CA3007703A1

CA3007703A1 - A method for prevention of ingress of hydrogen isotopes and their removal from components made from hydride forming metals and alloys

Info

Publication number: CA3007703A1
Application number: CA3007703A
Authority: CA
Inventors: Glenn Aldon Mcrae; Christopher Edward Coleman; Scott Thomas Langille
Original assignee: Coleman Christopher Edward; Langille Scott Thomas; Mcrae Glenn Aldon; Carleton University
Current assignee: Carleton University
Priority date: 2018-06-08
Filing date: 2018-06-08
Publication date: 2019-12-08

Abstract

Hydrogen in metals is sometimes a problem because of embrittlement, and methods are sought to reduce the concentration and ingress of hydrogen. Specifically, by way of an example that is not meant to be limiting, a method is disclosed to reduce the rate of ingress of hydrogen isotopes and their subsequent concentrations in zirconium alloy pressure tubes in a CANDU reactor where they are joined to a stainless-steel end-fitting, by the addition of a hydrogen getter to the outboard portion of the end fitting. The hydrogen getter can be any material that has a lower chemical potential for hydrogen than zirconium and can be attached to the end fitting so that a free path for hydrogen movement between the zirconium, steel, and getter is produced. Suitable candidate getter materials include zirconium, titanium, niobium, hafnium, vanadium, or yttrium, as metal, metal alloys or metal composites.

Description

McRae, Coleman, Langille A method for prevention of ingress of hydrogen isotopes and their removal from components made from hydride forming metals and alloys Glenn Aldon McRae, 13 Pommel Cres. Ottawa, Ontario, Canada K2M 1A3 Christopher Edward Coleman, 6 Ryans Camp Lane, Deep River, Ontario, Canada, Scott Thomas Langille, 147 Rachael Ave. Ottawa, Ontario, Canada K1H 6C5 ABSTRACT
[0001] Hydrogen in metals is sometimes a problem because of embrittlement, and methods are sought to reduce the concentration and ingress of hydrogen.
Specifically, by 10- way of an example that is not meant to be limiting, a method is disclosed to reduce the rate of ingress of hydrogen isotopes and their subsequent concentrations in zirconium alloy pressure tubes in a CANDU reactor where they are joined to a stainless-steel end-fitting, by the addition of a hydrogen getter to the outboard portion of the end fitting.
The hydrogen getter can be any material that has a lower chemical potential for hydrogen than zirconium and can be attached to the end fitting so that a free path for hydrogen movement between the zirconium, steel, and getter is produced. Suitable candidate getter materials include zirconium, titanium, niobium, hafnium, vanadium, or yttrium, as metal, metal alloys or metal composites.
TECHNICAL FIELD

[0002] The present invention relates to the use of a hydrogen getter to reduce ingress and concentration of hydrogen isotopes at the ends of Zr-2.5Nb pressure tubes in a nuclear reactor.
BACKGROUND

[0003] Zirconium alloys are commonly used in nuclear reactors because of a combination of desirable mechanical properties, and low thermal neutron capture cross Carleton University McRae, Coleman, Langille section. At reactor operating temperatures a corrosion reaction between the heat transport water and zirconium produces an oxide and hydrogen isotopes, some of which are absorbed into the metal matrix. Dissolved hydrogen, and its isotopes, may result in hydrogen embrittlement of zirconium when the hydrogen concentration becomes high enough to exceed the solubility limit, and in some situations can result in delayed hydride cracking (DHC), a form of subcritical crack growth. For some reactor components, such as fuel sheathing, hydrogen ingress is not a grave concern as the component life in reactor is short enough that significant amounts of hydrogen are not absorbed into the metal matrix and the fuel is exchanged at intervals much shorter than the life of the reactor. In CANDU
reactors, and other similar pressurized heavy or light water reactors, large permanent components known as pressure tubes made from zirconium alloys (for example, length 6 m, inside diameter 103 mm and thickness 4 mm) are used to contain the fuel and the primary heat transport water. As the reactor ages, concentrations of hydrogen isotopes in pressure tubes can increase to the point where brittle hydrides may form that can initiate DHC and reduce fracture toughness to the extent that fitness for service becomes an issue and can limit the life of the component. A location of particular concern is where the pressure tube is joined to the reactor at a 403 stainless steel end-fitting using a mechanical joint known as a rolled joint (Figure 1).

[0004] Several different zirconium alloys, and manufacturing procedures have been tried and implemented to reduce the rate of hydrogen ingress into pressure tubes with some success, but hydrogen embrittlement is still a potential issue. Several methods to reduce the rate of hydrogen ingress at the connection between the pressure tube and end-fitting and along the body of the tube have been investigated. Using chrome plating on the bore of end-fittings acted as a partial barrier to hydrogen ingress and reduced the ingress by at least 50% [1]. Shot peening the inside surface of the pressure tube produces a microstructure that has high resistance to corrosion and subsequent hydrogen pick-up could be halved [2]. Palladium has been added as a coating to the outside of pressure tubes to act as a one-way window that allows hydrogen in the metal to react with oxygen Carleton University McRae, Coleman, Langille in the surrounding ambient gas and has been shown to reduce the concentration of hydrogen in the metal by a factor of five [3]. None of these methods have been implemented because of uncertainty of long term benefit.

[0005] Another method would be to move the hydrogen to an innocuous position and hold it in a non-retrievable form. This movement can be achieved by having a material with a low chemical potential for hydrogen in either direct contact or sequential contact with the zirconium. In couples of zirconium and yttrium, hydrogen has been shown to preferentially migrate to the yttrium [4]. Thus, yttrium can be a getter for hydrogen out of zirconium. In experiments [5] small pieces of yttrium have been encapsulated at the end of a pressure tube outboard of the rolled joint and found to much reduce the amount of hydrogen in the rolled joint region. This potential mitigation was not implemented because of the perceived danger of activation products and the embedded yttrium expanding when it absorbed lots of hydrogen leading to high stresses and cracking within the pressure tube section, and perhaps a harmful corrosion reaction if the yttrium became exposed to the heat transport water.

[0006] There is therefore a need for an improved method and system for reducing hydrogen ingress into pressure tubes, and the resulting hydrogen embrittlement.
SUMMARY

[0007] The invention has a number of aspects that may be exploited individually or in combination.

[0008] One aspect of the invention provides a method to reduce hydrogen concentrations in hydride forming metals used to retain pressure.

[0009] Another aspect of the invention provides a method to lower the amount of hydrogen from the end fittings in CANDU reactors entering the pressure tubes.
Carleton University McRae, Coleman, Langille

[0010] Another aspect of the invention provides a method to limit the amount of hydrogen entering the pressure tube through the end fitting as a result of corrosion reactions.

[0011] Another aspect of the invention provides a method to remove hydrogen previously absorbed by in-service pressure tubes as part of a retrofit.
OVERVIEW

[0012] An improved hydrogen getter methodology and system is the subject of this patent. By placing the hydrogen sink at the outboard region of the end-fitting, outside the reactor core and without being in direct contact with the liquid flowing within the pressure tubes, issues of activation products and corrosion reactions with the heat transport water are avoided. Hydrogen dissolved in the stainless steel of the end fitting, will be preferentially drawn to the yttrium getter instead of the zirconium pressure tube, and hydrogen generated through corrosion reactions will also preferentially travel to the getter lowering the hydrogen concentrations in the pressure tube, and extending the life of the component. Locating the getter outside the core of the reactor also lends itself to implementation as a retrofit of existing reactors and routine replacement of the getter as necessary during maintenance shutdowns.

[0013] An interpretation of the mechanism explaining how the invention might work is provided here; the invention may be practiced even if the interpretation is incorrect. Hydrogen has a lower chemical potential in the getter than in both the stainless steel and the zirconium alloy making up the rolled joint. Hydrogen isotopes will preferentially diffuse to regions of lower chemical potential and will be partitioned within the three metals with concentration differences depending on the differences of the standard chemical potentials of the dissolved hydrogen isotopes in the metals.
As the concentration of hydrogen isotopes increases in each metal so does the corresponding chemical potential. Equilibrium concentrations will be obtained when the chemical Carleton University McRae, Coleman, Langille potentials of hydrogen isotopes in the three metals are equal. Any additional hydrogen entering the system will cause a shift in the equilibrium and the additional hydrogen isotopes will be partitioned such that equilibrium is reached again, with the hydrogen isotopes preferentially residing in the getter.

[0014] The teaching in the past was to place a hydrogen getter within the pressure tubes at each end. As explained above, this raises numerous concerns regarding potential activation products and corrosion, as well as requiring reactor shutdown and disassembly to replace the hydrogen getter. Contrary to the general understanding in the art, the inventors have found that a hydrogen getter can be effectively positioned within the end fitting and outside the calandria vessel, where there is no potential contact with the heat transport liquid in the pressure tubes. The inventors surmise that this positioning of a hydrogen getter within the end fitting and outside the calandria vessel was never considered before because steel was assumed to act as a barrier for hydrogen movement because it has such a low solubility for hydrogen. But the inventors have discovered that despite the low solubility for hydrogen in steel, steel has a very high hydrogen diffusion rate, so even though the hydrogen concentrations might be low, hydrogen moves quickly enough to the getter within the steel to reduce hydrogen concentrations by significant amounts in the zirconium pressure tubes for times and temperatures relevant to reactor operation.

[0015] In other words, the inventors have found that the low solubility for hydrogen in steel is not a limiting variable. You can have very little hydrogen in the steel, but if you move hydrogen through quickly, then you can take hydrogen out.
Hydrogen will move into the steel if there is a 'sink' at the other end of the steel that is at a lower chemical potential. The process is analogous to that of a syphon in that hydrogen will be drawn from a region with high chemical potential for hydrogen (i.e., the high-water level in the syphon), to a region with low chemical potential for hydrogen (i.e., the low end of the syphon). You can move hydrogen through the steel (i.e., the syphon hose) as long as you Carleton University McRae, Coleman, Langille release it at a lower potential, in our case chemical potential, but gravitational potential for the syphon.

[0016] In the past, it was thought that one needed to place the hydrogen getter in the pressure tube beside the rolled joint, which invariably meant in the reactor, and this placement is difficult to manage, as described above. But, as the inventors have discovered, you can draw hydrogen from a distance through the steel to a location outside of the reactor to a 'bolt' or similar mechanical device that is easy to manage.
BRIEF DESCRIPTION OF DRAWINGS
end fitting I
"
, ;
i i pressure tube ___________________________________________ =
rolled joint Ow-! :
!! ________________________________________ r P
Figure 1: the rolled-joint Region in a CANDU fuel channel Carleton University McRae, Coleman, Langille FEEDERS END CALANDRIA PRESSURE FEEDERS
FITTING TUBE TUBE
= .1-, _____________________________________________________________ . , õ .
______________________________________ _ ye , GAS FUEL GAS
ANNULUS BUNDLES SPACERS BELLOWS ANNULUS
OUTLET INLET
Figure 2: an example showing the placement of a single bolt in the end fitting.

[0017] Figure 2 shown above is adapted from [6] showing the placement of a single yttrium bolt in the end fitting, not to scale. The number, size and positioning of the bolts would vary with the amount of hydrogen and the desired time to remove hydrogen from the component into the getter. In one embodiment, the bolt would be tapped into the end fitting, but not to a depth where it would come into contact with the water of the heat transport system. As explained in the background, contacting the water could result in dangerous activation products entering the heat transport system, or harmful corrosion or both. The bolt could be designed to allow for any expansion from absorbed hydrogen, for example, having the bolt hollowed, or split, so it would have room to expand.
Rather than yttrium other hydrogen getters could also be used, including zirconium, titanium, niobium, hafnium, or vanadium, as metal, metal alloys or metal composites.

[0018] The ranges for dimensions and the numbers of bolts, foils, straps, clamps, fittings or another similar forms, would depend on how much hydrogen one wishes to remove, and how often one changes the bolts, foils, straps, clamps, fittings or another similar forms. The greater the surface area of the getter, the faster the hydrogen removal, so a thin foil with a large surface area instead of a bolt might be preferable in some Carleton University McRae, Coleman, Langille applications. Addressing these design considerations are all within the capability of a person skilled in the art, in view of the teachings herein.
DESCRIPTION

[0019] Throughout the following description, specific details provide an understanding of the invention. In the following examples, a rolled joint is simulated with stainless steel pressed onto Zircaloy-2, which is an alloy used for pressure tubes in early CANDU reactors. These examples are not meant to be interpreted as limiting, and someone skilled in the art would know that other zirconium alloys, such as Zr-2.5Nb, would behave similarly. The mass ratio of stainless steel to zirconium was chosen to be approximately that found for the rolled joint end fitting. The hydrogen in the Zircaloy-2 was determined with a differential scanning calorimeter (DSC) used to measure the temperature corresponding to the maximum change in heat flow during heating (often called TSSD maximum slope). The hydrogen concentration was determined from an independent calibration of this temperature with hydrogen concentration determined from High Vacuum Extraction Mass Spectroscopy [7].
EXAMPLES

[0020] Example 1. A sample of zirconium alloy fuel sheath (Zircaloy-2, with initial concentration of hydrogen of 14 wt.ppm, micrograms of hydrogen divided by grams of zirconium) was placed inside a stainless-steel tube, and this tube pressed around the zirconium sample to produce good metal-to-metal contact to simulate a rolled joint; this couple was Sample A.

[0021] Sample A was placed in an oven at 350 C for 7 days before being removed and quenched in water at room temperature. The Zircaloy-2 sample was then removed from the stainless-steel tube and its hydrogen concentration determined with DSC as described above.
Carleton University McRae, Coleman, Langille

[0022] Sample B. Another sample of Zircaloy-2 was placed inside a stainless-steel tube, and a piece of yttrium was added such that the Zircaloy-2 and yttrium were not directly in contact, and the tube pressed as for sample A. The approximate mass ratio of zirconium to yttrium was 2:1. Sample B was placed in an oven at 350 C for 7 days before being removed and quenched in water at room temperature. The Zircaloy-2 sample was then removed from the stainless-steel tube and analyzed for hydrogen concentration with DSC as for Sample A.

[0023] The hydrogen concentrations calculated for both Samples A
and B are presented in Table 1. Also shown in Table 1 are the concentrations normalized with respect to the mass ratio of stainless steel to zirconium in Sample A to account for the differences in absolute masses in Samples A and B. (i.e., the normalized concentration of hydrogen in Sample B equals 53 wt.ppm * 292.1/359.5=43 wt.ppm, which is the concentration expected in Sample B.). The results for Sample A show that the Zircaloy-2 getters hydrogen from the stainless steel, which can be interpreted as initial hydrogen being picked up at the rolled joint in a CANDU fuel channel. This discovery that the zirconium alloy apparently getters the initial hydrogen from the stainless-steel end fitting was the impetus for the current invention to lower hydrogen ingress and hydrogen concentrations in the zirconium alloy with an appropriately placed getter. The results for Sample B show that the yttrium getters hydrogen sufficiently to lower the final hydrogen concentration in the Zircaloy-2 from the expected value of 43 wt.ppm, with no yttrium, to 27.5 wt.ppm, with yttrium. This reduction of 37% demonstrates the method for reducing hydrogen in a pressure tube at a rolled joint by placing yttrium within the 403 stainless steel of the end fitting. To hasten the diffusion process, Example 1 was conducted at 350 C, which is higher than operating temperatures for CANDU reactors. It is well known to those skilled in the art that similar results would be obtained at lower temperatures, they would just take longer to realize, on the order of months and years for CANDU
operating conditions, well within the 30-year design life of current reactors.
Carleton University McRae, Coleman, Langille Table 1 Sample A ¨ Fuel Sample B ¨ Fuel Sheath without Sheath with Yttrium Yttrium Sink Sink Hydrogen Concentration [wt.ppm] 53 27.5 Mass Ratio of Stainless Steel:Zr 359.5 292.1 Hydrogen Concentration [wt.ppm] 53 43 normalized with the Stainless Steel:Zr Mass Ratio of Samples B
and A
Mass Ratio of Zr:Y Not applicable 1.89

[0024] Example 2. A mechanical hydrogen addition technique developed to add high concentrations of hydrogen to zirconium [8] was modified so that hydrogen produced by a chemical reaction in situ would have to travel through stainless steel before reaching a zirconium sample. The source of hydrogen was the chemical decomposition of zirconium hydride powder (ZrH2). Stainless steel was placed between the powder and the Zircaloy-2 sample, labeled Sample C, and everything was encased in copper to prevent loss of hydrogen and interaction with air. The amount of powder used for this test was large enough to achieve a hydrogen concentration in the Zircaloy-2 of 500 wt.ppm. This test aimed to simulate hydrogen generated in reactor through corrosion reactions passing through the stainless-steel end fitting and into the zirconium pressure tube. After seven days at 425 C
and 140 MPa compression, Sample C was quenched and evaluated by DSC to determine the hydrogen concentration in the Zircaloy-2.

[0025] A second sample, Sample D, was subjected to the same mechanical hydrogen addition process as sample C, with the exception that another sheet of stainless steel, and a piece of yttrium were added, such that any hydrogen had equal opportunity to go to either Carleton University McRae, Coleman, Langille the yttrium or zirconium; i.e., the powdered hydrogen source was between two sheets of stainless steel, with Zircaloy-2 on the far side of one sheet, and yttrium on the far side of the other sheet. The whole assembly was encased in copper. The source of hydrogen for this test was large enough to achieve a hydrogen concentration in the Zircaloy-2 of 250 wt.ppm, if none of the hydrogen went to the yttrium. The experimental conditions were the same as for Sample C. After seven days, Sample D was quenched and analyzed by DSC to determine the hydrogen concentration achieved in the presence of yttrium.

[0026] The achieved hydrogen concentrations calculated for Samples C
and D are presented in Table 2, along with the predicted hydrogen concentrations in each sample. To hasten the hydrogen partitioning process, Example 2 was conducted at 425 C
and 140 MPa, which are higher than operating temperatures and pressures for CANDU
reactors. It is well known to those skilled in the art that similar results would be obtained at lower temperatures and pressures, they would just take longer to realize, on the order of months and years for CANDU operating conditions, well within the 30-year design life of current reactors.
Table 2 Sample C Sample D
Achieved Hydrogen Concentration 491 93.4 [wt.ppm]
Predicted Hydrogen Concentration 500 250 without yttrium [wt.ppm]
Mass Ratio of Zr:Y Not 1.99 applicable

[0027] The results from Sample C show that hydrogen readily migrates through 403 stainless steel and is picked up by the Zircaloy-2 in contact with the steel:
the achieved Carleton University McRae, Coleman, Langille concentration of 491 wt.ppm is within the accuracy and precision of the predicted concentration for the hydrogen addition technique. In Sample D the yttrium provides 62%
protection from hydrogen pick-up by the zirconium alloy: instead of 250 wt.ppm, only 93.4 wt.ppm was picked up by the Zircaloy-2.

[0028] The principle of the proposed invention is for a hydrogen getter, such as yttrium as a non-limiting example, to be placed at the outboard end of the end fitting where hydrogen isotopes can be gettered from the zirconium alloy pressure tube via the stainless-steel end fitting. The form of the getter may be as sheets or rods (for example in the form of screws or bolts) which could be placed in the end fittings of a new reactor or added as a retrofit. Figure 2 shows the placement of a bolt in the end fitting as an example. The getter can be replaced should it become saturated by hydrogen.
Some getter materials may be reactive metals, so any device will have to be protected from the ambient conditions at the outboard end of the fuel channel.

[0029] Further, a portion of the end fitting could be coated with palladium to allow hydrogen in the metal to react with ambient oxygen (02) in the reactor vault during operation [3]. Palladium coatings on the outside of CANDU pressure tubes have been shown to reduce hydrogen concentrations in the metal when oxygen gas was present on the outside of the metal. In this example, the oxygen would be the getter. For application to the rolled joint of a CANDU reactor, this application of the present invention requires a method of containing the hydrogen isotopes from contaminating the reactor vault with tritium, which could include any additional process to sequester the hydrogen isotopes in a stable chemical form. For application of the present invention to pressure vessels made of other hydride-forming metal alloys used in the chemical industry, such as titanium alloys, the hydrogen could simply be reacted with ambient oxygen to produce water without any further chemical modification.
Carleton University

Claims

WHAT IS CLAIMED IS:
1. A method for reducing the amount of hydrogen in hydride forming metals and their alloys used to retain pressure comprising attaching a hydrogen getter;
2. A method according to claim 1 where the hydride forming metals and alloys include titanium and zirconium alloys;
3. A method according to claim 1 where the getter is in the form of a screw or bolt;
4. A method according to claim 1 where the getter is in the form of a sheet;
5. A method according to claim 1 where a coating on the hydride forming metal alloy is used to provide a pathway for hydrogen to react on the free surface of the coating with ambient oxygen as the getter;
6. A method according to claim 5 where the coating is palladium;
7. A method for reducing the amount of hydrogen entering a pressure tube at a rolled joint as a result of diffusion of hydrogen comprising attaching a hydrogen getter to a fitting outside of the reactor core;
8. A method according to claim 7 where the getter is a metal, metal alloy, or metal composite that has a lower chemical potential for hydrogen than the zirconium alloy in the rolled joint;
9. A method according to claim 8 where the getter is composed of zirconium, titanium, niobium, hafnium, vanadium, or yttrium, as metal, metal alloys or metal composites;
10. A method according to claim 7 where the getter is in the form of a screw or bolt;
11. A method according to claim 7 where the getter is in the form of a sheet;
12. A method according to claim 7 where the getter is oxygen via a chemical reaction at the free-metal surface;

13. A method of reducing the amount of hydrogen isotopes entering a pressure tube through a rolled joint by diffusion, when the source of hydrogen isotopes is from reactor operation, including corrosion, comprising attaching a hydrogen getter to a fitting outside of the reactor core;
14. A method according to claim 13 where the getter is a metal, metal alloy, or metal composite that has a lower chemical potential for hydrogen than the zirconium alloy in the rolled joint;
15. A method according to claim 14 where the getter is composed of zirconium, titanium, niobium, hafnium, vanadium, or yttrium, as metal, metal alloys or metal composites;
16. A method according to claim 13 where the getter is in the form of a screw or bolt;
17. A method according to claim 13 where the getter is in the form of a sheet;
18. A method according to claim 13 where the getter is oxygen via a chemical reaction at the free-metal surface;
19. A method of reducing the amount of hydrogen isotopes accumulated during reactor operation in the pressure tube in the rolled joint, as part of a retrofit to refurbish the rolled joint comprising attaching a hydrogen getter to a fitting outside of the reactor core and heat-transport system;
20. A method according to claim 19 where the getter is a metal, metal alloy, or metal composite that has a lower chemical potential for hydrogen than the zirconium alloy in the rolled joint;
21. A method according to claim 20 where the getter is composed of zirconium, titanium, niobium, hafnium, vanadium, or yttrium, as metal, metal alloys or metal composites;
22. A method according to claim 19 where the getter is in the form of a screw or bolt;
23. A method according to claim 19 where the getter is in the form of a sheet;

24. A method according to claim 19 where the getter is oxygen via a chemical reaction at the free-metal surface.
REFERENCES
1. White, A.J., Urbanic, V.F., Bahurmuz A.A., Clendening, W.R., Joynes, R., MacDougall, G.M., Skinner, B.C., and Venkatapathi, S., "Plating End Fittings to Reduce Hydrogen Ingress at Rolled Joints in CANDU Reactors", Proceedings, International Conference of Expanded and Rolled Joint Technology, Canadian Nuclear Society, Toronto, Ontario, Canada, September 1993, pp. G47-G55.
. 2. Amouzouvi, K.F., Clegg, L.J., Styles, R.C., Winegar, J.E., "Effect of Shot Peening and Post-Peening Heat Treatments on the Microstructure, the Residual Stress and Hardness, Corrosion and Deuterium Uptake Resistance of Zr-2.5Nb Pressure Tube Material", Computer Methods and Experimental Measurements for Surface Treatment Effects, M.H. Aliabadi and C.A. Bzebbia, Eds., Computational Publications, Southampton, 1993.
3. Coleman, C.E. Cheadle, B.A., Cann, C.D., Theaker, J.R., "Development of Pressure Tubes with Service Life of Greater than 30 Years", Zirconium in the Nuclear Industry:
Eleventh International Symposium, ASTM STP 1295, E.R. Bradley and G.P. Sabol, Eds., American Society for Testing and Materials, 1996, pp. 884-898.
4. Spalthoff, W., Wilhelm, H., "Use of hydrogen getters for prevention of hydrogen embrittlement in zirconium alloy fuel cans, Applications-Related Phenomena for Zirconium and Its Alloys", 1968, ASTM STP 458, E.F. Baroch, Ed., American Society for Testing and Materials, Philadelphia, PA., (1969), 338-344.
5. Cann, C.D., Bahurmuz A.A., Sexton, E.E., Degregorio, R., Grant, I., Inglis, I., Murphy, E.V., Natesan, M., "Removal of Hydrogen from Rolled Joints in CANDU Reactors by Yttrium Sinks", Proceedings, International Conference of Expanded and Rolled Joint Technology, Canadian Nuclear Society, Toronto, Ontario, Canada, September 1993, pp. G47-G55.
6. Coleman, C.E., "Simulating the Behaviour of Zirconium-Alloy Components in Nuclear Reactors". Zirconium in the Nuclear Industry: Eleventh International Symposium, ASTM STP 1423, G.D. Moan and P. Rudling, Eds., American Society for Testing and Materials, 2002, pp. 3-19. Kroll Medal Presentation 7. Bickel, G.A., Green, L.W., James, M.W.D., Lamarche, T.G., Leeson, P.K., Michel, H., "The determination of hydrogen and deuterium in Zr-2.5Nb material by hot vacuum extraction mass spectrometry", J. Nucl. Mater. 306 (2002) 21- 29.
8. "Mechanically-assisted gaseous addition of hydrogen to metal alloys". Filed June 21, 2017. USPTO Provisional Patent. McRae, G.A., Coleman, C.E., St. Louis, C.J., Langille, S.T., Corrigall, J.L.M., Hanlon, S.M.K., Read, S.A.D., McCaugherty, K.W.