US nuclear device for monitoring China lost in Himalayas

In 1965, during a secret CIA operation on Mount Nanda Devi (India’s second-highest peak at 7,816 meters) in the Himalayas, a SNAP-19 radioisotope generator containing plutonium went missing. The device was intended to monitor China’s nuclear tests, according to The New York Times.

American and Indian climbers planned to install equipment on the summit, including a 22-kilogram portable nuclear device, but were unable to complete the operation due to a sudden snowstorm. Following orders from the mission leader, Captain M.S. Kohli, they hid the device at a camp on the mountain slope and evacuated.

Since then, the generator has never been recovered. It contained plutonium-239 and plutonium-238 — isotopes used in nuclear weapons and space power sources. Washington officially never acknowledged the loss of the equipment.

The operation aimed to monitor Chinese nuclear tests after Beijing conducted its first atomic bomb test in 1964 at the Xinjiang test site. NYT notes that tracking China’s nuclear program was especially difficult for both the U.S. and India, as neither country had sufficient intelligence.

The mission remained secret for more than ten years. The story of the “Nanda Devi affair” only came to light on April 12, 1978, when journalist Howard Kohn reported on the operation in Outside magazine (a spin-off of Rolling Stone). Following the revelation, Democratic Congressmen John Dingell and Richard Ottinger urged President Jimmy Carter to “take whatever steps may be necessary to resolve this serious and embarrassing situation.”

Indian environmentalists continue to express concern that the device could enter the Ganges’ headwaters as glaciers melt, potentially causing radioactive contamination, the NYT reports.

By Vugar Khalilov