100-Year Closure Performance Verification Protocol (GISTM v3.1)

The GISTM v3.1 Protocol establishes a tiered, staged verification methodology that progresses from conceptual design validation through construction compliance checks to post-closure monitoring and performance confirmation. Central to its approach is the 'Performance Function Framework', which defines quantifiable, time-dependent performance functions (e.g., slope stability factor of safety ≥ 1.3 at 100 years; seepage flux < 0.1 L/s/ha beneath containment covers) tied to specific failure modes and receptors (e.g., groundwater, surface water, ecosystems). The protocol mandates probabilistic modeling (e.g., Monte Carlo simulations of climate-driven infiltration), uncertainty propagation analysis, and scenario testing—including extreme climate events, institutional failure, and land-use change—to evaluate robustness across epistemic and aleatory uncertainties. It further requires integration of Indigenous Knowledge Systems and community-defined success criteria where applicable, embedding social license and intergenerational equity into technical verification. Documentation, traceability, and independent peer review are embedded at every verification gate, with digital twin-enabled data management recommended for longitudinal performance tracking.