v3.25.2
Regulatory Assets and Liabilities (Tables)
 9 Months Ended
Jun. 30, 2025
Regulatory Assets and Liabilities Disclosure [Abstract]  
Regulatory Assets and Liabilities Components of regulatory assets and regulatory liabilities are summarized in the table below.
Regulatory Assets and Liabilities
(in millions)
 At June 30, 2025At September 30, 2024
Current regulatory assets  
Unrealized losses on commodity derivatives$22 $102 
Unrealized losses on interest rate derivatives51 54 
Fuel cost adjustment receivable79 35 
Total current regulatory assets152 191 
Non-current regulatory assets  
Non-nuclear decommissioning costs6,135 6,187 
Retirement benefit plans deferred costs1,915 1,979 
Nuclear decommissioning costs276 362 
Unrealized losses on interest rate derivatives321 447 
Environmental compliance and remediation costs313 215 
Unrealized losses on commodity derivatives8 64 
Other non-current regulatory assets169 154 
Total non-current regulatory assets9,137 9,408 
Total regulatory assets$9,289 $9,599 
Current regulatory liabilities  
Fuel cost adjustment tax equivalents$189 $169 
Unrealized gains on commodity derivatives13 5 
Total current regulatory liabilities202 174 
Non-current regulatory liabilities  
Retirement benefit plans deferred credits68 81 
Unrealized gains on commodity derivatives17 2 
Total non-current regulatory liabilities85 83 
Total regulatory liabilities$287 $257