Mr. J. Bryant) that this item was reportable under 10CFR50.55(e) on July 7,1980.

CP&L letter dated July 8, 1980, N.J. Chiangi to J.P. O'Reilly transmitting an interim report.

CP&L letter dated December 23, 1981, N.J. Chiangi to J. P. 0'Reilly transmitting a second interim report.

CP&L letter dated June 1,1983, R.M. Parsons to J.P. O'Reilly transmitting a third interim ' report.

CP&L letter dated March 30, 1984, R.M. Parsons to J.P. O'Reilly transmitting a fourth interim report.

SCOPE OF PROBLEET Unit 1 steam generators (three per unit).

SAFETY IMPLICATIONS: An erroneous indication of the steam generator water level could result in delayed signals to the reactor protection system.

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REASON PROBLEM IS REPORTABLE: Delayed reactor protection signnis could lead to a I degraded safety condition.

CORRECTIVE ,

ACTION: Westinghouse has now adopted insulation of the steam H

. generator reference leg as a permanent solution to I the heatup concern. Since centainment piping  ;

insulation is not yet scheduled, corrective action will be achieved by implementing design changes to incorporate insulation of the steam generator reference legs.

FINAL REPORT: A final report will be' issued when the corrective action has been completed. This is anticipated to be October 2, 1984.

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