Public MeetingPublic Meeting

April 23, 2012

1

NRC ◦ Introduction and informational needs in order to 

properly evaluate the ASR issueNextEra◦ ASR Plans and Schedule◦ Proposed Testing at University of TexasNextEra & NRC◦ Technical DiscussionSummary 

2

Large body of work ongoing to better understand this phenomenaNextEra has indicated the structures they have identified to date with ASR remain operable, despite some degraded conditions and localized cracking.  gThe NRC has independently reviewed the phenomena with onsite inspections and reviews of licensee  evaluations and analyses by our own experts. No immediate safety concern.ASR affected structures are operable but degraded:  ◦ Safety load factors in controlling load conditions and engineering 

conservatisms in design,◦ Field walk-downs confirm no visible indication of significant 

deformation, distortion, or displacement of structures, or rebar corrosion,

◦ ASR identified at localized areas in the concrete walls, and◦ Progression of ASR degradation occurs slowly. 

3

• What buildings are affected by ASR?  

• How do you plan to confirm ASR and what is your basis?

4

When do you plan to update operability determinations for all buildings affected by ASR and what key information do you plan to incorporate into it, including key assumptions, bases for inputs including material properties, and calculation 

th d d?methods used?

If you continue to use the empirical relationships in the American Concrete Institute (ACI) design basis code for operability determinations, what is the basis for use of those relationships, and what is the explanation regarding why these are appropriate for the degraded conditions in the building? 

5

What are your ongoing or planned methods, analysis or testing that will be used to monitor/manage ASR affectedused to monitor/manage ASR-affected structures?What is your knowledge of the ASR reaction rate, possible end point, and how it affects operability?

6

When will you submit a letter to the NRC staff formalizing your Corrective Action Plan to address this issue?

7

When will you provide the technical details for the larger-scale testing planned at the  contracted research and development facility?development facility?

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New Program

Enhanced Program

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Existing Program

20 40 60YEARS0

The applicant has not completed the identification of the long term aging effects of ASR on the affected structures.  The applicant has not provided an agingThe applicant has not provided an aging management program for the ASR-affected structures to ensure that (10 CFR 54.21(a)(1)(ii)(3)):◦ aging effects will be managed◦ intended function(s) will be maintainedLRA review and schedule continue to be impacted.

10

The ASR structures are operable but degraded.◦ Safety load factors in controlling load 

conditions and engineering conservatisms inconditions and engineering conservatisms in design,◦ Field walk-downs confirm no visible indication 

of significant deformation, distortion, or displacement of structures, or rebar corrosion,◦ ASR identified at localized areas in the 

concrete walls, and◦ Progression of ASR degradation occurs slowly.

11

12:00 pm – 1:30 pm

12

3:00 pm – 3:30 pm

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Operable but degradedLRA review schedule has been impacted due to ASR NextEra’s followup actions

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3:45 pm – 4:30 pm

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