  In the Letter [J. Nucl. Mater. 444, 356 (2014)] and Comment [Phys Rev B 90,
157101 (2014)], Soderlind et al. argue that 1) DFT based on GGA already models
U metal and U-Zr alloy accurately, and 2) DFT + U models them worse than DFT
according to results they calculate or select from our recent study [Phys. Rev.
B 88, 235128 (2013)]. Here we demonstrate in response to 1) that previously
neglected and more recent experimental data indicate that DFT, even when
implemented in all-electron methods, does not model the bulk modulus and
elastic constants of {\alpha}U very accurately. Furthermore, Soderlind et al.'s
claim that deficiency exists in our PAW calculation is unfounded and hence our
results, including those that show DFT results compare unfavorably with
experimental/computational references, are valid. We also demonstrate in
response to 2) that Soderlind et al.'s arguments are unsound for three reasons.
First, they focus on just the BCC phases {\gamma}U and {\gamma}(U,Zr)--which at
the ab initio modeling temperature of 0 K are unstable and hence difficult to
model and benchmar--as primary subjects of examination; however it is results
for the stable phases mostly neglected by Soderlind et al. that are the primary
evidence of our argument. Second, they make unfounded generalization of DFT + U
results at selected U eff values to argue that DFT + U in general gives wrong
or unsatisfactory results. Third, some key points in Soderlind et al.'s
criticisms of DFT + U are not well supported, including the claims that for
{\gamma}(U,Zr) DFT + U at Ueff = 1.24 eV gives positive deviations from linear
dependence of composition that are unprecedentedly large and partially negative
enthalpies of mixing that are inconsistent with the existence of miscibility
gap in the experimental phase diagram. We therefore maintain our conclusion
that DFT + U can be of value for modeling U and U-Zr.
