ML20235W036
| ML20235W036 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 03/02/1989 |
| From: | Mcduffie M CAROLINA POWER & LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-88-007, IEB-88-7, NLS-89-057, NLS-89-57, NUDOCS 8903100469 | |
| Download: ML20235W036 (3) | |
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ceronne power a usht company P. O. Box 1551
- Raleigh, N. C. 27602 g
i MAR 0 21989 M. A. McDUFFIE Senior Vice President SERIAL: NLS-89-057 tvuclear Generation United States Nuclear Regulatory Commission ATTENTION: Document Control Desk Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS. 1 AND 2 DOCKET NOS, 50-325 & 50-324/ LICENSE NOS. DPR-71 & DPR-62 RESPONSE TO NRC BULLETIN 88-07, SUPPLEMENT 1 POWER OSCILLATIONS IN BOILING WATER REACTORS Gentlemen:
The NRC issued Bulletin 88-07, " Power Oscillations in Boiling Water Reactors,"
on June 15, 1987. Carolina Power & Light Company submitted its response for the Brunswick Steam Electric Plant (BSEP), Units 1 and 2 on September 15, 1988.
On December 30, 1988, the NRC issued Siipplement 1 to Bulletin 88-07, which requested that licensees perform several additional actions and advise the NRC by letter whether the actions have been completed and implemented. These actions are described in Enclosure 1.
Carolina Power & Light Company hereby submits its confirmation that Requested Actions 1 and 2 have been completed and Requested Action 3 will be completed by May 1, 1989 for BSEP-1 and BSEP-2, Please refer any questions regarding this submittal to Mr. Stephen D. Floyd at (919) 546-6901.
Yours very truly,
$ b'L M. A. McDuffie BAB/bab(\\cor\\8807supp)
Enclosure cc:
Mr. S. D. Ebneter g
Mr. W. H. Ruland Mr. E. G. Tourigny g
M. A. McDuffie, having been first duly sworn, did depose and say that the information contained herein is true and correct to the best of his
'information, knowledge and belief; and the sources of his information are l
l officers, employees, contractors, and agents of Carolina Power & Light C,9ppasuj,,,
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L, ENCLOSURE 1 BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 NRC DOCKETS 50-325 6 50-324 OPERATING LICENSES DPR-71 & DPR-62 RESPONSE TO NRC BULLETIN 88-07, SUPPLEMENT 1 POWER OSCILLATIONS IN BOILING WATER REACTORS Each of the NRC requested actions are described below with CP&L's response.
Reauested Action Number 1 Within 30 days of receipt of this supplement, all BWR Licensees should implement the General Electric interim stability recommendations, as described in Attachment 1 to Bulletin 88-07, Supplement 1.
However, those l
plants that do not have effective automatic scram protection in the event of I
regional oscillations, a manual scram should be initiated under all operating conditions when two recirculation pumps trip (or "no pumps operating") with the reactor in the RUN mode.
CP&L Response The normal operating procedures have been revised to address normal operation of the recirculation pumps and the region of instability.
These changes accomplish the following:
(1)
Prohibit intentional entry into Instability Regions A or B.
(2)
Add a caution which warns against operation in regions of instability and provides actions to exit the regions. Region A is exited with a manual scram.
Regions B and C are exitad by immediately inserting control rods or increasing recirculation flow.
(3)
Prohibit starting of a recirculation pump if in a region of instability.
(4)
Require a manual scram if the average power range monitor (APRM) oscillation exceed 10 percent peak to peak and the reactor is in a region of instability.
(5)
Require a manual scram if local power range monitors (LPRMs) begin to indicate upscale and/or downscale oscillations.
The abnormal operating procedures, AOP-04.0 and AOP-04.3, have been revised to handle the conditions which would inadvertently place the reactor in a region of instability.
The actions are the same as those provided in the normal operating procedures if the reactor is found to be in a region of instability. The abnormal operating procedures do not prohibit entry into the regions and do not prohibit going from one region to the others wh!1e exiting the regions of instability.
Carolina Power & Light Company believes that the actions currently incorporated into plant procedures will ensure that the reactor is operated in regions of instability for a minimum amount of time.
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Reauested Action Number 2 The' boundaries of Regions A, B, and C shown in Figure 1 of the GE recommendations in Attachment 1 to Bulletiu 88-07, Supplement 1, were derived for those BWRs using NRC approved GE fuel.
For BWRs using fuel supplied by other vendors, these regions should be adopted in principle, but the power / flow boundaries should be based on existing boundaries that have been previously approved by the NRC.
For proposed new fuel designs, the stability boundaries should be reevaluated and-justified based on any applicable operating experience, calculated changes in core decay ratio using NRC approved methodology, and/or. core decay ratio measurements.
There should be a high degree of assurance that instabilities will not occur under any circumstances of operation in Region C.
CP&L Resnonse The Brunswick Plant currently operates with GE fuel designs which have been reviewed and accepted by the NRC for stability characteristics on a generic design basis.
Fuel designs currently planned for use in the next several fuel cycles are GE designs which have been previously reviewed and accepted, or are expected to be reviewed and accepted, by the NRC prior to cycle startup. Current GE philosophy is that new fuel designs will have individual bundle stability characteristics that are at least as good as the CE7 fuel bundle design.
The present and planned BSEP operating power / flow regions are bounded by those of Bulletin 88-07, Supplement 1, including the maximum extended load line region.
The use of NRC reviewed and accepted GE fuel types provides high assurance that instabilities will not occur under any circumstances of operation in Region C.
Reauested Action Number.1
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The BWROG recommendations of Attachment 1 to Bulletin 88-07, Supplement 1 are ambiguous with respect to permissible conditions for entry into Regions B and C.
Although the recommendations state that intentional operation in Region B is not permitted and operation in Region C is permitted only for purposes of fuel conditioning during rod withdrawal
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I startup operations, intentional entry into Region B or C is also allowable in situations where rod insertion or a flow increase is required by procedures to exit Regions A and B after unintentional entry.
Licensees should ensure that the procedures and training employed for implementation of these recommendations avoid any similar ambiguity which could lead to operator confusion.
CP&L Response As stated in response to Requested Action Number 1, the abnormal operating procedures have been revised such that entry into the regions of instability and going from one region to the others while exiting a region of instability are not prohibited. The training material associated with instability will be revised by May 1, 1989 to incorporate the recoccendatlons of Attachment 1 to Bulletin 88-07, Supplement 1, to avoid l
ambiguity which could lead to operator confusion.
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