IAEA

Because variations in accurate isotope ratio measurements typically concern only a few parts per 1000 by mass and there are no universal absolute ratios, it is necessary to define some standards. For this purpose, samples of standard substances are produced and made available at two major centers IAEA (International Atomic Energy Authority, U.K.) and NIST (National Institute for Standards and Technology, U.S.). Standards from other sources are also available. These primary standards can be used as such, or alternative standards can be employed if the primary ones are not available. However, any alternative standards need to be related accurately to the primary ones (see formulae below). For example, the material PDB (PeeDee belemnite), used particularly as a standard for the ratio of isotopes, is no longer readily available, and a new standard, VPDB,... 

IAEA-NBS30 (NIST-8538) IAEA-CH-7 j (NIST-8540) I1AKA-NBS22 I (NIST-8539) IIAEA-NBS28 I (NIST-8546)... 

Quartz sand IAEA-NBS127 Barium sulphate Carbonatite... 

AEA-NBS18 (NIST-8543) i IAEA-NBS19 (NIST-8544)... 

Data obtained from IAEA, Vienna (http //www.iaea.oi bracketed data obtained from NIST, Gaithersburg, Md (http //ois.nist.gov/) Data correct at 30th October 2000. 

International Atomic Energy Agency, ITER Conceptual Design Report IAEA, Vienna, 1991. 

The U.S. Department of Energy (DOE) and the NEA/IAEA employ similar terms to classify uranium resources, as (7) reasonably assured, estimated additional (EA), or speculative. The NEA/IAEA divides the estimated additional resources into two types, EAR-I and EAR-II, describing known resources and undiscovered ones, respectively (8). 

Foreign. The OECD/NEA and IAEA have issued annual reports on world uranium resources, production, and demand since the mid-1960s (2—6). NEA/IAEA data for reasonably assured and estimated additional resources at costs of 80 and 130/kg uranium are given in Table 2 (21). These estimates incorporate data from both former world outside centrally planned economies (WOCA) and non-WOCA nations. A summary of other known uranium resources with and without cost range estimates is provided in Table 3 (22). These resources total about 1.4 x 10 t and include estimates that are not strictly consistent with standard NEA/IAEA definitions. 

As of 1995, there were no nuclear fuel reprocessing plants operating in the United States. Other nuclear nations have constmcted second- or third-generation reprocessing faciUties. These nations have signed the nuclear nonproliferation treaty, and the faciUties are under the purview of the International Atomic Energy Agency (IAEA). 

J. R. Merriman, M. J. Stephenson, B. E. Kmak, md D. K. Little, International Symposium on Management of Gaseous Wastesfrom Nuclear Fadlities, IAEA-SM-245 /53, International Atomic Energy Agency (IAEA), Vienna, Austria, 1980. 

W. L. Godfrey md D. G. Bouse, Tank Sludge Characterisation, Waste Mmagement Research Abstracts, IAEA, Vierma, Austria, 1971. 

Heavy-Water Power Reactors," Proceedings of the International Mtomic Energy Mgeny Symposium, Sept. 11—15,1967, IAEA, Vienna, Austria, 1968. 

Radioactive Waste Management A.n IAEA. Source Book, International Atomic Energy Agency, Vienna, Austria, 1992. 

Eig. 1. The relation between physical barriers and levels of protection in defense-in-depth design of a nuclear faciUty (12). Courtesy of IAEA. 

In addition, under the Nonproliferation Treaty, which most larger nations have signed, the IAEA monitors plutonium from power reactors so as to detect covert diversion. 

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