The Energy Department has ordered its contractor at the Savannah River Plant in South Carolina to rehire an employe who complained she was dismissed because she verified a coworker's reports of drug abuse at the nuclear weapons plant.

A DOE investigative panel concluded that the employe, Joy P. Adams, was laid off four months ago in retaliation for her support of Roger D. Wensil, a whistle-blower who was dismissed in 1985 after he complained of drug use among construction workers building a sensitive waste-handling facility at Savannah River.

In an unusually wide-ranging report, the DOE panel also recommended further investigation of key supervisors at Savannah River who may have been involved in the decision to dismiss Adams, and suggested that at least one supervisor may have attempted to falsify evidence in the case.

In addition, the panel criticized the plant's practice of hiring numerous relatives, and recommended that Savannah River contractors develop an antinepotism policy.

Adams, a clerk, and Wensil, a pipefitter, worked for the B.F. Shaw Co., a construction subcontractor at Savannah River that reports to the plant's main contractor, E.I. du Pont de Nemours & Co.

In June 1985 Wensil complained to plant officials that coworkers routinely sold and used drugs on the job. Wensil was laid off in October, and he complained to DOE that the dismissal was related to his whistle-blowing. Among coworkers he named as drug users were a Shaw supervisor's brother and nephew.

Shaw maintained that Wensil's dismissal was part of a routine layoff, and a DOE investigative panel declined to order him reinstated. Wensil has appealed the decision.

The earlier panel also said it found no evidence of significant drug abuse at Savannah River, despite testimony from other workers corroborating Wensil's account.

Adams was one of those who testified in Wensil's support. In her complaint to the DOE, Adams said that after her testimony, Shaw managers questioned the quality of her work, downgraded her to a lesser position, "threatened, harassed and intimidated" her, and finally dismissed her Dec. 31.

Following the DOE panel's report, Savannah River manager R.L. Morgan wrote last week to Du Pont, saying he had determined that Adams "was, in fact, discriminated against," and ordering the company to see that she was reinstated with back pay.

Morgan ordered Du Pont to review documents given to DOE by one of Adams' former supervisors. The documents conflict with other evidence, he said, and "may have been written after the fact."

The letter also ordered Du Pont to see that Shaw develops an antinepotism policy to avoid "the appearance of favoritism."

"The board noted that numerous . . . employes are closely related to other Shaw employes and supervisors (as husbands, wives, daughters, et cetera)," Morgan wrote.

Du Pont also has been instructed to review the case of Wensil's wife, Norma, who quit a clerical job at Shaw last year after receiving an unfavorable performance evaluation and being put on probation. Norma Wensil contended in her resignation letter that she had been singled out for abusive treatment because of her husband's complaints.

DOE investigators "noted certain irregularities . . . which, if verified, would tend to substantiate her allegations," Morgan wrote.

Adams said she had not been contacted by Shaw or Du Pont but is eager to go back to work. "It's been a long and hard fight, but it's been worth it," she said.

"We are extremely pleased," said Stephen Kohn of the Government Accountability Project, which represents Adams and Wensil. "But this action raises questions about why a similar order has not come down in the Roger Wensil case."