In accordance with accounting guidance for conditional AROs, NU, including CL&P, NSTAR Electric, PSNH and WMECO, recognizes a liability for the fair value of an ARO on the obligation date if the liability's fair value can be reasonably estimated and is conditional on a future event. Settlement dates and future costs are reasonably estimated when sufficient information becomes available. Management has identified various categories of AROs, primarily certain assets containing asbestos and hazardous contamination and has performed fair value calculations, reflecting expected probabilities for settlement scenarios.

The fair value of an ARO is recorded as a liability in Other Long-Term Liabilities with a corresponding amount included in Property, Plant and Equipment, Net on the balance sheets. As the Regulated companies are rate-regulated on a cost-of-service basis, these companies apply regulatory accounting guidance and the costs associated with the Regulated companies' AROs are included in Regulatory Assets. The ARO assets are depreciated, and the ARO liabilities are accreted over the estimated life of the obligation with corresponding credits recorded as accumulated depreciation and ARO liabilities, respectively. Both the depreciation and accretion were recorded as increases to Regulatory Assets on the balance sheets. For further information, see Note 3, "Regulatory Accounting," to the financial statements.

A reconciliation of the beginning and ending carrying amounts of ARO liabilities are as follows:

NU			As of December 31,
(Millions of Dollars)			2013		2012
Balance as of Beginning of Year			$	412.2	$	56.2
Liability Assumed Upon Consolidation of CYAPC and YAEC				-		284.2
Liability Assumed Upon Merger With NSTAR				-		35.9
Liabilities Incurred During the Year				0.1		1.5
Liabilities Settled During the Year				(13.8)		(7.2)
Accretion				23.8		20.2
Revisions in Estimated Cash Flows				2.6		21.4
Balance as of End of Year			$	424.9	$	412.2

	As of December 31,
	2013								2012
			NSTAR								NSTAR
(Millions of Dollars)	CL&P		Electric		PSNH		WMECO		CL&P		Electric		PSNH		WMECO
Balance as of Beginning of Year	$	33.6	$	31.4	$	18.4	$	4.3	$	32.2	$	27.5	$	17.0	$	4.0
Liabilities Incurred During the Year		-		-		-		-		-		-		0.3		-
Liabilities Settled During the Year		(0.7)		(0.1)		-		-		(0.9)		(1.0)		-		-
Accretion		2.2		1.5		1.2		0.3		2.0		1.5		1.1		0.3
Revisions in Estimated Cash Flows		(0.1)		-		(0.1)		(0.1)		0.3		3.4		-		-
Balance as of End of Year	$	35.0	$	32.8	$	19.5	$	4.5	$	33.6	$	31.4	$	18.4	$	4.3

The Liability Assumed Upon Consolidation of CYAPC and YAEC represents the CYAPC and YAEC ARO fair value as of the merger date. The fair value of the ARO for CYAPC and YAEC includes uncertainties of the fuel off-load dates related to the DOE's timing of performance regarding its obligation to dispose of the spent nuclear fuel and high level waste. The incremental asset recorded as an offset to the ARO was fully depreciated since the plants have no remaining useful life. Any changes in the assumptions used to calculate the fair value of the ARO are recorded as an offset to the related regulatory asset. The assets held in the decommissioning trust are restricted for settling the asset retirement obligation and all other decommissioning obligations. For further information on the assets held in trust to support this obligation, see Note 6, “Marketable Securities,” to the financial statements