ELV-00284, Application for Amends to Licenses NPF-68 & NPF-81,revising Tech Specs to Reflect Values for Ta (Total Allowance), (Statistical Summation of Errors Assumed in Analysis) & Low Pressurizer Pressure Safety Injection Setpoint
| ML20247C435 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 05/08/1989 |
| From: | Hairston W GEORGIA POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20247C441 | List: |
| References | |
| ELV-00284, ELV-284, NUDOCS 8905240470 | |
| Download: ML20247C435 (5) | |
Text
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w omwmn. m ELV-00284 May 8, 1989 0181e U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C.
20555 PLANT V0GTLE UNITS 1 AND 2 NRC DOCKETS 50-424, 50-425 OPERATING LICENSES NPF-68, NPF-81 REVISION TO TECHNICAL SPECIFICATION TABLE 3.3-3 PRESSURIZER' PRESSURE--LOW Gentlemen:
In accordance with the provisions of 10 CFR 50.90 and 10 CFR 50.59, Georgia Power Company (GPC) hereby proposes to amend the Vogtle Electric Generating Plant (VEGP) Units 1 and 2 Technical Specifications, Appendix A to Operating Licenses NPF-68 and NPF-81.
Thi s proposed change revises the values for TA (total all owance), Z (the statistical summation of errors assumed in the analysis) and the Allowable Value associated with the low Pressurizer Pressure Safety Injection setpoint, in Table 3.3-3.
The Trip Setpoint and Sensor Error remain unchanged. provides a detailed description of the proposed change and the circumstances necessitating the change request. provides the basis for a determination that the proposed change does not involve significant hazards considerations. provides instructions for incorporating the proposed change into the Technical Specifications.
The proposed revised page for the combined VEGP Units 1 and 2 lechnical Specifications is included with Enclosure 3.
Pursuant to the requirements of 10 CFR 50.91, the designated state official will be sent a copy of this letter and all applicable enclosures.
l 8905240470 890508 Acei PDR ADOCK 0500042W P
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k Georgia Poner m U. S. Nuclear Regulatory Commission ELV-00284 Page Two Mr. W. G. Hairston, III states that he is a Senior Vice President of Georgia Power Company, and is authorized to execute this oath on behalf of Georgia Power Company and that to the best of his knowledge and belief, the facts set forth in this letter and enclosures are true.
GEORGIA POWER COMPANY By:
h/. M. M W. G. Hairston,III Sworn to and Subscribed before me this day of D
, 1989 mnl&
Notary MJblic HWM/gm WY COMMISSION EXPlRES JANUARY 12,1993
Enclosures:
1.
Bases for Proposed Change 2.
10 CFR 50.92 Evaluation 3.
Revised Technical Specification Page cc: Georgia Power Company Mr. P. D. Rice Mr. C. K. McCoy Mr. G. Bockhold, Jr.
Mr. J. P. Kane Mr. J. A. Bailey U. S. Nuclear Regulatory Commission Mr. Stewart Ebneter, Regional Administrator' Mr. J. B. Hopkins, licensing Project Manager, NRR Mr. J. F. Rogge, Senior Resident Inspector - Operations, Vogtle State of Georgia Mr. J. L. Ledbetter, Commissioner, Department of Natural Resources l
ENCLOSURE 1 PLANT YOGTLE UNITS 1 and 2 l
'NRC DOCKETS 50-424, 50-425 OPERATING LICENSES NPF-68, NPF-81 REVISION TO TECHNICAL SPECIFICATION TABLE 3.3-3 PRESSURIZER PRESSURE BASIS FOR' PROPOSED CHANGE PROPOSED CHANGE This. proposed ' Technical Specification revi sion will change the. values associated with the Low Pressurizer Pressure Safety Injection trip Setpoint, in Technical Specification 3.3.-3 as described below:
l TOTAL SENSOR TRIP ALLOWABLE ALLOWANCE I
ERROR SETPOINT VALUE (TA)
(S)
L Current Specification 13.1 1 0. 71 1.67 1870 1860 Proposed Specification 21.2 5 18.36 1.67 1870 1856 The revisions are to the values of TA, Z and The Allowable value.
The Sensor Error and Trip' Setpoint remain unchanged.
BASIS In order to account for concerns related to Veritrak/Tobar transmitter uncertainties, the setpoint for the Low Pressurizer Pressure-Safety Injection Trip Setpoint. contained an additional conservatism in the form of a' footnote-that was added to 'the Technical Specifications.
Westinghouse conducted evaluations of the uncertainties associated with the instrument temperature compensation,. that demonstrated that the specified values are conservative and therefore the footnote was not included in the VEGP combined Units 1 and 2 Technical Specifications.
The purpose of this change to the combined Technical. Specifications is to assure consistency between the evaluations.used to resolve the Veritrak issue and the values that appear in the Technical Specifications.
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I ENCLOSURE 2 l
PLANT V0GTLE UNITS 1 AND 2 l
NRC DOCKETS 50-424, 50-425 OPERATING LICENSES NPF-68, NPF-81 REVISION TO TECHNICAL SPECIFICATION TABLE 3.3-3 PRESSURIZER' PRESSURE 10 CFR 50.92 EVALUATION Pursuant to 10 CFR 50.92, Georgia Power Company has evaluated the attached proposed amendment to the Vogtle Units 1 and 2 Technical Specifications and has. determined that operation of the facility in accordance with the proposed amendment would not involve significant hazards considerations.
The basis for this determination is as follows:
BACKGROUND In 1986 it was determined that Veritrak transmitter uncertainties due to temperature compensation, were greater than assumed in the safety analysis.
As an interim measure a footnote was added to this Technical Specification that revised the trip setpoint for the Low Pressurizer Pressure Safety Injection trip setpoint.
Westinghouse conducted evaluations that accounted for the increased uncertainty associated with the Veritrak transmitter temperature compensation, and as a result the footnote was removed when the combined Units 1
and 2 Technical Specifications were issued.
These i
evaluations included an increased statistical summation of errors and a lower safety analysis limit.
This included evaluating an increase in the difference between the specified trip setpoint and the value used in the analysis for the trip setpoint.
In order to make the Technical Specification consistent with the resolution of the Veritrak issue, it is appropriate to revise the value of Z (the statistical summation of errors assumed in the anlysis) along with the Total Allowance and the Allowable Value.
The evaluations demonstrated additional margin between the Trip Setpoint and the Allowable Value which will reduce the possibility of instrument setpoint drif t resulting in the instrument being declared inoperable.
For these reasons it was decided to request an amendment to this specification to incorporate parameters that are consistent with the evaluation used to resolve the Veritrak issue.
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ANALYSIS GPC has reviewed the proposed amendment with respect to the requirements of 10 CFR 50.92 and has determined that the ' change does not involve significant hazards considerations.
In support of this conclusion the following analysis is provided.
1.
The proposed change does not involve a significant increase in the probability or consequences of an accident'previously evaluated because the trip setpoint is not changed, and this change is not a result of a plant modification or design change.
The revisions to TA, Z and the Allowable Value are consistent with the evaluated accidents.
The values being changed are used in the determination of whether or not instrument drift is sufficient to cause the instrument to be declared inoperable.
The revision to thi s Technical Specification provides consistency with the manner in which the increased uncertainty associated with the Veritrak instrument was resolved.
2.
The proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated because it does not result in a change in equipment and the trip setpoint remains the same.
3.
The proposed change does not involve a significant reduction in a margin of safety because the setpoint has remained unchanged even though the safety analysis was evaluated by Westinghouse to account for additional uncertainty in the Veritrak i'istrument temperature compensation.
These evaluations show that the revised analysis limits would be bounded by the existing analysis.
The revision to TA, Z and Allowable Value are consistent with the safety analysis evaluation and I
will only effect the point at which a determination of significant instrument drif t would result in the instrument being declared l
inoperabl e.
CONCLUSION' Based on the preceding analysis, GPC has determined that the proposed change to the Technical Specifications does not involve a significant increase in the probability or consequences of an accident previously evaluated, create the possibility of a new or different ki nd of accident from any accident previously evaluated or involve a significant reduction in a margin of safety.
GPC therefore concludes that the proposed change meets the requirements of 10 CFR 50.92(c) and does not involve significant hazards considerations.
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