CNSC welcomes feedback on any regulatory document at any time REGDOC- supersedes RD, Design of New Nuclear Power. CNSC has issued its Fukushima report – posted on the CNSC website on that the design intent complies with CNSC design requirements (RD, RD-. Re: The Approvals Process for New Reactors in Canada – RD & RD ( CNSC) request for feedback on the comments received on the.
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The MCR contains a safety parameter display system that presents sufficient information on safety-critical parameters for the diagnosis and mitigation of DBAs and BDBAs, including severe accidents. Fuel design and design limits reflect a verified and auditable knowledge base. Cabling for the instrumentation and control equipment in the MCR is arranged such that a fire in the secondary control room cannot disable the equipment in the MCR. Structures, systems and components A general term encompassing all of the elements items of a facility or activity which contribute to protection and safety, except human factors.
The design provides for adequate removal of radioactive substances from the reactor coolant, including activated corrosion products and fission products leaking from the fuel.
Postulated initiating events can lead to AOO or accident conditions, and include credible failures or malfunctions of SSCs, as well as operator errors, common-cause cnscc hazards, and external hazards. Where MSIVs provide a containment barrier, they meet the containment requirements that apply to those conditions for which they are credited. This includes the adequate design of SSCs to:.
Document History of REGDOC-2.5.2, Design of Reactor Facilities: Nuclear Power Plants
Fail-safe rf-337 Design whose most probable failure modes do not result in a reduction of safety. All containment penetrations are subject to the same design expectations as the containment structure itself, and are to be protected from reaction forces stemming from pipe movement or accidental loads, such as those due to missiles, jet forces, and pipe whip.
For extreme events, there is at least one means of reactor shutdown and core cooling. In DBAs, the fuel assembly and rd-37 component parts remain in position with no distortion that would prevent effective post-accident core cooling or interfere with the actions of reactivity control devices or mechanisms. Most importantly, adequate protection is provided for the confinement function by way of a robust containment design.
Each safety group is able to perform the required safety functions under the worst permissible systems configuration, taking into account such considerations as maintenance, testing, inspection and repair, and equipment outage. The design authority establishes initial severe accident management guidelines, taking into account the plant design features and the understanding of accident progression and associated phenomena.
It may include certain safety and safety support systems, and any interacting process system. In the selection of equipment, due attention is given to spurious operation and to unsafe failure modes e. At least one of the two isolation valves is either automatic or powered, and operable from the main and secondary control rooms.
The design applies the principle that plant states that could result in high radiation doses or radioactive releases have a very low frequency of occurrence, and plant states with significant frequency of occurrence have only minimal, if any, potential radiological consequences. Risk significant system Any plant system whose failure to meet design and performance specifications could result in unreasonable risk to the health and safety of persons, to national security, or to the environment.
These activities are performed to standards commensurate with the importance of the respective safety functions of the SSCs, with no significant reduction in system rx-337 or undue exposure of the site personnel to radiation. The fuel is qualified for operation, either through experience with the same type of fuel in other reactors, or through a program of experimental testing and analysis, to ensure that fuel assembly requirements are met. Cabling for the instrumentation and control equipment in the SCR is such that a fire in the main control r-d337 cannot disable the equipment in the SCR.
These cnsf are capable of leading the plant first to a controlled state, and then to a safe shutdown state, and maintaining at least one barrier for the confinement of radioactive material. Where a direct trip parameter does not exist for a given credited means, there are two diverse trip parameters specified for that means.
Where the valves provide isolation of the heat transport ccnsc during normal operation, both valves are normally in the closed position. The adequacy of the design, including design tools and design inputs and outputs, are verified or validated by individuals or groups that are independent from those who originally performed the work. The design provides two independent means of preventing recriticality from any pathway or mechanism during the GSS.
The design includes provisions to treat liquid and gaseous effluents in a manner that will keep the quantities and concentrations of discharged contaminants within prescribed limits, and that will support application of the ALARA principle.
If operator action is required for actuation of any safety system or safety support system equipment, all of the following expectations apply:.
The safety analysis demonstrates achievement of all levels of defence-in-depth, and confirms that the design is capable of meeting the applicable expectations, dose acceptance criteria, and safety goals. The lifting of large and heavy loads, particularly those containing radioactive material, is considered in the NPP design. The design authority may assign responsibility for the design of specific parts of the plant to other organizations, known as responsible designers. Safety group Assembly of structures, systems and components designated to perform all actions required for a particular cnwc initiating event to ensure that the specified limits for AOOs and DBAs are not exceeded.
Various safety actions are automated so that rd-337 action is not necessary within a justified period of time from the onset of AOOs or DBAs. The control system and the inherent reactor characteristics keep all critical reactor parameters within the specified limits for a wide range of AOOs. To the greatest extent practicable, application of this principle enables plant cnc to pass into a safe state if a system or component fails, with no necessity for any action to be taken.
The tasks and functions of the design authority and any responsible designer need to be established in formal documentation; however, the overall responsibility remains with the design authority. Appropriate preventive and mitigation measures are provided to ensure that nuclear safety is not compromised. The design identifies the rules and practices that have been applied to the complementary design features.
The design authority classifies SSCs in a consistent and clearly defined classification scheme. The criteria for determining safety importance are based on:.
This methodology is applied to determine the margins available for shutdown and for containment of radioactivity. The design includes provisions for adequate redundancy, reliability, and effectiveness, to allow for online maintenance and online testing of systems important to safety, except where these activities are not possible due to access control restrictions. For each common-cause PIE, the hazards analysis then identifies:.
The design includes an emergency heat removal system EHRS which provides for removal of residual heat in order to meet fuel design limits and reactor coolant boundary condition limits. Where water is required for the EHRS, it comes from a source that is independent of normal supplies.
The SCR is to be provided with secure communication channels to the emergency support centre and to off-site emergency response organizations. Safety analyses are performed to confirm that these criteria and goals are met, to demonstrate effectiveness of measures for preventing accidents, and mitigating radiological consequences of accidents if they do occur.
RD Design of New Nuclear Power Plants – Canadian Nuclear Safety Commission
This includes instrumentation for measuring variables that can affect the fission process, the integrity of the reactor core, the reactor cooling systems, and containment, as well as instrumentation for obtaining any information on the plant that is necessary for its reliable and safe operation. This provides a high degree of assurance that no significant damage will occur to the reactor core, and dr-337 radiation doses will remain within established limits.
Where possible, this is achieved without operator intervention.