NRC SFST ISG-23: Application of ASTM Standard Practice C1671-07 when performing technical reviews of spent fuel storage and transportation packaging licensing actions

The standard review plans for storage of spent nuclear fuel and transportation of fissile
materials do not address, in detail, the technical considerations for crediting the neutron
absorber content of metal matrix composites used for preventing nuclear criticality. The Division
of Spent Fuel Storage and Transportation (SFST) considers the application of acceptance
criteria and methodology described in the recently developed American Standard for Testing
and Materials (ASTM) standard practice C1671-07, “Standard Practice for Qualification and
Acceptance of Boron Based Metallic Neutron Absorbers for Nuclear Criticality Control for Dry
Cask Storage Systems and Transportation Packaging,”1
with some exceptions, additions, and
clarifications, appropriate for staff use in their review activities. This Interim Staff Guidance
(ISG) provides guidance to the staff and is not a regulatory requirement. Alternative
approaches are acceptable if technically supportable.