Isoshld-Ii: Code Revision to Include Calculation of Dose Rate From Shielded Bremsstrahlung Sources.

GENII: The Hanford Environmental Radiation Dosimetry Software System: Volume 1, Conceptual representation

“…The ISOSHLD code that is the basis of the EXTDF module of GENII has been documented and verified numerous times (Engel , Greenborg, and Hendrickson 1966;Simmons et al 1967;Mansius 1969). It i s a basic shielding code using the commonly accepted techniques of Rockwe1 1 (1956) or other standard references.…”

“…1986). One o f the codes creates factors relating sources of various geometries to dose rate; this is essentially a modified version of the shielding code ISOSHLD (Engel, Greenborg, and Hendrickson 1966;Simmons et al 1967). An additional capability, that of predicting very-long-term doses from waste management operations to the public over periods of up to 10,000 years, is incorporated into the system essentially unchanged from the previously documented version o f DITTY (Dose Integrated over Ten Thousand Years) (Napier, Peloquin, and Strenge 1986).…”

Hanford Site National Environmental Policy Act (NEPA) characterization. Revision 7

“…A limited biotic transport capability is included that can simulate the results of BIOPORT/MAXI (McKenzie et al 1985). GENII contains a modified version of the shielding code ISOSHLD (Engle et al 1966; Simmons et al 1967) that creates f$ctors relating sources with various geometries to dose rates. An essentially unchanged version of DI"Y ) has been added for predicting doses from waste management operations to the public during periods as long as 10,OOO years.…”

Allowable residual-contamination levels for decommissioning facilities in the 100 areas of the Hanford Site

“…As shown in The direct exposure rate encountered by the intruder for various contamination levels is calculated using the model developed for decommissioning a reference room at a BWR (Oak et al 1980). External dose equivalent factors are calculated for the mixtures of radionuclides at the facilities using the ISOSHLD (Engel et al 1966;Simmons et al 1967) computer program. Because most of the safe-storage facility is assumed to be filled with radioactive wastes and concrete, access to the facility will be very limited.…”

“…These assumptions tend to maximize the dose to specific internal organs obtained from the TGLM equations and are rather "standard" for situations where the exact chemical properties of radionuclides are not known. External exposures are calculated using the BWR room model (Oak et al 1980) and dose factors from the ISOSHLD (Engel et al 1966;Simmons et al 1967) factors are calculated based on the conservative assumption that 100% of each radionuclide is in the form of removable surface contamination. Modifications can be made to these factors to account for fixed surface contamination.…”