Analysis of June 2003 Seizure of Cesium in Thailand


The following is an analysis of the seizure of radioactive cesium in Thailand in June 2003.  Initial reports of the case were summarized in abstract 20030400.

An eight-month long US-Thai joint operation culminated on 13 June 2003, with the arrest of an individual in possession of radioactive cesium-137—a substance that could fuel a radiological dispersal device (RDD)—one type of which is more commonly known as a "dirty bomb."[1] Royal Thai Police arrested Narong Penanam, a 44-year-old elementary school principal from the Thailand province of Surin, in the parking lot of the Royal Pacific Hotel in Bangkok while allegedly in the act of selling the cesium.[2] The sale was a set-up jointly organized by the Royal Thai Police and the US Bureau of Immigration and Customs Enforcement, the investigative arm of the US Department of Homeland Security (DHS).[3]

Although both US and Thai authorities have confirmed that Narong thought he was meeting with a potential client in what appears to be the last of a series of orchestrated contacts, was he actually aiding and abetting potential radiological terrorists? This and other major details remain unclear.

First, the exact quantity of seized cesium still needs to be confirmed. Initially, press reports indicated that a total of 30 kilograms of cesium had been seized.[2] More recent reporting substantially reduces that amount to less than one gram with a radioactivity content of about 75 millicuries,[4] which is far below the security threshold of concern as being considered by the International Atomic Energy Agency and the US Nuclear Regulatory Commission.[5] In other words, unlike 30 kilograms, this amount of cesium-137 would not contribute to a potent RDD.

Thirty kilograms of cesium-137, however, would contain some 2.5 million curies - a level comparable to the quantity of radioactive cesium released during the 1986 Chernobyl accident. A person standing one meter away from 2.5 million curies of unshielded cesium would receive a lethal dose of ionizing radiation in less than a minute. Safely shielding this much radioactivity would require more than 30 kilograms of lead. The lack of any reported deaths from radiation exposure further casts doubt that 30 kilograms of radioactive cesium were seized. The initial press reports apparently did not consider or at least raise the question of the near impossibility of this much cesium-137 being present in the seized package. The package probably contained mostly 30 kilograms of shielding and packing materials, while the amount of radioactive cesium was much less than that figure. Still, as reported by The Wall Street Journal, Thai officials also believe that the cesium seized in Bangkok is part of a larger quantity. In their opinion, two additional larger stashes are hidden with one or more of Narong's accomplices somewhere in Laos.[6]

Other uncertainties riddle this case. It is not clear whether Narong was acting as a middleman on behalf of some criminal organization and if any accomplices were backing him up during the actual sale in Bangkok.[2] Narong denies any terrorist involvement, and initial press reports indicated that both Thai and American authorities have recognized no known ties to terrorist groups.[2] His involvement appears to be financially driven, and Thai police officials said he was expecting to earn $240,000 out of the cesium sale.[7] As for its origin, Narong declared that he received the radioactive material from the aide of a now-deceased Thai Air Force Marshal.[6]

In an 18 June 2003 article published in the Bangkok Post, Praphai Charensuk, the 60-year-old widow of a Thai Air Force Marshal, told Thai authorities that her late husband might have been holding the cesium at some point in early 1997. According to her, around that time the Air Force Marshal had been contacted to help examine a substance suspected of being uranium from Russia. After the Air Force Marshal's death in 2001, Charensuk had received a call from an unknown man claiming to be in possession of the material. The individual also claimed to be planning to return the radioactive source to the Office of Atomic Energy for Peace (OAEP) - Thailand's nuclear regulatory agency.[8] If this unknown man proved to be Narong Penanam or the material analyzed by the Air Force Marshal is established as the cesium recently seized, this would mean that the radioactive material had already been in Thailand for a few years. Moreover, should the alleged Russian origin be confirmed, it might also be possible that the cesium entered Thailand after having been smuggled through Laos.[9] As reported by The New York Times, Narong himself has claimed that the metal box containing the seized cesium had been brought to Thailand from Russia and that it was stored for a period of time in Laos.[2] Laotian authorities deny this allegation.[10]

As for the final recipients of the material, DHS agents based in Bangkok believe in the possibility that terrorist organizations operating in Southeast Asia might be the most interested in acquiring a substance like cesium-137.[2] Several days after the arrest of Penanam, Thai authorities, working with information provided by the U.S. Central Intelligence Agency, arrested three men who allegedly have ties to the Jemaah Islamiah terrorist group. These men were planning to bomb five embassies in Bangkok during the Asia Pacific Economic Cooperation summit meeting, according to Thai authorities.[11]

The cesium-137 seizure in Thailand further illustrates that this isotope has increasingly become an object of illicit trafficking. Commonly found in medical and industrial equipment, cesium-137 has long been high on the list of security-critical isotopes.[12] Both the IAEA and the United Nations have included highly radioactive cesium-137 sources as potent material for building RDDs.[13] The interest of smugglers in radioactive cesium is also confirmed by other illicit trafficking incidents. For example, a few weeks prior to the cesium seizure in Thailand, police in the Republic of Georgia discovered two metal containers filled with strontium-90 and cesium-137.[14] The illicit interest in radioactive cesium dates back several years. From 1993 to 1998, IAEA illicit trafficking data show that 53 seizures of cesium-137 occurred, making up 22.6 percent of all radioactive seizures.[15]

However, these data do not necessarily imply terrorist involvement in all, or any, of this trafficking. While the profit motive appears to be driving the relatively strong interest in such radioactive materials, recent intelligence reports by both the US Central Intelligence Agency[16] and MI5, the United Kingdom's defensive security intelligence agency,[17] point to al Qaeda's continued capability to acquire radioactive materials and commit acts of radiological terrorism. With increased news media attention paid to RDD issues since September 11, 2001, traffickers and terrorists alike may be more inclined to target this material to capitalize on the public's heightened state of alert. In this tense environment, clearing the uncertainties surrounding criminal cases, such as the recent Thai arrest, is more important than ever.

Abstract Number:  20030500
Headline:  Analysis of Thailand Cesium Case Casts Doubt on Amount of Radioactive Material Involved
Date:  17 July 2003
Bibliography:  Center for Nonproliferation Studies,
Author:  Charles D. Ferguson and Alessandro Andreoni
Material:  Radioactive Isotopes

[1] Christine Kucia, "Radioactive Materials Discovered in Thailand, Georgia," Arms Control Today, (July/August 2003),
[2] Philip Shenon, "Police in Thailand Seize Radioactive Material," New York Times, June 14, 2003,
[3] U.S. Department of Homeland Security Statement, "Seizure of Cesium-137 in Thailand," June 13, 2003, See also, Shawn W. Crispin and Gary Fields, "Thai's Arrest Deepens Terror Fears; Seizure of Cesium-137 Stash Raises Concern About Sales of Radioactive Materials," Wall Street Journal, June 18, 2003, p. A14.
[4] Notes from discussion with Wall Street Journal reporter, July 8, 2003.
[5] Notes from presentations by IAEA and NRC officials at the International Conference on the Security of Radioactive Sources, Vienna, Austria, March 11-13, 2003.
[6] Crispin and Fields, "Thai's Arrest Deepens Terror Fears." (see footnote [3])
[7] Wassayos Ngarmkham, "Cesium Suspect Says Agent Working for US Framed Him," Bangkok Post, June 22, 2003,
[8] Wassayos Ngarmkham, "Confiscated Cesium Passed through Air Marshal's Hands," Bangkok Post, June 18, 2003, [].
[9] Wassayos Ngarmkham, "Lao Connection Seen in 'Dirty Bomb' Case," Bangkok Post, June 17, 2003, []
[10] "Laos Denies Smuggling of Radioactive Material," MSNBC website,
[11] "CIA Uncovered Thai Nuclear Material,", July 15, 2003.
[12] See, for example, the extensive information on cesium-137 in Charles D. Ferguson, Tahseen Kazi, and Judith Perera, Commercial Radioactive Sources: Surveying the Security Risks, Occasional Paper No. 11, CNS, January 2003;
[13] "U.N. Suspects Trafficking in Dirty Bomb Material," Reuters website,
[14] David Filipov, "Georgia Seizes 'Dirty Bomb' Materials," Boston Globe, June 17, 2003, page A4.
[15] Abel Gonzalez, "Strengthening the Safety of Radiation Sources and the Security of Radioactive Materials: Timely Action," IAEA Bulletin, 41/3/1999, p. 4;
[16] CIA, "Terrorist CBRN: Materials and Effects (U)," May 2003;
[17] Nick Hopkins and Suzanne Goldenberg, "MI5 Says Dirty Bomb Attack is Inevitable," The Guardian, June 18, 2003;,12780,979696,00.html?=rss.

July 17, 2003

This article is part of a collection examining reported incidents of nuclear or radioactive materials trafficking in or originating from the Newly Independent States.

This material is produced independently for NTI by the James Martin Center for Nonproliferation Studies at the Middlebury Institute of International Studies at Monterey and does not necessarily reflect the opinions of and has not been independently verified by NTI or its directors, officers, employees, or agents. Copyright 2019.