The Carter administration has run into sharp opposition both within its own ranks and from outside environmental groups as it strives for a drastic cut in the time required to license nuclear power plants.

The proposal the administration would like to send to Congress next month would cut in half the present 12-year licensing process by turning over much of it to individual states by bypassing existing bottlenecks in elements such as plant siting and design.

An initial draft of the proposed legislation circulated within the administration last week and evoked sharp criticism, including opposition from the Environmental Protection Agency and the Council on Environmental Quality.

At staff meetings on the initial proposal over the last two weeks, opponents have charged that it would remove the licensing process from the provisions of the National Environmental Policy Act (NEPA) and would undercut citizen input.

White House energy officials began circulating a hastily revised second draft of the proposed legislation Monday. They added a requirement that states dealing with license applications have a NEPA-like review system approved by the Nuclear Regulatory Commission in consultation with the Council on Environmental Quality.

Other officials expressed concern yesterday, however, that this portion exempts critical radiological issues such as waste management and reactor safety from the state NEPA review.

The latest draft also provides for more citizen input by requiring adjudicatory hearings on license applications.

Negative reaction among some environmental officials continues, however, and the administration's Sept. 7 target for submitting the proposed legislation to Congress may not be met.

One official said yesterday that the Council on Environmental Quality would express "strong opposition" to the newest draft proposal. "There are still substantial eliminations of opportunities the public has had before to take part in the licensing process," he said.

Officials of the Environmental Protection Agency also expressed continued dissatisfaction with the revised proposal, saying it still lacks adequate safety provisions.

The plant siting and design proposals have prompted some of the most critical reaction. Opponents have charged that a proposed "site bank", which would give states the opportunity to stockpile acceptable sites for nuclear power plants in advance, would place undue pressure on them later to use the sites.

The proposal to allow utilities to submit a standardized design for plants would lessen the chance for citizen review of projects on an individual basis, according to the critics.

The nuclear regulatory changes are sought by President Carter, who complained of the long licensing period in his April energy message.

An administration energy spokesman emphasized yesterday that the new proposal has not yet received formal agency review and could be changed again before ti reaches Congress.