An assessment of the modular HTGR containment system

Utility/user requirements of the MHTGR provide extremely stringent criteria for radionuclide release to the environment. In response to these top-level requirements, the MHTGR has evolved as a design emphasizing passive safety features. A crucial element of the MHTGR safety concept is the containment system which places primary emphasis on retention of fission products in the fuel. In addition to the particle-coating containment, the primary system pressure boundary and reactor building designs contribute to radionuclide retention. The philosophy of the MHTG containment system is discussed in this paper and an assessment of its effectiveness is provided