The U.S. Nuclear Regulatory Commission (NRC) intends to noncompetitively procure software upgrades and maintenance licenses for GoldSim Pro from the GoldSim Technology Group LLC in Issaquah, Washington. This is a brand-name, proprietary software essential for performance assessment modeling at complex decommissioning and waste repository sites. The NRC has determined that only this specific source can satisfy its requirements, as the software's proprietary format cannot be used or maintained by any other distributor. The acquisition is justified under specific federal acquisition regulations for noncompetitive procurement.