The Virginia Electric and Power Co. today suspended work on the final phase of its ambitious nuclear power program and company officials said they may cancel the construction of nuclear plants altogether if unnecessary federal relations make them uneconomical.

Top officers of the giant utility said they made the decision to delay construction of two nuclear generating units on the James River in Surry County because new projections of power demand indicate that they will not be needed "for at least one year" after their previously scheduled 1986 and 1987 completion dates.

"In this country that sired the nuclear industry it takes 11 years to build a nuclear power grnerating station," William L. Proffitt, senior vice president for power, said. "In other countries, it takes half that itme at no scarifice in safety."

As examples of the causes of regulatory delays Proffitt cited the formal hearings that precede issuance of construction and operating permits and hearings that often involve persons who intervene to oppose nuclear plants. In addition to the hearings, he said, "we have a continuing relationship with regulatory personnel during construction that requires almost daily design changes."

"Each plant is custom-reviewed," he said. "We thought the process would become standardized as experience built up, but it has not."

"In inflationary times like these, you add an ungodly amount of money to the cost of a generating station with that kind of delay. It is a sad commentary on this country that we can't benefit our customers with cost savings just because of the time frame "imposed by regulation. Surry I and II, at the Surry County station and is nearing completion of two others, North Anna I and II, in Louisa COunty. Tow other units, North Anna III and IV are under construction but the company announced today that their completion has been delayed by unrelated events and the dates pushed back from 1981 to 1982-83.

Even if Surry Units III and IV are eventually canceled, Vepco still will have a greater dependence on nuclear power than most other large utilities in this country.

About 25 per cent of the company's total energy output now is generated by Surry I and II and the North Anna units are expected to raise nuclear generation to 50 per cent of the total output next year.

Vepco made its nuclear plans in the early 1960s when utility officials decided that the lower prices for nuclear fuel would more than offset the high cost of constructing nuclear power plants.

Despite construction and operating problems and growing national offensive against nuclear power for safety reasons, skyrocketing prices for coal and oil have helped Vepco officials continue to justify their nuclear commitment.

Uranium prices are raising and Westinghouse Electric Co., primary supplier of nuclear fuel to Vepco, is currently trying to cancel its long term contracts that were based on the old, low prices.

However, Proffitt sadi, fuel supply problems did not figure in the decision to suspend work on Surry III and IV. He also said that Vepco officials have made no judgment tht coal-fired generating stations may now become more economical than nuclear powered stations because of the possibility that pollution standards for coal burning may be relaxed.

Vepco has been fined by the Nuclear Regulatory Commission for construction violations at both its Surry and North Anna stations, but Proffitt also denied that these fines played any role in the utility's decision to suspend work at Surry.

The suspension apparently will give Vepco time to assess the energy and environmental policies of the new Carter administration and how they will bear on the nuclear construction program.

Although Vepco's nuclear program has been under attack by environmental groups, Proffitt said fear that the new administration will be more attentive to such groups "was not a big factor in our thinking."

Among the charges made by environmentalists against Vepco is one that they have risked a radiation accident by building the North Anna plant over a geological fault. The NRC concluded that the fault poses no risk to safe operation of the plant but fined Vepco for failing to report its discovery of the fault in a proper manner.

Vepco president T. Justin Moore said in a prepared statement that "lack of a coordinated national energy policy" and "conflicting regulatory pressures" have contributed to the problems of electric utilities.

In the aftermath of the Arab oil embargo, federal energy officials pressured utilities to convert from oil to coal as a fuel for generating stations, but federal and state environmental officials refused to relax coal emission standards.

Vepco so far has spent about $45 million on engineering and construction of the suspended Surry units, but this is only 2.5 per cent of their estimated final cost of $1.8 billion.

Nuclear units being planned for completion in the 1980s now have a projected cost of about $1,000 per kilowatt of power they will produce. A kilowatt is enough power to operate an average-size hair dryer.

Proffitt said projected costs for large coal fired units "are not far behind that" but added, "The big difference is we could wait until 1982 before starting a coal-fired station and have it on line by the time we could complete Surry III and IV."