Prediction of axial and radial creep in

pressure tubes

Zhengqiang LIANG

PIE Hot Laboratory

China Institute of Atomic Energy 2-4 July 2013

1st Research Coordination Meeting for the Coordinated Research Project

Contents

1 Brief Introduction to the Laboratory

2 Work Performed Related with Pressure Tube

4 Future Plan and Suggestions

3 Proceedings of the Contract

1. Brief introduction to the hot laboratory

Research Activities:

PIE of fuel rods

Surveillance of RPV materials

Failure analysis of reactor components

Development of high activity Cobalt-60 sealed source: CN-101

1. Brief introduction to the hot laboratory

Research Facilities:

CARR non-destructive examination hot cell

CEFR non-destructive examination hot cell

Destructive examination hot cells

Cobalt-60 fabrication hot cells

1. Brief introduction to the hot laboratory

Research Facilities:

CARR non-destructive examination hot cell

1. Brief introduction to the hot laboratory

Research Facilities:

R52 Fuel rod transportation cask

1. Brief introduction to the hot laboratory

Research Facilities:

Destructive examination hot cells

1. Brief introduction to the hot laboratory

Research Facilities:

Cobalt-60 fabrication hot cells

2 Work Performed Related with Pressure Tube

Experiments to un-irradiated pressure tube and materials:

• Non destructive examination of the simulated PT;

• Specimen preparation technology ;

• Axial DHC tests;

• CT fracture toughness tests;

• Tensile test;

• Metallographic test;

• Hydrogen content measurement.

Visual inspection: By means of the multi-function bench, Periscope, Camera

1)NDE of the simulated PT inside hot cell

Results of visual inspection to SS tube out surface

Visual inspection: By means of the multi-function bench, Periscope, Camera

1)NDE of the simulated PT inside hot cell

Results of visual inspection to SS tube inner surface

1)NDE of the simulated PT inside hot cell

Dimensional measurement to the simulated PT

Out-diameter measurement device Inner-diameter measurement device

sensor sensor

1)NDE of the simulated PT inside hot cell

Eddy current test to the simulated PT inside hot cell

Eddy current test device

EC sensor

Equipments include: linear cutting machine,

electro sparkling machine, fitting device.

All operations are conducted by manipulators in

semi-hot cell

2) Specimen preparation equipments and technology

CCT specimen prepared

2) Specimen preparation equipments and technology

2) Specimen preparation equipments and technology

TT specimen prepared

CCT specimen: for fracture toughness and delayed hydride crack

(DHCR) test;

Tensile test specimen: for axial and radial

CCT specimen Axial TT specimen Radial TT specimen

2) Specimen preparation equipments and technology

3) DHC experiments to Zr-2.5Nb materials

Hydrogen permeation equipment

WH=25.76t0.45 R2=0.9563

Technical parameters:

Electrolyte ： 0.2mol·L-1

Temperature：65±5℃

Current density： 50mA/cm2

Time ：8h

Hydrogen content:

60μg/g

3) DHC experiments results to Zr-2.5Nb materials

Speci

men

H

μg/g

T(℃) a（mm） t（s） DHCR

×10-8m/s

loading

（kN） Peak Exp. V a0 aF aD Qestate DHC

DA1 60 320 250 0.675 2.08 3.11 16740 60336 5.15 0.904 16.55

DA2 60 320 250 0.675 1.67 3.62 62496 23904 15.14 0.996 16.91

DA3 60 320 250 0.675 1.85 3.37 379 50539 6.68 1.054 18.49

DA4 60 270 200 0.675 2.17 2.04 0 86400 2.36 1.408

26.22

DA5 60 270 200 0.675 2.03 1.74 3996 82404 2.11 1.703 30.89

DA6 60 220 150 0.675 —— —— —— —— —— —— ——

DT1 60 320 250 0.675 2.42 0.56 —— —— —— —— ——

DT2 60 320 250 0.675 —— —— —— —— —— —— ——

DT3 60 320 250 0.675 —— —— —— —— —— —— ——

DT4 60 320 250 0.675 —— —— —— —— —— —— ——

3) DHC experiments results to Zr-2.5Nb materials

SEM observation to the rupture

4)Tensile test to Zr-2.5Nb materials

Tensile test equipment

4)Tensile test to Zr-2.5Nb materials

SEM observations to ruptures before and after H permeation

Before permeation Ruptures after permeation

(65μg/g)

5) Fracture toughness test to Zr-2.5Nb materials

Fracture toughness test device

5) Fracture toughness test to Zr-2.5Nb materials

Results:

T(℃) H

(μg/g) Orientation

FQ kN

Fmax kN

KQ MPam1/2

KIC KC*

MPam1/2 J0

kJ/m2

20 10 ∥ 2.75 4.41 50.2 no 80.5 172

150 10 ∥ 1.35 2.64 27.4 no 53.6 148

250 10 ∥ 1.25 2.34 24.2 no 45.4 119

20 65 ∥ 2.34 3.34 44.8 no 64.0 88

150 65 ∥ 1.30 2.63 24.9 no 50.4 132

250 65 ∥ 1.10 2.13 21.8 no 42.2 113

20 10 ⊥ 2.35 3.55 43.3 no 65.4 98

150 10 ⊥ 1.4 2.57 26.7 no 49.1 82

250 10 ⊥ 1.07 2.08 21.7 no 42.1 73

20 65 ⊥ 2.42 3.51 42.9 no 62.4 86

150 65 ⊥ 1.25 2.5 24.0 no 48.0 64

250 65 ⊥ 1.06 2.09 20.6 no 40.5 80

3 Proceedings of the Contract

The contract (17589) signed between IAEA and CIAE in Nov. 2012

Main contents include:

From August to December 2012

-Preparing and submitting the CRP research proposal

-Discussing and preparing plan for overall CRP period. Specially discussing and preparing agreements on the ownership, scope of data to be included, database holder, and maintenance scheme for database.

-Assessing the existing database; summarizing data correlations by using large amounts of data and normalizing the data; studying the effect of intrinsic (material response) and extrinsic parameters (operating conditions); identifying the function corrections of variables; Identifying more future needed data.

3 Proceedings of the Contract

Main contents include:

From January to December 2013

-Selecting and designing the structure of database and template for data collection by sending questionnaire to all participants.

-Signing agreements on the ownership, scope of data to be included, database holder, and maintenance scheme for database.

-Establishing and testing the database. CIAE can send one person to help this work if IAEA need help.

-Preparing and submitting the existing data from China CANDU-6 reactors for the database.

3 Proceedings of the Contract

Main contents include:

From January to December 2013 (continued)

- Developing a prediction model for China CANDU-6 reactor plant. Firstly, the tri-axial creep characteristics are understood by analyzing the real in-reactor creep curves. Secondary, a creep model is established by using the methods of combined component model. Then the creep model parameters are got by data fitting.

-Planning future collaboration, Discussing and reviewing the creep models from all participants by convening one research coordination meeting.

-Assessing and improving the prediction model using the database.

-Preparing samples for microstructure characterization according to the guidelines from IAEA for channel selection and sample requirements.

3 Proceedings of the Contract

Work performed:

-CIAE submitted research proposal in Sept. 2012

-CIAE spent a lot of time persuading TQNPC to joining in the project and signing the agreement

Answers from TQNPC:

•Principally agreed to provide the original fitting specimen under additional conditions.

•Has no responsibility for providing the operation & inspection data of the PT before signing of the agreement.

So far TQNPC hasn’t signed the agreement/contract.

Research conditions become complicated.

3 Proceedings of the Contract

Issues concerned by TQNPC (3questions to be answered):

• 1、 Role and characterization of CIAE and TQNPC in the project.

Who plays a major role?

• 2、What kinds of benefits can TQNPC get after providing the creep test data? Can they share the data from other countries?

• 3、What kinds of benefits can TQNPC get after providing the test materials? How to guarantee these benefits?

4 Future Plan and Suggestions

Clarify the role and characterization of TQNPC in the research contract.

To guarantee that TQNPC can share the data base.

Make amendment to the contract, persuading TQNPC to join in the program

Since TQNPC has no sufficient specimen of the original PT, will AECL provide it to CIAE for microstructure characterization?

CIAE will sustainably provide technical assistance to CRP.

Establish data base for reactor fuel performance.