[en] Brazil has four research reactors in operation, all old and low power. The IEA-R1 reactor of IPEN/CNEN-SP has only limited radioisotope production capacity, materials irradiation, and neutron beam utilization. This reactor has been operating for fifty-nine years and has prospects of operation for a maximum period of ten years. It is necessary to implement a new reactor, which will support nuclear activities, and the national strategic objectives related to technological development in the areas of energy and defense; scientific and technological development; training of human resources and the growing production of radioisotopes for medical application. The Brazilian Multipurpose Reactor (RMB) will be a nuclear reactor for research and will be built in the state of São Paulo, in the municipality of Iperó. Its construction may involve the release of effluents into the environment. With monitoring before, during and after construction, it will be possible to verify if the construction itself will harm the environment. Several organics compounds are released daily in water bodies collaborating for environmental imbalance. Many of them have carcinogenic and mutagenic properties, receiving more attention by the scientific community. Most of the organic compounds are not included in environmental legislation and many of them present high toxicity, especially those classified as endocrine disrupters, as some Polycyclic Aromatic Hydrocarbons (PAHs). Only seven of the thirteen PAHs studied in this project are contemplated in Brazilian legislation, and just one is contained in international legislation. The PAHs studied in this work present, considered hazardous chemical compounds due to their toxicity, persistence in the environment, their bioaccumulative potential and their tendency to biomagnify. For the determination of the PAHs, the samples were concentrated by solid phase extraction (SPE) followed by quantification by High Performance Liquid Chromatography (HPLC). It was possible verify values of some PAHs below threshold limit 0.05 μg L^-1 in the water bodies that cross the RMB area. (author)