Early Plant Retirements (Tables)

6 Months Ended

Jun. 30, 2020

Property, Plant and Equipment [Abstract]

Restructuring and Related Costs [Table Text Block]

As a result of the early nuclear plant retirement decision at TMI, Exelon and Generation recognized incremental non-cash charges to earnings stemming from shortening the expected economic useful lives primarily related to accelerated depreciation of plant assets (including any ARC) and accelerated amortization of nuclear fuel, as well as operating and maintenance expenses. The total impact for the three and six months ended June 30, 2019 are summarized in the table below.

Income statement expense (pre-tax)	Three Months Ended June 30, 2019		Six Months Ended June 30, 2019
Depreciation and amortization
Accelerated depreciation	$	71	$	145
Accelerated nuclear fuel amortization	4		9
Operating and maintenance(a)	—		(83		)
Total	$	75	$	71

_________

(a) Primarily reflects the net impacts associated with the remeasurement of the TMI ARO. See Note 9 — Asset Retirement Obligations of the 2019 Form 10-K for additional information.

Implications of Potential Early Plant Retirement on Balance Sheet [Table Text Block]

The following table provides the balance sheet amounts as of June 30, 2020 for Exelon's and Generation’s significant assets and liabilities associated with the Mystic Units 8 and 9 and Everett Marine Terminal assets that would potentially be impacted by the failure to adopt long-term solutions for reliability and fuel security.

	June 30, 2020
Asset Balances
Materials and supplies inventory	$	33
Fuel inventory	6
Property, plant and equipment, net	898
Liability Balances
Asset retirement obligation	(3		)

The following table provides the balance sheet amounts as of June 30, 2020 for Exelon's and Generation's significant assets and liabilities associated with these four nuclear plants. Depreciation provisions are based on the estimated useful lives of these nuclear generating stations, which reflect the first renewal of the operating licenses.

	Dresden			Byron			Braidwood			LaSalle			Total
Asset Balances
Materials and supplies inventory, net	$	70		$	70		$	82		$	108		$	330
Nuclear fuel inventory, net	182			145			180			244			751
Completed plant, net	1,057			1,334			1,416			1,588			5,395
Construction work in progress	18			21			18			19			76
Liability Balances
Asset retirement obligation	(1,317		)	(604		)	(562		)	(915		)	(3,398		)
NRC License First Renewal Term	2029 (Unit 2)			2044 (Unit 1)			2046 (Unit 1)			2042 (Unit 1)
	2031 (Unit 3)			2046 (Unit 2)			2047 (Unit 2)			2043 (Unit 2)