ML20028E355

LER 82-029/03L-0:on 821216,automatic Monitoring & Alarm Program Constant Found Incorrect.Caused by Unknown Personnel W/Access to on-line Computer.Value of Constant Restored & Control Rods Alignment Verified

ML20028E355
Person / Time
Site:	Point Beach
Issue date:	01/13/1983
From:	Fay C WISCONSIN ELECTRIC POWER CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20028E351	List: ML20028E350 ML20028E355
References
LER-82-029-03L, LER-82-29-3L, NUDOCS 8301210258
Download: ML20028E355 (3)

Text

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NRC FORM 366 U. S. NUCLE A*) REIUL ATORY COMMISSION (7 77)

LICENSEE EVENT REPORT C NTROL BLOCV.: l l l l l l

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EVENT OFSCRIPTION AND PROBABLE CONSEQUENCES h 4

o 2 lOn 12/16/82, during normal operations, a review of the on-line computer l o 3 l monitoring programs was being conducted when an automatic monitoring andt o , [ alarm program constant was found to be incorrect. This value would l

o,q gallcw control rod misalignment greater than that al. lowed by the Techni- l o o l cal Specification without sounding an alarm. This event is reportable g o 2 lin accordance with Technical Specification 15.6.9.2.B.l., g I.2.LaJ l I 7 8 9 80 CODE C0DE S08 CODE COMPONENT CODE SUB DE SU E

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]g 42 Wg 43 lW l1l2 l0 lg de 47 CAUSE DESCRIPTION AND C.7RECTIVE ACTIONS h i O lThis unauthorized value change was made by unknown personnel with accessi gij lto the on-line computer. The value of the constant was restored to its l g,;,,l correct value and the control rods were verified not misaligned. Solu- l q ltions are being investigated to provide positive indication of program l

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C. W. Fay PHONE:

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NAME OF PREPARER

, A ATTACHMENT TO LICENSEE EVENT REPORT NO. 82-029/03L-0 Wisconsin Electric Power Company Point Beach Nuclear Plant Unit 1 Docket No. 50-266 On December 16, 1982, during normal operations, a review of the on-line computer monitoring program, redundant measuring program (RMP), was being conducted by the Reactor Engineering group when the value of the control and shutdown rod normal cluster limit, K0014, was found to be incorrect. This constant is used to generate a computer alarm for misalignment of individual control rods from their respective control rod banks.

The constant was observed to 20.0 inches but required to be 15.0 inches.

The effect of the constant being 20.0 vice 15.0 is that the redundant measuring program would generate a red printout on the alarm typewriter if a control rod's rod position indication

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(RPI) deviated from the average RPI of the remainder of the bank by more than 10 inches (20/2), instead of the required 7.5 inches (15/2) maximum difference permitted by Technical specification 15.3.10.D.1. This limit is applicable when the control banks are withdrawn between 30 and 215 steps. The control rods are normally withdrawn creater than 215 steps. At that time, the allowable misalignment is 15 inches.

Investigations by the plant staff have revealed.no reason _

why this constant was altered from 15.0 to 20.0; however, this parameter can be changed by personnel with access to the on-line computet. A review of paper tapes taken after computer program maintenance showed that on December 23, 1981 the constant was recorded correctly and on April 21, 1982 the constant was not

, correct. (These tapes are normally not printed or reviewed.

l They.are taken as a safety measure to avoid losing the programs l

in the event of computer failure.)

A review of the control room logs, which record individual rod positions each shift, was conducted for the period from December 23, 1981 to December 16, 1982. This review showed no l

actual Technical Specification control rod misalignment violations during this period.

l Although the reason for the change of the control and shutdown rod normal cluster limit value from 15.0 to 20.0 cannot be determined, corrective actions are currently under evaluation to provide the ability to have positive means of control or positive indication of the status of operator addressable I

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. Attachment to Licenseo Event J. Report No. 82-029/03L-0 constants which are important to technical specification monitoring functions. These corrective actions will include a periodic L review of the computer program constants important to the technical specification monitoring function. We are also in the process of specifying and purchasing a new on-line plant computer. The new ~

computer and associated software will greatly restrict the accessability of operators to these constants. It is expected that this new computer vill be operating in 1984.

Upon discovery of the incorrect limit value, the constant was restored to its correct value of 15.0 and the rods were verified to be within the alignment requirements of Technical Specification 15.3.10.D.l.

This event is reportable in accordance with Technical Specification 15.6.9.2.B.1.

The Resident Inspector has been notified of this event.

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