ML13364A286
| ML13364A286 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 12/30/2013 |
| From: | Kevin Mulligan Entergy Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML13364A284 | List: |
| References | |
| GNRO-2013-/00100 | |
| Download: ML13364A286 (21) | |
Text
1
.-.pEntergy contains PROPRIETARY information.
Withhold per 10 CFR 2.390.
GNRO-2013/00100 December 30,2013 u.s. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Entergy Operations, Inc.
P. O. Box 756 Port Gibson. MS 39150 Kevin J. Mulligan Site Vice President TeL (601) 437-7500
SUBJECT:
Maximum Extended Load Line Limit Analysis Plus (MELLLA+)
License Amendment Request -
Responses to Requests for Supplemental Information Grand Gulf Nuclear Station, Unit 1 Docket No. 50-416 License No. NPF-29
REFERENCES:
1.
Entergy Operations, Inc. letter to the NRC, Maximum Extended Load Line Limit Analysis Plus (MELLLA +) License Amendment Request, dated September 25, 2013 (ML13269A140) 2.
NRC letter to Entergy Operations, Inc., Grand Gulf Nuclear Station, Unit 1 - Supplemental Information Needed for Acceptance of Licensing Action, Request to Allow Operation in Expanded Maximum Extended Load Line Limit Analysis Plus Domain, dated December 19, 2013 (ML13345A182)
Dear Sir or Madam:
In Reference 1, Entergy Operations, Inc. (Entergy) submitted to the U.S. Nuclear Regulatory Commission (NRC) a license amendment request (LAR) that would allow Grand Gulf Nuclear Station, Unit 1 (GGNS) to operate in the expanded Maximum Extended Load Line Limit Analysis Plus (MELLLA+) domain. In Reference 2, the NRC requested supplemental information to support their acceptance review of the MELLLA+ LAR. Attachment 1 provides responses to these requests for supplemental information (RSls).
General Electric - Hitachi (GEH) considers certain information contained in Attachment 1 to be proprietary and, therefore, exempt from public disclosure pursuant to Title 10 Code of Federal Regulations (10 CFR) 2.390. The associated affidavit for withholding information, executed by GEH, is provided in Attachment 2. The responses to the RSls were provided by GEH to Entergy in a transmittal letter that is referenced in the affidavit. Therefore, on behalf of GEH, Entergy requests Attachment 1 be withheld from public disclosure in accordance with 10 CFR 2.390(b)(1). A non-proprietary version of Attachment 1 is provided in Attachment 3.
When Attachment 1 is removed from this letter, the entire document is NON-PROPRIETARY.
.-.pEntergy contains PROPRIETARY information.
Withhold per 10 CFR 2.390.
GNRO-2013/00100 December 30,2013 u.s. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Entergy Operations, Inc.
P. O. Box 756 Port Gibson. MS 39150 Kevin J. Mulligan Site Vice President TeL (601) 437-7500
SUBJECT:
Maximum Extended Load Line Limit Analysis Plus (MELLLA+)
License Amendment Request -
Responses to Requests for Supplemental Information Grand Gulf Nuclear Station, Unit 1 Docket No. 50-416 License No. NPF-29
REFERENCES:
1.
Entergy Operations, Inc. letter to the NRC, Maximum Extended Load Line Limit Analysis Plus (MELLLA +) License Amendment Request, dated September 25, 2013 (ML13269A140) 2.
NRC letter to Entergy Operations, Inc., Grand Gulf Nuclear Station, Unit 1 - Supplemental Information Needed for Acceptance of Licensing Action, Request to Allow Operation in Expanded Maximum Extended Load Line Limit Analysis Plus Domain, dated December 19, 2013 (ML13345A182)
Dear Sir or Madam:
In Reference 1, Entergy Operations, Inc. (Entergy) submitted to the U.S. Nuclear Regulatory Commission (NRC) a license amendment request (LAR) that would allow Grand Gulf Nuclear Station, Unit 1 (GGNS) to operate in the expanded Maximum Extended Load Line Limit Analysis Plus (MELLLA+) domain. In Reference 2, the NRC requested supplemental information to support their acceptance review of the MELLLA+ LAR. Attachment 1 provides responses to these requests for supplemental information (RSls).
General Electric - Hitachi (GEH) considers certain information contained in Attachment 1 to be proprietary and, therefore, exempt from public disclosure pursuant to Title 10 Code of Federal Regulations (10 CFR) 2.390. The associated affidavit for withholding information, executed by GEH, is provided in Attachment 2. The responses to the RSls were provided by GEH to Entergy in a transmittal letter that is referenced in the affidavit. Therefore, on behalf of GEH, Entergy requests Attachment 1 be withheld from public disclosure in accordance with 10 CFR 2.390(b)(1). A non-proprietary version of Attachment 1 is provided in Attachment 3.
When Attachment 1 is removed from this letter, the entire document is NON-PROPRIETARY.
GNRO-2013/00100 Page 2 of 2 contains PROPRIETARY information.
Withhold per 10 CFR 2.390.
This letter contains no new commitments.
If you have any questions or require additional information, please contact Mr. Jeff Seiter at (601) 437-2344.
I declare under penalty of perjury that the foregoing is true and correct; executed on December 30, 2013.
Sincerely,
~
C;'k<<.A ~ ~ /(. J I1,J/f1V7 KJM/slw dO 0
Attachments:
1.
Responses to NRC Requests for Supplemental Information (Proprietary Version) 2.
General Electric - Hitachi Affidavit Supporting Request to Withhold Information from Public Disclosure 3.
Responses to NRC Requests for Supplemental Information (Non-Proprietary Version) cc:
U.S. Nuclear Regulatory Commission ATTN: Mr. Mark Dapas, (w/2)
Regional Administrator, Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511 U. S. Nuclear Regulatory Commission ATTN: Mr. Alan Wang, NRRlDORL (w/2)
Mail Stop OWFN 8 B1 Washington, DC 20555-0001 NRC Senior Resident Inspector Grand Gulf Nuclear Station Port Gibson, MS 39150 When Attachment 1 is removed from this letter, the entire document is NON-PROPRIETARY.
GNRO-2013/00100 Page 2 of 2 contains PROPRIETARY information.
Withhold per 10 CFR 2.390.
This letter contains no new commitments.
If you have any questions or require additional information, please contact Mr. Jeff Seiter at (601) 437-2344.
I declare under penalty of perjury that the foregoing is true and correct; executed on December 30, 2013.
Sincerely,
~
C;'k<<.A ~ ~ /(. J I1,J/f1V7 KJM/slw dO 0
Attachments:
1.
Responses to NRC Requests for Supplemental Information (Proprietary Version) 2.
General Electric - Hitachi Affidavit Supporting Request to Withhold Information from Public Disclosure 3.
Responses to NRC Requests for Supplemental Information (Non-Proprietary Version) cc:
U.S. Nuclear Regulatory Commission ATTN: Mr. Mark Dapas, (w/2)
Regional Administrator, Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511 U. S. Nuclear Regulatory Commission ATTN: Mr. Alan Wang, NRRlDORL (w/2)
Mail Stop OWFN 8 B1 Washington, DC 20555-0001 NRC Senior Resident Inspector Grand Gulf Nuclear Station Port Gibson, MS 39150 When Attachment 1 is removed from this letter, the entire document is NON-PROPRIETARY.
to GNRO-2013/00100 General Electric - Hitachi idavit Supporting Request to Withhold Information from Public Disclosure to GNRO-2013/00100 General Electric - Hitachi Affidavit Supporting Request to Withhold Information from Public Disclosure
GE-Hitachi Nuclear Energy Americas LLC AFFIDAVIT I, Linda C. Dolan, state as follows:
(1)
I am the Manager of Regulatory Compliance, ofGE-Hilachi 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 Enclosure I of GEH letter, GEH-GGNS-AEP-634, "GEH Respon es to MELLLA Plus EICB Requests for Supplemental Information," dated December 19, 2013. The GEH proprietary information in Enclosure I, which is entitled "Responses to EICB Requests for Supplemental Information in Support of GGNS MFLLLA+ LAR," is identified by a dotted underline inside double square brackets.
((Ib.i~...~~n!~!1~~jL~-'L.~)5..~m.pJ.;... ~~.'.l]
In each case, the superscript notation :3: refers to Paragraph (3) ofthis 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 ofJriformation Act ("FOIA"), 5 U.S.c. Sec. 552(b)(4), and the Trade Secrets Act, 18 U.S.c.
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 F.2d 871 (D.C. Cir. 1992), and Public Citizen Health Research Group v. FDA, 704 F.2d 1280 (D.C. 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 ofproprielary 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 ofquality, or licensing ofa similar product; c.
Information that reveals aspects of past, present, or future GEH customer-funded development plans and programs, resulting in potential products to GEH; d.
Information that discloses trade secret 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 sOl1 customarily held in confidence by GEH, Affidavit for GEH-GGNS-AEP-634 Page 1 of3
GE-Hitachi Nuclear Energy Americas LLC 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 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 bod ies, 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 or confidentiality agreements.
(8)
The information identified in paragraph (2) above, is classified as proprietary because it contains the detailed GEH methodology for stability analysis 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 DSS-CD were achieved at a significant cost to GEH.
The development of the evaluation processes along with the interpretation and application of the analytical resu Its 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 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 Affidavit for GEH-GGNS-AEP-634 Page 2 of3
GE-Hitachi Nuclear Energy Americas LLC 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 19th day of December 2013.
Affidavit for GEH-GG S-AEP-634 Linda C. Dolan Manager, Regulatory Compliance GE-Hitachi Nuclear Energy Americas LLC 390 I Castle Hayne Rd.
Wilmington, NC 2840]
Linda.Dolan@ge.com Page 3 of3 to GNRO-2013/00100 Responses to NRC Requests for Supplemental Information (Non-Proprietary Version)
"",11\\+"\\11' information been square brackets 111"'r~:l""nlrnOlt"'a'" 1 from which
,.u*t"\\,"'U'u~t~I"'\\1 n\\......I1'\\n~ that have been removed are indicated here: ((
] to GNRO-2013/00100 Responses to NRC Requests for Supplemental Information (Non-Proprietary Version)
This is a non-proprietary version of Attachment 1 from which the proprietary information has been removed. The proprietary portions that have been removed are indicated by double square brackets as shown here: ((
1
Non-Proprietary Information - Class I (Public)
MELLLA+ LICENSE ENDMENT REQUEST RESPONSES TO C REQUESTS FOR SU INFORMATION u.s. Nuclear Commission (NRC)
September 201 Inc. (Entergy) submitted to the NRC a license amendment request (LAR) that would allow Grand Gulf Nuclear Station, Unit 1 (GGNS) to operate in the expanded Maximum Load Line Limit Analysis Plus (MELLLA+) domain. In a to Entergy dated 1
201 the NRC supplemental information to support their review of the MELLLA+ LAR.
to requests for supplemental information (RSls) are provided below.
RSI #1
""",,,.n"'J'' the a NRC-rMELLLA+
supplemental information on the uu..'v v
uuvn,uw
Response
(SSP) used when the Oscillation including in the SSP solution and the ASSP are maintained and approved in the DSS-CD LTR NEDC-33075P-A, Revision 8, that is applied to the GGNS MELLLA+ SAR application 1 1).
provides an means for stability protection by of growing power oscillations in the region of the power/flow map identified as likely to develop thermal-hydraulic instabilities.
In the June 2011 DSS-CD LTR (NEDC-33075P-A, Revision 6 (page 1
the NRC stated that "The asp documented in Section 7 of NEDC-33075P, Revision is a technically acceptable solution to the backup issue. to GNRO-2013/00100 Page 1 of 14 Non-Proprietary Information - Class I (Public)
MELLLA+ LICENSE AMENDMENT REQUEST RESPONSES TO NRC REQUESTS FOR SUPPLEMENTAL INFORMATION In a letter to the U.S. Nuclear Regulatory Commission (NRC) dated September 25, 2013, Entergy Operations, Inc. (Entergy) submitted to the NRC a license amendment request (LAR) that would allow Grand Gulf Nuclear Station, Unit 1 (GGNS) to operate in the expanded Maximum Extended Load Line Limit Analysis Plus (MELLLA+) domain. In a letter to Entergy dated December 19, 2013, the NRC requested supplemental information to support their acceptance review of the MELLLA+ LAR. Responses to these requests for supplemental information (RSls) are provided below.
RSI #1 Page xiii of the September 17, 2007, MELLLA+ topical report (TR) states: "Therefore, the NRC staff concluded that manual backup stability protection is not appropriate and a NRC-approved automatic backup stability protection must be implemented for MELLLA+
operation." Please provide the required supplemental information on the automatic backup stability protection.
Response
The NRC approved automatic backup stability protection is implemented for GGNS MELLLA+
Safety Analysis Report (SAR) application (Reference 1.1) as documented in Section 2.4.3 in Reference 1.1. The approval of this automatic backup stability protection is documented in the NRC Safety Evaluation (SE) included in Reference 1.2. All the information about this Automatic Backup Stability Protection (ABSP) is provided in Section 7 of Reference 1.2, which is the approved Detect and Suppress Solution - Confirmation Density (DSS-CD) licensing topical report (LTR) revision applicable to GGNS MELLLA+ SAR.
In the October 2008 MELLLA+ LTR NEDC-33006P-A, Revision 3 (page xiii), NRC stated:
"Therefore, the NRC staff concluded that manual backup stability protection is not appropriate and a NRC-approved automatic backup stability protection must be implemented for MELLLA+ operation." To meet this requirement, GEH has provided in the approved DSS-CD LTR (NEDC-33075P-A, Revision 6, Reference 1.3) a Backup Stability Protection (BSP) approach that includes an automatic function and that may be used when the Oscillation Power Range Monitor (OPRM) system is inoperable up to and including operation in the MELLLA+ domain. The BSP solution and the ABSP function are maintained and approved in the DSS-CD LTR NEDC-33075P-A, Revision 8, that is applied to the GGNS MELLLA+ SAR application (Reference 1.1).
This comprehensive BSP approach provides an alternative means for stability protection by preventing the onset of growing power oscillations in the specific region of the power/flow map identified as likely to develop thermal-hydraulic instabilities.
In the June 2011 DSS-CD LTR (NEDC-33075P-A, Revision 6 (page 5), Reference 1.3), the NRC stated that "The asp concept, documented in Section 7 of NEDC-33075P, Revision 5, is a technically acceptable solution to the backup issue."
Non-Proprietary Information - Class I (Public)
BSP is in Section 7 and implemented per (TS) changes documented in Appendix A of the approved 33075P-A, Revision 6, Reference 1.3) and includes two BSP options that are selected elements from three distinct constituents. The three constituents are:
4.
BSP Manual Regions that comprise plant-specific scram (Region I) and Controlled Entry (Region II) regions in the licensed power/flow operating domain and associated manual operator actions (Section of Reference 1.3).
BSP Boundary that defines the operating domain portion where potential instability can be effectively addressed by specific operator actions (Section of Reference 1 6.
ABSP Scram Region, which comprises an automatic scram region initiated by Power Range Monitor (APRM) flow-biased scram setpoint (Section 7.4 of 1.3).
The two options are:
BSP Manual L.lr\\I**.. r\\t\\l BSP Boundary Option of ABSP
"'1""""""-'1 scram setpoint, Region II and ""'_"""'_"_"""_
the APRM flow-or is inoperable, BSP Boundary, which is stability
))
NRC concluded in the DSS-CD LTR NEDC-33075P-A, Revision 6 (page 6), in 1
the proposed asp methodology an
- solution, it provides sufficient protection against Limit Minimum Critical Power Ratio (SLMCPR) violations commensurate with the probability of an instability event in the short period of time that they are active.
All functions BSP solution, including the ABSP function, are maintained and approved in the DSS-CD LTR NEDC-33075P-A, Revision 8, and of to GNRO-2013/00100 Page 2 of 14 Non-Proprietary Information - Class I (Public)
This comprehensive BSP is described in Section 7 and implemented per the Technical Specification (TS) changes documented in Appendix A of the approved DSS-CD LTR (NEDC-33075P-A, Revision 6, Reference 1.3) and includes two BSP options that are based on selected elements from three distinct constituents. The three constituents are:
4.
BSP Manual Regions that comprise plant-specific scram (Region I) and Controlled Entry (Region II) regions in the licensed power/flow operating domain and associated manual operator actions (Section 7.2 of Reference 1.3).
5.
BSP Boundary that defines the operating domain portion where potential instability events can be effectively addressed by specific operator actions (Section 7.3 of Reference 1.3).
6.
ABSP Scram Region, which comprises an automatic reactor scram region initiated by the Average Power Range Monitor (APRM) flow-biased scram setpoint (Section 7.4 of Reference 1.3).
The two BSP options are:
Option 1: Consists of the BSP Manual Regions, BSP Boundary and associated operator actions.
Option 2: Consists of the ABSP Scram Region, as implemented by the APRM flow-biased scram setpoint, Region II and associated operator actions.
The TS changes contained in Reference 1.3 and in the GGNS MELLLA+ LAR delineate specific implementation requirements for both BSP options in the unlikely event the OPRM system is declared inoperable. In such instance, the operators have 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> to manually implement the ASBP function. In the interim, instability protection is implemented via the Manual BSP regions, which are administratively implemented. With the ABSP (Option 2), a scram is automatically generated if the reactor enters a pre-determined scram region regardless of whether or not a thermal-hydraulic instability occurs.
In case the ABSP function cannot be implemented or is inoperable, the licensed stability solution becomes the Manual BSP region with the BSP Boundary, which is manually implemented through administrative actions. ((
))
Therefore, NRC concluded in the DSS-CD LTR NEDC-33075P-A, Revision 6 (page 6), in Reference 1.3 "that the proposed asp methodology is an acceptable solution, because it provides sufficient protection against Safety Limit Minimum Critical Power Ratio (SLMCPR) violations commensurate with the probability of an instability event in the short period of time that they are active."
All these elements and functions of the SSP solution, including the ABSP function, are maintained and approved in the DSS-CD LTR NEDC-33075P-A, Revision 8, and SE of
Non-Proprietary Information - Class I (Public)
((
))
References:
1 1 Analysis Report for Grand Gulf Nuclear Station -
Limit Plus," NEDC-3361 2013 (Attachment 4 to ML13269A140).
1 Hitachi Nuclear _~c',rc",
Solution - Confirmation (ML11161 Hitachi Boiling Water and Suppression Revision 8, November 2013 1
Response
r\\1"Y'l1"'\\.....4"",..,..*'r\\,.. in 1
This information and/or firmware as per As in 1-1 of approved topic (LTR) for Detect and Suppress Solution - Confirmation Density (DSS-CD), NEDC-33075P-A (Reference 2.1):
is based on the same hardware design as Option III, which is described in 1 through 3.
Also, in The references 1 through 3 cited are from to GNRO-2013/00100 Page 3 of 14 Non-Proprietary Information - Class I (Public)
NEDC-33075P, Revision 7, (Reference 1.2) that is applied to the GGNS MELLLA+ SAR application (Reference 1.1).
((
))
References:
1.1 GE Hitachi Nuclear Energy, "Safety Analysis Report for Grand Gulf Nuclear Station -
Maximum Extended Load Line Limit Analysis Plus," NEDC-33612P, September 2013 (Attachment 4 to ML13269A140).
1.2 GE Hitachi Nuclear Energy, "GE Hitachi Boiling Water Reactor Detect and Suppression Solution - Confirmation Density," NEDC-33075P-A, Revision 8, November 2013 (ML111610593).
1.3 GE Hitachi Nuclear Energy, "General Electric Boiling Water Reactor Detect and Suppression Solution - Confirmation Density," NEDC-33075P-A, Revision 6, January 2008.
RSI #2 Please provide hardware/software technical information as emphasized in the reference document General Electric - Hitachi (GEH) NEDC-33075P, pages 1-2. This information should specifically document the hardware and software and/or firmware designs as per any variations from MELLLA to the MELLLA+ algorithm.
Response
As noted in page 1-1 of the approved licensing topic report (LTR) for Detect and Suppress Solution - Confirmation Density (DSS-CD), NEDC-33075P-A (Reference 2.1):
'The DSS-CD is based on the same hardware design as Option III, which is described in References 1 through 3." 4 Also, in page 2-2:
4 The references 1 through 3 cited are from NEDC-33075P-A.
Non-Proprietary Information -
I (Public)
The NRC staff previously reviewed and approved the implementation of DSS-CD using the approved GEH Option III hardware and software. The DSS-CD solution is not generically approved for use with non-GEH hardware. The hardware components required to implement DSS-CD are those currently used for the approved Option III. If the DSS-CD hardware implementation deviates from the approved Option III solution, a hardware review by the NRC staff will required. Implementations on other Option III platforms will require plant-specific DSS-CD stability solution (CDA, ABSP, and Option III) for GGNS is implemented in the GGNS Power Range Neutron Monitor (PRNM)
Limitation Condition 5.1 in approved DSS-CD LTR NEDC-33075P-A (Reference 1)
UThe NRC staff previously reviewed and approved III S-CD,,",,'-'I\\..AU,-,I use with non-GEH hardware. The hardware components required to implement DSS-CD are
"""""""""",,,,"'" to Option III. If the DSS-CD hardware Irnr,'orno""-J1'j,..." ae"'Jalf~Sfrom the Option III solution, a by the NRC Implementations on other Option III platforms will require plant-specific MELLLA+.
PRNM C"\\.IC"ll"£:lrTl with all the required functionalities implementation of the I-101'~~ronjr"o 2.8 (RAI 4).
was used for the PRNM, Option III, DSS-CD (CDA GEH development process is noted in the The protection for MELLLA+ is which includes Density Algorithm (GOA) and Automatic Stability (ABSP). Option III is maintained for defense-in-depth purpose. Unless otherwise the term DSS-GD in this for supplement information response would mean both GOA and ABSP. to GNRO-2013/00100 Page 4 of 14 Non-Proprietary Information - Class I (Public)
'The DSS-CD solution introduces a number of changes relative to the Option III solution. In addition, it introduces a number of modifications and restrictions to the successive confirmation period element of the Period Based Detection Algorithm (PBDA) to improve its ability for early recognition of reactor oscillations. These changes only affect the system software/firmware, and therefore, may be able to be implemented on-line."
The NRC staff previously reviewed and approved the implementation of DSS-CD using the approved GEH Option III hardware and software. The DSS-CD solution is not generically approved for use with non-GEH hardware. The hardware components required to implement DSS-CD are those currently used for the approved Option III. If the DSS-CD hardware implementation deviates from the approved Option III solution, a hardware review by the NRC staff will be required. Implementations on other Option III platforms will require plant-specific reviews. The DSS-CD stability solution (CDA, ABSP,5 and Option III) for GGNS is implemented in the GGNS Power Range Neutron Monitor (PRNM) system.
Limitation and Condition 5.1 in the approved DSS-CD LTR NEDC-33075P-A (Reference 2.1) states that:
"The NRC staff previously reviewed and approved the implementation of DSS-CD using the approved GEH Option 11/ hardware and software. The DSS-CD solution is not approved for use with non-GEH hardware. The hardware components required to implement DSS-CD are expected to be those currently used for the approved Option 11/. If the DSS-CD hardware implementation deviates from the approved Option III solution, a hardware review by the NRC staff will be required. Implementations on other Option 11/ platforms will require plant-specific reviews."
The GGNS MELLLA+ safety analysis report (SAR), NEDC-33612P (Reference 2.2) documents in Appendix C compliance with this Limitation and Condition because the DSS-CD solution for GGNS is implemented on GEH hardware that is currently installed and approved by the NRC for the Option III solution.
Therefore, the technical information provided for the GGNS PRNM (Reference 2.3) is applicable to the DSS-CD design. Specifically, the PRNM LTR (References 2.4 and 2.5) provided technical information of the approved PRNM system. Reference 2.6 identified the plant-specific differences from the PRNM LTR. Reference 2.7 (RAI 5) provided additional explanation of the PRNM configuration for the GGNS PRNM system. The implementation strategy for the GGNS PRNM is to provide the system with all the required functionalities except that the DSS-CD trip will be inactive (using a jumper) until the implementation of the MELLLA+. Additional information about this approach is provided in Reference 2.8 (RAI 4).
The same software development process was used for the PRNM, Option III, DSS-CD (CDA and ABSP). The NRC approval of the GEH software development process is noted in the SER (Reference 2.3).
5 The stability protection for MELLLA+ is DSS-CD which includes Confirmation Density Algorithm (CDA) and Automatic Backup Stability Solution (ABSP). Option III is maintained for defense-in-depth purpose. Unless otherwise specified, the term DSS-CD in this request for supplement information (RSI) response would mean both CDA and ABSP.
Non-Proprietary Information - Class I (Public)
\\11",I~."_t""lnnr'I"11",....++"..."I'"\\I"I"'\\l"" evaluated in Uni'nl"'nnl"l"'\\
configuration and other prior licensing commitments.
MELLLA to the MELLLA+ algorithm.
References:
1 GE Hitachi Nuclear Energy, Hitachi Boiling Water Reactor Detect and Suppression Solution - Confirmation Density, NEDC-33075P-A, Revision 8, November 2013 (ADAMS Accession No, ML111610593).
GE Hitachi Nuclear Energy, "Safety Analysis Report for Grand Gulf Nuclear Station Maximum Extended Load Line Limit Analysis Plus, NEDC-33612P, September 2013.
A.Wang (NRC) to VP, Operations (Entergy Operation, Inc), "Grand Gulf Nuclear Station, Unit 1 of Amendment Power Range Neutron Monitoring System Replacement (TAC No. ME2531)," March 28,2012 (ADAMS Accession No. ML120400319).
Nuclear Energy, "Nuclear Measurement Analysis and Control Power Range Neutron Monitor (NUMAC PRNM) Retrofit Plus Option III Stability Trip Function," NEDC-32410P-A, October 1 NEDC-32410P-A, "Nuclear Measurement Analysis and Control Power Range Neutron Monitor (NUMAC PRNM) Retrofit Plus Option III Stability Trip Function," Supplement 1, 1\\.11".ur'Vih... 1 Gulf Nuclear _1"'1."
by NUMAC PRN Plus Option III
....,""'-4I...III1"Y (NEDC-32410P-A), GE-NE-0000-0102-0888.
Additional Information to Neutron Monitoring (TAC No. ME2531),"
14, 2010 (ML103490095) - Response to RAI Operations, Inc.) to Nuclear Regulatory Commission Document D
k, to NRC
.._"",..._....,,,...., for Additional Information Pertaining to Amendment Request for Range Neutron Monitoring System (TAC No.
- .--r,...... ~... ), GNRO-2011/00032, May 3,2011 (ML111230756) - Response to RAI 4.
RSI#3 Demonstrate common-cause failure vulnerabilities and the defense-in-depth for the algorithms and the backup stability solution. It is unclear if the primary and backup s
bility trip functions for MELLLA+ use the same software and are therefore subject to common-cause failure.
provide a discussion of the postulated Software Common-Cause Failure (SWCCF) with possible consequences on diversity and to GNRO-2013/00100 Page 5 of 14 Non-Proprietary Information - Class I (Public)
The plant-specific differences evaluated in Reference 2.6 were due to the plant-specific configuration and other prior licensing commitments. There was no deviation from the MELLLA to the MELLLA+ algorithm.
References:
2.1 GE Hitachi Nuclear Energy, "GE Hitachi Boiling Water Reactor Detect and Suppression Solution - Confirmation Density," NEDC-33075P-A, Revision 8, November 2013 (ADAMS Accession No, ML111610593).
2.2 GE Hitachi Nuclear Energy, "Safety Analysis Report for Grand Gulf Nuclear Station Maximum Extended Load Line Limit Analysis Plus," NEDC-33612P, September 2013.
2.3 A.Wang (NRC) to VP, Operations (Entergy Operation, Inc), "Grand Gulf Nuclear Station, Unit 1 -Issuance of Amendment RE: Power Range Neutron Monitoring System Replacement (TAC No. ME2531)," March 28,2012 (ADAMS Accession No. ML120400319).
2.4 GE Nuclear Energy, "Nuclear Measurement Analysis and Control Power Range Neutron Monitor (NUMAC PRNM) Retrofit Plus Option III Stability Trip Function," NEDC-32410P-A, October 1995.
2.5 NEDC-32410P-A, "Nuclear Measurement Analysis and Control Power Range Neutron Monitor (NUMAC PRNM) Retrofit Plus Option III Stability Trip Function," Supplement 1, November 1997.
2.6 GE Hitachi Nuclear Energy Report, "Grand Gulf Nuclear Station - Plant-Specific Responses Required by NUMAC PRNM Retrofit Plus Option III Stability Trip Function Topical Report (NEDC-32410P-A)," GE-NE-0000-01 02-0888.
2.7 M. A. Krupa (Entergy Operations Inc.) to U.S Nuclear Regulatory Commission Document Control Desk, "Response to NRC Request for Additional Information Pertaining to License Amendment Request for Power Range Neutron Monitoring System (TAC No. ME2531 ),"
GNRO-2010/00070, dated December 14, 2010 (ML103490095) - Response to RAI 5.
2.8 M.A. 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-2011/00032, dated May 3,2011 (ML111230756) - Response to RAI 4.
RSI #3 Demonstrate the common-cause failure vulnerabilities and the defense-in-depth for the detection algorithms and the backup stability solution. It is unclear if the primary and backup stability trip functions for MELLLA+ use the same software and are therefore subject to software common-cause failure. Please provide a discussion of the postulated Software Common-Cause Failure (SWCCF) with its possible consequences on diversity and defense-in-depth.
Non-Proprietary Information -
Response
As documented in response RSI
- above, DSS-CD and Suppress Solution - Confirmation Density) (Confirmation Density Algo m (CDA) and Automatic Backup Stability Protection (ABSP)) and Option III are all modules within Power Neutron Monitoring (PRNM) system that would provide the stability solution. Prior to the implementation MELLLA+, the Option III is the licensed solution for instability protection. With the implementation of MELLLA+, DSS-CD would become the solution. The Option III trips (Period Algorithm (PBA), Amplitude Algorithm (ABA), and Growth Rate Algorithm (GRA)) are maintained in the PRNM system to capability6. However, under the DSS-CD solution the Option III trips licensing In the unlikely that CDA inoperable, to meet the minimum number of cells requirements in more than one will manually to provide the stability the ABSP is an stability solution to CDA only in rare As Section 7 and in the Technical (TS) documented in the approved topical report (LTR), NEDC-33075P-A 1),
are two Protection (SSP) are on from three The are:
plant-specific scram (Region I) and Controlled 1I1""l,.......... t"r"t"'t n.!"'\\\\AII"... /1'III"'\\\\A' I"\\nL~r~t'lnn domain 1).
are:
Boundary 1
implementation the Oscillation Power Range Monitor (OPRM) operators have 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> to manually instability protection is implemented via the I""l....."I......n\\t
I""l,,,......1""'.......,.\\t"'t in uo'toronl"o for both BSP Options in the unlikely svs"[em is inoperable. In such ASBP function. In
.......+I""l..... 1"Y\\
1-3 of 3.1). The is meant to be additional that are not credited in the basis but provide additional protection against 11"'\\""3,.\\tll"\\lll"'\\""3t~~1"I oscillations. It is not meant to be a diverse stability solution. to GNRO-2013/00100 Page 6 of 14 Non-Proprietary Information - Class I (Public)
Response
As documented in the response for RSI #2 above, the DSS-CD (Detect and Suppress Solution - Confirmation Density) (Confirmation Density Algorithm (CDA) and Automatic Backup Stability Protection (ABSP)) and Option III are all software modules within the Power Range Neutron Monitoring (PRNM) system that would provide the stability solution. Prior to the implementation of MELLLA+, the Option III is the licensed solution for instability protection. With the implementation of MELLLA+, DSS-CD would become the licensed stability solution. The Option III trips (Period Based Algorithm (PBA), Amplitude Based Algorithm (ABA), and Growth Rate Algorithm (GRA)) are maintained in the PRNM system to provide defense-in-depth capabilitl. However, under the DSS-CD solution the Option III trips are not credited for licensing basis. In the unlikely event that the CDA becomes inoperable, such as not being able to meet the minimum number of cells requirements in more than one channel, the ABSP will be manually activated to provide the stability protection. Therefore, the ABSP is an alternative stability solution to CDA only in those rare instances. As described in the Section 7 and in the Technical Specification (TS) changes documented in the approved DSS-CD licensing topical report (LTR), NEDC-33075P-A (Reference 3.1), there are two Backup Stability Protection (BSP) options that are based on selected elements from three distinct constituents. The three constituents are:
4.
BSP Manual Regions that comprise plant-specific scram (Region I) and Controlled Entry (Region II) regions in the licensed power/flow operating domain and associated manual operator actions (Section 7.2 of Reference 3.1).
5.
BSP Boundary that defines the operating domain portion where potential instability events can be effectively addressed by specific operator actions (Section 7.3 of Reference 3.1).
6.
Automated BSP (ABSP) Scram Region, which comprises an automatic reactor scram region initiated by the APRM flow-biased scram setpoint (Section 7.4 of Reference 3.1).
The two BSP options are:
Option 1: Consists of the BSP Manual Regions, BSP Boundary and associated operator actions.
Option 2: Consists of the ABSP Scram Region, as implemented by the Average Power Range Monitor (APRM) flow-biased scram setpoint, Region II and associated operator actions.
The TS changes contained in Reference 3.1 delineate specific implementation requirements for both BSP Options in the unlikely event the Oscillation Power Range Monitor (OPRM) system is declared inoperable. In such instance, the operators have 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> to manually implement the ASBP function. In the interim, instability protection is implemented via the 6 See page 1-3 of NEDC-33075P-A (Reference 3.1). The "defense-in-depth" is meant to be additional algorithms that are not credited in the licensing basis but provide additional protection against unanticipated oscillations. It is not meant to be a diverse stability solution.
Non-Proprietary Information -
I (Public) through provide diversity for the COA algorithm, In addition
- this, ASSP function are Ir"l"n"..*,....hll" t"'t*,....t'*\\II....."
solution, which only on operator In Option III solution is only one SSP and operator actions.
Undetected Power Oscillations
(
it is postulated plant conditions until 1"'\\t"'\\1"\\1"'\\......... l""l anomalous. In the case of oscillations, thus, and flow would track consistently with other plant point where potential for high growth-rate power upper corner of the power/flow map), but somehow fail to provide any protection if large amplitude begin to occur. Nevertheless, even while maintaining of the CCF, the plant has the ability to with it in conjunction with oscillations. to GNRO-2013/00100 Page 7 of 14 Non-Proprietary Information - Class I (Public)
Manual BSP regions, which are administratively implemented. In case the ABSP function cannot be implemented or is inoperable, the licensed stability solution becomes the Manual BSP region with the BSP Boundary, which is manually implemented through administrative actions. Therefore, the ABSP function is not meant to provide diversity for the CDA algorithm, but to be an alternative solution to be adopted only in specific instances. In addition to this, even if both the OPRM system (Le., the CDA) and the ABSP function are inoperable, stability protection is provided through a Manual BSP solution, which only relies on operator actions and plant procedures. This is essentially the same backup approach utilized in Option III for the Period Based Detection Algorithm (PBDA). In Option III solution there is only one BSP Option, which is provided by the Manual BSP Regions and associated operator actions.
The evaluation of the Common-Cause Failure (CCF), including the SWCCF, for the PRNM and Option III trip functions are provided in References 3.2, 3.3 and 3.4. With the implementation of MELLLA+, there is no change to the other PRNM trip functions. The Option III trip functions are still maintained but not credited. Either the DSS-CD or the ABSP trip function will be activated to provide the stability solution. If neither function can be activated the stability protection is provided, per TS, via Manual BSP regions and BSP Boundary. The DSS-CD software is based on the Option III software for Local Power Range Monitor (LPRM) response within the OPRM cells whereas the ABSP software is based on the APRM software for core wide neutron flux and flow responses. In either case, the consequences of a postulated CCF for DSS-CD or ABSP are same as the response postulated CCF for Option III. Specifically, the discussion of "Undetected Power Oscillations" in Reference 3.2 is applicable to DSS-CD. For clarification, the discussion is presented below with additional emphasis on DSS-CD and ABSP.
Undetected Power Oscillations The OPRM system (supporting either DSS-CD or Option III solution) plays an important role in the detection and suppression of power oscillations. The postulated CCF, assumed to result in comprehensive loss of the PRNM system functionality, would also disable the OPRM system (Le., CDA for DSS-CD and PBDA for Option III). In addition to this, the loss of PRNM functionality would also disable the ABSP function of DSS-CD because the APRM system would no longer be available.
Although the GGNS Final Safety Analysis Report (FSAR) does not include power oscillations among the Anticipated Operational Occurrences (AOO) or Design Basis Accident (DBA), it is appropriate to discuss them. As discussed in Table 8-1 of Reference 3.2, the postulated CCF in the PRNM system results in the system providing valid indications of plant conditions until the transient, at which time they become anomalous. In the case of power oscillations, thus, the PRNM system indications of power and flow would track consistently with other plant indicators as they change to a state point where the potential exists for high growth-rate power oscillations (Le., the upper left corner of the power/flow map), but somehow fail to provide any protection if large amplitude oscillations begin to occur. Nevertheless, even while maintaining the severity of the postulated CCF, the plant has the ability to cope with it in conjunction with power oscillations.
Non-Proprietary Information -
))
I (Public)
GGNS procedures require immediate to reduce reactor power in order to mitigate possible high growth-rate power oscillations following unanticipated core flow reduction events, such as ((
))
The operators would know the statepoint the status of recirculation pumps is provided independent of the PRNM flow information is available from the recirculation flow system, and power level information is available from either the electrical power output or a core power calculation.
reactor recirculation flow Rod Control and Information System (RC&IS), and manual scram are unaffected by the is with can Nl"'\\'tl"'\\I"'\\t"lin/l"'\\
and those steps via immediate actions, Le., ((
_v""',......""..,..., the SLMCPR is not "V""""~"'I"~ throughout this
........!""\\.... '" provided in BTP 9
3.5) are automatically met.
((
)) to GNRO-2013/00100 Page 8 of 14 Non-Proprietary Information - Class I (Public)
((
))
GGNS procedures require immediate action to reduce reactor power in order to mitigate possible high growth-rate power oscillations following unanticipated core flow reduction events, such as ((
))
The operators would know the statepoint because the status of recirculation pumps is provided independent of the PRNM system; flow information is available from the recirculation flow system, and power level information is available from either the electrical power output or a core thermal power calculation. Furthermore, the reactor recirculation flow system, Rod Control and Information System (RC&IS), and manual scram are unaffected by the CCF.
Thus, the plant is able to cope with the CCF because they can determine that defensive steps are necessary and execute those steps via immediate actions, Le., ((
)) Because the SLMCPR is not exceeded throughout this event, the acceptance criteria provided in BTP 7-19 (Reference 3.5) are automatically met.
((
))
Non-Proprietary Information - Class I (Public) stability solution in the remote case CDA However, ABSP is designed to core from operating in regions with high potential for THI. Therefore, a postulated CCF of the ABSP would mean that the automatic scram would not occur when the reactor is operating in the BSP Scram region.
The procedures for immediate action to reduce reactor power as discussed above would apply. Thus, plant would still be able to cope with the CCF.
In summary, GGNS evaluation of the CCF for the PRNM system with DSS-CD was performed to disposition undetected power oscillations using the acceptance criteria provided in BTP
- 19. It was determined that sufficient redundancy and diversity exists so that the plant has the ability to cope with any CCF in the PRNM system with Option III or DSS-CD. The CCF evaluations in References 3.3 and 3.4 were reviewed by the NRC and the PRNM system was approved by the NRC (Reference
References:
3.1 Hitachi Nuclear Energy, Hitachi Boiling Water Reactor Detect and Suppression Solution
- Density, Revision 8, November 2013 (ML111610593).
M. A. Krupa (Entergy Operations Inc.) to U.S Nuclear Regulatory Commission Document Control' to NRC Request for Additional Information Pertaining to Amendment Request for Power Neutron Monitoring (TAC No. ME2531),"
GNRO-2011/00039, dated May 2011 (ML111460590) - Response to RAI 8.
Additional Information Pertaining to Neutron Monitoring System (TAC No. ME2531),
2011 (ML111460590) -
RAI 9.
USNRC of Diversity and Defense-In-in Digital Computer-Based Instrumentation and Controls BTP 7-19 (NUREG-0800),
July 3.6 GE Nuclear "Nuclear Measurement Analysis and Control Power Range Neutron Monitor (NUMAC PRNM) Retrofit Plus Option III Stability Trip Function," NEDC-32410P-A, 11""'l1""'l1#"'\\~""I"'\\'" 1 November 1997.
NRC (A.Wang)
Entergy Operation, Inc (VP, Operations), "Grand Gulf Nuclear Station, Unit 1 Issuance of Amendment RE:
Range Neutron Monitoring System Replacement (TAC No. ME2531)," March 28, 2012 (ML120400319). to GNRO-2013/00100 Page 9 of 14 Non-Proprietary Information - Class I (Public)
The ABSP is an alternative stability solution in the remote case where CDA becomes inoperable. However, ABSP is designed to prevent the core from operating in regions with high potential for THI. Therefore, a postulated CCF of the ABSP would mean that the automatic scram would not occur when the reactor is operating in the BSP Scram region.
The procedures for immediate action to reduce reactor power as discussed above would apply. Thus, the plant would still be able to cope with the CCF.
In summary, GGNS evaluation of the CCF for the PRNM system with DSS-CD was performed to disposition undetected power oscillations using the acceptance criteria provided in BTP 7-
- 19. It was determined that sufficient redundancy and diversity exists so that the plant has the ability to cope with any CCF in the PRNM system with Option III or DSS-CD. The CCF evaluations in References 3.2, 3.3 and 3.4 were reviewed by the NRC and the PRNM system was approved by the NRC (Reference 3.7).
References:
3.1 GE Hitachi Nuclear Energy, GE Hitachi Boiling Water Reactor Detect and Suppression Solution - Confirmation Density, NEDC-33075P-A, Revision 8, November 2013 (ML111610593).
3.2 M. A Krupa (Entergy Operations Inc.) to U.S Nuclear RegUlatory Commission Document Control Desk, "Response to NRC Request for Additional Information Pertaining to License Amendment Request for Power Range Neutron Monitoring System (TAC No. ME2531),"
GNRO-2011/00039, dated May 26,2011 (ML111460590) - Response to RAI 8.
3.3 M. A. Krupa (Entergy Operations Inc.) to U.S Nuclear Regulatory Commission Document Control Desk, "Response to NRC Request for Additional Information Pertaining to License Amendment Request for Power Range Neutron Monitoring System (TAC No. ME2531),"
GNRO-2011/00039, dated May 26,2011 (ML111460590) - Response to RAI 9.
3.4 M. A Krupa (Entergy Operations Inc.) to U.S Nuclear Regulatory Commission Document Control Desk, "Response to NRC Request for Additional Information Pertaining to License Amendment Request for Power Range Neutron Monitoring System (TAC No. ME2531),"
GNRO-2011/00039, dated May 26,2011 (No, ML111460590) - Response to RAI 10.
3.5 USNRC Standard Review Plan, "Guidance for Evaluation of Diversity and Defense-In-Depth in Digital Computer-Based Instrumentation and Controls Systems," BTP 7-19 (NUREG-0800), Revision 6, July 2012.
3.6 GE Nuclear Energy, "Nuclear Measurement Analysis and Control Power Range Neutron Monitor (NUMAC PRNM) Retrofit Plus Option III Stability Trip Function," NEDC-32410P-A, Supplement 1, November 1997.
3.7 NRC (AWang) to Entergy Operation, Inc (VP, Operations), "Grand Gulf Nuclear Station, Unit 1 - Issuance of Amendment RE: Power Range Neutron Monitoring System Replacement (TAC No. ME2531 )," March 28, 2012 (ML120400319).
1\\ 1'l"'... I""..... l""r"\\l"'\\lnl" 3 GNRO-201 10 of 14 RSI#4 Non-Proprietary Information-I (Public)
If a postulated SWCCF condition an appropriate response, then what diverse means not subject to the same common-cause failure would be available to provide
.....,IO:]CO
"",IV',,",,",,""V the proposed design with how it meets the of Branch Technical Position (BTP)
- 9. Provide a detailed analysis meeting the guidance contained in BTP 7-1
Response
and 4.3 provided the evaluation of the Common-Cause Failure (CCF) for the Power Neutron Monitor (PRNM) system. The discussion is applicable to both Option III and Suppress Solution - Confirmation Density (DSS-CD) solutions with the additional documented in the response to RSI #3 above. The evaluation shows that PRNM with Option III and DSS-CD (both Confirmation Density Algorithm (CDA) and Automatic Backup Stability Protection (ABSP))
the guidance of Branch Technical Position (BTP) 7-19 4.4). A summary of the CCF evaluation is (2) postulated accident in the design basis occurring in conjunction with single postulated CCF, the plant response calculated using realistic assum anal should not result in Table 8-1 of Reference 4.1 provided an evaluation for each AOO and DBA in Grand Gulf Nuclear Station (GGNS)
Updated Final Safety Analysis Report UFSAR.
on the evaluation to GNRO-2013/00100 Page 10 of 14 Non-Proprietary Information - Class I (Public)
RSI #4 If a postulated SWCCF condition disables an appropriate response, then what documented diverse means not subject to the same common-cause failure would be available to provide adequate protection? Please discuss the proposed design with respect to how it meets the guidance of Branch Technical Position (BTP) 7-19. Provide a detailed analysis meeting the guidance contained in BTP 7-19.
Response
References 4.1, 4.2, and 4.3 provided the evaluation of the Common-Cause Failure (CCF) for the Power Range Neutron Monitor (PRNM) system. The discussion is applicable to both Option III and Detect and Suppress Solution - Confirmation Density (DSS-CD) solutions with the additional explanation documented in the response to RSI #3 above. The CCF evaluation shows that the PRNM system with Option III and DSS-CD (both Confirmation Density Algorithm (CDA) and Automatic Backup Stability Protection (ABSP)) meets the guidance of Branch Technical Position (BTP) 7-19 (Reference 4.4). A summary of the CCF evaluation is presented below.
BTP 7-19 (Reference 4.4) Criterion Evaluation of PRNM with DSS-CD (1) For each anticipated operational occurrence in the design basis occurring in conjunction with each single postulated CCF, the plant response calculated using realistic assumptions (e.g., plant operating at normal power levels, temperatures, pressures, flows, normal alignments of equipment, etc.) analyses should not result Table 8-1 of Reference 4.1 provided an in radiation release exceeding 10 percent of evaluation for each Anticipated Operational the applicable siting dose guideline values Occurrences (AOO) and Design Basis or violation of the integrity of the primary Accident (DBA) in the Grand Gulf UFSAR.
coolant pressure boundary. The Based on the evaluation presented in Table applicant/licensee should 8-1, the proposed upgrade satisfies Acceptance Criteria (1).
(1) demonstrate that sufficient diversity exists to achieve these goals, (2) identify the vulnerabilities discovered and the corrective actions taken, or (3) identify the vulnerabilities discovered and provide a documented basis that justifies taking no action.
(2) For each postulated accident in the Table 8-1 of Reference 4.1 provided an design basis occurring in conjunction with evaluation for each AOO and DBA in the each single postulated CCF, the plant Grand Gulf Nuclear Station (GGNS) response calculated using realistic Updated Final Safety Analysis Report assumptions analvses should not result in (UFSAR). Based on the evaluation
Non-Proprietary Information -
I (Public) radiation exceeding siting dose guideline values, violation of the integrity of the primary coolant boundary, or violation of the integrity of the containment (i.e., exceeding coolant system or containment design limits). The applicant/licensee should (1) demonstrate that sufficient diversity exists to achieve these (2) identify the vulnerabilities discovered and the corrective actions taken, or (3) identify vulnerabilities discovered and provide a documented basis that justifies taking no function, then diverse means are not subject to or failed by the postulated failure should be provided to function.
The (JIt/F--~r."'R means should assure that the plant calculated using realistic assumptions does not result in radiation exceeding 10 percent of the applicable siting dose guideline values or violation the integrity of the primary presented in Table 8-1, the proposed upgrade satisfies Acceptance Criteria (2).
echelons when in a plant
~~~~~*~~~that an and also impairs ESF function. PRNM C'"C'"rr1orT"ll is not used for automatic control of plant operations, so if the postulated CCF occurs, it will not result in a plant response that requires an response.
Furthermore, neither the existing nor replacement PRNM system interface with the the type of CCF rt~~""I"U"'\\l"'\\rt in this criterion cannot occur in the u rade stem. Acce tance to GNRO-2013/00100 Page 11 of 14 Non-Proprietary Information - Class I (Public)
BTP 7-19 (Reference 4.4) Criterion Evaluation of PRNM with DSS-CD radiation release exceeding the applicable presented in Table 8-1, the proposed siting dose guideline values, violation of the upgrade satisfies Acceptance Criteria (2).
integrity of the primary coolant pressure boundary, or violation of the integrity of the containment (i.e., exceeding coolant system or containment design limits). The applicant/licensee should (1) demonstrate that sufficient diversity exists to achieve these goals, (2) identify the vulnerabilities discovered and the corrective actions taken, or (3) identify the vulnerabilities discovered and provide a documented basis that justifies taking no action.
(3) When a failure of a common element or signal source shared by the control system This criterion requires an evaluation of and reactor trip system (RTS) is postulated potential interaction between the Control and the CCF results in a plant response System and RTS echelons when a that requires reactor trip and also impairs postulated CCF results in a plant response the trip function, then diverse means that that requires a reactor trip and also impairs are not subject to or failed by the postulated the trip function. PRNM system is not used failure should be provided to perform the for automatic control of plant operations, so RTS function. The diverse means should if the postulated CCF occurs, it will not assure that the plant response calculated result in a plant response that requires a using realistic assumptions analyses does reactor trip. Therefore, the type of CCF not result in radiation release exceeding 10 described in this criterion cannot occur in percent of the applicable siting dose the upgrade system. Acceptance guideline values or violation of the integrity Criterion (3) is satisfied.
of the primary coolant pressure boundary.
(4) When a failure of a common element or This criterion requires an evaluation of potential interactions between the Control signal source shared by the control system System and Engineered Safety Features and ESFAS is postulated and the CCF results in a plant response that requires Actuation System (ESFAS) echelons when engineered safety features (ESF) and also a postulated CCF results in a plant impairs the ESF function, then diverse response that requires an ESF response means that are not subject to or failed by and also impairs ESF function. PRNM system is not used for automatic control of the postulated failure should be provided to plant operations, so if the postulated CCF perform the ESF function.
The diverse means should assure that the plant occurs, it will not result in a plant response response calculated using realistic that requires an ESF response.
assumptions analyses does not result in Furthermore, neither the existing nor radiation release exceeding 10 percent of replacement PRNM system interface with the applicable siting dose guideline values the ESFAS. Therefore, the type of CCF described in this criterion cannot occur in or violation of the integrity of the primary the upqrade system. Acceptance
l\\ 1'1:':11\\1\\ It"\\""'H'" Inl' 3 GNRO-201 12 14 Non-Proprietary Information -
I (Public) a JJL.l'-"""
.....JJ. then should demonstrate that the criteria are satisfied and sufficient diversity (7) If the 03 a potential a
then the method for accomplishing the independent and rJIV'AT.f;J;A means of actuating the protective safety functions can via an automated system Section 3.4, of Automation in Diverse Backu This criterion requires that a failure in the monitoring and display echelon will not adversely affect the RTS or ESFAS echelons. PRNM system does not rely on or any input from the monitoring and display echelon; therefore, a failure in monitoring and display systems will not propagate to PRNM system. If the failure in monitoring and display system results in an operator-induced transient, the automatic protective functions of PRNM
"'-="'-='IL.lII. are available for compensation.
Criterion (5) is satISTle,a.
This requires a Q~tot\\l_rOII~tt::ln means for manual initiation of the RTS and functions.
criteria require evaluations of the methods for accomplishing the independent and diverse means actuating the protective safety function when the Defense-In-Depth (03) analysis the nn't,t"\\I""\\'t.'"I for a to GNRO-2013/00100 Page 12 of 14 Non-Proprietary Information - Class I (Public)
STP 7-19 (Reference 4.4) Criterion Evaluation of PRNM with DSS-CD coolant pressure boundary.
Criterion (4) is satisfied.
This criterion requires that a failure in the (5) No failure of monitoring or display monitoring and display echelon will not systems should influence the functioning of adversely affect the RTS or ESFAS the RTS or ESFAS. If a plant monitoring echelons. PRNM system does not rely on system failure induces operators to attempt or receive any input from the monitoring to operate the plant outside safety limits or and display echelon; therefore, a failure in the monitoring and display systems will not in violation of the limiting conditions of propagate to PRNM system. If the failure in operation, the analysis should demonstrate the monitoring and display system results in that such operator-induced transients will be compensated by protection system an operator-induced transient, the function.
automatic protective functions of PRNM system are available for compensation.
Acceptance Criterion (5) is satisfied.
(6) For safety systems to satisfy IEEE Std. 603-1991 Clauses 6.2 and 7.2, which are incorporated by reference in 10 CFR 50.55a(h), a safety-related means shall be This criterion requires a safety-related provided in the control room to implement means for manual initiation of the RTS and manual initiation at the division level of the ESFAS functions.
The means provided shall minimize the number of This criterion is not applicable to the PRNM discrete operator manual manipulations and system upgrade. The evaluation performed shall depend on operation of a minimum of for Acceptance Criteria (1) and (2) equipment. If the means is independent demonstrates that if a CCF occurs in PRNM and diverse from the safety-related system, the plant is able to cope without automatically initiated RTS and ESFAS relying on a manual scram or ESF functions, the design meets the system-actuation. It is noted that the manual scram level actuation criterion in Point 4 of this and ESF actuation are retained, if needed BTP. If credit is taken for a manual for other reasons, because they are totally actuation method that meets both the IEEE separate from PRNM system and not Std.603-1991, Clauses 6.2 and 7.2 affected by the proposed upgrade in any requirements and a need for a diverse way.
manual backup, then the applicant/licensee should demonstrate that the criteria are satisfied and sufficient diversity exists.
(7) If the 03 assessment reveals a potential These criteria require evaluations of the for a CCF, then the method for methods for accomplishing the independent accomplishing the independent and diverse and diverse means of actuating the means of actuating the protective safety protective safety function when the functions can be accomplished via either an Defense-in-Depth (03) analysis reveals the automated system (see Section 3.4, "Use of potential for a CCF.
Automation in Diverse Backup Safety
GNRO-2013/00100 13 14 Non-Proprietary Information I (Public)
The Nuclear Measurement Analysis and Control (NUMAC) pi orm is not present in any part of RTS the PRNM system, is not present in the ESFAS. Their are not affected by proposed upgrade, and these systems are not vulnerable to the postulated CCF in PRNMS. Therefore, Acceptance Criterion (7) is not applicable to the PRNMS upgrade.
.r:::::lT'~TV'-r~jr:::lTt:..~n automated system did
\\L1L\\L.1\\L..ILI II' \\L.I function, and
- 3. the automated backup or manual is successful in performing the safety function.
criteria evaluations of methods for accomplishing the independent and diverse means of actuatin the to GNRO-2013/00100 Page 13 of 14 Non-Proprietary Information - Class I (Public)
BTP 7-19 (Reference 4.4) Criterion Evaluation of PRNM with DSS-CD Functions" below), or manual operator The Nuclear Measurement Analysis and actions that meet HFE acceptability criteria Control (NUMAC) platform is not present in (see Section 3.5, "Use of Manual Action in any part of RTS except the PRNM system, Diverse Backup Safety Functions" below).
and is not present in the ESFAS. Their designs are not affected by the proposed upgrade, and these systems are not vulnerable to the postulated CCF in PRNMS. Therefore, Acceptance Criterion (7) is not applicable to the PRNMS upgrade.
(8) If the 03 assessment reveals a potential for a CCF, then the method for accomplishing the independent and diverse means of actuating the protective safety functions should meet the following criteria:
The independent and diverse means should be:
a) at the division level; These criteria require evaluations of the b) initiated from the control room; methods for accomplishing the independent c) capable of responding with sufficient time and diverse means of actuating the protective safety function when the D3 available for the operators to determine the analysis reveals the potential for a CCF.
need for protective actions even with The NUMAC platform is not present in any part of RTS except the PRNM system, and malfunctioning indicators, if credited in the is not present in the ESFAS. Their designs 03 coping analysis; are not affected by the proposed upgrade, d) appropriate for the event; and these systems are not vulnerable to the postulated CCF in PRNMS. Therefore, e) supported by sufficient instrumentation Acceptance Criterion (8) is not applicable to that indicates:
the PRNMS upgrade.
- 1. the protective function is needed,
- 2. the safety-related automated system did not perform the protective function, and
- 3. the automated backup or manual action is successful in performing the safety function.
(9) If the 03 assessment reveals a potential These criteria require evaluations of the for a CCF, then, in accordance with the methods for accomplishing the independent auamented Quality auidance for the and diverse means of actuating the
00 Non-Proprietary Information - Class I (Public) independent and diverse backup system used to cope with a CCF, the design of a diverse automated or diverse manual backup actuation system should address how to minimize the potential for a spurious actuation of the protective system caused by the diverse system. Use of design techniques (for example: redundancy, conservative setpoint selection, and use of quality components) to mitigate these concerns is recommended.
protective safety function when the D3 analysis reveals the potential for a CCF.
The NUMAC platform is not present in any part of RTS except the PRNM system, and is not present in the ESFAS. Their designs are not affected by the proposed upgrade, and these systems are not vulnerable to the postulated CCF in PRNM system.
Therefore, Acceptance Criterion (9) is not applicable to the PRNM system upgrade.
In summary, the proposed upgrade was evaluated using the acceptance criteria provided in BTP 7-19 4.4). The GGNS disposition a CCF for the PRNMS with DSS-CD is documented in the to RSI #3 above and it is not repeated in this It was with the explanation documented for (provided in the response to RSI #3) that sufficient redundancy and diversity exists so that the plant has the ability to cope with any in PRNMS with Option III or DSS-CD. The CCF evaluation (References 4.1, 4.2, and 4.3) was reviewed by the NRC and the PRNM system was approved by the NRC (Reference 4.5).
References:
1 M. A. Krupa (Entergy Operations, Inc.) to U.S. Nuclear Regulatory Commission Document Control to NRC for Additional Information Pertaining to Request for Power Neutron Monitoring System (TAC No. ME2531),"
GNRO-2011/00039, May 2011 (ML111460590) - Response to RAI 8.
M. A. Krupa (Entergy Operations, Inc.) to U.S. Nuclear Regulatory Commission Document NRC for Additional Information Pertaining to License Amendment Request for Power Neutron Monitoring System (TAC No. ME2531),"
GNRO-2011/00039, May 1 (ML111460590) - Response to RAI 9.
M.
Krupa (Entergy to U.S. Nuclear Regulatory Commission Document Control "Response to NRC Request for Additional Information Pertaining to License Amendment Request for Power Range Neutron Monitoring System (TAC No. ME2531),"
GNRO-2011/00039, dated May 26,2011 (ML111460590) - Response to RAI 10.
4.4 USNRC Standard Review Plan, "Guidance for Evaluation of Diversity and Defense-In-Depth in Digital Computer-Based Instrumentation and Control Systems," NUREG 0800, BTP 7-19, Revision 6, July 201 NRC (A.Wang) to Operations, Inc. (VP, Operations), "Grand Gulf Nuclear Station, Unit 1 - Issuance Amendment Power Range Neutron Monitoring System Replacement (TAC No. ME2531)," March 28,2012 (ML120400319). to GNRO-2013/00100 Page 14 of 14 Non-Proprietary Information - Class I (Public)
BTP 7-19 (Reference 4.4) Criterion Evaluation of PRNM with DSS-CD independent and diverse backup system protective safety function when the 03 used to cope with a CCF, the design of a analysis reveals the potential for a CCF.
diverse automated or diverse manual The NUMAC platform is not present in any backup actuation system should address part of RTS except the PRNM system, and how to minimize the potential for a spurious is not present in the ESFAS. Their designs actuation of the protective system caused are not affected by the proposed upgrade, by the diverse system. Use of design and these systems are not vulnerable to the techniques (for example: redundancy, postulated CCF in PRNM system.
conservative setpoint selection, and use of Therefore, Acceptance Criterion (9) is not quality components) to mitigate these applicable to the PRNM system upgrade.
concerns is recommended.
In summary, the proposed upgrade was evaluated using the acceptance criteria provided in BTP 7-19 (Reference 4.4). The GGNS specific disposition of a CCF for the PRNMS with DSS-CD is documented in the response to RSI #3 above and it is not repeated in this response. It was confirmed with the additional explanation documented for DSS-CD (provided in the response to RSI #3) that sufficient redundancy and diversity exists so that the plant has the ability to cope with any CCF in PRNMS with Option III or DSS-CD. The CCF evaluation (References 4.1, 4.2, and 4.3) was reviewed by the NRC and the PRNM system was approved by the NRC (Reference 4.5).
References:
4.1 M. A. Krupa (Entergy Operations, Inc.) to U.S. Nuclear Regulatory Commission Document Control Desk, "Response to NRC Request for Additional Information Pertaining to License Amendment Request for Power Range Neutron Monitoring System (TAC No. ME2531),"
GNRO-2011/00039, dated May 26,2011 (ML111460590) - Response to RAI 8.
4.2 M. A. Krupa (Entergy Operations, Inc.) to U.S. Nuclear Regulatory Commission Document Control Desk, "Response to NRC Request for Additional Information Pertaining to License Amendment Request for Power Range Neutron Monitoring System (TAC No. ME2531),"
GNRO-2011/00039, dated May 26,2011 (ML111460590) - Response to RAI 9.
4.3 M. A. Krupa (Entergy Operations, Inc.) to U.S. Nuclear Regulatory Commission Document Control Desk, "Response to NRC Request for Additional Information Pertaining to License Amendment Request for Power Range Neutron Monitoring System (TAC No. ME2531),"
GNRO-2011/00039, dated May 26,2011 (ML111460590) - Response to RAI 10.
4.4 USNRC Standard Review Plan, "Guidance for Evaluation of Diversity and Defense-In-Depth in Digital Computer-Based Instrumentation and Control Systems," NUREG 0800, BTP 7-19, Revision 6, July 2012.
4.5 NRC (A.Wang) to Entergy Operations, Inc. (VP, Operations), "Grand Gulf Nuclear Station, Unit 1 - Issuance of Amendment RE: Power Range Neutron Monitoring System Replacement (TAC No. ME2531)," March 28, 2012 (ML120400319).