Yucca Flat Yucca Flat is a closed desert drainage basin , one of four major nuclear test regions within the Nevada Test Site ( NTS ) , and is divided into nine test sections : Areas 1 through 4 and 6 through 10 . Yucca Flat is located at the eastern edge of NTS , about ten miles ( 16 km ) north of Frenchman Flat , and from Las Vegas , Nevada . Yucca Flat was the site for 739 nuclear tests – nearly four of every five tests carried out at the NTS . Yucca Flat has been called " the most irradiated , nuclear - blasted spot on the face of the earth " . In March 2009 , " TIME " identified the 1970 Yucca Flat Baneberry Test , where 86 workers were exposed to radiation , as one of the world ' s worst nuclear disasters . Geology . The open , sandy geology of Yucca Flat in the Tonopah Basin made for straightforward visual documentation of atmospheric nuclear tests . When testing went underground , deep layers of sedimentary soil from the erosion of the surrounding mountains allowed for relatively easy drilling of test holes . Hundreds of subsidence crater s dot the desert floor . A crater could develop when an underground nuclear explosion vaporized surrounding bedrock and sediment . The vapor cooled to liquid lava and pooled at the bottom of the cavity created by the explosion . Cracked rock and sediment layers above the explosion often settled into the cavity to form a crater . At the south end of Yucca Flat is Yucca Lake , also called Yucca Dry Lake . The dry , alkaline lake bed holds a restricted runway ( Yucca Airstrip ) which was built by the Army Corps of Engineers before nuclear testing began in the area . To the west of the dry lake bed is News Nob , a rocky outcropping from which journalists and VIPs were able to watch atmospheric nuclear tests at Yucca Flat . Nearby . West of the dry lake bed , cresting the top of Yucca Pass , is Control Point , or CP - 1 , the complex of buildings which contains testing and monitoring equipment for nuclear tests , and a cafeteria that seats 32 . CP - 1 overlooks both Yucca and Frenchman Flats . Today , Control Point is the center for support of all activity at the NTS . A subsidence crater in nearby Area 5 is home to a number of storage containers holding contaminated scrap metal and debris , and is subject to periodic monitoring of radioactivity levels . Nuclear testing . Yucca Flat saw 739 nuclear tests , including 827 separate detonations . The higher number of detonations is from single tests that included multiple nuclear explosions occurring within a 0 . 1 second time window and inside a 2 km diameter circle . 62 such tests took place at NTS . No test at Yucca Flat ever exceeded 500 kilotons of expected yield . Tests of larger explosions were carried out at Rainier Mesa and Pahute Mesa , as their geology allowed deeper test shafts . First tests . The first test explosion at Yucca Flat came after five prior atmospheric tests at nearby Area 5 as part of Operation Ranger . On October 22 , 1951 , the " Able " test of Operation Buster was detonated at the top of a tower in Area 7 , resulting in a nuclear yield less than an equivalent kilogram of TNT ; the shot was a fizzle . It was the world ' s first failure of a nuclear device . Over the next two weeks , four successful tests were conducted via airdrop , with bomber aircraft releasing nuclear weapons over Area 7 . The first underground test at NTS was the " Uncle " shot of Operation Jangle . Uncle detonated on November 29 , 1951 within a shaft sunk into Area 10 . Operation Plumbbob . In Area 9 , the 74 - kiloton " Hood " test on July 5 , 1957 , part of Operation Plumbbob , was the largest atmospheric test ever conducted within the continental United States ; nearly five times larger in yield than the bomb dropped on Hiroshima . A balloon carried Hood up to 460 meters above the ground where it was detonated . Over 2 , 000 troops took part in the test in order to train them in conducting operations on the nuclear battlefield . of iodine - 131 ( I ) were released into the air . With a relatively brief half - life of eight days , I is useful as a determinant in tracking specific nuclear contamination events . I comprises about 2 % of radioactive materials in a cloud of dust stemming from a nuclear test , and causes thyroid problems if ingested . The " John " shot of Plumbbob , on July 19 , 1957 , was the first test firing of the nuclear - tipped AIR - 2 Genie air - to - air rocket designed to destroy incoming enemy bombers with a nuclear explosion . The two - kiloton warhead exploded approximately three miles above five volunteers and a photographer who stood unprotected at " ground zero " in Area 10 to show the apparent safety of battlefield nuclear weapons to personnel on the ground . The test also demonstrated the ability of a fighter aircraft to deliver a nuclear - tipped rocket and avoid being destroyed in the process . A Northrop F - 89J fired the rocket . Operation Plowshare . A dramatically different test shot was the " Sedan " test of Operation Storax on July 6 , 1962 , a 104 kiloton shot for the Operation Plowshare which sought to discover whether nuclear weapons could be used for peaceful means in creating lakes , bays or canals . The explosion displaced twelve million tons of earth , creating a crater wide and deep in Area 10 . For an underground shot , a relatively large amount of energy was vented to the atmosphere , estimated to be 2 . 5 kilotons ( 7 . 4 bars of pressure ) . Two radioactive dust clouds rose up from the explosion and traveled across the United States , one at and the other at . Both dropped radioactive particles across the USA before crossing into the sky above the Atlantic Ocean . Among many other radioisotopes , the clouds carried of I . Sedan Crater was added to the National Register of Historic Places in 1994 . Baneberry . Area 8 hosted the " Baneberry " shot of Operation Emery on December 18 , 1970 . The Baneberry 10 kiloton test detonated below the surface but its energy cracked the soil in unexpected ways , causing a fissure near ground zero and the failure of the shaft and cap . A plume of fire and dust was released three and a half minutes after ignition , raining fallout on workers in different locations within NTS . The radioactive plume released of radioactive material , including of iodine - 131 . After dropping a portion of its load locally , the hot cloud ' s lighter particles were carried to three altitudes and conveyed by winter storms and the jet stream to be deposited heavily as radionuclide - laden snow in Lassen and Sierra counties in northeast California , and to lesser degrees in southern Idaho , northern Nevada and some eastern sections of Oregon and Washington states . The three diverging jet stream layers conducted radionuclides across the US to Canada , the Gulf of Mexico and the Atlantic Ocean . Some 86 workers at the site were exposed to radioactivity , but according to the Department of Energy none received a dose exceeding site guidelines and , similarly , radiation drifting offsite was not considered to pose a hazard by the DOE . In March 2009 , TIME magazine identified the Baneberry Test as one of the world ' s worst nuclear disasters . Two US Federal court cases resulted from the Baneberry event . Two NTS workers who were exposed to high levels of radiation from Baneberry died in 1974 , both from acute myeloid leukemia . The district court found that although the Government had acted negligently , the radiation from the Baneberry test did not cause the leukemia cases . The district decision was upheld on appeal in 1996 . Huron King . As part of Operation Tinderbox , on June 24 , 1980 , a small satellite prototype ( DSCS III ) was subjected to radioactivity from the " Huron King " shot in a vertical line - of - sight ( VLOS ) test undertaken in Area 3 . This was a program to improve the database on nuclear hardening design techniques for defense satellites . The VLOS test configuration involved placing a nuclear device ( less than 20 kilotons ) at the bottom of a shaft . A communications satellite or other experiment was placed in a partially evacuated test chamber simulating a space environment . The test chamber was parked at ground level at the top of the shaft . At zero time , the radiation from the device shot up the vertical pipe to the surface test chamber . Mechanical closures then intercepted and sealed the pipe , preventing the explosive shock wave from damaging the targets . The test chamber was immediately disconnected by remote control from the pipe and quickly winched to safety before the ground could subside to form a crater . The Huron King test cost US $ 10 . 3 million in 1980 dollars . Last test . The final test at Yucca Flat ( also the last test at the entire Nevada Test Site ) was Operation Julin ' s " Divider " on September 23 , 1992 , just prior to the moratorium temporarily ending all nuclear testing . Divider was a safety experiment test shot that was detonated at the bottom of a shaft sunk into Area 3 . Abandoned tests . Three tests planned for 1993 have been abandoned in place , two in Yucca Flat . The Comprehensive Nuclear - Test - Ban Treaty had been strongly supported by the UN General Assembly in 1991 , and negotiations began in earnest in 1993 . The United States , on October 3 , 1992 , suspended all nuclear weapons testing programs in anticipation of eventual ratification of the treaty . The partially assembled cabling , towers and equipment for shot " Icecap " in Area 1 and shot " Gabbs " in Area 2 lie amid weeds and blowing dust , waiting for a possible resumption of nuclear testing . Shot " Greenwater " awaits its fate in Area 19 at Pahute Mesa . " Icecap " was to be a joint US - UK test event . Radioactivity . UGTA . The United States Department of Energy produced a report in April , 1997 , on a subproject of the Nevada Environmental Restoration Project . The larger project involves environmental restoration and mitigation activities in the NTS , Tonopah Test Range , Nellis Air Force Range , and eight further sites in five other states . The Underground Test Area ( UGTA ) subproject focuses on defining the boundaries of areas containing unsafe water contaminated with radionuclides from underground nuclear tests . The ongoing subproject is tasked with predicting the future extent of contaminated water due to natural flow and it is expected to quantify safe limits for human health . Yucca Flat was identified as a Corrective Action Unit ( CAU ) . Because of the great expense and virtual impossibility of cleaning up the Nevada Test Site , it has been characterized as a " national sacrifice zone . " USGS . In 2003 , the United States Geological Survey ( USGS ) collected and processed magnetotellurics ( MT ) and audio - magnetotelluric ( AMT ) data at the Nevada Test Site from 51 data stations placed in and near Yucca Flat to get a more accurate idea of the pre - Tertiary geology found in the Yucca Flat Corrective Action Unit ( CAU ) . The intent was to discover the character , thickness , and lateral extent of pre - Tertiary rock formations that affect the flow of underground water . In particular , a major goal was to define the upper clastic confining unit ( UCCU ) in the Yucca Flat area . First responder training . The radioactivity present on the ground in Area 1 provides a radiologically - contaminated environment for the training of first responders . Trainees are exposed to methods of radiation detection and its health hazards . Further training takes place in other areas of NTS .