A great uncertainty still exists in the critical tem­peratures, pressures, and densities of the LM of interest. These parameters are very important for the development of EOS and the extension of the

Temperature (K)

Figure 3 Saturated vapor pressure of Na, Pb, and Pb-Bi(e) (p < patm).

properties’ recommendations to higher temperatures and pressures.

With satisfactory precision they were determined only for sodium. The available experimental data and theoretical estimations for the critical parameters of Na were reviewed in 1985 by Ohse et at., who recommended Tc(Na) = 2497 ± 18 K, pc(Na) = 25.22 ± 0.60 MPa, and pc(Na) = 211 ± 2kgm-3.

Later, Fink and Leibowitz22 extended this review by including the results ofnew studies and analyses from Thurnay53 and Petiot and Seiler54 and suggested to use Tc(Na) = 2503.7 ± 12 K, pc(Na) = 25.64 ± 0.40 MPa, and pc(Na) = 219 ± 20 kgm-3. In the recent com­pilation of IAEA,26 the Na critical parameters are reproduced from the earlier review.30 The rounded within uncertainty values from the review of Fink and Leibowitz22 are recommended in the present compilation (see Table 6).

A lot of studies were performed to determine the critical point of lead, but the obtained results show a large variation. In 1990, Pottlacher and Jager55 published a summary of experimentally determined and theoretically estimated parameters for the criti­cal point of lead available in the literature as of that date. They considered 16 sets of data as well as their
own estimations based on the experimental results obtained using the pulse-heating technique. Their summary shows that the experimental and theoretical data on the critical temperature of lead lie within the range of 3584-6000 K, while their own estimation yields T((Pb) = 5400 ± 400 K. For the Pb critical pres­sure and density, they recommend pc(Pb) = 250 ± 30 MPa and p = 3200 ± 300 kgm-3. Morita et a/.56 analyzed the previous and later publications using different methods to estimate the critical parame­ters of lead. The IAEA compilation26 suggests to use Tqpb) = 5000 ± 200 K, pc(Pb) = 180 і 30 MPa, and Pc(Pb) = 3250 ± 100 kgm-3 with the reference to the handbook of Babichev et a/.57 These values give good compromise and they were selected in the present compilation (see Table 6).

Only theoretical estimations were found in the open literature for the critical parameters of

Pb-Bi(e).24,52,56,58 Based on these studies and on

the conclusions of the report,34 the following values and uncertainties are recommended for the critical temperature, pressure, and density of Pb-Bi(e): Tc(Pb-Bi) = 4800 і 500 K, Pc(Pb-Bi) = 160 і 70 MPa,

and pc(Pb-Bi) = 2200 і 200 kgm-3. The recommended values of the critical parameters of Na, Pb, and Pb-Bi(e) are summarized in Table 6.