ML13156A486

Mur - Request for Additional Information - MF0650

ML13156A486
Person / Time
Site:	Fermi
Issue date:	06/03/2013
From:	Mahesh Chawla Plant Licensing Branch III
To:	Hassoun A Detroit Edison, Co
Chawla M
References
TAC MF0650
Download: ML13156A486 (3)

Text

From: Chawla, Mahesh Sent: Monday, June 03, 20134:56 PM To: Alan I Hassoun Cc: Jessup, William; McMurtray, Anthony

Subject:

Fermi 2 - MUR - Request for Additional Information - MF0650 Attachments: FermLMUR_RAls_EMCB.docx By letter to the U.S. Nuclear Regulatory Commission (NRC) dated February 7,2013 (Agencywide Documents Access and Management System Accession No. ML13043A659), supplemented by letters dated March 8, 2013 (ADAMS Accession No. ML13070A197), and April 5, 2013 ( ADAMS Accession No. ML13095A456),

Detroit Edison Company submitted a license amendment request application to increase the licensed core thermal power level at the Fermi Unit 2 from 3430 MWt to 3486 MWt. The approved license amendment would revise the Operating License and Technical Specifications to support operation at the increased licensed core thermal power.

The NRC staff in the Mechanical & Civil Engineering Branch (EMCB) of the Office of Nuclear Reactor Regulation is currently reviewing your submittal. The staff has determined that additional information is required to continue its review and complete its technical evaluation. The request for additional information is attached.

Please provide your response by July 12, 2013.

You may request to discuss the contents of this RAI with the NRC staff in a conference call, including any change to the proposed schedule.

Please don't hesitate to contact me if you have any questions or concerns.

Sincerely, Mac Chawla 301-415-8371 1

REQUESTS FOR ADDITIONAL INFORMATION (RAIS)

DTE ELECTRIC COMPANY (DTE)

FERMI NUCLEAR GENERATING STATION, UNIT 2 (FERMI 2)

LICENSE AMENDMENT REQUEST (LAR)

FOR MEASUREMENT UNCERTAINTY RECAPTURE (MUR) POWER UPRATE DOCKET NO. 50-431 TAC NO. MF0650 REFERENCES

1) GE Nuclear Energy, "Generic Guidelines for General Electric Boiling Water Reactor Thermal Power Optimization," NEDC-32938P, Revision 1, November 2002 (ADAMS Accession Nos.: ML023170607 (non-proprietary) and ML023170605 (proprietary>>.

2) Letter from J. T. Conner, DTE Electric Company, to NRC Document Control Desk, "License Amendment Request for Measurement Uncertainty Recapture (MUR) Power Uprate)," dated February 7,2013. (ADAMS Accession No.: ML13043A659)

MECHANICAL AND CIVIL ENGINEERING (EMCB)-RAI-1 Section 5.5.1.2 of NEDC-32938P-A, "Generic Guidelines and Evaluations for General Electric Boiling Water Reactor Thermal Power Optimization" (Reference 1 or the TLTR), indicates that the structural evaluations performed for the reactor pressure vessel (RPV), to support the implementation of an MUR power uprate, typically involve the reanalysis of the feedwater (FW) nozzles, main steam (MS) nozzles and the FW sparger. Table 3-4 of the Thermal Power Optimization Safety Analysis Report (TSAR), included as Enclosure 7 to the February 7,2013, LAR submitted by DTE for Fermi 2 (Reference 2), presents the results of the stress and fatigue reconciliations for the RPV, performed to support the implementation of the proposed MUR power uprate at Fermi 2. Please address the following items related to the aforementioned table:

a) The table shows that the primary plus secondary stress intensity calculated for the recirculation outlet nozzle (nozzle end) increased from 75.9 kips per square inch (ksi) at the current power level to 85.3 ksi at the proposed power level, the latter value of which exceeds the 3S m limit prescribed by the American Society of Mechanical Engineers (ASME) Boiler & Pressure Vessel Code (the Code). Additionally, the liner portion of the recirculation inlet nozzle is shown to have an increase in the primary plus secondary stress intensity of almost 10 ksi upon implementation of the MUR power uprate; this increase also exceeds the 3S m stress limit. State why the stress intensities for these two components have increased by apprOXimately 12% each, considering that the TLTR indicates that this should not be expected for an MUR power uprate.

b) Note 2 to the aforementioned table states that the provisions of ASME Code Case 1441, "Waiving of 3S m Limit for Section "I Construction," were used to demonstrate the acceptability of the recirculation nozzle following the failure of the component to satisfy the 3S m limit. Confirm that this Code Case is part of the Fermi 2 licensing basis or provide the regulatory basis for its use in this application. Additionally, please submit a copy of the ASME Code Case 1441.

EMCB-RAI-2 Table 3-5 of the TSAR indicates that the FW sparger was qualified for operation at the proposed MUR power level using a qualitative assessment. As indicated above, Section 5.5.1.2 of the TLTR notes that the FW sparger is a component which may require re-analysis in support of the implementation of an MUR power uprate. Please discuss the qualitative assessment which was performed for the FW sparger and provide a technical justification for the conclusion reached in this assessment which provides reasonable assurance that the FW sparger is acceptable for use at the proposed power level. This justification should adequately demonstrate that the design basis requirements related to the FW sparger will remain satisfied at the proposed power level.

EMCB-RAI-3 Section 3.4 of the TSAR discusses the flow-induced vibration (FIV) evaluations performed for the piping and piping components at the proposed power level. The TSAR states that the MS and FW piping experience increased vibration levels as a result of the increased MS and FW flow rates accompanying the proposed power uprate. Provide the acceptance criteria used to determine that the piping vibration levels at the proposed power level will be acceptable.

Confirm that the vibration assessments performed in support of the proposed Fermi 2 MUR power uprate were performed consistent with the methods outlined in the TLTR for evaluating piping vibration levels.

EMCB-RAI-4 Section 3.5.2 of the TSAR indicates that the balance-of-plant (SOP) portion of the FW piping from the Number 6 FW heater to the containment required re-analysis in order to be qualified for operation at the proposed power level. Please state whether this "re-analysis" refers to the procedure outlined in Appendix K of the TLTR, which essentially scales the applicable piping stress equations associated with the "Code of Record" for the piping. or whether this re-analysis refers to a different procedure used to qualify this portion of SOP piping. If a procedure other than that prescribed by Appendix K in the TL TR was utilized, please provide additional information regarding why the guidance in the TLTR could not be utilized to qualify the piping and provide a summary of the results of the piping re-analysis which quantitatively demonstrates that the piping is qualified for the proposed power level.

EMCB-RAI-5 Section 3.4.2 of Enclosure 1 to Reference 2 discusses the potential adverse flow effects resulting from the proposed power uprate. The submittal notes that an independent analysis was performed to demonstrate that the stresses induced in the steam dryer at the proposed power level will remain within allowable limits. Confirm that the increased steam flow rate accompanying the proposed power uprate does not result in the generation of acoustic resonances resulting from flow over any MS branch connections (e.g., safety-relief valve standpipes) and describe the method or methods used to make this determination.