Radiological impact assessment of routine atmospheric releases of MAAMORA Nuclear Research Center (MNRC)

CNESTEN is the main national operator of nuclear facilities within the MAAMORA Nuclear Research Center (MNRC) in Morocco. MNRC is presently holding a radioisotopes production facility, radioactive waste treatment and storage facilities and several laboratories using nuclear techniques and radioactive sources. The construction of a TRIGA Mark II research reactor is still on going. In compliance with national regulations with regard of the licensing process, CNESTEN has performed a radiological impact assessment for the routine atmospheric releases of Maamora Nuclear Research Center facilities in order to obtain the first licence for environmental discharge. The objective of the study is to propose to the national nuclear safety authority the atmospheric release limits and conduct the assessment of radiological consequences to the population reference groups which will be compared to the 1 mSv regulatory annual limit to the public. A conservative estimation has been developed for: the source term of the annual atmospheric releases, the release conditions at the stacks, the local meteorological data, exposure pathways scenarios of population reference groups. The dose assessment has been performed using two different calculation codes: GASCON (France/Commissariat a l'Energie Atomique) and CAP88 (USA/Lawrence Livermore National Laboratory). Under the conditions and the assumptions related to the routine radioactive atmospheric releases of MNRC, both of the calculation codes had given comparable estimations of individual and collective effective doses to the members of the public. The highest individual effective dose is estimated to 6.80 x 10-4 mSv per year which represents 0.07% of the 1 mSv regulatory annual limit to the public. (author)