Nuclear Weapons: Technical Resources
The post cold war nuclear weapons research, design, and testing program, called Science Based Stockpile Stewardship, has been justified
as a means to understand the processes of aging in nuclear weapons, and to guarantee that each weapon in the U.S. arsenal remains in working order. Without full scale nuclear testing (which was the primary way of evaluating aging weapons and new designs prior to 1992) the National Laboratories have resorted to a program of advanced computer modeling/simulation, subcritical nuclear explosives testing, and a whole new gamut of new ways to carry out their nuclear weapons missions.
Plutonium (link to our section on the most recent plutonium plans at Los Alamos)
History of Statements on Pit Production Capacity, Jonathan E. Medalia, Congressional Research Service, (CRS), Apr 3, 2014
In Brief: U.S. Nuclear Weapon “Pit” Production: Background and Options, Jonathan E. Medalia, CRS, Mar 20, 2014
U.S. Nuclear Weapon “Pit” Production Options for Congress, Jonathan E. Medalia, CRS, Feb 21, 2014
Pit Production Options, Jonathan E. Medalia, CRS, Nov 20, 2013
Plutonium in Warhead Cores (“Pits”) Stable to 150 Years, Los Alamos Study Group press release, Dec 6, 2012
"The United States Plutonium Balance, 1944-2009," Jun 26, 2012, update of "Plutonium: The First 50 Years," Feb 1996
"The Proposed Chemistry and Metallurgy Research Replacement Nuclear Facility (CMRR-NF): New Realities Call for New Thinking," Dec 10, 2010
"U.S. Plutonium 'Pit' Production: Additional Facilities, Production Restart are Unnecessary, Costly and Provocative," Mar 2, 2010
"Lifetime Extension Program," JASON Executive Summary, Sep 9, 2009
Nuclear Matters: A Practical Guide, 2008 edition, Office of the Deputy Assistant to the Secretary of Defense for Nuclear Matters. (In-depth discussion of nuclear weapons written for the military. Good overview of the nuclear weapons enterprise and its terminology from the military perspective.)
"Pit Lifetime," JASON's review on plutonium aging, JSR-06-335, The Mitre Corporation, Nov 20, 2006
"A Little Primer on Plutonium and Poverty in New Mexico," (pdf file of brochure)
The WMD Way of Life: Pit production equipment in Los Alamos parking lot, (photo) Jan 2006
"Subcritical" Nuclear Tests Have Apparently Begun at Los Alamos, press release, Jan 13, 1999
LANL Plan to Detonate Plutonium Poses Risks to Region, press release, May 14, 1997
Los Alamos Study Group letter to Secretary of Energy Hazel O'Leary, Oct 22, 1996
Since the United States' last full nuclear weapons test at the Nevada
Test Site in September of 1992 all subsequent nuclear weapons explosives tests have been subcritical. A subcritical test is similar to a full scale nuclear detonation in that a plutonium core and other weapons grade elements are subjected to compression under a high explosives blast, but the implosion is not sufficient to sustain the criticality necessary for the process of nuclear fission.
Contrary to popular belief, the U.S. Military, Department of Energy,
and the nuclear weapons laboratories never stopped designing new
weapons. Some are modifications on pervious designs such as the
B61 which became the B61-11. Others such as the proposed earth penetrator
and low yield nuclear weapons will be new designs.
Between 1945 and 1992 the United States conducted over 1054 (official count)  full scale nuclear weapons tests on air, land, and sea, and even in space. Major test sites included several sites in the South Atlantic, Bikini Atoll, the Christmas Islands, Enewetak, and Johnston Atoll in the Pacific Ocean, Amchitka in Alaska, Rifle, and Grand Valley in Colorado, Farmington, Alomogordo, and Carlsbad in New Mexico, Hattiesburg in Mississippi, and approximately 904 nuclear explosions in Nevada at the Nevada Test Site.
1. Department of Energy, Nevada Operations Office.
United States Nuclear Test: July 1945 - September 1992.
DOE/NV - 209 Rev 15 December 2000.