Alpha radioactivity

Most chemical iavestigations with plutonium to date have been performed with Pu, but the isotopes Pu and Pu (produced by iatensive neutron irradiation of plutonium) are more suitable for such work because of their longer half-Hves and consequendy lower specific activities. Much work on the chemical properties of americium has been carried out with Am, which is also difficult to handle because of its relatively high specific alpha radioactivity, about 7 x 10 alpha particles/(mg-min). The isotope Am has a specific alpha activity about twenty times less than Am and is thus a more attractive isotope for chemical iavestigations. Much of the earher work with curium used the isotopes and Cm, but the heavier isotopes... 

Henshaw DL (1989) Application of sohd state nuclear track detectors to measurements of natural alpha-radioactivity in human body tissues. Nucl Tracks Radiat Meas 16(4) 253-270 Int J Radiat Appl lustrum Part D... 

Perlman, I., and F. Asaro Alpha radioactivity. Annual Review of Nuclear... 

A. Ghiorso and G. T. Seaborg Systematics of alpha-radioactivity. Physic. 

Alpha Radioactive Sources --- Monte Carlo Calculation, J. Atomic... 

A 1-mL sample of the leach solution is assayed for alpha radioactivity, and the sources are rejected if the alpha count exceeds 10 d/m above background. 

I. Perlman and J. O. Rasmussen, Alpha Radioactivity, in Handbuch der Physik, Vol. 42, Springer, BerUn, 1957... 

R. Vandenbosch and J. R. Huizenga, Nuclear Fission, Academic Press, New York, 1973 E. Roeckl, Alpha Radioactivity, Radiochim. Acta 70/71, 107 (1995)... 

Sources and Amounts of Plutonium in the Environment. Since 1945 approximately 3300 kg of plutonium has been injected into the environment, mostly (>90Z) from atmospheric explosions of nuclear weapons. This corresponds to about 380 kCi total alpha radioactivity. The addition to this amount by releases from nuclear power operations is much smaller the major continuing addition is ca. 0.1 kCi per month released to the Irish Sea from the British nuclear reprocessing plant at Windscale. About 2/3 of the plutonium from nuclear explosions would be formed into highfired oxides which would be rather inert chemically. However, the remainder, created during the explosion as single atoms via the U(n, J ) U(28 ) Pu... 

Alpha radioactivity is found principally among elements beyond bismuth in the periodic table. AH the nuclides important as fissionable or fertile material are alpha emitters, with half-lives and decay energies given in Table 2.1. These half-lives are so long that depletion of these fuel species by radioactive decay is not important, but all these nuclides are toxic, especially plutonium, which is even more toxic than radium. 

Radioactive decay of and Pu form Am and Am, which are also important and persistent sources of alpha radioactivity in discharge fuel. Another persistent americium radioisotope is 152-year Am, formed by neutron capture in Am. Its isomeric decay and the beta decay of its short-lived daughter result in 163-day Cm, which is the most intense source of alpha activity in discharged uranium fuel. Successive neutron captures lead to em, em, and Cm. Higher-mass curium nuclides are usually not important in power reactor fuel. 

Table 11.4 shows the contributions (more than 0.1 percent) of individual fission-product nuclides to the total fission-product activity and of individual actinide nuclides to the total actinide activity. After 6 years only nine fission products or fission-product mother/daughter pairs contribute significantly. After 100 years, Sr/ Y and Cs/ "Ba make up to 98 percent of the fission-product activity, and among the actinides Pu, Am, Am/ Np, and Cm are responsible for 90 percent of the total alpha radioactivity. 

Cohen, B., M. Eisenbud, and W. Harley Alpha radioactivity in cigarette smoke Radiation Res. 14 (1980) 190-196. 

I. Perlman, A. Ghiorso, and G. T. Seaborg, Systematics of alpha-radioactivity, Phys. Rev. 77 (1950) 26. 1. Perlman and J. O. Rasmussen, Alpha radioactivity, Handbuch der Physik 42, Springer-Verlag, 1957. W. J. Moore, Physical Chemistry, 3rd edn., Prentice-Hall, I. 1962. 

H2. Hasson, V., and Cherry, R. D., Alpha-radioactivity of human blood. Nature (London) 210, 591-593 (1966). 

Alpha-Zerfall, Behinderungsfaktor, alpha radioactivity, hindrance (or departure) factor 345. 

In the USA 15 pCi/1 is quoted for the total alpha radioactivity, for example, with radium 226 being included in the measured value, but not... 

TABLE VI-30. Source Preparation Methods for Alpha Radioactivity Measurements -)... 

The subject of the determination of the amount of alpha radioactivity has been re-... 

TABLE VI-31. Techniques for Measuring Alpha Radioactivity (Cont d)... 

Mang HJ (1960) Phys Rev 119 1069 Mang HJ (1964) Alpha radioactivity. In Annual review of nuclear science, vol 14. Annual Reviews, Palo Alto Mang HJ, Rasmussen JO (1962) Mat Fys Skr Danske Vid Selskab 2 3... 

Bou-Rabee F, BaMr YY, Bern H (1995) Contribution of manium to gross alpha radioactivity in some environmental samples in Kuwait. Environ Int 21 293-298... 

Alpha radioactivity has been observed for all the elements above lead in the periodic table, as well as for a few nuclei as light as the lanthanide elements. In a decay the a-particles have discrete energies. The a-particles emitted from decay has the 4.18 and 4.13 MeV kinetic energy with abundance of 77 and 23%, respectively, a-particles usually have between 3 and 9 MeV of kinetic energy but, since they are relatively massive and doubly charged, they do not penetrate very far into matter. A thick sheet of paper is sufficient to completely stop a particles emitted in radioactive decay. 

There is general agreement that the toxicity of plutonium is caused by its alpha radioactivity [65, 68]. Raymond [71], on the basis of very old work on animals [79], considers the acute chemical toxicity of to be about the same as... 

As far as the potential radioactivity of the zirconia prosthesis, although the detected activity has been small, the long term effects of the alpha radioactivity still must be evaluated. 

---