ML100480781

License Amendment Request Measurement Uncertainty Recapture Power Uprate Supplemental Information

ML100480781
Person / Time
Site:	Surry
Issue date:	02/04/2010
From:	Price J Virginia Electric & Power Co (VEPCO)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
09-223B, TAC MC8165, TAC MC8315
Download: ML100480781 (36)

Text

VIRGINIA ELECTRIC" AND POWER COMPANY RICHMOND, VIRGINIA 23261 February 4, 2010 U.S. Nuclear Regulatory Commission Serial No.

09-223B Attention: Document Control Desk NLOS/GDM R2 Washington, D.C. 20555 Docket Nos.

50-280 50-281 License Nos.

DPR-32 DPR-37 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)

SURRY POWER STATION UNITS 1 AND 2 LICENSE AMENDMENT REQUEST MEASUREMENT UNCERTAINTY RECAPTURE POWER UPRATE SUPPLEMENTAL INFORMATION

References:

1. Letter from Stephen Monarque (NRC) to David A. Christian (Dominion), "Surry Power Station, Units 1 and 2, Issuance of Amendments Regarding the Redefinition of the Exclusion Area Boundary", (TAC Nos. MC8315 and MC83165)", Serial No.06-701, August 10, 2006

2. Letter from Virginia Electric and Power Company to USNRC, "Virginia Electric and Power Company (Dominion), Surry Power Station Units 1 and 2, License Amendment Request, Measurement Uncertainty Recapture Power Uprate," Serial No.09-223, January 27, 2010 By letter dated January 27, 2010 (Serial No.09-223), Dominion submitted a measurement uncertainty recapture (MUR) power uprate License Amendment Request (LAR) for Surry Power Station Units 1 and 2 to increase the rated power of each unit by approximately 1.6%.

On the same date, proprietary information (for the Cameron ultrasonic flowmeter) required to support the license amendment request was submitted under separate cover (Serial No. 09-223A).

During a January 12, 2010 conference call, Dominion noted that we would also be providing a supporting submittal to facilitate the NRC's review of the plant accident analyses updates required by and discussed in the MUR power uprate LAR. These updates were identified during the preparation of the Surry MUR LAR. The attached information is being provided to support the NRC's overall MUR LAR review effort.

Serial No. 09-223B Docket Nos. 50-280/281 Page 2 of 3 Specifically, three independent changes in inputs and assumptions are required to be incorporated into the Surry Units 1 and 2 Steam Generator Tube Rupture (SGTR) and Main Steam Line Break (MSLB) accident analyses revisions as follows:

1. Updated Exclusion Area Boundary (EAB) X/Qs (approved in 2006, Reference 1),

2. Updated reactor coolant source term (change described in the MUR submittal, Reference 2), and

3. Updated steam flow (change described in the MUR submittal, Reference 2).

A discussion of the revised SGTR and MSLB dose consequences, based on the changes in the inputs and assumptions noted above, is provided in the attachment. In addition, the specific effect of the MUR power uprate on dose consequences as described in the MUR submittal is repeated in the attachment. The electronic media files and inputs to the RADTRAD model used for benchmarking are also enclosed in the attachment for the NRC's use as necessary.

In summary, the overall SGTR and MSLB dose consequences, as a result of all changes in inputs and assumptions supporting the MUR submittal, remain below the offsite and control room dose limits in 10 CFR 50.67 and Regulatory Guide 1.183.

If you have any questions or require additional information, please contact Mr. Gary Miller at (804) 273-2771.

Sincerely, J. Al 'n P ice Vic Pre ident - Nuclear Engineering COMMONWEALTH OF VIRGINIA COUNTY OF HENRICO The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by J. Alan Price, who is Vice President - Nuclear Engineering, of Virginia Electric and Power Company. He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that Company, and that the statements in the document are true to the best of his knowledge and belief.

Acknowledged before me this 414t.-day of *A

'jO., 2010.

My Commission Expires:

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Serial No. 09-223B Docket Nos. 50-280/281 Page 3 of 3 Commitments contained in this correspondence:

None

Attachment:

Revised SGTR and MSLB Dose Consequences Based on Changes in Inputs and Assumptions with Enclosed Electronic Media Files and Inputs to the RADTRAD Model Used for Benchmarking cc:

U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW Suite 23T85 Atlanta, Georgia 30303 NRC Senior Resident Inspector Surry Power Station State Health Commissioner Virginia Department of Health James Madison Building - 7th Floor 109 Governor Street Suite 730 Richmond, Virginia 23219 Ms. K. R. Cotton NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 G-9A 11555 Rockville Pike Rockville, Maryland 20852-2738 Dr. V. Sreenivas NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 G-9A 11555 Rockville Pike Rockville, Maryland 20852-2738

Serial No. 09-223B Docket Nos. 50-280, 281 ATTACHMENT Revised SGTR and MSLB Dose Consequences Based on Changes in Inputs and Assumptions with Enclosed Electronic Media Files and Inputs to the RADTRAD Model used for Benchmarkinci Measurement Uncertainty Recaoture Power Unrate License Amendment Reauest Virginia Electric Power Company (Dominion)

Surry Power Station Units I and 2

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 1 of 31 Revised SGTR and MSLB Dose Consequences Based on Changes in Inputs and Assumptions with Enclosed Electronic Media Files and Inputs to the RADTRAD Model used for Benchmarking By letter dated January 27, 2010 (Serial No.09-223), Dominion submitted a measurement uncertainty recapture (MUR) power uprate License Amrnendment Request (LAR) for Surry Power Station Units 1 and 2 to increase the rated power of each unit by approximately 1.6%. During a January 12, 2010 conference call with the NRC staff, Dominion noted that it would be providing a supporting submittal to address plant accident analyses updates, which were identified during the Surry MUR technical review process, in support of the NRC's overall MUR LAR review effort.

Consequently, detailed supporting information is provided herein regarding the dose consequence analyses revised as a result of the MUR power uprate. There are a number of analysis assumptions, plant features, and specific modeling utilized in the calculation of the Steam Generator Tube Rupture (SGTR) and Main Steam Line Break (MSLB) accident analyses. The overall assumptions and modeling are unchanged from the current licensing basis.

Information is being provided that is pertinent to the SGTR and MSLB accidents. Within this supplement to the MUR power uprate LAR, the following information is provided:

" Analysis Assumptions and Key Parameter Values (Including current licensing basis values, revised values, and basis for any changes as a result of the MUR power uprate)

Dose modeling information applicable to RADTRAD 3.02

" RADTRAD 3.02 input and output files for the major release pathways associated with the SGTR and MSLB accidents (See enclosed electronic media.)

Benchmark comparisons to analysis results presented in the MUR power uprate LAR, comparing Dominion's LOCADOSE code with RADTRAD 3.02 results In general, three independent changes in inputs and assumptions are incorporated into the SGTR and MSLB analyses revisions:

1. Updated exclusion area boundary (EAB) X/Qs (approved in 2006, Reference 1)

2. Updated reactor coolant source term (change described in the MUR power uprate LAR, Reference 2)

3. Updated steam flow (change described in the MUR power uprate LAR, Reference 2)

The specific effect of the MUR power uprate on dose consequences is described in the LAR and is repeated in this -supplement. The overall SGTR and MSLB dose

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 2 of 31 consequences, revised as a result of the changes in inputs and assumptions supporting the MUR power uprate LAR, remain below the offsite and control room dose limits contained in 10 CFR 50.67 and Regulatory Guide 1.183.

STEAM GENERATOR TUBE RUPTURE (SGTR)

SGTR Analysis Assumptions & Key Parameter Values The LOCADOSE code is used to calculate the radiological consequences from airborne releases resulting from a SGTR at Surry to the EAB, low population zone (LPZ), and Control Room.

For operation at the proposed MUR power uprate conditions, the RCS coolant activity source term was updated to accommodate the core power increase (2605 MWt),

current operation with 18 month fuel cycles and 1% fuel defects. The updated RCS source term indicates an increase in the inventory of long-lived isotopes in the coolant compared to the current license basis values.

The revised SGTR analysis incorporates previously approved EAB X/Q values, an updated RCS coolant activity source term, and conservative increases in accident steam discharge assumptions.

Changes to key SGTR parameters are indicated in Table 1 using a side by side comparison of changed data.

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 3 of 31 Table I - Basic Data and Assumptions for SGTR Parameter or Assumption Current Licensing Basis Proposed Value Reason for Change Source Term

1) Primary Coolant Specific Activity Limit DEQ 1-131 (pCi/gm) 1.0 No Change

2) Primary Coolant Concentrations updated to reflect Concentrations at TS RCS inventory for MUR power level.

Limit (puCi/.qm) 1-131 7.522E-01 7.45E-01 1-132 2.796E-01 3.76E-01 1-133 1.222E+00 1.23E+00 1-134 1.701 E-01 2.42E-01 1-135 6.402E-01 7.90E-01

3) Primary Coolant Noble Normalized to 1 pCi/gm No Change Gas and Particulate DEQ 1-131 Activity

4) Iodine Spike 335 No Change

5) Accident-Initiated Spike 8

No Change Duration (hr)

6) Primary to Secondary 150 gpd/SG No Change Leak Rate

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 4 of 31 Table 1 - Basic Data and Assumptions for SGTR Parameter or Assumption Current Licensing Basis Proposed Value Reason for Change

7) Iodine Appearance Rate Updated to reflect RCS inventory for (includes 335X spike)

MUR power level.

(Ci/hr) 1-131 7.680E+03 7.550E+03 1-132 7.947E+03 1.011E+04 1-133 1.470E+04 1.447E+04 1-134 9.904E+03 1.315E+04 1-135 1.047E+04 1.254E+04

8) Pre-Accident Spike 10 No Change Coolant Activity (pCi/gm DEQ 1-131)

9) Iodine Partitioning PC for iodine = 100 No Change 10)Iodine Chemical Form of Elemental 97 No Change Primary-to-Secondary Organic 3

Leakage (%)

Particulate 0

11)Moisture Carryover in 1%

No Change Unaffected Steam Generators 12)Tube Uncovery No tube bundle uncovery No Change assumed. No credit -for scrubbing.

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 5 of 31 Table 1 - Basic Data and Assumptions for SGTR Parameter or Assumption Current Licensing Basis Proposed Value Reason for Change 13)Secondary Iodine Activity 0.1 pCi/gm DEQ 1-131 No Change Concentration SGTR Parameters

14) Reactor Trip Time (sec) 0 No Change

15) Safety Injection Signal 247 365 Updated to reflect revised PORV (sec) flow rate analysis for "no LOOP" operation

16) Operator Action to 30 No Change Isolate Affected SG (min)

17) Action to Align RHRS 8

No Change (hr)

18) Release to Env (hr)

No Change Unaffected SG 0-8 Affected SG 0-0.5

19) Reactor Coolant Volume (density= 45.216 lb/ft3)

No Change (ft3) 8902

20) Initial Steam Generator (density= 48.047 lb/ft3)

No Change Liquid Volume (ft3)

Unaffected SG 4104 Affected SG 2052

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 6 of 31 Table I - Basic Data and Assumptions for SGTR Parameter or Assumption Current Licensing Basis Proposed Value Reason for Change 21)Initial Steam Generator (density= 1.723 lb/ft3)

No Change Steam Volume (ft3)

Unaffected SG 1 (2 SG modeled as 1 volume)

Affected SG 3889 22)LOOP - Unaffected 0-88 sec:

0 0-82 sec:

0 Updated to reflect revised PORV Steam Generator 88-500 sec:

127 82-225 sec:

.179 flow rates Release to Environment 225-427 sec:

66 (cfm).

500-1800 sec:

0 427-1800 sec:

0 1800 sec - 2 hr:

41 1800 sec - 2 hr:

87 2 - 8 hr:

37 2 - 8 hr:

33

23) LOOP -Affected Steam 0-88 sec:

0 0-80 sec:

0 Updated to reflect revised PORV Generator Steam 88-289 sec:

3735 80-225 sec:

4673 flow rates Releases (cfm) 289-1800 sec:

2038 225-1800 sec:

2701 24)LOOP - Liquid Break 0-88 sec:

91.6 0-80 sec:

105 Updated to reflect revised PORV Flow (cfm)88-289 sec:

79.4 80-225 sec:

104 flow rates 289-1800 sec:

77.0 225-1800 sec:

85.2 25)LOOP-Flashed Break 0-88 sec:

11.3 0-80 sec:

15.2 Updated to reflect revised PORV Flow (cfm)88-289 sec:

4.5 80-225 sec:

5.5 flow rates 289-1800 sec:

3.7 225-1800 sec:

6.6

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 7 of 31 Table 1 - Basic Data and Assumptions for SGTR Parameter or Assumption Current Licensing Basis Proposed Value Reason 'for Change 26)LOOP -Affected SG 0-88 sec:

1330 0-80 sec:

1330 Updated to reflect revised PORV Liquid to Steam (cfm)88-289 sec:

134 80-225 sec:

168 flow rates 289-1800 sec:

73 225-1800 sec:

96.9 27)No LOOP - Unaffected 0-88 sec:

0 0-341 sec:

0 Updated to reflect revised PORV Steam Generator 88-393 sec:

177-341-365 sec:

746 flow rates Releases (cfm) 365-539 sec:

173 393-1800 sec:

0 539-1800 sec:

0 1800 sec - 2 hr:

41 1800 sec - 2 hr:

97 2 - 8 hr:

37 2 - 8 hr:

49 28)No LOOP - Affected 0-88 sec:

0 0-263 sec:

0 Updated to reflect revised PORV Steam Generator Steam 88-247 sec:

4036 263-365 sec:

5088 flow rates Release to Environment 247-1800 sec:

3152 365-1800 sec:

3541 (cfm) 29)No LOOP - Liquid Break 0-88 sec:

94.1 0-263 sec:

91.4 Updated to reflect revised PORV Flow (cfm)88-247 sec:

83.4 263-365 sec:

78.8 flow rates 247-1800 sec:

77.1 365-1800 sec:

72.2 30)No LOOP-Flashed 0-88 sec:

7.6 0-263 sec:

9.83 Updated to reflect revised PORV Break Flow (cfm)88-247 sec:

0.68 263-365 sec:

6.39 flow rates 247-1800 sec:

0.58 365-1800 sec:

0.84 31)EAB X/Q (sec/m3)

NRC approved X/Q (Reference 1) 0-2 hr 4.61E-03 1.76E-03

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 8 of 31 Table 1 - Basic Data and Assumptions for SGTR Parameter or Assumption Current Licensing Basis Proposed Value Reason for Change 32)LPZ X/Q (sec/m 3)

Period LPZ No Change 0 - 8 hr 2.01E-04 2 -24 hr 1.22E-04 24 - 96 hr 4.18E-05 96 - 720 hr 8.94E-06

• !,Control Room 33)Control Room Isolation (sec)

LOOP 0

No Change No LOOP 247 365 Revised SI signal time 34)Control Room Emergency HVAC Parameters (cfm)

No Change Unfiltered Inleakage 500 Filtered Make-up Air 1000 35)Control Room Volume 223,000 No Change (ft3)

36) Normal Ventilation 3,000 No Change Unfiltered Makeup Air-(cfm)

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 9 of 31 Table 1 - Basic Data and Assumptions for SGTR Parameter or Assumption Current Licensing Basis Proposed Value Reason for Change 37)Filtered Recirculation 0

No Change Air Flow (cfm) 38)Control Room Make-up-Air Flow Filter Efficiency (%)

No Change Elemental 90 Organic 70 Particulate 99 39)Control Room X/Q There are no changes to the X/Q, (sec/m3) just the timing of control room isolation.

LOOP 0 - 8 hr 3.79E-3 No Change 8 - 24 hr 3.09E-3 24 - 96 hr 1.05E-3 CLB SI signal occurs at 247 sec.

96 - 720 hr 2.49E-4 MUR-SI signal occurs at 365 sec.

(See Item 33, above)

No LOOP 0 - 247 sec:

7.71-E-3 0 - 365 sec:

7.71E-03 247 sec - 8 hr: 3.79E-3 365 sec - 8 hr: 3.79E-03

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 10 of 31 SGTR Modeling This section describes modeling techniques using RADTRAD 3.02 to represent the SGTR accident. A brief description is provided along with names of the RADTRAD 3.02 input files generated. An electronic copy of the RADTRAD 3.02 files is provided in the enclosure.

The pre-accident spike scenario is broken up into three different RADTRAD models as follows: 1) iodine spike, 2) RCS particulate with no iodine, and 3) noble gas. Daughter production is factored into each model.

The concurrent spike scenario is also broken up into three slightly different RADTRAD models: 1) iodine spike, 2) RCS particulate with 1 pCi/gm DEQ 1-131, and 3) noble gas.

Daughter production is factored into each model.

Since the Nuclide Inventory Files (NIF) are based on activity in units of pCi/gm, the Plant Power Level in the RADTRAD files has been adjusted to 182.6 to convert the specific activity to total curies based on RCS mass of 1.826E+08 gin. The NIF file associated with the concurrent iodine spike reflects total curies so the Plant Power Level in the concurrent iodine spike runs has been adjusted to 1.

The source term fraction for the RCS is 1. Source term fractions for the steam generators are based on affected SG (ASG) volume of 2052 ft3 and 4104 ft3 for the two intact SGs (ISG). The source term fractions for the ASG bulk liquid and ISG bulk liquid are 2.3E-02 [2052/ 8902 = 0.23, adjusted for difference in primary-secondary iodine limits (XO.1)] and 4.6E-02 [4104/ 8902 = 0.46, also adjusted for difference in primary-secondary iodine limits (XO.1)], respectively. Initial SG steam activity is assumed to be (0.0007X) the SG liquid activity source term fraction (based upon the mass ratio of steam and liquid in a SG) and an adjustment for partitioning/moisture carryover of 0.01.

No noble gases are assumed to be in the initial inventory of the SGs. The pre-accident spike runs incorporate an additional factor (0.1X) to the SG liquid,and steam source terms, for the iodine spike model only, since the spike is (1 OX) for the RCS; this ensures the secondary side DEQ 1-131 limit of 0.1 pCi/gm is maintained.

The concurrent spike model uses a Plant Power Level of 1 since the eight hour spike inventory in the NIF file is in total curies. Also, source fraction is set as 1 for the RCS only.' The NIF file used for this spike has been modified so that the iodine inventory reflects the total curies due to a (335X) spike over eight hours.

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 11 of 31 RADTRAD 3.02 Files SGTR Pre-accident Spike RADTRAD files Files Description sps-rxcoolant.nif Represents iodine and gross gamma activity equivalent to 1 pCi/gm DEQ 1-131 sps-rxcoolant.inp Federal Guidance Report (FGR) 11 & 12 Dose Conversion Factors (DCFs) sps-sgtr-rcs-ng.rft Release Fraction Timing (RFT) file for only noble gases sps-sgtr-rcs-preaci.rft RFT file for pre-accident iodine spike only sps-sgtr-rcs-noi-nong.rft RFT file for particulate, no iodine, no noble gas SP500LPNG.psf RADTRAD input/output file for only the noble gas SP500LPNG.oO component, Control Room Unfiltered Inleakage (CR UFI) = 500 cfm, LOOP SP500LPI.psf RADTRAD input/output file for only the. pre-accident SP500LPI.o0 spike component, CR UFI = 500 cfm, LOOP SP500LPP.psf RADTRAD input/output file for only the non-iodine and SP500LPP.oO non-noble gas, CR UFI = 500 cfm component, LOOP SP010NLNG.psf RADTRAD input/output file for only the noble gas SP010NLNG.o0.

component, CR UFI = 10 cfm, no LOOP SP01ONLI.psf RADTRAD inpuit/output file for only the pre-accident SP010NLI.o0 spike component, CR UFI = 10cfm, no LOOP SP010NLP.psf RADTRAD input/output file for only the non-iodine and SP010NLP.o0 non-noble gas, CR UFI = 10 cfm component, no LOOP

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 12 of 31 SGTR Concurrent Spike RADTRAD files Files Description sps-rxcoolant.nif

'\\

Represents iodine and gross gamma activity equivalent to 1 pCi/gm DEQ 1-131 sps-rxcoolant-sgtr-coinc.nif Represents total spike activity of 1-131 through 1-135 based on 335X appearance rate over 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

sps-rxcoolant.inp FGR 11 & 12 DCFs sps-mslb-rcs-fractions-coinc-RFT file for only concurrent iodine spike, reflects only i.rft the iodine activity in the NIF file released over 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> sps-sgtr-rcs-ng.rft RFT file for only noble gases sps-mslb-rcs-fractions.rft RFT file for Tech Spec RCS activity (all fractions = 1)

SC500LPIP.psf RADTRAD input/output file for Tech Spec RCS activity SC500LPIP.oO SC500LPI.psf RADTRAD input/output file for only the concurrent SC500LPI.oO iodine spike SC500LPNG.psf RADTRAD input/output file for only the noble gas SC500LPNG.oO component

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 13 of 31 Comparison of LOCADOSE and RADTRAD 3.02 SGTR Dose Consequences The dose summary shown in Table 2 provides a comparison between the results from LOCADOSE versus RADTRAD 3.02. The LOCADOSE results are from the analyses of record (AOR); MUR reported results in the LAR are rounded up from the AOR values.

In general, the models and results produced using RADTRAD 3.02 compare well with the MUR power uprate SGTR dose consequences calculated with LOCADOSE.

Table 2 Summary of SGTR Results Concurrent I Spike LOOP LOCADOSE (A)

RADTRAD (B)

Diff( B /A)

Control Room EAB (0- 2 hr)

LPZ 1.221 1.645 0.199 1.221 1.648 0.199 1.00 1.00 1.00 Pre-accident I Spike LOOP Control Room EAB (0-2 hr)

LPZ LOCADOSE (A) 0.885 1.192 0.139 RADTRAD (B) 0.881 1.136 0.133 RADTRAD (B) 4.264 0.610 0.074 Diff( B /A) 1.00 0.95 0.95 Diff( B /A) 1.00 0.94 0.94 Pre-accident I Spike No-LOOP LOCADOSE (A)

Control Room 4.277 EAB (0- 2 hr) 0.650 LPZ 0.079

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 14 of 31 MAIN STEAM LINE BREAK (MSLB)

MSLB Analysis Assumptions & Key Parameter Values The LOCADOSE code is used to calculate the radiological consequences from airborne releases resulting from a MSLB at Surry to the EAB, LPZ, and Control Room.

For operation at the proposed MUR power uprate conditions, the RCS coolant activity source term was updated to accommodate the core power increase (2605 MWt),

current operation with 18 month fuel cycles, and 1 % fuel defects. The updated RCS source term indicates an increase in the inventory of long-lived isotopes in the coolant compared to the current license basis values.

The revised MSLB analysis incorporates previously approved EAB X/Q values, an updated RCS coolant activity source term, and conservative increases in accident steam discharge assumptions.

Changes to key MSLB parameters are indicated in Table 3 using a side by side comparison of changed data.

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 15 of 31 Table 3 Basic Data and Assumptions for MSLB Parameter or Assumption CLB-Value Proposed Value Reason for Change

• ~~

Source Term~

1) Primary Coolant Specific Activity Limit DEQ 1-131 (pCi/gm) 1 No Change

2) Primary Coolant Updated to reflect a revision in core Concentrations at Tech isotopic inventory and fuel Spec Limit (PCi/gm) management changes I-131 7.522E-01 7.45E-01 1-132 2.798E-01 3.76E-01 1-133 1.222E+00 1.23E+00 1-134 1.701E-01 2.42E-01 1-135 6.402E-01 7.90E-01

3) Primary Coolant Noble Based on activity from 1%

No Change Gas Activity fuel defects scaled to 1 pCi/gm DEQ 1-131

4) Accident Initiated 500 No Change (Concurrent) Iodine Spike

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 16 of 31 Table 3 Basic Data and Assumptions for MSLB Parameter or Assumption CLB Value Proposed Value Reason for Change

5) Accident-Initiated (Concurrent) Spike 8

No Change Duration (hr)

6) Iodine Appearance Rate Updated to reflect a revision in core at the Tech Spec Limit isotopic inventory and fuel (pCi/sec) management changes 1-131 6.37E+3 6.26E+3 1-132 6.59E+3 8.38E+3 1-133 1.22E+4 1.20E+4 1-134 8.21 E+3 1.09E+4 1-135 8.68E+3 1.04E+4

7) Primary to Secondary 1

No Change Leak Rate (gpm)

8) Pre-Accident Spike 10 No Change Coolant Activity (pCi/gm DEQ 1-131)

9) Iodine Chemical Form of Elemental 97 No Change Primary-to-Secondary Organic 3

Leakage (%)

Particulate 0

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 17 of 31 Table 3 Basic Data and Assumptions for MSLB Parameter or Assumption CLB Value Proposed Value Reason for Change

10) Moisture Carryover in 1%

No Change Intact Steam Generator

11) Steam Generator Iodine Partition Coefficient Faulted SG 1

No Change Intact SG 100

12) Secondary Technical 0.1 pCi/gm DEQ 1-131 No Change

-Specification Limit on Iodine Activity MSBParameters,

13) Operator Action to Close Affected SG Main Steam 30 No Change Isolation Valve (min)

14) Action to Align RHRS 8

No Change (hr) 15)Reactor Coolant Mass 1.826E+08 No Change (gm)

Serial No, 09ý223B Docket Nos. 50-280, 281 Attachment Page 18 of 31 Table 3 Basic Data and Assumptions for MSLB Parameter or Assumption CLB Value Proposed Value Reason for Change

16) Faulted Steam 6700 No Change Generator Steam Mass (Ibm) 17).Initial Steam Generator Liquid Volume (cfm)

Faulted SG 2052 No Change Intact SG 4104 No Change

18) Faulted SG Release to Turbine Bldg (cfm liquid) 0- 41 sec 1.632E+03 No Change 41 - 181 sec 3.818E+03 181 - 1800 sec 2.511E+-03

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 19 of 31 Table 3 Basic Data and Assumptions for MSLB Parameter or Assumption CLB Value Proposed Value Reason for Change

19) Intact SG Release to PORV flow rates were increased Environment (cfm liquid) after 0.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />.

0 - 41 sec 1669 1669 41 - 181 sec 0

0 181 - 1800 sec 0

0 0.5 - 2.0 hour0 days <br />0 hours <br />0 weeks <br />0 months <br /> 41 74 2.0 - 8.0 hour0 days <br />0 hours <br />0 weeks <br />0 months <br /> 37 45

20) Turbine Building Volume 6.OOE+06 No Change (ft3)

21) RCS Volume (ft3) 8902 No Change

22) Release points MSL Break (Affected Turbine Building No Change SG)

Intact SG PORV

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 20 of 31 Table 3 Basic Data and Assumptions for MSLB Parameter or Assumption CLB Value Proposed Value Reason for Change

23) Turbine Building Release to Environment Control Room Dose Cases No Change (0.2 volumes/hr min. turnover)

(cfm steam) 0-41 sec 2.416E+06 41 - 181 sec 1.152E+06 181 - 1800 sec 4.296E+05 0.5 - 2.0 hour0 days <br />0 hours <br />0 weeks <br />0 months <br /> 2.OOOE+04 2.0 - 8.0 hour0 days <br />0 hours <br />0 weeks <br />0 months <br /> 2.OOOE+04 EAB and LPZ Dose Cases (12 volumes/hr min. turnover) 0 - 41 sec 3.5960E+06 41 - 181 sec 2.3320E+06 181 - 1800 sec 1.6096E+06 0.5 - 2.0 hour0 days <br />0 hours <br />0 weeks <br />0 months <br /> 1.2000E+06 2.0 - 8.0 hour0 days <br />0 hours <br />0 weeks <br />0 months <br /> 1.2000E+06

24) EAB X/Q (sec/m3) 0- 720 hr 4.61E-03 1.76E-03 NRC approved X/Q (Reference 1)

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 21 of 31 Table 3 Basic Data and Assumptions for MSLB Parameter or Assumption CLB Value Proposed Value Reason for Change

25) LPZ X/Q (sec/M3)

Period LPZ No Change 0 - 8 hr 2.01E-04 8 - 24 hr 1.22E-04 24 - 96 hr 4.18E-05 96 - 720 hr 8.94E-06 Gontrol Room

26) Control Room Isolation 0

No Change (sec)

27) Control Room Filtered 1000 No Change Flow Following Isolation (starts 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> into event)

(cfm)

28) Control Room Unfiltered 500 No Change Inleakage (cfm)

29) Control Room Volume 223,000 No Change (ft3)

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 22 of 31 Table 3 Basic Data and Assumptions for MSLB Parameter or Assumption CLB Value Proposed Value Reason for Change

30) Control Room Makeup Air Flow Filter Efficiency (%)

Elemental

,90 No Change Organic 70 Particulate 99

31)

Control Room X/Q 0 - 8 hr 3.79E-3 No Change-(sec/m3) 8 -24 3.09E-3 24-96 1.05E-3 96 - 720 2.49E-4 List of Acronyms Used:

CLB - Current License Basis DEQ - Dose Equivalent RCS - Reactor Coolant System MUR - Measurement Uncertainty Recapture SG - Steam Generator PC - Partition Coefficient PORV - Power Operated Relief Valve RHRS - Residual Heat Removal System LOOP - Loss of Offsite Power SI - Safety Injection HVAC - Heating, Ventilation and Air Conditioning EAB - Exclusion Area Boundary LPZ - Low Population Zone

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 23 of 31 MSLB Modeling This section describes modeling techniques using RADTRAD 3.02 to represent the MSLB accident. A brief description is provided along with names of the RADTRAD 3.02 input files generated. An electronic copy of the RADTRAD 3.02 files is provided in the enclosure.

The pre-accident spike scenario is broken up into three different RADTRAD models: 1) iodine spike, 2) RCS particulate with no iodine, and 3) noble gas.

Daughter production is factored into each model.

The concurrent spike scenario is also broken up into three slightly different RADTRAD models: 1) iodine spike, 2) RCS particulate with 1 pCi/gm DEQ 1-131 and 3) noble gas. Daughter production is factored into each model.

Since the NIF files are based on activity in units of pCi/gm, the Plant Power Level in the RADTRAD files has been adjusted to 182.6 to convert the specific activity to total curies based on RCS mass of 1.826E+08 gm. The NIF file associated with the concurrent iodine spike reflects total curies so the Plant Power Level in the concurrent iodine spike runs have been adjusted to 1.

The source term fraction for the RCS is 1. Source term fractions for the steam generators are based on affected SG (ASG) volume of 2052 ft3 and 4104 ft3 for-the two intact SGs (ISG). The source term fractions for the ASG bulk liquid and ISG bulk liquid are 2.3E-02 [2052/ 8902 = 0.23, adjusted for difference in primary-secondary iodine limits (XO.1)] and 4.6E-02 [4104/ 8902 = 0.46, also adjusted for difference in primary-secondary iodine limits (XO.1)], respectively.

Initial SG steam activity is assumed to be (0.0007X) the SG liquid activity source term fraction (based uponrthe mass ratio of steam and liquid in a SG) and an adjustment for partitioning/moisture carryover of 0.01. No noble gases are assumed to be in the initial inventory of the SGs. The pre-accident spike runs incorporate an additional factor (0.1X) to the SG liquid and steam source terms, for iodine only, since the spike is (1OX) for the RCS; this ensures the secondary side DEQ 1-131 limits are not exceeded.

The concurrent spike model uses a Plant Power Level of 1 since the eight hour spike inventory in the NIF file is in total curies. Also, source fraction is set as 1 for the RCS only. The NIF file used for this spike has been modified so that the iodine inventory reflects the total curies due to a (50OX) spike over eight hours.

The dose results represent a composite of the 0.2/hr and 12/hr Turbine Building air changes because the 0.2/hr results in higher control room dose and the 12/hr results in higher EAB and LPZ doses. Maximum two hour EAB doses occurred in the 0 - 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> time frame for both pre-accident and concurrent events.

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 24 of 31 It should be noted that control room ventilation modeling is somewhat unique because it is assumed that the control room is isolated at T=O and unfiltered inleakage (500 cfm) is from the intakes located in the Turbine Building because the ASG discharges into the Turbine Building. It is also assumed that an additional 500 cfm unfiltered inleakage occurs from the environment. Control room exhaust associated with these 2 inleakage terms is assumed as only 500 cfm even though inleakage totals 1000 cfm. This modeling technique is known to produce higher control room dose consequences and is therefore conservative.

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 25 of 31 RADTRAD 3.02 Files MSLB Pre-accident Spike RADTRAD files Files Description sps-rxcoolant.nif Represents iodine and gross gamma activity equivalent to 1 pCi/gm DEQ 1-131 sps-rxcoolant.inp FGR 11 & 12 DCFs sps-mslb-rcs-fractions-RFT file for only pre-accident iodine spike, reflects preac-i.rft 1OX the iodine activity in the NIF file sps-mslb-rcs-fractions-RFT file for only noble gases preac-NG.rft sps-mslb-rcs-fractions-RFT file for Tech Spec RCS activity with no preac-no-i.rft iodines MPIP50002i.psf RADTRAD input/output file for only the 10 pCi/gm MPIP50002i.oO iodine spike component with 0.2 air changes per hour in the Turbine Building MPIP50002noi.psf RADTRAD input/output file for only the Tech Spec MPIP50002noi.oO RCS particulate activity component (w/o iodine) with 0.2 air changes per hour in the Turbine Building MPNG50002.psf RADTRAD input/output file for only the noble gas MPNG50002.oO component with 0.2 air changes per hour in the Turbine Building MPIP50012i.psf RADTRAD input/output file for only the 10 pCi/gm MPIP50012i.oO iodine spike component with 12 air changes per hour in the Turbine Building MPIP50012noi.psf RADTRAD input/output file for only the Tech Spec MPIP50012noi.oO RCS activity component (w/o, iodine) with 12 air changes per hour in the Turbine Building MPNG50012.psf RADTRAD input/output file for only the noble gas, MPNG50012.oO component with 12 air changes per hour in the Turbine Building

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 26 of 31 MSLB Concurrent Spike RADTRAD files Files Description sps-rxcoolant.nif Represents iodine and gross gamma activity equivalent to 1 pCi/gm DE 1-131 sps-rxcoolant-mslb-coinc.nif Represents total spike activity of 1-131 through I-135 based on 500X appearance rate over 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

sps-rxcoolant.inp FGR 11 & 12 DCFs sps-mslb-rcs-fractions-RFT file for only pre-accident iodine spike, reflects coinc-i.rft only the iodine activity in the NIF file released over 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> sps-mslb-rcs-fractions-RFT file for only noble gases preac-NG.rft sps-mslb-rcs-fractions-RFT file for Tech Spec RCS activity with no preac-no-i.rft iodines sps-mslb-rcs-fractions.rft RFT file for Tech Spec RCS activity (all fractions 1)

MCIP50002i.psf RADTRAD input/ output file for only the concurrent MCIP50002i.oO iodine spike component with 0.2 air changes per hour in the Turbine Building MCIP50002wi.psf RADTRAD input/ output file for only the Tech Spec MCIP50002wi.oO RCS particulate activity component with 0.2 air changes per hour in the Turbine Building MCNG50002.psf RADTRAD input/ output file for only the noble gas MCNG50002.o0 component with 0.2 air changes per hour in the Turbine Building MCIP50012i.psf RADTRAD input/ output file for only the concurrent MCIP50012i.oo iodine spike component with 12 air changes per hour in the Turbine Building MCIP50012wi.psf RADTRAD input/ output file for only the Tech Spec MCIP50012wi.oO RCS activity component with 12 air changes per hour in the Turbine Building MCNG50012.psf RADTRAD input/ output file for only the noble gas MCNG50012.oO component with 12 air changes per hour in the Turbine Building

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 27 of 31 Comparison of LOCADOSE and RADTRAD 3.02 MSLB Dose Consequences The dose summary shown in Table 4 provides a comparison between the results from LOCADOSE versus RADTRAD 3.02. The LOCADOSE results are from the analyses of record (AOR). MUR power uprate reported results in the LAR are rounded up from the AOR values.

In general, the models and results produced using RADTRAD 3.02 compare favorably with the MSLB dose consequences calculated with LOCADOSE.

Offsite dose comparisons show LOCADOSE calculating higher doses than RADTRAD 3.02 (anywhere from 4% to 8% higher). Differences noted in calculated control room dose are believed to be an artifact of modeling inconsistencies in RADTRAD 3.02 that were identified in the RADTRAD 3.03 model update. Using an unofficial (demo) version of RADTRAD 3.03, the control room dose was re-evaluated. RADTRAD 3.03 results shown in (), seem to confirm the RADTRAD 3.02 logic error and compare favorably to LOCADOSE, with LOCADOSE producing higher doses.

Table 4 Summary of MSLB Results Concurrent I Spike LOCADOSE (A)

RADTRAD (B)*

Diff ( B / A)

Control Room 1.516 1.719 (1.422) 1.13 (0.94)

EAB (0 - 2 hr) 0.406 0.373 0.92 LPZ 0.062 0.059 0.95 Pre-accident I Spike LOCADOSE (A)

RADTRAD (B)*

Diff ( B / A)

Control Room 1.335 1.551 (1.259) 1.16 (0.94)

EAB (0 - 2 hr) 0.395 0.379 0.96 LPZ 0.049 0.047 0.96

• These results Were generated using RADTRAD 3.02. It is believed that the reason for the large.

difference in control room dose is due to a RADTRAD 3.02 logic error identified and corrected in RADTRAD 3.03. This error is associated with multiple release paths from a compartment to the environment causing a conservative error in control room dose, proportional to the number of paths. In this MSLB model, the Turbine Building has 2 discharge pathways to the environment. The values listed in parentheses 0 were generated using the same input files but were run on a DEMO version of RADTRAD 3.03. Since RADTRAD 3.03 is not part of Dominion's software QA program, the results are presented for information purposes only and should not be used as the basis for any licensing determination.

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 28 of 31 Reported Dose Consequences Tables 5 and 6 are duplicates of the dose consequences for the SGTR and MSLB analyses reported in the MUR power uprate LAR (Reference 2). Both tables are structured to show, in stepwise fashion, how the resulting offsite and control room dose consequences changed with each change in analysis assumption or input. As described above, the three changes incorporated into the revised SGTR and MSLB analyses are:

1. Updated EAB X/Qs

2. Updated reactor coolant source term

3. Updated steam flow Columns in Table 5 and 6 are labeled (A - D) in this supplement to provide an easy way to differentiate the step changes that result from each of the three parameter changes.

Column Description A

Existing values in the UFSAR B

Revised EAB dose using the approved EAB X/Qs (New Baseline)

C Increased dose consequences from the updated RCS source term for MUR power uprate conditions above the new baseline. The increase from B to C represents the increase caused only by the 6pdated RCS source term to bound power uprate conditions.

D Final dose consequences incorporating increased steam flow. The increase from C to D represents the increase in dose from increasing SG PORV flow necessary to maintain fidelity with analyzed accident flow analyses.

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 29 of 31 Table 5 Reported SGTR Dose Consequences 1 Concurrent Iodine Spike - LOOP Current Revised MUR Analysis Increase due Proposed Acceptance UFSAR Design Basis with New RCS to MUR 4 MUR Dose Criteria3 Baseline with Source Term Consequences Approved with PORV EAB X/Q Flow Increase (Rem TEDE)

(Rem TEDE)

(Rem TEDE)

(Rem TEDE)

(Rem TEDE)

A B

C D

Control Room 2 0.7 0.7 0.8 17%

1.3 5

EAB 2.2 0.9 1.0 15%

1.7 2.5 LPZ 0.2 0.2 0.2 17%

0.2 2.5 Pre-accident Iodine Spike - No-LOOP Current Revised MUR Analysis Increase due Proposed Acceptance UFSAR Design Basis with New RCS to MUR 4 MUR Dose Criteria3 Baseline with Source Term Consequences Approved with PORV EAB X/Q Flow Increase (Rem TEDE)

(Rem TEDE)

(Rem TEDE)

(Rem TEDE)

(Rem TEDE)

A B

C D

Control Room 2 0.9 0.9 1.2 28%

4.3 5

EAB 1.7 0.7 0.8 20%

1.2 25 LPZ 0.1 0.1 0.1 24%

0.2 25

1)

All dose values have been rounded up to one decimal place.

2)

Control room unfiltered inleakage for the pre-accident iodine spike is 10 cfm and for the concurrent iodine spike is 500 cfm. The selection of 10 or 500 cfm of unfiltered inleakage was based on higher dose consequences.

3)

RG 1.183 and 10 CFR 50.67 4)

The increase is primarily due to an increase in primary and secondary Cs predicted in the updated RCS source term. The percentage change is based on actual calculated doses prior to rounding to the next highest 0.1 Rem TEDE.

Serial No, 09-223B Docket Nos. 50-280, 281 Attachment Page 30 of 31 Reported Table 6 MSLB Dose Consequences1 Concurrent Iodine Spike - LOOP Current Revised MUR Analysis Increase due Proposed Acceptance UFSAR Design Basis with New RCS to MUR 4 MUR Dose Criteria3 Baseline with Source Term Consequences Approved with PORV EAB X/Q Flow Increase (Rem TEDE)

(Rem TEDE)

(Rem TEDE)

(Rem TEDE)

(Rem TEDE)

C D

A B

Control Room 2 0.7 0.7 1.5 137%

1.6 5

EAB 0.4 0.2 0.4.

195%

0.5 2.5 LPZ 0.1 0.1 0.1 123%

0.1 2.5 Pre-accident Iodine Spike - No-LOOP Current Revised MUR Analysis Increase due Proposed Acceptance UFSAR Design Basis with New RCS to MUR 4 MUR Dose Criteria3 Baseline with Source Term Consequences Approved with PORV-EAB X/Q" Flow Increase (Rem TEDE)

(Rem TEDE)

(Rem TEDE)

(Rem TEDE)

(Rem TEDE)

A B

C D

Control Room2 0.5 0.5 1.4 187%

1.4 5

EAB 0.4 0.2 0.4 209%

1 0.4 25 LPZ 0.1 0.1 0.1 200%

0.1 25

1) All dose values have been rounded up to one decimal place.

2)

Based on control room unfiltered inleakage of 500 cfm.

3)

RG 1.183 and 10 CFR 50.67

4) The increase is primarily due to an increase in primary and secondary Cs predicted in the updated RCS source term. The MSLB results are very sensitive to the increase in Cs inventory in the SG liquid and primary-to-secondary leakage because no partitioning occurs in the faulted SG. The percentage change is based on actual calculated doses prior to rounding to the next highest 0.1 Rem TEDE.

Serial No. 09-223B Docket Nos. 50-280, 281 Attachment Page 31 of 31 References

1. Letter from Stephen Monarque (NRC) to David A. Christian (Dominion) "Surry Power Station, Units 1 and 2, Issuance of Amendments Regarding the Redefinition of the Exclusion Area Boundary", (TAC Nos. MC8315 and MC83165)", Serial No.06-701, August 10, 2006.

2. Letter from Virginia Electric and Power Company to USNRC dated January 27, 2010 (Serial No.09-223), "Virginia Electric and Power Company (Dominion), Surry Power Station Units 1 and 2, License Amendment Request, Measurement Uncertainty Recapture Power Uprate."

Serial No. 09-223B Docket Nos. 50-280, 281 ENCLOSURE Electronic Media Files and Inputs to the RADTRAD Model used for Benchmarking Virginia Electric Power Company (Dominion)

Surry Power Station Units 1 and 2