KR100935159B1 - System for Evaluating Safety of Transporting Nuclear Waste on the sea - Google Patents

Abstract

The present invention relates to a radioactive waste marine safety evaluation system, specifically, to set the transport conditions according to the various sea transport routes to predict the exposure dose and the likelihood of accidents occurring in the transport process and radioactive waste for each transport route The present invention relates to a marine transportation safety evaluation system for evaluating marine transportation safety so that radioactive waste can be safely transported through a secure transportation route.

Safety evaluation system according to the present invention comprises a transport condition selection module for determining each transport condition according to the sea transport; A data input module in which the transport condition data determined by the transport condition selection module is input and processed; A risk assessment module for evaluating risk for each transport condition from data input to the data input module; A comparison evaluation module for comparing the results according to the respective transport conditions of the risk assessment module; And a safety evaluation module for calculating an optimal safe transport condition from the result from the comparative evaluation module.

Radioactive waste, maritime transport, safety assessment, risk

Description

System for Evaluating Safety of Transporting Nuclear Waste on the sea}

The present invention relates to a radioactive waste transport safety evaluation system, specifically, to set individual transport conditions according to various sea transport routes to predict individual and collective exposure doses and the likelihood of accidents occurring in the transport process, The present invention relates to a marine transport safety evaluation system for evaluating the safety of radioactive wastes for transporting radioactive wastes so that radioactive wastes can be transported through a safe transport route.

Ensuring safety in the transport of radioactive waste is a prerequisite that must be taken into account during the transport process due to the risk of radioactivity. In order to ensure safety, measures must be taken to ensure that all relevant personnel comply with safety rules and protect residents and the environment from radiation hazards that may occur during transport. Although a number of factors must be considered in evaluating radioactive waste safety, the assessment of the radiation dose of workers and inhabitants with radiation safety is one of the important factors for predicting the impact on the safety and environment of the inhabitants. In activities involving radiation exposure, such as the transport of radioactive waste, the exposure dose should be kept as low as reasonably possible. The International Atomic Energy Agency's Safety Assessment Regulations for the Safe Transport of Radioactive Materials require that safety assessments, which assess the radiological effects of transport that may have on transport workers, routes and residents living in the vicinity of the transport routes, should be carried out prior to transport operations.

Radioactive waste may be carried by land, sea or air routes. Although it is easy to use land, it is inevitable to pass through the area where the inhabitants live. On the other hand, sea transport has the advantage that the general exposure dose due to transport is relatively small because it can carry a large amount of radioactive waste, and transport is carried out at nuclear power plant sites, facility sites, and the sea which are inaccessible to the general public. However, if an accident occurs during sea transportation, the risk of nuclide spreading into the ocean increases and the area of damage may increase. The air route has the advantages of rapid transportation and reduced radiation dose, but has the problem of high cost and limited availability.

Various computer interpretive codes are used in each country to evaluate the risk of transporting radioactive waste. The risk assessment code evaluates the individual and group dose rates received by the general public and workers during normal transport and the potential risks for radiation exposure subjects in case of virtual accidents. Such risk assessment codes include, for example, the CONDOR code in the UK, the INTERTRAN code in France and the RADTRARAN code in the USA. The CONDOR code evaluates the risk by calculating the exposure dose, and the RADTRAN code has the characteristics of assessing the risk by applying half-life, particle energy and nuclide characteristics. The RADTRAN code, the world's most widely used, is useful for calculating the radiation doses of radiation workers and locals for radioactive material transport and virtual accident conditions.

The radiological risk and safety assessments provide basic data on the transport conditions by evaluating the radiological effects on different transport conditions for each transport condition. Therefore, prior work on risk and safety assessments is required to carry out the safe transport of radioactive waste. It is important. For radioactive waste dumping, the risks and safety depend on the route due to the different routes available. On the other hand, in the case of sea transportation, the transport route is limited but the weather dependence is high because it is sensitive to the weather conditions. As such, the specific gravity of factors affecting the safety evaluation may be different according to the transport route, so the safety assessment of the radioactive waste needs to be conducted in the most suitable manner for each transportation method.

The present invention proposes a marine transport safety evaluation system for radioactive waste. In the case of maritime transport, the radiological effects on workers and crew should be considered first, rather than the direct radiation effects on the general population during transportation. In addition, it is characteristic that the impact of weather conditions on transportation is large, and in case of an accident, it is difficult to cope and the damage area is likely to be expanded. The maritime transport safety assessment system should therefore be able to fully assess the risks of these factors.

An object of the present invention is to determine a marine transport safety evaluation system that can determine the various types of risk factors according to the sea transport of radioactive waste and to evaluate the sea transport safety according to the risk factors to determine the radioactive waste transport method To provide.

According to a suitable embodiment of the present invention, the radioactive waste marine transport safety evaluation system includes a transport condition selection module for determining respective transport conditions according to the sea transport; A data input module in which the transport condition data determined by the transport condition selection module is input and processed; A risk assessment module for evaluating risk for each transport condition from data input to the data input module; A comparison evaluation module for comparing the results according to the respective transport conditions of the risk assessment module; And a safety evaluation module for calculating an optimal safe transport condition from the result from the comparative evaluation module.

According to another suitable embodiment of the present invention, the risk assessment module evaluates the risk for each transport condition based on the radioactive waste transport dose rate in the event of an accident and the exposure dose in the case of normal transport.

According to another suitable embodiment of the invention, in the event of an accident the radioactive waste marine transport dose rate is measured by determining the type of accident on the basis of a predetermined risk factor.

Marine transport safety evaluation system according to the present invention has the advantage that the radioactive waste can be transported through the sea route in a safe transport conditions. In addition, the various risk factors that occur during the actual transport process is reflected in the safety evaluation process has the advantage that the measures for safe transport can be further strengthened.

The invention is described in detail below with reference to the accompanying drawings and by presenting embodiments. The examples presented are for a clear understanding of the invention and are not intended to limit the scope of the invention.

In order to ensure safety, the sea transport of radioactive waste should be carried out according to a predetermined method through the designated sea route. For this purpose, the transport means, transport route, transport date and time and transport control means should be determined first. In the case of radioactive waste transport, the general exposure dose to the inhabitants due to transportation is very small. However, if an accident occurs during sea transport, the risk of nuclide spreading into the ocean can be increased, so the risk of radionuclide leakage due to an accident in radioactive waste marine transport becomes an important factor for evaluation. Radioactive waste is measured by radioactive group doses according to the type of package, and these data can be used as basic data for establishing transport conditions for safe sea transport. In the case of radioactive waste transport, another factor in risk assessment is the radiation exposure for workers engaged in transport and for crew working in transport ships. In the present specification, the worker includes a worker who performs loading and unloading work.

Radioactive waste Unlike seaborne transport, accidents at sea rarely lead to direct leakage of radioactive material due to breakage of radioactive waste containers. Moreover, the frequency of accidents at sea is less than by land, making it difficult to predict accidents. Therefore, accidents and navigational data already carried out at home and abroad can be used as important reference data.

In the transport of radioactive waste, the transport from the source of the radioactive waste to the marina should be based on the safety assessment of the land transport and the sea transport safety assessment on the route from the place of shipment to the disposal site of the repository. In most cases, however, maritime transport means the shortest land transport and most maritime transport. Sea freight in this specification includes such short-range land transport, but does not disclose a specific long-range land transport safety evaluation system. However, the embodiment shown in FIG. 1 may be applied for land transportation safety evaluation by applying necessary modifications.

Figure 1 schematically shows a safety evaluation system that can be applied to the radioactive waste transport in accordance with an embodiment of the present invention.

Referring to FIG. 1, the radioactive waste transportation safety evaluation system includes a central management server 10, a safety evaluation program 11, and a database 12. Although not shown, the central management server 10 includes an input / output device, a central processing unit (CPU), and a memory device. Since the input / output device, the central processing unit, and the memory device are commonly used in the central management server 10, detailed description thereof will be omitted. The safety evaluation program 11 includes a transport condition selection module 111, a data input module 112, a risk evaluation module 113, a comparative evaluation module 114, and a safety evaluation module 115. The safety evaluation program 11 is stored in the memory device and executed through the central processing unit. The database 12 is formed by storing data in a memory device.

The safety evaluation program 11 has a function of receiving the conditions of transport as data, evaluating the risks according to the transport conditions, and comparing the risks according to the possible transport conditions to calculate the best safe transport conditions. Specifically, the transport condition selection module 111 selects each transport condition according to the transport object, the packing state, the type of ship and the sea route, and the sea transport including the crew and the workers. The data input module 112 receives a transport condition data including a condition selected by the transport condition selection module through an input device. The input data includes the waste to be transported, the route to be transported, the container, the carrier, the number of ships entering and leaving, the number of passengers per vessel, unloading and loading, and the rate of accidents. The waste to be transported includes such items as general compressed packages, ultrahigh-pressure repackages, concentrated waste liquors, waste resins, and waste filters, and the route to be transported includes specific routes such as offshore, special ship routes and offshore. Data on the packaging includes internal dose doses, spaced dose rates and the number of drums loaded. Data on the hauling vessels include the number of occupants, the number of ships per year, the carrying capacity once, the size of the hold, the dose rate of 1m apart and the dose rate inside the ship. The data on unloading and loading includes matters relating to anchoring time, number of workers and work time. The risk assessment module 113 functions to assess the risk according to a given transport condition based on the input data. Risk assessment is a method of calculating both the exposure dose according to whether or not the species spreads to the ocean in the event of an accident and the exposure dose in the case of normal transportation, and weighting the risk based on the probability of occurrence of the accident and the probability of spreading the species. Can be done. In the case of radioactive waste transport, the general exposure doses to the inhabitants need not be calculated separately because they are very small or indirectly affected by the proliferation of nuclides. On the other hand, radiation exposures for workers engaged in transport in sea transport and for crew members in transport ship operations can be estimated to be significantly higher than for land transport due to the limited area of activity. Risk assessments for such sea transport are based on dose rates due to the spread of nuclide effluents and exposures to workers and sources. For example, a RADTRAN code or an INTRANRAN code may be used to calculate the dose rate and the exposure amount. The comparative evaluation module 114 compares the risk for each transport condition by applying the calculated risk data. The comparative evaluation module 114 may further compare and evaluate each transport condition, including other factors affecting the transport, such as cost, possible operating speed or weather conditions. The safety evaluation module 115 calculates an optimum safety transport condition during actual transport from each of the compared transport conditions and outputs the same through the output device. The data input to the safety evaluation program 11 and the output of the calculated result may be performed according to a manager's management work in the central management server. In addition, the input data and output for each module is stored in a separately installed database 12 to be used as a variety of data in the future.

2 schematically illustrates a process of virtually calculating the radioactive waste transport dose in order to evaluate the risk in the event of an accident.

Referring to Figure 2, in order to evaluate the radioactive waste transport risk, the conditions for the target carrier must first be determined (S21). Conditions relating to the object carrier may include such things as the quantity of the package, the type of package and the type and capacity of the container. Once the target cargo is determined, the vessel type and transport route for transport should be determined (S22). Once the basic matters of such transport are determined, safety evaluation according to the transport route is possible. Risk factors should be determined for safety assessment. Risk factors may include, for example, bad weather occurrences, marine algal flows and the presence of accidents. The probability of occurrence of an accident for each type is calculated based on the risk factors (S23). In addition, an accident condition for each type is assumed to calculate the exposure dose according to the occurrence of the accident (S24). Prediction of the spread and form of the nuclide to the ocean under the given fictitious accident conditions (S25), and the concentration of the nuclide in the ocean is predicted (S26). Modeling of ocean currents and oceanic diffusion can be used to predict ocean concentrations of nuclides. The external effective dose and the internal effective dose are evaluated from the predicted nuclide concentration (S27), and the final dose is comprehensively determined to evaluate the risk (S28).

If a ship is in shallow water, it can be recovered if the ship is sunk due to a collision or fire and the packaging has been lost to the sea floor. In addition, even if lost to the seabed and the packaging is difficult to recover, the release rate of radioactive material is very small and the expected dose from exposure to exposed seafood is negligible compared to the natural radiation dose. In addition, the incidence of accidents by sea transport is very low, making it difficult to estimate the probability of accidents based on the cases of accidents. Therefore, risk assessment based on specific data is difficult.

In the event of an accident, risk calculation programs such as the RADTRAN code and the INTERTRAN code can be applied by deriving an accident scenario according to the transport situation in order to measure the spread of the nuclide into the ocean and the concentration of the spread species. have. In addition, modeling of ocean currents and modeling of ocean diffusion may be used for estimating nuclide concentration in the ocean (S26).

If, for example, the Radtran code or the INTERTRAN code is used to derive an accident scenario, it is possible to provide data that can be variables such as pre-set transport conditions, transport materials and conditions and information around the site of the accident. You can enter to get an accident scenario. When data is entered into the Radtran code, probable accident scenarios, outcomes and risks are calculated. In addition, radioactive leakage frequency is calculated by referring to statistical data, and radioactive leakage rate is calculated. In addition, data such as ocean current modeling yield nuclide proliferation in the ocean. The release of radioactive material in a simulated accident can be estimated from the inventory of the package and the simulated leak rate. Through this process, the radiological risk of the transport accident is evaluated by synthesizing the data. To calculate the probability of accident occurrence, statistical data on the occurrence of accidents in marine traffic can be used. And in the event of an accident, radioactive releases are estimated from inventory inventory and virtual leak rates.

The RADTRAN code can also be used to calculate worker and community exposure doses for radioactive material transport and virtual accident conditions. The RADTRAN code allows you to analyze and evaluate the probabilistic effects of exposure doses using nuclide characteristics such as half-life, particle energy and internal dose conversion factor. Another advantage of Radtran code is its interoperability with INTERTRAN. When data is entered into the RADTRAN code, the accident result, the situation and the degree of danger are calculated according to the setting situation. In this case, the main input variables are the package type of radioactive material, the quantity of the package, the number of shipments per year, the amount of radioactivity in the package, the delivery index, the delivery distance and the transport situation. These RADTRAN codes can be used for the calculation of the exposure doses for shipping workers and operating personnel at the destination.

3 is a diagram schematically illustrating a process of calculating the exposure dose and the risk in the case of normal transportation.

Referring to FIG. 3, a transport material and a packaging state are first determined in order to evaluate an exposure dose and a risk (S31). Thereafter, various possible transport routes are set (S32) and the exposure targets for each transport route are assumed (S33). The exposure dose for the exposure target is then calculated (S34). The transport route can be largely divided into coastal, special ship route and territorial sea area, and can be determined by subdividing each area in detail. Subjects may include workers and ship crews at the radioactive waste loading site. In maritime transport, the calculation of exposure doses for inhabitants adjacent to the route is optional. If the transport route chosen does not need special consideration or if the value is small enough to be negligible, the dose to the population will not be calculated. In addition, if indirectly affecting farms or residents, for example by fish or in particular, current doses can be calculated for the population. Finally, the risk and safety for each route are evaluated based on the calculated dose (S35).

Although the safety evaluation according to the accident occurrence and the safety evaluation according to normal transportation have been separately described above, when the radioactive package and the transport route are determined, two safety evaluations are performed at the same time. The two safety assessments are then combined to assess the safety of the selected transport route. And based on this assessment, the optimal ocean transport for a particular radioactive package can be determined.

The marine transport safety evaluation system according to the present invention utilizes various data to evaluate safety and to obtain transport conditions with optimal safety. In particular, the risks of marine accidents are evaluated through the assumption of accidents, and the optimum conditions are obtained in advance to enable safe transportation. Based on the safety assessment, new risk factors may arise during the transport of radioactive waste along the optimal safety pathway. In such cases, safety assessments can be made again on the basis of the new risk factors and the optimal safety transport route can be determined again. As described above, the safety evaluation system according to the present invention can efficiently cope with newly generated radioactive waste transport conditions by providing feedback to the dangerous situation or risk factors occurring in the actual transport process.

The present invention has been described above in detail by using an embodiment. The presented embodiments are exemplary and can be made by those skilled in the art to various modifications and modifications to the disclosed embodiments without departing from the spirit of the present invention. The scope of the invention is not limited by these modifications and variations, but only by the claims appended below.

Figure 1 schematically shows a safety evaluation system that can be applied to the radioactive waste transport in accordance with an embodiment of the present invention.

2 schematically illustrates a process of virtually calculating the radioactive waste transport dose in order to evaluate the risk in the event of an accident.

3 is a diagram schematically illustrating a process of calculating the exposure dose and the risk in the case of normal transportation.

Claims (3)

A central management server having an input / output device, a central processing unit, and a memory device; And A safety evaluation program including a transport condition selection module, a data input module, a risk evaluation module, a comparative evaluation module, and a safety evaluation module is stored in a memory device of the central management server and executed through the central processing device. Include, The transport condition selection module selects transport conditions according to the sea transport including the object to be transported, the state of packaging, the type of ship and the sea route, and the crew and workers, The data input module receives data on the conditions selected by the transport condition selection module through the input device. The risk assessment module evaluates the risk for each transport condition based on the radioactive waste shipping dose rate in case of an accident and the exposure dose in the case of an accident from the data input to the data input module. The comparative evaluation module compares the results according to the respective transport conditions of the risk assessment module, The safety evaluation module calculates an optimal safe transport condition from the result of the comparative evaluation module, The radioactive waste marine transport dose rate of the radioactive waste marine transport safety evaluation system, characterized in that calculated by the risk assessment module to determine the type of accident based on a predetermined risk factor. delete delete

Images