Developing a Technical Basis for Embedded Digital Devices and Emerging Technologies (NUREG/CR-7273)

On this page:

Download complete document

Publication Information

Manuscript Completed: July 2020
Date Published: March 2021

Prepared by:Muhlheim, M. D. 1
Poore, W. P. 1
Nack, A. M. 2
Wood, R. T. 3
Melin, A. M. 1
Bull Ezell, N. D. 1
Hale, R. E. 1
Holcomb, D. E. 1
Huning, A. J. 1
Halverson, D. S.

1Oak Ridge National Laboratory
Managed by UT-Battelle, LLC
Oak Ridge, TN 37831-6285


3University of Tennessee
Knoxville, TN 37996

D. S. Halverson, NRC Project Manager

Office of Nuclear Regulatory Research
U.S. Nuclear Regulatory Commission
Washington DC 20555-0001

Availability Notice


An embedded digital device (EDD) is a component consisting of one or more electronic parts that requires the use of software, software-developed firmware, or software-developed programmable logic, that is integrated into hardware equipment to implement one or more system safety functions.

This report provides a technical basis for developing guidance for the safe use of EDDs in commercial nuclear power plants (NPPs) in the United States (U.S.), along with relevant observations, based on their classification, functionality, configurability, consequences of failure, and potential for common-cause failures (CCFs), and it reviews how other agencies worldwide, both nuclear and nonnuclear, regulate, approve the use of, and actually use EDDs.

Areas of interest include the types of components in safety-related applications most likely to have EDDs, methods used by other industries and countries to regulate the use of EDDs, and potential issues noted in industry. This information serves to support the technical basis for a graded approach in the selection and use of EDDs. A tangential supply chain issue is the use of replacement parts or parts in upgrades that may contain an undeclared digital device, as it may not meet the requirements for the safety-related application it is being used in.

Other attributes such as reliability (the ability to perform with correct, consistent results), diagnostics, operating experience, and failure modes were reviewed because of their use in risk informing the acceptance of the use of EDDs. Emerging technologies associated with EDDs were noted during this work, and are described in this report.

International experience is similar to that acquired in the United States, and regulators around the world are evaluating the safe use of EDDs. Other industries are further along in the use of EDDs and therefore can provide useful insights into their use and regulation.

Page Last Reviewed/Updated Friday, April 02, 2021