ML20072V376
| ML20072V376 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 09/12/1994 |
| From: | Mccoy C GEORGIA POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| LCV-0396-C, LCV-396-C, TAC-M90119, TAC-M90120, NUDOCS 9409190338 | |
| Download: ML20072V376 (3) | |
Text
-
' Georgia Power Company.
40 inverness Center Parkv.ay Post Offce Box 1295 Bamingham Alabama 35201 Telephone 205 877 7122 L
l
- c. K. uccoy -
Georgia Power Vee Prescient, Nuclear Vogtte Propct Ine Southem electnc system September 12, 1994 LCV-0396-C Docket Nos. 50-424 50-425' TAC Nos. M90119 M90120 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555 Gentlemen:-
VOGTLE ELECTRIC GENERATING PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING PROPOSED REVISION TO "Z" AND "S" FOR PRESSURIZER PRESSURE REACTOR TRIP INSTRUMENTATION SETPOINTS.
i i
l By letter LCV-0396 dated June 24,1994, Georgia Power Company requested a revision i
to the values of "Z" and "S" for pressurizer pressure instrumentation for the Vogtle l
Electric Generating Plant Technical Specifications. The change will allow the use of alternate types of pressure transmitters; In a telephone call on September 9,1994, the l
NRC staff requested cc ifirmation that the changes to the Technical Specifications and the use of Rosemount trans mitters will remain conservative with the Allowable Values that are currently in the Tecluical Specifications. This confirmation is contained in the attachment to this letter.
Sincerely, l
C. K. McCoy CKM/HWM/gmb Enclosure l
l cc: (See next page) l i
9409190338 940912 I
l hDR ADOCK 05000424 I
PDR l
4
GeorgiaIbwerd U. S. Nuclear Regulatory Commission Page 2 c(w): Georgia Power Company Mr. J. B. Beasley, Jr.
Mr. M. Sheibani NORMS U. S. Nuclear Regulatory Commission Mr. S. D. Ebneter, Regional Administrator Mr. D. S. Hood, Licensing Project Manager, NRR Mr. B. R. Bonser, Senior Resident Inspector, Vogtle State of Georgia Mr. J. D. Tanner, Commissioner, Department of Natural Resources LCV-0396-C I
l
ATTACHMENT VOGTLE ELECTRIC GENERATING PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING PROPOSED REVISION TO "Z" AND "S" FOR PRESSURIZER PRESSURE REACTOR TRIP INSTRUMENTATION SETPOINTS.
The current Allowable Values in the Technical Specifications are more conservative than the possible allowable values that are allowed for use with the Rosemount Model 1154 Series H transmitters. By using Rosemount transmitters in the pressurizer pressure loops, j
the allowable value could have been adjusted closer to the applicable setpoints, yielding additional process operating range. However, it is not our intent at this time to replace all the pressurizer pressure transmitters with Rosemount models. Defining different setpoints and allowable values between otherwise identical instrument loops could lead to human performance errors. In ourjudgement, it is prudent to leave the allowable values as currently shown in Tables 2.2-1 and 3.3-3.
In Table 3.3-3, Functional Unit 9 describes Engineered Safety Features Actuation System Interlocks. Unit 9a covers pressurizer pressure interlock P-11. While TA, Z, and S are not provided for this interlock, an allowable value is. Similar to the reactor trip allowable value in Table 2.2-1, this allowable value could have been raised for pressurizer pressure loops using Rosemount transmitters. Again, to minimize the potential for error, the existing allowable value will be used for all pressurizer pressure loops, whether they use Tobar or Rosemount transmitters.
i Taking full advantage of the improved Channel Statistical Allowance when using Rosemount transmitters, the table below shows the current and possible values. As can be seen from this table the current allowable values are more conservative than the possible allowable values.
Description Current Possible Current Possible Setpoint Setpoint Allowable Allowable Value Value j
1.
Low Pressure 21960 psi 21955 psi 21950 psi 21947 psi Reactor Trip 2.
High Pressure 52385 psi 52390 psi 52395 psi 52398 psi Reactor Trip 3.
Low Pressure 21870 psi 21830 psi 21856 psi 21838 psi Safety Injection 4.
ESFAS Pressurizer 52000 psi 52005 psi 52010 psi 52013 psi Pressure Interlock (P-11)