United States Nuclear Regulatory Commission - Protecting People and the Environment


ACCESSION #:  9803190268

                       LICENSEE EVENT REPORT (LER)



FACILITY NAME:  LaSalle County Station, Unit 1            PAGE: 1 OF 4



DOCKET NUMBER:  05000373



TITLE:  Abnormal Startup of Idle Reactor Recirculation Loop

        Analysis (UFSAR Ch. 15) Not Bounding Due To Vendor

        Inadequate Calculation



EVENT DATE:  02/10/98   LER #:  98-003-00   REPORT DATE:  03/12/98



OTHER FACILITIES INVOLVED:  LaSalle County          DOCKET NO:  05000374

                            Station, Unit 2



OPERATING MODE:  4/N POWER LEVEL:  000



THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR

SECTION:

OTHER (Voluntary Report)



LICENSEE CONTACT FOR THIS LER:

NAME:  Dave Henry, System Engineering       TELEPHONE:  (815) 357-6761

                                                        Extension 2250



COMPONENT FAILURE DESCRIPTION:

CAUSE:      SYSTEM:       COMPONENT:       MANUFACTURER:

REPORTABLE NPRDS:



SUPPLEMENTAL REPORT EXPECTED:  NO



ABSTRACT:



On February 10, 1998, while analyzing a potential setpoint change,

General Electric (GE) discovered that the LaSalle UFSAR Chapter 15

analysis for "Abnormal Startup of an Idle Reactor Recirculation Pump" is

not bounding.  Preliminary results from a GE analysis for a revised Flow

Control Valve (FCV) position for recirculation pump upshift indicated

that the current transient initial conditions are not the most severe.

In addition, using LaSalle's current approved setpoint of 15 percent FCV

position and the most limiting initial conditions, the thermal limits

acceptance criteria are not met.  The plant was never in a condition to

challenge plant safety.  LaSalle has never violated the procedural and

Technical Specification (3/4.4.1.4.b) requirements that govern idle

recirculation loop startup, thus maintaining thermal limits and fuel

cladding integrity.  Previous GE analyses were insufficient, since the GE

analysis of this UFSAR transient did not properly identify the bounding

conditions.  Events leading to this cannot be identified by ComEd, and

are being investigated by GE through the 10 CFR Part 21 process.

Bounding parameters and conditions will be established prior to restart

of either unit.  These results, when obtained, will be incorporated into

the UFSAR and applicable procedures.  There are no previous occurrences

of this event.  The event is being reported voluntarily.



END OF ABSTRACT



TEXT                                                          PAGE 2 OF 4



PLANT AND SYSTEM IDENTIFICATION



     General Electric - Boiling Water Reactor 3323 Megawatts Thermal

     Rated Core Power



     Energy Industry Identification System (EIIS) codes are identified in

     the text as [XX].



A.   CONDITION PRIOR TO EVENT



     Unit(s): 1/2             Event Date: 02/10/98     Event Time: 15:45

                                                                 Hours

     Reactor Mode(s): 4/N     Power Level(s):       RCS [AB] Temperature:

                              000/000            Unit 1 






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