NRC 2010-0163, License Amendment Request 241, Alternate Source Term, Response to Clarification Request
| ML102860121 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 10/12/2010 |
| From: | Meyer L Point Beach |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| NRC 2010-0163 | |
| Download: ML102860121 (17) | |
Text
POINT BEACH October 12,2010 NRC 2010-0163 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Point Beach Nuclear Plant, Units Iand 2 Dockets 50-266 and 50-301 Renewed License Nos. DPR-24 and DPR-27 License Amendment Reauest 241 Alternate Source Term Res~onseto Clarification Request
References:
(1) FPL Energy Point Beach, LLC letter to NRC, dated December 8, 2008, License Amendment Request 241, Alternate Source Term (ML083450683)
(2) NextEra Energy Point Beach, LLC letter to NRC, dated September 3,2010, License Amendment Request 241, Response to Request for Additional Information (MLl02460115)
NextEra Energy Point Beach, LLC (NextEra) submitted License Amendment Request (LAR) 241 (Reference I ) to the NRC pursuant to 10 CFR 50.90. The proposed amendment would revise the current licensing basis to implement the alternative source term (AST) through reanalysis of the radiological consequences of the Point Beach Nuclear Plant (PBNP) final safety analysis report (FSAR) Chapter 14 accidents. Reference (2) provided a revised LOCA control room dose analysis without credit for the Auxiliary Building Ventilation System (VNPAB).
During a conference call on held September 30, 2010, the NRC staff determined that clarification of the information provided in Reference (2) was required to enable the staffs continued review of the request. Enclosure Iprovides the NextEra response to the NRC staff's request for clarification. Enclosure 2 provides ARCON96 data for the x/Q values presented in Reference (2). Enclosure 3 provides figures identifying the release points evaluated in Reference (2).
This letter contains no new Regulatory Commitments and no revisions to existing Regulatory Commitments.
NextEra Energy Point Beach, LLC,6610 Nuclear Road, Two Rivers, WI 54241
Document Control Desk Page 2 The information contained in this letter does not alter the no significant hazards consideration contained in Reference (1) and continues to satisfy the criteria of 10 CFR 51.22 for categorical exclusion from the requirements of an environmental assessment.
In accordance with 10 CFR 50.91, a copy of this letter is being provided to the designated Wisconsin Official.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on October 72,201 0.
Very truly yours, NextEra Energy Point Beach, LLC Enclosures cc: Administrator, Region Ill, USNRC Project Manager, Point Beach Nuclear Plant, USNRC Resident Inspector, Point Beach Nuclear Plant, USNRC PSCW
ENCLOSURE I NEXTERA ENERGY POINT BEACH, LLC POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 LICENSE AMENDMENT REQUEST 241 ALTERNATE SOURCE TERM RESPONSE TO CLARIFICATION REQUEST The NRC staff determined that additional information was required to enable the review of License Amendment Request (LAR) 241, Alternate Source Term (AST) (Reference 1). The following information is provided by NextEra Energy Point Beach, LLC (NextEra) in response to the NRC staff's request.
Clarification I Provide the ARCON96 data for the x/Q values presented in the response to Question I (ML102460115) of the NRC1srequest for additional information.
NextEra Response The ARCON96 data for the x/Q values presented in Reference (2) is included in Enclosure 2.
Clarification 2 Provide a figure showing the release points.
NextEra Response The figures showing release points evaluated in Reference (2) are included in Enclosure 3.
Clarification 3 Discuss the selection of the release points versus other release points that were not selected.
NextEra Response The activity flow paths for Cases 7 and 8 are the most direct. Activity from El. 8' (residual heat removal [RHR] equipment) can flow directly through the facade (via normal doors) and to the environment via facade roof vents 2-V7 or 1-V9. Case 7 results in the most conservative x/Q values since vent 2-V7 is closest to the control room air intake.
Page 1 of 5
Cases 1 through 6A assume releases from the PAB roof. There are no direct pathways from the RHR and containment spray (CS) areas to the roof. The pathways include floor hatches and sealed interfaces between piping and ducts which penetrate the floors and exit the pipe chases. These seals and hatches provide long and restricted activity transport pathways to reach the upper elevations of the PAB. Further, there are at least two floors through which activity is assumed to pass, in order to reach the roof, and there are no physical openings on the roof area of interest.
The xIQ values discussed as Case 7 in Table 1 below and included in Reference (2) represent the most direct path to the environment for the revised loss of coolant accident (LOCA) control room dose analysis without credit for the primary auxiliary building ventilation system (VNPAB).
The 2-V7 roof vent is the assumed source location for Unit 2 RHR system leakage. The source parameters and resulting xIQ values are summarized in Table I.
Figure 1 in Enclosure 3 provides a plan view of the release location and control room (CR) air intake. The RHR pumps are located on El. -19' 3". Other RHR equipment is located on El. -5' 3" and El. 8'. A doorway is located on El. 8' (See Figure 2 in Enclosure 3) which leads directly into the containment facade area. To reach the 2-V7 release location, activity released from El. 8' passes directly to the facade. Activity inside the facade travels through the open space and out through the facade roof vent to the environment.
Other Release Locations The following cases are illustrated in Figures 3 through 6 of Enclosure 3:
- 1. Primary Auxiliary Building (PAB) to Unit 1 Facade Roof Vent (Case 8)
The flow path to the facade area includes doors. This path potentially allows flow from the RHR rooms to the Unit 1 Facade. The facade roof vent closest to the CR air intake is 1-V9. This case assumes a release path similar to Case 7, but the resulting x/Q values are less conservative.
- 2. PAB Roof (Cases 1 through 6A)
The PAB roof directly above the RHR and CS areas, were assumed to be potential activity sources. There are floor hatches and sealed interfaces between the piping and ducts, which penetrate the floors and exit the pipe chases. These seals and hatches were assumed to be potential paths for leakage activity to reach the upper elevations of the PAB.
The RHR pumps are located on El. -19' 3". Other RHR equipment is located on El. -5' 3 and El. 8'. To reach the PAB roof release location, activity is assumed to pass through two to four floors (via closed hatches and sealed pipe chases), into the open space of the PAB and diffuse through the PAB roof. There are no physical openings on the roof area of interest. Additionally, the PAB roof cases (Cases 1 through 6A) assumes a long and restricted activity transport pathway to the environment (compared to Cases 7 and 8).
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Table I: Summary of All Evaluated ARCQN96 Cases for ECCS Leakage Parameter Case I Case 2 Case 2A Case 3 Case 4 Case 4A Figure 3 3 3 4 4 4 Release height above grade, m 25.7 Intake height above grade, m 26.1 Sector width constant 4.3 Surface roughness length, m 0.2 Wake area, m2 1690 Distance to receptor, m 25.5 32.6 25.5 30.6 38.8 30.6 Direction to source, degrees 245 238 245 215 215 215 (Note I)
Horizontal Horizontal Release type Point Point Point Point Area Area Initial diffusion coefficients, m OYO 1.9 0 0 1.9 0 0 uzo 0 0 0 0 0 0 Resulting xIQ , seclm3 0-2 hours 7.67E-03 5.1 0E-03 1.06E-02 6.71 E-03 4.63E-03 7.34E-03 2-8 4.58E-03 2.91E-03 8.68E-03 5.39E-03 3.81E-03 6.00E-03 8-24 1.90E-03 1.I 1E-03 3.4 9E-03 2.01 E-03 1.41E-03 2.24E-03 1-4 days 1.39E-03 7.67E-04 2.96E-03 1.82E-03 1.28E-03 2.02E-03 4-30 1.13E-03 6.51 E-04 2.35E-03 1.45E-03 1.O1E-03 1.60E-03 Note 1: The indicated directions are corrected to True North. True North = plant north - 25 deg Case 1: Unit 2 PAB Roof, above RHR pump room, area source Case 2: Unit 2 PAB Roof, above RHR pump room, point source Case 2A: Like Case 2, but point source moved to edge closest to CR air intake Case 3: Unit 1 PAB Roof, above RHR pump room, area source Case 4: Unit 1 PAB Roof, above RHR pump room, point source Case 4A: Like Case 4, but source moved to edge closest to CR air intake Page 3 of 5
Table I(continued) 1 Parameter I Case 5 1 Case 6 1 Case 6A I Case 7 1 Case 8 /
I Figure I I I I 5 5 5 1 6 I Release height above grade, m I 25.7 I 42.7 I Intake height above grade, m 26.1 Sector width constant Surface roughness length, m Wake area, m2 Distance to receptor, m Direction to source, degrees (Note 11 Horizontal Release type Point Point Point Point Area Initial diffusion coefficients, m YO G o Resulting xIQ , seclm3 0-2 hours 2-8 8-24 1-4 days 4-30 / 2.38E-03 1 2.68E-03 1 3.05E-03 1 1.34E-03 1 6.34E-04 1 Note 1: The indicated directions are corrected to True North. True North = plant north - 25 deg Case 5: PAB Roof, above CS pump room, area source Case 6: PAB Roof, above CS pump room, point source Case 6A: Like Case 6, but source moved to edge closest to CR air intake Case 7: Unit 2 Fa~aderoof vent 2-V7 Case 8: Unit 1 Fa~aderoof vent 1-V9 Page 4 of 5
References (1) FPL Energy Point Beach, LLC letter to NRC, dated December 8, 2008, License Amendment Request 241, Alternate Source Term (ML083450683)
(2) NextEra Energy Point Beach, LLC letter to NRC dated September 3, 2010, License Amendment Request 241, Response to Request for Additional Information (MLI 02460115)
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ENCLOSURE 2 NEXTERA ENERGY POINT BEACH, LLC POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 LICENSE AMENDMENT REQUEST 241 ALTERNATE SOURCE TERM RESPONSE TO CLARIFICATION REQUEST ARCON96 DATA 2 pages follow
File: C:\PBWON\ECC7B.l0g 1/1/2009, 4:07:05 PM Program
Title:
ARCON96.
Developed For: U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Division of Reactor Program Management Date: June 25, 1997 11:OO a.m.
NRC contacts: J. Y. Lee Phone: (301) 415 1080 e-mail: jyll@nrc.gov J. J. Hayes Phone: 1301) 415 3167 e-mail: jjh@nrc.gov L. A Brown Phone: (301) 415 1232 e-mail: labZ@nrc.gov Code Developer: J. V. Ramsdell Phone: (509) 372 6316 e-mail: j-ramsdell@pnl.gov Code Documentation: NUREG/CR-6331 Rev. 1 The program was prepared for an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or Implied, or assumes any legal liability or responsibilities for any third party's use, or the results of such use, of any portion of this program or represents that its use by such third party would not infringe privately owned rights.
Program Run 1/ 1/2009 at 16:07:04
- ."* ARCON INPUT 1**"***Cf Number of Meteorological Data Files = 1 Meteorological Data File Names C:\ARCON96\PBARCON\POINTB-1.MW Height of lower wind instrument (m)
Height of upper wind instrument (mi =
- 10.0 45.0 Wind speeds entered as miles per hour Ground-level release Release height (m)
Building Area (m-2)
=
42.7 1690.0 Effluent vertical velocity (m/s) = .OO Vent or stack flow (m13/s) .OO Vent or stack radius (ml = .OO Direction .. intake to source (deg)
Wind direction sector width (degt
= 264 90
=
Wind direction window (deg) = 219 309 Distance to intake lm) 25.7 Intake height (m) = 26.1 '
Terrain elevation difference (m) = .O output file names c:\pbArcon\ECC7B.log c:\PBArcon\ECC7B.cdf Minimum Wind Speed Imls) = .5 Surface roughness length (m) .20 Sector averaging constant = 4.3 Initial value of sigma y .OO Initial value of sigma z - .OO Expanded output for code testing not selected Total number of hours of data processed = 44335 Hours of missing data = 1729 Hours direction in window = 13814 Hours elevated plume w/ dir. in window = 0 Hours Hows of calm winds direction not in window or calm -
= 51 28741 DISTRIBUTION
SUMMARY
DATA BY AVERAGING INTERVAL AVER. PER. 1 2 4 8 12 Page 1 of 2
File: C:\PBARCON\ECC7B.log 1/1/2009, 4:07:05 PM 360 720 UPPER LIM. 1.00E-02 1.OOE-02 1.00E-02 1.00E-02 LOW LIM. 1.00E-06 1.00E-06 1.00E-06 1.00E-06 ABOVE RANGE 0. 0.
- 0. 0.
IN RANGE 13865. 15380.
41155. 40978.
BELOW RANGE 0. 0.
- 0. 0.
ZERO 28741. 26773.
- 0. 0.
TOTAL XIQs 42606. 42153.
41155. 40978.
% NON ZERO 32.54 36.49 100.00 100.00 95th PERCENTILE X/Q VALUES 6.78E-03 6.50E-03 1.55E-03 1.42E-03 95% XIQ for standard averaging intervals 0 to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> 6.78E-03 2 to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> 5.03E-03 8 to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 1.72E-03 1 to 4 days 1.6OE-03 4 to 30 days 1.34E-03 HOURLY VALUE RANGE MAX X/Q CENTERLINE 8.26E-03 SECTOR-AVERAGE 4.82E-03 NORMAL PROGPAM COMPLETION Page 2 of 2
ENCLOSURE 3 NEXTERA ENERGY POINT BEACH, LLC POINT BEACH NUCLEAR PLANT, UNITS I AND 2 LICENSE AMENDMENT REQUEST 241 ALTERNATE SOURCE TERM RESPONSE TO CLARIFICATION REQUEST FIGURES SHOWING RELEASE POINTS EVALUATED 6 pages follow
Figure I: Unit 2 Facade Roof Vent 2-V7 to Control Room Intake Page 1 of 6
4-4 BAYS @ 26::O".104'-Oa ' H 30'-0" ---24'-8" ----" 28'-8" t Figure 2: Activity Transport Path from Unit 2 Residual Heat Removal Area to Facade Page 2 of 6
Figure 3: Unit 2 Primary Auxiliary Building Room, Residual Heat Removal Area Page 3 of 6
Figure 4: Unit 1 Primary Auxiliary Building Roof, Residual Heat Removal Area Page 4 of 6
Figure 5: Primary Auxiliary Building Room, Containment Spray Pump Room Page 5 of 6
Figure 6: Unit 1 Facade Roof Page 6 of 6