The Obama administration inched closer today to letting Royal Dutch Shell PLC drill for oil in the Arctic Ocean this summer by approving the company's oil spill response plan for the Beaufort Sea.

Today's move -- which follows Interior's approval last month of the company's oil spill response plan in the neighboring Chukchi Sea (Greenwire, Feb. 17) -- brings the Dutch oil giant one step closer to developing what is believed to be the nation's largest untapped source of oil.

"We have conducted an exhaustive review of Shell's response plan for the Beaufort Sea," Bureau of Safety and Environmental Enforcement Director James Watson said. "Our focus moving forward will be to hold Shell accountable and to follow up with exercises, reviews and inspections to ensure that all personnel and equipment are positioned and ready."

Interior Secretary Ken Salazar this morning told reporters that he has reviewed the oil spill response plans and that they have been significantly modified from earlier proposals.

The company was required to "substantially rewrite" plans that had been approved before the Deepwater Horizon spill in the Gulf of Mexico, Interior said.

Among other changes, today's approval requires that Shell:

• Prepare for a worst-case discharge of nearly three times what was calculated in previous Beaufort plans, and in adverse weather conditions;

• Chart where oil may flow during a worst-case spill scenario over a 30-day period, as opposed to three days in the company's previous plan;

• Identify the specific equipment workers would use for dispersant application and in-situ burning;

• Provide additional information on how it plans to transport equipment into a region that lacks most of the infrastructure available in the Gulf.

"I believe these plans are in good shape," Salazar said, adding that the company must still obtain permits for each of the 10 wells it plans to drill over the next two summers. "We're not going to prejudge that yet."

The company will be required to comply with new safety standards implemented after the BP PLC spill in the Gulf of Mexico, including those related to well design, workplace safety, and the ability to deal with the potential for a blowout and worst-case discharge, Interior said.

The agency said it will also inspect Shell's well-control containment plans, which include a combination of a subsea capping stack and surface separation equipment to be located on a newly built containment vessel.

Environmentalists blasted today's approval as reckless, citing the risks of developing an area prone to hurricane-force storms, ocean swells, sea ice, subzero temperatures and months-long darkness.

"There is no viable way to clean up an oil spill in the extreme conditions of America's Arctic Ocean, yet the Obama administration continues to give the green light to Shell Oil's plans for drilling this summer," said Cindy Shogan, executive director at the Alaska Wilderness League.

"We can only hope that President Obama shows the leadership he promised and refuses to bow to the demands of Big Oil by not granting Shell the final permits it needs to begin drilling in July."

In addition to final drilling permits, Shell must also obtain approvals from the National Marine Fisheries Service and the Fish and Wildlife Service in order to disturb marine mammals or endangered species.

Bruce Woods, a spokesman for FWS in Anchorage, said that it has received Shell's application for a "letter of authorization," and that it plans to complete its review by the end of April.