About Nuclear and Radiation Safety Center

Nuclear and Radiation Safety Center

The Nuclear and Radiation Safety Center, usually shortened to NSC, is the principal technical support organisation for nuclear and radiation safety regulation in China. Based in Beijing, it serves the National Nuclear Safety Administration (NNSA) within the Ministry of Ecology and Environment (MEE). Its work is technical rather than political: it reviews, assesses, calculates, tests and researches, so that the regulator can decide whether civil nuclear facilities and radiation activities meet safety requirements. That distinction matters. The Center is not the ministry itself, and it is not the licensing authority. It is the permanent expert body whose assessments form the technical basis on which licensing and supervision decisions are made.

Identity, Location and Institutional Role

Published papers by the Center's staff give its address as No. 54 Hongliannancun, Haidian District, Beijing 100082, China, and identify it in affiliations as the Nuclear and Radiation Safety Center of the Ministry of Ecology and Environment. China's Ninth National Report for the Convention on Nuclear Safety, published in August 2022, states the position plainly: the Nuclear and Radiation Safety Center is the permanent technical support organization under the MEE (NNSA).

The same national report gives a sense of scale. It recorded 590 employees in the Nuclear and Radiation Safety Center, compared with 85 employees in the regulator's headquarters and 331 employees in its six regional offices. In other words, much of the technical depth of the Chinese nuclear safety regulatory system sits in this Center, rather than in the administrative headquarters that issues licences.

China's 2019 white paper, Nuclear Safety in China, describes a three-pronged regulatory system consisting of headquarters, regional offices and technical support organisations. It names professional technical support organisations such as the Nuclear and Radiation Safety Center and the Radiation Monitoring Technical Center as providing technical support for nuclear safety review, independent verification, surveillance, law enforcement and assessment of the radiation environment.

Place in China's Regulatory System

Understanding the Center requires understanding the system around it. The Ministry of Ecology and Environment, acting as the National Nuclear Safety Administration, is China's nuclear and radiation safety regulator. It undertakes overall regulation of national nuclear safety, radiation safety and radiation environmental protection, and regulates civil nuclear facilities and nuclear technologies in a centralised manner. The NNSA was officially established on 2 July 1984.

Within that history, the NNSA's own overview records that technical support units, including a Beijing nuclear safety review centre and a Suzhou nuclear safety centre, came into being after the administration's creation, and that during the integration and improvement stage from 1998 to 2008 the Nuclear and Radiation Safety Center, the Technical Center for Radiation Monitoring and other technical support organisations expanded or were upgraded and their technical power was strengthened.

The Center's relationship to the regulator is governed by a principle of independence from the applicant. The Convention on Nuclear Safety report explains that, under China's Nuclear Safety Act, the regulatory department must entrust a technical support organisation having no interest relationship with the applicant when organising safety and technical review, and that the entrusted organisation is responsible for the authenticity and accuracy of its technical assessment result. The Center fills that role on a permanent basis.

Technical Review and Assessment for Licensing

Nuclear safety review constitutes the technical basis for issuing an administrative licence for a nuclear power plant in China, and a licence is issued by the MEE (NNSA) only after that safety review. The regulator organises technical support organisations to perform the overall review and assessment of the application documents submitted by a facility's operating organisation. Review covers nuclear safety-related activities across the full lifetime of a plant, including siting, construction, operation and decommissioning.

The methods used in that review are documented in the national report. Technical review includes compliance checking of application materials against regulations and standards, review of analysis and calculation results, review of test results, document review, audit calculation, test verification, technical communication and expert consultation. The operating organisation must respond to questions raised during the review and supplement documents where necessary.

A 2014 presentation by the Center to an International Atomic Energy Agency (IAEA) conference on technical and scientific support organisations listed the technical areas in which the Center was then involved. They included core and event analysis, probabilistic safety analysis, civil and mechanical calculation, criticality safety, radiation protection, nuclear facility siting, environmental impact assessment, radioactive consequence evaluation and emergency response. That list, given by the Center itself, remains a useful map of the breadth of review work a national technical support organisation must be able to perform.

The National Research and Development Base

The Center's capabilities were substantially expanded by the National Research and Development Base for Nuclear and Radiation Safety Regulation Technology. According to China's Ninth National Report, construction of the Base started in March 2016 and the Base was officially put into operation in June 2019.

The Base brought together a number of experimental facilities and platforms. The national report lists an environmental radiation monitoring laboratory, a risk management laboratory, a Generation II Plus full-scale verification simulator laboratory, the MEE (NNSA) Nuclear and Radiation Accident Emergency Command Center, and the State Environmental Protection Key Laboratory of Nuclear and Radiation Safety Regulatory Simulation and Validation. Together, the report says, the Base provides a full range of capabilities in environmental radiation monitoring, real-time domestic nuclear power plant risk monitoring, timely response to nuclear and radiation emergencies, and independent nuclear and radiation safety check calculation.

The Base also pointed to future work. The report noted plans to strengthen regulatory information technology and smart technology, and nuclear safety and nuclear facility decommissioning safety verification capabilities, in order to further improve the capacity and efficiency of nuclear and radiation safety supervision.

The State Environmental Protection Key Laboratory

The State Environmental Protection Key Laboratory of Nuclear and Radiation Safety Regulatory Simulation and Validation is hosted by the Center and appears repeatedly as an affiliation in the Center's published research. Journal articles list it, alongside the Nuclear and Radiation Safety Center of the MEE in Beijing, as the institutional home of authors working on regulatory simulation and validation.

The laboratory's name describes its function. Simulation and validation are the processes by which the calculations used to judge a reactor's safety are checked against test data, operating experience and independent analysis. Work published under the laboratory's affiliation includes a 2025 study, in the International Journal of Advanced Nuclear Reactor Design and Technology, on the applicability of containment test data for the HPR1000 reactor design. Based on similarity analysis of the pressure response process in containment, the study examined test data from scaled containment facilities including HDR, Battelle and CVTR, and assessed whether small-scale test data could suitably be used for verification and validation of the HPR1000 containment thermal-hydraulic response analysis code in large-break loss-of-coolant and main steam line break accidents.

Earlier work under the same affiliation addressed tritium release from pressurised water reactors. That study established a calculation model for tritium release, compared its results with operational feedback data from a Chinese nuclear power plant during normal operation from 2003 to 2018, and concluded that the simulation values were consistent with actual operation.

Autonomous Nuclear Safety Analysis Software Evaluation Since 2015

One of the Center's best-documented programmes is its work on evaluating Chinese-developed, or autonomous, nuclear safety analysis software. A peer-reviewed account published in Frontiers in Energy Research in December 2021, co-authored by Center staff, records the chronology in detail. In 2015, the Nuclear and Radiation Safety Center began to conduct research on the evaluation methods of autonomous software, carrying out detailed research and planning on licensing conditions, autonomous software evaluation procedures and document requirements for applying such software in reactor safety analysis. The Center also wrote the draft safety analysis software assessment methods research report, which initially determined the implementation plan for autonomous software evaluation.

In 2016, under the framework of the preliminary validation stage of the NESTOR software package, the Center carried out verification, validation and third-party testing of NESTOR. NESTOR, developed under the China National Nuclear Corporation for the Hualong One design, consists of 68 pieces of software covering reactor design, safety analysis, testing, refuelling and emergency response. By participating in the development process as a third party, the Center gained a full understanding of NESTOR's theoretical model, software framework and verification status, laying the foundation for later software safety evaluation.

The wider system followed. In November 2017 the NNSA officially published guidelines on the development and application of computer software for safety analysis of nuclear power plants, together with implementation measures for evaluation, and software assessment was officially launched. In 2018 the NNSA began engineering applicability evaluation for software developed by Chinese companies, because no software had been formally approved before that date and unevaluated software could not be used in reactor safety analysis. After several years of review, the core physics analysis software PCM, developed by the China General Nuclear Power Group, became the first approved Chinese domestic software, passing the software safety evaluation. The NNSA and the Center together performed the assessment on PCM, covering its physical models and its verification and validation.

The evaluation framework the Center helped to build covers five categories of code: nuclear reactor design codes, thermal-hydraulics codes, containment thermal-hydraulic analysis codes, fuel performance analysis codes and radioactive safety analysis codes. Severe accident codes were not included, because the NNSA held that the theory of severe accidents had not yet been clarified and sufficient verification tests were lacking. Evaluations examine not only the code itself but also input parameters, model selection and meshing, are carried out only on a frozen version of the software, and normally take no less than 18 months for an autonomous code. As of October 2021, 25 pieces of software had been submitted to the NNSA.

Emergency Response, Monitoring and Environmental Work

The Center's responsibilities extend beyond design review. Its 2014 presentation described work to improve the emergency response plan system and procedures, enhance staffing and training for the emergency group, and update the Nuclear and Radiation Accident Emergency Technical Center, including a real-time nuclear power plant data transmission system and an event consequence prediction and assessment system. It also described building a radiation environment monitoring laboratory with advanced instruments to perform measurement and analysis of various media, noting that the Center's monitoring laboratory had passed review by the China National Accreditation Committee.

Environmental research by Center staff has also addressed more specific questions. A 2025 study published in the journal Biology, with authors from the State Environmental Protection Key Laboratory at the Center, examined the thermal tolerance of a farmed oyster species to the warm water discharges of coastal nuclear power plants, using simulated seasonal water temperatures to assess effects on survival, growth and nutritional quality. The authors presented the work as providing data and technical support for optimising thermal discharge management at nuclear power plants.

Standards, Guidelines and Regulatory Research

The Center also contributes to writing the rules it later applies. It is listed as a drafting organisation for Chinese national standards on nuclear power plant emergency preparedness and response and on intelligent operation and maintenance systems for nuclear power plants. More recently, the Guidelines for Ecological and Environmental Impact Assessment of Magnetic Confinement Fusion Devices, issued by the Ministry of Ecology and Environment (National Nuclear Safety Administration), were compiled by the Nuclear and Radiation Safety Center. The guidelines were drawn up from domestic and international regulations and standards and from the construction and operation characteristics of China's fusion devices, and are intended to standardise ecological and environmental impact assessment across the full life cycle of fusion devices in China. Their issuance was described as filling a gap in China's specialised guidelines for environmental impact assessment of fusion devices.

Center staff have also published analytical work on the regulatory system itself. A 2022 technical note in the Journal of Nuclear Fuel Cycle and Waste Technology, authored by staff of the Nuclear and Radiation Safety Center of the MEE, examined how China's nuclear safety supervision technical support ability could be improved. It described the NNSA as the decision-making department, alongside six regional safety supervision stations, the Nuclear and Radiation Safety Center, a nuclear safety expert committee and the national research and development base serving as the test, verification and research platform, and argued that future work must focus on improving technical support capacity so that regulatory independence rests on capability as well as on institutions.

International Cooperation and the IAEA Collaborating Centre Designation

The Center has long worked internationally. In October 2014, Beijing hosted the IAEA International Conference on Challenges Faced by Technical and Scientific Support Organizations in Enhancing Nuclear Safety and Security, organised by the IAEA and hosted by the Government of China through the Nuclear and Radiation Safety Centre, at which the Center presented its capability-building work. Its staff have also contributed to international common positions on the licensing of safety-critical software for nuclear reactors, in which the Center appears as China's participating organisation alongside regulators and technical support organisations from other countries.

The most significant recognition came in May 2023. During IAEA Director General Rafael Mariano Grossi's visit to China from 22 to 26 May 2023, his first official visit to the country since taking office in 2019, Grossi designated China's Nuclear and Radiation Safety Centre as an IAEA Collaborating Centre. Reporting of the visit noted that the designation highlighted China's commitment to nuclear safety. Care with wording is important here: the IAEA and international reporting use the British spelling “Centre” and the form “Nuclear and Radiation Safety Centre” for the designated institution, while the Center's own English name in its journal affiliations uses the American spelling “Center.” Both forms refer to the same Beijing institution profiled here. An IAEA Collaborating Centre is a member-state institution designated by the IAEA, through a collaborating centre agreement, to support the agency's programme activities through research, development and training.

Why the Center Matters

A nuclear regulator can only be as strong as the technical work behind its decisions. Licences for siting, construction, operation and decommissioning depend on reviews of calculations, tests and safety cases that the regulator cannot simply take on trust. In China, that independent checking function is institutionalised in the Nuclear and Radiation Safety Center: the permanent technical support organisation under the MEE (NNSA), responsible for the authenticity and accuracy of its assessment conclusions, equipped since 2019 with a dedicated research and development base and a key laboratory for regulatory simulation and validation, experienced since 2015 in building the methods by which domestic safety analysis software is judged, and recognised in 2023 as an IAEA Collaborating Centre. For anyone tracing how a Chinese nuclear facility was reviewed, how a safety code was approved, or how a new regulatory guideline such as the fusion assessment guidelines was produced, this Beijing center is very often the technical author behind the decision.