ML102880525

OL - FW: TVA Letter to NRC - 10-5-10_I&C RAI Response

ML102880525
Person / Time
Site:	Watts Bar
Issue date:	10/05/2010
From:	Office of Nuclear Reactor Regulation
To:	Division of Operating Reactor Licensing
References
Download: ML102880525 (109)

Text

WBN2Public Resource From: Poole, Justin Sent: Tuesday, October 05, 2010 4:39 PM To: Garg, Hukam; Carte, Norbert; Darbali, Samir; Singh, Gursharan; Marcus, Barry; Halverson, Derek Cc: WBN2HearingFile Resource

Subject:

FW: TVA letter to NRC 5-10_I&C RAI Response Attachments: 10-5-10_I&C RAI Response Letter_NRC copy.pdf This is an unofficial copy which does not have all of the attachments as they were too large. The licensee should be bringing copies on disk tomorrow which contain everything.

Justin C. Poole Project Manager NRR/DORL/LPWB U.S. Nuclear Regulatory Commission (301)4152048 email: Justin.Poole@nrc.gov From: Boyd, Desiree L [1]

Sent: Tuesday, October 05, 2010 4:28 PM To: Wiebe, Joel; Raghavan, Rags; Milano, Patrick; Campbell, Stephen Cc: Hamill, Carol L; Boyd, Desiree L; Knuettel, Edward Terry

Subject:

TVA letter to NRC 5-10_I&C RAI Response Please see attached letter sent to NRC.

The attachments are too large to e-mail, but I have sent a disk of the attachments with the hard copies.

Thank You,

~*~*~*~*~*~*~*~*~*~*~*~*~*~*~

Désireé L. Boyd WBN 2 Licensing Support Sun Technical Services dlboyd@tva.gov 4233658764

~*~*~*~*~*~*~*~*~*~*~*~*~*~*~

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Hearing Identifier: Watts_Bar_2_Operating_LA_Public Email Number: 131 Mail Envelope Properties (19D990B45D535548840D1118C451C74D6FD3539632)

Subject:

FW: TVA letter to NRC 5-10_I&C RAI Response Sent Date: 10/5/2010 4:38:47 PM Received Date: 10/5/2010 4:38:50 PM From: Poole, Justin Created By: Justin.Poole@nrc.gov Recipients:

"WBN2HearingFile Resource" <WBN2HearingFile.Resource@nrc.gov>

Tracking Status: None "Garg, Hukam" <Hukam.Garg@nrc.gov>

Tracking Status: None "Carte, Norbert" <Norbert.Carte@nrc.gov>

Tracking Status: None "Darbali, Samir" <Samir.Darbali@nrc.gov>

Tracking Status: None "Singh, Gursharan" <Gursharan.Singh@nrc.gov>

Tracking Status: None "Marcus, Barry" <Barry.Marcus@nrc.gov>

Tracking Status: None "Halverson, Derek" <Derek.Halverson@nrc.gov>

Tracking Status: None Post Office: HQCLSTR02.nrc.gov Files Size Date & Time MESSAGE 1037 10/5/2010 4:38:50 PM 10-5-10_I&C RAI Response Letter_NRC copy.pdf 786130 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

Withhold from Public Disclosure Under 10 CFR 2.390 Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381-2000 October 5, 2010 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Unit 2 10 CFR 50.4 NRC Docket No. 50-391

Subject:

WATTS BAR NUCLEAR PLANT (WBN) UNIT 2 - INSTRUMENTATION AND CONTROLS STAFF INFORMATION REQUESTS

References:

1. Licensee Open Items to be Resolved for SER Approval List

2. TVA Letter dated July 30, 2010, Watts Bar Nuclear Plant (WBN) Unit 2 -

Instrumentation and Control Staff Information Request and NRC/TVA Telecom on July 6, 2010, Information Request The purpose of this letter is to provide TVAs responses to NRCs information requests on the Licensee Open Items to be Resolved for SER Approval List. Enclosure 1 provides TVAs responses to the information requested by NRC and Enclosure 2 provides a listing of the supporting documents attached to this letter. , Attachments 29, 36, 37 and 41 contain information proprietary to Westinghouse and Foxboro. TVA requests that the Westinghouse and Foxboro proprietary information be withheld from public disclosure in accordance with 10 CFR § 2.390. The nonproprietary versions and affidavit for withholding will be submitted to NRC as detailed in Enclosure 4. provides a listing of references that supports TVAs responses, and Enclosure 4 provides the Regulatory Commitments contained in this letter and two other commitments that were submitted in Reference 2 that need to be revised. Specifically, the dates by which TVA had originally committed to provide vendor documents to NRC have changed based on projected input from the vendor.

U.S. Nuclear Regulatory Commission Page 3 October 5, 2010 bcc (Enclosures):

Stephen Campbell U.S. Nuclear Regulatory Commission MS 08H4A One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2738 Hukam C. Garg U.S. Nuclear Regulatory Commission MS 09D2 One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2738 William E. Kemper U.S. Nuclear Regulatory Commission MS 09E3 One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2738 Justin C. Poole U.S. Nuclear Regulatory Commission MS 08H4A One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2738 Loren R. Plisco, Deputy Regional Administrator for Construction*

U. S. Nuclear Regulatory Commission Region II Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, Georgia 30303-1257

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

1. NRC Request (Item Number 4)

Please identify the documentation that will be submitted for each unreviewed digital I&C system and component and the associated docketing schedule.

TVA Response:

TVA letter dated June 30, 2010 docketed WNA-LI-00058-WBT-P &-NP, "Post-Accident Monitoring System (PAMS) Licensing Technical Report," Section 4.11 addressed Common Cause Failure (CCF) and BTP 7-19, Guidance for Evaluation of Diversity and Defense-in-Depth in Digital Computer-Based Instrumentation and Control Systems.

Revised Request:

(a) TVA to address the question of how a Foxboro IA common mode or complete failure impacts the plant accident analysis as described in Chapter 15 of the FSAR.

(Demonstrate segments are independent and how a common mode or complete failure is prevented by power supply design and segmentation.)

(b) Provide an architectural description (drawing) of the network interconnections similar to the ICS overview.

(c) Identify the credible failure modes caused by the mesh network and what component(s) prevent mesh network failures from disabling the entire system.

(d) What prevents a segment failure from propagating across the mesh network and affecting other segments.

TVA Revised Response:

(a) Foxboro Intelligent Automation (I/A) Segmentation Analysis, Calculation DCSSEGMENT, Rev. 0 submitted in TVA letter to NRC dated August 11, 2010 (Reference 1) demonstrates the segments are independent and how failure is prevented by power supply design.

(b) Attachment 36 contains Foxboro proprietary drawing 08F802403-SC-2001 sheets 1 through 6. An affidavit for withholding and nonproprietary versions of the drawings will be submitted by January 31, 2011.

(c) Credible Mesh Network Failure Modes Fault Handling in the I/A Series System Revision 1, contained in Attachment 42 identifies the credible mesh network failure modes and how the system is designed to prevent a network failure from disabling the entire system.

(d) Refer to the response to item (c) above.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

2. NRC Request (Item Number 22)

Verify the auxiliary feedwater control refurbishment results in a like-for-like replacement, and identify any changes from the identified precedents.

TVA Response:

TVA letter dated April 27, 2010 (Reference 12), provided a response to this request for information (Enclosure, Item No. 9).

Revised Request:

TVA should confirm if Woodward Governor is the only change.

TVA Revised Response:

TVAs original understanding of this question was that it was addressing only changes to the Woodward Governor. After further discussion with NRC, it was understood that this question was to address any changes to the Auxiliary Feedwater (AFW) System controls.

The following paragraphs describe the changes to the AFW controls not previously addressed.

The control function of the AFW Flow for Steam Generator Level is the same as Unit 1.

The controllers and signal modifiers/conditioners are Foxboro SPEC 200 discrete analog modules which are the same as the Unit 1 control loops. The only difference is that Unit 1 uses 10-50ma signal and Unit 2 uses 4-20ma. The SPEC 200 control modules operate with a 0-10mv system for both Unit 1 and Unit 2.

The differences between the units that have a control function for the AFW system are the differential pressure controls upstream of motor driven AFW pumps 2A-A and 2B-B. The control loops are 2-P-3-122A, 2-P-3-122C, 2-P-3-132A and 2-P-3-132C. Unit 1 still has the analog Bailey/GEMac controllers and signal conditioners, whereas Unit 2 has converted the controllers and signal conditioners to Foxboro SPEC 200 discrete analog components. Both loops still maintain a Fisher modifier for valve control.

Unit 2 controllers are Foxboro Model N-250HM-M2NH-F; Signal Converters, current-voltage IN are Model N-2AI-I2V, and voltage-current OUT are N-2AO-VAI; Control Card is Model N-2AX+A4.

All components are supplied in accordance with requirements of 10 CFR 50 Appendix B and ASME NQA-1 as defined in Invensys Systems, Inc., Corporate Quality Assurance Program Requirements, QMS, Revision S, dated October 26, 2007.

All components were manufactured with the same materials and processes as those qualified for Nuclear Class 1E Service per IEEE-323-1974 and IEEE-344-1975.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

3. NRC Request (Item Number 28)

For the turbine control AEH system, verify that the refurbishment results in a like-for-like replacement.

TVA Response:

TVA letter dated April 27, 2010 (Reference 12), provided the response to this request for information (Enclosure, Item No. 15)

Revised Request:

Provide 50.59 evaluation.

TVA Revised Response:

The Unit 1 Turbine Analog Electro-Hydraulic (AEH) Servo control Valve Card 10 CFR 50.59 evaluation is contained in Attachment 1.

4. NRC Request (Item Number 30)

Regarding the refurbishment of I&C equipment, identify any component digital upgrades and, if so, provide the supporting design information.

TVA Response:

TVA responded to this request for information in letter dated April 27, 2010 (Enclosure, Item No. 17) (Reference 12).

Revised Request:

Does not state if there are no other upgrade which contain imbedded digital processor.

TVA Revised Response:

There are no other Instrumentation and Control (I&C) upgrades which contain an imbedded digital processor.

5. NRC Request (Item Number 35)

Please provide a system description of the Digital Metal Impact Monitoring System that contains sufficient detail to support a review of this system using current staff positions.

TVA Response:

TVA Letter dated March 12, 2010, Enclosure 1, item 4 responded to this request for information (Reference 18).

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses Revised Request:

Description provided is not of sufficient detail to allow a regulatory determination.

TVA Revised Response:

Enclosure 2, Attachment 2 contains the nonproprietary system description which was developed from proprietary Westinghouse Watts Bar Unit 2 DIMMS-DX Operations and Maintenance Manual, 1TS3176 Rev.0 (Reference 2). Westinghouse approved this nonproprietary version for public release in letter WBT-D-2281 dated August 17, 2010 (Reference 3).

6. NRC Request (Item Number 37)

Is the plant computer a safety-related display system?

TVA Response:

As identified in TVA letter dated March 12, 2010, (Reference 18) Enclosure 1, item 2, the plant computer system is non-safety related.

FSAR Section 7.5 describes both safety and non-safety-related devices and systems.

FSAR Section 7.1.1.2 was revised to clarify that the plant computer system is non-safety-related in FSAR Amendment 100 submitted to NRC in TVA letter to NRC dated September 1, 2010 (Reference 23).

7. NRC Request (Item Number 38)

Please provide a description of the interfaces between: (1) the Safety Parameter Display System and (2) the Technical Support Center and Nuclear Data Links with the plant control and safety systems. This Description should contain sufficient detail to support a review of these interfaces using current staff positions.

TVA Response:

The requested interface descriptions have been incorporated into FSAR Sections 7.1.1.2 and 7.5.2 in Amendment 100 submitted to NRC in TVA letter to NRC dated September 1, 2010 (Reference 23).

8. NRC Request (Item Number 41 Please provide the following Westinghouse documents:

(1) WNA-DS-01617-WBT Rev. 1, "PAMS System Requirements Specification" (2) WNA-DS-01667-WBT Rev. 0, "PAMS System Design Specification" (3) WNA-CD-00018-GEN Rev. 3, "CGD for QNX version 4.5g" 4

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses Please provide the following Westinghouse documents or pointers to where the material was reviewed and approved in the CQ TR or SPM:

(4) WNA-PT-00058-GEN Rev. 0, "Testing Process for Common Q Safety systems" (5) WNA-TP-00357-GEN Rev. 4, "Element Software Test Procedure" TVA Response:

TVA docketed Items (1) and (2) in letter dated April 8, 2010 (Reference 19).

As agreed at NRC/TVA meeting on September 1, 2010, item (3) will be addressed by NRC audit of Westinghouse in Windsor, Connecticut, on September 20 and 21.

Item (4) will be addressed by Westinghouse developing a WBN Unit 2 Common Q PAMS Specific Test Plan to compensate for the fact that NRC disapproved WNA-PT-00058-GEN during the original Common Q review. TVA will submit the test plan document to NRC by November 30, 2010. NRC RAI Matrix Item 245 tracks the commitment to develop and submit the WBN Unit 2 Specific Test Plan.

Item (5) WNA-TP-00357-GEN is superseded by the Software Program Manual (SPM) compliance matrix in the next revision to the Common Q PAMS Licensing Technical Report. TVA will submit the revised report to NRC by October 22, 2010.

9. NRC Request (Item Number 43)

The PAMS ISG6 compliance matrix supplied as Enclosure 1 to TVA letter dated February 5, 2010 is a first draft of the information needed. The shortcomings of the first three lines in the matrix are:

Line 1: Section 11 of the Common Q topical report did include a commercial grade dedication program, but this program was not approved in the associated SE.

Westinghouse stated that this was the program and it could now be reviewed. The NRC stated that TVA should have identified what they believe was previously reviewed and approved.

Line 2: TVA stated the D3 analysis was not applicable to PAMS, but provided no justification. The NRC asked for justification since SRP Chapter 7.5 identified SRM to SECV-93-087 Item II.Q as being SRP acceptance criteria for PAMS.

Line 3: TVA identified that the Design report for computer integrity was completed as part of the common Q topical report. The NRC noted that this report is applicable for a system in a plant, and the CQ topical report did not specifically address this PAMS system at Watts Bar Unit 2.

NRC then concluded that TVA should go through and provide a more complete and thorough compliance matrix.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses TVA Response:

The PAMS ISG6 compliance matrix supplied as Enclosure 1 to TVA letter dated February 5, 2010 is a first draft of the information needed.

By letter dated April 8, 2010, TVA provided the PAMS Licensing Technical Report which provided additional information.

Attachment 3 contains the revised Common Q PAMS ISG-6 Compliance Matrix, dated June 11, 2010, that addresses these items (Reference 13).

By letter Dated June 18, 2010 (see Attachment 3), TVA provided a table, Watts Bar 2 -

Common Q PAMS ISG-6 Compliance Matrix.

Revised Request:

Revised compliance matrix is unacceptable.

TVA Revised Response:

It is TVAs understanding that this comment is focused on the fact that there are documents that NRC has requested that are currently listed as being available for audit at the Westinghouse offices. For those Common Q PAMS documents that are TVA deliverable documents from Westinghouse, TVA has agreed to provide those to NRC.

Westinghouse documents that are not deliverable to TVA will be available for audit as stated above. Requirements Traceability Matrix issues will be tracked under NRC RAI Matrix Items 142 (Software Requirements Specification) and 145 (System Design Specification). Commercial Item Dedication issues will be tracked under NRC RAI Matrix Item 138. This item is considered closed.

10. NRC Request (Item Number 49)

Please provide 00000-ICE-30156 Rev. 7. The PAMS SysRS incorporates sections of this document by reference.

TVA Response:

Per Westinghouse letter WBT-D-2024 (Reference 21), this document is available for audit at the Westinghouse Rockville office.

Revised Request:

This information must be on the docket.

TVA Revised Response:

This item was submitted in TVA letter to NRC dated September 2, 2010 (Reference 4).

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

11. NRC Request (Item Number 57)

Please describe the ability to change the software of the RM-1000 at site, including all required equipment and administrative controls (e.g., temporary digital connections).

TVA Response:

Firmware/software changes are done by connecting a laptop to a port on the front of the RM-1000 and placing the Operate/Calibrate switch in the Calibrate position. The first physical barrier to access is the location of the RM-1000 in the Main Control Room (MCR) which has limited access. The RM-1000 Operate/Calibrate switch is located behind the hinged front panel. The front panel must be opened (held closed by two thumbscrews) to access the switch. This provides a physical barrier to inadvertent switch operation. The system malfunction alarm is visible locally and will annunciate on the control board when the switch is in the Calibrate position.

Administrative control of software/firmware updates is in accordance with TVA Standard Specification SS-E18.15.01, Software Requirements for Real-Time Data Acquisition and Control Computer Systems, and TVA procedures SPP-9.3, Plant Modifications and Engineering Change Control, and SPP-2.6, Computer Software Control. Approved changes to software/firmware are implemented utilizing the TVA work order process.

Revised Request:

Please confirm:

(1) That the laptop is secure and access to this laptop is commensurate with the access to the equipment for which it will be used.

(2) Is the laptop dedicated for calibration of radiation monitors?

(3) If the laptop is used for more than one application then please describe the equipment for which the laptop may be used.

(4) In addition please explain how software security is assured and that only the software intended for the specific application is used.

(5) Is the connection to the radiation monitors made via a special cable/connectors?

(6) That the RS-232 communication port of the radiation monitors will only be used for calibration purposes.

(7) That the radiation monitor will not be in operation during the calibration mode.

(8) That password protection is provided for logging on to the laptop prior to start of calibration.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses TVA Revised Response (1) A laptop is not used to calibrate the monitor. All TVA in-house activities (calibration, alarm setpoint adjustment, etc.) are performed using the touchpad on the monitor.

An external computer (laptop, etc.) is only used to perform software or firmware updates. TVA does not perform software or firmware updates using in-house resources; therefore, no TVA computer is ever connected to the monitor. If software or firmware updates are required, they are approved via the TVA design change process previously described and implemented by a vendor representative under the TVA work order and Quality Assurance (QA) processes.

(2) A laptop is not used to calibrate the monitor.

(3) Refer to the response to (1) above.

(4) Refer to the response to (1) above.

(5) No. The connection between the computer and the RM-1000 is made via a standard RS-232 cable.

(6) The RS-232 connection on the RM-1000 is used to upload new software versions and is not for calibration.

(7) A physical control switch is located behind the front panel on the front edge of the Output Board to change between Operate and Calibration modes on the RM-1000.

Placing the switch in the Calibrate position makes the monitor inoperable.

(8) Refer to the response to (1) above.

12. NRC Request (Item Number 64)

By letter dated March 12, 2010 TVA stated that the target submittal date for the D3 Analysis was April 2, 2010.

TVA Response:

By letter dated April 8, 2010 (Reference 19), TVA docketed WNA-LI-00058-WBT Rev. 0, April 2010. Section 4.11, "Plant Specific Action Item 6.11." addresses the D3 Analysis.

Revised Request:

TVA to provide requested information [ISG-4 D3 analysis].

TVA Revised Response:

WBN Unit 2 Common Q PAMS ISG-4 D3 Analysis The WBN Unit 2 Common Q PAMS provides redundant signal processing and indication of two RG-1.97 Type A variables: Core-Exit Temperature (CET) and Subcooled Margin. In the event of a common-cause failure of the Common Q PAMS, instrumentation diverse from Common Q is available for these two variables. Wide Range (WR) Hot Leg Temperature indication is specified as a diverse variable for CET in the Post-Accident Monitoring Design Criteria, WB-DC-30-7 (Attachment 40). WR Hot Leg Temperature indication from all four hot legs is available on control board indicators and plant computer displays.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses Temperature and pressure saturation margin calculations are also performed in the plant computer independently of Common Q utilizing different hardware and software. Isolated outputs from the Eagle 21 protection system are provided to the plant computer for four WR Hot Leg Temperature channels and four WR reactor coolant system (RCS) Pressure channels. The temperature channels and two of the pressure channels are the same as those used in the Common Q saturation margin calculations.

The plant computer temperature saturation margin is calculated as the difference in the maximum temperature input and the saturation temperature of the minimum pressure input. The temperature saturation margin is displayed as point ID U0987.

The plant computer pressure saturation margin is calculated as the difference in the minimum pressure input and the saturation pressure of the maximum temperature input.

The pressure saturation margin is displayed as point ID U0984.

Reactor Vessel Level Indication System (RVLIS) is defined as a Type B1 variable.

Redundant indication for this variable is provided by the core exit thermocouples/Thot and RCS pressure. So long as the RCS pressure is greater than the saturation pressure for the temperature indicated by the core exit thermocouples/Thot, there is reasonable assurance that a steam void has not formed in the core and the vessel is full. This is indicated by the subcooled margin monitor/plant computer previously discussed.

13. NRC Request (Item Number 65)

By letter dated March 12, 2010 TVA stated that the target submittal date for the FMEA was August 31, 2010.

TVA Response:

Attachment 37 contains the proprietary versions of the Common Q PAMS Failure Modes and Effects Analysis (FMEA), the Post Accident Monitoring System Reliability Analysis, and the affidavits for withholding. The nonproprietary versions will be submitted by November 5, 2010.

14. NRC Request (Item Number 66)

By letter dated March 12, 2010 TVA stated that the target submittal date for the "Watts Bar 2 PAMS Software Design Description (two documents, one for flat panel display and one for AC160)" was March 31, 2010.

TVA Response:

Per Westinghouse letter WBT-D-1961 (Reference 22), these items are available for audit at the Westinghouse Rockville office.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses Revised Request:

Regulations require that the NRC review be based on docketed material. The SRP directs that reviewer to review the Software Design Specification (sometimes called an SDD)

TVA Revised Response:

x TVA submitted WNA-SD-00250-WBT Rev. 0 (AC160) in TVA letter to NRC dated August 20, 2010 (Reference 6).

x TVA submitted WNA-SD-00248-WBT, Rev. 0 (FPDS) in TVA letter to NRC dated September 2, 2010. (Reference 4).

15. NRC Request (Item Number 70)

By letter dated March 12, 2010 TVA stated that the target submittal date for the "Concept and Definition Phase IV&V Report" was March 31, 2010.

TVA Response:

Per Westinghouse letter WBT-D-1961 (Reference 22), this document is available for audit at the Westinghouse Rockville office.

Revised Request:

Regulations require that the NRC review be based on docketed material. Awaiting for document to be docketed by TVA.

TVA Revised Response:

TVA submitted WNA-VR- 00283-WBT, Rev 0 to NRC in letter dated August 20, 2010 (Reference 6).

The next Independent Verification and Validation (IV&V) report will include the Design Phase Requirements Traceability Matrix. The Design Phase IV&V Report will be submited to NRC by Februay 11, 2011.

16. NRC Request (Item Number 78)

FSAR Section 7.1.2.1.8 adds a reference 6 to the FSAR. However, Reference 6 is for instrument setpoint and has nothing to do with the diversity discussion on the FSAR Section. We believe the TVA wants to add reference 7 which is the diversity document, WCAP 13869, "Reactor Protection System Diversity in Westinghouse Pressurized Water Reactors." Please confirm this and add commitment to revise FSAR to correct the reference. (Q1) Also, confirm whether this WCAP has been reviewed by NRC, if yes, provide reference and if not, then submit the WCAP to NRC. (Q2) Also provide the justification for this reference to WBN2. (Q3) 10

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses TVA Response:

(Q1) The cross reference information was corrected in FSAR Amendment 100 submitted to NRC on September 1, 2010 (Reference 23).

(Q2) WCAP-13869 Revision 1 was previously reviewed under WBN Unit 1 SSER 13 (Reference 8). Unit 2 references Revision 2. An analysis of the differences and their acceptability will be submitted to NRC by November 15, 2010.

(Q3) Westinghouse confirmed the applicability of this WCAP to WBN Unit 2 in letter WBT-D-1321, Final Response to WBT-TVA-0713 Unit 2 WCAP Reviews, dated December 2, 2009 (Reference 9).

17. NRC Request (Item Number 79)

FSAR Section 7.1.2.1.9, Trip Setpoints, adds reference to 3, 4, and 5. However, reference 3 was deleted by FSAR amendment 81. Reference 4 has been changed to ISA-DS-67.04-1982. Justify applicability of this standard for WBN 2.(Q1) Why the latest ISA standard endorsed by NRC has not been used? (Q2) Also reference 5 is a topical report for Eagle 21 system. Please confirm that this topical report also discusses the setpoint for Eagle 21 system and whether it meets the recent guidance for the setpoint issued by the staff. (Q3) Also, W setpoint methodology does not provide discussion on the As Found Tolerance and As left value determination and how these values are used for the instrument operability, therefore, add the discussion of these topics in the FSAR. (Q4) and add reference to other documents if it is discussed in some other document. (Q5) Provide this document to the staff for review and approval. (Q6)

TVA Response:

(Q1) The WBN Unit 2 licensing basis is based on WBN Unit 1 as agreed to by NRC in SECY-07-0096, dated July 25, 2007 titled Possible Reactivation of Construction and Licensing Activities for the Watts Bar Nuclear Plant Unit 2. The WBN Unit 1 licensing basis is ISA-DS-67.04-1982. Therefore, this methodology is used for the same SSDs for WBN Unit 2. This maintains consistency in the licensing bases for both units.

(Q2) Please refer to the response to Q1.

(Q3) FSAR Reference 4 is the Eagle 21 Topical Report. FSAR Reference 5, WCAP-17044, Westinghouse Setpoint Methodology for Protection Systems Watts Bar Unit 2 submitted under TVA letter to NRC dated February 5, 2010 (Reference 10),

discusses the setpoint methodology used for Eagle 21 loops.

(Q4) FSAR Amendment 100 submitted on September 1, 2010 (Reference 23),

incorporated as-found and as-left setpoint tolerance discussion into Section 7.1.2.1.9.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses (Q5) Please refer to the response to Q4.

(Q6) EEB-TI-28, Setpoint Methodology was submitted in TVA letter to NRC dated May 13, 2010 (Reference d).

18. NRC Request (Item Number 115)

Provide a list of digital 1E systems that have a digital communications path to non safety related systems and if it has:

A. Been reviewed before for unit 1 B. Or installed in unit 1 under 50.59, or C. Is unique to unit 2 TVA Response:

Response states that Eagle 21 and the CQ PAMS Maintenance Test Panel (MTP) have communications links to non-safety-related systems.

NOTE: The following revised requests and responses are merged from RAI items 115, 187 and 188. This was done because the same response applies to each RAI.

Revised Request:

The CQ PAMS SysRS (WNA-DS-01617-WBT Rev. 1 Figure 2..1-1) shows that the OM has a TCP interface to non-safety. Please provide a list of ALL digital communications paths to non-safety-related systems.

Why did TVA not catch this on the review of the PAMS SysRS or SRS? Does TVA check that the CQ PAMS system meets the requirements in its purchase specifications?

TVA Revised Response:

The original Common Q PAMS design allowed printing from both the Operator Module (OM) and MTP via the plant computer. This required both to be connected to the plant computer. Westinghouse did not perceive this as an issue.

The OM interface, however, creates an additional digital communications path to a non-safety-related system. During the design review, TVA commented that the path needed to be eliminated or isolated. The final determination was made to eliminate the path.

Westinghouse will eliminate the description of this path from the associated documentation by January 31, 2011.

The Common Q PAMS Licensing Technical Report has been revised to reflect the deletion of the OM connection to the plant computer. The remaining Common Q PAMS documents will be corrected at the next revision. The Common Q PAMS schedule is currently under revision. The revised schedule will be submitted to NRC by October 22, 2010.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

19. NRC Request (Item Number 116)

The Eagle 21 boards originally had a conformal coating. However, the new boards do not.

Provide the basis for deletion of the conformal coating.

TVA Response:

Only the Eagle 21 Analog Input, RTD Input, Partial Trip, and Analog Output boards were originally conformally coated. The original design conformally coated these boards in their entirety. The technical reason for coating was to ensure performance at high humidity, with the major concern being the effects of humidity on low level analog circuitry.

Following the original Eagle 21 system qualification, the Analog Input, RTD Input, and Analog Output boards were successfully tested at high humidity without being conformal coated in their entirety as part of the Eagle Series Hardware Verification test effort.

Currently, the manufacturing specifications for the Analog Input and RTD Input boards specify selective areas of conformal coating, and the Analog Output board does not require any conformal coating. The Partial Trip board is a high signal level digital output board that is not susceptible to slight changes in high levels of resistance between traces as is possible with a low level analog circuit. Thus, there is no technical reason to conformally coat the Partial Trip board.

NRC may view the Westinghouse testing and qualification reports at the Westinghouse WBN site office.

Revised Request:

How is the tin whisker issue addressed? I think conformal coating was credited to protect against tin whisker issue.

TVA Revised Response:

As previously stated, the technical reason for the coating was to ensure performance at high humidity, with the major concern being the effects of humidity on low level analog circuitry. Westinghouse letter (WBT-D-2063, dated June 16, 2010, Basis for Removal of Conformal Coating Requirement on Eagle 21 Boards, Reference 7) does not credit the conformal coating as addressing the tin whisker issue.

As addressed in Resolution of Generic Safety Issues: Issue 200: Tin Whiskers (NUREG-0933, Main Report with Supplements 1-33):

CONCLUSION The low number of reported events associated with this issue, the lack of any increasing trend, the lack of any apparent decrease in reliability of systems or 13

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses components due to tin whiskers, the existence of applicable regulatory requirements and programs (i.e., 10 CFR Part 21, the maintenance rule requirements, and the Reactor Oversight Program), and the issuance of Information Notice 2005-25 to alert licensees collectively indicated that tin whiskers did not meet the requirements of NRC Management Directive 6.4. "Generic Issues Program," for further pursuit. Based on the considerations discussed above, RES recommended that the issue be returned to the originator to be evaluated for other possible options. As a result, the issue was DROPPED from further pursuit.

Based on the preceding NRC position, no further discussion of the tin whisker issue is required.

20. NRC Request (Item Number 117)

Does TVA use a single sided or double sided methodology for as-found and as-left instrument setpoint values. (RIS2006-7)

TVA Response:

Note: NRC review of the preliminary response that was incorporated into FSAR Amendment 100 found the response to be unacceptable. The following is the revised response to address NRC review comment.

TVA uses double-sided methodology for Reactor Trip and engineered safety features actuation system (ESFAS) parameters. The FSAR will be clarified in a future amendment to reflect this methodology.

21. NRC Request (Item Number 129)

TVA will provide non-proprietary versions of the following Common Q attached proprietary documents and the affidavits for the proprietary documents by June 30, 2010.

1. System Design Specification WNA-DS-01667-WBT, Rev. 1

2. System Requirements Specification WNA-DS-01617-WBT, Rev. 1

3. Software Requirements Specification WNA-SD-00239-WBT, Rev. 1 TVA Response:

The documents and affidavits for withholding for the listed documents were submitted to NRC in TVA letter to NRC dated July 14, 2010 (Reference 15).

22. NRC Request (Item Number 130)

TVA committed to revise in Amendment 100: table 4.3-1 to add ID and OD nomenclature to thimble guide tube dimensions.

14

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses TVA Response:

FSAR Amendment 100 submitted to NRC in TVA letter to NRC dated September 1, 2010 (Reference 23) added the inside diameter (ID) and outside diameter (OD) nomenclature.

23. NRC Request (Item Number 131)

TVA committed to revise in Amendment 100: FSAR 3.10 references to eliminate (LATER) for document numbers.

TVA Response:

FSAR Amendment 100 submitted to NRC in TVA letter to NRC dated September 1, 2010 (Reference 23) updated the reference document number information.

24. NRC Request (Item Number 132)

TVA committed to revise in Amendment 100: FSAR 3.10 to correct differences between the list on page 3.10-4 and the numbering referenced by the text below the list.

TVA Response:

FSAR Amendment 100 submitted to NRC in TVA letter to NRC dated September 1, 2010 (Reference 23) corrected the numbering in the text.

25. NRC Request (Item Number 133)

TVA committed to revise in Amendment 100: FSAR 3.10 to remove references to IEEE 344-1987.

TVA Response:

FSAR Amendment 100 submitted to NRC in TVA letter to NRC dated September 1, 2010 (Reference 23) removed the reference to IEEE 344-1987.

26. NRC Request (Item Number 134)

TVA committed to revise in Amendment 100: FSAR Table 1.3-3 to reflect modifications to WBN2 .

TVA Response:

FSAR Amendment 100 submitted to NRC in TVA letter to NRC dated September 1, 2010 (Reference 23) updated the table to reflect the WBN Unit 2 modifications.

15

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

27. NRC Request (Item Number 135)

TVA committed to add in Amendment 100 a reference to 7.3.1.1.1 in 6.2.5.2.b.

TVA Response:

The reference to 7.3.1.1.1 in 6.2.5.2.b was added in FSAR Amendment 100 and submitted to NRC in TVA letter to NRC dated September 1, 2010 (Reference 23).

28. NRC Request (Item Number 136)

TVA committed to replace in Amendment 100 the terms "service water" and "emergency raw cooling water" where they are used incorrectly with "Essential Raw Cooling Water" in sections 7.4, 6.2.1, Table 3.7-25, Table 9.3-3, Table 15.4-14, 1.9.2.7, 7.3.2.2.5 and 11.2.4.

TVA Response:

FSAR Amendment 100 submitted to NRC on TVA letter to NRC dated September 1, 2010 (Reference 23) updated the "service water" and "emergency raw cooling water" nomenclature as required to read essential raw cooling water.

29. NRC Request (Item Number 137)

Several WBN2 PAMS documents contain a table titled, Document Traceability &

Compliance.

(a) Please explain the purpose of this table.

(b) Please describe how this table is different than a reference list.

(c) What does it mean for a document to be listed in this table?

TVA Response:

(a) The table is to show the document hierarchy (i.e., which documents are predecessors to the document in relationship to the design life cycle).

(b) This table is showing a hierarchical relationship between documents. These documents are also in the reference list along with other documents that have no hierarchical relationship with the document.

(c) This question is similar to (a). It is to identify the documents that are predecessors to this document in relationship to the design life cycle.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

30. NRC Request (Item Number 139)

The WBN2 PAMS System Requirements Specification (WBN2 PAMS SysRS) contains a table (see page iii) titled, Document Traceability & Compliance, which states that the WBN2 PAMS SysRS was created to support no documents. Please explain.

TVA Response:

The table is to show the document hierarchy (i.e., which documents are predecessors to the document in relationship to the design life cycle). The table purpose is to provide references to internal Westinghouse documents and is not intended to reference the preceeding TVA documents.

31. NRC Request (Item Number 144)

The WBN2 PAMS Software Requirements Specification (WBN2 PAMS SRS) contains a table (see page iii) titled, Document Traceability & Compliance, which states that the WBN2 PAMS SRS was created to support the three documents identified (two of these documents have been provided on the docket).

(a) Please describe the third document (i.e., NABU-DP-00014-GEN Revision 2, Design Process for Common Q Safety Systems).

(b) Please describe the flow of information between these three documents.

(c) Does the PAMS SRS implement the requirements in these three documents?

(d) Please describe if and how these three documents are used in the development of the PAMS Software Design Description.

(e) Do the WBN2 V&V activities include verification that the requirements of these three documents have been incorporated into the WBN2 PAMS SRS.

TVA Response:

(a) The purpose of NABU-DP-00014-GEN document is to define the process for system level design, software design and implementation, and hardware design and implementation for Common Q safety system development. This document supplements the Common Q SPM, WCAP-16096-NP-A. The scope of NABU-DP-00014-GEN includes the design and implementation processes for the application development. For a more detailed description of the design process described in NABU-DP-00014-GEN please refer to the Design Process for AP1000 Common Q Safety Systems, WCAP-15927 on the AP1000 docket. Since this is a Westinghouse process document that is not specifically referenced in the SRS, it will be removed in the next revision of the document. The next revision of the SRS will be submitted to NRC by October 29, 2010.

(b) Closed to NRC RAI Matrix Items 142 and 145.

17

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses (c) Closed to NRC RAI Matrix Item 142.

(d) Closed to NRC RAI Matrix Item 142.

(e) WBN Unit 2 PAMS Software Requirements Specification (WNA-SD-00239-WBT, Rev. 1) refers to Document Traceability & Compliance table on page iii. This table has three entries; Design Process for Common Q Safety Systems (NABU-DP-00014-GEN, Rev. 2), RRAS Watts Bar 2 NSSS Completion Program I&C Projects Post Accident Monitoring System - System Requirements Specification (WNA-DS-01617-WBT, Rev. 1), and RRAS Watts Bar 2 NSSS Completion Program I&C Projects Post Accident Monitoring System - System Design Specification (WNA-DS-01667-WBT, Rev. 1).

IV&V performed a Requirements Traceability Assessment during which it reviewed Software Requirements Specification (WBN Unit 2 PAMS SRS, WNA-SD-00239-WBT, Rev. 1) against System Requirements Specification (WNA-DS-01617-WBT, Rev. 1) and System Design Specification (WNA-DS-01667-WBT, Rev. 1). During IV&V's RTA effort the anomaly reports V&V-769 and V&V- 770 have been initiated and reported in the IV&V Phase Summary Report for the System Definition Phase, WNA-VR-00283-WBT, Rev. 0.

IV&V has verified that the requirements in SRS are derived from the specified documents listed in the Document Traceability and Compliance Table of WBN Unit 2 PAMS SRS.

32. NRC Request (Item Number 149)

FSAR Section 7.1.1.2(2), Overtemperature delta T and Overpressure delta T equations have been simplified and many values are removed from the FSAR. Provide the justification for this change.

TVA Response:

In FSAR Amendment 96 the equations were revised to agree with the Unit 1 UFSAR which is the basis document for the Unit 2 FSAR. This resulted in the equations being simplified and the removal of the values for the constants. The equations were revised to match those used in the Technical Specifications. The values for the constants are contained in the Technical Specifications and were removed as redundant.

Additional changes were made in FSAR Amendments 98 and 99 to correct typographical errors found during FSAR review.

33. NRC Request (Item Number 150)

Many of the changes were based on the Westinghouse document N3-99-4003. Provide this document for staffs review so the staff can determine the basis for these changes.

18

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses TVA Response:

TVA System description N3-99-4003, Reactor Protection System, is contained in Attachment 3.

34. NRC Request (Item Number 151)

Provide the EDCR 52378 and 54504 which discusses the basis for many changes to this FSAR section.

TVA Response:

Engineering Design Construction Release (EDCR) 54504 has been voided. The software documentation which was to be issued by EDCR 54504 will be provided under Field Change Requests (FCRs) against EDCRs 52378 (Attachment 4) and 52671 (Attachment 5). EDCR 52671 contains a document proprietary to ATC Nuclear, Incorporated, titled Report PA4235-SAR-01, Revision 1 Seismic Analysis Report for Elma Engineering Corporation (OPTIMA) Cabinets TVA ID Numbers 2-L-906, 2-L-907 and 2-L-916. At this time TVA does not have permission to supply this vendor document. To facilitate NRCs review, the EDCR is being supplied without this proprietary document.

Additionally, on October 4, 2010, the NRC reviewer informed TVA that the software drawings are not required to be submitted at this time.

35. NRC Request (Item Number 152)

Deleted portion of FSAR section 7.2.3.3.4 and moved to FSAR section 7.2.1.1.5.

However, the FSAR section 7.2.1.1.5 does not include the discussion of ambient temperature and also on the calibration of the sealed reference leg system. No justification was provided for deleting this discussion. Please explain the bases for deletion of this information.

TVA Response:

The text was revised to match the Unit 1 UFSAR. The Unit 1 text was modified in Amendment 1 by FSAR Change Package 1553 S00 which is contained in Attachment 30.

The basis for the change in the change package is (text in brackets is added for clarity):

16 (page 7.2-14, 34, 35) The update to Section 7.2.1.1.5 is taken from text in Section 7.2.2.3.4 with clarifications and editorial changes. The relocated discussion of the pressurizer water level instrumentation is more appropriately included in this section than Section 7.2.2.3.4, which deals with control and protection system interaction. The changes to 7.2.1.1.5 are based on a general description of the Westinghouse pressurizer level design, channel independence, and actual installation attributes found on TVA physical drawings. Also, the hydrogen gas entrainment issue documented in NRC Information Bulletin No. 92-54, Level Instrumentation Inaccuracies Caused by Rapid Depressurization, is retained and clarified. Similar clarification is made to Reactor Protection System Description N3-9g.4003 Section 3.1.1.2(d). The original text in 7.2.2.3.4 provides some information that is too detailed and is not pertinent to the subject of discussion. It also 19

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses includes a statement that the error effect on the level measurement during a blowdown accident would be about one inch. The basis for this value is not known; however, the worst case reference leg loss of fill error due to a rapid RCS depressurization event is no more than 12 inches elevation head. This value is based on the relative elevation difference between the condensing chamber and the reference leg sensor bellows. The Westinghouse Owners Group response to this issue is found in RIMS # L44930216800

[Letter OG-93-12, WOG Response to Water Level Instrument Inaccuracies Due to Non-Condensable Gases dated February 4, 1993].The channel error value discrepancy is documented in WBPER980417 [This PER documents discrepancies identified during the review of the UFSAR to implement WBNs commitment in TVAs letter dated February 12, 1997, in response to NRCs 10 CFR 50.54(f) letter regarding adequacy and availability of design bases information dated October 9, 1996.]. The remaining text in 7.2.2.3.4 is revised to clarify the control and protection system interaction discussion.

Attachment 43 contains Letter OG-93-12 and WBPER980417.

36. NRC Request (Item Number 154)

FSAR section 7.2.1.1.10, setpoints: NRC staff has issued RIS 2006-17 to provide guidance to the industry regarding the instrument setpoint methodology which complies with 10 CFR 50.36 requirements. (Q1) Provide the information on how the WBN2 setpoint methodology meets the guidance of RIS 2006-17 and include this discussion in this section. Also, by letter dated May 13, 2010, TVA provided Rev. 7 of EEB-TI-28 to the staff. (Q2) The staff noted that section 4.3.3.6 of EEB-TI-28 discusses the correction for setpoints with a single side of interest. It should be noted that the staff has not approved this aspect of setpoint methodology for Unit 1. The staff finds this reduction in uncertainties is not justified unless it can be demonstrated that the 95/95 criteria is met.

Therefore, either remove this reduction factor for single sided uncertainties or justify how you meet the 95/95 criteria given in RG 1.105.

TVA Response:

(Q1) This information is included in FSAR Amendment 100 submitted on September 1, 2010 (Reference 23).

(Q2) EEB-TI-28's single sided methodology conforms with WBN's design basis commitment to ensure that 95% of the analyzed population is covered by the calculated tolerance limits as defined in NRC Regulatory Guide 1.105, Revision 2, 1986 that was in effect during WBN Unit 1 licensing. The single sided methodology is not used for any TSTF-493 setpoints.

37. NRC Request (Item Number 156)

FSAR section 7.2.2.1.1 states that dashed lines in Figure 15.1-1designed to prevent exceeding 121% of power.The value of 121% is changed from 118%. The justification for this change states that this was done to bring the text of this section in agreement with section 4.3.2.2.5, 4.4.2.2.6 and table 4.1-1. However, Table 4.1-1 and section 4.3.2.2.5 still show this value as 118%. Justify the change.

20

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses TVA Response:

Per Westinghouse letter WBT-D-2340, dated August 30, 2010, FSAR Markups Units 1 and 2 118% vs 121% and Correction to RAI Response SNPB 4.3.2-7, (Reference 17) the 118% value should be 121%. Depending on the use in the FSAR, either 118% or 121% is the correct value. As a result of the question, Westinghouse reviewed all locations where either 118% or 121% are used and the context of use and provided a FSAR markup to reflect the correct value at the specific location. These changes will be incorporated in FSAR Amendment 101.

38. NRC Request (Item Number 157)

FSAR section 7.2.2.1.1, fifth paragraph was deleted except for the last sentence. The last sentence states that, The P-8 interlock acts essentially as a high nuclear power reactor trip when operating in this condition. This sentence is confusing because the condition is not defined. Please clarify this discrepancy.

TVA Response:

The condition is defined in the preceding discussion as operating with a reactor coolant pump out of service and core power less than 25%.

39. NRC Request (Item Number 158)

FSAR section 7.2.2.1.1, paragraph six was changed to state that the design meets the requirements of Criterion 23 of the 1971 GDC instead of the Criterion 21 of the GDC. The Criterion 21 is about protection system reliability and testability, while Criterion 23 is about protection system failure modes. Since this paragraph deals with the evaluation of design with respect to common-mode failure, the staff believes that Criterion 23 is the right reference for this paragraph. Please clarify.

TVA Response:

FSAR Amendment 99 reflects the change to Criterion 23.

40. NRC Request (Item Number 159)

FSAR section 7.2.2.1.2 discusses reactor coolant flow measurement by elbow taps.

However, it further states that for Unit 2, precision calorimetric flow measurement methodology will be used. If elbow taps are not used for Unit 2, then why does this section discuss this methodology? It is the staffs understanding that TVA plans to use elbow taps methodology in the future for Unit 2. Please revise this section to describe the current plant design/methodology.

TVA Response:

For the purposes of measuring reactor coolant flow for Reactor Protection functions, elbow taps are used for both Unit 1 and 2. The discussion and equation are valid for establishing 21

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses the nominal full power flow which is used to establish the Reactor Protection System low flow trip setpoint. However, the method used to verify reactor coolant flow, as required by the Technical Specifications, is not the same. Unit 1 uses a simplified methodology based on elbow tap P measurements correlated with precision calorimetric data over several cycles of operation as described in FSAR Reference 17, WCAP-16067, Rev 0, RCS Flow Measurement Using Elbow Tap Methodology at Watts Bar Unit 1. The plan is for Unit 2 to transition to this method after sufficient data is obtained. Pending this transaction, 7.2.2.1.2 will be revised to read as follows:

Nominal full power flow is established at the beginning of each fuel cycle by either elbow tap methodology or, performance of the RCS calorimetric flow measurement. Unit 1 utilizes elbow tap methodology Reference [17]. Unit 2 utilizes the RCS calorimetric flow measurement. The results are used to normalize the RCS flow indicators and provide a reference point for the low flow reactor trip setpoint.

This change will be incorporated in FSAR Amendment 101.

41. NRC Request (Item Number 160)

FSAR section 7.2.2.2(7) deleted text which has references 12 and 14. These references are not included in the revised text. Provide the basis for the deletion of these references.

Also, the revised text states that typically this requirement is satisfied by utilizing 2/4 logic for the trip function or by providing a diverse trip. Provide any exception to this and their basis for acceptability.

TVA Response:

The text was revised to match the Unit 1 UFSAR. The Unit 1 text was modified in Amendment 1 by FSAR Change Package 1553 S00 which is contained in Attachment 30.

The basis for the change in the change package is:

23 (page 7.2-24): Portions of the discussion of control and protection system interaction are revised to clarify the requirement. The discussion of how the SG low-low water level protective function and the control system Median Signal Selector satisfy this requirement is deleted since it is redundant to the information provided in Section 7.2.2.3.5. Reactor Protection System Description N3-99-4003 is also revised to move and clarify the discussion of the requirements for control and protection system interaction from Section 3.1.1.2 to Section 2.2.11, where the issue is also discussed.

42. NRC Request (Item Number 161)

FSAR section 7.2.2.3 states that changes to the control function description in this section are expected to be required after vendor design of the Unit 2 Foxboro IA design is complete. Provide the schedule for the completion of the design and when this information will be available to the staff for review and approval.

22

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses TVA Response:

FSAR Amendment 99 submitted in TVA letter to NRC dated May 27, 2010 (Reference 24) reflects the changes associated with the Foxboro I/A system design.

43. NRC Request (Item Number 162)

FSAR section 7.2.2.2(14) states that bypass of a protection channel during testing is indicated by an alarm in the control room. Explain how this meets RG 1.47.

TVA Response:

The Bypassed and Inoperable Status Indication System (BISI) compliance with Regulatory Guide 1.47 is described in detail in FSAR Section 7.5.2.2.

44. NRC Request (Item Number 164)

FSAR section 7.2.2.2(20) has been revised to include the plant computer as a means to provide information read out for all signals which can cause a reactor trip. Justify the use of the plant computer for this function. Include the discussion on the effect of plant computer failure on the system functions.

TVA Response:

The primary purpose of the plant computer is to present plant process and equipment status information to the control room operators to assist them in the normal operations of the unit, and inform them of any abnormal conditions. The plant computer obtains real-time plant parameter information via Data Acquisition Systems (DAS), multiplexers, etc.,

by scanning pre-assigned analog, pulse, and contact sensors located throughout the plant.

The computer is not defined as being primary safety-related, and it is not required to meet the single failure criterion or be qualified to IEEE criteria for Class 1E equipment.

The plant computer system acquires, processes, and displays all data to support the assessment capabilities of the MCR. To help ensure that reactor trip and other information presented to the Operations staff is reliable:

• The data undergoes several validation steps before being presented to the operators.

When redundant sensors are used, the computer software is able to determine if the quality of one or more points is questionable.

• Any software associated with the computer and the DAS must meet the quality requirements of plant procedure SPP-2.6, Computer Software Control, which is based on requirements in NUREG/CR-4640, the Watts Bar Nuclear Quality Assurance Plan, and SS-E18.15.01, Software Requirements for Real-Time Data Acquisition and Control Computer Systems, which complies with IEEE Std. 279-1971, Criteria for Protection Systems for Nuclear Power Generating Stations. The computer software is controlled by a Software Quality Assurance Plan.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

• One of the requirements in 10 CFR 50, Appendix A states that Appropriate controls shall be provided to maintain variables monitored and systems within prescribed operating ranges. Periodic maintenance and calibration will be performed on the computer and DAS. In addition, calibration procedures for instrumentation which is used for input to the computer include verification of the computer input signal at the DAS and as displayed on the display stations.

• The software and associated hardware undergoes a detailed Factory Acceptance Test prior to installation in the plant. After installation in the plant, a Site Acceptance Test (SAT) will be conducted. The SAT will include several tests: computer accuracy, analog input accuracy, calculated value accuracy, computer performance, system response times, all input/output (from termination strip to display stations/printers), all data ports, and computer power supplies.

• In order to minimize the possibility of bad sensor inputs to the Safety Parameter Display System (SPDS) and/or inaccurate SPDS display of sensor inputs, routine instrument loop calibration of sensors that provide input to the SPDS will include verification that the SPDS-displayed values are correct.

Effect of plant computer failure on system functions The WBN Unit 2 is designed on the basis that it can still operate when the plant computer is inoperable. The computer is not required for safe shutdown of the plant during external design basis events such as tornadoes, floods, rain, and transportation accidents.

Operators are trained to respond to accidents both with and without the computer information available. The control room instrumentation provides the operators with the information necessary for safe reactor operations under normal, transient, and accident conditions.

The DAS is mechanically and electrically isolated from the safety systems to avoid degradation of the systems should the computer and/or DAS fail.

The computer is not expected to perform any nuclear safety-related function, nor is it designed to meet nuclear safety-related Class 1E, single-failure criteria. Therefore, the computer is not used to perform functions essential to the health and safety of the public.

45. NRC Request (Item Number 165)

FSAR section 7.2.2.3.2, last paragraph of this section has been deleted. The basis for this deletion is that discussion regarding the compliance with IEEE-279, 1971 and GDC 24 is covered in section 7.2.2.2. However, there is no reference to this section in 7.2.2.3.2 to direct the reader to 7.2.2.2. Please revise 7.2.2.2 accordingly.

TVA Response:

The reference to Section 7.2.2.2 for the general discussion for control and protection interactions is provided in Section 7.2.2.3. The reference in Section 7.2.2.3 is applicable 24

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses to all sub-section paragraphs, including 7.2.2.3.2. An additional reference in this section is not necessary and would be redundant to the Section 7.2.2.3 reference.

46. NRC Request (Item Number 166)

Changes to FSAR section 7.2.2.2(20) are justified based on the statement that the integrated computer system is implemented through EDCR 52322. Provide a copy of EDCR 52322 for staff review.

TVA Response:

EDCR 52322 is contained in Attachment 7.

47. NRC Request (Item Number 167)

FSAR section 7.2.2.4, provide an analysis or reference to chapter 15 analysis which demonstrate that failure of rod stop during a rod withdrawal event will not affect the safety limit.

TVA Response:

Continuous rod withdrawal events are analyzed in FSAR Sections 15.2.1 and 15.2.2.

While the rod stops are mentioned, they are not credited in the analysis.

48. NRC Request (Item Number 168)

FSAR table 7.2-4, item 9 deleted loss of offsite power to station auxiliaries (station blackout) based on the fact that station blackout is not listed in AAPC events. Explain what are AAPC events and how it justifies deleting this accident from the list.

TVA Response:

This change is in accordance with the Unit 1 UFSAR. The change was made by FSAR Change Package 1553 S00 (Attachment 30). The justification for the change is:

38 (Table 7.2-4): This table lists the reactor trips and the various accident analyses for which each trip could provide protection. The intent of the table is to demonstrate the diversity of and comprehensive protection provided by the reactor trip system against various postulated events and to correlate the trip functions with the analyses in which they may be utilized, either as a primary or secondary protective function. Chapter 15, along with the Accident Analysis Parameters Checklist, WB-DC-40-70, provides the accident analysis discussion and identifies the protection system functions which provide accident mitigation. The additions and deletions to the table are made for consistency with the safety analyses of record as reflected in the design and licensing basis and do not represent analysis changes or protection system changes. Therefore, they are considered to be non-significant as discussed at the beginning of this section. Neutron Monitoring System Description N3-92-4003 Table 2 is also revised for consistency with WB-DC 70.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

49. NRC Request (Item Number 177)

FSAR Amendment 99 Section 7.5.1.2 states: "Type A Variables Those variables that provide primary information to the MCR operators to allow them to take preplanned manually controlled actions for which no automatic action is provided and that are required for safety systems to accomplish their safety functions for Chapter 15 design basis events.

Primary information is information that is essential for the direct accomplishment of specified safety functions."

Clarify whether Unit 2 has the same Type A variables as Unit 1.

TVA Response:

The Type A variables are the same in Unit 1 and Unit 2. See Calculation WBN-OSG-4047, PAM Type A Variables Determination, Rev. 4 (Attachment 8).

50. NRC Request (Item Number 178)

Please provide WBN-OSG4-047, "PAM Type A Variable Determination."

TVA Response:

See response to Item 49 above.

51. NRC Request (Item Number 186)

Along with Amendment 96, TVA submitted a list of Bechtel changes for each section.

Change number 45 addresses a change to section 7.7.1.12, AMSAC, however, the Justification column states This change is not included. EDCR 52408 installs the AMSAC in Unit 2. It does not have a trouble alarms. The existing words better reflect the operation of the system.

Even thought this change was not included in Amendment 96, will it be included in a future amendment?

Also, please submit a summary of EDCR 52408.

TVA Response:

No. The previous wording reflected operation of the computer based AMSAC system.

The change reflects the operation of the relay logic based system that replaced the original computer based system in Unit 1. Unit 2 is installing a similar relay logic based system, so the change to the Unit 1 wording is applicable to Unit 2.

26

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses EDCR 52408 Summary A Purchase Order was issued to Nutherm International to provide a Unit 2 cabinet with the same functions as the current Unit 1 AMSAC. EDCR 52408 will install the cabinet and route/install cabling to provide the necessary inputs/outputs for/from the AMSAC cabinet.

In the Main Control Room, three cables will be installed for the AMSAC handswitch on 2-M-3 and AMSAC NOT ARMED and AMSAC ACTUATED annunciator windows.

In the Turbine Building, two pressure transmitters will be installed in two local panels to sense turbine pressure. Cables will be routed to the transmitters to provide the signal and power. Four cables will be routed to a local panel to provide steam generator level signals.

In the Control Building, three cables will be routed to isolation relays which will provide the start signal for the Motor Driven Auxiliary Feedwater Pumps, Turbine Driven Auxiliary Feedwater Pump, and initiate a Turbine Trip. Additionally, a cable will be routed to Unit 2 ICS for AMSAC NOT ARMED and AMSAC ACTUATED log points.

This EDCR is intended to configure Unit 2 AMSAC like Unit 1, except when not possible due to hardware obsolescence.

52. NRC Request (Item Number 187)

By letter dated June 18, 2010, TVA docketed responses to NRC requests for information.

1) Enclosure 1, Item No. 33 of the TVA letter dated June 18, 2010, did not identify any connection from the PAMS Operator Modules (OMs) to the plant computer and printers; however, Figure 2.1-1 of the PAMS System Requirements Specification (WNA-DS-01617-WBT Rev. 1 - ML101680578) shows a TCP connection from the OMs to the plant computer and printer. Please explain.

2) Please clarify whether any digital safety-related systems or components have a digital communications path to non-safety-related systems or with safety related systems in another division. If so, NRC staff will need these paths identified on the docket.

TVA Response:

1) Please refer to the revised response to letter Item 18.

2) This is a duplicate of closed RAI Matrix Item 45 (Refer to Reference 20).

53. NRC Request (Item Number 188)

By letter dated June 30, 2010, TVA docketed, Tennessee Valley Authority (TVA) Watts Bar Unit 2 (WBN2) - Post-Accident Monitoring System (PAMS) Licensing Technical Report, (Document Number WNA-LI-00058-WBT- P, Revision 0, June 2010)

(Westinghouse Proprietary Class 2).

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

1) Figure 2.2-1 of the PAMS Licensing Topical Report does not show any connection between the Operators Modules and the plant computer or printer; however, Figure 2.1-1 of the PAMS System Requirements Specification (WNA-DS-01617-WBT Rev. 1

- ML101680578) shows a TCP connection from the OMs to the plant computer and printer. Please explain.

2) Section 5.3, Response to individual criteria in DI&C-ISG-04, of the PAMS Licensing Topical Report does not address the TCP connection between the OM and non-safety components depicted in Figure 2.1-1 of the PAMS System Requirements Specification (WNA-DS-01617-WBT Rev. 1 - ML101680578). Please explain.

TVA Response:

1) Please refer to the revised response to letter Item 18.

2) Please refer to the revised response to letter Item 18.

54. NRC Request (Item Number 189)

FSAR Section 7.6.7 states: Conformance with Regulatory Guide 1.133, Revision 1 is discussed in Table 7.1-7. FSAR Chapter 7 does not contain any such numbered table.

Please explain.

TVA Response:

This is a typographical error. The correct reference is Table 7.1-1. The reference was corrected in FSAR Amendment 100 submitted to NRC September 1, 2010 (Reference 23).

55. NRC Request (Item Number 190)

FSAR Table 7.1-1 states: Regulatory Guide 1.133, May 1981 Loose-Part Detection Program for the Primary System of Light-Water Cooled Reactors, Revision 1 (See Note 12)Note 12 Conforms except as noted belowPositions C.3.a.(3) and C.5.c.

recommend a channel calibration be performed at least once per 18 months. In lieu of this recommendation, the DMIMS will be calibrated at the frequency stated in subsection TSR 3.3.6.3 of TR 3.3.6 (Loose-Part Detection System).

1) Clarify what frequency is specified in TSR 3.3.6.3.

2) Please explain why the stated calibration frequency is adequate for meeting regulatory requirements.

3) Please provide sufficient documentation for the NRC to independently evaluate the conformance claims stated in the FSAR.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses TVA Response:

1) TSR 3.3.6.3 specifies 18 months as the calibration frequency.

2) In accordance with the Technical Requirements Manual (TRM) Bases 3.3.6 (Attachment 9), the surveillance requirements and frequency are provided in Regulatory Guide 1.133, "Loose-Part Detection Program for the Primary System of Light-Water-Cooled Reactors."

3) TRM Section 3.3.6 and its bases are contained in Attachment 9.

56. NRC Request (Item Number 191)

The FSAR did not include any description of data communications systems. [This question is based on section 7.9 of the Standard Review Plan.]

1) Please identify all data communications systems.

2) Please describe each data communications system identified above.

3) Please provide a regulatory evaluation of each data communications system against the applicable regulatory criteria.

TVA Response:

WBN Unit 2 is in compliance with the regulatory requirements for data communications systems as described in Attachment 34 (Data Communications Systems Description and Regulatory Compliance Analysis).

57. NRC Request (Item Number 192)

The NRC Staff is using SRP (NUREG-0800) Chapter 7 Section 7.5, Instrumentation Systems Important to Safety, to review the WBU2 FSAR Section 7.5, Instrumentation Systems Important to Safety. The following requests are for information that the SRP directs the reviewers to evaluate.

The role of the EICB Technical reviewer is to determine if there is reasonable assurance that the equipment will perform the required functions. The WBU2 FSAR, Section 7.5.2, Plant Computer System, does not contain any description of the equipment that performs the functions described in the section. Enclosure 1 Item 3 of letter dated March 12, 2010, TVA stated that the platform of the Process Computer was, Hewlett Packard RX2660 and Dell Poweredge R200 servers with RTP Corp 8707 I/O. In addition TVA provided (a) two pages of marketing literature by DELL on the Poweredge R200 Server, (b) the HP Integrity rx2660 Server Unser Service Guide, and (c) the Integrated Computer System Network Configuration Connection Diagram (2-45W2697-1-1 dated 8/27/09). This provided information is not sufficient for evaluating whether the equipment will, with reasonable assurance, perform the functions described in the FSAR.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

1) Is the Plant Computer System another name for the Process Computer?

2) Please provide an architectural description of the Plant Computer System.

3) Please describe the relationship between the Plant Computer System and the Integrated Computer System.

TVA Response:

1) At WBN Unit 1 and 2, there is a single computer system named the Integrated Computer System or ICS. The system is sometimes referred to as the Plant Computer System, the Process Computer, the Technical Support Center Data System (TSCDS) or the Emergency Response Facility Data System (ERFDS). At one time, the TSCDS and ERFDS were separate computers on Unit 1, but their functions were all incorporated into the ICS when it was installed.

2) The WBN ICS is a non-safety-related system designed as a single, large-scale nuclear plant computer system which integrates balance of plant (BOP) monitoring with extensive nuclear steam supply system (NSSS) application software into a comprehensive computer based tool for plant operations. The system is comprised of the following major components:

x Remote multiplexers in the Computer Room, Auxiliary Instrument Room, and 480V Board rooms x Redundant Central Processing Units (CPUs) x Data Storage Devices x Man-Machine Interfaces (MMI) - Satellite Display Station (SDS) terminals in the MCR, Technical Support Center (TSC), and Computer Room x Networking equipment including switches, firewalls and terminal servers x Printers x Data Links to other plant computer devices (serial and network) - These systems or devices include but are not limited to:

o Foxboro I/A Systems (Unit 2 only) o Areva Beacon core monitoring systems o Multi-pen recorders o Landis & Gyr switchyard monitoring system o Computer Enhanced Rod Position Indication (CERPI) o Eagle 21 o Ronan Annunciator o Leading Edge Flow Meter (LEFM) o Bentley-Nevada vibration monitoring system o Inadequate Core Cooling Monitor (ICCM) (Unit 1 only) o Common Q PAMS (Unit 2 only) o WINCISE (Unit 2 only) o Plant Engineering Data System (PEDS) 30

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses In support of normal plant operations, each units ICS:

x Scans and converts analog and digital plant process inputs to engineering units for displaying, alarming, and reporting.

x Receives analog and digital inputs as pre-processed values from other digital systems for displaying, alarming, archiving, and reporting.

x Performs data validity checking.

x Performs calculations to obtain parameters such as difference, flows, and rates.

x Displays alarms when data point value exceeds predefined set points.

x Displays alarms received from the digital Annunciator system.

x Generates periodic station logs and pre-selected special logs.

x Performs BOP and NSSS related calculations.

x Provides graphical and digital trending displays of plant data.

x Provides graphical P&ID type displays of plant data.

In support of emergency plant operations each units ICS:

x Provides plant emergency support with the SPDS functions based upon the Westinghouse Owners Group CSF status trees and historical data collection, storage, and retrieval functions required to support NUREG-0737 and NUREG-0737, Supplement 1 category 1 variables (except for containment isolation).

x Provides SPDS and Emergency Response Data System (ERDS) data to the Emergency Offsite Facility via PEDS.

x Provides BISI functions (not including operating and trip bypasses of RPS and ESFAS).

x Provides continuous monitoring of RHR system performance when RHR is in use.

ICS is not required to be safety-related and is not required to meet IEEE single-failure criteria for Class 1E equipment.

3) The Plant Computer System and the Integrated Computer System are the same system.

58. NRC Request (Item Number 193)

The WBU2 FSAR, Section 7.5.2, Plant Computer System, contains three subsections, 7.5.2.1, Safety Parameter Display System 7.5.2.2, Bypassed and Inoperable Status Indication System (BISI) 7.5.2.3, Technical Support Center and Nuclear Data Links Are there three separate sets of hardware that implement these functions, or are these three functions that are implemented on a single set of hardware?

TVA Response:

The response to this RAI is included in the response to RAI Item 203, letter Item 67.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

59. NRC Request (Item Number 194)

The WBU2 FSAR Section 7.5.2.1, Safety Parameter Display System, contains a description of the Safety Parameter Display System.

SRP Section 7.5, Subsection II, Acceptance Criteria states:

Requirements applicable to the review of SPDS10 CFR 50.55a(a)(1), Quality Standards.

Please provide a description of how SPDS meets this regulatory requirement.

TVA Response:

The principal purpose and function of the SPDS is to aid control room personnel during abnormal and emergency conditions in determining the safety status of the plant and in assessing if abnormal conditions require corrective action by the operators to avoid a degraded core. It also operates during normal operations, continuously displaying information from which the plant safety status can be readily and reliably accessed.

To ensure quality, the design, testing, and inspection of the SPDS is controlled by qualified personnel and by using TVA procedure SPP-2.6, Computer Software Control (Attachment 35). The procedure details controls and processes required for the development, modification, and configuration management of computer software used to support the design, operation, modification, and maintenance of TVAs nuclear power plants consistent with the Nuclear Quality Assurance Plan.

This ensures that the design and operation of the SPDS complies with the 10 CFR 50.55a(a)(1) quality standards requirements. The controls and processes outlined in the procedure provide assurance that the SPDS will perform its intended function correctly.

The plant ICS provides the SPDS for WBN. Any changes to the SPDS software must be documented and controlled using a Software Service Request (per SPP-2.6) and must be implemented under the engineering design change process (Design Change Notice

[DCN]). Controls in SPP-2.6 guide the development and testing of the SPDS changes.

Other controls established by this procedure to further maintain quality standards are:

• Changes to SPDS software from remote locations is prohibited.

• The application custodian implements controls to prevent unauthorized changes to the software.

• Changes are made in a non-production environment, and validation testing takes place before the change is installed on the ICS.

• Once validation testing begins, the source code is placed under configuration control.

• When the modifications are installed on the ICS, an operability test is performed to demonstrate that the software is installed correctly and is functioning correctly in its operating environment.

• All documentation related to the SPDS software changes is QA records.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

• The software source code is kept in a physically secure, environmentally controlled space to prevent inadvertent changes.

• Cyber security considerations are also considered in the storage environment.

The data goes through several validation steps before being presented to the operators.

When redundant sensors are used, the data received by the computer can be processed by software to determine if the quality of one or more points is questionable.

60. NRC Request (Item Number 195)

Bypassed and Inoperable Status Indication (BISI)

The WBU2 FSAR Section 7.5.2.2, Bypassed and Inoperable Status Indication System (BISI), contains a description of the Bypassed Inoperable Status Indication System (BISI).

SRP Section 7.5, Subsection II, Acceptance Criteria states:

Requirements applicable to bypassed and inoperable status indication 10 CFR 50.55a(a)(1), Quality Standards.

Please provide a description of how BISI meets this regulatory requirement.

TVA Response:

The BISI system is a computer-based system that provides automatic indication and annunciation of the abnormal status of each ESFAS actuated component of each redundant portion of a system that performs a safety-related function.

To ensure quality, the design, testing, and inspection of the BISI system is controlled by qualified personnel and by using TVA procedure SPP-2.6, Computer Software Control (Attachment 35). The procedure details controls and processes required for the development, modification, and configuration management of computer software used to support the design, operation, modification, and maintenance of TVAs nuclear power plants consistent with the Nuclear Quality Assurance Plan.

This ensures that the design and operation of the BISI System complies with the 10 CFR 50.55a(a)(1) quality standards requirements. The controls and processes outlined in the procedure provide assurance that the BISI system will perform its intended function correctly.

The ICS provides the BISI system for WBN. Any changes to the BISI software must be documented and controlled using a Software Service Request (per SPP-2.6) and must be implemented under the engineering design change process (DCN). Controls in SPP-2.6 guide the development and testing of the BISI changes.

Other controls put in place by this procedure to further maintain quality standards are:

• Changes to BISI software from remote locations is prohibited.

• The application custodian implements controls to prevent unauthorized changes to the software.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

• Changes are made in a non-production environment and validation testing takes place before the change is installed on the ICS.

• Once validation testing begins, the source code is placed under configuratio control.

• When the modifications are installed on the ICS, an operability test is performed to demonstrate that the software is installed correctly and is functioning correctly in its operating environment.

• All documentation related to the BISI software changes is QA records.

• The software source code is kept in a physically secure, environmentally controlled space to prevent inadvertent changes.

• Cyber security considerations are also considered in the storage environment.

61. NRC Request (Item Number 196)

Bypassed and Inoperable Status Indication (BISI)

The NRC staff is performing its review in accordance with LIC-110, Rev. 1, Watts Bar Unit 2 License Application Review. LIC-110 directs the staff to review systems unique to Unit 2 in accordance with current staff guidance. Regulatory Guide (RG) 1.47 Revision 1, Bypassed and Inoperable Status indication for Nuclear Power Plant Safety Systems, is the current regulatory guidance for BISI. Please provide a regulatory evaluation of BISI against the current RG.

TVA Response:

Section C of the Regulatory Guide lists the following six regulatory positions for guidance to satisfy NRC requirements with respect to the BISI for nuclear power plant safety systems:

1. Administrative procedures should be supplemented by an indication system that automatically indicates, for each affected safety system or subsystem, the bypass or deliberately induced inoperability of a safety function and the systems actuated or controlled by the safety function. Provisions should also be made to allow the operations staff to confirm that a bypassed safety function has been properly returned to service.

TVA Response:

The BISI system provides indication (displays and annunciation) that a functional path for each train of a safety system or support system has been rendered in a state which could cause inoperability. The BISI system monitors and provides system level alarms for these plant safety-related systems:

x Main and Aux Feedwater x Safety Injection x Residual Heat Removal x Containment Spray x Emergency Gas Treatment 34

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses x Essential Raw Cooling Water x Chemical and Volume Control x Ventilating x Component Cooling x Control Air( including Aux Control Air) x Standby Diesel Generator The system level displays/indicating lights indicate the status of each systems train functional path as well as the status of any support system that might put the system in an inoperable or bypassed condition.

The BISI system software runs on the ICS, and it provides the capability to monitor in real time the parameters required to provide a BISI system as described in the Regulatory Guide.

The system level display or indicating lights indicate NORMAL status when a previously bypassed system returns to normal operational status. The Operations staff will determine the impact of each alarm on the process flow path indication during plant modes of operation. The final decision of system operability is left up to the Operations staff to determine per Technical Specifications.

2. The indicating system for BISI should also be activated automatically by the bypassing or the deliberately induced inoperability of any auxiliary or supporting system that effectively bypasses or renders inoperable a safety function and the systems actuated or controlled by the safety function.

TVA Response:

The ICS obtains real-time plant parameter information system by continuously scanning pre-assigned analog, pulse, and contact sensors located throughout the plant to provide status information to the BISI system and automatically displays that information on the BISI terminals in the MCR. Alarms are also initiated to gain the Operations staffs attention.

3. Annunciating functions for system failure and automatic actions based on the self-test or self-diagnostic capabilities of digital computer-based I&C safety systems should be consistent with Positions 1 and 2.

TVA Response:

The data goes through several validation steps before being presented to the operators. When redundant sensors are used, the data received by the computer can be processed by software to determine if the quality of one or more points is questionable.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

4. The bypass and inoperable status indication system should include a capability for ensuring its operable status during normal plant operation to the extent that the indicating and annunciating functions can be verified.

TVA Response:

The BISI system is designed to operate during all normal plant modes of operations including startup, shutdown, standby, refueling, and power operation. The ICS is designed to provide a very high degree of reliability, and the accuracy of the displayed data is not significantly less than the accuracy of comparable data displayed in the MCR.

5. Bypass and inoperable status indicators should be arranged such that the operator can determine whether continued reactor operation is permissible. The control room of all affected units should receive an indication of the bypass of shared system safety functions.

TVA Response:

A system level display via the BISI display or indicating lights is provided to the operators to indicate the status of the systems being monitored as well as any support systems. If an alarm condition exists, additional detailed information is provided to the Operations staff so as to allow determination of the abnormal condition. The information provided will identify to the Operations staff the exact nature of the initiating condition for the abnormal alarm. Each BISI system point will allow the user to access a detailed system screen.

These indicators and alarms will provide critical information to help the Operations staff determine whether continued reactor operation is/is not permissible. As stated previously, the final decision of system operability/inoperability is left to the Operations staff to determine per Technical Specifications.

6. Bypass and inoperable status indicators should be designed and installed in a manner that precludes the possibility of adverse effects on plant safety systems. The indication system should not be used to perform functions that are essential to safety, unless it is designed in conformance with criteria established for safety systems.

TVA Response:

The BISI system is not designed to safety system criteria and therefore is not to be used to perform functions essential to the health and safety of the public, nor are operator actions based solely on BISI indications.

Appropriate electrical and physical isolation from safety-related equipment to the non-safety system is provided to meet the requirements identified in the FSAR. The ICS is independent of existing sensors and equipment in safety-related systems.

Independence is achieved through qualified safety-related Class 1E isolators. The ICS 36

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses is also isolated to preclude electrical or electronic interference with existing safety systems.

Inputs and outputs are isolated from the plant inputs such that normal faults on the plant side of the loops will have no adverse impact on the ICS other than loss of the one circuit with the fault. The inputs/outputs meet the isolation requirements of Watts Bar Design Criteria WB-DC-30-4, Separation/Isolation, which defines the design requirements for electrical separation/isolation of the distribution equipment and wiring for Class 1E electrical systems and components in the plant.

62. NRC Request (Item Number 198)

SRP Section 7.5, Subsection III, Review Procedures states: Recommended review emphasis for BISI F. Scope of BISI indications - As a minimum, BISI should be provided for the following systems:

- Reactor trip system (RTS) and engineered safety features actuation system (ESFAS) - See SRP Appendix 7.1-B subsection 4.13, Indication of Bypasses, and SRP Appendix 7.1-C subsection 5.8.3, Indication of Bypasses.

- Interlocks for isolation of low-pressure systems from the reactor coolant system -

See SRP BTP 7-1.

- ECCS accumulator isolation valves - See SRP BTP 7-2.

- Controls for changeover of residual heat removal from injection to recirculation mode - See SRP BTP 7-6.

G. Conformance with Regulatory Guide 1.47, Bypassed and Inoperable Status Indication for Nuclear Power Plant Safety Systems.

H. Independence - See SRP Appendix 7.1-B subsection 4.7, Control and Protection System Interaction, and SRP Appendix 7.1-C subsections 5.6, Independence, and 6.3, Interaction Between the Sense and Command Features and Other Systems. The indication system should be designed and installed in a manner that precludes the possibility of adverse effects on plant safety systems. Failure or bypass of a protective function should not be a credible consequence of failures occurring in the indication equipment, and the bypass indication should not reduce the required independence between redundant safety systems.

I. Use of digital systems - See SRP Appendix 7.0-A and Appendix 7.1-D.

Please provide a description of how BISI meets each item above, or provide appropriate justification for not doing so.

TVA Response:

F. The scope of the WBN BISI indications are based on engineering calculation WBPEVAR8807025 Rev. 7 (Attachment 10). This calculation has not been updated for Unit 2. The calculation does include Common and Unit 2 equipment required to support Unit 1 operation. The calculation will be submitted to NRC by February 14, 2011.

G. Compliance to Regulatory Guide 1.47 is described in design criteria document WB-DC-30-29 Rev. 8, Integrated Computer System (submitted under TVA letter dated 37

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses August 11, 2010 [Reference 1]) which is a design input to calculation WBPEVAR8807025 Rev. 7.

H. Design criteria document WB-DC-30-29 Rev. 8, Integrated Computer System submitted under TVA letter dated August 11, 2010 (Reference 1) section 3.4.1, BISI Design and Operation states: The BISI shall not be designed to safety related system criteria and therefore is not to be used to perform functions essential to the health and safety of the public. Class 1E isolation is required, however, to maintain the independence of safety related equipment and systems.

I. Development of the BISI application of the ICS is performed in accordance with NPG SPP 2.6, Computer Software Control, Rev. 12 (Attachment 35). The development process starts with classifying the application depending on how the output of the software will be used. BISI software is currently classified as Category C in accordance with Appendix B which defines Category C as:

Application Software Categories Category Description C Software and data which are an integral part of a quality-related but not safety-related plant system or component and are essential to the performance of that function.

Software, portions of software, and data essential to the implementation of quality-related programs listed in Section 5.1.B of the Nuclear Quality Assurance Plan, including software used to implement regulatory physical security requirements.

Software and data which implements NQAP requirements but not specifically identified as an augmented quality-related program as defined in Section 5.1.B of the NQAP.

Software, not associated with a specific plant system, which stores, maintains, controls, distributes or manages data which can be used without further verification in activities which affect safety- or quality-related plant structures, systems, and components.

Software, portions of software, and data which are an integral part of a non safety-related, non-quality related plant system or component whose failure would significantly impact plant operations.

Software used in the design of non quality-related, non safety-related plant structures, systems, and components Based on Category C classification, SPP 2.6, Annex C defines the documentation that is required for the software.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses For BISI, a Software Requirements Specification (SRS) based on the engineering calculation will be generated along with a Software Design Description. A Software Verification and Validation Report (SVVR) consisting of a Validation Test and results and an Operability Test and results will be prepared. User documentation for BISI will be incorporated into the overall ICS user documents.

Future changes to BISI will be driven foremost by changes to the engineering calculation that defines the overall functionality of the system. Any changes to the engineering calculation will cause a Software Services Request (SSR) to be generated. Depending on the scope of the change, the various documents (SRS, SDD, SVVR and user documentation) will be updated or re-issued.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

63. NRC Request (Item Number 199)

The WBU2 FSAR Section 7.5.2.3, Technical Support Center and Nuclear Data Links, contains a description of the Technical Support Center and Nuclear Data Links.

SRP Section 7.5, Subsection II, Acceptance Criteria states:

Requirements applicable to the review ofERF information systems, and ERDS information systems 10 CFR 50.55a(a)(1), Quality Standards.

Please provide a description of how the nuclear data links meets this regulatory requirement.

TVA Response:

The TSC is intended to be an accident mitigation support center and provides SDSs capable of displaying information on plant systems for Unit 1, Unit 2, or the Simulator.

Work stations in the TSC receive data from the plant ICS over the ICS network. Separate PCs receive data from the simulator computer over the WBN site network to support drills and training exercises. Those PCs can also access the PEDS as a backup to ICS. The TSC also has a separate computer that connects to the Central Emergency Control Center (CECC) to allow additional access to meteorological station.

The ICS data is also transmitted from the PEDS server through the PEDS Firewall over the WBN Site Network to the CECC computers (Chattanooga). The CECC computers transmit the data over the TVA Corporate Network, through the TVA Firewall (provided by NRC), through the NRC Firewall to NRC. Transmission of this data from the ICS and Meteorological Station over data link (High Speed Communications Link) to the CECC and NRC meet the requirements of NUREG-0696, Functional Criteria for Emergency Response Facilities, and NUREG-1394, Emergency Response Data System Implementation.

64. NRC Request (Item Number 200)

Amendment 99 of the Watts Bar Unit 2 FSAR Section 7.5, Instrumentation Systems Important to Safety, does not include any description of instrumentation for normal operation; therefore, Section 7.5 of the FSAR does not support statements made in the SER Section 7.5; compare SER (ML072060490) Section 7.5.1 and FSAR Amendment 99 Section 7.5. Please identify where, in the docketed material, information exists to support the statements in the SER Section 7.5.1.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses TVA Response:

The statement in SER Section 7.5.1 is supported by the following:

I&C Systems for Normal Operation FSAR Section Eagle 21 7.2 Neutron Monitoring 7.2 Foxboro Spec 200 7.3 (List of other sections in attachment 34)

Foxboro I/A 7.7.11 (new section will be added by amendment 101) (other sections have been previously provided)

Plant Computer 7.5.2 Rod Control 7.7.1.2 CERPI 7.7.1.2 Control Rod Drive 7.7.1.1 Incore Neutron Monitoring 7.7.1.9 Lose Part Detection/Monitoring 7.6.7 Vibration Monitoring RCP 5.5.1.2 Control Boards 7.1.1.10 RVLIS 7.5, 5.6

65. NRC Request (Item Number 201)

Amendment 99, FSAR Section 7.7.1.1.1, "Reactor Control Input Signals (Unit 2 Only),"

contains a description of functions performed uniquely for Unit 2. Please describe the equipment that performs this function (in sufficient detail to support a regulatory evaluation), and evaluate this equipment against the appropriate regulatory criteria.

TVA Response:

These functions are within the scope of the Foxboro I/A system. Section 7.7.1.11 will be added to FSAR Amendment 101 to provide a discussion of the Distributed Control System.

66. NRC Request (Item Number 202)

The letter (ML0003740165) which transmitted the Safety Evaluation for the Common Q topical report to Westinghouse stated: "Should our criteria or regulations change so that our conclusions as to the acceptability of the report are invalidated, CE Nuclear Power and/or the applicant referencing the topical report will be expected to revise and resubmit their respective documentation, or submit justification for continued applicability of the topical report without revision of the respective documentation." Question No 81 identified many criteria changes; please revise the respective documentation or submit justification for continued applicability of the topical report.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses TVA Response:

Revision 1 of the Common Q PAMS Licensing Technical Report will provide more detailed information on the changes to the platform. Revision 1 of the Licensing Technical Report will be submitted to NRC by October 22, 2010.

Revision 2 of the Common Q PAMS Licensing Technical Report will include the applicability of the guidance in the Common Q PAMS Topical Report. Revision 2 of the Licensing Technical Report will be submitted to NRC by December 7, 2010.

67. NRC Request (Item Number 203)

By letter dated April 27, 2010 (ML101230248), TVA stated (Enclosure Item No.19): "The WBN Unit 2 Integrated Computer System (ICS) modification merges the ERFDS and plant computer into a single computer network."

FSAR Section 7.5.2, "Plant Computer System," has three subsections:

7.5.2.1, "Safety Parameter Display System" 7.5.2.2, "Bypassed and Inoperable Status Indication System (BISI)"

7.5.2.3, "Technical Support Center and Nuclear Data Links" This arrangement implies that the each of these functions are part of the plant computer, and not a separate set of equipment. Please describe the equipment for each function and identify any equipment common to more than one function.

TVA Response:

The plant computer system is one set of hardware. The Safety Parameter Display System (SPDS), Bypassed and Inoperable Status Indication System (BISI), Technical Support Center (TSC) and Nuclear Data Links are all functions of the Plant Computer System. Historically the Westinghouse P2500 Plant Process Computer and ERFDS were individual systems but were merged together with the implementation of DCN 39911-A, implemented for WBN Unit 1 in December 1998, to become the ICS. A similar system is being installed for WBN Unit 2 based on the same software with more modern hardware.

The ICS is composed of a number of pieces of hardware, all utilized as a system, to provide the functions listed in the FSAR Sections 7.5.2.1, 7.5.2.2, and 7.5.2.3. This hardware includes but is not limited to Hewlett Packard (HP) servers (CPU), DELL servers (CPU), Fiber Optic Panels, Fiber Optic Converters, Switches, Firewalls, Network Taps, Multiplexors (RTP), LCD displays, and fiber optic and copper Ethernet cables. As all the applicable hardware make up the system it is all common to more than one function, and there is no separate set of equipment for any of the functions referenced in FSAR Sections 7.5.2.1 and 7.5.2.2.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses The Nuclear Data Link and EOF functions described in 7.5.2.3 are provided by the CECC in Chattanooga. In order for the CECC to have access to ICS data, both the PEDS and the data diode isolating the PEDS from the ICS must be operational.

Meteorological data from the Environmental Data Station (EDS) is gathered by the Unit 1 ICS. That data is sent over to the Unit 2 ICS via the inter-unit firewall.

68. NRC Request (Item Number 204)

By letter dated March 12, 2010 (ML101680577) TVA provided drawing No. 2-45W2697 1, "Integrated Computer System Network Configuration Connection Diagram," that depicts three "Data Diodes. Please provide a detailed description of the equipment, software, and configurations of each "Data Diode".

TVA Response:

1. The ICS uses three data diodes.

2. Two provide an interface between train A and B of Common Q and the ICS.

a. These are identical systems consisting of the following:

i. Dual DELL R200 computers ii. Red Hat Enterprise Linux software that is locked down by CTI iii. 55 Mbs Owl cards iv. Fiber optic Ethernet interface to trained Maintenance test panel

b. Software is configured to allow only specific traffic from the MTP to pass through to the ICS

c. The secure side of the data diode will initiate the connection to the MTP, so there will be a bidirectional connection between the secure side of the data diode and the MTP. There will be no bidirectional data flow from the ICS to the MTP since the diode will block all incoming traffic from the ICS.

3. The third data diode is placed between the two ICS systems and the two PEDS computer systems.

a. Hardware is identical to that used by TVA in other plants

i. Dual HP DL360GS computers ii. Red Hat Enterprise Linux software that is locked down by CTI iii. 155 Mbs OWL cards iv. RJ45 Ethernet to PEDS network

b. Diode is configured to allow certain types of data to flow from the ICS network to the PEDS network. This includes but is not limited to the following:

i. Once per second current values and qualities for all points ii. History data archived by the ICS iii. Data files

c. There will be no bidirectional data flow from the PEDS to the ICS since the diode will block all incoming traffic from the PEDS.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

69. NRC Request (Item Number 205)

Regarding the Foxboro Spec 200 system installed at Unit 2:

a- Is it similar to Unit 1? If not, identify the differences and evaluation of the acceptability of these differences.

b- deleted c- For each system which is discussed in the FSAR and utilizes the Spec 200 system, please provide the instrument logic diagram, loop/block diagram with reference to where the system is discussed in the FSAR.

TVA Response:

As discussed at the August 3 and 4 meeting in Knoxville between TVA and NRC, the Foxboro Spec 200 is not a system. The Foxboro Spec 200 analog hardware is used to replace the existing obsolete hardware with the same functions. There are no interconnections between the analog loops unless such interconnections existed prior to the replacement. This is strictly an analog-to-analog upgrade due to equipment obsolescence. The Foxboro hardware is installed in existing cabinets which require modifications to accept the Foxboro hardware racks.

a- A listing of the replacements and differences was previously provided as Attachment 1 to TVA letter to NRC dated June 21, 2010 (Reference 14). Within Unit 1, only portions of the AFW controls were replaced. In Unit 2, all safety-related analog loops were replaced. The Foxboro Spec 200 is a fully qualified industry standard for replacement of obsolete analog instrument and control loop hardware.

b- deleted c- The Foxboro Spec 200 hardware has not been installed. Therefore, the revised drawings have not been issued. Based on this, EDCR excerpts for the logic diagrams and loop/logic drawings were provided as attachments to TVA letter to NRC dated July 30, 2010 (Reference 20). The cross reference between the functions upgraded as part of the Foxboro Spec 200 change and the appropriate FSAR section is contained in Attachment 33.

70. NRC Request (Item Number 206)

The NRC requested a description of the plant computer and TVA provided:

(1) Dell marketing literature for Dell Poweredge R200 Server, which can be found on the internet (http://www.dell.com/downloads/global/products/pedge/en/pe_R200_spec_sheet_new.pdf) and (2) HP Integrity rx2660 Server User Service guide (edition 6), which has not yet been found on the internet, but many other editions have been found.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses This information is not adequate for answering the question. (Note: TVA also provided a network configuration connection diagram, which is necessary but not sufficient.)

Please provide a description of the plant computer:

(1) Please include sufficient detail so that an evaluation can be made against the SRP acceptance criteria in SRP Section 7.7.

(2) Please identify the equipment (hardware and software) that performs each function described in the FSAR.

TVA Response:

(1) The Plant Computer is not a single computer but a computer network designated the ICS. The ICS is composed of multiple computer CPUs, LCD displays, RTP Multiplexer Assemblies, network fiber optic panels, fiber optic converters, Ethernet switches and network taps previously described in Items 57 through 60 above. For a detailed discussion of the ICS functions, refer to design criteria document WB-DC-30-29 Rev. 8, Integrated Computer System, submitted under TVA letter dated August 11, 2010 (Reference 1).

(2) As previously discussed in letter Item 58 (RAI Matrix Item 193), there is no unique set of hardware for any specific function.

71. NRC Request (Item Number 208)

By letter dated June 18, 2010 (ML101940236), TVA responded to an NRC request for additional information. Enclosure 1 Item No. 6 of this letter identified, for each PAM variable whether the variable was: (1) implemented identically to Unit 1 and reviewed by the NRC, (2) implemented identically to Unit 1 but modified under 10 CFR 50.59 after it was reviewed by the NRC, and (3) implemented in a manner that is unique to Unit 2.

There were sixteen variables modified under 10 CFR 50.59; please describe the changes that were performed under 50.59.

TVA Response:

The notes provided with the table include the change to the variable under 10 CFR 50.59.

For ease of review, the other note references have been deleted for these variables, and only the note dealing with the Unit 1 change has been retained in the Notes column of the table excerpt. The applicable notes are included in the notes list.

Var. U2 Variable U1 = U1 Unique

1. Variable Name Source U2 50.59? to U2? Notes Containment Sump Level 5 Eagle 21 Y Y N 15 (Wide Range) 9 RCS Pressurizer Level Eagle 21 N Y Y 20 10 RCS Pressure Wide Range Eagle 21 N Y Y 20 11 RCS Temperature T Cold Eagle 21 N Y Y 20 45

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses Var. U2 Variable U1 = U1 Unique

1. Variable Name Source U2 50.59? to U2? Notes 12 RCS Temperature T Hot Eagle 21 N Y Y 20 Steam Generator Level 14 Eagle 21 N Y Y 20 (Narrow Range) 15 Steam Generator Pressure Eagle 21 N Y Y 20 20 Control Rod Position CERPI Y Y N 17 53 ERCW Supply Temperature ICS Y Y N 9, 11 Inverter Current (120V ac Ammeter 58 Y Y N 10 Vital) shunt Inverter Voltage (120V ac 59 Direct Y Y N 10 Vital) 63 Main Feedwater Flow Eagle 21 Y Y N 20 Pressurizer Heater Status 66 ICS Y Y N 9 (Electric Current)

RHR Heat Exchanger Outlet 73 Foxboro I/A N Y Y 20 Temperature Steam Generator Level 82 Eagle 21 N Y Y 20 (Wide Range) 83 Main Steam Flow Eagle 21 N Y Y 20 NOTES:

9. In Unit 1, this variable was within the scope of the 10 CFR 50.59 for the ICS modification which replaced the plant P2500 and ERFDS mainframe computers.

10. In Unit 1, this variable was within the scope of the 50.59 for the vital inverter replacement modification.

11. In service for Unit 1 Operation.

15. In Unit 1, the transmitter and transmitter configuration were changed to improve reliability due to problems with the fill fluid in the original capillary type transmitters (DCN 39608). This included changing the transmitters, recorder and indicators to 4-20ma technology. Unit 2 copied the Unit 1 change (EDCR 52419 excerpts submitted March 12, 2010) (Reference 18).

16. For Unit 2, the hydrogen recombiners are abandoned in place.

17. Unit 1 replaced the rod position indication with the CERPI in 2003 (DCN 51072) under 10 CFR 50.59. The Unit 1 system has been upgraded several times, most recently in 2009. Unit 2 copied the Unit 1 system including all upgrades through 2009.

20. In Unit 1, the recorders have been replaced due to obsolescence.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

72. NRC Request (Item Number 209)

By letter dated June 18, 2010 (ML101940236), TVA responded to an NRC request for additional information. Enclosure 1 Item No. 6 of this letter identified, for each PAM variable whether the variable was: (1) implemented identically to Unit 1 and reviewed by the NRC, (2) implemented identically to Unit 1 but modified under 10 CFR 50.59 after it was reviewed by the NRC, and (3) implemented in a manner that is unique to Unit 2.

There were nine variables that were identified as both Unique to Unit 2 and identical to what was reviewed and approved on Unit 1. Please explain.

TVA Response:

The first eight variables in question are primary chemistry parameter. The parameters are the same for both units, but in Unit 1, the sample is obtained via the post accident sampling system, while in Unit 2 the sample is obtained using a grab sample via the normal sample system.

The last variable was somewhat difficult to characterize. The method of detection and the hardware manufacturer is the same in both units. However, due to obsolescence some of the parts are different than what is installed in Unit 1. The differences are described in Note 21 of the original response.

Var. U2 Variable U1 = U1 Unique

1. Variable Name Source U2 50.59? to U2? Notes Grab sample Reactor Coolant Chloride 97a with onsite Y N Y 7 Concentration analysis Grab sample Reactor Coolant Dissolved 97b with onsite Y N Y 7 Hydrogen analysis Grab sample Reactor Coolant Dissolved 97c with onsite Y N Y 7 Oxygen analysis Grab sample Reactor Coolant Total 97d with onsite Y N Y 7 Dissolved Gas analysis Grab sample 97e Reactor Coolant Boron with onsite Y N Y 7 analysis Grab sample 97f Reactor Coolant pH with onsite Y N Y 7 analysis 47

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses Var. U2 Variable U1 = U1 Unique

1. Variable Name Source U2 50.59? to U2? Notes Grab sample Reactor Coolant Sample 97g with onsite Y N Y 7 Activity analysis Grab sample Reactor Coolant Gamma 97h with onsite Y N Y 7 Spectrum analysis Steam Generator Discharge Acoustic 101 Vent (Flow Rate and Noble Monitor Y N Y 21 Gas) System NOTES:

7. These variables are obtained via portable sampling equipment and laboratory analysis.

21. In Unit 2, the accelerometers and pre-amplifiers have been replaced due to obsolescence. Other components were replaced due to end of qualified life with newer versions of the same components.

73. NRC Request (Item Number 210)

By letter dated June 18, 2010 (ML101940236), TVA responded to an NRC request for additional information. Enclosure 1 Item No. 6 of this letter identified, for each PAM variable whether the variable was: (1) implemented identically to Unit 1 and reviewed by the NRC, (2) implemented identically to Unit 1 but modified under 10 CFR 50.59 after it was reviewed by the NRC, and (3) implemented in a manner that is unique to Unit 2.

There were seven variables that were identified as both identical to Unit 1 and changed under 10 CFR 50.59. Please explain.

TVA Response:

The design basis for Unit 2 is to match Unit 1 as closely as possible. This includes incorporating changes made to Unit 1 after licensing under 10 CFR 50.59. The changes in question fall into this category and are described in the Notes for each variable in the original submittal.

74. NRC Request (Item Number 211)

FSAR Table 7.1-1 shows: "The extent to which the recommendations of the applicable NRC regulatory guides and IEEE standards are followed for the Class 1E instrumentation and control systems is shown below. The symbol (F) indicates full compliance. Those which are not fully implemented are discussed in the referenced sections of the FSAR and in the footnotes as indicated."

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses Please describe how systems that are important to safety, but not 1E, comply with 10 CFR 50.55a(a)1: "Structures, systems, and components must be designed, fabricated, erected, constructed, tested, and inspected to quality standards commensurate with the importance of the safety function to be performed."

TVA Response:

The WBN Unit 2 FSAR Section 7.5 defines the following systems as important to safety:

1. Post Accident Monitoring including:

a. Common Q Post Accident Monitoring System (Safety-Related)

i. Reactor Vessel Level ii. Core Exit Thermocouples iii. Subcooling Margin Monitor

b. Eagle 21 indications (Safety-Related)

c. Foxboro Spec 200 indications (Safety-Related)

d. Neutron Monitoring (Source and Intermediate Range) (Safety-Related)

e. Radiation Monitors (Safety-Related)

f. Unit 1 and Common shared indications (Safety-Related)

g. Foxboro I/A indications (Non-Safety-Related)

h. Radiation Monitors (Non-Safety-Related)

i. CERPI (Non-Safety-Related)

j. ICS (Non-Safety-Related)

k. Unit 1 and Common shared indications (Non-Safety-Related)

Post Accident Monitoring Instrumentation Design Criteria, WB-DC-30-7, (Attachment 40), Appendix A provides the minimum quality requirements for each Category (1, 2 or 3) of variable. By definition, no Category 1 variable can be non-safety-related. Therefore, non-safety-related variables and the source equipment are limited to Category 2 or 3. Since some variables are designated as having more than one category, the requirements of the highest category apply. Additional design criteria information for specific systems is contained in:

g. Foxboro I/A - Site-Specific Engineering Specification WBN Unit 2 NSSS and BOP Controls Upgrade Specification Rev. 1 (Attachment 23)

h. CERPI - Rod Control System Description, N3-85-4003, Rev. 12 Section 2.2, Design Requirements (Attachment 21)

i. Radiation Monitors - Design Criteria Document WB-DC-40-24, Radiation Monitoring - (Unit 1 / Unit 2), Rev. 21 (Attachment 38)

j. ICS - Design Criteria Document WB-DC-30-29 Plant ICS, Rev. 8 (Submitted under TVA to NRC letter dated August 11, 2010) (Reference 1).

2. Plant Computer (ICS) - See Item j above.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses The WBN Unit 2 FSAR Section 7.6 defines the following non-safety-related systems as other systems required for safety:

1. Foxboro I/A - While not specifically described, functions performed by the system are described in this section. The qualify requirements are described above. A description of the distributed control system will be added as FSAR Section 7.7.11 in a future FSAR amendment.

2. Loose Part Monitoring System - Design Criteria Document WB-DC-30-31, Loose Parts Monitoring System, Rev. 4, (Attachment 39) provides the quality requirements for this system.

Installation is performed in accordance with the quality requirements of either the Bechtel or TVA work order processes based on the quality classification of the equipment being installed. Vendor testing is performed in accordance with procurement specification requirements which are based on the type and quality classification of the equipment.

Preoperational testing is performed in accordance with Chapter 14 of the FSAR.

75. NRC Request (Item Number 214)

By letter dated June 18, 2010 (ML101940236) TVA stated (Enclosure 1, Attachment 3, Item No. 10) that the approved Common Q Topical Report contains information to address the "Safety Analysis." The Common Q SPM however states that a Preliminary Hazards Analysis Report and the V&V reports document the software hazards analysis. Please provide these documents TVA Response According to "The Software Program Manual for Common Q Systems," WCAP-16096-NP-1A, the Software Safety Plan only applies to Protection class software, and PAMS is classified as Important-to-safety. Exhibit 4-1 of the SPM shows that PAMS is classified as Important-to-Safety.

76. NRC Request (Item Number 216)

By letter dated March 12, 2010 (ML101680577), TVA stated that it would provide five documents to describe the Process computer: (1) EDCR 52322 Rev. A excerpts, (2) HP RX2660 Users Guide AB419-9002C-ed6, (3) Dell Poweredge R200 Server sheet November 2007, (4) RTP Corp 8707 I/O Brochure RTP 8707-02, 2004, and (5) Integrated Computer System Drawing.

By letter dated April 27, 2010 (ML101230248), TVA stated (Enclosure Item No. 20) that design changes are planned, therefore a revision to the drawing (5) and EDCR (1) are required. Please provide updated version of (1) and (5).

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses TVA Response:

(1) EDCR 52322 is contained in Attachment 7.

(5) The design change referred to is the addition of a data diode. Installation of the data diode is part of a Unit 1 design change scheduled for installation during the Unit 1 Spring 2011 outage. Until the work is complete, the change will not be incorporated into the drawing. Please see the response to letter Item 80 (RAI Matrix Item 224).

77. NRC Request (Item Number 220)

For Safety Related SSPS, submit letter justifying delta between U1 [utilizing ARs] & U2

[utilizing ARs and MDRs]. [Requires TS change ???]

TVA Response:

The Westinghouse ARLA latch attachment is obsolete. In order to provide a latching relay for Unit 2 Solid State Protection System (SSPS), a MDR latching relay must be used.

MDR relays are currently in use and shown to be reliable as SSPS Slave Relays in other Westinghouse plants.

The Technical Specification Bases was updated in Amendment B to indicate acceptability of testing MDR ESFAS Slave relays on an 18-month interval based on the assessment done in WCAP-13878-P-A, Revision 2, Reliability Assessment of Potter & Brumfield MDR Series Relays.

An initial Unit 2 ESFAS SSPS Slave Relay Service Life and Contact Load study similar to that done in Unit 1 has been completed to show that Unit 2 satisfies the conditions of WCAP-13877-P-A, Revision 2, Reliability Assessment of Westinghouse Type AR Relays used as SSPS Slave Relays, and WCAP-13878, Revision 2, Reliability Assessment of Potter & Brumfield MDR Series Relays. The Contact Load study also identifies locations in which MDR relays are not acceptable for use.

The Unit 2 Technical Specifications are based on the Unit 1 Technical Specifications which already have the 18-month surveillance frequency which was carried over to the Unit 2 Technical Specifications. Therefore, no Technical Specification change is required.

78. NRC Request (Item Number 221)

Submit EDCR Technical Evaluation for the source and intermediate range updated electronics for Unit 2 TVA Response:

The EDCR 52421 Source and Intermediate Range, Scope and Intent, Unit Difference and Technical Evaluations are contained in Attachment 31.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

79. NRC Request (Item Number 222)

Submit updated list for Foxboro Spec 200 [replacement of Bailey and Robert-Shaw electronics].

TVA Response:

The updated listing of Foxboro Spec 200 loop functions is contained in Attachment 33.

80. NRC Request (Item Number 224)

Mike Norman [TVA Computer Eng. Group] will check status of DCN/50.59 for Integrated Computer System upgrade that will install the data diode between the WBN PEDS and the Unit 1 and Unit 2 ICS.

TVA Response:

The Data diode to isolate the WBN Unit 1 and Unit 2 ICS computers from the WBN PEDS computers will be installed in PIC 56278 as part of DCN 54971. This DCN is scheduled for implementation in Spring 2011. This date was included in the Cyber Security Plan Implementation Schedules submitted to NRC on July 23, 2010.

81. NRC Request (Item Number 225)

Provide EDCR Technical Evaluation Justify/explain updated hardware [functionally equivalent to Unit 1] for the RCP and Turbine Generator vibration monitoring equipment.

TVA Response:

The requested information is contained in the Scope and Intent, Unit Difference and Technical Evaluations for EDCRs 52420 (Attachment 11) and 53559 (Attachment 12).

82. NRC Request (Item Number 227)

Provide copies of 50.59s for the following Unit 1 changes A. CERPI (initial installation and 2009 upgrade)

B. Vibration monitoring (RCP, TG and FW pumps to Bentley-Nevada 3300)

C. Containment Sump Level Transmitter replacement D. Turbine Servo Control Valve Card replacement E. Pressurizer Heater deletion of Backup Heaters on for PZR High Level F. AMSAC G. Significant ESFAS changes 52

Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses TVA Response:

Attached are copies of the 50.59s for the following Unit 1 changes:

A. CERPI, initial installation DCN 51072 and 2009 upgrade DCN 52957 (Attachment 13)

B. Upgrade of RCP, TG and FW pumps vibration monitoring to Bentley-Nevada 3300, DCN 39242, DCN 39506, DCN 39548, and DCN 50750 (Attachment 14)

C. Containment Sump Level Transmitter replacement, DCN 39608 (Attachment 15)

D. Turbine Servo Control Valve Card replacement, DCN 38993 (Attachment 1)

E. Pressurizer Heater deletion of Backup Heaters on PZR High Level, DCN 51102 (Attachment 16)

F. AMSAC DCN 50475 (Attachment 17)

G. Significant ESFAS changes

i. Relocate the containment isolation valve function and the 6.9KV Shutdown Boards Emergency Feeder Breaker Trip function from relays K626 and K602, respectively, to minimize disruption on plant operation. DCN 38238 (Attachment 18) ii. Revise OT'T and OP'T turbine runback setpoints, DCN 38842 (Attachment 19) iii. Install ICS Stages 4 and 5, DCN 50301 (Attachment 20)

83. NRC Request (Item Number 228)

Submit rod control system description N3-85-4003.

TVA Response:

The Rod Control System Description N3-85-4003 is contained in Attachment 21.

84. NRC Request (Item Number 229)

Submit Annunciator design criteria document.

TVA Response:

Condition Status/Alarm Design Criteria Document WB-DC-30-21 is contained in Attachment 22.

85. NRC Request (Item Number 230)

Submit Foxboro I/A Procurement Specification excerpts that provide system description information.

TVA Response:

The requested Foxboro I/A Procurement Specification is contained in Attachment 23.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

86. NRC Request (Item Number 231)

Update FSAR Amendment 100 Section 7.1.1.2 markup based on discussion with Hukam Garg.

TVA Response:

FSAR Section 7.1.1.2 Amendment 100 submitted in TVA to NRC letter dated September 1, 2010 (Reference 23) reflects the changes requested by the reviewer to clarify that the plant computer is not safety-related.

87. NRC Request (Item Number 232)

Submit EDCR Technical Evaluation for LPMS EDCR.

TVA Response:

The EDCR 52418 Loose Part Monitoring Scope and Intent, Unit Difference and Technical Evaluations are contained in Attachment 24.

88. NRC Request (Item Number 233)

Submit EDCR Technical Evaluation for Foxboro I/A EDCR.

TVA Response:

Foxboro I/A EDCRs 52378 and 52671 Scope and Intent, Unit Difference and Technical Evaluations are contained in Attachment 25.

89. NRC Request (Item Number 236)

Submit EDCR Technical Evaluation for Foxboro Spec 200 EDCRs.

TVA Response:

Foxboro Spec 200 EDCRs 52343 and 52427 and DCN 52641, Scope and Intent, Unit Difference and Technical Evaluations are contained in Attachment 26.

90. NRC Request (Item Number 237)

Submit EDCR Technical Evaluation for Annunciator EDCR.

TVA Response:

The Annunciator EDCR 52315 Scope and Intent, Unit Difference and Technical Evaluations are contained in Attachment 27.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

91. NRC Request (Item Number 240)

Submit EDCR Technical Evaluation for Vibration Monitoring EDCR(s).

TVA Response:

The Scope and Intent, Unit Difference and Technical Evaluations for EDCRs 53559 and 52420 are contained in Attachment 28.

92. NRC Request (Item Number 241)

Review CERPI WCAPs for system description information to be submitted to the NRC.

TVA Response:

The document that provides the most detailed information is the CERPI System Requirements Specification WNS-DS-00001-WBT Rev. 2. The proprietary version of this document and the affidavit for withholding are contained in Attachment 29. The demarcated proprietary and nonproprietary documents will be submitted to NRC by November 12, 2010.

93. NRC Request (Item Number 242)

TVA to make firm decision on date of transfer (before or after initial startup) of Unit 2 loops in service for Unit 1 to new Foxboro Spec 200 hardware.

TVA Response:

The Unit 2 loops in service for Unit 1 that are scheduled to be transferred to the Foxboro Spec 200 hardware will be transferred prior to Unit 2 fuel load.

94. NRC Request (Item Number 253)

TVA provided information by letter dated July 30, 2010 (ML102160349) - See Enclosure 1 Item No. 8 - that some AC160 module contain FPGAs. For those modules that have not been previously approved, please provide information to address regulatory criteria for FPGAs.

TVA Response:

All AC160 modules used for the Common Q PAMS have been previously approved. The original response listed all Field Programmable Gate Arrays (FPGAs) while the request was only for components that had not been previously approved.

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Enclosure 1 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval RAI Responses

95. NRC Request (Item Number 273)

In WBN2 FSAR Table 7.5-2, "Regulatory Guide 1.97 Variable List (Deviation and Justification for Deviations)," (WBNP-96) for Variable 97g, "Reactor Coolant Sample Activity," Deviation 5 (page 21 of 41), the last two sentences of the Justification read, "TVA meets the intent of RG 1.97 recommended range by monitoring this variable using the gross activity analysis of primary coolant samples taken in the post accident sampling facility. Samples are obtained from the post accident sampling system in Unit 1 only."

Please describe how the samples are obtained for Unit 2.

TVA Response:

Post accident samples will be obtained from the normal sample system.

96. NRC Request (Item Number 299)

Provide Common Q Software Requirements Specification Post Accident Monitoring System 00000-ICE-3238 Rev. 5.

TVA Response:

Attachment 41 contains the proprietary version of Common Q Software Requirements Specification Post Accident Monitoring System 00000-ICE-3238 Rev. 5 and the affidavit for withholding. The nonproprietary version will be submitted to NRC by April 8, 2011.

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Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval Attachments

1. Turbine AEH Servo Control Valve Card Unit 1 DCN 38993 50.59 Evaluation

2. Non-proprietary System Description for the Westinghouse DIMMS-DX Lose Part Detection System.

3. System Description N3-99-4003, Reactor Protection System, Revision 21, dated June 30, 2006

4. EDCR 52378

5. EDCR 52671

6. Not Used

7. EDCR 52322

8. WBNOSG4047, PAM Type A Variables Determination, Rev. 4

9. Technical Requirements Manual Section 3.3.6 and Bases

10. WBN Engineering Calculations WBPEVAR8807025 Rev. 7

11. EDCR 52420 Scope and Intent, Unit Difference and Technical Evaluations

12. EDCR 53559 Scope and Intent, Unit Difference and Technical Evaluations

13. CERPI, Initial Installation DCN 51072 and 2009 Upgrade DCN 52957 50.59 Evaluations

14. Upgrade of RCP, TG and FW Pumps Vibration Monitoring to Bentley-Nevada 3300, DCN 39242, DCN 39506, DCN 39548, and DCN 50750 50.59 Evaluations

15. Containment Sump Level Transmitter Replacement, DCN 39608 50.59 Evaluation

16. Pressurizer Heater Deletion of Backup Heaters on for PZR High Level, DCN 51102

17. AMSAC DCN 50475, 50.59 Evaluation

18. Relocate Containment Isolation Valve Functions on Relays K602 and K626 to Prevent Plant Shutdown During Routine Surveillance tTesting. DCN 38238 50.59 Evaluation

19. Revise OT'T and OP'T Turbine Runback Setpoints, DCN 38842 50.59 Evaluation

20. Install Integrated Computer System (ICS), DCN 50301 50.59 Evaluation

21. Rod Control System Description N3-85-4003

22. Design Criteria Document WB-DC-30-21, Condition Status/Alarm, Rev. 9

23. Foxboro I/A Procurement Specification

24. EDCR 52418 Loose Part Monitoring Scope and Intent, Unit Difference and Technical Evaluations

25. EDCRs 52378 and 52671 Foxboro I/A Scope and Intent, Unit Difference and Technical Evaluations

26. EDCRs 52343, 52427 and DCN 52641 Foxboro Spec 200 Scope and Intent, Unit Difference and Technical Evaluations

27. EDCR 52315 Annunciator Scope and Intent, Unit Difference and Technical Evaluations 1

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval Attachments

28. EDCRs 52420 and 53559 Vibration Monitoring Scope and Intent, Unit Difference and Technical Evaluations

29. Proprietary Version of the CERPI System Requirements Specification WNS-DS-00001-WBT Rev. 2 and Affidavit for Withholding.

30. Unit 1 UFSAR Amendment 3 Change Package 1553 S00

31. The EDCR 52421 Source and Intermediate Range, Scope and Intent, Unit Difference and Technical Evaluations

32. Not Used

33. Cross reference between the Functions Upgraded as Part of the Foxboro Spec 200 change to FSAR section.

34. Data Communications Systems Description and Regulatory Compliance Analysis.

35. SPP-2.6, Computer Software Control, Rev. 12.

36. Foxboro Proprietary Drawings 08F802403-SC-2001 Sheets 1 through 6.

37. Proprietary versions of the Failure Modes and Effects Analysis (FMEA) for the Post Accident Monitoring System WNA-AR-00180-WBT, Rev. 0, Post Accident Monitoring System Reliability Analysis WNA-AR-00189-WBT, Rev. 0 and Affidavits for Withholding

38. Design Criteria Document WB-DC-40-24, Radiation Monitoring - (Unit 1 / Unit 2), Rev. 21

39. Design Criteria Document WB-DC-30-31, Loose Part Monitoring System, Rev. 4

40. Design Criteria Document WB-DC-30-7, Post Accident Monitoring Instrumentation, Rev.

22, Dated August 27, 2008

41. Proprietary version of Common Q Software Requirements Specification Post Accident Monitoring System, 00000-ICE-3238 Rev. 5 and Affidavit for Withholding.

42. Fault Handling in the I/A Series System, Revision 1.

43. Westinghouse Letter OG-93-12, WOG Response to Water Level Instrument Inaccuracies Due to Non-Condensable Gases Dated February 4, 1993 and WBPER980417.

2

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 1 Turbine AEH Servo Control Valve Card Unit 1 DCN 38993-A 50.59 Evaluation

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 2 Non-proprietary system description for the Westinghouse DIMMS-DX Lose Part Detection System

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 3 System description N3-99-4003, Reactor Protection System, Revision 21, Dated June 30, 2006

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 4 EDCR 52378

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 5 EDCR 52671

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 7 EDCR 52322

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 8 WBNOSG4047, PAM Type A Variables Determination, Rev. 4

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 9 Technical Requirements Manual section 3.3.6 and bases

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 10 WBN Engineering Calculations WBPEVAR8807025 Rev. 7

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 11 EDCR 52420 Scope and Intent, Unit Difference and Technical Evaluations

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 12 EDCR 53559 Scope and Intent, Unit Difference and Technical Evaluations

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 13 CERPI, Initial Installation DCN 51072 And 2009 Upgrade DCN 52957 50.59 Evaluations

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 14 Upgrade of RCP, TG and FW Pumps Vibration Monitoring To Bentley-Nevada 3300, DCN 39242, DCN 39506, DCN 39548, and DCN 50750 50.59 Evaluations

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 15 Containment Sump Level Transmitter Replacement, DCN 39608 50.59 Evaluation

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 16 Pressurizer Heater deletion Of Backup Heaters On PZR High Level, DCN 51102

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 17 AMSAC DCN 50475, 50.59 Evaluation

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 18 Relocate Containment Isolation Valve Functions On Relays K602 and K626 To Prevent Plant Shutdown During Routine Surveillance Testing, DCN 38238 50.59 Evaluation

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 19 Revise OT'T and OP'T turbine Runback Setpoints, DCN 38842 50.59 Evaluation

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 20 Install Integrated Computer System (ICS), DCN 50301 50.59 Evaluation

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 21 Rod Control System Description N3-85-4003

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 22 Design Criteria Document WB-DC-30-21, Condition Status/Alarm, Rev. 9

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 23 Foxboro I/A Procurement Specification

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 24 EDCR 52418 Loose Part Monitoring Scope And Intent, Unit Difference And Technical Evaluations

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 25 EDCRs 52378 and 52671 Foxboro I/A Scope And Intent, Unit Difference And Technical Evaluations

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 26 EDCRs 52343, 52427 and DCN 52641 Foxboro Spec 200 Scope And Intent, Unit Difference nd Technical Evaluations

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 27 EDCR 52315 Annunciator Scope And Intent, Unit Difference And Technical Evaluations

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 28 EDCRs 52420 and 53559 Vibration Monitoring Scope and Intent, Unit Difference And Technical Evaluations

Withhold from Public Disclosure Under 10 CFR 2.390 Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 29 Proprietary Version Of The CERPI System Requirements Specification WNS-DS-00001-WBT Rev. 2 And Affidavit For Withholding

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 30 Unit 1 UFSAR Amendment 3 Change Package 1553 S00

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 31 The EDCR 52421 Source And Intermediate Range, Scope and Intent, Unit Difference And Technical Evaluations

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 33 Cross reference between The Functions Upgraded As Part Of The Foxboro Spec 200 Change To FSAR Section

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 34 Data Communications Systems Description And Regulatory Compliance Analysis

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 35 SPP-2.6, Computer Software Control, Revision 12

Withhold from Public Disclosure Under 10 CFR 2.390 Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 36 Foxboro Proprietary Drawings 08F802403-SC-2001 Sheets 1 Through 6

Withhold from Public Disclosure Under 10 CFR 2.390 Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 37 Proprietary Versions Of The Failure Modes And Effects Analysis (FMEA) For The Post Accident Monitoring System WNA-AR-00180-WBT, Rev. 0, Post Accident Monitoring System Reliability Analysis WNA-AR-00189-WBT, Rev. 0 And Affidavits For Withholding

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 38 Design Criteria Document WB-DC-40-24, Radiation Monitoring (Unit 1 / Unit 2), Rev 21

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 39 Design Criteria Document WB-DC-30-31, Loose Part Monitoring System, Rev. 4

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 40 Design Criteria Document WB-DC-30-7, Post Accident Monitoring Instrumentation, Rev. 22, Dated August 27, 2008

Withhold from Public Disclosure Under 10 CFR 2.390 Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 41 Proprietary Version Of Common Q Software Requirements Specification Post Accident Monitoring System, 00000-ICE-3238 Rev. 5 And Affidavit For Withholding

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 42 Fault Handling In The I/A Series System, Revision 1

Enclosure 2 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval ATTACHMENT 43 Westinghouse Owners Group (WOG) To NRC, WOG Response To Water Level Instrument Inaccuracies Due To Non-Condensible Gases, dated February 4, 1993 and WBPER980417

Enclosure 3 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval References

1. TVA Letter to NRC Dated August 11, 2010, Watts Bar Nuclear Plant (WBN) Unit 2, NRC August 3-4, 2010, Instrumentation and Controls Meeting, Request for Additional Information [Letter Items: 1(a), 62G, 62H, 70 and 74]

2. Westinghouse Watts Bar Unit 2 DMIMS-DX Operations and Maintenance Manual, 1TS3176 Rev.0 [Letter Item 5]

3. Westinghouse Letter WBT-D-2281 to TVA dated August 17, 2010,Tennessee Valley Authority, Watts Bar Unit 2, Approval of DIMMS System Description [Letter Item 5]

4. TVA Letter to NRC Dated September 2, 2010, Watts Bar Nuclear Plant (WBN) Unit 2, Instrumentation and Controls Staff Information Request, . [Letter Items 10 and 14]

5. Not Used

6. TVA Letter to NRC dated August 20, 2010, Watts Bar Nuclear Plant (WBN) Unit 2, Instrumentation and Controls Staff Information Requests [Letter Items 14 and 15]

7. Westinghouse letter WBT-D-2063, Dated June 16, 2010, Tennessee Valley Authority Watts Bar Nuclear Plant Unit 2, Basis for Removal of Conformal Coating Requirement on Eagle 21 Boards [Letter Item 19]

8. WBN Unit 1 SER SSER 13 [Letter Item 16]

9. Westinghouse Letter WBT-D-1321, Dated December 2, 2009 to TVA, Final Response to WBT-TVA-0713 Unit 2 WCAP Reviews [Letter Item 16]

10. TVA Letter to NRC dated February 5, 2010, Watts Bar Nuclear Plant (WBN) Unit 2, Information Available for NRC Review and Setpoint Methodology for Protection Systems,

[Letter Item 17]

11. TVA Letter to NRC Dated May 13, 2010, Watts Bar Nuclear Plant (WBN) Unit 2, Transmittal of TVA EEB-TI-28, Branch Technical Instruction, Setpoint Calculations [Letter Item 17]

12. TVA Letter to NRC Dated April 27, 2010, Watts Bar Nuclear Plant (WBN) Unit 2, Staff Information Requests Resulting from NRC December 15, 2009, Meeting with Tennessee Valley Authority (TVA) Regarding Digital Instrumentation and Controls Review and NRC Clarifications to the Requests Provided During February 18, 2010, Telephone Conference Call (TAC No. ME0853) [Letter Items 2, 3 and 4]

13. Not Used

14. TVA Letter to NRC dated June 18, 2010, Watts Bar Nuclear Plant (WBN) Unit 2, Instrumentation and Controls Staff Information Requests [Letter Item 69a-]

15. TVA Letter to NRC Dated July 14, 2010, Watts Bar Nuclear Plant (WBN) Unit 2, Additional Information Regarding Final Safety Analysis Report (FSAR), Chapter 7, Instrumentation and Controls Review, Requested Common Q Proprietary Documents. [Letter Item 21]

16. Not Used

17. Westinghouse Letter WBT-D-2340, Dated August 30, 2010, Tennessee Valley Authority, Watts Bar Nuclear Plant, Unit 2, FSAR Markups Units 1 and 2 118% vs 121% and Correction to RAI Response SNPB 4.3.2-7 [Letter Items 1 and 40]

1

Enclosure 3 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval References

18. TVA Letter to NRC Dated March 12, 2010, Watts Bar Nuclear Plant (WBN) Unit 2, Additional Information Regarding Final Safety Analysis Report (FSAR), Chapter 7, Instrumentation and Controls Review [Letter Items 5, 6 and 71]

19. TVA Letter to NRC Dated April 8, 2010 Watts Bar Nuclear Plant (WBN) Unit 2, Additional Information Regarding Final Safety Analysis Report (FSAR), Chapter 7, Instrumentation and Controls Review, Requested Common Q Proprietary Documents [Letter Items 8 and 12]

20. TVA Letter to NRC Dated July 30, 2010, Watts Bar Nuclear Plant (WBN) Unit 2, Instrumentation and Controls Staff Information Requests, and NRC/TVA Telecom on July 6, 2010, Information Requests [Letter Items 52 and 69c-]

21. Westinghouse Letter WBT-D-2024 to TVA Dated June 9, 2010, NRC Access to Common Q Document at the Westinghouse Rockville Office [Letter Item 10]

22. Westinghouse Letter WBT-D-1961 to TVA Dated May 21, 2010, NRC Access to Common Q Document at the Westinghouse Rockville Office [Letter Items 14 and 15]

23. TVA Letter to NRC Dated September 1, 2010, Watts Bar Nuclear Plant (WBN) - Unit 2 -

Final Safety Analysis Report (FSAR), Amendment 100 [Letter Items 6, 7, 16, 17, 22, 23, 24, 25, 26, 27, 28, 36, 54 and 86]

24. TVA Letter to NRC Dated May 27, 2010,, Watts Bar Nuclear Plant (WBN) - Unit 2 - Final Safety Analysis Report (FSAR), Amendment 99 [Letter Items 42]

2

Enclosure 4 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval Commitments

1. Common Q PAMS hardware details will be provided when the hardware drawings are updated to the as-tested configuration. TVA will submit a hardware listing to NRC by March 11, 2011. (RAI Item Number 14 [NRC RAI Matrix Item 120]). [Cover Letter, Reference 2]

2. The Common Q PAMS Factory Acceptance Test report will be submitted to NRC by February 25, 2011. (RAI Item Number 14 [NRC RAI Matrix Item 120]). [Cover Letter, Reference 2]

3. Attachment 36 contains Foxboro proprietary drawings 08F802403-SC-2001 sheets 1 through 6. An affidavit for withholding and nonproprietary versions of the drawings will be submitted by January 31, 2011 [Letter Item 1(b)].

4. Item (4) will be addressed by Westinghouse developing a WBN Unit 2 Common Q PAMS Specific Test Plan to compensate for the fact that NRC disapproved WNA-PT-00058-GEN during the original Common Q review. TVA will submit the test plan document to NRC by November 30, 2010. NRC RAI Matrix Item 245 tracks the commitment to develop and submit the WBN Unit 2 Specific Test Plan [Letter Item 8].

5. Item (5) WNA-TP-00357-GEN is superseded by the SPM compliance matrix in the next revision to the Common Q PAMS Licensing Technical Report. TVA will submit the revised report to NRC by October 22, 2010 [Letter Item 8].

6. Attachment 37 contains the proprietary version of the Common Q PAMS FMEA and the affidavit for withholding. The nonproprietary versions will be submitted by November 5, 2010 [Letter Item 13].

7. WCAP-13869 Revision 1 was previously reviewed under WBN Unit 1 SER SSER 13 (Reference 8). Unit 2 references Revision 2. An analysis of the differences and their acceptability will be submitted to NRC by November 15, 2010 [Letter Item 16(Q2)].

8. Per Westinghouse letter WBT-D-2340, TENNESSEE VALLEY AUTHORITY WATTS BAR NUCLEAR PLANT UNIT 2 FSAR Markups Units 1 and 2 118% vs 121 % and Correction to RAI Response SNPB 4.3.2-7, (Reference 17) the 118% value should be 121%. Depending on the use in the FSAR either 118% or 121% is the correct value. As a result of the question, Westinghouse reviewed all locations where either 118% or 121% are used and the context of use and provided a FSAR markup to reflect the correct value at the specific location. These changes will be incorporated in FSAR Amendment 101 [Letter Item 37].

9. For the purposes of measuring reactor coolant flow for Reactor Protection functions, elbow taps are used for both Unit 1 and 2. The discussion and equation are valid for establishing the nominal full power flow which is used to establish the Reactor Protection System low flow trip setpoint. However the method used to verify reactor coolant flow, as required by the Technical Specifications, is not the same. Unit 1 uses a simplified methodology based on elbow tap P measurements correlated with precision calorimetric data over several cycles of operation as described in FSAR Reference 17, WCAP-16067, Rev 0, RCS Flow Measurement Using Elbow Tap Methodology at Watts Bar Unit 1. The plan is for Unit 2 to transition to this method after sufficient data is obtained. Pending this transition, 7.2.2.1.2 will be revised to read as follows:

1

Enclosure 4 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval Commitments Nominal full power flow is established at the beginning of each fuel cycle by either elbow tap methodology or, performance of the RCS calorimetric flow measurement. Unit 1 utilizes elbow tap methodology Reference [17]. Unit 2 utilizes the RCS calorimetric flow measurement. The results are used to normalize the RCS flow indicators and provide a reference point for the low flow reactor trip setpoint.

This change will be incorporated in FSAR Amendment 101 [Letter Item 40].

10. The Common Q PAMS Licensing Technical Report has been revised to reflect the deletion of the OM connection to the plant computer. The remaining Common Q PAMS documents will be corrected at the next revision. The Common Q PAMS schedule is currently under revision. The revised schedule will be submitted to NRC by October 22, 2010 [Letter Item 18].

11. The scope of the WBN BISI indications are based on engineering calculation WBPEVAR8807025 Rev. 7 (Attachment 10). This calculation has not been updated for Unit 2.

The calculation does include Common and Unit 2 equipment required to support Unit 1 operation. The calculation will be submitted to NRC by February 14, 2011 [Letter Item 62F].

12. Section 7.7.1.11 will be added to FSAR Amendment 101 to provide a discussion of the Distributed Control System [Letter Item 65].

13. Revision 1 of the Common Q PAMS Licensing Technical Report will provide more detailed information on the changes to the platform. Revision 1 of the Licensing Technical Report will be submitted to the NRC by October 22, 2010 [Letter Item 66].

14. Revision 2 of the Common Q PAMS Licensing Technical Report will include the applicability of the guidance in the Common Q PAMS Topical Report. Revision 1 of the Licensing Technical Report will be submitted to NRC by December 7, 2010 [Letter Item 66].

15. Not used

16. Attachment 41 contains the proprietary version of the Common Q Software Requirements Specification Post Accident Monitoring System 00000-ICE-3238 Rev. 5 and the affidavit for withholding. The nonproprietary version will be submitted to NRC by April 8, 2011 [Letter Item 96].

17. The scope of NABU-DP-00014-GEN includes the design and implementation processes for the application development. For a more detailed description of the design process described in NABU-DP-00014-GEN, please refer to the Design Process for AP1000 Common Q Safety Systems, WCAP-15927 on the AP1000 docket. Since this is a Westinghouse process document that is not specifically referenced in the SRS, it will be removed in the next revision of the document. The next revision of the SRS will be submitted to NRC by October 29, 2010 [Letter Item 31(a)].

18. The Unit 2 loops in service for Unit 1 that are scheduled to be transferred to the Foxboro Spec 200 hardware will be transferred prior to Unit 2 fuel load [Letter Item 93].

2

Enclosure 4 TVA Letter Dated October 5, 2010 Responses to Licensee Open Items to be Resolved for SER Approval Commitments

19. The document that provides the most detailed information is the CERPI System Requirements Specification WNS-DS-00001-WBT Rev. 2. The proprietary version of this document and the affidavit for withholding are contained in Attachment 29. The demarcated proprietary and nonproprietary documents will be submitted to NRC by November 12, 2010

[Letter Item 92].

20. The next IV&V report will include the Design Phase Requirements Traceability Matrix. The Design Phase IV&V Report will be submited to NRC by Februay 11, 2011 [Letter Item 15].

21. TVA uses double-sided methodology for Reactor Trip and ESFAS parameters. The FSAR will be clarified in a future amendment to reflect this methodology [Letter Item 20].

22. The OM interface, however, creates an additional digital communications path to a non-safety-related system. During the design review, TVA commented that the path needed to be eliminated or isolated. The final determination was made to eliminate the path.

Westinghouse will eliminate the description of this path from the associated documentation by January 31, 2011 [Letter Item 18].

3