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NRC-2018-000831 - Resp 14 - Interim, Agency Records Subject to the Request Are Enclosed, Part 2 of 3
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From: Hiser, Matthew Sent: Wed, 26 Apr 2017 20:36 :34 +0000 To: Purtscher, Patrick

Subject:

Harvesting Workshop Report Attachments: Harvesting Workshop Summary Report draft 4-26-17.docx Hi Pat, I've started putting together the harvesting workshop report. So far, I've got the general outline, background stuff, and session 1 complete . Can you take a look and give any feedback on what I've got so far. I'm hoping to make some good progress tomorrow .. .

Thanks!

Matt Matthew Hiser Materials Engineer US uclear Regulatory Comm ission I Office of uclear Regulatory Research Division of Engineering I Corrosion and Metallurgy Branch Phone: 301-415-2454 I Office: TWFN J0D62 Matthew.Hiser@nrc.gov

Harvesting Workshop Summary Report Outline

Background

Objective and Approach

Workshop Organization and Sessions

Summary of Workshop Discussion o Session 1 Motivation for Harvesting o Session 2 Technical Data Needs for Harvesting o Session 3 Sources of Materials o Session 4 Harvesting Experience: Lessons Learned and Practical Aspects o Session 5 Future Harvesting Program Planning

Key Takeaways from Workshop

Future Activities

Background

On March 7-8, 2017, the Office of Nuclear Regulatory Research of the United States Nuclear Regulatory Commission (NRC) hosted a 2-day workshop on the topic of "Ex-Plant Materials Harvesting." NRC staff worked in close coordination with staff from the U.S. Department of Energy (DOE) and the Electric Power Research Institute (EPRI) to plan and arrange the workshop.

The decision to organize this workshop was driven by developments in the U.S. and global nuclear industry. In the U.S., there is strong interest in extending plant lifespans through subsequent license renewal (SLR) from 60 to 80 years. Extended plant operation and SLR raise a number of technical issues that may require further research to understand aging mechanisms, which may benefit from harvesting.

Meanwhi le, in recent years, a number of nuclear plants, both in the U.S. and internationally, have shut down or announced plans to shut down. Unlike in the past when there were very few plants shutting down, this new development provides numerous opportunities for harvesting components that were aged in highly representative light water reactor (LWR) environments. In a related development, economic challenges for the nuclear industry and limited government spending have limited the resources available to support new research, including harvesting programs. Given this constrained budget environment, aligning interests and leveraging with other organizations is important to allow maximum benefit and value for future research programs.

Objective and Approach The objective of the workshop was to generate open discussion of all aspects of ex-plant materials harvesting, from deciding whether to harvest to planning and implementing a harvesting to using the harvested materials in research programs. Through presentations and open discussion, the workshop was organized to allow for all participants to be better informed of the benefits and challenges of harvesting as well as to identify potential areas of common interest for future harvesting programs.

Workshop sessions were aligned in broad topics to cover all aspects of harvesting, but allow for participants to drive the discussion.

To help accomplish the workshop objectives, the workshop organizers intentionally sought a diverse group of participants. There are a large number of decommissioning plants and interested researchers outside the U.S., so the organizers focused on outreach to international participants through connections such as IAEA, OECD/NEA, and existi ng professional contacts. In addition, a key goal for this workshop was to capture the broader practical perspective from plant owners and decommissioning companies, which are vital to any successful harvesting program, but may sometimes be overlooked in researcher-driven discussions. Workshop participants were also diverse in terms of technical area of focus, with metal components such the reactor pressure vessel (RPV) and internals being discussed along with structural and electrical components. Ultimately, participating organizations includled domestic and international researchers, industry, regulators, and decommissioning companies covering a range of technical areas. The final list of workshop participants can be found at the end of this report in Appendix I.

Workshop Organization and Sessions The workshop was held at NRC headquarters in Rockville, MD and also via webinar to remote participants. Due to limited space in the meeting room and the need for a limited group size for discussion, a webinar was used to allow remote observers to benefit from the workshop. Workshop sessions were organized topically with about half the time on the agenda dedicated to presentations and the remaining time set aside for discussion. Presentations were solicited from participants to cover a range of perspectives and technical areas. The final workshop agenda can be found at the end of this summary report in Appendix II.

The workshop was organized into five sessions as follows:

Session 1 Motivation for Harvesting

Session 2 Technical Data Needs for Harvesting

Session 3 Sources of Mate rials

Session 4 Harvesting Experience: Lessons Learned and Practical Aspects

Session 5 Future Harvesting Program Planning Summary of Workshop Discussion The subsections below will summarize the presentations and discussion in each session and highlight the key takeaways from the session.

Session 1 Motivation for Harvesting Session 1 focused on the motivation for harvesting and why workshop participants are interested in harvesting. Present ations were provided in t his session by:

Richard Reister from DOE,

Sherry Bernhoft from EPRI,

Robert Tregoning from the NRC,

Uwe Jendrich from the Gesellschaft fur Anlagen- und Reaktorsicherheit (GRS), and

Taku Arai from the Central Research Institute of the Electric Power Industry (CRIEPI).

DOE described the role of harvesting within the Light Water Reactor Sustainability (LWRS) Program, including the benefits and cha llenges associated with harvesting. Benefits include the opportunity to fill knowledge gaps where there is limited data or experience and to inform degradation models with data from actual plant components. Challenges include cost, complexity, scheduling, logistics, limited opportunities, acquiring sufficient material pedigree information, and potential negative resullts impacting operating plants.

EPRI discussed the role of harvesting within the context of aging management for Long-Term Operations (LTO), includ ing their experience and criteria for future harvest ing. Their experience emphasized the challenges of cost, schedule, logistics, complicated contracting and acquiring material pedigree information. EPRl' s criteria for harvesting include value to their members that addresses a prioritized need and knowledge gap that cannot be otherwise filled through other means. For EPRI, a well-developed project plan that covers funding, risk management, exit ramps, and clear roles and responsibilities is essential. EPRI presented the question of what the goal is of harvesting to support resea rch for operation out to 80 years, whether a full understanding of all aspects of the degradation or a snapshot to confirm other lab results and models.

NRC shared its perspective on the benefits and challenges of harvesting in regulatory research .

Harvested materials are valuable due to the representative nature of their aging conditions, which may reduce the uncertainty associated with the applicability of the results to operating plants. Harvested materials may be the best option to address technical data needs identified for extended plant operation. Increasing harvesting opportunities from decommissioning plants suggests a proactive approach to harvesting planning may allow for better value by choosing the right material that experienced the right aging conditions for the identified knowledge gap. There are significant challenges associated with harvesting, including cost, schedule, and logistics, but hopefully these can be mitigat ed or avoided by leveraging with other organizations and learning from past experience.

GRS described its role as the main technical support organization in nuclear safety for the German federal government. GRS provides technical advice and assessment and knowledge transfer for decommissioning act ivities, aging management, and long-term operation for German federal and international organizations.

CRIEPI discussed its view of how harvested materials and laboratory prepared materials contrii bute to addressing technical issues. Harvested materials provide exposure to actual plant conditions, but are more limited in availability and the size of the data set that can be generat ed. Laborat ory prepared materials general involve accelerated or simulated aging cond itions, but can be used to produce larger data sets and varying parameters can allow understanding of the effect on the mechanism or property of interest. Harvested materials offer fact finding of actual plant conditions as well as confirmation and verification of results from laboratory prepared specimens.

The discussion following the presentations in this session focused on clearly identifying the need to be addressed by a harvesting project and the myriad cost, scheduile, and logistical challenges associated with harvesting. The clear takeaway from this discussion on the motivation for harvesting is that harvesting requires significant resources to be done successfullly; t herefore it is paramount to clearly identify how the planned harvesting will clearly address a significant need to ensure the harvesting project provides strong value. Leveraging with other organizations to defray costs can also help improve

the value of a given program, but also adds complexity as another organization may have a different set of priorities that changes the focus of the harvesting effort.

Session 2 Technical Data Needs for Harvesting Session 3 Sources of Materials Session 4 Harvesting Experience : Lessons Learned and Practica l Aspects Session 5 Future Harvesting Program Planning Key Takeaways from Workshop Future Activities

Appendix I Workshop Participants Name Organization Email Taku Arai CRIEPI arait@crieoi.denken.or.io Sadao Higuchi CRIEPI higuchi@criegi.denken.or.jg Japan Kazunobu Sakamoto JNRA kazunobu sakamoto@nsr.go.jg Yasuhiro Chimi JAEA chimi.yasuhiro@jaea.go.jg Uwe Jendrich GRS Uwe .Jendrich (ci) ins.de Europe Rachid Chaouadi SCK-CEN rachid.chaouadi@sckcen.be Guy Roussel BelV guy.roussel@Belv.be Daniel Tello CNSC daniel.tello@canada.ca Canada Desire Ndomba CNSC desire.ndomba@canada.ca Karen Huynh AECL kh uynh@aecl.ca Gerrv van Noordennen Energy Solutions 12ovannoordennen@energvsolutions.com us Bill Zipp Dominion william.f.zigg@dom.com industry Mark Richter NEI mar@nei.org Arzu Alpan W estinghouse alganfa@westinghouse.com Sherrv Bernhoft EPRI sbern hoftca>eori .com Robin Dyle EPRI rdy:le@egri.com EPRI Jean Smith EPRI jmsmith@egri.com Al Ahluwalia EPRI kahluwal@egri.com Tom Rosseel ORNL rosseeltmca>ornl.gov Rich Reister DOE Rich a rd. Reister@nuclea r .energy.gov Keith Leonard ORNL leonardk@ornl.gov DOE Mikhail A. Sokolov ORNL sokolovm@ornl.gov John Wagner INL john.wagner@inl.gov John Jackson IN L john.jackson@inl.gov Pradeep Ramuhalli PNNL Pradeeg.Ramuhalli@gnnl.gov Pat Purtscher NRC Patrick. Pu rtscherca> nrc.12ov Rob Tregoning NRC Ro bert.Tregoning@nre.gov Matt Hiser NRC Matthew.Hiser@nrc.gov Mita Sircar NRC Madhumita.Sircar@nrc.gov Tom Koshy NRC Thomas.Koshy@nrc.gov NRC Jeff Poehler NRC Jeffrey. Poehler@nrc.gov Allen Hiser NRC Allen .Hiser@nrc.gov Angela Buford NRC Anigela.Buford@nrc.gov M ark Kirk NRC Mark.Kirk@nrc.gov Amy Hull NRC Amy.Hull@nrc.gov Pete Ricardella NRC/ACRS Pri cca rdel la@Structint.com

Appendix II Workshop Agenda Tuesday, March 7 Session Time Organization Speaker Presentation Title Michael Weber Intro 8:00 NRC Welcome and Introduction to Workshop Robert Tregoning DOE Rich Reister DOE Perspectives on Material Harvesting EPRI Sherry Bernhoft EPRI Perspective on Harvesting Projects 8:15- 8:45 NRC Robert Tregoning NRC Perspective on Motivation for Harvesting 1

GRS Uwe Jendrich Role of GRS in Decommissioning and LTO CRIEPI Taku Arai CRIEPI Motivations for Harvested Material 8:45 - 9:45 DISCUSSION 9:45-10:00 BREAK 10:00-PNNL (for NRC) Pradeep Ramuhalli Data Needs Best Addressed By Harvesting 10:20 10:20-NRC Matthew Hiser High-Priority Data Needs for Harvesting 10:30 10:30 - LWRS Program Perspective on the Technical DOE Keith Leonard 10:55 Needs for Harvesting 2

10:55 - Review of past RPV sampling test programs SCK-CEN Rachid Chaouadi 11:20 and perspective for long term operation 11:20 - Importance of Harvesting to Evaluate Westinghouse Arzu Alpan 11:45 Radiation Effects on Concrete Prooerties 11:45 -

DISCUSSION 12:30 12:30- 2:00 LUNCH Sources of Materials: Past NRC Harvesting and 2:00 - 2:10 NRC Matthew Hiser U.S. Decommissioning Plants Harvesting Plans for Materials Aging 2:10- 2:35 EPRI Al Ahluwalia Degradation Research in Korea and Sweden 2:35- 2:50 DOE/ORNL Tom Rosseel Materials Harvested by the LWRS Program 2:50 - 3:00 DOE/I NL John Jackson NSUF Material Sample Library Gerry van 3:00- 3:15 Energy Solutions Zion Material Harvesting Program Noordennen 3

Potential Harvesting of Concrete from Mihama 3:15- 3:30 Westinghouse Arzu Alpan Unit 1 3:30- 3:45 BREAK 3:45-4:00 GRS Uwe Jendrich Plants in Decommissioning i n Germany Evaluating Structures, Systems & Components 4:00-4:15 CNSC Daniel Tello from Decommissioned/Decommissioning Nuclear Facilities in Canada 4:15- 5:00 DISCUSSION

Wednesday, March 8 Session Time Or~anization Speaker Presentation Title Lessons Learned: Harvesting and Shipping of 8:00-8:30 EPRI Jean Smith Zorita Materials 8:30-9 :00 DOE Tom Rosseel LWRS Program : Harvesting Lessons Learned NRC Perspective on Harvesting Experience and 9:00- 9:30 NRC Matthew Hiser Lessons Learned CRIEPI Research Activities with Harvested 4 9:30-10:00 CRIEPI Taku Arai Materials 10:00-10:15 BREAK Energy Gerry van Zion Harvesting Experience and Lessons 10:15 - 10:45 Solutions Noordennen Learned 10:45 -11:15 Dominion Bill Zipp Kewaunee Insights on Material Harvesting 11:15 -12:00 DISCUSSION 12:00-1:30 LUNCH PNNL (for Technical Information Needed for Informed 1:30-1:45 Pradeep Ramuhalli NRC) Harvesting Decisions 1:45- 2:30 DISCUSSION 2:30- 3:00 Action Items and Next Steps 5

EPRI Sherry Bernhoft DOE Rich Reister 3:00-4:00 Closing Thoughts NRC Robert Tregoning ALL

Note to requester: The attachment is immediately following this email.

From: Hiser, Matthew Sent: Mon, 1 May 2017 14:45 :13 +0000 To: Tregoning, Robert Cc: Pu rtscher, Patrick

Subject:

Harvesting Workshop Summary Report Draft Attachments: Harvesting Workshop Summary Report draft 5-1-17.docx Hi Rob, I have started working on the workshop summary report (attached). I bounced this off of Pat last week and he and I are largely aligned in terms of scope and level of detail.

I have currently written up through the background / intro, session 1 and session 2. When you get a chance, please take a look and provide any feedback on the organization , scope , and level of detail. There is a high-level outline on the first page.

I am hoping to get to a complete first draft by the end of next week and then hopefully something ready to share with workshop participants by the end of May.

Thanks!

Matt Matthew Hiser Materials Engineer US uclear Regulatory Commission I Office of uclear Regulatory Research Division of Engi neering I Corrosion and Metallurgy Branch Phone: 301-415-2454 I Office: TWFN 10D62 Matthew.Hiser@nrc.gov

Harvesting Workshop Summary Report Outline

Background

Objective and Approach

Workshop Organization and Sessions

Summary of Workshop Discussion o Session 1 Motivation for Harvesting o Session 2 Technical Data Needs for Harvesting o Session 3 Sources of Materials o Session 4 Harvesting Experience: Lessons Learned and Practical Aspects o Session 5 Future Harvesting Program Planning

Key Takeaways from Workshop

Future Activities

Background

On March 7-8, 2017, the Office of Nuclear Regulatory Research of the United States Nuclear Regulatory Commission (NRC) hosted a 2-day workshop on the topic of "Ex-Plant Materials Harvesting." NRC staff worked in close coordination with staff from the U.S. Department of Energy (DOE) and the Electric Power Research Institute (EPRI) to plan and arrange the workshop.

The decision to organize this workshop was driven by developments in the U.S. and global nuclear industry. In the U.S., there is strong interest in extending plant lifespans through subsequent license renewal (SLR) from 60 to 80 years. Extended plant operation and SLR raise a number of technical issues that may require further research to understand aging mechanisms, which may benefit from harvesting.

Meanwhi le, in recent years, a number of nuclear plants, both in the U.S. and internationally, have shut down or announced plans to shut down. Unlike in the past when there were very few plants shutting down, these new developments provide opportunities for harvesting components that were aged in representative light water reactor (LWR) environments. In a related development, economic challenges for the nuclear industry and limited government spending have limited the resources available to support new research, including harvesting programs. Given this constrained budget environment, aligning interests and leveraging with other organizations is im portant to allow maximum benefit and value for future research programs.

Objective and Approach The objective of the workshop was to generate open discussion of all aspects of ex-plant materials harvesting, including:

1. Deciding whether to harvest,

2. Planning and implementing a harvesting program,

3. Using the harvested materials in research programs.

Through presentations and open discussion, the workshop was organized to allow for all participants to be better informed of the benefits and challenges of harvesting as well as to identify potentia l areas of

common interest for future harvesting programs. Workshop sessions were aligned in broad topics to cover all aspects of harvesting, but allow for participants to drive the discussion.

To help accomplish the workshop objectives, the workshop organizers intentionally sought a diverse group of participants. There are a large number of decommissioning plants and interested researchers outside the U.S., so the organizers focused on outreach to international participants through connections such as IAEA, OECD/NEA, and existing professional contacts. In addition, a key goal for this workshop was to capture the broader practical perspective from plant owners and decommissioning companies, which are vital to any successful harvesting program, but may sometimes be overlooked in researcher-driven discussions. Workshop participants were also diverse in terms of technical area of focus, with metal components such as the reactor pressure vessel (RPV) and internals being discussed along with concrete and electrical components. The final list of workshop participants can be found at the end of this report in Appendix I.

Workshop Organization and Sessions The workshop was held at NRC headquarters in Rockville, MD. Due to limited space in the meeting room and the need for a limited group size for discussion, a webinar was used to allow remote observers to benefit from the workshop. Workshop sessions were organized topically with about half the time dedicated to presentations and the remaining time set aside for discussion. Present ations were solicited from participants t o cover a range of perspectives and technical areas. The final workshop agenda can be found at the end of this summary report in Appendix II.

The workshop was organized into five sessions as follows:

Session 1 Motivation for Harvesting

Session 2 Technical Data Needs for Harvesting

Session 3 Sources of Mate rials

Session 4 Harvesting Experience: Lessons Learned and Practical Aspects

Session 5 Future Harvesting Program Planning Summary of Workshop Discussion The subsections below will summarize the presentations and discussion in each session and highlight the key takeaways from the session.

Session 1 Motivation for Harvesting Session 1 focused on the motivation for harvesting and why workshop participants are interested in harvesting. Present ations were provided in th is session by:

Richard Reister from DOE,

Sherry Bernhoft from EPRI,

Robert Tregoning from NRC,

Uwe Jendrich from the Gesellschaft fur Anlagen- und Reaktorsicherheit (GRS) in Germany, and

Taku Arai from the Central Research Institute of the Electric Power Industry (CRIEPI) in Japan.

Presentation Summaries

DOE described the role of harvesting within the Light Water Reactor Sustainability (LWRS) Program, including the benefits and cha llenges associated with harvesting. Benefits include the opportunity to fill knowledge gaps where there is limited data or experience and to inform degradation models with data from actual plant components. Challenges include cost, complexity, scheduling, logistics, limited opportunities, acquiring sufficient material pedigree information, and potential negative resullts impacting operating plants.

EPRI discussed the role of harvesting within the context of aging management for Long-Term Operations (LTO), includ ing their experience from past harvesting programs and criteria for future harvesting. Their experience emphasized the challenges of cost, schedule, logistics, complicated contracting and acquiring material pedigree information. EPRl's criteria for harvesting include value to their members that addresses a prioritized need and knowledge gap that cannot be otherwise filled through other means.

For EPRI, a well-developed project plan that covers funding, risk management, exit ramps, and clear roles and responsibilities is essential.

NRC shared its perspective on the benefits and challenges of harvesting in regulatory research.

Harvested materials are valuable due to the representative nature of their aging conditions, which may reduce the uncertainty associated with the applicability of t he results to operating plants compared to tests with alternative aging conditions. Harvested materials may be the best option to address technical data needs identified for exten ded plant operation. Increasing harvesting opportunities from decommissioning plants suggests a proactive approach to harvesting planning may optimize benefits by identifying the appropriate material with the aging conditions of interest for the identified knowledge gap. There are significant challenges associated with harvesting, including cost, schedule, and logistics, but hopefully these can be mitigated or avoided by leveraging with other organizations and learning from past experience.

GRS described its role as the main technical support organization in nuclear safety for the German federal government. GRS provides technical assessment and knowledge transfer for decommissioning activities, aging management, and long-term operation for German federal and int ernational organizations.

CRIEPI discussed its view of how harvested materials and laborat ory prepared materials contrii bute to addressing technical issues. Harvested materials provide exposure to actual plant conditions, but are more limited in availability and the size of the data set that can be generated. Laboratory prepared materials general involve accelerated or simulated aging cond itions, but can be used to produce larger data sets and varying parameters can allow understanding of the effect on the mechanism or property of interest. Harvested materials offer fact finding of actual plant conditions as well as confirmation and verification of results from laboratory prepared specimens.

Discussion Summary The discussion following the presentations in this session focused on clearly identifying the need to be addressed by a ha rvesting project and the myriad cost, sched uile, and logistical challenges associated with harvesting. Leveraging with other organizations to defray costs can also help improve the value of a given program, but also adds complexity as another organization may have a different set of priorities that changes the focus of the harvesting effort.

The clear takeaway from this discussion on the motivation for harvesting is that harvesting requires significant resources to be done successfully; therefore it is par amount to clearly identify how the planned harvesting will clearly address a significant need to ensure the harvesting project provides strong value. In the context of need for data, EPRI suggested the goal of harvesting to support research for operation out to 80 years is not a full comprehensive understanding of all aspects of the degradat ion, but rather a snapshot to confirm other lab results and models. This is an important point for all organizations and researchers to keep in mind before investing significant resources in harvesting.

Session 2 Technical Data Needs for Ha rvesting Session 2 focused on discussing the technical data needs for harvesting and what specific knowledge gaps organizations are interested in addressing through harvesting. This discussion included general perspectives on how to determine when harvesting should be pursued rather than other types of resea rch. Presentations were provided in this session by:

Pradeep Ramuhalli from the Pacific Northwest National Lab (PNNL),

Matthew Hiser from NRC,

Keith Leonard from DOE,

Rachid Chaouadi from SCK-CEN in Belgium, and

Arzu Alpan from Westinghouse.

Presentation Summaries PNNL presented their work, under a small NRC contract, to develop a systematic approach to prioritize data needs for harvesting. PN NL proposed five primary criteria for prioritizing harvesting:

Unique field aspects of degradation o For example, unusual operating experience or legacy materials (composition, etc.) that be no longer available

Ease of laboratory replication of environment-materia I combination o For example, simultaneous thermal and irradiation conditions may be difficult to replicate or mechanism sensitive to dose rate may not be good for accelerated aging

Applicability of harvested mat erial for addressing critical gaps o Prioritize harvesting for critical gaps over less essential data needs

Avai lability of reliable in-service inspection (ISi) techniques for the material/ component o If inspection methods are mature and easy to apply to monitor and track degradation, perhaps the effort of research with harvested materials is not needed.

Avai lability of material for harvesting o The necessary materials/ components must be available to be harvested.

PNNL then presented their application of these criteria to four materials degradation issues as an example: electrical cables, cast austenitic stainless steel (CASS), reactor vessel internals, and dissimilar metal welds. Based on applying these criteria to the examples, PNNL concludes that electrical cables, CASS, and reactor internals are all higher priority for harvesting due to unique aspects of the degradation that are challenging to replicate in the lab. Meanwhile, dissimilar metal welds are of low priority due to the ease of replication in lab aging studies as well as the significant body of knowledge and research on the phenomena.

NRC presented a summary of data needs it is interested in pursuing through harvesting. These included RPV materials to validate fluence and attenuation models and to demonstrate the conservatism of regulatory approaches for transition temperature prediction. Other metal components of interest for harvesting would address data gaps in irradiated stainless steels, as well as improve understanding of inspection capabilities and fatigue life calculations. Electrical components of interest include low and medium voltage cables and other electrical components for degradation studies, and electrical enclosures and cables for fire research. Concrete components of interest include irradiated concrete, concrete undergoing alkali-aggregate reactions, post-tensioned structures, reinforcing steel, tendons, and spent fuel pool concrete to assess potential boric acid attack.

DOE presented their perspective on data needs for harvesting and it s role in providing validation of experimental and theoretical research. DOE performed a signif icant reactor pressure vessel (RPV) harvesting program at the Zion nuclear power plant to reduce uncertainties in the Master Curve methodology, validate modeling predictions and study flux and fluence attenuation effects. The harvesting is largely complete, but the testing program is currently underway. DOE also indicated interest in using harvested materials to validate its models for swelling and microstructural changes of stainless steel internals under LWR irradiation conditions. Harvesting concrete components would be of interest due to lack of literature data and the multiple dependent variables that may affect concrete performance. Finally, DOE has been involved in harvesting cables from the Crystal River and Zion plants to address cable aging as a function of material composition and environment.

SCK-CEN presented their interest in a international cooperative program to harvest reactor pressure vessel (RPV) materials. SCK-CEN presented their survey of the literature for past testing programs of harvested RPV materials, and tlhe limitations of these past program. Key limitations include a lack of archive materials, generally lower temperatures, and poor surveillance programs and dosimetry. SCK-CEN then shared some thoughts on their criteria for a new harvesting efforts, including higher fluence levels and temperatures, available archive materials and reliable information on operating history, dosimetry and surveillance program. Other topics relevant to a new RPV harvesting effort include technical issues such as material variability and irradiation conditions as well as logistical and financial considerations.

The final presentation in Session 2 by Westinghouse focused on the need for harvesting irradiat ed concrete to better understand the threshold radiation level for significant strength reduction.

Westinghouse has installed ex-vessel neutron dosimetry (EVND) at a number of plants in the world and proposed to use these dosimetry measurements to validate fluence model calculations to better understand the uncertainty in these calculations. If concrete can be harvested at one of these plants with EVND data, then irradiated concrete properties from testi ng can be paired with fluence data to improve research benefits.

Discussion Summary The discussion following Session 2 presentations touched on a number of topics. EPRI shared that they developed a report related to the topics of session 2, but more narrowly focused on PWR internals.

MRP-320, "Testing Gap Assessment and Material Identification for PWR Internals," focuses on prioritizing opportunistic harvesting of stainless steel reactor internals components that may be removed from service following MRP-227 inspections. The methodology and approach in this report

may be relevant to the broader harvesting data needs discussion. This report is not publicly available, but is available to EPRI member utilities.

Workshop participants discussed the criteria proposed by PNNL in the first presentation. One additional criteria suggested by EPRI was to consider fleet-wide vs. plant-specific applicability. More broadly applicable materials would be of greater interest for harvesting than those that represent conditions at only a few plants. Another criteria suggested is the availability of material pedigree information, such as composition, processing, environmental conditions (temperature, humidity, fluence, etc.). Another suggested criteria was the ease of harvesting. For example, highly irradiated internals are probably much more difficult and expensive to harvest than electrical cables or unirradiated concrete. This discussion would capture the idea of weighing costs vs. benefits as well as. Further discussion touched on the idea that different organizations may prioritize the various criteria differently, but all will probably at least want to consider the same set of criteria.

Another key theme from this discussion was that a successful program should be guided by a clearly defined objective or problem statement to be addressed. This objective should be well-understood at the initiation of a program and used to guide decision-making through implementation of a harvesting project. This also raises a related point or potential criteria: the timeliness of the expected research results relative to the objective. If the results are needed in the next two years, but a harvesting project will not provide results for at least five years, that should be a strong consideration.

Key Takeaways The criteria proposed by PNNL are a good starting point for prioritizing issues to address by harvesting.

Three additional important criteria would be:

Fleet-wide vs. plant-specific applicability of data,

Ease of harvesting (in terms of cost and project risk), and

Timeliness of the expected research results relative to the objective.

Once a potential harvesting project has reached the point of looking at different sources of materials, the availability of material pedigree information, such as composition, processing, environmental conditions (temperature, humidity, fluence, etc.) is very important to t he overall value of harvesting from that particular plant.

Based on the presentations and discussion in Session 2, there appeared to be two areas with broad interest in pursuing further harvesting: high fluence reactor internals and irradiated concrete. The common drivers for the interest in these issues is a lack of representative data at the fluences of interest and significant challenges with acquiring representative data through other means. High fluence reactor internals has been addressed somewhat by the Zorita Internals Research Project (ZIRP), but stainless steel materials exposed to higher fluence levels at higher temperatures, where void swelling may become significant, could help validate DOE and EPRI models and provide further technical basis for PWR internals aging management. Irradiated concrete harvesting is currently being pursued from the Zorita reactor in Spain, with international collaboration and potential testing at the Halden Reactor Project.

Other areas wit h some, but less widespread, interest expressed from workshop participants for new harvesting efforts included RPV materials and electrical cables and components. SCK-CEN and NRC expressed interest in RPV harvesting, and NRC expressed interest in elect rical component harvesting.

Session 3 Sources of Materials Session 4 Harvesting Experience : Lessons Learned and Practica l Aspects Session 5 Future Harvesting Program Planning Key Takeaways from Workshop Future Activities References to Harvested Materials Research