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 C, Nakoski J A 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 m rn I~.A... ..... .... ..... .. ...M -7.7; ... ..... .....1-IJ.LL:1 4:.,4: 10

• W/AMAG CROSSFLOW REGULATORY IMPACT Potentially effected measurement uncertainty recapture power uprates: Plant % Uprate MWt 1 Increase Salem 1&, 8 2 1.4 48 x 2 =96 Hope Creek 1.4 46 SONGS 2&3 1.42 48 x 2 =96 STP 1&2 1.4 53 x 2= 106 Plant % Uprate MWt Increase Pilgrim 1.5 30 Hatch 1&2 1.4 48 x 2 = 96 Kewaunee 1.4 23 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