DCL-16-044, Response to NRC Request for Additional Information Regarding License Amendment Request 15-03, Application of Alternative Source Term.

Response to NRC Request for Additional Information Regarding License Amendment Request 15-03, Application of Alternative Source Term.

ML16120A027
Person / Time
Site:	Diablo Canyon
Issue date:	04/21/2016
From:	Welsch J Pacific Gas & Electric Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
Shared Package
ML16120A026	List: DCL-16-044, Response to NRC Request for Additional Information Regarding License Amendment Request 15-03, Application of Alternative Source Term.
References
DCL-16-044, TAC MF6340, TAC MF6399
Download: ML16120A027 (75)

Text

PacHic Gas and Bectric Company.,

James M. Welsch Diablo Canyon Power Plant Vice President, Nuclear Generation P.O. Box 56 Avila Beach, CA 93424 805.545.3242 E*Mail: JMW1@pge.com April 21, 2016 PG&E Letter DCL-16-044 U.S. Nuclear Regulatory Commission 10 CFR 50.90 A TIN: Document Control Desk Washington, DC 20555-0001 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1 and 2 Response to NRC Request for Additional Information Regarding License Amendment Request 15-03, "Application of Alternative Source Term"

References:

1. PG&E Letter DCL-15-069, "License Amendment Request 15-03,

'Application of Alternative Source Term,"' dated June 17, 2015 (ADAMS Accession No. ML15176A539)

2. PG&E Letter DCL-15-105, "Supplement to License Amendment Request 15-03, 'Application of Alternative Source Term,"' dated

~ugust 31, 2015 (ADAMS Accession No. ML15243A363)

3. E-mail from NRC Project Manager Siva P. Lingam, "Diablo Canyon 1 and 2 - Requests for Additional Information for License Amendment Request 15-03 to Adopt the Alternative Source Term per 10 CFR 50.67 (TAC Nos. MF6399 and MF6400)," dated October 1, 2015 (ADAMS Accession No. ML15278A049)

4. PG&E Letter DCL-.15-130, "Response to NRC Request for Additional Information Regarding License Amendment Request 15-03, 'Application of Alternative Source Term,"' dated November 2, 2015 (ADAMS Accession No. ML15321A235)

• 5. E-mail from NRC Project Manager Siva P. Lingam, "Diablo Canyon 1 and 2 - Met Data Second Round of Requests for Additional Information for License Amendment Request 15-03 to Adopt the Alternative Source Term per 10 CFR 50.67 (TAC Nos. MF6399 and MF640," dated February 17, 2016 (ADAMS Accession No. ML16048A232)

6. PG&E Lett~r DCL-15-152, "Response to NRC Request for Additional Information Regarding License Amendment.

Request 15-03, 'Application of Alternative Source Term,"' dated December 17, 2015 (ADAMS Accession Numbers ML16004A354, ML16004A355, ML16004A356, ML16004A357, ML16004A359, and ML16004A361)

A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Diablo Canyon

• Palo Verde

• Wolf Creek

191 Document Control Desk PG&E Letter DCL-16-044

~~~ April 21, 2016

~ Page2 *

Dear Commissioners and Staff:

License Amendme~t Request (LAR) 15-03, "Application of Alternative Source Term,"

was submitted by Pacific Gas and Electric Company (PG&E) in Reference 1 and supplemented by PG&E in Reference 2.

In Reference 3, the NRC Radiation Protection and Consequence Branch (ARCB) requested additional information required to complete the review of LAR 15~03.

PG&E responded to this request for additional information (RAI) in Reference 4.

In Reference 5, the ARCB provided a follow-up RAI associated with the meteorological data provided -in Reference 4. PG&E's response to the follow-up RAI is provided in the Enclosure to this letter.

Th_e Enclosure includes the following attachments:

• Attachment 1 - Diablo Canyon Power Plant Technical Assessment Prepared by WECTEC (previously CB&I Stone and Webster, Inc.), "Implementation of Alternative Source Terms, Summary of Dose Analyses and Results,"

Revision 2

• Attachment 2 - Diablo Canyon Power Plant Updated Final Safety Analysis Report Markup (For Information Only), Revision 2

• Attachment 3 - Data files in support of the RAI responses in the Enclosure.

Attachment 1 supersedes Reference 1, Enclosure Attachment 4 and Reference 6, Enclosure Attachment 2(ML16004A354). The revised Updated Final Safety Analysis Report tables contained in Attachment 2 supersede those contained in Reference 1, Enclosure Attachment 8 and Reference 6, Enclosure Attachment 4 (ML16004A357, ML16004A359, and ML16004A361).

This information does not affect the results of the technical evaluation or the no significant hazards consideration determination previously transmitted in References 1 and 2.

PG&E makes no regulatory commitments (as defined by NEI 99-04) in this letter.

This letter includes no revisions to existing regulatory commitments.

If you have any questions or require additional information, please contact

• Mr. Hossein Hamzehee at (805) 545-4720.

A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Diablo Canyon

• Palo Verde

• Wolf Creek

. . Document Control Desk PG&E Letter DCL-16-044

~~~ April 21, 2016 Page3 I state under penalty, of perjury that the foregoing is true and correct.

Executed on April 21, 2016.

Sincerely,

~/\_*-/-~

J~Welsch .

Vice President, Nuclear Generation e 1d?/4418/50705089 Enclosure cc: Diablo Distribution cc/enc: Marc L. Dapas, NRC Region IV Administrator Gonzalo L. Perez, Branch Chief, California Department of Public Health John P. Reynoso, NRCActing Senior Resident Inspector Balwant K. Singal, NRR Project Manager A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Diablo Ca,nyon

• Palo Verde

• Wolf Creek

Enclosure PG&E Letter DGL-16-044 Pacific Gas and Electric Company (PG&E) Response to NRC Request for Additional Information (RAI) Regarding Diablo Canyon Power Plant (DCPP)

License Amendment Request (LAR) 15-03, "Application of Alternative Source Term" NRC ARCB-RAl-1 Either confirm and reconcile all noted and any other discrepancies within the RG 1. 23-formatted hourly data sets and between those data sets and the presumably parallel hourly data sets input to the ARCON96 dispersion modeling analyses used to estimate onsite impacts at CR and TSC receptor locations, or provide technical justification for each of those differences. In addition, and as necessary, *the licensee should: [refer to RAl-1a thru RAl-1g]

PG&E Response PG&E has determined there are no discrepancies within the Regulatory Guide (RG) 1.23, Revision 1, "Meteorological Monitoring Programs for Nuclear Power Plants,"

March 2007, formatted data files submitted to the NRG in Enclosure Attachment 3 of Reference 4.

PG&E has confirmed that discrepancies exist between the RG 1.23-formatted data sets and the sequential hourly ARGON96 input files provided to the NRG in Enclosure Attachment 3 of Reference 4. The meteorological (Met) data that PG&E provided to WECTEC, previously Chicago Bridge and Iron (CB&I) Stone and Webster, Inc., to perform the ARGON96 analysis contained wind speed, wind direction, and stability class. The wind speed and wind direction data were based on the RG 1.23 format, consistent with the data supplied to NRG in the Annual Radioactive Effluent Release Reports. The stability class data were not determined based on Table 1 of RG 1.23.

The actual stability class data used in the ARGON96 run files were developed by the

• PG&E meteorologist using an alternate methodology. The NRG found, and PG&E confirmed, that the PG&E supplied stability data used in the development of the atmospheric dispersion .factors and the RG 1.23 delta temperature-based stability classes are different approximately 30 percent of the time. This difference in methodology for developing the stability classes used by the PG&E meteorologist explains the difference between the ARGON96 input files and RG 1.23 data. The ARGON96 Met input files have been revised using the RG 1.23-formatted data and its associated stability classification methodology and are included in the response to RAl-1d. Note that the updated ARGON96 hourly data set has some additional missing data as discussed in response to RAl-1d.

In summary, to be consistent with the RG 1.23 methodology, the ARGON96 Met ipput files have been revised using the RG 1.23-formatted data and its associated stability classification methodology, and are included in the response to RAl-1d.

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Enclosure PG&E Letter DCL-16-044 .

NRC ARCB-RAl-1 a verify that the DELT3 and DELT1 values listed in the RG 1.23-formatted data files represent the vertical temperature differences per 100 meters consistent with the guidance in Appendix A to RG 1.-23 and stability classification methodology rather than the temperature differences over the literal vertical distances petween the temperature measurement heights (i.e., respectively, 66 m between the 76- and 10-m measurement heights and 36 m between the 46-and 10-m measurement heights);

PG&E Response The DELT3 and DELT1 values listed in the RG 1.23-formatted data files submitted to the NRC in Enclosure Attachment 3 of Reference 4, represent the vertical temperature difference per 100 meters (m) consistent with the stabilitY classification methodology of Appendix A to RG 1.23.

NRC ARCB-RAl-1 b identify and explain any differences between the wind speed, wind direction, and atmospheric stability class values listed in the MS Excel files of ARCON96 sequential hourly Met data provided in Attachment 3 to the RA/ responses of November 2, 2015 (PG&E Letter. DCL-15-130) and those listed in the Met data

• files specified in the ARCON96 run files (i.e., DCPP2007.MET, DCPP2008.MET, DCPP2009.MET, DCPP2010.MET, and DCPP2011.MET);

PG&E Response The wind speed, wind direction, and stability class values listed in the ARCON96 run files (filenames= DCPP2007.MET, DCPP2008.MET, DCPP2009.MET, DCPP201 O.MET, and DCPP2011.MET) are the same as those listed in the Microsoft Excel files provided. in Enclosure Attachment 3 of Reference 4. The ARCON96 Met input files have been revised using the RG 1.23-formatted data and its associated stability classification methodology and are included in the response to RAl-1d.

NRC ARCB-RAl-1 c resubmit any corrected RG 1.23-formatted Met data files and document any changes to the previously submitted data files; PG&E Response The RG 1.23-formatted data supplied in Enclosure Attachment 3 of Reference 4 are correct. No changes to the RG 1.23-formatted Met data files are necessary.

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Enclosure PG&E Letter DCL-16-044 NRC ARCB-RAl-1 d resubmit any corrected Met data files input to the ARCON96 dispersion modeling runs and document any changes to the previously submitted data files; PG&E Response The corrected ARCON96 input files are provided in the zipped file (filename= dcpprg711) provided in the Attachment 3 Data Disc. This fiie provides the updated 5-year Met hourly data files with stability class based on the RG 1.23-formatted hourly data sets, which were used as input to the updated ARCON96 dispersion ,

modeling runs. These Met data files used in ARCON96 (which contain the hourly wind direction and wind speed at two elevations, and the stability class) differ from the previously submitted Met data files in that the stability class determination is based on the RG 1.23, Table 1, vertical temperature difference classification methodology.

Note that the updated ARCON96 hourly data set has 280 additional missing values of 10 m wind speed and/or wind direction since the previously submitted data set had contained substituted values based on the 76-m wind speed and wind direction data.

There are also 118 additional missing values of stability class in the updated ARCON96 hourly data set since the previously submitted data set had substituted values. The updated ARCON96 data set still exceeds the "90 percent data recovery" guidance identified in RG 1.23, Revision 1, for the 2007-2011 data period.

NRC ARCB-RAl-1 e revise (if necessary) the previously submftted ARCON96 dispersion modeling runs and resubmit any corrected model input and output files and affected summaries of results, .or otherwise justify the previously submitted modeling results and downstream dose calculations and related impact evaluations; PG&E Response The revised ARCON96 dispersion modeling runs are provided in the zipped files (filenames = dclocarg, dcfhrg, dcmssvrg, dctscrg) provided in the Attachment 3 Data Disc. These files represent the updated ARCON96 dispersion modeling runs developed using the RG 1.23-formatted Met data (filename= dcpprg711) as input, as discussed in response to NRC RAl-1d. Tables 2-1 through 2-4 of this enclosure provide a description of the ARCON96 input/output file names. The .revised input files are identical to the previously submitted files except for the new Met data files used (filenames= DCPPRG07, DCPPRG08, DCPPRG09, DCPPRG10, and DCPPRG11)~

A summary of results is provided in Tables 1-1to1-3 of this enclosure, which show comparisons between the previously reported on-site atmospheric dispersion factor (X/Q, expressed in seconds per cubic meter or sec/m 3 ) values in Section 5 of Reference 1, LAR 15-03, Enclosure Attachment 4, and the updated X/Q values developed using the revised Met data (i.e., corrected for stability classes) in the ARCON96 dispersion modeling runs.

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Enclosure PG&E Letter DCL-16-044

• Table 1 DCPP Unit 1 - Control Room Atmospheric Dispersion Factor (sec/m 3 )

Comparisons

• Table 1 DCPP Unit 2 - Control Room Atmospheric Dispersion Factor (sec/m 3 )

Comparisons

• Table 1 DCPP Units 1 and 2 - Technical Support Center Atmospheric Dispersion Factor (sec/m 3) Comparisons The revised X/Q values developed from the updated Met data are labeled "RG 1.23 Met Data" in red font. The percent change in X/Q values from that reported previously is also provided. Positive "percent change" values (identified in red bold italicized font) indicate that the X/Q values developed using the updated Met data are higher than the previously reported values. Negative "percent change" values indicate the X/Q values developed using the updated Met data are lower than the previously reported values .

Tables 1-1 to 1-3 indicate that for a large majority of the 116 release point-receptor combinations , the X/Q values show improved dispersion for all five time periods.

NRC ARCB-RAl-1f update (if necessary) any previously submitted data recovery statistics or summaries of time periods during which data substitution was stated to have occurred; and PG&E Response The previously submitted data recovery statistics of the time periods during which data substitution was stated to have occurred are bounded by the updated RG 1.23-formatted data . Therefore, the data submitted do not need to be updated.

As noted in the RAl-1 d response , the updated ARCON96 hourly data set has 280 additional missing values of 10-m wind speed and wind direction since the previously submitted data set had contained substituted values based on the 76-m wind speed and wind direction data. There are also 118 additional missing values of stability class in the updated ARCON96 hourly data set since the previously submitted data set had substituted values. The updated ARCON96 data set still exceeds the "90 percent data recovery" guidance identified in RG 1.23 for the 2007-2011 data period .

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Enclosure PG&E Letter DCL-16-044 NRC ARCB-RAl-1g update (if necessary) the UFSAR and LAR 15-03 discussions.

PG&E Response of this response provides Revision 2 of the Diablo Canyon Power Plant Technical Assessment prepared by WECTEC (previously CB&I Stone and Webster, Inc.), "Implementation of Alternative Source Terms, Summary of Dose Analyses and Results." This updated report provides the revised on-site , post-accident atmospheric dispersion factor (X/Q) values that support LAR 15-03. of this response provides the affected tables of the previously submitted Updated Final Safety Analysis Report (UFSAR) markup to address the change in the X/Q values.

As discussed in the response to RAl-1, the NRC found , and PG&E confirmed , that the PG&E-supplied stability class data used to develop the DCPP X/Q values, and the RG 1.23-based stability classes are different approximately 30 percent of the time due to use by the PG&E meteorologist of an alternate methodology to establish hourly stability class .

The revisions provided in this response are consistent with use of RG 1.23 stability classification methodology in the development of hourly stability classes for purposes of developing post-accident off-site and on-site X/Q values.

PG&E has:

• Revised the ARCON96 dispersion modeling runs supporting LAR 15-03, by using as input, the updated RG 1.23-formatted Met data discussed in response to RAl-1d.

• Assessed the impact of the updated X/Qs on the dose consequences reported in LAR 15-03 at the Exclusion Area Boundary (EAB), the Low Population Zone (LPZ) , and the Control Room (CR) for each of the analyzed accidents, and at the Technical Support Center (TSC) for the Loss-of-Coolant Accident (LOCA).

Tables 1-1 through 1-3 of this enclosure show that the limited number of on-site XIQ values that were adversely impacted were primarily those associated with releases from the containment edge , and seven X/Q values at other locations (six for Unit 1 and one for Unit 2) . These containment edge X/Q values were not utilized in the AST dose consequence analyses since other X/Q values were considered more restrictive for releases from the containment building . PG&E determined that the updated X/Q values that were actually utilized in the dose consequence analyses continue to be more restrictive than the increased X/Q values for the containment edge. The seven XIQ values at other locations are included in the assessments summarized in Table 3-2 through Table 3-9.

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Enclosure PG&E Letter DCL-16-044 Tables 3-2 through Table 3-9 provide the X/Q values selected for use for each accident for the purpose of estimating the dose consequences at the CR and TSC . These X/Q values represent the bounding values applicable for the release points/receptor combinations associated with each accident. The listed tables provide a comparison between the previously reported X/Q values and the updated X/Q values per accident.

The updated values are provided in red font below the previously reported values. The few X/Q values that have increased are in red bold italicized font.

Tables 3-2 through 3-9 also provide a summary of the results of the assessment of the effect of the updated X/Q values on the currently reported on-site dose consequences in LAR 15-03 (specifically, Enclosure Attachment 2 of Reference 6) .

• Table 3 Effect of Updated CR X/Qs on the Dose Consequences in the CR following a Loss-of-Coolant Accident (LOCA)

• Table 3 Effect of Updated TSC X/Qs on the Dose Consequences in the TSC following a Loss-of-Coolant Accident (LOCA)

• Table 3 Effect of Updated CR X/Qs on the Dose Consequences in the CR following a Fuel Handling Accident

• Table 3 Effect of Updated CR X/Qs on the Dose Consequences in the CR following a Locked Rotor Accident

• Table 3 Effect of Updated CR X/Qs on the Dose Consequences in the CR following a Control Rod Ejection Accident

• Table 3 Effect of Updated CR X/Qs on the Dose Consequences in the CR following a Main Steam Line Break

• Table 3 Effect of Updated CR X/Qs on the Dose Consequences in the CR following a Steam Generator Tube Rupture

• Table 3 Effect of Updated CR X/Qs on the Dose Consequences in the CR following a Loss of Load PG&E concluded that the use of the updated X/Q values do not adversely impact the dose consequences reported in LAR 15-03 (specifically, Enclosure Attachment 2 of Reference 6) for the CR or TSC .

Based on the above:

• Upon AST implementation , the updated X/Q values reported herein will become the DCPP licensing basis.

• The dose consequences reported in LAR 15-03 are considered conservative and bounding , and will remain unchanged .

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Enclosure PG&E Letter DCL-.16-044 NRC ARCB-RAl-2 As explained previously, the NRG staff did not initially request the sequential hourly Met data used as input to the EN-113 dispersion model for estimating offsite impacts at the EAB and the LPZ. However, given the issues identified in the staff's initial evaluation, the licensee should: "

NRC ARCB-RAl-2a confirm, reconcile, and document any additional discrepancies between the RG 1.23-formatted and/or ARCON96 sequential hourly input Met data files; PG&E Response The differences between the RG 1.23-formatted and the ARCON96 input files are confined to the determination of stability class as described in the response to RAl-1 and a small amount of additional missing data in the RG 1.23-formatted data as described in the response to RAl-1d. The corrected ARCON96 input files, using RG 1.23 methodology to establish stability class are supplied as part of the response to RAl-1d.

NRC ARCB-RAl-2b resubmit any corrected RG 1.23-formatted Met data files and document any additional changes to _the previously submitted data files; PG&E Response The RG 1.23-formatted Met data files submitted to the NRG in Enclosure Attachment 3 of Reference 4 are correct. No changes to the RG 1.23-formatted Met data files are necessary.

NRC ARCB-RAl-2c submit that portion of the EN-113 input data files for the 2007 through 2011 POR that includes sequential hourly Met data and provide detailed formatting information for each parameter to facilitate the staff's understanding and review of those input data;

• PG&E Response The listed file (filename= met113_dcpp_0711 RG.inp) provided in the Attachment 3 Data Disc represents the 5_-year Met data file based on the RG 1.23-formatted hourly data used as input to the EN-113 dispersion modelingTuns. This RG 1.23-formatted Met data file differs from that previously used in the EN-113 dispersion model runs in that the stability class is determined based on the RG 1.23, Table 1, vertical temperature difference classification methodology.

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Enclosure PG&E Letter DCL-16-044 As noted in the response to NRC RAl-1d the updated hourly data set has 280 additional missing values of 10-m wind speed and/or wind direction since the previously submitted data set had contained substituted values based on the 76-m wind data. Moreover, there are also 118 additional missing values of stability class in the updated data set since the previously submitted data set had substituted values. The updated EN-113 data set exceeds the "90 percent data recovery" guidance identified in RG 1.23, Revision 1, for the 2007-2011 period.

Detailed formatting information for each Met parameter used as input to the EN-113 dispersion models is provided in Table 2-5.

NRC ARCB-RAl-2d revise (if necessary) the previously analyzed EN-113 dispersion modeling .runs and resubmit any affected summaries of results, or otherwise justify the previously submitted modeling results and downstream dose calculations and related impact evaluations; PG&E Response Table 1-4, "DCPP Unit 1 and Unit 2 - Offsite Receptor Atmospheric Dispersion Factor (se~/m 3 ) Comparisons," provides comparisons between the previously reported off-site atmospheric dispersion factors in Section 5 of LAR 15-03, Enclosure Attachment 4, and the updated values developed using the revised Met data corrected for stability classes in the EN-113 dispersion modeling runs.

Table 1-4 indicates that with the exception of the last two time periods for the LPZ, the updated X/Q values show improved dispersion.

NRC ARCB-RAl-2e update (if necessary) any previously submitted data recovery statistics or summaries of time period$ during which data substitution was stated to have occurred; and PG&E Response The previously submitted data recovery statistics of the time periods during which data ,/

substitution was stated to have occurred are bounded by the updated" RG 1.23-formatted data. Therefore, the data submitted do not need to be updated.

As noted in the RAl-2c response, the updated ARCON96 hourly data set has 280 additional missing values of 10-m wind speed and wind direction since the previously submitted data set had contained substituted*values based on the 76-m wind speed and wind direction data. There are also 118 additional missing values of stability class in the

-updated ARCON96 hourly data set since the previously submitted data set had substituted values. The updated ARCON96 data set still exceeds the "90 percent data recovery" guidance identified in RG 1.23, Revision 1, for the 2007-2011 data period.

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Enclosure PG&E Letter DCL-16-044 NRC ARCB-RAl-2f update (if,necessary) the UFSAR and LAR 15-03 discussions. )

PG&E Response of this response provides Revision 2 of the Diab lo Canyon Power Plant Technical Assessment Prepared by WECTEC (previously CB&I Stone and Webster, Inc.), "Implementation of Alternative Source Terms, Summary of Dose Analyses *and Results." This updated report provides the revised off-site X/Q values that support LAR 15-03. . of this response provides the affected tables of the previously submitted UFSAR markup to address the change in the off-site X/Q values.

Summarized in Table 3-1 are the results of the assessment of the effect of the updated X/Q values on the currently reported off-site dose consequences in LAR 15-03 (specifically, Enclosure Attachment 2 of Reference 6).

PG&E concluded that the use of the updated X/Q values do not adversely impact the dose consequences reported in LAR 15-03 (speci~ically, Enclosure Attachment 2 of Reference 6) for the EAB and LPZ.

Based on the above:

• Upon AST implementation the updated X/Q values reported herein will become 1 DCPP licensing basis.

• The dose consequences reported in LAR 15-03 are considered conservative and bounding and will remain unchanged.

NRC ARCB-RAl-3 In marked contrast to the typical daily variation in atmospheric stability class, the NRG staff has identified quite a few extended, and for the most part unbroken except for a few hours, time periods when moderately or extremely stable atmospheric conditions (i.e., For G Pasqui/1-Gifford stability classes) persisted with very little or no variation.

This includes two separate occasions that lasted the better part of five (5) consecutive days with a total of only 12 and 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> scattered over those entire, time intervals not being designated as For G stability. To the extent that the licensee believes that any of the time periods identified by the staff are valid (or other similar persistence periods in the RG 1.23 formatted Met data files), the licensee should:

NRC ARCB-RAl-3a provide technical and climatological justification of these frequencies and durations to establish the validity of these portions of the basic Met data sets; 9 of 53

Enclosure PG&E Letter DCL-16-044 PG&E Response The apparent unusual persistence of stable atmospheric conditions is a direct result of the marine environment climate where the DCPP primary and backup Met towers are sited, in combination with a high frequency of onshore afternoon sea breeze winds . The Figure below shows the proximity of the primary and backup Met towers to the Pacific Ocean , which , due to upwelling , is cold throughout the year.

Primary Tower Backup Tower In this marine environment, the mean 10-m above ground level (AGL) temperature is generally within a narrow range of 54°F - 59°F throughout the year as a result of the persistence of moderate to strong afternoon onshore northwest winds from the cold Pacific Ocean . Table RAl-3a-1 presents annual wind frequencies for 2007-201 1, showing the high frequency of West Northwest and Northwest winds at DCPP. When the fetch is from the Northwest, West Northwest, West, West Southwest, Southwest and South Southwest, winds are always blowing inland from a cold ocean surface , with water temperatures generally 50°F - 60°F , to the primary and backup Met tower locations.

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Enclosure PG&E Letter DCL-16-044 Direction 2007 2008 2009 2010 2011 Average IN 2.9 3.4 2.6 2.9 3.3 3.0 INN E 2.9 2.7 2.5 2.3 2.9 2.7 INE 3.6 2.8 3.2 3.5 3.5 3.3 E E 3.0 2.9 2.4 2.3 2.5 2.6 E 2.0 2.2 1.8 1.9 2.2 2.0 ESE 3.2 4.1 ".2 5.3 5.1 .4 SE 7.9 8.9 8.7 9.7 9.0 8.8 SSE 6.6 5.5 6.8 7.4 5.7 6.4 s 2.7 2.3 3.2 2.8 2.4 2.7 SS 1.7 1.9 1.8 1.6 1.4 1.7 sv 1.5 1.4 1.7 1.4 1.2 1.4

,ws 1.2 1.4 1.7 1.2 '1.4 1.4 w 2.0 2.6 2.5 2.0 2.3 2.3 w~ 11 .8 20.1 14.9 13.0 1 .5 1 .1 NW 38.3 30.3 35.3 35.3 34.8 34.8 NNW 8.7 7.4 6.8 7.5 6.8 7.4 Total 100 100 100 100 100 100 Table RAl-3a-1 This very high persistence of the onshore winds (wind from the cold Pacific Ocean) significantly modifies the effects of surface heating during the day and generates a much higher frequency of stable or neutral conditions during the time of maximum solar heating (i.e., 10 AM - 4 PM) than what occurs at locations farther inland with little to no marine influence. Furthermore , the presence and persistence of summertime coastal low-lying stratus clouds further inhibit surface warming and add to the decrease in the frequency of unstable conditions . Figure RAl-3a-2, based on 2007-2011 RG 1.23 stability class data derived from vertical temperature differences, shows that neutral and slightly stable stability classes are the most frequent due to persistent onshore winds and coastal stratus clouds, but also that unstable conditions (stability classes A, B, and C) increase during the diurnal cycle and occur with a frequency near 20 - 25 percent during the afternoon hours (12 PM -4 PM).

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Enclosure PG&E Letter DCL-16-044 Stability Cl ass by Time of Day : 2007-2011 60'(

~ 50'(

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" 2 3 J 5 6 S 9 10 11 12 l'om *of D*y 13 U 15 16 V 10 19 D 21 22 23 U Note: Stability Class 1 =Class A, Class 2 =Class B, Class 3 =Class C, Class 4 =Class D, Class 5 =Class E, Class 6 =Class F, Class 7 =Class G Figure RAl-3a-2 The 2007-2011 analysis, shown on Figure RAl-3a-3 , correlates well with a 1986-2010 stability by Delta T data analysis performed by PG&E meteorologists Clifford and McCarthy shown in Figures RAl-3a-4 , RAl-3a-5 , and RAl-3a-6 . Averaging the data between 1986 and 2010 indicates that 45 percent of the data are Stability Class D (neutral) , while 30 percent of the data are Class E (slightly stable) . This average of the data between 1986 and 2010 is consistent with the data shown on Figure 3a-3 , for years 2007-2011 where approximately 45 percent of the data were Stability Class D and approximately 27 percent of the data were stability Class E. Additionally, Stability Class A, B, and C (very unstable, moderately unstable, and slightly unstable, respectively) each remained below 5 percent, while Stability Class F and G (moderately stable and very stable, respectively) remained below 10 percent throughout the 1986-2010 time period.

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Enclosure PG&E Letter DCL-16-044 Stability by AT Frequency Distribution 2007 - 2011 50%

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40%

35 %

ij 30%

c:

~ 25%

C"

~ 20%

15%

10%

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A B c D E F G M issing Stability Class Figure RAl-3a-3 SnbUi-W by 4 T Fre*q ueni;;.y l'.>"stmibution 113005

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Enclosure PG&E Letter DCL-16-044

.Stability by AT

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Figure RAl-3a-5 Stab~lity by AT Frequency DiWilu.1:tiion 2000s 50%

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• E 20"~

• F

• O 2000 20Cl 1 2002 2003 2004 2005 :2006 2007 2006 2000 :2010 Figure RAl-3a-6 14 of 53

Enclosure PG&E Letter DCL-16-044 NRC ARCB-RAl-3b confirm, reconcile, and document any additional related discrepancies and changes to the RG 1. 23-formatted Met data sets; PG&E Response The response to RAl-3a explains the apparent unusual persistence of stable atmospheric conditions, which is a reflection of the marine climate at DCPP, and is not a discrepancy. Accordingly, no changes to data sets are warranted.

NRC ARCB-RAl-3c incorporate any related corrections to the Met data.input to the ARCON96 and EN 113 dispersion modeling analyses and revised* (if necessary) model runs; PG&E Response As described in the response to RAl-3a, no corrections are required.

NRC ARCB-RAl-3d update (if necessary) any previously submitted data recovery statistics or summaries of time periods during which data substitution was state_r:J to have occurred; and PG&E Response The previously submitted data recovery statistics of the time periods during which data substitution was stated to have occurred are bounded by the updated RG 1.23-formatted data. Therefore, the data submitted do not need to be updated.

As noted in the RAl-1 d and RAl-2c responses, the updated ARCON96 hourly data set has 280 additional missing values of 10-m wind speed and wind direction since the previously submitted data set had contained substituted values based on the 76-m wind speed and wind direction data. There are also 118 additional missing values of stability class in the updated ARCON96 hourly data set since the previously submitted data set had substituted values. The updated ARCON96 data set still exceeds the "90 percent data recovery" guidance identified in RG 1.23, Revision 1, for the 2007-2011 data period. ,

NRC ARCB-RAl-3e update (if necessary) the UFSAR and LAR 15-03 discussions.

PG&E Response As described in the response to RAl-3a, no updates are required.

15 of 53

Enclosure PG&E Letter DCL-16-044

- NRC ARCB-RAl-4 As indicated previously, the NRG staff is continuing to evaluate the appropriateness of.

determining atmospheric stability class based on the DEL T1 measurements monitored on the primary Met tower (i.e., the verlical temperature differences between the 46- ancf 10-m measurement levels), when appropriate, in lieu of the DEL T3 measurements between 76 and 10 mas used in the current licensing basis. To facilitate the staffs review, the licensee should address the following technical issues:

NRC ARCB-RAl-4a All 116 accident scenarios evaluated by the licensee with the ARCON96 dispersion model to estimate onsite impacts at the CR and TSC air intakes have been assumed to be ground-level releases consistent with the guidance in Regulatory Positions C.3.2.1 and C.3.2.2 of RG 1.194. Of these, only 14 (or about 12%) have been assigned a release height of 74. 1 m. The remainder of the modeled release heights and all of the receptor (intake) elevations are well within the verlical layer covered by the DEL T1 temperature difference measurements. Under the ground-level release assumption, ARCON96 does not consider release velocity and all effluent verlical velocities appear to have been assigned a value of zero (0.00 m!sec). The ARCON96 model does not calculate plume rise due .to "buoyancy or mechanical jet effects." However, the NRG staff understands that the LAR submittal indicates accident releases from the main steam safety valves and the 10% atmospheric dump valves would have significant verlical velocities. Of the remaining onsite accident release scenarios, confirm whether which (if any) of these would be subject to significant buoyancy and/or mechanical plume rise effects during parl or all of the accident release duration.

PG&E Response Aside from the Main Steam Safety Valves (MS.SVs) and the 10 percent Atmospheric Dump Valves (ADVs), no other onsite post-accident environmental release points (or accident release scenarios) would be subject to significant buoyancy or mechanical plume rise effects during part or all of the accident release duration.

NRC ARCB-RAl-4b Provide any additional documentation (including NRG staff interactions and correspondence) regarding the specification and rationale for measuring the verlical temperature difference between 46 and 10 m and the intended application(s) of those data.

PG&E Response The vertical temperature difference between 46-m and 10-m from the primary Met tower

.is available on the Emergency Assessment and Response System (EARS) and the plant process computer (PPG) for both units. The Met tower temperature instrumentation is discussed in numerous documents as being available, but the vertical 16 of 53

Enclosure PG&E Letter DCL-16-044 temperature difference between 46-m and 10-m from the Met tower is not described as being utilized to perform any dose analysis functions. .

Additional documentation regarding the specification and rationale for measuring the vertical temperature difference between 46-m and 10-m and the intended application(s) of those data is provided below.

• The UFSAR includes in Section 2.3, "Meteorology," analysis of historical vertical temperature difference data between 76-m and 10-m collected in the late 1960s and early 1970s. Temperature instrumentation at the 46-m location is mentioned in UFSAR Section 2.3 as being installed but no use for the data is identified.

• Equipment Control Guideline (ECG) 40.0, "Meteorological Monitoring," identifies Met tower instrumentation that is required to be available at alrtimes to .ensure the capabijity to provide Met data to evaluate need for initiating protective measures to protect the health and safety of the public. The Met data available are consistent with the recommendations of Safety Guide 23, "Onsite Meteorological Programs," February 1972 (which-is the initial version of RG 1.23). The 10-m m differential air temperature instrumentation is included in Table 40.1-1, which lists Met tower instrumentatiop along with the 10-m m differential temperature indication. The Bases section of the ECG states that "differential air temperature is used to derive the vertical wind stability input for radiological release dose assessment." The ECG Bases section does not specifically state which of the two differential temperature indications are used for dose assessment. For additional explanation on which set of instrumentation is used to determine the vertical wind stability class, refer to the response to RAl-4c.

• In a letter to the NRC dated January 13, 1981 (prior to plant operations), PG&E provided additional information in response to a request from the NRC on the DCPP Site Emergency Plan. The information included a description of the emergency facilities and equipment. Included in the description of the emergency equipment is the 46-m temperature *instrumentation, but no description of its use is included in the letter.

• In a letter dated August 14, 1985, the NRC provid~d the results of an inspection of the DCPP Emergency Response Facilities. Described in this inspection report are the Met data available at the TSC, which include the "vertical temperature difference data between 10 and 46 meter levels and between 10 and 76 meter _

levels." No use for the Met data is provided in the inspection report.

• As part of PG&E's ongoing license renewal effort, the NRC RAI dated July 6, 2010, requested PG&E to "justify that ~he meteorological data used in the

[Severe Accident Mitigation Alternative] SAMA analysis (collected at 10 meters) are higfJ quality data representative of the Diablo Canyon site and are not adversely affected by the siting of the meteorological tower." PG&E responded to the RAI in Letter DCL-10-082, "Response to NRC Letter dated July 6, 2010, 17 of 53

Enclosure PG&E Letter DCL-16-044 Request for Additional Information for the Applicant's Environmental Report -

Operating License Renewal Stage," dated August 2, 2010. To evaluate the siting of the primary Met tower, PG&E examined Met data from before and after the addition of the Simulator Building including wind rose plots at DCPP and vertical temperature differences. PG&E stated that vertical temperature data are calculated- between the 10-m level and the 76-m level and the 10-m and 46-m level of the primary Met tower. The analysis of the impact of the Simulator Building included in this PG&E letter only used the 10-m m historical vertical temperature differential data (did not use 10-m m data).

In conclusion, the additional documentation regarding the specification and rationale for measuring the vertical temperature difference between 46-m and 10-m does not specify an application for the data other than it be available.

NRC ARCB-RAl-4c Confirm whether vertical temperature differences between the 46- and 10-m measurement levels (i.e., DELT1) on the primary Met tower are relied on (even as a back-up source of information) by DCPP for characterizing atmospheric stability for purposes of emergency preparedness and planning. If so, explain the situation(s) under which this information would be used.

PG&E Response The vertical temperature differences between the 46-m and 10-m measurement levels

• on the primary Met tower is not relied on (even as a backup source of information) for

• any aspect of performing .accident dose assessment calculations at DCPP.

The EARS obtains the 46-m (as well as the 10-m and 76-m) temperature in degrees Celsius (°C) from the primary Met tower computer and forwards the value to the EARS and PPC servers. This 46-m temperature value is displayed on the Unit 1 and Unit 2 PPCs on the meteorology page and is also displayed on the Plant Data Network Server web application.

The vertical stability class is calculated by the primary tower meteorology computer based on 10-m and 76-m temperature delta-T; the horizontal stability class is based on the sigma theta value of wind direction on the 10-m and 76-m anemometers. The calculation does not use the 46-m temperature data for vertical stability class determination.

The vertical stability class is calculated by the backup tower meteorology computer based on 10-rn and 60-m temperature delta-T; the horizontal stability class is based on sigma theta of wind direction on the 10-m and 60-m anemometers. The backup tower does not have an intermediate elevation temperature sensor. '

The Meteorological Information and Dose Assessment System (MIDAS) emergency response dose assessment software program obtains primary Met tower and backup 18 of 53

Enclosure PG&E Letter DCL-16-044 Met tower input data in automatic mode. These MIDAS program data points include the actual vertical and horizontal stability class; they do not include tower temperature data.

DCPP's manual dose assessment dispersion calculation procedure provides instructions for determining the vertical stability class based on RG 1.23, Revision 1, Section 2.2, "Table 1 Classification of Atmospheric Stability." The procedure includes three tables; one with °C/1 oo~m, one adjusted for degrees °C/6_6-m (for the 76-m primary Met tower), and one adjusted for degrees °C/50-m (for the 60-m backup Met tower). - The procedure does not use the primary tower 46-m temperatures for calculating vertical stability.

In all of the above instances, the primary Met tower 46-m temperature is not.used in any capacity for performing accident dose assessment calculations or emergency response consequence assessment calculations at DCPP.

References:

• 1. PG&E Letter DCL-15-069, "License Amendment Request 15-03, 'Application of Alternative Source Term,"' dated June 17, 2015 (ADAMS Accession No. ML15176A539)

2. PG&E Letter DCL-15-105, "Supplement to License Ame.ndm~nt Request 15-03,

'Application of Alternative Source Term,"' dated August 31, 2015 (ADAMS Accession No. ML15243A363) * '

3. E-mail from NRG Project Manager Siva P. Lingam, "Diablo Canyon 1 and 2-Requests for Additional Information for License Amendment Request 15-03 to

• Adopt the Alternative Source Term per 10 CFR'50.67 (TAC Nos. MF6399 and MF6400)," dated October 1, 2015 (ADAMS Accession No. ML15278A049)

4. PG&E Letter DCL-15:.130, "Response to NRG Request for Additional Information Regarding License Amendment Request 15-03, 'Application of Alternative Source Term,"' dated November 2, 2015 (ADAMS Accession No. ML15321A235)

5. E-mail from NRG Project Man~ger Siva P. Lingam, "Diablo Canyon 1 and 2 - Met Data Second ~ound of Requests for Additional Information for License Amendment Request 15-03 to Adopt the Alternative Source Term per 10 CFR 50.67 (TAC Nos. MF6399 and MF640," dated February 17, 2016 (ADAMS Accession No. ML16048A232)

6. PG&E Letter DCL-15-152, "Response to NRG Request for Additional Information Regarding License Amendment Request 15-03, 'Application of Alternative Source Term,'" dated December 17, 2015 (ADAMS Accession Numbers ML16004A354, ML16004A355, ML16004A356, ML16004A357, ML16004A359, and ML16004A361}

19 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 1-f' DCPP Unit 1 - Control Room Atmospheric Dispersion Factor (sec/m 3 ) Comparisons 2-8 8-24 4-30 Release Point and On-Site Receotor 0-2 hours hours hours 1-4 davs davs Unit 1 Containment EdQe to Unit 1 Control Room (CR) Normal Intake 1.28E-03 7.12E-04 2.87E-04 2.90E-04 2.84E-04 RG 1.23 Met Data 1.44E-03 7.03E-04 3.00E-04 3.06E-04 3.04E-04 Percent Change 12.5 -1 .3 4.5 5.5 7.0 Unit 1 Containment EdQe to Unit 2 CR Normal Intake 6.52E-04 3.51 E-04 1.51 E-04 1.49E-04 1.37E-04 RG 1.23 Met Data 6.41 E-04 3.51 E-04 1.49E-04 1.49E-04 1.36E-04 Percent Chanqe -1 .7 0.0 -1 .3 0.0 -0 .7 Unit 1 Containment Edqe to Unit 1 CR Emeroencv lntake 4 4.11E-04 2.30E-04 9.62E-05 8.69E-05 7.03E-05 RG 1.23 Met Data 4.09E-04 2.31E-04 9.54E-05 8.61E-05 7.04E-05 Percent Chanae -0 .5 0.4 -0.8 -0.9 0.1 Unit 1 Containment Edge to Unit 2 CR Emergency lntake 4 1.67E-04 7.95E-05 2.63E-05 2.81 E-05 2.34E-05 RG 1.23 Met Data 1.57E-04 7.82E-05 2.57E-05 2.71 E-05 2.32E-05 Percent ChanQe -6.0 -1 .6 -2.3 -3 .6 -0.9 Unit 1 Containment Edqe to CR Center 8.85E-04 4.43E-04 1.75E-04 1.??E-04 1.65E-04 RG 1.23 Met Data 9.21 E-04 4.38E-04 1.??E-04 1.80E-04 1.67E-04 Percent Change 4.1 -1.1 1.1 1.7 1.2 Unit 1 Plant Vent to Unit 1 CR Normal Intake 1.67E-03 1.22E-03 4.90E-04 4.90E-04 4.44E-04 RG 1.23 Met Data 1.67E-03 1.22E-03 4.93E-04 4.89E-04 4.36E-04 Percent Chanae 0.0 0.0 0.6 -0 .2 -1.8 Unit 1 Plant Vent to Unit 2 CR Normal Intake 9.10E-04 6.57E-04 2.68E-04 2.62E-04 2.45E-04 RG 1.23 Met Data 9.08E-04 6.53E-04 2.69E-04 2.62E-04 2.38E-04 Percent Chanoe -0.2 -0.6 0.4 0.0 -2 .9 4

Unit 1 Plant Vent to Unit 1 CR EmerQency lntake 5.59E-04 3.38E-04 1.32E-04 1.12E-04 8.38E-05 RG 1.23 Met Data 5.56E-04 3.33E-04 1.29E-04 1.11 E-04 8.34E-05 Percent Chanoe -0.5 -1 .5 -2 .3 -0 .9 -0 .5 20 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 1-1 5 DCPP Unit 1 - Control Room Atmospheric Dispersion Factor (sec/m 3 ) Comparisons 2-8 8-24 4-30 Release Point and On-Site Receotor 0-2 hours hours hours 1-4 davs davs Unit 1 Plant Vent to Unit 2 CR Emerqency lntake4 2.26E-04 1.48E-04 5.40E-05 5.47E-05 4.45E-05 RG 1.23 Met Data 2.22E-04 1.47E-04 5.44E-05 5.52E-05 4.45E-05 Percent Chanqe -1.8 -0 .7 0.7 0.9 0.0 Unit 1 Plant Vent to CR Center 1.26E-03 8.96E-04 3.44E-04 3.44E-04 2.99E-04 RG 1.23 Met Data 1.25E-03 8.93E-04 3.47E-04 3.46E-04 2.98E-04 Percent Chanqe -0.8 -0 .3 0.9 0.6 -0.3 Unit 1 Containment Penetration (GE Area) to Unit 1 CR Normal Intake 6.84E-03 3.08E-03 1.21 E-03 1.12E-03 8.75E-04 RG 1.23 Met Data 6.59E-03 2.81 E-03 1.16E-03 1.07E-03 8.31 E-04 Percent Chanae -3.7 -8.8 -4.1 -4 .5 -5.0 Unit 1 Containment Penetration (GE Area) to Unit 2 CR Normal Intake 2.24E-03 1.15E-03 3.98E-04 3.89E-04 3.20E-04 RG 1.23 Met Data 2.07E-03 1.13E-03 3.73E-04 3.78E-04 3.05E-04 Percent Chanqe -7.6 -1.7 -6.3 -2 .8 -4 .7 Unit 1 Containment Penetration (GE Area) to Unit 1 CR Emen::iency lntake 4 3.75E-04 2.33E-04 9.12E-05 8.45E-05 6.62E-05 RG 1.23 Met Data 3.67E-04 2.31 E-04 9.02E-05 8.38E-05 6.42E-05 Percent Chanqe -2.1 -0.9 -1 .1 -0 .8 -3 .0 Unit 1 Conta inment Penetration (GE Area) to Unit 2 CR Emerqency lntake 4 2.55E-04 1.25E-04 4.42E-05 4.38E-05 3.55E-05 RG 1.23 Met Data 2.39E-04 1.20E-04 4.27E-05 4.22E-05 3.39E-05 Percent Chanqe -6.3 -4.0 -3.4 -3.7 -4.5 Unit 1 Containment Penetration (GE Area) to CR Center 3.22E-03 1.42E-03 5.54E-04 5.20E-04 4.21 E-04 RG 1.23 Met Data 3.01E-03 1.33E-03 5.43E-04 4.93E-04 4.01 E-04 Percent Chanqe -6.5 -6 .3 -2.0 -5.2 -4 .8 Unit 1 Containment Penetration (GW/FW Area) to Unit 1 CR Normal Intake 4.90E-03 3.45E-03 1.37E-03 1.37E-03 1.28E-03 RG 1.23 Met Data 4.86E-03 3.43E-03 1.35E-03 1.37E-03 1.25E-03 Percent Chanqe -0.8 -0.6 -1.5 0.0 -2.3 21 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 1-1 5 DCPP Unit 1 - Control Room Atmospheric Dispersion Factor (sec/m 3 ) Comparisons 2-8 8-24 4-30 Release Point and On-Site Receotor 0-2 hours hours hours 1-4 davs davs Unit 1 Conta inment Penetration (GW/FW Area) to Unit 2 CR Normal Intake 1.38E-03 9.83E-04 3.92E-04 3.88E-04 3.65E-04 RG 1.23 Met Data 1.35E-03 9.79E-04 3.86E-04 3.84E-04 3.46E-04 Percent Change -2 .2 -0.4 -1 .5 -1 .0 -5.2 4

Unit 1 Containment Penetration (GW/FW Area) to Unit 1 CR Emeraencv lntake 8.20E-04 5.40E-04 2.15E-04 1.87E-04 1.43E-04 RG 1.23 Met Data 8.05E-04 5.32E-04 2.12E-04 1.86E-04 1.40E-04 Percent Change -1 .8 -1 .5 -1.4 -0.5 -2 .1 Unit 1 Containment Penetration (GW/FW Area) to Unit 2 CR Emeraencv lntake4 2.58E-04 1.54E-04 4.95E-05 5.26E-05 4.48E-05 RG 1.23 Met Data 2.40E-04 1.53E-04 4.83E-05 5.20E-05 4.41E-05 Percent Change -7.0 -0 .6 -2.4 -1.1 -1 .6 Unit 1 Containment Penetration (GW/FW Area) to CR Center 2.59E-03 1.81 E-03 7.29E-04 7.15E-04 6.64E-04 RG 1.23 Met Data 2.55E-03 1.80E-03 7.17E-04 7.13E-04 6.50E-04 Percent Change -1.5 -0 .6 -1.6 -0.3 -2 .1 Unit 1 Refueling Water Storage Tank (RWST) Vent to Unit 1 CR Emergency lntake4 3.27E-04 1.90E-04 7.13E-05 6.99E-05 5.76E-05 RG 1.23 Met Data 3.24E-04 1.83E-04 6.94E-05 6.82E-05 5.57E-05 Percent Chanae -0 .9 -3.7 -2 .7 -2.4 -3.3 4

Unit 1 RWST Vent to Unit 2 CR Emeraencv lntake 2.10E-04 9.83E-05 3.73E-05 3.53E-05 2.86E-05 RG 1.23 Met Data 1.88E-04 9.18E-05 3.40E-05 3.28E-05 2.69E-05 Percent Change -10.5 -6 .6 -8 .8 -7.1 -5.9 Unit 1 RWST Vent to CR Center 1.07E-03 4.86E-04 1.99E-04 1.75E-04 1.43E-04 RG 1.23 Met Data 1.01 E-03 4.26E-04 1.85E-04 1.62E-04 1.31 E-04 Percent Chanae -5.6 -12.3 -7.0 -7.4 -8.4 22 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 1-1 5 DCPP Unit 1 - Control Room Atmospheric Dispersion Factor (sec/m 3) Comparisons 0-2 2-8 8-24 1-4 4-30 Release Point and On-Site Receotor hours hours hours davs davs Unit 1 MSSVs to Unit 1 CR Normal Intake 1 * :< NIA NIA NIA NIA NIA Unit 1 MSSVs to Unit 2 CR Normal Intake" 4.29E-03 2.76E-03 1.04E-03 1.06E-03 9.46E-04 RG 1.23 Met Data 4.05E-03 2.65E-03 1.02E-03 1.02E-03 8.95E-04 Percent Chanqe -5.6 -4.0 -1 .9 -3.8 -5.4 Unit 1 MS SVs to Unit 1 CR Emergency lntakeJ, 4 4.66E-04 2.92E-04 1.16E-04 1.04E-04 8.08E-05 RG 1.23 Met Data 4.52E-04 2.86E-04 1.14E-04 1.01 E-04 7.82E-05 Percent Chanqe -3.0 -2.1 -1 .7 -2 .9 -3 .2 Unit 1 MSSVs to Unit 2 CR Emerqencv Intake"* q 3.14E-04 1.53E-04 5.12E-05 5.29E-05 4.38E-05 RG 1.23 Met Data 2.75E-04 1.49E-04 4.79E-05 5.02E-05 4.14E-05 Percent Chanqe -12.4 -2 .6 -6.4 -5 .1 -5.5 Unit 1 MSSVs to CR CenterJ 1.39E-02 7.40E-03 2.38E-03 2.56E-03 2.15E-03 RG 1.23 Met Data 1.23E-02 7.28E-03 2.21 E-03 2.43E-03 2.06E-03 Percent Chanqe -11.5 -1.6 -7.1 -5 .1 -4.2 Unit 1 10 Percent ADVs to Unit 1 CR Normal Intake 1

• L NIA NIA NIA NIA NIA Unit 1 10 Percent ADVs to Unit 2 CR Normal lntakeJ 4.30E-03 2.79E-03 1.05E-03 1.06E-03 9.49E-04 RG 1.23 Met Data 4.06E-03 2.66E-03 1.03E-03 1.02E-03 9.03E-04 Percent Change -5.6 -4.7 -1.9 -3.8 -4.8 Unit 1 10 Percent ADVs to Unit 1 CR Emergency lntakeJ, 4 4.66E-04 2.92E-04 1.16E-04 1.04E-04 8.07E-05 RG 1.23 Met Data 4.52E-04 2.86E-04 1.14E-04 1.01 E-04 7.82E-05 Percent Chanqe -3.0 -2 .1 -1.7 -2 .9 -3.2 4

Unit 1 10 Percent ADVs to Unit 2 CR Emergency lntakeJ, 3.13E-04 1.54E-04 5.13E-05 5.30E-05 4.39E-05 RG 1.23 Met Data 2.75E-04 1.50E-04 4.82E-05 5.03E-05 4.15E-05 Percent Chanae -12.1 -2 .6 -6.0 -5.1 -5.5 23 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 1-1:i DCPP Unit 1 - Control Room Atmospheric Dispersion Factor (sec/m 3) Comparisons 0-2 2-8 8-24 1-4 4-30 Release Point and On-Site Rece otor hours hours hours davs davs Unit 1 10 Percent ADVs to CR Center~ 1.39E-02 7.45E-03 2.39E-03 2.59E-03 2.15E-03 RG 1.23 Met Data 1.23E-02 7.34E-03 2.22E-03 2.45E-03 2.08E-03 Percent Change -11 .5 -1 .5 -7.1 -5.4 -3 .3 Unit 1 MSLB Location to Unit 1 CR Normal lntake 1 N/A N/A N/A N/A N/A Unit 1 MSLB Location to Unit 2 CR Normal Intake 4.23E-03 2.90E-03 1.13E-03 1.11 E-03 1.02E-03 RG 1.23 Met Data 4.07E-03 2.86E-03 1.11 E-03 1.10E-03 9.70E-04 Percent Chanqe -3.8 -1.4 -1.8 -0 .9 -4.9 Unit 1 MSLB Location to Unit 1 CR Emergency Intake" 4.35E-04 2.94E-04 1.15E-04 1.01 E-04 7.76E-05 RG 1.23 Met Data 4.30E-04 2.89E-04 1.14E-04 1.00E-04 7.63E-05 Percent Chanqe -1 .1 -1.7 -0.9 -1.0 -1 .7 Unit 1 MSLB Location to Unit 2 CR Emergency lntake 4 3.06E-04 1.54E-04 5.19E-05 5.32E-05 4.38E-05 RG 1.23 Met Data 2.74E-04 1.54E-04 4.98E-05 5.12E-05 4.20E-05 Percent Chanqe -10.5 0.0 -4 .0 -3.8 -4 .1 Unit 1 MSLB Location to CR Center 1.24E-02 7.10E-03 2.24E-03 2.43E-03 2.07E-03 RG 1.23 Met Data 1.14E-02 7.05E-03 2.19E-03 2.37E-03 1.98E-03 Percent Chanqe -8.1 -0.7 -2 .2 -2 .5 -4 .3 Unit 1 Fuel Handling Building (FHB) to Unit 1 CR Normal Intake 6.98E-03 - - - -

RG 1.23 Met Data 6.68E-03 - - - -

Percent Chanqe -4 .3 Unit 1 FHB to Unit 2 CR Normal Intake 2.93E-03 - - - -

RG 1.23 Met Data 2.69E-03 - - - -

Percent Change -8.2 Unit 1 FHB to Unit 1 CR Emergency lntake 4

3.31E-04 - - - -

RG 1.23 Met Data 3.28E-04 - - - -

Percent Change -0.9 24 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 1-1 5 DCPP Unit 1 - Control Room Atmospheric Dispersion Factor (sec/m 3) Comparisons 0-2 2-8 8-24 1-4 4-30 Release Point and On-Site Receotor hours hours hours davs davs Unit 1 FHB to Unit 2 CR Emergency lntake 4 2.56E-04 - - - -

RG 1.23 Met Data 2.39E-04 - - - -

Percent Change -6 .6 Unit 1 FHB to CR Center 3.78E-03 - - - -

RG 1.23 Met Data 3.54E-03 - - - -

Percent Change -6 .3 Unit 1 Equipment Hatch to Unit 1 CR Normal Intake 2.61 E-02 - - - -

RG 1.23 Met Data 2.43E-02 - - - -

Percent Change -6 .9 Unit 1 Equipment Hatch to Unit 2 CR Normal Intake 2.88E-03 - - - -

RG 1.23 Met Data 2.67E-03 - - - -

Percent Chanoe -7.3 Unit 1 Equipment Hatch to Unit 1 CR Emergency lntake 4

4 .36E-04 - - - -

RG 1.23 Met Data 4.32E-04 - - - -

Percent Change -0 .9 Unit 1 Equipment Hatch to Unit 2 CR Emergency lntake 4

2.64E-04 - - - -

RG 1.23 Met Data 2.45E-04 - - - -

Percent Change -7 .2 Unit 1 Equipment Hatch to CR Center 5.51 E-03 - - - -

RG 1.23 Met Data 5.06E-03 - - - -

Percent Change -8 .2 25 of 53

Enclosure PG&E Letter DCL-16-044

1. ARCON96-based X/Q values are not applicable for these cases given that the horizontal distance from the source to the receptor is 1.5-m (which is much less than the 10-m required by the ARCON96 methodology).

2. Due to the proximity of the release from the MSSVs and 10 Percent ADVs to the normal operation CR intake of the affected unit, and due to the high vertical velocity of the steam discharge from the MSSVs and10 Percent ADVs , the resultant plume from the MSSVs and 10 Percent ADVs will not contaminate the normal operation CR intake of the affected unit.

3. For releases from the MSSVs and 10 percent ADVs (which are uncapped, vertically oriented, and have a high vertical velocity discharge for the first 10.73 hrs of the accident), a X/Q reduction factor of 5 is applicable to the values listed above. Since X/Q values are averaged over the identified period (i.e., 0-2 hrs, 2-8 hrs, 8-24 hrs, etc.) , and the vertical velocity has been estimated only up to 10. 73 hrs, application of the factor of 5 reduction is not appropriate for X/Q values applicable to averaging periods beyond the 2-8 hrs averaging period . For assessment of an environmental release between T=8 to T=10 .73 hrs, continued use of the 2-8 hr X/Q (with the factor of 5 reduction) is acceptable and conservative.

4. The more favorable X/Q value presented above for the CR Pressurization intakes is further reduced by a factor of 4 to address the "dual intake" credit, the capability of initial selection of the cleaner intake, and the expectation that the operator will manually make the proper intake selection throughout the event.

5. X/Q values for RWST vent releases to the CR normal intakes are not needed for the dose calculations since the normal intakes are isolated prior to releases occurring from the RWST vent.

26 of 53

Enclosure PG&E Letter DCL- 16-044 TABLE 1-25 DCPP Unit 2 - Control Room Atmospheric Dispersion Factor (sec/m 3 ) Comparisons 8-24 Release Point and On-Site Receotor 0-2 hours 2-8 hours hours 1-4 davs 4-30 davs Unit 2 Containment Edqe to Unit 2 CR Normal Intake 1.96E-03 9.42E-04 4.48E-04 3.98E-04 3. 18E-04 RG 1.23 Met Data 1.99E-03 9.59E-04 4.60E-04 4.04E-04 3.20E-04 Percent Chanqe 1.5 1.8 2.7 1.5 0.6 Unit 2 Containment Edqe to Unit 1 CR Normal Intake 6.93E-04 3.84E-04 1.67E-04 1.42E-04 1.08E-04 RG 1.23 Met Data 6.89E-04 3.85E-04 1.66E-04 1.41 E-04 1.08E-04 Percent Chanqe -0.6 0.3 -0.6 -0 .7 0.0 Unit 2 Containment Edqe to Unit 1 CR Emerqency lntake4 1.70E-04 1.06E-04 4.23E-05 3.81 E-05 2.95E-05 RG 1.23 Met Data 1.66E-04 1.05E-04 4.19E-05 3.73E-05 2.93E-05 Percent Chanqe -2.4 -0.9 -0 .9 -2.1 -0.7 Unit 2 Containment Edqe to Unit 2 CR Emerqencv lntake 4 3.85E-04 1.47E-04 5.94E-05 5.84E-05 4.84E-05 RG 1.23 Met Data 3.78E-04 1.47E-04 5.99E-05 5.87E-05 4.90E-05 Percent Change -1.8 0.0 0.8 0.5 1.2 Unit 2 Containment Edqe to CR Center 1.08E-03 5.46E-04 2.47E-04 2.12E-04 1.68E-04 RG 1.23 Met Data 1.09E-03 5.49E-04 2.47E-04 2.12E-04 1.70E-04 Percent Chanqe 0.9 0.5 0.0 0.0 1.2 Unit 2 Plant Vent to Unit 2 CR Normal Intake 1.51E-03 9.41 E-04 3.86E-04 3.23E-04 2.23E-04 RG 1.23 Met Data 1.49E-03 9.29E-04 3.80E-04 3.16E-04 2.21 E-04 Percent Chanqe -1.3 -1 .3 -1.6 -2 .2 -0 .9 Unit 2 Plant Vent to Unit 1 CR Normal Intake 7.88E-04 4.86E-04 2.01 E-04 1.69E-04 1.17E-04 RG 1.23 Met Data 7.79E-04 4.80E-04 1.98E-04 1.65E-04 1.15E-04 Percent Chanqe -1. 1 -1 .2 -1.5 -2.4 -1 .7 Unit 2 Plant Vent to Unit 1 CR Emergency lntake 4 2.03E-04 1.29E-04 5.13E-05 4.32E-05 3.19E-05 RG 1.23 Met Data 2.02E-04 1.27E-04 5.11E-05 4.20E-05 3.15E-05 Percent Chanqe -0.5 -1 .6 -0.4 -2.8 -1 .3 27 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 1-25 DCPP Unit 2 - Control Room Atmospheric Dispersion Factor (sec/m 3 ) Comparisons 8-24 Release Point and On-Site Receotor 0-2 hours 2-8 hours hours 1-4 davs 4-30 davs Unit 2 Plant Vent to Unit 2 CR Emerqencv lntake4 5.71E-04 2.96E-04 1.20E-04 1.04E-04 8.19E-05 RG 1.23 Met Data 5.61 E-04 2.91 E-04 1.16E-04 1.02E-04 8.03E-05 Percent Change -1 .8 -1 .7 -3 .3 -1 .9 -2.0 Unit 2 Plant Vent to CR Center 1.13E-03 7.08E-04 2.85E-04 2.39E-04 1.70E-04 RG 1.23 Met Data 1. 12E-03 6.99E-04 2.82E-04 2.34E-04 1.68E-04 Percent Chanqe -0.9 -1.3 -1.1 -2 .1 -1 .2 Unit 2 Containment Penetration (GE Area) to Unit 2 CR Normal Intake 6.71 E-03 3.12E-03 1.21 E-03 1.22E-03 1.02E-03 RG 1.23 Met Data 6.60E-03 3.01E-03 1.17E-03 1.20E-03 1.01 E-03 Percent Chanqe -1.6 -3 .5 -3 .3 -1 .6 -1 .0 Unit 2 Containment Penetration (GE Area) to Unit 1 CR Normal Intake 2.14E-03 1.39E-03 5.72E-04 4.83E-04 3.62E-04 RG 1.23 Met Data 2.08E-03 1.38E-03 5.62E-04 4.76E-04 3.59E-04 Percent Chanqe -2.8 -0.7 -1 .7 -1.4 -0.8 4

Unit 2 Containment Penetration (GE Area) to Unit 1 CR Emerqencv lntake 2.28E-04 1.60E-04 6.25E-05 5.52E-05 4.21 E-05 RG 1.23 Met Data 2.26E-04 1.57E-04 6.15E-05 5.47E-05 4.08E-05 Percent Change -0.9 -1.9 -1.6 -0.9 -3 .1 4

Unit 2 Containment Penetration (GE Area) to Unit 2 CR Emerqencv lntake 3.97E-04 1.76E-04 6.93E-05 6.44E-05 5.27E-05 RG 1.23 Met Data 3.74E-04 1.67E-04 6.72E-05 6.14E-05 5.08E-05 Percent Chanqe -5 .8 -5.1 -3 .0 -4 .7 -3 .6 Unit 2 Containment Penetration (GE Area) to CR Center 3.16E-03 1.85E-03 7. 17E-04 6.84E-04 5.43E-04 RG 1.23 Met Data 3.09E-03 1.83E-03 7.22E-04 6.74E-04 5.35E-04 Percent Change -2.2 -1. 1 0.7 -1 .5 -1.5 Unit 2 Containment Penetration (GW/FW Area) to Unit 2 CR Normal Intake 3.55E-03 1.19E-03 4.82E-04 4.56E-04 3.03E-04 RG 1.23 Met Data 3.45E-03 1.14E-03 4.70E-04 4.42E-04 2.93E-04 Percent Chanqe -2.8 -4 .2 -2 .5 -3 .1 -3 .3 28 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 1-2:i DCPP Unit 2 - Control Room Atmospheric Dispersion Factor (sec/m 3 ) Comparisons 8-24 Release Point and On-Site Receotor 0-2 hours 2-8 hours hours 1-4 davs 4-30 davs Unit 2 Containment Penetration (GW/FW Area) to Unit 1 CR Normal Intake 1.22E-03 6.26E-04 2.53E-04 2.12E-04 1.41E-04 RG 1.23 Met Data 1.20E-03 6.21 E-04 2.49E-04 2.09E-04 1.41 E-04 Percent ChanQe -1 .6 -0.8 -1 .6 -1.4 0.0 Unit 2 Containment Penetration (GW/FW Area) to Unit 1 CR Emerqencv lntake4 2.28E-04 1.62E-04 6.58E-05 5.43E-05 3.99E-05 RG 1.23 Met Data 2.26E-04 1.59E-04 6.50E-05 5.36E-05 3.96E-05 Percent Chanqe -0 .9 -1 .9 -1 .2 -1 .3 -0.8 Unit 2 Containment Penetration (GW/FW Area) to Unit 2 CR Emerqencv lntake4 8.64E-04 4.23E-04 1.50E-04 1.48E-04 1.20E-04 RG 1.23 Met Data 8.08E-04 4.07E-04 1.43E-04 1.42E-04 1.14E-04 Percent ChanQe -6.5 -3.8 -4 .7 -4.1 -5.0 Unit 2 Containment Penetration (GW/FW Area) to CR Center 2.21 E-03 1.17E-03 4 .70E-04 3.90E-04 2.61 E-04 RG 1.23 Met Data 2.19E-03 1.16E-03 4.56E-04 3.83E-04 2.58E-04 Percent Chanqe -0.9 -0.9 -3.0 -1.8 -1.1 Unit 2 RWST Vent to Unit 1 CR Emerqencv lntake 4 1.91 E-04 1.21 E-04 4.58E-05 4.39E-05 3.53E-05 RG 1.23 Met Data 1.89E-04 1.17E-04 4 .52E-05 4.30E-05 3.40E-05 Percent ChanQe -1 .0 -3 .3 -1 .3 -2.1 -3 .7 Unit 2 RWST Vent to Unit 2 CR Emerqency lntake4 3.29E-04 1.61 E-04 6.10E-05 5.53E-05 4.45E-05 RG 1.23 Met Data 3.17E-04 1.40E-04 5.64E-05 5.12E-05 4.16E-05 Percent ChanQe -3 .6 -13 .0 -7.5 -7.4 -6 .5 Unit 2 RWST Vent to CR Center 1.07E-03 5.80E-04 2.18E-04 2.19E-04 1.79E-04 RG 1.23 Met Data 1.05E-03 5.55E-04 2.12E-04 2.12E-04 1.72E-04 Percent ChanQe -1 .9 -4.3 -2.8 -3 .2 -3.9 29 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 1-2:.

DCPP Unit 2 - Control Room Atmospheric Dispersion Factor (sec/m 3) Comparisons Source and Receotor 0-2 hours 2-8 hours 8-24 hours 1-4 davs 4-30 davs Unit 2 MSSVs to Unit 1 CR Normal lntakej 3.87E-03 2.42E-03 9.89E-04 8.17E-04 6.09E-04 RG 1.23 Met Data 3.80E-03 2.36E-03 9.80E-04 8.00E-04 5.99E-04 Percent Chanqe -1.8 -2 .5 -0.9 -2 .1 -1 .6 Unit 2 MSSVs to Unit 2 CR Normal Intake' *" NIA NIA NIA NIA NIA Unit 2 MSSVs to Unit 1 CR Emergency lntake"*4 2.89E-04 1.91 E-04 7.45E-05 6.62E-05 5.08E-05 RG 1.23 Met Data 2.79E-04 1.87E-04 7.33E-05 6.50E-05 4.89E-05 Percent Change -3 .5 -2.1 -1.6 -1.8 -3.7 Unit 2 MSSVs to Unit 2 CR Emergency lntake"*4 4.90E-04 2.29E-04 8.24E-05 8.07E-05 6.49E-05 RG 1.23 Met Data 4.39E-04 2.14E-04 7.68E-05 7.54E-05 6.09E-05 Percent Chanqe -10.4 -6.6 -6.8 -6 .6 -6 .2 Unit 2 MSSVs to CR Center3 1.22E-02 8.10E-03 3.27E-03 2.76E-03 2.08E-03 RG 1.23 Met Data 1.19E-02 7.90E-03 3.22E-03 2.68E-03 2.05E-03 Percent Chanqe -2 .5 -2 .5 -1 .5 -2.9 -1.4 Unit 2 10 Percent ADVs to Unit 1 CR Normal lntakej 3.88E-03 2.43E-03 9.94E-04 8.19E-04 6.10E-04 RG 1.23 Met Data 3.82E-03 2.36E-03 9.86E-04 8.01 E-04 6.01 E-04 Percent Chanqe -1 .5 -2.9 -0 .8 -2.2 -1.5 Unit 2 10 Percent ADVs to Unit 2 CR Normal Intake' *" NIA NIA NIA NIA NIA Unit 2 10 Percent ADVs to Unit 1 CR Emergency lntake"* 4 2.87E-04 1.92E-04 7.48E-05 6.61 E-05 5.07E-05 RG 1.23 Met Data 2.??E-04 1.88E-04 7.35E-05 6.49E-05 4.89E-05 Percent Change -3.5 -2.1 -1 .7 -1 .8 -3.6 Unit 2 10 Percent ADVs to Unit 2 CR Emergency lntake"* 4 4.90E-04 2.29E-04 8.24E-05 8.08E-05 6.48E-05 RG 1.23 Met Data 4.39E-04 2.14E-04 7.68E-05 7.54E-05 6.09E-05 Percent Chanqe -10.4 -6.6 -6 .8 -6.6 -6 .2 30 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 1-25 DCPP Unit 2 - Control Room Atmospheric Dispersion Factor (sec/m 3) Comparisons Source and Receotor 0-2 hours 2-8 hours 8-24 hours 1-4 davs 4-30 davs Unit 2 10 Percent ADVs to CR Center~ 1.22E-02 8.16E-03 3.28E-03 2.78E-03 2.09E-03 RG 1.23 Met Data 1.19E-02 7.94E-03 3.23E-03 2.70E-03 2.05E-03 Percent Change -2.5 -2.7 -1.5 -2.9 -1 .9 Unit 2 MSLB Location to Unit 1 CR Normal Intake 3.81 E-03 2.40E-03 1.01 E-03 8.09E-04 5.88E-04 RG 1.23 Met Data 3.75E-03 2.37E-03 1.00E-03 7.93E-04 5.81E-04 Percent Chanqe -1 .6 -1.2 -1.0 -2. 0 -1.2 1

Unit 2 MSLB Location to Unit 2 CR Normal lntake N/A N/A N/A N/A N/A Unit 2 MSLB Location to Unit 1 CR Emerqency Intake" 2.75E-04 1.91 E-04 7.45E-05 6.53E-05 4.86E-05 RG 1.23 Met Data 2.72E-04 1.88E-04 7.40E-05 6.42E-05 4.80E-05 Percent Chanoe -1.1 -1.6 -0.7 -1.7 -1 .2 4

Unit 2 MSLB Location to Unit 2 CR Emergency lntake 4 .76E-04 2.24E-04 8.14E-05 7.94E-05 6.40E-05 RG 1.23 Met Data 4.29E-04 2.19E-04 7.73E-05 7.57E-05 6.11E-05 Percent Chanqe -9 .9 -2 .2 -5.0 -4.7 -4.5 Unit 2 MSLB Location to CR Center 1.09E-02 7.35E-03 3.01 E-03 2.48E-03 1.86E-03 RG 1.23 Met Data 1.08E-02 7.22E-03 3.00E-03 2.44E-03 1.83E-03 Percent Change -0 .9 -1.8 -0 .3 -1.6 -1.6 Unit 2 FHB to Unit 1 CR Normal Intake 2.72E-03 - - - -

RG 1.23 Met Data 2.68E-03 Percent Chanqe -1 .5 Unit 2 FHB to Unit 2 CR Normal Intake 6.98E-03 - - - -

RG 1.23 Met Data 6.68E-03 Percent Chanqe -4.3 Unit 2 FHB to Unit 1 CR Emergency lntake 4

2.49E-04 - - - -

RG 1.23 Met Data 2.45E-04 Percent Chanqe -1 .6 31 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 1-25 DCPP Unit 2 - Control Room Atmospheric Dispersion Factor (sec/m 3) Comparisons Source and Receotor 0-2 hours 2-8 hours 8-24 hours 1-4 davs 4-30 davs Unit 2 FHB to Unit 2 CR Emergency lntake 4 3.50E-04 - - - -

RG 1.23 Met Data 3.23E-04 Percent Chanae -7.7 Unit 2 FHB to CR Center 3.71 E-03 - - - -

RG 1.23 Met Data 3.61 E-03 Percent Chanqe -2 .7 Unit 2 Equipment Hatch to Unit 1 CR Normal Intake 2.49E-03 - - - -

RG 1.23 Met Data 2.47E-03 Percent Change -0.8 Unit 2 Equipment Hatch to Unit 2 CR Normal Intake 2.51 E-02 - - - -

RG 1.23 Met Data 2.48E-02 Percent Chani:ie -1.2 Unit 2 Equipment Hatch to Unit 1 CR Emeri:iencv lntake 4

2.49E-04 - - - -

RG 1.23 Met Data 2.46E-04 Percent Chanae -1.2 Unit 2 Equipment Hatch to Unit 2 CR Emergency lntake 4

4.68E-04 - - - -

RG 1.23 Met Data 4.26E-04 Percent Change -9.0 Unit 2 Equipment Hatch to CR Center 5.19E-03 - - - -

RG 1.23 Met Data 5.09E-03 Percent Chanae -1 .9 32 of 53

Enclosure PG&E Letter DCL-16-044

1. ARCON96-based X/Q values are not applicable for these cases given that the horizontal distance from the source to the receptor is 1.5-m (which is much less than the 10-m required by the ARCON96 methodology) .

2. Due to the proximity of the release from the MSSVs and 1O Percent ADVs to the normal operation CR intake of the affected unit, and due to the high vertical velocity of the steam discharge from the MSSVs and 10 Percent ADVs , the resultant plume from the MSSVs and 10 Percent ADVs will not contaminate the normal operation CR intake of the affected unit.

3. For releases from the MSSVs and 10 Percent ADVs (which are uncapped , vertically oriented and have a high vertical velocity discharge for the first 10.73 hrs of the accident), a XJQ values reduction factor of 5 is applicable . Since X/Q values are averaged over the identified period (i .e., 0-2 hrs, 2-8 hrs, 8-24 hrs, etc.) , and the vertical velocity has been estimated only up to 10.73 hrs, application of the factor of 5 reduction is not appropriate for X/Q values applicable to averaging periods beyond 2-8 hrs. For assessment of an environmental release between T=8 to T=10.73 hrs, continued use of the 2-8 hr X/Q (with the factor of 5 reduction) is both acceptable and conservative.

4. The more favorable X/Q value presented above for the CR Pressurization Intakes is further reduced by a factor of 4 to address the "dual intake" credit, the capability of initial selection of the cleaner intake, and the expectation that the CR operator will manually choose the proper intake selection throughout the event.

5. XJQ values for RWST vent releases to the CR normal intakes are not needed for the dose calculations since the normal intakes are isolated prior to releases occurring from the RWST vent.

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Enclosure PG&E Letter DCL-16-044 TABLE 1-3 DCPP Units 1 and 2 - Technical Support Center Atmospheric Dispersion Factor (sec/m 3) Comparisons 0-2 1-4 Release Point and On-Site Receotor hours 2-8 hours 8-24 hours davs 4-30 davs UNIT 1 Unit 1 Containment Edge to TSC Normal Intake 2.57E-04 1.18E-04 4.27E-05 4.24E-05 3.50E-05 RG 1.23 Met Data 2.45E-04 1.16E-04 4.08E-05 4.17E-05 3.48E-05 Percent Chanqe -4.7 -1 .7 -4.4 -1 .7 -0.6 Unit 1 Containment Edqe to TSC Center 2.90E-04 1.33E-04 4.98E-05 4.83E-05 4.02E-05 RG 1.23 Met Data 2.74E-04 1.31 E-04 4.80E-05 4.70E-05 4.00E-05 Percent Change -5 .5 -1.5 -3.6 -2.7 -0.5 Unit 1 Plant Vent to TSC Normal Intake 3.12E-04 1.77E-04 6.91 E-05 6.29E-05 5.21 E-05 RG 1.23 Met Data 3.04E-04 1.76E-04 6.82E-05 6.21 E-05 5.20E-05 Percent Change -2.6 -0.6 -1.3 -1 .3 -0 .2 Unit 1 Plant Vent to TSC Center 3.54E-04 1.95E-04 7.7 1E-05 6.70E-05 5.67E-05 RG 1.23 Met Data 3.41 E-04 1.94E-04 7.63E-05 6.61 E-05 5.62E-05 Percent Change -3 .7 -0.5 -1.0 -1.3 -0.9 Unit 1 RWST Vent to TSC Normal Intake 2.72E-04 1.27E-04 4.80E-05 4.49E-05 3.71 E-05 RG 1.23 Met Data 2.48E-04 1.15E-04 4.52E-05 4.11E-05 3.40E-05 Percent Chanqe -8.8 -9.4 -5 .8 -8 .5 -8.4 Unit 1 RWST Vent to TSC Center 2.94E-04 1.38E-04 5.40E-05 4.89E-05 3.97E-05 RG 1.23 Met Data 2.76E-04 1.23E-04 5.00E-05 4.53E-05 3.65E-05 Percent Change -6 .1 -1 0.9 -7.4 -7.4 -8 .1 Unit 1 Containment Penetration (GE Area) to TSC Normal Intake 3.64E-04 1.74E-04 6.55E-05 6.14E-05 5.00E-05 RG 1.23 Met Data 3.51 E-04 1.61 E-04 6.43E-05 5.89E-05 4.83E-05 Percent Change -3.6 -7.5 -1.8 -4 .1 -3.4 Unit 1 Containment Penetration (GE Area) to TSC Center 4.27E-04 1.91 E-04 7.45E-05 6.84E-05 5.62E-05 RG 1.23 Met Data 4.05E-04 1.80E-04 7.26E-05 6.60E-05 5.37E-05 Percent Chanoe -5.2 -5.8 -2.6 -3 .5 -4.4 34 of 53

Enclosure PG&E Letter DCL- 16-044 TABLE 1-3 DCPP Units 1 and 2 - Technical Support Center Atmospheric Dispersion Factor (sec/m 3) Comparisons 0-2 1-4 Release Point and On-Site Receotor hours 2-8 hours 8-24 hours davs 4-30 davs Unit 1 Containment Penetration (GW/FW Area) to TSC Normal Intake 4.80E-04 2.51 E-04 8.31E-05 8.64E-05 6.95E-05 RG 1.23 Met Data 4.44E-04 2.48E-04 8.04E-05 8.31 E-05 6.68E-05 Percent Chanqe -7.5 -1 .2 -3 .2 -3 .8 -3 .9 Unit 1 Containment Penetration (GW/FW Area) to TSC Ce nter 5.98E-04 3.03E-04 1.04E-04 1.03E-04 8.46E-05 RG 1.23 Met Data 5.61E-04 2.93E-04 1.00E-04 9.86E-05 8.16E-05 Percent Chanae -6 .2 -3.3 -3.8 -4.3 -3.5 UNIT2 Unit 2 Containment Edqe to TSC Normal Intake 5.48E-04 2.00E-04 8.52 E-05 8. 37E-05 6.84E-05 RG 1.23 Met Data 5.31 E-04 1.97E-04 8.36E-05 8.25E-05 6.72E-05 Percent Chanae -3.1 -1.5 -1 .9 -1.4 -1 .8 Unit 2 Containment Edqe to TSC Center 5.57E-04 2.01 E-04 8.81E-05 8.89E-05 6.92E-05 RG 1.23 Met Data 5.39E-04 2.01 E-04 8.73E-05 8.78E-05 6.84E-05 Percent Chanqe -3.2 0.0 -0 .9 -1.2 -1.2 Unit 2 Plant Vent to TSC Normal Intake 5.52 E-04 2.35E-04 1.06E-04 8.71 E-05 6.95E-05 RG 1.23 Met Data 5.47E-04 2.27E-04 1.03E-04 8.46E-05 6.68E-05 Percent Chanqe -0 .9 -3.4 -2.8 -2 .9 -3.9 Unit 2 Plant Vent to TSC Center 5.43E-04 2.16E-04 9.97E-05 8.1 1E-05 6.58 E-05 RG 1.23 Met Data 5.41 E-04 2.09E-04 9.67E-05 7.95E-05 6.43E-05 Percent Chanae -0.4 -3 .2 -3.0 -2 .0 -2.3 Unit 2 RWST Vent to TSC Normal Intake 3.63E-04 1.68E-04 6.47E-05 6.04E-05 4.91 E-05 RG 1.23 Met Data 3.52E-04 1.46E-04 6.12E-05 5.66E-05 4.63E-05 Percent Chanae -3.0 -13 .1 -5.4 -6 .3 -5 .7 Unit 2 RWST Vent to TSC Center 3.72E-04 1.68E-04 6.64E-05 6.17E-05 5.10E-05 RG 1.23 Met Data 3.61 E-04 1.48E-04 6.30E-05 5.80E-05 4.69E-05 Percent Chanqe -3 .0 -11 .9 -5 .1 -6 .0 -8.0 35 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 1-3 DCPP Units 1 and 2 - Technical Support Center Atmospheric Dispersion Factor (sec/m 3) Comparisons 0-2 1-4 Release Point and On-Site Receotor hours 2-8 hou rs 8-24 hou rs davs 4-30 davs Unit 2 Containment Penetration (GE Area) to TSC Normal Intake 5.47E-04 2.41 E-04 9.36E-05 8.83E-05 7.02E-05 RG 1.23 Met Data 5.22E-04 2.21 E-04 9.14E-05 8.61 E-05 6.71E-05 Percent Change -4.6 -8 .3 -2.4 -2 .5 -4.4 Unit 2 Containment Penetration (GE Area) to TSC Center 5.72E-04 2.43E-04 9.75E-05 9.12E-05 7.52E-05 RG 1.23 Met Data 5.49E-04 2.24E-04 9.60E-05 8.85E-05 7.05E-05 Percent Chanqe -4.0 -7 .8 -1 .5 -3 .0 -6 .2 Unit 2 Containment Penetration (GW/FW Area) to TSC Normal Intake 1.80E-03 7.72E-04 3.07E-04 2.87E-04 2.33E-04 RG 1.23 Met Data 1.71E-03 7.07E-04 2.98E-04 2.76E-04 2.21 E-04 Percent Change -5.0 -8.4 -2.9 -3 .8 -5 .2 Unit 2 Containment Penetration (GW/FW Area) to TSC Center 1.83E-03 7.49E-04 3.16E-04 2.92E-04 2.41 E-04 RG 1.23 Met Data 1.76E-03 7.16E-04 3.01E-04 2.84E-04 2.28E-04 Percent Chanqe -3.8 -4.4 -4.7 -2.7 -5.4 36 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 1-4 DCPP Unit 1 and Unit 2 - Offsite Receptor Atmospheric Dispersion Factor (sec/m 3 )

Comparisons Off-Site Receptor 0 - 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> 2 - 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> 8 - 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 1 - 4 days 4 - 30 days Unit 1 EAB 2.50E-04 RG 1.23 Met Data 2.50E-04 ----- ----- ----- -----

Percent Chanqe 0.0 Un it 2 EAB 2.30E-04 RG 1.23 Met Data 2.17E-04 ----- ----- ----- -----

Percent Change -5.7 Units 1 and 2 LPZ 2.12E-05 9.26E-06 6.26E-06 2.67E-06 7.86E-07 RG 1.23 Met Data 2.00E-05 8.94E-06 6.14E-06 2.72E-06 8.48E-07 Percent Change -5.7 -3.5 -1 .9 1.9 7.9 Notes:

3

1. An EAB X/Q value of 2.5E-4 sec/m is used for all release points.

2. The 0.5 percent sector dependent X/Q values are presented above. The worst-case downwind sector for the 0-2 hr period for all receptors is northwest. For Un its 1 and 2 LPZ the worst-case sector for periods 2-8 hrs and longer is southeast.

37 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 2-1 Atmospheric Dispersion Factors (X/Qs) at Control Room Receptors for Post- Accident LOCA Radiological Releases Input I Output File Names File Name Description of Release-Receptor Cases XIQ (sec/m )

3 0 - 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> 2 - 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> 8 - 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 1 -4 days 4 - 30 days dccase01 Unit 1 CB Edge to Unit 1 CR Normal Intake 1.44E-03 7.03E-04 3.00E-04 3.06E-04 3.04E-04 dccase02 Unit 1 CB Edge to Unit 1 CR Emergency Intake 4.09E-04 2.31 E-04 9.54E-05 8.61E-05 7.04E-05 dccase03 Unit 1 CB Edge to Unit 2 CR Emergency Intake 1.57E-04 7.82E-05 2.57E-05 2.71 E-05 2.32E-05 dccase04 Unit 1 CB Edge to CR Center 9.21 E-04 4.38E-04 1.77E-04 1.80E-04 1.67E-04 dccase05 Unit 1 PV to Unit 1 CR Emergency Intake 5.56E-04 3.33E-04 1.29E-04 1.11 E-04 8.34E-05 dccase06 Unit 1 PV to Unit 2 CR Emergency Intake 2.22E-04 1.47E-04 5.44E-05 5.52E-05 4.45E-05 dccase07 Unit 1 PV to CR Center 1.25E-03 8.93E-04 3.47E-04 3.46E-04 2.98E-04 dccase08 Unit 1 RWST Vent to Unit 1 CR Emergency Intake 3.24E-04 1.83E-04 6.94E-05 6.82E-05 5.57E-05 dccase09 Unit 1 RWST Vent to Unit 2 CR Emergency Intake 1.88E-04 9.18E-05 3.40E-05 3.28E-05 2.69E-05 dccase10 Unit 1 RWST Vent to CR Center 1.01 E-03 4.26E-04 1.85E-04 1.62E-04 1.31 E-04 dccase11 Unit 2 CB Edge to Unit 2 CR Normal Intake 1.99E-03 9.59E-04 4.60E-04 4.04E-04 3.20E-04 dccase12 Unit 2 CB Edge to Unit 1 CR Emergency Intake 1.66E-04 1.05E-04 4.19E-05 3.73E-05 2.93E-05 dccase13 Unit 2 CB Edge to Unit 2 CR Emergency Intake 3.78E-04 1.47E-04 5.99E-05 5.87E-05 4.90E-05 dccase14 Unit 2 CB Edge to CR Center 1.09E-03 5.49E-04 2.47E-04 2.12E-04 1.?0E-04 dccase15 Unit 2 PV to Unit 1 CR Emergency Intake 2.02E-04 1.27E-04 5.11 E-05 4.20E-05 3.15E-05 dccase16 Unit 2 PV to Unit 2 CR Emergency Intake 5.61 E-04 2.91E-04 1.16E-04 1.02E-04 8.03E-05 dccase17 Unit 2 PV to CR Center 1.12E-03 6.99E-04 2.82E-04 2.34E-04 1.68E-04 dccase18 Unit 2 RWST Vent to Unit 1 CR Emergency Intake 1.89E-04 1.17E-04 4.52E-05 4.30E-05 3.40E-05 dccase19 Unit 2 RWST Vent to Unit 2 CR Emergency Intake 3.17E-04 1.40E-04 5.64E-05 5.12E-05 4.16E-05 dccase20 Unit 2 RWST Vent to CR Center 1.05E-03 5.55E-04 2.12E-04 2.12E-04 1.72E-04 dccase21 Unit 1 140' Leakage to Unit 1 CR Normal Intake 6.59E-03 2.81 E-03 1.16E-03 1.0?E-03 8.31 E-04 dccase22 Unit 1 140' Leakage to Unit 1 CR Emergency Intake 3.67E-04 2.31 E-04 9.02E-05 8.38E-05 6.42E-05 dccase23 Unit 1 140' Leakage to Unit 2 CR Emergency Intake 2.39E-04 1.20E-04 4.27E-05 4.22E-05 3.39E-05 dccase24 Unit 1 140' Leakage to CR Center 3.01 E-03 1.33E-03 5.43E-04 4.93E-04 4.01 E-04 dccase25 Unit 1 PL to Unit 1 CR Normal Intake 4.86E-03 3.43E-03 1.35E-03 1.37E-03 1.25E-03 dccase26 Unit 1 PL to Unit 1 CR Emergency Intake 8.05E-04 5.32E-04 2.12E-04 1.86E-04 1.40E-04 dccase27 Unit 1 PL to Unit 2 CR Emergency Intake 2.40E-04 1.53E-04 4.83E-05 5.20E-05 4.41 E-05 dccase28 Unit 1 PL to CR Center 2.55E-03 1.80E-03 7.17E-04 7.13E-04 6.50E-04 38 of 53

Enclosure PG&E Letter DCL-16-044 File Name Description of Release-Receptor Cases XIQ Csec/m 3 )

0 - 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> 2 - 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> 8 - 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 1 -4 days 4- 30 days dccase29 Unit 2 140' Leakage to Unit 2 CR Normal Intake 6.60E-03 3.01 E-03 1.17E-03 1.20E-03 1.01 E-03 dccase30 Unit 2 140' Leakage to Unit 1 CR Emergency Intake 2.26E-04 1.57E-04 6.15E-05 5.47E-05 4.0SE-05 dccase31 Unit 2 140' Leakage to Unit 2 CR Emergency Intake 3.74E-04 1.67E-04 6.72E-05 6.14E-05 5.0SE-05 dccase32 Unit 2 140' Leakage to CR Center 3.09E-03 1.83E-03 7.22E-04 6.74E-04, 5.35E-04 dccase33 Unit 2 PL to Unit 2 CR Normal Intake 3.45E-03 1.14E-03 4.?0E-04 4.42E-04 2.93E-04 dccase34 Unit 2 PL to Unit 1 CR Emergency Intake 2.26E-04 1.59E-04 6.50E-05 5.36E-05 3.96E-05 dccase35 Unit 2 PL to Unit 2 CR Emergency Intake 8.0SE-04 4.0?E-04 1.43E-04 1.42E-04 1.14E-04 dccase36 Unit 2 PL to CR Center 2.19E-03 1.16E-03 4.56E-04 3.83E-04 2.58E-04 dccase37 Unit 1 PV to Unit 1 CR Normal Intake 1.67E-03 1.22E-03 4.93E-04 4.89E-04 4.36E-04 dccase38 Unit 2 PV to Unit 2 CR Normal Intake 1.49E-03 9.29E-04 3.SOE-04 3.16E-04 2.21 E-04 dccase39 Unit 1 CB Edge to Unit 2 CR Normal Intake 6.41E-04 3.51 E-04 1.49E-04 1.49E-04 1.36E-04 dccase40 Unit 2 CB Edge to Unit 1 CR Normal Intake 6.89E-04 3.85E-04 1.66E-04 1.41 E-04 1.0SE-04 dccase41 Unit 1 PV to Uriit 2 CR Normal Intake 9.0SE-04 6.53E-04 2.69E-04 2.62E-04 2.38E-04 dccase42 Unit 2 PV to Unit 1 CR Normal Intake 7.79E-04 4.SOE-04 1.98E-04 1.65E-04 1.15E-04 dccase43 Unit 1 140' Leakage to Unit 2 CR Normal Intake 2.0?E-03 1.13E-03 3.73E-04 3.78E-04 3.05E-04 dccase44 Unit 1 PL to Unit 2 CR Normal Intake 1.35E-03 9.79E-04 3.86E-04 3.84E-04 3.46E-04 dccase45 Unit 2 140' Leakage to Unit 1 CR Normal Intake 2.0SE-03 1.38E-03 5.62E-04 4.76E-04 3.59E-04 dccase46 Unit 2 PL to Unit 1 CR Normal Intake 1.20E-03 6.21 E-04 2.49E-04 2.09E-04 1.41 E-04 Notes:

File names = Input (.rsf), Output (.log)

CR = Control Room CB = Containment Building PV =Plant Vent 140' Leakage = Containment Penetration (GE Area)

RWST = Refueling Water Storage Tank PL = Containment Penetration (GW/FW Area) 39 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 2-2 Atmospheric Dispersion Factors (X/Qs) at Control Room Receptors for Fuel Handling Accident

' Radiological Releases Input I Output File Names File Name Description of Release-Re~eptor Case X/Q (sec/m 3 )

O - 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> dcfhc1 Unit 1 FHB to Unit 1 CR Normal Intake 6.68E-03 dcfhc2 Unit 1 FHB to Unit 2 CR Normal Intake 2.69E-03 dcfhc3 Unit 1 FHB to Unit 2 CR Emergency Intake 2.39E~04 dcfhc4 Unit 1 FHB to CR Center 3.54E-03 dcfhc5 Unit 1 EH to Unit 1 CR Normal Intake 2.43E-02 dcfhc6 Unit 1 EH to Unit 2 CR Normal Intake 2.67E-03 dcfhc7 Unit 1 EH to Unit 2 CR Emergency Intake 2.45E-04 dcfhc8 Unit 1 EH to CR Center 5.06E-03 dcfhc9 Unit 2 FHB to Unit 1 CR Normal Intake 2.68E-03 dcfhc10 Unit 2 FHB to Unit 2 CR Normal Intake 6 ..68E-03 dcfhc11 Unit 2 FH.B to Unit 1 CR Emergency Intake 2.45E-04 dcfhc12 Unit 2 FHB to CR Center 3.61 E-03 dcfhc13 Unit 2 EH to Unit 1 CR Normal Intake 2.47E-03 dcfhc14 Unit 2 EH to Unit 2 CR Normal Intake 2.48E-02 dcfhc15 Unit 2 EH to Unit 1 CR Emergency Intake 2.46E-04 dcfhc16 Unit 2 EH to CR Center 5.09E-03 dcfhc1.7 Unit 1 FHB to Unit 1 CR Emergency Intake* 3.28E~04 dcfhc18 Unit 2 FHB to Unit 2 CR Emergency Intake 3.23E-04 dcfhc19 . Unit 1 EH to Unit 1 CR Emergency Intake 4.32E-04 dcfhc20 Unit 2 EH to Unit 2 CR Emergency Intake 4.26E-04 Notes:

File names ' = Input (.rsf), Output (.log)

CR =Control Room FHB ' = Fuel Handling Building EH =Equipment Hatch 40 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 2-3 Atmospheric Dispersion Factors (X/Qs) at Control Room Receptors for Radiological Releases from MSSVs/ADVs/MSLB Input I 0 utput File Names File Name 3 Description of Release-Receptor Cases XIQ (sec/m )

0 - 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> 2 - 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> 8 - 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 1 - 4 days 4- 30 days

- Unit 1 MSSVs to Unit 1 CR Normal Intake NIA NIA NIA NIA NIA dcmssv02 Unit 1 MSSVs to Unit 2 CR Normal Intake 4.05E-03 2.65E-03 1.02E-03 1.02E-03 8.95E-04 dcmssv03 Unit 1 MSSVs to Unit 2 CR Emergency Intake 2.75E-04 1.49E-04 4.79E-05 5.02E-05 4.14E-05 dcmssv04 Unit 1 MSSVs to CR Center 1.23E-02 7.28E-03 2.21 E-03 2.43E-03 2.06E-03 dcmssv05 Unit 2 MSSVs to Unit 1 CR Normal Intake 3.80E-03 2.36E-03 9.SOE-04 8.00E-04 5.99E-04

- Unit 2 MSSVs to Unit 2 CR Normal Intake NIA NIA NIA NIA NIA dcmssv07 Unit 2 MSSVs to Unit 1 CR Emergency Intake 2.79E-04 1.87E-04 7.33E-05 6.50E-05 4.89E-05 dcmssv08 Unit 2 MSSVs to CR Center 1.19E-02 7.90E-03 3.22E-03 2.68E-03 2.05E-03

- Unit 1 ADVs to Unit 1 CR Normal Intake NIA NIA NIA NIA NIA dcmssv10 Unit 1 ADVs to Unit 2 CR Normal Intake 4.06E-03 2.66E-03 1.03E-03 1.02E-03 9.03E-04 dcmssv11 Unit 1 ADVs to Unit 2 CR Emergency Intake 2.75E-04 1.50E-04 4.82E-05 5.03E-05 4.15E-05 dcmssv12 Unit 1 ADVs to CR Center 1.23E-02 7.34E-03 2.22E-03 2.45E-03 2.08E-03 dcmssv13 Unit 2 ADVs to Unit 1 CR Normal Intake 3.82E-03 2.36E-03 9.86E-04 8.01 E-04 6.01 E-04

- Unit 2 ADVs to Unit 2 CR Normal Intake NIA NIA NIA NIA NIA dcmssv15 Unit 2 ADVs to Unit 1 CR Emergency Intake 2.77E-04 1.88E-04 7.35E-05 6.49E-05 4.89E-05 dcmssv16 Unit 2 ADVs to CR Center 1.19E-02 7.94E-03 3.23E-03 2.70E-03 2.05E-03

- Unit 1 MSLB to Unit 1 CR Normal Intake NIA NIA NIA NIA NIA dcmssv18 Unit 1 MSLB to Unit 2 CR Normal Intake 4.07E-03 2.86E-03 1.11 E-03 1.10E-03 9.70E-04 dcmssv19 Unit 1 MSLB to Unit 2 CR Emergency Intake 2.74E-04 1.54E-04 4.98E-05 5.12E-05 4.20E-05 dcmssv20 Unit 1 MSLB to CR Center 1.14E-02 7.05E-03 2.19E-03 2.37E-03 1.98E-03 dcmssv21 Unit 2 MSLB to Unit 1 CR Normal Intake 3.75E-03 2.37E-03 1.00E-03 7.93E-04 5.81 E-04

- Unit 2 MSLB to Unit 2 CR Normal Intake NIA NIA NIA NIA NIA dcmssv23 Unit 2 MSLB to Unit 1 CR Emergency Intake 2.72E-04 1.88E-04 7.40E-05 6.42E-05 4.80E-05 dcmssv24 Unit 2 MSLB to Control Room Center 1.08E-02 7.22E-03 3.00E-03 2.44E-03 1.83E-03 dcmssv25 Unit 1 MSSVs to Unit 1 CR Emergency Intake 4.52E-04 2.86E-04 1.14E-04 1.01 E-04 7.82E-05 dcmssv26 Unit 2 MSSVs to Unit 2 CR Emergency Intake 4.39E-04 2.14E-04 7.68E-05 7.54E-05 6.09E-05

. dcmssv27 Unit 1 ADVs to Unit 1 CR Emergency Intake 4.52E-04 2.86E-04 1.14E-04 1.01 E-04 7.82E-05 dcmssv28 Unit 2 ADVs to Unit 2 CR Emergency Intake 4.39E-04 2.14E-04 7.68E-05 7.54E-05 6.09E-05 41 of 53

Enclosure PG&E Letter DCL-16-044 3

Case No. Description of Rele~se-Receptor Cases X/Q Csec/m )

0 - 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> 2 - 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> 8 - 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 1 -4 days 4-30 days dcmssv29 Unit 1 MSLB to Unit 1 CR Emergency Intake 4.30E-04 2.89E-04 1.14E-04 1.00E-04 7.63E-05 dcmssv30 Unit 2 MSLB to Unit 2 CR Emergency Intake 4.29E-04 2.19E-04 7.73E-05 7.57E-05 6.11 E-05 Notes:

File names = Input (.rsf), Output (.log)

NIA =Not applicable due to the source-receptor distance being much less than 1O meters, outside of the applicability of ARCON96.

CR =Control Room MSSVs = Main Steam Safety Valves AD Vs =10 percent Atmospheric Dump Valves

• MSLB =Main Steam Line Break 42 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 2-4 Atmospheric Dispersion Factors (X/Qs) at TSC Receptors for LOCA Radiological Releases Input I Output File Names 3

File Name Release-Receptor Case Description XIQ (sec/m )

0 - 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> 2 - 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> 8 - 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 1 - 4 days 4 -30 days dctsc01 Unit 1 CB Edge to TSC Normal Intake 2.45E-04 1.16E-04 4.0BE-05 4.17E-05 3.48E-05 dctsc02 Unit 1 CB Edge to TSC Center 2.74E-04 1.31 E-04 4.BOE-05 4.70E-05 4.00E-05 dctsc03 Unit 1 PV (ECCS Leakage) to TSC Normal Intake 3.04E-04 1.76E-04 6.82E-05 6.21 E-05 5.20E-05 dctsc04 Unit 1 PV(ECCS Leakage) to TSC Center 3.41E-04 1.94E-04 7.63E-05 6.61E-05 5.62E-05 dctsc05 Unit 1 RWST Vent to TSC Normal Intake 2.48E-04 1.15E-04 4.52E-05 4.11 E-05 3.40E-05 dctsc06 Unit 1 RWST Vent to TSC Center 2.76E-04 1.23E-04 5.00E-05 4.53E-05 3.65E-05 dctsc07 Unit 1 140' Elevation Area Leakage to TSC Normal Intake 3.51E-04 1.61 E-04 6.43E-05 5.89E-05 4.83E-05 dctsc08 Unit 1 140' Elevation Area Leakage to TSC Center 4.05E-04 1.BOE-04 7.26E-05 6.60E-05 5.37E-05 dctsc09 Unit 1 PL to TSC Normal Intake 4.44E-04 2.48E-04 8.04E-05 8.31E-05 6.68E-05 dctsc10 Unit 1 PL to TSC Center 5.61 E-04 2.93E-04 1.00E-04 9.86E-05 8.16E-05 dctsc11 Unit 2 CB Edge to TSC Normal Intake 5.31 E-04 1.97E-04 8.36E-05 8.25E-05 6.72E-05 dctsc12 Unit 2 CB Edge to TSC Center 5.39E-04 2.01 E-04 8.73E-05 8.78E-05 6.84E-05 dctsc13 Unit 2 PV (ECCS Leakage) to TSC Normal Intake 5.47E-04 2.27E-04 1.03E-04 8.46E-05 6.68E-05 dctsc14 Unit 2 PV (ECCS Leakage) to TSC Center 5.41 E-04 2.09E-04 9.67E-05 7.95E-05 6.43E-05 dctsc15 Unit 2 RWST Vent to TSC Normal Intake 3.52E-04 1.46E-04 6.12E-05 5.66E-05 4.63E-05 dctsc16 Unit 2 RWST Vent to TSC Center 3.61 E-04 1.48E-04 6.30E-05 5.BOE-05 4.69E-05 dctsc17 Unit 2 140' Elevation Area Leakage to TSC Normal Intake 5.22E-04 2.21 E-04 9.14E-05 8.61E-05 6.71E-05 dctsc18 Unit 2 140' Elevation Area Leakage to TSC Center 5.49E-04 2.24E-04 9.60E-05 8.85E-05 7.05E-05 dctsc19 Unit 2 PL to TSC Normal Intake 1.71E-03 7.07E-04 2.98E-04 2.76E-04 *2.21 E-04 dctsc20 Unit 2 PL to TSC Center 1.76E-03 7.16E-04 3.01E-04 2.84E-04 2.28E-04 Notes:

File names =Input (.rsf), Output (.log)

CB = Containment Building PV =Plant Vent 140' Leakage = Containment Penetration (GE Area)

RWST = Refueling Water Storage Tank PL = Containment Penetration (GW/FW Area) 43 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 2-5 Meteorological Data Format for EN-113 Dispersion Model The order of information in the EN-113 format (A3, 12, 13, 2413) is:

A3 = meteorological parameter identifier as given below '

131=10-meterwind speed (0.1 mph) 132 = 10-meterwind direction (degrees azimuth) 136 = 1DO-meter temperature difference (0.1 QC) 12 = last 2 digits of calendar year 13 = Julian day

• 2413 = hourly parameter values (1 - 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />)

A sample of the EN-113 formatted meteorological data is provided below:

Sample D~y 1/1/07 13187001c60 78 92 72 85 96 87 94 94 58 67 49 45 85 72150163114 87 49 69 81 49 54 13287001 4337336 44 46 44 41 25 46 58 57 65 52 13 33311306300321 37360 37334355 13687001 5 3 5 5 5 10-12-10-11 i2 3 4 6 -2 2

Notes: 131=10-meterwind speed (0.1 mph) 132 = 10-meterwind direction (degrees azimuth) 136 = 1OD-meter temperature difference (b.1 QC)

The year is shown as 87 in place of 07 due to a Year 2000 incompatibility 44 of 53

Enclosure PG&E Letter DCL-16-044 Table 3-1 Effect of Updated Site Boundary X/Qs on Dose Consequences at the EAB and LPZ All Accidents X/Q (sec/m 3 )

Receptor 0 - 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> 2 - 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> 8 - 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 1 - 4 days 4 - 30 days Unit 1 EAB (NW) 2.50E-04 RG 1.23 Met Data 2.50E-04 Unit 2 EAB (NW) 2.30E-04 RG 1.23 Met Data 2.17E-04 Unit 1/2 LPZ (NW) 2.12E-05 9.26E-06 6.26E-06 2.67E-06 7.86E-07 RG 1.23 Met Data 2.00E-05 8.94E-06 6.14E-06 2.72E-06 8.48E-07 Impact of Updated X/Qs on EAB and LPZ Dose Consequences (All Accidents)

EAB Since the updated 0-2 hr EAB X/Q values are equal to or less than the original 0-2 hr EAB X/Q values, the EAB doses reported in LAR 15-03 (specifically, Enclosure Attachment 2 of Reference 6) for the Fuel Handling Accident (FHA) , Main Steam Line Break (MSLB) , Locked Rotor Accident (LRA) , Control Rod Ejection Accident (CREA), Steam Generator Tube Rupture (SGTR), Loss of Load (LOL) , and LOCA remain bounding .

LPZ The updated LPZ X/Q values are less than the original X/Q values with the exception of the X/Qs associated with time periods between 1 day to 30 days. Provided below is an assessment of the potential impact on dose consequences at the LPZ for each accident.

The following accidents are not impacted by the updated LPZ X/Q values since: (a) the releases are terminated prior to 24 hrs or (b) the LPZ doses reported in LAR 15-03 are conservatively based on X/Q values that bound the updated X/Q values for impacted time periods.

• FHA (release term inated in less than or equal to 2 hrs)

• SGTR (release terminated in 10. 73 hrs after the accident)

• LRA (release terminated in 10.73 hrs after the accident)

• Loss of Load (release terminated in 10. 73 hrs after the accident)

• MSLB (is not adversely impacted by the updated X/Q values even though releases from the affected steam generator continue for up to 30 hrs after the postulated accident. This is because the original 8-24 hr X/Qs values were conservatively used for the time period between 8 to 30 hrs)

The LOCA and the CREA both have 30-day releases of radioactivity. The LPZ dose estimates for the LOCA and CREA were re-run using the updated X/Qs and it was determined that the LPZ dose reported in LAR 15-03 (specifically, Enclosure Attachment 2 of Reference 6) for the LOCA and the CREA remain bounding . This result reflects the fact that the reduction in X/Qs during the earlier time periods (when the radiation source term in the post-accident environmental releases are significantly higher) is more than sufficient to offset the increase in X/Qs during the later time periods.

Note

~n EAB X/Q value of 2.5E-4 sec/m 3 is used for all release points .

2. The 0.5 percent sector dependent X/Q values are presented above. The worst-case downwind sector for the 0-2 hour period for all receptors is northwest. For Unit 1/2 LPZ the worst-case sector for periods 2-8 hrs and longer is southeast.

45 of 53

Enclosure PG&E Letter DCL-16-044 Table 3-2 3

Effect of Updated CR X/Qs (sec/m ) on the Dose Consequences in the CR Following a Loss-of-Coolant Accident Release Location I Receptor 0-2 hr 2-8 hr 8-24 hr 1-4 days 4-30 days Control Room (CR} Normal Intakes Plant Vent Release 1.67E-03

- Affected Unit Intake 1.67E-03 9.10E-04

- Non-Affected Unit Intake 9.08E-04 Containment Penetration Areas 6.84E-03

- Affected Unit Intake 6.60E-03 2.24E-03

- Non-Affected Unit Intake 2.08E-03 CR Infiltration 1.26E-03 8.96E-04 3.44E-04 3.44E-04 2.99E-04 Plant Vent 1.25E-03 8.93E-04 3.47£-04 3.46£-04 2.98E-04 3.22E-03 1.85E-03 7.29E-04 7.15E-04 6.64E-04 Containment Penetration Areas 3.09E-03 1.83E-03 7.22E-04 7.13E-04 6.50E-04 1.0?E-03 5.80E-04 2.18E-04 2.19E-04 1.79E-04 RWSTVent 1.05E-03 5.55E-04 2.12E-04 2.12E-04 1.72E-04 CR Pressurization Intake 5.65E-05 3.?0E-05 1.35E-05 1.37E-05 1.11 E-05 Plant Vent 5.55E-05 3.68E-05 1.36E-05 1.38£-05 1.11 E-05 6.45E-05 4.05E-05 1.65E-05 1.38E-05 1.12E-05 Containment Penetration Aroas 6.00E-05 3.98E-05 1.63E-05 1.37E-05 1.10E-05 5.25E-05 3.03E-05 1.15E-05 1.10E-05 8.83E-06 RWSTVent 4.73E-05 2.93E-05 1.13E-05 1.08E-05 8.50E-06 Impact of Updated X/Qs on the CR Dose All of the updated X/Q values are either the same or less than the original X/Q values with the exception of the X/Qs associated w ith time periods between 8 to 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br /> for releases from the plant vent, to receptors associated with CR infiltration and the CR Pressurization intake. The maximum increase in XJQ values for these time intervals/release pathways is less than 1 percent. Taking into cons ideration the corresponding decrease in X/Q values for the other time intervals with more dominant dose consequences , as well as the general reduction in X/Q values for all of the other release pathways, it is concluded that the CR doses reported in LAR 15-03 (specifically, Enclosure Attachment 2 of Reference

6) for th e LOCA remain bounding .

Note 1:

Release from the Containment penetration areas (i.e., areas GE or GW and FW): applicable to containment leakage and ESF system leakage that occurs in the Containment Penetration Area .

Note 2:

Release from Plant Vent: applicable to ESF system leakage that occu rs in the Auxil iary Building , Miscellaneous Equipment Drain Tank (MEDT) release , Residual Heat Removal (RHR) pump seal failure release , and containment vacuum/pressure relief line release.

46 of 53

Enclosure PG&E Letter DCL-16-044 Table 3-3 Effect of Updated TSC X/Qs (sec/m 3 ) on the Dose Consequences in the TSC Following a Loss-of-Coolant Accident Release Location I Receptor 0-2 hr 2-8 hr 8-24 hr 1-4 days 4-30 days TSC Normal Intakes 5.52E-04 Plant Vent Release 5.47E-04 1.80E-03 Containment Penetration Areas 1.71E-03 3.63E-04 RWSTVent 3.52E-04 TSC Infiltration 5.43E-04 2.16E-04 9.97E-05 8.11E-05 6.58E-05 Plant Vent 5.41 E-04 2.09E-04 9.67E-05 7.95E-05 6.43E-05 1.83E-03 7.49E-04 3.16E-04 2.92E-04 2.41 E-04 Containment Penetration Areas 1.76E-03 7.16E-04 3.01 E-04 2.84E-04 2.28E-04 3.72E-04 1.68E-04 6.64E-05 6.17E-05 5.10E-05 RWSTVent 3.61 E-04 1.48E-04 6.30E-05 5.80E-05 4.69E-05 CRfTSC Pressurization Intake 3.?0E-05 1.35E-05 1.37E-05 1.11 E-05 Plant Vent ----- 3.68E-05 1.36E-05 1.38E-05 1.11 E-05 4.05E-05 1.65E-05 1.38E-05 1.12E-05 Containment Penetra tion Areas ---*-- 3.98E-05 1.63E-05 1.37E-05 1.10E-05 3.03E-05 1.15E-05 1.10E-05 8.83E-06 RWSTVent ----- 2 .93E-05 1.13E-05 1.08E-05 8.50E-06 Impact of Updated X/Qs on the TSC Dose All of the updated X/Q values are either the same or less than the original X/Q values with the exception of the X/Qs associated with time periods between 8 to 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br /> for releases from the plant vent, to receptors associated with the TSC Pressurization intake. The maximum increase in X/Q values for these time intervals/release pathways is less than 1 percent. Taking into consideration the correspond ing decrease in X/Q values for the other time intervals, as well as the general reduction in X/Q values for all of the other release pathways, it is concluded that the TSC doses reported in LAR 15-03 (specifica lly, Enclosure Attachment 2 of Reference 6) for the LOCA remain bound ing .

Note 1:

Release from the Containment penetration areas (i.e., areas GE or GW and FW): applicable to containment leakage and ESF system leakage that occurs in the Containment Penetration Area .

Note 2:

Release from Plant Vent: applicable to ESF system leakage that occurs in the Auxiliary Bu ilding , MEDT release, RHR pump seal failure release , and containment vacuum/pressure relief line release .

47 of 53

Enclosure PG&E Letter DCL-16-044 Table 3-4 3

Effect of Updated CR X/Qs (sec/m ) on the Dose Consequences in the CR Following a Fuel Handling Accident.

Release Location I Receptor 0-22 sec 22 sec - 2 hr 2-8 hr 8-24 hr 1-4 d 4-30 d Control Room (CR) Normal Intakes Containment Hatch Release 2.61 E-02

- Affected Unit Intake 2.48E-02 2.88E-03

- Non-Affected Unit Intake 2.67E-03 Plant Vent Release 1.67E-03

- Affected Unit Intake 1.67E-03 9.1OE-04

- Non-Affected Unit Intake 9.08E-04 FHB Out-leakaqe points 6.98E-03

- Affected Unit Intake 6.68E-03 2.93E-03

- Non-Affected Unit Intake 2.69E-03 CR Infiltration 5.51 E-03 5.51E-03 Containment Hatch Release 5.09E-03 5.09E-03 1.26E-03 1.26E-03 Plant Vent 1.25E-03 1.25E-03 3.78E-03 3.78E-03 FHB Out-leakage points 3.61 E-03 3.61E-03 CR Pressurization Intake 6.60E-05 Containment Hatch Release 6.15E-05 5.65E-05 Plant Vent 5.55E-05 6.40E-05 FHB Out-leakaqe points 6.13E-05 Impact of Updated X/Qs on the CR Dose Since all of the updated X/Q values are either the same or less than the original X/Q values , the CR doses reported in LAR 15-03 (specifically, Enclosure Attachment 2 of Reference 6) for the FHA remain bounding .

Note 1:

Release from the Containment Hatch : applicable to FHA in Containment Note 2:

Release from Plant VenUFHB Out-leakage: applicable to FHA in FHB 48 of 53

Enclosure PG&E Letter DCL-16-044 Table 3-5 3

Effect of Updated CR X/Qs (sec/m ) on the Dose Consequences in the CR Following a Locked Rotor Accident Release E!Oint and receE!tor 0-2hr 2-8 hr 8-10.73 hr 8.60E-04 5.58E-04 5.58E-04 MSSVs/10 Percent ADVs to CR NOP Intake (Note 1) 8.12E-04 5.32E-04 5.32E-04 MSSVs/10 Percent ADVs to CR In-leakage (CR 2.78E-03 1.63E-03 1.63E-03 Centerline) 2.46E-03 1.59E-03 1.59E-03 Impact of Updated X/Qs on the CR Dose Since all of the updated X/Q values are less than the original X/Q values, the CR doses reported in LAR 15-03 (specifically, Enclosure Attachment 2 of Reference 6) for the LRA remain bounding .

Note 1:

Due to the proximity of the release from the MSSVs/10 Percent ADVs to the normal operation (NOP) CR intake of the affected unit, and due to the high vertical velocity of the steam discharge from the MSSVs/10 Percent ADVs , the resultant plume from the MSSVs/10 Percent ADVs will not contaminate the normal operation CR intake of the affected unit. Thus, the X/Qs presented reflect those appl icable to the CR intake of the unaffected unit.

49 of 53

Enclosure PG&E Letter DCL-16-044 Tab le 3-6 Effect of Updated CR X/Qs (sec/m 3 ) on the Dose Consequences in the CR Following a Control Rod Ejection Accident 8-10.73 Release Location I Receptor 0-2 hr 2-8 hr 10.73-24 hr 24-96 hr 96 -720 hr hr Control Room (CR} Normal Intakes Containment leakage 6.84E-03

- Affected Unit Intake 6.60E-03 2.24E-03

- Non-Affected Unit Intake 2.08E-03 MSSVs/10 Percent ADVs

- Affected Unit Intake Note 3 ----- ----- ----- ----- -----

8.60E-04

- Non-Affected Unit Intake 8.12E-04 CR Infiltration 3.22E-03 1.85E-03 7.29E-04 7.29E-04 7.15E-04 6.64E-04 Containment leakage 3.09E-03 1.83E-03 7.22E-04 7.22E-04 7.13E-04 6.50E-04 2.78E-03 1.63E-03 1.63E-03 MSSVs/10 Percent ADVs 2.46E-03 1.59E-03 1.59E-03 CR Pressurization Intake 6.45E-05 4.05E-05 1.65E-05 1.65E-05 1.38E-05 1.12E-05 Containment leakaae 6.00E-05 3.98E-05 1.63E-05 1.63E-05 1.37E-05 1.10E-05 1.57E-05 9.60E-06 9.60E-06 MSSVs/10 Percent ADVs 1.40E-05 9.40E-06 9.40E-06 Impact of Updated X/Qs on the CR Dose Since all of the updated X/Q values are less than the orig inal X/Q values, the control room doses reported in LAR 15-03 (specifically, Enclosure Attachment 2 of Reference 6) for the CREA remain bounding .

Note 1:

Containment leakage: Used for Containment release scenario ; based on Containment penetration area release point.

Note 2:

MSSV/1 O Percent ADVs: Used for Secondary System Release Scenario.

Note 3:

Due to the proximity of the release from the MSSVs/10 Percent AD Vs to the normal operation CR intake of the affected unit, and due to the high vertical velocity of the steam discharge from the MSSVs/10 Percent ADVs , the resultant plume from the MSSVs/10 Percent ADVs will not contaminate the normal operation CR intake of the affected unit.

50 of 53

Enclosure PG&E Letter DCL-16-044 Table 3-7 3

Effect of Updated CR X/Qs (sec/m )on the Dose Consequences in the CR Following a Main Steam Line Break Rece1;1tor - Release Point 0-2hr 2-8 hr 8-10.73 hr 10.73-30 hr CR NOP Intake - Faulted SG (Break Location) Note 1 CR NOP Intake - Intact SG (MSSVs/10 Percent ADVs) - 8.60E-04 Note 2 8.12E-04 1.24E-02 7.35E-03 3.01 E-03 3.01 E-03 CR lnleakage - Faulted SG (Break Location) 1.14E-02 7.22E-03 3.00E-03 3.00E-03 2.78E-03 1.63E-03 1.63E-03 CR lnleakage - Intact SG (MSSVs/10 Percent ADVs) -----

2.46E-03 1.59E-03 1.59E-03 CR Emergency Intake & Bypass - Faulted SG (Break 7.65E-05 4.78E-05 1.86E-05 1.86E-05 Location) 6.85E-05 4.70E-05 1.85E-05 1.85E-05 CR Emergency Intake & Bypass - Intact SG (MSSVs/10 1.57E-05 9.60E-06 9.60E-06 Percent ADVs) 1.40E-05 9.40E-06 9.40E-06 Impact of Updated X/Qs on the CR Dose Since all of the updated X/Q values are less than the original X/Q values, the CR doses reported in LAR 15-03 (specifically, Enclosure Attachment 2 of Reference 6) for the MSLB rema in bounding .

Note 1:

ARCON96-based X/Qs are not applicable for these cases given that the horizontal distance from the source to the receptor is 1.5 m (which is much less than the 10-m required by the ARCON96 methodology).

Note 2:

Due to the proximity of the release from the MSSVs/10 Percent ADVs to the normal operation CR intake of the affected unit, and due to the high vertical velocity of the steam discharge from the MSSVs/10 Percent ADVs , the resultant plume from the MSSVs/10 Percent ADVs will not contaminate the normal operation CR intake of the affected unit. Thus the X/Qs presented reflect those applicable to the CR intake of the unaffected unit.

51 of 53

Enclosure PG&E Letter DCL-16-044 TABLE 3-8 3

Effect of Updated CR X/Qs (sec/m ) on the Dose Consequences in the CR Following a Steam Generator Tube Rupture Release Location I Receptor 0-179 s 179-257.2 s 257.2 s- 2 h 2-8 hr 8-10.73 hr Control Room (CR} Normal Intakes 1.29E-03

- Plant Vent ----- ----- ----- -----

1.29E-03 8.60E-04

- MSSVs/10 Percent ADVs (Note 1) ----- ----- ----- -----

8.12E-04 CR Infiltration 1.26E-03

- Plant Vent ----- ----- ----- -----

1.25E-03 2.78E-03 2.78E-03 1.49E-03L 1.49E-03L

- MSSVs/10 Percent ADVs ----- 2 2 2.46E-03 2.46E-03 1.47E-03 1.47E-03 CR Pressurization Intake 1.57E-05 7.65E-06L 7.65E-06L

- MSSVs/10 Percent ADVs ----- -----

1.40E-05 9.40E-062 9.40E-062 Impact of Updated X/Qs on the CR Dose All of the updated X/Q values are either the same or less than the original X/Q values with the exception of the X/Q values associated with time period s between 2 to 10.73 hours8.449074e-4 days <br />0.0203 hours <br />1.207011e-4 weeks <br />2.77765e-5 months <br /> for releases from the MSSVs/10 Percent ADVs to the CR Pressurization intakes. The increase in X/Q values for the time period s between 2 to 10.73 hours8.449074e-4 days <br />0.0203 hours <br />1.207011e-4 weeks <br />2.77765e-5 months <br /> is an artifact of the method of selection of the X/Q values as described in Note 2 below.

Taking into consideration the decrease in X/Q values for the earlier time interval with more dominant dose consequences, as well as the fact that the dose contribution in the CR due to the MSSV/10 Percent ADV releases via the CR Pressurization intake is several decades less than the dose contribution due to CR in-leakage, it is concluded that the effect of the above increase in X/Q values is insignificant, and that the CR doses reported in LAR 15-03 {specifically, Enclosure Attachment 2 of Reference 6) for the SGTR remain bounding .

Note 1:

Due to the proximity of the release from the MSSVs/10 Percent ADVs to the normal operation CR intake of the affected unit, and due to the high vertical velocity of the steam discharge from the MSSVs/10 Percent AD Vs, the resu ltant plume from the MSSVs/10 Percent ADVs will not contaminate the normal operation CR intake of the affected unit. Thus the X/Qs presented reflect those applicable to the CR intake of the unaffected unit.

Note 2:

Since the 0-2 hour activity intake following a SGTR controls the 30-day integrated dose, the SGTR dose model utilizes a simplified model with respect to selection of the X/Q values for the 2-10.73 hr time period . Specifically, the bounding X/Q value is selected for the release point/receptor for the 0-2 hr time period , but unlike the dose models used for the other accidents, the X/Q values for time periods beyond t=2 hr, are not switched to the other unit if they display higher values .

52 of 53

Enclosure PG&E Letter DCL-16-044 Table 3-9 Effect of Updated CR X/Qs (sec/m 3 ) on the Dose Consequences in the CR Following a Loss of Load Release 1;1oint and rece1;1tor 0-2 hr 2-8 hr 8-10.73 hr 8.60E-04 5.58E-04 5.58E-04 MSSVs/10 Percent ADVs to CR NOP Intake (Note 1) 8.12E-04 5.32E-04 5.32E-04 MSSVs/10 Percent ADVs to CR In leakage (CR 2.78E-03 1.63E-03 1.63E-03 Centerline) 2.46E-03 1.59E-03 1.59E-03 Impact of Updated X/Qs on the CR Dose Since all of the updated XJQ values are less than the original XJQ values, the CR doses reported in LAR 15-03 (specifically, Enclosure Attachment 2 of Reference 6) for the Loss-of-Load remain bounding .

Note 1:

Due to the proximity of the release from the MSSVs/10 Percent ADVs to the normal operation CR intake of the affected unit, and due to the high vertical velocity of the steam discharge from the MSSVs/10 Percent ADVs , the resultant plume from the MSSVs/10 Percent ADVs will not contaminate the normal operation CR intake of the affected unit. Thus , the X/Qs presented reflect those applicable to the CR intake of the unaffected unit.

53 of 53

Enclosure Attachment 1 PG&E Letter DCL-16-044 ATTACHMENT 1 Diablo Canyon Power Plant Technical Assessment Prepared by WECTEC Global Project Services Inc. (WECTEC)

Implementation of Alternative Source Terms Summary of Dose Analyses and Results Revision 2

Enclosure Attachment 2 PG&E Letter DCL-16-044 ATTACHMENT 2 Diablo Canyon Power Plant Updated Final Safety Analysis Report Markup (For Information Only)

Revision 2

DCPP UNITS 1 & 2 FSAR UPDATE TABLE 2.3-145 EXCLUSION AREA BOUNDARY AND LOW POPULATION ZONE ATMOSPHERIC DISPERSION FACTORS 3

x!Q (sec/m )

Receptor 0 - 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> 2 - 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> 8 - 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 1 - 4 days 4 - 30 days Unit 1 EAB 2.50E-04 Unit 2 EAB 2.17E-04 Unit 1/2 LPZ 2.00E-05 8.94E-06 6.14E-06 2.72E-06 8.48E-07 Notes:

3

1. An EAB x/O value of 2 .5E-04 sec/m is used for radiological dose calculations from all release points.

2 . The 0.5% sector dependent X/Q va lues are presented above. The worst-case downwind sector for the 0-2 hour period for all receptors is northwest. For Un it 1/2 LPZ the worst case sector for periods 2-8 hours and longer is southeast.

DCPP UNITS 1 & 2 FSAR UPDATE TABLE 2.3-147 UNIT 1 CONTROL ROOM INTAKE AND CENTER ATMOSPHERIC DISPERSION FACTORS (SEC/M 3)

Release Point and Receptor 0-2 Hour 2-8 Hour 8-24 Hour 1-4 Day 4-30 Day Unit 1 Containment Building Edge to Unit 1 Control Room (CR) Normal Intake 1.44E-03 7.03E-04 3.00E-04 3.06E-04 3.04E-04 Unit 1 Containment Building Edge to Unit 2 CR Normal Intake 6.41E-04 3.51 E-04 1.49E-04 1.49E-04 1.36E-04 Unit 1 Containment Building Edge to Unit 1 CR Emergency lntake 4 4.09E-04 2.31 E-04 9.54E-05 8.61E-05 7.04E-05 Unit 1 Containment Building Edge to Unit 2 CR Emergency lntake 4 1.57E-04 7.82E-05 2.57E-05 2.71E-05 2.32E-05 Unit 1 Containment Building Edge to CR Center 9.21E-04 4.38E-04 1.77E-04 1.80E-04 1.67E-04 Unit 1 Plant Vent to Unit 1 CR Normal Intake 1.67E-03 1.22E-03 4.93E-04 4.89E-04 4.36E-04 Unit 1 Plant Vent to Unit 2 CR Normal Intake 9.08E-04 6.53E-04 2.69E-04 2.62E-04 2.38E-04 Unit 1 Plant Vent to Unit 1 CR Emergency lntake 4 5.56E-04 3.33E-04 1.29E-04 1.11 E-04 8.34E-05 Unit 1 Plant Vent to Unit 2 CR Emergency lntake 4 2.22E-04 1.47E-04 5.44E-05 5.52E-05 4.45E-05 Unit 1 Plant Vent to CR Center 1.25E-03 8.93E-04 3.47E-04 3.46E-04 2.98E-04 Unit 1 Containment Penetration (GE Area) to Unit 1 CR Normal Intake 6.59E-03 2.81E-03 1.16E-03 1.07E-03 8.31E-04 Unit 1 Containment Penetration (GE Area) to Unit 2 CR Normal Intake 2.07E-03 1.13E-03 3.73E-04 3.78E-04 3.05E-04 Unit 1 Containment Penetration (GE Area) to Unit 1 CR Emergency lntake 4 3.67E-04 2.31E-04 9.02E-05 8.38E-05 6.42E-05 Unit 1 Containment Penetration (GE Area) to Unit 2 CR Emergency lntake 4 2.39E-04 1.20E-04 4.27E-05 4.22E-05 3.39E-05 Unit 1 Containment Penetration (GE Area) to CR Center 3.01E-03 1.33E-03 5.43E-04 4.93E-04 4.01E-04 Unit 1 Containment Penetration (GW/FW Area) to Unit 1 CR Normal Intake 4.86E-03 3.43E-03 1.35E-03 1.37E-03 1.25E-03 Unit 1 Containment Penetration (GW/FW Area) to Unit 2 CR Normal Intake 1.35E-03 9.79E-04 3.86E-04 3.84E-04 3.46E-04 Unit 1 Containment Penetration (GW/FW Area) to Unit 1 CR Emergency lntake 4 8.05E-04 5.32E-04 2.12E-04 1.86E-04 1.40E-04 Unit 1 Containment Penetration (GW/FW Area) to Unit 2 CR Emergency lntake 4 2.40E-04 1.53E-04 4.83E-05 5.20E-05 4.41 E-05 Unit 1 Containment Penetration (GW/FW Area) to CR Center 2.55E-03 1.80E-03 7.17E-04 7.13E-04 6.50E-04 Unit 1 RWST Vent to Unit 1 CR Emergency lntake 4 *5 3.24E-04 1.83E-04 6.94E-05 6.82E-05 5.57E-05 45 Unit 1 RWST Vent to Unit 2 CR Emergency lntake

• 1.88E-04 9. 18E-05 3.40E-05 3.28E-05 2.69E-05 5

Unit 1 RWST Vent to CR Center 1.01 E-03 4.26E-04 1.85E-04 1.62E-04 1.31E-04

DCPP UNITS 1 & 2 FSAR UPDATE TABLE 2.3-147 (Continued)

UNIT 1 CONTROL ROOM INTAKE AND CENTER ATMOSPHERIC DISPERSION FACTORS 3

(SEC/M )

Release Point and Receptor 0-2 Hour 2-8 Hour 8-24 Hour 1-4 Day 4-30 Day 1

Unit 1 MSSVs to Unit 1 CR Normal Intake

• 2 NIA NIA NIA NIA NIA 3

Unit 1 MSSVs to Unit 2 CR Normal Intake 4.05E-03 2.65E-03 1.02E-03 1.02E-03 8.95E-04 Unit 1 MSSVs to Unit 1 CR Emergency Intake 3* 4 4.52E-04 2.86E-04 1.14E-04 1.01E-04 7.82E-05 Unit 1 MSSVs to Unit 2 CR Emergency lntake 3

• 4 2.75E-04 1.49E-04 4.79E-05 5.02E-05 4.14E-05 3

Unit 1 MSSVs to CR Center 1.23E-02 7.28E-03 2.21E-03 2.43E-03 2.06E-03 1 2 Unit 1 10% ADVs to Unit 1 CR Normal Intake

• NIA NIA NIA NIA NIA Unit 1 10% ADVs to Unit 2 CR Normal lntake 3 4.06E-03 2.66E-03 1.03E-03 1.02E-03 9.03E-04 Unit 1 10% ADVs to Unit 1 CR Emergency lntake 3* 4 4.52E-04 2.86E-04 1.14E-04 1.01E-04 7.82E-05 Unit 1 10% ADVs to Unit 2 CR Emergency lntake 3* 4 2.75E-04 1.50E-04 4.82E-05 5.03E-05 4.15E-05 Unit 1 10% ADVs to CR Center3 1.23E-02 7.34E-03 2.22E-03 2.45E-03 2.08E-03 Unit 1 MSL Break Location to Unit 1 CR Normal Intake 1 NIA NIA NIA NIA NIA Unit 1 MSL Break Location to Unit 2 CR Normal Intake 4.0?E-03 2.86E-03 1.11 E-03 1.10E-03 9.?0E-04 Unit 1 MSL Break Location to Unit 1 CR Emergency lntake 4 4.30E-04 2.89E-04 1.14E-04 1.00E-04 7.63E-05 Unit 1 MSL Break Location to Unit 2 CR Emergency lntake 4 2.74E-04 1.54E-04 4.98E-05 5.12E-05 4.20E-05

• Unit 1 MSL Break Location to CR Center 1.14E-02 7.05E-03 2.19E-03 2.37E-03 1.98E-03 Unit 1 FHB to Unit 1 CR Normal Intake 6.68E-03 Unit 1 FHB to Unit 2 CR Normal Intake 2.69E-03 Unit 1 FHB to Unit 1 CR Emergency lntake 4 3.28E-04 Unit 1 FHB to Unit 2 CR Emergency lntake 4 2.39E-04 Unit 1 FHB to CR Center 3.54E-03 Unit 1 Equipment Hatch to Unit 1 CR Normal Intake 2.43E-02 Unit 1 Equipment Hatch to Unit 2 CR Normal Intake 2.67E-03 Unit 1 Equipment Hatch to Unit 1 CR Emergency lntake 4 4.32E-04 Unit 1 Equipment Hatch to Unit 2 CR Emergency lntake 4 2.45E-04 Unit 1 Equipment Hatch to CR Center 5.06E-03

DCPP UNITS 1 & 2 FSAR UPDATE TABLE 2.3-148 UN IT 2 CONTROL ROOM INTAKE AND CENTER ATMOSPHERIC DISPERSION FACTORS (S EC/M3)

Release Point and Receptor 0-2 Hour 2-8 Hour 8-24 Hour 1-4 Day 4-30 Day Unit 2 Containment Edge to Unit 2 CR Normal Intake 1.99E-03 9.59E-04 4.60E-04 4.04E-04 3.20E-04 Unit 2 Conta inment Edge to Unit 1 CR Normal Intake 6.89E-04 3.85E-04 1.66E-04 1.41E-04 1.08E-04 Unit 2 Containment Edge to Unit 1 CR Emergency lntake 4 1.66E-04 1.05E-04 4.19E-05 3.73E-05 2.93E-05 4

Unit 2 Containment Edge to Unit 2 CR Emergency lntake 3.78E-04 1.47E-04 5.99E-05 5.87E-05 4.90E-05 Unit 2 Containment Edge to CR Center 1.09E-03 5.49E-04 2.47E-04 2.12E-04 1.?0E-04 Unit 2 Plant Vent to Unit 1 CR Normal Intake 1.49E-03 9.29E-04 3.80E-04 3.16E-04 2.21 E-04 Unit 2 Plant Vent to Unit 1 CR Normal Intake 7.79E-04 4.80E-04 1.98E-04 1.65E-04 1.15E-04 Unit 2 Plant Vent to Unit 1 CR Emergency lntake 4 2.02E-04 1.27E-04 5.11E-05 4.20E-05 3.15E-05 Unit 2 Plant Vent to Unit 2 CR Emerge ncy lntake 4 5.61E-04 2.91E-04 1.16E-04 1.02E-04 8.03E-05 Unit 2 Plant Vent to CR Center 1.12E-03 6.99E-04 2.82E-04 2.34E-04 1.68E-04 Unit 2 Containment Penetration (GE Area) to Unit 2 CR Normal Intake 6.60E-03 3.01E-03 1.17E-03 1.20E-03 1.01 E-03 Unit 2 Containment Penetration (GE Area) to Unit 1 CR Normal Intake 2.08E-03 1.38E-03 5.62E-04 4.76E-04 3.59E-04 Unit 2 Containment Penetration (GE Area) to Unit 1 CR Emergency lntake 4 2.26E-04 1.57E-04 6.15E-05 5.47E-05 4.08E-05 Unit 2 Containment Penetration (GE Area) to Unit 2 CR Emergency lntake 4 3.74E-04 1.67E-04 6.72E-05 6.14E-05 5.08E-05 Unit 2 Containment Penetration (GE Area) to CR Center 3.09E-03 1.83E-03 7.22E-04 6.74E-04 5.35E-04 Unit 2 Containment Penetration (GW/FW Area) to Unit 2 CR Normal Intake 3.45E-03 1.14E-03 4.?0E-04 4.42E-04 2.93E-04 Unit 2 Containment Penetration (GW/FW Area) to Unit 1 CR Normal Intake 1.20E-03 6.21E-04 2.49E-04 2.09E-04 1.41 E-04 Unit 2 Containment Penetration (GW/FW Area) to Unit 1 CR Emergency lntake 4 2.26E-04 1.59E-04 6.50E-05 5.36E-05 3.96E-05 Unit 2 Containment Penetration (GW/FW Area) to Unit 2 CR Emergency lntake 4 8.08E-04 4.0?E-04 1.43E-04 1.42E-04 1.14E-04 Unit 2 Containment Penetration (GW/FW Area) to CR Center 2.19E-03 1.16E-03 4.56E-04 3.83E-04 2.58E-04 Unit 2 RWST Vent to Unit 1 CR Emergency lntake 4 *5 1.89E-04 1.17E-04 4.52E-05 4.30E-05 3.40E-05 Unit 2 RWST Vent to Unit 2 CR Emergency lntake 4 *5 3.1 7E-04 1.40E-04 5.64E-05 5.12E-05 4.16E-05 Unit 2 RWST Vent to CR Center5 1.05E-03 5.55E-04 2.12E-04 2.12E-04 1.72E-04

DCPP UNITS 1 & 2 FSAR UPDATE TABLE 2.3-148 (Continued)

UNIT 2 CONTROL ROOM INTAKE AND CENTER ATMOSPHERIC DISPERSION FACTORS (SEC/M 3)

Release Point and Receptor 0-2 Hour 2-8 Hour 8-24 Hour 1-4 Day 4-30 Day Unit 2 MSSVs to Unit 1 CR Normal Intake 3 3.80E-03 2.36E-03 9.80E-04 8.00E-04 5.99E-04 12 Unit 2 MSSVs to Unit 2 CR Normal Intake

• N/A NIA N/A N/A N/A Unit 2 MSSVs to Unit 1 CR Emergency lntake 3 .4 2.79E-04 1.87E-04 7.33E-05 6.50E-05 4.89E-05 Unit 2 MSSVs to Unit 2 CR Emergency lntake 3 .4 4.39E-04 2.14E-04 7.68E-05 7.54E-05 6.09E-05 Unit 2 MSSVs to CR Center 3 1.19E-02 7.90E-03 3.22E-03 2.68E-03 2.05E-03 Unit 2 10% ADVs to Unit 1 CR Normal lntake 3 3.82E-03 2.36E-03 9.86E-04 8.01E-04 6.01E-04 Unit 2 10% ADVs to Unit 2 CR Normal Intake 1*2 N/A N/A N/A N/A N/A Unit 2 10% ADVs to Unit 1 CR Emergency lntake 3.4 2.77E-04 1.88E-04 7.35E-05 6.49E-05 4.89E-05 Unit 2 10% ADVs to Unit 2 CR Emergency lntake 3*4 4.39E-04 2.14E-04 7.68E-05 7.54E-05 6.09E-05 Unit 2 10% ADVs to CR Center3 1.19E-02 7.94E-03 3.23E-03 2.70E-03 2.05E-03 Unit 2 MSL Break Location to Unit 1 CR Normal Intake 3.75E-03 2.37E-03 1.00E-03 7.93E-04 5.81 E-04 Unit 2 MSL Break Location to Unit 2 CR Normal Intake 1 N/A N/A N/A N/A N/A Unit 2 MSL Break Location to Unit 1 CR Emergency lntake 4 2.72E-04 1.88E-04 7.40E-05 6.42E-05 4.80E-05 Unit 2 MSL Break Location to Unit 2 CR Emergency lntake 4 4.29E-04 2. 19E-04 7. 73E-05 7.57E-05 6.11 E-05 Unit 2 MSL Break Location to CR Center 1.0BE-02 7.22E-03 3.00E-03 2.44E-03 1.83E-03 Unit 2 FHB to Unit 1 CR Normal Intake 2.68E-03 Unit 2 FHB to Unit 2 CR Normal Intake 6.68E-03 Unit 2 FHB to Unit 1 CR Emergency lntake 4 2.45E-04 Unit 2 FHB to Unit 2 CR Emergency lntake 4 3.23E-04 Unit 2 FHB to CR Center 3.61E-03 Unit 2 Equipment Hatch to Unit 1 CR Normal Intake 2.47E-03 Unit 2 Equipment Hatch to Unit 2 CR Normal Intake 2.48E-02 Unit 2 Equipment Hatch to Unit 1 CR Emergency lntake 4 2.46E-04 Unit 2 Equipment Hatch to Unit 2 CR Emergency lntake 4 4.26E-04 Unit 2 Equipment Hatch to CR Center 5.09E-03

DCPP UNITS 1 & 2 FSAR UPDATE TABLE 2.3-149 UNITS 1 AND 2 TECHNICAL SUPPORT CENTER INTAKE AND CENTER ATMOSPHERIC 3

DISPERSION FACTORS (SEC/M )

Release Point and Receptor 0-2 Hour 2-8 Hour 8-24 Hour 1-4 Day 4-30 Day UNIT 1 Unit 1 Containment Build ing Edge to TSC Normal Intake 2.45E-04 1.16E-04 4.08E-05 4.17E-05 3.48E-05 Unit 1 Containment Building Edge to TSC Center 2.74E-04 1.31 E-04 4.80E-05 4.70E-05 4.00E-05 Unit 1 Plant Vent to TSC Normal Intake 3.04E-04 1.76E-04 6.82E-05 6.21 E-05 5.20E-05 Unit 1 Plant Vent to TSC Center 3.41 E-04 1.94E-04 7.63E-05 6.61 E-05 5.62E-05 Unit 1 RWST Vent to TSC Normal Intake 2.48E-04 1.15E-04 4.52E-05 4.11 E-05 3.40E-05 Unit 1 RWST Vent to TSC Center 2.76E-04 1.23E-04 5.00E-05 4.53E-05 3.65E-05 Unit 1 Containment Penetration (GE Area) to TSC Normal Intake 3.51 E-04 1.61 E-04 6.43E-05 5.89E-05 4.83E-05 Unit 1 Containment Penetration (GE Area) to TSC Center 4.05E-04 1.80E-04 7.26E-05 6.60E-05 5.37E-05 Unit 1 Containment Penetration (GW/FW Area) to TSC Normal Intake 4.44E-04 2.48E-04 8.04E-05 8.31 E-05 6.68E-05 Unit 1 Containment Penetration (GW/FW Area) to TSC Center 5.61 E-04 2.93E-04 1.00E-04 9.86E-05 8.16E-05 UNIT2 Unit 2 Containment Building Edge to TSC Normal Intake 5.31E-04 1.97E-04 8.36E-05 8.25E-05 6.72E-05 Unit 2 Containment Building Edge to TSC Center 5.39E-04 2.01E-04 8.73E-05 8.78E-05 6.84E-05 Unit 2 Plant Vent to TSC Normal Intake 5.47E-04 2.27E-04 1.03E-04 8.46E-05 6.68E-05 Unit 2 Plant Vent to TSC Center 5.41E-04 2.09E-04 9.67E-05 7.95E-05 6.43E-05 Unit 2 RWST Vent to TSC Normal Intake 3.52E-04 1.46E-04 6.12E-05 5.66E-05 4.63E-05 Unit 2 RWST Vent to TSC Center 3.61 E-04 1.48E-04 6.30E-05 5.80E-05 4.69E-05 Unit 2 Containment Penetration (GE Area) to TSC Normal Intake 5.22E-04 2.21E-04 9.14E-05 8.61E-05 6.71 E-05 Unit 2 Containment Penetration (GE Area) to TSC Center 5.49E-04 2.24E-04 9.60E-05 8.85E-05 7.05E-05 Unit 2 Containment Penetration (GW/FW Area) to TSC Normal Intake 1.71E-03 7.07E-04 2.98E-04 2.76E-04 2.21 E-04 Unit 2 Containment Penetration (GW/FW Area) to TSC Center 1.76E-03 7.16E-04 3.01 E-04 2.84E-04 2.28E-04

DCPP UNITS 1 & 2 FSAR UPDATE TABLE 15.5-98 LOSS OF ELECTRICAL LOAD Control Room Limiting Atmospheric Dispersion Factors (sec/m 3 )

Release QOint and receQtor 0-2hr 2-8 hr 8-10.73hr MSSVs/10% ADVs to CR NOP Intake (Note 1) 8.12E-04 5.32E-04 5.32E-04 MSSVs/10% AD Vs to CR In leakage (CR 2.46E-03 1.59E-03 1.59E-03 Centerline)

Note 1: Due to the proximity of the release from the MSSVs/10% ADVs , to the normal operation CR intake of the affected unit, and due to the high vertical velocity of the steam discharge from the MSSVs/10% ADVs, the resultant plume from the MSSVs/10%

ADVs will not contaminate the normal operation CR intake of the affected unit. Thus the x!Q s presented reflect those applicable to the CR intake of the unaffected unit.

Note 2: The selection of the x!Q values for the release points/ receptors listed above are intended to provide bounding dose estimates for an event at either unit.

Revision 19 May 2010

DCPP UNITS 1 & 2 FSAR UPDATE 15.5-238 LOSS OF COOLANT ACCIDENT 3

Control Room Limiting Atmospheric Dispersion Factors (sec/m )96-720 Release Location I Receptor 0-2 hr 2-8 hr 8-24 hr 24-96 hr hr Control Room Normal Intakes Plant Vent Release

- Affected Unit Intake 1.67E-03 ----- ----- ----- -----

- Non-Affected Unit Intake 9 .08E-04 ----- ----- ----- -----

Containment Penetration Areas

- Affected Unit Intake 6.60E-03 ----- ----- ----- -----

- Non-Affected Unit Intake 2.08E-03 ----- ----- ----- -----

Control Room Infiltration Plant Vent 1.25E-03 8.93E-04 3.47E-04 3.46E-04 2.98E-04 Containment Penetration Areas 3.09E-03 1.83E-03 7.22E-04 7.13E-04 6 .50E-04 RWST Vent 1.05E-03 5.55E-04 2.12E-04 2 .12E-04 1.72E-04 Control Room Pressurization Intake Plant Vent 5.55E-05 3.68E-05 1.36E-05 1.38E-05 1.11 E-05 Containment Penetration Areas 6.00E-05 3.98E-05 1.63E-05 1.37E-05 1.1OE-05 RWST Vent 4.73E-05 2 .93E-05 1.13E-05 1.08E-05 8.50E-06 Note 1: Release from the Containment penetration areas (i.e., areas GE or GW & FW):

applicable to containment leakage and ESF system leakage that occurs in the Containment Penetration Area Note 2: Release from Plant Vent: applicable to ESF system leakage that occurs in the Auxiliary building, MEDT releases , RHR Pump Seal Failure Release and Containment Vacuum/Pressure Relief Line Release Note 3: The selection of the x/Q values for the release points/ receptors listed above are intended to provide bounding dose estimates for an event at either unit Revi sion 11 November 1996

DCPP UNITS 1 & 2 FSAR UPDATE TABLE 15.5-23E LOSS OF COOLANT ACCIDENT 3

TSC Limiting Atmospheric Dispersion Factors (sec/m )96-720 Release Location I Rece12tor 0-2 hr 2-8 hr 8-24 hr 24-96 hr hr I TSC Normal Intakes I Plant Vent Release 5.47E-04 ----- ----- ----- -----

Containment Penetration Areas 1.71E-03 RWST Vent 3.52E-04 ----- ----- ----- ----- I TSC Infiltration I Plant Vent 5.41 E-04 2 .09E-04 9.67E-05 7.95E-05 6.43E-05 Containment Penetration 1.76E-03 7 .16E-04 3.01 E-04 2.84E-04 2.28E-04 Areas RWST Vent 3.61 E-04 1.48E-04 6.30E-05 5.80E-05 4.69E-05 I CR/TSC Pressurization Intake I Plant Vent ----- 3.68E-05 1.36E-05 1.38E-05 1.11 E-05 I Containment Penetration Areas ----- 3.98E-05 1.63E-05 1.37E-05 1.10E-05 I RWST Vent ----- 2 .93E-05 1.13E-05 1.08E-05 8.50E-06 I I

Note 1: Release from the Containment penetration areas (i.e., areas GE or GW & FW):

applicable to containment leakage and ESF system leakage that occurs in the Containment Penetration Area Note 2: Release from Plant Vent: applicable to ESF system leakage that occurs in the Auxiliary building , MEDT releases , RHR Pump Seal Failure Release and Containment Vacuum/Pressure Relief Line Release Note 3: The selection of the x!O values for the release points/ receptors listed above are intended to provide bounding dose estimates for an event at either unit Revision 11 November 1996

DCPP UNITS 1 & 2 FSAR UPDATE TABLE 15.5-34B MAIN STEAM LINE BREAK 3

Control Room Limiting Atmospheric Dispersion Factors (sec/m )

Rece12tor - Release Point 0-2hr 2-8 hr 8-10.73 hr 10.73-3g hr I

CR NOP Intake - Faulted SG (Break Note 1 Location)

CR NOP Intake - Intact SG (MSSVs/10%

8.12E-04 AD Vs) - Note 2 CR lnleakage - Faulted SG (Break 1.14E-02 7.22E-03 3.00E-03 3.00E-C3 Location)

CR lnleakage - Intact SG (MSSVs/10%

2.46E-03 1.59E-03 1.59E-03 -----

ADVs)

CR Emergency Intake & Bypass -

6.85E-05 4.?0E-05 1.85E-05 1.85E-C 5 Faulted SG (Break Location)

CR Emergency Intake & Bypass - Intact 1.40E-05 9.40E-06 9.40E-06 -----

SG (MSSVs/10% ADVs)

Notes:

1. ARCON96 based x/Q s are not applicable for these cases given that the horizontal distance from the source to the receptor is 1.5 meters (which is much less than the 10 meters required by ARCON96 methodology) .

2. Due to the proximity of the release from the MSSVs/10% ADVs, to the normal operation CR intake of the affected unit, and due to the high vertical velocity of the steam discharge from the MSSVs/10% ADVs, the resu ltant plume from the MSSVs/10% ADVs will not contaminate the normal operation CR intake of the affected unit. Thus the x!O s presented reflect those applicable to the CR intake of the unaffected unit.

3. The selection of the xtQ values for the release points/ receptors listed above are intended to provide bounding dose estimates for an event at either unit Revision 19 May 2010

DCPP UNITS 1 & 2 FSAR UPDATE TABLE 15.5-428 LOCKED ROTOR ACCIDENT Control Room Limiting Atmospheric Dispersion Factors (sec/m 3 )

Release point and receptor 0-2hr 2-8 hr 8-10.73 hr MSSVs/10% ADVs to CR NOP Intake (Note 1) 8.12E-04 5.32E-04 5.32E-04 MSSVs/10% ADVs to CR In-leakage (CR 2.46E-03 1.59E-03 1.59E-03 Centerline)

Note 1: Due to the proximity of the release from the MSSVs/10% ADVs, to the normal operation CR intake of the affected unit, and due to the high vertical velocity of the steam discharge from the MSSVs/10% ADVs , the resultant plume from the MSSVs/10% ADVs will not contaminate the normal operation CR intake of the affected unit. Thus the x!Q s presented reflect those applicable to the CR intake of the unaffected unit.

Note 2: The selection of the y)Q values for the release points/ receptors listed above are intended to provide bounding dose estimates for an event at either unit Revision 19 May 2010

DCPP UNITS 1 & 2 FSAR UPDATE TABLE 15.5-47B FUEL HANDLING ACCIDENT IN THE FUEL HANDLING BUILDING OR CONTAINMENT Control Room Limiting Atmospheric Dispersion Factors (sec/m 3 )

Release Location I Receptor 0-22 s 22 sec - 2 hr 2-8 hr 8-24 hr 1-4 d 4-30 ~

Control Room Normal Intakes I Containment Hatch Release

- Affected Unit Intake 2.48E-02 ----- ----- ----- ----- -----

- Non-Affected Unit Intake 2.67E-03 ---- ----- ----- ----- -----

Plant Vent Release

- Affected Unit Intake 1.67E-03 ---- ----- ----- ----- -----

- Non-Affected Unit Intake 9.08E-04 ----- ----- ----- ----- -----

FHB Out-leakaqe points

- Affected Unit Intake 6.68E-03 ----- ----- ----- - --- -----

- Non-Affected Unit Intake 2.69E-03 ----- ----- ----- ----- -----

Control Room Infiltration I Containment Hatch Release 5.09E-03 5.09E-03 ----- ----- ----- -----

Plant Vent 1.25E-03 1.25E-03 ----- ----- ----- -----

FHB Out-leakaqe points 3.61 E-03 3.61 E-03 ----- ----- ----- -----

Control Room Pressurizati on Intake I Containment Hatch Release ----- 6.15E-05 ----- ----- ----- -----

Plant Vent ----- 5.55E-05 ----- ----- ----- -----

FHB Out-leakaqe points ----- 6.13E-05 ----- ----- ----- -----

Note 1: Release from the Containment Hatch: applicable to FHA in Containment Note 2: Release from Plant Vent I FHB Out-leakage: applicable to FHA in FHB Note 3: The selection of the x/Q values for the release points/ receptors listed above are intended to provide bounding dose estimates for an event at either unit Revision 18 October 2008

DCPP UNITS 1 & 2 FSAR UPDATE TABLE 15.5-528 CONTROL ROD EJECTION ACCIDENT 3

Control Room Limiting Atmospheric Dispersion Factors (sec/m )

Release Location I 10.73-0-2hr 2-8hr 8-10.73hr 24-96hr 96-72phr Receptor 24hr CR Normal Intakes I Containment leakage

- Affected Unit Intake 6.60E-03 ----- ----- ----- ----

- Non-Affected Unit Intake 2.08E-03 ----- ----- ----- ----

MSSVs/10% ADVs

- Affected Unit Intake Note 3 ----- ----- ----- ----- ----

- Non-Affected Unit Intake 8.12E-04 ----- ----- ----- ----- ----

CR Infiltration I Containment leakaoe 3.09E-03 1.83E-03 7.22E-04 7.22E-04 7.13E-04 6.50E 04 MSSVs/10% ADVs 2.46E-03 1.59E-03 1.59E-03 ----- ----- ----

CR Pressurization Intake I Containment leakage 6.00E-05 3.98E-05 1.63E-05 1.63E-05 1.37E-05 1.10E 05 MSSVs/10% ADVs 1.40E-05 9.40E-06 9.40E-06 ----- ----- ----

Note 1: Containment leakage: Used for Containment release scenario; based on Containment penetration area release point.

Note 2: MSSV /10% ADVs: Used for Secondary System Release Scenario; Note 3: Due to the proximity of the release from the MSSVs/10% ADVs, to the normal operation CR intake of the affected unit, and due to the high vertical velocity of the steam discharge from the MSSVs/10% ADVs, the resultant plume from the MSSVs/10% ADVs will not contaminate the normal operation CR intake of the affected unit.

Note 4: The selection of the x/Q values for the release points/ receptors listed above are intended to provide bounding dose estimates for an event at either unit Revision 11 November 1996

DCPP UNITS 1 & 2 FSAR UPDATE TABLE 15.5 64 Sheet 2 of 2 PARAMETERS USED IN EVALUATING RADIOLOGICAL CONSEQUENCES FOR SGTR ANALYSIS TABLE 15.5-64B STEAM GENERATOR TUBE RUPTURE 3

Control Room Limiting Atmospheric Dispersion Factors (sec/m )

Release Location I Receptor 0-179 s 179-257.2 s 257.2 s- 2 h 2-8 hr 8-10.73 hr CR Normal Intakes I

- Plant Vent 1.29E-03 ----- ----- ----- ----- I

- MSSVs/10% ADVs (Note 1) ----- 8.12E-04 ----- ----- ----- I CR Infiltration I

- Plant Vent 1.25E-03 ----- ----- ----- ----- I 2

- MSSVs/10% ADVs ----- 2.46E-03 2.46E-03 1.47E-032 1.47E-Op CR Pressurization Intake I 2

9.40E-0~

2

- MSSVs/10% ADVs ----- ----- 1.40E-05 9.40E-06 I

Revision 19 May 2010

DCPP UNITS 1 & 2 FSAR UPDATE TABLE 15.5 68 ATMOSPHERIC DISPERSION i:=ACTORS Ar>lD 8REATl=ll~JG RATES SGTR ANALYSIS OFFSITE EXPOSURE

+tme Exclusion Area Boundary Low Population Breathing RateW (hours) x!Q (Sec/ma......

) -- Zone y/Q (Sec/mat -----fma/Sec) 4 4 4 5.29 x 10 2.2x10 3.47 x 10 4

2.2 x 104 3.47 x 10 CONTROL ROOM EXPOSURE

+tme Control Room Filtered Control Room Control Room Pressurization Unfiltered Breathing RateW Pressurization (hours) y /Q (Sec/ma) Zone x!Q (Sec/mat -----fma/Sec)

G..g 4 4 4 7.05 x 10 1.96 x 10 3.47 x 10 4 4 4 8-24 5.38 x 10 1.49 x 10 3.47 x 10 4 4 4

~ 3.91 x 10 1.08 x 10 3.47 x 10

~ 2.27 x 104 6.29 x 10 4

3.4 7 x 10 4

Note 1: Due to the proxim ity of the release from the MSSVs/10% ADVs, to the normal operation CR intake of the affected unit, and due to the high vertical velocity of the steam discharge from the MSSVs/10% ADVs, the resultant plume from the MSSVs/10% ADVs will not contaminate the normal operation CR intake of the affected un it. Thus the x/Q s presented reflect those applicable to the CR intake of the unaffected unit.

Note 2: Since the 0-2hour activity intake following a SGTR controls the 30-day integrated dose, the SGTR dose model utilizes a simplified model with respect to selection of the X/Q values for the 2-10 .73hr time period. Specifically, the bounding X/Q value is selected for the release point I receptor for the 0-2 hr time period, but unlike the dose models used for the other accidents, the X/Q values for time periods beyond t=2hr, are not switched to the other unit if they display higher values.

Note 3: The selection of the x/Q values for the release points/ receptors listed above are intended to provide bounding dose estimates for an event at either unit.

Revision 16 June 2005

Enclosure Attachment 3 PG&E Letter DCL-16-044 ATTACHMENT 3 b~) 6: f.-..56 +- ~

(b.()-5 DATA DISC ~M~~

-di-3 tl 11 '

ATTENTION DCD FILES ON CD-ROM WERE NOT ADDED TO ADAMS