Daily Load-Follow Operation in LEU+-Loaded APR1400 Using Mode-K+ Control Logic

Table 1

Comparison between different types of BA materials for PWRs.

BA material	Pros	Cons
Gd2O3-integral BA	(i) Uniform loading in fuel pellet.; (ii) Good compatibility with UO2.; (iii) Partial loading in the fuel assembly.	(i) Limited weight due to thermal conductivity degradation.; (ii) Noticeable residual reactivity.; (iii) Zoning is required due to local loading.
IFBA-integral BA	(i) Relatively low depletion speed.; (ii) Very low residual reactivity.; (iii) A rather uniform loading in the fuel assembly.	(i) Limited loading and detrimental impact due to He gas generation.; (ii) Relatively high fabrication cost.
Pyrex-nonintegral BA	(i) Relatively low cost due to separate fabrication.; (ii) Low residual reactivity due to B-10 absorber.	(i) Reduced number of fuel rods.; (ii) Increased local power peaking.; (iii) Additional waste.
Er2O3-integral BA	(i) Uniform loading in fuel pellet.; (ii) Good compatibility with UO2.; (iii) More negative moderator temperature coefficient.	(i) Limited weight due to thermal conductivity degradation.; (ii) Relatively high residual reactivity.