1 Scope
This standard specifies the requirements for control of hydrogen concentration in the containment after accidents in nuclear power plants of pressurized water reactor (including design basis accidents and beyond design basis accidents) and the design principles and arrangement principles of the hydrogen concentration control system.
This standard is applicable to control of hydrogen concentration in the containment after accidents in nuclear power plants of pressurized water reactor.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 15761 Design and Construction Rules for Nuclear Island Systems of 2×600MW PWR Nuclear Power Plants
GB/T 17569 Classification for the Items of Pressurized Water Reactor Nuclear Power Plants
GB 18871 Basic Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources
HAF 102 Safety Specifications for Design of Nuclear Power Plant
3 General
3.1 The nuclear power plant of pressurized water reactor shall be equipped with a hydrogen concentration control system to control the hydrogen concentration in the containment after the accidents and to prevent the hydrogen and oxygen accumulated in the containment from reaction to cause slow combustion (slow diffusion combustion) and deflagration (fast turbulent combustion or flame acceleration) or detonation (combustion at supersonic speeds in a mixture of hydrogen, water vapor and air) which may cause failure of containment due to over-temperature and over-pressure. See Annex C for guidelines for judgment of the combustion state of hydrogen.
3.2 Under the design basis accidents, the control of hydrogen concentration can be completed by the mixing, sampling and compounding subsystems in the containment gas monitoring system, or by the hydrogen concentration control system of beyond design basis accident.
3.3 Beyond design basis accident conditions, the hydrogen concentration control system shall include a hydrogen concentration monitoring system, a hydrogen elimination system, and a possible hydrogen mixing system. The hydrogen elimination system shall include a system of a passive hydrogen combination system or a hydrogen ignition system or a passive hydrogen combiner combined with a hydrogen igniter.
3.4 The analysis and calculation of the generation and distribution of hydrogen in the containment during the accident process shall be conducted to provide a basis for the design of the hydrogen concentration control system. See Annex B for examples of hydrogen behavior evaluation for sequence of a number of beyond design basis accidents.
3.5 The concentration of hydrogen in the containment under the accident shall be monitored.
3.6 Effective measures shall be taken to prevent the hydrogen concentration in the containment from exceeding the design limits. If local hydrogen detonation cannot be avoided, it shall be considered in the structure or system design.
3.7 Materials that are susceptible to emergency coolant or spray solution corrosion and may generate hydrogen shall be restricted as much as possible within the containment.
Foreword i
1 Scope
2 Normative References
3 General
4 Design Principles for Hydrogen Concentration Control Systems
5 Arrangement Principle for Main Equipment in Hydrogen Concentration Control System
Annex A (Informative) Mechanism of Hydrogen Generation in Containment Under Accident of Nuclear Power Plants of Pressurized Water Reactor
Annex B (Informative) Examples of Hydrogen Behavior Evaluation for a Number of Beyond Design Basis Accident Sequences
Annex C (Informative) Criteria for Judging the State of Hydrogen Combustion
