ML100700446

Request for Additional Information Regarding Request to Adopt the Alternate Source Team (TAC ME1624 & ME1625)

ML100700446
Person / Time
Site:	Turkey Point
Issue date:	03/24/2010
From:	Jason Paige Plant Licensing Branch II
To:	Nazar M Florida Power & Light Co
Paige, Jason C, NRR/DORL,301-415-5888
References
TAC ME1624, TAC ME1625
Download: ML100700446 (8)

Text

UNITED NUCLEAR REGULATORY WASHINGTON, D.C. 20555*0001 March 24, 2010 Mr. Mano Nazar Senior Vice President, Nuclear and Chief Nuclear Officer Florida Power and Light Company P.O. Box 14000 Juno Beach, Florida 33408-0420 TURKEY POINT UNITS 3 AND 4 -REQUEST FOR ADDITIONAL INFORMATION REGARDING REQUEST TO ADOPT THE ALTERNATE SOURCE TERM (TAC NOS. ME1624 AND ME1625)

Dear Mr. Nazar:

By letter dated June 25, 2009 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML092050277), Florida Power and Light Company (FPL) requested an amendment to Facility Operating License Nos. DPR-31 and DPR-41 for Turkey Point, Units 3 and 4. The proposed changes would revise the Turkey Point licensing bases to adopt the alternative source term, as described in Title 10 of the Code of Federal Regulations, Part 50.67, following the guidance provided in Regulatory Guide 1.183, "Alternative Radiological Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors," July 2000. The U.S. Nuclear Regulatory Commission staff has reviewed your submittal and finds that the information contained in the enclosed Request for Additional Information is needed before we can complete the review. This was discussed with members of the FPL staff and, on March 1, 2010, Mr. Bob Tomonto indicated that a response would be provided within 30 days of the date of this letter. If you have any questions, please contact me at (301) 415-5888.

rely, ason C. Paige, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-250 and 50-251

Enclosure:

Request for Additional Information cc w/encl: Distribution via Listserv REQUEST FOR ADDITIONAL INFORMATION FLORIDA POWER AND LIGHT COMPANY TURKEY POINT UNITS 3 AND 4 DOCKET NUMBERS 50-250 and 50-251 By letter dated June 25, 2009 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML092050277), Florida Power and Light Company (FPL, the licensee) requested an amendment to Facility Operating License Nos. DPR-31 and DPR-41 for Turkey Point, Units 3 and 4. The proposed changes would revise the Turkey Point licensing bases to adopt the alternative source term (AST), as described in Title 10 of the Code of Federal Regulations (10 CFR), Part 50.67, following the guidance provided in Regulatory Guide (RG) 1.183, "Alternative Radiological Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors," July 2000. To complete its review of the license amendment request (LAR), the Nuclear Regulatory Commission staff requests the following additional information. The AST LAR Enclosure 1, Section 10.0 "References," Reference 6 cites "NEI 99-03, Control Room Habitability Guidance, Nuclear Energy Institute, Revision 0, June 2001 and Revision 1, March 2003." NEI 99-03, Revision 0, June 2001 is an acceptable reference, however, Revision 1 has not been reviewed and accepted by the Nuclear Regulatory Commission (NRC). Provide additional information describing whether or not NEI 99-03, Revision 1 is being relied upon to support the assumptions or methods used in the AST submittal.

If NEI 99-03 Revision 1 is being used to support the AST submittal, it will be necessary to submit NEI 99-03 Revision 1 on the docket with a request for NRC staff review. In addition, the licensee will be responsible for addressing questions that may result from that review and the review will have to be completed before the staff completes its review of the AST submittal.

If NEI 99-03 Revision 1 is not being relied upon to support the AST submittal, and it is not the licensee's intention for the staff to review it, then it should be removed from the AST submittal as a reference. On page 18 of 81 of Numeric Applications, Inc. (NAI)-1396-045 Rev 1, the second paragraph under item 5 states the following: "The GOTHIC analysis utilized for Turkey Point to demonstrate the level of spray induced mixing in containment included both subdivided and lumped parameter models. The detailed subdivided models were used to calculate flow patterns produced by the containment sprays and the emergency containment coolers. Gas concentrations from the subdivided models were compared with concentrations in the lumped parameter model and used to determine equivalent mixing flow rates for the lumped model." Enclosure

-2 Provide the following additional information: Describe how many subdivided models were analyzed using GOTHIC, and the differences among each of the subdivided models. Provide a tabulation of the results (gas concentrations, flow rates) showing the differences within the subdivided models analyzed and show the comparison with results from the lumped parameter model. Describe how the equivalent mixing flow rates for the lumped model were determined. Describe the relationship between the equivalent mixing flow rates that were determined for the lumped model with the mixing flow rates in the subdivided models. Provide additional information to ensure that the cool-down times assumed in the main steam line break (MSLB), the steam generator tUbe rupture (SGTR), locked rotor (LRA) and rod cluster control assembly (RCCA) ejection accident analyses can be achieved by exclusive reliance on safety-grade equipment. For each of the affected accident analyses, MSLB, SGTR LRA and RCCA, provide additional information to describe the basis for the determination of the potential for 30 minutes of steam generator tube bundle uncovery and a description of the actions required to recover the bundles. For the fuel-handling accident, gap fractions from NUREG/CR-5009 were used, which are approximately twice those of RG 1.183 to account for high burn-up fuel not meeting the limits described in Footnote 11. In addition, the gap fractions from Table 3 of RG 1.183 were used without the use of any stated correction factors in the evaluation of the LRA and RCCA ejection accident analyses.

Provide additional information, including the basis, describing whether or not correction factors were used to adjust the gap fractions from Table 3 of RG 1.183 to account for high burn-up fuel in the LRA and the RCCA ejection accident analyses. LAR Attachment 3, NAI-1396-045 Rev. 1, Table 1.6.3-1 lists the unfiltered make-up flow rate and inleakage as 1000 cubic feet per minute (cfm) during the normal mode of operation.

For the waste gas decay tank rupture, Table 2.7.1 lists the unfiltered in leakage as 115 cfm and the makeup flow rate as 1000 cfm for the non-isolated control room implying that the total air exchange would be calculated using 1115 cfm. Provide additional information to clarify the assumed total air exchange rate for the control room during normal operation. TS bases section 3/4.4.5, Applicable Safety Analysis, states that, "No credit for iodine removal is taken for any steam released to the condenser prior to reactor trip and concurrent loss of offsite power." This statement appears to be in conflict with the revised AST analyses crediting a partition factor of 100 for releases through the condenser prior to reactor trip.

-3 Provide additional information to clarify whether or not the revised AST analyses credit a partition factor of 100 for releases through the condenser prior to reactor trip. The licensee has proposed TS changes to revise limiting condition of operation (LCO) 3.4.8, "RCS [Reactor Coolant System] Specific Activity," APPLICABILITY requirements to specify that the LCO is applicable in MODES 1, 2, 3, and 4 removing MODE 5 from the APPLICABILITY.

The licensee asserts and the NRC staff agrees that: "In MODE 5 with the RCS loops filled, the SGs [steam generators]

are specified as a backup means of decay heat removal via natural circulation.

In this mode, however, due to the reduced temperature of the RCS, the probability of a design basis accident [DBA] involving the release of significant quantities of RCS inventory is greatly reduced. Therefore, monitoring of RCS specific activity is not required.

In MODE 5 with the RCS loops not filled, the SGs are not used for decay heat removal; the RCS and SGs are depressurized and primary to secondary leakage is minimal. Therefore, the monitoring of RCS specific activity is not required.

The change to modify the TS 3.4.8 Applicability to include only MODES 1 through 4 retains the necessary constraints to limit the potential radiological consequences of a SGTR or MSLB that may occur during these MODES and is therefore acceptable from a radiological dose perspective." The cited discussion provides the basis for not requiring the monitoring of RCS specific activity in MODE 5; however the implication is that the monitoring of RCS specific activity is required in MODES 1 though 4. The NRC staff notes that the TS Table 4.4-4 specifies that the sample and analyses required to demonstrate compliance with LCO 3.4.8 are only required to be performed in MODE 1. After transient conditions (Le., reactor trip, plant depressurization, shutdown or startup) that end in MODES 2,3, or 4, the surveillance is not required to be performed.

Isotopic spiking and fuel failures are more likely during transient conditions than during steady state plant operations.

Provide additional information to justify why there is an apparent disparity between the modes of applicability (MODES 1, 2, 3, and 4) and the limited mode (MODE 1) under which the surveillance for TS 3.4.8 is required. LAR Attachment 3, NAI-1396-045 Rev. 1, Table 1.7.2-1 does not contain values for 135m or Xe-138, which are needed for staff verification of the proposed limiting value of DEX-133. Provide additional information documenting the values used to support the proposed limiting value of DEX-133 as well as the basis for their selection. What are the heights above ground of all wind direction, wind speed and temperature difference measurements used in the analysis to support the June 25, 2009, AST LAR. Page 15 of Attachment 3 to the LAR states that wind speeds are measured at a height of 11.58 meters above ground. Page 16 cites a 10 meter wind speed. Were all measurements made on a single tower and the reference to 10 meters is simply a convenient approximation to data measured at 11.58 meters? NRC staff noted a

-relatively lower occurrence of winds from the north northeast direction than from the north and easterly directions between 2003 and 2007. To what may this be attributed?

Provide a drawing or provide a reference to an existing docketed drawing, which shows the location of the Turkey Point meteorological tower(s) with respect to plant structures and site features. Provide additional information describing how the Turkey Point 2003 through 2007 meteorological data were measured, processed, and selected to ensure that the data were appropriate for input into the ARCON96 and PAVAN computer codes. During the 5-year period, highlight any changes in the way in which the data were measured, processed, or selected for inclusion in the files and discuss why the changes were made. Identify each resultant temporal subset that comprises a homogeneous measurement, process, or selection grouping.

The following specific areas should be addressed further. FPL provided two sets of ARCON96 hourly meteorological data files for 2005 and 2006. Files were sent by letter dated July 21, 2009 (e-mail confirmation of receipt dated March 8, 2010, ADAMS Accession No. ML100680672) as part of the current LAR. In addition, files for the same 2-year period were subsequently submitted as part of another, unrelated, LAR by letter dated August 7, 2009 (ML092250585).

There appears to be some differences between the two sets of files for the 2005 and 2006 data. Clarify the basis for the apparent differences, which are particularly apparent with respect to the atmospheric stability categorization.

Are both sets of data measured at the same location and categorized by temperature difference with height measurements only? In addition, the data provided by letter dated August 7,2009, were for 2002,2005, and 2006, while the data provided previously by letter dated July 21, 2009, for the current LAR is for the period 2003 through 2007. Provide justification that the 2003 through 2007 data are appropriate for use in the current LAR. While the yearly data recovery rate by parameter is generally above 90 percent as recommended by RG 1.23, Rev. 0, "Onsite Meteorological Programs," the recovery rate in 2007 for the upper level wind direction appears to be in the upper 60 percentile.

Discuss the impact of this lower recovery rate on calculation of the atmospheric dispersion factors (X/Q values). The occurrence of atmospheric stability category A in 2004 appears to be approximately 22.5 percent and in the following year, 2005, approximately 4.5 percent. During the other three years, the value ranged between about 6 and 9 percent. To what is this variability attributed? Provide one or more scaled figures with all postulated sources and receptors highlighted from which distance and direction inputs can be approximated.

Provide the scale of the figure. Explain whether distance inputs into the ARCON96 calculations were directly estimated as horizontal straight line distances.

If the distances were not estimated directly as straight line horizontal distances, explain how they were determined.

Did the procedure used to estimate the distances account for differences in heights between each source and receptor pair? Were any sources modeled as diffuse releases?

-5Provide additional information on the following.

Table 1.8.1-1 of Attachment 3 suggests that Unit 4 and the southeast emergency intake are more limiting than releases from Unit 3 or to the northeast emergency intake. Provide the basis for this determination (i.e., were calculations made to qualitatively confirm this?). Page 2 of 02-052, Rev. 2, "Release/Receptor Combination Table," appears to provide a more inclusive list of potential source and receptor pairs. However, some of the values in the PTN table do not match those in Table 1.8.1-1. Further, the PTN table refers to east and west emergency intakes, whereas references in the proposed revision to the TS and in Attachment 3 refer to southeast and northeast intakes. Does the phrase "credit for dilution allowed" refer to the assumed cross sectional building area of 1254 m 2? Provide discussion on why the 4.8 meters from the plant stack to the east emergency intake provided in the PTN table was not the limiting pair? Is the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> temperature swing discussed on page 16 of Attachment 3 the difference between daily maximum and minimum temperatures?

How does this swing vary by time of year? Given that the accident is assumed to be of 30-day duration, why should an annual average value be used rather than a more limiting value such as that for the limiting 30-day period? How is the swing temperature used in the calculation? Page 16 of Attachment 3 discusses the 95th percentile wind speed with respect to calculations for assumed releases from the main steam safety valves (MSSVs) and atmospheric dump valves (ADVs). Per RG 1.194, "Atmospheric Relative Concentrations for Control Room Radiological Habitability Assessments at Nuclear Power Plants," provide an example of how the wind speed adjustment was calculated to demonstrate that the effluent velocity is at least five times higher than the 95th percentile wind speed. How was the effluent velocity determined for the MSSVs and ADVs and how does it vary as a function of time? Confirm that the effluent release is uncapped and in a vertical upward direction. Regarding the DBAs analyzed in support of this LAR, please confirm that the generated X/a values model the limiting doses and that all credible potential release scenarios were considered, including those due to loss of offsite power or other single failures. What wind speed values were used in developing the joint frequency distributions (JFDs) used as input to the PAVAN computer code calculations?

For example, if two consecutive categories are defined as 1-3 miles per hour (mph) and 4-7 mph, what is the value used to define the upper limit of the lower category (e.g., 3 mph, 3.5 mph, 4 mph)? The choice of wind speed categories used in the PAVAN calculations appears to result in some clustering of the data in the lower categories.

This may affect the resultant X/a value estimates generated by the PAVAN computer code. NRC Regulatory Issues Summary (RIS) 2006-4, "Experience with Implementation of Alternative Source Terms," states that input to PAVAN should have a large number of wind speed categories at the lower wind speeds in order to produce the best results. Provide a supplement to Section 4, "Atmospheric Dispersion," of Attachment 6 to provide justification for the selection of wind speed categories used in PAVAN calculations considering the recommendation in RIS 2006-4.

-6Page 16 of Attachment 3 states several conversions were performed to the JFD to result in the file provided in support of the LAR. Provide further discussion of how the was developed in comparison to the hourly data files provided in the ARCON96 format. Other than the JFD, provide a consolidated list of all inputs and assumptions used in the PAVAN calculations.

A copy of the summary pages of the PAVAN outputs is acceptable to show inputs. For TS 3/4.7.5 "Control Room Emergency Ventilation System," the action statement for modes 1, 2, 3, and 4 states, "with the Control Room Emergency Ventilation System inoperable, suspend all movement of fuel in the spent fuel pool and restore the inoperable system to OPERABLE status within 84 hours9.722222e-4 days <br />0.0233 hours <br />1.388889e-4 weeks <br />3.1962e-5 months <br /> ..." Provide a discussion describing what action will be taken to mitigate the consequences of a DBA that may occur during the 84 hours9.722222e-4 days <br />0.0233 hours <br />1.388889e-4 weeks <br />3.1962e-5 months <br /> when the system is inoperable.

The discussion should include details describing how compliance with Appendix A to 10 CFR Part 50 GDC 19, "Control Room" will be maintained.

The discussion should also state whether the 84 hours9.722222e-4 days <br />0.0233 hours <br />1.388889e-4 weeks <br />3.1962e-5 months <br /> are factored into the calculated dose of the licensing basis analyses of DBA consequences.

March 24, 2010 Mr. Mano Nazar Senior Vice President, Nuclear and Chief Nuclear Officer Florida Power and Light Company P.O. Box 14000 Juno Beach, Florida 33408-0420 TURKEY POINT UNITS 3 AND 4 -REQUEST FOR ADDITIONAL INFORMATION REGARDING REQUEST TO ADOPT THE ALTERNATE SOURCE TERM (TAC NOS. ME1624 AND ME1625)

Dear Mr. Nazar:

By letter dated June 25, 2009 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML092050277), Florida Power and Light Company (FPL) requested an amendment to Facility Operating License Nos. DPR-31 and DPR-41 for Turkey Point, Units 3 and 4. The proposed changes would revise the Turkey Point licensing bases to adopt the alternative source term, as described in Title 10 of the Code of Federal Regulations, Part 50.67, following the guidance provided in Regulatory Guide 1.183, "Alternative Radiological Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors," July 2000. The U.S. Nuclear Regulatory Commission staff has reviewed your submittal and finds that the information contained in the enclosed Request for Additional Information is needed before we can complete the review. This was discussed with members of the FPL staff and, on March 1, 2010, Mr. Bob Tomonto indicated that a response would be provided within 30 days of the date of this letter. If you have any questions, please contact me at (301) 415-5888.

Sincerely, IRA! Jason C. Paige, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-250 and 50-251

Enclosure:

Request for Additional Information cc w/encl: Distribution via Listserv DISTRIBUTION:

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NAME JPaige BClayton RDennig* TTate* DBroaddus DATE 03/12/10 03/11/10 02/03/2010 02/3/2010 03/24/10 *vla OFFICIAL RECORD COPY