ML17335A472

LER 98-055-00:on 981207,potential for Condition Outside of Design Bases for Rod Control Sys Was Noted.Caused by Calibration Error Coupled with Single Rod Failure.Condition Rept Investigation Is Ongoing

ML17335A472
Person / Time
Site:	Cook
Issue date:	01/06/1999
From:	Kovarik J INDIANA MICHIGAN POWER CO.
To:
Shared Package
ML17335A471	List: ML17335A470 ML17335A472
References
LER-98-055, LER-98-55, NUDOCS 9901130072
Download: ML17335A472 (2)

Text

NRC Form 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150 0104 EXPIRES 06/30/2001 (6-1998)

ESTSIATED BURDEN PKR RKSPONSE TO COMPLY WITH THrS MANDATORY INFORMATION COLLECTION REGVESTI 50.0 HRS. REPORTED LESSONS LEARNKD ARE INCORPORATED VITO THE LICENSING PROCESS AND FED BACK TO INOVSTRY.

LICENSEE EVENT REPORT (LER) FORWARD COMMENTS REGARDING BVRDKN ESTasATE TO THE BFORMATION AND RECORDS MANAGEMENT BRANCH IT 0 Fss), U.S. NVCLEAR REGIAATORY COMMLSSON. WASIBNGTON. DC 205554005, AND TO THE PAPERWORK REDVCTION PRGIEGT ISI5001IH). OFF)OK DF MANAGEMENT AND BUDGET. wAsreNGTDN. Dc (See reverse for required number of 20505 digits/characters for each block)

FACILITYNAME (5) DOCKET NUMBER (2) PAGE (5)

Cook Nuclear Plant Unit 1 05000-315 1 of1 TITLE (4)

Interim - Potential for Condition Outside Design Bases for Rod Control System EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

A II AM D KETNUMB R SEQUENTIAL REVISION D.C. Cook Unit 2 05000-316 MONTH DAY YEAR YEAR NUMBER NUMBER MONTH DAY YEAR A ILI YNAM K NUM 12 07 1998 1998 055 00 01 06 1999 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR Ii: (Check'one or mo re) (11)

MODE (9) 20.2201 (b) 20.2203(a)(2)(v) 50.73(a)(2)(i) 50.73(a)(2)(viii)

POWER 20.2203(a)(1) 20.2203(a)(3)(i) 50.73(a)(2)(ii) 50.73(a)(2)(x)

LEVEL(10) 000 20.2203(a)(2)(i) 20.2203(a)(3)(ii) 50.73(a)(2)(iii) 73.71 20.2203(a)(2)(ii) 20.2203(a)(4) 50.73(a)(2)(iv) OTHER 20.2203(a)(2)(iii) 50.36(c)(1) 50.73(a)(2)(v)

Specify at Abstract below 20.2203(a)(2)(iv) 50.36(c)(2) 50.73(a)(2)(vii). or n NRC Form 366A LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER (Induce Area Code)

Mr. Jay Kovarik, Electrical Instrumentation and Controls Engineering (616) 697-5147 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

REPORTABLE REPORTABLE TO CAUSE SYSTEM COMPONENT MANUFACTURER TO EPIX CAUSE SYSTEM COMPONENT MANUFACTURER EPIX SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED MONTH DAY YEAR X YES SUBMISSION 03 01 1999 (If Yes, complete EXPECTED SUBMISSION DATE). NO DATE (15)

Abstract (Limit to 1400 spaces, I.e., approximately 15 single-spaced typewritten lines) (16)

On December 7, 1998, during a system readiness review of the Rod Control System by Instrumentation and Control Engineering, it was discovered that a potential calibration error in the rod speed control circuits for the Rod Cluster Control Assemblies (RCCAs), coupled with a single failure of the rod withdrawal circuit, could result in a rod cluster to withdraw up to a maximum rate of 77 steps per minute (spm). This condition is contrary to UFSAR Section 3.1.2, Page 3.1-11, which states that "No single credible mechanical or electrical control system malfunction can cause a rod cluster to be withdrawn at a speed greater than 72 steps per minute." In accordance with 10CFR50.73(a)(2)(ii)(B), this interim LER is being reported as a condition that is outside the design basis of the plant.

The original Precautions, Limitations and Setpoints (PLS) provided by Westinghouse included the recommendations for a maximum automatic rod speed of 72 spm, which was also used by the accident analysis by postulating two banks of rods withdrawing at 72 spm. This resulted in a maximum rod speed used in the analysis that did not reflect the maximum possible rod withdrawal rate.

The completion of the condition report investigation and evaluation of the safety significance of this condition is ongoing.

Once completed, this LER will be supplemented to include that information. The supplement is expected to be submitted by March 1, 1999.

9901130072 990i06 PDR ADOCK 050003l.5 S PDR NRC FORM 366 (6-1998)

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