  Using the transport and magnetization measurements the influence of neutron
irradiation at a fluence of 5x10$^{17}$ n cm$^{-2}$ on
(B0.65C0.35)Ba1.4Sr0.6Ca2Cu3Oz has been investigated. The neutron irradiation
was found to decrease critical temperature and transport critical current
density, increase the residual and normal state resistivity, and improve the
intragranular critical current density with 1.6x10$^{57}$ A/cm$^{2}$ (at 77.3K
and in the applied field up to 160 kA m) and \Delta Mirr/\Delta Mnonirr ratio
(up to factor of 3) at highest field used for investigation. The field
dependence of this ratio, which is below the unity at very low field but higher
than 1 at high fields, correlated with the shape of the hystertic loops as well
as with the change of the transport parameters after irradiation suggests the
role of the irradiation induced effects on the grain edges. We discuss these
effects in the framework of the Bean-Livingstone surface barriers and
geometrical barriers.
