摘要:

The Manhattan Project required a large amount of innovative work to develop new techniques and new materials. A review of such activities could be useful for future developments of the actinides. It is important to work out techniques for handling radioactive waste. I will review the activities dealing with the development of plutonium containment that could serve as a guide for future needs. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1292178

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

Already during the well-known IAEA International Fuel Cycle Evaluation Study of 1976–80,[1] the different aspects of plutonium utilization in the form of MOX fuel were discussed and followed up in the many international meetings during the last two decades. An International Symposium on MOX Fuel Cycle Technologies for Medium and Long Term Deployment, organized by the IAEA in co-operation with OECD/NEA and held in Vienna in May 1999, was a milestone which reviewed the past, present and future of Pu recycling in nuclear power reactors.[2] This paper presents major results of the Symposium in the context of present conditions of deregulated electricity market and in the future and its role in the reduction of stockpiles of separated civil and surplus ex-weapons plutonium. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1292179

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

Plutonium fits near the middle of the actinide series. It is of practical interest principally because the 239 isotope has attractive nuclear properties for energy production and nuclear explosives. Its structural properties are particularly unusual. The thermal instability of plutonium—that is, the large length (or volume) changes during heating or cooling—is the most important consequence of the unusual properties of plutonium. The huge volume changes in the solid state result primarily from structural transformations among an unprecedented six solid allotropes. In addition, plutonium’s continuous radioactive decay causes self-irradiation damage that can fundamentally change its properties over time. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1292180

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

Self-irradiation of Pu, its alloys and compounds by products of known &agr;-decomposition is a continuous complicated process, which includes numerous different phenomena. The accumulation of Pu decomposition products causes material structure and properties change. This problem is the subject of many works, most of them concerned with the behavior of Pu and its alloys at low (liquid He and N) temperatures. The survey is given of the results of our experiments connected with radiogenic helium behavior, crystal structure and properties of Pu metallic compounds and Pu oxide ceramics in a self-irradiation process at room temperature under isochronal heat treatments. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1292181

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

In this study, we present the results of analytical models that have been used to determine the homogenization characteristics of Pu-Ga alloys. Modeling methods include modified thin film, residual segregation index, and several separation-of-variables solutions to Fick’s Second Law. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1292182

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

The pyrochlore structure-type is a proposed host phase for the immobilization of plutonium. Previous studies have shown that a wide variety of actinide pyrochlores can be synthesized. Gadolinium zirconate with the pyrochlore structure has been shown to be remarkably radiation resistant. We report additional results of ion-beam irradiation studies. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1292183

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

Zircon(ZrSiO4)is the most thoroughly studied of all candidate ceramic phases for the stabilization of plutonium. Self-radiation damage from &agr;-decay of the239Pu,which releases a 5.16 MeV &agr;-particle and a 0.086 MeV235Urecoil nucleus, can significantly affect the structure and properties of zircon. Recent computer simulations using energy minimization techniques indicate that the lowest energy configuration occurs for a defect cluster composed of two near-neighborPu3+substitutions onZr4+sites and a neighboring charge-compensating oxygen vacancy. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1292184

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

In conventional U-based nuclear fuels, both Pu and higher actinides (mainly Am, but also Np and Cm) are formed by neutron capture reactions and &agr;- or &bgr;-decay. If a strategy of reprocessing is adopted as in some European nations and in Japan, the separated Pu can be recycled as(U,&hthinsp;Pu)O2(or mixed-oxide—MOX) fuel. The high-level liquid waste of reprocessing is presently vitrified. However, the alternative of separating the minor actinides from the fission products (partitioning) and subsequent transmutation in existing reactors or in new dedicated actinide burners is widely studied as a possible means to reduce the radiotoxicity of the waste. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1292185

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

Long-term storage of plutonium separated from fission products is not a good solution according to the current non-proliferation criteria as well as from an economic point of view. This material has thus to be converted to the equivalent of the “spent fuel standard.” Only one technique has so far reached the industrial maturity necessary to convert the important existing plutonium stockpiles: it is the use of plutonium to manufacture and irradiate mixed-oxide (MOX) fuel. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1292186

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

Disposition of weapons Pu (W-Pu) aims at the replacement of military access restrictions by inherent longlasting technical barriers to make the return into the weapons state difficult and not rewarding anymore. At the time of the NAS-study in 1994, two ways were perceived to be mature and selected: Fissioning of W-Pu as LWR-MOX and the disposal in a vitrified radionuclide-spiked form.1Both options since have been questioned for equality, met different acceptance at both superpowers and showed slow progress. A criterion to measure disarmament would be the amount of W-Pu in the different proliferation resistant forms, multiplied by the effort needed for each form to return to weapons quality. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1292187

出版商:AIP    

年代:1900

数据来源: AIP