Customers of the Virginia Electric and Power Co. may lose as much as $146 million if the company cancels construction of two reactor units of its Surry nuclear power plant on the James River, a company spokesman said yesterday.

Vepco recently suspended work on the two units, and executive vice president Stanley Ragone said the company intends to decide by its annual stockholders' meeting on April 20 whether to cancel the units outright. There is a strong likelihood that the decision will be to cancel, Ragone indicated.

A Virginia State Corporation Commission spokesman said that if vepco canceled it would have to justify its action at a hearing before the SCC.

Regone and the SCC spokesman, James C. Dunstan, director of the divisionof public utilities, both said it is unclear at this point whether customers would be required to pay the total loss through higher charges for electricity or whether stockholders would have to absorb all or some of the costs.

"Rate payers must be protected," Dunstan said, "but on the other hand you don't want to break the company or drive away investors. We have to walk a tightrope."

Ragone said the $146 million is an "outside figure." There is speculation that the total could be reduced by as much as $70 million.

Of the total, $46 million has been spent on the facility already, $7 million is a prepayment on ordered nuclear fuel and $93 million is in contracts with manufacturers and other companies for material and work for the future. Ragone said "there is going to be some hard negotiating" and Vepco may be able to sell some of the material it has already purchased and also may be released from some contracts. For example, there is a $30 million contract for nuclear fuel enrichment and Vepco has received indication it could not be met by the other party anyway.

Vepco suspended work on the two units because of a reduction in the forecast of electricity needs of customers in the late 1980s. When the company decided in 1972 to build the two units, electricity consumption was growing at the rate of 10.8 per cent. Now growth is forecast as 5.5 per cent through 1987.

Company executives also have expressed concern about the effects of the environmental movement against nuclea power as a source of energy and at the attitude of government policy-makers and regulators.

The SCC's Dunstan said "Vepco has been one of the leaders of the country in nuclear power and if it admits there are problems stopping them from nuclear expansion thenit probably means a reassessment is going on all over the country."

Vepco's objective has been to produce between 50 and 60 per cent of its electricity needs from nuclear power, with the rest coming from coal and water power. Its two operating nuclear units at Surry produced about 28 per cent in 1976. Vepco hopes that when the four nuclear units under construction at North Anna in Louisa County are operating in the late 1980s they will bring the total to 50 to 60 per cent of the needsof consumers a decade from now.