NANPA – North American Numbering Plan Administrator: An integrated telephone numbering plan serving 19 North American countries that share its resources.

NARUC – National Association of Regulatory Utility Commissioners: A non-profit organization founded in 1889. Its members include the governmental agencies that are engaged in the regulation of utilities and carriers in the fifty States, the District of Columbia , Puerto Rico and the Virgin Islands . NARUC's member agencies regulate the activities of telecommunications, energy, and water utilities.

Natural Gas: A naturally occurring mixture of hydrocarbon and nonhydrocarbon gases found in porous geological formations beneath the earth's surface, often in association with petroleum. The principal constituent is methane.

Natural Recharge: The natural replenishment of an aquifer.

NDIEC – Non-dominant Interexchange Carrier: Telephone companies, excluding AT&T, which provide long distance service interstate or between LATAs within a state.

NEI – Nuclear Energy Institute: Policy organization of the nuclear energy and technologies industry and participates in both the national and global policy-making process. NEI's objective is to ensure the formation of policies that promote the beneficial uses of nuclear energy and technologies in the U.S. and around the world.

NENA – National Emergency Number Association: NENA's mission is to foster the technological advancement, availability, and implementation of a universal emergency telephone number system. In carrying out its mission, NENA promotes research, planning, training and education. The protection of human life, the preservation of property and the maintenance of general community security are among NENA's objectives.

Net Capability: The maximum load-carrying ability of the equipment, exclusive of station use, under specified conditions for a given time interval, independent of the characteristics of the load. Capability is determined by design characteristics, physical conditions, adequacy of prime mover, energy supply, and operating limitations such as cooling and circulating water supply and temperature, headwater and tailwater elevations, and electrical use.

Net Generation: Gross generation minus the electric energy consumed at the generating station for station use.

Net Operating Income: The amount of revenue from utility operations remaining after operation and maintenance expenses, depreciation expenses, and taxes are deducted. The revenues and expenses that produce net operating income are commonly referred to as "above-the-line" items.

NF – Nanofiltration: A form of filtration using membranes with larger pores than reverse osmosis.

NFCA – Noncore Fixed Cost Account: A balancing account that matches the authorized base revenue requirement and certain other costs for noncore customers with recorded revenues intended to recover that revenue requirement and the other specified costs. The balances in the NFCA have been recoverable through rates in varying degrees over time, as determined by the PUC.

NGA – Natural Gas Act: Federal legislation enacted in 1938 that established regulatory control over companies engaged in the interstate sale and transmission of natural gas.

NGV – Natural Gas Vehicle: A vehicle that uses conventional combustion engines modified to run on natural gas.

NII – National Information Infrastructure: Refers to a nationwide network of integrated telecommunications that connects people, businesses, schools, institutions and governments with one another.

NOI – Notice of Inquiry: A Notice of Inquiry is adopted by the Federal Communications Commission (FCC) Commissioners for fact gathering purposes; and as a method for seeking public comments. Or, Notice of Intent: Preliminary data filed with the PUC by a utility in preparation for the formal filing of a general rate increase application.

NOPR – Notice of Proposed Rulemaking: A Notice of Proposed Rulemaking is adopted by the Federal Communications Commission (FCC) Commissioners to detail proposed changes to FCC rules and to seek public comment on these proposals.

NP - Number Porting: Number porting allows customers to switch between telephone service providers while retaining their original telephone number. Also called Local Number Portability (LNP).

NPA – Numbering Plan Area: A geographical area in which no two telephones have the same seven-digit number.

NPTOR – Net-Plant Turnover Ratio: Gross operating revenue divided by net-plant. Net plant is total utility plant less accumulated depreciation reserve.

NPV – Net Present Value: Form of calculating discounted cash flow. It encompasses the process of calculating the discount of a series of amounts of cash at future dates, and summing them.

NRC – Nuclear Regulatory Commission: An independent agency established by the Energy Reorganization Act of 1974 to regulate civilian use of nuclear materials. The NRC is headed by a five-member Commission. 

NRDC – National Resources Defense Council: An environmental action organization. On the Internet at

NRF – New Regulatory Framework: Adopted in 1989, the New Regulatory Framework (NRF) is the PUC's designation for a price cap form of regulation used to regulate California 's four largest ILECs (SBC, Verizon California, Roseville Telephone Company, Citizens Telephone Company of California ). Previously, these ILECs were regulated under traditional cost of service rate of return regulation, which required substantial PUC oversight. The NRF relies on a profit to motivate utilities to operate in the most efficient way possible in order to maximize revenues. Under price caps, the prices of utility services are declined from costs. The utility is allowed to earn a higher rate of return than under rate of return regulation to provide the profit incentive.

NTSB – National Transportation Safety Board: An independent Federal agency charged by Congress with investigating every civil aviation accident in the U.S. and significant accidents in the other modes of transportation -- railroad, highway, marine and pipeline -- and issuing safety recommendations aimed at preventing future accidents.

Nuclear Fuel: Fissionable materials that have been enriched to such a composition that, when placed in a nuclear reactor, will support a self-sustaining fission chain reaction, producing heat in a controlled manner for process use.

Nuclear Power Plant: A facility in which heat produced in a reactor by the fissioning of nuclear fuel is used to drive a steam turbine.

NVWT – Napa Valley Wine Train: A year-round gourmet-dining excursion through Napa Valley for brunch, lunch or dinner.

NXX: Term refers to the three-digit central office prefix assigned to a seven-digit telephone number; an acronym for North American Direct Distance Dialing Numbering Plan.