ML110550475
| ML110550475 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 03/02/2011 |
| From: | Wang A Plant Licensing Branch IV |
| To: | Entergy Operations |
| Wang A, NRR/DORL/LPL4, 301-415-1445 | |
| References | |
| TAC ME4679 | |
| Download: ML110550475 (7) | |
Text
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OFFICIAL USE ONLY PROPRIETARY INFORMATION UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 March 2, 2011 Vice President, Operations Entergy Operations, Inc.
Grand Gulf Nuclear Station P.O. Box 756 Port Gibson, MS 39150
SUBJECT:
GRAND GULF NUCLEAR STATION, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION REGARDING EXTENDED POWER UPRA TE APPLICATION LICENSE AMENDMENT REQUEST (TAC NO. ME4679)
Dear Sir or Madam:
By letter dated September 8,2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML102660409), Entergy Operations, Inc., submitted a license amendment request for the Grand Gulf Nuclear Station, Unit No.1 (GGNS). The proposed amendment requests an increase in the maximum steady-state power level at GGNS from 3898 megawatts thermal (MWt) to 4408 MWt. This represents an approximate 13 percent increase above the current licensed thermal power or an approximate 15 percent increase above the original licensed thermal power.
The U.S. Nuclear Regulatory Commission (NRC) staff has determined that the following additional information is needed for the NRC staff to complete our review of this amendment.
This request for additional information (RAI) was discussed with Mr. Jerry Burford of your staff on February 10, 2011, and it was agreed that a response all RAls except RAls 9 and 13 would be provided within 30 days of receipt of this letter. Responses to RAls 9 and 13 are due within 45 days of receipt of this letter. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-1445 or via e-mail at Alan.Wang@nrc.gov.
Sincerely, AI~ng~Xr Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-416
Enclosure:
As stated cc wInon-proprietary encl: Distribution via Listserv NOTICE: The Enclosure to this letter contains Proprietary Information. Upon separation from the Enclosure, this letter is DECONTROLLED.
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REQUEST FOR ADDITIONAL INFORMATION GRAND GULF NUCLEAR STATION, UNIT NO, 1 EXTENDED POWER UPRATE LICENSE AMENDMENT REQUEST ENTERGY OPERATIONS, INC.
DOCKET NO. 50-416 By letter dated September 8, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML102660409), Entergy Operations, Inc. (Entergy), submitted a license amendment request (LAR) for the Grand Gulf Nuclear Station, Unit No.1 (GGNS). The proposed amendment requests an increase in the maximum steady-state power level at GGNS from 3898 megawatts thermal (MWt) to 4408 MWt. This represents an approximate 13 percent increase above the current licensed thermal power (CL TP) or an approximate 15 percent increase above the original licensed thermal power (OL TP).
The U.S. Nuclear Regulatory Commission (NRC) staffs review of the LAR has identified areas regarding the steam dryer for which additional information is required for the NRC staff to complete its review. Please note that we have determined that there is proprietary information contained in this request and we have made the document proprietary.
- 1)
The GE Hitachi Nuclear Energy Americas LLC (GEH) report NEDC-33601 pl, Revision 0, "Engineering Report Grand Gulf Replacement Steam Dryer Fatigue Stress Analysis Using PBLE [Plant Based Load Evaluation] Methodology,"
provides several comparisons between the design loading functions at the extended power uprate (EPU) level for the steam dryer of GGNS and sample loadintiiunctions from other plants. Figures 3.19 to 3.21 show that the loading on the steam dryer is higher than the EPU design load for GGNS over a wide range 0 frequencies (up to 200 Hertz (Hz)). While the GGNS loading at the safety relief resonance frequencies has been increased to envelope the loading, the broadband loading function at the lower Hz) has not been increased to envelope the loading of The licensee is requested to substantiate the reasons GNS low frequency loading to envelope the loading
, similar to the approach used in the high frequency range.
In NEDC-33601 P, Revision 0, the licensee states that the plant measurements at high power levels in 2010. Based benchmark the PBLE methodology, the licensee concluded that no additional bias error due to Publicly available version: GE Hitachi Nuclear Energy, NEDO-33601, Revision 0, "Engineering Report Grand Gulf Replacement Steam Dryer Fatigue Stress Analysis Using PBLE Methodology," dated September 2010, Cover through Appendix A (ADAMS Accession No, ML102660401); Appendix B through Appendix D (ADAMS Accession No. ML102660406); and Appendix E through Appendix G (ADAMS Accession No. ML102660407).
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the for function of the
- 2) on the main steam lines (MSLs) of GGNS were in 2008 and at low power levels on comparisons of the noise floor of GGNS with
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- 2 differences in the noise floor levels is needed in the stress analysis computations of the steam dryer of GGNS. Since the noise floor for GGNS appears to be determined from the low power measurements in 2010, while the CLTP measurements were pelformed in 2008, the licensee is requested to explain how the conservatism is maintained in the stress analysis computations In addition.
the licensee is requested to explain how the noise floor level measured at high power in 2008 is ensljred to be similar to that determined at low power measurements during 2010.
- 3)
NEDC-33601 p, Revision 0, Section 3.3.4.3.1, "Weld Quality Factor," states that, To assure high quality welds, new or replacement steam dryer fabrication weld cesses that have been full lified.
The licensee is requested to confirm that the minimum detectable faw size wil!
be less than the critical flaw size. The licensee is also requested to confirm that the critical flaw size will be larger than the thickness of the '..veld bead for root and final pass.
- 4)
NEDC-3360'IP, Revision 0, Section 5.6.1.2, "Structural FEM [Finite Element Model] Bias and Uncertainty," states that, The licensee is requested to provide a basis or a reference in support of this statement 5}
Figure 320 in Appendix A, "Steam Dryer Integrity Analysis Methodology,' of NEDC-33601 Revisjon 0, shows the method of extrapolating the SRV resonance amplitudes. The licensee is requested to explain:
(a)
Why the higher SRV resonance frequencies (e.g.
excited at reduced velocities, lower than those corre resonance frequencies (e.g.,
?
(b)
What is meant by "Total dryer pressure load," which represents the Y-axis?
- 6)
I n Appendix A of NEDC-33601P, Revision 0, the licensee states that CL TP Bias and Uncertainty are needed to adjust "SRV resonance load adders to observed CLTP amplitude." Since CLTP load, indlJding SRV the plant and the SRV load adders at EPU are determined from the CLTP measurements, it is not clear to the N r~c staff why S OFFIC!l\\L USE ONLY PROPRIETARY INFORMATION
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- 3 are needed at CLTP. The licensee is requested to clarify the need for SRV load adders at CL TP.
- 7)
In Appendix A of NEDC-33601P, Revision 0, the licensee explains the procedure of determining the amplitudes of SRV load adders at EPU conditions. However, the bandwidth of these adders is not discussed in the report. The licensee is requested to explain how the bandwidth of the SRV load adders is determined.
- 8)
The licensee is requested to confirm that, after accounting for all bias and uncertainties, the projected SRV load adders at EPU conditions do bound the dryer loads of similar plants (BWR6, BWR4, and ABWR) operating at conditions similar to those of GGNS.
- 9)
Based on the information provided regarding EPU operation of GGNS, some or all SRVs will be continuously exposed to acoustic resonance in their standpipes at EPU operating conditions. The licensee is requested to explain the measures that will be taken to ensure safe operation of the SRVs and avoid any eventual damage such as those that occurred to the SRVs of the Quad Cities, Unit 2 plant.
- 10)
In Appendix A of I'JEDC-33601 P, Revision 0, Section 5.0, "Non-Prototype Justification," discusses the basis and method used to project the dryer load to EPU conditions. The trend lines of the pressure data are based on the measured For some ncy ranges g., as shown nds are not maintained at power levels lower than In fact, the pressure itude is substantiall than the tre nes over velocity range from Please explain why the pressure data power eve postulated for high power levels. In addition, please explain why the prOjected trends at EPU conditions are considered conservative, despite the large non-conservative deviations observed at low power levels.
- 11)
In Appendix A of NEDC-33601P, Revision 0, Section 5.3, "SRV Scaling Factor,"
describes the SRV scali factor at CLTP and EPU conditions. It a rs that the am p
ves are used. The licensee is requested to provide a concise step-by-step explanation of the procedure used to determine the SRV scaling factors.
- 12)
On page 67 of Appendix E, "Steam Dryer Structural An NEDC-33601 P Revision it is stated that is req exp I
provides the maximum stress intensity. If not, section path, providing the maximum stress intensity in the fillet weld, is determined.
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- 13)
On page 30 of Appendix E of NEDC-33601P, Revision 0, the licensee explains how the master degrees of freedom are selected. Please explain how the selected master degrees of freedom preserve the relevant dynamic characteristics of the model (Le., natural frequencies in the range of 0 to 250 Hz and the corresponding mode shapes). The licensee is also requested to explain what errors are introduced in the calculated stresses because of the use of substructure analysis.
- 14)
Section 9.0 of Appendix E of NEDC-33601P, Revision 0, provides templates (Tables 9.0-1 to 9.0-5) in table format for final stress processing. Only two of these tables, Tables 9.0.3 and 9.0.4, have been completed and presented in Section 4.0 of the main report as Tables 4.1 and 4.4, respectively. The licensee is requested to complete the remaining tables (Tables 9.0.1, 9.0.2, and 9.0.5) and submit them for the NRC staff's review. Additionally, the licensee is requested to confirm whether component-b~ency-based bias and uncertainty errors have been applied to the ~ analysiS results.
- 15)
In Section F.2 of Appendix F, "Power Ascension Test Plan," of NEDC-33601P, Revision 0, the licensee evaluates the dryer stress nse for each of the different potential resonance in addition to the base case for the resonance peaks observed in the CL TP mea The is requested to explain why the dryer dynamic response, considering all_
resonance peaks taking place simultaneously. is not evaluated.
- 16)
In Section F.2 of Appendix F of NEDC-33601 PRevision three criteria to the during power assure that the allowable stress are not exceeded.
Tables F-2 to F-7 provide quantitative data for these criteria for Level 1 and Level 2 limit curves. The licensee is requested to provide an example of the detailed calculations performed in determining the quantitative data (for dryer region 1) presented in these tables.
- 17)
Section F.2 of Appendix F of NEDC-33601P, Revision 0, states that, The licensee is requested to clarify the meaning of the term "load energy in frequency domain" and explain the statement.
- 18)
In Appendix G, "Grand Gulf Nuclear Station Main Steam Line Test Report," of NEDC-33601 P, Revision 0, the licensee states that during the primary pressurization tests at GGNS, the strain gauges were checked against the plant OFFICIAL USE ONLY PROPRIETARY INFORMATION ~'b~
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-5 data of static pressure. However, as discussed in Section 5.3 of this appendix, the intemal dynamic pressure during the tests was calculated from the strain gauge data using the formula for thick walled cylinder (with closed ends) and the MSL dimensions (diameter and wall thickness). The licensee is requested to (1) explain whether there is any variation in the wall thickness at a given strain gauge location, and (2) compare the calibration factors obtained by these two different procedures to assess any bias and uncertainties in the conversion of hoop stress to pressure.
- 19)
The test results presented in Appendix G of NEDC-33601P, Revision 0, include plots of averaged time history data for the strain gauge pairs at various locations.
The licensee is requested to elaborate on how these time averages were obtained and explain the relevance of these averaged time history spectra.
- 20)
In Appendix G of NEDC-33601P, Revision 0, the licensee states that, The strain gauges were wired in series, because there were a limited number of penetration cables available.
The licensee is requested to provide additional details about the wiring circuit of the strain gauges.
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OFFICIAL USE ONLY PROPRIETARY INFORMATION March 2, 2011 Vice President, Operations Entergy Operations, Inc.
Grand Gulf Nuclear Station P.O. Box 756 Port Gibson, MS 39150
SUBJECT:
GRAND GULF NUCLEAR STATION, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION REGARDING EXTENDED POWER UPRATE APPLICATION LICENSE AMENDMENT REQUEST (TAC NO. ME4679)
Dear Sir or Madam:
By letter dated September 8,2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML102660409), Entergy Operations, Inc., submitted a license amendment request for the Grand Gulf Nuclear Station, Unit No.1 (GGNS). The proposed amendment requests an increase in the maximum steady-state power level at GGNS from 3898 megawatts thermal (MWt) to 4408 MWt. This represents an approximate 13 percent increase above the current licensed thermal power or an approximate 15 percent increase above the original licensed thermal power.
The U.S. Nuclear Regulatory Commission (NRC) staff has determined that the following additional information is needed for the NRC staff to complete our review of this amendment.
This request for additional information (RAI) was discussed with Mr. Jerry Burford of your staff on February 10, 2011, and it was agreed that a response all RAls except RAls 9 and 13 would be provided within 30 days of receipt of this letter. Responses to RAls 9 and 13 are due within 45 days of receipt of this letter. If circumstances result in the need to revise the requested response date. please contact me at (301) 415-1445 or via e-mail at Alan.Wang@nrcgov.
Sincerely, IRA!
Alan B. Wang. Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-416
Enclosure:
As stated cc wlnon-proprietary encl: Distribution via Listserv NOTICE: The Enclosure to this letter contains Proprietary Information. Upon separation from the Enclosure, this letter is DECONTROLLED.
DISTRIBUTION:
NON-PUBLIC RidsNrrDeEmcb Resource RldsNrrPMGrandGulf Resource LPLIV rlf RidsNrrDorlLpl4 Resource RidsRgn4MailCenter Resource RidsAcrsAcnw_MailCTR Resource RidsNrrLAJBurkhardt Resource CBasavaraju. NRRlDEIEMCB ADAMS Accession Nos.: Pro rieta
- ML110480821; N OFFICIAL AGENCY RECORD OFFICE NRRlDORULPL4/PM NRRIDORULPL4/LA NAME
- AWang JBurkhardt MMarkley NRR/DORULPL4/PM
- DATE 1311111 2124111 3/2/11 AWang
.3/2/11 OFFICIAL USE ONLY PROPRIETARY INFORMATION \\>.~J