The 'BBB' corporate credit rating on Exelon Generation LLC. reflects parent Exelon Corp.'s consolidated business risk profile, which we view as 'strong'. (We categorize business profiles from 'excellent' to 'vulnerable'.) Exelon's business profile reflects the higher-risk operations of unregulated supply affiliate Exelon Generation LLC (ExGen) and the 'excellent' business risk profiles of its two regulated delivery businesses, Commonwealth Edison (ComEd) and PECO Energy (PECO). ExGen, which accounts for about 70% of the consolidated enterprise by cash flow and capital expenditures, is characterized by long-term exposure to market risk and meaningful exposure to nuclear assets (17,000 megawatts [MW] across 19 units). The enterprise's risks are partially offset by the solid operating performance of its low-cost nuclear. As of June 30, 2010,
