ASME BPVC 2025 Section III div. 5 PDF

Full title and description

ASME Boiler and Pressure Vessel Code (BPVC), Section III — Rules for Construction of Nuclear Facility Components, Division 5: High Temperature Reactors (2025 Edition). This Division provides the construction, material, design, fabrication, examination and testing rules for components intended for high‑temperature reactor service (including HTGR and LMR designs) and includes new rules for graphite and other nonmetallic core components.

Abstract

Division 5 of ASME BPVC Section III establishes mandatory and non‑mandatory requirements for high‑temperature reactor components: metallic pressure‑boundary parts and supports, core support structures, graphite and composite core components, material property data for elevated‑temperature service, and methods for evaluating time‑dependent phenomena such as creep, creep‑fatigue and irradiation effects. The 2025 Edition organizes updated design‑by‑analysis and design‑by‑test provisions and consolidates prior Code Cases into the main Code text to support advanced reactor deployment.

General information

• Status: Current / Active (2025 Edition).
• Publication date: July 1, 2025 (2025 Edition).
• Publisher: American Society of Mechanical Engineers (ASME).
• ICS / categories: Nuclear power plants; reactor components and safety (ICS area for nuclear power plants / safety).
• Edition / version: 2025 Edition (replaces/succeeds earlier 2023 edition).
• Number of pages: Approximately 672 pages (varies by format).

Scope

Applies to the material selection, design, construction, examination, testing and overpressure protection of components for high‑temperature reactors (HTGRs and liquid‑metal reactors). The rules address metallic pressure boundary components and supports for elevated‑temperature service, graphite and composite core components (including irradiation effects and probabilistic considerations for graphite), and specific provisions for time‑dependent material behavior such as creep and creep‑fatigue. It is intended for components whose service temperatures exceed the thresholds used in lower Divisions and for which long‑term, temperature‑dependent phenomena control design life and allowable stresses.

Key topics and requirements

• Design rules for High‑Temperature Gas‑Cooled Reactors (HTGR) and Liquid‑Metal Reactors (LMR), including metallic pressure boundaries and supports.
• Specific provisions for graphite and other nonmetallic core components: material characterization, irradiation effects, and probabilistic assessment of graphite properties.
• Time‑dependent behavior: creep, tertiary creep, creep‑fatigue interaction, and strain‑range partitioning for long‑term cyclic service.
• Elevated‑temperature applicability thresholds (examples used in Division 5 guidance: ~700 °F / 370 °C for many ferritic materials and ~800 °F / 425 °C for many austenitic alloys) and updated allowable stress/property data for high‑temperature alloys.
• Integration of updated material property databases and explicit guidance for design‑by‑analysis and design‑by‑test approaches for advanced reactor components.
• Provision for examination, testing and overpressure protection appropriate to high‑temperature nuclear service; consolidation of certain Code Cases into mandatory text.

Typical use and users

Used by nuclear design engineers, materials engineers, fabricators, test laboratories, code reviewers, regulatory bodies and plant operators involved in advanced reactor design, manufacture, quality assurance and inservice evaluation. Developers of HTGR and LMR concepts, as well as regulators and third‑party reviewers assessing compliance with 10 CFR and other national requirements, commonly reference Division 5.

Related standards

Other BPVC volumes and ASME standards (Section II materials parts, Section V NDE, Section IX welding qualifications, Section XI inservice inspection) are commonly used alongside Division 5. Regulatory guidance such as NRC Regulatory Guide 1.87 (and related NUREG analyses and Code Case reviews) and the Code Cases referenced in endorsement/reviews are also relevant.

Keywords

ASME BPVC, Section III, Division 5, High‑Temperature Reactors, HTGR, LMR, graphite, creep, creep‑fatigue, elevated‑temperature design, probabilistic design, material properties, design‑by‑analysis, design‑by‑test.

FAQ

Q: What is this standard?

A: It is ASME BPVC Section III, Division 5 — the portion of the Boiler and Pressure Vessel Code that contains rules and requirements for the construction and qualification of components used in high‑temperature reactor systems (2025 Edition).

Q: What does it cover?

A: Material selection and qualification, design rules for metallic and nonmetallic (graphite/composite) core components, time‑dependent failure modes (creep, creep‑fatigue), testing, examination and overpressure protection specific to HTGR and LMR service.

Q: Who typically uses it?

A: Reactor designers, materials and mechanical engineers, fabricators, inspectors, testing labs, and regulators involved with advanced high‑temperature reactor projects and component certification.

Q: Is it current or superseded?

A: The 2025 Edition is the current published edition (published July 1, 2025). Users should verify the edition required by their regulator or project specification; NRC endorsement and applicability guidance have been issued with exceptions and limitations for earlier and related editions.

Q: Is it part of a series?

A: Yes — Division 5 is one Division within ASME BPVC Section III (the Rules for Construction of Nuclear Facility Components). Section III includes Divisions 1, 2, 3, 4 and 5; Division 5 specifically focuses on high‑temperature reactors.

Q: What are the key keywords?

A: High‑temperature reactors (HTGR, LMR), elevated‑temperature materials, graphite core components, creep, creep‑fatigue, strain‑range partitioning, design‑by‑analysis, design‑by‑test, ASME BPVC Section III Division 5.