Dr. Louis Jean Groven, 70, a Belgian diplomat and nuclear physicist who researched peaceful uses of nuclear energy, died Sunday at Suburban Hospital after a stroke. He lived in Chevy Chase.

Dr. Groven, who was born in Kerniel, Belgium, earned master's and doctor's degrees in physics from the University of Brussels. From 1934 to 1955, the year he came to the United States and settled in this area, he served on the faculty of the university's physics department.

He began his research on the peaceful use of the atom in Belgium in 1952 and continued his work in this country at the Argonne National Laboratory in Chicago, the Oak Ridge National Laboratory in Tennessee, and Brookhaven National Laboratory in New York.

In 1955, he became scientific counselor for the Belgium Embassy and subsequently became dean of scientific counselors for all embassies here. He remained in both capacities until his death.

Dr. Groven was honored by Belgium with the Order of the Crown and by being made an Officer of the Order of Leopold Society.

He was a UNESCO Fellow and a member of the American Nuclear Society and the Societe Francaise de Physique.

Survivors include his wife of 43 years, Simone, of Chevy Chase; a daughter, Annie Long of Chapel Hill, N.C.; two sons, Jean-Pierre of White Plains, N.Y., and Claude, of Bethesda, and seven grandchildren.