Improvement of neutronic performance of a catalyzed (D,D)‎ driven hybrid reactor using various moderators and coolants materials

Abstract EN

In this study, improvement of neutronic performance by means of various coolants/ moderators (Be, Pb, C, BeF2, H20, Li2BeF4, and D20) inserted between the fusion plasma chamber and the fissile zone of a catalyzed (D,D) driven hybrid reactor was investigated.

The fissile zone is considered to be cooled with gas coolants (He, C02, and air).

The neutronic calculations were carried out for different thickness of the coolant/moderator zone (DR).

In addition, in order to compare with coolant/moderator zone, the calculations were also repeated for the zone without coolant/moderator.

Our calculations has proved that Be, D20, BeF2, and C showed better performance than other materials in terms of new fuel breeding (239Pu) and increased energy production.

In the case of use of coolant and moderator materials in the hybrid blanket, energy production in the fissile zone with Be, D20, BeF2, and C inserted between the plasma chamber and the fissile zone increased in comparison with the case without moderator/ coolant (void case).

According to the calculations, this energy increase reaches a maximum value at a certain DR.

For Be, D20, BeF2, and C, these maximum values expressed as blanket energy multiplication ratio (M) are: 9.79,11.05,7.5, and 7.2 times that of a (D,D) fusion neutron energy at DR = 28,45, 48, and 40 cm, respectively.

Whereas, the M value for zone without moderator/coolant material is about 4.5 at the same DR values.

239Pu breeding capability of the hybrid blanket showed a similar trend as to energy released in the fissile zone, and maximum 239Pu breeding values are reached at DR < 20 cm.

239Pu nuclides breeding per (D,D) fusion neutron are calculated as 1.05, 1.35, 1.3,1.28, and 0.5 for C, Be, BeF2, D20, and void case, respectively.

These values are very attractive in terms of rejuvenation of LWR and CANDU spent fuels and enrichment of fertile fuel such as 238U and 232Th in the hybrid blanket as sources for the nuclear fuel requirement of present-day LWR and CANDU reactors .

As a result of these calculations, it is recommended that the DR value be about 30 cm in order to reach optimum energy production and new fuel breeding with C, Be, BeF2, and D,0 coolants/moderators.