Close this search box.

NNSA releases “Final” earthquake study


The National Nuclear Security Administration has released its Final Supplement Analysis [SA] addressing the earthquake risks at the Y-12 Nuclear Weapons Complex in Oak Ridge, Tennessee. As expected, NNSA found it does not need to study earthquake risks any further—except that it is studying them and will continue to until at least the end of next year.

NNSA’s conclusion in the Final SA is that “the earthquake consequences and risks do not constitute a substantial change” from the analysis in the original 2011 Site-Wide Environmental Impact Statement; and “there are no significant new circumstances of information relevant to environmental concerns,” so “no additional NEPA documentation is required at this time.”

Later in the document, though, NNSA admits that it does not actually have a clear understanding of the earthquake risks, noting differences in some of the analytical tools “merit more formal review, which is currently underway.”  It describes how the Extended Life Program for old, out-of-compliance buildings it plans to use for weapons operations for 20-30 more years “includes a commitment to update the Y-12 [safety documentation] and then perform new seismic evaluations for the [old buildings].” That work is described as “underway, and anticipated…by the end of 2021.”

In other words, NNSA is giving itself the full-on okay right now for operating in facilities for the next 20-30 years even though it has not actually completed the detailed assessments it admits that it needs to understand how the old buildings will or won’t perform in an earthquake, and won’t have that information until late next year. Even then, says the next paragraph, “Upgrading both structures to meet modern seismic standards for new facilities may not be feasible or practical.”

Those admissions notwithstanding, NNSA purports to describe with confidence what the risks to workers and the public are from a “design-basis earthquake.”

The Final SA is full of contradictions. Although acknowledging that several of the bomb manufacturing buildings that will be used for the next 20-30 years “do not meet modern earthquake standards” (that is, they will likely fail in the event of major earthquake), the study says if a nuclear criticality event were triggered by an earthquake, the effects would be mitigated by “the walls of the facility.” Those walls, of course, might well be piles of rubble on the ground.

The SA states: “With a seismically-qualified system, a criticality would be detected by the criticality alarm system, and an evacuation alarm would be sounded. All workers would leave the building.” That sounds pretty good until you read the next sentence: “The criticality alarm systems in the 9215 Complex and the 9204-2E Facility [the old buildings] are not seismically qualified.” Won’t be for more than 5 years at best.

The Final SA estimates 5,700 workers would be within 1,000 meters of the accident location in their earthquake scenario, but no more than 100 would be seriously injured or killed. The document does not explain how the earthquake will make its choices about who is taken and who is spared.

One of the more alarming findings in the Draft Supplement Analysis was the  acknowledgment that the consequences of the worst case design basis accidents for the current plan “are approximately ten times higher” than the plan they approved in 2011. That finding not only alarmed us when we read it, it apparently alarmed NNSA as well—they made it disappear in the Final version that just says the current plan “has higher consequences.”


After a waiting period, typically 30 days, NNSA will publish an Amended Record of Decision based on the Final SA. During those thirty days, OREPA will be consulting with our legal team and preparing a response to the Final SA. That response will become part of the Administrative Record.

When the Amended Record of Decision is published, NNSA is locked into its plan and exposed to legal challenge. Whether or not we continue to pursue litigation depends on two things—the strength of our case and the availability of funds.

To date, OREPA donors have made it possible for us to persist in litigation for almost three years—and to win in September of last year. We currently have a motion before the judge asking her to enforce her earlier decision and stop construction of the UPF bomb plant. The current Supplement Analysis, produced at record speed, is an attempt to undercut that Enforcement motion.

The huge win last fall, and the current motion before the judge, belongs to all of us: OREPA, Nuclear Watch New Mexico, Natural Resources Defense Council, the individual plaintiffs, our legal team and our experts, and everyone who invested in the case.

If you are able to continue to support the legal challenge, you can send your contribution to OREPA at P O Box 5743, Oak Ridge, TN 37831 or you can donate on-line via credit card at Just note “Defining Moment Legal” on your check. All donations to OREPA are tax deductible to the full extent of the law.

The Final SA can be viewed here.


OREPA Newsletter


Reflections for Nonviolent Community


Sunday Vigil at Y-12 in Oak Ridge Tennessee

Sunday Vigil

OREPA has held Sunday vigils every week for more than 22 years at the main entrance to the Y-12 Nuclear Weapons Complex (intersection of Scarboro Rd and East Bear Creek Road). We will now be holding the vigil at 4:00PM ET during the winter months so we don’t have to be sitting out in the dark. We are outdoors and space our chairs; when covid numbers are up, we encourage people to wear masks. Bring your own chair, we have some umbrellas for sun shade or rain.

Learn More »
Where Should I park? vigil-map.jpg

Please Share!