Nuclear proliferation Alliance of Nuclear Weapons and Nuclear Power", tritium is not classified as a "special nuclear material" but rather as a by-product. It is seen as an important litmus test on the seriousness of the United States' intention to nuclear disarm. This radioactive super-heavy hydrogen isotope is used to boost the efficiency of fissile materials in nuclear weapons. The United States resumed tritium production in 2003 for the first time in 15 years. This could indicate that there is a potential nuclear arm stockpile replacement since the isotope naturally decays. In May 1995, NPT parties reaffirmed their commitment to a Fissile
Tritium penetration of bomb tritium can be separated into 3 distinct layers. Layer 1 is the shallowest layer and includes the deepest, ventilated layer in winter; it has received tritium via radioactive fallout and lost some due to advection and/or vertical diffusion and contains approximately 28% of the total amount of tritium. Layer 2 is below the first layer but above the 26.81 isopycnal and is no longer part of the mixed layer. Its 2 sources are diffusion downward from the mixed layer and lateral expansions outcropping strata (poleward); it contains about 58% of the total tritium. Layer 3 is representative