GO2-12-135, Response to Request for Additional Information Regarding License Amendment Request to Implement Prnmiarts/Mellla

Response to Request for Additional Information Regarding License Amendment Request to Implement Prnmiarts/Mellla

ML122920735
Person / Time
Site:	Columbia
Issue date:	10/05/2012
From:	Sawatzke B Energy Northwest
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
GO2-12-135
Download: ML122920735 (62)

Text

i Bradley J. Sawatzke ENERGY Columbia Generating Station ENERGY P.O. Box 968, PE08 Richland, WA 99352-0968 NORTHW EST Ph. 509.377.43001 F 509.377.4150 bjsawatzke @ energy-northwest.com Proprietary-Withhold under 10 CFR 2.390. Attachment 1 and Enclosure 1 contain PROPRIETARY information.

October 5, 2012 G02-12-135 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

Subject:

COLUMBIA GENERATING STATION, DOCKET NO. 50-397 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNMIARTS/MELLLA

References:

1) Letter, G02-12-017, dated January 31, 2012, BJ Sawatzke (Energy Northwest) to NRC, "License Amendment Request to Change Technical Specifications in Support of PRNM / ARTS / MELLLA Implementation" (ADAMS Accession No. ML12040A072)

.2) Letter dated September 5, 2012, NRC to ME Reddemann (Energy Northwest), "Columbia Generating Station - Request for Additional Information Regarding License Amendment Request to Implement PRNM/ARTS/MELLLA (TAC NO. ME7905)" (ADAMS Accession No. ML12249A011)

Dear Sir or Madam:

By Reference 1, Energy Northwest requested approval of a license amendment request to revise the Columbia Generating Station Technical Specifications to reflect improvements in the Average Power Range Monitor / Rod Block Monitor Technical Specifications (ARTS) and expand the facility operating domain to reflect operations using the Maximum Extended Load Line Limit Analysis (MELLLA). These improvements coincide with the installation of the digital General Electric-Hitachi (GEH)

Nuclear Measurement Analysis and Control (NUMAC) Power Range Neutron Monitoring (PRNM) System.

Via Reference 2, the Nuclear Regulatory Commission (NRC) requested additional information related to the Energy Northwest submittal. Transmitted herewith in is the Energy Northwest response to the request for additional information.

When Attachment 1 and Enclosure 1 are removed from this letter, the letter and remaining Attachments are NON-PROPRIETARY.

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNMIARTS/MELLLA Page 2 Regulatory commitments are identified in Attachment 5. Should you have any questions or require additional information regarding this matter, please contact Mr. ZK Dunham, Licensing Supervisor,. at (509) 377-4735. and Enclosure 1 contain proprietary information as defined by 10 CFR 2.390. GEH, as the owner of the proprietary information, has executed the affidavit, included in Attachment 3, which identifies that the enclosed proprietary information has been handled and classified as proprietary, is customarily held in confidence, and has been withheld from public disclosure. The proprietary information was provided to Energy Northwest in a GEH transmittal that is referenced by the affidavit. The proprietary information has been faithfully reproduced in the respective Attachment and Enclosure such that the affidavit remains applicable. GEH hereby requests that the enclosed proprietary information be withheld from public disclosure in accordance with the provisions of 10 CFR 2.390 and 9.17. Information that is not considered proprietary is provided in Attachment 2.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the date of this letter.

Respectfully, BJ Sawafk Vice President, Nuclear Generation & Chief Nuclear Officer - Response to Request for Additional Information (Proprietary version) - Response to Request for Additional Information (non-proprietary version) - Affidavit - Revised TS Bases Page 3.3.1.1-29 (for information only) - List of Commitments - NUMAC Power Range Neutron Monitoring (PRNM) Components 268X1 331 TCGO01, 268X1 332TCG001, G002 268X1 333TCG001 Qualification Summary cc:

NRC Region IV Administrator NRC NRR Project Manager NRC Senior Resident Inspector/988C AJ Rapacz - BPA/1 399 WA Horin - Winston & Strawn JO Luce - EFSEC RR Crowley - WDOH

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Response to Request for Additional Information (non-proprietary)

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATGON REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 1 of 52 Response to Request for Additional Information NRC Request:

1. This request relates to Enclosure 2, Attachment 2, "NEDC-33685P, Revision 1,

'Digital I&C-ISG-06 Compliance for Columbia Generating Station NUMAC Power Range Neutron Monitoring Retrofit Plus Option III Stability Trip Function,'

(ML12040A082)," paragraph 1.4.4, "Communication Modules."

Are all the fiber-optic communications that are used in the Power Range Neutron Monitoring System (PRNMS) for digital data communication permanently constrained to the unidirectional mode or do any of them support reconfiguration to be bidirectional? If a fiber-optic communication supports reconfiguration to be bidirectional, then can this feature be reconfigured remotely (i.e., from outside a safety channel's boundary)?

Please confirm that each fiber-optic interface used is fixed unidirectional and cannot be reconfigured or could identify any that are reconfigurable to be bidirectional. If single-mode simplex fiber connection is used throughout to achieve each point-to-point connection and/or distinct fiber-optic transmitters and receivers are used rather than a configurable transceiver, then please state this and provide associated vendor part numbers. If any fiber-optic interface is reconfigurable, then please provide an explanation of what detects and reports this reconfiguration as an equipment failure/error.

Response

NEDC-33685P (Reference 1-1), describes a ((

)) Therefore, all fiber-optic communications used in PRNMS are constrained to unidirectional mode and cannot be reconfigured to be bidirectional.

Reference 1-1, paragraph 1.4.4, "Communication Modules" describes three types of fiber-optic communication modules. These modules are the Fiber Direct Data Interface (FDDI)

Communication Module (paragraph 1.4.4.1), General Electrical Data Acquisition &

Communication (GEDAC) Module (paragraph 1.4.4.3) and the Broadcaster Module (paragraph 1.4.4.4). Also, an additional type of fiber-optic communication module is described in paragraph 1.4.5.2, 'Two-Out-Of-Four Fiber Optic Interface Card." These four types of fiber-optic communication interfaces are discussed below.

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 2 of 52 Reference 1-1.

GE Hitachi Nuclear Energy, "Digital I&C-ISG-06 Compliance for Columbia Generating Station NUMAC Power Range Monitoring Retrofit Plus Option III Trip Function," NEDC-33685P, Revision 1, January 2012 (ADAMS Accession No. ML12040A74).

NRC Request:

2. This request relates to Enclosure 2, Attachment 2, "NEDC-33685P, Revision 1,

'Digital I&C-ISG-06 Compliance for Columbia Generating Station NUMAC Power Range Neutron Monitoring Retrofit Plus Option III Stability Trip Function,'

(ML12040A082)," paragraph 1.4.13, "Communications."

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 3 of 52 With regard to the communication of gain adjustments from ((

)), please clarify what type of switch is used within each PRNMS channel's instrument chassis to perform or accept instrumentation gain and calorimetric gain adjustments. Is it a physical hardware switch with electrical contacts or something else? Please describe the characteristics as well as the vendor's name and model number.

Response

A physical keylock switch is used on the average power range monitor (APRM) instrument front panel to place the instrument in the INOPerative mode. ((

))

NRC Request:

3. This request relates to Enclosure 2, Attachment 2, "NEDC-33685P, Revision 1,

'Digital I&C-ISG-06 Compliance for Columbia Generating Station NUMAC Power Range Neutron Monitoring Retrofit Plus Option III Stability Trip Function,'

(ML12040A082)," paragraph 1.4.4, "Communication Modules."

With regard to communication among the PRNMS components and its interfacing systems, please provide the communication diagrams for the different types of communication used (e.g., the communication diagrams should clearly indicate whether the communication is one-way or two-way). The communication diagrams should clearly identify whether the communication is relied upon to perform a safety function, and should clearly identify the isolation boundary for redundant safety-related components (interdivisional or safety with non-safety) that provides electrical and data independence. Please also describe the communication protocols for each of the communication systems used. It is the staff's understanding that ((

)) Please confirm if this is true or describe any other

((I))

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 4 of 52

Response

Communication Diagram A diagram with the requested information is provided in Figure 3-1. This diagram shows the links associated with each of the four (4) communication modules discussed in Section 1.4.4 of NEDC-33685P, Revision 1 (Reference 3-1). These communication modules are:

Fiber Direct Data Interface (FDDI) Module (Section 1.4.4.1 of Reference 3-1)

GE Input/Output (I/O) Module (Section 1.4.4.2 of Reference 3-1)

GE Data Acquisition & Communication (GEDAC) Module (Section 1.4.4.3 of Reference 3-1)

Broadcaster Module (Section 1.4.4.4 of Reference 3-1)

This RAI also requested confirmation regarding Ethernet-based communications, thus the diagram shows the use of this type of communication.

Figure 3-1 indicates whether communication is 1 -way or 2-way, shows the boundaries between safety and non-safety equipment, and shows the boundaries between the redundant safety divisions. The diagram also includes a note that states communication from the non-safety systems is not relied upon to perform any safety functions.

Figure 3-1 shows details for average power range monitor (APRM) Channel 1 and rod block monitor (RBM) Channel A. Communication involving the other channels is the same. There are no other types of communication that cross the boundaries between redundant safety divisions or the boundary between safety and non-safety equipment. For additional information about the communication involving the other channels, please see Figure 6 in NEDC-33696P, Revision 1 (Reference 3-2). The diagram provided in response to this RAI is intentionally similar to the figure in NEDC-33696P, Revision 1 (Reference 3-2).

Please note that for fiber optic communication, double ended arrows mean that information goes two ways but should not be interpreted to mean the bi-directional communication occurs on a single fiber. For more information about this topic, please see the response to RAI #1.

Independence Electrical independence in the power range neutron monitoring system (PRNMS) is discussed in Section 9.2.6 of NEDC-33685P (Reference 3-1), and Section 4 of NEDC-33697P (Reference 3-3). The important point here is that when nuclear measurement analysis and control (NUMAC) components communicate across a safety-to-non-safety boundary or across a divisional boundary, this does not compromise electrical independence because the communication is by fiber optic cables.

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 5 of 52 Communication independence in the PRNMS is discussed in Section 7 of NEDC-33685P (Reference 3-1), and Section 2 and Enclosure 1 of NEDC-33697P (Reference 3-3). In particular, Enclosure 1 of NEDC-33697P provides a matrix that demonstrates compliance with DI&C-ISG-04, as well as additional information that was provided in response to RAI's for a previous similar application.

Communication Protocols (1) FDDI A GEH proprietary specification defines the timing and content of messages, ((

I]

The APRM and RBM channels use FDDI communication to send and receive LPRM, APRM, and recirculation flow values, status information and gain factors between instruments. For more detailed information about the process of gain adjustment using values that originate at the plant process computer network, please see Section 3.2 of

..Enclosure 1 in NEDC-33697P (Reference 3-3).

FDDI communication between the APRM and RBM instruments crosses the boundary between safety and non-safety, but is not used for the PRNMS safety functions. The safety system does not rely upon information from the non-safety system in order to perform the safety function. The FDDI communication between the APRM master and slave instruments is used for the PRNMS safety functions, but does not cross any boundary between safety divisions or between safety and non-safety. For information about how the GEH protocols meet DI&C-ISG-04, please see Enclosure 1 to NEDC-33697P (Reference 3-3). For more information about the FDDI communication module in general, please see Section 5.3.3.9 of NEDC-3241 OP-A (Reference 3-4).

(2) Broadcaster A GEH proprietary specification defines the timing and content of the messages, ((

))

The Broadcaster modules in the APRM instruments send trip signals and self-test messages to the 2-Out-Of-4 Logic Modules, and receive bypass switch inputs and self-test messages from the 2-Out-Of-4 Logic Modules.

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 6 of 52 Broadcaster communication crosses the boundary between redundant divisions, but does not cross the boundary between safety and non-safety. Broadcaster communication from the APRM instrument to the 2-Out-Of-4 Logic Modules is used for the PRNMS safety functions, but communication from the 2-Out-Of-4 Logic Modules to the associated APRM instrument is not. For information about how the GEH protocols meet DI&C-ISG-04, please see Enclosure 1 to NEDC-33697P (Reference 3-3). For more information about the Broadcaster communication module in general, please see Section 5.3.3.13 of NEDC-3241 OP-A (Reference 3-4).

(3) GEDAC A GEH proprietary specification defines the timing and content of the messages. ((

1]

The GEDAC communication occurs between the RBM channels and the NIC, which is the PRNMS interface to the Cyber Security Interface Computer.

GEDAC communication does not cross any boundary between safety divisions or any boundary between safety and non-safety. It only involves non-safety equipment. GEDAC Communication is not used for the PRNMS safety functions. The safety system does not rely upon information from the non-safety system in order to perform the safety function. For more information about the GEDAC communication module, please see Section 5.3.3.12 of NEDC-3241 OP-A (Reference 3-4).

(4) GE I/O The GE I/O communication module performs serial communication between the RBM channels and the selected rod input data originating from the reactor manual control system (RMCS).

GE I/O communication does not cross any boundary between safety divisions or any boundary between safety and non-safety. It only involves non-safety equipment. GE I/O communication is not used for the PRNMS safety functions. The safety system does not rely upon information from the non-safety system in order to perform the safety function.

(5) Ethernet The staff understanding about Ethernet communication is correct. That is, ((

1]

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 7 of 52 Ethernet communication does not cross any boundary between safety divisions or any boundary between safety and non-safety. Ethernet communication is not used for the PRNMS safety functions. The safety system does not rely upon information from the non-safety system in order to perform the safety function.

References 3-1.

GE Hitachi Nuclear Energy, "Digital I&C-ISG-06 Compliance for Columbia Generating Station NUMAC Power Range Monitoring Retrofit Plus Option III Trip Function," NEDC-33685P, Revision 1, January 2012 (ADAMS Accession No. ML1 2040A74).

3-2.

GE Hitachi Nuclear Energy, "Columbia Generating Station Power Range Neutron Monitoring System Architecture & Theory of Operations Report," NEDC-33696P, Revision 1, July 2012 (ADAMS Accession No. ML12249A011).

3-3.

GE Hitachi Nuclear Energy, "Columbia Generating Station Power Range Neutron Monitoring Design Analysis Report, NEDC-33697P, Revision 1, January 2012 (ADAMS Accession No. ML12040A077).

3-4.

(a)

GE Nuclear Energy, "Nuclear MeasurementAnalysis and Control Power Range Neutron Monitor (NUMAC PRNM) Retrofit Plus Option III Stability Trip Function," NEDC-32410P-A Volume 1, October 1995.

(b)

GE Nuclear Energy, "Nuclear Measurement Analysis and Control Power Range Neutron Monitor (NUMAC PRNM) Retrofit Plus Option III Stability Trip Function," NEDC-3241 OP-A Volume 2 -- Appendices, October 1995.

(c)

GE Nuclear Energy, "Nuclear Measurement Analysis and Control Power Range Neutron Monitor (NUMAC PRNM) Retrofit Plus Option III Stability Trip Function," NEDC-3241 OP-A, Supplement 1, November 1997.

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNWARTS/MELLLA Page 8 of 52

.1 Figure 3-1. NUMAC PRNMS Communication Diagram. Details are shown for communication to/from APRM Channel 1 and to/from RBM Channel A. The details for the other APRM channels and for RBM Channel B are similar. In particular they do not introduce new types of communication across the boundaries between redundant safety divisions or between safety and non-safety equipment.

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 9 of 52 NRC Request:

4. This request relates to Enclosure 2, Attachment 9, "NEDC-33685, Revision 1,

'Digital I&C-ISG-06 Compliance for Columbia Generating Station NUMAC Power Range Neutron Monitoring Retrofit Plus Option III Stability Trip Function,'

(ML12040A074)."

Paragraph 4.4.3.3, Software Design Specification DI&C ISG-06 D.4.4.3.3, refers to References 68 and 69 as specifications for functional software design specifications and data sheets for the Average Power Range Monitor (APRM) software functional design. Please identify and submit the document that describes the MELLLA functional software design specifications/data sheets.

Response

A software design specification (SDS) is not created for the MELLLA function. Software design specifications are only created for modules that contain software. For the Columbia Generating Station (CGS) average power range monitor (APRM) instrument, there is an SDS for the functional, display, automatic signal processor (ASP) stability, and ASP scanning modules.

Option III supports MELLLA operation, and it is implemented within the APRM functional and ASP Stability modules. The APRM Functional SDS specification is 26A8428, and the CGS associated datasheet is 26A8428TC. The ASP stability SDS is 26A7713.

Note the APRM SDS's, references 68 and 69 of NEDC-33685P (Reference 4-1), were changed to 26A8428 and 26A8428TC during the design phase.

Reference 4-1.

GE Hitachi Nuclear Energy, "Digital I&C-ISG-06 Compliance for Columbia Generating Station NUMAC Power Range Monitoring Retrofit Plus Option III Trip Function," NEDC-33685P, Revision 1, January 2012 (ADAMS Accession No. ML1 2040A74).

NRC Request:

5. This request relates to Enclosure 2, Attachment 2, "NEDC-33685P, Revision 1,

'Digital I&C-ISG-06 Compliance for Columbia Generating Station NUMAC Power Range Neutron Monitoring Retrofit Plus Option III Stability Trip Function,'

(ML12040A082)."

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 10 of 52 Paragraph 4.4.5.2.7, Design Verification, in part states the following:

'All design verifications, including verification by an individual within the same organization, must abide by the following independence requirements for the RV

[Responsible Verifier]. Reference 29, Section 7.1.3, states that the following independence criteria shall be met.

((i 1]

The use of words, ((

)) in the above three sentences implies that the responsible verifier (RV) could have a role in the design process. Please note that the NUMAC SVVP (Software Verification and Validation Plan), Section 2.2, in Appendix A to the document states in part that ((

)) References 34 and 42 specify various requirements for independent design verification. The GEH (General Electric-Hitachi) design process requires independent design verification at various stages of the design. The words

((

)) have been used while describing the role of the RVs in the design verification process which is not in compliance with the concept of independent design verification. Please justify the use of words ((

)) as stated and used above. This clarification is required to ensure that RV is independent of the design process.

Response

GEH policies and procedures require that the responsible verifier (RV) cannot have a role in the design process for the work he or she is verifying. By itself, the quoted part of Reference 5-1, paragraph 4.4.5.2.7, appears to imply that the RV (in some cases) may have a role in the design process. In the broader context of the procedure the quote originated from, it is clear that the RV is not allowed to have a role in the design.

[I

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 11 of 52 From the broader context, the RV that is selected is not allowed to have a role in the design process for the work he or she is verifying. In particular, Reference 5-2 Section 7.1.3.2 states that the RV is someone who ((

)). In this case the words "may not" are properly interpreted as "shall not." Therefore GEH policies and procedures are in compliance with the concept of independent design verification.

References 5-1.

GE Hitachi Nuclear Energy, "Digital I&C-ISG-06 Compliance for Columbia Generating Station NUMAC Power Range Monitoring Retrofit Plus Option III Trip Function," NEDC-33685P, Revision 1, January 2012 (ADAMS Accession No. ML1 2040A74).

5-2.

Common Procedure - Independent Design Verification, CP-03-09, Revision 3.

NRC Request:

6. This request relates to Enclosure 2, Attachment 9, "NEDC-33685, Revision 1,

'Digital I&C-ISG-06 Compliance for Columbia Generating Station NUMAC Power Range Neutron Monitoring Retrofit Plus Option III Stability Trip Function,'

(ML12040A074)."

Paragraph 5.2, Equipment qualification, in part states that:

New PRNM equipment being installed in the main control room must meet the environmental design conditions for the main control room. The CGS specific analyses and testing performed to support qualification of the CGS PRNM equipment as installed in CGS is documented (Reference 73).

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 12 of 52 Please submit an EQ summary report that provides sufficient information for staff review to ensure the adequacy of the tests and test results.

Response

Please find the attached environmental qualification summary report in Enclosure 1.

NRC Request:

7. This request relates to Enclosure 2, Attachment 9, "NEDC-33685, Revision 1,

'Digital I&C-ISG-06 Compliance for Columbia Generating Station NUMAC Power Range Neutron Monitoring Retrofit Plus Option III Stability Trip Function,'

(ML12040A074)."

Paragraph 9.3.8, Clause 6.8 Setpoints states, in part, the following:

'"he margin between the AL [analytic limit] and the final NTSP [nominal trip setpoint]

is at least equal to, and generally greater than that needed to meet the 95%

probability requirement of RG [Regulatory Guide] 1.105.

GEH's setpoint methodology for operating plants uses single-sided distributions in the development of A Vs [allowable values] and NTSPs for instrument channels that provide trips when the process variable being measured approaches the setpoint in one direction, as described in ISA [Instrument Society of America] standard 67.04 part IH."

Please be advised that NRC has not endorsed ISA Standard 67.04 part I1. RG 1.105, Rev. 3 (issued in December 1999) states, in part, "That is, there is a 95%

probability that the constructed limits contain 95% of the population of interest for the surveillance interval selected." The licensee statement addresses the part regarding the 95% of the population only. Please explain specifically how you ensure the constructed limits contain 95% of the population with a confidence/probability of 95%.

Response

1. Overview The setpoints (or constructed limits) are determined to assure with high confidence (95%)

that 95% of the data due to errors is on the conservative side of the AL. To assure such high confidence, the margins are constructed using conservative errors that have high confidence of not being exceeded. For example when nuclear measurement analysis and control (NUMAC) local power range monitor (LPRM) cards used in the NUMAC power

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 13 of 52 range average power range monitor (APRM) instrument specify a maximum linearity error of 1%, this specification implies that all of the LPRM cards will have a linearity error equal to or less than 1%. Data taken on a large number of NUMAC LPRM cards have confirmed this, so there is high confidence (95%) that the 1 % linearity error specification is applicable to the entire NUMAC LPRM card population. The error is random and for such random instrumentation errors it is valid to consider that the population error distribution is normal.

Thus, for the NUMAC LPRM card, the 1 % error can be treated as a 3-sigma normally distributed error with virtually 100% confidence. If this was the only error to be considered in the margin between the constructed setpoint and the AL, then for the case where the AL is approached from one direction, the margin that assures with 95% confidence that 95% of the error data would be on the conservative side of the AL would be 1.645-sigma. Because for this example the 3-sigma is 1%, the margin would be 1.645 * (1/3) % or 0.548%. For a normal error distribution, the 1.645-sigma margin assures 95% probability of not exceeding the AL when the AL is approached from one direction, and is well described in statistics texts (Reference 7-1) and recent communications with the NRC (Reference 7-2). The 95%

confidence in the margin is assured by ensuring that the error specification (1% for this example) used to calculate the margin has high (95%) confidence. For the real setpoint margin calculation many additional independent errors need to be considered, and the composite standard deviation of all pertinent random errors is obtained by the square root of the sum of the squares (SRSS) addition of the standard deviation (or sigma) of each independent random error component. The 95% confidence in the margin for this composite error case is assured by ensuring with high confidence (95%) that the composite standard deviation is conservative. This means that the actual standard deviation is no larger than the computed composite standard deviation at a 95% confidence level. A description of the errors that are considered in determining the margins for the constructed setpoints in GEH setpoint methodology is given in Section 2.

2. GEH Setpoint Methodology and APRM Setpoints This section describes the GEH setpoint methodology and the pertinent errors that are considered in determining the margins for the constructed setpoints. Section 2.1 provides a description for general setpoints and Section 2.2 specifically addresses the APRM setpoints contained in the NUMAC power range neutron monitor (PRNM).

2.1 General In GEH setpoint methodology the key constructed limits are the allowable value (AV), the first nominal setpoint (NTSP1) also referred to as the limiting trip setpoint (LTSP), and the final adjusted setpoint (NTSPF). The setpoints are based on the GEH setpoint methodology contained in NEDC-31336P-A (Reference 7-3) which has been approved by the NRC.

During the original NRC review of the GEH setpoint methodology the NRC Safety Evaluation Report (SER) concluded that the GEH setpoint methodology used acceptable

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 14 of 52 methods for calculating setpoints that provide 95% probability at high confidence (95%) of getting channel trip before the process variable reaches the analytical limit (AL).

A pictorial representation of the methodology for calculating the setpoints is shown in Figure RAI 7-1.

Figure RAI 7-1: GEH Setpoint Methodology The GEH setpoint calculation methodology determines an AV that has margin to the AL based on all errors for an instrument channel during operating conditions, except drift. ((

)) Conservative values for each of the error components are used to assure, with high confidence (95%) that ((

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 15 of 52 I].

The GEH methodology then calculates an initial value for the nominal trip setpoint (NTSP1),

which has margin to the AL, based on all errors (i.e., all errors used in the AV calculation and also including conservative values for drift of all devices in the channel), as illustrated in Figure RAI 7-1. NTSP1 is calculated using all errors (including drift) and is referred to as the Limiting Trip Setpoint (LTSP) because it meets the Regulatory Guide (RG) 1.105 Revision 3 (henceforth referred to as RG 1.105 in this document) requirement of providing 95%

probability of not exceeding the AL with high confidence (95%).

Although NTSP1 has the required margin to the AL to meet RG 1.105, GEH methodology also requires the final setpoint to have an adequate margin to the AV, which is referred to as the LER (Licensee Event Report) avoidance margin. The LER margin is prescribed by GEH methodology. Therefore, in the GEH setpoint calculation process, the setpoint is adjusted conservatively from NTSP1 to the final value (NTSPF) to assure with high confidence (95%)

)) as defined by the ALIAV margin provided in GEH methodology. NTSPF is always equal to or more conservative (further from the AL) than NTSP1. Thus generally, and specifically for PRNM setpoints, the final setpoint (NTSPF) is more conservative than NTSP1 and has margin to the AL that is significantly larger than the AL/NTSP1 margin required to meet RG 1.105. Therefore generally, and specifically for PRNM, the final setpoint (NTSPF) implemented in the instrument conservatively exceeds the 95% RG 1.105 probability requirement for not exceeding the AL.

Note that meeting the RG 1.105 requirement of 95% probability of not exceeding the AL at 95% confidence is assured by the following two basic steps:

Using values for the random instrument errors, measured in terms of standard deviation (i.e., sigma) of the normal error distribution function that has high confidence, and statistically combining the standard deviation of pertinent random errors for each device in the channel using the Square Root of the Sum of the Squares (SRSS) technique gives the channel error standard deviation (StndDev) that has high confidence (95%). Also adding all the non-conservative bias errors algebraically gives the channel bias error (B) that is incorporated in the setpoint margin calculation.

" Calculating the setpoint margins by multiplying StndDev by 1.645 for setpoints where the variables approach the setpoints in one direction as described in Reference 7-3, and algebraically adding the channel bias error B. It has been shown from statistical first principles (Reference 7-2) that when StndDev is known to 95% confidence, a setpoint

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 16 of 52 margin of B + 1.645

• StndDev meets the RG 1.105 setpoint margin 95/95 requirement (i.e., it provides 95% probability at 95% confidence) of not exceeding the AL for setpoints approached from one direction. Use of the single-sided 1.645 statistical factor for setpoint margin calculations where the variable approaches the setpoint from one direction, has been endorsed by the NRC staff for GEH setpoint methodology (Reference 7-3) and also by Instrumentation Society of America (ISA) Standard ISA-RP67.04, Part II, 1994 (and later revision ISA-RP67.04.02-2000).

During NRC review of the GEH setpoint methodology, GEH presented field data that demonstrated, and the NRC agreed (Reference 7-3), that the margins calculated by GEH setpoint methodology bounded 95% of the data with high confidence (95% confidence limits).

Note that the final setpoint margin to the AL is the AL/NTSPF margin. This is the margin that needs to be large enough to meet or exceed the 95/95 requirements specified in RG 1.105.

Thus, since the AL/NTSP1 meets the 95/95 margin requirement and NTSPF is generally more and never less conservative than NTSP1, the AL/NTSPF margin is therefore generally more and never less conservative than that required to meet the 95/95 requirement. Note that the larger the ALINTSPF margin, the more conservative the setpoint is with respect to the 95/95 requirement.

2.2 APRM Setpoints The APRM neutron flux loop consists of the pre-assigned number of LPRM sensors connected in parallel to the PRNM LPRM signal processing electronics, and the flow loop consists of the flow sensors from the recirculation loops connected in parallel to the PRNM flow signal processing electronics. Errors in both the neutron flux loop and the flow loop are included in the APRM setpoint calculations. Following is a list of errors used in this setpoint calculation:

PMA (includes random errors due to APRM tracking and neutron noise for the neutron flux loop and flow noise error for the Recirculation Flow loops).

" PEA (includes bias and random errors due to non-linearity and drift of the LPRM detectors, and error due to accuracy of the flow elements used in the Recirculation Loop flow measurements).

" Accuracy of the PRNM APRM neutron flux measurement electronics and PRNM APRM flow measurement electronics under trip conditions (same as accuracy under calibration conditions).

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 17 of 52 Drift of PRNM APRM neutron flux measurement electronics and PRNM APRM flow measurement electronics between calibrations.

PRNM calibration errors.

" Accuracy of the flow transmitters.

Drift of the flow transmitters.

" Calibration error of the flow transmitters.

Values of these errors for the Columbia PRNM equipment are shown in the summary APRM Inputs/Outputs document (Reference 7-4). The PMA error and PEA errors are part of the historical GEH design base and there is high confidence that they are conservative. The errors in the PRNM electronics are due to errors in the PRNM analog front end electronics that interface with the LPRM sensors and the recirculation loops flow sensors. The rest of the downstream PRNM signal processing functions (including the trip function) are done digitally and have no error. The specified errors of the pertinent PRNM LPRM card and flow processing cards (which form the analog front end) are based on extensive testing that verified that the accuracy of the equipment designed according to the design specifications was within the performance specifications at the specified temperature and humidity extremes. Moreover, each pertinent PRNM instrument component is tested to meet its performance specification before shipment, so there is high confidence (95%) that the specified PRNM instrument errors are applicable to all PRNMs in the field.

The composite error for the loop (or channel) is a statistical combination of the errors as described in Section 2a properly taking into account the parallel and series combination of components in the channel. Note that the combination requires all errors to be in the same units, so when calculations are done in process variable engineering units, appropriate transfer functions are used to convert instrument errors into process variable engineering units. Since the error components are conservative there is high confidence (95%) that the composite error is conservative.

The use of the conservative and high confidence (95%) errors together with GEH setpoint methodology provides assurance that RG 1.105 95/95 requirements are met for the constructed APRM setpoints. Note that the calculated NTSPF for these APRM setpoints is significantly more conservative than NTSP1, so the ALINTSPF margin is more conservative than that required to meet the 95/95 requirement.

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 18 of 52 References 7-1.

"Applying Statistics", NUREG-1475 Rev 1, Table 7.1, Page 123. Also, ISA-RP67.04, Part II, 1994, Section 8.1 (and later revision ISA-RP67.04.02-2007 Draft, Section 7.3).

7-2.

GE Hitachi Nuclear Energy letter to NRC, "Supplemental Information following NRC Public Meeting on GEH Setpoint Methodology," including Enclosure 1 "Response to NRC Summary Points on Application of Single-Sided Factor for Setpoint Margin Calculations," MFN 10-334, October 25, 2010.

7-3.

GE Nuclear Energy, "General Electric Instrument Setpoint Methodology,"

NEDC-31336P-A, September 1996 (ADAMS Accession No ML073450560).

7-4.

GE Hitachi Nuclear Energy, "Columbia Generating Station, Instrument Limits Calculation, Average Power Range Monitor (NUMAC ARTS-MELLLA)," NEDC-33753P, Revision 0, June 2012 (ADAMS Accession No. ML12219A255).

NRC Request:

8. This request relates to Enclosure 2, Attachment 9, "NEDC-33685, Revision 1,

'Digital I&C-ISG-06 Compliance for Columbia Generating Station NUMAC Power Range Neutron Monitoring Retrofit Plus Option III Stability Trip Function,'

(ML12040A074)."

Paragraph 11.5 addresses the secure development and environmental controls. In part, this paragraph states that "only GEH personnel would have access to the digital safety system under development." Please confirm that the development network was not connected to any other network during the software design and development phase and that the access to the development area was limited to the personnel involved with the design and development phase. Also, please describe how access to the development system computers was controlled (e.g., physical access, adequacy of password protections and user privileges, etc.).

Response

For development of the Columbia Generating Station (CGS) Power Range Neutron Monitor (PRNM), software design and development was performed on GEH computer assets, which includes desktops, laptops, and servers. A separate development network was not created for the software design and development phase for the CGS PRNM. GEH computer assets

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 19 of 52 are used for multiple projects within GEH, and were not limited to personnel involved with the design and development phases for the CGS PRNM.

Programmatic security controls during software design and development were the primary method to prevent the introduction of unwanted, unneeded, and undocumented functionality into the CGS PRNM. Physical and logical security controls provide additional protection for the development system computers.

Programmatic Security Controls The primary programmatic security controls utilized throughout the development life-cycle phases are separation of duties and configuration management. Separation of duties is provided through independent design verifications, which are performed as described in Section 2.4.12 and Section 4.4.1.10 of NEDC-33685P (Reference 8-1). Configuration management is governed by a software configuration management plan (SCMP), which is discussed in Section 2.4.6 and Section 4.4.1.11 of Reference 8-1.

Per Reference 42 of Reference 8-1, ((

Per Section 4.4.1.10 of Reference 8-1, ((

Per Section 4.4.1.11 of Reference 8-1, ((

]11 These programmatic security controls provide high assurance that unwanted, unneeded, and undocumented functionality was not introduced into the CGS PRNM.

Physical Security Controls In addition to the programmatic security controls, multiple physical security controls were implemented ((

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 20 of 52 Loqical Security Controls The programmatic security controls were also supplemented by logical security controls.

((

1]

Conclusion Robust programmatic, physical, and logical security controls were implemented by GEH to maintain the integrity of the CGS PRNM during the software design and development phase. These security controls provide a defense-in-depth strategy to ensure that unwanted, unneeded, and undocumented functionality was not introduced into the CGS PRNM.

References 8-1.

GE Hitachi Nuclear Energy, "Digital I&C-ISG-06 Compliance for Columbia Generating Station NUMAC Power Range Monitoring Retrofit Plus Option III Trip Function," NEDC-33685P, Revision 1, January 2012 (ADAMS Accession No. ML1 2040A74).

NRC Request:

9. This request relates to Enclosure 2, Attachment 9, "NEDC-33685, Revision 1,

'Digital I&C-ISG-06 Compliance for Columbia Generating Station NUMAC Power Range Neutron Monitoring Retrofit Plus Option III Stability Trip Function,'

(ML12040A074)."

Table 11-1 addresses regulatory positions 2.1 through 2.5 of RG 1.152. Under subsection 2.4 it addresses code review. Was the code reviewed for unwanted and undocumented functions? If so, what were the results? If not, please provide the justification to assure that no unwanted or undocumented code was present.

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 21 of 52

Response

The average power range monitor (APRM) functional, display, and stability code sets had specific analyses performed to review for unused code. A call tree analysis of the source code used in the APRM instrument was performed to identify any unused code functions.

Unused code functions were found in the APRM Functional and Display code sets and these unused functions were removed. No unused functions were found within the stability code set. The results of these analyses are documented in NEDC-33756P (Reference 9-1).

Reference 9-1.

GEH Nuclear Energy, "Columbia Generating Station Power Range Neutron Monitor V&V Test Summary Report," NEDC-33756P, Revision 1, June 2012 (ADAMS Accession No. ML12219A255).

NRC Request:

10.This request relates to Enclosure 2, Attachment 10, "NEDC-33690, Revision 0,

'Columbia Generating Station Power Range Neutron Monitoring System Response Time Analysis Report,' (ML12040A075)."

The following paragraph has been extracted from the bottom of page 4 of Enclosure 2, :

'With respect to system response time, the CGS FSAR [Final Safety Analysis Report] (Reference 5) Chapter 15 requirements use the timing requirements from the Licensee Controlled Specification Manual (Reference 4) Table 1.3.1.1-1. This meets the IEEE-603-1991 Clause 4.10 (Reference 7) requirement for the safety system design basis."

Please provide the elements of this program as they apply to the four subsections (subsections 4.10.1 through 4.10.4) under section 4.10 of IEEE 603-1991.

Response

Compliance with IEEE Standard 603-1991 (Reference 10-4), Clause 4.10, for power range neutron monitoring system (PRNMS) is discussed in the context of the overall Clause 4, Design Basis. The following statements are made in Section 9.1 of NEDC-33685P (Reference 10-3), regarding compliance with IEEE Standard 603-1991 (Reference 10-4),

Clause 4, Design Basis.

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 22 of 52 Requirement: A specific basis shall be established for the design of each safety system of the nuclear power generating station. The design basis shafl also be available as needed to facilitate the determination of the adequacy of the safety system, including design changes.

The PRNMS upgrade only affects a very small portion of the reactor protection system (RPS), and the design basis is unchanged from that of the existing PRM system.

The PRNMS upgrade generally replaces only portions of the sense and command features.

The sensors are not to be replaced per this upgrade. The execute features for RPS are considered to be the RPS trip actuators and pilot scram valve solenoids, which are unaffected by this change. For conservatism, the output relays from the PRNMS are considered as part of the execute features for the purposes of this evaluation.

No timing requirements for the RPS are altered by this project. Thus, compliance with IEEE Standard 603-1991 (Reference 10-4), Clause 4.10 is discussed below for the PRNMS project.

IEEE Standard 603-1991 (Reference 10-4) Clause 4.10 requires the safety system design basis to include the critical points in time or the plant conditions, after the onset of a design basis event, including:

4.10.1.

The point in time or plant conditions for which the protective actions of the safety system shall be initiated.

Section 2.2 of NEDC-33690P (Reference 10-2) specifically addresses the response time requirements for initiation of the RPS protective actions (reactor trip) contained within Chapter 15 of the CGS Final Safety Analysis Report (FSAR) and the licensee controlled specifications (LCS), Table 1.3.1.1-1.

Table 1.3.1.1-1 of the LCS identifies the RPS response time requirement for the average power range monitor (APRM) Fixed Neutron Flux - High scram function as 0.09 seconds. The 0.09 second (90 millisecond) RPS response time for this function is used in the transient analysis for the CGS FSAR Chapter 15 Accident Analyses (Table 15.0-2, Item 33). This response time requirement is split between the RPS trip logic and scram contactor (50 milliseconds), and the PRNMS (40 milliseconds). NEDC-33690P (Reference 10-2) concludes that the PRNMS (including output relays) meets the 40 millisecond response time requirement. The RPS trip logic and scram

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 23 of 52 contactor are unchanged by the PRNMS modification. Thus, the APRM Fixed Neutron Flux - High scram response time requirement is met.

Table 1.3.1.1-1 of the LCS identifies the RPS response time requirement for the oscillation power range monitor (OPRM) function as 0.49 seconds (490 milliseconds). Chapter 15 of the CGS FSAR does not credit OPRM functions in the transient analyses, so its response time is not discussed in the context of total RPS response time. However, the 50 millisecond requirement for the RPS trip logic and scram contactor still applies for this function, which would allow 440 milliseconds for the PRNMS per the LCS. Reference 10-1 (c) provides a more restrictive response time requirement for the PRNMS OPRM function of 400 milliseconds. NEDC-33690P (Reference 10-2) concludes that the PRNMS (including output relays) meets the 400 millisecond response time requirement. Thus, the OPRM scram response time requirement is met.

4.10.2.

The point in time or plant conditions that define the proper completion of the safety function.

The NEDC-33690P (Reference 10-2) analysis shows that response time requirements for the PRNMS portions of reactor trip initiation have been met.

Once a trip condition has occurred and the trip signals have been provided to the RPS trip logic, the reactor trip continues to completion, as described in Section 9.2.2 of NEDC-33685P (Reference 10-3). The points in time or plant conditions that define the proper completion of the safety functions (reactor trips) for the RPS have not changed as a result of the PRNMS project.

4.10.3.

The points in time or the plant conditions that require automatic control of protective actions.

For the PRNMS required functions, no automatic control is required or provided for the RPS, other than initiation of trip, which is addressed in the response to Clause 4.10.1 above.

4.10.4.

The point in time or the plant conditions that allow returning a safety system to normal.

There are no specific response time requirements for resetting the outputs from the PRNMS to the RPS trip logic once the trip condition clears.

As described in Section 7.2.1.1 of the CGS FSAR, "To restore the RPS to normal operation following any single actuator logic trip or a scram, the trip actuators must be reset manually. After a 10-sec delay reset is possible only if the

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 24 of 52 conditions that caused the scram have been cleared. The trip actuators are reset by operating switches in the main control room." This design does not change as a result of the PRNMS project. Once the sensed trip condition clears, the PRNMS output relays will automatically revert to the no-trip condition, thus appropriately enabling the RPS reset function.

References 10-1. (a)

GE Nuclear Energy, "Nuclear Measurement Analysis and Control Power Range Neutron Monitor (NUMAC PRNM) Retrofit Plus Option III Stability Trip Function," NEDC-32410P-A Volume 1, October 1995.

(b)

GE Nuclear Energy, "Nuclear Measurement Analysis and Control Power Range Neutron Monitor (NUMAC PRNM) Retrofit Plus Option III Stability Trip Function," NEDC-3241 OP-A Volume 2 -- Appendices, October 1995.

(c)

GE Nuclear Energy, "Nuclear Measurement Analysis and Control Power Range Neutron Monitor (NUMAC PRNM) Retrofit Plus Option III Stability Trip Function," NEDC-3241OP-A, Supplement 1, November 1997.

10-2 GE Hitachi Nuclear Energy, "Columbia Generating Station Power Range Neutron Monitoring System Response Time Analysis Report," NEDC-33690, Revision 0, November 2011 (ADAMS Accession No. ML1 2040A75).

10-3 GE Hitachi Nuclear Energy, "Digital I&C-ISG-06 Compliance for Columbia Generating Station NUMAC Power Range Monitoring Retrofit Plus Option III Trip Function," NEDC-33685P, Revision 1, January 2012 (ADAMS Accession No. ML1 2040A74).

10-4 IEEE Standard 603, IEEE Standard Criteria for Safety Systems for Nuclear Power Generating Stations," 1991.

NRC Request:

11.

This request relates to Enclosure 2, Attachment 3, "NEDC-33690P, Revision 0,

'Columbia Generating Station Power Range Neutron Monitoring System Response Time Analysis Report,' (ML12040A083)."

D&IC ISG-04, Staff Position 1.20 discusses data error rates. Part of the response to these items states on the bottom of page 12,

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 25 of 52 1]"

The data error rate for each safety-related communication link was established and used to determine the effect of data errors on safety system response time. The established data error rates will be supported by testing a similar PRNM system for GGNS during integration testing. Therefore, the criteria of Staff Position 1.20 are met."

Will the same number, structure, and length of messages be sent on each data link on CGS as was tested for GGNS? Please confirm. In addition please, confirm that the CGS and/or GGNS test results will be available within the CGS documentation for audit by NRC Staff.

Will the data error rates be tested for CGS or the data error rates tested for GGNS be utilized to take credit for CGS? If credit is to be taken for the GGNS data, then a justification for use of GGNS data for CGS must be provided. Please clarify.

Response

The same number, structure, and length of messages will be sent on each data link on Columbia Generating Station (CGS) as was tested for Grand Gulf Nuclear Station (GGNS).

The GGNS test results will be available within the CGS documentation for audit by NRC staff. The data error rates tested for GGNS will be utilized to take credit for data error rate testing for CGS. The use of GGNS data for CGS is justified for the following reasons. ((

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 26 of 52 NRC Request:

12.

This request relates to Enclosure 2, Attachment 6, "NEDC-33697P, Revision 1,

'Columbia Generating Station Power Range Neutron Monitoring System Design Report on Computer Integrity, Test and Calibration, and Fault Detection,'

(ML12040A086)." to this attachment provides D&IC-ISG-04 Compliance Matrix. Staff position for item 55 of the compliance matrix is as follows:

"Staff Position 1.12 (Implementation details). Messages may occur at a high rate that degrades or causes the system to fail (i.e., broadcast storm).

The licensee response discusses how messages, if lost, could not affect any safety function. In particular the response states,

'1((

Equipment failure or software malfunction can cause broadcast data storms. Please explain how data storms are prevented and, if they do happen, how they affect plant operation and safety.

Response

Reference 12-1, paragraph 1.4.4, "Communication Modules" describes two types of fiber-optic communication modules used for safety function messaging. These modules are the

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 27 of 52 Fiber Direct Data Interface (FDDI) Communication Module (paragraph 1.4.4.1), and the Broadcaster Module (paragraph 1.4.4.4).

The safety-related communication links implemented in the CGS power range neutron monitoring system (PRNMS) use point-to-point fiber optic communications links between each instrument in the PRNMS.

The send and receive message buffers implemented for the point-to-point links do not queue messages, (i.e., the communications hardware overwrites these buffers with the latest validated message data). Per design, the communications hardware processes the latest validated data. This ensures the latest validated data is always available for safety function processing.

((

The design and implementation of the CGS PRNMS point-to-point fiber optic communication links provide effective isolation between the execution of safety functions and the management of the fiber optic communications interfaces. In conclusion, the design and implementation of the FDDI and Broadcaster fiber optic communication links prevent a data storm event from adversely affecting the CGS PRNMS safety functions.

References 12-1. GE Hitachi Nuclear Energy, "Digital I&C-ISG-06 Compliance for Columbia Generating Station NUMAC Power Range Neutron Monitoring Retrofit Plus Option III Stability Trip Function," NEDC-33685P, Revision 1, January 2012 (ADAMS Accession No. ML12040A074).

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 28 of 52 NRC Request:

13. This request relates to Enclosure 2, Attachment 6, "NEDC-33697P, Revision 1,

'Columbia Generating Station Power Range Neutron Monitoring System Design Analysis Report,' (ML12040A086).", page E2-9 in part states the following with regard to compliance to regulatory guide 1.152:

)) Extensive field experience of NUMAC equipment, including PRNM, demonstrates that the design process applied for the NUMAC equipment, including PRNM, provides a fully adequate digital design for the NUMAC applications."

The paragraph above does not clarify the steps taken during the design of CGS PRNMS project to implement the guidance of regulatory guide 1.152. Please state the specific measures taken for the CGS PRNM/ARTS/MELLLA upgrade project during software design and development stage.

Response

Per conference call on August 24, 2012, the NRC clarified that the response only needs to address Positions C2.1 to C2.5 of either Revision 2 or 3 of Regulatory Guide (RG) 1.152.

Revision 3 of RG 1.152 is used as the basis for the response.

The five positions of RG 1.152 Revision 3 can be summarized as a requirement in the development of safety related software to consider the necessary features to establish a secured operational environment and secured development environment throughout the life cycle of the digital system development. Such consideration must be reflected in each phase of the life cycle: Concept, Requirements, Design, Implementation, and Testing.

The Columbia Generating Station (CGS) nuclear measurement analysis and control (NUMAC) power range neutron monitor system (PRNMS) was developed in accordance with the NUMAC software management plan (SMP), 23A5162 (Reference 13-1). The NUMAC SMP defines the life cycle into 6 phases or baselines:

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 29 of 52 1))

The CGS NUMAC PRNMS provides three (3) levels of security as described in Section 5.3.13 of NEDC-3241 OP-A (Reference 13-2) and pages E1-43 and E1-44 of.NEDC-33697P (Reference 13-3). These are:

1. Password authorized entry to the OPERATE/SET mode. This ((

I]

2. Keylock switch is required to place the instruments in the ((

1]

3. ((

1]

In addition, the CGS PRNMS meets the requirements of DI&C ISG-04 by ensuring that the communication between safety and non-safety systems and inter-divisional systems are properly separated. This is explained in NEDC-33697P (Reference 13-3). The consideration of these design features throughout the life cycle is described as follows.

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 30 of 52 In ((

)) (equivalent to the Concept Phase), the PRNMS requirements for the CGS PRNM are documented in a plant specific datasheet 24A5221 TC (Reference 13-4). The datasheet invokes the generic specification in 24A5221 (Reference 13-5) and incorporates the plant specific design requirements for CGS. Section 4.2.2.3 of 24A5221 describes the three modes of operation and the security features that meet the secured operational requirements as specified in Position C2.1 of RG 1.152, Revision 3.

Reference 13-5 also specifies the interface and communication requirements for the PRNMS. The plant specific data sheet for CGS, 24A5221TC (Reference 13-4), invokes the same requirements to the CGS design.

As described in NEDC-33685P (Reference 13-6), all configurable items in the phase were independently verified ((

)).

In ((

)) (Requirements Phase), the requirements for the safety related systems are documented as follows:

1. APRM Performance Specification Data Sheet 25A5916TC, Revision 6.

2. APRM Performance Specification, 25A5916, Revision 5.

3. APRM User's Manual, 26A7865, Revision 6.

4. LPRM User's Manual, 26A7866, Revision 5.

5. PRNM FDDI Protocol Specification Data Sheet, 24A5244TC, Revision 2.

6. PRNM FDDI Protocol Specification, 24A5244, Revision 2.

As explained above, the datasheet is used to invoke the generic requirements and to incorporate the plant specific requirements.

The APRM Performance Specifications and datasheet allocate the security design features to the ((

)) These meet Position C2.2.1 of RG 1.152, Revision 3.

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 31 of 52 As described in NEDC-33685P (Reference 13-6), all configurable items in the phase were independently verified per i[

)). These reviews ensure that requirements defined in this phase do not contain or introduce unnecessary or unwanted requirements into the system. A requirements traceability matrix was utilized to ensure that each software design requirement originated from a performance requirement.

This minimizes the possibility of introducing unused or unwanted software functions into the safety system. Therefore, the activities in Baseline 2 meet Position C2.2.1 and C2.2.2 of RG 1.152, Revision 3.

In ((

)) (Design Phase), the following safety related software design specifications were issued for the CGS PRNM system:

1. APRM Functional Software Design Specification 26A8428, Revision 0.

2. APRM Functional Software Design Specification Data Sheet 26A8428TC, Revision 0.

3. Stability Monitor Software Design Specification 26A7713, Revision 1.

4. APRM Display Software Design Specification Data Sheet 26A6776TC, Revision 2.

5. LPRM Display Software Design Specification Data Sheet 26A6777TC, Revision 2.

6. APRM Internal Communication Protocol Spec 26A7960, Revision 4.

7. ASP (Stability) Comm Block, 26A7839, Revision 1.

8. Scanning ASP Comm, 26A7100, Revision 0.

9. Scanning ASP Firmware Design Specification, 26A7102, Revision 0.

The safety system design features of the PRNM identified in the system performance specifications in Baseline 2 are translated into software design specifications listed above.

The safety system design requirements for a secure operational environment are translated into the APRM Functional Software Design Specification (26A8428, Revision 0) and the datasheet for CGS (26A8428TC, Revision 0) and the APRM Display Software Design Specification Data Sheet (26A6776TC, Revision 2) and the LPRM Display Software Design Specification Data Sheet (26A6777TC, Revision 2).

The three levels of security were established based on the potential consequences of actions authorized by each security level. Placing the system in OPERATE mode is to enable it to perform its intended safety functions. ((

)) Placing the system in INOP-CAL mode would remove the system from performing its safety functions but would allow it to perform the safety functions more accurately after calibration. ((

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 32 of 52

)) Placing the system in INOP-SET mode would remove the system from performing its safety functions and would allow changes to user input parameters, which may affect the performance of the safety functions.

1))

As described in NEDC-33685P (Reference 13-6), all configurable items in the phase were independently verified ((

)) These reviews ensure that requirements defined in this phase do not contain or introduce unnecessary or unwanted design features or functions into the system. A requirements traceability matrix was utilized to ensure that each software design requirement originated from a performance requirement. This minimizes the possibility of introducing unused or unwanted software functions into the safety system. Therefore, the baseline 3 activities for the CGS PRNM meet Position C2.3.1 and C2.3.2 of RG 1.152, Revision 3.

((

)) in the GEH process (Implementation Phase) is comprised of two portions.

The design team would implement the software design requirements established in the Design Phase ((

)) into the software. The design team would then perform necessary internal code reviews and module tests to ensure that the requirements have been implemented into the software properly and that the software does not contain any errors. The design team would also perform a call tree analysis to ensure that the software does not contain any unused software. A requirements traceability matrix is also prepared to ensure each software function meets the requirements as stated in the software design specifications. This would also ensure that there is no unwanted software within the system.

This portion of the GEH process is consistent with the Implementation Phase as defined in in Regulatory Guide 1.152, Revision 3. The software is then transmitted to the independent verification and validation (IV&V) team ((

)) to perform the independent module testing. Both the design team and the IV&V team test results are documented in the V&V Summary Report (Reference 13-7). This V&V Summary Report is the result of the Special Purpose Review conducted for the CGS PRNMS in compliance with RG 1.168, Revision 1. This is in addition to the independent design verifications, baseline reviews and technical design reviews that are the standard GEH development process. The GEH's testing effort to ensure the proper implementation of the security features in the CGS PRNMS and to ensure that it does not contain any unused or unwanted software meet Position C2.4.1 and C.2.4.2 of RG 1.152, Revision 3.

The GEH's Integration Test ((

)) is also comprised of two portions, internal integration test performed by the design team and independent integration test performed by the IV&V team ((

)). The integration test performed by the design team can be considered as part of the Implementation Phase as defined in RG 1.152, Revision 3.

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 33 of 52 The module test and integration test performed by the IV&V team and the GEH's V&V testing are equivalent to the Test Phase as defined in RG 1.152, Revision 3. As in the case of the IV&V module test, the IV&V integration test is designed to ensure that each software function is traceable to a software requirement. The V&V test is designed to ensure that each test case is traceable to a performance requirement established in the Requirements Phase ((

)). This includes the security features and the required safety functions for the CGS PRNMS. All test results are documented in the V&V Summary Report (Reference 13-7). The scope and purpose of the various tests meet Position C2.5.1 and C2.5.2 of RG 1.152, Revision 3.

In summary, while the life cycle in the GEH's SMP is different from the five life cycle phases defined in RG 1.152, Revision 3, application of the GEH's SMP for the CGS PRNM system and the resulting documentation shows that the GEH process meets Positions C2.1 through C2.5 of RG 1.152, Revision 3.

References 13-1.

NUMAC Software Management Plan, 23A5162, Revision 3.

13-2. GE Nuclear Energy, "Nuclear Measurement Analysis and Control Power Range Neutron Monitor (NUMAC PRNM) Retrofit Plus Option III Stability Trip Function,"

NEDC-3241OP-A Volume 1, October 1995.

13-3. GE Hitachi Nuclear Energy, "Columbia Generating Station Power Range Neutron Monitoring Design Analysis Report", NEDC-33697P, Revision 1, January 2012 (ADAMS Accession No. ML12040A077).

13-4. NUMAC PRNM System Requirements Specification Datasheet, 24A5221TC, Rev. 6.

13-5. NUMAC PRNM System Requirements Specification, 24A5221, Revision 18.

13-6. GE Hitachi Nuclear Energy, "Digital I&C-ISG-06 Compliance for Columbia Generating Station NUMAC Power Range Neutron Monitoring Retrofit Plus Option III Stability Trip Function", NEDC-33685P, Revision 1, January 2012 (ADAMS Accession No. ML12040A074).

13-7. GE Hitachi Nuclear Energy, "Columbia Generating Station PRNM V&V Summary Report," NEDC-33756P, Revision 1, dated June 2012 (ADAMS Accession No. ML12219A255 Attachment 5).

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 34 of 52 NRC Request:

14. This request relates to Enclosure 2, Attachment 1, "0000-0101-7647-R3, 'Columbia Generating Station Plant-Specific Responses Required by NUMAC PRNM Retrofit Plus Option III Stability Function Topical Report (NEDC-3241 OP-A) (ML12040A073)"

and Attachment 2, "NEDC-33685P, Revision 1, 'Digital I&C-ISG-06 Compliance for Columbia Generating Station NUMAC Power Range Neutron Monitoring Retrofit Plus Option III Stability Trip Function,' (ML12040A082)."

Section 4.4.2.2.1.4 of Table in Attachment 1 discusses plant-specific response for temperature and humidity. In part it states:

'The PRNM control room electronics are qualified for continuous operation under the following relative humidity conditions: 10 to 90% (non-condensing)."

In Enclosure 2, Attachment 2, Section 5.4 in Table 5-2 lists the environmental qualifications of the PRNM panel. It lists that the lower humidity qualified value is

((

)) humidity. Table 5-3 in the same section lists the CGS plant specific environmental requirement as [L......... )) humidity. There is an apparent anomaly in the two statements i.e. Enclosure 2, Attachment 1 and Enclosure 2, Attachment 2. In, attachment 2, CGS further explained that similar equipment has been tested for ((

)) humidity levels.

Please explain this apparent anomaly. Also provide the applicable test documentation and address whether the equipment that was tested was the same or substantially similar to the equipment at CGS.

Response

The Columbia Generating Station's (CGS) requirement is for operational equipment to 10%

relative humidity (RH). The NUMAC instrument minimum qualified levels are to (Table 5-2 of Enclosure 2 Attachment 2) 20% RH. GE Hitachi (GEH) used analysisto qualify the equipment down from the 20% RH to 10% RH. Subsequent testing was performed on equipment that is substantially similar to the CGS equipment. Analysis of the equipment tested versus the CGS equipment established adequate similarity between the two systems.

Therefore, based on these tests which encompass the ranges of operation for CGS, GEH states the CGS instruments are qualified via similarity analysis to these tested instruments.

In response to RAI #6 the Reference 14-2 document is included for evaluation as Enclosure 1 to this letter.

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 35 of 52 References 14-1 GE Nuclear Energy, "General Electric Nuclear Energy Business Operations Environmental Qualification Program Description (GEQUAL)," NEDO-30239 83NED118, August 1983.

14-2 GE Hitachi Nuclear Energy, "NUMAC Power Range Neutron Monitoring (PRNM)

Components 268X1 331 TCGO01, 268X1 332TCG001, G002 268X1 333TCG001 Qualification Summary for Energy Northwest (ENW) Columbia Generating Station (CGS)" eDRF Section 0000-0119-1413, Revision 1, dated November 8, 2010.

NRC Request:

15. This request relates to Enclosure 1, "Description of Proposed Technical Specifications Changes (ML12040A072)."

Section 2.2.4.3, Table 3.3.1.1 -1 Note (d) states that, "If the as-found channel setpoint is outside its predicted as-found tolerance, then the channel shall be evaluated to verify that it is functioning as required before returning the channel to service." CGS is requested to confirm that a corrective action program or an equivalent plant specific program is in place to track and evaluate all such deviations.

Energy Northwest Response:

Energy Northwest commits to revising the affected calibration procedures to ensure that all such non-compliances are entered into the Corrective Action Program to ensure that these deviations are appropriately tracked and evaluated. This new commitment is reflected in to this letter.

NRC Request:

16. This request relates to Enclosure 1, "Description of Proposed Technical Specifications Changes (ML12040A072)."

Notes (d) and (e) have been added on page B.3.3.1.1-29 of the TS bases document for SR [Surveillance Requirement] 3.3.1.1.10. These notes address only limiting trip setpoint (LTSP) and do not mention the fact that if the field trip setpoints are more conservative than the LTSP then those setpoints are to be considered for evaluating as-left and as-found settings. These notes should be modified by CGS to appropriately reflect the guidance of TSTF-493, Option A.

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 36 of 52 Energv Northwest Response:

The notes regarding notes to incorporate TSTF-493, Option A requirements will be revised for TS Bases page 3.3.1.1-29 for SR 3.3.1.1.10 to read as follows (changes identified in italics):

Note (d) requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is not the Limiting Trip Setpoint (LTSP) but is conservative with respect to the Allowable Value. For digital channel components, no as-found tolerance or as-left tolerance can be specified. Where a setpoint more conservative than the LTSP is used in the plant surveillance procedures (i.e., nominal trip setpoint, or NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint.

Evaluation of instrument performance will verify that the instrument will continue to behave in accordance with design basis assumptions. The purpose of the assessment is to ensure confidence in the instrument performance prior to returning the instrument to service. Any nonconformance will be entered into the Corrective Action Program which will ensure required review and documentation of the condition for continued OPERABILITY.

Note (e) requires that the as-left setting for the instrument be returned to within an acceptable as-left tolerance around the LTSP. Where a setpoint more conservative than the L TSP is used in the plant surveillance procedures (i.e.,

nominal trip setpoint, or NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint. This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained. If the as-left instrument setting cannot be returned to the LTSP, then the instrument channel shall be declared inoperable. The LTSPs are specified in the Licensee Controlled Specifications.

An information only copy of the revised TS Bases page 3.3.1.1-29 is included as. This page supersedes the page that was previously submitted in Reference 16-1.

Reference 16-1.

Letter, G02-12-017, dated January 31, 2012, BJ Sawatzke (Energy Northwest) to NRC, "License Amendment Request to Change Technical Specifications in Support of PRNM / ARTS / MELLLA Implementation" (ADAMS Accession No. ML12040A072).

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 37 of 52 NRC Request:

17. This request relates to Enclosure 3, Attachment 1, "NEDO-33507, Revision 1,

'Columbia Generating Station APRM/RBM/Technical Specifications/ Maximum Extended Load Line Limit Analysis (ARTS/MELLLA) (ML12020A080)."

Attachment A to the above enclosure lists sigma as "3" on page A-5, and on page A-1 2, as well as various other places. Please justify the use of 3 sigma for the applications where used.

Response

Calculation Documents:

Values and inputs for the errors for the CGS PRNM equipment are shown in the summary RBM Inputs/Outputs document (Reference 17-1) and in the summary APRM Inputs/Outputs document (Reference 17-2). These were used in the respective setpoint calculations.

These summary Inputs/Outputs documents were recently transmitted for the NRC's review of the instrument uncertainty inputs used in the setpoint calculations (Reference 17-3).

Reference 17-1 is the same document as Attachment 4 to Reference 17-3. Reference 17-2 is the same document as Attachment 3 to Reference 17-3.

GEH's Use of Sigma Numbers in Setpoint Calculation Methodology:

General/Background Information:

GEH setpoint calculations are based on the GEH setpoint methodology contained in NEDC-31336P-A (Reference 17-3) which has been reviewed and approved by the NRC.

Conceptually, the GEH method is based on Instrument Society of America (ISA) Method 2, but leads to more conservative setpoints and is referred to as "Method 2 plus". During the original review of the GEH setpoint methodology the NRC Safety Evaluation Report (SER) concluded that the GEH setpoint methodology used acceptable methods for calculating setpoints that provide 95% probability at high confidence (95%) of getting a channel trip before the process variable reaches the analytical limit (AL).

In the GEH setpoint calculation methodology conservative values for each of the error components are used to assure, with high confidence (95%) that ((

A].

Note that meeting the RG 1.105 requirement of 95% probability of not exceeding the AL at 95% confidence is assured, in part, by the following treatment of random instrument errors in

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 38 of 52 the GEH setpoint calculation methodology, as was previously explained (in RAI 24 of Reference 17-4 for GGNS) and is repeated here in response to RAI 17 for CGS:

Using values for the random instrument errors, measured in terms of standard deviation (i.e., Sigma) of the normal error distribution function that has high confidence, and statistically combining the standard deviation of pertinent random errors for each device in the channel using the Square Root of the Sum of the Squares (SRSS) technique, gives the channel error standard deviation (StndDev) that has high confidence (95%).

Selection of Sigma Number:

For each random instrument error used by GEH in a setpoint calculation, a Sigma number is assigned based on the confidence held in that error being the maximum error. The default Sigma number for an error is two (2). A three (3) sigma number is assigned to a specific error when there is high confidence that the error represents the maximum error.

For errors where there is a higher confidence that the error represents the maximum error, the Sigma number assigned by GEH for the setpoint calculation is three (3). For example, one instrument vendor, Rosemount, has stated that 100% of the instruments that they ship to their customers for use within a nuclear plant are tested prior to shipping to confirm that the instrument errors are within the error specifications for that instrument. Therefore, GEH has a higher confidence in those errors and assigns a three (3) Sigma number to them.

Another common example of errors with higher confidence that are assigned three (3)

Sigma numbers are the errors used for the Calibration tools, Calibration standards, and As-Left Tolerances (ALTs). The ALTs are specified in the plant's calibration procedures. The accuracies associated with calibration devices are considered to be 3 Sigma numbers because the tools are used repeatedly and are continuously tested against standards to ensure that the errors do not exceed the specified values. ALT and Leave Alone Tolerance (LAT 1) values are considered to be 3 Sigma because each represents the maximum deviation (error) permitted by procedure.

Typically, the errors for Drift, Seismic Error, and Radiation Error are treated as 2 Sigma numbers for all vendors in GEH setpoint calculations.

For each error that has been assigned a three (3) Sigma number, a two-thirds (2/3) multiplier is used to convert that error to a 2 Sigma number for statistically combining the standard 1 Note per the guidance provided in RIS 2006-17 (Ref. 17-5) and TSTF-493 (Ref. 17-6), the instrument setting must be set equal to the Limiting Trip Setpoint after periodic testing. In practice, the instrument setting is reset to the Final NTSP +/-ALT after each calibration. Thus, the LAT is set equal to the ALT in the GEH setpoint calculations.

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 39 of 52 deviation of pertinent random errors for each device in the channel using the SRSS technique.

Specific Use of Sigma Numbers in the RBM Setpoint Calculations:

For the use of the Process Measurement Accuracy (PMA) Tracking error for the RBM Trip Setpoints (e.g., Low Trip Setpoint (LTSP)), on page A-5 ((

1))

For the use of the APRM Gain Adjustment Factor (AGAF) of +/- 2 % RTP as a 3 Sigma number on page A-1 2, the weekly calibration of the APRMs includes setting the APRM readings to match the power calculation results of the weekly Heat Balance calculations, per Technical Specifications Surveillance Requirement (SR) 3.3.1.1.2. As such, the AGAF is being used as an ALT for the APRM NTSPs and the RBM Power Setpoint NTSPs (e.g.,

Intermediate Power Setpoint (IPSP)). Thus, as described in this RAI 17 response General section, the Sigma number is assigned as a three.

Calculations:

The associated setpoint calculation spreadsheets for References 17-1 and 17-2 may be viewed by the NRC at a GEH office, upon request, including the use of Sigma numbers.

References 17-1.

GE Hitachi Nuclear Energy, "Columbia Generating Station, Instrument Limits Calculation, Rod Block Monitor (NUMAC ARTS-MELLLA)," NEDC-33754P, Revision 0, June 2012 (ADAMS Accession No. ML12219A255).

17-2.

GE Hitachi Nuclear Energy, "Columbia Generating Station, Instrument Limits Calculation, Average Power Range Monitor (NUMAC ARTS-MELLLA)," NEDC-33753P, Revision 0, June 2012 (ADAMS Accession No. ML12219A255).

17-3.

GE Nuclear Energy, "General Electric Instrument Setpoint Methodology",

NEDC-31336P-A, September 1996 (ADAMS Accession No. ML073450560).

17-4.

Entergy Letter, "Response to NRC Request for Additional Information Pertaining to License Amendment Request for Power Range Neutron Monitoring System (TAC No. ME2531)," GNRO-2011/00042, dated May 31, 2011 (ADAMS Accession No. ML111520123), and

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 40 of 52 Entergy Letter, "Response to NRC Request for Additional Information Pertaining to License Amendment Request for Power Range Neutron Monitoring System (TAC No. ME2531)," GNRO-2011/00066, dated September 2011 (ADAMS Accession No. ML112720128).

17-5.

NRC Regulatory Issue Summary (RIS) 2006-17, NRC Staff Position on the Requirements of 10 CFR 50.36, "Technical Specifications," regarding Limiting Safety System Settings during Periodic Testing and Calibration of Instrument Channels, August 24, 2006 (ADAMS Accession No. ML051810077).

17-6.

Letter, TSTF to NRC, "Transmittal of TSTF-493 Revision 4, Errata." TSTF-1 0-07, dated April 23, 2010 (ADAMS Accession No. ML101160026).

17-7.

Energy Northwest Letter, "Submittal of Phase 2 Information in Support of License Amendment Request to Change Technical Specifications in Support of PRNM / ARTS / MELLLA Implementation," G02-12-105, dated July 31, 2012 (ADAMS Accession No. ML12219A255).

NRC Request:

18.This request relates to Enclosure 3, Attachment 1 "NEDE-33507, Revision 1,

'Columbia Generating Station APRM/RBM/Technical Specifications/ Maximum Extended Load Line Limit Analysis (ARTS/MELLLA) (ML12020A080)."

In order to confirm that the licensee is following the guidance of RG 1.105, Revision 3 and RIS 2006-17 staff would like to review a sample calculation. As such, CGS is requested to provide the High Power Trip Setpoint (HTSP) calculation along with the supporting documents for staff review. The HTSP setpoint function and the values are noted on page A-13 of Attachment A to Enclosure 3, Attachment 1. Also, please provide the setpoint methodology document, unless it has already been provided as part of the license change request.

Response

Calculations:

Values and inputs for the errors for the Columbia Generating Station (CGS) power range neutron monitor (PRNM) equipment are shown in the summary rod block monitor (RBM)

Inputs/Outputs document (Reference 18-1) and in the summary average power range monitor (APRM) Inputs/Outputs document (Reference 18-2). These were used in the respective setpoint calculations. These summary Inputs/Outputs documents were recently

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 41 of 52 transmitted for the NRC's review of the instrument uncertainty inputs used in the setpoint calculations.

The associated setpoint calculation spreadsheets for References 18-1 (and Reference 18-2) may be viewed by the NRC at a GEH office, upon request.

GEH Instrument Setpoint Calculation Methodology Document:

GEH setpoint calculations are based on the GEH setpoint methodology contained in NEDC-31336P-A (Reference 18-3) which has been reviewed and approved by the NRC. It is already available to the NRC via Agencywide Documents Access and Management System (ADAMS) Accession No. ML073450560. The next section of this response to RAI 18 gives an overview of GEH's setpoint calculation methodology.

Guidance of Regulatory Guide (RG) 1.105 Revision 3:

General Conceptually, the GEH method is based on Instrument Society of America (ISA) Method 2, but leads to more conservative setpoints and is referred to as "Method 2 plus". During the original review of the GEH setpoint methodology the NRC safety evaluation report (SER) concluded that the GEH setpoint methodology used acceptable methods for calculating setpoints that provide 95% probability at high confidence (95%) of getting channel trip before the process variable reaches the analytical limit (AL).

The GEH setpoint calculation process for technical specification setpoints starts with the AL when there is an analytical basis in the safety analysis for the setpoint function. For some technical specification setpoint functions there is no analytical basis for an AL because the setpoint function is not credited in any safety analysis. However these setpoints have an allowable value (AV) in the Technical Specifications. The setpoint calculation procedure for the case where there is no AL is a subset of the setpoint calculation procedure for the general case where there is an AL, and is discussed at the end of this "General" Section.

For the general case where there is an AL, an overview of the methodology used by GEH to calculate the AV, limiting trip setpoint (LTSP), called the first NTSP in GEH methodology (NTSP1), and the final adjusted NTSPF, was previously explained (in RSI 8 of Reference 18-4 for CGS, and in RSI 24 of Reference 18-5 for GGNS) and is repeated here in response to RAI 18 with some additional clarifications and explanations. Also, some of this information is in the response to the current RAI 7.

A pictorial representation of the methodology is shown in Figure RAI 18-1. The methodology for calculating the setpoints shown in Figure RAI 18-1 is exactly the same as

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 42 of 52 what was previously described in Figure 8-1 of Reference 18-4. However, Figure 18-1 has been simplified to discuss the pertinent features described in this RAI response. Some of the terminology has been changed for clarity. For example the final setpoint called "NTSP(ADJ)" and "NTSP(Adj)" in Reference 18-4 is currently called NTSPF in Figure RAI 18-1 and in this text response to RAI 18. Additional features (such as spurious trip avoidance) that are not germane to this response for RAI 18 have been removed for clarity.

Figure RAI 18-1: GEH Simplified Setpoint Methodology

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 43 of 52 The GEH setpoint calculation methodology determines an AV that has margin to the AL based on all errors for an instrument channel during operating conditions, except drift. ((

)) Conservative values for each of the error components are used to assure, with high confidence (95%) that ((

)). The GEH methodology then calculates an initial value for the Nominal Trip Setpoint (NTSP1), which has margin to the AL, based on all errors (i.e., all errors used in the AV calculation and also including conservative values for drift of all devices in the channel), as illustrated in Figure RAI 18-1. NTSP1 is calculated using all errors (including drift) and is referred to as the Limiting Trip Setpoint (LTSP) because it meets the RG 1.105 Revision 3 (henceforth referred to as RG 1.105 in this document) requirement of providing 95% probability of not exceeding the AL with high confidence (95%).

Although NTSP1 has the required margin to the AL to meet RG 1.105, GEH methodology also requires the final setpoint to have an adequate margin to the AV, which is referred to as the LER (Licensee Event Report) avoidance margin. The LER avoidance margin is prescribed by GEH methodology (Reference 18-3). Therefore, in the GEH setpoint calculation process, the setpoint is adjusted conservatively from NTSP1 to the final value (NTSPF) to assure with high confidence (95%) ((

)), as defined by the ALIAV margin provided in GEH methodology. NTSPF is always equal to or more conservative (further from the AL) than NTSP1. Thus generally, and specifically for PRNM setpoints, the final setpoint (NTSPF) is more conservative than NTSP1 and has margin to the AL that is significantly larger than the AL/NTSP1 margin required to meet RG 1.105.

Therefore generally, and specifically for PRNM, the final setpoint (NTSPF) implemented in the instrument conservatively exceeds the 95% RG 1.105 probability requirement for not exceeding the AL.

Note that meeting the RG 1.105 requirement of 95% probability of not exceeding the AL at 95% confidence is assured by the following two basic steps:

Using values for the random instrument errors, measured in terms of standard deviation (i.e., sigma) of the normal error distribution function that has high confidence, and statistically combining the standard deviation of pertinent random errors for each device in the channel using the Square Root of the Sum of the Squares (SRSS) technique gives the channel error standard deviation (StndDev) that has high confidence (95%). Also

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 44 of 52 adding all the non-conservative bias errors algebraically gives the channel bias error (B) that is incorporated in the setpoint margin calculation.

Calculating the setpoint margins by multiplying StndDev by 1.645 for setpoints where the variables approach the setpoints in one direction as described in Reference 18-3, and algebraically adding the channel bias error B. It has been shown from statistical first principles (Reference 18-7) that when StndDev is known to 95% confidence, a setpoint margin of B + 1.645

• StndDev meets the RG 1.105 setpoint margin 95/95 requirement (i.e., it provides 95% probability at 95% confidence) of not exceeding the AL for setpoints approached from one direction. Use of the single-sided 1.645 statistical factor for setpoint margin calculations where the variable approaches the setpoint from one direction, has been endorsed by the NRC staff for GEH setpoint methodology (Reference 18-3) and also by Instrument Society of America (ISA) Standard ISA-RP67.04, Part II, 1994 (and later revision ISA-RP67.04.02-2000).

During review of the GEH setpoint methodology, GEH presented field data that demonstrated, and the NRC agreed (Reference 18-3), that the margins calculated by GEH setpoint methodology bounded 95% of the data with high confidence (95% confidence limits).

Note that the final safety margin is the NTSPF margin to the AL or the AL/NTSPF margin.

This is the margin that needs to be large enough to meet or exceed the 95/95 requirements specified in RG 1.105. Thus, since the AL/NTSP1 meets the 95/95 margin requirement and NTSPF is generally (and specifically for PRNM) more conservative than NTSP1, the AL/NTSPF margin is larger and therefore more conservative than that required to meet the 95/95 requirements. Moreover, the larger the AL/NTSPF margin is, the more conservative the setpoint is with respect to the 95/95 requirement.

The margin of NTSPF to the AV (i.e., AV/NTSPF margin) is based on the errors during calibration conditions and is not the safety margin for which RG 1.105 is applicable. The requirement for the AV/NTSPF margin is the LER avoidance margin which is an operational requirement ((

)), and that it is small enough to detect when instruments are not performing as expected.

For conformance with NRC requirements in RG 1.105, the NTSPF calculated by GEH methodology has to meet the following two conditions:

1) NTSPF must be far enough on the conservative side of AL so that the AL/NTSPF margin is equal to or greater than 95/95 margin based on all errors during trip conditions. This complies with RG 1.105. If NTSPF is further from the AL than this

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 45 of 52 95/95 margin then AL/NTSPF margin is more conservative than required and therefore complies with RG 1.105.

2) NTSPF must be far enough on the conservative side of the AV (i.e., away from the AL) to assure ((

)). Note that since by GEH methodology NTSPF cannot be closer to the AL than NTSP1, the 95/95 safety margin to the AL is assured.

Note also that there is no NRC requirement that the AV/NTSPF margin be equal to or greater than the 95/95 margin based on errors during calibration.

As mentioned in the beginning of this "General" section, for some setpoints there is no safety analysis basis for an AL because the setpoint function is not credited in any safety analysis (accident or anticipated operational occurrence). However these setpoints are in the technical specifications and GEH believes they need to continue to be in the Technical Specifications because although no credit is taken for these setpoints in protecting plant Safety Limits, they have historically been included because they are part of safety related trip systems. For these setpoints the AV in the Technical Specifications is based on operational experience and engineering judgment. RG 1.105 is not applicable to these setpoints because there is no AL, and therefore the 95/95 margin to the AL specified in RG 1.105 is also not applicable. Only the TSTF-493 performance monitoring guidance is applicable (Reference 18-8 and Reference 18-9), specifically for those Technical Specification setpoints that are annotated in TSTF-493. Thus, the setpoint calculation procedure for setpoints without ALs but with AVs is a subset of the setpoint calculation procedure described above for the general case where there is an AL. The starting point for the setpoint calculation procedure for this case of setpoints without ALs, is the AV.

Note that since there is no AL there is no safety analysis basis for the setpoint, and there is no corresponding NTSP1 (LTSP). The NTSPF is calculated from the AV using the same procedure as described earlier for the general case with an AL. The errors involved in the AV/NTSPF margin are the errors during calibration conditions. As for the general case, the requirements for this AV/NTSPF margin are that NTSPF must be far enough from the AV to provide ((

)). Note that since for GEH methodology the AV/NTSPF margin is only a performance monitoring margin and not a safety margin, there is no NRC requirement that the AV/NTSPF margin be equal to or greater than the 95/95 margin based on errors during calibration. As a matter of fact a smaller margin would provide tighter performance monitoring and would therefore be more conservative from the performance monitoring point of view.

Setpoint Calculations The power range neutron monitor (PRNM) setpoints are calculated as described previously in this RAI 18 Response "General" section, using errors specified in the PRNM

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 46 of 52 specifications and customer documents as summarized in Reference 18-1 and Reference 18-2. The specified PRNM errors are conservative and have high confidence (95%). Thus, the PRNM setpoint calculations based on specified PRNM errors and the approved GEH setpoint methodology meet the RG 1.105 95/95 requirements for AL/NTSPF margin.

Specifically, because NTSP1 (Limiting Trip Setpoint) has the required margin to the AL to meet RG 1.105 requirements and because NTSPF is equal or more conservative than NTSP1, it also meets RG 1.105 requirements.

The equations for calculating the setpoints (AV, NTSP1 and NTSPF) and relevant explanations are given in in RSI 8 (Reference 18-4) for CGS and in RAI 10 for GGNS (Reference 18-6). In RSI 8 for CGS and RAI 10 for GGNS, the final setpoint is referred to as "NTSP(Adj)" whereas in this document it is referred to as "NTSPF" for clarity. Note that because NTSP1 (LTSP) meets the RG 1.105 requirements and NTSPF is generally more and never less conservative than NTSP1, it also meets RG 1.105 requirements. As an example, note that according to GEH methodology, the AL/NTSP1 margin is the algebraic addition of the bias errors plus a random error margin equal to 1.645

• Standard Deviation of the total channel random error under trip conditions, whereas the ALINTSPF margin, for APRM Neutron Flux High setpoint with typical PRNM errors, is much larger and equal to the same bias errors plus a random error margin which is larger than 2.5

• Standard Deviation of the totalchannel random error under trip conditions.

In GEH methodology, the final setpoint (NTSPF) is based on satisfying the following two criteria as described in RAI 18 Response "General" Section:

Minimum margin to the AL to satisfy RG 1.105 and assure 95% probability of not exceeding the AL with high confidence (95%). This calculation uses all the errors under trip conditions and includes the process errors and primary element errors that are present during operation but not during calibration, and the accuracy calibration and drift errors of the measuring equipment. The setpoint with this required minimum margin to the AL is referred to as NTSP1 in GEH methodology and corresponds to the Limiting Trip Setpoint (LTSP) in TSTF-493 terminology. This criterion is only applicable to setpoints with ALs.

)) This calculation uses all the errors under calibration conditions and includes the accuracy calibration and drift errors of the measuring equipment. For setpoints with ALs, this requirement generally, and specifically for PRNM, results in the final setpoint (NTSPF) being significantly more conservative than NTSP1, and never less conservative than NTSP1. The reasons for this are as follows:

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 47 of 52 o Generally (and specifically for PRNM) there is not a significant difference between NTSP1 and AV because by GEH methodology the ALIAV margin is calculated with all the same errors used in the AL/NTSP1 (i.e., ALILTSP) calculation except drift, and the drift generally (and specifically for PRNM) does not increase the margin significantly.

Generally (and specifically for PRNM) the margin between AV and NTSPF is significantly larger than between AV and NTSP1 because this margin includes the same calibration and drift errors used in the AV and NTSP1 calculations, and also includes the accuracy under calibration conditions. Calculation of NTSPF ((

))2 Note that AV/NTSPF margin is a measure of the performance of the instrument, and is not a safety margin. The safety margin is the margin to the AL (for setpoints where the AL protects a Safety Limit). The fact that NTSPF is equal to or more conservative than NTSP1 assures that the safety setpoint margin to the AL is equal to or more conservative than the 95/95 requirement in RG 1.105. So the AV/NTSPF margin is merely an instrument performance margin which assures that when the measured value is within this margin the instrument is performing as expected.

For PRNM, the setpoint calculation method described herein is also applicable to the RBM trip and power setpoints which are used in safety analyses and they have ALs. On the other hand no credit is taken for the APRM scrams and rod blocks in any GEH safety analysis including the minimum critical power ratio (MCPR) determination. So the APRM setpoints do not protect a plant safety limit and do not have ALs.

APRM Setpoint Calculations with No Analytical Limits:

For the PRNM APRM setpoint calculations, note that since there are no ALs, there are no safety analysis basis for the setpoints, and there are no corresponding results for NTSP1 (LTSP). However, the APRM setpoints are part of the reactor protection system (RPS) providing protection against excessively high power conditions and slow flux excursions, and have AVs in the technical specifications. The setpoint calculations for the APRM setpoint functions without ALs, are a subset of the calculation of setpoints with ALs, and starts from the AV as described in this RAI 18 response "General" Section. For each APRM setpoint, the errors involved in the AV/NTSPF margin are the errors during calibration conditions. As 2 Note per the guidance provided in RIS 2006-17 (Ref. 18-8) and TSTF-493 (Ref. 18-9), the instrument setting must be set equal to the Limiting Trip Setpoint after periodic testing. In practice, the instrument setting is reset to the Final NTSP +_ALT after each calibration. Thus, the LAT is set equal to the ALT in the GEH setpoint calculations.

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNMIARTS/MELLLA Page 48 of 52 for the general case, the requirements for this AV/NTSPF margin are that NTSPF must be far enough from the AV to provide ((

))

Guidance of Regulatory Issue Summary (RIS) 2006-17 and TSTF-493:

AFT/ALT - General Consistent with TSTF-493 (Reference 18-9), the (as-found tolerance) AFT and ALT requirements only apply to surveillance tests for setpoint functions that are annotated in TSTF-493, and do not apply to surveillance tests that test purely digital components in the channel.

The errors for AFT and ALT calculations are specific to the applicable surveillance tests. For example, for device calibrations, the accuracy of the devices and the drift and calibration errors that are applicable to the device calibration tests are used.

Note that the pertinent portions of the CGS surveillance requirement (SR) 3.3.1.1.10 test and calibrates all the analog LPRM neutron flux and Recirculation (Recirc) Flow signal processing devices at the front end of the PRNM, because these devices can drift for the APRM. This is also true for the CGS SR 3.3.2.1.5 for the LPRM neutron flux signal processing devices at the front end of the PRNM for the RBM.

These SRs do not test the portion of the PRNM that performs the downstream processing of these signals in firmware. Thus, the SR does not test the APRM signal processing portion of the PRNM (which averages the signals from the various LPRM amplifiers) or the APRM flow processing (which adds the flow signals from the two recirc flow loops), nor does it test the processing that generates the APRM and RBM trip signals because this processing is done in PRNM firmware and is not subject to drift. So the AFTs and ALTs for any surveillance of this portion of the PRNM signal processing and trip signal generation are zero.

AFT/ALT Data for PRNM APRM The APRM and its components are calibrated by several different surveillance tests in the Technical Specifications. Each APRM channel is calibrated every 7 days as a system in CGS SR 3.3.1.1.2 where the APRM gain is adjusted so that the APRM output matches the heat balance to within a prescribed amount (i.e., 2% Rated Thermal Power). The gain adjustment compensates for changes in all parts of the system and is the appropriate test basis for calculating the AV and setpoints (NTSP1 and NTSPF) for the APRM setpoint functions. The pertinent errors for this SR are used to calculate APRM setpoints by GEH setpoint methodology for both the new digital PRNM and the older analog APRM equipment

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 49 of 52 that the PRNM replaced. For PRNM, the APRM trip setpoint is set in firmware and does not drift once it is set. The individual components of the PRNM APRM system that could drift and are calibrated are the analog components at the front end of the PRNM that process the inputs from the LPRM detectors and recirc flow transmitters. The PRNM front end and recirc flow transmitters are tested and calibrated by CGS SR 3.3.1.1.10. TSTF-493 only annotates SR 3.3.1.1.10 and so requires that the AFTs and ALTs for the analog devices in the PRNM front end used in the SR are equivalent or more conservative than those based on the PRNM accuracy and drift specifications, and Measurement and Test Equipment (M&TE) errors.

For SR 3.3.1.1.10, all the analog components in the PRNM that could drift are calibrated, so that after calibration the entire PRNM chassis is calibrated to perform according to its design and performance specifications for the next operating cycle. In this SR 3.3.1.1.10 calibration, the analog front end of the PRNM equipment is calibrated once every 24 months and the LPRM detectors are excluded (Reference 18-10). The SR 3.3.1.1.10 calibration is performed by the PRNM "Auto-Calibration" procedure which involves sending a known calibrated current into each LPRM and flow amplifier and internally adjusting the output after it is processed by the amplifier, and the associated sample-and-hold and Analog to Digital (A/D) converter circuits, for any drift that may have occurred since the previous calibration.

A simple way of determining drift since the last "Auto-Calibration" is to run the PRNM "Cal Check' procedure on each LPRM or Flow amplifier, just before running the "Auto-Calibration" procedure to bring the devices back into calibration. When "Cal Check" is performed, the embedded software (firmware) in the PRNM internally disconnects the actual LPRM detector or flow amplifier input and connects the amplifier input to a precision current source designed to give a specified output if the amplifier has not drifted and is at its desired value. If the amplifier has drifted since the last "Auto-Calibration", the amount it has drifted can be determined by plant personnel from the outputs displayed on the PRNM/APRM screen. No manual calibration equipment is required when this "Cal Check" process is used. Plant personnel can compare the measured as-found settings (AFSs) to predetermined AFTs, which are based on accuracy, drift (for 24 months) and calibration tool errors. These actions are compliant with TSTF-493 guidance.

When "Auto-Calibration" is performed, the gain and offset of each amplifier are adjusted automatically by the PRNM firmware to compensate for instrument drift and provide the correct output. This automatically assures that the as-left settings (ALSs) after "Auto-Calibration" are within the predetermined ALTs, which are based on accuracy and calibration tool errors. These actions are also compliant with TSTF-493 guidance.

The "Auto-Calibration" procedure automatically returns each analog front end processor to the desired state after calibration. No manual adjustments are required. If any AFS is beyond the AFT tolerance limit, then additional instrument evaluations are performed by

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 50 of 52 plant personnel in accordance with TSTF-493 guidance, and if necessary the instrument may need to be repaired or replaced before the "Auto Calibration" procedure is performed to bring the devices into calibration.

Note that the pertinent portions of the CGS SR 3.3.1.1.10 test and calibrate all the analog LPRM neutron flux and Recirculation Flow signal processing devices at the front end of the PRNM, because these devices can drift. It does not test the portion of the PRNM that performs the downstream processing of these signals in firmware. Thus, the SR does not test the APRM signal processing portion of the PRNM (which averages the signals from the various LPRM amplifiers) or the APRM flow processing (which adds the flow signals from the two recirculation flow loops), nor does it test the processing that generates the APRM trip signal because this processing is done in PRNM firmware and is not subject to drift. So the as-found and as-left tolerances for any surveillance of this portion of the PRNM signal processing and trip signal generation are zero.

AFT/ALT Data for PRNM RBM In addition to the previous discussion for the APRMs, the RBM and its components are calibrated by several different surveillance tests in the Technical Specifications. Each RBM channel is calibrated every 24 months as a system in CGS SR 3.3.2.1.5. The pertinent errors for this SR are used to calculate RBM setpoints by GEH setpoint methodology for both the new digital PRNM and the older analog APRM equipment that the PRNM replaced.

For PRNM, the RBM trip setpoint is set in firmware and does not drift once it is set. The individual components of the PRNM RBM system that could drift and are calibrated are the analog components at the front end of the PRNM that process the inputs from the LPRM detectors. The PRNM front end are tested and calibrated by CGS SR 3.3.2.1.5. TSTF-493 only annotates SR 3.3.2.1.5 and so requires that the AFTs and ALTs for the analog devices in the PRNM front end used in the SR are equivalent or more conservative than those based on the PRNM accuracy and drift specifications, and measurement and test equipment (M&TE) errors.

The rest of the APRM discussion regarding calibrations and tolerances discussed in the "AFT/ALT Data for PRNM APRM" section in this RAI 18 response apply similarly to the RBM, except that the flow amplifiers would not apply to the RBM, as it has power-dependent setpoint functions.

AFT and ALT Applicability For PRNM the TSTF-493 guidance is only applied to the CGS SR 3.3.1.1.10 for APRM fixed Neutron Flux High setdown, flow biased Simulated Thermal Power high, and Fixed Neutron Flux high setpoints, and to the CGS SR 3.3.2.1.5 for the RBM Upscale setpoints.

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 51 of 52 As described in the AFT/ALT data for PRNM sections, these SRs calibrate all the-PRNM analog input devices, so that after the SR is successfully completed, the entire PRNM equipment is calibrated to perform according to its design and performance specifications.

The calibration required by SR 3.3.1.1.10 is to be performed once every 24 months (Reference 18-10), through the PRNM "Auto-Calibration" process. The "Auto-Calibration" process is initiated manually, and then performs the required calibration steps automatically.

The "Auto-Calibration" procedure involves sending a known calibrated current into each LPRM and flow amplifier and internally adjusting the output after it is processed by the amplifier, and the associated sample-and-hold and A/D converter circuits, for any drift that may have occurred since the previous calibration. The "Auto-Calibration" procedure automatically assures that after "Auto-Calibration" each device is reset to the desired value within the ALT in compliance with TSTF-493 guidance. The procedure for determining the as-found setting (AFS) (or how much the instrument has drifted since the previous "Auto-Calibration") and comparing it to the AFT in compliance with TSTF-493 guidance, is described in the AFT/ALT data for PRNM sections of this RAI 18 response.

Energy Northwest utilizes the GEH calculation method described above for determining the AFT and ALT for the analog inputs to the PRNM system.

References 18-1. GE Hitachi Nuclear Energy, "Columbia Generating Station, Instrument Limits Calculation, Rod Block Monitor (NUMAC ARTS-MELLLA)," NEDC-33754P, Revision 0, June 2012 (ADAMS Accession No. ML12219A255).

18-2. GE Hitachi Nuclear Energy, "Columbia Generating Station, Instrument Limits Calculation, Average Power Range Monitor (NUMAC ARTS-MELLLA)," NEDC-33753P, Revision 0, June 2012 (ADAMS Accession No. ML12219A255).

18-3. GE Nuclear Energy, "General Electric Instrument Setpoint Methodology," NEDC-31336P-A, September 1996 (ADAMS Accession No. ML073450560).

18-4. Energy Northwest Letter, "Columbia Generating Station, Docket No. 50-397 Response to Request for Supplemental Information for Completion of Acceptance Review for PRNM/ARTS/MELLLA System Upgrade," G02-10-099, dated July 30, 2010 (ADAMS Accession No. ML102360357).

18-5. Entergy Letter, "Response to NRC Request for Additional Information Pertaining to License Amendment Request for Power Range Neutron Monitoring System (TAC No. ME2531)," GNRO-2011/00042, dated May 31, 2011 (ADAMS Ascension No. ML111520123).

and

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 52 of 52 Entergy Letter, "Response to NRC Request for Additional Information Pertaining to License Amendment Request for Power Range Neutron Monitoring System (TAC No. ME2531)," GNRO-2011/00066, dated September 2011 (ADAMS Ascension No.

ML112720128).

18-6. MA Krupa (Entergy Operations Inc.) to U.S Nuclear Regulatory Commission Document Control Desk, "Responses to NRC Requests for Additional Information Pertaining to License Amendment Request for Power Range Neutron Monitoring System (TAC No. ME2531)," GNRO-2010/00040, dated June 3, 2010 (ADAMS Accession No. ML101790436).

18-7. GE Hitachi Nuclear Energy letter to NRC, "Supplemental Information following NRC Public Meeting on GEH Setpoint Methodology," including Enclosure 1 "Response to NRC Summary Points on Application of Single-Sided Factor for Setpoint Margin Calculations," MFN 10-334, October 25, 2010.

18-8. NRC Regulatory Issue. Summary (RIS) 2006-17, NRC Staff Position on the Requirements of 10 CFR 50.36, "Technical Specifications," regarding Limiting Safety System Settings during Periodic Testing and Calibration of Instrument Channels, August.24, 2006 (ADAMS Accession No. ML051810077).

18-9. Letter, TSTF to NRC, "Transmittal of TSTF-493 Revision 4, Errata," TSTF-1 0-07, dated April 23, 2010 (ADAMS Accession No. ML101160026).

18-10. BJ Sawatkze (Energy Northwest) to NRC, "Columbia Generating Station, Docket No. 50-397, License Amendment Request to Change Technical Specifications in Support of PRNM / MELLLA Implementation," G02-12-017, dated January 31, 2012 (ADAMS Accession No. ML12040A072).

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Affidavit

GE-Hitachi Nuclear Energy Americas LLC AFFIDAVIT I, Edward D. Schrull, PE, state as follows:

(1) I am the Vice President, Regulatory Affairs, Services Licensing, of GE-Hitachi Nuclear Energy Americas LLC ("GEH"), and have been delegated the function of reviewing the information described in paragraph (2) which is sought to be withheld, and have been

'authorized to apply for its withholding.

(2) The information sought to be withheld is contained in Enclosures 1 and 3 of GEH letter, GE-MS-CT-106244-JC 19, "ENW-CGS PRNMAARTS/MELLLA Round 2 RAI Responses,"

dated September 26, 2012. The GEH proprietary information in Enclosure 1, which is entitled "GEH Responses to NRC EICB RAIs," is identified by a dotted underline inside double square brackets. ((This sentence.is.an.exampJe.3)) Large figures containing GEH proprietary information are identified with double square brackets before and after the object. In each case, the superscript notation {3} refers to Paragraph (3) of this affidavit, which provides the basis for the proprietary determination. Enclosure 3, which is entitled, "NUMAC Power Range Neutron Monitoring (PRNM) Components 268X1331TCG001, 268X1332TCG001, G002 268X1333TCG001 Qualification Summary for Energy Northwest (ENW) Columbia Generating Station (CGS)," Revision 1, November 8, 2010,"

is proprietary in its entirety. The {3} included in the header of each page refers to paragraph (3) of this affidavit, which provides the basis for the proprietary determination.

(3)

In making this application for withholding of proprietary information of which it is the owner or licensee, GEH relies upon the exemption from disclosure set forth in the Freedom of Information Act ("FOIA"), 5 USC Sec. 552(b)(4), and the Trade Secrets Act, 18 USC Sec. 1905, and NRC regulations 10 CFR 9.17(a)(4), and 2.390(a)(4) for trade secrets (Exemption 4). The material for which exemption from disclosure is here sought also qualifies under the narrower definition of trade secret, within the meanings assigned to those terms for purposes of FOIA Exemption 4 in, respectively, Critical Mass Energy Project v. Nuclear Regulatory Commission, 975 F2d 871 (DC Cir. 1992), and Public Citizen Health Research Group v. FDA, 704 F2d 1280 (DC Cir. 1983).

(4) The information sought to be withheld is considered to be proprietary for the reasons set forth in paragraphs (4)a. and (4)b. Some examples of categories of information that fit into the definition of proprietary information are:

a.

Information that discloses a process, method, or apparatus, including supporting data and analyses, where prevention of its use by GEH's competitors without license from GEH constitutes a competitive economic advantage over other companies;

b.

Information that, if used by a competitor, would reduce their expenditure of resources or improve their competitive position in the design, manufacture, shipment, installation, assurance of quality, or licensing of a similar product; Affidavit for Enclosures 1 and 3 Pagel1 of 3

GE-Hitachi Nuclear Energy Americas LLC

c.

Information that reveals aspects of past, present, or future GEH customer-fumded development plans and programs, resulting in potential products to GEH;

d.

Information that discloses trade secret and/or potentially patentable subject matter for which it may be desirable to obtain patent protection.

(5) To address 10 CFR 2.390(b)(4), the information sought to be withheld is being submitted to NRC in confidence. The information is of a sort customarily held in confidence by GEH, and is in fact so held. The information sought to be withheld has, to the best of my knowledge and belief, consistently been held in confidence by GEH, not been disclosed publicly, and not been made available in public sources. All disclosures to third parties, including any required transmittals to the NRC, have been made, or must be made, pursuant to regulatory provisions or proprietary and/or confidentiality agreements that provide for maintaining the information in confidence. The initial designation of this information as proprietary information, and the subsequent steps taken to prevent its unauthorized disclosure, are as set forth in the following paragraphs (6) and (7).

(6) Initial approval of proprietary treatment of a document is made by the manager of the originating component, who is the person most likely to be acquainted with the value and sensitivity of the information in relation to industry knowledge, or who is the person most likely to be subject to the terms under which it was licensed to GEH. Access to such documents within GEH is limited to a "need to know" basis.

(7)

The procedure for approval of external release of such a document typically requires review by the staff manager, project manager, principal scientist, or other equivalent authority for technical content, competitive effect, and determination of the accuracy of the proprietary designation. Disclosures outside GEH are limited to regulatory bodies, customers, and potential customers, and their agents, suppliers, and licensees, and others with a legitimate need for the information, and then only in accordance with appropriate regulatory provisions or proprietary and/or confidentiality agreements.

(8)

The information identified in paragraph (2), above, is classified as proprietary because it contains the detailed setpoint methodology and design information for the instrumentation and control equipment that is used in the design and analysis of the power range neutron monitoring system for the GEH Boiling Water Reactor (BWR). These methods, techniques, and data along with their application to the design, modification, and analyses associated with the power range neutron monitoring system was achieved at a significant cost to GEH.

The development of the evaluation processes along with the interpretation and application of the analytical results is derived from the extensive experience databases that constitute a major GEH asset.

(9)

Public disclosure of the information sought to be withheld is likely to cause substantial harm to GEH's competitive position and foreclose or reduce the availability of profit-making opportunities. The information is part of GEH's comprehensive BWR safety and technology base, and its commercial value extends beyond the original development cost.

The value of the technology base goes beyond the extensive physical database and Affidavit for Enclosures 1 and 3 Page 2 of 3

GE-Hitachi Nuclear Energy Americas LLC analytical methodology and includes development of the expertise to determine and apply the appropriate evaluation process. In addition, the technology base includes the value derived from providing analyses done with NRC-approved methods.

The research, development, engineering, analytical and NRC review costs comprise a substantial investment of time and money by GEH. The precise value of the expertise to devise an evaluation process and apply the correct analytical methodology is difficult to quantify, but it clearly is substantial. GEH's competitive advantage will be lost if its competitors are able to use the results of the GEH experience to normalize or verify their own process or if they are able to claim an equivalent understanding by demonstrating that they can arrive at the same or similar conclusions.

The value of this information to GEH would be lost if the information were disclosed to the public. Making such information available to competitors without their having been required to undertake a similar expenditure of resources would unfairly provide competitors with a windfall, and deprive GEH of the opportunity to exercise its competitive advantage to seek an adequate return on its large investment in developing and obtaining these very valuable analytical tools.

I declare under penalty of perjury that the foregoing affidavit and the matters stated therein are true and correct to the best of my knowledge, information, and belief.

Executed on this 26th day of September 2012.

Edward D. Schrull, PE Vice President, Regulatory Affairs Services Licensing GE-Hitachi Nuclear Energy Americas LLC 3901 Castle Hayne Rd.

Wilmington, NC 28401 Affidavit for Enclosures 1 and 3 Page 3 of 3

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Revised TS Bases Page 3.3.1.1-29 (for information only)

RPS Instrumentation B 3.3.1.1 BASES SURVEILLANCE REQUIREMENTS Note (d) requires evaluation of channel performance for the condition where the as-found setting for the channel setpoint is not the Limiting Trip Setpoint (LTSP) but is conservative with respect to the Allowable Value. For digital channel components, no as-found tolerance or as-left tolerance can be specified.

Where a setpoint more conservative than the LTSP is used in the plant surveillance procedures (i.e. nominal trip setpoint, or NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure.setpoint. Evaluation of instrument performance will verify that the instrument will continue to behave in accordance with design basis assumptions. The purpose of the assessment is to ensure confidence in the instrument performance prior to returning the instrument to service.

Any nonconformance will be entered into the Corrective Action Program which will ensure required review and documentation of the condition for continued OPERABILITY.

Note (e) requires that the as-left setting for the instrument be returned to within an acceptable as-left tolerance around the LTSP. Where a setpoint more conservative than the LTSP is used in the plant surveillance procedures (i.e., nominal trip setpoint, or NTSP), the as-left and as-found tolerances, as applicable, will be applied to the surveillance procedure setpoint. This will ensure that sufficient margin to the Safety Limit and/or Analytical Limit is maintained.

If the as-left instrument setting cannot be returned to the LTSP, then the instrument channel shall be declared inoperable. The LTSPs are specified in the Licensee Controlled Specifications.

SR 3.3.1.1.9 and SR 3.3.1.1.10 (continued) calorimetric calibration (SR 3.3.1.1.2) and the 1130 MWD/T LPRM calibration against the TIPs (SR 3.3.1.1.7).

A second Note is provided that requires the APRM Rad IRM SRs to be performed within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> of entering MODE 2 from MODE 1.

Testing of the MODE 2 APRM and IRM Functions cannot be performed in MODE I without utilizing jumpers, lifted leads, or moveable links.

This Note allows entry into MODE 2 from MODE I if the associated Frequency is not met per SR 3.0.2.

Twelve hours is based on operating experience and in consideration of providing a reasonable time in which to complete the SR.

The Frequen. y

.f SR.3 1

is based L 9 JVI L.II'..

uj..*..U*L.4,,p*.

r, U

U J'.t,"T tUJ V

I,.. I,,.JU.J~ir

JIIL,

.[

VU i r

l' II e~inatic of the magnituide of equi pment. drift4 in the tpeint an"alysis.

The Frequency of SR 3.3.1.1.10 is based on the assumption of an 18 month calibration interval for Functions

".hough 4, 6, 7, and 9 through 11 in the determination

ýte magnitude of equipment drift in the setpoint analysis.

1,3,4, 1 5Ian A Frequency of 24 months is assumed for Functions 5 and 8 acause the position switches that perform these Functions ar not susceptible to instrument drift.

SR 3.3.1.1.11

-Notused.

The AveragP*.....

Ra.ge M;aiter Flow Biased Simul at Therm-al Power High F-nction uses an electrni filtr ciruit to geneprate a signal propor*t4on4l to the core-THIERMAL: POWER fromff the APRM neuitron flubx si gnal.

Th i fil...teF.r c

uit i

Qn 4 t-h @ faul heat tranAfer dym-icS that produac tho relationship between the neutron flux and the core THERMAL PO*,ER The filter time Pconta* t mubst be Yen fi d to enrsur-e that "the ehannel i, accuir-ately-reflecting the desired parameter.

The Frequen.y of 18 mo..nths is based on enRg*n..ing judgment

-and-reliability of th componentu.

(continued) ig Station B 3.3.1.1-29 Revision 29

RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT PRNM/ARTS/MELLLA Page 1 of 1 List of Commitments The following table identifies the regulatory commitments in this document. Any other statements in this submittal regarding intended or planned actions are provided for information purposes and are not considered to be regulatory commitments.

Scheduled Completion Commitment Date The affected calibration procedures will be revised to ensure that the Corrective Action Program will be utilized to track and Prior to Startup from evaluate when the as-found channel setpoint is outside its Refuel 22 (Spring 2015) predicted as-found tolerance.