[en] The report describes work which is part of the fuel rod behavior modeling task performed at EG and G Idaho, Inc. It is an interim addition to work previously published in the Materials Properties (MATPRO) Handbook and will replace Section A-3 (Fuel Emissivity) of the MATPRO-11 handbook. This update of the fuel emissivity subcode includes new data and an estimate of the standard error to be expected with the subcode. The material property correlations and computer subcodes described in MATPRO are developed for use in Light Water Reactor (LWR) analytical programs such as the Fuel Rod Analysis Program--Steady-State (FRAPCON-1) code and the Fuel Rod Analysis Program--Transient (FRAP-T4) code. This work is being performed as part of a broad effort to develop and verify analytical models capable of describing nuclear fuel rod behavior