Glossary

Rad

Radiation Absorbed Dose. The rad is a largely obsolete unit of absorbed radiation dose, with symbol rad. First proposed in 1918, the rad was "that quantity of X rays that, when absorbed, will cause the destruction of the [malignant mammalian] cells in question..." The rad is now superseded in the SI by the gray; 100 rad are equal to 1 gray.

Radiation

Energy emitted from an atomic nucleus in the form of electromagnetic waves or subatomic particles in a process of radioactive disintegration or radioactive decay.
Major forms are alpha-, beta- and gamma-radiation.

Radiation syndrome (also called radiation sickness)

The complex of symptoms characterizing the disease known as radiation injury, resulting from excessive exposure of the whole body (or large part) to ionizing radiation. The earliest of these symptoms are nausea, fatigue, vomiting, and diarrhea, then loss of hair, hemorrhage, inflammation of the mouth and throat, and general loss of energy. In severe cases, where the radiation has been approximately 1,000 rad or more, death may occur within two to four weeks. Those who survive six weeks after the receipt of a single large dose of radiation to the whole body may generally be expected to recover.

Radioactive contamination

Deposition of radioactive material in any place where it may harm persons or equipment.

Radioactive decay

The progressive decrease in the amount of radioactive material in a sample due to the spontaneous disintegration of unstable atomic nuclei.  In the course of this process, energy is emitted in the form of particles or electromagnetic waves. The decay process has a definite half-life which can last from a few microseconds to billions of years.

Radioactive fallout

The deposition of minute radioactive particles in the atmosphere following a nuclear explosion or discharged from nuclear-power and atomic installations.

Radioactive particle

A particle that exhibits spontaneous emission of radiation either directly from unstable atomic nuclei or as a result of a nuclear reaction.

Radioactive particles

A particle that exhibits spontaneous emission of radiation either directly from unstable atomic nuclei or as a result of a nuclear reaction.

Radioactive waste

Materials which are radioactive and for which there is no further use.

Radioactivity

The spontaneous emission of radiation, generally alpha or beta particles, often accompanied by gamma rays, from the nucleus of an unstable isotope; also, the rate at which radioactive material emits radiation.

Radioisotope

An unstable isotope of an element that decays or disintegrates spontaneously, emitting radiation. Approximately 5000 natural and artificial radioisotopes have been identified.

Radiological dispersal device (RDD)

A device that involves radioactive materials and some method by which those materials can be spread over a wide area. It can be a variety of sizes, and the radiation can cause contamination, economic and some physical harm. One type of RDD is the popularly named "dirty bomb." A dirty bomb uses the force of conventional explosives, such as TNT, to scatter radioactive material.

Radiological terrorism

Terrorist acts carried out either by attacking a nuclear facility or through malicious use of a radiological device.

Radiological weapons

Devices that release radiation with the intent of inflicting severe injury or financial and psychological costs. The radiological isotopes used to produce radiological dispersal devices are found in waste from medical facilities, industrial plants, and nuclear power plants.

Radionuclide

An isotope with an unstable nucleus that disintegrates and emits energy in the process. Radionuclides may occur naturally, but they can also be artificially produced. Radionuclides are often called radioisotopes.

Radionuclide laboratories

Provide independent analysis of radionuclide particulate samples. Only samples with specific radionuclides that may point to a nuclear explosion are sent to radionuclide laboratories for repeat measurements. The laboratories also conduct regular quality control analysis of routine samples from all radionuclide monitoring stations. Being part of the International Monitoring System, the 16 radionuclide laboratories are located in 16 countries worldwide.

Radionuclide laboratory

Provide independent analysis of radionuclide particulate samples. Only samples with specific radionuclides that may point to a nuclear explosion are sent to radionuclide laboratories for repeat measurements. The laboratories also conduct regular quality control analysis of routine samples from all radionuclide monitoring stations. Being part of the International Monitoring System, the 16 radionuclide laboratories are located in 16 countries worldwide.

Radionuclide monitoring

A technology that detects radioactive particles released from atmospheric explosions or vented from underground and underwater explosions. Please see also Xenon.

Radionuclide network

A network of 80 globally distributed radionuclide monitoring stations.  The stations enable a continuous worldwide observation of aerosol samples of solid radionuclides or radionuclide particles.  As part of an experiment to increase the efficiency of radionuclide monitoring, half of these stations are equipped with noble gas monitoring technology to measure radioactive noble gases generated by nuclear explosions.

Radionuclide particles

A dust particle which carries solid radionuclides, i.e. isotopes with unstable nuclei that lose energy by emitting radiation.

Radionuclide station

A monitoring station to detect radionuclide particles in the air. A radionuclide monitoring station contains an air sampler, detection equipment, computers and a communication set-up. At the air sampler, air is forced through a filter, which retains most particles that reach it. The used filters are processed and resulting gamma radiation spectra are sent to the IDC for further analysis. 40 stations are equipped with radionuclide noble gas technology to detect the abundance of the noble gas xenon in the air.

Radionuclide stations

Monitoring stations to detect radionuclide particles in the air. Radionuclide monitoring stations contain an air sampler, detection equipment, computers and a communication set-up. At the air sampler, air is forced through a filter, which retains most particles that reach it. The used filters are processed and resulting gamma radiation spectra are sent to the IDC for further analysis. 40 stations are equipped with radionuclide noble gas technology to detect the abundance of the noble gas xenon in the air.

Radionuclides

Isotopes with an unstable nucleus that disintegrates and emits energy in the process. Radionuclides may occur naturally, but they can also be artificially produced. Radionuclides are often called radioisotopes.

Radioxenon

Radioactive isotope of Xenon, a chemical element in gaseous form. It is called a noble gas since it is inert and rarely reacts with other chemicals. Several radioactive isotopes of this chemical element can only be produced by a nuclear reaction and are therefore measured to detect clandestine underground nuclear explosions. These isotopes are xenon-131m, xenon-133m, xenon-133 and xenon-135. See also Radionuclide monitoring and noble gas.

Rapacki Plan

A proposal to establish a zone free of nuclear weapons in Central and Eastern Europe named after the Polish foreign minister, Adam Rapacki, in 1958. This plan sought to initially keep nuclear weapons from being deployed in Poland, Czechoslovakia, West Germany, and East Germany, but other European countries would have the opportunity to accede. Although the plan was not negotiated seriously due to the Cold War security environment, several elements of the Rapacki Plan were later adopted as guidelines for the establishment of denuclearized zones.

Ratification

The implementation of the formal process established by a country to legally bind its government to a treaty, such as approval by parliament. The country then submits the required legal instrument of ratification of the treaty's depositary governments. In the case of the CTBT, Signatory States must deposit their instrument of ratification with the UN Secretary-General in order to officially ratify the Treaty.

Ratifications

The implementation of the formal process established by a country to legally bind its government to a treaty, such as approval by parliament. The country then submits the required legal instrument of ratification of the treaty's depositary governments. In the case of the CTBT, Signatory States must deposit their instrument of ratification with the UN Secretary-General in order to officially ratify the Treaty.

Ratified

Ratification is the implementation of the formal process established by a country to legally bind its government to a treaty, such as approval by parliament. The country then submits the required legal instrument of ratification of the treaty's depositary governments. In the case of the CTBT, Signatory States must deposit their instrument of ratification with the UN Secretary-General in order to officially ratify the Treaty.

Ratify

Ratification is the implementation of the formal process established by a country to legally bind its government to a treaty, such as approval by parliament. The country then submits the required legal instrument of ratification of the treaty's depositary governments. In the case of the CTBT, Signatory States must deposit their instrument of ratification with the UN Secretary-General in order to officially ratify the Treaty.

REB

Reviewed Event Bulletin. A bulletin listing events built from waveform data that have been reviewed by a human analyst.  Using the Standard Event List 3 (SEL3) as the basis, the analyst corrects erroneously identified events and lists them in the REB.

Regime

An institution in which rules or practices (sometimes memorialized in a treaty or convention) are generally accepted by a group of states to help them work together in an otherwise anarchic world.

Relative timing accuracy

The allowable timing difference between any two sensor elements at a single station.

Resolution

The theoretical minimum change that a digital system can sense.

Reviewed Event Bulletin (REB)

A bulletin listing events built from waveform data that have been reviewed by a human analyst.  Using the Standard Event List 3 (SEL3) as the basis, the analyst corrects erroneously identified events and lists them in the REB.

Reviewed Radionuclide Report (RRR)

A bulletin listing radionuclide analysis results after the review by an analyst. Using the automatically produced list of radionuclide events, the Automatic Radionuclide Report (ARR), the analysts reviews the listed radionuclide detections for their significance and accuracy and corrects erroneous results. The categorization level of the spectrum is also included.

Richter scale

A scale to quantify the amount of seismic energy released by an earthquake. The scale is named after seismologist Charles Richter who developed the scale in 1935.  Based on a logarithmic scale, each whole number in the Richter scale represents a ten-fold increase in magnitude.  This means that the waves of a magnitude 5 earthquake are ten times bigger than the waves causing a magnitude 4 earthquake.

Robert Oppenheimer

U.S. physicist who oversaw the development of the world's first nuclear weapon in the U.S. Manhattan Project from 1942 - 1945, achieving him nation-wide recognition as the "father of the A-bomb". After the war, he was Chairman of the General Advisory Committee to the U.S. Atomic Energy Commission. In this function, he advocated international control of atomic energy and opposed the the development of the H-bomb. This and his alledged sympathy to Communism led to the revocation of his security clearance in 1954. Political rehabilitation followed in 1963 with U.S. President John F. Kennedy awarding Oppenheimer the Enrico Fermi Award.

ROV

Remotely operated vehicle. A submersible “robot” vehicle equipped with a video camera used to monitor underwater hydroacoustic installations.

RRR

Reviewed Radionuclide Report.  A bulletin listing radionuclide analysis results after the review by an analyst. Using the automatically produced list of radionuclide events, the Automatic Radionuclide Report (ARR), the analysts reviews the listed radionuclide detections for their significance and accuracy and corrects erroneous results. The categorization level of the spectrum is also included.

Russel-Einstein Manifesto

Issued by Bertrand Russell on July 9 1955, the Manifesto underscored the great peril of nuclear weapons.  It also urged world leaders to find peaceful solutions to international disputes. Albert Einstein was one of the eleven signatories of the Manifesto, signing the document just days before his death. It was his last major act for peace. Other signatories were Max Born, Perry W. Bridgman, Leopold Infeld, Frederic Joliot-Curie, Herman J. Muller, Linus Pauling, Cecil F. Powell, Joseph Rotblat and Hideki Yukawa. Almost all of these men had already received or would receive the Nobel Prize. The Manifesto was subsequently endorsed by thousands of scientists from many countries. The Pugwash Conferences on Science and World Affairs Movement, which were the direct outcome of the Russell-Einstein Manifesto, carry out their activities in the spirit of the Manifesto to this day.