The Supreme Court unanimously upheld the windfall-profits tax on crude oil, which is expected to pour some $66 billion into government coffers. The 9-to-0 decision reversed a Wyoming judge's ruling the tax was unconstitutional on grounds it singled out Alaskan oil for preferential treatment. The government had been battling to have the court reinstate the tax , saying the revenues were crucial to planning the 1984 budget, which projects a deficit of nearly $200 billion.
In other action Monday, the court:
* Upheld 8 to 0 the government's controversial assumption that no dangerous radioactive waste will escape from eventual permanent storage sites for used nuclear fuel.
* Agreed to consider a Memphis case over whether cities in a financial bind may lay off white workers with seniority to protect the jobs of recently hired minority workers. The justices last month avoided ruling in a similar case from Boston.
* Unanimously struck down a Tennessee law that required mothers to file within two years paternity suits against the fathers of illegitimate children.
* Voted 9 to 0 that the government may shield the work product of its lawyers when investigating a company for possible legal violations, even after any litigation is resolved.