Establishment of Material Properties Database for Irradiated Core Structural Components for Continued Safe Operation and Lifetime Extension of Ageing Research Reactors

QUESTIONNAIRE

FOR POTENTIAL CRP PARTICIPANTS


Establishment of Material Properties Database for Irradiated Core Structural
Components for Continued Safe Operation and Lifetime Extension of Ageing
Research Reactors


Please provide, when possible, your

Country:

Name*:

Title/position:

Affiliation:

E
-
mail*:

*The names and addresses will not be disclosed to any third parties but are needed, should we
need further clarification or follow up regarding the questionnaire
.


The proposed CRP will provide a forum
for input and discussion of relevant materials data and
operating experience with research reactors leading to establishment of a “
Research Reactor
Components and Material Properties Database
” to be used by research reactor operators and
regulators to help

predict ageing related degradation so as to mitigate lengthy and costly shutdowns
and to promote safe and reliable operation and lifetime extension. The Database will be a
compilation of data from research reactor operator input, comprehensive literature
reviews and
experimental data from research reactor. The Database will be provided to all potential end users of
Member States to provide a structure for future incorporation of new data that becomes available.
Moreover, the CRP will specify further activi
ties needed to address the identified data gaps of the
Database for potential follow
-
on activities required by Member States.

The purpose of this
questionnaire is to collect from Member States operating RRs (≥1MW) preliminary information on
the
needs and
t
ypes of activities
considering the prediction of ageing related degradation of core
components.
In

order to get an overview of the practices on follow up of
ageing
core structural
materials and to define the CRP in a more efficient way, the operators or re
gulators involved in the
operation of research reactors are asked to answer

the

following questions:


Please note that this information is of interest, even if you do not want to participate in the CRP.


Deadline: you should submit this questionnaire electronically to
Andrea Borio di Tigliole

(
A.Borio@iaea.org
) or Nathan D. Peld (
N.D.Peld@iaea.org
)





1.

What are the components

and

materials

affected by ageing

in your facility?


2.

What information is available to you for those materials?


3.

What information is not available that you would like to have?


4.

What form of database would be most useful to you?


□

MS Access

□

MS Excel
(Spreadsheet)

□

DBase

□

SQL, (Dedicated Web
-
based)

□

Other (Please specify below)



5.

What specific monitoring and surveillance programmes are implemented at your
facility

to address ageing of core components and materials
?


APPENDIX

1


DATA NEEDED
FOR EVALUATION OF MATERIAL CAPABILITY TO PERFORM ITS
SAFETY FUNCTION:


Material properties for un
-
irradiated material and for high to very high neutron and gamma fluence for a
given material and at appropriate fast/thermal ratios:

Environment:



Definition
of fast and thermal neutron energies.



Fast to thermal ratio for each test.



Fluxes



Irradiation and test temperatures.



Coolant chemistry (e.g. for water: pH, conductivity; for NaK: mass ratio; for He: impurities)

Sample:



Definition of un
-
irradiated specimen

material (certificated composition and thermal
-
mechanical
treatment, material properties, residual stresses etc.).



Standard used for specimen manufacture.

Measurements and calculations:



Composition changes (chemical and isotopic) (calculated or measured?)
.



Displacements per atom (with method of determination).



Formation of loops and dislocation density (m
-
2
).



Voids and bubble density and composition (
1
H,
3
H, He) (% volume or m
-
2
).



Swelling (volume %).



Corrosion rate (dimensional, mass changes).



Changes in
resistance to Stress Corrosion Cracking (SSR test, ECP
-
diagram).



Changes in UTS, yield strength, 2% yield (MPa).



Changes in ductility (uniform and total elongation) (%).



Changes in fracture toughness (MPa.m
½

).



Changes in stress and strain driven fatigue p
roperties (threshold stress; N
f

with definition).



Changes in fatigue crack growth rate (da/dn).


The list above gives the main parameters of interest for most irradiated structural materials. Additional
parameters should be provided, as appropriate, for ma
terials with special applications. Some (non
-
exhaustive) examples follow:



Epoxy resins and glues: initial curing conditions and subsequent bond degradation with neutron
and gamma fluence,



Fastening and joining aspects: bolting (relaxation, galvanic), weldi
ng (heat affected zone,
galvanic), compatibility of materials,



Graphite: Swelling, accumulation of Wigner energy,



Zirconium: Growth, directionality of properties,



Concrete: density, compression strength.



Cable insulation: Insulation degradation.



APPENDIX

III

RESEARCH REACTOR CORE COMPONENTS AND MATERIALS


This Appendix contains a listing of typical research reactor core components and structures and the most
common materials used. In the Table, components that are generally fixed and difficult to replace
are
indicated by (1) and those that are more readily replaced are indicated by (2). The ease of replacement of
components is determined by the research reactor design and the indications given may not be accurate for
all designs.


Components

Materials


Co
mponents

Materials

Pressure(Tank) vessel + connecting pipes


Reflector Devices/Systems

Pressurized vessel (1)

Low alloy steel

Aluminium alloys

Stainless steel


Heavy Water tank &
accessories (1)

Aluminium alloys

Zirconium

Metallic sealing rings

Low
pressure tank (1)

Aluminium alloys

Stainless steel

Zirconium


Beryllium (1/2)

Beryllium

Aluminium
-
Be alloy

Connecting pipes (1/2)

Aluminium alloys

Stainless steel


Graphite (2)

Graphite

Beam ports/nozzles (1)

Aluminium alloys

Low alloy steels

Zirconium


Beam related devices, highly irradiated portion (2)

Poolside irradiation facility
(1)

Aluminium alloys

Stainless steel


Cold source

Zirconium

Aluminium alloys

Liners (Pool type RR) (1)

Aluminium alloys

Stainless steels

Epoxy resins

Ceramic tiles


Thermal

column

Zirconium

Aluminium alloys

Core support structure components


Neutron guide tubes

Aluminium alloys

Stainless steels

Core support grid (1/2)

Aluminium alloys

Stainless steels

Low alloy steels


Shielding structures

Other structural and internal
support structures

Aluminium alloys

Stainless steels

Low alloy steels


Concrete (1/2)

High density concrete

Structural concrete

Core box/vessel (1/2)

Aluminium alloys

Stainless steels

Low alloy steels


Lead (2)

Lead types

Guide Tubes (2) for:


Tungsten
(2)

Tungsten alloys

Control devices

Aluminium alloys

Stainless steels

Inconel

Zirconium


Other

Fuel elements

Aluminium alloys

Zirconium


Cables

Organic insulation

Experimental facilities

Aluminium alloys

Stainless steels

Inconel

Zirconium




Isotope
production

Aluminium alloys

Stainless steels

Zirconium