ML20235Z517
| ML20235Z517 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 03/06/1989 |
| From: | Tucker H DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 8903150497 | |
| Download: ML20235Z517 (2) | |
Text
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Du!.e fouer Company Hu H kun PQ llax33198 Mce President Charlotte, N C. 28242 Nuclear Production l
(70I)373 4531 DUKEFOWER l
Mcrch 6, 1989 Document Control Desk
[
U. S. Nuclear Regulatory Commission Washington, D. C.
20555
Subject:
Catawba Nuclear Station
)
Docket No. 50-414 Technical Specification Amendment
)
Steam Generator Level Tap Relocation Gentlemen:
)
Provided below is additional information to clarify my December 28, 1988 submittal to allow for complete review of our request to allow for changing the setpoints for the Unit 2 steam generator level trips due to the relocation of the level taps.
The differential pressure transmitters to be installed in Unit 2 are Barton
{
764. These are the same type of transmitters used in Unit 1.
The t
transmitters are environmentally qualified for post-accident conditions.
The new values for trip setpoints for Unit 2 are being revised based on the latest error componer,t data. The Unit i values, which were calculated using the best available data at the time, are more restrictive than necessary and thus conservative.
The Z and S terms are determined using the same methodology as presented in 4
the Westinghouse Setpoint Methodology with the following input differences:
Westinghouse Duke Notes Process Measurement Accuracy 2.0 1.5 1
0.5 2
Sensor Drift 1.0 1.5 3,a
)
Sensor Pressure Effect 0.5 0.24 3
)
)
Notes: 1-The first PMA component accounts for the effect on icvel indication of changes in steam generator temperature.
f 2-The second PMA component accounts for the effect on level indication j
of changes in containment temperature.
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U. S. Nuclear Regulatory Commission March 6, 1989 Page Two 3-Values Duke Power took directly from manufacturer specifications.
a) Westinghouse assumed a calibration frequency of once per twelve months, Duke assumed a calibration frequency of once per eighteen months.
These input differences do not affect the conclusions reached by Duke Power or Westinghouse in the evaluations of the Chapter 15 transients evaluated in my December 28, 1988 letter.
Very truly yours,
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llal B. Tucker PGL/
xc: Mr. S. Ebneter, Regional Administrator U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. W. T. Orders NRC Resident Inspector Catawba Nuc1 car Station I
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