For Immediate Release January 13, 1999
"Subcritical" Nuclear Tests Have Apparently Begun
at Los Alamos
- TESTS WILL BE USED TO HELP CERTIFY DESIGN OF ADVANCED NEW WARHEAD
FOR NAVY MISSILES, UNDERCUTTING TEST BAN TREATY
- EXPLOSIONS WITH PLUTONIUM IN TANKS RAISE SERIOUS SAFETY CONCERNS
- DOE ATTEMPTED TO KEEP STARTUP OF TESTS SECRET FROM PUBLIC
Santa Fe -- The Defense Nuclear Facilities
Safety Board (DNFSB) has raised safety questions regarding the start-up
of a series of "subcritical" nuclear test explosions at Los Alamos National
Laboratory (LANL). These "test-site-in-a-bottle" explosions test
the nuclear components of nuclear weapons, but stop short of a actual
nuclear explosion. The explosions will eventually involve plutonium
in a full-scale nuclear weapons configuration, in whole or in part, if
they have not already done so.
Up to now, these types of tests have usually been conducted deep underground
in Nevada -- amid a chorus of domestic and international protest.
The most recent Nevada test, code-named "Cimarron," involved simultaneous
implosion of two halves of a full-scale, newly-manufactured plutonium
"pit" from Los Alamos. Today's revelation is the first indication
that the long-planned series of above-ground subcritical tests at LANL
has apparently already begun, complementing the controversial and expensive
tests in Nevada.
Los Alamos has conducted subcritical experiments in the past, both underground
(1) and in vessels (an unknown number,
at unknown times). The series of underground experiments left a
permanent legacy of approximately 90 pounds of plutonium about 100 feet
deep at LANL.
The top-secret program that is apparently now starting up again, code-named "Appaloosa," uses either weapons-grade plutonium (primarily Pu-239), with
configurations modified as necessary to prevent a nuclear explosion, or
the rare isotope Pu-242, code-named "Cider," which can be used to make
exact replicas of weapons prototypes for high-fidelity development tests.
New development work may be interspersed (and masked for public relations
purposes) with so-called "aging" studies. Proof tests of newly-manufactured
pits may also be done.
Since the safety of existing designs is an intrinsic property of the design
and has already been certified, any so-called "safety" studies will refer
to the safety of new designs.
The history of the Appaloosa program and its predecessors is shrouded
in secrecy. It is not known how many explosions have been conducted,
what the size of the explosions has been, how many of those explosions
involved the special Pu-242 isotope, or what the purposes of the experiments
have been. We believe the program was idle but for one test during
the 1982-1992 period.
The Study Group has photographs of vessels used in the historic Appaloosa
program, as well as working drawings of the some of the vessels to be
used in the current program, vessel specifications, invoices, and related
documents. In 1970, an internal safety study suggested that the
need for the experiments had been "reevaluated" in light of the potential
for widespread contamination and radiation exposure that could result
in the event of catastrophic vessel failure.
In addition to subcritical tests at Nevada and Los Alamos, additional
dynamic studies of shocked plutonium have recently begun at LANL's Materials
Science Laboratory. These are the so-called plutonium "mini-flyer"
experiments, where lasers are used to accelerate metal plates that strike
plutonium at high speeds. These experiments can be conducted on
a one-day turnaround basis, giving very rapid data acquisition.
Dynamic experiments are also done at LANL's main plutonium facility, which
houses a high-speed plutonium "gas gun" for dynamic measurements.
These four categories of dynamic experiments, together with a wide battery
of static laboratory tests, comprise a highly advanced and redundant suite
of techniques that go far beyond those required to maintain existing nuclear
DOE has refused to answer questions from the Study Group about the DNFSB
concerns, and would not even identify the nature of the program that was
raising these concerns. All documents were stamped "Secret--Restricted
Data," except for a cover letter, dated November 17, 1998, from DNFSB
Chairman John Conway to DOE that was posted on the DNFSB web site.
The response from Dr. Victor Reis, dated December 17, 1998, was likewise
classified except for its cover letter. It was obtained by the Freedom
of Information Act from DNFSB.
The Study Group has modelled the impact of an accident from these experiments,
using a standard plume model written at Lawrence Livermore National Laboratory
(LLNL). DOE and LANL used a similar model in their, partially classified,
study, with similar results. DOE subsequently did more detailed
modelling, which suggested that the impacts of an accident could be somewhat
According to documents obtained by the Study Group from DOE, LANL has
a 2003 deadline for certification of a new warhead for the Navy's Trident
D-5 (Trident II) ballistic missile. LLNL is also designing a warhead
for this missile, using existing plutonium "pits." LANL's design
would require a manufacturing campaign for thousands of new pits. LANL
is now the only site where this manufacturing could take place, but DOE
has, if its internal documents can be believed, indefinitely delayed its
earlier commitment to a 50-pit-per-year manufacturing capacity at LANL.
Full pit manufacturing would, under DOE's current plans, apparently
take place at "another site."
1. Thirty-five "hydronuclear" tests, most of
which involved subcritical assemblies (i.e. assemblies which were designed
to avoid a self-sustaining nuclear reaction) were conducted between 1958
and 1961. (Back to Text)