Criticality accident alarm systems (CAAS) can be difficult to analyze because they consist of both criticality calculations and deep-penetration radiation transport calculations. Radiation transport codes are typically optimized for one of these two aspects but not both. A three-dimensional CAAS modeling capability within SCALE 6 has been created by linking the KENO-VI criticality code to the MAVRIC shielding sequence. KENO-VI has been optimized for criticality calculations and used for more than 20 years. MAVRIC (Monaco with Automated Variance Reduction using Importance Calculations) is a new sequence in SCALE 6 designed for radiation transport in deep-penetration problems. MAVRIC contains features such as automated variance reduction and mesh tally capabilities, which are quite useful in CAAS modeling.