ML18066A804

LER 96-014-00:on 961124,class 1E Raychem Cable Splices Were Installed Incorrectly.Caused by Incorrectly Made Electrical Splices.Total of 270 Splices Have Been Replaced within Containment

ML18066A804
Person / Time
Site:	Palisades
Issue date:	12/23/1996
From:	Flenner P CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
Shared Package
ML18066A803	List: ML18066A802 ML18066A804
References
LER-96-014, LER-96-14, NUDOCS 9701020142
Download: ML18066A804 (4)

Text

NRC FORM 366 e

U.S. NUCLEAR REGULA TORY APPROVED BY OMB NO. 3150-0104 COMMISSION EXPIRES 4130/98 (4/95)

ESTIMATEO BURDEN PER RESPONSE TO COMPLY WITH THIS MANDATORY INFORMATION COUECTION REQUEST: 50.0 HRS. REPORTED LESSONS LEARNED ARE INCORPORATEO INTO THE LICENSING PROCESS ANO FED BACK TO INDUSTRY.

FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION ANO LICENSEE EVENT REPORT (LER) RECORDS MANAGEMENT BRANCH (T ~ F33), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC ~1. ANO TO THE PAPERWORK REDUCTION PROJECT (31~104, OFFICE OF MANAGEMENT ANO BUDGET. WASHINGTON, DC 20503 (See reverse for required number of digits/characters for each block)

FACILITY NAME (1) DOCKET NUMBER (2) Page (3)

CONSUMERS POWER COMPANY - PALISADES PLANT 05000255 1of4 TITLE (4) LICENSEE EVENT REPORT 96-014, CLASS 1E RAYCHEM CABLE SPLICES INSTALLED INCORRE~TLY I

EVENT DATE (5) LER NUMBER (6) REPORT *DATE (7) OTHER FACILITIES INVOLVED (8)

REVISIO FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR SEQUENTIAL N MONTH DAY YEAR 05000

. NUMBER NUMBER FACILITY NAME 11 24 96 96 - 014 - 00 12 23 96 DOCKET NUMBER OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check one or more) (11)

MODE (9) N 20.2201(b) 20.2203(a)(2)(v) 50. 73(a)(2)(i) 50. 73(a)(2)(iii) x 50. 73(a)(2)(ii) 50. 73(a)(2)(x)

I I POWER 20.2203(a)(1) 20.2203(a)(3)(i)

I LEVEL (10) 0 20.2203(a)(2)(i) 20.2203(a)(2)(ii) 20.2203(a)(3)(ii) 20.2203(a)(4)

50. 73(a)(2)(iii)

50. 73(a)(2)(iv) 73.71 OTHER 20.2203(a)(2)(iii) 50.36(c)(1) 50. 73(a)(2)(v) Specify in Abstract below

• .*: .. :  ::. 20.2203(a)(2)(iv) 50.36(c)(2) 50.73(a)(2)(vii) or in NRC Form 366A LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER (Include Area Code)

Philip D. Flenner, Licensing Engineer (616) 764-8913 1,.;uMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THfS REP-ORT (13)

CAUS SY STE COMPONENT MANUFACTURER REPORTABLE

• CAUS SYSTEM COMPONENT MANUFACTURER REPORTABLE E M TONPRDS E TONPRDS SUPPLEMENTAL REPORT EXPECTED (14) MONTH DAY YEAR x I YES If yes, COMPLETE EXPECTED COMPLETION DATE I NO EXPECTED SUBMISSION DATE (15) 05 15 97 ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16) .

On November 24, 1996, during a routine refueling outage maint~nance activity, a Class 1E elect.rical cable splice was discovered to be installed incorrectly. This installation could not be considered qualified tor the tlass._fE service-. Subsequent investigation.tor similar cable'*splices ~* -

within containment resulted in the identification of 381 potentially susceptible cable splices. These splices were either confirmed to be acceptable by field inspection or w.ere replaced with correctly installed splices. A total of 270 cable splices were replaced. An evaluation of the potentially susceptible cable Splices was also done in areas where a postulated high energy line break.

outside of containment would present a harsh environment. These cable splices were accepted based on an evaluation in accordance*with 10 CFR Part 50.49.

9701020142 961223 PDR ADOCK 05000255 S PDR

NRC FORM 366a

• U.S. NUCLEAR REGULA TORY COMMISSION 4/95 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION I

FACILITY NAME 11 \ DOCKETl2\ LER NUMBER 61 PAGE 13\

YEAR SEQUENTIAL REVISION CONSUMERS POWER COMPANY NUMBER NUMBER 05000255 20F4 PALISADES NUCLEAR PLANT 96 014 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

EVENT DESCRIPTION On November 24, 1996, during a routine refueling outage maintenance activity, a Class 1E electrical cable splice was discovered to be installed incorrectly. This installation couid not be considered qualified for the Class 1E service.

The splice was made in a manner that included the polyvinyl chloride (PVC) jacket on a Rome cable conductor within the Raychem splice. The PVC conductor jacket is required to be peeled back prior to installing the Raychem splice so the splice adhesion occurs against the environmentally qualified cross-linked polyethylene (XLPE) insulation rather than the PVC conductor jacket. The inclusion of the PVC conductor jacket within the splice resulted in a configuration not qualified by test.

CAUSE OF THE EVENT The original installation of the affected Raychem electrical splices were made incorrectly.

ANALYSIS OF THE EVENT In response to the original discovery of the unqualified cable splice configuration, a review of the cables in the Equipment Qualification (EQ) Program was completed. This resulted in the determination that only Rome and Essex power and control cables have a PVC conductor jacket.

Review of qualified circuits identified 381 splices within containment that could have been affected.

These splices were either confirmed to be acceptable by field walkdown or were replaced with correctly installed splices. Some splices were replaced without inspection because the splice would have been destroyed in order to do the inspection.

Additionally, two locations outside of containment were determined to contain susceptible splices in a potentially harsh environment during a postulated high energy line break (HELB) accident. *The environment under the HELB conditions outside of containment is considerably less severe than that in containment. The identified cable splices in these locations were qualified in accordance with 10 CFR Part 50.49. .

NRC FORM 366a

• U.S. NUCLEAR REGULA TORY COMMISSION 4/95 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME 11l CONSUMERS POWER COMPANY DOCKET12l 05000255 YEAR l LER NUMBER 6l SEQUENTIAL NUMBER REVISION NUMBER PAGE 13) 30F4 PALISADES NUCLEAR PLANT 96 014 - 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

SAFETY SIGNIFICANCE Unqualified splices could result in moisture intrusion into the areas of the electrical conductor during LOCA or HELB events. The conductivity of the moisture would then allow for increased leakage current between the conductors or to ground. This leakage current, if of sufficient magnitude, could affect the operation of the connected equipment and trip the associated protective device. The splices in question, however, were all associated with control and power circuits. For these types of circuits, leakage current would have to increase significantly to affect circuit operation. Although no formal qualification exists for the splice configuration in question, qualification reports for similar configurations suggests that leakage currents would not increase to a point that would affect the operation of control and power circuits. This assumption will be verified by further evaluations of splices removed from the plant.

If the leakage currents are found to be of a sufficient magnitude to affect circuit operation, then the following components could have been affected:

Low Pressure Safety Injection Valves High Pressure Safety Injection Valves Containment Air Cooler Fan Motors Service Water Valves to the Containment Air Coolers Position Indications for the Above Valves If the evaluations determine that the splices may not limit the leakage currents to an acceptable magnitude, the significance of these conditions will be reported in the supplement to this LER.

CORRECTIVE ACTION Review of qualified circuits identified 381 splices within containment that could have been affected.

These splices were either confirmed to be acceptable by field inspection orwere replaced with correctly installed splices. A total of 270 splices have been replaced within containment. The remaining 111 were determined to be acceptable since it could be confirmed that the PVC conductor jacket was not included within the Raychem splice.

,I

• • 1F============

NRC FORM 366a

• U.S. NUCLEAR REGULA TORY COMMISSION

'; 4/95 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION I

FACILITY NAME (1) DOCKETl2\ LER NUMBER 6\ PAGE (3)

YEAR SEQUENTIAL REVISION CONSUMERS POWER COMPANY NUMBER NUMBER 05000255 40F4 PALISADES NUCLEAR PLANT 96 014 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

Potentially susceptible cable splices were also identified in areas with a potentially harsh environment outside of containment. This harsh environment would only exist during postulated HELB accident conditions. Although the environment under the HELB conditions is considerably less severe than that in containment, the identified cable splices outside of containment were qualified in accordance with 10 CFR Part 50.49.

An investigation will continue to evaluate the unqualified Raychem cable splice over a PVC condudor jacket to determine its capability to meet the postulated accident conditions within containment during prior operation. The results of this investigation will be provided in a supplement to this LER.

PREVIOUS EVENTS Problems with cable splices/connections have been reported previously in the following LERs:

• LER 91-002 - Non-Qualified Cable Splices Inside Containment

• LER 92-019 - Electrical Connections Not Environmentally Qualified In Position Switch Circuits Requiring Environment Qualification

• LER 95-007 - Exposed Kapton Cable Insulation Results In Unqualified EQ Cable Splice

• LER 95-012 - Unqualified Electrical Connection In Containment Service Water Outlet Valve Controller In addition, a previous problem with *cable that had not been environmentally qualified was reported in LER 94-015 - Unqualified Cable Found Being Used In A Application Requiring Environmentally Qualified Cable.