Hardtack II

Technical Report · Mon Sep 12 04:00:00 EDT 2022

DOI:https://doi.org/10.2172/1887122· OSTI ID:1887122

Meade, Roger Allen ^[1]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Armed and ready to fire, Adams remained suspended under a balloon high over the Nevada Test Site throughout the day and night of October 31, 1958. Shortly after midnight, Adams was lowered to the ground and disarmed. With that, Operation Hardtack II ended and a test moratorium, primarily a gentlemen’s agreement between the United States and the Soviet Union, took effect. As the possibility of a moratorium became more and more likely in late 1957, the Atomic Energy Commission and its two weapon laboratories sought Presidential approval for an unprecedented number of tests for the coming year, including a proposal by the UCRL for a series of underground and safety tests in an operation called Millrace. Not wanting to jeopardize ongoing international disarmament talks as well as the moratorium, itself, Eisenhower resisted giving approval for Millrace until late August 1958, barely two months before the anticipated start of the moratorium. Millrace, quickly renamed Hardtack II, was expanded to thirty-seven tests beginning with Otero on September 12^th and concluding with Titania on October 30^th. Eighteen devices, including Otero and Titania, were safety tests. Three of these tests explored “safety characteristics for underground detonations” in tunnels. Two of the three such tests vented. In this respect, Hardtack II was a harbinger of the future in that the problem of venting was never fully resolved. Other safety tests, designed to give no yield, were more successful with San Juan, Oberon, and Ganymede having “no measurable yield.”

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: 89233218CNA000001
• OSTI ID: 1887122
• Report Number(s): LA-UR-22-29434
• Country of Publication: United States
• Language: English

Related Subjects

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE