Historical Review and Observations of Defense-in-Depth (NUREG/KM-0009)

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Publication Information

Manuscript Completed: March 2016
Date Published: April 2016

Prepared by:
Mary Drouin, Brian Wagner; NRC
John Lehner, Vinod Mubayi, BNL

Brookhaven National Laboratory
PO Box 5000
Upton, NY 11973-5000

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

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The concept of defense-in-depth is an important element of the U.S. Nuclear Regulatory Commission's (NRC) safety philosophy. Though the term has been in use for many years, it has not always been used or defined consistently. This Knowledge Management NUREG documents the historical use of the term (based on NRC literature – for example, technical reports, letters, regulations, regulatory guides, speeches, SECY papers, ACRS presentations and letters) for reactors, materials, and waste for both safety and security applications. Perspectives are included from other government agencies as well as the international community. This report includes general observations in the consistencies and inconsistencies in how defense-in-depth has been defined and used.

Page Last Reviewed/Updated Wednesday, March 24, 2021