Los Alamos National Laboratory (LANL) has disposed at least 17,500,000
ft3 of hazardous and radioactive wastes on-site at twenty-four
different officially-designated material disposal areas (MDAs) since
1944. Information about these sites is summarized in Table
A-1, and, in more detail, in Tables B-1 through
B-24. The locations of these sites are shown in Figure
A-1, and more detailed site maps are provided in Figures B-1 through
B-24, which have been integrated into Tables B-1 through B-24.
These twenty-four dumps pose varying risks to the environment. Sixteen
are thought to pose "moderate" to "high" risk of long-term groundwater
contamination by the New Mexico Environment Department (NMED).
Some of these dumps are on hills, or very close to canyons, and some
are in zones of relatively high precipitation and hence infiltration
of rain and snow. At some sites, such as MDA P in Technical Area
(TA) - 16, ground-water contamination has already occurred.
At almost all of the sites, there has been little to no action taken
by LANL to prevent the movement of contaminants--such as capping the
closed disposal sites so that rain and snowmelt cannot enter and mobilize
the hazardous or radioactive constituents. There are, at the present
time, no definite plans or commitments to stabilize or remediate any
of these sites, save MDA P, which is being entirely removed this year.
This lack of action persists despite the expenditure by the LANL
Environmental Remediation program of more than $500 million in the past
The quantity of waste at each site ranges from 15,885 ft3
to 10,800,000 ft3. In many cases the waste volume is
unknown and must be estimated from old plans and maps. In some
cases the types of waste disposed are known fairly well; in other cases
the contaminants present can only be inferred. Least well known
is the amount of each specific contaminant, such as plutonium or other
radionuclide, that the disposal records (often crude) may show to be
LANL continues to generate and dispose of radioactive waste on-site
at a facility called "Area G," which is the largest MDA (63 acres) and
contains the most waste (10,800,000 ft3; enough to fill 1.4 million
55-gallon drums). LANL would like to expand MDA-G by 66 acres,
more than doubling its size. Several small Indian ruins lie in
the expansion path.
Historically, Area G has received a wide variety
of wastes, including spent nuclear fuel and highly-radioactive fission
products, to large quantities of plutonium and tritium, to building
rubble and contaminated soil. LANL maintains that only low level
waste (LLW) is disposed there today. The term "low-level," however,
is somewhat misleading, as many types of LLW are highly radioactive.
Area G, for example, received spent nuclear reactor fuel.
MDA-G is also used for storage of transuranic waste (TRUW), about 60,000
drums' worth so far, which is to be eventually shipped to the Waste
Isolation Pilot Plant (WIPP) in southern New Mexico. According
to Department of Energy (DOE) sources, an unknown but large fraction,
perhaps 50%, of this so-called "TRUW" is actually LLW, and is likely
to be buried on site.
Figure A-2 shows current waste generation rates for LANL for LLW, hazardous
chemical wastes, low-level "mixed" (radioactive and chemically-hazardous)
waste (LLMW), and both TRUW and TRU "mixed" waste (TRUMW), by principal
generating facility. Most of this waste originates in nuclear
weapons programs. Efforts to reduce waste generation have been
made; further waste-minimization is in many cases possible.
The radioisotopes disposed in these dumps will eventually decay.
"Eventually" can be a very long time in some cases, leaving a legacy
of environmental problems for generations to come. Common radioactive
isotopes disposed at LANL and their half-lives are shown below:
One of the most interesting mysteries regarding waste at LANL is the
whereabouts of hundreds of kilograms of plutonium-239. Some 610
kg are unaccounted for by program use. This plutonium has been
assumed by DOE to have been disposed, or stored, in MDAs at LANL. Where
In addition to the MDAs officially used for waste disposal, there are
close to two thousand contaminated sites at LANL, so-called "potential
release sites" (PRSs). Some of these contain large sources of
contamination, others are almost entirely benign. Many have not
been thoroughly investigated, let alone stabilized or removed.
Some lie in canyon bottoms, in or near watercourses and floodways, while
others receive runoff from parking lots and rooftops. As in the
case of the MDAs, there are no definite plans to remediate most of these
MDA Waste Quantities
Los Alamos Nuclear Waste