Editing Three Mile Island accident (section)

===Cleanup===
[[File:TMI cleanup-2.jpg|thumb|A clean-up crew working to remove [[radioactive contamination]] at [[Three Mile Island Nuclear Generating Station|Three Mile Island]]]]
Initially, GPU planned to repair the reactor and return it into service.<ref>{{cite web |last=Holton |first=W. C. |date=September 1990 |title=The Cleanup of Three Mile Island Unit 2 – A Technical History: 1979 to 1990 |url=http://svcf.jp/pdf/Three_Mile_Iland2NP-6931.PDF |access-date=October 24, 2021 |publisher=EPRI (Electric Power Research Institute) |pages=1–4 |quote=For some time after the accident, before the actual damage conditions were well understood, GPU envisioned the unit to return to service. Extensive planning efforts were directed towards this end. |location=Palo Alto, CA}}</ref> However, TMI-2 was too badly damaged and contaminated to resume operations; the reactor was gradually deactivated and permanently closed. TMI-2 had been online for only three&nbsp;months but now had a ruined reactor vessel and a containment building that was unsafe to walk in. Cleanup started in August 1979 and officially ended in December 1993, with a total cleanup cost of about $1&nbsp;billion.<ref name="nytimes1993"/> [[Benjamin K. Sovacool]], in his 2007 preliminary assessment of major energy accidents, estimated that the TMI accident caused a total of $2.4&nbsp;billion in property damages.<ref>{{cite journal |last=Sovacool |first=Benjamin K. |year=2008 |title=The costs of failure: A preliminary assessment of major energy accidents, 1907–2007 |journal=[[Energy Policy (journal)|Energy Policy]] |volume=36 |issue=5 |page=1807 |doi=10.1016/j.enpol.2008.01.040|bibcode=2008EnPol..36.1802S }}</ref>

Efforts focused on the cleanup and decontamination of the site, especially the defueling of the damaged reactor. Starting in 1985, almost {{convert|100|ST|t|abbr=on}} of radioactive fuel were removed from the site. Planning and work was partially hampered by too-optimistic views about the damage.<ref>{{cite web |last=Holton |first=W. C. |date=September 1990 |title=The Cleanup of Three Mile Island Unit 2 – A Technical History: 1979 to 1990 |url=http://svcf.jp/pdf/Three_Mile_Iland2NP-6931.PDF |access-date=October 24, 2021 |publisher=EPRI (Electric Power Research Institute) |page=8-1 |quote=A persistent optimism existed that the damage beyond the known areas was not as bad as some estimates would have it. In fact, it was worse. |location=Palo Alto, California}}</ref>

In 1988, the NRC announced that, although it was possible to further decontaminate the Unit&nbsp;2 site, the remaining radioactivity had been sufficiently contained as to pose no threat to public health and safety. The first major phase of the cleanup was completed in 1990, when workers finished shipping {{convert|150|ST|t|abbr=on}} of radioactive wreckage to Idaho for storage at the Department of Energy's National Engineering Laboratory. However, the contaminated cooling water that leaked into the containment building had seeped into the building's concrete, leaving the radioactive residue too impractical to remove. Accordingly, further cleanup efforts were deferred to allow for decay of the radiation levels and to take advantage of the potential economic benefits of retiring both Unit&nbsp;1 and Unit&nbsp;2 together.<ref name= "nytimes1993"/>