D.C. City Council member David A. Clarke (D-Ward 1) introduced a bill yesterday that would authorize a disability grant of about $480,000 to a former volunteer assistant in Clarke's office who was seriously injured during the Hanafi Muslim takeover at the District Building a year ago.

Robert J. Pierce, now 53, was an unpaid legislative intern to the council's judiciary committee at the time of the incident. Clarke is chairman of that committee.

During the takeover, Pierce was hit in the back with a shotgun blast and is paralyzed below the waist. The bill proposed by Clarke would provide Pierce with a grant comparable to one for which a full-time city employe would be eligible.

Pierce also filed a lawsuit yesterday in D.C. Superior Court that asks for a total of $5 million in damages for both Pierce and his wife. The suit contends that the District government failed to provide adequate safety precautions at the District Building.

Hostages also were taken at two other downtown buildings, during the Hanafi siege.

Clarke said yesterday that he was not aware of Pierce's lawsuit when he drafted the bill. He said however, that under federal law, such a grant could be made only if Pierce accepted it as full settlement of any claims against the city government.