05000315/LER-1998-055, :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

: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: 05000315/LER-1998-055, :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
References
LER-98-055, LER-98-55, NUDOCS 9901130072
Download: ML17335A472 (2)

LER-1998-055, 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

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(ii) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(viii) 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(iv), System Actuation 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition
3151998055R00 - NRC Website

text

NRC Form 366 U.S. NUCLEAR REGULATORY COMMISSION (6-1998)

LICENSEE EVENT REPORT (LER)

(See reverse for required number of digits/characters for each block)

APPROVED BY OMB NO. 3150 0104 EXPIRES 06/30/2001 ESTSIATED BURDEN PKR RKSPONSE TO COMPLY WITH THrS MANDATORY INFORMATIONCOLLECTION REGVESTI 50.0 HRS. REPORTED LESSONS LEARNKDARE INCORPORATED VITO THE LICENSING PROCESS AND FED BACK TO INOVSTRY.

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 20505 FACILITYNAME(5)

TITLE(4)

Cook Nuclear Plant Unit 1 DOCKET NUMBER(2) 05000-315 PAGE (5) 1 of1 Interim - Potential for Condition Outside Design Bases for Rod Control System EVENT DATE (5)

LER NUMBER (6)

REPORT DATE (7)

OTHER FACILITIESINVOLVED(8)

MONTH DAY YEAR YEAR SEQUENTIAL NUMBER REVISION NUMBER MONTH DAY YEAR A II AM D.C. Cook Unit 2 D

KETNUMB R 05000-316 12 07 1998 1998 055 00 01 06 1999 A ILI YNAM K

NUM OPERATING MODE (9)

POWER LEVEL(10) 000 20.2201 (b) 20.2203(a)(1) 20.2203(a)(2)(i) 20.2203(a)(2)(v) 20.2203(a)(3)(i) 20.2203(a)(3)(ii) 50.73(a)(2)(i) 50.73(a)(2)(ii) 50.73(a)(2)(iii) 50.73(a)(2)(viii) 50.73(a)(2)(x) 73.71 THIS REPORT IS SUBMITTEDPURSUANT TO THE REQUIREMENTS OF 10 CFR Ii: (Check'one or more) (11) 20.2203(a)(2)(ii) 20.2203(a)(2)(iii) 20.2203(a)(2)(iv) 20.2203(a)(4) 50.36(c)(1) 50.36(c)(2)

LICENSEE CONTACT FOR THIS LER (12) 50.73(a)(2)(iv) 50.73(a)(2)(v) 50.73(a)(2)(vii).

OTHER Specify at Abstract below or n NRC Form 366A 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)

CAUSE

SYSTEM COMPONENT MANUFACTURER REPORTABLE TO EPIX

CAUSE

SYSTEM COMPONENT MANUFACTURER REPORTABLE TO EPIX SUPPLEMENTAL REPORT EXPECTED (14)

X YES (IfYes, complete EXPECTED SUBMISSION DATE).

NO EXPECTED SUBMISSION DATE (15)

MONTH 03 DAY 01 YEAR 1999 Abstract (Limitto 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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