Updated

ANCHORAGE, Alaska (AP) — The president of Shell Oil Co. says the company will take additional steps to ensure safety during the Arctic Ocean exploratory drilling it hopes to begin this summer.

The measures include staging a "prefabricated coffer dam" in Alaska that would help contain any spillage, more testing of the blowout preventer, and designing a "hot stab system" so the preventer could be activated remotely.

Shell President Marvin Odum outlined the measures in a letter to Elizabeth Birnbaum, director of the federal Minerals Management Service. Birnbaum requested the information in light of the oil spill in the Gulf of Mexico.

Odum's five-page letter also says Shell's plan to drill in the relatively shallow water off Alaska is safer than drilling in the deep gulf water where the spill occurred.