The following is an excerpt from the relevant national standard, copy a little messy, from the "basic standards of radiation health protection" (GB4792-84) The relevant national standards and GB22448-2008 GBZ117-2006, etc., which on the safety measurement of the provisions are the same. That is, an average of 20mSv per year for five consecutive years, not exceeding 50mSv in any one year
The following is an excerpt.
2. Dose Limits for Radiation Workers 2.1 The annual dose equivalent for radiation workers is the sum of the dose equivalent of external exposures received during a year's work and the dose equivalent to be accrued from the ingestion of radionuclides during that year, excluding natural background exposures and medical exposures. 2.2 Dose limits for radiation workers take into account both stochastic and non-stochastic effects. 2.2.1 In order to prevent harmful non-random effects, the annual dose equivalent to any one organ or tissue shall not exceed the following limits. 2.2.2 To limit stochastic effects, the annual dose equivalent to a radiation worker exposed to a uniform whole-body dose should not exceed 50 mSv (5 rem). In case of inhomogeneous exposure, the effective dose equivalent should satisfy the following inequality: ∑T WT HT ≤ 50MSv (5rem) where: HT - annual dose equivalent to tissue or organ (T), mSy (rem) WT - relative risk weighting for tissue or organ (T) （WT - Relative risk weighting factor for tissue or organ (T) (see Appendix F) ∑T WTHT - Effective dose equivalent, expressed as HE 2.3 The intake of radionuclides by radiation workers in a year should not exceed the annual intake limits (ALI) listed in Appendix B. 2.4 For the purpose of monitoring and management, it is recommended that the annual intake limits (ALI) be set as follows: ∑T ≤ 50MSv (5rem) where 2.4 In order to facilitate monitoring and management, the derived concentration of radionuclides in the air at the workplace is derived. Concentrations may be increased or decreased based on actual intake without exceeding the ALI and in accordance with paragraph 2.6. 2.5 In the case of combined internal and external exposures, fulfillment of the following inequalities and the requirements of 2.2.1 and 2.6 can be considered as not exceeding the prescribed dose limits for radiation workers. HE Ij (---------)+∑ ----≤1 -1 ALIj 50mSv-year Where: HE - annual effective dose equivalent of external irradiation -1 ∑T WT HT , mSv year -1 Ij - annual intake of radionuclide j Bg year ALIj - annual intake limit of radionuclide j, Bg -1 year -1 50mSv year - effective dose equivalent limit for radiation workers 2.6 The total dose equivalent received in one or more doses over a period of three consecutive months should not normally exceed half of the annual dose limits (paragraphs 2.2 to 2.5). 2.7 Classification of radiological working conditions: For ease of management, radiological working conditions are divided into three types: Type A working conditions: the effective dose equivalent of one year's exposure is likely to exceed 15mSv (1.5re m). For staff working under these conditions, there should be individual dose monitoring, regular monitoring of the premises, and the establishment of individual staff exposure dose and premises monitoring files. B working conditions: the effective dose equivalent of one year's exposure is rarely likely to exceed 15mSv (1.5re em). However, it is possible to exceed 5mSv (0.5rem). Sites with such working conditions should be monitored regularly. Individual dose monitoring should be carried out and individual exposure dose files should be established. C working conditions: the effective dose equivalent of one year's exposure is rarely likely to exceed 5mSv (0.5re m) for this kind of working conditions of the site, can be monitored as needed, and make records. 2.8 In the course of normal operation, special circumstances may occur that require a small number of staff to be exposed to doses in excess of the annual dose equivalent limit. Such exposures must be carefully planned in advance and approved by the head of the unit and the person in charge of protection, and the effective dose equivalent should not be greater than 100mSv (10re m) in a single event and 250mSv (25rem) in a lifetime, and should satisfy the requirements of paragraph 2.2.1. The effective dose equivalent of such pre-planned special exposures should be medically observed and recorded in detail in the individual dose and health records. 2.9 Pregnant women, lactating women (for internal exposure only) and interns between 16 and 18 years of age engaged in radiological work should not work under Category A working conditions and should not receive pre-planned special exposures. 2.10 Exposure of women of childbearing age who are engaged in radiological work should be strictly controlled by a uniform monthly dose rate. 2.11 Persons under 16 years of age shall not be involved in radiological work. 3. Dose limits for individuals in the public 3.1 The annual dose equivalent for individuals in the public shall be less than the following limits: Whole body 5mSv (0.5rem) Any individual tissue or organ 50mSv (5rem) 3.2 When exposed to ionizing radiation continuously over a long period of time, individuals in the public shall be subjected to an annual dose equivalent limit of not more than 1mSv (0.1rem) per year of whole-body irradiation throughout their lives. The annual dose equivalent referred to above is the sum of the dose equivalent from external exposures in any one year and the dose equivalent to be accrued from ingested radionuclides in that year, excluding natural background exposures and medical exposures. 3.3 The annual intake limits and derived concentrations for individuals in the general public are for adults only. When calculating the effective dose equivalent to a child due to radionuclide ingestion, differences in organ size and metabolism should be taken into account, and appropriate models should be selected to reduce the intake of the radionuclide accordingly. 3.4 When formulating radiation protection regulations, provinces, municipalities, autonomous regions and relevant organizations must take into account the exposure of the public to existing and anticipated radioactive sources, so that the total dose equivalent of personal exposure to the public will be lower than the above limit values. This must also be taken into account in the pre-evaluation of radiation protection for new radiation workplaces. 3.5 Future dose-equivalent burden: There are many practices that release long-lived radionuclides that accumulate in the environment over long periods of time and will continue to increase the exposure of the public. At the same time, the variety and number of other radioactive sources will also increase. Therefore, it is important to plan and design in such a way that doses from current and future practices do not result in excessive exposures to the public. 3.6 In order to estimate the dose equivalent to an individual member of the public, a dose evaluation should be carried out by selecting a suitable key population group among those likely to be exposed, and by choosing appropriate parameters and mathematical models to estimate the average effective dose equivalent to this group. 3.7 Human activities sometimes lead to changes in the level of exposure of the public to natural ionizing radiation, and it is necessary to limit the additional exposures caused by this increase, and specific levels of investigation, regulatory limits and intervention levels should be established for different types of radioactive sources and their dose distributions.