Right at Your Door (2006) on Netflix

Plot summary

Brad, an out-of-work musician, is home alone in a Los Angeles suburb when he hears on the radio that dirty bombs have gone off across the city. He cannot reach his wife Lexi, at work downtown, and police blockades on every road force him back. Alvaro, a worker at the neighbor's house, asks to shelter with him, and the two seal the house with plastic and tape after authorities warn that survivors are being quarantined and that people should close off every opening. Brad leaves clothes, food and water outside the back door in case Lexi comes home. She arrives covered in dust, and Brad must decide whether to open the house to her.