ML20133A427
| ML20133A427 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 12/23/1996 |
| From: | Graham P NEBRASKA PUBLIC POWER DISTRICT |
| To: | NRC |
| References | |
| FRN-61FR55675, RTR-REGGD-01.105, RTR-REGGD-1.105, TASK-*****, TASK-RE 61FR55675-00002, 61FR55675-2, NLS960244, NUDOCS 9612310090 | |
| Download: ML20133A427 (2) | |
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NLS960244 December 23,1996 E
cs U.S. Nuclear Regulatory Commission GN Rules Review and Directive Branch
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Subject:
Draft Regulatory Guides DG-1045 g
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F Gentlemen:
Cooper Nuclear Station (CNS) has completed its review of the subject regulatory guide and the following comments are offered for your information and use.
1.
Page 3, founh paragraph, second sentence, states "The calibration tolerance uncertainties depicted by region "E" should be defined and accounted for in the licensee's setpoint methodology."
Comment:
CNS uses General Electric (GE) setpoint methodology. GE setpoint methodology does not take into account Leave Alone Tolerance (LAT) to calculate Nominal Trip Setpoint (NTSP). However, this methodology does take into account As-Left Tolerance (ALT) to calculate NTSP. How would this affect plants who follow GE setpoint methodology? Does GE setpoint methodology need to be revised to incorporate LAT between NTSP and Allowable Values (AV)?
2.
Page 6, third bullet states, "A large number of data points was provided for a limited number of instruments."
Comment:
CNS feels it is conservative to have large numbers of data points to calculate drift study for some similar instruments (i.e., manufacturer, model no., and range).
3.
Page 6, last bullet states, " Drift projections, including those based on regression analyses, may not account for penalties for uncertainty projection (extended surveillance interval-drift) beyond the time range for data collected."
//p Comment:
The regression analyses method is used as a statistical approach to make prediction, based on the mathematical equation.
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NLS960244 December 23,1996 Page 2 of 2 4.
Page 11, Impact Section Comment:
Because CNS uses GE setpoint methodology, we are unclear as to the impact this will have on CNS. GE setpoint methodology states that it is consistent with ISA S67.04-1982, with minor differences.
If you have any questions regarding these comments, please contact me.
Sincerely
/
b P. D. Graham Vice President of Nuclear Energy
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