U.S. patent application number 11/501664 was filed with the patent office on 2007-06-28 for method and device for measuring the power dissipated by a hydridation reaction in tubes and tubular claddings and the corresponding variation in electric resistance.
Invention is credited to Marcos Diaz Munoz, Jaime Izquierdo Gomez, Jose Serafin Moya Corral, Begona Remartinez Zato, Jose Luis Sacedon Adelantado.
Application Number | 20070144625 11/501664 |
Document ID | / |
Family ID | 34833895 |
Filed Date | 2007-06-28 |
United States Patent
Application |
20070144625 |
Kind Code |
A1 |
Sacedon Adelantado; Jose Luis ;
et al. |
June 28, 2007 |
Method and device for measuring the power dissipated by a
hydridation reaction in tubes and tubular claddings and the
corresponding variation in electric resistance
Abstract
The invention relates to a method and device for measuring
hydridation kinetics at different temperatures in tubular
industrial components. The invention consists in measuring the
power dissipated by a hydridation reaction over time as well as the
variation in the electric resistance during said reaction. The
inventive method and device can be used to optimise industrial
components, such as tubes and fuel claddings for nuclear reactor
cores. In this way, safety is increased, with the prevention of
unplanned shutdowns of commercial reactors and a decrease in
high-activity nuclear waste.
Inventors: |
Sacedon Adelantado; Jose Luis;
(Madrid, ES) ; Diaz Munoz; Marcos; (Madrid,
ES) ; Moya Corral; Jose Serafin; (Madrid, ES)
; Remartinez Zato; Begona; (Madrid, ES) ;
Izquierdo Gomez; Jaime; (Madrid, ES) |
Correspondence
Address: |
KLAUBER & JACKSON, LLC
4TH FLOOR
411 HACKENSACK AVE.
HACKENSACK
NJ
07601
US
|
Family ID: |
34833895 |
Appl. No.: |
11/501664 |
Filed: |
August 9, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/ES05/70011 |
Feb 1, 2005 |
|
|
|
11501664 |
Aug 9, 2006 |
|
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Current U.S.
Class: |
148/509 |
Current CPC
Class: |
G01N 25/4846 20130101;
G21C 17/06 20130101; Y02E 30/30 20130101; G01N 27/041 20130101;
G21C 21/00 20130101 |
Class at
Publication: |
148/509 |
International
Class: |
C21D 11/00 20060101
C21D011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 9, 2004 |
ES |
P200400294 |
Claims
1. Method for measuring hydridation kinetics, at different
temperatures, in industrial components such as tubes and tubular
claddings of metallic elements, metal alloys and any other material
with and without protective coverings, wherein it consists of the
measurement of: a) the power dissipated by the hydridation
reaction, hereinafter dissipated hydridation power, as a function
of time, and of the dissipated hydridation energy, measured during
the process, and b) the variation in electric resistance during
that reaction, and in particular during the stage of dissolution of
hydrogen in the component preceding the precipitation of hydrides
in the material. the stages making up this method being: i)
insertion of the tubular component in a high or ultra-high vacuum
chamber, ii) circulation of hydrogen or a mixture of hydrogen with
other gas(es) through the interior of the component, it being the
permeation of the hydrogen via the wall of the component that
causes the hydridation of the material, iii) heating of the
component by the Joule effect, iv) determination of the power
dissipated by the hydridation reaction as a function of time, of
the dissipated hydridation energy measured during the process, and
of the electric resistance in the component by means of: iv.1) the
voltage drop along the component, and iv.2) the variation in
electric current applied for maintaining its temperature at the
predetermined value for the hydridation reaction.
2. Device for carrying out the measurement method of hydridation
kinetics at different temperatures, in industrial components such
as tubes and tubular claddings of metallic elements, metal alloys
and any other material with and without protective coverings,
wherein it comprises the following elements: a) a high or
ultra-high vacuum chamber in which the component to be analysed is
inserted, b) a gas line for causing hydrogen or a mixture of
hydrogen with other gas(es) to pass through the interior of the
component, c) heating systems by the Joule effect, thermocouples
and systems for temperature control in the component, and d) two
electrodes in the form of a ring or other well-defined geometry,
arranged symmetrically and equidistant from the central
thermocouple.
3. The method according to claim 1, wherein the measurements of
hydridation kinetics are made in industrial components of metallic
elements, metal alloys and any other material with and without
protective coverings.
4. The method according to claim 3, wherein the industrial
components are tubular, among others, the tubes and tubular
claddings for fuel in the cores of nuclear reactors.
5. The device according to claim 2, wherein the measurements of
hydridation kinetics are made in industrial components of metallic
elements, metal alloys and any other material with and without
protective coverings.
6. The device according to claim 5, wherein the industrial
components are tubular, among others, the tubes and tubular
claddings for fuel in the cores of nuclear reactors
Description
RELATED APPLICATIONS
[0001] The present application is a Continuation of co-pending PCT
Application No. PCT/ES2005/070011, filed Feb. 1, 2005 which in
turn, claims priority from Spanish Application Serial No.
P200400294, filed on Feb. 9, 2004. Applicants claim the benefits of
35 U.S.C. .sctn.120 as to the PCT application and priority under 35
U.S.C. .sctn.119 as to said Spanish application, and the entire
disclosures of both applications are incorporated herein by
reference in their entireties.
SECTOR OF THE ART
[0002] Measurement of hydridation reactions and kinetics of tubes
and tubular claddings of metallic elements, metal alloys and any
other material with and without protective coverings.
STATE OF THE ART
[0003] The massive hydridation of metallic industrial components is
one of the causes of their becoming brittle and can lead to
catastrophic fracture due to the formation of cracks. This process
takes place in components in contact with water under pressure
and/or boiling and at high temperature, and can become acute when
the component is exposed to high concentrations of hydrogen as a
consequence of other processes. A case that has been known for some
years is the hydridation of tubular fuel claddings in the cores of
nuclear reactors, which can take place massively from inside the
cladding in the event of loss of airtightness as a result of a
primary failure. Patent WO0223162 describes a method and device for
measuring the resistance to hydridation in these tubular components
in order to help in the selection of materials and design aimed at
reducing these problems. Nevertheless, other measurements need to
be determined in order to compare the hydridation kinetics, which
permits the response to hydridation of the different elements and
alloys of the tubular components to be compared and a choice to be
made of those designs and compositions that will prevent or delay
the appearance of these fractures in metallic industrial
components.
[0004] So far, the determination of the hydridation kinetics of
metals and alloys has been carried out by thermogravimetry and
morphological studies of hydridation processes of pieces of
material in an autoclave, which in some cases, as in the
hydridation of fuel claddings, represents working conditions that
are very different from those in which the hydridation of the
component is produced.
DESCRIPTION OF THE INVENTION
BRIEF DESCRIPTION OF THE INVENTION
[0005] The present invention tackles the problem of providing new
methods and tools for measuring the hydridation kinetics taking
place in tubular components for industrial use.
[0006] The solution provided by this invention permits measurement
of the hydridation kinetics in the actual tubular components,
generally multi-layer, and under the same conditions of working
temperature in which the hydridation of the component takes place,
which is of particular economic relevance since it permits the
design and choice of the appropriate composition of the different
alloys used. An optimisation of these components will be able to
help prevent unplanned shutdowns of commercial reactors. This
possible improvement will also allow greater exploitation of the
fuel by making it more robust, and a decrease in the mass of
high-activity nuclear waste for the same amount of energy
generated. By eliminating a possible source of leakage of
components in the reactor water, the dosage of radiation received
by maintenance personnel and personnel having to perform operations
in the exchange zone will be reduced.
[0007] So, the first object of this invention consists of a new
method for measuring hydridation kinetics at different
temperatures, in industrial components, wherein it consists of
measuring: a) the power dissipated by the hydridation reaction,
hereinafter referred to as the dissipated hydridation power (DHP),
as a function of time, along with its integral as a function of
time hereinafter referred to as the dissipated hydridation energy
(DHE), and b) the variation in electric resistance during that
reaction, and in particular during the stage of dissolution of
hydrogen in the component preceding the precipitation of hydrides
in the material;
[0008] The second object of this invention consists of a device
(FIG. 4) for carrying out the aforementioned measurement method
consisting of: [0009] a) a high or ultra-high vacuum chamber in
which the component to be analysed is inserted, [0010] b) a gas
line for causing hydrogen or a mixture of hydrogen with other
gas(es) to pass through the interior of the component, [0011] c)
heating systems by the Joule effect, thermocouples and systems for
temperature control in the component, and [0012] d) two electrodes
in the form of a ring or other well-defined geometry, arranged on
the component symmetrically and equidistant from the central
thermocouple connected with the outside of the device where the
measurements are going to be made.
[0013] Finally, the third object of this invention consists of the
use of the said method and device for making measurements of
hydridation kinetics in industrial components of metallic elements,
metal alloys and any other material with and without protective
coverings, preferably tubular components such as tubes and tubular
claddings for fuel in the cores of nuclear reactors.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The first object of this invention consists of a new method
for measuring hydridation kinetics, herein after the inventive
method, at different temperatures, in industrial components of
metallic elements, metal alloys and any other material with and
without protective coverings, wherein it consists of measuring:
[0015] a) the power dissipated by the hydridation reaction,
hereinafter the dissipated hydridation power (DHP), as a function
of time, along with its integral as a function of time hereinafter
referred to as the dissipated hydridation energy (DHE), [0016] b)
the variation in electric resistance during that reaction, and in
particular during the stage of dissolution of hydrogen in the
component preceding the precipitation of hydrides in the material;
and because the stages making up this method are: [0017] i)
insertion of the tubular component in a high or ultra-high vacuum
chamber, [0018] ii) circulation of hydrogen or a mixture of
hydrogen with other gas(es) through the interior of the component,
it being the permeation of the hydrogen via the wall of the
component that causes the hydridation of the material, [0019] iii)
heating of the component by the Joule effect, [0020] iv)
determination of the dissipated hydridation power as a function of
time, of the dissipated hydridation energy measured during the
process, and of the electric resistance in the component by means
of: [0021] iv.1) the voltage drop along the component, and [0022]
iv.2) the variation in electric current applied for maintaining its
temperature at the predetermined value for the hydridation
reaction.
[0023] As used in the present invention, the term "industrial
components" refers to tubular components, with a wall consisting of
a single element or with multi-layer wall, as are tubes and tubular
claddings for fuel in the cores of nuclear reactors.
[0024] The control of these industrial components by means of the
inventive method will permit the design and choice of the suitable
composition of the different alloys used for the manufacture of
those components, thereby avoiding their fracture.
[0025] During the precipitation reaction and formation of hydrides,
the heat of reaction causes a drop in the electric current being
applied in order to keep the temperature constant, which leads to a
decrease in the power necessary for maintaining that temperature.
The variation or difference in the necessary power corresponds to
the dissipated hydridation power (DHP) and is roughly proportional
to the hydride precipitated per unit time. This variation or
decrease is measured as a function of time and permits a comparison
to be made of the hydridation kinetics in components of different
structure and composition, which permits a criterion to be had for
the choice of materials and design. During the process and by means
of integration with respect to time, one obtains the energy
dissipated in the hydridation reaction which is roughly
proportional to the quantity of hydride precipitated.
[0026] The second object of this invention consists of a device
(FIG. 4), hereinafter the inventive device, for carrying out the
inventive measurement method and which consists of: [0027] a) a
high or ultra-high vacuum chamber in which the component to be
analysed is inserted, [0028] b) a gas line for causing hydrogen or
a mixture of hydrogen with other gas(es) to pass through the
interior of the component, [0029] c) heating systems by the Joule
effect, thermocouples and systems for temperature control in the
component, and [0030] d) two electrodes in the form of a ring or
other well-defined geometry, arranged on the component
symmetrically and equidistant from the central thermocouple
connected with the outside of the device where the measurements are
going to be made.
[0031] During the hydridation reaction, the temperature in the
interior of the component has to remain constant, for which a
thermocouple and a temperature control system is used which acts on
the current applied for heating the component (c). Moreover, in
order to measure the voltage drop, and consequently the variation
in electric resistance and the power dissipated during the
hydridation reaction along the component during said reaction, the
two electrodes are used arranged on the component (d)
[0032] Finally, the third object of this invention consists of the
use of the inventive method and device for making measurements of
hydridation kinetics in industrial components of metallic elements,
metal alloys and any other material with and without protective
coverings, preferably tubular components such as tubes and tubular
claddings for fuel in the cores of nuclear reactors.
DETAILED DESCRIPTION OF THE FIGURES
[0033] FIG. 1. Variation in electric resistance during the
hydridation process. Following the variation in electric resistance
owing to the increase in temperature, the first stage of growth,
and once the temperature of the experiment has been reached, a
sharp growth takes place, marked between the arrows, due to the
dissolution of H in the metal, and the final maximum of this stage
roughly coincides with the start of the precipitation of H in the
form of hydrides.
[0034] FIG. 2. Variation in dissipated hydridation power. Once the
temperature of the experiment has been reached, the DHP remains
constant for a short interval, the incubation time, during which
the H is dissolved without precipitating. Once that period has
passed coinciding with the growth of electric resistance, the DHP
grows rapidly, corresponding to the start of precipitation of H in
the form of hydrides in the material.
[0035] FIG. 3. Variation in dissipated hydridation energy. This
corresponds to the integral of FIG. 2.
[0036] FIG. 4. Diagram of the hydridation kinetics measurement
device. This shows the position of the electrodes used for
measuring the voltage drop in the tube.
EXAMPLES OF EMBODIMENT OF THE INVENTION
Example 1
Measurement of the Hydridation Kinetics in Tubes or Tubular
Claddings
[0037] A method for measuring the dissipated power and the electric
resistance and thereby obtain the hydridation kinetics in tubes or
tubular claddings is embodied as stated below.
[0038] A nuclear fuel cladding of Zircaloy 2 is inserted in a high
or ultra-high vacuum chamber; hydrogen or mixtures of hydrogen with
other gas(es) is made to circulate via the interior of the tube at
a pressure of 1 atmosphere and a renewal stream of 200 cm.sup.3 per
minute. The partial pressure in the vacuum zone is 10.sup.-9 Torr
owing to the permeation of hydrogen through the walls of the
cladding. The cladding is heated by the Joule effect and the
temperature in the centre of the cladding is monitored and kept
constant at 360.degree. C. (or other pre-established value) with a
thermocouple and a temperature control system which acts on the
current being applied in order to heat the cladding, the amount of
current needed in order to maintain a constant temperature of
360.degree. C. in the absence of reaction being 30 A. The
electrodes, located on both sides of the thermocouple, provide a
measurement of the voltage drop in the cladding during the
hydridation reaction. Together with the measurement of the current
applied, this permits us to obtain the value of the power necessary
for keeping the temperature constant, and to measure the electric
resistance of the cladding. When the dilution of the hydrogen in
the cladding starts, the electric resistance can grow up to 3%
(FIG. 1), though this variation can be less if the cladding
previously contains a quantity of hydrogen, and no major changes
are observed in the power necessary for keeping the temperature
constant. When the precipitation and the formation of hydride
starts, the heat of reaction means that the power necessary for
keeping the temperature constant decreases, the difference in which
gives us the value of DHP and, by integration, the dissipated
hydridation energy or DHE. The DHP is roughly proportional to the
hydride precipitated per unit time and the DHE to the total
quantity of precipitated hydride. By stopping the process at
different value of DHE, samples can be obtained with different
thicknesses of the hydrides ring. These samples are very useful for
mechanical studies and studies of the geometry of the precipitated
hydrides. The comparison of the DHP curves permits a criterion to
be had for selection of materials and design. FIG. 1 shows the
variation curve of electric resistance, in which the first maximum
corresponds to the end of the dissolution process of hydrogen and
the final maximum corresponds to the end of the hydridation
process. FIG. 2 shows the DHP curve, in which the maximum indicates
that the precipitation reaction is very rapid at the start of the
process. FIG. 3 corresponds to the DHE curve.
* * * * *