Direct releases to the surface and associated complementary cumulative distribution functions in the 1996 performance assessment for the Waste Isolation Pilot Plant: direct brine release

The following topics related to the treatment of direct brine releases to t he surface environment in the 1996 performance assessment for the Waste Iso lation Pilot Plant (WIPP) are presented: (i) mathematical description of mo dels; (ii) uncertainty and sensitivity analysis results arising from subjec tive (i.e. epistemic) uncertainty for individual releases; (iii) constructi on of complementary cumulative distribution functions (CCDFs) arising from stochastic (i.e, aleatory) uncertainty; and (iv) uncertainty and sensitivit y analysis results for CCDFs. The presented analyses indicate that direct b rine releases do not constitute a serious threat to the effectiveness of th e WIPP as a disposal facility fur transuranic waste. Even when the effects of uncertain analysis inputs are taken into account, the CCDFs for direct b rine releases fall substantially to the ten of the boundary line specified in the US Environmental Protection Agencys standard for the geologic dispos al of radioactive waste (40 CFR 191, 40 CFR 194). Published by Elsevier Sci ence Ltd.