[en] Two field tests in the Climax Stock are being conducted. The Climax Stock, a granitic instrusive, has been administratively excluded from consideration as a full-scale repository site. However, it provides a readily available facility for field testing with high-level radioactive materials at a depth (420 m) approaching that of a repository. The major test activity in the 1980 fiscal year has been initiation of the Spent Fuel Test-Climax (SFT-C). This test, which was authorized in June 1978, is designed to evaluate the generic feasibility of geologic storage and retrievability of commercial power reactor spent fuel assemblies in a granitic medium. In addition, the test is configured and instrumented to provide thermal and thermomechanical response data that will be relevant to the design of a repository in hard crystalline rock. The other field activity in the Climax Stock is a radionuclide migration test. It combines a series of field and laboratory migration experiments with the use of existing hydrologic models for pretest predictions and data interpretation. Goals of this project are to develop: (1) field measurement techniques for radionuclide migration studies in a hydrologic regime where the controlling mechanism is fracture permeability; (2) field test data on radionuclide migration; and (3) a comparison of laboratory- and field-measured retardation factors. This radionuclide migration test, which was authorized in the middle of the 1980 fiscal year, is in the preliminary design phase. The detailed program plan was prepared and subjected to formal peer review in August. In September/October researchers conducted preliminary flow tests with water in selected near-vertical fractures intersected by small horizontal boreholes. These tests were needed to establish the range of pressures, flow rates, and other operating parameters to be used in conducting the nuclide migration tests. 21 references, 14 figures, 1 table