Operation Peppermint

Operation Peppermint was the codename given during World War II to preparations by the Manhattan Project and the European Theater of Operations United States Army (ETOUSA) to counter the danger that the Germans might disrupt the June 1944 Normandy landings with radioactive poisons.

In response, the Metallurgical Laboratory in Chicago and the Victoreen Instrument Company in Cleveland developed portable radiation detection devices suitable for use in the field. In 1944, Major General Leslie R. Groves, Jr., director of the Manhattan Project, sent Major Arthur V. Peterson to brief General Dwight D. Eisenhower and his senior staff officers at the Supreme Headquarters Allied Expeditionary Force (SHAEF).

In response, ETOUSA initiated Operation Peppermint. Special equipment was prepared. Eleven survey meters and a Geiger counter were shipped to England in early 1944, along with 1,500 film packets, which were used to measure radiation exposure. Another 25 survey meters, 5 Geiger counters and 1,500 film packets were held in storage in the United States, but in readiness to be shipped by air with the highest priority. Chemical Warfare Service teams were trained in its use, and Signal Corps personnel in its maintenance. The equipment was held in readiness, but the preparations were not needed, because the Germans had not developed such weapons.