This annotated chronology is based on the data sources that follow each entry. Public sources often provide conflicting information on classified military programs. In some cases we are unable to resolve these discrepancies, in others we have deliberately refrained from doing so to highlight the potential influence of false or misleading information as it appeared over time. In many cases, we are unable to independently verify claims. Hence in reviewing this chronology, readers should take into account the credibility of the sources employed here.

Inclusion in this chronology does not necessarily indicate that a particular development is of direct or indirect proliferation significance. Some entries provide international or domestic context for technological development and national policymaking. Moreover, some entries may refer to developments with positive consequences for nonproliferation.

24 March 1950
Minister for Scientific Research, Sir Prakasa, emphasizes to parliament that Indian governmental policy does not include atomic weapons production.
—Shyam Bhatia, India's Nuclear Bomb (Ghaziabad: Vikas, 1979), pp. 89-90.

24 April 1951
Amidst the US Congressional debate on the India food-grain bill, the Senate approves a bill for $190 million in grants or gift aid to India while the US House Rules Committee approves a version of the bill to provide a $190 million loan to India. According to the terms of the loan proposed by the House, India would partially repay the sum in "strategic materials." India's stated intention of refining the sands, keeping the thorium for itself, and selling the other "rare earth compounds" to the United States proves unpopular; several US congressmen and senators express their support for leveraging the food-grain bill to bring an end to the Indian ban on the sale of its monazite sands.
—Robert J. McMahon, The Cold War on the Periphery: The United States, India, and Pakistan, 1947-1965 (New York: Columbia University Press, 1994), pp. 98-99.

10 May 1951
Despite initial resistance to the food-grain bill on grounds that it infringes on Indian sovereignty, Prime Minister Nehru states before parliament that India will agree to the terms of either the House or Senate bill, with a preference for the loan proposed by the House. In regard to "strategic materials," he expresses opposition to ending the embargo on the export of monazite sands by saying that India will provide such materials as are available and may be spared by India, with the exception of those materials that may be utilized to produce atomic weapons.
—Robert J. McMahon, The Cold War on the Periphery: The United States, India, and Pakistan, 1947-1965 (New York: Columbia University Press, 1994), p. 100.

15 June 1951
President Truman signs into law a compromise food-grain bill agreed upon by both the House and Senate that closely follows the original House bill and leaves the term "strategic materials" unspecified. This compromise language allows India's monazite export embargo to continue unchallenged.
—Robert J. McMahon, The Cold War on the Periphery: The United States, India, and Pakistan, 1947-1965 (New York: Columbia University Press, 1994), p. 101.

4 October 1952
At a press conference in Madras, Prime Minister Nehru speaks about the values of developing atomic energy. He states, "We are interested in atomic energy for social purposes. Atomic energy represents a tremendous power. If this power can be utilized as we use hydroelectric power, it will be a tremendous boon to mankind, because it is likely to be more available and cheaper than the building of huge hydroelectric works. Therefore, we are interested in the development from the social point of view."
—The Hindu (Madras), 14 March 1953, cited in Shyam Bhatia, India's Nuclear Bomb (Ghaziabad: Vikas, 1979), p. 90.

1952
Prime Minister Nehru unveils a four-year plan to begin developing India's nuclear infrastructure. His plans cover the survey for atomic materials, processing of monazite to obtain thorium and the application of atomic energy in medicine and biology. Dr. Bhabha begins to "discreetly" seek technical information on reactor theory, design, and technology from the United States, Canada, and the United Kingdom, while also negotiating the sale or trade of raw materials such as monazite and beryl ore. [Note: Beryl ore is the source for beryllium, which was considered vital for British and US nuclear weapons at the time.]
—Shyam Bhatia, India's Nuclear Bomb (Ghaziabad: Vikas, 1979), p. 88; Itty Abraham, The Making of the Indian Atomic Bomb (London: Zed Books, 1998), pp. 78-81.

1953
The Atomic Energy Commission (AEC) publishes its annual report for 1952-53. This report states that "easily available and abundant power is the key to all industrialization. India needs cheap power and atomic energy will permit the industrialization for areas remote from cheap sources of coal or hydroelectric power. The objective of the commission is to achieve this ultimately."
—The Ministry of Natural Resources and Scientific Research, "Atomic Energy Commission," Annual Report 1952-53, pp. 16-27, in Shyam Bhatia, India's Nuclear Bomb (Ghaziabad: Vikas, 1979), pp. 89-90.

13 March 1953
Deputy Minister for Scientific Research, Mr. Malaviya, outlines a seven-point plan for the development of atomic energy in India and states before the parliament that "it was the policy of the government not to employ atomic energy for defense or destructive purposes."
—Shyam Bhatia, India's Nuclear Bomb (Ghaziabad: Vikas, 1979), p. 90.

July 1953
In Bombay an Indian government-owned company makes preparations to ship two tons of thorium nitrate on a Polish vessel bound for China. The US Ambassador to India, George V. Allen, informs the Indian government that under the US Mutual Defense Assistance Act of 1951, the United States is required to deny military, economic, or financial assistance to any country trading such material with the Soviet Union or its satellites, which includes China. Nehru rejects the US pressure on grounds of sovereignty. Eventually, the dispute is resolved through a compromise proposed by the US Secretary of State John Foster Dulles. India agrees to make a statement that the thorium nitrate is being exported to China for strictly commercial purposes, and that India has reached the contract with China without knowledge of the applicability of the US legislation. In addition, India declares that although it does not accept the US legislation as binding, it has no plans for future shipments of such materials to the Soviet Union or its satellites. The United States agrees to purchase all thorium nitrate that India might wish to export in the future at a mutually acceptable price.
—Robert J. McMahon, The Cold War on the Periphery: The United States, India, and Pakistan, 1947-1965 (New York: Columbia University Press, 1994), pp. 181-82.

1954
The Indian government creates the Department of Atomic Energy (DAE), which takes over the execution of Atomic Energy Commission (AEC) policies. Dr. Bhabha becomes a Secretary to the government of India.
—Robert S. Anderson, "Building Scientific Institutions in India: Saha and Bhabha," Occasional Paper No. 11, Centre for Developing-Area Studies, McGill University, Montreal, Canada, 1975, p. 40.

10 May 1954
Prime Minister Nehru reacts negatively to US President Eisenhower's Atoms for Peace plan and exhorts the Indian parliament to support plans to expand India's atomic energy activities. In the same speech, he declares that "the use of atomic energy for peaceful purposes is far more important for a country like India, whose power resources are limited, than for a country like France, an industrially advanced country."
—"Control of Nuclear Energy," speech to the Lok Sabha, May 10, 1954, in Jawaharlal Nehru's Speeches, vol. 3, p. 254.

Spring-Summer 1954
Dr. H. Bhabha and Dr. Bhatnagar conduct a series of meetings with British officials to request assistance in constructing a nuclear reactor and in converting uranium ores into metal for fabrication.
—Itty Abraham, The Making of the Indian Atomic Bomb (London: Zed Books, 1998), p. 84.

June 1954
Dr. H. Bhabha requests five tons of heavy water for use in a planned Indian research reactor from Britain. The British express reluctance to supply India with heavy water, claiming that their stock is committed to British needs. Dr. H. Bhabha is instead encouraged to approach the vice-president of Atomic Energy of Canada Limited (AECL), former Cambridge colleague W. Bennett Lewis.
—Itty Abraham, The Making of the Indian Atomic Bomb (London: Zed Books, 1998), p. 84.

23 September 1954
British atomic scientist Sir John Crockcroft writes a letter to Dr. H. Bhabha to propose a solution to his problems of obtaining heavy water and other assistance for the construction of a research reactor. Sir Crockcroft writes, "Have you considered the possibility of building a research reactor of the "swimming pool" type? These have been described fairly exhaustively in Nucleonics and other publications. They require, of course, enriched uranium but it is possible that this could be made available to you from the UK."
—Itty Abraham, The Making of the Indian Atomic Bomb (London: Zed Books, 1998), p. 84.

September 1954
Dr. H. Bhabha replies to Sir Crockcroft's letter stating his receptiveness to the suggestion of developing a swimming pool-type reactor. He writes, "I would like to know how much enriched uranium it would be possible to make available, and the terms and conditions including time schedules under which it could be made available. The time element is very important, since we would like to undertake such a reactor if it could be set up in a very short time, so we have something to work with while our other plans mature."
—Itty Abraham, The Making of the Indian Atomic Bomb (London: Zed Books, 1998), p. 84.

26-27 November 1954
Prime Minister Nehru opens the Conference on the Development of Atomic Energy for Peaceful Purposes in New Delhi by saying that atomic energy is "a tremendous tool for the benefit of humanity, whether it is disease or poverty. It therefore becomes necessary for us to try not to lag behind in this, although we may not have the great resources that some other countries have." Prime Minister Nehru also outlines the foreign contacts established by the Indian Atomic Energy Commission. He states, "we have been in fairly intimate touch with a number of countries, with their atomic energy establishments. With others there are no agreements formally, but we are nevertheless in intimate touch. For instance, mention was made of France, the atomic energy establishment there. We have a formal agreement with them and I think this agreement has yielded good results in the most important thing, in our men getting trained in this work, and then coming and working here. Having got training in France or elsewhere, they work with added confidence after seeing actual things being done and not merely reading about them. With the USA, we have an agreement, too; with the United Kingdom, and with Norway and Sweden we have no formal agreements, but we cooperate and are likely to cooperate much more without the necessity of agreement...." Also at this conference, Dr. H. Bhabha presents a three-stage plan to "tap the power of the atom" for economic development. According to this plan, India will first build natural uranium-fueled reactors to produce power and plutonium. The first-stage reactors will be built with Canadian assistance. In the second stage of the plan, reactors will be built to run on a combination of thorium and the plutonium recycled from the first-stage reactors. In the third stage, the uranium produced as a by-product of the combined plutonium-thorium fuel from the second stage, would be used to fuel breeder reactors.
—Shyam Bhatia, India's Nuclear Bomb (Ghaziabad: Vikas, 1979), p. 90; G. Venkataraman, Bhabha and His Magnificent Obsessions (Hyderabad: Universities Press India, 1994), p. 158; Itty Abraham, The Making of the Indian Atomic Bomb (London: Zed Books, 1998), p. 73.

12 December 1954
Dr. H. Bhabha addresses a joint session of Parliament and expresses concern that at the current rate of energy consumption, the world's existing power sources are likely to run out within the next 350 years. He proposes that tapping nuclear fission would alleviate this problem and assure the world sufficient power supplies for centuries.
—Shyam Bhatia, India's Nuclear Bomb (Ghaziabad: Vikas, 1979), p. 95.

Late 1954-Early 1955
Britain provides Dr. H. Bhabha with six kilograms of enriched uranium fuel rods, detailed engineering drawings, and other technical data for the construction of a "swimming pool" type research reactor. In return, Dr. H. Bhabha informs his British colleagues that the AEC would consider purchasing a British reactor in the future.
—Itty Abraham, The Making of the Indian Atomic Bomb (London: Zed Books, 1998), pp. 84-85.