Session: 02-06: Design Analyses and Optimisation

Paper Number: 64716

Start Time: August 6, 2021, 12:00 PM

64716 - Research on DTS Analysis Method for 1000MWe PWR NPP 

The design transients (DTS) are intended to be used to evaluate component stress analysis, which bound the plant operation over the design plant life, and will be as a reference document regarding plant usage factor surveillance.

The conditions of DTS represent umbrella cases for plant events that are expected to occur, or that may occur, during the plant lifetime. For different operating conditions, DTS analysis methods would be different.

This report describes the DTS analysis method to be used when designing the major reactor coolant system components of the HPR1000 plant. Some of components will be considered: RPV, Main Coolant Lines, Reactor Coolant Pumps, Pressurizer and Steam Generators.

Generally, variations in fluid pressure, fluid temperature and flowrate are used to represent the DTS. For this report will supply three methods to explain the main thermal hydraulic parameters changes:

1)         The bounding analysis was carried out according to the operating procedures ;

2)         Through the program simulation ;

3)         Based on engineering judgment and experience.

The detailed of DTS is made up of the following informations :

―   An initiating event and a scenario

―   A classification

―   An expected number of occurrences during the whole plant operation: 60 years (HPR1000)

―   A list of the systems that are or can be actuated during the considered T/H  condition

―   A list of components on which the loading condition will be applied

―   Time history of the main thermal hydraulic parameters:

·     CL and HL Temperatures,

·     SG Pressure,

·     PZR Pressure,

·     Primary loops flow rate,

·     Normal spray flow rate …

a)        SBLOCA transient analysis

With the CATHARE program, the design transient calculation under penalty condition is applied to SBLOCA.

b)       FLB transient analysis

After the FLB happened, the affected steam generator quickly relieve pressure, a large number of steam and water instantaneous discharge. The steam and water of the steam generator are also discharged through the break.

The results show that the DTS analysis method is reasonable and feasible, which can meet the requirements of system function and subsequent equipment curing.

Presenting Author: yubin zhang China Nuclear Power Research Institute Ltd

Authors: