Text

Diablo Canyon Power Plant Er Changes Reflected in the Environmental Report Update Amendment 2. Part 6 of 9
	ML15056A763
Person / Time
Site:	Diablo Canyon
Issue date:	02/25/2015
From:	; Pacific Gas & Electric Co
To:	; Office of Nuclear Reactor Regulation
Shared Package
ML15057A102	List: DCL-15-027, Diablo Canyon Power Plant Environmental Report Changes Reflected in the Environmental Report Update Amendment 2. Part 1 of 9; DCL-15-027, Diablo Canyon Power Plant Er Changes Reflected in the Environmental Report Update Amendment 2. Part 2 of 9; DCL-15-027, Diablo Canyon Power Plant Er Changes Reflected in the Environmental Report Update Amendment 2. Part 3 of 9; DCL-15-027, Diablo Canyon Power Plant Er Changes Reflected in the Environmental Report Update Amendment 2. Part 4 of 9; DCL-15-027, Diablo Canyon Power Plant Er Changes Reflected in the Environmental Report Update Amendment 2. Part 5 of 9; DCL-15-027, Diablo Canyon Power Plant Er Changes Reflected in the Environmental Report Update Amendment 2. Part 6 of 9; DCL-15-027, Diablo Canyon Power Plant Er Changes Reflected in the Environmental Report Update Amendment 2. Part 7 of 9; DCL-15-027, Diablo Canyon Power Plant Er Changes Reflected in the Environmental Report Update Amendment 2. Part 8 of 9; DCL-15-027, Er Changes Reflected in the Environmental Report Update Amendment 2. Part 8 of 9; ML15056A705; ML15056A741; ML15056A755; ML15056A756; ML15056A758; ML15056A759; ML15056A763; ML15056A765; ML15057A240;
References
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Model Change(s):

APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Refer to the model changes described for SAMA 12 in Section F.7.2.1.6. The SAMA 12 model changes envelope the changes for SAMA 10. Results of SAMA Quantification:

The SAMA 12 quantification is used as a bounding estimate of the SAMA 10 benefit. As documented in Section F.7.2.1.6 , the baseline averted cost-risk for SAMA 12 is $813,995.

Based on a $22,572,878 cost of implementation for DCPP, the net value for this SAMA is -$21,758,883

($813.,995 -$22,572,878).

When the 95th percentile PRA results are used, the averted cost-risk is increased by a factor of 3.0 to $2,441,985, which still yields a negative net value ($2,441 ,985 -$22,572,878

= -$20, 130,893).

This SAMA is not cost-beneficial.

F.7.2.1.6 SAMA 12: Use an Alternate EDG to Support Long Term AFW Operation and a 480V AC Self-Cooled PDP for Primary Side Makeup A low cost SBO mitigation strategy is to use a small, alternate EDG to power a station battery charger for level instrumentation and AFW control. In addition, if power can be supplied to a 480V AC self-cooled, high pressure positive displacement pump, primary side makeup could be maintained to make up for normal seal leakage and potentially for boil off in longer timeframes . . Change

Description:

The seismic pretree SEISPRE models the fragility of the DC system. When top event SOC fails electric power event tree ELECPWR DC top events D2F, D2G and D2H are failed. A seismically qualified DC generator that could be used to power loads requiring DC power. A way to model that is to not fail one of the DC buses due to seismic initiators and to decrease the failure probability due to the additional redundant components.

To account for the impact on DC in the long term all the split fractions for top event OF must be reduced in probability by a factor of 100. Assume fire damage to 125V DC bus F prevents the use of the alternate DC equipment.

Diablo Canyon Power Plant License Renewal Application Page F-123 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Top event CH models cold leg injection via the CCPs. Because this SAMA provides a redundant injection pump from a separate stand-alone AC power source, each split fraction can be reduced by the failure rate of such a system. The assumed failure rate is 1.0E-02. The guaranteed failed split fraction (CHF) is no longer 1.0E+OO, but defaults to the failure rate of the stand-alone redundant train, 1.0E-02. Charging is also modeled in top events CHI for interfacing system LOCAs, and CHM for medium LOCAs. These need to be changed as well. The split fractions developed for fire that involve the flow control valves (8801, 8803, 8805) should not be changed in value. Model Change(s):

In ELECPWR:

Delete the split fraction rule (D2FF: SCD=F), which fails DC bus F due to seismic initiators.

In rule 44 allow the bus to fail due to DC bus F initiators.

Delete the seismic Macros (i.e., SEISA, SEISB, and SEISC) from the split fraction rules for the Long-Term DC split fractions DF*SB and DF*SC. In MFF change the following:

Reduce the value of SF D2F1 by a factor of 100 (DHUMFA -=1 E-2 which is an operator action to align a backup charger) to 2.5E-6 to account for the additional equipment.

Reduce the probability of all the OF split fractions by a factor of 100 to account for the additional equipment.

Top Events CH, CHI, CHM:

Reduce the each split fraction by a factor of 100 except for those that reflect fire failure of valves 8801, 8803, or 8805. Event Tree(s): GENTRN, ATWT, MLOCA, ILOCA, SGENTRN, SGTREARLY Diablo Canyon Power Plant License Renewal Application Page F-124 Results of SAMA Quantification:

APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 The following table summarizes the changes to the internal events CDF, Dose-Risk, and Offsite Economic Cost-Risk resulting from the implementation of this SAMA: Base Value SAMA Value Percent Change CDF 8.64E-05 8.31 E-05 3.8% Dose-Risk OECR 98.89 $246,912 84.71 $228,732 14.3% 7.4% A further breakdown of the Dose-Risk and OECR information is provided in the table below according to release category:

Release Category ST1 ST2 ST3 ST4 ST5 ST6 Total FrequencysAsE 7.24E-06 6.74E-06 6.42E-05 1.79E-06 2.97E-06 1.79E-06 8.52E-05 FrequencysAMA 5.82E-06 6.77E-06 6.27E-05 1.77E-06 2.94E-06 1.77E-06 8.21E-05 Dose-RisksASE 71.20 6.46 1.60 1.38 18.24 0.01 98.89 Dose-RisksAMA 57.21 6.49 1.56 1.36 18.08 0.01 84.71 OECRsAsE $88,372 $48,941 $751 $9,774 $99,072 $2 $246,912 OECRsAMA $71,004 $49,150 $734 $9,647 $98,196 $2 $228,732 This information was used as input to the averted cost-risk calculation.

The results of this calculation are provided in the following table: SAMA 12 Averted Cost-Risk Unit Base Case Revised Averted Cost-Risk Cost-Risk Cost-Risk DCPP Unit 1 $9,315,791

$8,501,796

$813,995 Based on a $13,560,218 cost of implementation for DCPP, the net value for this SAMA is -$12,746,223

($813,995

-$13,560,218).

When the 95th percentile PRA results are used, the averted cost-risk is increased by a factor of 3.0 to $2,441,985, which still yields a negative net value ($2,441,985-

$13,560,218

= -$11,118,233).

This SAMA is not cost-beneficial.

Diablo Canyon Power Plant License Renewal Application Page F-125 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 F.7.2.1.7 SAMA 17: Install Flood Sensors to Mitigate Fire Protection System Pipe Breaks There are multiple scenarios related to Fire Protection system pipe breaks that, if isolated, lead to significant equipment damage. In order to improve the likelihood of flood termination, water sensors could be installed in areas containing critical equipment that can be impacted by fire protection system floods, such as those containing the AFW, CCW, and RHR pumps. The water level sensor could be linked to logic that would trip the fire protection pumps and/or isolate a critical valve for scenarios where there is not a coincident fire alarm. Change

Description:

For the following initiators, change the frequency, lowering it by a factor of 1 00. Related to SF WFL02N:

Y14AFWMP1 E (break In area 14-A),

Y3B85FWLP1 (area 3-BB-85, 3-BB-1 00, or 3-BB-115),

Y54FT61N (area not listed),

Y31 FWLP2C (area not listed),

Y31 FWMP2C1 (Areas 31, or 3-P-2),

Y3B15FWMP1 (area not listed),

Y3H 1 FWLP1A (area not listed) Related to SF CD1 FL:

Y3Q1 FWLP2A (rooms 3-Q-1 and 3-Q-2),

Y31 FWLP2A2 (area 3-Q-1),

Y31 FWMP2C1 (Areas 31, 3-Q-1, or 3-P-2) Model Change(s):

Reduce the following IE frequencies by a factor of 100: Diablo Canyon Power Plant License Renewal Application Page F-126 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2

Y14AFWMP1 E from 3.998700E-004 to 3.998700E-006

Y3B85FWLP1 from 1.060000E-003 to 1.060000E-005

Y54FT61N from 3.111900E-004 to 3.111900E-006

Y31 FWLP2C from 2. 7 41700E-004 to 2. 7 41700E-006

Y31 FWMP2C1 from 1.047500E-004 to 1.047500E-006

Y3B15FWMP1 from 1.075000E-005 to 1.075000E-007

Y3H1FWLP1A from 7.241200E-005 to 7.241200E-007

Y3Q1 FWLP2A from 3.8201 OOE-004 to 3.8201 OOE-006

Y31 FWLP2A2 from 1.390800E-004 to 1.390800E-006

Y31 FWMP2C1 from 1.047500E-006 to 1.047500E-008.

Event Tree(s): FLOOD Results of SAMA Quantification:

The following table summarizes the changes to the internal events CDF, Dose-Risk, and Offsite Economic Cost-Risk resulting from the implementation of this SAMA: Base Value SAMA Value Percent Change CDF 8.64E-05 8.33E-05 3.6% Dose-Risk 98.89 96.95 2.0% OECR $246,912 $234,906 4.9% A further breakdown of the Dose-Risk and OECR information is provided in the table below according to release category:

Release Category ST1 FrequencysAsE 7.24E-06 FrequencysAMA 7.23E-06 Dose-RisksAsE 71.20 Dose-RisksAMA 71.07 OECRsASE $88,372 OECRsAMA $88,206 Diablo Canyon Power Plant License Renewal Application ST2 6.74E-06 6.72E-06 6.46 6.44 $48,941 $48,787 ST3 6.42E-05 6.13E-05 1.60 1.53 $751 $717 ST4 ST5 ST6 Total 1.79E-06 2.97E-06 1.79E-06 8.52E-05 O.OOE+OO 2.91 E-06 O.OOE+OO 8.04E-05 1.38 18.24 0.01 98.89 0.00 17.90 0.01 96.95 $9,774 $99,072 $2 $246,912 $0 $97,194 $2 $234,906 Page F-127 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 This information was used as input to the averted cost-risk calculation. The results of this calculation are provided in the following table: SAMA 17 Averted Cost-Risk Unit Base Case Revised Averted Cost-Risk Cost-Risk Cost-Risk DCPP Unit 1 $9,315,791

$8,982,236

$333,555 Based on a $9,610,440 cost of implementation for DCPP, the net value for this SAMA is -$9,276,885

($333,555

-$9,61 0,440). When the 95th percentile PRA results are used, the averted cost-risk is increased by a factor of 3.0 to $1,000,665, which still yields a negative net value ($1 ,000,665 -$9,610,440

= -$8,609,775).

This SAMA is not beneficial.

The cost estimate of $9,610,440 was only for an Aux Bldg flooding alarm system with local sensors and alarms at both the Aux Control Board and Main Control Room (i.e., it does not account for the changes required to perform automatic system isolation).

Adding the capability to automatically isolate the Fire Protection System would significantly increase the implementation cost. The risk reduction for this SAMA, however, is based on the availability of the automatic isolation capability.

Therefore, the net value for this SAMA would be more negative if the automatic isolation capability were to be included in the cost estimate.

F.7.2.1.8 SAMA 20: Use Alternate Signal (such as AMSAC) to De-energize the 480V AC Buses that Supply the Rod Drive Motor Generator Sets In the event that the MG set breakers do not trip in an ATWS, an alternate signal, such as an AMSAC signal, could be used to depower the 480V AC supply that powers the MG sets to ensure the control rod drive units are shut down. The 480V trip could be delayed so that it is only performed after 30 seconds with a valid ATWS signal. Change

Description:

Reduce the probability of all split fractions for top event RT by the failure rate of an AMSAC-Iike system (use split fraction AM1), which is approximately 1.0E-02. No split Diablo Canyon Power Plant License Renewal Application Page F-128 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 fraction should be less than RT6 (6.16E-06) which is the failure probability of the control rods to insert. Split fraction RT6 is used for station blackout scenarios where power to the RPS bus is unavailable and it is certain the RPS bus has de-energized.

Model Change(s):

In MFF, set all RT split fractions to 6.16E-6 except for RT7, whose new frequency should be 1.86E-05.

Event Tree(s): MECHSUP Results of SAMA Quantification:

The following table summarizes the changes to the internal events CDF, Dose-Risk, and Offsite Economic Cost-Risk resulting from the implementation of this SAMA: Base Value SAMA Value Percent Change CDF 8.64E-05 8.57E-05 0.8% Dose-Risk OECR 98.89 $246,912 72.99 $223,255 26.2% 9.6% A further breakdown of the Dose-Risk and OECR information is provided in the table below according to release category:

Release Category ST1 ST2 ST3 ST4 ST5 STG Total FrequencysAsE 7.24E-06 6.74E-06 6.42E-05 1.79E-06 2.97E-06 1.79E-06 8.52E-05 FrequencysAMA 4.46E-06 7.93E-06 6.51 E-05 1.83E-06 3.01 E-06 1.83E-06 8.46E-05 Dose-RisksAsE 71.20 6.46 1.60 1.38 18.24 0.01 98.89 Dose-RisksAMA 43.84 7.60 1.62 1.41 18.51 0.01 72.99 OECRsAsE $88,372 $48,941 $751 $9,774 $99,072 $2 $246,912 OECRsAMA $54,412 $57,572

$762 $9,974 $100,534 $2 $223,255 This information was used as input to the averted cost-risk calculation.

The results of this calculation are provided in the following table: Diablo Canyon Power Plant License Application SAMA 20 Averted Cost-Risk Page F-129 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Unit Base Case Revised Averted Cost-Risk Cost-Risk Cost-Risk DCPP Unit 1 $9,315,791 $8,127,775 $1,188,016 Based on an $11,173,059 cost of implementation for DCPP, the net value for this SAMA is -$9,985,043

($1 , 188,016 -$11, 173,059).

When the 95th percentile PRA results are used, the averted cost-risk is increased by a factor of 3.0 to $3,564,048, which still yields a negative net value ($3,564,048

-$11,173,059

= -$7,609,011).

This SAMA is not cost-beneficial.

F.7.2.1.9 SAMA 22: Install Containment Combustible Gas Igniters Early containment failure is a contributor to the LERF release category.

Although inerting containment in accident conditions could help prevent burns of combustible gases, a better solution is to install battery-backed igniters throughout upper dome of containment.

Change

Description:

Hydrogen burn in containment is modeled through top event HECET (within 4hrs of vessel breach) and CECET (early hydrogen burn). These associated split fractions could be reduced by the failure probability of a hydrogen ignitor system that is battery backed -1 E-03. Top Event HECET:

HECET1 from 7.1 E-01 to 7.1 E-04

HECET2 from 7.1 E-01 to 7.1 E-04

Leave HECETO = 1.0 Top Event CECET

CECET1 from 2.8E-02 to 2.8E-05 Model Change(s):

Top Event HECET

HECET1 from 7.1 E.:.01 to 7.1 E-04 Diablo Canyon Power Plant License Renewal Application Page F-130 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2

HECET2 from 7.1 E-01 to 7.1 E-04

Leave HECETO = 1.0 Top Event CECET

CECET1 from 2.8E-02 to 2.8E-05 Event Tree(s): CET, CETIT, CETML, CETORG, SCET Results of SAMA Quantification:

The following table summarizes the changes to the internal events CDF, Dose-Risk, and Offsite Economic Cost-Risk resulting from the implementation of this SAMA: CDF Dose-Risk OECR Base Value 8.64E-05 98.89 $246,912 SAMA Value 8.64E-05 97.90 $245,748 Percent Change 0.0% 1.0% 0.5% A further breakdown of the Dose-Risk and OECR information is provided in the table below according to release category:

Release Category ST1 ST2 ST3 ST4 ST5 ST6 Total FrequencysAsE 7.24E-06 6.74E-06 6.42E-05 1.79E-06 2.97E-06 1.79E-06 8.52E-05 FrequencysAMA 7.14E-06 6.74E-06 6.43E-05 1.79E-06 2.97E-06 1.79E-06 8.52E-05 Dose-RisksAsE 71.20 6.46 1.60 1.38 18.24 0.01 98.89 Dose-RisksAMA 70.19 6.46 1.60 1.37 18.27 0.01 97.90 OECRsASE $88,372 $48,941 $751 $9,774 $99,072 $2 $246,912 OECRsAMA $87,108 $48,932 $752 $9,756 $99,198 $2 $245,748 This information was used as input to the averted cost-risk calculation.

The results of this calculation are provided in the following table: Unit DCPP Unit 1 Diablo Canyon Power Plant License Renewal Application SAMA 22 Averted Cost-Risk Base Case Revised Averted Cost-Risk Cost-Risk Cost-Risk

$9,315,791

$9,266,969

$48,822 Page F-131 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Based on a $13,083,120 cost of implementation for DCPP, the net value for this SAMA is -$13,034,298

($48,822 -$13,083, 120). When the 95th percentile PRA results are used, the averted cost-risk is increased by a factor of 3.0 to $146,466, which still yields a negative net value ($146,466-

$13,083,120

= -$12,936,654).

This SAMA is not beneficial.

F.7.2.2 PHASE 2 IMPACT As discussed above, a single factor based on the 95th percentile for the base case is used to determine the impact of the cost-benefit analysis for the proposed SAMA candidates.

The uncertainty analyses that are available for the Level 1 model are not available (or not used) for the Level 2 and 3 PRA models. In order to simulate the use of the 95th percentile results for the Level 2 and 3 models, the same scaling factor calculated for the Level 1 results was implicitly applied to the Level 2 and 3 models. The Phase 2 SAMA list was re-examined by multiplying the nominal averted cost risk by a factor of 3.0 (see Section F.7.2) to identify SAMAs that would be re-characterized as cost beneficial, i.e., positive net value. Those SAMAs that were previously determined to be not cost beneficial due to implementation costs exceeding their associated nominal averted cost risk may be potentially cost beneficial at the revised 95th percentile averted cost risk. In this case, two (2) additional Phase 2 SAMAs become potentially cost-beneficial (SAMAs 8 and 16). F.7.2.395TH PERCENTILE

SUMMARY

The following table provides a summary of the impact of using the 95th percentile PRA results on the detailed cost-benefit calculations that have been performed.

Summary of the Impact of Using the 95th Percentile PRA Results Averted Averted Change in SAMA Cost of Cost Risk Net Value Cost Risk Net Value (95th Cost ID Implementation (Base) (Base) (95th Percentile)

Effective-Percentile) ness? $3,020,424

$584,227 -$2,436,197

$1,752,681

-$1,267,743 No 2 $17,492,616

$792,847 -$16,699,769

$2,378,541

-$15,114,075 No 3 $376,342 $845,287 $468,945 $2,535,861

$2,159,519 No 5 $3,133,404

$31,219 -$3,102,185

$93,657 -$3,039,747 No Diablo Canyon Power Plant Page F-132 License Renewal Application APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Summary of the Impact of Using the 95th Percentile PRA Results Averted Averted Change in SAMA Cost of Cost Risk Net Value Cost Risk Net Value (95th Cost ID Implementation (Base) (Base) (95th Percentile)

Effective-Percentile) ness? 6 $9,993,910

$325,104 -$9,668,806

$975,312 -$9,018,598 No 7 $10,616,468

$339,888 -$10,276,580

$1,019,664

-$9,596,804 No 8 $1,072,493

$584,227 -$488,266

$1,752,681

$680,188 Yes 9 $25,520,160

$71,677 -$25,448,483

$215,031 -$25,305,129 No 10 $22,572,878

$813,995 -$21,758,883

$2,441,985

-$20,130,893 No 12 $13,560,218

$813,995 -$12,746,223

$2,441,985

-$11, 118, 2 3 3 No 14 $5,620,896

$269,718 -$5,351,178

$809,154 -$4,811,742 No 16 $372,788 $225,882 -$146,906

$677,646 $304,858 Yes 17 $9,610,440

$333,555 -$9,276,885

$1,000,665

-$8,609,775 No 20 $11,173,059

$1,188,016

-$9,985,043

$3,564,048 No 21 $256,817 $1,666,133 $1,409,316 $4,998,399

$4,741,582 No 22 $13,083,120

$48,822 -$13,034,298

$146,466 -$12,936,654 No 23 $491,021 $2,706 -$488,315 $8,118 -$482,903 No When the 95th percentile PRA results were applied to the Phase 1 analysis, the increase in the MACR resulted in the retention of nine (9) SAMAs that were screened in the baseline Phase 1 analysis (SAMAs 2, 6, 7, 9, 10, 12, 17, 20, and 22). The Phase 2 analysis' performed for these SAMAs using the 95th percentile PRA results confirmed that none are cost-beneficial.

When the 95th percentile PRA results were applied to the Phase 2 analysis, two (2) SAMAs (8 and 16) that were previously classified as not cost-effective were determined to be potentially cost-effective.

The use of the 95th percentile PRA results is not considered to provide the best assessment of the cost-effectiveness of a SAMA. Instead, it is intended to address the uncertainties inherent in the SAMA analysis.

Nonetheless, these additional SAMAs identified as cost-beneficial through this sensitivity case (none of which is related to aging management under 10 C.F.R. Part 54) should be further evaluated for possible implementation using current, applicable plant procedures.

Diablo Canyon Power Plant License Renewal Application Page F-133 F.7.3 MACCS21NPUT VARIATIONS F.7.3.1 OVERVIEW APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 The MACCS2 model was developed using the best information available for the DCPP site; however, reasonable changes to modeling assumptions can lead to variations in the Level 3 results. In order to determine how certain assumptions could impact the SAMA results, a sensitivity analysis was performed on parameters that have previously been shown to impact the Level 3 results. These parameters include: Meteorological data Evacuation timing and speed Release height and heat Deposition velocity Population estimates Population resettlement planning Generic economic inputs Economic rate of return Value of farm and non-farm wealth The risk metrics produced by MACCS2 that are evaluated in the sensitivity analyses are the 50 mile population dose and the 50 mile offsite economic cost. The subsections below discuss the changes in these results for each of the sensitivity parameters noted above. The final subsection, F.7.3.11, correlates the worst case changes identified in the sensitivity runs to a change in the site's averted cost-risk and discusses the implications of the sensitivity analysis on the SAMA analysis.

The results of these sensitivity analyses (i.e., changes in dose and cost risk relative to the baseline values) are shown in Table F.7-1. Diablo Canyon Power Plant License Renewal Application Page F-134 F.7.3.2 METEOROLOGICAL SENSITIVITIES APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 In addition to the year 2002 base case meteorological data, years 2004 and 2006 were also analyzed.

Analysis of year 2004 and 2006 data sets yielded population dose-risks and cost risks that were 1 °/o to 11 °/o less than 2002 results. As no particular criteria have been defined by the industry related to determining which meteorological data set should be used as a base case for a site, the year 2002 data is chosen for DCPP given that it results in higher results than the other data sets evaluated.

F.7.3.3 EVACUATION SENSITIVITIES The sensitivity of two evacuation parameters was assessed.

The evacuation speed sensitivity decreased the average radial evacuation speed by a factor of two, from 0. 76 m/sec to 0.38 m/sec. The decreased speed results in a negligible impact to dose and cost risk. A further decrease in the relatively slow base case evacuation speed did not materially impact the dose results. Cost results are not normally impacted by evacuation parameters, as discussed further below. The delay time sensitivity explores the impact of an increased delay time before evacuation begins (i.e., vehicles begin moving in the 10 mile , region). For this sensitivity, the base case delay time of 1 00 minutes is arbitrarily doubled to 200 minutes. For many evacuation conditions, the population dose would be expected to increase for an increased delay time since more individuals would be expected to be exposed to the release due to their later departure (i.e., they failed to out run the release).

The increased delay time results in decrease in dose risk of about 20°/o. This decrease is attributed to people receiving some shielding from their houses during the most dominant release types (LGEARL Y and ISLOCA) prior to evacuation.

The shielding factor provided by structures is greater than that of automobiles and mitigates some dose to the public from passing plumes. For many individuals in the 10 mile evacuation region, their evacuation vehicle movement will begin slightly before or nearly coincident with the arrival of the first plume (depending upon their radial distance from the site) for the LGEARLY and ISLOCA categories for the base case. At this time, individuals are leaving their homes (which provide some radiological shielding) to enter their vehicles (which provide less Diablo Canyon Power Plant License Renewal Application Page F-135 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 radiological shielding).

Due to the slow evacuation speed (0.76 m/s; -2 mph) compared to the average wind speed (-1 0 mph), the individuals tend to experience the plume passing over them as they progress in traffic. When the additional delay of 1 00 minutes is included (for a total delay of 200 minutes), the evacuation vehicle movement for many individuals will begin after the first plume passes while they were afforded more radiological shielding in their homes. The sensitivity case with no evacuation and no population relocation for 7 days resulted in a 9°/o decrease in dose risk. Similar to the evacuation delay sensitivity, this decrease is attributed to people being shielded more in structures relative to automobiles.

It is noted that while evacuation assumptions do impact the population dose-risk estimates, they do not impact MACCS2 offsite economic cost-risk estimates because MACCS2 calculated cost-risks are based on land contamination levels which remain unaffected by evacuation assumptions and the number of people evacuating.

F.7.3.4RELEASE HEIGHT & HEAT SENSITIVITIES The release height sensitivity case quantifies the impact of the assumption related to the height of the release of the plumes. The baseline case assumes that the releases occur near the top of reactor building (67m) which tends to disperse material over a wider geographical region, generally impacting more people and creating larger cleanup costs. A ground level release height shows a decrease in dose risk and cost risk of 1 0°/o and 3°/o, respectively.

The release heat sensitivity case evaluates the impact of neglecting thermal plume effects. The base case assumed no thermal plume heat in the releases (e.g., no buoyant plumes). The sensitivity case assumed a heat content of 10 MW per plume segment, except for the intact containment release category.

Increasing the plume heat contents resulted in differing results for individual releases (i.e., results of some release categories increased while others decreased.)

The net result is a decrease in dose-risk of 14%> and a negligible change to cost risk when 10 MW plume heat content values are applied. Diablo Canyon Power Plant License Renewal Application Page F-136 F.7.3.5 DEPOSITION VELOCITY APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 The dry deposition velocity sensitivity case evaluates the impact of the fission product particle size as reflected in the deposition velocity parameter.

The base case assumes a deposition velocity of 0.01 m/sec, consistent with the NRC recommendation documented in MACCS2 Sample Problem A (Reference 22). The sensitivity case uses a deposition velocity of 0.003 m/sec, reflective of a smaller particle size. The NRC's State-of-the-Art Reactor Consequence Study (Reference

90) notes that the average deposition velocity used in the analysis is approximately 0.003 m/s. Assuming a lower deposition velocity results in an increase in population dose risk of about 20°/o, but a decrease in cost risk of about 35°/o. The increase in dose is attributed to particles traveling further from the site before depositing and thereby impacting more people in the population centers located further from the site. The decrease in costs is attributed to more of the particles exiting the 50-mile analysis region prior to deposition.

F.7.3.6 POPULATION SENSITIVITY A population sensitivity case assesses the impact of population assumptions.

The base case year 2045 population is uniformly increased by 30°/o in all spatial elements of the 50-mile radius. This change has a significant impact on the dose risk and cost risk, increasing dose risk and cost risk by 30o/o and 29°/o, respectively.

This sensitivity case demonstrates a significant dependence upon population estimates.

This dependence is expected given that population dose and offsite economic costs are primarily driven by the regional population.

F.7.3.7 RESETTLEMENT PLANNING SENSITIVITIES The MACCS2 consequence modeling incorporates an "intermediate phase" which depicts the time period following the release and immediate evacuation actions (termed the "early phase") and extends to the time when recovery efforts such as decontamination and resettlement of people are begun (termed the "long term phase"). The intermediate phase thus models the time period when decontamination and resettlement plans are being developed.

MACCS2 allows the habitation of land during the intermediate phase unless projected dose criteria is exceeded, in which case individuals are relocated.

MACCS2 allows an intermediate phase ranging from no Diablo Canyon Power Plant License Renewal Application Page F-137 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 intermediate phase to a maximum of one year. The intermediate phase sensitivities show significant impacts and are therefore discussed further:

The no intermediate phase resettlement planning case is developedbased on the NUREG-1150 modeling approach. The 31 °/o reduction in cost risk seen in the sensitivity results, however, is judged too optimistic in that the land decontamination efforts are modeled as starting one week after the accident (i.e., directly after the early phase ends) such that a significant portion of population relocation costs are omitted. For instance, the costs associated with temporary housing of interdicted individuals while decontamination strategies are developed and decontamination teams are contracted are not accounted for without an intermediate phase. It is believed that the NUREG-1150 studies omitted the intermediate phase because the intermediate phase coding was not validated at that time. A competing factor is that the population dose increases (6°/o increase over the base case) because people are allowed to re-occupy the decontaminated land sooner.

The 1 year intermediate phase resettlement planning case is developed based on the maximum length of time allowed by MACCS2 for the intermediate phase. A long intermediate phase can be unrealistic in that re-occupation of contaminated land is not performed during this phase even if contamination levels decrease (by natural radioactive decay and weathering) to levels which would allow it (i.e., resettlement is evaluated as part of the long term phase, not the intermediate phase). Therefore population relocation costs may be overestimated using a long (i.e., one year) intermediate phase. An intermediate phase of one year shows a 32% increase in cost risk estimates compared with the base case selection of 6 months. The population dose decreased by 3o/o with a longer intermediate phase due to later resettlement on decontaminated land. The six month intermediate phase (base case) is judged to be a best estimate approach in that it provides reasonable time for both decontamination and resettlement planning to be performed.

The sensitivity cases demonstrate that the six month value used in the base case provides mid-range results for the modeling choices available.

F.7.3.8 GENERIC ECONOMIC INPUTS SENSITIVITY MACCS2 requires certain site specific economic data (fraction of land devoted to farming, annual farm sales, fraction of farm sales resulting from dairy production, and property value of farm and non-farm land) for each of the 160 spatial elements.

The site specific base case values are calculated based on regional economic data. Diablo Canyon Power Plant License Renewal Application Page F-138 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 In addition to these site specific values, generic economic data are utilized by MACCS2 to address costs associated with per diem living expenses (applied to owners of interdicted properties and relocated populations), relocation costs (for owners of interdicted properties), and decontamination costs. For the DCPP base case, these generic costs are based on values used in the NUREG-1150 study (Reference

19) as documented in the NUREG/CR-4551 (Reference

20) updated to July 2014 using the consumer price index. This sensitivity case is performed to determine the variability in population dose risk and cost risk based on changes to these generic based values. The sensitivity case increases key generic based economic parameters as identified in Table F.?-2. In general, the inputs were arbitrarily increased by factor of 2.0. The increase in these economic parameters resulted in an .increase in cost risk of 44% and a decrease in dose risk of about 2%. A significant increase in cost risk is expected since population relocation and decontamination costs are major contributors to total cost as calculated by MACCS2. F.7.3.9 RATE OF RETURN SENSITIVITIES One of the economic cost components included in the MACCS2 calculated cost result is the financial loss associated with property and associated improvements (e.g., buildings) not achieving their expected annual rate of return during interdiction periods. A piece of land that is interdicted (i.e., not occupied) for a period of years will not achieve the historical rate of return or the rate of return achieved by other non-impacted properties during the interdiction period. This lack of expected return is an economic loss for the owner I society. The base case assumes a 7°/o expected rate of return, consistent with NRC guidance (Reference 25). A sensitivity case using a 3°/o expected rate of return shows a decrease in the expected cost risk of approximately 9°/o. This decrease in cost risk associated with the lower rate of return is expected since there is a lower expectation associated with the land's return on investment.

A sensitivity case using a 12°/o expected rate of return, the value used in NUREG-1150 MACCS2 analyses, shows an increase cost risk of approximately 11 °/o. For both sensitivity cases the dose risk changes are minor (<=1 °/o). Diablo Canyon Power Plant License Renewal Application Page F-139 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 F.7.3.10 VALUE OF FARM AND NON-FARM WEALTH SENSITIVITY This sensitivity assesses the impact of doubling the average farm and non-farm wealth values for the area surrounding DCPP. The base case wealth values, 12,241 $/hectare for farm wealth and 370,506 $/person for non-farm wealth, were increased to 24,482 $/hectare and 741,012 $/person, respectively.

This increase in the wealth parameters results in a population dose risk increase of 1 °/o and a cost risk increase of 68°/o. The dose risk increases slightly because it becomes feasible to decontaminate more land relative to the base case and as a result people inhabit more partially contaminated land. The cost risk increases significantly because on a per-person and per-farm basis, more wealth is being impacted.

This sensitivity indicates there is significant cost risk dependency upon the farm and non-farm wealth values. F.7.3.11 IMPACT ON SAMA ANALYSIS Several different Level 3 input parameters are examined as part of the DCPP MACCS2 sensitivity analysis.

The primary reason for performing these sensitivity runs is to identify any reasonable changes that could be made to the Level 3 input parameters that would impact the conclusions of the SAMA analysis.

While the table in Section F. 7.3 summarizes the changes to the dose-risk and OECR estimates for each sensitivity case, it is prudent to consider if any of these changes would result in the retention of the SAMAs that were screened using the baseline results. Of all the MACCS2 sensitivity cases, the largest dose-risk increase, 30°/o, occurred in the Population (Year 2045 population uniformly

, increased 30°/o) case. The largest OECR increase, 68%>, occurred in the value of farm and non-farm wealth sensitivity case (values doubled). Subsequently, the DCPP MMACR was recalculated using these results to determine the impact of using the worst case for each parameter simultaneously.

The resulting MACR is a factor of 1.38 greater than the base case, which is significantly less than the factor of 3.0 used in Section F.7.2 for the 95th percentile individual SAMA PRA model results. Therefore, the 95th percentile PRA results sensitivity is considered to bound this case and no SAMAs would be retained based on this sensitivity that were not already identified in Section F.7.2. Diablo Canyon Power Plant License Renewal Application Page F-140 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 F.7.4 IMPACT OF BINNING TRUNCATED FREQUENCY TO RC ST5 After the level 1 quantification is complete and binned as CDF, the sequences are processed by the Level 2 model logic. As part of the containment response evaluation, these sequences are further subdivided and binned into different release categories according to the events that occur in the post core damage evolution.

Some of these Level 2 evolutions are very low frequency scenarios and they are truncated during the Level 2 quantification.

As a result of this truncation step, the CDF is slightly larger than the sum of the Level 2 release* category frequencies for the DCPP RISKMAN model. While the difference in the frequencies is relatively small at 1.18E-6/yr, there is no information available that could be used to determine how the "truncated frequency" would be distributed among the DCPP release categories.

In order to assess the impact of the truncated frequency on the SAMA analysis, the entire frequency of 1.18E-6/yr is conservatively assumed to belong to the release category with the largest consequences (the ST5 release category).

Binning the truncated frequency to ST5 increases the baseline MACR from $9,315,791 to $10,151,241.

The increase in the MACR would result in the retention of 2 SAMAs for the Phase 2 analysis that were screened in the baseline Phase 1 analysis.

In order to assess the impact on the Phase 2 screening, the truncated frequency was assumed to be proportional to the CDF, and for each SAMA quantification, the truncated frequency was likewise binned to the ST 5 release category.

The results of this change are summarized in the following table. The impact of using the 95th percentile PRA results in conjunction with binning the truncated frequency to ST5 is also included in this table to document the combined impact of these sensitivities.

The impact of applying the 95th percentile PRA results was performed using the same process that is described in Section 7.2.2. Diablo Canyon Power Plant License Renewal Application Page F-141 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Summary of the Impact of Binning the Truncated Frequency to ST5 Averted Averted Net Value SAMA Cost of Cost Risk Net Value Cost Risk (with 95th ID Implementation (with Baseline (with Baseline (with 95th Percentile PRA Results) Percentile PRA PRA PRA Results) results) results) $3,020,424

$668,910 -$2,351,514

$2,006,730

-$1,013,694 2 $17,492,616

$874,298 -$16,618, 318 $2,622,894

$14,869,722 3 $376,342 $892,171 $515,829 $2,676,513

$2,300,171 5 $3,133,404

$36,843 -$3,096,561

$110 , 529 -$3,022,875 6 $9,993,910

$357,884 -$9,636,026

$1,073,652

-$8,920,258 7 $10,616,468

$387,711 -$10,228,757

$1,163,133

-$9,453,335 8 $1,072,493

$668,910 -$403,583

$2,006,730

$934,237 9 $25,520,160

$84,409 -$25,435,751

$253,227 $25,266,933 10 $22,572,878

$846,154 -$21,726,724

$2,538,462

$20,034,416 12 $13,560,218

$846,154 -$12,714, 064 $2,538,462

$11,021,756 14 $5,620,896

$299,525 -$5,321,371

$898,575 -$4,722,321 16 $372,788 $249 , 912 -$122,876

$749,736 $376,948 17 $9,610,440

$363,799 -$9,246,641

$1,091,397

-$8,519,043 20 $11,173,059

$1,194,781

-$9,978,278

$3,584,343

-$7,588,716 21 $256,817 $1,664,716

$1,407,899

$4,994,148

$4,737,331 22 $13,083,120

$49,150 -$13,033,970

$147,450 $12,935,670 23 $491,021 $2,971 -$488,050

$8,913 -$482,108 As indicated in the table above, only SAMAs 3 and 21 are potentially cost beneficial when the baseline PRA results are considered.

When the 95th percentile PRA results are applied, SAMAs 8 and 16 are also potentially cost beneficial.

These conclusions are the same as those documented in Section 7.2.2. While accounting for the truncated frequency does have an impact on the MACR, it does not have a significant impact of the averted cost-risk calculations or conclusions of the SAMA analysis.

Diablo Canyon Power Plant License Renewal Application Page F-142 F.S CONCLUSIONS APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 The benefits of revising the operational strategies in place at DCPP and/or implementing hardware modifications can be evaluated without the insight from a based analysis.

However, use of the PRA in conjunction with cost-benefit analysis methodologies provides an enhanced understanding of the effects of the proposed changes relative to the cost of implementation and projected impact on a larger future population.

The results of this study indicate that several potential improvements were identified that warrant further review for potential implementation at DCPP. In summary, based on the given implementation costs, a number of SAMAs have been identified as potentially cost-beneficial and may be considered for potential implementation at DCPP. While these results are believed to accurately reflect potential areas for improvement at the plant, PG&E notes that this analysis should not necessarily be considered a formal disposition of these proposed changes as other engineering reviews are necessary to determine the ultimate resolution.

For the identified cost-beneficial SAMAs listed below, PG&E will disposition them using existing action-tracking and design change processes.

In the baseline analysis, two SAMAs were identified as potentially cost beneficial:

SAMA 3: Change Procedures to Explicitly Address Vulnerability of Auto Sl SAMA 21: Change Fire Procedures to Include Fire Area Specific Guidance on Containment Isolation Valves When the 95th percentile PRA results are considered, SAMAs 8 and 16 are also potentially cost beneficial:

SAMA 8: Protect RHR Cables in Fire Areas 6-A-2 and 6-A-3 SAMA 16: Change Procedures to Caution About Spurious Sl Signals in Specific Fire Areas For SAMAs 3 and 16, it should be noted that the vulnerability for the fire areas associated with both SAMAs are the same, which is that there is the potential to Diablo Canyon Power Plant License Renewal Application Page F-143 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 damage cables/equipment associated with the generation of the Sl signal. However, in some fire areas, failure to generate an Sl signal is a significant risk while in other fire areas, spurious actuation of the Sl signal may be a more risk significant consequence of the fire damage. Ultimately, implementation of procedure enhancements could warn of both types of consequences for fires that can damage cables and equipment associated with Sl signal generation, but the SAMA analysis has delineated the procedure changes into two separate SAMAs to distinguish between the consequences of the fire related failures.

Diablo Canyon Power Plant License Renewal Application Page F-144 F.9 TABLE SECTION TABLES Table F.2-1 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 DEFINITION OF THE PLANT DAMAGE STATE MATRIX BINNING LOGIC (CORE DAMAGE SEQUENCES PARAMETER I RATIONALE FOR CATEGORY SELECTION I CODE I WHEN APPLICABLE ONLY) RCS INSIDE THE RCS AT TIME OF L =LOW (<200 FOR LARGE OR EXCESSIVE LOCAFOR GENTRN. ATWT. SGTR. MLOCA LLOCA PRESSURE VESSEL MELT-THROUGH IS IMPORTANT PSIA) INITIATING EVENTS OR WHERE VESSELELOCA TREES BECAUSE HIGH PRESSURE CAN EJECT INTEGRITY FAILS RCSPL:= INIT=LLOCA

+ INIT=ELOCA

+ VI=F (NO VI MOL TEN DEBRIS THROUGH PENETRATIONS TOP EVENT FOR ATWT TREE) IN THE BOTTOM HEAD .OF THE REACTOR FOR ISLOCA TREES VESSEL. IF PRESSURE EXCEEDS RCSPL:= SM=F APPROXIMATELY 200 PSIA, POTENTIAL FOR I= INTERMEDIATE FOR SMALL LOCA'S (INCLUDING SGCOOL:= AW=S EJECTION OF DISPERSED CORE DEBRIS TO (200-TRANSIENT INDUCED) WITH SG FOR GENTRN TREE CONTAINMENT EXISTS. THIS INCREASES 650PSIA) COOLING & HIGH PRESSURE INJECTION.

RCSPI:= (PR=F + SE=F)*SGCOOL

(CH=S + SI=S) CONTAINMENT LOADING AT TIME OF FOR MEDIUM LOCAS. FORATWTTREE VESSEL FAILURE. PO=F*SGCOOL *(CH=S+SI=S)*(RS=S+

DE=S) PRESSURE OF 650 PSIA REPRESENTS APPROXIMATE ACCUMULATOR PRESSURE.

PRESSURE OF 2250 PSIA REPRESENTS THE NORMAL OPERATING PRESSURE.

ABOVE THIS PRESSURE , THE PORV SETPOINT CAN BE REACHED. FOR SGTR TREE RCSPI:= (PR=F+SE=F+SL=F+SL=B+OP=F)*SGCOOL

(CH=S+ SI=S) FOR LLOCA ELOCA TREES RCSPI:= CI=S*CI=F (DOESN'T EXIST) FOR ISLOCA TREE RCSPI:= SM=S*SGCOOL

(CH=S + SI=S) FOR MLOCA TREE RCSPI:= INIT=MLOCA

VI=S H =HIGH (650-IFOR EVENTS WHERE HOT STANDBY FOR GENTRN ATWT TREES 2250 FAILS; OR FOR SMALL LOCA'S RCSPH:= (PR=F+SE=F)

PSIA) (INCLUDING TRANSIENT INDUCED) -SGCOOL * (CH=S + SI=S) + (PR=F+SE=F)

WHERE SG COOLING FAILS AND HIGH SGCOOL * -(CH=S + SI=S) + -(RCSPL + RCSPI + PRESSURE ECCS INJECTION IS RCSPS) SUCCESSFUL; OR FOR SAMLL LOCA'S FOR SGTR TREES (INCLUDING TRANSIENT INDUCED) RCSPH:= (PR=F+SE=F+SL=F+SL=B+OP=F)

WHERE SG COOLING IS SUCCESSFUL-SGCOOL

(CH=S+SI=S)

+ AND HIGH PRESSURE ECCS INJECTION (PR=F+SE=F+SL=F+SL=B+OP=F)

SGCOOL * -FAILS. (CH=S+SI=S)

FOR MLOCA LLOCA ELOCA TREES RCSPH:= CI=S*CI=F (DOESN'T EXIST) FOR ISLOCA RCSPH:= SM=S* -SGCOOL * (CH=S + SI=S) + SM=S*SGCOOL

-(CH=S + SI=S) s = PORV IFOR ATWT CASES; OR FOR CASESIFOR GENTRN TREE SETPOIN WHERE PRESSURE RELIEF IS RCSPS:= RT=F + -PR=F*-SGCOOL

(OB=F + CH=F) T (> 2250 SUCCESSFUL, SG COOLING FAILS, AND FOR ATWT TREE Diablo Canyon Power Plant License Renewal Application Page F-145 Table F.2-1 DEFINITION OF THE PLANT DAMAGE STATE MATRIX TABLE SECTION PARAMETER RATIONALE FOR CATEGORY SELECTION 2 3 STEAM AVAILABILITY OF STEAM GENERATOR GENERATOR SECONDARY SIDE COOLING WILL COOLING DETERMINE WHETHER THE STEAM GENERATOR TUBES WILL BE SUBJECT TO HIGH TEMPERATURES AND POTENTIAL FAILURE, IF COMBINE WITH HIGH RCS PRESSURE.

RWST IT IS ASSUMED THAT WATER IS PRESENT IN INJECTED THE REACTOR CAVITY IF THE RWST IS INJECTED.

PRESENCE OF WATER IN REACTOR CAVITY AT TIME OF MELT-THROUGH IS IMPORTANT TO CONTAINMENT RESPONSE BECAUSE INTERACTION OF WATER WITH HOT CORE DEBRIS CAN FRAGMENT AND DISPERSE THE CORE DEBRIS FROM THEE REACTOR CAVITY INTO OTHER REGIONS OF THE CONTAINMENT . CAUSE THE CONTAINMENT PRESSURE TO INCREASE BY VAPORIZATION OF THE WATER (I.E. STEAM SPIKES) AND DIRECT HEATING OF CONTAINMENT ATMOSPHERE (I.E. DIRECT CONTAINMENT HEATING) ENHANCE RELEASE OF FISSION PRODUCTS FROM THE CORE DEBRIS DUE TO OXIDATION OF Diablo Canyon Power Plant License Renewal Application CODE WHEN APPLICABLE

-PSIA) BLEED AND FEED FAILS. A= AVAILABLE WHEN AFW IS AVAILABLE X=NOT WHEN AFW IS UNAVAILABLE AVAILABLE N= NOT FOR LOW PRESSURE CONDITIONS APPLICABLE Y=YES CASES WHERE RWST IS SUCCESSFUL AND ECCS INJECTION IS SUCCESSFUL.

N=NO CASES WHERE RWST OR ASSOCIATED VALVES FAIL; OR ECCS INJECTION FAILS; OR FOR ISLOCAS . APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 BINNING LOGIC (CORE DAMAGE SEQUENCES ONLYJ (PO=S+PR=F)

-SGCOOL

CH-F + RS-F + OE-F FOR SGTR TREES RCSPS:= CI=S*CI=F (DOESN'T EXIST) FOR MLOCA, LLOCA AND ELOCA TREES RCSPS:= CI=S*CI=F (DOESN'T EXIST) FOR ISLOCA TREE RCSPS:= MU=F*MU=S (DOESN'T EXISTJ SGCOOL:= AW=S FOR GENTRN, ATWT, SGTR, ISLOCA TREES SGA:= SGCOOL FOR MLOCA, LLOCA, ELOCA SGA:= SGCOOL *-SGCOOL _{DOESN'T EXISTJ FOR GENTRN, ATWT, SGTR, ISLOCA TREES SGX:= -SGCOOL FOR MLOCA LLOCA ELOCA SGX:= SGCOOL *-SGCOOL (DOESN'T EXIST) FOR GENTRN ATWT SGTR ISLOCA TREES SGN:= SGCOOL *-SGCOOL (DOESN'T EXIST) FOR MLOCA, LLOCA, ELOCA TREES SGN:= INIT=MLOCA

+ INIT=LLOCA

+ INIT=ELOCA FOR GENTRN ATWT MLOCA LLOCA, ELOCA TREES RWY:= RW=S * (CH=S + SI=S + (LA=S + LB=S)

LV=S + CSI*(FC=F

+ VI=F + INIT=ELOCA))

FOR ISLOCA TREES RWY:= RW=S * (CH=S + SI=S) (THIS PLANT DAMAGE STATE DOES NOT EXIST) FOR SGTR TREES RWY:= RW=S * (CH=S + SI=S + (LA=S + LB=S)

LV=S + CSI*(FC=F

+ VI=F))

SL=S

OP=S FOR GENTRN, ATWT SGTR, MLOCA LOCA ELOCA TREES RWN:=-RWY FOR ISLOCA TREES RWN:=-RWY Page F-146 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Table F.2-1 DEFINITION OF THE PLANT DAMAGE STATE MATRIX TABLE I I I I BINNING LOGIC (CORE DAMAGE SEQUENCES SECTION PARAMETER RATIONALE FOR CATEGORY SELECTION CODE WHEN APPLICABLE ONLY) THE PARTICULATES.

4 I CONTAINME STATUS OF CONTAINMENT SPRAY AND A= ALL SYSTEMS CASES WHERE CONTAINMENT SPRAY CSI:= CS=S NT SPRAY CONTAINMENT HEAT REMOVAL SYSTEMS AVAILABLE (CSI, INJECTION, CONTAINMENT SPRAYCSI:=

CS=S*(FC=F

+ VI=F) FOR GT AND HEAT ARE IMPORTANT BECAUSE THESE CAN CSR, AND CHR) RECIRCULATION, AND CONTAINMENTCSR:=

WL=S

RF=S * (VA=S*LA=S

+ VB=S*LB=S)

REMOVAL PROVIDE HEAT REMOVAL FOR COOLING HEAT REMOVAL ARE AVAILABLE.

CSI RC=S

SR=S THE CONTAINMENT ATMOSPHERE; INCLUDES CS OPERATING AND CSCHR:= FC=S + CSR CONTROL PRESSURE IN THE AVAILABLE (BUT NOT REQUIRED TO FOR GENTRN, ATWT SGTR MLOCA. LLOCA. CONTAINMENT

AND PROVIDE FISSION OPERATE PRIOR TO CORE MELT). ITELOCA TREES PRODUCT REMOVAL BEFORE AND AFTER WOULD IN THAT CASE BE AVAILABLE CNSPA: = CSI

CSR

CHR FAILURE OF THE REACTOR VESSEL. CSI AFTER CORE MELT. FOR ISLOCA TREES INCLUDES CASES WHERE CONTAINMENT CNSPA:= CSI * -CSI (DOESN'T EXIST) SPRAY IS OPERATING AND CASES IN B =ALL SPRAY CASES WHERE ALL SPRAY SYSTEMS FOR GENTRN ATWT SGTR MLOCA. LLOCA WHICH CONTAINMENT SPARY WOULD SYSTEMS AVAILABLE; NO CONTAINMENT HEAT ELOCA TREES OPERATE IF DEMANDED (SUPPORT AVAILABLE REMOVAL CNSPB:= CSI

CSR *-CHR AVAILABLE AND PUMPS COULD OPERATE). (CSI,CSR);

NO FOR ISLOCA TREES . 'CSR HAS SIMILAR DEFINITION.

CONTAINMENT CNSPB:= CSI * -CSI (DOESN'T EXIST) HEAT REMOVAL Diablo Canyon Power Plant License Renewal Application (CHR) C =SPRAY CASES WHERE CONTAINMENT SPRAY FOR GENTRN ATWT SGTR MLOCA LLOCA INJECTION (CSI) INJECTION AND CONTAINMENT HEATELOCA TREES AND REMOVAL AVAILABLE; SPRAYCNSPC

= CSI *-CSR *CHR CONTAINMENT RECIRCULATION UNAVAILABLE FOR ISLOCA TREES HEAT REMOVAL CNSPC:= CSI * -CSI (DOESN'T EXIST) (CHR) AVAILABLE; SPRAY RECIRCULATION (CSR) UNAVAILABLE D =SPRAY CASES WHERE CONTAINMENT SPRAY FOR GENTRN ATWT SGTR MLOCA LLOCA INJECTION (CSI) INJECTION AVAILABLE; CONTAINMENTELOCA TREES AVAILABLE; SPRAY RECIRCULATION ANDCNSPD:= CSI * -CSR * -CHR SPRAY CONTAINMENT HEAT REMOVAL FOR ISLOCA TREES RECIRCULATION UNAVAILABLE CNSPD:= CSI * -CSI (DOESN'T EXIST) (CSR)AND CONTAINMENT HEAT REMOVAL (CHR) UNAVAILABLE E =SPRAY CASES WHERE CONTAINMENT SPRAY FOR GENTRN, ATWT SGTR MLOCA LLOCA INJECTION (CSI) INJECTION UNAVAILABLE; ELOCA TREES UNAVAILABLE; CONTAINMENT SPRAY RECIRCULATION CNSPE:= -CSI

CSR

CHR SPRAY AND CONTAINMENT HEAT REMOVAL FOR ISLOCA TREES Page F-147 Table F.2-1 DEFINITION OF THE PLANT DAMAGE STATE MATRIX APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 TABLE I I I I I BINNING LOGIC (CORE DAMAGE SEQUENCES SECTION PARAMETER RATIONALE FOR CATEGORY SELECTION CODE WHEN APPLICABLE ONL YJ RECIRCULATION ACCORDING TO DEFINITION\CNSPE:=

CSI * -CSI (DOESN'T EXIST) (CSR) AND OF CSI AND CSR, THIS MACRO IS CONTAINMENT IMPOSSIBLE.

HEAT REMOVAL (CHR) AVAILABLE F =SPRAY CONTAINMENT SPRAY INJECTION AND FOR GENTRN ATWT SGTR MLOCA LLOCA INJECTION (CSI) CONTAINMENT HEAT REMOVAL ELOCA TREES AND UNAVAILABLE

CONTAINMENT SPRAYCNSPF

= -CSI

CSR * -CHR CONTAINMENT RECIRCULATION AVAILABLE FOR ISLOCA TREES HEAT REMOVAL CNSPF:= CSI * -CSI (DOESN'T EXIST) (CHR) UNAVAILABLE; SPRAY RECIRCULATION (CSR) AVAILABLE G =SPRAY CONTAINMENT SPRAY INJECTION AND FOR GENTRN. ATWT SGTR MLOCA LLOCA INJECTION AND CONTAINMENT SPRAY RECIRCULATION ELOCA TREES RECIRCULATION UNAVAILABE

CONTAINMENT HEATCNSPG: = -CSI * -CSR

CHR + (CSI AND CSR) REMOVAL AVAILABLE -CSI*RW=F (FAN COOLER FIX) UNAVAILABLE

FOR ISLOCA TREES CONTAINMENT CNSPG: = CSI * -CSI (DOESN'T EXIST) HEAT REMOVAL (CHR) AVAILABLE N =ALL ALL CONTAINMENT SPRAY AND HEAT FOR GENTRN ATWT SGTR. MLOCA LLOCA CONTAINMENT REMOVAL SYSTEMS UNAVAILABLE ELOCA TREES SPRAY AND HEAT CNSPN:= -CSI * -CSR * -CHR REMOVAL FOR ISLOCA TREES SYSTEMS ARE CNSPN:= CSI * -CSI (DOESN'T EXIST) UNAVAILABLE 5 I CONTAINME THE STATE OF THE CONTAINMENT ITSELF I= CONTAINMENT CASES (NON-ISLOCA AND NON-SGTR)

FOR GENTRN LLOCA ELOCA TREES NT (INTACT OR FAILED) AT TIME WHEN SEVERE ISOLATED AND WITH CONTAINMENT ISOLATION CNTINTI:=

WL=S

CP=S

CI=S + (WL=F + CP=F + INTEGRITY CORE DAMAGE STARTS INCLUDES NOT BYPASSED CI=F)

OI=S AT TIME OF CONTAINMENT ISOLATION FAILURE AND FOR MLOCA TREES VESSEL INTERFACING SYSTEM LOCA CNTINTI:= WL=S

CP=S

CI=S + (WL=F + CP=F + MELT-CONSIDERATIONS. ALSO EXTERNAL CI=F)

OI=F + CORMLT

CP=B

VI=F THROUGH EVENTS THAT CAN CAUSE CONTAINMENT FOR SGTR TREES FAILURE SUCH AS EARTHQUAKES , SEVERE CNTINTI:= (WL=S

CP=S

CI=S + (WL=F + CP=F + STORMS , OR EXTERNAL MISSILES ARE OF CI=F)

OI=S)

NI=S IMPORTANCE AT TIME OF CORE DAMAGE. FOR ISLOCA TREES THERE IS POTENTIAL FOR FILTRATION CNTINTI:= MU=F*MU=S (DOESN'T EXIST) AND/OR OTHER MECHANISMS FOR FISSION S = SMALL LEAK CASES (NON-ISLOCA AND NON-SGTR)

FOR GENTRN. ELOCA TREES PRODUCT REMOVAL IN CONTAINMENT

(<3 INCHES WITH A LEAK< 3 INCHES DIAMETER CNTINTS:=

CP=S * (WL=F + CI=F)

OI=F Diablo Canyon Power Plant License Renewal Application Page F-148 Table F.2-1 DEFINITION OF THE PLANT DAMAGE STATE MATRIX TABLE SECTION PARAMETER RATIONALE FOR CATEGORY SELECTION LEAKAGE PATH (SUCH AS AUXILIARY BUILDING FILTERS FOR INTERFACING SYSTEMS LOCA'S OR PURGE FILTERS FOR SEQUENCES INVOLVING ISOLATION FAILURE) IF CONTAINMENT IS FAILED AT TIME OF CORE DAMAGE. Diablo Canyon Power Plant License Renewal Application CODE WHEN APPLICABLE DIAMETER) L = LARGE LEAK CASES (NON-ISLOCA AND NON-SGTR)

(>31NCHES WITH A LEAK> 3 INCHES DIAMETER DIAMETER)

B =SMALL UNISOLATED SGTR'S BYPASS V= LARGE V SEQUENCE ISLOCA BYPASS APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 BINNING LOGIC (CORE DAMAGE SEQUENCES ONLY) FOR SGTR TREES CNTINTS:= (CP=S * (WL=F + CI=F)

OI=F)

NI=S FOR ISLOCA TREES CNTINTS:=

MU=F*MU=S (DOESN'T EXIST) FOR MLOCA LLOCA CNTINTS:=

CP=S

CI=F

OI=F + CP=S

WL=F FOR GENTRN LLOCA MLOCA ELOCA TREES CNTINTL:=

CP=F

OI=F FOR SGTR TREES CNTINTL:= (CP=F

OI=F)

NI=S FOR ISLOCA TREES CNTINTL:=

MU=F*MU=S (DOESN'T EXIST) FOR GENTRN LLOCA, MLOCA ELOCA TREES CNTINTB:=

CP=F

CP=S (DOESN'T EXIST) FOR SGTR TREES CNTINTB:=

NI=F FOR ISLOCA TREES CNTINTB:=

MU=F

MU=S (DOESN'T EXIST) FOR GENTRN LLOCA MLOCA ELOCA SGTR TREES CNTINTV:=

CP=F

CP=S (DOESN'T EXIST) FOR ISLOCA TREES CNTINTV:=

INIT=VDI + INIT=VSI Page F-149 Table F.2-2 Plant Damage State Matrix RCS CONDITIONS WATER CONTAINMENT ISOLATION AND BYPASS STATUS (5) EXPECTED RCS PRESSURE f.T ONSET OF CORE DAMAGE (1) < 200 PSIA (L) 200 TO 600 PSIA (I) 600TO 2000 PSIA (H) > 2000 PSIA(S) IN SPRAY & STEAM CONT. CHR CONTAINMENT ISOLATED AND NOT CONTAINMENT NOT ISOLATED OR FAILED GEN PRIOR 4) BYPASSED (I) COOLING TO LEAK< 3 IN. DIAMETER (S) LEAK > 3 IN. DIAMETER (2) VESSEL BREACH (L) (3)

CSI &CSI ONLY CSR NONE CSI &CSR CSI ONLY CSR NONE CSI bPER. CSR ONLY ONLY & CSR YES NO YES NO YES NO YES NO YES NO YES NO YES NO YES NO -(A) (B) (C) (D) (E) (F) (G) (N) (A) (B) (C) (D) (E) (F) (G) (N) (A) (N) NO(N) 1 1 ,2 1 1 1,6 1 , 6 1 1,2 1 1 1,6 1,6 1 YES(Y) 2 6 6 2 6 6 (N) NO(N) 1 1,2 1 1 1 ,6 1 , 6 1 1 ,2 1 1 1 , 6 1,6 1 YES (Y) 2 6 6 2 6 6 YES(A) NO(N) 1 1,2 1 1 1 , 6 1,6 1 1 ,2 1 1 1 ,6 1 , 6 1 YES(Y) 2 6 6 2 6 6 NO(X) NO (N) 1 1 ,2 1 1 1,6 1 , 6 1 1,2 1 1 1 ,6 1 , 6 1 YES (Y) 2 6 6 2 6 6 YES(A) NO(N) 1 1 ,2 1 1 1 ,6 1 , 6 1 1 ,2 1 1 1 ,6 1 , 6 1 YES(Y) 2 6 6 2 6 6 NO(X) NO(N) 1 1 ,2 1 1 1 , 6 1 , 6 1 1,2 1 1 1 , 6 1,6 1 YES(Y) 2 6 6 2 6 6 PDS MATRIX NOTES 1. IF RWST HAS FAILED , CSI AND CSR ARE IMPOSSIBLE. 2. CONTAINMENT HEAT REMOVAL IS GUARANTEED IF CSR IS SUCCESSFUL (REQUIRES MAAP CONFIRMATION).

3. CONTAINMENT SPRAY WILL NOT BE INITIATED FOR LARGE CONTAINMENT BYPASS EVENTS. 4. WON'T HAVE WATER IN REACTOR CAVITY FOR LARGE CONTAINMENT BYPASS EVENTS. 5. LARGE BYPASS WILL PREVENT RCS PRESSURE GREATER THAN 600 PSIA (REQUIRES MAAP CONFIRMATION). 6. CSR ONLY IMPOSSIBLE-(E & F IMPOSSIBLE). Diablo Canyon Power Plant License Renewal Application CSI CSR NONE ONLY ONLY ---(C) (E) (N) 1 1 , 6 6 1 1,6 6 1 1 , 6 6 1 1,6 6 1 1,6 6 1 1 , 6 6 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 CONTAINMENT BYPASSED SMALL BYPASS (B) LARGE BYPASS M CSI &CSR CSI ONLY CSR NONE CSI & CSI CSR ONLY CSR ONLY ONLY YES NO YES NO YES NO YES NO (A) (B) (C) (D) (E) (F) (G) (N) (A) (C} (E) 1 1,2 1 1 1,6 1 , 6 1 , 3 1,3 1 , 3 2 6 6 3 3 3 1 1 ,2 1 1 1,6 1,6 1 , 3 1,3 1 , 3 2 6 6 3 3 3 1 1 ,2 1 1 1 ,6 1 , 6 1,3 1 ,3 1 , 3 2 6 6 3 3 3 1 1 , 2 1 1 1,6 1,6 1 ,3 1 , 3 1,3 2 6 6 3 3 3 1 1,2 1 1 1,6 1,6 1 , 3 1,3 1 , 3 2 6 6 3 3 3 1 1 ,2 1 1 1 , 6 1,6 1 , 3 1,3 1 , 3 2 6 6 3 3 3 Page F-150 NONE -(N) 4 4 4 4 , 5 5 4 , 5 5 4 , 5 PDS HAYDI S XY AI INYCI LNYAI HANNI S X NNS HANNS S X NNI INNGB INNNS LNYCI S XY CI H X YAI S XY GS S XY DI LNNNS H XY CI H X NNS HAY AI IN Y GS LNYGI HA Y DS INNNB S X NG I HANG I S XY GI INNGV INYCS HAYCI INYGI PDS Cum Cum% Freq. Freq.

ofCDF HAYDI 4.79E-05 4.79E-05 5.45E+01 4.79E-05 8.96E-06 5.68E-05 6.47E+01 6.78E-06 6.36E-05 7.24E+01 3.98E-06 6.76E-05 7.69E+01 3.74E-06 7.13E-05 8.11E+01 3.67E-06 7.50E-05 8.5 3 E+01 2.06E-06 7.7 1E-05 8.77E+01 1.15E-06 7.82E-05 8.90E+01 1.09E-06 7.93E-05 9.02E+01 1.07E-06 8.04E-05 9.14E+01 1.06E-06 8.14E-05 9.26E+01 7.53E-07 8.22E-05 9.35E+01 6.68E-07 8.29E-05 9.42E+01 6.58E-07 8.35E-05 9.50E+01 5.40E-07 8.41E-05 9.56E+01 4.75E-07 8.45E-05 9.61E+01 3.93E-07 8.49E-05 9.66E+01 3.64E-07 8.53E-05 9.70E+01 3.16E-07 8.56E-05 9.74E+01 2.74E-07 8.59E-05 9.77E+01 2.70E-07 8.62E-05 9.80E+01 2.64E-07 8.64E-05 9.83E+01 2.04E-07 8.66E-05 9.85E+01 1.95E-07 8.68E-05 9.87E+01 1.84E-07 B.?OE-05 9.89E+01 1.23E-07 8.71E-05 9.91E+01 8.16E-08 8.72E-05 9.92E+01 7.96E-08 8.73E-05 9.93E+01 6.50E-08 8.73E-05 9.93E+01 6.50E-08 6.40E-08 8.74E-05 9.94E+01 Diablo Canyon Power Plant License Renewal Application SXYAI INYCI 8.96E-06 6.78E-06 6.68E-07 3.1 6E-07 Table F.2-3 DCPP Kev Plant D " LNYAI HANNI SXNNS HANNS 3.98E-06 3.74E-06 3.67E-06 2.06E-06 4.75E-07 3.64E-07 2.64E-07 1.84E-07 Stat -Key Plant Damage State IDs SXNNI INNGB 1.15E-06 1.09E-06 2.04E-07 1.95E-07 6.40E-0!3_ _ INNNS LNYCI SXYCI 1.07E-06 1.06E-06 7.53E-07 3.93E-07 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 SXYGS SXYDI INNGV SXNNL 6.58E-07 5.40E-07 2.74E-0 7 2.70E-07 1.23E-07 8.1 6E-08 7.96E-08 Page F-151 PDS INYDI SAYCI HXYDI HXNNI SXYAS HXNGB LNYDI LNYCS LNYAS LNNGB INNNI HXYGI INNNL LNNNI SXNNL HXYAS HXNNB HXNGI SXYNS HAYGI LNNNL SXYCS HXNNL HANNB SXYDS INYNS HAN NV HAY AS HXYCS HXYGS PDS Cum Cum% Freq. Freq. ofCDF HAYDI 6.35E-08 8.75E-05 9.95E+01 6.32E-08 8.75E-05 9.96E+01 6.06E-08 8.76E-05 9.96E+01 5.43E-08 8.77E-05 9.97E+01 5.13E-08 8.77E-05 9.97E+01 2.98E-08 8.77E-05 9.98E+01 2.70E-08 8.78E-05 9.98E+01 2.49E-08 8.78E-05 9.98E+01 1.58E-08 8.78E-05 9.99E+01 1.42E-08 8.78E-05 9.99E+01 1.42E-08 8.78E-05 9.99E+01 1.17E-08 8.78E-05 9.99E+01 8.76E-09 8.79E-05 9.99E+01 8.27E-09 8.79E-05 9.99E+01 7.70E-09 8.79E-05 9.99E+01 7.35E-09 8.79E-05 9.99E+01 6.88E-09 8.79E-05 9.99E+01 5.92E-09 8.79E-05 9.99E+01 5.85E-09 8.79E-05 1.00E+02 5.61E-09 8.79E-05 1.00E+02 3.74E-09 8.79E-05 1.00E+02 3.67E-09 8.79E-05 1.00E+02 2.99E-09 8.79E-05 1.00E+02 2.91E-09 8.79E-05 1.00E+02 2.68E-09 8.79E-05 1.00E+02 2.46E-09 8.79E-05 1.00E+02 2.07E-09 8.79E-05 1.00E+02 1.87E-09 8.79E-05 1.00E+02 1.79E-09 8.79E-05 1.00E+02 1.72E-09 8.79E-05 1.00E+02 Diablo Canyon Power Plant License Renewal Application SXYAI INYCI Table F.2-3 DCPP Kev Plant D LNYAI HANNI SXNNS HANNS -5.85E-09 5.61E-09 2.68E-09 2.46E-09 Stat Key Plant Damage State IDs SXNNI INNGB INNNS 5.43E-08 1.42E-08 1.42E-08 8.27E-09 5.92E-09 LNYCI SXYCI 6.32E-08 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 SXYGS SXYDI INNGV SXNNL 6.35E-08 6.06E-08 5.13E-08 2.98E-08 2.70E-08 2.49E-08 1.58E-08 1.17E-08 8.76E-09 7.70E-09 7.35E-09 6.88E-09 3.74E-09 3.67E-09 2.99E-09 2.91E-09 2.07E-09 1.87E-09 1.79E-09 1.72E-09 Page F-152 PDS REMAIN SUM PDS Cum Cum% Freq. Freq.

ofCDF HAYDI . 7.817E-9 B.BOE-05 1.00E+02 B.BOE-05 4.79E-05 Diablo Canyon Power Plant License Renewal Application SXYAI INYCI 9.94E-06 6.77E-06 Table F.2-3 DCPP Kev Plant D LNYAI HANNI SXNNS HANNS 3.98E-06 3.92E-06 4.52E-06 2.32E-06 Stat Key Plant Damage State IDs SXNNI INNGB INNNS LNYCI SXYCI 1.46E-06 1.30E-06 1.09E-06 1.06E-06 1.20E-06 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 SXYGS SXYDI INNGV SXNNL 7.82E-09 1.12E-06 1.09E-06 1.31E-07 2.31E-08 Page F-153 Table F.2-4 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 General Release Category Considerations for Large, Dry Containment PWRs Issue Containment Bypass RCS Pressure at Vessel Failure Time of Containment Failure Size of Containment Failure Containment Spray System Debris Coolability Diablo Canyon Power Plant License Renewal Application Discussion Interfacing system LOCA or SGTR bypassing containment have the potential for core melt without having the containment "involved" until after vessel failure. High RCS pressure can lead to direct containment heating and containment failure at vessel failure. Also, fission product retention in the RCS is greater for high RCS pressure. I In general , the earlier the containment failure, the greater the source term. I In general, but not always , the larger the containment failure, the greater the source i term. I Sprays are an important mechanism for fission product removal from the containment I atmosphere. Additionally , recirculation spray operation may provide a mechanism for containment heat removal. I After vessel failure, if the core debris cannot be cooled, heat transfer from the debris can i cause chemical decomposition of the concrete. As concrete is eroded by core debris, slag and gases are added to the debris and chemical reactions occur among the compounds.

I Concrete offgas acts as a carrier for volatile and semi-volatile reaction ' products which may be radioactive thus increasing the source term as the core-concrete interaction progresses. Page F-154 RELEASE CATEGORY RC01 RC01U RC02 RC02U RC03 RC03U RC04 RC04U RC05 RC05U RC06 RC06U RC07 RC07U RC08 RC08U RC09 RC09U Diablo Canyon Power Plant License Renewal Application RCS PRESSURE HIGH MED. X X X X X X X X X X X X X X X X X X X X Table F.2-5 Containment Event Tree Bins CONTAINMENT FAILURE LOW EARLY LATE SMALL LARGE X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X DEBRIS COOLABLE X X X X X X X X X APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 SPRAYS X X X X X X X X X X Page F-155 RELEASE CATEGORY RC10 RC10U RC11 RC11U RC12 RC12U RC13 RC13U RC 1 4 RC14U RC15 RC15U RC16 RC16U RC17 RC18 RC19 RC20 Diablo Canyon Power Plant License Renewal Application Table F.2-5 Containment Event Tree Bins RCS PRESSURE CONTAINMENT FAILURE HIGH MED. LOW EARLY LATE SMALL LARGE X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X SGTR Interfacing System LOCA Non-Severe Core Damage Sequence Long Term Containment Intact Sequence DEBRIS COOLABLE X X X X X X X APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 SPRAYS X X X X X X Page F-156 RELEASE CATEGORY RC21 Diablo Canyon Power Plant License Renewal Application RCS PRESSURE HIGH I MED. I Table F.2-5 Containment Event Tree Bins CONTAINMENT FAILURE LOW EARLY I LATE I SMALL I LARGE Basemat Melt-Through Sequence DEBRIS COOLABLE APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 SPRAYS Page F-157 Release Category Group Name ST1 ST2 ST3 ST4 ST5 ST6 Table F.2-6 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Release Category Group Definition Description of Release Category Release Categories in Group Group Large, Early Containment Failures RC01 I RC01 U, RC02, RC02U, RC03, RC03U, RC04, RC04U Small, Early Containment Failure RC13, RC13U, RC14, RC14U , RC15, RC15U, RC16, RC16U Late Containment Failures RC05, RC05U, RC06, RC06U, RC07, RC07U, RC08,RC08U, RC09,RC09U, RC10, RC10U, RC11, RC11U, RC12, RC12U, RC21 Containment Bypass RC1i Interfacing System LOCA RC1i, RC18 Long-Term Containment Intact RC19, RC20 Note 1 -The frequency of sequences initiated by SGTR with containment not isolated (SGTRN) are allocated to ST5. Diablo Canyon Power Plant License Renewal Application SGTRN contributes approximately 50% of the ST4 frequency and the remainder is moved to ST5. Page F-158 Table F.2-7 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Mapping between Release Category Group, Individual Release Category, and Key Release Category Group Name ST1 ST2 ST3 Diablo Canyon Power Plant License Renewal Application Damage Plant State Release Release Category Group Category RC01 RC01U RC02 Large, Early Containment RC02U Failures RC03 RC03U RC04 RC04U RC13 RC13U RC14 Small, Early Containment RC14U Failures RC15 RC15U RC16 RC16U RC05 RC05U RC06 Late Containment Failures RC06U RC07 RC07U Frequency KDPS (Note 1) 3.73E-10 SXYAI 8.26E-11 SXYAI 5.87E-06 SXNNS 1.02E-1 0 SXYCI 8.46E-11 SXYAI 1.40E-09 SXYAI 1.28E-06 HAYDI 9.27E-08 HAYDI 6.20E-13 SXYAI 1.02E-13 Note 2 3.39E-06 SXNNS 9.96E-07 SXNNS O.OOE+OO Note 2 3.05E-12 SXYAI 2.84E-10 HANNS 2.35E-06 SXNNS 9.66E-11 SXYAI O.OOE+OO Note 2 8.97E-06 HAYDI 2.44E-06 HANNI 1.83E-11 SXYAI O.OOE+OO Note 2 Page F-159 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Table F.2-7 Mapping between Release Category Group, Individual Release Category, and Key Damage Plant State Release Release Category Release Category Group Category Frequency KDPS (Note 1) Group Name RC08 1.92E-08 HAYDI RC08U 3.80E-06 HAYDI RC09 O.OOE+OO Note 2 RC09U O.OOE+OO Note 2 RC10 2.81 E-05 HAYDI RC10U 7.55E-06 HANNI RC11 O.OOE+OO Note 2 RC11U O.OOE+OO Note 2 RC12 6.84E-08 HAYDI RC12U 1.11 E-05 HAYDI RC21 2.17E-06 I NYC I ST4 Containment Bypass RC17 4 3.59E-06 INNGB ST5 Interfacing System LOCA RC18 1.28E-08 INNGV RC19 9.12E-07 Note 3 ST6 Long-Term Containment Intact RC20 1.32E-06 SXYAI -----------Note 1: The assignment of a representative key damage plant state (KPDS) to each release category is based on Table 4.7-4 of the individual plant examination (IPE) submittal.

Note 2: No KPDS is assigned because of zero or very low release frequency.

Note 3: Non-severe Core Damage Sequence Note 4: The frequency of sequences initiated by SGTR with containment not isolated (SGTRN) are allocated to ST5. SGTRN contributes approximately 50% of the ST4 frequency andthe remainder is moved to ST5. Diablo Canyon Power Plant License Renewal Application Page F-160 TABLE F.3-1 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 COUNTY BASED POPULATION GROWTH RATES 2010-2045 California County 2010 Census Population 2045 Projected Population(1 l Kern 841,146 1,747,402 Monterey 416,259 529,005 San Luis Obispo 269,713 333,135 Santa Barbara 424,050 499,987 Note to Table F.3-1: (1) Projection from California Department of Finance (Reference 92). Diablo Canyon Power Plant License Renewal Application Growth Rate 2010 -2045 Percentage 107.7% 27.1% 23.5% 17.9% Page F-161 TABLE F.3-2 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 INCLUDED TRANSIENT POPULATION WITHIN A 20-MILE RADIUS OF DIABLO CANYON(1), YEAR 2010 0-1 1-2 2-3 3-4 4-5 5-10 10-20 0-20 miles Sector mile miles miles miles miles miles miles Total N 0 0 0 333 0 2,081 7,724 10,138 NNE 0 0 0 0 0 1,150 0 1,150 NE 0 0 0 0 0 18 7,981 7,999 ENE 0 0 0 0 0 3,519 38,582 42,101 E 0 0 0 0 0 640 5,936 6,576 ESE 0 0 0 0 0 3,195 38,576 41,771 SE 0 0 0 0 0 0 512 512 SSE 0 0 0 0 0 0 0 0 s 0 0 0 0 0 0 0 0 ssw 0 0 0 0 0 0 0 0 sw 0 0 0 0 0 0 0 0 WSW 0 0 0 0 0 0 0 0 w 0 0 0 0 0 0 0 0 WNW 0 0 0 0 0 0 0 0 NW 0 0 0 0 0 0 0 0 NNW 0 0 0 0 0 0 0 0 Total 0 0 0 333 0 10,603 99,311 110,247 Note to Table F.3-2: (i) Transient population includes employees and special facilities based on data in the DCPP ETE (Reference 67). Although most site ETEs only cover regions out to about 10 miles from the site, the DCPP ETE covers regions out to 20 miles in some directions.

Transient data in the 10-20 mile radial interval were conservatively included.

Diablo Canyon Power Plant License Renewal Application Page F-162 TABLE F.3-3 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 SECPOP 4.2 BASED RESIDENTIAL POPULATION DISTRIBUTION WITHIN A 50-MILE RADIUS OF DIABLO CANYON<1), YEAR 2010 0-10 10-20 20-30 30-40 40-50 50-mile Sector miles miles miles miles miles Total N 10,325 13,136 800 3 , 182 603 28,046 NNE 4,095 2,023 48 , 399 24,097 441 79 , 055 NE 345 12,350 9 , 076 1,256 1,271 24,298 ENE 7 , 081 40,617 727 118 130 48 , 673 E 1 , 591 5,432 200 21 158 7,402 ESE 1,209 52,074 22 , 055 1,328 154 76,820 SE 0 1,261 69,326 68,146 4,619 143,352 SSE 0 0 11 3 , 338 51,477 54,826 s 0 0 0 0 0 0 ssw 0 0 0 0 0 0 sw 0 0 0 0 0 0 WSW 0 0 0 0 0 0 w 0 0 0 0 0 0 WNW 0 0 0 0 0 0 NW 0 0 0 0 19 19 NNW 0 103 6,332 821 364 7,620 Total 24,646 126,996 156,926 102,307 59,236 470,111 Note to Table F.3-3: (1) Resident population for 0-50 miles does not include transient, employee , or special facility populations.

Diablo Canyon Power Plant License Renewal Application Page F-163 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 TABLE F.3-4 PROJECTED POPULATION DISTRIBUTION WITHIN A 20-MILE RADIUS OF DIABLO CANYON(1), YEAR 2045 0-1 1-2 2-3 3-4 4-5 5-10 10-20 0-20 miles Sector mile miles miles miles miles miles miles Total N 0 0 0 411 0 15,321 25,762 41,494 NNE 0 0 0 0 0 6,478 2,498 8,976 NE 0 0 0 0 0 448 25,109 25,557 ENE 0 0 0 0 7 13,084 97,811 110,902 E 0 0 0 0 0 2,755 14,039 16,794 ESE 0 0 0 1 0 5,438 111,953 117,392 SE 0 0 0 0 0 0 2,190 2,190 SSE 0 0 0 0 0 0 0 0 s 0 0 0 0 0 0 0 0 ssw 0 0 0 0 0 0 0 0 sw 0 0 0 0 0 0 0 0 WSW 0 0 0 0 0 0 0 0 w 0 0 0 0 0 0 0 0 WNW 0 0 0 0 0 0 0 0 NW 0 0 0 0 0 0 0 0 NNW 0 0 0 0 0 0 127 127 Total 0 0 0 412 7 43,524 279,489 323,432 Note to Table F.3-4: (1) Population projection for 0-20 miles includes transients, employees, special facilities, and permanent residents.

This population projection is based on year 2010 census data. Diablo Canyon Power Plant License Renewal Application Page F-164 TABLE F.3-5 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 PROJECTED POPULATION DISTRIBUTION WITHIN A 50-MILE RADIUS OF DIABLO CANYON(1), YEAR 2045 Sector 0-10 miles 10-20 miles 20-30 miles 30-40 miles 40-50 miles 50-mile Total N 15,732 25,762 988 3,936 766 47,184 NNE 6,478 2,498 59,773 29,760 556 99,065 NE 448 25,109 11,209 1,551 1,788 40,105 ENE 13,091 97,811 898 146 183 112,129 E 2,755 14,039 247 26 195 17,262 ESE 5,439 111,953 27,238 1,611 182 146,423 SE 0 2,190 83,053 80,480 5,446 171,169 SSE 0 0 13 3,936 60,691 64,640 s 0 0 0 0 0 0 ssw 0 0 0 0 0 0 sw 0 0 0 0 0 0 WSW 0 0 0 0 0 0 w 0 0 0 0 0 0 WNW 0 0 0 0 0 0 NW 0 0 0 0 23 23 NNW 0 127 7,820 1,014 456 9,417 Total 43,943 279,489 191,239 122,460 70,286 707,417 Note to Table F.3-5: (1) Population projection for 0-20 miles includes transients, employees, special facilities, and permanent residents.

Although most site ETEs only cover regions out to about 10 miles from the site, the DCPP ETE covers regions out to 20 miles in some directions.

Transient data in the 10-20 mile radial interval were conservatively included.

Population projection for 20-50 miles includes permanent residents only. This population projection is based on year 2010 census data. Diablo Canyon Power Plant License Renewal Application Page F-165 TABLE F.3-6 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 COUNTY SPECIFIC LAND USE AND ECONOMIC PARAMETERS INPUTS CALIFORNIA FRACTION COUNTY FARM Kern 0.448 Monterey 0.604 San Luis Obispo 0.634 Santa Barbara 0.400 Diablo Canyon Power Plant License Renewal Application FRACTION DAIRY 0.124 0.001 0.007 0.011 FARM NON-FARM FARM PROPERTY PROPERTY SALES VALUE VALUE ($/HECTARE)

($/HECTARE)

($/PERSON) 4,399 11,373 286,033 6,024 12,539 357,274 1,273 10,803 362,787 4,307 18,880 397,357 Page F-166 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 TABLE F.3-7 MACCS2 ECONOMIC PARAMETERS INPUTS Base Case Variable Description DPRATEt 1> Property depreciation rate (per yr) DSRATE\LJ Investment rate of return (per yr)

Daily cost for a person who has been evacuated

($/person-day)

Daily cost for a person who is relocated

($/person-day)

POPCST\3) Population relocation cost ($/person)

CDFRM0\3) Cost of farm decontamination for two levels of decontamination

($/hectare

)<5> TIMDEC\1) Decontamination time for each leveltoJ CDNFRMt 3> Cost of non-farm decontamination per levels of decontamination

($/person)

<5> resident person for two DLBCSTP> Average cost of decontamination labor ($/man-year)

TFWKFt 1> Time workers spend in farm land contaminated areastoJ TFWKNFt 1> Time workers spend in non-farm land contaminated areastoJ VALWFOt 4> Weighted average value of farm wealth ($/hectare)

VALWNFtoJ Weighted average value of non-farm wealth ($/person)

Notes to Table F.3-7: (1) Uses NUREG/CR-4551 (Reference

20) value. (2) DSRATE based on NUREG/BR-0058 (Reference 25). (3) These parameters use the NUREG/CR-4551 (Reference

20) value, updated to the July 2014 using the CPl. (4) . VALWFO is based on the 2012 Census of Agriculture (Reference 63), Bureau of Labor Statistics (Reference Value 0.20 0.07 58.59 58.59 10,850 1,221 2,713 2&4 months 6,510 17,360 75,950 1/10 1/3 1/3 1/3 12,241 370,506 64), and Bureau of Economic Analysis (Reference

2) data, updated to July 2014 using the CPI for the counties within 50 miles. (S) Two decontamination levels are modeled. The first value is associated with a dose reduction factor of 3. The second value is associated with a dose reduction factor of 15. (S) VALWNF is based on 2007 data from the Bureau of Labor Statistics (Reference 64), U.S. Census Bureau (References 88 and 86), National Resources Conservation Service (Reference 87), Bureau of Economic Analysis (Reference 2), 2007 and 2012 U.S. Census of Agriculture (Reference 85 and 63), and the Journal of Monetary Economics (Reference 91 ). Diablo Canyon Power Plant License Renewal Application Page F-167 TABLE F.3-8 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 COMIDA2 RELATED INPUT PARAMETER VALUES Parameter Parameter Descri tion DOSEMILK Maximum allowable food ingestion dose from milk crops during the year of the accident DOSEOTHER Maximum allowable food ingestion dose from non-milk crops during the year of the accident DOSELONG Maximum allowable long term annual dose to an individual from ingestion of the combination of milk and non-milk crops. Nuclide Co-58 Co-60 Kr-85 Kr-85m Kr-87 Kr-88 Rb-86 Sr-89 Sr-90 Sr-91 Sr-92 Y-90 Y-91 Y-92 Y-93 Zr-95 Zr-97 Nb-95 Mo-99 Tc-99m Ru-103 Ru-105 Ru-106 Rh-1 05 Sb-127 Sb-129 Te-127 Te-127m Te-129 Te-129m Diablo Canyon Power Plant License Renewal Application TABLE F.3-9 MACCS2SOURCETERM Activity (Bq) Nuclide 2.44E+16 Te-131m 7.96E+14 Te-132 3.44E+16 1-131 8.35E+17 1-132 1.67E+18 1-133 2.32E+18 1-134 6.45E+15 1-135 3.28E+18 Xe-133 3.02E+17 Xe-135 4.06E+18 Cs-134 4.32E+18 Cs-136 3.23E+17 Cs-137 4.26E+18 Ba-139 4.36E+18 Ba-140 3.32E+18 La-140 5.91 E+18 La-141 5.72E+18 La-142 5.96E+18 Ce-141 6.26E+18 Ce-143 5.55E+18 Ce-144 5.23E+18 Pr-143 3.59E+18 Nd-147 1.70E+18 Np-239 3.30E+18 Pu-238 2.84E+17 Pu-239 1.06E+18 Pu-240 2.79E+17 Pu-241 4.60E+16 Am-241 1.01E+18 Cm-242 2.05E+17 Cm-244 Value Effective (Rem) 0.25 0.25 0.50 Value Thyroid (Rem) 2.5 2.5 5.0 Activity (Bq) 6.54E+17 4.79E+18 3.33E+18 4.88E+18 6.87E+18 7.62E+18 6.56E+18 6.88E+18 1.88E+18 5.64E+17 1.76E+17 4.07E+17 6.08E+18 6.12E+18 6.33E+18 5.54E+18 5.42E+18 5.61 E+18 5.19E+18 4.25E+18 5.07E+18 2.25E+18 6.53E+19 1.26E+16 1.15E+15 1.52E+15 4.93E+17 6.48E+14 1.63E+17 1.30E+16 Page F-168 TABLE F.3-10 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 MACCS2 RADIOISOTOPE GROUPS VS. DCPP LEVEL 2 RADIOISOTOPE GROUPS Notes: MACCS2 Radioisotope Groups Xe/Kr I Cs Te Sr Ru La Ce Ba DCPP Level 2 Radioisotope Groups<4) 1 -noble gases 2-Csl 6 & 2 -CsOH and Csl<3> 3, 10 & 11-Te02, Sb<2> & Te 2<1> 4-SrO 5 -Mo0 2 (Mo is in Ru MACCS category) 8-La203 9 & 12-ceo2 & uo2<1> 7-BaO \11These release fractions are typically negligible compared to others in the group. (2) The mass of Sb in the core is typically much less than the mass of Te. (3) The mass of Cs contained in Csl is typically much less than the mass of Cs contained in CsOH. (4) The DCPP Level 2 radioisotope groups represent the twelve (12) MAAP 4.0. 7 radioisotope groups. Diablo Canyon Power Plant License Renewal Application Page F-169 TABLE F .3-11 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 REPRESENTATIVE MAAP LEVEL 2 CASE DESCRIPTIONS AND KEY EVENT TIMINGS Source Release MAAP Representative Case CSI Term Category Case Description RF(1) ST1 LG/EARLY RC04U Loss of all injection, AFW, 6.01 E-02 containment sprays. Depressurize SGs at 15 min. Large (7 ft 2) containment breach at time of vessel failure. ST2 SM/EARLY RC16U Loss of all injection, AFW, 4.30E-02 containment sprays. Low pressure core melt with hot leg creep rupture, pre-existing containment failure. ST3 LATE RC10 180 gpm/pump seal 4.05E-04 LOCA. AFW OK, CS OK. Containment failure when pressure > 150 psia. ST4 BYPASS RC17 SGTR with loss of all 2.60E-02 w/AFW injection and with AFW. SG PORV stuck open. ST5 ISLOCA RC18 6" RHR pipe break, 8.70E-01 release directly to environment, no inj, w/ AFW ST6 INTACT RC20 MLOCA with failure to 3.17E-05 recirc. HPI OK. AFW OK. CS with heat removal OK. Notes: (1) Csl RF-Cesium Iodide release fraction to the environment (2) Ted-Time of core damage (maximum core temperature

>1800°F) (3) Tvf-Time of vessel breach (4) Tcf-Time of containment failure (S) Tend-Time at end of run Diablo Canyon Power Plant License Renewal Application TCD TVF TCF TEND (HRS)(2 l (HRS)(3 l (HRS)(4) (HRS)(5 l 2.6 3.7 3.7 48 2.8 6.5 0.0 48 3.8 6.1 37.9 72 42.1 66.5 0.0 72 1.1 2.5 NA 48 6.9 9.3 NA 48 Page F-170 TABLE F.3-12 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 DCPP SOURCE TERM RELEASE

SUMMARY

MAAP Case Run Duration Time after Scram when GE is declared 11 l Fission Product Group: 1) Noble Total Release Fraction Total Plume 1 Release Fraction Start of Plume 1 Release (hr) End of Plume 1 Release (hr) Total Plume 2 Release Fraction Start of Plume 2 Release (hr) End of Plume 2 Release (hr) Total Plume 3 Release Fraction Start of Plume 3 Release (hr) End of Plume 3 Release (hr) 2) Csl Total Release Fraction Total Plume 1 Release Fraction Start of Plume 1 Release (hr) End of Plume 1 Release (hr) Total Plume 2 Release Fraction Start of Plume 2 Release (hr) End of Plume 2 Release (hr) Total Plume 3 Release Fraction Start of Plume 3 Release (hr) End of Plume 3 Release (hr) 3)Te02 Total Release Fraction Total Plume 1 Release Fraction Start of Plume 1 Release (hr) End of Plume 1 Release (hr) Total Plume 2 Release Fraction Start of Plume 2 Release (hr) End of Plume 2 Release (hr) Total Plume 3 Release Fraction Start of Plume 3 Release (hr) End of Plume 3 Release (hr) Diablo Canyon Power Plant License Renewal Application ST 1 ST 2 LEARLY SMEARLY RC04U RC16U 48 hr 48 hr 2.6 hr 2.8 hr 7.60E-01 3.70E-01 5.80E-01 2.80E-01 3.60 3.00 4.00 8.00 9.00E-02 9.00E-02 4.00 8.00 6.00 11.00 9.00E-02 O.OOE+OO 6.00 16.00 6.00E-02 4.30E-02 5.50E-02 4.10E-02 3.60 3.00 4.00 8.00 5.00E-03 2.00E-03 4.00 8.00 6.00 11.00 O.OOE+OO O.OOE+OO 2.60E-02 6.10E-02 2.50E-02 6.00E-02 3.60 3.00 4.00 8.00 1.00E-03 1.00E-03 4.00 8.00 6.00 11.00 O.OOE+OO O.OOE+OO Release Category ST 3 ST 4 BYPASS ST5. ST6 LATE wAFW ISLOCA INTACT RC10 RC17WAFW RC18 RC20 72 hr 72 hr 48 hr 48 hr 3.8 hr 36 hr 1.1 hr 6.9 hr 9.70E-01 1.00E+OO 1.00E+OO 1.80E-03 6.40E-01 8.10E-01 9.70E-01 3.00E-04 38.00 42.10 1.10 6.90 48.00 46.00 2.00 14.00 2.30E-01 6.00E-02 3.00E-02 5.00E-04 48.00 46.00 2.00 14.00 58.00 56.00 5.00 24.00 1.00E-01 1.30E-01 O.OOE+OO 1.00E-03 58.00 . 63.00 24.00 68.00 66.00 34.00 4.00E-04 2.60E-02 8.70E-01 3.20E-05 3.00E-04 2.50E-02 8.20E-01 2.80E-05 38.00 42.10 1.10 6.90 48.00 46.00 2.00 14.00 ?.OOE-05 O.OOE+OO 2.00E-02 1.00E-06 48.00 2.00 14.00 58.00 5.00 24.00 3.00E-05 1.00E-03 3.00E-02 3.00E-06 58.00 63.00 5.00 24.00 68.00 66.00 15.00 34.00 1.00E-04 1.30E-02 8.30E-01 2.20E-05 9.00E-05 1.1 OE-02 7.90E-01 2.00E-05 38.00 42.10 1.10 6.90 48.00 46.00 2.00 14.00 1.00E-05 1.00E-03 4.00E-02 2.00E-06 48.00 46.00 2.00 14.00 58.00 56.00 5.00 24.00 O.OOE+OO 1.00E-03 O.OOE+OO O.OOE+OO 63.00 66.00 Page F-171 TABLE F .3-12 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 DCPP SOURCE TERM RELEASE

SUMMARY

MAAP Case Run Duration Time after Scram when GE is declared 111 Fission Product Group: 4) SrO Total Release Fraction Total Plume 1 Release Fract i on Start of Plume 1 Release (hr) End of Plume 1 Release (hr) Total Plume 2 Release Fraction Start of Plume 2 Release (hr) End of Plume 2 Release (hr) Total Plume 3 Release Fraction Start of Plume 3 Release (hr) End of Plume 3 Release (hr) 5)Mo02 Total Release Fraction Total Plume 1 Release Fraction Start of Plume 1 Release (hr) End of Plume 1 Release (hr) Total Plume 2 Release Fraction Start of Plume 2 Release (hr) End of Plume 2 Release (hr) Total Plume 3 Release Fraction Start of Plume 3 Release (hr) End of Plume 3 Release (hr) 6) CsOH Total Release Fraction Total Plume 1 Re l ease Fraction Start of Plume 1 Release (hr) End of Plume 1 Release (hr) Total Plume 2 Re l ease Fract i on Start of Plume 2 Release (hr) End of Plume 2 Release (hr) Total Plume 3 Release Fraction Start of Plume 3 Release (hr) End of Plume 3 Release (hr) Diablo Canyon Power Plant License Renewal Application ST 1 LEARLY RC04U 48 hr 2.6 hr 4.30E-02 4.20E-02 3.60 4.00 1.00E-03 4.00 6.00 O.OOE+OO 4.40E-02 4.20E-02 3.60 4.00 2.00E-03 4.00 6.00 O.OOE+OO 1.50E-02 1.40E-02 3.60 4.00 1.00E-03 4.00 6.00 O.OOE+OO ST2 SMEARLY RC16U 48 hr 2.8 hr 5.30E-04 5.20E-04 3.00 8.00 1.00E-05 8.00 11.00 O.OOE+OO 9.50E-03 9.40E-03 3.00 8.00 1.00E-04 8.00 11.00 O.OOE+OO 3.20E-02 3.10E-02 3.00 8.00 1.00E-03 8.00 11.00 O.OOE+OO Release Categ_o_!Y ST 3 ST 4 BYPASS ST5 ST6 LATE wAFW ISLOCA INTACT RC10 RC17WAFW RC18 RC20 72 hr 72 hr 48 hr 48 hr 3.8 hr 36 hr 1.1 hr 6.9 hr 1.60E-05 3.50E-04 2.30E-02 ?.OOE-07 1.30E-05 3.10E-04 1.40E-02 5.80E-07 38.00 42.10 1.10 6.90 48.00 46.00 2.00 14.00 2.00E-06 2.00E-05 8.00E-03 1.10E-07 48.00 46.00 2.00 14.00 58.00 56.00 5.00 24.00 1.00E-06 2.00E-05 1.00E-03 1.00E-08 58.00 63.00 5.00 24.00 68.00 66.00 15.00 34.00 1.80E-05 2.40E-03 3.80E-02 9.10E-06 1.50E-05 2.20E-03 3.70E-02 7.10E-06 38.00 42.10 1.10 6.90 48.00 46.00 2.00 14.00 3.00E-06 2.00E-04 1.00E-03 2.00E-06 48.00 46.00 2.00 14.00 58.00 56.00 5.00 24.00 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO 1.20E-04 2.40E-02 8.50E-02 2.20E-05 ?.OOE-05 2.20E-02 8.20E-01 2.10E-05 38.00 42.10 1.10 6.90 48.00 46.00 2.00 14.00 2.00E-05 O.OOE+OO 2.00E-02 1.00E-06 48.00 2.00 14.00 58.00 5.00 24.00 3.00E-05 2.00E-03 1.00E-02 O.OOE+OO 58.00 63.00 5.00 68.00 66.00 15.00 Page F-172 TABLE F .3-12 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 DCPP SOURCE TERM RELEASE

SUMMARY

MAAP Case Run Duration Time after Scram when GE is declared(11 Fission Product Group: 7)Ba0 Total Release Fract i on Total Plume 1 Release Fraction Start of Plume 1 Release (hr) End of Plume 1 Release (hr) Total Plume 2 Release Fraction Start of Plume 2 Release (hr) End of Plume 2 Release (hr) Total Plume 3 Release Fraction Start of Plume 3 Release (hr) End of Plume 3 Release (hr) 8) La203 Total Release Fraction Total Plume 1 Release Fraction Start of Plume 1 Release (hr) End of Plume 1 Release (hr) Total Plume 2 Release Fraction Start of Plume 2 Release (hr) End of Plume 2 Release (hr) Total Plume 3 Release Fraction Start of Plume 3 Release (hr) End of Plume 3 Release (hr) 9) Ce02 Total Release Fraction Total Plume 1 Re l ease Fraction Start of Plume 1 Release (hr) End of Plume 1 Release (hr) Total Plume 2 Release Fraction Start of Plume 2 Release (hr) End of Plume 2 Release (hr) Total Plume 3 Release Fraction Start of Plume 3 Release (hr) End of Plume 3 Release (hr) Diablo Canyon Power Plant License Renewal Application ST 1 LEARLY RC04U 48 hr 2.6 hr 4.30E-02 4.10E-02 3.60 4.00 2.00E-03 4.00 6.00 O.OOE+OO 4.30E-02 4.20E-02 3.60 4.00 1.00E-03 4.00 6.00 O.OOE+OO 4.30E-02 4.20E-02 3.60 4.00 1.00E-03 4.00 6.00 O.OOE+OO ST2 SMEARLY RC16U 48 hr 2.8 hr 2.60E-03 2.60E-03 3.00 8.00 O.OOE+OO 8.00 11.00 O.OOE+OO 1.70E-05 3.00 8.00 O.OOE+OO 8.00 11.00 O.OOE+OO 3.80E-05 3.70E-05 3.00 8.00 1.00E-06 8.00 11.00 O.OOE+OO Release Category_

ST 3 ST 4 BYPASS ST5 ST 6 LATE wAFW ISLOCA INTACT RC10 RC17WAFW RC18 RC20 72 hr 72 hr 48 hr 48 hr 3.8 hr 36 hr 1.1 hr 6.9 hr 1.60E-05 9.50E-04 3.70E-02 1.90E-06 1.30E-05 8.40E-04 3.30E-02 1.50E-06 38.00 42.10 1.10 6.90 48.00 46.00 2.00 14.00 3.00E-06 8.00E-05 4.00E-03 4.00E-07 48.00 46.00 2.00 1 4.00 58.00 56.00 5.00 24.00 O.OOE+OO 3.00E-05 O.OOE+OO O.OOE+OO 63.00 66.00 1.60E-05 8.20E-06 9.10E-04 1.70E-08 1.30E-05 5.30E-06 2.90E-04 1.40E-08 38.00 42.10 1.10 6.90 48.00 46.00 2.00 14.00 2.00E-06 1.10E-06 6.00E-04 3.00E-09 48.00 46.00 2.00 14.00 58.00 56.00 5.00 24.00 1.00E-06 1.80E-06 2.00E-05 O.OOE+OO 58.00 63.00 5.00 68.00 66.00 15.00 1.60E-05 5.20E-05 1.00E-02 4.20E-08 1.30E-05 4.30E-05 1.00E-03 3.70E-08 38.00 42.10 1.10 6.90 48.00 46.00 2.00 14.00 2.00E-06 4.00E-06 8.00E-03 4.00E-09 48.00 46.00 2.00 14.00 58.00 56.00 5.00 24.00 1.00E-06 5.00E-06 1.00E-03 1.00E-09 58.00 63.00 5.00 24.00 68.00 66.00 15.00 34.00 Page F-173 TABLE F.3-12 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 DCPP SOURCE TERM RELEASE

SUMMARY

Release Category ST 1 ST 2 ST 3 ST 4 BYPASS ST5 ST 6 LEARLY SMEARLY LATE wAFW ISLOCA INTACT MAAP Case RC04U RC16U RC10 RC17WAFW RC18 RC20 Run Duration 48 hr 48 hr 72 hr 72 hr 48 hr 48 hr Time after Scram when GE is declared 11' 2.6 hr 2.8 hr 3.8 hr 36 hr 1.1 hr 6.9 hr Fission Product Group: 1 0) Sb (Grouped with Te02) Total Release Fraction 5.20E-02 3.80E-02 3.10E-04 6.30E-03 4.50E-01 2.40E-05 Total Plume 1 Release Fraction 5.00E-02 3.70E-02 7.00E-05 5.20E-03 3.70E-01 1.70E-05 Start of Plume 1 Release (hr) 3.60 3.00 38.00 42.10 1.10 6.90 End of P l ume 1 Release (hr) 4.00 8.00 48.00 46.00 2.00 14.00 Total Plume 2 Release Fraction 2.00E-03 1.00E-03 9.00E-05 1.00E-04 5.00E-02 6.00E-06 Start of Plume 2 Release (hr) 4.00 8.00 48.00 46.00 2.00 14.00 End of Plume 2 Release (hr) 6.00 11.00 58.00 56.00 5.00 24.00 Total Plume 3 Release Fraction O.OOE+OO O.OOE+OO 1.50E-04 1.00E-03 3.00E-02 1.00E-06 Start of Plume 3 Release (hr) 58.00 63.00 5.00 24.00 End of Plume 3 Release (hr) 68.00 66.00 15.00 34.00 11) Te2 (Grouped with Te02) Total Release Fraction 1.30E-04 O.OOE+OO 2.20E-05 4.00E-07 9.60E-04 O.OOE+OO Total Plume 1 Release Fraction 1.30E-04 O.OOE+OO 1.40E-05 O.OOE+OO O.OOE+OO O.OOE+OO Start of Plume 1 Release (hr) 3.60 3.00 38.00 End of Plume 1 Release (hr) 4.00 8.00 48.00 Total Plume 2 Release Fraction O.OOE+OO O.OOE+OO 5.00E-06 O.OOE+OO 9.20E-04 O.OOE+OO Start of Plume 2 Release (hr) 8.00 48.00 2.00 End of Plume 2 Release (hr) 11.00 58.00 5.00 Tota l Plume 3 Release Fraction O.OOE+OO O.OOE+OO 3.00E-06 4.00E-07 4.00E-05 O.OOE+OO Start of Plume 3 Release (hr) 58.00 63.00 5.00 End of Plume 3 Release (hr) 68.00 66.00 15.00 12) U02 (Grouped with Ce02) Total Release Fraction 3.80E-08 O.OOE+OO O.OOE+OO 2.20E-09 5.00E-05 O.OOE+OO Total Plume 1 Release Fraction 3.60E-08 O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO O.OOE+OO Start of Plume 1 Release (hr) 3.60 3.00 End of Plume 1 Release (hr) 4.00 8.00 Total Plume 2 Release Fraction 2.00E-09 O.OOE+OO O.OOE+OO O.OOE+OO 4.60E-05 O.OOE+OO Start of Plume 2 Release (hr) 4.00 8.00 2.00 End of Plume 2 Release (hr) 6.00 11.00 5.00 Total Plume 3 Release Fraction O.OOE+OO O.OOE+OO O.OOE+OO 2.20E-09 4.00E-06 O.OOE+OO Start of Plume 3 Release (hr) 63.00 5.00 End of Plume 3 Release (hr) 66.00 15.00 Note to Table F.3-12 (1) General Emergency (GE) declaration estimated from DCPP Emergency Classification Guide (Reference 60). All scenario GE times correspond to the time to core damage except for the ST 4 " BYPASS w AFW" where the GE is evaluated to occur at t = 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . Diablo Canyon Power Plant License Renewal Application Page F-174 Source Release Term Category ST1 LGEARLY ST2 SMEARLY ST3 LATE ST4 BYPASS w AFW ST5 ISLOCA ST6 INTACT Diablo Canyon Power Plant License Renewal Application TABLE F.3-13 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 MACCS2 BASE CASE MEAN RESULTS Dose Offsite Economic Freq. Dose-Risk OECR (p-rem) Cost($) (/yr) (p-rem/yr)

($/yr) 9.83E+06 1.22E+10 7.24E-06 12E+01 8.84E+04 9.59E+05 7.26E+09 6.74E-06 6.46E+OO 4.89E+04 2.49E+04 1.17E+07 6.42E-05 1.60E+OO 7.51 E+02 7.68E+05 5.45E+09 1.79E-06 1.38E+OO 9.77E+03 6.15E+06 3.34E+10 2.97E-06 1.82E+01 9.91 E+04 3.68E+03 9.31 E+05 2.24E-06 8.23E-03 2.08E+OO FREQUENCY WEIGHTED TOTALS 8.52E-05 9.89E+01 2.47E+05 Page F-175 EVENT PROBABILITY NAME ZHTRP2 1.60E-01 AWR1 2.93E-04 PRB1A 1.76E-01 Diablo Canyon Power Plant License Renewal Application RISK REDUCTION WORTH 1.11 E+OO 1.07E+OO 1.07E+OO APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Table F.S-1 DCPP Level 1 Importance List Review DESCRIPTION POTENTIAL SAMAS Elevated human error This event represents the failure to trip the RHR pumps before failure probability due to fire-when they have been "deadheaded" without CCW flow to the RHR heat induced degraded exchangers. A potential means of precluding the need to trip the RHR instrument-cue to pumps would be to install a normally open CCW flow bypass line around operator to trip potentially the RHR Hx outlet valve. This would ensure that minimum cooling flow dead-headed RHR would be available to prevent damage to the RHR pumps when they are pumps running with the RCS at high pressure (SAMA 1 ). Failure to provide long-This event represents the failure to align a long-term water source (e.g., term supply water from the fire water storage tank) to AFW upon depletion of the CST to meet FWST or RWR (non 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months mission time. The top contributors including this SF are cases seismic) to auxiliary where service water or CCW have failed and the CST is depleted.

The feedwater pumps to meet HFE for this action is based on a relatively long process that is assumed 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months mission time for to include venting of the initially operating pump. This function becomes the decay heat removal important, especially when the decay removal via the RHR system is not (DHR) function available for a long-term cooling. The improvement of the reliability of the RH R system via SAMA 1 is one of two options. Another alternate approach would be to provide an engine driven SG makeup pump that can be aligned in time to mitigate loss of SG makeup scenarios. This could simplify alignment in cases where CST rupture may have resulted in air entrainment in the *initially operating pump (SAMA 2). PR Failed due to PORV For fires in the containment annular area (91' and 115'), the cables for 455C 80008 Failure-PORV 455C are impacted, leading to an induced LOCA scenario.

In FOR FIRE AREA 1A and most of the scenarios including this split fraction, the failure to trip the 9A RHR pumps while "deadheaded" leads to loss of the containment heat removal function.

A potential means of precluding the need to trip the RHR pumps would be to install a normally open CCW flow bypass line around the RHR Hx outlet valve. This would ensure that minimum cooling flow would be available to prevent damage to the RHR pumps when they are running with the RCS at high pressure (SAMA 1 ). Page F-176 EVENT PROBABILITY NAME RECSR 6.50E-02 OSZ1 5.30E-02 Diablo Canyon Power Plant License Renewal Application RISK REDUCTION WORTH 1.06E+OO 1.06E+OO APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Table F.S-1 DCPP Level 1 Importance List Review DESCRIPTION POTENTIAL SAMAS Recovery actions for CSR This SF represents the failure of recovery actions performed at the hot Scenarios from HSP shutdown panel for cable spreading room fires. The cable spreading room (area 7 A) is (or will be) equipped with multiple types of fire detection equipment, including smoke, heat, and incipient smoke detectors. Auto C02 suppression is also installed to help reduce the frequency of the fires. Fires in this area, however, can lead to the need to perform a large number of mitigating actions at the remote shutdown panel. The significant sequence that include this SF, however, all include the SF for failure to trip a "deadheaded" RHR pump and an otherwise available low pressure injection/heat removal system is lost. A potential means of precluding the need to trip the RHR pumps would be to install a normally open CCW flow bypass line around the RHR Hx outlet valve. This would ensure that minimum cooling flow would be available to prevent damage to the RHR pumps when they are running with the RCS at high pressure (SAMA 1 ). MANUAL ACTUATION IN. This event represents the failure to manually initiate Sl in fire scenarios EVENT SSPS FAILS: in which auto initiation has been failed by the fire and the Instrumentation degraded instrumentation used for action diagnosis has been degraded (at least one train impacted by the fire). The fire procedure already identifies the instruments and equipment that can potentially be impacted for each fire area and directs actions to mitigate those failures.

A potential means of improving the response would be to update the fire procedures to explicitly identify that auto Sl is vulnerable to failure and to identify the instruments that should be used to check for the need to manually initiate Sl (SAMA 3). Page F-177

DCL-15-027, Diablo Canyon Power Plant Er Changes Reflected in the Environmental Report Update Amendment 2. Part 6 of 9

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