(489a) Habit 2.1: Assessing Consequences of Chemical Releases on Control Room Habitability Considering the Impact of a Dividing Streamline

HABIT is a package of computer codes designed to assist in the evaluation of control room habitability in the event of accidental spills of hazardous materials in the area and is part of the U.S. Nuclear Regulatory Agency’s Radiological Protection Computer Code Analysis and Maintenance Program (RAMP). Developed at Pacific Northwest laboratory (PNL), HABIT was originally written to model atmospheric dispersion based on standard passive dispersion models. In addition to an extensive update of the user interface, HABIT 2.0 was also extended to include the effects of denser-than-air contaminant cloud behavior using the SLAB and DEGADIS models. This paper summarizes how the previous HABIT source models (instantaneous and finite duration releases) were used to generate inputs to SLAB and DEGADIS. HABIT 2.1 has considered how the concept of a dividing stream line can successfully refine the predicted concentration expected at a control room air intake. Model results are presented for a hypothetical chlorine release which reflects the importance of denser-than-air behavior on the potential impact of the air intake height on control rooms of light-water reactors (LWR).