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| Fig. 1: Three Mile Island nuclear plant. (Source: Wikimedia Commons) |
On a seemingly normal Wednesday morning in Pennsylvania, one of the first mainstream nuclear accidents occurred at the Three Mile Island (TMI) nuclear plants (Fig. 1) - the TMI accident. At 4AM, a sudden malfunction in the inner workings of water pumps at TMI nuclear plant, led to a cascade of subsequent internal malfunctions, and the onset of a sudden nuclear emergency. [1]
One of the initial concerns associated with the TMI accident was its potential impact on the surrounding environment and human health. [1] In the ensuing months following the TMI accident, nuclear waste, mostly in the form of radioactive gases, escaped into the nearby environment. [1] The primary constituents of this nuclear contamination were various Xenon, Iodine, and Krypton isotopes (i.e. Xenon-133, Xenon-135, Iodine-131, Krypton-81, etc.). [1] Upon further testing of local radioactive contamination, it was found that radioactive contaminants like Iodine-131 were found in both goat's milk and cow's milk at concentrations of approximately 41 picocuries per liter and 36 picocuries per liter, respectively. [1] Although this was 300 times lower than regulated levels, and could be a result of other non-TMI-related causes, this fact incited fear in the press and surrounding communities. [1,2] According to a report posted to the IAEA Bulletin, Secretary Califano estimated at the time that a total exposure of roughly 3500 rem was distributed across a 50 mile radius of TMI in the ensuing 6 days after the TMI accident. [2,3] Working out that there lived approximately 2,000,000 people in the aforementioned 50 mile radius, it was determined that each individual received an average exposure of 1.7 millirem (1.7 × 10-5 Sv), an amount with no health consequences, as natural sources of radiation account for more. [2] This estimate was meant to serve as a baseline approximation and the actual distribution of this radiation exposure is nearly impossible to accurately determine. Although the levels of radiation exposure were considered to be non-lethal, the Kemeny Report highlighted how TMI may have incited other human health-related issues like mental distress among those that lived in a 20 mile radius of TMI. [4]
Although the exact value of emitted and absorbed radiation remains a highly contested topic, due to the lack of clarity revolving how the 3500 man-rem was distributed, this estimate will serve as grounds for comparison with other nuclear disasters. Bouville et al. found that in the regions surrounding Chernobyl (Belarus, Ukraine, Russia), the average exposure was ~ 0.01 Sv. [5] Following the Fukushima disaster, the Government of Japan conducted a study which reported mean radiation doses of ~0.8 millisieverts. [6] Thus Chernobyl had an approximately 588 times higher dosage to the surrounding regions, and Fukushima had an approximately 47 times higher dosage to the surrounding regions.
Even though TMI was less damaging in terms of radioactive exposure than other accidents, it had a significant effect on the nuclear industry. In the weeks following the TMI accident, large amounts of news coverage revolved around the surrounding regions. [7] It was reported that within two days of the accident, crowds of news teams began assembling in the region, broadcasting the accident to those around the nation. [7] Additionally, the genuine possibility of meltdown and atomic bomb-like consequences percolated through news reports. [7]
In the years following the TMI accident there was a dramatic slowdown of nuclear progression. How much of this slowdown is directly a result of the TMI accident? Hultman et. al investigated this very topic, and found that many factors can be attributed to the following nuclear slowdown. [8] They found that although accidents like TMI contributed to growing apprehension regarding nuclear energy and safety, a multitude of additional factors can have larger effects on the subsequent nuclear slowdown (i.e. poor economic conditions, declining energy demand, lower interest in nuclear science, etc.). [8]
© Justin Shen. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] D. Reid, "The Three Mile Island (TMI) Nuclear Accident: Revisited," Prehosp. Disaster Med 1, Suppl. S1, 401 (1985).
[2] G. R. Corey, "A Brief Review of the Accident at Three Mile Island," IAEA Bull. 21, No. 5, 54 (October 1979).
[3] C. Mohr, "Califano Reassesses Radiation Hazards," New York Times, 4 May 79.
[4] J. G. Kemeny, Report Of The President's Commission On The Accident At Three Mile Island," U.S. Government Printing Office, October 1979.
[5] A. Bouville et al., "Radiation Dosimetry For Highly Contaminated Belarusian, Russian and Ukrainian Populations, and For Less Contaminated Populations in Europe," Health Phys. 93, 487 (2007).
[6] A. Sakai et al., "Effects of External Radiation Exposure Resulting From the Fukushima Daiichi Nuclear Power Plant Accident on the Health of Residents in the Evacuation Zones: The Fukushima Health Management Survey," J. Epidemiol. 32, Suppl. 12, S84 (2022).
[7] A. Trunk and E. V. Trunk, "Impact of the Three Mile Island Accident as Perceived by Those Living in the Surrounding Community," in The Analysis of Actual Versus Perceived Risks, ed. by V. T. Covello et al. (Springer, 1983).
[8] N. Hultman and J. Koomey, "Three Mile Island: The Driver of US Nuclear Powers Decline?," Bull. Atom. Sci. 69, No. 3, 63 (2013).
