RU2158010C2 - Environment radiation monitoring and personal radiation control system - Google Patents

Abstract

FIELD: radiation monitoring facilities. SUBSTANCE: system employs personal dosimeters of its users incorporating means for radio communication with regional station. UserТs personal dosimeter enters in communication with regional station as soon as its measuring transducer detects abnormally high radiation level within area where its owner resides. Regional station is provided with means for spatially spread reception of signals coming from usersТ dosimeters enabling detection of their location. Two operating thresholds of detector system make it possible for system to establish communication without direct attention of personal dosimeter owners. The latter are informed about high radiation background only in case radiation hazard really exists. So, proposed system enables detection of high-radiation areas in the framework of usual activities of personal dosimeter owners using this system and sending of relevant information to regional station. EFFECT: improved reliability of warning personal dosimeter owners about abnormal radiation situation.

Description

 1. Field of technology.

 The invention relates to radiation monitoring and personal dosimetry and is intended to monitor the radiation situation in one or more extended areas when using personal dosimetry.

 2. The prior art.

 A known system for monitoring the radiation situation, containing a system of stations for collecting radiation information distributed over a controlled area with radio communications, ensuring the transmission of the collected information to interested consumers, as well as for prevention [1].

 It is advisable to use such a system close to radiation hazardous facilities such as nuclear power plants for the purpose of prompt warning of radioactive releases and leaks, but it is practically impossible to use it to control random local or temporary radiation hazardous situations, for example, in case of unauthorized dumping of radioactive objects in places accessible to people , or when transporting radioactive materials.

 The closest technical solution is a system for monitoring the radiation situation and personal dosimetry, which contains at least one zone station for collecting and processing radiation data, which includes a radio transmitter and receiver, data processing and storage facilities, a set of personal dosimeters, each of which Transmitter included means for processing and storing dose and dose rate data with threshold means for fixing the maximum allowable dose rate; indicator light and acoustic signaling device; means of two-way radio communication with a zonal station [2]. In this case, the acoustic signaling device turns on when the maximum permissible dose rate is reached.

 This system, due to the presence of radio communications with a zonal station in personal dosimeters, allows, in addition to personal dosimetry, monitoring of the radiation situation at the places of residence of the owners of these devices.

 However, the corresponding function of the system is not complete: there are no means of objectively determining in real time the coordinates of the dosimeter, and, therefore, the coordinates of the place of increased radiation.

 Involving the owners of dosimeters in solving this problem introduces an element of subjectivity in the measurement results, and also opens up the possibility of their deliberate distortion for one or another, in particular criminal, purpose. Even in the best case, involving the owners of individual dosimeters in solving the problem of determining their location requires a change in the nature of their life activities (getting in touch, distracting from current activities, etc.); in addition, the widespread use of this kind of practice can have negative social consequences - panic among the population, which is especially dangerous in large cities and densely populated areas.

 All this significantly limits the performance of the system under discussion [2] as a means of measuring the distribution of radiation over the territory of the controlled zone.

 3. The invention.

 The purpose of the invention is the creation of such a system for monitoring the radiation situation and personal dosimetry, which could ensure the identification of areas with increased radioactivity and measure the full set of their parameters (at least the dose, dose rate, coordinates, time, number of the personal dosimeter) in real time without the participation of a personal dosimeter carrier, i.e., within the framework of his normal life and without his knowledge, if the dose rate does not exceed the maximum permissible level, and when this level is exceeded, the nose The personal dosimeter should be warned about the danger that threatens him in order to take part in actions to overcome it, but not as an intermediary in the process of the above measurements.

 This goal is achieved by the fact that in the radiation monitoring system and personal dosimetry, which contains at least one zone telemetry data collection and processing station and a combination of the primary sources of these data - personal dosimeters, each of which has in its composition means for measuring dose and dose rate operating at the place of stay of the personal dosimeter carrier, alarm means warning the personal dosimeter carrier about the danger that threatens him, and the telemetry channel At least two threshold dose rate personal dosimeters are used to communicate with the zonal station, and the zonal station is equipped with location means of the transmitting personal dosimeter, while the lowest dose rate threshold — the threshold for activating the telemetry link of the personal dosimeter to the zonal station — is selected to exceed the mid-level power level doses, but less than the maximum permissible level of dose rate - the threshold for activating a warning personal alarm.

The components of the invention are not only known, but also widely used in technical solutions that are not analogues of the invention:
B. Personal dosimetry.

 C. Telemetry systems for measuring parameters of mobile objects and radio communications with them, in particular a mobile radiotelephone.

 D. Systems of (passive) location of sources of radio emission - navigation systems.

 E. Differentiation of radiation hazard levels.

 F. Computers, in particular microcomputers, as a means of digital information processing and decision-making for system management.

 It would be more accurate to say that these are fundamental technical terms that refer to principles, on each of which many technical solutions are built, about which many applied theories have been created, many experimental facts have been accumulated, experience in technical operation and commercial implementation.

 However, the authors are not aware of technical solutions in which all these principles would be consolidated to solve the tasks of monitoring the radiation situation, personal dosimetry, and personal radiation safety.

 Not only 5 of the above principles are used in the invention, but their specific implementations can also be used, which are referenced in the description of the invention.

 The system proposed by the authors has the following advantages.

 1. The ability to measure by known means (see section 3.D) in automatic mode the coordinates of a personal dosimeter (hereinafter PD) and its carrier. This turns the PD carrier from a passive object of observation of a personal dosimetry system into an effective tool for a radiation monitoring system and personal dosimetry.

 2. The relevance of monitoring the space controlled by the system: many PD carriers monitor precisely that part of it that people are in and the state of which for this reason is most important to know to ensure their radiation safety.

 3. The system automatically sets the weighting factors for different parts of the probed space: that part of the space where the PD carrier stays longer, is more often measured, ceteris paribus.

 4. Efficiency of the system when using means of communication with PD: the active state of the PD (switching on the radio emitter to determine its coordinates, establishing telemetric communication with the system and transmitting measured data) occurs only when it is significant.

 5. The system implements a “soft” (anonymous, without the participation of the PD carrier) radiation monitoring mode. For this, the activation threshold of the PD telemetric communication channel (the "level of interest" of the monitoring system) should be significantly lower than the radiation safety threshold of the PD carrier. The PD activates when the dose rate has exceeded the “level of interest”, but the activation of the PD does not attract the attention of the PD carrier until the dose rate has reached its maximum permissible level, above which a sound signal is sent warning the PD carrier about the danger.

 6. The system provides an increased level of efficiency in assisting the PD carrier in conditions that threaten his safety. If the increase in dose rate is not the result of an explosion, but arises as a result of the approach of the PD carrier to the source of increased radiation, then by the time the warning signal occurs, the PD is already in the active state, so the PD carrier can connect to the system immediately.

 4. Description of the invention.

4.1. Some terms and their symbols:
PD - personal dosimeter
And - the carrier of a personal dosimeter: a person, a pet, a service dog, cattle, a robot, a wild animal in vivo, etc.

N - number of personal dosimeter
If - background dose rate
K1 - coefficient of permissible excess of background: K1> 1
I1 - dose rate, above which the telemetric communication channel is activated PD-zonal station: I1 = K1 • If
Ir - maximum permissible dose rate level: dose rate beyond which human radiation safety is not guaranteed
I2 - threshold for activating a warning personal alarm: I2 = Ir
Dr = dose beyond which radiation safety of a person is not guaranteed or the dose is probably dangerous to human health
{X} - the set (set) of elements of the same type X. Other terms and notation will be introduced in the description of the corresponding elements of the system.

 4.2. The composition of the system. In the general case, the system consists of several zone stations - {ЗС}, each of which serves one of the zones and is connected with the corresponding set {ПД}. In the particular case, the system can serve only one zone. In terms of the interaction of zonal stations with each other and PD with zonal stations, the system can be constructed according to any of the known schemes of cellular radiotelephone communication systems with mobile objects. For this reason, in the future we will describe a system containing only one zone and, accordingly, only one ZS associated with the corresponding set {PD}.

 4.3. The composition of the AP.

 4. 3. 1. Reception and transmission zone radio station - RZS - such as a cellular telephone station or a satellite radiotelephone communication station for the corresponding number of subscribers.

 4.3.2. A location-based zonal station is an LZS, the most famous analogue of which can be considered a satellite navigation system for driving vehicles, including automatic control of both individual cars and the transport system as a whole (Japan, 1989).

 4.3.3. The zone station for data processing and storage is OXDS, the closest analogue of which is an automated station for listening, analysis, recording and storage of telephone network subscribers' conversations.

 5. The functioning of the system.

 PD measures radiation parameters (dose rate I, total dose Dsum) and presents the measurement data in digital form. Compares I with two dose rate levels I1 and I2.

 If I <I1, then communication with the AP is not performed.

 If I1≤I <I2, then the AP establishes a connection with the AP and transmits information (I, Dsum) without giving a warning sound signal.

 If I> I2, then information (I, Dsum) is transmitted to the AP with the warning sound signal; A standard voice message is transmitted to the PD carrier containing a recommendation on how to behave in this situation, and telephone communication of the PD carrier with the operator of the AP is automatically established.

 AP operates as follows.

 1. With the help of an OSS, in real time, it receives information (I, Dsum) from each AP from the set of {AP}, fixing at the same time its own number of the AP and the moment of the beginning of information transfer: (N, T), and using the LSS determines the coordinates of the AP (x, y, h) at this moment; all information (N, T, I, D, x, y, h) for each of the PD messages is sent further to the OCHDS data processing and storage station.

 2. In special cases (I> I2 and / or Dsum> Dr) supports two-way telephone communication between the PD and the AP, which can be initiated by both the carrier of the AP and the operator of the AP, while all telephone conversations are recorded in OXDS. In the event of the incapacity of the PD carrier or its radiation damage (Dsum> Dr), the AP calls for special or ordinary ambulance.

 3. AP can additionally perform more complex functions: calculate, in addition to coordinates, the speed of movement of the AP - this will help give more accurate advice to its carrier in threatening situations; carry out group communication of the PD carrier who has got into a threatened situation with his immediate environment: relatives, friends, colleagues; to communicate with a pet that has got into a threatened situation and its owner, if both of them have PD, etc.

 4) In the event of the receipt of danger signals according to claim 2 from the ground, the AP ZS gives a signal to the radiation danger to “Everyone”.

 5) ZS with the help of OXDS remembers data on the radiation situation in the controlled area; on their basis compiles radiation maps and a forecast of changes in the radiation situation over time; identifies and identifies uncontrolled sources of increased radiation; estimates radiation emissions of industrial facilities in a controlled area; calculates the total dose received by the population in the controlled area, as well as the total dose for each PD carrier, etc.

 6. The ability to implement the system.

 All of the above elements of the system, as noted above (Section 3), actually exist and are operated and can be used to create the proposed system with virtually no design changes. Changes will require only software.

List of references
1. German application laid out N 3618162, G 01 T 1/169, 1987.

 2. Application of France N 2660761, G 01 T 1/10, 1991.

Claims (1)

 A system for monitoring the radiation situation and personal dosimetry, containing at least one zone telemetry data collection and processing station and a combination of the primary sources of this data - personal dosimeters, each of which has in its composition means for measuring the dose and dose rate operating at the place of stay personal dosimeter carrier, alarm means warning the personal dosimeter carrier about the danger that threatens it, and the telemetry communication channel with the zonal station, The system uses at least two-threshold dose rate personal dosimeters, and the zonal station is equipped with location means of the transmitting personal dosimeter, while the lowest dose rate threshold — the threshold for activating the telemetry channel of the personal dosimeter and the zonal station — is selected to exceed the average background dose rate level, but lower than the maximum permissible dose rate level - threshold for activating a warning personal alarm.