Creating simulation capabilities

On September 23, 1992, scientists and engineers of the US nuclear weapons complex in Nevada made the Earth move for the last time. The US government decided to stop developing new nuclear weapons now that the Cold War had ended. The need for underground nuclear tests, which had traditionally served primarily for testing and developing new designs, naturally decreased dramatically once the need for those new designs disappeared. But that last underground blast also marked the beginning of a new era in computer simulation. Besides testing new designs, underground testing had also answered critical questions about the safety, reliability, and performance of existing weapons. If anything, those needs would increase, not decrease, as the US nuclear weapons stockpile aged. So, as part of an effort to address those questions by developing a more thorough scientific understanding of the issues involved, the US Department of Energy propounded the Accelerated Strategic Computing Initiative (ASCI). ASCI´s objective is to support high confidence assessments and stockpile certifications through high fidelity simulations. The ASCI program will create these simulation capabilities as part of the DOE´s larger Stockpile Stewardship and Management program. The formidable nuclear weapons science issues involved in making this shift will require a significant investment in terms of scientific understanding and funding. The article discusses the steps the ASCI program will take in meeting that challenge