In the winter of 1945–1946, Slotin shocked some of his colleagues with a bold action by repairing an instrument 6 feet (1.8 m) under water inside the Clinton Pile while it was operating, rather than wait an extra day for the reactor to be shut down. He did not wear his dosimetry badge, but his dose was estimated to be at least 100 roentgen. A dose of 1 Gy (≈100 roentgen) can cause nausea and vomiting in 10% of cases, but is generally survivable.