Regulatory Assets and Liabilities (Tables)

6 Months Ended

Mar. 31, 2018

Components of regulatory assets and regulatory liabilities are summarized in the table below:



Regulatory Assets and Liabilities
	At March 31, 2018		At September 30, 2017
Current regulatory assets
Deferred nuclear generating units	$	237	$	237
Unrealized losses on interest rate derivatives	80		93
Unrealized losses on commodity derivatives	44		68
Fuel cost adjustment receivable	39		1
Environmental agreements	3		2
Environmental cleanup costs - Kingston ash spill	44		44
Gallatin coal combustion residual facilities	21		—
Other current regulatory assets	3		2
Total current regulatory assets	471		447

Non-current regulatory assets
Deferred pension costs and other post-retirement benefits costs	3,881		4,009
Unrealized losses on interest rate derivatives	824		982
Gallatin coal combustion residual facilities	878		899
Nuclear decommissioning costs	821		823
Deferred nuclear generating units	645		759
Non-nuclear decommissioning costs	701		703
Environmental cleanup costs - Kingston ash spill	242		263
Unrealized losses on commodity derivatives	36		9
Environmental agreements	11		13
Other non-current regulatory assets	201		238
Total non-current regulatory assets	8,240		8,698
Total regulatory assets	$	8,711	$	9,145

Current regulatory liabilities
Fuel cost adjustment tax equivalents	$	147	$	153
Fuel cost adjustment	—		2
Unrealized gains on commodity derivatives	12		8
Total current regulatory liabilities	159		163

Non-current regulatory liabilities
Deferred other post-retirement benefits cost	16		23
Unrealized gains on commodity derivatives	3		2
Total non-current regulatory liabilities	19		25
Total regulatory liabilities	$	178	$	188