1 Scope
This standard specifies the basic requirements of overpressure analysis for reactor coolant system and main steam system for pressurized water reactor nuclear power plants.
This standard is applicable to the overpressure analysis for reactor coolant system and main steam system for pressurized water reactor nuclear power plants.
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.
NB/T 20035-2011 (2014RK) Categorization of conditions of PWR nuclear power plants
NB/T 20104 Analysis requirements for anticipated transient without scram on pressurized water reactor nuclear power pants
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
condition II
possible deviation from normal operation or fault of a nuclear power unit within one calendar year
3.2
condition III
event that may occur during the service life of a nuclear power unit but at a very low frequency
3.3
condition IV
hypothetical accident that is unlikely to occur during the service life of a nuclear power unit but shall be provided with targeted design measures
3.4
reactor coolant system
circulating system for transferring heat generated by the reactor core to the secondary side of steam generator
3.5
main steam system
system for transferring steam from the steam generator to other equipment, consisting of secondary side of steam generator, main steam pipe, main steam atmospheric relief valve, main steam safety valve, main steam isolation valve, etc.
3.6
reactor coolant system pressure boundary
outermost physical boundary that contains reactor coolant and bears system design pressure and design temperature, usually limited to the first isolation valve that connects the auxiliary system pipe with the main pipeline
3.7
anticipated transients without scram (ATWS)
anticipated event that occurs in the nuclear power plants and changes the reactor physical and thermal parameters to the shutdown thresholds, without reactor shutdown when subsequent automatic shutdown is required (also referred to as ATWS)
3.8
water solid
status in which reactor has been shut down, the residual heat removal system is put into operation and the pressurizer is full of water
3.9
low temperature overpressure
system overpressure that may be caused by energy injection or mass injection when the reactor coolant system is at low temperature and the pressurizer is in a water solid status
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Requirements for overpressure analysis of power operation condition
5 Requirements for low temperature overpressure analysis
6 Criteria for overpressure analysis
