HOUSTON, Jan 15 (Reuters) - BP Plc's 240,000 barrelper day (bpd) Los Angeles-area refinery in Carson, Calif.,restarted a jet fuel hydrotreater, which was shut down by smallfire on Monday, sources familiar with refinery operations saidon Tuesday. A hydrocracker was also shut due to the fire on Monday andremains out of production. A hydrocracker uses hydrogen to boostthe production of motor fuel. A hydrotreater reduces sulfurcontent in a motor fuel. A BP spokesman declined to discuss operations at therefinery. (Reporting by Erwin Seba; editing by Carol Bishopric)