The Level 1 probabilistic risk assessment standard for nuclear power plant applications

August 29, 2022, 9:30AMNuclear NewsPatricia Schroeder

The American Society of Mechanical Engineers/American Nuclear Society Joint Committee on Nuclear Risk Management (JCNRM) has issued a new edition of its flagship standard, ANSI/ASME/ANS RA-­S-­1.1-­2022, Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessment for Nuclear Power Plant Applications. This standard was approved by the JCNRM, the ANS Standards Board, and the ASME Board on Nuclear Codes and Standards before being approved on May 11 by the American National Standards Institute (ANSI), earning the title of an American National Standard. With most of the text stable for the past year, the production process was started early, allowing the 400-­page standard to be published on May 31, 2022.

Overview of Holtec's SMR-160

April 5, 2021, 9:30AMANS Nuclear CafeJodine Jansen Vehec
Fig. 1: The layout of a typical SMR-160 site.

Holtec International’s SMR-160 is a pressurized light-water thermal spectrum reactor that relies on natural circulation, thereby eliminating the need for reactor coolant pumps during normal operation. The reference design incorporates a lower pressure conventional steam turbine and wet cooling via a tube-and-shell condenser coupled with forced-draft cooling towers. Optionally, the plant can use dry cooling via Holtec’s HI-KOOL air-cooled condenser.

PRA standard for Advanced Non-Light Water Reactors just issued

February 9, 2021, 7:03AMNuclear News

ANSI/ASME/ANS RA-S-1.4-2021, “Probabilistic Risk Assessment Standard for Advanced Non-Light Water Reactor Nuclear Power Plants,” has just been issued. Approved by the American National Standards Institute (ANSI) on January 28, 2021, this joint American Society of Mechanical Engineers (ASME)/American Nuclear Society (ANS) standard sets forth requirements for probabilistic risk assessments (PRAs) used to support risk-informed decisions for commercial nuclear power plants and prescribes a method for applying these requirements for specific applications.

ANSI/ANS-RA-S-1.4-2021 and its preview are available in the ANS Standards Store.

Alloy 617 is new option for high-temp reactors

May 7, 2020, 9:40AMNuclear News

When it comes to advanced, high-temperature reactors—using working fluids such as molten salt, high-temperature gases, or sodium—there simply are not many qualified materials for nuclear component construction. Alloy 617 is not a new material, but it made the news after Idaho National Laboratory announced that it was recently added to the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (BPV) Code for high-temperature nuclear applications, bringing the total number of qualified high-temperature materials to six.