ML18011A382

Responds to NRC 940203 Ltr Re Violations Noted in Insp Rept 50-400/93-25.Corrective Actions:Tie Wraps Will Be Installed on Field Cables in Two Dc Distribution Panels & PSU-111 Connectors Replaced

ML18011A382
Person / Time
Site:	Harris
Issue date:	03/07/1994
From:	Robinson W CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
HNP-94-018, HNP-94-18, HO-940507, NUDOCS 9403140274
Download: ML18011A382 (9)

Text

ACCELERATED DISTMBUTION DEMONSTRATION SYSTEM REGULATORY INFORMATION DISTRXBUTION SYSTEM (RXDS)

CESSION NBR:9403140274 DOC.DATE: 94/03/07 NOTARIZED: NO DOCKET FACIL:50-400 Shearon Harris Nuclear Power Plant, Unit 1, Carolina 05000400 AUTH. NAME ROBINSON,W.R.

'UTHOR AFFILIATXON Carolina Power & Light Co.

RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Responds to NRC 940203 ltr re violations'oted in insp rept 50-400/93-25.Corrective actions:tie wraps will be installed on field cables in two dc distribution panels & PSU-111 D connectors replaced.

DISTRIBUTION CODE: IE01D COPIES RECEIVED:LTR ENCL SIZE:

TITLE: General (50 Dkt)-Insp Rept/Notice of Violation R sponse NOTES:Application for permit renewal filed. 05000400 A RECIPIENT COPIES D RECIPIENT COPIES ID CODE/NAME LTD ENCL ID CODE/NAME LTTR ENCL D

PD2-1 PD 1 ( 1 LE,N 1 1 INTERNAL: ACRS 2 2 AEOD/DE IB 1 1 AEOD/DSP/ROAB 1 1 AEOD/DSP/TPAB 1 1 AEOD/TTC 1 1 DEDRO 1 1 NRR/DORS/OEAB 1 1 NRR/DRCH/HHFB 1 1 NRR/DRIL/RPEB 1 1 NRR/DRSS/PEPB 1 1 NRR/PMAS/ILPB1 1 1 NRR/PMAS/ILPB2 1 1 NUDOCS-ABSTRACT OGC/HDS1 RES/HFB 1

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FILE 02 01 1

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1 EXTERNAL: EG&G/BRYCE,J.H. 1 1 NRC PDR 1 1 NSIC 1 1 D

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NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE iVASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOiVI Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TAL NUMBER OF COPIES REQUIRED: LTTR 24 ENCL 24

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<jy CPA.L Carolina Power 8 Light Company William R. Robinson PO Box 165 Vice President New Hill NC 27562 Harris Nuclear Plant

, MAR -"f lgg File: HO-.940507 Serial: HNP-94-018 10CFR2.201 United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT DOCKET NO. 50400/LICENSE NO. NPF-63 REPLY TO A NOTICE OF VIOLATION Gentlemen:

In reference to your letter of February 3, 1994, referring to NRC Inspection Report 50-400/93-25, the attached is Carolina Power Bc Light Company's reply to the

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violations identified in Enclosure 1.

II It is considered that the corrective actions taken/planned are satisfactory for resolution of the violations. Questions regarding this matter may be referred to Mr. D. C. McCarthy at (919) 362-2100.

Very truly yours, W. R. Robinson SDC:sdc Attachment c: Mr. S. D. Ebneter (NRC-RII)

M . N. S. Z (NRR)

Mr. J. E. Tedrow (NRC-SHNPP) 9403140274 940307 PDR ADOCK 05000400 9 PDR State Road1134 New Hill NC Tel 919362-2502 Fax 919362-6950

Attachment to HNP-94-018 REPLY TO A NOTICE OF VIOLATION NRC INSPECTION REPORT NO. 50400/93-25 Re orted Violation A:

10 CFR 50, Appendix B, Criterion XVIrequires that measures shall be established to assure conditions adverse to quality, such as failures, malfunctions,'deficiencies, deviations, and non-confor'mance are properly identified and corrected.

The licensee's Corporate Quality Assurance Manual, Section 12, requires that significant conditions adverse to quality be identified and that corrective actions be determined which will preclude repetition of the condition.

Contrary to the above, following the failure of an auxiliary feedwater system valve in November 1992, the identification and determination of corrective actions for deficiencies noted in the motor control center wiring of auxiliary feedwater system motor operated valves was not sufficient to preclude the repetition of another auxiliary feedwater system valve failure on December 14, 1993.

This is a Severity Level IV violation (Supplement g.

Denial or Admission:

The violation is admitted.

Reason for the Violation:

Plant Change Request PCR-3551 was initiated for the DC electrical distribution system in August 1988 by the Technical Support Unit to disposition concerns of loose electrical connector strips found in DC distribution panels DP-1A2-SA and DP-1B2-SB'. The connectors of concern were Connectron Model PSU-111, separable modular plugs. The PCR prompted an investigation to discern the scope of potential problem(s) with the connectors. A review of records found no equipment failures resulting f'rom these connectors coming loose. It was believed that the PCR was initiated as a result of problems experienced f'rom movement of the cables associated with activities within the DC" distribution panels during construction of the facility. Given that no documented failures could be associated with these connectors after commencement of plant operations, PCR-3551 was canceled in August 1990.

Meanwhile, on July 18, 1989, the Operations Unit issued a Standing Order and mounted placards on the access doors of the two DC distribution panels to heighten operations and maintenance personnel awareness of concerns associated with these connectors. The There are a total of five valves routed through the distribution panels DP-1A24A and DP-1B2-SB.

MEM/HO 940507/OS1

4 Attachment to HNP-94-018 tw Standing Order required verifying proper operation of each valve whose control circuitry is

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routed through a DC distribution panel in which work is done in the breaker cubicle or to

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the access doors. ~

PCR-5511 was initiated in September 1990 by the Operations Vnit based on the same concerns that resulted in initiation of PCR-3551. Subsequently, a single failure attributable to a loose PSU-111 connector occurred on November 26, 1992 in the control circuit of valve 1MS-70'. The engineering review stemming from the failure'concluded that the design of the distribution panels, including the PSV-111 terminals, was sufficient if the cables are supported in accordance with design requirements., Further, the review stated that the terminal blocks unlatch due to forces on them f'rom supporting cable weight and pulling forces exerted by the moving of cables. The pull-apart terminal blocks used in the two DC

.~'.".l~hu<3on. g~a~ls have s>>fficient frictional force holding them together such that without the introduction of outside forces the terminal blocks would not pull apart.

Investigation of PCR 5511 prompted another review to discern if there had been any changes since the previous PCR's review. This review identified the single failure on November 26, 1992 in the control circuit of valve 1MS-70 as the only failure. However, given the population of greater than 3500 PSU-111 terminal blocks in service for seven years of operation, a single failure attributable to a loose PSU-111 connection was not considered to be sufficient cause to warrant any design changes. Therefore, PCR-5511 was also canceled on November 12, 1993 and no additional actions were taken.

On December 14, 1993, valve 1AF-137 failed. The root-cause investigation attributed the failure to a loose PSU-111 connector resulting from movement of the cables, possibly by settling, given that the cables had been recently disturbed and were not properly supported by tie-wraps.

The PSU-111 separable modular connectors are used in the two DC distribution panels as well as in other AC Motor Control Centers (MCC). Carolina Power & Light Company believes that the component inoperability concern is limited to the two DC distribution panels because 1) inspection of several AC MCCs confirmed that the cables were appropriately supported by tie-wraps, 2) the AC distribution panels are not entered for routine testing comparable to the two DC panels, and 3) there have been no documented problems with loose connectors within the AC MCCs. The combination of the cables being disturbed to acquire current test readings for DC motor driven MOVs and the lack of supporting tie-wraps has been determined as the probable cause of the two terminal block failures.

Note: A second failure of 1MS-70, on March 8, 1993, referred to in the Inspection Report 93-25 Details Section Paragraph b.(2) was the result of a main contactor problem with the motor operator for valve iMS-70. It did not have any correlation to loose PSU-111 connectors.

MEM/HO940507/osi

Attachment to HNP-94-018 Corrective Ste s Taken and Results Achieved:

Since the failure of 1MS-70, revision to the Root Cause Investigation Procedure (AP-605) requires a more rigorous root cause evaluation. That more rigorous process was followed for the 1AF-137 valve failure investigation. As a result of the failure of 1AF-137 on December 14, 1993, Adverse Condition Report (ACR)93-594 was initiated. Investigation reconfirmed the findings of the engineering review performed in association with PCR-5511, i.e., that the design of the distribution panels was sufficient ifthe cables are tie-wrapped and not disturbed. To that end, the ACR requires the installation of tie-wraps on field cables in the two DC distribution panels.

Corrective Ste s To Be Taken to Prevent Further Violations:

As stated above, tie-wraps will be installed on the field cables in the two DC distribution panels. In addition, Carolina Power & Light Company willreplace the PSU-111 connectors in the DC distribution panels DP-1A2-SA and DP-1B2-SB with a non separable connector.

Date When Full Com liance Will Be Achieved:

Full compliance is expected upon completion of the corrective actions described above. The reinstallation of tie-wraps willbe completed by March 25, 1994. The replacement of the DC panels PSU-111 connectors willbe performed during the upcoming outage. This action will be completed by May 15, 1994.

MEM/H0940507/Osl

Attachment to HNP-94-018 Re orted Violation B:

Technical Specification 6.8.1(a) requires that written procedures be properly established and implemented covering procedures outlined in Appendix A of Regulatory Guide 1.33, Revision 2, February 1978.

Regulatory Guide 1.33, Appendix A, paragraph 2.f requires procedures for changing turbine load, Operating Procedure OP-131.01, Main Turbine, Section 7.1 provides specific guidance for reducing turbine load.

Ccr~ avg to the above, on December 31, 1993, the directions provided in procedure OP-131.01 were determined to be inadequate and could not be performed in the sequerice specified to reduce the turbine load.

This is a Severity Level V violation (Supplement I).

Denial or Admission:

The violation is admitted.

Reason for the Violation:

On December 31, 1993, the plant was to reduce power to perform required testing. In preparation to reduce load, the Control Operator added 50 gallons of boric acid (about an 8 ppm increase in the RCS boron concentration). When the boron took effect, approximately 10 minutes after injection, the turbine load reduction was to start per OP-131.01. While preparing for the power down, the Balance of Plant (BOP) Operator saw that two procedure steps in OP 131.01 were out of sequence. OP-131.01 gives instructions for changing turbine load with the DEH control panel. Step 7.1.2.1.g should have directed the enabling of the Megawatt and Turbine Impulse'ressure feedback loops and then inputting the desired load change. However, the steps were reversed, which would result v the ioac coiiilnand oeing deleted upon activation of the feedback control.

A check of the Operator Feedback Report (OFR) database showed that the problem was already identified. At the time the OFR was initiated, the time frame for revising the procedure was not considered to be critical given the operator knowledge of this evolution through training and experience, plus the fact that this evolution was correctly sequenced in General Operating Procedure GP-006. Hence, the information was in the procedure working file to be added to the procedure during the next revision. However, in October 1993, this work sequence was removed from GP-006 since it was believed to be redundant to OP-131.01.

Management in the Control Room directed the BOP Operator to reduce load based on his knowledge of how to reduce turbine load. The plant load reduction was subsequently completed, but no action was taken to immediately correct OP-131.01. Thus the violation MEM/HO 94507/os1

Attachment to HNP-94-018 Ct occurred because the identified procedure defect was not corrected when first identified.

'econdly, the rediscovery of the error was not appropriately addressed. Proper application of plant procedural use and adherence requirements (AP-100) allows achieving safe stable conditions. In this event, performing a load decrease to maintain RCS average temperature at the program value would be acceptable. However, this should have been immediately followed'with a temporary change to OP-131.01.

Corrective Ste s Taken and Results Achieved:

Procedures have been revised to incorporate the correct sequence of steps for reducing turbine load. This was completed by January 20, 1994.

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. b.~..~. >iv~ ~> .;,s, Yaken to Prevent Further Violations:

The individuals involved were counseled on the proper response to the discovery of errors in procedures. A discussion of compliance with AP-100 was presented by the Manager-Operations in a Shift Supervisor - Nuclear meeting held on February 8, 1994.

The Operations Unit procedure revision working files were reviewed and seven additional procedure revisions were identified. The seven procedures were subsequently revised.

Date When Full Com liance Will Be Achieved:

Full compliance was achieved as described above by February 14, 1994.

MEM/HO940507/osl

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