JAFP-07-0015, Response to Request for Additional Information Regarding Resolution of Generic Letter 2006-02, Grid Reliability and the Impact on Plant Risk and the Operability of Offsite Power

Response to Request for Additional Information Regarding Resolution of Generic Letter 2006-02, Grid Reliability and the Impact on Plant Risk and the Operability of Offsite Power

ML070380311
Person / Time
Site:	FitzPatrick
Issue date:	01/29/2007
From:	Peter Dietrich Entergy Nuclear Northeast, Entergy Nuclear Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
GL-06-002, JAFP-07-0015, TAC MD0982
Download: ML070380311 (5)

Text

Entergy Nuclear Northeast Entergy Nuclear Operations, Inc.

James A. Fitzpatrick NPP

-Enbtergy P.O. Box 110 Lycoming, NY 13093 Tel 315 349 6024 Fax 315 349 6480 Pete Dietrich Site Vice President - JAF January29, 2007 JAFP-07-0015 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001

Subject:

Entergy Nuclear Operatons, Inc.

James A. Fitzpatrick Nuclear Power Plant Docket No(s) 50-333 Response to Request for Additional Information Regarding Resolution of Generic Letter 2006-02, Grid Reliability and the Impact on Plant Risk and the Operability of Offsite Power (TAC Nos. MD0982)

References:

1. Request for Additional Information Regarding Resolution of Generic Letter 2006-02, Grid Reliability and the Impact on Plant Risk and the Operability of Offsite Power, dated December 5, 2006.

2. Revised Response Date for Request for Additional Information Regarding Resolution of Generic Letter 2006-02, Grid Reliability and the Impact on Plant Risk and the Operability of Offsite Power, dated December 13, 2006.

Dear Sir or Madam:

The referenced documents requested additional information regarding the resolution of Generic Letter 2006-02. Attachment 1 to this letter provides the responses to the request for additional information for the James A. Fitzpatrick Nuclear Power Plant.

There are no commitments co, "ai d in this letter. If you have any questions, please contact Mr. Jim C.QstgIip at 6615) 349-6358.

Site Vice President PD:cf Attachment cc: (see list)

,4tiz3

cc:

Mr. Samuel J. Collins Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406-1415 Mr. John Boska, Project Manager Plant Licensing Branch I-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop O-8-C2 Washington, DC 20555-0001 NRC Resident Inspector U.S. Nuclear Regulatory Commission James A. Fitzpatrick Nuclear Power Plant P.O. Box 136 Lycoming, NY 13093 Mr. Paul Eddy NYS Department of Public Service 3 Empire State Plaza, 1 0 th Floor Albany, NY 12223 Mr. Peter R. Smith President NYSERDA 17 Columbia Circle Albany, NY 12203-6399

3. Verification of RTCA PredictedPost-Trip Volta-ge Your response to question 2(g) indicates that you have not verified by procedure the voltages predictedby the online grid analysis tool (software program)with actual real plant trip voltage values. It is important that the programsused for predictingpost-trip voltage be verified to be reasonablyaccurateand conservative. What is the range of accuracyfor your GO's contingency analysis program? Why are you confident that the post-trip voltages calculatedby the GO's contingency analysis program (that you are using to determine operabilityof the offsite power system) are reasonablyaccurateand conservative? What is your standardof acceptance?

The online grid analysis tool is not owned or operated by Entergy.

The Grid Operator (GO) National Grid-NY owns and operates a state estimator and a contingency evaluation program to analyze real time and contingency voltage levels and thermal loading for the 115kV system, which is FitzPatrick's off-site power source.

The contingency evaluation program creates a real-time network model starting with bus/branch connectivity, branch impedances and ratings, and steady state generator models. The program then superimposes real-time switch and breaker status to determine network topology. Real-time generation and bus loads are also applied to this model.

The state estimator and contingency evaluation program utilizes this real-time transmission system information, nuclear plant unit specific Loss-of-Coolant-Accident (LOCA) shutdown loads and minimum voltage requirements to determine if voltage and thermal limits are observed and alarms if the results are outside of these limits. If any limit is violated, an alarm is generated and the plant is notified.

The state estimator's on-line contingency analysis application has been in service for approximately twenty years. The accuracy of this analysis tool has been shown to be adequate by the GO via its successful operation over the extended period it has been in use. Although there are no current industry standards that govern the accuracy of contingency analysis models, the GO has indicated that the state estimator contingency analysis application at the 115 kV voltage level has been demonstrated to be accurate.

North American Electric Reliability Corporation (NERC) has been established to ensure that the bulk electric system in North America is reliable, adequate and secure. Two of the responsibilities of NERC are:

• Set standards for the reliable operation and planning of the bulk electric system.

• Monitor, assess, and enforce compliance with reliability standards.

Attachment 1 Page 1 of 3 JAFP-07-0015

NERC has eight regional reliability councils whose members come from all segments of the electric industry, and are responsible for overseeing and implementing the NERC criteria at the regional levels. Entergy's FitzPatrick nuclear generator is located within the Northeast Power Coordinating Council's oversight area. National Grid - NY Energy Control Center has overall responsibility for ensuring reliability of the 115kV transmission system supplying FitzPatrick's off-site power source.

3a) What is the range of accuracyfor your GO's contingency analysis program?

The accuracy of the state estimator and contingency analysis program is not specified. There are two approved North American Electric Reliability Council Standards (IRO-002-1, "Reliability Coordination - Facilities" and TOP-006-1, "Monitoring System Condition"), which establish the criteria the Reliability Coordinators and Transmission Operators shall follow to ensure an acceptable transmission system monitoring capability. Neither of these standards establishes an accuracy range for the system.

3b) Why are you confident that the post-trip voltages calculatedby the GO's contingency analysisprogram (thatyou are using to determine operabilityof the offsite power system) are reasonablyaccurateand conservative?

The on-line contingency analysis system is one of the primary tools used by the GO to ensure the reliability of the bulk electric system by identifying system contingencies, which could result in unacceptable system conditions if the contingency were to occur. Based on these post, contingency predictions the GO will implement the necessary corrective action to mitigate the potential unacceptable conditions.

In addition, the GO utilizes the on-line contingency analysis system to plan bulk electric system line and equipment outages. If the results predicted by the on-line contingency analysis system are not consistent with the actual system response the GO investigates the discrepancies and implements any necessary adjustments.

The on-line contingency analysis program utilizes the same National Grid-NY transmission system configuration for 115kV and above as the off-line planning programs but has the advantage of real-time system data in determining the post-contingency system response. This coupled with the inclusion of accurate nuclear plant specific accident shutdown loads, provides the best available indicator as to the response of the off-site source to the loss of the nuclear unit and transfer of accidents loads.

Our confidence in the accuracy of the on-line contingency analysis system is based on the inclusion of accurate nuclear plant specific accident shutdown loads provided by FitzPatrick to the GO and the GO's operating experience in the use of the on-line contingency analysis system in identifying and responding to potential unacceptable bulk electric system conditions.

Attachment 1 Page 2 of 3 JAFP-07-0015

3c) What is your standardof acceptance?

As stated above, our confidence in the accuracy of the on-line contingency analysis system is based on the inclusion of accurate nuclear plant specific accident shutdown loads provided by FitzPatrick to the GO and the GOs operating experience in the use of the on-line contingency analysis system in identifying and responding to potential unacceptable bulk electric system conditions.

Attachment 1 Page 3 of 3 JAFP-07-0015

Text

Entergy Nuclear Northeast Entergy Nuclear Operations, Inc.

James A. Fitzpatrick NPP

-Enbtergy P.O. Box 110 Lycoming, NY 13093 Tel 315 349 6024 Fax 315 349 6480 Pete Dietrich Site Vice President - JAF January29, 2007 JAFP-07-0015 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001

Subject:

Entergy Nuclear Operatons, Inc.

James A. Fitzpatrick Nuclear Power Plant Docket No(s) 50-333 Response to Request for Additional Information Regarding Resolution of Generic Letter 2006-02, Grid Reliability and the Impact on Plant Risk and the Operability of Offsite Power (TAC Nos. MD0982)

References:

1. Request for Additional Information Regarding Resolution of Generic Letter 2006-02, Grid Reliability and the Impact on Plant Risk and the Operability of Offsite Power, dated December 5, 2006.

2. Revised Response Date for Request for Additional Information Regarding Resolution of Generic Letter 2006-02, Grid Reliability and the Impact on Plant Risk and the Operability of Offsite Power, dated December 13, 2006.

Dear Sir or Madam:

The referenced documents requested additional information regarding the resolution of Generic Letter 2006-02. Attachment 1 to this letter provides the responses to the request for additional information for the James A. Fitzpatrick Nuclear Power Plant.

There are no commitments co, "ai d in this letter. If you have any questions, please contact Mr. Jim C.QstgIip at 6615) 349-6358.

Site Vice President PD:cf Attachment cc: (see list)

,4tiz3

cc:

Mr. Samuel J. Collins Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406-1415 Mr. John Boska, Project Manager Plant Licensing Branch I-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop O-8-C2 Washington, DC 20555-0001 NRC Resident Inspector U.S. Nuclear Regulatory Commission James A. Fitzpatrick Nuclear Power Plant P.O. Box 136 Lycoming, NY 13093 Mr. Paul Eddy NYS Department of Public Service 3 Empire State Plaza, 1 0 th Floor Albany, NY 12223 Mr. Peter R. Smith President NYSERDA 17 Columbia Circle Albany, NY 12203-6399

3. Verification of RTCA PredictedPost-Trip Volta-ge Your response to question 2(g) indicates that you have not verified by procedure the voltages predictedby the online grid analysis tool (software program)with actual real plant trip voltage values. It is important that the programsused for predictingpost-trip voltage be verified to be reasonablyaccurateand conservative. What is the range of accuracyfor your GO's contingency analysis program? Why are you confident that the post-trip voltages calculatedby the GO's contingency analysis program (that you are using to determine operabilityof the offsite power system) are reasonablyaccurateand conservative? What is your standardof acceptance?

The online grid analysis tool is not owned or operated by Entergy.

The Grid Operator (GO) National Grid-NY owns and operates a state estimator and a contingency evaluation program to analyze real time and contingency voltage levels and thermal loading for the 115kV system, which is FitzPatrick's off-site power source.

The contingency evaluation program creates a real-time network model starting with bus/branch connectivity, branch impedances and ratings, and steady state generator models. The program then superimposes real-time switch and breaker status to determine network topology. Real-time generation and bus loads are also applied to this model.

The state estimator and contingency evaluation program utilizes this real-time transmission system information, nuclear plant unit specific Loss-of-Coolant-Accident (LOCA) shutdown loads and minimum voltage requirements to determine if voltage and thermal limits are observed and alarms if the results are outside of these limits. If any limit is violated, an alarm is generated and the plant is notified.

The state estimator's on-line contingency analysis application has been in service for approximately twenty years. The accuracy of this analysis tool has been shown to be adequate by the GO via its successful operation over the extended period it has been in use. Although there are no current industry standards that govern the accuracy of contingency analysis models, the GO has indicated that the state estimator contingency analysis application at the 115 kV voltage level has been demonstrated to be accurate.

North American Electric Reliability Corporation (NERC) has been established to ensure that the bulk electric system in North America is reliable, adequate and secure. Two of the responsibilities of NERC are:

• Set standards for the reliable operation and planning of the bulk electric system.

• Monitor, assess, and enforce compliance with reliability standards.

Attachment 1 Page 1 of 3 JAFP-07-0015

NERC has eight regional reliability councils whose members come from all segments of the electric industry, and are responsible for overseeing and implementing the NERC criteria at the regional levels. Entergy's FitzPatrick nuclear generator is located within the Northeast Power Coordinating Council's oversight area. National Grid - NY Energy Control Center has overall responsibility for ensuring reliability of the 115kV transmission system supplying FitzPatrick's off-site power source.

3a) What is the range of accuracyfor your GO's contingency analysis program?

The accuracy of the state estimator and contingency analysis program is not specified. There are two approved North American Electric Reliability Council Standards (IRO-002-1, "Reliability Coordination - Facilities" and TOP-006-1, "Monitoring System Condition"), which establish the criteria the Reliability Coordinators and Transmission Operators shall follow to ensure an acceptable transmission system monitoring capability. Neither of these standards establishes an accuracy range for the system.

3b) Why are you confident that the post-trip voltages calculatedby the GO's contingency analysisprogram (thatyou are using to determine operabilityof the offsite power system) are reasonablyaccurateand conservative?

The on-line contingency analysis system is one of the primary tools used by the GO to ensure the reliability of the bulk electric system by identifying system contingencies, which could result in unacceptable system conditions if the contingency were to occur. Based on these post, contingency predictions the GO will implement the necessary corrective action to mitigate the potential unacceptable conditions.

In addition, the GO utilizes the on-line contingency analysis system to plan bulk electric system line and equipment outages. If the results predicted by the on-line contingency analysis system are not consistent with the actual system response the GO investigates the discrepancies and implements any necessary adjustments.

The on-line contingency analysis program utilizes the same National Grid-NY transmission system configuration for 115kV and above as the off-line planning programs but has the advantage of real-time system data in determining the post-contingency system response. This coupled with the inclusion of accurate nuclear plant specific accident shutdown loads, provides the best available indicator as to the response of the off-site source to the loss of the nuclear unit and transfer of accidents loads.

Our confidence in the accuracy of the on-line contingency analysis system is based on the inclusion of accurate nuclear plant specific accident shutdown loads provided by FitzPatrick to the GO and the GO's operating experience in the use of the on-line contingency analysis system in identifying and responding to potential unacceptable bulk electric system conditions.

Attachment 1 Page 2 of 3 JAFP-07-0015

3c) What is your standardof acceptance?

As stated above, our confidence in the accuracy of the on-line contingency analysis system is based on the inclusion of accurate nuclear plant specific accident shutdown loads provided by FitzPatrick to the GO and the GOs operating experience in the use of the on-line contingency analysis system in identifying and responding to potential unacceptable bulk electric system conditions.

Attachment 1 Page 3 of 3 JAFP-07-0015