Editing Three Mile Island accident (section)

===Identification of released radioactive material===
The release occurred when the cladding was damaged while the PORV was still stuck open. [[Nuclear fission product|Fission products]] were released into the reactor coolant. Since the PORV was stuck open and the loss of coolant accident was still in progress, primary coolant with fission products and/or fuel was released and ultimately ended up in the auxiliary building. The auxiliary building was outside the containment boundary.

This was evidenced by the radiation alarms that eventually sounded. However, since very little of the fission products released were solids at room temperature, very little [[radiological contamination]] was reported in the environment. No significant level of radiation was attributed to the TMI-2 accident outside of the TMI-2 facility. According to the Rogovin report, the vast majority of the radioisotopes released were noble gases xenon and krypton resulting in an average dose of {{convert|1.4|mrem|uSv|abbr=on}} to the two million people near the plant.<ref>{{cite book |last=Rogovin |first=Mitchell |title=Three Mile Island: a report to the commissioners and to the public. Volume I |date=January 1980 |publisher=U.S. Nuclear Regulatory Commission |location=Washington, D.C. |url=https://www.osti.gov/servlets/purl/5395798 |access-date=October 26, 2021 |pages=25, 153 |doi=10.2172/5395798 |osti=5395798 |quote=The effects on the population in the vicinity of Three Mile Island from radioactive releases measured during the accident, if any, will certainly be nonmeasurable and nondetectable. During the course of the accident, approximately 2.5 million curies of radioactive noble gases and 15 curies of radioiodines were released. These releases resulted in an average dose of 1.4 mrem to the approximately two million people in the site area. This average dose is less than 1 % of the annual dose from both natural background radiation and medical practice. The 1.4-mrem dose may also be compared to differences in annual doses in background radiation from living in a brick versus a frame house, an additional 14 mrem/yr; or living in the high altitude of Denver rather than in Harrisburg, an additional 80 mrem/yr.}}</ref> In comparison, a patient receives {{convert|3.2|mrem|uSv|abbr=on}} from a chest X-ray—more than twice the average dose of those received near the plant.<ref>{{cite web |url=http://www.physics.isu.edu/radinf/risk.htm |title=Radiation and Risk |website=ISU Health Physics Radinf |access-date=March 6, 2018 |url-status=dead |archive-url=https://web.archive.org/web/20170406055010/http://www.physics.isu.edu/radinf/risk.htm |archive-date=April 6, 2017}}</ref> On average, a U.S. resident receives an annual radiation exposure from natural sources of about {{convert|310|mrem|uSv|abbr=on}}.<ref>{{cite web |title=Backgrounder on Biological Effects of Radiation |url=https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/bio-effects-radiation.html |website=NRC Library |publisher=U.S. Nuclear Regulatory Commission |access-date=October 26, 2021 |date=March 2017 |quote=On average, a U.S. resident receives an annual radiation exposure from natural sources of about 310 millirem (3.1 millisieverts or mSv). Radon and thoron gases account for two-thirds of this exposure. Cosmic, terrestrial, and internal radiation account for the rest. Man-made sources of radiation from medical, commercial and industrial activities contribute roughly 310 mrem more to our annual exposure. Among the largest of these sources is a computed tomography scan, which accounts for about 150 mrem. Other medical procedures make up another 150 mrem or so each year. Some consumer products such as tobacco, fertilizer, welding rods, exit signs, luminous watch dials and smoke detectors contribute about 10 mrem per year. The pie chart (on the page) shows the sources that make up the average annual U.S. radiation dose of 620 mrem.}}</ref>

Within hours of the accident, the [[United States Environmental Protection Agency]] (EPA) began daily sampling of the environment at the three stations closest to the plant. Continuous monitoring at 11&nbsp;stations was established on April 1 and was expanded to 31 stations on April 3. An inter-agency analysis concluded that the accident did not raise radioactivity far enough above background levels to cause even one additional cancer death among the people in the area, but measures of [[Beta particle|beta radiation]] were not included because the EPA found no contamination in water, soil, sediment, or plant samples.<ref name="EPA's Role at Three Mile Island">{{cite web |url=http://www.epa.gov/history/topics/tmi/02.htm |title=EPA's Role At Three Mile Island |last=Perham |first=Christine |date=October 1980 |website=EPA.gov |access-date=March 17, 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110318094452/http://www.epa.gov/history/topics/tmi/02.htm |archive-date=March 18, 2011}}</ref>

Researchers at nearby [[Dickinson College]]—which had [[radiation monitoring equipment]] sensitive enough to detect Chinese atmospheric atomic weapons-testing—collected soil samples from the area for the ensuing two weeks and detected no elevated levels of radioactivity, except after rainfalls (likely from natural [[radon]] plate-out, not the accident).<ref>{{cite web |url=http://www.threemileisland.org/science/pdfs/what_dickinson_found.pdf |title=What did Dickinson Research Find? |website=ThreeMileIsland.org |access-date=March 17, 2011 |url-status=usurped |archive-url=https://web.archive.org/web/20061003164838/http://www.threemileisland.org/science/pdfs/what_dickinson_found.pdf |archive-date=October 3, 2006}}</ref> Also, the tongues of white-tailed deer harvested over {{convert|50|mi|km|abbr=on}} from the reactor subsequent to the accident were found to have significantly higher levels of cesium-137 than in deer in the counties immediately surrounding the power plant. Even then, the elevated levels were still below those seen in deer in other parts of the country during the height of atmospheric nuclear weapons testing.<ref>{{cite journal |last=Field |first=R. W. |date=June 1993 |title=137Cs levels in deer following the Three Mile Island accident |journal=Health Phys |volume=64 |issue=6 |pages=671–674 |doi=10.1097/00004032-199306000-00015 |pmid=8491625}}</ref> Had there been elevated releases of radioactivity, increased levels of iodine-131 and cesium-137 would have been expected to be detected in cattle and goat's milk samples. Elevated levels were not found.<ref>{{cite web |last1=Battist |first1=Lewis |last2=Buchanan |first2=John |last3=Congel |first3=Frank |last4=Nelson |first4=Christopher |last5=Nelson |first5=Mark |last6=Peterson |first6=Harold |last7=Rosenstein |first7=Marvin |url=http://www.threemileisland.org/downloads/210.pdf |title=Population Dose and Health Impact of the Accident at the Three Mile Island Nuclear Station |date=May 10, 1979 |website=ThreeMileIsland.org |access-date=March 6, 2018 |url-status=usurped |archive-url=https://web.archive.org/web/20120401001347/http://www.threemileisland.org/downloads/210.pdf |archive-date=April 1, 2012}}</ref> A later study noted that the official emission figures were consistent with available [[dosimeter]] data,<ref name=hatch97>{{cite journal |last=Hatch |first=M. |display-authors=etal |title=Comments on "A Re-Evaluation of Cancer Incidence Near the Three Mile Island Nuclear Plant" |url=http://www.pubmedcentral.nih.gov/pagerender.fcgi?artid=1469856&pageindex=1 |journal=Environmental Health Perspectives |volume=105 |issue=1 |page=12 |year=1997 |pmid=9074862 |pmc=1469856 |doi=10.1289/ehp.9710512|bibcode=1997EnvHP.105...12H }}</ref> though others have noted the incompleteness of this data, particularly for releases early on.<ref>{{cite journal |last1=Wing |first1=S. |last2=Richardson |first2=D. |last3=Armstrong |first3=D. |title=Reply to comments on 'A reevaluation of cancer incidence near the Three Mile Island' |pmc=1469992 |pmid=9171981 |volume=105 |issue=3 |date=March 1997 |journal=Environ. Health Perspect. |pages=266–268 |doi=10.2307/3433255 |jstor=3433255}}</ref>