In the aftermath of a nuclear attack, shelters can offer potentially important protection. How well they fill that role depends on a set of interdependent decisions made by the individuals and organizations that must prepare and use them. We look at three such decisions. For each, we begin with formal analysis of the consequences expected from different possible actions. Those analyses are, the...

Expanding missions in nuclear explosion monitoring (NEM) and nuclear security have highlighted the need for high-resolution ambient-temperature gamma detectors that can provide radionuclide-specific monitoring under demanding field conditions. Recent improvements in high-pressure xenon (HPXe) detectors indicate that this technology has potential to provide rugged, large volume ambient temperatu...

The manuscript reviews progress achieved in recent years in various aspects of nuclear astrophysics, including stellar nucleosynthesis, nuclear aspects of supernova collapse and explosion, neutrino-induced reactions and their possible role in the supernova mechanism and nucleosynthesis, explosive hydrogen burning in binary systems, and finally the observation of γ-rays from supernova remnants.

Underground nuclear weapon testing produces radionuclide gases which may seep to the surface. Barometric pumping of gas through explosion-fractured rock is investigated using a new sequentially-coupled hydrodynamic rock damage/gas transport model. Fracture networks are produced for two rock types (granite and tuff) and three depths of burial. The fracture networks are integrated into a flow and...

The Ground-Based Nuclear Explosion Monitoring Research and Development (GNEM R&D) program at Sandia National Laboratories (SNL) is regarded as the primary center for unbiased expertise in testing and evaluation of geophysical sensors and instrumentation for nuclear explosion monitoring. We had four main areas of interest to make progress on this year; this report will cover the advances made in...

Multielectron ionization and Coulomb explosion of methane clusters (CA4)n, A ) H, D, and T, in very intense (I ) 1018-1019 W cm-2) laser fields were studied using classical dynamics simulations. The products of Coulomb explosion involve light A+ ions (p, d, and t nuclei) with energies up to 20 keV, C4+ ions at I ) 1018 W cm-2, and C6+ ions (carbon nuclei) with energies up to 110 keV at I ) 1019...

OVER THE LAST 25 years the United States has become increasingly dependent on space-based systems to support its military forces, and this trend is likely to continue for some time. Satellite systems have become an integral part of nuclear deterrence by providing strategic warning of an attack, tactical warning of missile launches, reliable communications between command authorities and nuclear...