**8. References**

El-Wakil, M.M., Nuclear Energy Conversion, Thomas Y. Crowell Company Inc., USA (El-Wakil, 1982)

Epstein,M., Trans. ASME J. Heat Transfer, 110, pp885 -893 (Epstein, 1988)

Fumizawa,M. et. al., J. At. Energy Soc. Japan, Vol.31, pp1127-1128 (Fumizawa, 1989)

Fumizawa,M.; Proc. HT2005 ASME Summer Heat Transfer Conference, HT2005-72131, pp.1- 7, Track 1-7-1 (Fumizawa, 2005)

Juni-1965, "Sicherheitsbericht fuer das Atom-Versuchskraftwerk Juelich", Arbeitsgemeinschaft Versuchs-Reactor AVR (Juni-1965, 1965)

Kang,T. et al., NURETH-5, pp541-546 (Kang, 1992)

**4** 

**New Coolant from Lead Enriched** 

**Minerals for Nuclear Energy Needs** 

*2Institute for Applied Physics, Sumy* 

*1Russian Federation*

*2Ukraine* 

**with the Isotope Lead-208 and Possibility** 

 **of Its Acquisition from Thorium Ores and** 

Georgy L. Khorasanov1, Anatoly I. Blokhin1 and Anton A. Valter2 *1Institute for Physics and Power Engineering Named After A.I. Leypunsky, Obninsk* 

In critical and subcritical fast reactors functional materials fulfill various tasks, including:


As such of materials molten heavy metals – mercury, lead, eutectic of lead (45%) and

Heavy metals posses acceptable for FRs and ADSs neutron and physical characteristics while due to some their properties, for example chemical passivity to water, high boiling temperature, they are better as coolant in comparison to liquid light metal which is now

One of important parameters of functional material considered is a value of neutron absorption in coolant because it is desirable the neutron losses in the core of FR and ADS

Ways of minimization of neutron absorption in FR are well-known: it is offered to use wrapper less fuel assemblies, low neutron absorbing nitrogen isotope 15N in nitride fuel

The authors of this paper are pointing out on one more possibility of reducing the neutron losses in the core cooled with lead: it is connected with enrichment of lead isotope, lead-208, from its value in the natural lead isotope mix, equal to 52.3%, up to the value of 99.0% [1-9]. Lead-208 as a twice magic nucleus possesses a very low cross section of neutron radiation capture. This unique feature leads to economy of neutrons in the core and other profitable

**1. Introduction** 

blanket have to be minimized.


factors which are listed in the Part I of this paper.

in the liquid metal – a source of spallation neutrons.

bismuth (55%) and others are using or to be used in future.

used in sodium cooled FRs such as BN-600 and BOR-60 in Russia.

contents, structural materials with low cross section of neutron capture, etc.

Keulegan,G.H., U.S.N.B.S.Report 5831 (Keulegan, 1958) Kiso et.al.; JSME Annual MTG, pp.339-340 (Kiso, 1999) Mercer, A. and Thompson.H., J. Br. Nucl. Energy Soc., 14, pp327-340 (Mercer, 1975) Merzkirch,W., "Flow Visualization", Academic Press (Merzkirch, 1974)
