Each year on the 8th to 16th days of the 12th month of the Tibetan calendar, the nuns of Nagi Nunnery perform the 9-day Ocean of Amrita (Ngakso) Drubchen (Tantric Mending and Purification Practice). This year, the Ngakso Drubchen was from February 7th-15th.
There are 3 primary yanas (vehicles) in Buddhism—Hinayana (vehicle of personal liberation), Mahayana (vehicle of universal salvation), and Vajrayana (vehicle of tantra). The Ngakso Drubchen is a Vajrayana ritual composed by the great terton, Chokgyur Dechen Lingpa. It was later practiced by Kyabje Tulku Urgyen Rinpoche (the great-grandson of Chokgyur Dechen Lingpa and father of Kyabje Chokyi Nyima Rinpoche) and became one of the annual events at Nagi Nunnery, performed each year before the start of the Tibetan new year.
The main purpose of the Ngakso Drubchen is to purify and repair broken samaya (spiritual commitments) and to eradicate negative energy, with an emphasis on restoring the Vajrayana for the empowerment of the 3 yanas. In addition, it is very effective for dispelling obstacles—including in the bardo state for those who have recently passed away.
