Читать книгу Disarmament and Decommissioning in the Nuclear Domain - Jean-Claude Amiard - Страница 28

Future nuclear arms reduction efforts will require technologies that can verify that the warheads to be dismantled are genuine, without revealing any sensitive warhead design information to international inspectors.

How can a claim be proved about an extremely sensitive object, a nuclear weapon, for example, without revealing information about it? This paradox has been challenging the control of nuclear weapons for more than five decades. A mechanism in the form of an interactive evidence system has been proposed, that can validate the structure and composition of an object, such as a nuclear warhead, with arbitrary precision, without revealing its structure and composition [KEM 16].

Confirming the authenticity of nuclear warheads and their components is at the heart of the challenge of verifying future reductions in nuclear arsenals. An overview of the development of verification systems and the challenges and opportunities highlighted for future research in this area are provided in [YAN 15].

For a long time, low-resolution gamma spectrometry (sodium iodide crystal probes) has been used in verification systems. Thus, the programs CIVET (Controlled Intrusiveness Verification Technology) from 1998 to 1991, TRIS (Trusted Radiation Identification System) from 1999 to 2001 and NG-TRIS (Next Generation Trusted Radiation Identification System) since 2007 have been successively used. Since 1984, the FNMIS (Fieldable, Nuclear Material Identification System) has used neutron activation. The parameters most frequently sought are the presence of plutonium, its various isotopes, its mass or its age, and sometimes the presence of uranium 235, its enrichment or its mass. Recently, some authors have proposed the use of intensities of nuclear resonance fluorescence (NRF) close to 2.2 MeV to distinguish between real computer objects and hoax objects, with great confidence and realistic measurement times [VAV 18].

A concept that exploits isotope-specific nuclear resonance phenomena in order to authenticate the fissile components of a warhead by comparing them to a previously authenticated model, has been submitted [HEC 18].

Most of the plutonium in the world resides inside the rods of spent fuel from nuclear reactors. Only the United States, France and Japan have isolated and stored plutonium. This high-activity radioactive waste is generally stored long term in large, heavily shielded casks. The measurements of the diffusion angles of cosmic muons that pass through a storage cask can be used to determine whether the radioactive waste in the casks is in the form of intact spent fuel assemblies, or whether the plutonium has been recovered by reprocessing, without opening the cask [DUR 18].