Part 21 Report - 1997-823
ACCESSION #: 9801150020
SIEMENS
January 6, 1998
LJM:98:001
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
/pg
Attachment
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
Attachment
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
exposures.
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
rated.
(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
completed.
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
1998.
(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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