(NOTE TO EDITIORS: The following is being released simultaneously in Albuquerque, New Mexico; Washington, D.C.; and Las Vegas, Nevada.}

A series of low-yield nuclear tests will be conducted at the U.S. Atomic Energy Commission's Nevada Test Site with the cooperation of the Department of Defense and beginning in late spring 1957. Test of high yield devices are not conducted in Nevada.

The program of tests is aimed to attain new knowledge important to the defense of the United States and the Free World, which must be maintained pending ultimate attainment of international agreement on safe-guarded disarmament. The development of weapons for defense against attack is a major objective. Studies of weapons effects will also be continued in order to improve military and civil defense against nuclear attack. The Federal Civil Defense Administration will participate in the series.

An extensive radiation monitoring network will again be used during the series. About 12 monitoring teams supplied by the U.S. Public Health Service will be stationed in communities near the test site. In addition, the U.S. Public Health Service network of monitors in about 40 cities across the nation, established prior to the last Eniwetok test series in the spring of 1956, will be in operation. Radiological monitoring also will be conducted at 12 Commision installations. About 100 U.S. Weather Bureau stations will cooperate in this program.

The 1957 test series will be called "Operation Plumbbob." When finally established, the scheduled date for the beginning of the series will be announced. A termination date cannot be definitely annnounced at this time.

In addition to the series of nuclear tests, there will be further experiments at the Nevada Test Site similar to those announced in October 1955, related to the safety of various weapons and experimental devices in the event of accidents such as fires during handling or storage. These saftey tests will occur intermittently throughout the year.

Following standard practice in connection with U.S. nuclear tests, announcement is being made well in advance of the start of the series. Arrangements will be made for limited on-site reportage of some of the test explosions by representatives of public news media, and a limited number of civil defense observers will be present.

The Commission, through its Las Vegas office, is advising public officials, stockmen, miners and others in southwestern Utah and southern Nevada that the test site will be used for the tests beginning in late spring 1957.