GNRO-2014/00088, Response to Item 20 Request for Additional Information Regarding Maximum Extended Load Line Limit Plus Amendment Request, Dated 5/19/2014
| ML15029A454 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 01/20/2015 |
| From: | Kevin Mulligan Entergy Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| GNRO-2014/00088, TAC MF2798 | |
| Download: ML15029A454 (36) | |
Text
Entergy Operations, Inc.
SEntergy' P. O. Box 756 Port Gibson, MS 39150 Kevin Mulligan Site Vice President Grand Gulf Nuclear Station Tel. (601) 437-7400 Attachment 1 contains PROPRIETARY information GNRO-2014/00088 January 20, 2015 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001
SUBJECT:
Response to Item 20 Request for Additional Information Regarding Maximum Extended Load Line Limit Plus Amendment Request, dated 5/19/2014.
Grand Gulf Nuclear Station, Unit 1 Docket No. 50-416 License No. NPF-29
REFERENCES:
1 Electronic Request for Additional Information Regarding "Maximum Extended Load Line Limit Plus" Amendment Request Dated 5/19/2014 (TAC MF2798) 2 Entergy Letter, "Maximum Extended Load Line Limit Analysis Plus (MELLLA+) License Amendment Request," GNRO-2013/00012, dated September 25, 2013 (ADAMS Accession No. ML13269A140).
3 Entergy Letter, "Response to Request for Additional Information Regarding Maximum Extended Load Line Limit Plus Amendment Request, dated 8/27/14 (ADAMS Accession No. ML14239A184).
Dear Sir or Madam:
Entergy Operations, Inc. is providing in the Attachments a response to the Reference 1 Item 20 Request for Additional Information (RAI). Item 20 discusses Code-to-Code Comparisons. All other items with regard to this RAI were previously answered via Reference 3. All figures, along with their tabulated data will also be provided on a CD enclosed with this letter.
Attachment 1 contains proprietary information as defined by 10 CFR 2.390. General Electric-Hitachi (GEH), as the owner of the proprietary information, has executed the attached affidavit, which identifies that the attached 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 Entergy in a GEH transmittal that is referenced by the affidavit. The proprietary information has been faithfully reproduced in the attached such that the affidavit remains applicable. GEH hereby requests that the attached 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. Attachment 3 NON-PROPRIETARY When Attachment I is removed from this letter, the entire document is Do.)
pt
GNRO-2014-00088 Page 2 of 2 contains the affidavit which identifies that the information contained in Attachment 1 has been handled and classified as proprietary to GEH. On behalf of GEH, Entergy requests that be withheld from public disclosure in accordance with 10 CFR 2.390(b)(1).
This letter contains no new commitments. If you have any questions or require additional information, please contact Mr. James Nadeau at 601-437-2103.
I declare under penalty of perjury that the foregoing is true and correct; executed on January 20, 2015.
Sincerely, KJM/tmc Attachments:
1 AEP-647 Proprietary Responses to Item 20 of the Request for Additional Information 2 AEP-647 Non-Proprietary Responses to Item 20 of the Request for Additional Information 3 GEH Affidavit for Attachment 1
Enclosure:
1 CD of Figures with Tabulated Data cc: with Attachments U.S. Nuclear Regulatory Commission ATTN: Mr. Marc L. Dapas Regional Administrator, Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511 U.S. Nuclear Regulatory Commission ATTN: Mr. A. Wang, NRR/DORL Mail Stop OWFN/8 G14 Washington, DC 20555-0001 NRC Senior Resident Inspector Grand Gulf Nuclear Station Port Gibson, MS 39150 State Health Officer Mississippi Department of Health P. 0. Box 1700 Jackson, MS 39215-1700
Attachment 2 to GNRO-2014/00088 AEP-647 Non-Proprietary Responses to Item 20 of the Request for Additional Information NON-PROPRIETARY NOTICE This is a non-proprietary version of Attachment 1 which has the proprietary information removed. Portions of the document that have been removed are indicated by an open and closed bracket as shown here (( fl.
to Non-Proprietary Information GNRO-2014/00088 Page 1 of 28 RAI 20.0 CODE-TO-CODE COMPARISON Events leading to reactor instabilities cause oscillations in PCT over time. The magnitude of these oscillations has been seen to vary from code to code. Analyses completed by the Office of Nuclear Regulatory Research at the NRC have documented TRACE results for ATWS-I that lead to reactor instabilities with high PCT.
- 1. Develop a synonymous model using TRACG.
- 2. Compare TRACG results with TRACE results for an ATWS-I turbine trip with 100%
bypass event initiated from 120% Originally Licensed Thermal Power (OLTP) and 85%
reactor core flow at beginning of cycle and the peak hot excess point in the cycle.
Provide discussion of differences between the two calculation results, in particular, wherever possible, identify candidate constitutive models, modeling procedures, input assumptions, or other factors that contribute to the differences.
- 3. Provide results in tabular form and in plots of the same two cases in RAI 20.2 above (ATWS-I turbine trip with 100% bypass event initiated from 120% Originally Licensed Thermal Power (OLTP) and 85% reactor core flow at beginning of cycle and the peak hot excess point in the cycle) using a constant Train of 900K.
GEH Response
- 1. A synonymous TRACG model to the TRACE model used by the NRC has been developed. The TRACG and TRACE models were developed from the same TRACG basedeck (as referenced in Reference 20-1). The input and modeling assumptions used in the TRACE analysis are not applicable to any specific nuclear plant; however are adequate for the intended purpose. Comparisons between key parameters are provided in Table 20-1. In some cases the modeling inputs and assumptions are different and more conservative than standard GEH ATWSI assumptions; however, the changes are reasonable and appropriate given the purpose of these comparisons. All TRACG cases were performed with the quench model turned on consistent with GEH ATWSI modeling.
Table 20 Input Comparison Between TRACE and TRACG TRACE TRACG.:. Notes Vessel Radial Rings 3 3 to Non-Proprietary Information GNRO-2014/00088 Page 2 of 28
_________ _ :TRACE TRACG Notes Channel Groups 382 382 Channel group locations are consistent with Figure 2.5 of Reference 20-1. It is noted that this TRACE grouping assumes a specific harmonic plane of symmetry.
Hot Rod Single Rod Single Rod Consistent with Table 2.1 of Reference with with 20-1 relative rod relative rod power power (CPOWR) (CPOWR) of 1.2 of 1.2 Recirculation Pump 1095 psig 1095 psig Trip (RPT) Setpoint Standby Liquid Upper Upper Control System Plenum Plenum (SLCS) Location SLCS Timing Ramp up Ramp up Section 4.1 of Reference 20-1.
from 120 to from 120 to 180 seconds 180 after the seconds turbine trip after the turbine trip Train -725 K -725 K TRACG cases are performed at two
-900 K -900 K exposures, with a low Tmin and with a high Tmin. 725 K is an estimated value from TRACE used for TRACG purposes.
Feedwater (FW) Reduce to Reduce to Consistent with comment on page A-44 Temperature 11 OF with 1 OF with of Reference 20-1 Reduction 75-second 75-second lag lag Water Level 110 seconds 110 Section 4.1 of Reference 20-1 Reduction Initiation after turbine seconds Time trip after turbine trip Water Level 180 seconds 180 Section 4.1 of Reference 20-1. It is Reduction Duration seconds noted that this rate in level reduction is Time slower (more conservative) than typical plant response.
Initial Water Level 14.9 m 14.9 m The TRACE initial water level increases Control After above and is maintained higher than the Turbine Trip (before initial level; therefore, TRACG is 110 seconds) modeled similarly for consistency.
to Non-Proprietary Information GNRO-2014/00088 Page 3 of 28 TRACE TRACG Notes Pressure Control Constant Turbine The TRACG normal pressure regulator pressure of pressure setpoint is adjusted to result in a similar 924 psi at inlet dome pressure response compared to turbine first controlled TRACE for representative steam flows.
stage inlet as a Some differences in the modeling function of produce some differences in the results.
steam flow.
Bypass Capacity and 100% 100% Both models assume 100% bypass Timing Bypass Bypass capacity, but they open at different rates Capacity. Capacity. based on differences in input Valves open Valves are assumptions. These differences only linearly controlled affect the initial part of the transient.
from 0.0 to per the TRACE results in higher peak pressure.
1.0 seconds bypass Long-term instabilities are not affected.
control system
- 2. Figures 20-1 through 20-18 show the comparison for key parameters with Tmin approximately equal to 725 K: Figures 20-1 through 20-9 shows the results for Peak Hot Excess (PHE), and Figures 20-10 through 20-18 shows Beginning of Cycle (BOC) results. All figures, along with the tabulated data, are also included in files Plots-Compare-BOC-Tmin725.xlsx and Plots-Compare-PHE-Tmin725.xlsx, which are located on a CD enclosed with this letter. Considering the differences in codes, the overall response matches well. Power and steam flow in both cases level off around 50%
power, and core flow around 25% before the level reduction occurs; however, the TRACE core flow is slightly lower from about 10 to 120 seconds. Dome pressure levels around 955 psia for both cases. The FW temperature drop is nearly identical. The lower predicted core flow in TRACE results in higher inlet subcooling.
The main difference in the results is the timing of oscillations. In TRACG, these oscillations commence ((
)) but it is noted that the TRACG results are more conservative. ((
- 3. Both TRACG and TRACE models were re-performed with higher Tmin values around 900 K. The results are very similar to the results discussed in #2 with the exception that
((
)) It is concluded that the Tmin value is an important parameter to predict to Non-Proprietary Information GNRO-2014/00088 Page 3 of 28
..TRACE TRACG' Notes...
Pressure Control Constant Turbine The TRACG normal pressure regulator pressure of pressure setpoint is adjusted to result in a similar 924 psi at inlet dome pressure response compared to turbine first controlled TRACE for representative steam flows.
stage inlet as a Some differences in the modeling function of produce some differences in the results.
steam flow.
Bypass Capacity and 100% 100% Both models assume 100% bypass Timing Bypass Bypass capacity, but they open at different rates Capacity. Capacity. based on differences in input Valves open Valves are assumptions. These differences only linearly controlled affect the initial part of the transient.
from 0.0 to per the TRACE results in higher peak pressure.
1.0 seconds bypass Long-term instabilities are not affected.
control I system
- 2. Figures 20-1 through 20-18 show the comparison for key parameters with Tmin approximately equal to 725 K: Figures 20-1 through 20-9 shows the results for Peak Hot Excess (PHE), and Figures 20-10 through 20-18 shows Beginning of Cycle (BOC) results. All figures, along with the tabulated data, are also included in files Plots-Compare-BOC-Tmin725.xlsx and Plots-Compare-PHE-Tmin725.xlsx, which are located on a separate CD. Considering the differences in codes, the overall response matches well. Power and steam flow in both cases level off around 50% power, and core flow around 25% before the level reduction occurs; however, the TRACE core flow is slightly lower from about 10 to 120 seconds. Dome pressure levels around 955 psia for both cases. The FW temperature drop is nearly identical. The lower predicted core flow in TRACE results in higher inlet subcooling.
The main difference in the results is the timing of oscillations. In TRACG, these oscillations commence ((
)) but it is noted that the TRACG results are more conservative. ((
))
- 3. Both TRACG and TRACE models were re-performed with higher Tmin values around 900 K. The results are very similar to the results discussed in #2 with the exception that
)) It is concluded that the Tmin value is an important parameter to predict to Non-Proprietary Information GNRO-2014/00088 Page 4 of 28 fuel cladding temperatures during an ATWSI event. Figures 20-19 through 20-36 show the comparison for key parameters: Figures 20-19 through 20-27 shows the results for PHE, and Figures 20-28 through 20-36 shows BOC results. All figures, along with the tabulated data, are also included in files Plots-Compare-BOC-Tmin900.xlsx and Plots-Compare-PHE-Tmin900.xlsx, which are located on a separate CD.
Figure 20-0 shows a comparison of the calculated PCTs for both Tmjn values.
Figure 20-0. PCT Comparison, PHE I))
References 20-1 BNL-97068-2012, "Brookhaven National Laboratory - BWR Anticipated Transients Without Scram in the MELLLA+ Expanded operating Domain," March 30, 2012.
to Non-Proprietary Information GNRO-2014/00088 Page 5 of 28 ATWSI-TTWBP PLOTS Tmin = 725 K, PHE to Non-Proprietary Information GNRO-2014/00088 Page 6 of 28 Figure 20-1. Reactor Power, Tmin = 725 K, PHE (1)
Figure 20-2. Core Flow, T.,i = 725 K, PHE to Non-Proprietary Information GNRO-2014/00088 Page 7 of 28 Figure 20-3. Dome Pressure, T.,. = 725 K, PHE
((
))
Figure 20-4. Maximum Peak Clad Temperature, TW. = 725 K, PHE to Non-Proprietary Information GNRO-2014/00088 Page 8 of 28 Figure 20-5. Downcomer Level, Tj,, = 725 K, PHE Figure 20-6. Feedwater Flow, Tmin 725 K, PHE
((
1]
to Non-Proprietary Information GNRO-2014/00088 Page 9 of 28 Figure 20-7. Steamline Flow, Tmi. = 725 K, PHE
((
Fe Figure 20-8. Feedwater Temperature, Tmin = 725 K, PHE to Non-Proprietary Information GNRO-2014/00088 Page 10 of 28 Figure 20-9. Core Inlet Subcooling, Tmjn = 725 K, PHE to Non-Proprietary Information GNRO-2014/00088 Page 11 of 28 ATWSI-TTWBP PLOTS Tmin - 725 K, BOC to Non-Proprietary Information G NRO-2014/00088 Page 12 of 28 Figure 20-10. Reactor Power, Twn = 725 K, BOC
((
FF Figure 20-11. Core Flow, Train= 725 K, BOC
[II to Non-Proprietary Information GNRO-2014/00088 Page 13 of 28 Figure 20-12. Dome Pressure, Tmin = 725 K, BOC
((
Figure 20-13. Maximum Peak Clad Temperature, Tmin, 725 K, BOC
((
to Non-Proprietary Information GNRO-2014/00088 Page 14 of 28 Figure 20-14. Downcomer Level, Tmin = 725 K, BOC
((
FF Figure 20-15. Feedwater Flow, Tn* n= 725 K, BOC
((
to Non-Proprietary Information GNRO-2014/00088 Page 15 of 28 Figure 20-16. Steamline Flow, Tmin = 725 K, BOC Figure 20-17. Feedwater Temperature, Tminz 725 K, BOC to Non-Proprietary Information GNRO-2014/00088 Page 16 of 28 Figure 20-18. Core Inlet Subcooling, Train = 725 K, BOC
((
to Non-Proprietary Information GNRO-2014/00088 Page 17 of 28 ATWSI-TTWBP PLOTS Tmin = 900 K, PHE to Non-Proprietary Information GNRO-2014/00088 Page 18 of 28 Figure 20-19. Reactor Power, Tmin = 900 K, PHE Figure 20-20. Core Flow, T*. = 900 K, PHE 1]
to Non-Proprietary Information GNRO-2014/00088 Page 19 of 28 Figure 20-21. Dome Pressure, Tmin = 900 K, PHE Figure 20-22. Maximum Peak Clad Temperature, Tnn = 900 K, PHE to Non-Proprietary Information GNRO-2014/00088 Page 20 of 28 Figure 20-23. Downcomer Level, Tmin = 900 K, PHE
((
Figure 20-24. Feedwater Flow, Train = 900 K, PHE to Non-Proprietary Information GNRO-2014/00088 Page 21 of 28 Figure 20-25. Steamline Flow, Tmin = 900 K, PHE Figure 20-26. Feedwater Temperature, T..= 900 K, PHE to Non-Proprietary Information G NRO-2014/00088 Page 22 of 28 Figure 20-27. Core Inlet Subcooling, Trin = 900 K, PHE to Non-Proprietary Information G NRO-2014/00088 Page 23 of 28 ATWSI-TTWBP PLOTS Trin = 900 K, BOC to Non-Proprietary Information GNRO-2014/00088 Page 24 of 28 Figure 20-28. Reactor Power, Tmin = 900 K, BOC Figure 20-29. Core Flow, Tn.. = 900 K, BOC to Non-Proprietary Information GNRO-2014/00088 Page 25 of 28 Figure 20-30. Dome Pressure, Tn. = 900 K, BOC
((I 1]
Figure 20-31. Maximum Peak Clad Temperature, Tna. = 900 K, BOC to Non-Proprietary Information GNRO-2014/00088 Page 26 of 28 Figure 20-32. Downcomer Level, Trai = 900 K, BOC Figure 20-33. Feedwater Flow, Trn = 900 K, BOC to Non-Proprietary Information G NRO-2014/00088 Page 27 of 28 Figure 20-34. Steamline Flow, Tmin = 900 K, BOC Figure 20-35. Feedwater Temperature, T",i = 900 K, BOC to Non-Proprietary Information GNRO-2014/00088 Page 28 of 28 Figure 20-36. Core Inlet Subcooling, Tni = 900 K, BOC
[I
Attachment 3 to GNRO-2014/00088 GEH Affidavit for Attachment 1
GE-Hitachi Nuclear Energy Americas LLC AFFIDAVIT I, James F. Harrison, state as follows:
(1) I am the Vice President, Regulatory Affairs, Fuel 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, GEH-GGNS-AEP-647, "GEH Response to MELLLA+ NRC RAI 20," dated October 30, 2014. The GEH proprietary information in Enclosure 1, which is entitled "GEH Response to NRC RAI 20 in Support of GGNS MELLLA+ LAR," is identified by a dotted underline inside double square brackets. ((.Tlis sentence is.an example..* )) The content of Enclosure 3 is proprietary in its entirety. The labelling of the Enclosure 3 content carries the notation "GEH Proprietary Information - Class II (Internal)13 .' In each case, the superscript notation 13 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 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 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;
- 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.
GEH-GGNS-AEP-647 Page I of 3
GE-Hitachi Nuclear Energy Americas LLC (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 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.
(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 or confidentiality agreements.
(8) The information identified in paragraph (2), above, is classified as proprietary because it contains the details of GEH methodology. These methods, techniques, and data along with their application to the design, modification, and analyses were 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 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 GEH-GGNS-AEP-647 Page 2 of 3
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 is true and correct.
Executed on this 30th day of October 2014.
r James F. Harrison Vice President, Fuel Licensing, Regulatory Affairs GE-Hitachi Nuclear Energy Americas LLC 3901 Castle Hayne Rd.
Wilmington, NC 28401 James.Harrison@ge.com GEH-GGNS-AEP-647 Page 3 of 3