ML20100L897

Seventh Part 21/deficiency Rept,Item 41 Re Potential Significant Failure of Reactor Protection Sys Following Secondary High Energy Line Rupture (Steam Generator Ref Leg Heatup).Initially Reported on 800707.Final Rept by 850228

ML20100L897
Person / Time
Site:	Harris
Issue date:	11/30/1984
From:	Parsons R CAROLINA POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
CON-NRC-298, REF-PT21-85-087-000 41, PT21-85-087-000, PT21-85-87, NUDOCS 8412120125
Download: ML20100L897 (4)

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c-u7GF<Grg Carolina Power & Light Company

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P. O. Box 101, New Hill, N C 27562

• 80 November 30,1984 Mr. James P. O'Reilly NRC-298 United States Nuclear Regulatory Commission Region II 101 Marietta Street, Northwest (Suite 2900)

Atlanta, Georgia 30323 CAROLINA POWER & LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT 1986 - 900,000 KW - UNIT 1 POTENTIALLY SIGNIFICANT FAILURE OF THE REACTOR PROTECTION SYSTEM FOLLOWING A SECONDARY HIGH ENERGY LINE RUPTURE (STEAM GENERATOR REFERENCE LEG HEATUP)-ITEM 41

Dear Mr. O'Reilly:

Attached is our seventh interim report on the subject item which was 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 February 28,1985.

Thank eou for your consideration in this matter.

Yours very truly, f;pyf =c 2 R. M. Parsons Project General Manager Completion Assurance

! Shearon Harris Nuclear Power Plant RMP/sae Attachment CC: Messrs. G. Maxwell /R. Prevatte (NRC-SHNPP)

Mr. R. C. DeYoung (NRC) 8412120125 841130

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CAROLINA POWER & LIGHT COMPANY.

SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 SEVENTH INTERIM REPORT POTENTIAL SIGNIFICANT' FAILURE OF THE-REACTOR PROTECTION SYSTEM FOLLOWING A SECONDARY HIGH ENERGY LINE RUPTURE (STEAM GENERATOR REFERENCE LEG HEATUP).

ITEM 41.

NOVEMBER 29, 1984 f

REPORTABLE'UNDER 10CFR50.55(e)

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SUBJECT:

" 10CFR50.55'(e)' Reportable Item .

, .Shearon Harris Nuclear Power Plant Unit l '

. Potential Significant Failure of~the. Reactor Protection. System Followingfa Secondary High, Energy Line Break (Steam Generator Reference Leg Heatup)

ITEM: Steam Generator Level Measurement:for.SHNPP Unit #1 -

SUPPLIED BY: 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 system generator level-measurement reference leg. A heatup of the reference leg would result in' severe density, changes which would give erroneous indication of steam generator water level.

DATE PROBLEM WAS CONFIRMED TO EXIST:- Westinghouse Letter CQL-5801 dated' March 20, 1980, 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.

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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. O'Reilly. transmitting a second interim report.

CP&L letter. dated Juae 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..

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

CP&L letter dated October.1,'1984, R. M. Parsons to 4" J. P. O'Reilly transmitting'a sixth interim-report.

SCOPE OF PROBLEM: Unit I 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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k, REASON PROBLEM.

IS REPORTABLE: Delayed reactor protection signals could lead to a degraded safety condition.

c CORRECTIVE _

ACTION: Westinghouse has now adopted insulation of the steam generator reference leg as.a permanent solution to-the heatup concern. Corrective action will be-achieved by the-issuance of design-changes that 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 now anticipated to be February 29, 1985.

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