This work illustrates a methodology based on photon interrogation and coincidence counting for determining the characteristics of fissile material. The feasibility of the proposed methods was demonstrated using the Monte Carlo-based MCNPX/MCNPPoliMi code system capable of simulating the full statistics of the neutron and photon field generated by the photon interrogation of fissile and non-fiss...

Based on general arguments presented in this report, nuclear criticality was eliminated from performance assessment calculations for the Waste Isolation Pilot Plant (WIPP), a repository for waste contaminated with transuranic (TRU) radioisotopes, located in southeastern New Mexico. At the WIPP, the probability of criticality within the repository is low because mechanisms to concentrate the fis...

Negotiations on a fissile material cut-off treaty (FMCT) were agreed to in 1998 at the Conference on Disarmament (CD) in Geneva after several years’ delay caused by debates over its scope and linkage to nuclear disarmament measures. However, the negotiations have yet to get underway, as they have not been reauthorized by the CD in subsequent years. Should the negotiations move forward, it is ex...

spring 1944. Work at Los Alamos, Oak Ridge, and Hanford to design, build, and provide fissionable material for the first atomic bombs was shifting into high gear. In stark contrast, initial bomb project studies on the nuclear chain reaction and plutonium were winding down at the Chicago Metallurgical Laboratory, Argonne National Laboratory’s wartime predecessor. Even as others zeroed in on the ...

Nuclear weapon states historically have attached great secrecy to their nuclear weapon and fissile material production programs and stockpiles, despite warnings that this would fuel fears, handicap informed debate and decision making, and drive arms races. As evidenced by the “Action Plan on Nuclear Disarmament” agreed upon at the 2010 Treaty on the Non-Proliferation of Nuclear Weapons (NPT) Re...

Dr. Victor Bragin has been involved in the development of a fissile material cut-off treaty since 1994, first as Safeguards Analyst at the International Atomic Energy Agency, and since January 1996 as Safeguards Adviser at the Australian Safeguards and Non-Proliferation Office (ASNO). Mr. John Carlson is Director-General of ASNO, and is a statutory officer responsible directly to the Australian...

A newly developed numerical Laplace transform inversion (NLTI) will be presented to determine the transient flux distribution within a subcritical fissile sample. The NLTI considered in this presentation has evolved to its present state over the past 10 years of application. The methodology adopted relies on the evaluation of the Bromwich contour through acceleration of the convergence of an in...