Many existing containments in the United States have been shown to acc
ommodate credible severe accident loads. Future containments should be
explicitly designed for severe accident loads to reduce the uncertain
ty associated with the response of containments to these low-probabili
ty events. This paper examines the experiences from the application of
current structural design codes for concrete containments, ultimate p
ressure capacity evaluation of existing containments, and pressure fra
gility testing of scale model concrete containments to arrive at the d
irections for modification of national codes. Recommendations are prov
ided to consider the severe accidents directly in the concrete contain
ment design.