Nuclear power reactor designs feature multiple diverse safety components to prevent a fuel meltdown and the release of radiation should a meltdown occur. Called defense-in-depth, these multiple barriers would all have to fail for radiation to be released. If any individual barrier was 100% reliable, the remaining barriers would not be necessary. But because neither any individual barrier nor all the barriers collectively guarantee protection, each barrier must be as effective as possible if the inherent risks are to be minimized.
The protection afforded by multiple diverse safety measures will be weakened if problems with individual safety components are tolerated rather than corrected, making it more likely that an extreme event can overwhelm all the barriers to cause disaster.
In a new series of blog posts—Disaster by Design/Safety by Intent—UCS will explore how defense-in-depth can be eroded, and how it can be enhanced. Read More