ML19235A320

INT029 - Summary of Rebuttal Testimony of Victor E. Saouma, Ph.D Regarding Scientific Evaluation of Nextera'S Aging Management Program for Alkali-Silica Reaction at the Seabrook Nuclear Power Plant (Non-Proprietary Version)

ML19235A320
Person / Time
Site:	Seabrook
Issue date:	08/23/2019
From:	C-10 Research & Education Foundation, Harmon, Curran, Harmon, Curran, Spielberg & Eisenberg, LLP
To:	Atomic Safety and Licensing Board Panel
SECY RAS
References
50-443-LA-2, ASLBP 17-953-02-LA-BD01, RAS 55199
Download: ML19235A320 (16)

Text

UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION ATOMIC SAFETY AND LICENSING BOARD In the Matter of Docket No. 50-443-LA-2 NEXTERA ENERGY SEABROOK, LLC ASLBP No. 17-953-02-LA-BD01 (Seabrook Station, Unit 1)

Hearing Exhibit Exhibit Number: INT029 Exhibit

Title:

Summary of Rebuttal Testimony of Victor E. Saouma, Ph.D Regarding Scientific Evaluation of NextEra's Aging Management Program for Alkali-Silica Reaction at the Seabrook Nuclear Power Plant (Non-Proprietary Version)

UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD

)

In the Matter of )

NextEra Energy Seabrook, LLC ) Docket No. 50-443 (Seabrook Station, Unit 1) )

_____________________________________)

PRE-FILED REBUTTAL TESTIMONY OF VICTOR E. SAOUMA, PH.D REGARDING SCIENTIFIC EVALUATION OF NEXTERAS AGING MANAGEMENT PROGRAM FOR ALKALI-SILICA REACTION AT THE SEABROOK NUCLEAR POWER PLANT SUBMITTED ON BEHALF OF C-10 RESEARCH AND EDUCATION FUND August 23, 2019 PUBLICLY AVAILABLE

SUMMARY

A Introduction A.1 Please state your name and employment.

My name is Victor E. Saouma. I am Professor of Civil Engineering at the University of Colorado in Boulder. I am also the Managing Partner of XElastica, LLC, a consulting firm. In addition, I am Professeur des Universités in France.

A.2 Do you consider yourself qualified to fully respond to NextEras and the NRC Staffs testimony?

Yes. As earlier indicated, I consider myself an expert in ASR, finite element analysis, fracture mechanics, computational and experimental mechanic. I have also taught reinforced concrete design, advanced reinforced concrete, finite element, and fracture mechanics.

I have nearly 15 years of continuous research on ASR, 11 major research projects, one book, 5 major reports, 3 short courses, 11 published peer reviewed papers, 5 more submitted, all related to ASR. I was a key contributor to EPRIs report on ASR, Modeling Existing Concrete Containment Structures; Lessons Learned. 3002007777 (2017). For the past four years, I have chaired an International committee (through RILEM (French acronym of International Meeting of Laboratories and Experts of Materials, Construction Systems and Structures)), addressing the diagnosis and prognosis of structures affected by ASR. And I serve as editor of a RILEM report with over 450 pages, and 30 contributors among the top researchers on the related topic of ASR.

I have also been President of the International Association of Fracture Mechanics for Concrete and Concrete Structures (and hence am quite familiar with issues pertaining to cracking in concrete). I have advised the Tokyo Electric Power Company (TEPCO) on nonlinear dynamic analysis of large arch dams subjected to strong seismic excitation, conducted shear tests for them (and for EPRI), and consulted for a massive reinforced concrete structure suffering from ASR.

I am the past President (and Fellow) of the IA-FraMCoS, International Association of Fracture Mechanics for Concrete and Concrete Structures In addition to my training and experience as a scientist, I am also a trained and experienced civil engineer. Most of my research funding has been from sponsors seeking advanced scientific based solutions to practical engineering problems. I have taught linear and nonlinear structural analyses reinforced and advanced reinforced concrete design. Therefore, I am familiar with and able to evaluate NextEras engineering-based approach to the problem at ASR at Seabrook.

In studying ASR over many decades, I have found that ASR is an extraordinarily complex and nefarious reaction. While it has been known since the 1940s, only recently have we witnessed an emergence of structures suffering from this problem (as it may take many years to manifest itself). As a result, ASR has attracted the attention of researchers from many disciplines:

chemists, mineralogists, geologists, material scientists, mechanicians, experimentalists, and yes structural engineers. Not a single one of those disciplines can provide a definite answer to questions posed by ASR. However, those who have taken a comprehensive view to the problem 1

are best positioned to opinionate. By virtue of the diversity of my research and publications, and my leadership in an international committee addressing ASR with some of the best researchers in the world, I have acquired a global understanding of the problem that position me to opine with confidence on the adequacy of the work done at Seabrook.

A.3 Are you a Professional Engineer (PE)?

No, I am not a licensed PE. I found no necessity to obtain a PE as my consulting contracts for commercial engineering projects (TEPCO, Tropicana casino parking (for Weidlinger & Assoc.),

Gilboa dam, Crystal River nuclear power plant, to name a few) generally require knowledge and expertise far beyond those of a PE.

A.4 Please identify this document.

This is my written pre-filed rebuttal testimony regarding my scientific evaluation of NextEras Aging Management Program for Alkali-Silica Reaction (ASR) at the Seabrook nuclear power plant.

My written pre-filed rebuttal testimony is submitted in two versions: EXHIBIT INT028 is my complete testimony, and includes some proprietary information. I am also submitting EXHIBIT INT029, which contains the introductory section and a summary of my conclusions. I also plan to submit a redacted version of ExhibitINT028 as soon as possible.

A.5 What is the purpose of your Rebuttal Testimony?

The purpose of my Rebuttal Testimony is to respond to criticisms of my Opening Testimony by NextEra and the NRC Staff, and to confirm my continuing professional opinion that the large-scale test program (LSTP), undertaken for NextEra at the Ferguson Structural Engineering Laboratory (FSEL) of the University of Texas, has yielded data that are not representative of the progression of ASR at Seabrook; and that as a result, the proposed monitoring, acceptance criteria, and inspection intervals are not adequate.

A.6 Your pre-filed Opening Testimony had about 25 questions and answers. In response, you have received a total of more than 400 questions and answers from twelve witnesses (53 Q/A from NRC Staff, 125 Q/A from SGH, and 236 Q/A from MPR). Are you going to reply to each one of those 400-plus Q/A?

While I have reviewed all of the testimony by NextEras and the NRC Staffs witnesses, it would not be possible for me to respond in this document to all of their statements. I will focus on the most relevant and significant statements.

A.7 What documents have you reviewed in preparing your rebuttal testimony?

I have reviewed the position statements filed by NextEra and the NRC Staff, and the testimony of their expert witnesses. The documents I reviewed consists of the following:

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• Testimony of NextEra Witnesses Michael Collins, John Simons, Christopher Bagley, Oguzhan Bayrak, and Edward Carley (July 24, 2019) (Exhibit NER001) (MPR Testimony);

• Testimony of NextEra Witnesses Said Bolourchi, Glenn Bell, and Matthew Sherman (July 24, 2019) (Exhibit NER004) (SGH Testimony);

• NRC Staff Testimony of Angela Buford, Bryce Lehman, and George Thomas (July 24, 2019)

(Exhibit NRC001) (NRC Staff Testimony);

• NRC Staff Testimony of Jacob Phillip (July 24, 2019) (Exhibit NRC005) (Phillip Testimony);

• NextEra Energy Seabrook LLCs Statement of Position (July 24, 2019) (NextEra SOP); and

• NRC Staff Initial Written Statement of Position (July 24, 2019) (NRC Staff SOP).

A.8 According to NextEra, The LAR is based on sound science and well-established engineering principles and is fully compliant with applicable codes and regulations. NextEra SOP at 2. Do you agree that both scientific and engineering principles were well-applied here?

No. Everything begins with science. When science is well understood, we can translate scientific principles to engineering and eventually write codes. With ASR, one must begin with an adequate scientific understanding in order to verify the adequacy or appropriateness of the engineering principles to apply.

All engineering approaches to ASR should be supported by accurate assumptions. In this case, NextEra applied engineering models without first ensuring that the underlying assumptions were scientifically sound. Therefore, it is now necessary to go back to science and make sure that ASR is well understood according to sound scientific principles. Only then can an adequate engineering approach, i.e., the development of codes and acceptance criteria, be devised or undertaken. I would also add that any engineering codes that are applied to the problem of ASR must be up-to-date and suitable to the problem.

In this case, NextEra took an engineering method that was specifically created for the initial design of the plant and tweaked it for purposes of addressing ASR at the long-operating Seabrook reactor. The application of an outdated design engineering code to a current operational condition yielded an analysis that was inadequate for either diagnosing the ASR problem at Seabrook or conceiving an effective monitoring plan.

A.9 Can you explain in simple terms, possibly through an analogy how you view the differences in approach?

I see a very strong analogy between the Seabrook Containment Enclosure Building (CEB) and a patient suffering from cancer. Indeed, ASR has often been casually referred to as cancer of the concrete. In the 21st century, when a patient has cancer, the general practitioner refers her/him to a specialist (oncologist). The specialist in turn, performs state of the art laboratory tests, then a diagnosis is first established (extent of the cancer), a prognosis is given of the likely course of the disease, and a treatment plan is established. The treatment plan will include additional laboratory tests to monitor the cancer and determine if the cancer is in remission, spreading, or metastasized. In the worst-case scenario, the patient will be told his or her chances of survival.

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In the case of the Seabrook ASR, NextEra is pursuing methods more appropriate to the 19 th or 20th Century. There is no written record that NextEra consulted an ASR specialist for the diagnosis or prognosis of ASR. An outdated and flawed tool (a 1971 design code) and primitive surficial observations (comparable to auscultation by stethoscope in a medical context) were used to make a simplistic diagnosis and questionable prognosis of a slow evolving reaction. The treatment plan included a monitoring program that was based on the unjustifiably optimistic conclusions reached during the flawed steps of diagnosis and prognosis. Finally, the whole problem was left entirely in the hands of general practitioners (i.e., engineers), without the assistance of any specialists. Despite their expertise to deal with common nuclear plant maladies, they lack the specialized expertise to make a sophisticated diagnosis or prognosis, to create an adequately informed treatment plan for monitoring the complex problem of ASR, or to analyze and respond appropriately to the monitoring results.

A.10 Can you name examples where so-called scientific approach was followed in lieu of an engineering one for CEB?

Yes, the analysis of the Gentilly-2 (G-2) nuclear plant by Gocevski (Exhibit NER038) at Hydro-Quebec (HQ) is a perfect example. It has been referenced by NextEra, yet the Seabrook analysis is much less sophisticated than the one carried by their Canadian counterpart.

In addition, there are many other examples for dams and even bridges. For dams, an example of modern safety assessment can be found in the report by the Swiss Committee on dams: Swiss Committee on Dams, Concrete Swelling of Dams in Switzerland (2017) which took a very comprehensive and scientific approach to fully understand the impact of ASR on dams. (Note that all the authors are either practicing engineers or employees of utility companies).

A.11 Can you be more specific and contrast what HQ did for G-2 that was not performed by NextEra for Seabrook?

Hydro-Quebec performed a very detailed safety assessment of Gentilly-2 which suffered from ASR. Like NextEra, HQ was seeking to demonstrate compliance with an industry code (in that case CSA Standard N-278). The approach followed by Gocevski in Exhibit NER038 is indeed very much in line with what I have been advocating in terms of rigor and reliability. It is to be contrasted with the very simplistic approach taken by NextEra and approved by the NRC.

Some of the key differences between HQs evaluation of ASR at Gentilly and NextEras evaluation of ASR at Seabrook are:

• HQ used a much more sophisticated approach than NextEra in considering humidity.

Humidity distribution was considered, including the impact of internal relative humidity.

Id. at 15. These humidity-factors were found to have a significant impact on the long-term expansion rate and the accumulated total expansion of ASR-affected concrete structures.

NextEra, in contrast, ignored the impact of internal relative humidity in both its CI measurements and finite element analyses.

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• HQ recognized that as a general matter, the currently available commercial finite element codes are not prepared to adequately address some of the complex problems involving ASR-related swelling. In particular, most of these codes lack material models with constitutive relations that are suitable for the description and the evolution of complex material properties related to ASR. Thus, HQ modified a commercial code to address those particular conditions. NextEra, in contrast, used a commercial code for finite element analysis that was not sufficiently sophisticated nor appropriately modified.

Id. at 14-15, 43.

• HQ simulated the behavior of hydroelectric and nuclear plant structures affected by ASR swelling and identified essential inputs to the concrete/reinforced concrete constitutive model accounting for the chemo-mechanical interaction that should be incorporated in advanced Finite Element (FE) codes, which include the following:

o Adequate description of the kinetics of the reaction; o General failure criterion, provision for the development of irreversible deformations, general criterion for the onset of macro-cracking in both compression and tension regimes; o Degradation law for strength and deformation characteristics; o Proper description of propagation of damage in both tension and compression regimes (viz. homogenization incorporating a characteristic dimension, XFEM or similar); and o Constitutive relation for the interface material relating the velocity discontinuity to the traction vector.

In contrast, NextEra and its consultants failed to list the necessary or desirable features of a code, or its limitations prior to analysis.

• HQ implicitly recognized the need to perform nonlinear analysis, and did not even consider performing a linear elastic analysis. On the other hand, a nonlinear analysis was not even considered by NextEra.

• HQs methodology also included a multi-step and detailed calibration of a large range of factors, using data collected over time. Id. at 15-16. As stated by HQ, the step of calibration is of great importance in any nonlinear static or dynamic analysis as it is a basic requirement for obtaining reliable and accurate results. Id. In contrast, NextEras methodology is extremely simplistic and did not consider these many factors.

Not surprisingly, HQs far more sophisticated methods yielded a more comprehensive understanding of ASR than obtained by NextEra, and that contradicted NextEras own conclusions. For instance, HQ found that:

• Humidity distribution plays an important role in determining the long-term, expansion rate and the accumulated total expansion of ASR-affected concrete structures.

• The influence of 1D, 2D or 3D confinement combined with the influence of humidity distribution have to be evaluated based on in-situ measurements of the real structure or based on laboratory tests conducted on concrete samples with sufficiently large dimensions.

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Id. at page 13.

And HQ reached a conclusion about the effect of chemical prestressing that is completely at odds with NextEras conclusion that prestressing is beneficial in the presence of ASR. As stated by HQ:

The results reveal areas (regions) of the containment with relatively high tensile stresses perpendicular to the planes of the post tensioning cables. The continuous loss of tensile strength of the concrete as a result of AAR may provoke concrete splitting parallel to these planes as it was the case at the Montreal Olympic Stadium (constructed using the same concrete aggregate used at G-2).

Id. at page 28.

A.12 Do you have concerns about the expertise of NextEras and the NRC Staffs witnesses?

As a general matter, NextEras and the NRC Staffs witnesses are experienced engineers, and they have demonstrated experience in simple code-based engineering. It is evident that they are more versed in designing (or reviewing) using code-based engineering than in assessing the capacity of an existing deteriorated structure and using/adapting modern techniques. However, as I explained above, code-based engineering expertise is only one of the skills necessary to address a problem as complex as ASR in the aging safety structures at Seabrook. When a structure as critical as a containment enclosure building is affected by ASR, the need to use tools adequate to ensure the safety of the public is compounded.

As best as I can determine none of NextEras or the NRC Staffs witnesses has demonstrated previous involvement in the specific study of ASR, including recent nonlinear analyses of concrete. Nor have I found any evidence that scientists with ASR expertise were involved in any of the investigations of ASR at Seabrook starting in 2009. The absence of such scientific expertise throughout the investigation and LAR has severely handicapped the LAR process.

Dr. Bayraks qualifications regarding ASR are also limited. He is a Civil/Structural engineering faculty member with no prior record of accomplishment of research directly related to ASR. His only known previous activity related to ASR was testing large concrete girders suffering from ASR (for the Texas Department of Transportation) with the participation of Prof. Folliard (a leading authority on ASR). However, while Dr. Bayrak may be qualified to conduct large-scale ASR-related experiments, or address code procedures, his testimony does not reflect familiarity with some sophisticated aspects pertaining to ASR (such as impact of relative humidity gradients, impact of reactive sands versus aggregates, inhomogeneity of the ASR reaction within a massive concrete pour and others).

I note that on one occasion, NextEra has indeed solicited the help of an external expert to perform an independent peer review of the evaluation of load amplification factors (for ASR).

Prof. Bruce Ellingwood is indeed very well-respected expert in load resistance factor design (LRFD) who has endorsed the proposed methodology. (For the record, I do not disagree with the methodology he endorsed, but instead I disagree with the manner in which it was applied.) It is 6

very regretful that the same attention was not extended to ASR experts to advise NextEra on the multiple ASR-related aspects of this project.

A.13 Do NextEras and the NRC Staffs experts show sufficient familiarity with the scientific literature that is relevant to ASR at Seabrook?

No. An example of the limited expertise of NextEras witnesses is provided by a list of key sources used by NextEra and its consultants that are representative of current industry guidance for addressing ASR (MPR Testimony, A33):

• The Institution of Structural Engineers, Structural Effects of Alkali-Silica Reaction (July 1992) (ISE Guideline) (Exhibit NER012);

• U.S. Department of Transportation, Federal Highway Administration, Report on the Diagnosis, Prognosis, and Mitigation of Alkali-Silica Reaction (ASR) in Transportation Structures (FHWA-HIF-09-004) (Jan. 2010) (FHWA Guideline) (Exhibit NER013); and

• Canadian Standard Association International, Guide to the Evaluation and Management of Concrete Structures Affected by Aggregate Reaction, General Instruction No. 1, A864-00, (Feb. 2000), Reaffirmed 2005 (CSA Guideline) (Exhibit NRC076).

These documents may be adequate general references for addressing ASR in ordinary structures like bridge piers, but they fall far short of supporting the analysis of a critical safety structure such as the Seabrook containment enclosure building. NextEra completely fails to mention a much larger set of more recent documents that provide more comprehensive and appropriate guidance. To draw such a list would be meaningless in this context (a mere Google scholar search for Alkali+reaction+concrete+nuclear+dam yields about 11,000 entries. Of course, only about a hundred would be relevant in this context.) Furthermore, NextEra should have known that there is a wide body of knowledge on ASR coming from the dam community that could have inspired it. To name one, the US Bureau of Reclamations 2005 report, provides very relevant data on the degradation of mechanical properties for structures as old as 30 years.

Similarly, NextEra (and the NRC) should have been very much inspired/guided by the G-2 analysis by H-Q. See A.11 above.

A.14 Can you think of current or former DOE/NRC employees who would have had the skills needed to evaluate the condition of ASR at Seabrook?

Abdul Sheikh and Herman Graves (formerly with the NRC) had the skill sets to review such complex structures. Within DOE, Dan Naus (formerly with ORNL), and Yann LePape (with ORNL),

or Ben Spencer (INL) have the in-depth understanding of ASR and computational techniques necessary to evaluate ASR at Seabrook.

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B Legal and Industry Standards B.1 In its Statement of Position, NextEra asserts that you would impose requirements on NextEra far beyond what is necessary to satisfy the NRCs reasonable assurance standard. Please comment.

I strongly dispute that assertion. As I have testified in both my Opening Testimony and this Rebuttal Testimony, the work done by NextEra is insufficient to characterize the current condition of ASR at Seabrook or to support a monitoring plan that can identify and assess ASR progression during the 30 years of future operation for which Seabrook has been licensed. As I have repeatedly testified, the simplistic methods used by NextEra to gather data and assess the condition of ASR at Seabrook are fundamentally inadequate to address such a complex problem with such significant safety implications. NextEra effectively put on blinders to a wide range of available techniques and sources of outside expertise, choosing instead to take a code-based engineering approach that could only scratch at the problem. As a result, the basic safety of the population living within 10 miles of Seabrook cannot be reasonably assured.

I have also suggested a set more modern and effective alternative methods for gathering and analyzing data about ASR (i.e., accelerated expansion tests, periodic damage rating index (DRI) measurements, detailed petrographic studies, and modern computational methods). This approach is not just a different way to do the job, or even just a better way. It is demonstrably effective (for example, Hydro-Quebec), in contrast to the demonstrably ineffective measures used by NextEra.

B.2 Is there agreement among the experts regarding the lack of regulatory or industry standards for ASR in nuclear power plants?

Yes. All of the experts agree that the NRC has no standard that specifically applies to ASR. I also am aware of no regulations or industry standards that have been developed to address specifically the presence of ASR and its implications with respect to serviceability and strength in any field. The often-referenced Federal Highway Administration FHWA document (Exhibit NER013) are guidelines and not standards. A guideline is very different from a standard. A guideline provides recommendations to be accounted for in the specific context of their application. A standard or a code is a must-follow directive. Furthermore, one should always contextualize a document. FHWA document cannot be applied to a CEB with the same assurance as it is applied to a bridge pier. The requirements for a CEB would have of course to be much more stringent. At times, NextEra seems to confuse the two.

B.3 What is the significance to this case of the lack of legal or industry standards for ASR?

It should be made clear that there is no industry-standard guidance for ASR (nor for finite element analysis for that matter). As I stated in my Opening Testimony, as a result of the absence of any legal or industry standards for ASR, for all practical purposes it was effectively left to 8

NextEra to write their own guidelines for ASR through their License Amendment Request. This is unusual. As a general matter, guidance documents for evaluating and addressing phenomena like ASR are written by engineering/scientific organizations. For instance, the FHWA report has been written by University Professors/researchers (Prof. Fournier, Berube, Folliard and Thomas). In this case, the NRCs decision to allow NextEra to write its own standards (without consulting academic professors/researchers in related area to ASR) for testing and analysis of a safety-significant phenomenon that is new to NRC is concerning. The NRC should have done more to ensure that standards and guidance would be established independently, objectively, and with rigor.

The NRC Staffs testimony is also somewhat misleading by giving the impression that some ASR standards exist. For instance, in NRC-001 the NRC states:

NextEra has identified reasonable and justifiable structure-specific expansion limits, which account for potential future expansion by setting the maximum level of expansion at which the code acceptance criteria are met, and is actively monitoring all safety-related structures to ensure that they remain within these limits.

This is misleading and of concern as reference is made to code acceptance criteria as though there is some industry code that contains acceptance criteria for ASR. It has been recognized by all parties that there is no code for ASR. Indeed, no industry code or regulation contains any maximum level of expansion. Nor does any industry code exist that contains requirements as to how expansion should be measured. Instead, NextEra has proposed to extrapolate the results of the LSTP to Seabrook, despite the dissimilarity between the environmental conditions, concrete mix, in the LSTP specimen and the Seabrook structures. I continue to hold the opinion that what is missing are: accelerated expansion tests on cores recovered from Seabrook (as covered by EPRI Report 3002013192, Exhibit NER018), periodic damage rating index measurements, and more appropriate computational methods to assess safety.

B.4 NextEra has testified that it evaluated parts of its LSTP against the 1971 ACI-318 code. Does that concern you?

ACI-318-71 was written in the pre-computer age (1971). It stipulates a linear elastic analysis, and of course it does not mention ASR or alternative analyses methods, and it is a contortionist exercise to use it in the 21st century for such a complex problem as ASR in a CEB. Furthermore, we should bear in mind that the design process is composed of two parts: first, one analyzes the structure to determine the load demand, and then one must examine the capacity of the structure to resist the demand. In the ACI code, there is a dichotomy because one uses linear elastic analysis to determine demand, but one uses a nonlinear (plasticity) approach to determine capacity. In the vast majority of structures, this is acceptable, but for the assessment of the CEB (having a nuclear reactor inside), this approach is highly questionable.

On the other hand, a more recent versions of the ACI code -- ACI 318 which existed at the time NextEra submitted its LAR -- stipulates that inelastic (i.e. nonlinear) Finite Element analysis are permitted for purposes of determining load demand. And in every 21st Century research paper that I have seen addressing ASR and/or cracking, nonlinear finite element analysis is 9

performed. Such an approach should have been followed for Seabrook, just as HQ pursued it for Gentilly-2.

Another major concern, is that the margin of errors in the investigative procedure has not been quantified and is likely to be unacceptable. This makes it too risky to be adopted.

B.5 According to NextEra, NIST is currently performing a test program for the NRC on ASR that is intended to provide technical data supporting regulatory guidance to evaluate ASR-affected concrete. Of what relevance is this to the Seabrook LAR?

The NIST research, as described in the Regulatory Information Conference (RIC)

(https://www.nrc.gov/public-involve/conference-symposia/ric/past/2018/docs/abstracts/sessionabstract-31.html ) has had no bearing on this process. It is not referenced in any of the reports prepared by MPR or SGH. Nor is my own research referenced in any of those documents. Furthermore, the NRC Staff does not mention the NIST research or my research in the Safety Evaluation for the LAR.

Of course, this is a matter of concern to me, because it shows that neither NextEra nor the NRC Staff attempted to apply current (NRC-funded) research to the Seabrook LAR or consult outside ASR experts.

B.6 NextEra and the NRC Staff have testified that independent peer reviews were provided by various individuals and entities, including Profs. Ellingwood and Folliard, the Advisory Committee on Reactor Safeguards, and EPRI. Please comment.

With all due respect to the ACRS, there is no indication that they had an appropriate scientific background in Concrete/ASR or that they sought ASR-related expertise outside the NRC. For instance, when the FHWA needed to develop new guidelines, they asked four well-known university researchers (Profs. Berube, Folliard, Fournier, Thomas) to write them. Those guidelines, written for bridges have been extensively referenced by NextEra though a far more important structure is being investigated.

The briefing by EPRI (an industry organization), DOE and the NRC office of research on concrete degradation were very general presentation attended by EPRI, NRC, and DOE employees only.

No invited academic speaker attended, including myself (although I was under contract to the NRC at the time.)

As I testified above, Prof. Ellingwood is a very well-respected expert in his field, one of the fathers of the load resistance factor design (LRFD) used by the ACI code. But he is not an ASR expert per se, although he developed a load amplification factor to the ASR demand. I would also note that his participation in the project was limited to a review of the load amplification factors.

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In addition, third-hand reports by NextEra and MPR witnesses regarding the content of telephone conversations with Dr. Folliard simply do not rise to the level of an independent peer review. It is surprising that Dr. Folliard was an active participant in the previous Texas-DOT project, and not on this one, which could have such extremely serious repercussions. In-fine, there is no evidence that he had an input on the project.

In A86, NextEra testifies that it submitted MPRs analysis and recommendation for a large-scale testing program (MPR-3727) to EPRI as an independent third party reviewer. EPRI is an industry-funded research institute. As such, it is not truly independent of the nuclear industry, including NextEra. Also, unless there have been some recent significant changes in the EPRI staff, it does not have the in-house expertise to fully assess ASR-affected structures. For instance, I recently was contracted to write part of EPRIs report Structural Modeling of Nuclear Containment Structures 00-10006428). It is reasonable to assume that EPRI sought my assistance because it did not have sufficient in-house expertise for the task.

With respect to other reviews were performed by NRC staff and employees of the national laboratories, there is no indication that anyone of them had the technical background to fully capture the ASR problem. I note that Dr LePape from the ORNL was not one of the reviewers; nor was Herman Graves, formerly at NRC; or Dan Nauss, formerly at ORNL. All of these individuals would have had the proper technical background for such a task.

C

Background:

ASR C.1 In your Opening Testimony, you provided a technical description of ASR.

Does it differ significantly from the description given NextEras and the Staffs testimony, and if so, what is the significance of the difference?

With regard to ASR itself, generally, we all agree that:

• ASR is an irreversible reaction.

• Expansion is limited if constrained (such as by reinforcement).

• ASR is temperature dependent (e.g., the LSTP accelerated the reaction through an increase in temperature).

However, there is a lack of explicit recognition by NextEra regarding the following:

• Relative humidity/temperature is a driver of the ASR reaction (if over 80%) or an impediment (if below 80%). This has an influence on CI readings; see below. NextEra does not account for it in the field measurement of the CI or the subsequent finite element analysis.

• Ignored are the characteristics of aggregates (early or late expansion), ensuing type of gel (in terms of viscosity), or whether the sand or the aggregates are the reactive element.

All of the above will influence both the types of cracks (small/larger), the age at which they will develop (early or late). NextEra does not account for this phenomenon.

• The kinetics of the reaction are not accounted for. NextEra makes multiple references to a slow reaction and the assumption that the expansion is linear. This is wrong. NextEra 11

is ignoring the well-established sigmoidal shape of the expansion. Seabrook is most likely in the very early slower phase, but the rate of expansion will accelerate at some point.

Hence, the kinetics should play an important role in the LAR (although NextEra repeatedly states that it is irrelevant). Kinetics can be assessed through accelerated expansion tests as described in EPRI Report 3002013192, Exhibit NER018).

• NextEra does not account for degradation of concrete mechanical properties in the Structural Evaluation Methodology (SEM), such as the elastic modulus, or tensile/compressive/shear strengths.

• NextEra does not acknowledge the fact that ASR is not uniform or homogeneous within the CEB walls. Some locations will have more ASR than others. Similarly, pockets or hot spots are not distributed uniformly. This will result in localized weakness that is difficult to pinpoint and are likely to cause stress concentrations missed by a uniform/smooth distribution of ASR.

D Final Remarks D.1 Please summarize the key conclusions of your rebuttal testimony.

1. NextEras testimony reflects a narrow code-based engineering approach rather than a combination of scientific and engineering approaches as is required for a problem with the complexity of ASR in the concrete enclosure of a nuclear reactor. The contrast can be seen by comparing the Seabrook ASR project to Hydro-Quebecs investigation of ASR at the Gentilly-2 nuclear plant, a much more sophisticated and effective investigation.

2. Through their testimony, NextEras and the NRC Staffs witnesses have demonstrated a lack of sufficient expertise in the field of ASR assessment and analysis. This lack of expertise was compounded by a failure to obtain independent peer review of NextEras work.

3. NextEras proposed code-based-engineering approach may comply with the 1971 ACI code. However, the corresponding margin of error has not been quantified and is likely to be unacceptable. This makes it too risky to be adopted.

4. ACI 318-71, is not an adequate tool because it stipulates linear elastic analysis rather than inelastic (i.e., nonlinear) analysis. Use of nonlinear analysis is common and widely performed in the 21st century for complex structures such as Seabrook (as in the post-mortem investigation of Crystal-River). It should have been employed at Seabrook.

5. The finite element simulation used by NextEra is very rudimentary, completely inappropriate modeling of the ASR and the possible in-plane degradation.NextEra has failed to recognize some of the key characteristics of ASR, namely the driving force of relative humdity, the relationship between the characteristics of aggregates to both the nature of cracks and the timing of their development, the kinetics of the ASR reaction, the degradation of concrete mechanical properties in the SEM, and the lack of uniformity in the location and progression of ASR. NextEra also fails to acknowledge that the progression of ASR over time follows a sigmoid curve and is not linear. NextEras failure 12

to account for all these factors plays a significant role in undermining the reliability of its assessment of ASR.

6. I do not give much credence to the shear tests for the purpose of assessing the impact of ASR and the ultimate strength of the beam. Those results could have been easily anticipated and confirmed by proper finite element studies (i.e. they were un-necessary in my opinion). On the other hand, a by-product was the development of the inspection methodology.

7. The environmental conditions under which the CI and through crack extension were measured in the laboratory do not correspond to the conditions at the Seabrook Plant.

As a result, the extent of internal expansion will most certainly be misleading.

Furthermore, NextEra failed to recognize the impact of the reinforcement close to the surface of the wall that would inhibit crack opening.

8. Due to the confinement, the expansion will be radial, hence the cracking will be internal and propagate vertically (along the lines of compression). Furthermore, it will seldom daylight to be captured by CI. Hence, the walls of the CEB could very well delaminate internally, and this delamination will either not be captured by the instrumentation, or not captured in a timely way.

9. The ten-year effort to understand ASR at Seabrook and establish a program to adequately monitor ASRs progression over the next 30 years (including the remainder of Seabrooks current license term and a 20-year renewal term) has fallen far short of providing a reasonable assurance that NRC seismic design requirements are satisfied and that the public will be protected in the event of an earthquake. Yet, some progress has been made, especially in the program to install extensometers for more accurate monitoring.

10. In my expert opinion, NextEra should return to the drawing board, applying greater expertise, collecting more meaningful data, and using more appropriate and commensurate scientific and engineering approaches. Some of the work that has been done will still be useful and should be expanded on, such as the use of extensometers.

But overall, the investigation should take a new approach that is more scientific, rigorous and sophisticated and subject it to a panel of independent expert reviewers in various related disciplines.

E References Bentz, E. C. (2005). Empirical modeling of reinforced concrete shear strength size effect for members without stirrups. ACI structural journal, 102(2), 232.

da Silva, G. and de Oliveira, A. (2008) Injection of Microcement in Pile Caps Cracked by Alkali-Aggregate Reaction by in the 13th International Conference on Alkali Aggregate Reaction Conference.

EPRI (2017) Report #3002007777, Modeling Existing Concrete Containment Structures; Lessons Learned,.

Geyskens, P., Kiureghian, A. D., & Monteiro, P. Bayesian. Prediction of Elastic Modulus of Concrete. Journal of structural engineering, 124(1), 89-95 (1998).

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Hillerborg, A., Modéer, M., & Petersson, P. E. (1976). Analysis of crack formation and crack growth in concrete by means of fracture mechanics and finite elements. Cement and concrete research, 6(6), 773-781.

Kojima, T., Hayashi, H., Kawamura, M., Kuzume., K.2000, Maintenance of Highway Structures Affected by Alkali-Aggregate Reaction, Proc. of 11 th Inter. Conf. on Alkali-Aggregate Reaction in Concrete, Quebec, pp.1159-1166.

Hansen, E. J., & Saouma, V. E. (1999). Numerical simulation of reinforced concrete deterioration:

Part 2-Steel corrosion and concrete cracking. ACI Materials Journal, 96, 331-338.

Inoue, Oshita, Sawai and Hatano in 13th International Conference on Alkali Aggregate Reaction (ICAAR) 2008 Miyagawa et al. (2006) Fracture of Reinforcing Steels in Concrete Structures Damaged by Alkali-Silica-Reaction- Field Survey, Mechanism and Maintenance; Journal of Advanced Concrete Technology, Vol. 4, No. 3, October 2006 Stark, D., & De Puy, G. W. (1987). Alkali-silica reaction in five dams in southwestern United States.

Special Publication, 100, 1759-1786.

Ulm, F. J., Coussy, O., Kefei, L., & Larive, C. (2000). Thermo-chemo-mechanics of ASR expansion in concrete structures. Journal of engineering mechanics, 126(3), 233-242.

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