(extracted from "Area
51 - Dreamland - Fifty Years of Secret Flight Testing in Nevada" by Peter W.
A secret place in the desert
Just over the hills at Yucca Flat, the Atomic Energy Commission (AEC) was detonating nuclear bombs. Since Watertown was downwind of the Nevada Test Site (NTS), it received much of the radioactive fallout. Consequently, there was a standing agreement that Watertown personnel would be evacuated prior to a nuclear shot to limit their exposure. Most of the tests, and all of those involving full-scale nuclear explosions, took place more than 10 miles away.
One shot however took place on
According to Chuck Hansen, in U.S. Nuclear Weapons: The Secret History, the weapon used was an XW-25 warhead, with a design yield of 1.5 kilotons. The XW-25 was 26.7-inches long, 17.4-inches wide, and weighed about 218 pounds. It was designed to be the warhead for the Douglas MB-1 Genie air-to-air-missile.
A formerly secret document detailing the
minutes of the first meeting on Project 57 states that the weapon
was to be "fired on the ground at the bottom detonator."
This map shows the location of the Project 57 site in Area 13 and its relation to Area 51.
The groom lake airbase is shown much as it appears today.
Both sites were considered equal from an operational viewpoint, but the decision was ultimately based on soil contamination levels from previous testing. Samples taken by K. H. Larson of the University of California at Los Angeles (UCLA) indicated that "in the first inch of cover, maximum plutonium backgrounds differed by a factor of 60."
Soil in the Groom Lake area contained a maximum of 0.5-micrograms of plutonium per-square-meter versus 30-micrograms per-square-meter around Papoose Lake. After reviewing these results, according to the minutes of the first meeting, "the choice of Groom Lake Valley went uncontested."
An appendix to the report contained a letter to Brigadier General Alfred D. Starbird from Maj. Gen. Alvin R. Luedecke, USAF, Chief of the AFSWP, further explained that "entry into the area has also been approved and has been coordinated with the agency which has been using the Range." The XW-25 warhead was flown to the airstrip at Yucca Flat, then trucked to Watertown.
It was stored in Building 10 prior to
being moved to Area 13 for final placement.
There was none, but all personnel
entering the area were required to wear full protective suits and
respirators to shield themselves from alpha radiation emitted by
This Russian satellite image shows Area 51 and Area 13.
Groom Lake is about three miles long from north to south.
Ground Zero for the Project 57 plutonium dispersal test was located five miles northwest of the edge of Groom Lake.
Several isotopes of plutonium (Pu) are typically found at safety experiment sites: Pu-238 (with a half-life of 89 years), Pu-239 (24,300 years), Pu-240 (6,600 years), and Pu-241 (14 years). Pu-239 is the most abundant. The decay of Pu-241 produces an americium isotope, Am-241, which emits gamma rays and has a half-life of 432 years.
Radiation Safety (Rad-Safe) technicians measure gamma emissions from Am-241 with a device called a FIDLER (Field Instrument for the Determination of Low-Energy Radiation). Am-241 activity in contaminated soil provides a reasonable indication of Pu-239/240 levels.
Particles of plutonium that are absorbed
into the bloodstream may be deposited in the lungs, liver, lymph
nodes, or in the surfaces of newly formed bone. There, they can
cause damage leading to cancer, chronic anemia, osteoporosis, or
bone necrosis that may produce spontaneous bone fractures. Such
results may not manifest until 10, 20, or even 30 years after
deposition, depending on the size of the dose. Lung damage may
become apparent in only a few years.
The exact amount of plutonium expended
for the test remains classified, but one pound of plutonium involved
in a fire or explosion could produce, under moderate wind
conditions, hazardous contamination as far as a mile downwind.
According to The Hazards and Characteristics of Plutonium and Uranium Contamination, published by the Atomic Weapons Training Group in 1962,
Initial readings at radiation monitoring sites indicated no detectable fallout at Watertown. According to a declassified telex dated from the day after the shot, air samplers were "operating in all populated areas," and would be checked "after a five day seasoning period and it [was] expected that readings [would] be minor."
After all samples were studied, it was
determined that there was minor alpha activity for 12 days following
the shot, but it was "well below operational guidelines."
Nevertheless, this meant that re-suspended plutonium dust was
reaching the airbase in small amounts.
Water from the Deer Camp Watering Hole
east of Area 13 was also sampled, but only contained a small amount
of alpha radiation.
A Project 57 technician in anti-contamination gear picks up a sample tray with a magnetic device.
Rad-Safe workers from Task Group 57 at the NTS collected data on particulate physics, plutonium inhalation, alpha monitoring, and decontamination techniques on experimental surfaces at Area 13.
They also analyzed the fractionation
characteristics and physical nature (size, shape, and distribution)
of the fallout particles. Interestingly, the maximum air
concentration levels of alpha contaminants were found at a distance
of 5,000 feet from the detonation point.
Methods of soil decontamination and fixation included wetting, oiling, leaching and stabilizing agents, and spraying with fire-fighting foam, as well as disking, plowing, and scraping. The top two inches of soil was scraped and hauled away for burial at the NTS. The ground was plowed to a depth of 12 inches. Rad-safe technicians decontaminated test materials by washing, steam cleaning, and vacuuming.
Contaminated equipment was disposed of
in waste burial sites adjacent to Valley Road within Area 13.
This map shows the location of Project 57 ground zero (GZ) and the fence surrounding the Alpha Contaminated Zone.
Reynolds Electrical and Engineering Company (REECo) provided operational radiation safety support for Project 57. Prior to the day of the test, REECo personnel erected a temporary decontamination facility at the entrance to the access road to ground zero. It was stocked with supplies of radiation detection instruments, protective clothing, and other equipment.
The building also contained an equipment issue room, showers, and a dressing room. All personnel entering or leaving the contaminated zone had to pass through the Rad-Safe building. Containers were made available to dispose of contaminated clothing. Northwest of the building, a parking area was established for contaminated vehicles. Uncontaminated vehicles parked on the south side of the building. There was also an area for processing fallout trays and soil samples for shipment to Sandia Corporation for analysis.
These provided positive pressure inside protective clothing so that any leaks would be outwards to prevent contaminants from entering the suit. After the extent of hazardous conditions in the test area was determined, workers were given the option of wearing supplied-air respirators or full-face filter respirators. As restrictions were further reduced, half-face respirators with high-efficiency filters were adopted for areas with less than 100 micrograms of plutonium contamination per square meter. All participants in field activities for Project 57 received bioassay tests to check for exposure to plutonium.
These tests consisted primarily of nasal
swabs and, occasionally, urinalysis.
The Project 57 site lay abandoned and
nearly forgotten for almost 20 years as nearby Watertown (designated
Area 51 in June 1958) grew into a thriving clandestine flight test
Map illustrating radioactive contamination levels within the fenced section of Area 13.
In the 1970s, the contaminated area was studied by the DOE Nevada Applied Ecology Group (NAEG) to estimate the amount and distribution of plutonium in the soil.
NAEG scientists took numerous soil samples for analysis. In 1974, A. Wallace and E. M. Romney (UCLA Laboratory of Biomedical and Environmental Sciences) inspected the Area 13 test plots to evaluate vegetation recovery and compare soil surface conditions. They found that the plowed and scraped areas had recovered about 25% of their vegetation, compared to the surrounding undisturbed landscape.
Areas treated with road oil appeared approximately the same as untreated areas except for some remaining oil residue. Based on a FIDLER survey, R. O. Gilbert estimated (in a paper included in Transuranics in Desert Ecosystems, NVO-181, 1977) that the inventory of Pu-239/240 remaining in the top two inches of soil at Area 13 was approximately 46-Curies, covering a 4,017,000-square-meter area. An aerial survey in 1979 by A. E. Fritzsche yielded an estimated inventory of 62.1 to 90.5-Curies of Pu-239/240, based on Am-241 levels.
In their 1980 report, Estimates of Soil Removal for Cleanup of Transuranics at NAEG Offsite Safety-Shot Sites, R. R. Kinnison and R. O. Gilbert used available summary data to determine the amount of soil removal necessary to decontaminate the project 57 site down to 160-picoCuries of plutonium. They determined that roughly 198,000 tons of the top six inches of soil would need to be removed from an area covering 269 acres. Soil profiles studies indicated that most of the plutonium contaminants are located in the top two inches.
In fact, the contaminated zone was located just east of Valley Road, which is the primary thoroughfare from Area 51 to the town of Rachel in Sand Springs Valley to the north of Area 13. The "public road" described by Bicker was the road to Groom Mine.
Three years later, the road, the mine,
and most of the Groom Mountains were seized by the Air Force to
prevent public access, and provide additional security for Area 51.
Estimates of contaminated soil volumes indicated that it would take 10 years to complete the cleanup if the funding was made available.
The application was reviewed by the SFMP Facility Acceptance Review Board to determine whether the site was eligible.
Specifically, a current
radiation/contamination survey of the facility and surrounding area
had to be available, structures and monitoring equipment had to be
adequate to contain and monitor any radioactivity, and security
systems and procedures had to be adequate to prevent unauthorized
entry. The Review Board was very concerned about these points.
The application had also stated that
"minimal DOE surveillance is being performed at Area 13 because the
contaminated area is not within direct control of DOE." The Board
held off on accepting Area 13 into SFMP, stating that "with the
limited information available, the board was unable to assess the
current radiological safety of Project 57."
The Board also required that DOE-NV
provide a description of safety measures that would ensure that
plutonium would not continue to migrate off-site.
First of all, a preliminary site characterization was made for both the Project 57 contaminated zone and the inactive contaminated waste dump adjacent to Valley Road. Also included in the Fiscal Year (FY) 1983 budget were plans for perimeter survey work, pathway and criteria analysis, clean-up technique investigation, engineering design and equipment specification, and procurement of mobile laboratory equipment.
This phase was scheduled to be completed in September 1983 at a total cost of $500,000.
The plan called for removal of 100,000
cubic yards of soil per year from FY-1986 through FY-1991 at an
annual cost of $2,500,000.
A Russian spy satellite photo from 1988 apparently shows that large amounts of soil had been recently removed from an area just north of the Project 57 contaminated zone in Area 13.
According to Steve L. Hoeffner et al (Clemson University-Research Park) and Richard Smalley (Waste Policy Institute, Savanna River Research Campus) in Evaluation of Remediation Methods for Plutonium Contaminated Soil,