ANCHORAGE, Alaska -- A Shell oil drilling rig that ran aground last week reached a safe harbor on Monday, where it will be examined to assess its seaworthiness after a week on the rocks near an Alaskan island.

Stormy weather had wrestled the Kulluk from towing ships a week ago, and tossed it to the shore of Sitkalidak Island. On Sunday night, it was refloated ahead of the 30-mile (48-km) tow, before dropping anchor just past noon on Monday in Kiliuda Bay, which was previously designated a refuge for disabled vessels.

The fortunes of the saucer-shaped drillship, which worked in the Beaufort Sea late last year, face particular scrutiny because it was a major part of Royal Dutch Shell's controversial and error-prone 2012 Arctic drilling program.