Causes of design basis accidents. Accidents at radiation hazardous facilities. Beyond design basis accident – ​​an accident caused by initiating events not taken into account for design basis accidents or accompanied by additional failures of safety systems compared to design basis accidents

Land lease and design documentation After you select a site for a parking lot, you should obtain the right to rent it. This is a rather difficult issue, the solution of which will require a number of approvals, documents and considerable cash. If

55. Project documentation

55. Design documentation Design documentation, which is the result of the design of the ACS and control, as a rule, consists of two parts.1. At the “design task” stage, issues related to the object itself are studied; basic characteristics questions

Under design basis accident is understood as an accident for which the initial events of emergency processes characteristic of a particular facility are defined in the project.

Maximum design basis accidents are characterized by the most severe initiating events that cause the occurrence of an emergency process at a given facility.

Under beyond design basis (hypothetical) accident refers to an accident that is caused by initiating events that are not taken into account for design basis accidents and is accompanied by additional failures of safety systems compared to design basis accidents.

66. Features and advantages of ru brest:

natural radiation safety

long-term provision of fuel resources due to effective use natural uranium;

eliminating the production of weapons-grade plutonium

environmentally friendly energy production and waste disposal

economic competitiveness due to the natural safety of nuclear power plants and fuel cycle technologies, abandonment of complex engineering systems security

67. Environmental consequences of nuclear power plant operation

The main environmental problems of nuclear power plant operation. Compared to fresh fuel, its composition contains less uranium-235 (since it burns out), but it accumulates isotopes of plutonium, other transuranium elements, as well as fragments, or fission products - medium-mass nuclei. Over time, the physical characteristics of the structural materials of fuel assemblies also change.

Dismantling of a nuclear power plant upon completion of its normal operation.

68. Main radionuclides generated during the operation of nuclear power plants and their effects on the body

Tritium − can enter the human body through inhalation, as well as through the skin. In the presence of tritium, the entire human body is exposed to β-radiation with a maximum energy of 18 keV.

Carbon-14− The effect of ionizing radiation on humans is mainly due to the consumption of food (milk, vegetables, meat).

Krypton− The radiological impact of 85 Kr on humans occurs mainly due to irradiation of the skin.

Strontium− 90 Sr enters the human body with food (milk, vegetables, fish, meat, drinking water). Like calcium, 90 Sr is deposited mainly in bone tissues, which contain vital hematopoietic organs.

Cesium− The radiological impact of cesium, like 90 Sr, on humans is associated with its penetration into the human body along with food. In living organisms, cesium can largely replace potassium and, like the latter, spread throughout the body in the form of highly soluble compounds.

69. SNF− irradiated nuclear fuel, spent fuel elements (fuel elements) of nuclear reactors of nuclear power plants removed from the active zone.

RAO− substances in any state of aggregation in which the content of radionuclides exceeds levels not intended for further use.

70. Features of handling spent fuel:

Nuclear hazard (criticality);

Radiation safety;

Residual heat release.

Ensuring subcriticality throughout the entire operation time;

Prevention of physical damage to the fuel assembly and/or fuel rods;

Ensuring reliable heat supply;

Maintaining the level of radiation exposure and release of radioactive substances when handling irradiated fuel at a reasonably achievable level.

72. The list of technological operations for SNF management may include:

Interim storage of spent fuel assemblies in the spent fuel pool;

Transportation of spent fuel to a reprocessing plant, temporary storage facility or repository;

Interim storage before processing or disposal;

Reprocessing or preparation of spent fuel assemblies for temporary storage or disposal;

Temporary storage or burial.

73. Radioactive waste management

The typical sequence of waste management operations is collection, separation, characterization, treatment, conditioning, transportation, storage and disposal.

74. Characteristics of radioactive waste used for their classification+75. RW classification

There are a number of criteria by which radioactive waste is classified.

By activity and heat levels, with the definition of quantitative characteristics:

High level waste; long rao

Intermediate level waste;

Low level waste; briefly rao

Very low level waste.

By half-life of radionuclides, which determines the time of their potential danger:

Very short-lived;

Short-lived;

Medium-living;

Long-lived.

According to the nature of the prevailing radiation:

α-emitters;

β-emitters;

TEST TASKS FOR PREPARATION FOR GIA IN THE DISCIPLINE “RADIATION HYGIENE”

Choose one correct answer:

1. The main measures to ensure radiation safety include:

1) legal, epidemiological, sanitary and hygienic

2) legal, organizational, sanitary and hygienic

3) economic, organizational, epidemiological

4) operational, organizational, sanitary and hygienic

5) legal, organizational, epidemiological

2. Reducing the radiation exposure of patients during radiography is ensured by:

1) serviceability of the device

2) compliance of the device technical standards

3) correct choice of picture mode

4) filtration of the primary beam

5) all of the above are true

3. Weighting factors for individual species ionizing radiation is used in calculations:

1) exposure dose

2) absorbed dose

3) equivalent dose

4) effective dose

5) radiation output

A copy of the worker’s radiation dose card must be kept in medical organization after his dismissal for ______ years

5. The main contribution to public exposure comes from the following sources:

1) global radioactive fallout

2) accidents at nuclear power plants

3) natural background radiation, technologically modified

natural background radiation, x-ray and radiological

diagnostics in medicine

4) nuclear power plants in conditions regular work

5) everything is true

6. Irradiation of patients during X-ray diagnostics is regulated by:

1) Radiation safety standards (NRB-99/2009)

2) Basic sanitary rules for ensuring radiation safety (OSPORB-2010)

3) SanPiN 2.6.1. 1192-03 “Hygienic requirements for the design and operation of X-ray rooms, devices and the conduct of X-ray examinations”

4) Federal law“On radiation safety of the population”

5) everything is correct

Scheduled radiation monitoring at enterprises,

using sources of ionizing radiation, includes:

1) determination of natural background radiation levels

2) duration assessment technological processes

3) assessment of dose rates at workplaces, determination of the content of radionuclides in the air of the work area, medical control for staff

4) determination of levels of technologically altered natural background radiation

6) everything is correct

8. Radiation monitoring devices are divided into:

1) individual

2) wearable

3) portable

4) stationary

5) everything is correct

Sanitary dosimetric control in medical institutions

includes:

1) measurement of external radiation dose rate

2) individual dosimetric control

3) determination of concentrations of radioactive gases and aerosols in

4) control over the collection, storage and disposal of radioactive waste

5) everything is true

10. The level of radioactive contamination of surfaces is expressed in:

3) Frequency/cm 2 /min

4) microR/hour

11. Weighting factors for tissues and organs are used when calculating:

1) exposure dose

2) absorbed dose

3) equivalent dose

4) effective dose

5) ambient equivalent dose

12. The principle of optimizing radiation safety when conducting x-ray studies assumes:

1) organization of a single radiology department for hospitals and clinics

2) conducting x-ray examinations as directed by the attending physician

3) establishing control levels of exposure for different types procedures and refusal of unjustified studies

4) maintaining radiation doses to patients as low as possible while maintaining the quality of their examination and treatment

5) compliance with radiation safety standards

Solid radioactive waste is treated before disposal

methods:

1) burning

2) vitrification, bituminization, cementation of vitrification,

cementing

3) grinding

4) pressing

5) everything is true

14. The activity of a radioactive substance is:

1) absorbed energy calculated per unit mass

2) the amount of radiation emitted by radioactive atoms

3) the number of radioactive decays of atomic nuclei per unit time

4) time of removal of radionuclides from the body

5) dose created per unit of time

15. Radiation monitoring at personnel workplaces, adjacent rooms and areas adjacent to the X-ray room must be carried out at least once every:

16. Highest concentration radon is noted:

1) in the ground layer of air in winter

2) in the ground layer of air in summer

3) in the air over the ocean

4) in soil air

5) in the upper atmosphere

17. Observation and control of the radiation situation beyond the sanitary protective dose is carried out by:

1) radiation control groups of the enterprise itself

2) organizations licensed to carry out such work

3) territorial offices of Rospotrebnadzor

4) regional bodies of Rostechnadzor

5) public organizations

An accident for which the project defines the initial and final events is called:

2) design

3) actual

4) technical

5) hypothetical

19. The biological effect of radiation depends on:

1) dose received

2) body reactivity

3) irradiation time, intervals between irradiations

4) dimensions and localization of the irradiated surface

5) all of the above are true

20. Radioactive waste in medical institutions includes:

1) radioactive aerosols removed from fume hoods and

2) liquid radioactive waste resulting from

equipment decontamination

3) radioactive waste released with the excrement of patients

4) used tools, overalls, personal protective equipment from open source departments














Design basis accident

• Design basis accident – an accident for which the design defines the initial events and final states and provides safety systems that, taking into account the principle of a single failure of safety systems or one personnel error independent of the initial event, limit its consequences to the limits established for such accidents.

• Beyond design basis accident – an accident caused by initiating events not taken into account for design basis accidents or accompanied by additional failures of safety systems in comparison with design basis accidents in excess of a single failure, or the implementation of erroneous decisions of personnel.

• Severe beyond design basis accident – a beyond design basis accident with damage to fuel elements above the maximum design limit, in which the maximum permissible emergency release of radioactive substances into the environment can be achieved.


















• Rice. 1. Schematic diagram of PHRS PG and PHRS ZO

• 1 – emergency heat removal tanks; 2 - steam lines; 3 – condensate pipelines; 4 – SG PHRS valves; 5 – heat exchangers-condensers SPOT-ZO; 6 – steam generators; 7 – shut-off valves








• 1 - reactor; 2 – melt localization device; 3 – fuel pool; 4 – shaft for inspection of internal devices; 5 – pit tanks; 6 – pipeline for supplying water to the surface of the melt; 7 – water supply pipeline to the ULR heat exchanger