Editing SL-1 (section)

==Cleanup==
[[General Electric]] was hired to remove the reactor vessel and dismantle and clean up the contaminated buildings at the SL-1 project site.<ref name=ido19311 /> The site was cleaned from 1961 to 1962, removing the bulk of the contaminated debris and burying it.<ref name=ido19311 /> The massive cleanup operation included the transport of the reactor vessel to a nearby "hot shop" for extensive analysis.<ref name=ido19311 /> Other items of less importance were disposed of or transported to decontamination sites for various kinds of cleaning. About 475 people took part in the SL-1 site cleanup, including volunteers from the U.S. Army and the Atomic Energy Commission.<ref name=ido19311 />

The recovery operation included clearing the operating room floor of radioactive debris. The extremely high radiation areas surrounding the reactor vessel and the fan room directly above it contributed to the difficulty of recovering the reactor vessel. Remotely operated equipment, cranes, boom trucks, and safety precautions had to be developed and tested by the recovery team. Radiation surveys and photographic analysis was used to determine what items needed to be removed from the building first.<ref name=ido19311 /> Powerful vacuum cleaners, operated manually by teams of men, collected vast quantities of debris.<ref name=ido19311 /> The manual overhead crane above the operating floor was used to move numerous heavy objects weighing up to {{convert|19600|lbs}} for them to be dumped out onto the ground outside.<ref name=ido19311 /> Hot spots up to 400 R/hr were discovered and removed from the work area.

With the operating room floor relatively clean and radiation fields manageable, the manual overhead crane was employed to do a trial lift of the reactor vessel.<ref name=ido19311 /> The crane was fitted with a dial-type load indicator and the vessel was lifted a few inches. The successful test found that the estimated {{convert|23000|lb}} vessel plus an unknown amount of debris weighed about {{convert|26000|lbs}}. After removing a large amount of the building structure above the reactor vessel, a 60-ton Manitowoc Model 3900 crane lifted the vessel out of the building into an awaiting transport cask attached to a tractor-trailer combination with a low-boy 60-ton capacity trailer.<ref name=ido19311 /> After raising or removing 45 power lines, phone lines, and guy wires from the proposed roadway, the tractor-trailer, accompanied by numerous observers and supervisors, proceeded at about {{convert|10|mph|abbr=on}} to the ANP Hot Shop (originally associated with the [[Aircraft Nuclear Propulsion]] program), located in a remote area of the NRTS known as [[Test Area North]], about {{convert|35|miles}} away.<ref name=ido19311 />

A burial ground was constructed about {{convert|1600|ft|-2}} northeast of the original site of the reactor. It was opened on May 21, 1961.<ref name=SEC /> Burial of the waste helped minimize radiation exposure to the public and site workers that would have resulted from transport of contaminated debris from SL-1 to the Radioactive-Waste Management Complex over {{convert|16|mi}} of public highway. The original cleanup of the site took about 24 months. The entire reactor building, contaminated materials from nearby buildings, and soil and gravel contaminated during cleanup operations were buried in the burial ground. The majority of buried materials consist of soils and gravel.<ref name=95rod>{{cite web|url=http://www.epa.gov/superfund/sites/rods/fulltext/r1096147.pdf|title=EPA Superfund Record of Decision: Idaho National Engineering Laboratory |author=EPA |website=EPA.gov |archive-url=https://web.archive.org/web/20041116072052/http://www.epa.gov/superfund/sites/rods/fulltext/r1096147.pdf |date=December 1, 1995 |archive-date=November 16, 2004}}</ref><ref>[http://ar.inel.gov/images/pdf/199602/1996020812012503W-T.pdf Record of Decision] {{Webarchive|url=https://web.archive.org/web/20110718104923/http://ar.inel.gov/images/pdf/199602/1996020812012503W-T.pdf |date=2011-07-18 }}, Stationary Low-Power Reactor-1 and Boiling Water Reactor Experiment-I Burial Grounds (Operable Units 5-05 and 6-01), and 10 No Action Sites (Operable Units 5-01, 5-03, 5-04, and 5-11), January 1996.</ref>
[[File:SL-1Burial.jpg|thumb|SL-1 burial site in 2003, capped with [[rip rap]]]]
Recovered portions of the reactor core, including the fuel and all other parts of the reactor that were important to the accident investigation, were taken to the ANP Hot Shop for study. After the accident investigation was complete, the reactor fuel was sent to the [[Idaho Chemical Processing Plant]] for reprocessing. The reactor core minus the fuel, along with the other components sent to the Hot Shop for study, was eventually disposed of at the Radioactive Waste Management Complex.<ref name=95rod />

The remains of SL-1 were buried at {{Coord|43|31|18|N|112|49|05|W|display=inline}}, about {{Convert|500|m|ft}} northeast of the original site (about 5 miles north of Atomic City). <ref>{{cite web|title=2003 Annual Inspection Summary for the Stationary Low-Power Reactor-1 Burial Ground|url=https://ar.icp.doe.gov/images/pdf/200311/2003110400237GSJ.pdf|publisher=INEEL|access-date=2019-01-29|archive-date=2019-09-01|archive-url=https://web.archive.org/web/20190901185202/https://ar.icp.doe.gov/images/pdf/200311/2003110400237GSJ.pdf|url-status=dead}}</ref> The burial site consists of three excavations, in which a total volume of {{convert|99,000|ft3|m3}} of contaminated material was deposited. The excavations were dug as close to [[basalt]] as the equipment used would allow and ranges from {{convert|8|to|14|feet|m|spell=in}} in depth. At least {{convert|2|ft|m|spell=in}} of clean backfill was placed over each excavation. Shallow mounds of soil over the excavations were added at the completion of cleanup activities in September 1962. The site and burial mound are collectively known as [[United States Environmental Protection Agency]] [[Superfund]] Operable Unit 5-05.<ref name=95rod/><ref name=epa2003>{{Cite web |url=http://ar.inel.gov/images/pdf/200311/2003110400237GSJ.pdf |title=2003 Annual Inspection Summary for the Stationary Low-Power Reactor Burial Ground, Operable Unit 5-05 |access-date=2011-02-11 |archive-date=2011-07-18 |archive-url=https://web.archive.org/web/20110718104442/http://ar.inel.gov/images/pdf/200311/2003110400237GSJ.pdf |url-status=dead }}</ref>

Numerous radiation surveys and cleanup of the surface of the burial ground and surrounding area have been performed in the years since the SL-1 accident. Aerial surveys were performed by [[EG&G]] Las Vegas in 1974, 1982, 1990, and 1993. The Radiological and Environmental Sciences Laboratory conducted [[gamma radiation]] surveys every three to four years between 1973 and 1987 and every year between 1987 and 1994. Particle-picking at the site was performed in 1985 and 1993. Results from the surveys indicated that [[cesium-137]] and its progeny (decay products) are the primary surface-soil contaminants. During a survey of surface soil in June 1994, "hot spots," areas of higher radioactivity, were found within the burial ground with activities ranging from 0.1 to 50 milliroentgen (mR)/hour. On November 17, 1994, the highest radiation reading measured at {{convert|2.5|ft|m}} above the surface at the SL-1 burial ground was 0.5 mR/hour; local background radiation was 0.2 mR/hour. A 1995 assessment by the EPA recommended that a cap be placed over the burial mounds. The primary remedy for SL-1 was to be containment by capping with an engineered barrier constructed primarily of native materials.<ref name=95rod/> This remedial action was completed in 2000 and first reviewed by the EPA in 2003.<ref name=epa2003 />