Nuclear reactors operating in the United States are safe. They pose no threat to the people who live near them, even in the event of a severe accident.
Though many pro nuclear advocates believe that the above statements are true, we are generally reluctant to use those simple, declarative statements. Instead, we often obscure the truth with eye rolling complexity. We hedge our bets by talking about probabilistic risk models, worst case scenarios, and fault tree logic.
The official publications from the Nuclear Regulatory Commission available up until now contradict the simple statements; studies with “conservative” assumptions, including a rapid release of a large portion of the radioactive material from an operating core, have been published that calculate hundreds to thousand of early deaths. According to those old studies, some fatalities happen quickly and most of the rest are the result of increased cancer risk to a large population of exposed individuals.
In 2007, the US Nuclear Regulatory Commission began a study designed to take advantage of many decades worth of testing, experience, analysis and risk assessment to determine a more realistic prediction of consequences. The study picked two reactors as generally representative of the types of reactors in operation in the United States. Peach Bottom Atomic Power Station in Pennsylvania was the chosen representative for boiling water reactors; Surry Power Station in Virginia was picked to represent pressurized water reactors with large containment buildings.
On February 1, 2012, the US Nuclear Regulatory Commission announced that it had released the State-of-the-Art Reactor Consequence Analysis (SOARCA) research study. The complete report can be found by entering ML120250406 in the ADAMS public data base search engine. (After you click on the link, click on the “Content Search” tab to get the search term entry field.)
Buried in that exhaustive report written in scientific, engineering or bureaucratic language are a few key paragraphs that combine to support the declarative sentences used at the beginning of this post. Here are quotes that I gleaned that should help even the most fearful person sleep soundly. Well, maybe not, but at least they should not lose sleep worrying about the specific issue of early death because they happen to live in close proximity to an operating nuclear power station.
“All SOARCA scenarios, even when unmitigated, progress more slowly and release much less radioactive material than the 1982 Siting Study SST1 case. As a result, the calculated risks of public health consequences from severe accidents modeled in SOARCA are very small.” (pg. xxiii)
Here are two quotes that quantify the size of the calculated risk.
“SOARCA’s analyses show essentially zero risk of early fatalities. Early fatality risk was calculated to be ~ 10E-14 (0.00000000000001) for the unmitigated Surry ISLOCA (for the area within 1 mile of Surry’s exclusion area boundary) and zero for all other SOARCA scenarios. In comparison, 92 early fatalities for Peach Bottom and 45 early fatalities for Surry were calculated for the SST1 case in the 1982 Siting Study.” (pg. xix)
“The calculated cancer fatality risks from the selected, important scenarios analyzed in SOARCA are thousands of times lower than the NRC Safety Goal and millions of times lower than the general U.S. cancer fatality risk.” (pg. xxiii)
This exhaustive study updates the consequence predictions from reports of studies that were completed several decades ago including NUREG/CR-2239, “Technical Guidance for Siting Criteria Development” (1982), NUREG-1150, “Severe Accident Risks: An Assessment for Five U.S. Nuclear Power Plants” (1990), and WASH-1400, “Reactor Safety Study: An Assessment of Accident Risks in U.S. Commercial Nuclear Power Plants” (1975).
It was nearly ready to be released when the Great North East Japan Earthquake and subsequent tsunami resulted in an event that substantially melted three nuclear reactor cores at the Fukushima Daiichi nuclear power station. There is a new appendix that compares the assumptions and methods used in the study to what is currently known about the progress of the Fukushima Daiichi accident.
The SOARCA study was a topic of conversation during an NRC public hearing in April 2011, as Dr. Ed Lyman from the Union of Concerned Scientists revealed the existence of some internal NRC email traffic questioning some of the assumptions used in the study.
An early draft report of the study surfaced in late July 2011, when Matt Wald published an article in the New York Times titled N.R.C. Lowers Estimate of How Many Would Die in Meltdown. I wrote about that early release and my initial reading of the draft report on August 1 in a post titled Spreading Calm, Certainty, and Reassurance About Nuclear Energy (counteracting focused FUD).
Nuclear reactors that have been built in the United States, operated by well-trained, licensed operators inculcated in a safety culture, and overseen by the watchful, always questioning Nuclear Regulatory Commission are safe neighbors. That statement is true even if an accident happens that is not mitigated by any protective actions other than the robust materials chosen during the initial design. If there is any effective operator action, the probability of damage is non-existent. Even in the event of a severe accident, areas near the plant will be suitable for human habitation.
Their liability insurance coverage is more than adequate.
Update: (May 5, 2014) The NRC’s State of the Art Reactor Consequences (SOARCA) research project was completed in June 2012 and the final report was published in November 2012. For some unknown reason, the NRC web pages that describe the project in detail have no indication that the project was completed and the final report was released. Neither does the Frequently Asked Questions About State-of-the-Art Reactor Consequence Analyses (SOARCA). Both pages indicate they were last updated in July 2013, more than eight months after the final report was released.
A researcher looking for information on SOARCA at the NRC web site has a high probability of believing that the project was never completed. This must be an unintended state of affairs. Commissioners are tasked with transparency and ensuring full public access to information. Page 85 of the final report (Warning – link is to a 40 MB PDF) retained the two key points noted in the draft report as described in the original version of this post, which was published on August 1, 2011.
- The individual early fatality risk from SOARCA scenarios is essentially zero.
- Individual LCF risk from the selected specific, important scenarios is thousands of times lower than the NRC Safety Goal and millions of times lower than the general cancer fatality risk in the United States from all causes, even assuming the LNT dose-response model.