RS-17-101, Response to Request for Additional Information Regarding License Amendment Request to Revise Suppression Pool Swell Design Analysis

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Response to Request for Additional Information Regarding License Amendment Request to Revise Suppression Pool Swell Design Analysis
ML17209A733
Person / Time
Site: LaSalle  Constellation icon.png
Issue date: 07/28/2017
From: Gullott D
Exelon Generation Co
To:
Document Control Desk, Office of Nuclear Reactor Regulation
Shared Package
ML17213A139 List:
References
RS-17-101
Download: ML17209A733 (36)
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4300 Winfield Road Warrenville, IL 60555

~--'" Exeton G 630 657 2000 Office Proprietary Information Withhold from Public Disclosure Under 10 CFR 2.390 RS-17-101 10 CFR 50.90 July 28, 2017 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 LaSalle County Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-11 and NPF-18 NRC Docket Nos. 50-373 and 50-374

Subject:

Response to Request for Additional Information Regarding LaSalle County Station License Amendment Request to Revise Suppression Pool Swell Design Analysis

References:

1) Letter from P. R. Simpson (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, "License Amendment Request to Revise Suppression Pool Swell Design Analysis," dated October 27, 2016 (ADAMS Accession No. ML16305A295)

2) Letter from B. Vaidya (U.S. Nuclear Regulatory Commission) to B. C. Hanson (Exelon Generation Company, LLC), "LaSalle County Station, Units 1 and 2, Request for Additional Information Regarding License Amendment Request to Revise Suppression Pool Swell Design Analysis (CAC Nos. MF8702 and MF8703)," dated June 14, 2017 (ADAMS Accession No. ML17163A422)

By a letter dated October 27, 2016 (Reference 1), Exelon Generation Company, LLC (EGC) submitted an amendment request for LaSalle County Station (LSCS), Units 1 and 2. The proposed amendment would revise the suppression pool swell analysis for a design basis loss-of-coolant accident (LOCH). These changes are necessary because the current design analysis determining the suppression pool swell response to a LOCH was determined to be non-conservative.

In Reference 2, the U.S. Nuclear Regulatory Commission (NRC) requested additional information related to its review of Reference 1. The requested information is provided in Attachments 1 through 4 of this letter.

Attachment 2 contains Proprietary Information. Withhold from Public Disclosure Under 10 CFR 2.390.

When separated from Attachment 2, this document is decontrolled.

July 28, 2017 U.S. Nuclear Regulatory Commission Page 2 Attachment 2 contains proprietary information as defined by 10 CFR 2.390. GEH, as the owner of the proprietary information, has executed the enclosed affidavit, which identifies that the enclosed proprietary information has been handled and classified as proprietary, is customarily held in confidence, and has been withheld from public disclosure. The proprietary information was provided to EGC in a GEH transmittal that is referenced by the affidavit. The proprietary information has been faithfully reproduced in the enclosed document such that the affidavit remains applicable. Accordingly, it is respectfully requested that the enclosed proprietary information be withheld from public disclosure in accordance with 10 CFR 2.390 and 10 CFR 9.17. Attachment 3 provides the non-proprietary version of Attachment 2.

Attachment 4 provides the GEH affidavit supporting the proprietary nature of the information in Attachment 2.

EGC has reviewed the information supporting a finding of no significant hazards consideration that was previously provided to the NRC in Attachment 1 of Reference 1. The additional information provided in this submittal does not affect the bases for concluding that the proposed license amendment request does not involve a significant hazards consideration. In accordance with 10 CFR 50.91, "Notice for public comment; State consultation," paragraph (b), EGC is notifying the State of Illinois of this application for license amendment by transmitting a copy of this letter and its attachments to the designated State Official.

There are no regulatory commitments contained within this letter. Should you have any questions concerning this letter, please contact Ms. Lisa A. Simpson at (630) 657-2815.

1 declare under penalty of perjury that the foregoing is true and correct. Executed on the 28th day of July 2017.

Respectfully, David M. Gullott Manager Licensing Exelon Generation Company, LLC Attachments:

1) Response to Request for Additional Information
2) GEH Responses to SRXB RAIs in Support of LaSalle Pool Swell Design Analysis LAR dated July 2017 (GEH PROPRIETARY)
3) GEH Responses to SRXB RAIs in Support of LaSalle Pool Swell Design Analysis LAR dated July 2017 (NON-PROPRIETARY)
4) GEH Hitachi Affidavit Supporting Proprietary Nature of Information in Attachment 2 cc: NRC Regional Administrator, Region III NRC Senior Resident Inspector, LaSalle County Station Illinois Emergency Management Agency Division of Nuclear Safety contains Proprietary Information. Withhold from Public Disclosure Under 10 CFR 2.390.

When separated from Attachment 2, this document is decontrolled.

ATTACHMENT 1 Response to Request for Additional Information By letter to the Nuclear Regulatory Commission (NRC) dated October 27, 2016 (Reference 1),

Exelon Generation Company, LLC (EGC) requested a license amendment to revise the suppression pool swell analysis for a design basis loss-of-coolant accident (LOCA) for LaSalle County Station (LSCS), Units 1 and 2. In a letter dated June 14, 2017 (Reference 2), the NRC requested that EGC provide additional information in support of its review of the proposed LAR.

SRXB - RAI 1 Reference 1, Table 5, Attachment 1, second column of item 4 states:

TRACG represents a change in methodology, it does not change conservatisms Please provide reasons why the conservatism is not changed in using TRACG [GEH Proprietary Version of the Transient Reactor Analysis Code (TRAC), GEH Computer Code for Best Estimate BWR Transient and Accident Analysis Calculations] which is the best-estimate methodology compared to using the current conservative M3CPT [Mark 111 Containment Pressure and Temperature; GEH Computer Code M3CPT for Short-term DBA-LOCH floss-of-coolant accident] Containment Response Analysis] methodology for mass and energy release analysis for a design basis accident (DBA) LOCA.

EGC Response The response to SRXB - RAI 1 is provided in Attachment 2 to this letter.

SRXB - RAI 2 Reference 1, Section 4.4 in Attachment 1, stated all systems, structures, and components (SSCs) affected were not assessed, instead a representative sample of low margin SSC were selected. Provide the following information:

(a) Further explanation on the basis of selection of the SSCs (i.e., low margin of which parameter) for analyzing structural impacts, (b) Specify the systems to which the piping, associated supports and penetrations that are analyzed belong to, and any special reasons for selecting these systems.

(c) What is total number of SSCs that are affected and how many were selected for structural re-analysis, (d) Maximum and minimum value of percentage in stress margins in the SSCs selected for structural analysis, (e) Revised (new) maximum and minimum percentage in the stress margin in the SSCs structurally analyzed, (f) Justification as to why the SSCs not structurally analyzed will have adequate stress margin.

Page 1 of 13

ATTACHMENT 1 Response to Request for Additional Information EGC Response (a) Further explanation on the basis of selection of the SSCs (i. e., low margin of which parameter) for analyzing structural impacts, Piping subsystems located in the suppression pool along with their pipe supports and associated containment penetrations were divided into four groups based on type and elevation inside the suppression pool. The subsystems are screened into the following groups based on elevation:

below the initial pool surface between the initial pool surface and the maximum velocity height (2 groups) above the maximum velocity height As shown in Figure 1 below, the groups capture the elevations where the largest velocity increases occur relative to the original profile. Two groups are formed between the initial pool surface and the maximum velocity height to ensure the largest velocity difference is captured. No subsystems (other than Main Steam, see below) exist between approximately 5 feet and 18.5 feet. See Figure 1 for a graphical representation of the subsystem groups with regards to pool swell height and velocity. The Main Steam piping in the suppression pool is oriented vertically and is normally submerged. As such, the projected area for the pool swell to act on is minimal and impact loads are not a concern.

Therefore, the Main Steam subsystems were excluded from this screening.

One subsystem from each of the four groups was then chosen based on the lowest available stress margin. A table of the existing maximum ASME Code Equation 9C stresses, the associated stress interaction coefficients (I.C.), associated supports, associated penetrations and existing loads is included below in response for section SRXB - RAI 2(d). Based on this tabulated subsystem data, the four piping subsystems chosen are as follows.

  • RE04 = Reactor Drains and Vents
    • Except at a different azimuth and having a shorter overhang from the wall, subsystem R177 has the same pipe (size and material), elevation, and maximum operating pressure and temperature. Therefore, the analysis of R167 also covers R177 and no analysis was performed for the latter.

The analyses of the four subsystems also include piping penetrations M-79, M-82, M-92 and M-98 as well as analyses of the respective piping supports.

The revised pool swell and fall back loads were also used to evaluate against existing loads on downcomers, lower downcomer bracing, gusset plates and temperature monitor supports. The swell profile and loadings are the same for both units. Additionally, the SSCs affected are virtually identical for both units, so the evaluations are valid for both units as well.

Page 2 of 13

ATTACHMENT 1 Response to Request for Additional Information i iyui G 1. r iNn iy QU VOYa<<i 11 w~.auvi i r IUL (b) Specify the systems to which the piping, associated supports and penetrations that are analyzed belong to, and any special reasons for selecting these systems.

The selections for re-analysis are described in the above response to SRXB - RAI 2(a).

(c) What is total number of SSCs that are affected and how many were selected for structural re-analysis, The systems, structures, and components (SSCs) directly affected by the pool swell phenomena include the items bulleted below. The selections for re-analysis are described in the above response to SRXB - RAI 2(a).

  • 58 piping subsystems, associated supports and downcomer vent lines per operating unit. See Table 1 below.
  • Suppression pool walls and floor Reactor pedestal Support columns Lower downcomer bracing Containment monitoring suppression pool temperature instrumentation (RTDs)
  • Structural steel As described in the response to SRXB RAI 2(a), there were four piping subsystems including their associated supports and penetrations that were selected for reanalysis.

Additionally, the lower downcomer bracing and containment monitoring suppression pool temperature instrumentation supports were reanalyzed.

Page 3 of 13

ATTACHMENT 1 Response to Request for Additional Information Table 1 System Subsystem CM CMC7, CMC8, CMC9, CMD1 HIS HG07, HG08 HPCS HPO4, HP05, HP65, HP69, HPC1 RH14, RH33, RH34, RH35, RH36, RH37, RH38, RH39, LPCIIRHR RH40, RH41, RH42, RH43, RH44, RH45 LPCS LP04, LP05, LP68, LP69 R108, R160, R161, R166, RCIC R167, R169, R177 MS33, MS34, MS35, MS36, MS37, MS38, MS39, MS40, SRV discharge lines and MS41, MS42, MS43, MS44, T-Quenchers MS45, MS46, MS47, MS48, MS49, MS50 Downcomer vent lines -

NA 98 vent lines Equipment drain and RE03, RE04, RE05 floor drain piping VG VG05 Table 2 Pen Elev Number Penetrations below suppression pool water surface M-75 688'-6" (These penetrations are subject to drag loads) 1-41 698'-10" 1-43 698'-10" 1-49 698'-10" M-76 _ 704'-6" M-77 703'-6"

_ M-78 704'-6" M 704'-9" M-80 701'-10" M-81 704'-6" M 82 _ 703'-6" Penetrations above suppression pool water surface - M-83 701'-0" M-84 701'-0" (These penetrations are subject to drag loads, impact M-85 703'-6" loads, and fallback loads)

M-86 704'-6" M-87 704'-6" M-88 704'-6" M-89 704'-6" M-90 704'-6" M-91 701'-0" M 92 704'-6" M-93 701'0" M-94 704'-6" M-95 701'-0" M-96 718'-6" M-97 718'-6" M- 98 _ 718'-6" M-99 704'-6" M-101 704'-6" M-102 701'-0" M-113 714'-0" M-114 714'-0" 1-40 701'-3" 1-42 701'-5" 1-48 701'-5"

  • The four Penetration Numbers highlighted yellow represent the piping subsystems selected for reanalysis.

Page 4 of 13

ATTACHMENT 1 Response to Request for Additional Information (d) Maximum and minimum value of percentage in stress margins in the SSCs selected for structural analysis, Table 3 summarizes the currently available stress margins for affected piping subsystems.

As shown, the four subsystems selected for additional analysis have I.C.s greater than 90%. Since deadweight stresses and thermal stresses are not affected by pool swell loads, only the ASME Code Equation 9C stresses are reported. The highest ASIVIE Code Equation 9C stresses for each subsystem are listed in Table 3 below.

U-1 Maximum Stress Allowable I.C. (Eq. 9C}

Subsystem Psi Stress(Psi]Stress 1 HPO4 25472 27000 0.943 1 RE04 25247 27000 0.935 1 RH34 24691 27000 0.914 1R167/1R177 24449 27000 0.906 PPnPtratinnc The new loads applied to the piping subsystems selected for reevaluation also apply to the respective piping system penetrations. The Analysis of Record (AOR) penetration stress margins were not identified in advance because load changes to the penetrations are a downstream effect of load changes to the pipe system.

Pipe Supports The reevaluations are performed by prorating the I.C. by the ratio of new support load to the support load used in the AOR. When the prorating factor is < 1.0, the adequacy of the support design is considered acceptable by engineering judgement. When the prorating factor is > 1.0, the original resultant stresses are multiplied by the prorating factor to determine a revised I.C.

The AOR stress margins for the reanalyzed pipe supports were only identified by exception when the prorating factor was > 1.0. When the factor was > 1.0, the AOR stress margins were examined in detail to understand the aggregate effect and AOR I.C.s are noted in Table 4. Where the prorating factor was < 1.0, the AOR I.C.s are noted as "<1.0" in Table 4. See Piping Support section in the response to item SRXB - RAI 2(e) for the prorating factors applied to the revised analysis.

Maximum Subsystem Support I.C.

1 HPO4 HP08-1003G-Penetration No. M-82 0.778 1RE04 M09-RF19-1512G-Penetration No. M-98 < 1.0 1RE04 M09-RF19-1513X < 1.0 1 RE04 M09-RF19-1514X < 1.0 1RE04 M09-RF19-1515X < 1.0 1RH34 M09-RH13-1143G-Penetration No. M-79 0.946 1RH34 M09-RH13-1146X < 1.0 1RH34 M09-RH13-1147X < 1.0 1 R167 M09-R140-1505G-Penetration No. M-92 0.615 Page 5 of 13

ATTACHMENT 1 Response to Request for Additional Information (e) Revised (new) maximum and minimum percentage in the stress margin in the SSCs structurally analyzed, All of the four chosen subsystems meet code stress and functional capacity limits using the modified pool swell. The majority of the support loads and containment penetration anchors experience a load increase. Since deadweight stresses and thermal stresses are not affected by the revised pool swell loads, only the ASME Code Equation 9C stresses are reported. The highest ASME Code Equation 9C stresses for each subsystem are listed in the table below.

For subsystem RE04, the maximum pool swell impact loads were reduced using the revised pool swell profile. As shown on Figure 1, these SSCs are affected only by the portion of the pool swell phenomenon when the swell is nearly at its maximum elevation.

At the maximum elevations noted on Figure 1, the revised pool swell profile is locally bounded by the AOR swell profile, thus the swell velocities and associated impact loads are reduced. As such, the initially low stress margin RE04 subsystem has a revised stress margin as noted in Table 5. The changes in Stress I.C. are improved as a result of modeling piping analyses, which was completed in accordance with approved industry guidance.

For subsystem R167/77, the maximum pool swell impact loads were increased using the revised pool swell profile, while the pool swell drag and fallback loads decreased. The aggregate effect is that the maximum stress is reduced with the new margin noted in Table 5.

Table 5 Piping Maximum Stress Allowable Stress I.C.

Subsystem Psi Stress Psi E .9C 1 HPO4 26800 27000 0.993 1 RE04 7510 27000 0.278 1 RH34 26400 27000 0.978 1 R167/77 18400 27000 0.681 Penetrations Only 'Emergency' loading conditions are applicable for penetration and head fittings with respect to Pool Swell loading components. The revised results are shown in Table 6.

Table 6 Calculated Service Stress Allowable Penetration Maximum Stress I.C.

Condition Category (psi)

Stress(psi)Stress Membrane 23198 45000 0.52 M-79 Emergency Membrane 26274 37417 0.70

& Bending Membrane 17423 28379 0.61 M-82 Emergency Membrane 26372 42568 0.62

& Bending Membrane 21628 45000 0.48 M-92 Emergency Membrane 22421 45000 0.50

& Bending Membrane 12478 45000 0.28 M-98 Emergency Membrane 13058 45000 0.29

& Bending Page 6 of 13

,A7 ,CHlVlENT 1 Response to Raquas~ -,'for Additional Information Pipe Supports Supports are evaluated for increased service level D loads. The evaluations are performed by prorating the I.C. by the ratio of new support load to the support load used in the AOR. When the prorating factor is < 1.0, the adequacy of the support design is considered acceptable by engineering judgement. When the prorating factor is > 1.0, the original resultant stresses are multiplied by the prorating factor to determine a revised I.C.

H=

Prorating Maximum Subsystem Support Factor I.C.

1 HPO4 HP08-1003G-Penetration No. M-82 1.265 0.986 1 RE04 M09-RF19-1512G-Penetration No. M-98 0.148 < 1.0 1 RE04 M09-RF19-1513X 0.34 < 1.0 1RE04 M09-RF19-1514X 0.069 < 1.0 1 RE04 M09-RF19-1515X 0.301 < 1.0 1RH34 M09-RH13-1143G-Penetration No. M-79 1.089 < 1.0""

1RH34 M09-RH13-1146X 0.846 < 1.0 1RH34 M09-RH13-1147X 0.846 < 1.0 1 R167 M09-R140-1505G-Penetration No. M-92 1.004 0.617

  • For support M09-RH13-1143G, the revised I.C. was > 1.0. For this case there are several load conditions evaluated where the revised I.C. is no greater than 0.845, with one load condition resulting in a revised I.C. of 1.03. For this specific instance engineering judgement determined that the assumed load path through the welds of the member was overly conservative and the condition is in fact acceptable using the revised loads.

Temperature Monitoring Supports Temperature monitor supports attached to the containment wall were evaluated for the revised pool swell loads. Within the evaluation the supports are referenced by their respective drawing view numbers and other descriptors, and as such they do not have distinct part numbers. The evaluation does not provide an aggregate I.C. value for each support, but rather it provides I.C. checks for various stress states of the structures. The application of the revised pool swell loads marginally increased the stresses on all of the supports, with new I.C. results ranging from 0.11 up to a maximum of 0.91.

(f) Justification as to why the SSCs not structurally analyzed will have adequate stress margin.

The identified SSCs were initially screened using the methodology noted in SRXB -

RAI 2(a). The SSCs located in the upper elevations of the pool swell (e.g., after the maximum swell velocity occurs) are judged to be minimally impacted by revised loads.

Most of the SSCs that are located above the maximum velocity swell height are considered bounded locally (between 9 and 18.5 feet swell height) by the AOR swell profile as shown on Figure 1. Because these SSCs are bounded locally by the AOR swell profile, by inspection the swell velocities are lower and the resulting loads will be lower.

The RE04 subsystem is one such group of SSCs in this case and it also has the least stress margin available. The evaluation demonstrated the loads and stresses were reduced. As such, most SSCs in this category (located above the maximum swell velocity height) are deemed by engineering judgement to have adequate stress margin.

Page 7 of 13

ATTACHMENT 1 Response to Request for Additional Information Other SSCs are located below the initial pool surface or between the initial pool surface and the maximum velocity swell height. In these cases the SSCs were screened to determine which have the lowest available stress margin while having the largest swell velocity increase between the AOR swell profile and the revised swell profile (see Figure 1, between 0 and 9 feet swell height). The results of these piping subsystem evaluations were found to be acceptable, and there is a high degree of confidence that other SSCs in this category with lower magnitude load changes would prove to have acceptable results as well.

Reference 1, item 2 of Table 6 in Attachment 1, Section 6.2.2, and Tables 6-1 through 6-4 in .

(a) Explain how the 0.7 ft [foot] adder to the PICSM [General Electric-Hitachi pool swell response code] predicted pool swell height which accounts for the difference between initial pre-LOCH elevation and initial PICSM elevation which corresponds to the elevation after vent clearing was determined.

(b) In Tables 6-1 through 6-4, explain if the 0.7 ft adder is included in the data for pool swell elevation above initial elevation.

The response to SRXB - RAI 3 is provided in Attachment 2 to this letter.

Reference 1, Note 3 in Table 4-1, Attachment 2. Explain the basis for selecting feedwater temperature reduction of 100°F (degree Fahrenheit) from its normal operating temperature 428.5°F at the current licensed thermal power. Provide justification that the 100°F reduction is conservative.

A reduction in feedwater temperature can occur in two instances:

Intentionally taking equipment out of service Transients that result in equipment being out of service For intentionally taking equipment out of service, the feedwater temperature reduction is controlled by station operating procedures and is limited by the LSCS Unit 1 and Unit 2 Core Operating Limits Report (COLR), Section 10, "Modes of Operation," Table 10-1, "Allowed Modes of Operation and [Equipment Out-of-Service] EOOS Combinations." For transients that result in equipment being out of service, LSCS has completed an evaluation to predict the steady-state impact on final feedwater temperature in response to a variety of off-normal alignments resulting from failures of components/instruments in the Condensate, Feedwater, and/or Heater Drains Systems. These include isolation of extraction steam flows, heater trips, Page 8 of 13

1 isolation of heater drains forwarding, and heater bypass scenarios. The results of this evaluation show that the limiting event results in a reduction of feedwater temperature by approximately 63 °F; therefore, 100 °F is conservative.

Reference 1, Section 4.3.1, Attachment 2, states:

Other plant performance improvement and equipment out of service options identified in Reference 1 AGE Hitachi Nuclear Energy, "Safety Analysis Report for LaSalle County Station Units 1 and 2 Thermal Power Optimization, " NEDC-33485P, Revision 0, January 2010, ADAMS Accession No. ML1003213271 have no effect on the RSLB

[Recirculation Suction Line Break] mass and energy release analyses. The current analysis, therefore, continues to support all flexibility and equipment out of service options.

Table in Section 1.3.2 of NEDC-33485P, Revision 0 shows several performance improvement and equipment out-of-service (OOS) features currently licensed at LSCS are acceptable at the thermal power optimization (TPO) reactor thermal power (RTP) level. Explain how it is determined that these features have no effect on the RSLB Mass and Energy (M&E) release analysis.

EGC Response The response to SRXB - RAI 5 is provided in Attachment 2 to this letter.

Reference 1, assumption (ii), Section 6.1.1 in Attachment 2. The PICSM analysis for cases 3 and 4, assumes a constant value of steam/air ratio (air fraction = 0.61 as per Figure 7-1 in ) after the initial air in the downcomer vent is purged. The value assumed is at the time (0.87 seconds as per Figure 7-1 in Attachment 2) when all air in the downcomer vent is purged. Describe the analysis that resulted in the graph shown in Figure 7-1, "Drywell Air Fraction (Air Mass/(Air Mass+ Steam Mass))."

The response to SRXB - RAI 6 is provided in Attachment 2 to this letter.

-g-sa \ ]

Reference 1, Section 6.1.1, Attachment 2, assumption 3, states:

The mass flow rate of non-condensables into the bubble is calculated assuming adiabatic flow through a duct with friction.

(a) Clarify which duct (i.e., downcomer vent or other) is meant to be feeding the non-condensables into the bubble.

Page 9 of 13

G,i YZACHMEN1T 1 Response to Raquast -Yor AddKdonal Information (b) What is the assumed value of frictional loss coefficient and how is it determined?

(c) Justify the assumption of adiabatic flow with friction is conservative.

EGC Response The response to SRXB - RAI 7 is provided in Attachment 2 to this letter.

Reference 1, Section 6.1.1, Attachment 2, assumption 6, states:

Following vent clearing, the water above the exit of the vent (equal to the initial vent submergence plus the pool displacement due to vent clearing) accelerates as a slug of constant thickness.

The water column in the downcomer vent cleared during a LOCA is cylindrical in shape having its diameter same as the vent diameter and length equal to the length of the water column. Describe the geometric shape of the slug assumed in the above assumption and how its dimensions are determined from the dimensions of the initial water column in the vent. Provide the basis for assuming a constant thickness of the slug.

EGC Response The response to SRXB - RAI 8 is provided in Attachment 2 to this letter.

Reference 1, Section 6.1.1, Attachment 2, assumption 7, states:

Frictional losses between the water and the confining walls are negligible.

Describe which confining walls are referred to in the above assumption.

The response to SRXB - RAI 9 is provided in Attachment 2 to this letter.

SRXB - RAI 10 Reference 1, Section 6.1.1, Attachment 2, assumption 10, states:

The air velocity in the DW [drywell] is sufficiently small so that static and stagnation conditions are equivalent.

Specify with justification at what time during the transient, the air velocity in the drywell is assumed sufficiently small so that its velocity head is negligible.

Page 10 of 13

ATTACHMENT 1 Response to Request for Additional Information EGC Response The response to SRXB - RAI 10 is provided in Attachment 2 to this letter.

The drywell pressure response described in Reference 1, Section 5.0 of Attachment 2, used TRACG for M&E analysis, and M3CPT code for drywell pressure analysis and the assumption and inputs listed Section 5. 1.1 and Appendix A, respectively. Provide the following information:

(a) Computer codes used in the analysis of record (AOR) for calculation of "Pa (pressure absolute)."

(b) Differences in the inputs and assumptions for M&E and drywell pressure response between the AOR and the proposed analysis with justification in the inputs and assumptions for which the conservatism in the proposed analysis is reduced.

(c) In case the peak drywell pressure calculated using the assumptions and inputs in the proposed analysis results in a greater value than its current Pa, please explain and justify why Pa is not being revised.

EGC Response to SRXB - RAI 11(c)

(c) The value for Pa has been recently revised. EGC submitted a LAR (ADAMS Accession No. ML13249A231) and supplements dated June 12 and October 7, 2014 (ADAMS Accession Nos. ML14163A690 and ML14280A497) to change the value of Pa to 42.6 psig based upon using a lower initial drywell temperature. The change incorporates an increase in Pa resulting from using a lower initial drywell temperature as well as an increase resulting from secondary issues regarding the AOR. On January 29, 2015, the NRC issued a Safety Evaluation (ML14353A083) to EGC for the change.

With respect to SRXB - RAI 11(c), Reference 1, Attachment 2 uses an initial drywell temperature of 98°F as reported in Appendix A. This initial drywell temperature of 98°F is the new value noted in the aforementioned LAR, and for this topic of pool swell analysis, consideration has been taken into account for the revised Pa value.

The responses to SRXB - RAI 11 Part (a) and SRXB - RAI 11 Part (b) and a supplemental response to SRXB - RAI Part (c) are provided in Attachment 2 to this letter.

SRXB - RAI12 In Reference 1, Attachment 2, refer to Figures 5-1, 6-3, and 6-3A, (a) Figure 5-1; describe the analysis to which the graphs labelled "LSCS Design Calc 3C7-1075-001" and "LAMB CLTP 100P 100F" belong.

(b) Figures 6-3 and 6-3A; describe the analysis to which the graphs labelled "LSCS Design Calc 3C7-1075-001 R6" belong.

Page 11 of 13

ATTACHMENT 1 Response to Request for Additional Information (a) Analysis 3C7-1075-001 is titled "Loads Due to Loss-of-Coolant Accidents in LaSalle Containment." The purpose of this calculation is to determine the best assessment loads due to a LOCH in the suppression pool. The analytical models are used to compute the elevation, velocity and acceleration of the suppression pool surface, as well as the pressures of both the air bubble and the free air spaces as functions of time during the pool swell phenomenon.

The plot labeled "LAMB CLIP 100P 10017" is provided as a sensitivity study. The plot demonstrates the effect of using the AOR methodology (GEH's LAMB code) with the proposed new methodology where downcomer vent back pressure upon vent flow is not taken into account. Similarly, the plots for TRACG cases A through E ignore the downcomer vent back pressure upon vent flow.

(b) Analysis 3C7-1075-001 Revision 6 is the same calculation document mentioned in the first part of the response to item (a) above.

In Reference 1, Attachment 2, refer to Figure 5-1. Provide reasons for the discontinuity (drastic reversal of slope) in the graph labelled "LSCS Design Calc 3C7-1075-001," and why does it differ from other graphs shown in this figure, with respect to its reversal of slope after vent clearing.

The plot "LSCS Design Calc 3C7-1075-001" is LSCS's AOR drywell pressure response for a DBA LOCH, utilizing GEH's LAMB-based prediction. In this AOR response, downcomer vent back pressure upon vent flow is taken into account. The slope reversal shown on Figure 5-1 at approximately t = 0.7 seconds occurs at the completion of the vent clearing. Following vent clearing, there is a very short period when drywell pressure decreases that coincides with the beginning of the suppression chamber pressurization. While the decrease in drywell pressure is not extensively explained, it is mentioned in Section III.B.3.a.1 of NUREG-0487, "Mark II Containment Lead Plant Program Load Evaluation and Acceptance Criteria," October 1978.

NUREG-0487 accepted the use of the predicted drywell pressure based on the GEH containment models (Reference NEDM-10320) for input to the pool swell model (Reference NEDE-21544-P), without accounting for LOCA bubble formation backpressure effects on vent flow. This was based upon pool swell model-to-test data comparisons which are discussed in NUREG-0487.

The other plots (TRACG cases A through E and the LAMB case) shown on Figure 5-1 all ignore the effects of vent back pressure from the vent flow. The TRACG cases were run to ensure that subsequent calculations were based upon the most limiting combination of operating and equipment out of service conditions permitted by the power to flow map.

Page 12 of 13

ATTACHMENT I Response to Request for Addffiona0 WormaUon

1) Letter from P. R. Simpson (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "License Amendment Request to Revise Suppression Pool Swell Design Analysis," dated October 27, 2016 (Agencywide Documents Access and Management System (ADAMS) Package Accession No. ML16305A295)
2) Letter from B. Vaidya (U.S. Nuclear Regulatory Commission) to B. C. Hanson, "LaSalle County Station, Units 1 and 2, Request for Additional Information Regarding License Amendment Request to Revise Suppression Pool Swell Design Analysis (CAC Nos.

MF8702 and MF8703)," dated June 14, 2017 (ADAMS Accession No. ML17163A422)

Page 13 of 13

ATTACHMENT 3 GEH Responses to SRXB RAls in Support of LaSalle Pool Swell Design Analysis LAR July 2017 NON-PROPRIETARY 15 pages follow

ENCLOSURE 2

'~~Z~IZIIIZi 1 GEH Responses to SRXB RAIs in Support of LaSalle Pool Swell Design Analysis LAR Non-Proprietary Information - Class I (Public)

INFORMATION NOTICE This is a non-proprietary version of DOC-0008-4344-01 Enclosure 1, which has the proprietary information removed. Portions of the document that have been removed are indicated by white space inside an open and closed bracket as shown here Non-Proprietary Information - Class I (Public)

DOC-0008-4344-01 Page 1 of 14 SRXB RAI 1 Reference 1, Table 51, Attachment 1, second column of item 4 states:

TRACG represents a change in methodology, it does not change conservatisms.

Please provide reasons why the conservatism is not changed in using TRACG [GEH Proprietary Version of the Transient Reactor Analysis Code (TRAQ, GEH Compute° Code for Best Estimate BWR Transient and Accident Analysis Calculations] which is the best-estimate methodology compared to using the current conservative M3CPT [Mark Ill Containment Pressure and Temperature; GEH Computer Code M3CPT for Short-term DBA-LOCA [loss-of-coolant accident] Containment Response Analysis] methodology for mass and energy release analysis for a design basis accident (DBA) LOCA.

GEH Response The M3CPT methodology with respect to the containment response calculation is consistent with the model in NEDM-10320 (Reference 1-1) as accepted in NUREG-0487 (Reference 1-2). The LAMB code is also acceptable to use for the mass and energy release in the M3CPT methodology rather than the built-in vessel model in the M3CPT code (please see the response to SRXB - RAI 11).

The LAMB and M3CPT vessel models are simpler than the TRACG model. Due to the limitations in computing power, the models were made in the past with a number of assumptions for the purpose of simplifying the model, not for the purpose of adding more margin. The TRACG model represents the conditions in the vessel more accurately, calculates the break flow more accurately, and has an extensive benchmarking to a number of test and plant data for both the separate effects and the integral tests.

Although the TRACG vessel and vessel blowdown models are different than the methodology described in NEDM-10320 (Reference 1-1) as accepted in NUREG-0487, the conservatism in the results with TRACG is not significantly affected, relative to the results which would be obtained with the methodology ofNEDM-10320. ((

References 1-1 General Electric Company, "The GE Pressure Suppression Containment Analytical Model," NEDM-10320, March 1971.

1-2 NUREG-0487, "Mark II Containment Lead Plant Program Load Evaluation and Acceptance Criteria," October- 1978.

Non-Proprietary Information - Class I (Public)

DOC-0008-4344-01 Page 2 of 14 1-3 Letter, Patrick R. Simpson (Exelon) to Document Control Desk (NRC), "License Amendment Request to Revise Suppression Pool Swell Design Analysis," RS-16-193, October- 27, 2016.

Non-Proprietary Information - Class I (Public)

DOC-0008-4344-01 Page 3 of 14 SRX B RA 13 Reference 1, item 2 of Table 6 in Attachment 1, Section 6.2.2, and Tables 6-1 through 6-4 in Attachment (a) Explain how the 0.7 ft [foot] adder to the PICSM [General Electric-Hitachi pool swell response code] predicted pool swell height which accounts for the difference between initial pre-LOCA elevation and initial PICSM elevation which corresponds to the elevation after vent clearing was determined.

(b) In Tables 6-1 through 6-4, explain if the 0.7 ft adder is included in the data for pool swell elevation above initial elevation.

GEH Response (a) The PICSM code calculates the pool swell height as the increase from the Suppression Pool (SP) level at the end of the vent clearing period. The increase in the pool height during the vent clearing period prior to the start of the PICSM calculation is (b) Yes, (( )) is added to the PICSM results in the fourth columns of Tables 6-1 through 6-4 in Attachment 2 of the license amendment request (Reference 3-1).

Reference 3-1 Letter, Patrick R. Simpson (Exelon) to Document Control Desk (NRC), "License Amendment Request to Revise Suppression Pool Swell Design Analysis," RS-16-193, October 27, 2016.

Non-Proprietary Information - Class I (Public)

DOC-0008-4344-01 Page 4 of 14 SRXB RAI 5 Reference 1, Section 4.3.1, Attachment 2, states:

Other plant performance improvement and equipment out of'service options identified in Reference I [GE Hitachi Nuclear Energy, "Safety Analysis Report for LaSalle Couno)

Station Units I and 2 Thermal Power Optimization, " NE DC-33485P, Revision 0, Januar)~ 2010, ADAMS Accession No. ML100321327] have no effect on the RSLB

[Recirculation Suction Line Break] mass and energ)~ release analyses. The current analysis, therefore, continues to support all flexibility and equipment out of service options.

Table in Section 1.3.2 of NEDC-33485P, Revision 0, shows several performance improvement and equipment out-of--service (OOS) features currently licensed at LSCS are acceptable at the thermal power optimization (TPO) reactor thermal power (RTP) level. Explain how it is determined that these features have no effect on the RSLB Mass and Energy (M&E) release analysis.

GEH Response As stated in Section 4.1 of Attachment 2 of the license amendment request (Reference 5-1), the analysis covers the entire power flow map, including the reduced feedwater temperature operation. A bounding value is used for the dome pressure in all cases.

The peak pool swell loads occur in less than two seconds. During this time, the only parameters that may potentially affect the mass and energy release from a recirculation suction line break (RSLB) are the power, pressure, and subcooling in the recirculation loop. Subcooling in the recirculation loop is affected by the feedwater temperature as well as core flow.

11 Non-Proprietary Information - Class I (Public)

DOC-0008-4344-01 Page 5 of 14 Table 5-1 Effect of Performance Improvement and Equipment OOS Options Pool Swell Analysis Performance Improvement Feature Effect References 5-1 Letter, Patrick R. Simpson (Exelon) to Document Control Desk (NRC), "License Amendment Request to Revise Suppression Pool Swell Design Analysis," RS-16-193, October 27, 2016.

Noil-Proprietary Information - Class I (Public)

DOC-0008-4344-01 Page 6 of 14 5-2 GE Hitachi Nuclear Energy, "Safety Analysis Report for LaSalle County Station Units 1 and 2 Thermal Power Optimization," NEDC-33485P, Revision 0, January 2010.

5-3 GE Hitachi Nuclear Energy, "TRACG Application for Emergency Core Cooling Systems

/ Loss-of-Coolant-Accident Analyses for BWR/2-6," NEDE-33005P-A, Revision 1, February 2017.

Non-Proprietary Information - Class I (Public)

DOC-0008-4344-01 Page 7 of 14 SRXB RAI 6 Reference 1, assumption (ii), Section 6.1.1 in Attachment 2. The PICSM analysis for cases 3 and 4, assumes a constant value of steam/air ratio (air fraction = 0.61 as per Figure 7-1 in ) after the initial air in the downcomer vent is purged. The value assumed is at the time (0.87 seconds as per Figure 7-1 in Attachment 2) when all air in the downcomer vent is purged. Describe the analysis that resulted in the graph shown in Figure 7-1, "Drywell Air Fraction (Air Mass/(Air Mass+ Steam Mass))."

GEH Response The mass and energy release is obtained from the TRACG analysis for the Case A reduced feedwater temperature (RFWT) conditions in Table 4-1 of Attachment 2.

The mass and energy release rate from the TRACG output is Input into the M3CPT code to calculate the transient daywell and wetwell parameters such as pressure, temperature, steam, and air mass in the air space. The blue curve labeled "Drywell Air Fraction RFWT Case A" is the ratio of the air mass in the daywell to the total steam and air mass in the daywell, as obtained from the M3CPT results.

11 Non-Proprietary Information - Class I (Public)

DOC-0008-4344-01 Page 8 of 14 SRXB RAI 7 Reference 1, Section 6.1.1, Attachment 2, assumption 3, states:

The mass flow rate of non-condensables into the bubble is calculated assuming adiabatic flow through a duct with friction.

(a) Clarify which duct (i.e., downcomer vent or other) is meant to be feeding the non-condensables into the bubble.

(b) What is the assumed value of frictional loss coefficient and how is it determined?

(c) Justify the assumption of adiabatic flow with friction is conservative.

GEH Response (a) The duct refers to the downcomers.

(b) The vent loss coefficient is 5.2. This value is calculated using the common loss coefficient correlations for the LaSalle downcomer geometry.

(c) A higher bubble temperature results in a higher bubble pressure, and therefore, higher pool swell velocity. ((

Non-Proprietary Information - Class I (Public)

DOC-0008-4344-01 Page 9 of 14 SRXB RAI 8 Reference 1, Section 6.1.1, Attachment 2, assumption 6, states:

Following vent clearing, the water above the exit of the vent (equal to the initial vent submergence plus the pool displacement due to vent clearing accelerates as a slug of constant thickness.

The water column in the downcomer vent cleared during a LOCH is cylindrical in shape having its diameter same as the vent diameter and length equal to the length of the water column.

Describe the geometric shape of the slug assumed in the above assumption and how its dimensions are determined from the dimensions of the initial water column in the vent. Provide the basis for assuming a constant thickness of the slug.

GEH Response The diameter of the water column is the same as the inner diameter of the downcomers.

)) An adder equal to 1.125 times the downcomer diameter is used to account for the virtual mass in the suppression pool based on the Bodega Bay test data as described in Assumption (2) of Section 4.1 of NEDM-10320 (Reference 8-1).

Reference 8-1 General Electric Company, "The GE Pressure Suppression Containment Analytical Model," NEDM-10320, March 1971.

Non-Proprietary Information - Class I (Public)

DOC-0008-4344-01 Page 10 of 14 SRXB RAI 9 Reference 1, Section 6.1.1, Attachment 2, assumption 7, states:

Frictional losses between the water and the confining walls are negligible.

Describe which confining walls are referred to in the above assumption.

GEH Response This statement refers to the friction effects of the structures in the suppression pool and the suppression pool walls which would confine the flow. Note that the friction effects in the downcomers are also neglected in calculating the acceleration of the liquid initially contained in the downcomers (please see the response to SRXB - RAI 8). Friction in the downcomers is not neglected after vent clearing.

Non-Proprietary Information - Class I (Public)

DOC-0008-4344-01 Page 11 of 14 SRXB IZAI 10 Reference 1, Section 6.1.1, Attachment 2, assumption 10, states:

The air velocity in the DW [dr)rwell] is sifficiently small so that static and stagnation conditions are equivalent.

Specify with justification at what time during the transient, the air velocity in the drywell is assumed sufficiently small so that its velocity head is negligible.

GEH Response This assumption applies at all times following a loss-of-coolant accident (LOCA), which is inherent in the lumped parameter analysis used for the drywell. Even if the jet issuing from a break is directed toward a few of the downcomer entrances, there are baffle plates (top hats) at the entrance of the downcomers to prevent any dynamic head from affecting the flow in the vent.

Therefore, the velocity of the jet from a break does not affect the calculations.

Non-Proprietary .Information - Class I (Public)

DOC-0008-4344-01 Page 12 of 14 SRXB RAI I I The drywell pressure response described in Reference 1, Section 5.0, Attachment 2, used TRACG for M&E analysis, and M3CPT code for drywell pressure analysis and the assumption and inputs listed in Section 5.1.1 and. Appendix A, respectively. Provide the following information:

(a) Computer codes used in the analysis of record (AOR) for calculation of "Pa (pressure absolute."

(b) Differences in the inputs and assumptions for M&E and drywall pressure response between the AOR and the proposed analysis with justification in the inputs and assumptions for which the conservatism in the proposed analysis is reduced.

(c) In case the peak drywell pressure calculated using the assumptions and inputs in the proposed analysis results in a greater value than its current Pa, please explain and justify Why Pa is not being revised.

GEH Response (a) The analysis in Reference 11-1, referred to as the P-sub-A analysis below and referenced in Reference 11-2 to revise the peak calculated primary containment internal pressure, used.

ISCOR for the initial thermal-hydraulic conditions (e.g., steady state pressure drops),

LAMB for the break flow mass and energy, and M3CPT for the containment analysis.

(b) The following key inputs for the vessel and containment are the same in the P-sub-A LAMB analysis and in the pool swell TRACG analysis:

  • Initial operating conditions for the vessel
  • The safety relief valves (SRVs) do not lift in either analysis; therefore, the SRV setpoints have no effect However, there are differences in the initial values resulting from modeling differences.

The most significant of those are as follows.

  • ((

Non-Proprietary Information - Class I (Public)

DOC-0008-4344-01 Page 13 of 14 As discussed in the response to SRXB - RAI 1, the TRACG model has a number of modeling parameters which represent the vessel conditions and break flow more accurately as compared to the coarse nodalization and simplified models in the LAMB code.

In addition to the mass and energy release from the break, the containment inputs used in the M3CPT analyses have the following difference between the P-sub-A analysis and the pool swell analysis:

The M3CPT vent back pressure model is used in the P-sub-A analysis but not in the pool swell analysis. Section 3.a.6 of NUREG-0487 (Reference 11-3) states that the containment method used for the drywell pressure history in Reference 21 in NUREG-0487 is acceptable for the purposes of calculating the pool swell based on the comparisons to the test data. Reference 21 in NUREG-0487 does not account for the vent back pressure.

All other inputs and assumptions are the same.

(c) The peak drywell pressure occurs after 10 seconds. The drywell history is calculated for two seconds in the pool swell analysis, long before the peak is reached. Only the pressurization slopes for the first two seconds can be compared. The slope of the drywell pressurization history for the .first two seconds calculated by TRACG is compared to the drywell pressurization history calculated by the LAMB M3CPT method in Figure 5-1 of Attachment 2 to Reference 11-4. ((

Although the bounding drywell pressurization histories calculated for the P-sub-A analysis and the pool swell loads may be different from each other, both methods are conservative.

RPfPrnn -P 11-1 GE Hitachi Nuclear Energy, "Exelon Nuclear LaSalle County Generating Station Units 1

& 2 Short Term Containment Bounding Pa Assessment," 0000-0149-2311-R0, Revision 0, August 2012.

11-2 Letter, David M. Gullott (Exelon) to Document Control Desk (NRC), "License Amendment Request to Revise Peak Calculated Primary Containment Internal Pressure,"

RS-13-092, September 5, 2013.

11-3 NUREG-0487, "Mark II Containment Lead Plant Program Load Evaluation and Acceptance Criteria," October 1978.

Non-Proprietary Information - Class I (Public)

DOC-0008-4344-01 Page 14 of 14 11-4 Letter, Patrick R. Simpson (Exelon) to Document Control Desk (NRC), "License Amendment Request to Revise Suppression Pool Swell Design Analysis," RS-16-193, October 27, 2016.

ATTACHMENT GEH Hitachi Aff idavit Supporting Proprietary Nature of Wormation in Attachment 2 4 pages foHo y

ENCLOSURE 3 DOC-0008-4344-01 Affidavit for Enclosure 1

GE-Hitachi Nuclear Energy Americas LLC AFFIDAVIT 1, Lisa K. Schichlein, state as follows:

(1) I am a Senior Project Manager, NPP/Services Licensing, Regulatory Affairs, GE-Hitachi Nuclear Energy Americas I_,LC (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 1 of GEH letter, DOC-0008-4344-01, "GEH Responses to LaSalle County Station Suppression Pool Swell Design Analysis License Amendment Request RAls SRXB RAI 1, 3, and 5 through 11,"

dated July 19, 2017. GEH proprietary information in Enclosure 1, which is entitled "GEH Responses to SRXB RALs in Support of LaSalle Pool Swell Design Analysis LAR," is identified by a dotted underline inside double square brackets. ((This__sentence__is an, e xample_{31_)) GEH proprietary information in figures and large objects is identified with double square brackets before and after the obiect. In each case, the superscript notation 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 Freedoin Of 7nforination 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 Enemy 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 G.EH; Affidavit for DOC-0008-4344-01 Enclosure 1 Paget of 3

GE-Hitachi Nuclear Energy Americas LLC

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 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) is classified as proprietary because it contains detailed results and conclusions regarding supporting evaluations pertaining to the pool swell response for a GEH Boiling Water Reactor (`BWR").

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

(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 Affidavit for DOC-0008-4344-01 Enclosure 1 Page 2 of 3

GE-Hitachi Nuclear Energy Americas LLC quantify, but it clearly is substantial. GEH's competitive advantage will be lost if its competitors are able to use the results of the GEH experience to normalize or verify their own process or if they are able to claim an equivalent understanding by demonstrating that they can arrive at the same or similar conclusions.

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

I declare under penalty of perjury that the foregoing is true and correct.

Executed on this 19th day of July 2017.

/1 646 //4064:

)

Lisa K. Schichlein Senior Project Manager, NPP/Services Licensing Regulatory Affairs GE-Hitachi Nuclear Energy Americas LLC 3901 Castle Hayne Road Wilmington, NC 28401 Lisa. Schichlein a ge.com Affidavit for DOC-0008-4344-01 Enclosure 1 Page 3 of 3

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