Foreword
In order to implement the "Environmental Protection Law of the People's Republic of China", "Nuclear Safety Law of the People's Republic of China", "Radioactive Pollution Prevention Law of the People's Republic of China" and other relevant laws and regulations, to protect the environment and safeguard human health, this standard is formulated.
Prevention and Control Law" and other relevant provisions of laws and regulations, to protect the environment and protect human health, the development of this standard. This standard specifies the purpose, content and requirements of radiation environmental monitoring at different stages of the near-surface disposal site of radioactive solid waste. This standard is a revision of the "general requirements for environmental radiation monitoring of low and medium level radioactive waste near-surface disposal sites" (GB/T 15950-1995).
This standard was first published in 1995, and the original standard drafting unit is the Institute of Nuclear Industry Standardization of China National Nuclear Corporation. This is the first revision. The main content of this revision.
-The standard name is revised to "radioactive solid waste near-surface disposal site radiation environmental monitoring requirements"; increased the "preface" "preliminary survey of the radiation environment background", "environmental monitoring outline " and "monitoring of passive monitoring period", etc.
In the terminology of "near-surface disposal site", "investigation level", "reporting level" and "active monitoring period The definition of "near-surface disposal site", "investigation level", "reporting level" and "active monitoring period" are given in the terminology; the radiation environment monitoring of the near-surface disposal site of radioactive solid waste is divided into "pre-operational phase", "operational phase" and "closure
After the phase" three stages, and detailed additional requirements: - in Chapter 5 and Chapter 6 were added to the pre-operation phase and operation phase of the radiation monitoring program table. From the date of implementation of this standard, "General requirements for environmental radiation monitoring of low and medium level radioactive waste near surface disposal sites" GB/T 159501995) is repealed.
This standard by the Ministry of Ecology and Environment, the Department of radiation source safety supervision, regulations and standards organization.
The main drafting unit of this standard: China National Nuclear Power Engineering Corporation, Beijing Institute of Nuclear Industry Chemical Processing Institute This standard was approved by the Ministry of Ecology and Environment on February 2, 2023.
This standard has been implemented since June 1, 2023.
This standard is interpreted by the Ministry of Ecology and Environment.
1 Scope of application
This standard specifies the radioactive solid waste near-surface disposal site pre-operational phase, operational phase and post-closure phase of the radiation environment monitoring requirements.
This standard applies to the radiation environment monitoring of the near-surface disposal site of radioactive solid waste, and does not apply to the radiation environment monitoring of the cavern disposal site.
2 normative reference documents
This standard cites the following documents or provisions therein. Where the date of the cited document is indicated, only the dated version is applicable to this standard.
Where the reference document is not dated, its latest version (including all the revision sheets) is applicable to this standard.
GB 8999 General requirements for quality assurance of ionizing radiation monitoring
GB 9132 low and medium level radioactive solid waste near-surface disposal safety requirements
GB 18871 Basic standards for ionizing radiation protection and radiation source safety
HJ 61 Technical Specification for Radiation Environmental Monitoring
EJ 428 General Provisions for the Collection and Preparation of Soil Samples in Environmental Nuclear Radiation Monitoring
EJ 527 Basic Provisions for Biological Sampling in Environmental Radiation Monitoring
3 Terminology and definitions
The following terms and definitions are applicable to this standard.
3.1
Near surface disposal sitenear surface disposal repository
Radioactive solid waste disposal facilities within a few tens of meters below or on the surface of the ground and with an engineered barrier, the facility has defined boundaries and is subject to organized control, the near surface disposal site generally consists of a number of disposal units, structures and buffers, etc.
3.2
Investigation levelinvestigation level
When a measured quantity (such as dose rate, activity concentration, etc.) is higher than this level, it is necessary to investigate the causes and consequences of its occurrence.
3.3
Report levelreport level
When a measured quantity (such as dose rate, activity concentration, etc.) is higher than this level, it should be reported to the relevant department.
3.4
Active guard periodinitiative guard period
The period when facility maintenance and monitoring activities continue in an organized manner after the disposal site is closed.
4 General requirements
4.1 Radioactive solid waste near-surface disposal site of the radiation environment monitoring should be consistent with GB 9132, HJ61, GB18871 and other standards, sampling methods for various types of environmental media should be consistent with the requirements of HJ61, EJ428, EJ527 and other relevant standards and specifications, quality assurance should be consistent with the requirements of GB8999 and other standards.
4.2 The radiation environment monitoring of the near-surface disposal site of radioactive solid waste is divided into the pre-operation phase, operation phase and post-closure phase.
4.3 radiation environment monitoring range to the disposal site as the center, a radius of 3km ~ 5km, focusing on groundwater and other environmental media, and according to the environmental characteristics of the disposal site in the region, the appropriate adjustment.
4.4 disposal site radiation environment monitoring of the three stages are required to develop the corresponding monitoring outline. Monitoring outline should be in line with the requirements of this standard, and give full consideration to the source of radioactive solid waste items, disposal site characteristics and site environmental characteristics and other factors.
5 pre-operation phase
5.1 Monitoring purpose
The purpose of radiation environmental monitoring in the pre-operation phase is to collect background information on site characteristics and to obtain background data on the radiation environment.
5.2 Monitoring auxiliary parameters acquisition
Collect information on the radiation environment, meteorology, hydrology, geology, geochemistry and water chemistry, natural resources, population and its distribution within 5km of the site, as well as the operation of other nuclear facilities that may affect the site within 5km, and the distribution of radiation sources, to provide a basis for the development of the monitoring outline.
5.3 Preliminary survey of radiation environment background
Disposal site in the site selection stage need to carry out preliminary investigation of the radiation environment background. New site site selection stage of the radiation environment background preliminary survey should be carried out a necessary site monitoring, monitoring content including instantaneous environmental γ radiation dose rate and environmental media (aerosol, soil, sediment, surface water, groundwater) in the radionuclide activity concentration level, monitoring projects and deployment requirements refer to Table 1. If the concentration of artificial radionuclide activity in the above environmental media is found to be abnormal during the preliminary survey, additional biological media survey should be considered or focused on during the pre-operation survey. If the site is located within the environmental monitoring range of other nuclear facilities, the environmental monitoring data of other nuclear facilities can be used directly as the background preliminary survey data.
5.4 Radiation environment background survey
5.4.1 The background data of the radiation environment around the site should be obtained for the last two consecutive years before the operation of the disposal site, as the basic data for the environmental impact evaluation and safety analysis during the operation and after the closure of the disposal site.
5.4.2 The survey includes the ambient γ radiation level and the activity concentration of the main radionuclides in the environmental media related to the operation of the disposal site.
5.4.3 The scope of the survey of the radiation environment background to the disposal site as the center, the radius is generally taken 5km.
5.4.4 The radiation environment background survey should follow the following principles of deployment:
(a) should follow the provisions of the relevant standards and norms, and combined with the environmental characteristics of the survey area to consider point placement;
(b) close to the dense far away, taking into account all directions;
(c) in the main settlements, agriculture, animal husbandry and fishery concentrated areas, environmentally sensitive areas (in addition to the main settlements), the dominant wind downwind of the deployment of points;
(d) sparsely populated and inaccessible areas can be appropriately reduced monitoring points;
(e) As far as possible, choose the location that is less likely to be disturbed and damaged in the future, so that the operational phase and long-term use after closure;
f) The selected points should be representative and avoid being affected by disturbing factors as far as possible;
(g) set at least one control point in the area that can be negligibly affected by the disposal site and can maintain the original environmental characteristics in the long term.
5.4.5 Disposal site pre-operation phase of the radiation environment background survey program reference table 1 implementation. Monitoring projects can be adjusted according to the main radionuclides involved in the disposal site, site characteristics and monitoring method maturity.
Table 1 pre-operational phase of the radiation environment background survey program
5.4.6 If the site is located within the influence of the surrounding nuclear facilities, it is also necessary to consider increasing the monitoring of the release of major artificial radionuclides from the nuclear facilities.
5.4.7 In the background survey of the radiation environment in the pre-operational phase of the disposal site, the nuclides to be concerned about in the γ-spectrum nuclide analysis should be set according to the source items of the disposal waste, including at least 137Cs, 60Co, 134Cs, 54Mn, etc.. The activity concentrations of238U,232Th,226Ra,40K in soil and substrate should also be concerned.
5.4.8 Indicator biological deployment points can be set with reference to the recommendations of EJ527. If the disposal site is in an area without the recommended range of species, it is appropriate to recommend possible indicator organisms through the pre-operational environmental background survey for monitoring during operation.
5.4.9 If the source item of the disposal waste contains transuranic nuclides and their content may have an impact on the environment, these nuclides need to be added to the monitoring items of soil, aerosol, sediment, and groundwater.
5.5 Environmental monitoring outline
The environmental monitoring outline contains at least the following elements:
a) the organizational structure and its responsibilities for carrying out environmental monitoring tasks;
b) the basis for the development of the monitoring outline;
c) details of the monitoring program;
d) description of measurement methods, equipment and detectable limits;
e) data processing methods;
f) Quality assurance measures.
6 Operational phase
6.1 Monitoring purpose
The purpose of radiation environmental monitoring during the operation phase is to continuously obtain monitoring data of the radiation environment around the disposal site, to grasp the level of the radiation environment and its changing trends, to evaluate the radiation impact of the operation of the disposal site on the surrounding environment, and to provide data support for the assessment of public exposure dose and evaluation of the inclusive performance of the facilities during the operation of the disposal site.
6.2 Monitoring focus
The radiation environment monitoring should focus on the main emission source items of the disposal site, the environmentally sensitive points within the survey area and the relevant pathways of potential leakage, and should also fully integrate the findings of the background survey of the radiation environment before operation.
6.3 Layout principles
In order to make the sampling and monitoring points are selected with sufficient representation, the sampling and monitoring points should be laid out considering the following principles:
(a) to meet the relevant standards and technical specifications requirements;
(b) focus on monitoring the area near the site, focusing on the main residential points and other environmentally sensitive points within the survey area, and increase the monitoring points for dense residential areas as appropriate;
(c) fully integrated with the pre-operational radiation environment background survey of the deployment program, and according to the findings of the survey appropriate adjustments;
(d) should set up environmental control points, it is appropriate to set up in the same point with the background survey;
(e) in addition to the above requirements, should also meet the relevant requirements in Table 2.
6.4 Groundwater
6.4.1 groundwater monitoring is the focus of the disposal site radiation environment monitoring. Monitoring wells for groundwater sampling is generally not less than four, of which one is set upstream as a comparison well, the rest are set in the downstream. The distribution of monitoring wells should be distributed in a fan shape in accordance with the direction of groundwater flow. Monitoring wells need to be monitored for a long period of time, and the changes in groundwater runoff should be taken into account.
6.4.2 Non-radioactive parameters (e.g. pH, conductivity, nitrate, fluoride, total organic carbon, etc.) can be used as auxiliary indicators to indicate potential problems.
6.5 Surface water
If there are surface rivers within the survey area, a sampling point can be set up in the upstream and downstream of the river. If there are lakes and reservoirs within the survey area, one sampling point will be set up in each lake and reservoir.
6.6 Indicator organisms
If there is no clear indicator organism in the monitoring area, if conditions are available, it is appropriate to plant one kind of indicator plant recommended by EJ527 near the plant area for sampling and measurement.
6.7 Monitoring program
The radiation environment monitoring program of the operation phase of the disposal site is implemented with reference to Table 2
6.8 Environmental monitoring program
The monitoring items, frequencies and points of the environmental monitoring outline in the operation phase should be consistent with Table 2, and other content requirements are the same as in section 5.5.
The environmental monitoring program can be optimized periodically (usually 5 years) based on feedback from experience, advances in monitoring technology, changes in the characteristics of the received waste, and changes in the environment around the site.
The environmental monitoring items, frequency, and locations can be adjusted appropriately during the closure process period from the time the disposal site stops receiving waste to the time of formal closure.
6.9 Emergency environmental monitoring
The operating unit needs to develop an emergency environmental monitoring program based on the accident analysis of the facility before the disposal site is put into use, and equipped with the appropriate personnel and equipment, and organize regular drills. Emergency environmental monitoring should be able to quickly provide relevant environmental monitoring data under abnormal conditions to provide data support for emergency response.
6.10 Other auxiliary parameters acquisition
6.10.1 Hydrological parameters
During the operation phase of the disposal site, the groundwater flow and water level should be evaluated in a five-year cycle.
6.10.2 Geological parameters
For the settlement, deformation, cracks of disposal units, slopes (if any), interceptor ditches (if any), as well as the surface deformation and soil erosion of the whole site should be monitored or inspected annually during the reception of waste at the facility to assess the environmental safety of the site, and the disposal site constructed in phases should be evaluated after
The cycle of monitoring or inspection can be lengthened after the completion of capping and surface backfill of the previous phase.
6.11 Investigation level
The survey level should be linked to a multiple of background concentration or a share of the dose limit and used as a management standard for the disposal site, and the following actions should be taken when a physical quantity is found to reach the survey level:
a) Review laboratory procedures;
b) Inspection for contamination;
c) resampling;
d) radionuclide analysis;
e) Increased sampling frequency;
f) Monitoring outline extension.
6.12 Reporting Levels
When a measured quantity reaches or exceeds the reporting level, then the monitoring results and mitigation measures taken to resolve the problem should be reported to the regulatory authority.
7 Post-Closure Phase
7.1 Purpose of monitoring
After closure of the disposal site in accordance with statutory procedures and conditions, appropriate environmental monitoring functions are retained based on the operational history of the disposal site and the closure and stabilization situation as part of the safe guardianship program for the closure of the disposal site. The purpose is to evaluate the stability performance of the facility after closure of the disposal site by detecting radioactive material in the environment that may come from the disposal site, to provide early warning of abnormal radionuclide releases from the disposal waste and to provide data support for assessing the long-term environmental impact of radiation.
7.2 Active monitoring of the custody period
7.2.1 General requirements
The environmental monitoring medium during the active guardianship period should be mainly groundwater samples from the monitoring wells of the site, with appropriate retention of some ambient γ radiation levels and plant samples for monitoring, and continuous attention should be paid to surface movement and soil erosion of the disposal site.
7.2.2 Groundwater and Plant Samples
In the initial period after site closure, groundwater monitoring should be continued to analyze whether it contains radioactive materials that may come from the disposal site, so as to indirectly judge the integrity of the engineering barrier. If no potential problems are confirmed after a period of monitoring, the frequency of groundwater monitoring can be gradually reduced.
Plant samples (especially deep-rooted plants) within the disposal site (focusing on the disposal unit area) should be collected regularly during the active monitoring period to analyze whether the samples contain radioactive substances that may come from the disposal site and judge the environmental impact.
7.2.3 Ambient γ radiation level
Retain one continuous monitoring point of ambient γ radiation air absorbed dose rate set during operation to continue continuous monitoring, and retain periodic γ radiation air absorbed dose rate instantaneous measurement at some points.
7.2.4 Other monitoring
Conduct regular monitoring or inspection of surface movement and soil erosion of the disposal site, and analyze the possible impact of changes on the disposal unit in time when obvious changes are found, and judge whether engineering measures are needed.
7.3 Environmental monitoring outline
The implementation period of the environmental monitoring outline of the post-closure phase should cover the active monitoring period after the closure of the disposal site. The monitoring items, frequency and points in the outline should be set according to the requirements of section 7.2, and other content requirements should be the same as section 5.5.
7.4 Monitoring of the passive monitoring period
The monitoring results of the active monitoring period to determine whether to continue to carry out monitoring of the radiation environment during the passive monitoring period. If you need to continue to carry out the radiation environment monitoring, passive monitoring period
8 Data processing and monitoring reports
8.1 Data processing and preservation
8.1.1 It is appropriate to carry out data processing in accordance with the relevant requirements of HJ61 and other standards and specifications, and the final results of radiation environmental monitoring should be scientific and reasonable.
8.1.2 It is recommended that the construction of the disposal site radiation environment information management system to save all environmental monitoring process and results data, to provide data support for the entire life of the disposal site.
8.2 Monitoring report requirements
8.2.1 Monitoring report should be prepared to comprehensively introduce the monitoring process and results, and the format and frequency of the report should be decided according to the purpose of the report.
8.2.2 The content of the monitoring report should include at least
a) A comprehensive description of the monitoring task or plan;
b) Detailed site surroundings associated with the measurement program;
c) detailed description of the sample collection process, giving a clear layout map of each monitoring item, giving the sample type, sampling process, sampling equipment, sampling volume, sampling location and frequency;
(d) give the analytical nuclides, analytical methods, analytical instruments and minimum detection limits;
(e) a detailed description of the sample preparation and measurement process, measurement results, including measured values and standard deviations, measurement results should be scientific and reasonable;
(f) a detailed description of quality assurance measures and their effects;
(g) combined with the collected monitoring data to evaluate in detail the state of the radiation environment around the site, for the existence of abnormal data, should be a detailed analysis of the reasons for the abnormal;;
(h) operation phase and post-closure monitoring should also be compared with the data of the pre-operation radiation environment background survey and control point data to analyze the environmental impact and change trends;
i) According to the current radiation environment monitoring results on the subsequent radiation environment monitoring work to make recommendations.
9 Quality assurance
9.1 Quality assurance should be throughout all stages of the disposal site radiation environment monitoring, and should be throughout the process from the development of the monitoring outline to the evaluation of the monitoring results.
9.2 Each stage of radiation environmental monitoring work undertaken by the unit should establish a quality assurance system and make it continuous, compliant and effective operation.
9.3 quality assurance both to ensure that the monitoring outline in the monitoring of the whole process of correct implementation and obtain credible monitoring results, but also to ensure that the evaluation of monitoring results in line with the quality assurance requirements.
9.4 Quality assurance measures should consider at least the following factors:
a) operational procedures for sampling, transport, preservation, sample preparation and measurement of various types of samples are well documented;
b) the quality of equipment, instruments, articles, apparatus, and reagents;
c) Calibration and verification of equipment and instruments and ensuring that they are within the validity period;
d) Training and qualification of personnel;
e) confirmation of methods through routine analysis of control samples and application of standard analytical methods;
f) traceability of monitoring results to national standards;
g) data processing and uncertainty analysis;
h) comparative measurement content with other laboratories;
(i) to prove that the required quality is achieved and maintained and the need for document management and preservation.
9.5 disposal site operators need to save the pre-operational phase of the radiation environment background survey of soil, sediment and biological ash samples obtained. Properly preserve the original records and quality records of the survey to ensure the traceability of the survey. Pre-operation radiation environment background survey results and reports need to be kept permanently.
Monitoring outline and monitoring report of each stage are included in the systematic analysis of the whole safety process.
Foreword
1 Scope of application
2 normative reference documents
3 Terminology and definitions
4 General requirements
5 pre-operation phase
6 Operational phase
7 Post-Closure Phase
8 Data processing and monitoring reports
9 Quality assurance
