THE MINISTRY OF SCIENCE AND TECHNOLOGY --------	SOCIALIST REPUBLIC OF VIETNAM Independence - Freedom - Happiness ---------------
No. 19/2012/TT-BKHCN	Hanoi, November 08, 2012

 

CIRCULAR

ON CONTROLLING AND ENSURING RADIATION SAFETY IN OCCUPATIONAL EXPOSURE AND PUBLIC EXPOSURE

Pursuant to the Law on Atomic Energy dated June 03, 2008;

Pursuant to the Government's Decree No. 07/2010/ND-CP dated January 25, 2010, detailing and guiding the implementation of a number of articles of the Law on Atomic Energy;

Pursuant to the Government's Decree No. 28/2008/ND-CP dated March 14, 2008 defining the functions, tasks, powers and organizational structure of the Ministry of Science and Technology.

The Minister of Science and Technology prescribes the control and assurance of radiation safety in occupational exposure and public exposure as follows:

Section 1. GENERAL PROVISIONS

Article 1. Scope of regulation and subjects of application

1. This Circular deals with the requirements for controlling and ensuring radiation safety in occupational exposure and public exposure.

2. This Circular is applicable to the following organizations and individuals:

a) The organizations and individuals that do radiological works.

b) The organizations and individuals that operate and participate in response to radiation accidents and nuclear accidents;

c) The organizations and individuals working in places where the concentration of Radon-222 gas exceeds 1,000 Bq/m³;

d) The State agencies appointed to inspect the radiation safety and nuclear safety;

dd) The organizations and individuals that provide personal dose measuring services;

e) Organizations and individuals that export, import, collect metal scrap and recycle metal.

Article 2. Interpretation of terms

In this Circular, the terms below are construed as follows:

1. Occupational exposure is the exposure to radiation of individuals in the course of their works, responding to nuclear and radiation accidents, working at places where the concentration of Radon-222 gas exceeds 1,000 Bq/m³, or carrying out inspection at premises that do radiological works, not including excluded exposure (such as K-40 from human body, cosmic rays on earth…) and exposure to excepted radiation sources, radiological works, and medical exposure. Occupational exposure includes external exposure and internal exposure

2. Public exposure is the exposure incurred by members of the public by reason of the licensed radiological works, nuclear accidents, and radiation accidents, except for occupational exposure, medical exposure, and exposure to natural background radiation locally.

3. The controlled area is the area where protective measures and special safety regulations must be implemented in order to control the radiation exposure, prevent the spread of radioactive contamination in normal working conditions, prevent or limit the level of potential exposure.

4. Supervised area is the area where the exposures are always monitors, though the protective measures and special safety regulations are not as necessary as in controlled areas.

5. Potential exposure is the exposure that may occur by reason of nuclear accidents, radiation accidents, an incident or a series of probable incidents, including equipment malfunctions and errors during the operation.

6. The dose limit is a coefficient to determine the maximum radiation dose of an individual, absorbed from a radiation source, a facility, or a radiological work, that is used when calculating and designing the protection, including the optimization that ensure the radiation safety or the potential exposure in the future.

7. The investigated level is the excess level of effective dose, dose rate, absorbed dose or the level of radioactive contamination of a unit of area or volume that must be investigated to find the reasons and take remedial measures.

8. Radiological workers are workers that work in controlled areas and supervised areas.

9. Dose limits are the maximum permissible levels of effective doses or equivalent doses of individuals exposed to radiation from the controlled radiological works.

10. The residual dose is the subtraction of the expected dose and avertable dose after taking some certain countermeasures.

11. The expected dose is the dose that might be absorbed when a radiation accident happens without taking any countermeasures.

12. Avertable dose is the dose that might be reduced when making intervention.

Section 2. REQUIREMENTS OF OCCUPATIONAL RADIATION PROTECTION AND PUBLIC RADIATION PROTECTION

Article 3. The rules for controlling the occupational exposure and public exposure

1. The organizations and individuals that do radiological works must ensure that the personal radiation doses of radiological workers and the public do not exceed the dose limits prescribed in Annex I enclosed with this Circular.

2. The organizations and individuals that do radiological works must take the technical and administrative measures prescribed in this Circular in order to reasonably minimize the personal radiation doses of radiological workers and the public.

Article 4. Employing radiological workers

1. Do not employ radiological workers under the age of 18. The radiation apprentices, students at the age of 16 -18 using radiation sources during their study may only work within controlled areas or supervised areas as long as they are instructed by experts.

2. Do not employ people suffered from illnesses that must stay away from radiation as prescribed by the Ministry of Health.

3. The radiological workers of whom the ineligibility for doing radiological works has been certified by medical facilities must be enabled to change the work conditions.

4. Pregnant female radiological workers must notify their pregnancy to the person in charge of the radiation safety, and the manager must appoint them to do appropriate jobs if they wish to temporarily change the work conditions.

Article 5. The training in radiation safety for radiological workers

1. The organizations and individuals that do radiological works must provide training in radiation safety to their radiological workers periodically and when they are employed.

2. Radiological workers must take the training sources in radiation safety at the request of the person in charge of radiation safety.

Article 6. Controlling radiation sources

The organizations and individuals that do radiological works must comply with the following requirements to control radiation sources:

1. Ensure the smallest quantity of radiation sources and activity of radioactive sources to do radiological works.

2. Store radioactive sources in safe places with proper covers, and take measure to control the exposure and radioactive contamination.

3. Periodically check the radiation sources.

4. Regularly check the leak of radioactive sources.

5. Take measures to ensure the radiation safety when moving the radioactive sources inside and outside the premises.

6. Collect, treat, keep, and dispose of radioactive waste, used radioactive sources, and control the level of discharging radioactive waste to the environment as prescribed by law.

Article 7. Designing radiation covers

1. When calculating and designing radiation protection for the controlled area and supervised area, the organizations and individuals that do radiological works must apply the dose limit of occupational radiation that is smaller than or equal to 3/10 of the dose limit for radiological workers.

2. When calculating and designing radiation protection for public areas, the organizations and individuals that do radiological works must apply the dose limit of occupational radiation that is smaller than or equal to 3/10 of the dose limit for the public based on the following factors:

a) The dose contribution from radiation sources and other radiations works, including the radiations sources and radiological works that might arise in the future;

b) The potential changes that might affect the public exposure such as changing the characteristics and the operation of sources;

c) The experiences in effectively operating the radiation sources or doing similar radiological works.

3. The facility design of the radiation facilities that treat or store radioactive waste must contain information about the foundation, the underground water, surface water, tap water; the assessment of osmosis, the delivery of radioactive nuclei in the soil and the water; proof that the design is able to prevent the leak of radioactive substances into the soil, the water, and the air.

Article 8. Controlled areas and supervised areas

1. The organizations and individuals that do radiological works must set up a controlled area in the place that satisfies the following conditions:

a) The potential dose rate is higher than or equal to 6 mSv per year;

b) Able to cause radioactive contamination;

c) The reactor control room, radiotherapy machines, accelerators, and industrial irradiators.

2. The organizations and individuals that do radiological works must set up a supervised area where the potential dose rate is higher than 1 mSv per year and lower than 6 mSv per year.

Article 9. Controlling the access to radiation sources, the entry and exit of controlled areas and supervised areas

1. The organizations and individuals that do radiological works must take the following administrative and technical measures for controlling the access to radioactive sources:

a) Set up a system of interlocks or mechanical locks at places for storing or using radioactive sources of class 1 and class 2 in accordance with the Technical regulation QCVN 6:2010-BKHCN on radiation protection - Categorization and classification of radioactive sources; places for using accelerators; places for treating radioactive substances, radioactive pharmaceuticals, and places for storing radioactive waste;

b) Set up signs and fences to prevent the access to the sources;

c) Oblige the use of entrance and exit licenses or ID cards in such areas; appoint persons to supervise the entry and exit in controlled areas;

d) Formulate a regulation on controlling the persons authorized to access radioactive sources.

2. The organizations and individuals that do radiological works must take the following administrative and technical measures for controlling the entry and exit in supervised areas:

a) Formulate the regulation on entering and exiting such areas;

b) Set up signs and fences to prevent the entry and exit in such areas.

Article 10. Controlling the surface radioactive contamination and air radioactive contamination

The organizations and individuals that do radiological works using open radioactive sources must control the surface radioactive contamination and air radioactive contamination by implementing the following measures:

1. Use closed systems such as sucking cabinets.

2. Use materials for radioactive decontamination for the walls, the floor, and the surface susceptible to radioactive contamination.

3. Take measures to prevent the spread of radioactive contamination.

4. Use a ventilation system having radioactive substance filters.

5. Use devices to measure dose rates, radioactive contamination, and other test methods to monitor and assess the level of contamination.

Article 11. Personal protective equipment and radiation measuring instruments

1. The organizations and individuals that do radiological works must provide their radiological workers with the following personal protective equipment:

a) Workers doing radiations works likely to cause radioactive contamination must be provided with protective clothing, gloves, shoes, boots, socks, caps, and facemasks against radioactive contamination;

b) The workers using x-ray devices for diagnosis must be provided with lead-rubber aprons, and lead rubber sheets to protect the thyroid gland, and lead glasses;

c) The operators x-ray devices, doctors and technicians performing in x-ray techniques must be provided with lead-rubber aprons, and lead rubber sheets to protect the thyroid gland, and lead glasses;

d) The workers using radioactive sources in well logging exploration must be provided with clamps and gloves.

2. At the entrance of the controlled area facing the risk of radioactive contamination, the organizations and individuals that do radiations works must provide their radiological workers with instruments for controlling doses, at the exit must have bathrooms, sinks, and places to keep radioactively contaminated items, devices for testing the contamination of the body, clothing, and items being taken out.

3. The personal protective equipment, the dose controlling devices, and body contamination testing devices must meet the standards according to National Technical Regulations or recognized international standards; be properly preserved, and periodically tested and maintained.

4. The radiological workers must be instructed to use and test personal protective equipment, dose controlling devices, and body radioactive contamination testing devices.

5. The radiological workers must use personal protective equipment, dose controlling devices, and body radioactive contamination testing devices in accordance with the instruction.

Article 12. The regulation on radiation safety and the work process

1. The organizations and individuals that do radiations works must formulate a regulation on radiation safety and a suitable work process. The radiation safety regulation must specify the work processes and safety instruction, the individual dose measurement, the use of personal protective equipment, radiation test devices, and personal dosimeters, the responsibility to report unusual phenomena that may cause radiation insecurity, and other requirements suitable for the radiations works.

2. Radiological workers must comply with the regulation on radiation safety and the work process.

Article 13. Controlling the exposure visitors, caretakers, and discharged patients

The organizations and individuals that do radiological works using radioactive sources for diagnosing and treating diseases must control the exposure to radiation of visitors, caretakers, and discharged patients using the following methods:

1. Appointing people proficient in the safety measures and radiation prevention to instruct the visitors and caretakers when they enter controlled areas.

2. Provide information and instruction about radiation safety for visitors before they enter supervised areas.

3. Ensure that the radiation doses of the caretakers, during the diagnosis, testing, or treatment by ionizing radiation or radioactive pharmaceuticals, do not exceed the dose limits prescribed in Annex I enclosed with this Circular.

4. Only discharge the patients that have absorbed radioactive pharmaceuticals during the diagnosis and treatment when the activity of radioactive substances in their bodies does not exceed the levels prescribed by laws on medical radiation safety.

Article 14. Radiation inspection in workplaces

1. The organizations and individuals that do radiological works must inspect the radiation at their workplaces.

2. The radiation inspection at workplaces must be carried out regularly, systematically, and proportionally to the level and potential of radiation exposure to radiations works, and satisfy the following requirements:

a) Comply with the measurement quantities, the method and process of measurement, the position and time of measurement, and the frequency of radiation inspection that have been determined;

b) The level of investigation at the measuring positions prescribed in Point a this Clause must be established based on the actual assessment data, or the experience from other premises that do similar radiations works;

c) The frequency of radiation inspection at workplace must suit the danger of the radiations works being done therein, and must not be fewer than once a year.

d) The radiation inspecting devices must satisfy the technical regulations and national technical standards or international standards, must be periodically maintained, tested, and calibrated.

3. The requirements of radiation inspection prescribed in Clause 2 this Article must be made into an observation program, sent together with the application for licensing, and kept in the dossier of radiation inspection at the workplace.

4. The radiation inspection results at the workplace must be notified to radiological workers and their direct managers.

Article 15. Monitoring and assessing occupational exposure

1. The organizations and individuals that do radiological works must provide personal dosimeters for all workers working in controlled areas and supervised areas.

2. The organizations and individuals that do radiations works must use the personal radiation dose measuring services at the premises licensed to provide services supporting the application of atomic energy.

3. The organizations and individuals that do radiations works must formulate and comply with the process of using personal dosimeters, and resolve unusual incidents during the use of personal dosimeters, in particular:

a) The radiological workers must properly and reasonably use the radiation inspecting devices and personal dosimeters, and notify the person in charge of safety when the personal dosimeters is put into radioactive fields, radioactively contaminated, damaged, or lost;

b) The personal dosimeters that is put into radioactive fields, radioactively contaminated, or damaged, must be immediately sent to the unit that provide personal dosimeter measuring services. While pending the dose results, the premises owner must provide new dosimeters to their workers, or comply with the safety measures to make sure that the dose is not higher than the average dose absorbed by the workers. The incident and relevant documents must be filed and deposited;

c) Ensure that the characteristics, frequency, and accuracy of monitoring the dose of occupational radiation are determined, with regard to the potential changes and the level of exposure, the probability and level of potential exposure. The measurement must be carried out at least once every 3 months.

4. The organizations and individuals that do radiations works must ensure that their radiological workers are provided with personal dosimeters when there is internal exposure, and take the measures for assessing the direct or indirect exposure based on the result of monitoring the radiation background, the concentration of radioactive substances at workplaces, the protective equipment being used, and the information about the positions and duration of exposure of workers.

Article 16. Health-checks for radiological workers

1. The organizations and individuals that do radiological works must provide their radiological workers with health-checks periodically, when they are employed, and when they stop doing radiological works.

2. Radiological worker must undergo health-checks at the request of the person in charge of radiation safety.

Article 17. The radiation safety documents

1. The organizations and individuals doing radiations works must make, update, and deposit the documents prescribed in Clause 1 Article 29 of the Law on Atomic Energy, including:

a) The documents about the radioactive sources, nuclear materials, radiation devices, nuclear devices; the changes, repairs, and upgrades of radiation and nuclear devices;

b) The documents about radiation inspection at the workplace, the measurement, maintenance, and testing, specifying the radiation inspection plan, the radiation inspection works, the results of periodic radiation inspection, the documents about the maintenance, testing, and calibration of radiation inspecting devices, and other relevant documents.

c) The logbook and documents about nuclear and radiation accidents while doing radiations works;

d) The training documents of radiological workers;

dd) The health documents of radiological workers, specifying the results of annual and irregular health-checks of each worker;

e) The form of documents about radiation dose of radiological workers is provided in Annex III of this Circular. The documents about radiation dose of radiological workers must be updated once a year and after the radiation dose exceeds the investigated level, the dose limits, and on demand;

g) The conclusion of the inspection and the documents about the implementation of the request from competent agencies;

h) The public radiation inspection documents include: the observation program and the result of environmental radiation observation, the result of observation device calibration.

2. Organizations and individuals that do radiations works must provide the radiological workers and other relevant subjects with the documents about occupational exposure; deposit and send the documents about the control of occupational exposure as prescribed in Article 29 of the Law on Atomic Energy. The documents about the health and radiation doses of radiological worker must be kept for 30 years as from they stop doing radiological works.

3. Radiological workers must preserve and keep the personal radiation dose logbooks.

Provide the organizations and individuals that do radiological works with the previous information about their occupational exposure.

Article 18. Internal supervision about the compliance to the requirements of controlling occupational exposure

The organizations and individuals that do radiological works must periodically reconsider the following contents;

1. The regulation on radiation safety and the work process

2. The radiation inspection areas at the workplace and the ambient environment observation program.

3. The monitoring and assessment of personal radiation dose.

4. The deposit of documents.

5. The range of controlled areas and supervised areas.

Article 19. Controlling public exposure

Organizations and individuals doing radiological works must establish and implement observation programs to ensure that the public exposure to their radiation sources is accurately and sufficiently assessed, and accepted by State management agencies.

Article 20. Reporting the assessment of occupational exposure and public exposure control

1. In November every year or on demand, the organizations and individuals doing radiations works must send reports on the safety as prescribed in Article 20 of the Law on Atomic Energy, and report the results of occupational exposure and public exposure control to the Vietnam Agency for radiation and nuclear safety. The premises using x-ray devices for medical diagnosis shall send these reports to the Service of Science and Technology that issues the license to do radiations works.

2. The report on the result of controlling the occupational exposure and public exposure includes:

a) The personal occupational dose;

b) The result of radiation inspection in workplaces and public places;

c) Assessment of the variations compared to the licensed safety assessment;

d) Assessment of radiation overdoses (if any);

dd) The report on the happened nuclear and radiation accidents and the doses that exceed the investigated level.

Section 3. RADIATION CONTROL IN NUCLEAR AND RADIATION ACCIDENTS, AND IN OTHER CASES

Article 21. Radiation control in nuclear and radiation accidents

The organizations and individuals that do radiological works, of which the radiation level, radioactive contamination level, and the level of discharging radioactive waste exceed the permissible limits, must take the following measures:

1. Establish and maintain the capability of urgent radiation inspection.

2. Take all measures to bring such levels below the permissible level.

3. Implement the plan for responding to nuclear and radiation accidents.

Article 22. Controlling the exposure to radiation of workers that respond to nuclear and radiation accidents

The organizations and individuals doing radiological works, employers, and organizations that respond to nuclear and radiation accidents shall:

1. Manage and control, and keep the radiation dose of the workers that participate in responding to nuclear and radiation accidents.

2. Ensure that the radiation dose of the workers that participate in responding to nuclear and radiation accidents does not exceed 50 mSv, except for the following cases:

a) Rescuing other people;

b) Preventing the serious injuries or death, or preventing the conditions that may cause catastrophes that may remarkably affect the humans and the environment;

c) Taking actions to avoid massive collective doses.

3. Ensure that the workers participating in response to nuclear and radiation accidents are notified of the risk to their health, as well as the safety measures before making the intervention that the radiation dose absorbed might exceed 50 mSv.

4. Ensure that the effective dose of the workers that participate in response to nuclear and radiation accidents does not exceed 500 mSv in all cases.

The radiation doses of radiological workers when participating in response to nuclear and radiation accidents is not considered as occupational doses for dose limit control. The workers that participate in response to nuclear and radiation accidents that have absorbed a dose higher than 200 mSv must be given health-checks and medical advices before carrying on the incomplete works.

Article 23. Controlling the public exposure in nuclear and radiation accidents

The organizations and individuals that do radiological works and organizations that respond to nuclear and radiation accidents shall:

1. Take actions to protect and respond to nuclear and radiation accidents immediately when the exposure to radiation happens. The dose rates for deciding the urgent protection in nuclear and radiation accidents are provided in Annex II enclosed with this Circular.

2. Assess the efficiency of the actions taken, and appropriately regulate them.

3. Compare the residual doses to the reference level (20 – 100 mSv) to give a protection priority to the group of people of whom residual doses exceed the reference level.

4. The nuclear facilities must set up a Protective action zone (PAZ), an urgent protective action-planning zone (UPZ) based on the dose rates prescribed in Annex II enclosed with this Circular.

Article 24. Controlling the exposure to radiation from radioactively contaminated metal

The organizations and individuals that export, import, produce, sell, and recycle metal scrap and steel must:

1. Monitor and detect the radioactive substances, radioactively contaminated items and radioactive sources mixed in metal scrap and semi-finished products steel.

2. Send written daily reports to the State management agency in charge of radiation and nuclear safety when detecting the radioactive substances, radioactively contaminated items and radioactive sources mixed in metal scrap and semi-finished products steel.

3. Immediately take the following measures:

a) Return the consignment that is radioactively contaminated or contains uncontrollable radioactive sources to the exporting country;

b) Collect, store, and preserve the radioactively contaminated goods in accordance with the regulations on managing radioactive waste;

c) Take technical and administrative measures to limit people passing the area that have radioactively contaminated goods.

Article 25. Controlling and ensuring the radiation safety for workers working in places with high concentration of Radon-222 gas

1. The employers must take measures for controlling and ensuring the radiation safety for the workers working in places where the concentration of Radon-222 exceeds 1,000 Bq per m³ of air.

2. The employers at places where the concentration of Radon-222 gas exceeds the limit prescribed in Clause 1 this Article, depending on the specific condition, must take measures for controlling and minimizing the concentration of radon air such as enhancing the ventilation, diluting the air in the working area with natural air, cleaning the air using activated carbon or other suitable instruments.

Article 26. Controlling exposure to radiation of persons in charge of inspecting the radiation safety

The State agencies in charge of inspecting the radiation safety must provide personal dosimeters for, and assess the individual radiation dose of, the officers and employees that directly inspect the radiation safety.

Section 4. REQUIREMENTS OF PROVIDERS OF PERSONAL DOSE MEASURING SERVICES

Article 27. Personal dosimeters used for measuring personal doses

1. The personal dosimeters must be suitable for the radiations works, and the values on the dosimeter must not be changed by the users.

2. The measurements and calibration of dosimeters must comply with the following practical quantities:

a) Hp (10) for systemic effective doses;

b) Hp (3) for eye equivalent doses;

c) Hp (0.07) for skin equivalent doses

Article 28. Responsibility of providers of individual dose measuring services

Providers of individual dose measuring services must:

1. Provide sufficient equipment and human resources for personal dose services as prescribed by law.

2. Formulate and implement the quality assurance program.

3. Instruct the organizations and individuals to use personal dosimeters.

4. The personal dose result sheet must contain the following information: the name of the organization or individual that do radiations works, the address, the measuring time, the list of radiological workers and dose values, the measurements, and the certification of the service provider.

5. Report the overdoses of radiological workers to the Vietnam Agency for radiation and nuclear safety and the local Service of Science and Technology.

6. Update the personal occupational radiation doses to the national database of occupational exposure as guided by the Vietnam Agency for radiation and nuclear safety.

Section 5. IMPLEMENTATION ORGANIZATION

Article 29. Implementation responsibilities

The Vietnam Agency for radiation and nuclear safety, Services of Science and Technology of central-affiliated cities and provinces, relevant organizations and individuals are responsible for implementing this Circular.

Article 30. Effects

1. This Circular takes effect after 45 days as from the date of its signing.

2. Organizations and individuals are recommended to send feedbacks on the difficulties arising during the course of implementation to the Ministry of Science and Technology for consideration and amendment./.