Neutron absorber materials (NAMs) are used for criticality control in spent fuel pools (SFPs). An
aluminum-clad, aluminum/boron carbide cermet core, is a common NAM material. The corrosion
performance of clad and core components of this NAM over both long-term-service at nominal pool
chemistry/temperature conditions, and over short-term, off-normal transients were evaluated. This NAM
material obtained from the Zion Nuclear Power Plant following 22 years of service in the SFP were
physically characterized and were prepared as specimens for electrochemical testing at nominal and offnormal
water chemistry conditions. The surface conditions of the cladding were also tested: i) as a freshly
ground (initial oxide-free) surface; and ii) a condition following up to several weeks of water immersion
during which an attendant oxide film formed. The exposed cermet core was also tested to evaluate
corrosion behavior in the postulated case of de-clad material. The testing, testing results, and evaluation
of material response to expected long-term and hypothetical transient water chemistry and temperature
conditions are presented.