ML18152B674

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Enclosure 3 - ANS Anlwr May 2 2018 Presentations
ML18152B674
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Issue date: 05/11/2018
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NRC/RES/DE
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Mehta S
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5/11/2018 High Temperature Reactors Codes and Standards ANS - NRC Workshop May 2, 2018 Developers BWXT Framatome (previous AREVA)

Kairos Power Star Core Nuclear XEnergy Supporters DOE, Duke Energy, EPRI and NEI Technology Overview High Temperature GasCooled Reactor (Framatome, XEnergy, StarCore)

  • Graphite moderator and Helium coolant
  • TriIsotropic (TRISO) coated particle fuel
  • Block or pebble type fuel elements
  • Fixed (block) or moving (Pebble) core
  • Epithermal neutron spectrum
  • Primary system pressure (~6 MPa)
  • Core inlet/outlet Temperature (~325 °C / ~750 °C)
  • Steam conditions Temp/Press (~16 Mpa, ~560 °C) 5/2/2018 1

5/11/2018 Technology Overview KPFHR (Kairos Power)

  • Fluoride SaltCooled HighTemperature Reactor, which leverages TRISO particle fuel in pebble form and a hightemperature, chemically inert, single phase coolant, flibe (7Li2BeF4).
  • FHR technology requires high temperature, but lowpressure (and thus stress) materials. Inherent fission product retention with the combination of TRISO particle fuel and flibe coolant would benefit from updated standards on SSC classification and treatment of source terms.

5/2/2018 Codes and Standards

  • Similar to any other reactor design our designs will be governed by hundreds of codes and standards.
  • Most will be of little consequence; since they govern routine design, fabrication, construction, and installation activities

- Heat exchanger design standards for air blast heat exchangers which we will simply order out of a catalog

- Relevant standards which the NRC would be most interested in are various ASME, IEEE, ASCE standards

- These standards will be invoked for major parts of the nuclear island, e.g. ASME B&PV Sect III , Div. 5 High Temperature Reactors 5/2/2018 Page 4 2

5/11/2018 Codes and Standards ASME Section III, Div. 5

  • Section III, Div. 5 includes graphite and other high temperature materials
  • It provides high temperature design rules for some conventional materials
  • The value of the graphite section of Div. 5 remains to be seen, since they have never actually been applied in practice to the design of an actual reactor
  • We believe they are usable and beneficial beyond the laboratory context
  • The parts for metallic materials will be useful to us and essential for our next generation of HTGRs, i.e. the VHTGR
  • Good progress has already been made on Div. 5, we are not certain whether substantial additional efforts are needed until we start our design activities 5/2/2018 Page 5 Typical Standards for for HTGRs
  • I&C IEEE Standard (Analog or Digital)
  • Silo Concrete ACI standard
  • Refueling machine TBD robotics or elevator standards 5/2/2018 Page 6 3

5/11/2018 HTGRTWG Priority Standards

  • ANS30.1201x, Integration of RiskInformed, PerformanceBased Principles and Methods into Nuclear Safety Design for Nuclear Power Plants (new standard)
  • ANS30.2201x, Categorization and Classification of Structures, Systems, and Components for New Nuclear Power Plants (new standard)
  • ANSI/ANS53.12011, Nuclear Safety Design Process for Modular Helium Cooled Reactor Plants, R2016
  • ANSI/ANS 67.02.1 2014, Nuclear SafetyRelated InstrumentSensing Line Piping and Tubing Standard for Use in Nuclear Power Plants
  • ANS20.1201x, Nuclear Safety Criteria and Design Criteria for Fluoride SaltCooled HighTemperature Reactor Nuclear Power Plants
  • Potential revisions to ASTM standards that are consistent with ASME code requirements (e.g. Sec. III Div. 5, 316SS composition in Table HBBU1, Revised Case 2581) 5/2/2018 Page 7 Missing Standards
  • At this time we cannot readily identify any additional standards outside the context of an active design program 5/2/2018 Page 8 4

5/11/2018 Q&A 5/2/2018 Page 9 5

5/11/2018 Strategic Vision for Advanced Reactor Standards Workshop May 2, 2018 Molten Salt Reactors Technology Working Group Report By Jason Redd, PE Technology Overview

  • Molten Salt Reactors (MSR) utilize salt compounds in a liquid phase to provide reactor core cooling, neutron moderation, and/or fuel form. Typically operating at low pressure and high temperature, MSRs are capable of providing high quality steam or process heat for numerous uses. A wide combination of nucleonics, fuel, and coolant designs are under development.
  • Characteristics of some MSR designs that differ from the operating LWR fleet include: higher coolant temperatures, potentially corrosive salt compounds, higher fast neutron exposure of reactor internals and vessel, and liquid fuel circulating outside of a conventional reactor vessel.

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5/11/2018 Benefit of Standards in the Licensing Process

  • The National Technology Transfer and Advancement Act (March 1996) codified existing OMB guidance to Federal agencies to utilize consensus standards were appropriate.
  • Reactor developers and the NRC Staff benefit from standards which can be reviewed once, and then be recognized as acceptable for use within the scope of the standard for other reactor designs.
  • Costs savings include designers not having to each develop and justify to the NRC Staff common techniques and processes.
  • NRC Staff benefits by not having to repeatedly consume review time and resources on issues common to multiple reactors.
  • Consensus standards reflect a broader knowledge and experience base than any one reactor developer could provide which reduces the uncertainty inherent in any new design. 3 Standards Needs
  • MSR technology can be deployed today based on existing consensus standards and reactorspecific design details.
  • Such an approach is not preferable due to the resources required to individually develop and defend the design details which would be better addressed by industry standards.
  • Many general industry and LWRcentric standards are completely appropriate for MSR plants; the further from the reactor, the more existing standards are applicable or may be easily adopted in MSR licensing via limited exceptions.
  • As a rapidly developing technology, standards acceptance criteria needs to be performance based, rather than prescriptive.

4

  • MSR standards needs are focused around materials and design standards.

2

5/11/2018 Top 10 Standards

  • ACI - Standard for concrete exposed to high service and accident temperatures;
  • ANS20.2 Nuclear Safety Design Criteria and Functional Performance Requirements for LiquidFuel MoltenSalt Reactor Nuclear Power Plants;
  • ANS30.1 Integrating Risk and Performance Objectives into New Reactor Nuclear Safety Designs;
  • ANS30.2 Categorization and Classification of Structures, Systems, and Components for New Nuclear Power Plants;

Top 10 Standards (Continued)

  • ASME BPV Sec. III Div. 5 - Seek additional content on considerations for corrosion and contact irradiation damage;
  • ASME BPV Sec. III Div. 5 - Need more material options such as high strength nickel alloys to broaden the approved material choices for high temperature structural applications;
  • ASME BPV Sec. III Div. 5 - Need more material options (metallic, graphite, etc.) for core components in a high fast neutron flux environment;
  • ASME BPV Sec. III - Direction regarding design, materials, and fabrication of structural components clad or lined with corrosion resistant materials;
  • ASTM and AWS - Refractory alloys need development work - i.e.

welding techniques, fabrication techniques, joining techniques, 6

understanding of embrittlement and fracture behavior.

3

5/11/2018 Priority Standards

  • Among the preceding Top 10 standards, the below topics are the highest priority to a broad cross section of MSR developers; representatives of the MSR TWG will volunteer to support the below efforts:
  • ASME BPV Sec. III Div. 5 - Need more material options such as high strength nickel alloys to broaden the approved material choices for high temperature applications;
  • ASME BPV Sec. III - Direction regarding design, materials, and fabrication of structural components clad or lined with corrosion resistant materials;
  • ASTM - Refractory alloys need development work - i.e. welding techniques, fabrication techniques, joining techniques, understanding of embrittlement and fracture behavior. 7 QUESTIONS?

8 4

Advanced Reactor Standards Workshop May 2, 2018 Fast Reactor Working Group

 Multiple developers working on multiple technologies

 Spans variety of fast reactor technologies in development ARC Columbia Basin Elysium Industries General Atomics GE Hydromine Oklo TerraPower Westinghouse Duke Exelon Southern Studsvik Scandpower EPRI NEI 2

Industry Engagement

 Fast reactors offer a near limitless source of clean and affordable energy, which have attracted the participation of a diverse group of technology developers and other stakeholders

 The FRWG works with developers and fast reactor stakeholders to further the state-of-the-art Technology development Regulatory International collaboration 3

High Level Perspectives

 Diverse technologies spanning a spectrum of technical readiness with varying needs

 General consensus that standards need to be modernized as the industry grows, but are generally adequate to support initial deployment strategies Concerns about certain technology-specific gaps Concerns about standards development timeframes and delays 4

High Level Perspectives

 Standards are most effective when there are multiple industry stakeholders with significant technology maturity and overlap, who have a sophisticated understanding of what is needed in particular areas

 Must consider industry needs in light of industry maturity

 Standard modernization will become increasingly useful as the advanced reactor industry grows 5

Paradigm Shifts from LWRs LWRs (PWR & BWR) Non-LWRs Fuel UO2 Metals, oxides, carbides, nitrides, salts Cladding Zirconium alloys Steels, ceramics, no cladding Coolant Water Sodium, lead, other liquid metals, gas, salts Moderator Water Graphite, hydrides, no moderator Spectrum Thermal Fast, epithermal, thermal Temperature 280ºC to 320ºC 300ºC to >850ºC Fuel cycle 1 to 2 years Up to 60 years, possibly more 6

Standards of Interest

 NQA-1 Useful to advanced reactor work currently Continue to modernize as appropriate and as needed 7

Standards of Interest

 Materials Structural alloys, cladding materials, and coating materials for the temperature ranges and fluences of interest

 BPV code for GFR Concrete considerations at high temperature and fluence

 I&C Spectral, material, temperature, and lifetime considerations

 Fuel and material handling variations 8

Standards of Interest

 Decay heat Different from LWR standard due to fast spectrum, fuel management, and fuel configuration variations

 Risk-informed design and risk analysis Important to consider implications of inherent safety characteristics

 General reactor design standards

 Varying considerations for fire protection, operations, offsite/backup power, and seismic standards 9

Standards Gaps

 Standards gap analysis efforts for sodium fast reactors provides initial insights into future standards needs

 This work benefits other technologies Similar investigations may be desired, but results must be kept in context to technology and industry maturity 10

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