ML20217N352
| ML20217N352 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 03/31/1998 |
| From: | Sorensen J NORTHERN STATES POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9804090083 | |
| Download: ML20217N352 (9) | |
Text
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Northern States Power Company Prairie island Nuclear Generating Plant 1717 Wakonade Dr. E.
Welch, MN 55089 March 31,1998 10 CFR Part 50 Section 50.90 U S Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 PRAIRIE ISLAND NUCLEAR GENERATING STATION Docket Nos. 50-282 License Nos. CPR-42 50-306 DPR-60 1
Response to March 13,1998 Request for Additional Information for License Ammendment Request dated March 6,1998 On March 13,1998, the NRC Staff requested additionalinformation regarding our i
License Amendment Request dated March 6,1998, which proposed changes to the Technical Specifications to update the heatup and cooldown rate curves, incorporate the use of a pressure and temperature limits report, and change the pressurizer power operated relief valves operabihty temperature. Our response to the March 13,1998, request for additional information is provided as Attachment 1.
In this attachment NSP makes no new commitments.
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if you have any questions concerning this supplemental response, please contact John Stanton at 612-388-1121 x4083.
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Joel P. Sorensen Plant Manager Prairie Island Nuclear Generating Plant 9804090083 980331 PDR ADOCK 05000282 P
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USNRC NORTHERN STATES POWER COMPANY March 31,1998 Page 2
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Regional Administrator-Ill, NRC NRR Project Manager, NRC Senior Resident inspector, NRC State of Minnesota, Attn: Kris Sanda J. E Silberg Attachments:
Affidavit Response to March 13,1998 Request for Additional Information for License Ammendment Request dated March 6,1998 WestingSouse transmittal letter (NSP-98-0120), dated February 27,1998 1
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UNITED STATES NUCLEAR REGULATORY COMMISSION NORTHERN STATES POWER COMPANY PRAIRIE ISLAND NUCLEAR GENERATING PLANT DOCKET NO.
50-282 50-306 Response to March 13,1998 Request for Additional Information for License Amendment Request dated March 6,1998 Northern States Power Company, a Minnesota corporation, with this letter is submitting information to support a requested license amendment.
This letter contains no restricted or other defense information.
NORTHERN STATES POWER COMPANY s
1x(AldQ By g6el P Soren'sen ' ~
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Plant Manager Prairie Island Nuclear Generating Plant On this th ay of di ff?8efore me a notary public in and for said county, personally appeareDoel P Sorensen, Plant Manager, Prairie Island Nuclear Generating Plant, and being first duly sworn acknowledged that he is authorized to execute this document on behalf of the Northem States Power Company, that he knows the contents thereof, and that to the bestkf his knowledge, information, and belief the statements ma e in it r e and that 11is not interposed for delay.
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Response to March 13,1998 Request for Mditional information for License Ammendment Request dated March 6,1998 Question 1:
Confirm that the calculated enable temperature of 243*F (225 F + 18 F for instrument uncertainties) have included the consideration of the temperature difference between the reactor coolant and the reactor vessel metai at 1/4t or 3/4t due to the temperature gradient between the vessel walls to demonstrate that the proposed enable temperature of 310*F is selected with sufficient margin.'
Response
The calculated enable temperature of 225 F does include the temperature difference between the reactor coolant and the vessel metal temperature. The enable temperature was calculated by applying code case N-514, which specifies that the enable temperature is the limiting material Adjusted Reference Temperature (ART) + 50*F at the 1/4t location. The limiting ART for the Prairie Island Vessels is 154 'F found for the Unit i nozzle to intermediate circumferential weld (Exhibit E of submittal). The metal temperature limit then becomes 204 'F (ART + 50'F). The limiting temperature drop between the coolant temperature and the 1/4t location was found to be 18.5 'F, which makes the indicated coolant temperature limit 222.5 *F.
The enable temperature was then rounded up to 225 'F. Finally the calculated instrument.
uncertainty of 18 'F was added for operator indication and thus the value of 243 F. This is well below the 310 'F enable temperature chosen for use at Prairie Island.
Question 2:
Confirm that the ISA standard, S67.04-1994, is used for determining the instrumentation uncertainties applied in the design of Over Pressure Protection System (OPPS) per the WCAP 14040-NP-A.
Response
As stated in Westinghouse's transmittal letter (NSP-98-0120), dated February 27,1998, the instrument uncertainty calculations performed to support the design setpoint of the Over Pressure Protection System (OPPS) meet or exceeded ISA 67.04,1994. A copy of this letter is provided in Attachment 2.
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Att: chm nt 1 Paga 2 Question'3:
Provide the specific method used to assure the safety injection pumps are incapable of injecting water into the RCS when the restriction is needed (below 218 F) during low temperature operation. The method should be single failure proof.
Response
The Technical Specifications and associated bases proposed by the March 6,1998 License Amendment Request will be revise' s described below, to incorporate additional measures to ensure that the safety injection pue ;. se incapable of injecting water into the reactor coolant system. Revised Technical Specification pages incorporating the changes described below will be submitted following completion of the NRC Staff review of the March 6,1998 License Amendment Request. The changes described below are consistent with the requirernents of the Improved Standard Technical Specifications for Westinghouse Plants Specification 3.3.A.1.c will be revised to read as follows:
Two safety injection pumps are OPERABLE except as specified in 3.3.A.3 and 3.3.A.4 below.
Specification 3.3.A.2.g.3 will be revised to read as follows:
A maximum of one safety injection pump shall be capable of injecting into the RCS whenever RCS temperature is less than the Overpressure Protection System Enable Temperature specified in the PTLR except that both Si pumps may be run for up to one hour while conducting the integrated Si test" when either of the following conditions is met:
(a) There is a steam or gas bubble in the pressurizer and an isolation valve between the Si pump and the RCS is shut, or (b) The reactor vessel head is rernoved.
Specification 3.3.A.2.g.4 will be revised to read as follows:
No safety injection pumps *" shall be capable of injecting into the RCS whenever RCS temperature is less than the temperature specified in the PTLR for disabling both safety injection pumps (except one or both pumps may be run as specified in 3.3.A.3 and 3.1.A.1.d.(2)).
The following discussion will be incorporated into the Bases for Technical Specification 3.3 in place of the discussion (page B.3.3-2) proposed in the March 6,1998 License Amendment Request:
Maintaining the safety injection pumps incapable of injecting into the RCS, as specified in 3.3.A.3 and 3.3.A.4, and isolating the accumulators, as specified in 3.3.A.5, will provide assurance that the plant operating conditions will be bounded by the assumptions applied to the determination of the OPPS setpoints in the mass injection trancient analysis. These setpoints will actuate the PORVs upon an RCS pressure increase to maintain RCS pressure within the acceptable operating region of the pressure / temperature (brittle fracture) limit curves in the PTLR. The provisions of these specifications are not applicable when the O
Attachm:nt 1 Pags 3
' reacto'r ve.ssel head is removed since in that condition, RCS overpressurization can not occur.
The safety injection pumps are rendered incapable of injecting into the RCS by employing at least two independent means to prevent a pump start such that a single action will not result in an injection into the RCS. This may be accomplished through the pump control switch being placed in pullout with a blocking device installed over the control switch that would prevent an unplanned pump start.
Question 4:
Provide the basis of the vent size of 3 square inch.
Response
The bases for the 3 beh vent size is contained in the present Prairie Island Technical Specification bases for section 3.1 " Reactor Coolant System", page B.3.1-3. It states that the vent size is based on the 2.956 square inch cross sectional flow area of the pressurizer PORV.
Question 5:
Confirm that corrections will be made for the errors in the Exhibit H of the submittal:
- a. Page 5 - The peak pressure for the mass injection rate of 1016.5 gpm should be listed 766 psig.
- b. Page 12 -The mass injection rate fro n 3 charging pumps should be listed as 181.5 gpm.
- c. Page 12 and 13 -The delta-p should be 31.1 psi for 1 RCP running and 61.1 psi for 2 RCPs running.
Response
In review of the listed pages Prairie Island agrees that the listed values are typographical errors in Exhibits G and H of the submittal. The values as corrected are the ones applied in the analysis of the OPPS setpoint analysis. The corrected pages will be issued.
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Westinghou se transmittal letter (NSP-98-0120), dated February 27,1998 1
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( 2 pages )
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1 t0950 Bren Read Eas:
h Westin9 ouse Minnetonka. Minnesota 55343 Electric Company Phone (612) 939-5226 Fax (612) 939-5260 February 27,1998 NSP-98-0120 Mr. Roy Waterman Northern States Power Company Prairie Island Nuclear Generatina Plant
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l 1717 Wakonade Drive East Welch.MN 55089
References:
- 1) NSP Purchase OrderPL4455SQ
- 2) Westinghouse CN-IC4 T(96)-044, Rev. 3
- 3) Westinghouse ICE-LCA T(97)-163 (Final Report - Ref 1)
- 4) NSPPurchase OrderPM0908SQ 1
Subject:
COMS Serpoint.4nalysis - Revised Final Report (Rev. 2)
Prairie Island-Units 1 & 2 I
Dear Mr. Waterman:
Westinghouse has revised the Prairie Island COMS Serpoint Development Report in order to reflect the increase in charging flow from 160 gpm to 181.5 gpm (when three charging pumps are operating simultaneously) and revised heatup and cooldown curves.
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Results of the analyses indicate that the current serpoint of 500 psig is acceptable for both Prairie Island Units, for the following plant contigurations:
- 1. The analyses performed for the mass injection event support the current setpoint of 500 psig for operation of a maximum of 3 charging pumps below an RCS temperature of 200 F. At RCS j
temperatures greater than or equal to 200*F. a single safety injection pump plus 3 positive displacement charging pumps is acceptable.
2.
Adequate margin to the Appendix G limits is also available over the range of temperatures analyzed (1310*F) for the heat injection transient.
- 3. Results are applicable for both I and 2 reactor coolant pumps in operation over the range of j
temperatures when COMS is enabled.
Please note:
Instrument uncenainty calculations meet or exceed ISA 67.04,1994.
The COMS methodology presented in WCAP-14040 applies 800 psig as the PORV piping limit.
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~ Mr.'Roy Waterman
. Northern Statei Power Company Febntary 27.1998 Letter NSP-98-0120 Page2of2
' Westinghcuse has instituted a customer feedback program on engineering efforts in order to enable us to track our performance against an objective of providing the highest quality products and services As a valued customer. your panicipation in this survey is most imponant to us. Your completion and return of -
~ the enclosed quality survey is appreciated.
This letter transmits one copy each of proprietary and non-proprietary versions of"COMS Setpoint
' Analysis" dated February 1998 to be included in your submittal to the NRC for review and approval.-
In addition to the proprietary and non-proprietary versions of the COMS repon and Engineering Service Report, there are four other enclosures for your used
- 1) Information which should be included in your NRC transmittal letter
- 2) 'roprietary Information Notice to be attached to your NRC transmittal letter 3) opyright Notice to be attached to your NRC transmittal letter
- 4). Westinghouse letter " Application for Withholding Proprietary Information from Public Disclosure"
-(CAW-98-1199)with Affidavit (CAW-98-1199).
Please transmit the original ofItem 4 to the NRC in your transmittal.
We appreciate this opponunity to be of service to NSP. If you have any questions regarding this offer, or need any additional information, please feel free to contact either Teresa Miller or me.
Very truly yours, Jeffrey A. Usem Senior Sales Engineer
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Enclosures 1!!
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