  Uncertainty in the operating temperatures of Oklo reactor zones impacts the
precision of bounds derived for time variation of the fine structure constant
$\alpha$. Improved $^{176}$Lu/$^{175}$Lu thermometry has been discussed but its
usefulness may be complicated by photo excitation of the isomeric state
$^{176m}$Lu by $^{176}$Lu($\gamma,\gamma^\prime $) fluorescence. We calculate
prompt, delayed and equilibrium $\gamma$-ray fluxes due to fission of $^{235}$U
in pulsed mode operation of Oklo zone RZ10. We use Monte Carlo modeling to
calculate the prompt flux. We use improved data libraries to estimate delayed
and equilibrium spectra and fluxes. We find $\gamma$-ray fluxes as a function
of energy and derive values for the coefficients
$\lambda_{\gamma,\gamma^\prime}$ that describe burn-up of $^{176}$Lu through
the isomeric $^{176m}$Lu state. The contribution of the ($\gamma,\gamma^\prime
$) channel to the $^{176}$Lu/$^{175}$Lu isotopic ratio is negligible in
comparison to the neutron burn-up channels. Lutetium thermometry is fully
applicable to analyses of Oklo reactor data.
