| Srl | Item |
| 1 |
ID:
164685
|
|
|
|
|
| Summary/Abstract |
Before a nuclear warhead is dismantled, the special nuclear material and explosives must be identified and authenticated. This paper proposes a passive method to detect and identify weapons-grade plutonium cores and explosives in nuclear warheads based on neutron analyses techniques. This paper first describes the principles of a passive detection method that calculates the element number ratio (namely the ratio between the nucleus numbers of two different elements) of the element of interest to identify a source and how this method could be applied to the detection of warhead explosives. Second, a simulation of weapons-grade plutonium using JMCT software is described. The simulation assumes the elemental components of the explosives are activated by the production and transport of neutrons from the weapons-grade plutonium core and counted the gamma ray emissions of from the resultant hydrogen, carbon, and nitrogen nuclides with a high-purity germanium detector (HPGe) array. After an hour of counting, the element number ratios of these elements in the simulation were reconstructed and accurately matched the values for the explosives in the warhead. These results suggest that the passive method can be used to identify the presence of weapons-grade plutonium in the warhead. In addition, the simulation showed that the passive method can also discriminate between the various types of explosives in warheads, providing important physical information for the verification process during dismantlement.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 2 |
ID:
142272
|
|
|
|
|
| Summary/Abstract |
The growing concern about nuclear terrorism threats has enhanced the need to develop fast and accurate nuclear forensics analysis techniques for nuclear material source attribution and to create a credible nuclear deterrence. Plutonium produced as a by-product in nuclear reactor fuel, especially in fuel discharged at low burn-up (1 to 2 MWd/kg), is potentially weapons usable material. In the event of plutonium interdiction from a smuggling act, its origin has to be established through nuclear forensics attribution methods before any response is initiated against this malicious act. The characteristics of separated plutonium from discharged reactor fuel and the associated fission product traces depend on factors such as the reactor type (thermal or fast reactor), fuel burn-up, irradiation history, and the chemical process used to separate plutonium. A new methodology of using trace fission product to plutonium ratios for nuclear forensics attribution of plutonium to the type of reactor used for its production is presented along with results obtained for case studies of a fast neutron spectrum breeder reactor and a thermal neutron spectrum reactor using open literature design information of these two types of nuclear reactors.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|