Stymied by growing opposition to underground disposal of radioactive waste in the United States, the federal government is edging toward another option: ocean dumping.
The US Environmental Protection Agency (EPA) has just given a clean bill of health to waters off the coast of Massachusetts where large amounts of low-level nuclear waste are believed to have been deposited between 1947 and 1958.
The EPA ''will be opening up the issue of radioactive waste disposal and will be revising its regulations,'' says Steven Schatcow, director of the EPA's Office of Water Regulations and Standards. And one environmental group, Greenpeace, says the positive results of the Massachusetts Bay testing will encourage the reopening of old sites.
The EPA says it has not received any formal requests for ocean dumping. But the US Navy may be the first. According to a public information officer, Lt. (jg) Tom Miller, the Navy has prepared an environmental impact statement with several proposals for land and sea dumping of defueled nuclear powered submarines. Currently, four submarines have been decommissioned and await disposal.
The Navy presented its impact statement to the EPA in December but has not made a formal proposal yet. Lieutenant Miller says he believes it will be several years before the Navy has a place to deposit its submarines.
Congress, concerned over possible use of the oceans for low-level waste disposal, has passed a bill to reinstate a moratorium on radioactive waste dumping in the US oceans imposed between 1972 and 1974. The bill, which also places restrictions on any future dumping after the new two-year moratorium, now awaits the President's signature.
The investigation of Massachusetts Bay in September 1982 by researchers aboard the EPA vessel Antelope was proposed by the Congressional Committee on Oceanography in an effort to monitor the effects of past deposits. But the EPA's ocean monitoring plan submitted to the House at a hearing in September 1981 stated that the voyage was ''designed mainly to provide data for developing permit criteria.''
Of the many ocean dump sites off the US, the Massachusetts Bay site, 15 miles east of Marblehead, is significant because, as Rep. Gerry E. Studds (R) said during a hearing on ocean dumping last year, ''it is located closest to shore, closest to large population centers, and has the shallowest water.''
To begin its research, the Antelope's crew in September took background readings of ocean water, animals, and sediments in waters north of the previous dump site. Then, moving south, it studied these three indicators in the area where dumping was believed to have taken place. The readings of both areas were compared, and the amount of radioactivity in the old dump site was found to be no greater than the untouched northern area, which contained a natural amount of radioactivity, according to Raymond Johnson, director of the Antelope voyage.
Saying this was a hasty conclusion, Greenpeace greeted the returning Antelope with a banner - ''No more ocean dumping of rad-waste'' - strung between two boats.
Until two decades ago there were no laws to regulate US industries that had radioactive material to dump. Eventually concern grew over possible ill effects on the environment.
In 1972, 91 nations agreed to the London Dumping Convention, which bans the dumping of high-level radioactive wastes and regulates low-level waste deposits. In the same year, the US Marine Protection, Research, and Sanctuaries Act established a policy strictly limiting the dumping of hazardous wastes and requiring the EPA to research the effects of past radioactive waste dumping. This bill included the two-year moratorium on dumping which ended in 1974.