  It is shown that the non-zero transition magnetic moment ($\mu_{tran}$)
between the sterile neutrino ($\nu_{s}$) and the muon neutrino ($\nu_{\mu}$)
could be effectively searched for via the Primakoff effect, in the process of
$\nu_{\mu} Z \to \nu_{s}Z$ conversion in the external Coulomb field of a
nucleus $Z$, with the subsequent $\nu_{s}\to \nu_{\mu} + \gamma$ decay. From
the recent results of the NOMAD neutrino detector at CERN a model-independent
constraint of $\mu_{tran} < (10^{-6} - 10^{-9}) \mu_{B}$ is obtained depending
on the value of $\nu_{s}$ mass. For the $m_{s}\sim O(1) GeV$ region these
bounds are comparable with the present experimental ones on $\nu_{\mu}$ and
$\nu_{e}$ diagonal magnetic moments and are more sensitive than those on
$\nu_{\tau}$ magnetic moment.
  From the same analysis the constraint on $\nu_{\tau}(\nu_{s})\to \nu_{\mu}
+\gamma + \gamma$ decay lifetime $\tau > 2\times10^{13} sec/m_{\nu}^{7}(MeV)$
is obtained. The limit is valid for neutrino masses up to $m_{\nu}\sim
O(1)GeV$.
