United States Nuclear Regulatory Commission - Protecting People and the Environment

ACCESSION #: 9801150020


January 6, 1998


U.S. Nuclear Regulatory Commission

Document Control Desk

Attn: Chief, Planning, Program and Management Support Branch

Washington, D.C. 20555

Dear Gentlemen:

Subject:  10 CFR 21 Notification Regarding Transient Analyses at

          Exposures Prior to End of Cycle

This letter and its attachment provide written notification of a

reportable defect per 10 CFR Part 21 reported to the NRC Operations

Center by facsimile on December 10, 1997.  Report No. 33377 was assigned

to the notification by the Duty Officer.

Very truly yours,

L.  J.  Maas, Manager

Regulatory Compliance



cc:  E.  Y.  Wang (NRR/DRPM/PECB)

     E.  W. Merschoff, Administrator, NRC Region IV

Siemens Power Corporation

Nuclear Division              2101 Horn Rapids Road  Tel: (509) 375-8100

Engineering & Manufacturing   P.O. Box 130           Fax: (509) 375-8402

                              Richland, WA 99352-0130


                            REPORTABLE DEFECT

(i.)      Name and address of the individual informing the Commission.

          L.J.  Maas, Manager, Regulatory Compliance, Siemens Power

          Corporation, 2101 Horn Rapids Road, Richland, WA 99352.

(ii.)     Identification of the facility, the activity, or the basic

          component supplied for such facility or such activity within

          the United States which fails to comply or contains a defect.

          Operating limits based upon transient analyses for LaSalle Unit

          2 Cycle 8.

(iii.)    Identification of the firm constructing the facility or

          supplying the basic component which fails to comply or contains

          a defect.

          Siemens Power Corporation, Richland, WA.

(iv.)     Nature of the defect or failure to comply and the safety hazard

          which is created or could be created by such a defect or

          failure to comply.

          INPO operating experience report (OE 8422) indicated that

          transient analysis results at end of cycle (EOC) might not

          always be limiting for the entire cycle.  SPC had performed

          analyses at EOC which were expected to bound analyses at other


          An evaluation of the impact of cycle exposure on transient

          analyses for both normal operation (no equipment out-of-

          service) and equipment out-of-service (EOOS) conditions was

          performed.  Under normal operating (NO EOOS) conditions,

          transient results at EOC are bounding at power levels greater

          than Pbypass (direct scram on valve position operable).

          Although results at exposures prior to EOC can be more severe

          at power levels below Pbypass (non-direct scram), current

          operating limits for all plants remained protected during

          normal operation.  Similar analyses performed under various

          EOOS conditions indicate that current operating limits remain

          applicable in all cases with the exception of LaSalle Unit 2

          Cycle 8.

          More specifically, the evaluation concluded that for LaSalle

          Unit 2 Cycle 8, thermal limits previously provided would not be

          adequate when operating with ail of the following conditions:

          1.  Turbine bypass valves out-of-service (TBVOOS) or feedwater

          heaters out-of-service (FHOOS), 2.  Reactor power less than 30%

          of rated (Pbypass), and 3.  Core flow greater than 50% of


(v.)      The date on which the information of such defect or failure to

          comply was obtained.

          The deviation was initially identified in the SPC

          Nonconformance Report (NCR) 6230 which was prepared on August

          18, 1997.  An interim report (SPC Interim Report No. 97-009) of

          an evaluation of a deviation pursuant to 10 CFR 21.21(a)(2) was

          provided to the NRC on October 16, 1997 (Letter, J. S. Holm

          (SPC) to Document Control Desk, "Interim Report of Evaluation

          of a Deviation Pursuant to 10 CFR 21.21 (a) (2)," dated October

          16, 1997).  A 10 CFR 21 notification was conveyed to the NRC

          Operations Center on December 10, 1997 and was assigned Report

          No. 33377.

(vi.)     In the case of a basic component which contains a defect or

          fails to comply, the number and the location of a# such

          components in use at, supplied for, or being supplied for one

          or more facilities or activities subject to the regulations in

          this part.

          The impact of the deviation is restricted to operating limits

          for Commonwealth Edison, LaSalle Unit 2 Cycle 8.

(vii)     The corrective action which has been, is being, or will be

          taken; the name of the individual or organization responsible

          for the action, and the length of time that has been or will be

          taken to complete the action.

          Commonwealth Edison has been notified of this defect and has

          been provided with revised limits by SPC on December 12, 1996.

          Four additional corrective actions are planned:

          1)   Include a recommendation in the BWR core wide transient

               analysis guideline that analyses at power levels where

               direct scram is inoperable be performed assuming the high

               flux scram is also inoperable.

          2)   Develop an interim process to set MCPRp limits and

               LHGRFACp values until Corrective Actions 3 and 4 can be


          3)   Investigate the mechanisms that cause transient analysis

               results at exposures prior to EOC to be more limiting than

               results at EOC.

          4)   Develop/identify a process or processes that can be used

               to ensure that MCPRp limits and LHGRFACp values are

               established that provide the necessary protection across

               the entire exposure domain for which they are intended.

          These additional corrective actions will be completed by March


(viii.)   Any advice related to the defect or failure to comply about the

          facility, activity, or basic component that has been, is being,

          or will be given to purchasers or licensees.

          This notification is being provided to SPC BWR customers.


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