ML12339A573

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Official Exhibit - ENT000459-00-BD01 - IP-RPT-09-00044, Rev. 0, Re-Analysis of IP2 and IP3 Severe Accident Mitigation Alternatives (Samas) (Dec. 3, 2009)
ML12339A573
Person / Time
Site: Indian Point  Entergy icon.png
Issue date: 12/03/2009
From: Favara J, Hong K
Entergy Corp
To:
Atomic Safety and Licensing Board Panel
SECY RAS
References
RAS 22158, 50-247-LR, 50-286-LR, ASLBP 07-858-03-LR-BD01 IP-RPT-09-00044, Rev 0
Download: ML12339A573 (39)
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Text

United States Nuclear Regulatory Commission Official Hearing Exhibit Entergy Nuclear Operations, Inc.

In the Matter of:

(Indian Point Nuclear Generating Units 2 and 3)

ASLBP #: 07-858-03-LR-BD01 Docket #: 05000247 l 05000286 Exhibit #: ENT000459-00-BD01 Identified: 10/15/2012 Admitted: 10/15/2012 Withdrawn: ENT000459 Rejected: Stricken: Submitted: March 30, 2012 Other:

Engineering Report No. IP-RPT-09-00044 Rev. o Page 1 of 39 ENTERGY NUCLEAR Engineering Report Cover Sheet Engineering Report

Title:

Re-Analysis of IP2 and IP3 Severe Accident Mitigation Alternatives (SAMAs)

Engineering Report Type:

New ~ Revision D Cancelled D Superseded D Applicable Slte(s)

IP1 0 IP2 [8J IP3 [8J JAF 0 PNPS 0 VY 0 WPO 0 AN01 0 AN02 0 ECH 0 GGNS 0 RSS 0 WF3 0 DRN No. ~N1A; 0 __

Report Origin: ~. Entergy 0 Vendor Vendor Document No.: _ _ __

Quality-Related: 0 Yes ~ No Prepared by: K. Hong 7L~ J. Favara

~~--~~~~~~~~~~~~-

Responsible Engineer (Prin Design Verified by: Date:

Design Verifier (if required) (Print Name/Sign)

Reviewed by: D. Gaynor ~ ~r;~ Date: I zjsJb 1

~~~gn)

Reviewed by: Date:

ANII (if required) (Print Name/Sign)

Approved by: C. Yeh Date I~b/ol Supervisor (Print Name/Sign)

RECORD OF REVISIONS Engineering Report No. IP-RPT-09-00044 Page 2 of 39 Revision No. Description of Change Reason For Change 0 Original report NA

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 3 of 39 TABLE OF CONTENTS Description Page SECTION 1 INTRODUCTION ................................................................................................................................... 5 1.1. PURPOSE................................................................................................................................................... 5 1.2. BACKGROUND .......................................................................................................................................... 5 SECTION 2

SUMMARY

OF RESULTS..................................................................................................................... 8 SECTION 3 EVALUATION........................................................................................................................................ 9 3.1. SAMA IDENTIFICATION ............................................................................................................................ 9 3.2. ESTABLISHING THE BASELINE IMPACTS OF A SEVERE ACCIDENT ................................................. 9 3.2.1. The PSA Internal Events Model - Level 1 and Level 2 Analysis................................................................. 9 3.2.2. The PSA External Events Model - Individual Plant Examination of External Events (IPEEE) Model....... 10 3.2.3. MACCS2 Model - Level 3 Analysis .......................................................................................................... 10 3.2.4. Baseline Population Dose and Off-site Economic Cost Risk.................................................................... 11 3.2.5 Present Dollar Value Equivalent Baseline Benefit .................................................................................... 12 3.2.5.1 Accident-Related Off-Site Dose Costs (APE) ........................................................................................... 12 3.2.5.2 Accident-Related Off-Site Property Damage Costs (AOC)....................................................................... 12 3.2.5.3 Total Accident-Related Occupational Exposures (AOE) .......................................................................... 13 3.2.5.4 Averted Costs Associated with Accident-Related On-Site Property Damage (AOSC)............................. 16 3.3. EVALUATION OF SAMA CANDIDATE BENEFITS.................................................................................. 19 3.4. EVALUATION OF SAMA CANDIDATE IMPLEMENTATION COST ESTIMATES .................................. 19 3.5. FINAL SCREENING AND COST BENEFIT EVALUATION (PHASE II) ................................................... 20 3.6. THERMALLY INDUCED STEAM GENERATOR TUBE RUPTURE SENSITIVITY ANALYSIS............... 33 SECTION 4 CONCLUSIONS .................................................................................................................................. 36 SECTION 5 REFERENCES .................................................................................................................................... 39

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 4 of 39 LIST OF TABLES Table 1: IP2 Mean PDR and OECR Using Year 2000 Meteorological Data ......................................................... 11 Table 2: IP3 Mean PDR and OECR Using Year 2000 Meteorological Data ......................................................... 11 Table 3: Estimated Present Dollar Value Equivalent of Internal Events CDF at IP2 ............................................ 18 Table 4: Estimated Present Dollar Value Equivalent of Internal Events CDF at IP3 ............................................ 18 Table 5: Results of Cost-Benefit Analysis of IP2 SAMA Candidates .................................................................... 21 Table 6: Results of Cost-Benefit Analysis of IP3 SAMA Candidates .................................................................... 27 Table 7: IP2 TI-SGTR Sensitivity Results ............................................................................................................. 34 Table 8: IP3 TI-SGTR Sensitivity Results ............................................................................................................. 35 Table 9: Final List of Potentially Cost-Benefit IP2 SAMA Candidates.................................................................. 37 Table 10: Final List of Potentially Cost-Benefit IP3 SAMA Candidates.................................................................. 38

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 5 of 39 SECTION 1 INTRODUCTION 1.1. PURPOSE The purpose of this analysis is to re-evaluate the risk-reduction benefit and cost of implementation for potential plant-specific Severe Accident Mitigation Alternatives (SAMAs) at the Indian Point 2 (IP2) and Indian Point 3 (IP3) Nuclear Power Plants using revised meteorological input to identify potentially cost-effective plant modifications. This re-evaluation is required to address an error discovered in methodology used to derive five year average wind direction input into the benefit analysis used for the SAMA evaluation. This re-evaluation uses a single, bounding year (i.e. year 2000) rather than the five year average. The previous IP2 and IP3 evaluations are documented in Engineering Reports IP-RPT 00007 and IP-RPT-07-00008, respectively.

1.2. BACKGROUND The NRC regulation, 10CFR51.53(c)(3)(ii)(L), requires a consideration of alternatives to mitigate severe accidents (SAMAs) in operating plant license renewal applications. To consider SAMAs at IP2 and IP3, the following analytical steps were taken and detailed in this (and the previous) engineering reports:

(1) Establish the Baseline Impacts of a Severe Accident Severe accident impacts were evaluated in four areas:

1. Off-site exposure costs - Monetary value of consequences (dose) to off-site population.

The PSA model was used to determine total accident frequency (core damage frequency and containment release frequency). The Melcor Accident Consequences Code System 2 (MACCS2) was used to convert release input to public dose. Dose was converted to present worth dollars based on a 20 year license renewal period, a valuation of $2,000 per person-rem and a present worth discount rate of 7%.

2. Off-site economic costs - Monetary value of damage to off-site property.

The PSA model was used to determine total accident frequency (core damage frequency and containment release frequency). MACCS2 was used to convert release input to off-site property damage. Off-site property damage was converted to present worth dollars based on a 20 year license renewal period and a discount rate of 7%.

3. On-site exposure costs - Monetary value of dose to workers.

Best estimate occupational dose values were used for immediate and long-term dose. Dose was converted to present worth dollars based on a 20 year license renewal period, a valuation of

$2,000 per person-rem and a present worth discount rate of 7%.

4. On-site economic costs - Monetary value of damage to on-site property.

Best estimate cleanup and decontamination costs were used. On-site property damage estimates were converted to present worth dollars based on a 20 year license renewal period and a discount rate of 7%. It was assumed that, subsequent to a severe accident, the plant would be decommissioned rather than restored. Therefore replacement/refurbishment costs were not included in on-site costs. Replacement power costs were considered.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 6 of 39 (2) Identification of Potential SAMA Candidates Potential SAMA candidates were identified from the following sources:

x Severe Accident Mitigation Design Alternative (SAMDA) analyses submitted in support of original licensing activities for other operating nuclear power plants and advanced light water reactor plants, including the evolutionary Westinghouse Advanced Pressurized Water Reactor (AP 600 and AP 1000) designs; x SAMA analyses for other PWR plants; x NRC and industry documentation discussing potential plant improvements; x Reports documenting the plant specific Individual Plant Examinations (IPEs) of internal and external events and their updates. In these reports, several enhancements related to severe accident insights were recommended and implemented; and x IP2 and IP3 PSA model risk significant contributors.

(3) Preliminary Screening (Phase I)

Potential SAMA candidates for IP2 and IP3 were screened out if they modified features not applicable to the unit, if they had already been implemented at the unit, or if they were similar in nature and could be combined with another SAMA candidate to develop a more comprehensive or plant-specific SAMA candidate.

(4) Final Screening and Cost-Benefit Evaluation (Phase II)

The remaining SAMA candidates were evaluated individually to determine the benefits and costs of implementation, as follows.

The total benefit of implementing a SAMA candidate was estimated in terms of averted cost risks associated with off-site population dose, off-site economic costs, on-site dose, and on-site economic costs.

The baseline PSA model was modified to reflect the maximum benefit of the improvement.

Generally, the maximum benefit of a SAMA candidate was determined with a bounding modeling assumption. For example, if the objective of the SAMA candidate was to reduce the likelihood of a certain failure mode, then eliminating the failure mode from the PSA would bound the benefit, even though the SAMA candidate would not be expected to be 100% effective in eliminating the failure. The modified model was then used to produce a revised accident frequency.

Using the revised accident frequency, the method previously described for the four baseline severe accident impact areas was used to estimate the cost associated with each impact area following implementation of the SAMA candidate.

The benefit in terms of averted consequences for each SAMA candidate was then estimated by calculating the arithmetic difference between the total estimated cost associated with all four impact areas for the baseline plant design and the revised plant design following implementation of the SAMA candidate.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 7 of 39 The cost of implementing a SAMA was estimated by one of the following methods (cost estimate).

o An estimate for a similar modification considered in a previously performed SAMA analysis was used. These estimates were developed in the past and no credit was taken for inflation when applying them to IP2 or IP3.

o Engineering judgment on the cost associated with procedural changes, engineering analysis, testing, training and hardware modification was applied to formulate a conclusion regarding the economic viability of the SAMA candidate.

(4) Sensitivity Analyses Three sensitivity analyses were conducted to gauge the impact of key assumptions upon the analysis. The first sensitivity analysis was to investigate the sensitivity of assuming a 26-year period for remaining plant life for IP2 (i.e. six years on the original plant license plus the 20-year license renewal period) and assuming a 28-year period for remaining plant life for IP3 (i.e. eight years on the original plant license plus the 20-year license renewal period). The second sensitivity analysis was to investigate the sensitivity of each analysis case assuming a discount rate of 3%. The third sensitivity analysis was to investigate impacts resulting from economic losses due to tourism and business, which were not included in the base case. This third sensitivity analysis was re-quantified accounting for uncertainty in response to Item 4e in the NRC request for additional information (RAI), dated December 12, 2007. This re-evaluation assesses the impact of the change in meteorological input on this re-quantified third sensitivity case.

An additional sensitivity was performed in response to Item 5 in the NRC RAI dated April 9, 2008

[Reference 1] regarding the impact of assuming a more pessimistic approach for addressing scenarios that may lead to thermally induced steam generator tube ruptures (TI-SGTRs). The impact of the revised meteorological input on the results of that sensitivity study was also re-evaluated, and the results of that re-evaluation are also included in this report.

(5) Additional NRC requested SAMA Candidate An additional item in the NRC RAI (Reference 1, Item 6) requested an evaluation of an additional SAMA related to use of a gagging device to close a stuck open main steam safety valve following a steam generator tube rupture, taking into account the modified TI-SGTR assumptions. That SAMA was evaluated using a very conservative simplified benefit analysis in response to that RAI and was determined to be potentially cost beneficial, given the estimated implementation cost of $50,000. For the purposes of completeness, the same conservative approach was taken for this re-analysis and produced a benefit with uncertainty of $13 million for IP2 and $19 million for IP3.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 8 of 39 SECTION 2

SUMMARY

OF RESULTS This re-analysis addresses the SAMA candidates that were not screened out in Phase I of the SAMA analysis.

Indian Point 2 This re-analysis addresses the 68 IP2 SAMA candidates that were not screened out in Phase I of the SAMA analysis. The previous analysis, described in Engineering Report IP-RPT-07-00007, identified nine potentially cost beneficial IP2 SAMA candidates. As a result of this re-analysis three additional IP2 SAMA candidates were determined to be potentially cost-beneficial.

The full list of potentially cost beneficial IP2 Phase II SAMA candidates is presented in Table 9.

Indian Point 3 This re-analysis addresses the 62 IP3 SAMA candidates that were not screened out in Phase I of the SAMA analysis. The previous analysis, described in Engineering Report IP-RPT-07-00008, identified five potentially cost beneficial IP3 SAMA candidates. As a result of this re-analysis three additional IP3 SAMA candidates were determined to be potentially cost-beneficial.

The full list of potentially cost beneficial IP3 Phase II SAMA candidates is presented in Table 10.

As noted above, an additional SAMA requested by the NRC related to use of a gagging device to close a stuck open main steam safety valve following a steam generator tube rupture, taking into account the modified TI-SGTR assumptions was evaluated and determined to be potentially cost beneficial for both units.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 9 of 39 SECTION 3 EVALUATION 3.1. SAMA IDENTIFICATION For the purpose of this evaluation candidate SAMAs are defined as potential enhancements to the plant design, operating procedures, inspection programs, or maintenance programs that have the potential to reduce the severe accident risk at IP2 or IP3. These SAMAs can be characterized as either hardware (i.e., physical modification of plant structures, systems, and/or components) or non-hardware (i.e.,

operation, maintenance programs, and procedure changes) enhancements, or a combination of the two.

The candidate SAMAs considered encompass both hardware and non-hardware modifications.

A list of SAMA candidates was developed in Phase I by reviewing industry documents and considering plant-specific enhancements not identified in published industry documents. Since IP2 and IP3 are typical pressurized water reactors, considerable attention was paid to the SAMA candidates from SAMA analyses for other pressurized water reactor plants. Additional discussion of this initial task is provided in IP-RPT-07-00007 and IP-RPT-07-00008, for IP2 and IP3, respectively (References 2 and 3). This task was not impacted by the current re-evaluation. Phase I SAMA candidates which were found to be applicable to IP2 or IP3, and not already implemented, were retained for further evaluation in Phase II of the SAMA analysis.

Tables 5 and 6 provide the results of the re-analysis of each of the IP2 and IP3 Phase II SAMA candidates, treating Sensitivity Case 3, with uncertainty, as the baseline case. The benefit values in this table represent the total SAMA benefits for both internal and external events.

3.2. ESTABLISHING THE BASELINE IMPACTS OF A SEVERE ACCIDENT A baseline for each unit was established to enable estimation of the risk reductions attributable to implementation of potential SAMA candidates. These severe accident risks were estimated using the PSA model for each unit and the MACCS2 consequence analysis software code. The PSA models used for the SAMA analysis are internal events risk models.

3.2.1. The PSA Internal Events Model - Level 1 and Level 2 Analysis The PSA models (Level 1 and Level 2) used for this re-evaluation were the same internal event risk models used for the previous SAMA analysis. The IP2 and IP3 PSA models (References 4 and 5) are complete, updated versions of the models used in the original IPE and reflect the plant specific configuration and design as of December 2005. They use component failure and unavailability data as of December 2005, and resolve all findings and observations from prior industry peer reviews.

The IP2 and IP3 PSA models utilize the small event tree / large fault tree approach and use the CAFTA code for quantifying CDF.

An uncertainty analysis associated with internal events CDF was performed for each unit. The ratio of the CDF at the 95th percent confidence level to the mean CDF is a factor of 2.10 for IP2 and 1.40 for IP3.

The analyses are presented in Attachment C of IP-RPT-07-00007 and IP-RPT-07-00008.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 10 of 39 The IP2 and IP3 Level 2 analyses uses a Containment Event Tree (CET) to analyze all core damage sequences identified in the Level 1 analysis. The CET evaluates systems, operator actions, and severe accident phenomena in order to characterize the magnitude and timing of radionuclide release. The result of the Level 2 analysis is a list of sequences involving radionuclide release, along with the frequency and magnitude/timing of release for each sequence.

3.2.2. The PSA External Events Model - Individual Plant Examination of External Events (IPEEE) Model The IPEEE models for both units (References 6 and 7) were reviewed and used for the SAMA analysis.

The seismic portion of the IPEEE was completed in conjunction with the Seismic Qualification Utility Group (SQUG) program. Both IP2 and IP3 performed a seismic Probabilistic Risk Assessment (PRA) following the guidance of NUREG-1407, Procedural and Submittal Guidance for the Individual Plant Examination of External Events (IPEEE) for Severe Accident Vulnerabilities, June 1991. A number of plant improvements were identified and, as described in NUREG-1742, Perspectives Gained from the IPEEE Program, Final Report, April 2002, these improvements were implemented.

The IP2 fire analysis was performed using the conservative EPRI Fire Induced Vulnerability Evaluation (FIVE) methodology for initial screening of fire zones. Unscreened fire zones were then analyzed in more detail using a fire PRA approach. The end result of IP2 IPEEE fire analysis identified the CDF for significant fire areas. A number of administrative procedures were revised to improve combustible and flammable material control.

The IP3 fire analysis was performed using the EPRI PRA Implementation Guide for quantitative screening of fire areas and for fire analysis of areas that did not screen. The fire analysis utilized the PSA internal event models to address fire induced initiators and equipment failure modes. A number of plant improvements were identified and, are described in NUREG1742, Perspectives Gained from the IPEEE Program, Final Report, April 2002. These improvements have been implemented. In addition, a number of administrative procedures were revised to improve combustible and flammable material control.

The IP2 IPEEE submittal, in addition to the internal fires and seismic events, examined a number of other external hazards:

x High Winds and /Tornadoes x External Flooding x Ice, Hazardous Chemical, Transportation and Nearby Facility Incidents 3.2.3. MACCS2 Model - Level 3 Analysis A Level 3 model was developed using the MACCS2 consequence analysis software code to estimate the hypothetical impacts of severe accidents on the surrounding environment and members of the public.

The principal phenomena analyzed were atmospheric transport of radionuclides; mitigation actions (i.e.,

evacuation, condemnation of contaminated crops and milk) based on dose projection; dose accumulation by a number of pathways, including food and water ingestion; and economic costs. Input for the Level 3 analysis included the core radionuclide inventory, source terms from each units PSA model, site meteorological data, projected population distribution (within 50-mile radius) for the year 2034, emergency response evacuation modeling, and economic data. The Level 3 analyses performed for IP2 and IP3 are documented in IP-CALC-09-00265 (Reference 8).

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 11 of 39 3.2.4. Baseline Population Dose and Off-site Economic Cost Risk The plant-specific risk models estimated the baseline population dose risk (PDR) to be 87.4 person-rem/yr for IP2 and 94.8 person-rem/yr for IP3. These values were determined based on each units baseline containment release fractions from the PSA model and the off-site dose parameters developed in the Level 3 PSA evaluation. The off-site dose was calculated in a 50-mile radius from the plant site The PDR for each release mode was calculated by multiplying frequency by dose, (and multiplying by 100 to convert sieverts to rem).

The plant-specific risk models estimated the baseline off-site economic cost risk (OECR) to be approximately $212,000/yr for IP2 and $261,000 for IP3. These values were determined based on the baseline containment release fractions from the PSA model and the off-site economic costs developed in the Level 3 PSA evaluation. The OECR is calculated for a 50-mile radius from the plant site.

The mean PDR and OECR for each release mode are provided in Table 1 for IP2 and Table 2 for IP3.

Table 1: IP2 Mean PDR and OECR Using Year 2000 Meteorological Data Population Offsite Population Dose Offsite Economic Release Frequency Dose Economic Cost Risk (PDR) Cost Risk (OECR)

Mode (/yr) (person-sv)* ($) (person-rem/yr) ($/yr)

NCF 1.19E-05 4.75E+01 9.98E+04 5.64E-02** 1.18E+00 EARLY HIGH 6.50E-07 6.51E+05 2.05E+11 4.23E+01 1.33E+05 EARLY MEDIUM 4.23E-07 1.94E+05 5.87E+10 8.21E+00 2.48E+04 EARLY LOW 1.11E-07 7.93E+04 6.39E+09 8.81E-01 7.10E+02 LATE HIGH 6.88E-07 1.63E+05 4.64E+10 1.12E+01 3.19E+04 LATE MEDIUM 3.43E-06 6.87E+04 6.06E+09 2.36E+01 2.08E+04 LATE LOW 6.43E-07 1.61E+04 6.59E+08 1.04E+00 4.24E+02 LATE LOWLOW 5.82E-08 1.38E+04 5.62E+08 8.04E-02 3.27E+01 Totals 8.74E+01 2.12E+05

    • 5.64E-02 (person-rem/yr) = 1.19E-05 (/yr) x 4.75E+01 (person-sv) x 100 (rem/sv)

Table 2: IP3 Mean PDR and OECR Using Year 2000 Meteorological Data Population Offsite Population Dose Offsite Economic Release Frequency Dose Economic Cost Risk (PDR) Cost Risk (OECR)

Mode (/yr) (person-sv)* ($) (person-rem/yr) ($/yr)

NCF 6.30E-06 8.04E+01 2.95E+05 5.06E-02** 1.86E+00 EARLY HIGH 9.43E-07 5.08E+05 1.70E+11 4.79E+01 1.60E+05 EARLY MEDIUM 1.24E-06 2.00E+05 5.55E+10 2.47E+01 6.87E+04 EARLY LOW 1.46E-07 5.21E+04 3.58E+09 7.59E-01 5.21E+02 LATE HIGH 4.23E-07 1.63E+05 4.61E+10 6.89E+00 1.95E+04 LATE MEDIUM 2.01E-06 6.85E+04 6.06E+09 1.37E+01 1.22E+04 LATE LOW 3.75E-07 1.61E+04 6.58E+08 6.03E-01 2.47E+02 LATE LOWLOW 5.66E-08 1.38E+04 5.62E+08 7.81E-02 3.18E+01 Totals 9.48E+01 2.61E+05

    • 5.06E-02 (person-rem/yr) = 6.30E-06 (/yr) x 8.04E+01 (person-sv) x 100 (rem/sv)

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 12 of 39 3.2.5 Present Dollar Value Equivalent Baseline Benefit The cost associated with each of the four impact areas for the baseline case (i.e., without SAMA implementation) were calculated for each unit using the methodology described in the following sections.

This analysis was used to establish the maximum benefit that a SAMA could achieve if it eliminated all risk due to at-power internal events.

3.2.5.1 Accident-Related Off-Site Dose Costs (APE)

The Level 3 baseline analysis resulted in an annual off-site exposure risk of 87.4 person-rem for IP2 and 94.8 person-rem for IP3. This value was converted to its monetary equivalent (dollars) via application of the $2,000 per person-rem conversion factor from the Regulatory Analysis Technical Evaluation Handbook (Reference 9). This monetary equivalent was then discounted to present value using the formula from the same source:

 rt f 1 e APE FS D PS  FA D PA R r

Where, APE = monetary value of accident risk avoided from population doses, after discounting R = monetary equivalent of unit dose, ($/person-rem)

F = accident frequency (events/year)

DP = population dose factor (person-rem/event)

S = status quo (current conditions)

A = after implementation of proposed action r = discount rate tf = license renewal period (years)

Because there are eight accident releases considered in this study, the product FDP, which represents population dose risk (PDR), was estimated by summing the product of the release frequency of each accident release and population dose over all eight releases.

For IP2, using a 20-year license renewal period, a 7% discount rate, assuming FA is zero, and the baseline PDR value of 87.4 person-rem/ry resulted in the monetary equivalent value of $1,881,355.

For IP3, using a 20-year license renewal period, a 7% discount rate, assuming FA is zero, and the baseline PDR value of 94.8 person-rem/ry resulted in the monetary equivalent value of $2,040,646.

These values are presented in Tables 3 and 4.

3.2.5.2 Accident-Related Off-Site Property Damage Costs (AOC)

The Level 3 baseline analysis resulted in an annual off-site economic risk monetary equivalent of

$212,000 for IP2 and $261,000 for IP3. This value was discounted in the same manner as the public health risks in accordance with the following equation:

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 13 of 39

 rt f 1 e AOC FS PDS  FA PDA r

Where, AOC = monetary value of risk avoided from off-site property damage, after discounting PD = off-site property loss factor ($/event)

F = accident frequency (events/year)

S = status quo (current conditions)

A = after implementation of proposed action r = discount rate tf = license renewal period (years)

The product F PD, which represents off-site economic cost risk (OECR), was estimated by summing the product of the release frequency of each accident release and off-site economic costs over all eight releases.

For IP2, using previously defined values and the baseline OECR value of $212,000/yr, the resulting monetary equivalent is $2,281,735.

For IP3, using previously defined values and the baseline OECR value of $261,000/yr, the resulting monetary equivalent is $2,809,117.

These values are presented in Tables 3 and 4.

3.2.5.3 Total Accident-Related Occupational Exposures (AOE)

The values for occupational exposure associated with severe accidents were not derived from the PSA model, but from information in the Regulatory Analysis Technical Evaluation Handbook (Reference 9).

The values for occupational exposure consist of immediate dose and long-term dose. The best estimate value provided for immediate occupational dose is 3,300 person-rem, and long-term occupational dose is 20,000 person-rem (over a 10-year clean-up period). The following equations were used to estimate monetary equivalents.

Immediate Dose

 rt f 1 e WIO FS DIOS  FA DIO A R (1) r

Where, WIO = monetary value of accident risk avoided from immediate doses, after discounting IO = immediate occupational dose R = monetary equivalent of unit dose, ($/person-rem)

F = accident frequency (events/year)

DIO = immediate occupational dose (person-rem/event)

S = status quo (current conditions)

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 14 of 39 A = after implementation of proposed action r = discount rate tf = license renewal period (years)

The values used in the analysis were:

R = $2,000/person rem r = 0.07 DIO = 3,300 person-rem /accident tf = 20 years For the basis discount rate, assuming FA is zero, the bounding monetary value of the immediate dose is:

 rt f 1 e W IO FS D IOS R r

1  e .07* 20 WIO 3300

  • FS * $2000 *

.07 WIO = ($7.10x107) FS For IP2, the baseline CDF is 1.79X10-5/ry, and WIO = $1,272 For IP3, the baseline CDF is 1.15X10-5/ry, and WIO = $817 Long-Term Dose

 rt f 1 e 1  e  rm WLTO FS DLTOS  FA DLTO A R * * (2) r rm

Where, WLTO= monetary value of accident risk avoided long-term doses, after discounting, ($)

LTO = long-term occupational dose m = years over which long-term doses accrue R = monetary equivalent of unit dose, ($/person-rem)

F = accident frequency (events/year)

DLTO =long-term occupational dose (person-rem/event)

S = status quo (current conditions)

A = after implementation of proposed action r = discount rate tf = license renewal period (years)

The values used in the analysis were:

R = $2,000/person rem

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 15 of 39 r = .07 DLTO = 20,000 person-rem /accident m = 10 years tf = 20 years For the basis discount rate, assuming FA is zero, the bounding monetary value of the long-term dose associated with accident risk is:

 rt f 1e 1  e  rm W LTO FS D LTOS R *

  • r rm 1  e .07* 20 1  e .07*10 WLTO FS u 20000 $2000 * *

.07 .07

  • 10 WLTO = ($3.10x108) FS For IP2, the baseline CDF is 1.79X10-5/ry, and WLTO $5,542 For IP3, the baseline CDF is 1.15X10-5/ry, and WLTO $3,560 Total Occupational Exposures Combining equations (1) and (2) above, using delta (') to signify the difference in accident frequency resulting from the proposed actions, and using the above numerical values, the long-term accident related on-site (occupational) exposure avoided is:

AOE 'W IO  'W LTO ($)

Where, AOE = on-site exposure avoided The bounding value for occupational exposure (AOEB) for IP2 is:

AOE B WIO  WLTO $1,272  $5,542 $6,814 The bounding value for occupational exposure (AOEB) for IP3 is:

AOE B WIO  WLTO $817  $3,560 $4,377 The resulting monetary equivalents of $6,814 for IP2 and $4,377 for IP3 are presented in Tables 3 and 4.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 16 of 39 3.2.5.4 Averted Costs Associated with Accident-Related On-Site Property Damage (AOSC)

Clean-up/Decontamination The total cost of clean-up/decontamination of a power reactor facility subsequent to a severe accident is estimated in the Regulatory Analysis Technical Evaluation Handbook (Reference 9) to be $1.5x109; this same value was adopted for these analyses. Considering a 10-year cleanup period, the present value of this cost is:

§ CCD *§¨ 1  e *¸

 rm PVCD ¨ ¸¨ ¸

© m ¹© r ¹

Where, PVCD = present value of the cost of cleanup/decontamination CD = clean-up/decontamination CCD = total cost of the cleanup/decontamination effort, ($)

m = cleanup period (years) r = discount rate Based upon the values previously assumed,

§ $1.5E  9 *§¨ 1  e *

.07* 10 PVCD ¨ ¸¨ ¸

© 10 ¹© .07 ¸

¹ PVCD $1.08E  9 This cost is integrated over the term of the proposed license extension as follows:

 rt f 1 e U CD PVCD r

Where, UCD = total cost of clean-up/decontamination over the life of the plant Based upon the values previously assumed, U CD $1.16E  10 This applies to both IP2 and IP3.

Replacement Power Costs Replacement power costs were estimated in accordance with the Regulatory Analysis Technical Evaluation Handbook (Reference 9). Since replacement power will be needed for the time period following a severe accident, for the remainder of the expected generating plant life, long-term power replacement calculations have been used. The present value of replacement power was estimated as follows:

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 17 of 39

§ $1.2 x108

  • 2 PVRP ¨ ¸ 1  e rt f

¨ r ¸

© ¹

Where, PVRP = present value of the cost of replacement power for a single event tf = license renewal period r = discount rate The $1.2x108 value has no intrinsic meaning, but is a substitute for a string of non-constant replacement power costs that occur over the lifetime of a generic reactor after an event. This equation was developed in the Regulatory Analysis Technical Evaluation Handbook (Reference 9) for discount rates between 5% and 10% only.

Based upon the values previously assumed:

§ $1.2 x10 8 *  rt 2 § $1.2 x10 8

  • 2 PVRP ¨¨ ¸¸ 1  e f ¨¨ ¸¸ 1  e  0.07 20

$9.73 x10 8

© r ¹ © 0.07 ¹ To account for the entire lifetime of the facility, URP was then calculated from PVRP, as follows:

PVRP º  rt f 2 U RP << r >>1 e

¬ 1/4

Where, URP = present value of the cost of replacement power over the remaining life tf = license renewal period r = discount rate Based upon the values previously assumed:

§ PVRP

  • 2 § $9.73 x10 8

 rt

¸ 1 e f ¨¨ ¸¸ 1  e ( 0.07 )( 20 ) $7.89 x10 9

© r ¹ © 0.07 ¹ Since net generation can vary based on plant demands, a power level of 1071 MWe, which reflects typical gross generation levels, was used to conservatively bound the net generated power that would need to be replaced at either IP2 or IP3. After applying a correction factor to account for the difference in typical gross power generation level used for IP2 and IP3, and the generic reactor described in the Regulatory Analysis Technical Evaluation Handbook (i.e., 1071 MWe/910 MWe), the value of URP becomes 9.29 x 109.

This applies to both IP2 and IP3.

Total On-site Property Damage Costs Combining the cleanup/decontamination and replacement power costs, using delta ('F) to signify the difference in accident frequency resulting from the proposed actions, and using the above numerical values, the best-estimate value of averted occupational exposure can be expressed as:

AOSC 'F U CD  U RP 'F $1.16 x1010  $9.29 x10 9 'F $2.09 x1010

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 18 of 39

Where,

'F = difference in annual accident frequency resulting from the proposed action For IP2, the baseline CDF is 1.79X10-5/ry, and the AOSC = $374,303 For IP3, the baseline CDF is 1.15X10-5/ry, and the AOSC = $240,475 The resulting monetary equivalents of $374,303 for IP2 and $240,475 for IP3 are presented in Tables 3 and 4.

Table 3: Estimated Present Dollar Value Equivalent of Internal Events CDF at IP2 Parameter Present Dollar Value ($)

Off-site population dose $1,881,355 Off-site economic costs $2,281,735 On-site dose $6,814 On-site economic costs $374,303 Total $4,544,208 Table 4: Estimated Present Dollar Value Equivalent of Internal Events CDF at IP3 Parameter Present Dollar Value ($)

Off-site population dose $2,040,646 Off-site economic costs $2,809,117 On-site dose $4,377 On-site economic costs $240,475 Total $5,094,615 The values used in the above equations were used as inputs in the benefit evaluation. Other inputs used in the benefit estimates are discussed in Section 3.4.2 of IP-RPT-07-00007 and IP-RPT-07-00008.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 19 of 39 3.3. EVALUATION OF SAMA CANDIDATE BENEFITS The result of implementation of each SAMA candidate would be a change in the severe accident risk (i.e.,

a change in frequency or consequence of severe accidents). The method of calculating the magnitude of these changes is straightforward. First, the severe accident risk after implementation of each SAMA candidate was estimated using the same method as for the baseline. The results of the Level 2 model were combined with the Level 3 model to calculate these post-SAMA risks.

IP-RPT-07-00007 and IP-RPT-07-00008 describe:

x The key Level 2 inputs used in the SAMA evaluations (Section 3.4.2) x The model evaluations associated with each representative analysis case used in the Phase II analysis (Attachment B) x the original results for each of the remaining SAMAs after preliminary screening (Section 4)

Tables 5 and 6 provide the results, for IP2 and IP3 respectively, of the benefit analysis for each SAMA candidate. The Benefit with Uncertainty value for each SAMA represents the benefit associated with removing the associated contributions to CDF following implementation of the SAMA and includes both the additional benefit when considering external events as well as the impact of uncertainty. As described in Section 3.7 of IP-RPT-07-00007 and IP-RPT-07-00008, this was developed for each unit by using a multiplier of eight.

3.4. EVALUATION OF SAMA CANDIDATE IMPLEMENTATION COST ESTIMATES To assess the viability of each SAMA considered for a final cost-benefit evaluation, the cost of implementing that particular SAMA was estimated and compared with the estimated benefit. If the cost of implementation was greater than the attainable benefit of a particular SAMA, then the modification was not considered economically viable and was eliminated from further consideration.

The expected cost of implementation of each SAMA was established from existing estimates of similar modifications or from plant specific estimates. The cost estimates did not include the cost of replacement power during extended outages required to implement the modifications, nor did they include contingency costs associated with unforeseen implementation obstacles. Estimates based on modifications that were implemented or estimated in the past were presented in terms of dollar values at the time of implementation (or estimation), and were not adjusted to present-day dollars. This represents a conservatism for those cost estimates.

The benefit of implementing a SAMA candidate was estimated in terms of averted consequences. The benefit was estimated by calculating the arithmetic difference between the total estimated costs associated with the four impact areas for the baseline plant design and the total estimated impact area costs for the enhanced plant design (following implementation of the SAMA candidate).

Values for avoided public and occupational health risk were converted to a monetary equivalent (dollars) via application of the NUREG/BR-0184 (Reference 9) conversion factor of $2,000 per person-rem and discounted to present value. Values for avoided offsite economic costs were also discounted to present value.

As this analysis focuses on establishing the economic viability of each potential plant enhancement when compared to attainable benefit, detailed cost estimates often were not required to make informed decisions regarding the economic viability of a particular modification. As a result, conservatively low cost

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 20 of 39 estimates used for several of the SAMA candidates that were clearly in excess of the attainable benefit estimated from a particular analysis case.

For less clear cases, a more detailed cost estimate was necessary, addressing the plant specific scope and cost associated with procedural changes, engineering analysis, testing, training, and hardware modifications to formulate a conclusion regarding the economic viability of a particular SAMA. As part of this re-analysis, some additional SAMAs, previously screened using the conservative approach, were subjected to the more detailed cost estimate process.

3.5. FINAL SCREENING AND COST BENEFIT EVALUATION (PHASE II)

The cost/benefit analysis performed on the remaining SAMA candidates for this re-evaluation used the same process used for the original analysis. The method for determining if a SAMA candidate was cost beneficial consisted of determining whether the benefit provided by implementation of the SAMA candidate exceeded the expected cost of enhancement (COE). The benefit was defined as the sum of the reduction in dollar equivalents for each severe accident impact area (off-site exposure, off-site economic costs, occupational exposure, and on-site economic costs). If the expected implementation cost exceeded the estimated benefit, the SAMA was not considered cost-beneficial. Additional description of the process to perform the final cost benefit analysis is described in Section 3.7 of IP-RPT-07-00007 and IP-RPT-07-00008.

The results of the cost-benefit evaluation are displayed in Table 5 for IP2 and Table 6 for IP3. These tables provide a comparison of cost with the benefits of SAMA implementation and the final conclusions drawn for each candidate SAMA. SAMAs identified as Previously Retained were previously shown to be potentially cost beneficial. SAMAs identified as Retained Based on Revised Analysis are additional SAMAs found to be potentially cost beneficial based on this re-analysis.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 21 of 39 Table 5: Results of Cost-Benefit Analysis of IP2 SAMA Candidates Risk Reduction (%) Benefit with IP2 Phase II SAMA Benefit Estimated Cost Conclusion CDF PDR OECR Uncertainty 001 - Create an independent RCP seal injection system with a dedicated 9.59% 1.60% 1.42% $374,757 $788,963 $1,137,000 Not Cost Beneficial diesel.

002 - Create an independent RCP seal injection system without a dedicated 8.29% 1.49% 1.42% $350,396 $737,676 $1,000,000 Not Cost Beneficial diesel.

003 - Install an additional CCW pump. 0.12% 0.00% 0.00% $0 $0 $1,500,000 Not Cost Beneficial 004 - Enhance procedural guidance for use 1.88% 0.23% 0.00% $48,723 $102,574 $1,750,000 Not Cost Beneficial of service water pumps.

005 - Improve ability to cool the RHR heat exchangers by allowing manual 2.93% 0.34% 0.47% $105,892 $222,931 $565,000 Not Cost Beneficial alignment of the fire protection system.

006 - Add a diesel building high temperature 1.13% 0.11% 0.07% $30,496 $64,202 $274,000 Not Cost Beneficial alarm.

007 - Install a filtered containment vent to 0.00% 16.70% 6.13% $1,725,939 $3,633,555 $5,700,000 Not Cost Beneficial provide fission product scrubbing.

008 - Create a large concrete crucible with heat removal potential under the base 0.00% 47.03% 34.43% $6,347,528 $13,363,217 $108,000,000 Not Cost Beneficial mat to contain molten core debris.

009 - Create a reactor cavity flooding 0.00% 47.03% 34.43% $6,347,528 $13,363,217 $4,100,000 Previously Retained system.

010 - Create a core melt source reduction 0.00% 47.03% 34.43% $6,347,528 $13,363,217 $90,000,000 Not Cost Beneficial system.

011 - Provide a means to inert containment. 0.00% 17.51% 21.23% $3,091,966 $6,509,402 $10,900,000 Not Cost Beneficial 012 - Use the fire protection system as a backup source for the containment 0.00% 0.00% 0.00% $0 $0 $565,000 Not Cost Beneficial spray system.

013 - Install a passive containment spray 0.00% 0.00% 0.00% $0 $0 $2,000,000 Not Cost Beneficial system.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 22 of 39 Table 5: Results of Cost-Benefit Analysis of IP2 SAMA Candidates Risk Reduction (%) Benefit with IP2 Phase II SAMA Benefit Estimated Cost Conclusion CDF PDR OECR Uncertainty 014 - Increase the depth of the concrete base mat or use an alternative 0.00% 11.56% 4.25% $1,194,251 $2,514,214 >$5,000,000 Not Cost Beneficial concrete material to ensure melt-through does not occur.

015 - Construct a building connected to primary containment that is maintained 0.00% 40.50% 35.38% $5,963,077 $12,553,847 $61,000,000 Not Cost Beneficial at a vacuum.

016 - Install a redundant containment spray 0.00% 0.00% 0.00% $0 $0 $5,800,000 Not Cost Beneficial system.

017 - Erect a barrier that provides containment liner protection from 0.00% 10.07% 11.79% $1,742,298 $3,667,996 $5,500,000* Not Cost Beneficial ejected core debris at high pressure.

018 - Install a highly reliable steam generator shell-side heat removal 0.05% 0.46% 0.47% $73,618 $154,986 $7,400,000 Not Cost Beneficial system that relies on natural circulation and stored water sources.

019 - Increase secondary side pressure capacity such that a SGTR would not 2.42% 30.21% 39.15% $5,594,541 $11,777,981 >$100,000,000* Not Cost Beneficial cause the relief valves to lift.

020 - Route the discharge from the main steam safety valves through a structure where a water spray would 0.00% 2.97% 4.25% $580,766 $1,222,665 $9,700,000 Not Cost Beneficial condense the steam and remove most of the fission products.

021 - Install additional pressure or leak Retained Based on monitoring instrumentation for 0.83% 11.33% 14.62% $2,093,852 $4,408,109 $3,200,000*

Revised Analysis ISLOCAs.

022 - Add redundant and diverse limit Retained Based on switches to each containment isolation 0.40% 5.72% 7.55% $1,071,465 $2,255,716 $2,200,000*

Revised Analysis valve.

023 - Increase leak testing of valves in 0.40% 5.72% 7.55% $1,071,465 $2,255,716 $7,964,000 Not Cost Beneficial ISLOCA paths.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 23 of 39 Table 5: Results of Cost-Benefit Analysis of IP2 SAMA Candidates Risk Reduction (%) Benefit with IP2 Phase II SAMA Benefit Estimated Cost Conclusion CDF PDR OECR Uncertainty 024 - Ensure all ISLOCA releases are 0.83% 11.33% 14.62% $2,093,852 $4,408,109 $9,700,000 Not Cost Beneficial scrubbed.

025 - Improve MSIV design. 0.05% 0.57% 0.94% $122,697 $258,310 $476,000 Not Cost Beneficial 026 - Provide additional DC battery capacity. 1.94% 0.23% 0.00% $48,723 $102,574 >$1,875,000 Not Cost Beneficial 027 - Use fuel cells instead of lead-acid 1.94% 0.23% 0.00% $48,723 $102,574 $2,000,000 Not Cost Beneficial batteries.

028 - Provide a portable diesel-driven 4.79% 9.38% 7.08% $1,357,046 $2,856,939 $938,000* Previously Retained battery charger.

029 - Increase/ improve DC bus load 1.94% 0.23% 0.00% $48,723 $102,574 $460,000* Not Cost Beneficial shedding.

030 - Create AC power cross-tie capability 2.81% 0.23% 0.00% $56,813 $119,607 $1,156,000 Not Cost Beneficial with other unit.

031 - Create a backup source for diesel 1.69% 0.23% 0.00% $40,632 $85,541 $1,700,000 Not Cost Beneficial cooling (not from existing system).

032 - Use fire protection system as a backup 1.69% 0.23% 0.00% $40,632 $85,541 $497,000 Not Cost Beneficial source for diesel cooling.

033 - Convert under-voltage AFW and reactor protective system actuation 0.00% 0.00% 0.00% $0 $0 $1,254,000 Not Cost Beneficial signals from 2-out-of-4 to 3-out-of-4 logic.

034 - Provide capability for diesel-driven, low 0.02% 0.06% 0.05% $8,180 $17,221 >$632,000 Not Cost Beneficial pressure vessel makeup.

035 - Provide an additional high pressure injection pump with independent 0.29% 0.34% 0.47% $73,529 $154,798 $5,000,000 Not Cost Beneficial diesel.

036 - Create automatic swap-over to recirculation cooling upon RWST 4.08% 0.46% 0.47% $138,344 $291,251 >$1,000,000 Not Cost Beneficial depletion.

037 - Provide capability for alternate 0.02% 0.06% 0.05% $8,180 $17,221 $750,000 Not Cost Beneficial injection via diesel-driven fire pump.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 24 of 39 Table 5: Results of Cost-Benefit Analysis of IP2 SAMA Candidates Risk Reduction (%) Benefit with IP2 Phase II SAMA Benefit Estimated Cost Conclusion CDF PDR OECR Uncertainty 038 - Throttle low pressure injection pumps earlier in medium or large-break 0.60% 0.11% 0.07% $22,405 $47,169 $82,000 Not Cost Beneficial LOCAs to maintain reactor water storage tank inventory.

039 - Replace two of three motor-driven SI 0.29% 0.34% 0.47% $73,529 $154,798 $2,000,000 Not Cost Beneficial pumps with diesel-powered pumps.

040 - Create/enhance a reactor coolant 0.87% 3.20% 3.77% $572,408 $1,205,070 $2,000,000* Not Cost Beneficial depressurization system.

041 - Install a digital feed water upgrade. 4.85% 0.92% 0.47% $179,154 $377,167 $900,000 Not Cost Beneficial 042 - Provide automatic nitrogen backup to steam generator atmospheric dump 0.05% 0.23% 0.00% $16,360 $34,441 $214,000 Not Cost Beneficial valves.

043 - Add a motor-driven feed water pump. 4.85% 0.92% 0.47% $179,154 $377,167 $2,000,000 Not Cost Beneficial 044 - Use fire water system as backup for 33.00% 14.19% 9.91% $2,350,530 $4,948,485 $1,656,000 Previously Retained steam generator inventory.

045 - Replace current pilot operated relief valves with larger ones such that only 18.30% 3.32% 1.89% $667,806 $1,405,907 $2,700,000 Not Cost Beneficial one is required for successful feed and bleed.

046 - Modify emergency operating procedures for ability to align diesel 0.00% 0.00% 0.00% $0 $0 $82,000 Not Cost Beneficial power to more air compressors.

047 - Add an independent boron injection 0.00% 0.00% 0.00% $0 $0 $300,000 Not Cost Beneficial system.

048 - Add a system of relief valves that prevent equipment damage from a 1.98% 0.46% 0.47% $105,981 $223,119 $615,000 Not Cost Beneficial pressure spike during an ATWS.

049 - Install motor generator set trip 0.91% 0.23% 0.00% $32,541 $68,508 $716,000 Not Cost Beneficial breakers in control room.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 25 of 39 Table 5: Results of Cost-Benefit Analysis of IP2 SAMA Candidates Risk Reduction (%) Benefit with IP2 Phase II SAMA Benefit Estimated Cost Conclusion CDF PDR OECR Uncertainty 050 - Provide capability to remove power from the bus powering the control 0.91% 0.23% 0.00% $32,541 $68,508 $90,000 Not Cost Beneficial rods.

051- Provide digital large break LOCA 0.06% 0.00% 0.00% $0 $0 $2,036,000 Not Cost Beneficial protection.

052 - Install secondary side guard pipes up 0.45% 1.72% 1.89% $294,384 $619,756 $1,100,000 Not Cost Beneficial to the MSIVs.

053 - Keep both pressurizer PORV block 17.61% 3.32% 1.89% $659,715 $1,388,873 $800,000 Previously Retained valves open.

054 - Install flood alarm in the 480V 19.97% 39.24% 28.77% $5,591,781 $11,772,170 $200,000 Previously Retained switchgear room.

055 - Perform a hardware modification to allow high-head recirculation from 0.02% 0.00% 0.00% $0 $0 $1,330,000 Not Cost Beneficial either RHR heat exchanger.

056 - Keep RHR heat exchanger discharge motor operated valves (MOVs) 1.84% 0.23% 0.00% $48,723 $102,574 $82,000 Previously Retained normally open.

057 - Provide DC power backup for the 1.22% 0.46% 0.47% $89,800 $189,052 $376,000 Not Cost Beneficial PORVs.

058 - Provide procedural guidance to allow high-head recirculation from either 0.02% 0.00% 0.00% $0 $0 $82,000 Not Cost Beneficial RHR heat exchanger.

059 - Re-install the low pressure suction trip on the AFW pumps and enhance 0.68% 0.23% 0.00% $24,450 $51,474 $318,000 Not Cost Beneficial procedures to respond to loss of the normal suction path.

060 - Provide added protection against flood propagation from stairwell 4 into the 4.52% 8.92% 6.60% $1,275,337 $2,684,920 $216,000 Previously Retained 480V switchgear room.

061 - Provide added protection against flood propagation from the deluge room into 9.84% 19.34% 14.15% $2,754,991 $5,799,982 $192,000 Previously Retained the 480V switchgear room.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 26 of 39 Table 5: Results of Cost-Benefit Analysis of IP2 SAMA Candidates Risk Reduction (%) Benefit with IP2 Phase II SAMA Benefit Estimated Cost Conclusion CDF PDR OECR Uncertainty 062 - Provide a hard-wired connection to an Retained Based on SI pump from ASSS power supply. 3.08% 6.06% 4.25% $850,165 $1,789,822 $1,500,000*

Revised Analysis 063 - Provide a water-tight door for additional protection of the RHR 1.39% 0.11% 0.00% $32,452 $68,320 $324,000 Not Cost Beneficial pumps against flooding.

064 - Provide backup cooling water source 1.73% 0.23% 0.00% $40,632 $85,541 $710,000 Not Cost Beneficial for the CCW heat exchangers.

065 - Upgrade the ASSS to allow timely restoration of seal injection and 19.97% 39.24% 28.77% $5,591,781 $11,772,170 $560,000 Previously Retained cooling.

066 - Harden the EDG building and fuel oil transfer pumps against tornados and 85.05% 8.96% 6.19% $2,505,846 $5,275,465 $33,500,000* Not Cost Beneficial high winds.

067 - Provide hardware connections to allow the primary water system to cool the 0.17% 0.02% 0.00% $9,727 $20,477 $576,000 Not Cost Beneficial charging pumps.

068 - Provide independent source of cooling 0.27% 0.06% 0.01% $13,408 $28,227 $710,000 Not Cost Beneficial for the recirculation pump motors.

  • New estimated cost. See Tables E.2-3 and E.4-3 of LRA submittal for original estimated cost

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 27 of 39 Table 6: Results of Cost-Benefit Analysis of IP3 SAMA Candidates Risk Reduction (%) Benefit with IP3 Phase II SAMA Benefit Estimated Cost Conclusion CDF PDR OECR Uncertainty 001 - Create an independent RCP seal 6.87% 0.74% 0.38% $236,610 $342,913 $1,137,000 Not Cost Beneficial injection system with a dedicated diesel.

002 - Create an independent RCP seal 5.05% 0.63% 0.38% $201,222 $291,626 $1,000,000 Not Cost Beneficial injection system without a dedicated diesel.

003 - Install an additional CCW pump. 0.11% 0.00% 0.00% $0 $0 $1,500,000 Not Cost Beneficial 004 - Improved ability to cool the RHR heat exchangers by allowing manual alignment of 0.65% 0.53% 0.38% $130,575 $189,240 $565,000 Not Cost Beneficial the fire protection system.

005 - Install a filtered containment vent to 0.00% 9.60% 2.68% $1,497,163 $2,169,801 $5,700,000 Not Cost Beneficial provide fission product scrubbing.

006 - Create a large concrete crucible with heat removal potential under the base mat to 0.00% 24.16% 14.94% $5,038,071 $7,301,552 $108,000,000 Not Cost Beneficial contain molten core debris.

007 - Create a reactor cavity flooding system. Retained Based on 0.00% 24.16% 14.94% $5,038,071 $7,301,552 $4,100,000*

Revised Analysis 008 - Create a core melt source reduction 0.00% 24.16% 14.94% $5,038,071 $7,301,552 $90,000,000 Not Cost Beneficial system.

009 - Provide means to inert containment. 0.00% 8.76% 9.20% $2,412,095 $3,495,790 $10,900,000 Not Cost Beneficial 010 - Use the fire protection system as a backup source for the containment spray 0.11% 0.00% 0.00% $0 $0 $565,000 Not Cost Beneficial system.

011 - Install a passive containment spray 0.11% 0.00% 0.00% $0 $0 $2,000,000 Not Cost Beneficial system.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 28 of 39 Table 6: Results of Cost-Benefit Analysis of IP3 SAMA Candidates Risk Reduction (%) Benefit with IP3 Phase II SAMA Benefit Estimated Cost Conclusion CDF PDR OECR Uncertainty 012 - Increase the depth of the concrete base mat or use an alternative concrete 0.00% 5.59% 1.53% $867,404 $1,257,107 >$5,000,000 Not Cost Beneficial material to ensure melt-through does not occur.

013 - Construct a building connected to primary containment that is maintained at a 0.00% 21.73% 15.71% $4,883,602 $7,077,683 $61,000,000 Not Cost Beneficial vacuum.

014 - Install a redundant containment spray 0.11% 0.00% 0.00% $0 $0 $5,800,000 Not Cost Beneficial system.

015 - Erect a barrier that provides containment liner protection from ejected 0.00%** 4.32% 4.21% $1,140,695 $1,653,182 $5,500,000* Not Cost Beneficial core debris at high pressure.

016 - Install a highly reliable steam generator shell-side heat removal system that relies on 2.47% 5.27% 4.98% $1,401,717 $2,031,473 $7,400,000 Not Cost Beneficial natural circulation and stored water sources.

017 - Increase secondary side pressure capacity such that an SGTR would not cause 8.57% 45.15% 53.64% $13,520,698 $19,595,215 >$100,000,000* Not Cost Beneficial the relief valves to lift.

018 - Route the discharge from the main steam safety valves through a structure where a water spray would condense the 0.00% 11.08% 13.41% $3,327,028 $4,821,779 $12,000,000* Not Cost Beneficial steam and remove most of the fission products.

019 - Install additional pressure or leak Retained Based on 1.26% 7.07% 8.43% $2,126,663 $3,082,120 $2,800,000*

monitoring instrumentation for ISLOCAs. Revised Analysis 020 - Add redundant and diverse limit 0.68% 3.59% 4.21% $1,069,272 $1,549,670 $4,000,000* Not Cost Beneficial switches to each containment isolation valve.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 29 of 39 Table 6: Results of Cost-Benefit Analysis of IP3 SAMA Candidates Risk Reduction (%) Benefit with IP3 Phase II SAMA Benefit Estimated Cost Conclusion CDF PDR OECR Uncertainty 021 - Increase leak testing of valves in 0.68% 3.59% 4.21% $1,069,272 $1,549,670 $10,604,000 Not Cost Beneficial ISLOCA paths.

022 - Ensure all ISLOCA releases are 1.26% 7.07% 8.43% $2,126,663 $3,082,120 $9,700,000 Not Cost Beneficial scrubbed.

023 - Improve MSIV design. 0.11% 0.00% 0.00% $0 $0 $476,000 Not Cost Beneficial 024 - Provide additional DC battery capacity. 2.81% 0.11% 0.00% $47,141 $68,320 >$1,875,000 Not Cost Beneficial 025 - Use fuel cells instead of lead-acid 2.81% 0.11% 0.00% $47,141 $68,320 $2,000,000 Not Cost Beneficial batteries.

026 - Increase/ improve DC bus load 2.81% 0.11% 0.00% $47,141 $68,320 $460,000* Not Cost Beneficial shedding.

027 - Create AC power cross-tie capability 4.50% 0.11% 0.00% $70,647 $102,387 $1,156,000 Not Cost Beneficial with other unit.

028 - Create a backup source for diesel 0.56% 0.03% 0.00% $15,318 $22,199 $1,700,000 Not Cost Beneficial cooling (not from existing system).

029 - Use fire protection system as a backup 0.56% 0.03% 0.00% $15,318 $22,199 $497,000 Not Cost Beneficial source for diesel cooling.

030 - Provide a portable diesel-driven battery 3.69% 0.95% 0.38% $213,363 $309,222 $938,000* Not Cost Beneficial charger.

031 - Convert under-voltage, AFW and reactor protective system actuation signals 0.33% 0.53% 0.38% $118,822 $172,206 $1,254,000 Not Cost Beneficial from 2-out-of-4 to 3-out-of-4 logic.

032 - Provide capability for diesel-driven, low 0.24% 0.21% 0.00% $23,764 $34,441 >$632,000 Not Cost Beneficial pressure vessel makeup.

033 - Provide an additional high pressure 0.39% 0.42% 0.38% $118,693 $172,019 $5,000,000 Not Cost Beneficial injection pump with independent diesel.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 30 of 39 Table 6: Results of Cost-Benefit Analysis of IP3 SAMA Candidates Risk Reduction (%) Benefit with IP3 Phase II SAMA Benefit Estimated Cost Conclusion CDF PDR OECR Uncertainty 034 - Create automatic swap-over to 19.86% 1.27% 0.77% $530,551 $768,914 >$1,000,000 Not Cost Beneficial recirculation upon RWST depletion.

035 - Provide capability for alternate injection 0.24% 0.21% 0.00% $23,764 $34,441 $750,000 Not Cost Beneficial via diesel-driven fire pump.

036 - Throttle low pressure injection pumps earlier in medium or large-break LOCAs to 0.86% 0.00% 0.00% $11,753 $17,033 $82,000 Not Cost Beneficial maintain reactor water storage tank inventory.

037 - Replace two of three motor-driven SI 0.39% 0.42% 0.38% $118,693 $172,019 $2,000,000 Not Cost Beneficial pumps with diesel-powered pumps.

038 - Create/enhance a reactor coolant 0.55% 0.95% 0.77% $237,516 $344,225 $4,600,000 Not Cost Beneficial depressurization system.

039 - Install a digital feed water upgrade. 11.84% 0.95% 0.00% $271,481 $393,450 $900,000 Not Cost Beneficial 040 - Provide automatic nitrogen backup to 0.51% 0.95% 0.77% $237,516 $344,225 $950,000* Not Cost Beneficial steam generator atmospheric dump valves.

041 - Add a motor-driven feedwater pump. 11.84% 0.95% 0.00% $271,481 $393,450 $2,000,000 Not Cost Beneficial 042 - Provide hookup for portable generators to power the turbine-driven AFW pump after 2.81% 0.11% 0.00% $47,141 $68,320 $1,072,000 Not Cost Beneficial station batteries are depleted.

043 - Use fire water system as backup for 6.75% 1.58% 1.15% $450,490 $652,885 $1,656,000 Not Cost Beneficial steam generator inventory.

044 - Replace current pilot operated relief valves with larger ones such that only one is 4.46% 4.75% 4.21% $1,246,989 $1,807,230 $2,700,000 Not Cost Beneficial required for successful feed and bleed.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 31 of 39 Table 6: Results of Cost-Benefit Analysis of IP3 SAMA Candidates Risk Reduction (%) Benefit with IP3 Phase II SAMA Benefit Estimated Cost Conclusion CDF PDR OECR Uncertainty 045 - Add an independent boron injection 0.16% 0.00% 0.00% $0 $0 $300,000 Not Cost Beneficial system.

046 - Add a system of relief valves that prevent equipment damage from a pressure 10.28% 0.74% 0.00% $224,210 $324,943 $615,000 Not Cost Beneficial spike during an ATWS.

047 - Install motor generator set trip breakers 1.60% 0.11% 0.00% $35,388 $51,287 $716,000 Not Cost Beneficial in control room.

048 - Provide capability to remove power 1.60% 0.11% 0.00% $35,388 $51,287 $90,000 Not Cost Beneficial from the bus powering the control rods.

049 - Provide digital large break LOCA 0.30% 0.00% 0.00% $0 $0 $2,036,000 Not Cost Beneficial protection.

050 - Install secondary side guard pipes up 4.67% 9.07% 8.81% $2,447,095 $3,546,515 $9,671,000* Not Cost Beneficial to the MSIVs.

051 - Operator action: Align main feedwater 0.65% 0.11% 0.00% $23,635 $34,254 $55,000 Not Cost Beneficial for secondary heat removal.

052 - Open city water supply valve for 0.89% 1.05% 0.77% $249,398 $361,446 $50,000 Previously Retained alternative AFW pump suction.

053 - Install an excess flow valve to reduce 1.79% 2.07% 1.51% $498,795 $722,892 $228,000 Previously Retained the risk associated with hydrogen explosions.

054 - Provide DC power backup for the 0.20% 0.00% 0.00% $0 $0 $376,000 Not Cost Beneficial PORVs.

055 - Provide hard-wired connection to a SI or RHR pump from the Appendix R bus 16.48% 18.35% 11.49% $4,073,152 $5,903,118 $1,288,000 Previously Retained (MCC 312A).

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 32 of 39 Table 6: Results of Cost-Benefit Analysis of IP3 SAMA Candidates Risk Reduction (%) Benefit with IP3 Phase II SAMA Benefit Estimated Cost Conclusion CDF PDR OECR Uncertainty 056 - Install pneumatic controls and 2.81% 0.11% 0.00% $47,141 $68,320 $982,000 Not Cost Beneficial indication for the turbine-driven AFW pump.

057 - Provide backup cooling water source 2.51% 0.21% 0.00% $59,023 $85,541 $109,000 Not Cost Beneficial for the CCW heat exchangers.

058 - Provide automatic DC power backup. 4.83% 0.21% 0.00% $94,282 $136,640 $1,868,000 Not Cost Beneficial 059 - Provide hardware connections to allow the primary water system to cool the 0.19% 0.00% 0.00% $0 $0 $576,000 Not Cost Beneficial charging pumps.

060 - Provide independent source of cooling 0.20% 0.00% 0.00% $0 $0 $710,000 Not Cost Beneficial for the recirculation pump motors.

061 - Upgrade the ASSS to allow timely 17.43% 19.73% 12.26% $4,359,371 $6,317,929 $560,000 Previously Retained restoration of seal injection and cooling.

062 - Install flood alarm in the 480 VAC 17.43% 19.73% 12.26% $4,359,371 $6,317,929 $196,800 Previously Retained switchgear room.

  • New estimated cost. See Tables E.2-3 and E.4-3 of LRA submittal for original estimated cost
    • Reported as 0.11% in IP-RPT-07-00008 due to typographical error. This value is not used in the actual quantification of the SAMA benefit.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 33 of 39 3.6. THERMALLY INDUCED STEAM GENERATOR TUBE RUPTURE SENSITIVITY ANALYSIS As noted in Section 1.2, as part of an NRC RAI, Entergy was requested to evaluate the impact of more pessimistic assumptions regarding scenarios that involve the potential for a thermally induced steam generator tube rupture (TI-SGTR).

Although final industry consensus on this issue has not been reached, a sensitivity study was performed to determine the impact of applying values derived from NUREG-1570 (Reference 10). The full lists of IP2 and IP3 Phase II SAMAs were reviewed for impact. Of those, the following twenty seven IP2 SAMAs and twenty two IP3 SAMAs were identified as potentially impacted by the TI-SGTR assumption.

IP2 SAMAs: 1, 6, 18, 19, 20, 25, 26, 27, 28, 29 ,30 ,31, 32, 35, 39, 40, 42, 44, 46, 52, 54, 59, 60, 61, 62, 65, 66 IP3 SAMAs: 1, 16, 17, 18, 23, 24, 25, 26, 27, 28, 29, 30, 33, 38, 40, 42, 43, 55, 56, 58, 61, 62 Since IP2 SAMAs 28, 44, 54, 60, 61, 62 and 65 and IP3 SAMAs 55, 61 and 62 were previously determined to be potentially cost beneficial, they were not re-evaluated. Of the remaining SAMAs, a detailed evaluation was performed for those for which the cost outweighed the benefit by less than a factor of five. This screening criterion was applied to facilitate the re-evaluation by limiting it to those potentially impacted SAMA candidates with a realistic possibility of becoming cost-beneficial.

The unscreened IP2 SAMAs were SAMAs 1, 6, 25, 29, 40 and 52 The unscreened IP3 SAMAs were SAMAs 1, 16, 18, 30, 40 and 43 The baseline case (Table 5.8 of NUREG-1570) associated with moderate tube degradation was used for this sensitivity study. The full conditional induced SGTR value (0.25) shown for that case was used. The NUREG-1570 conditional probability was applied to all high/dry sequences in the Level 2 model for each unit; in both station blackout and transient sequences. Table 7 shows the values for the IP2 SAMAs re-evaluated in this sensitivity analysis. Table 8 shows the values for the IP3 SAMAs re-evaluated in this sensitivity analysis. While the costs of both the baseline case and the individual SAMAs increased, the extent to which the revised TI-SGTR assumption impacted the delta cost varied, based on the nature of the specific SAMA.

It should be noted that although the NUREG-1570 baseline case values were used for this sensitivity analysis, the baseline case applies to a steam generator with a moderate flaw distribution. The IP2 and IP3 steam generators have been replaced and are being maintained in accordance with the stringent standards recommended by NEI 97-06. The IP2 and IP3 steam generators have only 0.19% and 0.12%

of the tubes plugged, and would be classified as pristine in accordance with generic criteria established by Westinghouse for categorizing steam generator tube integrity. Corrosion has not been observed in the steam generators. Therefore, using the baseline case for this sensitivity study is considered conservative relative to application of the NUREG-1570 results for pristine generators (Table 5.8, Case 8).

An additional item in the NRC RAI (Reference 1, Item 6) requested an evaluation of an additional SAMA related to use of a gagging device to close a stuck open main steam safety valve following a steam generator tube rupture, taking into account the modified TI-SGTR assumptions. That SAMA was evaluated using a very conservative simplified benefit analysis in response to that RAI and was determined to be potentially cost beneficial, given the estimated implementation cost of $50,000. For the purposes of completeness, the same conservative approach was taken for this re-analysis and produced a benefit with uncertainty of $13 million for IP2 and $19 million for IP3.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 34 of 39 Table 7: IP2 TI-SGTR Sensitivity Results Original TI-SGTR Revised IP2 Phase II SAMA Benefit with Benefit with Estimated Cost Conclusion Uncertainty Uncertainty 001 - Create an independent RCP seal injection system with a

$788,963 $892,287 $1,137,000 Not Cost Beneficial dedicated diesel.

006 - Add a diesel building high temperature alarm. $64,202 $223,493 $274,000 Not Cost Beneficial 025 - Improve MSIV design. $258,310 $430,516 $476,000 Not Cost Beneficial 029 - Increase/ improve DC bus load shedding. $102,574 $257,560 $460,000* Not Cost Beneficial 040 - Create/enhance a reactor coolant depressurization system. $1,205,070 $1,325,614 $2,000,000* Not Cost Beneficial 052 - Install secondary side guard pipes up to the MSIVs. $619,756 $878,065 $1,100,000 Not Cost Beneficial

  • New estimated cost. See Tables E.2-3 and E.4-3 of LRA submittal for original estimated cost.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 35 of 39 Table 8: IP3 TI-SGTR Sensitivity Results Original TI-SGTR Revised IP3 Phase II SAMA Benefit with Benefit with Estimated Cost Conclusion Uncertainty Uncertainty 001 - Create an independent RCP seal injection system with a

$342,913 $480,678 $1,137,000 Not Cost Beneficial dedicated diesel.

016 - Install a highly reliable steam generator shell-side heat removal system that relies on natural circulation and stored water $2,031,473 $2,289,783 $7,400,000 Not Cost Beneficial sources.

018 - Route the discharge from the main steam safety valves Retained Based on through a structure where a water spray would condense the steam $4,821,779 $14,637,545 $12,000,000*

Revised Analysis and remove most of the fission products.

030 - Provide a portable diesel-driven battery charger. $309,222 $515,869 $938,000 Not Cost Beneficial 040 - Provide automatic nitrogen backup to steam generator

$344,225 $447,549 $950,000* Not Cost Beneficial atmospheric dump valves.

043 - Use fire water system as backup for steam generator

$652,885 $825,091 $1,656,000 Not Cost Beneficial inventory.

  • New estimated cost. See Tables E.2-3 and E.4-3 of LRA submittal for original estimated cost

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 36 of 39 SECTION 4 CONCLUSIONS The re-evaluation of the Sensitivity Case with Uncertainty, together with the impact of the revised approach to TI-SGTR, where applicable, resulted in 12 potentially cost beneficial IP2 SAMA candidates, including nine SAMAs that were previously found to be potentially cost beneficial in the previous evaluation (in IP-RPT-07-00007). The full IP2 list is presented in Table 9.

The re-evaluation of the Sensitivity Case with Uncertainty together with the impact of the revised approach to TI-SGTR, where applicable, resulted in eight potentially cost beneficial IP3 SAMA candidates, including five that were previously found to be potentially cost beneficial in the previous evaluation (in IP-RPT-07-00008). The full IP3 list is presented in Table 10.

As noted above, an additional SAMA requested by the NRC related to use of a gagging device to close a stuck open main steam safety valve following a steam generator tube rupture, taking into account the modified TI-SGTR assumptions was evaluated and determined to be potentially cost beneficial for both units.

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 37 of 39 Table 9: Final List of Potentially Cost-Beneficial IP2 SAMA Candidates Benefit with IP2 Phase II SAMA Estimated Cost Conclusion Uncertainty 009 - Create a reactor cavity flooding system. $13,363,217 $4,100,000 Previously Retained 021 - Install additional pressure or leak monitoring Retained Based on instrumentation for ISLOCAs. $4,408,109 $3,200,000*

Revised Analysis 022 - Add redundant and diverse limit switches to each Retained Based on containment isolation valve. $2,255,716 $2,200,000*

Revised Analysis 028 - Provide a portable diesel-driven battery charger. $2,856,939 $938,000* Previously Retained 044 - Use fire water system as backup for steam

$4,948,485 $1,656,000 Previously Retained generator inventory.

053 - Keep both pressurizer PORV block valves open. $1,388,873 $800,000 Previously Retained 054 - Install flood alarm in the 480V switchgear room. $11,772,170 $200,000 Previously Retained 056 - Keep RHR heat exchanger discharge motor

$102,574 $82,000 Previously Retained operated valves (MOVs) normally open.

060 - Provide added protection against flood propagation

$2,684,920 $216,000 Previously Retained from stairwell 4 into the 480V switchgear room.

061 - Provide added protection against flood propagation from the deluge room into the 480V switchgear $5,799,982 $192,000 Previously Retained room.

062 - Provide a hard-wired connection to an SI pump Retained Based on from ASSS power supply. $1,789,822 $1,500,000*

Revised Analysis 065 - Upgrade the ASSS to allow timely restoration of

$11,772,170 $560,000 Previously Retained seal injection and cooling.

  • New estimated cost. See Tables E.2-3 and E.4-3 of LRA submittal for original estimated cost

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 38 of 39 Table 10: Final List of Potentially Cost-Beneficial IP3 SAMA Candidates Benefit with Estimated IP3 Phase II SAMA Conclusion Uncertainty Cost 007 - Create a reactor cavity flooding system. Retained Based on

$7,301,552 $4,100,000*

Revised Analysis 018 - Route the discharge from the main steam safety valves Retained Based on through a structure where a water spray would condense the $14,637,545 $12,000,000*

Revised Analysis steam and remove most of the fission products.

019 - Install additional pressure or leak monitoring Retained Based on

$3,082,120 $2,800,000*

instrumentation for ISLOCAs. Revised Analysis 052 - Open city water supply valve for alternative AFW pump

$361,446 $50,000 Previously Retained suction.

053 - Install an excess flow valve to reduce the risk associated

$722,892 $228,000 Previously Retained with hydrogen explosions.

055 - Provide hard-wired connection to a SI or RHR pump

$5,903,118 $1,288,000 Previously Retained from the Appendix R bus (MCC 312A).

061 - Upgrade the ASSS to allow timely restoration of seal

$6,317,929 $560,000 Previously Retained injection and cooling.

062 - Install flood alarm in the 480 VAC switchgear room. $6,317,929 $196,800 Previously Retained

Engineering Report REPORT NO. IP-RPT-09-00044 Revision 0 Page 39 of 39 SECTION 5 REFERENCES

1. Request for Additional Information (RAI) Regarding the Analysis of Severe Accident Mitigation Alternatives (SAMAs) for Indian Point Nuclear Generating Unit Nos. 2 and 3 (IP2 and IP3), April 9, 2008
2. IP-RPT-07-00007, IP2 Cost-Benefit Analysis of Severe Accident Mitigation Alternatives, Revision 0, April 30, 2007
3. IP-RPT-07-00008, IP3 Cost-Benefit Analysis of Severe Accident Mitigation Alternatives, Revision 0, April 30, 2007
4. IP-RPT-07-00230 "Indian Point Unit 2 Nuclear Power Plant Probabilistic Safety Assessment Revision 1, April 2007.
5. IP-RPT-06-00071 "Indian Point Unit 3 Nuclear Power Plant Probabilistic Safety Assessment Revision 2, April 2007
6. Indian Point 2 Nuclear Generating Station Individual Plant Examination of External Events (IPEEE) Report, December 1995
7. IP3-RPT-UNSPEC-02182, Indian Point 3 Nuclear Generating Station Individual Plant Examination of External Events (IPEEE) Report, September 1997
8. IP-CALC-09-00265, Re-Analysis of MACCS2 Models for IPEC.
9. NUREG/BR-0184, Regulatory Analysis Technical Evaluation Handbook, U.S. Nuclear Regulatory Commission, January 1997
10. NUREG-1570, Risk Assessment of Severe-Accident Induced Steam Generator Tube Rupture, U.S.

Nuclear Regulatory Commission, March 1998

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