Deploying huge MX nuclear missiles on railroad cars would not interfere with the operation of the nation's rail network nor would it have any significant impact on the environment, the Air Force concluded Friday.

Releasing its final Environmental Impact Statement on the proposed program, the Air Force said a one-year study found there was only "a very slight potential for accidents" and that "the system would be safe and would pose negligible risk to human health and the environment . . ."The rail-car launchers would remain inside fortified military bases unless there was a threat of war and only then would scramble on the commercial rail network to avoid a Soviet first-strike attack, the Air Force said.

The biggest environmental impacts would stem from construction activities at any bases selected to serve as garrisons for the MX cars, the statement said. Those would consist primarily of increased traffic congestion, the short-term degradation of air quality and in a few instances, the relocation of inhabited buildings.

Of the 11 Air Force bases reviewed, however, four would likely suffer "significant degradation of biological resources" if rail garrisons were built, the Air Force reported.

Those four are Barksdale Air Force Base, La.; Fairchild Air Force Base, Wash.; Whiteman Air Force Base, Mo.,; , and Wurtsmith Air Force Base, Mich.

Despite those findings, the impact statement offers no ranking of the 11 bases, nor does it disqualify any base from consideration.

It repeats a decision made two years ago that F.E. Warren Air Force Base, Wyo., will be the headquarters and first home for any MX trains - taking the first four - while noting rail deployment has not been approved by Congress and that it is premature to select other bases.

The other bases considered candidates are Eaker Air Force Base and Little Rock Air Force Base in Arkansas; Dyess Air Force Base, Texas; Grand Forks Air Force Base and Minot Air Force Base in North Dakota; and Malmstrom Air Force Base, Mont.

The Reagan administration spent years fighting Congress for the right to put 100 MX missiles in underground silos at F.E. Warren but won permission to deploy only 50.

In hopes of overcoming concerns about the vulnerability of the missiles to a Soviet first strike, Reagan in December 1986 ordered the development of a "Rail Garrison Basing Mode" for the missile - which he dubbed the Peacekeeper.

The Air Force envisions 25 six-car trains, with each train carrying two MX missiles. Each garrison, or military base, could house up to four trains.