ML043630390
| ML043630390 | |
| Person / Time | |
|---|---|
| Site: | Kewaunee  |
| Issue date: | 12/20/2004 |
| From: | Coutu T Nuclear Management Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NRC-04-145, TS 6.21 | |
| Download: ML043630390 (3) | |
Text
NMC OpNerated Kewaunee Nuclear Power Plant C o Operated by Nuclear Management Company, LLC December 20, 2004 NRC-04-145 TS 6.21 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Kewaunee Nuclear Power Plant Docket 50-305 License No. DPR-43 Bases Revision(s) to the Kewaunee Nuclear Power Plant Technical Specifications Nuclear Management Company (NMC), licensee for the Kewaunee Nuclear Power Plant (KNPP), hereby submits a revision to the Bases for the Technical Specifications (TS) 3.10, "Control Rod and Power Distribution Limits." The change to the bases is being submitted because the curve fitting process within the Power Plant Computer System is removed due to the correction for the rod calibration curve now being performed within each NARPI module.
These changes have been screened for evaluation pursuant to the requirements of 10 CFR 50.59 in accordance with approved KNPP procedures and were determined to be acceptable.
Enclosed is a copy of the revised Technical Specification Bases page.
Thomas Coutu Site Vice President, Kewaunee Nuclear Power Plant Nuclear Management Company, LLC Enclosure (1) cc:
US NRC, Region IlIl US NRC, Senior Resident Inspector Electric Division, PSCW N490 Highway 42
- Kewaunee, Wisconsin 54216-9510 Telephone: 920.388.2560
ENCLOSURE 1 KEWAUNEE NUCLEAR POWER PLANT TECHNICAL SPECIFICATIONS BASIS REVISION I page follows
The time limits of six hours to achieve HOT STANDBY and an additional six hours to achieve HOT SHUTDOWN allow for a safe and orderly shutdown sequence and are consistent with most of the remainder of the Technical Specifications.
Rod Misalignment Limitations (TS 3.10.e)
During normal power operation it is desirable to maintain the rods in alignment with their respective banks to provide consistency with the assumption of the safety analyses, to maintain symmetric neutron flux and power distribution profiles, to provide assurance that peaking factors are within acceptable limits and to assure adequate shutdown margin.
Analyses have been performed which indicate that the above objectives will be met if the rods are aligned within the limits of TS 3.1 O.e. A relaxation in those limits for power levels < 85% is allowable because of the increased margin in peaking factors and available shutdown margin obtained while OPERATING at lower power levels. This increased flexibility is desirable to account for the nonlinearity inherent in the rod position indication system and for the effects of temperature and power as seen on the rod position indication system.
Rod position measurement is performed through the effects of the rod drive shaft metal on the output voltage of a series of vertically stacked coils located above the head of the reactor pressure vessel. The rod position can be determined by the analog individual rod position indicators (IRPI),
the plant process computer which receives a voltage input from the conditioning module, or through the conditioning module output voltage via a correlation of rod position vs. voltage.
The plant process computer converts the output voltage signal from each IRPI conditioning module to an equivalent position (in steps).
The rod position as determined by any of these methods can then be compared to the bank demand position which is indicated on the group step counters to determine the existence and magnitude of a rod misalignment. This comparison is performed automatically by the plant process computer.
The rod deviation monitor on the annunciator panel is activated (or reactivated) if the two position signals for any rod as detected by the process computer deviate by more than a predetermined value. The value of this setpoint is set to warn the operator when the Technical Specification limits are exceeded.
The rod position indicator system is calibrated once per REFUELING cycle and forms the basis of the correlation of rod position vs. voltage.
This calibration is typically performed at HOT SHUTDOWN conditions prior to initial operations for that cycle. Upon reaching full power conditions and verifying that the rods are aligned with their respective banks, the rod position indication may be adjusted to compensate for the effects of the power ascension. After this adjustment is performed, the calibration of the rod position indicator channel is checked at an intermediate and low level to confirm that the calibration is not adversely affected by the adjustment.
TS B3.10-6 12/16/2004 l