ML072130371
| ML072130371 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 07/27/2007 |
| From: | O'Grady B Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| TVA-BFN-TS-418, TVA-BFN-TS-431 | |
| Download: ML072130371 (13) | |
Text
Tennessee Valley Authority, Post Office Box 2000, Decatur, Alabama 35609-2000 Brian O'Grady Vice President, Browns Ferry Nuclear Plant July 27, 2007 TVA-BFN-TS-431 TVA-BFN-TS-418 10 CFR 50.90 U.S.
Nuclear Regulatory Commission ATTN:
Document Control Desk Mail Stop OWFN, P1-35 Washington, D.
C.
20555-0001 Gentlemen:
In the Matter of
)
Docket Nos.
50-259 Tennessee Valley Authority
)
50-260 50-296 BROWNS FERRY NUCLEAR PLANT (BFN)
UNITS 1, 2, AND 3 -
TECHNICAL SPECIFICATIONS (TS)
CHANGES TS-431 AND TS-418 -
EXTENDED POWER UPRATE (EPU)
STEAM DRYER EVALUATIONS By letters dated June 28, 2004 and June 25, 2004 (ADAMS Accession Nos. ML041840109 and ML041840301, respectively),
TVA submitted license amendment applications to the NRC for the EPU of BFN Unit 1 and BFN Units 2 and 3, respectively.
The proposed amendments would change the operating licenses to increase the maximum authorized core thermal power level of each reactor to 3952 megawatts.
This letter provides the completed BFN steam dryer stress analyses for Units 1, 2 and 3.
These analyses were performed by Continuum Dynamics, Inc.
(CDI) and are documented in the enclosed reports.
These reports supersede the previous stress analysis reports performed for EPU conditions.
,4o0 Prined on recycled Daper
U.S. Nuclear Regulatory Commission Page 2 July 27, 2007 BFN Steam Dryer Evaluation History Initially, a steam dryer evaluation for EPU conditions was performed for BFN and the evaluation was provided as to the June 28,
- 2004, and June 25, 2004 EPU license amendment submittals.
The evaluation consisted of a stress analysis which utilized the GE generic dryer load definition for both static equivalent and response spectrum.
Following the time of the initial steam dryer evaluation, considerable developments had taken place with respect to analysis methodologies and the acquisition of additional plant operating data for dryer loads.
These efforts included the development of scale model testing, acoustical analysis, main steam line monitoring, and the design and replacement of the two Quad Cities steam dryers.
Testing of a BFN scale model test (SMT) configuration utilizing the methodologies developed by GE to operate under the BFN EPU conditions was performed.
BFN provided the SMT benchmarking report by submittal dated March 9, 2006 (ADAMS Accession No. ML060720303) and the BFN SMT report by submittal dated April 13, 2006 (ADAMS Accession No. ML061070627).
By letter dated May 5, 2006 (ADAMS Accession No. ML061300436),
BFN provided the steam dryer stress analysis.
Based on this analysis, a few steam dryer components were predicted to exceed the fatigue endurance limit at EPU conditions.
A BFN stress report addendum submitted on June 23, 2006 (ADAMS Accession No. ML062400472) reflected planned modifications to the steam dryers.
The stress analysis results for the modified steam dryer at EPU conditions demonstrated that the BFN steam dryer stresses were generally below the endurance level screening criteria;
- however, a few dryer components were predicted to exceed design limits.
On July 11, 2006 (ADAMS Accession No. ML061910705),
TVA was notified of the NRC staff conclusions that the BFN submittals did not provide an adequate technical basis to enable the NRC staff to find the EPU applications acceptable.
For example, the NRC staff noted that the June 23,
- 2006, addendum indicated that the maximum stress on some components was calculated to be above the fatigue endurance limit during EPU conditions.
A revised BFN steam dryer stress report was provided on July 21, 2006 (ADAMS Accession No. ML062120411).
This
U.S. Nuclear Regulatory Commission Page 3 July 27, 2007 analysis reflected revised modifications and revised uncertainty determination for the acoustic circuit methodology.
The engineering analyses for the modified dryer demonstrated that the stresses on the steam dryer components will be within the fatigue endurance limits under EPU conditions.
On July 26, 2006 (ADAMS Accession Nos. ML062200277 and ML062200279),
TVA responded to Requests for Additional Information (RAI) associated with the steam dryer reports and provided a revised BFN steam dryer stress report which included revised uncertainties.
The NRC staff's initial review of the July 26 submittal (as provided by NRC letter dated August 1, 2006 -
ADAMS Accession No. ML062090555) identified concerns with the assumptions regarding specific aspects of the revised steam dryer stress analysis.
TVA responded to additional RAIs in an August 18, 2006 letter.
On October 10, 2006, TVA presented its plans to address the NRC staff's concerns regarding the structural integrity of the steam dryers.
In the October 10, 2006, meeting, and during subsequent informal conversations, TVA indicated that a revised stress analysis report incorporating an analysis of actual operating data from BFN Unit 2 would be submitted for NRC staff review.
By letter dated April 24, 2007 (ADAMS Accession No. ML071150371),
TVA reported that the steam dryer structural analyses would be performed by CDI and would be based on a proprietary load definition methodology also developed by CDI.
Current BFN Steam Dryer Evaluation is CDI Report No.07-05P entitled "Finite Element Model for Stress Assessment of Browns Ferry Nuclear Unit 1 Steam Dryer to 250 Hz." is CDI Report No.07-06P entitled "Finite Element Model for Stress Assessment of Browns Ferry Nuclear Unit 2 and 3 Steam Dryers to 250 Hz."
Separate reports are provided for Unit 1 and Units 2 and 3 because of modifications that were previously made to the BFN Unit 1 steam dryer.
The Units 2/3 model reflects the addition of planned modifications to the steam dryer tie bars.
The analyses utilize an ANSYS 10.0 finite element structural model of the steam dryer.
The analysis is carried out in the frequency domain.
Previous BFN steam
U.S. Nuclear Regulatory Commission Page 4 July 27, 2007 dryer stress analyses have been based on transient simulations performed in the time domain.
A comparison of these different methods is provided in Appendix B of the enclosed stress reports.
The value of structural damping utilized in the ANSYS finite element model has been a point of discussion in previous RAIs regarding the BFN steam dryer analyses.
CDI has used structural damping that is 1% of critical.
The stress analyses are based on an acoustic circuit model and load definition methodology developed by CDI.
For
- BFN, measured strain gage time history data in the four main steam lines at BFN Unit 2 were processed by a dynamic model of the steam delivery system to predict loads on the full scale steam dryer.
The acoustic circuit methodology was used to predict the fluctuating pressures applied to components of the steam dryer in the reactor vessel.
The acoustic circuit methodology included a low frequency hydrodynamic contribution in addition to an acoustic contribution at all frequencies. provides the latest acoustic circuit model methodology report, CDI Report No.07-09P, entitled "Methodology to Predict Full Scale Steam Dryer Loads from In-Plant Measurements, with the Inclusion of a Low Frequency Hydrodynamic Contribution."
The BFN analysis utilizing BFN Unit 2 strain gage data is provided in, CDI Report No.07-10P, entitled "Acoustic and Low Frequency Hydrodynamic Loads at CLTP Power Level on Browns Ferry Nuclear Unit 2 Steam Dryer to 250 Hz."
CDI has performed additional testing and evaluations to address dynamics of other components of the steam dryer.
The test report is provided in Enclosure 5, CDI Report No.07-11P, entitled "Dynamics of BWR Steam Dryer Components."
The results of this test program and evaluation were included in the structural modeling of the steam dryer to more accurately represent the dynamics of the dryer.
Due to the availability of main steam line strain gage data and the schedule for performing the BFN steam dryer stress analyses, all three units were analyzed utilizing main steam line strain gage data from BFN Unit 2.
Unit 2 strain gage data was obtained in October 2006 following a mid-cycle outage.
Unit 1 strain gage data was taken during the unit restart from the extended outage during the last half of June 2007.
To assess the applicability of the use of Unit 2 steam line data for the Unit 1 steam
U.S. Nuclear Regulatory Commission Page 5 July 27, 2007 dryer stress analysis, a comparison of the Unit 1 and Unit 2 main steam line strain gage data was performed.
This evaluation is provided in Enclosure 6, CDI Technical Memorandum No.07-26P, entitled "Comparison of Browns Ferry Nuclear Unit 1 and Unit 2 Main Steam Line Strain Gage/Pressure Readings."
This evaluation concluded that the use of the Unit 2 data for the Unit 1 analysis results in conservative prediction of dryer stresses on Unit 1.
The BFN steam dryer analyses have been reviewed by TVA and independent contractors.
Please note that the reports provided in Enclosures 1, 2, 3,
4, 5,
and 6 contain information that CDI considers to be proprietary in nature and subsequently, pursuant to 10 CFR 9.17(a) (4),
2.390(a) (4) and 2.390(d) (1),
requests that such information be withheld from public disclosure.
Enclosures 7 through 12 contain the redacted versions of the reports with the CDI proprietary material removed which is suitable for public disclosure. 3 is an affidavit from CDI supporting this request.
Results Analysis of the BFN steam dryers reveals a strong 218 Hz component which is attributable to acoustics in the blind flanged safety valve standpipes.
Elimination of this signal by filling the volume of these branches results in minimum alternating stress ratios of SR-a = 2.00 (Unit 1)
& 1.77 (Units 2/3) which qualifies the steam dryer with substantial margin for EPU conditions.
Accordingly, prior to operation at EPU conditions, TVA will perform modifications to each BFN unit to fill the volume of the blind flanged safety valve standpipes that are in the main steam flow path.
This is in addition to the planned tie bar modifications on Units 2 and 3.
Steam Dryer Monitoring Plan As stated in TVA's response to Request for Additional Information (RAI)
EEMB-D-7 (TVA letter of July 26, 2006),
TVA will implement a Steam Dryer Monitoring Plan (SDMP).
The SDMP is based on the Vermont Yankee SDMP that was reviewed and accepted by the NRC staff prior to that plant's EPU power ascension.
The SDMP will procedurally control power ascension in accordance with pre-determined acceptance criteria (including stress limit curves) and provide for the close monitoring of plant parameters.
U.S. Nuclear Regulatory Commission Page 6 July 27, 2007 Evaluations and action criteria will ensure that steam dryer integrity is maintained during the power ascension process.
The SDMP will also require visual inspections of the steam dryer that follow GE Service Information Letter and BWRVIP recommendations.
The comprehensive monitoring program includes provisions for flow induced vibration monitoring through system walkdowns and the use of accelerometers on selected plant components.
Stress Limit Curves for Power Ascension Testing TVA will provide frequency-dependent stress limit curves that will become operating restrictions during EPU power ascension.
The limit curves are scheduled to be submitted to NRC by August 21, 2007.
TVA has determined that the additional information provided by this letter does not affect the no significant hazards considerations associated with the proposed TS changes.
The proposed TS changes still qualify for a categorical exclusion from environmental review pursuant to the provisions of 10 CFR 51.22(c) (9).
No new regulatory commitments have been made in this submittal.
If you have any questions regarding this letter, please contact D. Tony Langley at (256)729-3612.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on this 271 day of July, 2006.
Sincerely, Brian 0 G\\
A a
\\
Enclosures:
N
- 1.
CDI Report No.07-05P, "Finite Element Model for Stress Assessment of Browns Ferry Nuclear Unit 1 Steam Dryer to 250 Hz" (proprietary version)
- 2.
CDI Report No.07-06P, "Finite Element Model for Stress Assessment of Browns Ferry Nuclear Unit 2 and 3 Steam Dryers to 250 Hz" (proprietary version)
- 3.
CDI Report No.07-09P, "Methodology to Predict Full Scale Steam Dryer Loads from In-Plant Measurements, with the Inclusion of a Low
U.S. Nuclear Regulatory Commission Page 7 July 27, 2007 Frequency Hydrodynamic Contribution" (proprietary version)
- 4.
CDI Report No.07-10P, "Acoustic and Low Frequency Hydrodynamic Loads at CLTP Power Level on Browns Ferry Nuclear Unit 2 Steam Dryer to 250 Hz" (proprietary version)
- 5.
CDI Report No.07-11P, "Dynamics of BWR Steam Dryer Components" (proprietary version))
- 6.
CDI Technical Memorandum No.07-26P, "Comparison of Browns Ferry Nuclear Unit 1 and Unit 2 Main Steam Line Strain Gage/Pressure Readings" (proprietary version
- 7.
CDI Report No.
07-05NP, "Finite Element Model for Stress Assessment of Browns Ferry Nuclear Unit 1 Steam Dryer to 250 Hz" (non-proprietary version)
- 8.
CDI Report No.
07-06NP, "Finite Element Model for Stress Assessment of Browns Ferry Nuclear Unit 2 and 3 Steam Dryers to 250 Hz" (non-proprietary version)
- 9.
CDI Report No.
07-09NP, "Methodology to Predict Full Scale Steam Dryer Loads from In-Plant Measurements, with the Inclusion of a Low Frequency Hydrodynamic Contribution" (non-proprietary version)
- 10.
CDI Report No.
07-10NP, "Acoustic and Low Frequency Hydrodynamic Loads at CLTP Power Level on Browns Ferry Nuclear Unit 2 Steam Dryer to 250 Hz" (non-proprietary version)
- 11.
CDI Report No.
07-11NP, "Dynamics of BWR Steam Dryer Components" (non-proprietary version)
- 12.
CDI Technical Memorandum No.
07-26NP, "Comparison of Browns Ferry Nuclear Unit 1 and Unit 2 Main Steam Line Strain Gage/Pressure Readings" (non-proprietary version)
- 13.
U.S. Nuclear Regulatory Commission Page 8 July 27, 2007 cc: State Health Officer Alabama Department of Public Health RSA Tower - Administration Suite 1552 P.O. Box 303017 Montgomery, AL 36130-3017 NRC Senior Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road Athens, Alabama 35611-6970 Mr.
James H. Moorman, III, Branch Chief U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303-8931 Ms.
Eva A. Brown, Project Manager U.S. Nuclear Regulatory Commission (MS 08G9)
One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739
ENCLOSURE 13 TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT (BFN)
UNITS 1, 2,
AND 3 TECHNICAL SPECIFICATIONS (TS)
CHANGES TS-431 AND TS-418 -
EXTENDED POWER UPRATE (EPU)
STEAM DRYER EVALUATIONS AFFIDAVIT Attached is CDI's Affidavit for the proprietary information contained in CDI Report No.07-05P, "Finite Element Model for Stress Assessment of Browns Ferry Nuclear Unit 1 Steam Dryer to 250 Hz,"
CDI Report No.07-06P, "Finite Element Model for Stress Assessment of Browns Ferry Nuclear Unit 2 and 3 Steam Dryers to 250 Hz,"
CDI Report No.07-09P, "Methodology to Predict Full Scale Steam Dryer Loads from In-Plant Measurements, with the Inclusion of a Low Frequency Hydrodynamic Contribution,"
CDI Report No.07-10P, "Acoustic and Low Frequency Hydrodynamic Loads at CLTP Power Level on Browns Ferry Nuclear Unit 2 Steam Dryer to 250 Hz,"
CDI Report No.07-11P, "Dynamics of BWR Steam Dryer Components,"
and CDI Technical Memorandum No.07-26P, "Comparison of Browns Ferry Nuclear Unit 1 and Unit 2 Main Steam Line Strain Gage/Pressure Readings."
OW Continuum Dynamics, Inc-(609) 538-0444 (609) 538-0464 fax 34 Lexington Avenue Ewing, NJ 08618-2302 24 July 2007 Ms. Marie Gillman TVA Browns Ferry Nuclear Plant Decatur, AL 35609
SUBJECT:
C.D.I. Report No.07-05P "Finite Element Model for Stress Assessment of Browns Ferry Nuclear Unit I Steam Dryer to 250 Hz," Revision 0 prepared by Continuum Dynamics, Inc., dated July 2007; C.D.I. Report No.07-06P "Finite Element Model for Stress Assessment of Browns Ferry Nuclear Unit 2 and 3 Steam Dryers to 250 Hz," Revision 0 prepared by Continuum Dynamics, Inc., dated July 2007; C.D.I. Report No.07-09P "Methodology to Predict Full Scale Steam Dryer Loads from In-Plant Measurements with the Inclusion of a Low Frequency Hydrodynamic Contribution,"
Revision 0 prepared by Continuum Dynamics, Inc., dated July 2007; C.D.I. Report No. 07-1OP "Acoustic and Low Frequency Hydrodynamic Loads at CLTP Power Level on Browns Ferry Nuclear Unit 2 Steam Dryer to 250 Hz," Revision 0 prepared by Continuum Dynamics, Inc., dated July 2007; C.D.I. Report No. 07-1iP "Dynamics of BWR Steam Dryer Components," Revision 0 prepared by Continuum Dynamics, Inc., dated July 2007; and C.D.I. Technical Memorandum No.07-26P "Comparison of Browns Ferry Nuclear Unit I and Unit 2 Main Steam Line Strain Gage/Pressure Readings," Revision 0 prepared by Continuum Dynamics, Inc., dated July 2007 To Whom It May Concern:
Enclosed please find one copy of each of the above referenced documents which are being submitted to TVA Browns Ferry in accordance with the Non-Disclosure Secrecy Agreement between Continuum Dynamics, Inc. and TVA Browns Ferry dated June 14, 2004. Should the documents be submitted to the Nuclear Regulatory Commission, we have also enclosed an Affidavit requesting withholding of disclosure, in accordance with 10 CFR 2.390.
Very truly yours, Alan J. Bilanin President & Senior Associate 07129 Enclosures
Orli Continuum Dynamics, Inc.
(609) 538-0444 (609) 538-0464 fax 34 Lexington Avenue Ewing, NJ 06618-2302 AFFIDAVIT Re:
C.D.I. Report No.07-05P "Finite Element Model for Stress Assessment of Browns Ferry Nuclear Unit 1 Steam Dryer to 250 Hz," Revision 0 prepared by Continuum Dynamics, Inc., dated July 2007; C.D.I. Report No.07-06P "Finite Element Model for Stress Assessment of Browns Ferry Nuclear Unit 2 and 3 Steam Dryers to 250 Hz," Revision 0 prepared by Continuum Dynamics, Inc., dated July 2007; C.D.I. Report No.07-09P "Methodology to Predict Full Scale Steam Dryer Loads from In-Plant Measurements with the Inclusion of a Low Frequency Hydrodynamic Contribution,"
Revision 0 prepared by Continuum Dynamics, Inc., dated July 2007; C.D.I. Report No. 07-1OP "Acoustic and Low Frequency Hydrodynamic Loads at CLTP Power Level on Browns Ferry Nuclear Unit 2 Steam Dryer to 250 Hz," Revision 0 prepared by Continuum Dynamics, Inc., dated July 2007; C.D.I. Report No. 07-1iP "Dynamics of BWR Steam Dryer Components," Revision 0 prepared by Continuum Dynamics, Inc., dated July 2007; and C.D.I. Technical Memorandum No.07-26P "Comparison of Browns Ferry Nuclear Unit 1 and Unit 2 Main Steam Line Strain Gage/Pressure Readings," Revision 0 prepared by Continuum Dynamics, Inc., dated July 2007 1, Alan J. Bilanin, being duly sworn, depose and state as follows:
- 1.
I hold the position of President and Senior Associate of Continuum Dynamics, Inc. (hereinafter referred to as C.D.I.), and I am authorized to make the request for withholding from Public Record the Information contained in the documents described in Paragraph 2. This Affidavit is submitted to the Nuclear Regulatory Commission (NRC) pursuant to 10 CFR 2.390(a)(4) based on the fact that the attached information consists of trade secret(s) of C.D.I. and that the NRC will receive the information from C.D.I. under privilege and in confidence.
- 2.
The Information sought to be withheld, as transmitted to TVA Browns Ferry as attachments to C.D.I. Letter No. 07129 dated 24 July 2007, C.D.I. Report No.07-05P "Finite Element Model for Stress Assessment of Browns Ferry Nuclear Unit I Steam Dryer to 250 Hz," Revision 0 prepared by Continuum Dynamics,
Inc., dated July 2007; C.D.I. Report No.07-06P "Finite Element Model for Stress Assessment of Browns Ferry Nuclear Unit 2 and 3 Dryers to 250 Hz," Revision 0 prepared by Continuum Dynamics, Inc., dated July 2007;C.D.I. Report No.07-09P "Methodology to Predict Full Scale Steam Dryer Loads from In-Plant Measurements with the Inclusion of a Low Frequency Hydrodynamic Contribution," Revision 0 prepared by Continuum Dynamics, Inc., dated July 2007; C.D.I. Report No. 07-lOP "Acoustic and Low Frequency Hydrodynamic Loads at CLTP Power Level on Browns Ferry Nuclear Unit 2 Steam Dryer to 250 Hz," Revision 0 prepared by Continuum Dynamics, Inc., dated July 2007; C.D.I. Report No.07-11P "Dynamics of BWR Steam Dryer Components,"
Revision 0 prepared by Continuum Dynamics, Inc., dated July 2007; and C.D.I.
Technical Memorandum No.07-26P "Comparison of Browns Ferry Nuclear Unit 1 and Unit 2 Main Steam Line Strain Gage/Pressure Readings," Revision 0 prepared by Continuum Dynamics, Inc., dated July 2007
- 3.
The Information summarizes:
(a) a process or method, including supporting data and analysis, where prevention of its use by C.D.I.'s competitors without license from C.D.I. constitutes a competitive advantage over other companies; (b) Information which, if used by a competitor, would reduce his expenditure of resources or improve his competitive position in the design, manufacture, shipment, installation, assurance of quality, or licensing of a similar product; (c) Information which discloses patentable subject matter for which it may be desirable to obtain patent protection.
The information sought to be withheld is considered to be proprietary for the reasons set forth in paragraphs 3(a), 3(b) and 3(c) above.
- 4.
The Information has been held in confidence by C.D.I., its owner.
The Information has consistently been held in confidence by C.D.I. and no public disclosure has been made and it is not available to the public. All disclosures to third parties, which have been limited, have been made pursuant to the terms and conditions contained in C.D.L.'s Nondisclosure Secrecy Agreement which must be fully executed prior to disclosure.
- 5.
The Information is a type customarily held in confidence by C.D.I. and there is a rational basis therefore. The Information is a type, which C.D.I. considers trade secret and is held in confidence by C.D.I. because it constitutes a source of competitive advantage in the competition and performance of such work in the industry. Public disclosure of the Information is likely to cause substantial harm to C.D.l.'s competitive position and foreclose or reduce the availability of profit-making opportunities.
I declare under penalty of perjury that the foregoing affidavit and the matters stated therein are true and correct to be the best of my knowledge, information and belief Executed on this day of a.ý,
2007.
Alan J. Bil~lin Continuum Dynamics, Inc.
Subscribed and sworn before me this day:
& c: 4 EILEEN P. BURMEISTER NOTARY PUBLIC OF NEW JERSEY MY COMM. EXPIRES MAY 6, 2012