Howard C. Brown, Assistant General Manager for Administration, Atomic Energy Commission, to John T. Conway, Executive Director, Joint Committee for Atomic Energy, enclosing “Preliminary Report of the Visits to Atomic Energy Sites in Israel, March 31 to April 4, 1966,” 21 April 1966, Secret

Date

Apr 21, 1966

Description

When Howard Brown sent the report of the April 1966 visit to Dimona, his cover letter considered two possibilities about the reactor’s actual operations. One was the “bare possibility that the reactor may have operated to produce about 3 kilograms of plutonium since the time of the last visit in January 1965.” But the other possibility, indeed what the team saw as the overall “most probable conclusion” was “that the reactor was operating as a research reactor,” since there was “no evidence of any nuclear weapons research and development work being conducted at the Dimona site.”

The 17-page report did not name the team’s three members, but from other documents we know it consisted of W. Kelly Woods, a General Electric employee at the AEC Hanford works in Richland, WA; Donald E. Erb, with the Division of Reactor Development and Technology at the AEC’s Headquarters, and Floyd L. Culler, the Oak Ridge scientist who participated in the 1965 visit to Dimona.[12]

Professor Amos De-Shalit, a prominent nuclear physicist at the Weizmann Institute for Science where he was also the Scientific Director, served as the visit’s host on behalf of the Prime Minister. Before Dimona was constructed, De-Shalit had been a critic of Israel’s pursuit of nuclear weapons. During the course of the visit, De-Shalit told a team member – believed to be Floyd Culler – that the Israeli government had “long recognized that it cannot develop weapons to the displeasure of either US Jews who contribute heavily to Israel’s support or, more particularly, the US Government.”[13] From the report. it is impossible to assess whether De-Shalit made this remark as a personal opinion or as a factual claim. That concern, along with Nasser’s threating statements about Dimona at that time, may have contributed to Prime Minister Eshkol’s cautiousness on Dimona during this period.[14]

It was not for want of looking that the 1966 U.S. team found no evidence that “Israel is or intends to produce nuclear weapons in the facilities which we have seen” (emphasis in the original). To support that conclusion it cited several considerations, including the apparent absence of a reprocessing facility at the Dimona site, the lack of a “capability in installed equipment for producing PU [plutonium] metal in any appreciable quantity,” the fact that the irradiation objectives at Dimona “will not produce PU that is particularly useful for nuclear weapons,” and that the “reactor has not been pushed to … full power operation at its design power of 26 MWT with any urgency.” Moreover, the past presence of French technicians, although in lessening numbers “mitigates against diversion or deviation from the patterns which we have observed.” There also was no evidence that diversion of the uranium inventory at Dimona had occurred. Some of those considerations were not as conclusive as the team may have assumed; for example, because the French were in on the secret of the underground reprocessing plant, the U.S. team was too sanguine in assuming that their presence acted as a check on Israeli weapons goals.[15]

The 1966 report prudently acknowledged the “possibility that the team may have been deliberately deceived,” but added that the team “believed that this is unlikely.” Now we know that Israel concealed the existence of its underground super-secret reprocessing plant and that plutonium production trials started in 1966. In retrospect, it is well understood that the U.S. visits at Dimona necessitated a systematic effort to deceive U.S. inspectors by concealing major operations, most prominently the reprocessing plant and the reactor’s actual power level.[16] One also wonders whether the official host on behalf of Prime Minister Eshkol, Professor Amos De Shalit, was fully aware of Dimona’s big secret, the underground reprocessing plant. We do not know.

In considering a theoretical possibility of deception, the report made several points. One was that the team could not affirmatively rule out whether there was a reprocessing plant in site or even another reactor elsewhere in Israel.[17] Thus, U.S. intelligence needed to “maintain a constant surveillance of the country to determine whether such a plant or plants exists or are being built.” Also relevant was the need to determine “as conclusively as possible” the disposition or shipment of the irradiated fuel discharged from the reactor” to ensure that it was not used for plutonium production.

Another concern about the possibility of deception was that nothing could be learned about the 80 or more tons of uranium from Argentina and how Israel was using it.[18] When asked about the uranium, Dimona’s new director, Joseph Tulipman said he “knows nothing and acted as though it was the first time he had heard of it when asked.” In its report, the U.S team correctly pointed to the risk that it “could be a supply of uranium that has been or could in the future be run through the reactor between our visits and not be detected so long as the indicated reactor utilization is low.” Israel would be doing something very much like that in its efforts to acquire weapons-grade plutonium during this period.

Besides the central question of whether the Israelis were using Dimona for weapons production purposes, the report covered a visit to the Soreq research reactor, the possibility of inspection by the IAEA or other international organizations, and the intense concern for secrecy about Dimona. A major worry was that the reactor’s vulnerability made the Israelis “very concerned about a possible leak to the media which again might draw Nasser’s attention to the reactor.” According to De-Shalit, “Israelis fear there may be an unannounced large strike at Dimona.” Those concerns made them so apprehensive about the security of the irradiated fuel from bombing that they wanted to ship the fuel elements to France as soon as the French were ready for them to do so. The team asked De-Shalit if the U.S. could observe the loading of the fuel, and he agreed to look into it.

De-Shalit believed that “open inspection” of Dimona would be to Israel’s advantage, but it could not be by the IAEA because any information its inspectors obtained would become available to Arab countries. Suggesting that the visits to Dimona by U.S experts were too “unstable” with their “potential for embarrassing both parties,” De-Shalit proposed inspections by EURATOM or NATO as an alternative. Once again, one cannot but wonder whether De-Shalit was fully aware of Dimona’s big secrets.

Source

RG 128, Records of the Joint Committee on Atomic Energy, Subject Files, Box 16, Foreign Activities- Israel 1957-1976

Document published in following posting(s):

1960 Intelligence Report Said Israeli Nuclear Site Was for Weapons

Dec 17, 2024