Date

Apr 22, 1968

Description

As Giller mentioned in his 23 February report, the weapons recovery efforts had not found the “secondary” for the fourth bomb. Apparently one of the missing pieces was a compact uranium rod, the cylinder-shaped fissile core of the weapons’ thermonuclear secondary (fusion) stage—its “spark plug.” A major study by Svend Aage Kristensen reviewed the search for weapons parts and carefully assessed the claims, repeated over the years, that there was a missing bomb. Kristensen found that the declassified evidence did not indicate any concern about a missing bomb, but pinpointed a lost uranium fissile core, resembling a “marshal’s baton,” that was a crucial element of the weapon’s secondary stage.[6]

Giller informed the Commission members that the Defense Department sought the AEC’s “consensus” on the suitability and the possible extent of an underwater search for missing bomb parts. As he mentioned, the “gentleman’s agreement” covered the possibility of a sea-bottom search of which the U.S. would inform the Danes of any results. The Air Force had commissioned a Navy study to evaluate possible methods of searching underwater. The Air Force did not “anticipate a very complicated search since the water is relatively shallow (approximately 600 feet at the most) and the bottom of the bay has the characteristics of a small desert.”

The Department of Defense was willing to support a “brief underwater survey” to determine the extent of a search. While an extensive search might be unsuccessful, “even a brief search might find sensitive classified debris which another nation might recover if we did not.”

Source

National Security Archive, DOE Releases on Thule Crash

Document published in following posting(s):

The United States and Greenland: Episodes in Nuclear History, 1957-1968
Part II: The B-52 Crash and Its Impact

Oct 15, 2025

Brig. General Edward B. Giller, Assistant General Manager for Military Application, to Atomic Energy Commission, “Underwater Search for Weapon Debris at Thule, Greenland,” 18 April 1968, with cover memorandum by AEC Secretary W. B. McCool, AEC 907/33, 22 April 1968, Secret, Excised Copy