[en] The operation of the U.S. Nuclear Regulatory Commission's (NRC) centralized repository of information on the exposure of personnel to radiation is reported. The bulk of the information summarized in the report was obtained from annual and termination reports (Sections I and II) submitted by four categories of NRC licensees: operating nuclear power reactors; industrial radiographers; fuel fabricators and processors; and commercial processors and distributors of specified quantities of byproduct materials, in accordance with the requirements set forth in Part 20.407 and Part 20.408 of Title 10, Chapter 1, Code of Federal Regulations. Annual reports were received from 457 covered licensees which indicated that 98,212 individuals, with an average annual exposure of 0.40 rems, were monitored during 1977. The number of termination reports submitted by these licensees continues to increase. Personal identification and exposure information has been taken from about 245,000 reports and incorporated into the repository during the ten years that it has been operating