LAS VEGAS – The Nevada National Security Site (NNSS) conducted the 100th experiment of the Joint Actinide Shock Physics Experimental Research (JASPER) Facility this week – a significant milestone in the National Nuclear Security Administration’s (NNSA) mission to assess the reliability of the nation’s nuclear weapons stockpile.
The 100th experiment, or shot, will help generate information that scientists at Lawrence Livermore National Laboratory will use to determine how plutonium would react under specific pressures, temperatures and strain-rates. The shots are conducted using a two-stage gas gun to fire projectiles into plutonium targets in a highly controlled environment.
“I applaud the work done by the men and women who have taken part in this remarkable milestone,” said NNSA Deputy Administrator for Defense Programs Don Cook. “Data gathered from experiments conducted on JASPER and the other tools and facilities throughout the national nuclear security enterprise helps NNSA meet its mission in ensuring the safety, security and effectiveness of the nuclear deterrent without underground nuclear explosive testing. These experiments also help achieve President Obama’s nuclear security objectives.”
JASPER experiments are conducted at the NNSS by Lawrence Livermore National Laboratory for NNSA, in conjunction with Joint Laboratory Operations-Nevada (JLON), a collaboration of Lawrence Livermore and Los Alamos national laboratories, and National Security Technologies (NSTec), the management and operating contractor for the site.
“Shot 100 is a significant milestone for the JASPER project,” said Laura Tomlinson, Assistant Manager for National Security for the Nevada Site Office for the NNSA. “It shows a strong integrated laboratory, contractor and federal team effort that produce the highest quality plutonium data.”
“JASPER has a long history of providing highly accurate materials data for the National Stockpile Stewardship Program,” said Jim Holt, Director of Defense Experimentation and Stockpile Stewardship for NSTec. “The JASPER Project Team, lead by NSTec Project Manager Lane Trammell, has done an outstanding job of mitigating technical and operational issues to keep JASPER on schedule and on budget while continuing to conduct experiments providing important relevant data on materials properties.”
The NNSS, formerly known as Nevada Test Site, has a long and storied history of nuclear weapons testing, both above and below ground. However, a moratorium signed by the president in 1992 put an end to that type of testing. This required the development of newer methods for ensuring the nation’s weapons stockpile remains safe and reliable.
The JASPER gun fires projectiles into targets within confinement chambers at high velocities, up to eight kilometers per second – about the same speed as a bullet fired from a hunting rifle. This allows for the measurement of data pertaining to the properties of nuclear weapons. Data from JASPER experiments is used to determine material equation-of-state and to validate computer models of material response for weapons applications.
“The quality and accuracy of the data is exceptional, considered best in class and contributes vastly to our understanding of the equation-of-state of plutonium,” Tomlinson said. “With the sustained success of JASPER, we help to ensure the safety and reliability of the nuclear stockpile. Congratulations to the entire JASPER team.”
The first JASPER shot involving plutonium was conducted in 2003. Since then, the JASPER team has developed new diagnostics and identified new experimental configurations that have aided in exploring various scientific regimes. JASPER has been operational since March of 2001. Of the 100 shots that have been executed, 41 have used plutonium. Surrogate materials were used in the others.
The two-stage gas gun consists of a first-stage breech, containing gunpowder and a pump filled with a light gas such as hydrogen, helium or nitrogen, and a second-stage evacuated barrel for guiding the high-velocity projectile to a target containing radioactive or surrogate material. Hot gases from the burning propellant drive a heavy piston down the pump tube, compressing the gas. At sufficiently high pressures, the gas eventually breaks a rupture valve and enters the narrow barrel, propelling a projectile toward the target.
When the projectile hits the target, it produces a high-pressure shock wave. In a fraction of a micro-second, the shock wave reverberates through the target. Diagnostic equipment, triggered by the initial wave, measures the properties of the shocked material.
Established by Congress in 2000, NNSA is a semi-autonomous agency within the U.S. Department of Energy responsible for enhancing national security through the military application of nuclear science. NNSA maintains and enhances the safety, security, reliability and performance of the U.S. nuclear weapons stockpile without nuclear testing; works to reduce global danger from weapons of mass destruction; provides the U.S. Navy with safe and effective nuclear propulsion; and responds to nuclear and radiological emergencies in the U.S. and abroad.