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LER 93-002-01:on 930205,software Vendor Discovered Error in User Manual for Updating Basss data-input Library.Caused by Failure of QA Procedures to Require Independent Review of User Manuals.Manual Surveillances performed.W/930629 Ltr
	ML20045E736
Person / Time
Site:	Calvert Cliffs
Issue date:	06/29/1993
From:	Cruse C, Maki W; BALTIMORE GAS & ELECTRIC CO.
To:	; NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
	LER-93-002, LER-93-2, NUDOCS 9307020375
	Download: ML20045E736 (5)
	v • d • e

4 0 B ALTIMORE

GAS AND ELECTRIC CALVERT CLIFFS NUCLEAR POWER PLANT 1650 CALVERT CLIFFS PARKWAY

LUSBY. MARYLAND 20657-4702 CHARLES H, CAUSE PLANT G&NERAL MANAGEA cALVERT CL,pr3 June 29, 1993 U S. Nuclear Regulatory Commission Washington, D.C. 20555 ,

ATTENTION: Document Control Desk SUBJ ECT : Calvert Cliffs Nuclear Power Plant Unit Nos. 1 and 2; Docket Nos. 50-317 and 50-318; License Nos. DPR 53 and DPR 69 Licensee Event Report 93-002, Revision 01 Missed Surveillance Requirements Due to Software Manual Error 3 Centlemen:

The attached report is being sent to you as required under 10 CFR 50.73 guidelines. Should you have any questions regarding this report, we will be pleased to discuss them with you.

Very truly yours, f,

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Attachment cc: D. A. Brune, Esquire J. E. Silberg, Esquire R. A. Capra, NRC D. G. Mcdonald, Jr. , NRC T. T. Martin, NRC P. R. Wilson, NRC R. I. McLean, DNR J. H. Walter, PSC Director, Office of Management Information and Program Control 020074 i 9307020375 930629 l{h'.

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F ACILITY NAME (1) DOCKET NUMBER (2) P AGE (3)

Calvert Clif f s, Unit 1 05000 317 1 OF 04 i TITLE (4)

Missed Surveillance Requirements Due to Sof tware Manual Error EVENT DATE (5) LER NUMBER (6) l REPORT DATE (7) OTHER FACILITIES INVOLVED 18)

MONTH DAY YEAR YEAR ECMM ESION MONTH DAY YEAR

#b II NWBER NUMBER Calvert Cuffs, U2 l 05000 318 02 05 93 93 - 002 -

01 06 29 93 05000 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REOUtPEMENTS OF 90 CFR -fChece one or emre) (11) 1 20,405(c) 50.73(a)(2)(iv)

MODE (9) j 20.402(b) l 73.7, gg j 20.405(aH1)(i) A.'6(c)(1) .

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LICENSEE OONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER (include Area Code)

W. D. Maki Compliance Engineer 410 260-3651 COMPLETE ONE LINE FoR EACH COMPONENT FAILURE DESCRIBED IN TIUS REPORT (13) l CAUSE SYSTEM COMPONENT CAUSE ENW M TURER NPRDS SYSTEM l COMPONENT TURER NPRDS I

X lD C490 NO l SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED MONTH I DAY hYEARi YES SUBMISSION X NO l of van comrdern FrPFCTFD SUBMISSION DATD DATE (15) I ABS i RACT (Lmt to 1400 spaces. t e., approximately15 sen<pe-space ypewrmen ones) (16)

Calvert Cliffs uses the Better Axial Shape Selector System (BASSS) version 3.3 computer code. This system monitors incore Axial Shape Index (ASI) and provides various alarm functions. The software vendor discovered an error in its user's manual which the vendor uses in updating BASSS's data-input library. The error rendered oru alarm function inoperable, resulting in Units 1 and 2 not fulfilling Technical Specification Surveillance Requirement 4.2.5.1. This Surveillance requires verification of incore ASl within limits every twelve hours. The cause of the user manual error was

, failure of the vendor's quality assurance procedures to require independent review of user's manuals. Corrective actions included manual performance of a

the S urve illanc'e , correcting BASSS's data-input library, verifying BASSS operable, and reviewing applicable sections of the user manual. After l issuance of the software but prior to the discovery of this event, the vendor i upgraded its quality assurance procedures to require independent review of software documentation. Baltimore Cas and Electric Company has audited the Vendor's quality assurance program and found it to be satisfactory.

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TEXT in .o. . a .emy. cop of NRc r== asAmn I. DESCRIPTION OF E\ :T on April 12, 1991 and July 21, 1992, Calvert Cliffs Nuclear Power Plant installed the Better Axial Shape Selector System (3ASSS) version 3.3 on the Units 2 and 1 plant computers respectively. The BASSS computer code calcula es incore axial shape index (AS1) in real time. Measuring incore ASI and maintaining it within prescribed Technical Specification (TS) limi s ensures that plant parameters do not exceed thermal / hydraulic limitations.

Because of an unrelated self-assessment requested by Baltimore Gas a d Electric Company (BC&E), the software vendor was reviewing the BASSS 3.3 user nanual on February 4, 1993. 's a result of this review, a user-man al error was discovered. After evaluating the error, the vendor notified BC&E on February 5, 1993.

The user-manual error resulted in '.ncorrect sequencing of program input data, rendering an important alarm function inoperable. The program input data is provided to BC&E on a refuel _ng outage basis. The affected alarm wa;ns lionsed plant operators when ASI exceeds the Small-8:eak Loss-of-Coolant Accident (LOCA)

ASI limit. Operating within the limit ensures plant conditions remain within the analyzed boundaries for this accident. Without the alar- the plant was relying on a slightly less conservative BASSS alarm to infor them of an unsatisfactory ASI condition. A review of historical plant data showed that the more conservative ASI limits were never violated.

This particular alarm function is necessary to meet the TS 4.5.2.1 surveillance.

TS 4.5.2.1 requires verification every twelve hours that ASI does not exceed its limits. As a result of the user-manual problem, these ASI verifications were not complete. Units 2 and I were started-up on April 28, 1991 and August 16, 1992 respectively. They operated for 566 and 169 days in this condition.

Calvert Cliffs immediately took alternate, compensatory measures to perform the TS 4.2.5.1 surveillances. The vendor issued a Part 21 report concerning the error on February 12, 1993.

II. CAUSE OF EVE'iT The software was procured under the vendor's 10 CFR 50 Appendix 3 quality assurance Program. Following discovery of the event, the vendor conducted a l

root cause analysis and determined that the root cause was failure of the quality assurance procedures in E-e at the time to require independent review of

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user nianuals. The manual containing the error was developed in 1989, prior to a i a 1990 upgrade of the vendor's procedures whica instituted such a recsirement. l J !

2 Few cnline software products are provided by this vendor. The other ones ths.

are do not require input-data updating. ;

III. ANALYSIS OF EVENT -

This event was not safety significant. Actual plant ASI values remained within i the small-break LOCA ASI limit during the operating periods. Additionally, ,

Nuclear Fuel . Management receives daily ASI trend c'ata which is reviewed i periodically. If ASI had violated any limits, earlier discovery of the manual I error would have been likely.

The failure to perform a TS Surveillance Requirement is reportable under !

10 CFR 50.73(a)(2)(1)(A) as a condition prohibited by plant Technical i SpecificaH ons.

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! IV. CORkiCTIVE ACTIONS I Immediate Corrective Actions f f

- A. The vendor and SC6E checked the remaining input data against the l BASSS code. No other errors were found. l i

B. Immediate action was taken to perform the surveillances manually ;

4 until the vandor's corrected input data was installed on l February 12, 1993, i C. Although the problem was unique to Calvert Cliffs, the vendor notified all other code users of the error. >

i i

D. The BASSS coding and related user-manual sections were reviewed. No -

ML20045E736

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