ML072710663

Viewgraphs of Use of Ultrasonic Flow Measurement to Determine Reactor Power

ML072710663
Person / Time
Site:	Calvert Cliffs, Byron, Braidwood, Fort Calhoun
Issue date:	06/06/2006
From:	Lyon W, John Nakoski NRC/NRO/DCIP/CQVB, NRC/NRR/ADES/DSS
To:
References
FOIA/PA-2007-0255
Download: ML072710663 (12)

Text

WLA/ýi[ Or'A USE OF ULTRASONIC FLOW MEASUREMENT TO DETERMINE REACTOR POWER

-PURPOSE OF THIS PRESENTATION.

• To inform the ET and the LT of the status of the staffs review of the application of ultrasonic flow meters (UFMs) in determining reactor power

• MEASURE FOR SUCCESS OF THIS PRESENTATION

+ ET and LT are aware of staff activities

+ ET and LT are advised of potential need for regulatory action to address deficiencies in the application of UFMs PRESENTERS: Warren Lyon Presentation Date: June 8, 2006 1

K.'.'

John Nakoski 2

BACKGROUND

,/ UFMs uses: Feedwater flow measurement for MURs and power recovery v/ Appendix K to 10 CFR 50.46 changed to allow decrease in 2% uncertainty assumption for reactor power used in LOCA analyses V Importance is tied to compliance with the licensed thermal power upon which accident and transient analyses are conducted V Currently, 2 UFM devices have approved topical reports

• Caldon - Check and CheckPlus

• Westinghouse/AMAG - Crossflow 3

CROSSFLOW UFM HISTORY 1999 Generic Crossflow UFM topical report approved. Licensees beging requesting MURs January 2003 - Byron/Braidwood operating above rated thermal power (RTP). Region III requests NRR assistance on review of allegation related to Crossflow application at Byron/Braidwood.

July 2003 - Ft. Calhoun submits first MUR LAR based on Crossflow August 2003 - Byron/Braidwood reduce power, staff begins assessment of basis for operating above RTP. Power recovery application of Crossflow UFM.

January 2004 - NRC approves Ft. Calhoun MUR LAR February 2004 - NRC establishes task group to review UFMs May 2004 - Ft. Calhoun licensed RTP returned to pre-MUR level July 2004 - NRC task group identifies issues and recommends actions.

January 2005, Calvert Cliffs and March 2005, Ft. Calhoun submit MUR LARs based on Crossflow August 2005 - Westinghouse, Calvert Cliffs, & Ft. Calhoun provided issues related to Crossflow 4

CROSSFLOW UFM HISTORY (con't)

• September 2005 - New issue identified with Crossflow use at Calvert Cliffs. Swirl in feedwater flow adversely affects Crossflow measurement.

• October 2005 - Staff places Calvert Cliffs and Ft. Calhoun MUR reviews on hold

• October 2005 to January 2006 - Calvert Cliffs, Ft. Calhoun, W/AMAG, Owners Group, & NRC continue interactions on issue resolution. NRC obze.es tracer testing at Calvert Cliffs.

• February 2006 - NRR staff completes theoretical assessment of Crossflow uncertainty claim.

Additional RAIs provided to W/AMAG

• March 2006 - NRC & W/AMAG meet to discuss RAI responses

• April 2006 - NRC provides detailed RAls on issues that must be resolved for use of Crossflow.

NRR issues User's Need memo to RES to peer review theoretical assessment. W/AMAG describe model being developed that confirms original bases. Staff informs W/AMAG of schedule for and issues to be resolved for completion of reviews.

• May 2006 - RES provides response to NRR User's Need memo. RES substantiated NRR position that Crossflow does not obtain sufficient information to support uncertainty analyses.

+ June 2006 - W/AMAG provide additional information on theoretical and empirical bases for Crossflow uncertainty claim.

5

OVERVIEW

$ Caldon Check and CheckPlus UFMs are acceptable

$ Westinghouse/Advanced Measurement and Analysis Group (W/AMAG) review is ongoing. Anticipated staff finding is unacceptable. RES supports NRR position on capability of Crossflow UFM.

,$ Use of external UFMs for power recovery under 10 CFR 50.59 has not been shown to be acceptable 6

PLANT-SPECIFIC STATUS - RECENT MUR LARs

/ Seabrook (Caldon) UFM is acceptable (ML061360034, May 22, 2006)

V Calvert Cliffs (W/AMAG) is on hold - an amended LAR is anticipated V Ft. Calhoun (W/AMAG) is on hold pending generic review completion 7

ACCEPTANCE CRITERIA Traceability - relating a measurement to a standard Standard maintained by a national laboratory - National Institute of Standards and Technology (NIST)

Each step between measurement and standard - clearly defined and no unverified assumptions Unbroken path between measurement and standard Total measurement uncertainty reflects aggregate uncertainties of each step Applicability - provide accurate information over range of use

• Sound basis (theoretical understanding or equivalent)

Calibration is constant or change is fully understood, predictable, and verifiable 8

ACCEPTANCE CRITERIA ASSESSMENT V Caldon Check and Checkplus meet all criteria

/ VW/AMAG Crossflow has not been shown to meet criteria, but staff has not completed review of all submitted information 9

Ultrasonic Flow Meter Comparison Caldon Check & CheckPlus W/AMAG Crossflow

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• W/AMAG CROSSFLOW REGULATORY IMPACT Potentially effected measurement uncertainty recapture power uprates:

Plant  % Uprate MWt 1 Plant  % Uprate MWt Increase Increase Salem 1&,82 1.4 48 x 2 =96 Pilgrim 1.5 30 Hope Creek 1.4 46 Hatch 1&2 1.4 48 x 2 = 96 SONGS 2&3 1.42 48 x 2 =96 Kewaunee 1.4 23 STP 1&2 1.4 53 x 2= 106 Palisades 1.4 35.4

• Total MWt increase from Use of Crossflow based MURs = 528 MWt

• This equates to about 185 MWe

• Regulatory impact from the use of Crossflow for power recovery has not been fully assessed 11

W/AMAG CROSSFLOW CONCLUSIONS

,/ Theoretical, analytical, and understanding basis is weak

,/ Empirical data basis is weak

/ Meter self-assessment does not appear viable S"'An unbroken path from calibration used during meter operation to reference standards has not been achieved

,/ NRC-approved topic report is no longer valid

,/ NRC review is nearing completion although work remains

/" Regulatory action may be required to address the use of Crossflow and other external UFMs for MURs and power recovery applications 12