Radioactive material released from

Airborne poisons in the nuclear weapons progam were not limited to radioactive materials released from weapons. The weapons technology involved the use of many exotic materials, some of which were toxic (e.g., beryllium). Hazardous releases of these materials occurred in industrial settings in urban areas and were studied by the Atomic Energy Commission as occupational and public health problems. 

NRC. 1993b. Radioactive materials released from nuclear power plants Annual report 1993. Washington, DC U.S. Nuclear Regulatory Commission. NUREG/CR-2907. BNL-NUREG-51581. 

The radioactive material released from the repository is carried to a drinking water well or... 

Requirements to Radioactive Materials Releases from CEFR... 

Radioactive materials released to the environment are sources of exposure and potentially harmful. Such releases may be from different activities in the nuclear fuel cycle, mining operations or industrial users. Strict control measures must be employed to keep the resulting doses as low as reasonably achievable . This implies the implementation of protective and control measures and includes the setting of limits for radiation exposure. 

The Chernobyl accident involved the largest short-term release from a single source of radioactive materials to the atmosphere ever recorded. Of the materials released from the reactor core, four elements have dominated the short-term and long-term radiological situation in the affected areas of the USSR iodine (primarily caesium ( Cs, Cs), strontium (primarily Sr) and plutonium ( Pu, " Pu). In addition, highly radioactive fuel fragments (hot particles) were released. 

In the United States, commercial nuclear power plant operators are required to monitor and report any detectable quantities of radioactive materials released to the environment (NRC 1996). Table 6-1 summarizes releases of radiostrontium isotopes with half-lives >8 hours to the atmosphere and water for 1993 from PWR and BWR nuclear power plants. Nearly all of the radioactive material reported as released in effluents are from planned releases from normal plant operation or anticipated operational occurrences. The latter includes unplanned releases of radioactive materials from miscellaneous actions such as equipment failure, operator error, or procedure error, and are not of such consequence as to be considered an accident (NRC 1993b). 

Another apparatus, which permits the recording of simultaneous ETA. DTA. and TG DTG. is shown in Figure 8.50 (192). The system consists of a commercial DTA apparatus and thermobalance manufactured by Netzsch-Geratebau, Selb, West Germany. For ETA measurements, an inert carrier gas is passed over the sample S and the standard material I situated in the isothermal region of the furnace F. The radioactive emanation released from the sample is carried into a measuring cell. The alpha-activity of the emanation E is counted by means of a silicon surface barrier detector D connected... 

Anthropogenic radioactive contamination of the marine environment has several sources disposal at sea, discharges to the sea, accidental releases and fallout from nuclear weapon tests and nuclear accidents. In addition, discharge of naturally occurring radioactive materials (NORM) from offshore oil and gas production is a considerable source for contamination. 

It is evident from Table 13.4-1 that the HCF ventilation system is the safety-related SSC whose human-machine interfaces are the most numerous and also the most critical with respect to preventing uncontrolled off-site radioactive material releases. This system thus warrants close operator attention. Ventilation system fans and dampers are operated from the EMCS keyboard located in the Operations Center. The following HCF ventilation system displays and alarms are input to the EMCS display monitor ... 

The Zone 1 exhaust fan inlet volume control damper is manually set to maintain the total SCB exhaust flow rate in order to achieve the necessary residence time for exhaust gas in the charcoal filters. This ensures that radioactive iodine is removed from the Zone 1 exhaust gas before the exhaust gas is released to the environment. An alarm is provided to alert the operations staff if the flow rate exceeds the established setpoint. Should this occur, HCF operations personnel will investigate the reason(s) for the abnormal condition and take appropriate corrective action, which may include re-adjustment of the volume control damper. Since such an occurrence is not an initiator for a radioactive material release event, operator action is an appropriate response. In addition, certain activities in the SCBs may be curtailed until the condition is corrected. 

The transport of the fuel aerosols and fission products from the cover gas to the various cells of the reactor building and to the environment is calculated with the CONTAIN-LMR. Papers on this code were presented during the IWGFR TCM [ref 4] on "Evaluation of Radioactive Materials Release and Sodium Fires in Fast Reactors". 

The safety issues of nuclear energy systems are discussed sometimes from the viewpoint of the inherent and passive safety characteristics of the system. The essential safety question concerning FRs is how to avoid radioactive material release to the environment during meltdown of the core. 

The analysis of the accident progression from core damage to radioactive material release should model the significant phenomena which challenge the integrity of the containment or influence the release of radioactive material. These phenomena are identified in para. 4.113 and are described more fully in the literature (see, for example, IAEA and OECD NEA reports on Level 2 PSA, Refs [11,12], respectively). 

TSR means the conditions, safe boundaries, and the management, or administrative controls (ACs) necessary to ensure the safe operation of a nuclear facility and to reduce the potential risk to the public and facility workers from uncontrolled releases of radioactive materials or from radiation exposures due to inadvertent criticality. A TSR consists of safety limits, operating limits, surveillance requirements, ACs, use and application instructions, and the basis thereof. 

Xe, Kr and tritium (T) that are released from molten salt fuel could be effectively trapped in an activated charcoal bed and/or other trapping materials. The container vessels in which the trapping equipment is installed have thick and heat-resistant steel walls and they can be isolated from the off-gas lines by passively operating valves. The production rate of T is estimated at about 6.2><10 Bq/(100 MW day) in normal operation. More than 90% of the T is transferred into the secondary coolant salt and finally, about 98% of the T is transferred to the trapping equipment through an off-gas line [XXX-22]. In this way, the hazard of radioactive gas release from the core under internal and external events and combinations thereof can be decreased ... 

On the basis of the data obtained from the investigation of the region, the possible atmospheric dispersion of any radioactive material released shall be... 

The Chernobyl nuclear accident in 1986 resulted in the largest radiation exposure in recent history. The radioactive materials released contained high levels of radioactive iodine (particularly, with a half-life of 8 days), an element that accumulates in the thyroid gland as a component of thyroid hormone. Following the explosion, people were exposed to deadly radioactive materials estimated to be 100 times greater than that associated with the detonation of the atomic bomb over Hiroshima. In Belarus, thyroid cancer in children under 18 increased from an incidence of 0.03-0.05 cases per 100,000 (1986-1988 data) to more than 10 times that level (5-8 cases per 100,000) in the period 1993-2002. Increases in thyroid cancer also were noted in Ukraine, with rates going from 0.02 per 100,000 (1986-1988 data) to 5-10 times that level (1-2.2 per 100,000) over the period from 1993-2002 (Reiners et al., 2013). There is little doubt that Chernobyl radiation exposure caused thyroid cancer among children in the affected area. 

Several modes of waste management are available. The simplest is to dilute and disperse. This practice is adequate for the release of small amounts of radioactive material to the atmosphere or to a large body of water. Noble gases and slightly contaminated water from reactor operation are eligible for such treatment. A second technique is to hold the material for decay. This is appHcable to radionucHdes of short half-life such as the medical isotope technetium-9 9m = 6 h), the concentration of which becomes negligible in a week s holding period. The third and most common approach to waste... 

Releases of radioactive materials from nuclear power plants have occurred, as at Three-Mile Island, Pennsylvania. In such situations, releases may be sufficient to require evacuation of residents. 

---