
		2013		2012
		(dollars in thousands)

Regulatory Assets:
Premium and loss on reacquired debt^(a)	$	83,292	$	86,319
Amortization on capital leases^(b)		25,536		28,670
Outage costs^(c)		45,294		30,901
Interest rate swap termination fees^(d)		16,328		17,326
Asset retirement obligations^(e)		—		11,382
Depreciation expense^(f)		49,429		49,785
Deferred charges related to Vogtle Units No. 3 and No. 4 training costs^(g)		24,423		23,030
Interest rate options cost^(h)		75,192		75,716
Deferral of effects on net margin—Smith Energy Facility⁽ⁱ⁾		35,279		21,394
Other regulatory assets^(j)		6,841		8,379

Total Regulatory Assets	$	361,614	$	352,902
Regulatory Liabilities:
Accumulated retirement costs for other obligations^(e)	$	27,529	$	28,846
Deferral of effects on net margin—Hawk Road Energy Facility⁽ⁱ⁾		19,095		17,113
Major maintenance sinking fund^(k)		29,861		30,948
Deferred debt service adder^(l)		49,911		47,486
Other regulatory liabilities^(j)		7,005		5,592

Total Regulatory Liabilities	$	133,401	$	129,985

Net Regulatory Assets	$	228,213	$	222,917

^(a): Represents premiums paid, together with unamortized transaction costs related to reacquired debt amortized over the period of the refunding debt, which range up to 30 years.
^(b): Recovered over the remaining terms of the leases through 2031.
^(c): Consists of both coal-fired and nuclear refueling outage costs. Coal-fired outages are amortized on a straight-line basis to expense over an 18 to 36-month period. Nuclear refueling outage costs are amortized on a straight-line basis to expense over the 18 to 24-month operating cycles of each unit.
^(d): Represents losses paid on settled interest rate swaps arrangements that are being amortized through 2016 and 2019.
^(e): Represents difference in timing of recognition of the costs of decommissioning for financial statement purposes and for ratemaking purposes.
^(f): Prior to Nuclear Regulatory Commission (NRC) approval of a 20 year license extension for Plant Vogtle, we deferred the difference between Plant Vogtle depreciation expense based on the then 40-year operating license and depreciation expense assuming an expected 20-year license extension. Amortization commenced upon NRC approval of the license extension in 2009 and is being amortized over the remaining life of the plant.
^(g): Deferred charges related to Vogtle Units No. 3 and No. 4 training and interest related carrying costs of such training. Amortization will commence effective with the commercial operation date of each unit and amortized to expense over the life of the units.
^(h): Deferral of net loss associated with the change in fair value of the interest rate options to hedge interest rates on a portion of expected borrowings related to Vogtle Units No. 3 and No. 4 construction. Amortization will commence effective with the expected principal repayment of the Department of Energy (DOE)-guaranteed loan and amortized over the expected remaining life of the DOE-guaranteed loan which will finance a portion of the construction project.
⁽ⁱ⁾: Effects on net margin for Smith and Hawk Road Energy Facilities are deferred until the end of 2015 and will be amortized over the remaining life of each respective plant.
^(j): The amortization period for other regulatory assets range up to 36 years and the amortization period of other regulatory liabilities range up to 13 years.
^(k): Represents collections for future major maintenance costs; revenues to be recognized as major maintenance costs are incurred.
^(l): Collections to fund debt payments in excess of depreciation expense through the end of 2025; deferred revenues will be amortized over the remaining useful life of the plants.