EP3635749A1 - Seal package face plate of a shaft sealing system of a reactor coolant pump - Google Patents

Seal package face plate of a shaft sealing system of a reactor coolant pump

Info

Publication number
EP3635749A1
EP3635749A1 EP18729677.7A EP18729677A EP3635749A1 EP 3635749 A1 EP3635749 A1 EP 3635749A1 EP 18729677 A EP18729677 A EP 18729677A EP 3635749 A1 EP3635749 A1 EP 3635749A1
Authority
EP
European Patent Office
Prior art keywords
ice
protective layer
sealing system
shaft
pump unit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP18729677.7A
Other languages
German (de)
French (fr)
Inventor
Zoe Tebby
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Areva NP SAS
Original Assignee
Framatome SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Framatome SA filed Critical Framatome SA
Publication of EP3635749A1 publication Critical patent/EP3635749A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21D—NUCLEAR POWER PLANT
    • G21D1/00—Details of nuclear power plant
    • G21D1/04—Pumping arrangements
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21C—NUCLEAR REACTORS
    • G21C15/00—Cooling arrangements within the pressure vessel containing the core; Selection of specific coolants
    • G21C15/18—Emergency cooling arrangements; Removing shut-down heat
    • G21C15/182—Emergency cooling arrangements; Removing shut-down heat comprising powered means, e.g. pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J15/00—Sealings
    • F16J15/16—Sealings between relatively-moving surfaces
    • F16J15/164—Sealings between relatively-moving surfaces the sealing action depending on movements; pressure difference, temperature or presence of leaking fluid
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J15/00—Sealings
    • F16J15/16—Sealings between relatively-moving surfaces
    • F16J15/34—Sealings between relatively-moving surfaces with slip-ring pressed against a more or less radial face on one member
    • F16J15/3496—Sealings between relatively-moving surfaces with slip-ring pressed against a more or less radial face on one member use of special materials
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21C—NUCLEAR REACTORS
    • G21C15/00—Cooling arrangements within the pressure vessel containing the core; Selection of specific coolants
    • G21C15/24—Promoting flow of the coolant
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21C—NUCLEAR REACTORS
    • G21C15/00—Cooling arrangements within the pressure vessel containing the core; Selection of specific coolants
    • G21C15/24—Promoting flow of the coolant
    • G21C15/243—Promoting flow of the coolant for liquids
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E30/00—Energy generation of nuclear origin
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E30/00—Energy generation of nuclear origin
    • Y02E30/30—Nuclear fission reactors

Definitions

  • the invention relates to the field of primary pump units of pressurized water nuclear reactors (PWR).
  • PWR pressurized water nuclear reactors
  • the invention relates to windows, also called active faces, of the gasket of the seal No. 1 of a primary pump unit shaft sealing system of a nuclear reactor.
  • the primary pump unit In pressurized water nuclear reactors, the primary pump unit, also called more simply primary pump, ensures the circulation of water in the primary circuit of the reactor.
  • a dynamic sealing system of the shaft seals between the primary circuit and the atmosphere.
  • This primary pump unit shaft sealing system is a controlled leakage system. It has three joints arranged in series. Each seal has two windows that provide the main seal.
  • One of the mirrors, called the rotating mirror is mounted in a rotating assembly integral with the shaft, the other ice, called floating ice, is mounted in a non-rotating assembly but which is free to move axially to follow the axial displacements possible from the tree.
  • the seal No. 1 ensures most of the pressure drop between the primary circuit and the atmosphere. It makes it possible to go from a pressure of 1 55 bars to a pressure of about 2 bars.
  • This seal No. 1 is a hydrostatic type seal, with a water film with a thickness of the order of 1 0 ⁇ .
  • the particular geometry of the faces of the windows ensures the main seal and allows, at the stop as in rotation, an automatic adjustment of their spacing.
  • the seal No. 1 operates with a controlled leak rate, of the order of 600 liters per hour in nominal operation, thanks to the specific profile machined on its active faces.
  • the hot primary fluid is confined in the primary circuit by an injection of cold water upstream of the seal No. 1 at a pressure slightly higher than that of the primary circuit. Part of this cold water passes through the primary circuit and a portion passes into the seal No. 1 so as to cool to maintain a temperature always lower than 100 ° C.
  • the ice cream of the No. 1 seal was alumina, but they are now mostly silicon nitride more resistant to friction.
  • the invention aims to overcome the disadvantages of the state of the art by proposing an effective solution, easy to implement, avoiding the degradation of the silicon nitride ice of the seal No. 1 of the primary pump unit shaft sealing system of a nuclear reactor, especially in accident conditions of loss of all cooling sources of the shaft seal system (SBO type situation).
  • the invention proposes to cover the ice surface of the seal No. 1 with a special protective layer conferring a hydrothermal protection to silicon nitride thus preventing its dissolution under normal operating conditions and in an accidental situation. type SBO.
  • the invention provides a silicon nitride ice for primary pump unit shaft sealing system of a nuclear reactor for sealing between the primary circuit and the atmosphere, said ice having a surface covered by a protective layer made of a non-porous material and chemically inert with superheated water at a temperature greater than or equal to 200 ° C and under pressure (pressure greater than or equal to the saturation vapor pressure of water) .
  • the invention therefore consists in using an inert and non-degradable protective layer in an aqueous medium and under accident conditions of the SBO type (ice temperature greater than 200 ° C.), and capable of preventing the degradation and degradation. erosion of the silicon nitride ice surface which transforms into silica under conditions of temperatures above 200 ° C.
  • the protective layer according to the invention resists erosion under normal operating conditions as well as SBO-type conditions.
  • the ice according to the invention may also have one or more of the following characteristics taken individually or in any technically possible combination: the protective layer has adhesion properties with the silicon nitride of said ice; the protective layer has chemical resistance properties to boric acid and / or lithium hydroxide and / or potassium hydroxide; the protective layer has a uniform thickness; the protective layer is uniform in thickness and respects the shape of the support; the protective layer has a hardness to resist friction (especially between the two active faces of the windows) and scratches; the protective layer has a roughness equivalent to the active surface of said ice; the protective layer has thermal shock resistance properties; the protective layer is micro-or nanocrystalline diamond or zirconium oxide; said protective layer has a thickness of a few micrometers; for example between 0.1 and 30 microns and advantageously between 0.2 and 10 microns; and preferably between 0.2 and 2 ⁇ ; the active surface of
  • the invention also relates to a seal comprising at least one ice according to the invention.
  • the invention also relates to a shaft sealing system of primary pump unit of a nuclear reactor comprising at least one seal according to the invention.
  • the invention also relates to a primary motor pump unit of a nuclear reactor comprising a shaft sealing system according to the invention.
  • the invention also relates to a pressurized water nuclear reactor comprising a primary pump unit according to the invention.
  • Figure 1 is a sectional view of a sealing system of a primary pump unit shaft according to one embodiment of the invention.
  • Figure 2 is a schematic sectional view of a seal No. 1 according to an embodiment of Figure 1.
  • Figure 3 is a schematic sectional view of the windows of the seal No. 1 according to one embodiment of the invention.
  • FIG. 4a is an electron microscope image illustrating the state of the surface of a sample of ice of a No. 1 seal comprising a protective layer according to the invention after exposure to an aqueous medium with 290 ° C and under pressure.
  • FIG. 4b is an electron microscope image illustrating the state of the surface of a sample of ice of a No. 1 seal without a protective layer after exposure to an aqueous medium at 290 ° C. and under pressure.
  • FIG. 5a is a graph illustrating the evolution of the leakage rate as a function of time of a seal No. 1 comprising ice-cream with a protective layer according to the invention, during an increase in the temperature at the of seal No. 1 following a rise of the primary fluid under SBO conditions.
  • FIG. 4a is an electron microscope image illustrating the state of the surface of a sample of ice of a No. 1 seal comprising a protective layer according to the invention after exposure to an aqueous medium with 290 ° C. and under pressure.
  • 5b is a graph illustrating the evolution of the leakage rate as a function of time of a seal No. 1 comprising ice-creams without a protective layer, during an increase in the temperature at the seal no. 1 following a rise of the primary fluid under SBO conditions.
  • FIG 1 shows a shaft seals mechanical seal system 7 of a primary pump unit of a pressurized water nuclear reactor.
  • This shaft sealing system comprises a seal No. 1 referenced 1 in Figure 1, a seal No. 2 referenced 2 in Figure 1 and a seal No. 3 referenced 3 in Figure 1.
  • Each seal No. 1, 2, 3 consists of a rotating mirror integral with the shaft 7 and a floating ice can follow the axial movements of the shaft 7 but not rotating.
  • the seal No. 1 is shown more specifically in Figure 2.
  • the seal No. 1 ensures most of the pressure drop between the primary circuit 8 and the atmosphere 9.
  • the seal No. 1 is hydrostatic type, water film with a thickness of the order of 10 ⁇ .
  • the seal No. 1 comprises a rotating mirror 10 secured to the shaft 7 and a floating ice 1 1 which can follow the axial displacements of the shaft 7.
  • the leakage flow of the seal No. 1 is determined by the double slope of the ice floe 1 1 or by the respective slopes of ice rotating and floating according to an embodiment of the ice cream of the seal No. 1 (not shown).
  • the lenses 1 0, 1 1 are made of silicon nitride.
  • the lenses 1 0, 1 1 of the seal No. 1 according to the invention are shown more precisely in Figure 3.
  • the surface 1 2 of at least one of the ice 1 0, 1 1 is covered with a layer Protective 13.
  • the two windows 10 and 1 1 are covered by a protective layer 1 3 at their active face.
  • This protective layer 1 3 is made of a non-porous material and chemically inert in an aqueous medium and at a temperature greater than or equal to 200 ° C. This protective layer 1 3 makes it possible to prevent the degradation and erosion of the silicon nitride ice surface under the SBO condition and does not disturb the normal operation of the seal No. 1.
  • the protective layer 1 3 also has chemical corrosion resistance properties including boric acid, lithium hydroxide and potassium hydroxide and resists erosion. More generally, the protective layer 13 withstands all the conditions that can undergo the joint No. 1 under normal operating conditions and under accident conditions and especially under SBO-type conditions for several hours, or even days.
  • the protective layer 1 3 preferably has a thickness e of between 0.1 and 30 micrometers.
  • the thickness of the protective layer e is preferably between 0.2 and 10 micrometers.
  • the protective layer 13 has a thickness e of between 0.2 and 2 microns.
  • the protective layer 1 3 is deposited uniformly with ad-hoc means, that is to say with a constant and homogeneous thickness respecting the shape of the support.
  • the protective layer 1 3 has a high hardness and is adapted to resist scratching and incidental friction that may occur between the two active faces of the windows.
  • the protective layer 1 3 is resistant to significant thermal shocks, such as the passage of a temperature of 1 5 ° -95 ° C to a temperature above 200 ° C in a few seconds.
  • the protective layer 1 3 may be made of nano- or microcrystalline diamond, or zirconium oxide.
  • FIGS. 4a and 4b are two electron micrographs illustrating the state of the ice surface with and without protective layer 1 3 after exposure to an aqueous medium at a temperature of 290 ° C. and under pressure of 155 bar. More specifically, FIG. 4a is a photograph of an ice cream seal No. 1 according to the invention comprising a protective layer 1 3 according to the invention with a thickness of 2 micrometers and FIG. 4b a cliché of FIG. a No. 1 seal glass without a protective layer.
  • the silicon nitride ice with the protective layer 1 3 in Figure 4a is intact while the surface of the ice without the protective layer in Figure 4b is degraded strongly silica (S1O2) over a thickness of a few tens of microns to a few hundred micrometers.
  • the silica upper layer dissolves with time causing degradation and dissolution of a larger height of silicon nitride ice, of the order of several hundred micrometers.
  • FIG. 5a is a graph illustrating the evolution of the leakage rate as a function of time of a seal No. 1 comprising ice creams with a protective layer according to the invention during an increase in the temperature of the primary fluid. at the joint # 1.
  • FIG. 5b is a graph illustrating the evolution of the leakage rate as a function of time of a No. 1 seal comprising ice-creams without a protective layer during an increase in the temperature of the primary fluid at the joint No. 1.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Mechanical Engineering (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Mechanical Sealing (AREA)

Abstract

The invention relates to a face plate (10, 11), made of silicon nitride, of a seal package (1) for a sealing system (4) of a shaft (7) of a reactor coolant pump in a nuclear reactor, said sealing system (4) being intended to ensure sealing between the primary circuit and the atmosphere, characterized in that said face plate (10, 11) has an active surface covered by a protective layer (13) made from a nonporous material that is chemically inert to pressurized water superheated to a temperature greater than or equal to 200°C.

Description

GLACE DE GARNITURE D'ETANCHEITE D'UN SYSTEME  ICE SEALING GLAZE OF A SYSTEM
D'ETANCHEITE D'ARBRE DE GROUPE MOTOPOMPE PRIMAIRE  PRIMARY MOTOR PUMP SEAL SEALING
DOMAINE TECHNIQUE DE L'INVENTION TECHNICAL FIELD OF THE INVENTION
[ 0001 ] L'invention se rapporte au domaine des groupes motopompes primaires de réacteurs nucléaires à eau sous pression (REP).  The invention relates to the field of primary pump units of pressurized water nuclear reactors (PWR).
[0002 ] Plus précisément, l'invention concerne les glaces, également appelées faces actives, de la garniture d'étanchéité du joint n°1 d'un système d'étanchéité d'arbre de groupe motopompe primaire d'un réacteur nucléaire. ETAT DE LA TECHNIQUE More specifically, the invention relates to windows, also called active faces, of the gasket of the seal No. 1 of a primary pump unit shaft sealing system of a nuclear reactor. STATE OF THE ART
[0003 ] Dans les réacteurs nucléaires à eau sous pression, le groupe motopompe primaire, appelé également plus simplement pompe primaire, assure la circulation d'eau dans le circuit primaire du réacteur. Un système d'étanchéité dynamique de l'arbre assure l'étanchéité entre le circuit primaire et l'atmosphère. Ce système d'étanchéité d'arbre de groupe motopompe primaire est un système à fuite contrôlée. Il comporte trois joints disposés en série. Chaque joint comporte deux glaces qui assurent l'étanchéité principale. Une des glaces, appelée glace tournante, est montée dans un ensemble tournant solidaire de l'arbre, l'autre glace, dite glace flottante, est montée dans un ensemble ne tournant pas mais qui est libre de se déplacer axialement pour suivre les déplacements axiaux éventuels de l'arbre. In pressurized water nuclear reactors, the primary pump unit, also called more simply primary pump, ensures the circulation of water in the primary circuit of the reactor. A dynamic sealing system of the shaft seals between the primary circuit and the atmosphere. This primary pump unit shaft sealing system is a controlled leakage system. It has three joints arranged in series. Each seal has two windows that provide the main seal. One of the mirrors, called the rotating mirror, is mounted in a rotating assembly integral with the shaft, the other ice, called floating ice, is mounted in a non-rotating assembly but which is free to move axially to follow the axial displacements possible from the tree.
[0004 ] Le joint n°1 assure la plus grande partie de la chute de pression entre le circuit primaire et l'atmosphère. Il permet de passer d'une pression de 1 55 bars à une pression de 2 bars environ. Ce joint n°1 est un joint de type hydrostatique, à film d'eau d'une épaisseur de l'ordre de 1 0 μηι. La géométrie particulière des faces des glaces assure l'étanchéité principale et permet, à l'arrêt comme en rotation, un ajustement automatique de leur écartement. The seal No. 1 ensures most of the pressure drop between the primary circuit and the atmosphere. It makes it possible to go from a pressure of 1 55 bars to a pressure of about 2 bars. This seal No. 1 is a hydrostatic type seal, with a water film with a thickness of the order of 1 0 μηι. The particular geometry of the faces of the windows ensures the main seal and allows, at the stop as in rotation, an automatic adjustment of their spacing.
[0005 ] Le joint n°1 fonctionne avec un débit de fuite maîtrisé, de l'ordre de 600 litres par heure en fonctionnement nominal, grâce au profil spécifique usiné sur ses faces actives. Le fluide primaire chaud est confiné dans le circuit primaire grâce à une injection d'eau froide en amont du joint n°1 à une pression légèrement supérieure à celle du circuit primaire. Une partie de cette eau froide passe dans le circuit primaire et une partie passe dans le joint n°1 de manière à le refroidir pour maintenir une température toujours inférieure à 1 00°C. The seal No. 1 operates with a controlled leak rate, of the order of 600 liters per hour in nominal operation, thanks to the specific profile machined on its active faces. The hot primary fluid is confined in the primary circuit by an injection of cold water upstream of the seal No. 1 at a pressure slightly higher than that of the primary circuit. Part of this cold water passes through the primary circuit and a portion passes into the seal No. 1 so as to cool to maintain a temperature always lower than 100 ° C.
[0006] Historiquement, les glaces du joint n°1 étaient en alumine, mais elles sont désormais le plus souvent en nitrure de silicium plus résistant aux frottements. Historically, the ice cream of the No. 1 seal was alumina, but they are now mostly silicon nitride more resistant to friction.
[0007 ] En situation accidentelle, de type SBO (pour Station Black Out en langue anglaise), correspondant à une perte totale des alimentations électriques de la centrale nucléaire, les circuits de refroidissement du système d'étanchéité d'arbre de groupe motopompe primaire deviennent inopérants et provoquent la perte de l'injection d'eau froide à haute pression en amont du joint n°1 et du refroidissement de la barrière thermique de la pompe. De ce fait, l'eau chaude du circuit primaire remonte jusqu'aux joints du système d'étanchéité d'arbre. In an accident situation, of the SBO type (for Black Out Station in English language), corresponding to a total loss of the power supplies of the nuclear power plant, the cooling circuits of the primary motor pump unit shaft sealing system become inoperative and cause the loss of injection of cold water at high pressure upstream of the seal No. 1 and the cooling of the thermal barrier of the pump. As a result, the hot water from the primary circuit rises to the seals of the shaft seal system.
[0008 ] La demanderesse a identifié lors de l'étude de ces scénarios que le passage d'eau chaude entre les glaces en nitrure de silicium du joint n°1 provoque leur dégradation. En effet, dans un milieu en eau surchauffée à une température supérieure à 200°C et sous pression (pression supérieure ou égale à la pression de vapeur saturante de l'eau), ce qui correspond à une situation accidentelle de type SBO, les glaces en nitrure de silicium subissent une dégradation et une décomposition. En effet, sous les conditions de SBO, le nitrure de silicium se transforme en ammoniaque et en silice. Cela a pour conséquence une dissolution et érosion des glaces qui perdent de la matière en surface, le profil des glaces évolue en conséquence et provoque donc une forte augmentation du débit de fuite du joint n°1 n'assurant plus sa fonction. [0009] Cette situation est problématique car elle peut rapidement mener au découvrement du cœur si les mesures palliatives nécessaires ne sont pas prises à temps par l'exploitant. The Applicant has identified during the study of these scenarios that the passage of hot water between the silicon nitride ice of seal No. 1 causes their degradation. Indeed, in a medium in superheated water at a temperature above 200 ° C and under pressure (pressure greater than or equal to the saturation vapor pressure of the water), which corresponds to an accidental situation of SBO type, ice silicon nitride undergo degradation and decomposition. Indeed, under the conditions of SBO, the silicon nitride is transformed into ammonia and silica. This results in a dissolution and erosion of the ice that lose material on the surface, the ice profile evolves accordingly and therefore causes a sharp increase in the leakage rate of the seal No. 1 no longer ensuring its function. This situation is problematic because it can quickly lead to the discovery of the heart if the necessary palliative measures are not taken in time by the operator.
EXPOSE DE L'INVENTION SUMMARY OF THE INVENTION
[0010 ] Dans ce contexte l'invention vise à remédier aux inconvénients de l'état de la technique en proposant une solution efficace, facile à mettre en œuvre, évitant la dégradation des glaces en nitrure de silicium du joint n°1 du système d'étanchéité d'arbre de groupe motopompe primaire d'un réacteur nucléaire, notamment en conditions accidentelles de perte de toutes les sources de refroidissement du système de joints d'arbre (situation type SBO). In this context the invention aims to overcome the disadvantages of the state of the art by proposing an effective solution, easy to implement, avoiding the degradation of the silicon nitride ice of the seal No. 1 of the primary pump unit shaft sealing system of a nuclear reactor, especially in accident conditions of loss of all cooling sources of the shaft seal system (SBO type situation).
[0011] Pour ce faire, l'invention propose de recouvrir la surface des glaces du joint n°1 d'une couche protectrice particulière conférant une protection hydrothermale au nitrure de silicium empêchant ainsi sa dissolution en conditions normales de fonctionnement et en situation accidentelle de type SBO.  To do this, the invention proposes to cover the ice surface of the seal No. 1 with a special protective layer conferring a hydrothermal protection to silicon nitride thus preventing its dissolution under normal operating conditions and in an accidental situation. type SBO.
[0012] Plus précisément, l'invention propose une glace en nitrure de silicium pour système d'étanchéité d'arbre de groupe motopompe primaire d'un réacteur nucléaire destinée à assurer l'étanchéité entre le circuit primaire et l'atmosphère, ladite glace présentant une surface recouverte par une couche protectrice réalisée dans un matériau non poreux et inerte chimiquement à une eau surchauffée à une température supérieure ou égale à 200°C et sous pression (pression supérieure ou égale à la pression de vapeur saturante de l'eau).  More specifically, the invention provides a silicon nitride ice for primary pump unit shaft sealing system of a nuclear reactor for sealing between the primary circuit and the atmosphere, said ice having a surface covered by a protective layer made of a non-porous material and chemically inert with superheated water at a temperature greater than or equal to 200 ° C and under pressure (pressure greater than or equal to the saturation vapor pressure of water) .
[0013] L'invention consiste donc à utiliser une couche protectrice inerte et non dégradable en milieu aqueux et dans des conditions accidentelles de type SBO (température au niveau des glaces supérieure à 200°C), et capable d'empêcher la dégradation et l'érosion de la surface des glaces en nitrure de silicium qui se transforme en silice dans des conditions de températures supérieures à 200°C. La couche protectrice selon l'invention résiste à l'érosion aussi bien en conditions normales de fonctionnement qu'en conditions de type SBO.  The invention therefore consists in using an inert and non-degradable protective layer in an aqueous medium and under accident conditions of the SBO type (ice temperature greater than 200 ° C.), and capable of preventing the degradation and degradation. erosion of the silicon nitride ice surface which transforms into silica under conditions of temperatures above 200 ° C. The protective layer according to the invention resists erosion under normal operating conditions as well as SBO-type conditions.
[0014] Grâce à l'adjonction d'une couche protectrice selon l'invention sur les glaces en nitrure de silicium, celles-ci présentent désormais une résistance hydrothermale aux conditions de type SBO et ne se dégradent plus. With the addition of a protective layer according to the invention on the silicon nitride ice, they now have a hydrothermal resistance to SBO-type conditions and no longer degrade.
[0015] Par conséquent, cette protection contre la dégradation des glaces en nitrure répond à une problématique spécifique, différente des problématiques d'encrassement des glaces connues par ailleurs. [0016] La glace selon l'invention peut également présenter une ou plusieurs des caractéristiques ci-après prise individuellement ou selon toutes les combinaisons techniquement possibles : la couche protectrice présente des propriétés d'adhérence avec le nitrure de silicium de ladite glace ; la couche protectrice présente des propriétés de résistance chimique à l'acide borique et/ou à l'hydroxyde de lithium et/ou à l'hydroxyde de potassium ; la couche protectrice présente une épaisseur homogène ; la couche protectrice est uniforme en épaisseur et respecte la forme du support ; la couche protectrice présente une dureté permettant de résister aux frottements (notamment entre les deux faces actives des glaces) et aux rayures ; la couche protectrice présente une rugosité équivalente à la surface active de ladite glace ; la couche protectrice présente des propriétés de résistance au choc thermique ; la couche protectrice est en diamant micro- ou nanocristallin ou encore en oxyde de zirconium ; ladite couche protectrice présente une épaisseur de quelques micromètres ; par exemple entre 0,1 et 30 micromètres et avantageusement entre 0,2 et 10 micromètres ; et préférentiellement entre 0,2 et 2 μηι ; la surface active de ladite glace destinée à être en contact avec un film d'eau est recouverte entièrement par une couche protectrice ; la couche protectrice résiste à l'érosion causée par l'eau en conditions normales et en conditions accidentelles de type SBO ; la couche protectrice ne perturbe pas le fonctionnement normal de la glace ; la couche protectrice résiste à toutes les conditions que peut subir le joint n°1 en fonctionnement normal ou en situation accidentelle ; ladite glace est une glace flottante ou une glace tournante ; Therefore, this protection against the deterioration of nitride ice meets a specific problem, different problems of fouling ice otherwise known. The ice according to the invention may also have one or more of the following characteristics taken individually or in any technically possible combination: the protective layer has adhesion properties with the silicon nitride of said ice; the protective layer has chemical resistance properties to boric acid and / or lithium hydroxide and / or potassium hydroxide; the protective layer has a uniform thickness; the protective layer is uniform in thickness and respects the shape of the support; the protective layer has a hardness to resist friction (especially between the two active faces of the windows) and scratches; the protective layer has a roughness equivalent to the active surface of said ice; the protective layer has thermal shock resistance properties; the protective layer is micro-or nanocrystalline diamond or zirconium oxide; said protective layer has a thickness of a few micrometers; for example between 0.1 and 30 microns and advantageously between 0.2 and 10 microns; and preferably between 0.2 and 2 μηι; the active surface of said ice intended to be in contact with a film of water is entirely covered by a protective layer; the protective layer resists erosion caused by water under normal conditions and accident conditions such as SBO; the protective layer does not disturb the normal operation of the ice; the protective layer withstands all conditions that joint No. 1 may experience in normal operation or in an accident situation; said ice is a floating ice or a rotating ice;
[ 0017 ] L'invention a également pour objet une garniture d'étanchéité comportant au moins une glace selon l'invention. The invention also relates to a seal comprising at least one ice according to the invention.
[0018 ] L'invention a également pour objet un système d'étanchéité d'arbre de groupe motopompe primaire d'un réacteur nucléaire comportant au moins une garniture d'étanchéité selon l'invention. The invention also relates to a shaft sealing system of primary pump unit of a nuclear reactor comprising at least one seal according to the invention.
[ 0019] L'invention a également pour objet un groupe motopompe primaire d'un réacteur nucléaire comportant un système d'étanchéité d'arbre selon l'invention. The invention also relates to a primary motor pump unit of a nuclear reactor comprising a shaft sealing system according to the invention.
[0020 ] L'invention a également pour objet un réacteur nucléaire à eau pressurisée comportant un groupe motopompe primaire selon l'invention. The invention also relates to a pressurized water nuclear reactor comprising a primary pump unit according to the invention.
BREVE DESCRIPTION DES FIGURES BRIEF DESCRIPTION OF THE FIGURES
[0021 ] D'autres caractéristiques et avantages de l'invention ressortiront à la lecture de la description qui suit, en référence aux figures annexées.  Other features and advantages of the invention will become apparent on reading the description which follows, with reference to the accompanying figures.
[0022 ] La figure 1 est une vue en coupe d'un système d'étanchéité d'un arbre de groupe motopompe primaire selon un mode de réalisation de l'invention. [ 0023 ] La figure 2 est une vue schématique en coupe d'un joint n°1 selon un mode de réalisation de la figure 1 . Figure 1 is a sectional view of a sealing system of a primary pump unit shaft according to one embodiment of the invention. Figure 2 is a schematic sectional view of a seal No. 1 according to an embodiment of Figure 1.
[0024 ] La figure 3 est une représentation schématique en coupe des glaces du joint n°1 selon un mode de réalisation de l'invention. Figure 3 is a schematic sectional view of the windows of the seal No. 1 according to one embodiment of the invention.
[ 0025 ] La figure 4a est une image réalisée au microscope électronique illustrant l'état de la surface d'un échantillon de la glace d'un joint n°1 comportant une couche protectrice selon l'invention après une exposition à un milieu aqueux à 290°C et sous pression. [0026] La figure 4b est une image réalisée au microscope électronique illustrant l'état de la surface d'un échantillon de la glace d'un joint n°1 sans couche protectrice après une exposition à un milieu aqueux à 290°C et sous pression. [ 0027 ] La figure 5a est un graphique illustrant l'évolution du débit de fuite en fonction du temps d'un joint n°1 comportant des glaces avec une couche protectrice selon l'invention, lors d'une augmentation de la température au niveau du joint n°1 suite à une remontée du fluide primaire en conditions de type SBO. [0028 ] La figure 5b est un graphique illustrant l'évolution du débit de fuite en fonction du temps d'un joint n°1 comportant des glaces sans couche protectrice, lors d'une augmentation de la température au niveau du joint n°1 suite à une remontée du fluide primaire en conditions de type SBO. FIG. 4a is an electron microscope image illustrating the state of the surface of a sample of ice of a No. 1 seal comprising a protective layer according to the invention after exposure to an aqueous medium with 290 ° C and under pressure. FIG. 4b is an electron microscope image illustrating the state of the surface of a sample of ice of a No. 1 seal without a protective layer after exposure to an aqueous medium at 290 ° C. and under pressure. FIG. 5a is a graph illustrating the evolution of the leakage rate as a function of time of a seal No. 1 comprising ice-cream with a protective layer according to the invention, during an increase in the temperature at the of seal No. 1 following a rise of the primary fluid under SBO conditions. FIG. 5b is a graph illustrating the evolution of the leakage rate as a function of time of a seal No. 1 comprising ice-creams without a protective layer, during an increase in the temperature at the seal no. 1 following a rise of the primary fluid under SBO conditions.
[0029] Dans toutes les figures, les éléments communs portent les mêmes références sauf précision contraire. In all the figures, the common elements bear the same references unless otherwise specified.
DESCRIPTION DETAILLEE D'UN MODE DE REALISATION DETAILED DESCRIPTION OF AN EMBODIMENT
[ 0030 ] La figure 1 représente un système de garnitures mécaniques d'étanchéité 4 d'arbre 7 d'un groupe motopompe primaire d'un réacteur nucléaire à eau pressurisée. Ce système d'étanchéité d'arbre comporte un joint n°1 référencé 1 sur la figure 1 , un joint n°2 référencé 2 sur la figure 1 et un joint n°3 référencé 3 sur la figure 1 . Chaque joint n°1 , 2, 3 se compose d'une glace tournante solidaire de l'arbre 7 et d'une glace flottante pouvant suivre les déplacements axiaux de l'arbre 7 mais non tournante. Figure 1 shows a shaft seals mechanical seal system 7 of a primary pump unit of a pressurized water nuclear reactor. This shaft sealing system comprises a seal No. 1 referenced 1 in Figure 1, a seal No. 2 referenced 2 in Figure 1 and a seal No. 3 referenced 3 in Figure 1. Each seal No. 1, 2, 3 consists of a rotating mirror integral with the shaft 7 and a floating ice can follow the axial movements of the shaft 7 but not rotating.
[0031 ] Le joint n°1 est représenté plus précisément à la figure 2. Le joint n°1 assure la plus grande partie de la chute de pression entre le circuit primaire 8 et l'atmosphère 9. Le joint n°1 est de type hydrostatique, à film d'eau d'une épaisseur de l'ordre de 10 μιτι. Le joint n°1 comporte une glace tournante 10 solidaire de l'arbre 7 et une glace flottante 1 1 qui peut suivre les déplacements axiaux de l'arbre 7. Le débit de fuite du joint n°1 est déterminé par la double pente de la glace flottante 1 1 ou encore par les pentes respectives des glaces tournante et flottante selon une variante de réalisation des glaces du joint n°1 (non représentée). Les glaces 1 0, 1 1 sont en nitrure de silicium. The seal No. 1 is shown more specifically in Figure 2. The seal No. 1 ensures most of the pressure drop between the primary circuit 8 and the atmosphere 9. The seal No. 1 is hydrostatic type, water film with a thickness of the order of 10 μιτι. The seal No. 1 comprises a rotating mirror 10 secured to the shaft 7 and a floating ice 1 1 which can follow the axial displacements of the shaft 7. The leakage flow of the seal No. 1 is determined by the double slope of the ice floe 1 1 or by the respective slopes of ice rotating and floating according to an embodiment of the ice cream of the seal No. 1 (not shown). The lenses 1 0, 1 1 are made of silicon nitride.
[0032 ] Les glaces 1 0, 1 1 du joint n°1 selon l'invention sont représentées plus précisément à la figure 3. La surface 1 2 d'au moins une des glaces 1 0, 1 1 est recouverte d'une couche protectrice 13. Préférentiellement, les deux glaces 10 et 1 1 sont recouvertes par une couche protectrice 1 3 au niveau de leur face active. The lenses 1 0, 1 1 of the seal No. 1 according to the invention are shown more precisely in Figure 3. The surface 1 2 of at least one of the ice 1 0, 1 1 is covered with a layer Protective 13. Preferably, the two windows 10 and 1 1 are covered by a protective layer 1 3 at their active face.
[0033 ] Cette couche protectrice 1 3 est réalisée dans un matériau non poreux et inerte chimiquement en milieu aqueux et à une température supérieure ou égale à 200°C. Cette couche protectrice 1 3 permet d'empêcher la dégradation et l'érosion de la surface des glaces en nitrure de silicium en condition de type SBO et ne perturbe pas le fonctionnement normal du joint n°1 . This protective layer 1 3 is made of a non-porous material and chemically inert in an aqueous medium and at a temperature greater than or equal to 200 ° C. This protective layer 1 3 makes it possible to prevent the degradation and erosion of the silicon nitride ice surface under the SBO condition and does not disturb the normal operation of the seal No. 1.
[0034 ] La couche protectrice 1 3 présente également des propriétés de résistance chimique à la corrosion et notamment à l'acide borique, à l'hydroxyde de lithium et à l'hydroxyde de potassium et résiste à l'érosion. Plus généralement, la couche protectrice 13 résiste à toutes les conditions que peut subir le joint n°1 dans des conditions normales de fonctionnement et dans des conditions accidentelles et notamment en conditions de type SBO pendant plusieurs heures, voire plusieurs jours. [0035 ] La couche protectrice 1 3 présente de préférence une épaisseur e comprise entre 0,1 et 30 micromètres. L'épaisseur de la couche protectrice e est de préférence comprise entre 0,2 et 1 0 micromètres. Préférentiellement, la couche protectrice 13 présente une épaisseur e comprise entre 0,2 et 2 micromètres. [0036] La couche protectrice 1 3 est déposée de manière uniforme avec des moyens ad-hoc, c'est-à-dire avec une épaisseur constante et homogène en respectant la forme du support. The protective layer 1 3 also has chemical corrosion resistance properties including boric acid, lithium hydroxide and potassium hydroxide and resists erosion. More generally, the protective layer 13 withstands all the conditions that can undergo the joint No. 1 under normal operating conditions and under accident conditions and especially under SBO-type conditions for several hours, or even days. The protective layer 1 3 preferably has a thickness e of between 0.1 and 30 micrometers. The thickness of the protective layer e is preferably between 0.2 and 10 micrometers. Preferably, the protective layer 13 has a thickness e of between 0.2 and 2 microns. The protective layer 1 3 is deposited uniformly with ad-hoc means, that is to say with a constant and homogeneous thickness respecting the shape of the support.
[0037 ] La couche protectrice 1 3 présente une grande dureté et est adaptée pour résister aux rayures et au frottement incidentel pouvant se produire entre les deux faces actives des glaces. [0038 ] La couche protectrice 1 3 résiste aux chocs thermiques importants, tels que le passage d'une température de 1 5°-95°C à une température supérieure à 200°C en quelques secondes. The protective layer 1 3 has a high hardness and is adapted to resist scratching and incidental friction that may occur between the two active faces of the windows. The protective layer 1 3 is resistant to significant thermal shocks, such as the passage of a temperature of 1 5 ° -95 ° C to a temperature above 200 ° C in a few seconds.
[ 0039] La couche protectrice 1 3 peut être réalisée en diamant nano- ou microcristallin, ou encore en oxyde de zirconium. The protective layer 1 3 may be made of nano- or microcrystalline diamond, or zirconium oxide.
[0040 ] A titre de comparaison, les figures 4a et 4b sont deux clichés réalisés au microscope électronique illustrant l'état de la surface des glaces avec et sans couche protectrice 1 3 après une exposition à un milieu aqueux à une température de 290°C et sous pression de 155 bar. [ 0041 ] Plus précisément, la figure 4a est un cliché d'une glace de joint n°1 selon l'invention comportant une couche protectrice 1 3 selon l'invention d'une épaisseur de 2 micromètres et la figure 4b un cliché d'une glace de joint n°1 sans couche protectrice. By way of comparison, FIGS. 4a and 4b are two electron micrographs illustrating the state of the ice surface with and without protective layer 1 3 after exposure to an aqueous medium at a temperature of 290 ° C. and under pressure of 155 bar. More specifically, FIG. 4a is a photograph of an ice cream seal No. 1 according to the invention comprising a protective layer 1 3 according to the invention with a thickness of 2 micrometers and FIG. 4b a cliché of FIG. a No. 1 seal glass without a protective layer.
[0042 ] On constate alors facilement par comparaison que la glace en nitrure de silicium avec la couche de protection 1 3 sur la figure 4a est intacte alors que la surface de la glace sans la couche de protection sur la figure 4b est dégradée fortement en silice (S1O2) sur une épaisseur de quelques dizaines de micromètres à quelques centaines de micromètres. Par ailleurs, la couche supérieure en silice se dissout avec le temps provoquant la dégradation et la dissolution d'une hauteur plus importante de glace en nitrure de silicium, de l'ordre de plusieurs centaines de micromètres. It is then easily found by comparison that the silicon nitride ice with the protective layer 1 3 in Figure 4a is intact while the surface of the ice without the protective layer in Figure 4b is degraded strongly silica (S1O2) over a thickness of a few tens of microns to a few hundred micrometers. Moreover, the silica upper layer dissolves with time causing degradation and dissolution of a larger height of silicon nitride ice, of the order of several hundred micrometers.
[0043 ] La figure 5a est un graphique illustrant l'évolution du débit de fuite en fonction du temps d'un joint n°1 comportant des glaces avec une couche protectrice selon l'invention lors d'une augmentation de la température du fluide primaire au niveau du joint n°1 . La figure 5b est un graphique illustrant l'évolution du débit de fuite en fonction du temps d'un joint n°1 comportant des glaces sans couche protectrice lors d'une augmentation de la température du fluide primaire au niveau du joint n°1 . FIG. 5a is a graph illustrating the evolution of the leakage rate as a function of time of a seal No. 1 comprising ice creams with a protective layer according to the invention during an increase in the temperature of the primary fluid. at the joint # 1. FIG. 5b is a graph illustrating the evolution of the leakage rate as a function of time of a No. 1 seal comprising ice-creams without a protective layer during an increase in the temperature of the primary fluid at the joint No. 1.
[0044 ] Ainsi, on remarque facilement le gain obtenu avec la couche protectrice 1 3 selon l'invention. En effet, sur le graphique de la figure 5b, les glaces selon l'état de la technique sans couche de protection se dégradent rapidement suite à une évolution importante de la température, ce qui provoque une forte augmentation du débit de fuite du joint n°1 en quelques heures. En comparaison, le débit de fuite du joint n°1 reste constant dans les mêmes conditions avec les glaces selon l'invention comportant la couche de protection. [0045] Naturellement l'invention n'est pas limitée aux modes de réalisation décrits en référence aux figures et des variantes pourraient être envisagées sans sortir du cadre de l'invention. On pourrait notamment utiliser d'autres matériaux que ceux cités dans la description détaillée à partir du moment où ces matériaux sont non poreux, inertes et stables en conditions de type SBO. Thus, it is easy to see the gain obtained with the protective layer 1 3 according to the invention. Indeed, on the graph of FIG. 5b, the ice creams according to the state of the art without a protective layer are degraded. quickly following a significant change in temperature, which causes a sharp increase in the leakage rate of seal No. 1 in a few hours. In comparison, the leakage rate of the seal No. 1 remains constant under the same conditions with the windows according to the invention comprising the protective layer. Naturally the invention is not limited to the embodiments described with reference to the figures and variants could be envisaged without departing from the scope of the invention. In particular, materials other than those mentioned in the detailed description could be used from the moment when these materials are non-porous, inert and stable under SBO-type conditions.

Claims

REVENDICATIONS
Glace (10, 1 1 ) en nitrure de silicium de garniture d'étanchéité (1 ) pour système d'étanchéité (4) d'arbre (7) de groupe motopompe primaire d'un réacteur nucléaire destinée à assurer l'étanchéité entre le circuit primaire et l'atmosphère, caractérisée en ce que ladite glace (10, 1 1 ) présente une surface active recouverte par une couche protectrice (13) réalisée dans un matériau non poreux et inerte chimiquement à une eau surchauffée à une température supérieure ou égale à 200°C et sous pression. Ice (10, 1 1) made of silicon nitride packing (1) for sealing system (4) shaft (7) primary pump unit of a nuclear reactor for sealing between the primary circuit and the atmosphere, characterized in that said ice (10, 1 1) has an active surface covered by a protective layer (13) made of a non-porous material and chemically inert with superheated water at a temperature greater than or equal to at 200 ° C and under pressure.
Glace (10, 1 1 ) en nitrure de silicium de garniture d'étanchéité (1 ) pour système d'étanchéité (4) d'arbre (7) de groupe motopompe primaire d'un réacteur nucléaire selon la revendication précédente caractérisée en ce que la couche protectrice (13) présente des propriétés d'adhérence avec le nitrure de silicium de ladite glace. Ice (10, 1 1) of silicon nitride packing (1) for sealing system (4) shaft (7) primary pump unit of a nuclear reactor according to the preceding claim characterized in that the protective layer (13) has adhesion properties with the silicon nitride of said ice.
Glace (10, 1 1 ) en nitrure de silicium de garniture d'étanchéité (1 ) pour système d'étanchéité (4) d'arbre (7) de groupe motopompe primaire d'un réacteur nucléaire selon l'une des revendications précédentes caractérisée en ce que la couche protectrice (13) présente des propriétés de résistance chimique à l'acide borique, et/ou à l'hydroxyde de lithium et/ou à l'hydroxyde de potassium. Ice (10, 1 1) made of silicon nitride packing (1) for sealing system (4) of shaft (7) primary pump unit of a nuclear reactor according to one of the preceding claims, characterized in that the protective layer (13) has chemical resistance properties to boric acid, and / or lithium hydroxide and / or potassium hydroxide.
Glace (10, 1 1 ) en nitrure de silicium de garniture d'étanchéité (1 ) pour système d'étanchéité (4) d'arbre (7) de groupe motopompe primaire d'un réacteur nucléaire selon l'une des revendications précédentes caractérisée en ce que la couche protectrice (13) présente une épaisseur homogène. Ice (10, 1 1) made of silicon nitride packing (1) for sealing system (4) of shaft (7) primary pump unit of a nuclear reactor according to one of the preceding claims, characterized in that the protective layer (13) has a homogeneous thickness.
Glace (10, 1 1 ) en nitrure de silicium de garniture d'étanchéité (1 ) pour système d'étanchéité (4) d'arbre (7) de groupe motopompe primaire d'un réacteur nucléaire selon l'une des revendications précédentes caractérisée en ce que la couche protectrice (13) présente une dureté permettant de résister aux frottements et aux rayures. Ice (10, 1 1) made of silicon nitride packing (1) for sealing system (4) of shaft (7) primary pump unit of a nuclear reactor according to one of the preceding claims, characterized in that the protective layer (13) has a hardness to withstand friction and scratching.
6. Glace (10, 1 1 ) en nitrure de silicium de garniture d'étanchéité (1 ) pour système d'étanchéité (4) d'arbre (7) de groupe motopompe primaire d'un réacteur nucléaire selon l'une des revendications précédentes caractérisée en ce que la couche protectrice (13) présente une rugosité équivalente à la surface active de ladite glace (10, 1 1 ). 6. Glass (10, 1 1) of silicon nitride packing (1) for sealing system (4) shaft (7) primary pump unit of a nuclear reactor according to one of claims previous characterized in that the protective layer (13) has a roughness equivalent to the active surface of said ice (10, 1 1).
7. Glace (10, 1 1 ) en nitrure de silicium de garniture d'étanchéité (1 ) pour système d'étanchéité (4) d'arbre (7) de groupe motopompe primaire d'un réacteur nucléaire selon l'une des revendications précédentes caractérisée en ce que la couche protectrice (13) présente des propriétés de résistance au choc thermique. 7. Glass (10, 1 1) of silicon nitride packing (1) for sealing system (4) shaft (7) primary pump unit of a nuclear reactor according to one of claims previous characterized in that the protective layer (13) has thermal shock resistance properties.
8. Glace (10, 1 1 ) en nitrure de silicium de garniture d'étanchéité (1 ) pour système d'étanchéité (4) d'arbre (7) de groupe motopompe primaire d'un réacteur nucléaire selon l'une des revendications précédentes caractérisée en ce que la couche protectrice (13) est en diamant micro- ou nanocristallin ou encore en oxyde de zirconium. 8. Glass (10, 1 1) of silicon nitride packing (1) for sealing system (4) of shaft (7) primary pump unit of a nuclear reactor according to one of claims preceding characterized in that the protective layer (13) is micro-diamond or nanocrystalline or zirconium oxide.
9. Glace (10, 1 1 ) en nitrure de silicium de garniture d'étanchéité (1 ) pour système d'étanchéité (4) d'arbre (7) de groupe motopompe primaire d'un réacteur nucléaire selon l'une des revendications précédentes caractérisée en ce que ladite couche protectrice (13) présente une épaisseur (e) comprise entre 0,1 et 30 micromètres ou une épaisseur (e) comprise entre 0,2 et 10 micromètres ou une épaisseur (e) comprise entre 0,2 et 2 μηι. 9. Ice (10, 1 1) of silicon nitride packing (1) for sealing system (4) shaft (7) primary pump unit of a nuclear reactor according to one of claims characterized in that said protective layer (13) has a thickness (e) of between 0.1 and 30 microns or a thickness (e) of between 0.2 and 10 microns or a thickness (e) of between 0.2 and 2 μηι.
10. Glace (10, 1 1 ) en nitrure de silicium de garniture d'étanchéité (1 ) pour système d'étanchéité (4) d'arbre (7) de groupe motopompe primaire d'un réacteur nucléaire selon l'une des revendications précédentes caractérisée en ce que la surface active de ladite glace (10, 1 1 ) destinée à être en contact avec un film d'eau est recouverte entièrement par une couche protectrice (13). 10. Glass (10, 1 1) of silicon nitride packing (1) for sealing system (4) shaft (7) primary pump unit of a nuclear reactor according to one of claims previous characterized in that the active surface of said ice (10, 1 1) intended to be in contact with a water film is completely covered by a protective layer (13).
1 1 . Glace (10, 1 1 ) en nitrure de silicium de garniture d'étanchéité (1 ) pour système d'étanchéité (4) d'arbre (7) de groupe motopompe primaire d'un réacteur nucléaire selon l'une des revendications précédentes caractérisée en ce que la couche protectrice résiste à l'érosion causée par l'eau en conditions normales et en conditions accidentelles de type SBO. 1 1. Ice (10, 1 1) made of silicon nitride packing (1) for sealing system (4) of shaft (7) primary pump unit of a nuclear reactor according to one of the preceding claims, characterized in that the protective layer resists erosion caused by water under normal conditions and accident conditions of the SBO type.
12. Glace (10, 1 1 ) en nitrure de silicium de garniture d'étanchéité (1 ) pour système d'étanchéité (4) d'arbre (7) de groupe motopompe primaire d'un réacteur nucléaire selon l'une des revendications précédentes caractérisée en ce que ladite glace (10, 1 1 ) est une glace flottante ou une glace tournante. 12. Glass (10, 1 1) of silicon nitride packing (1) for sealing system (4) shaft (7) primary pump unit of a nuclear reactor according to one of claims previous characterized in that said ice (10, 1 1) is a floating ice or a rotating ice.
13. Garniture d'étanchéité (1 ) comportant au moins une glace (10, 1 1 ) selon l'une des revendications précédentes. 13. Gasket (1) comprising at least one ice (10, 1 1) according to one of the preceding claims.
14. Système d'étanchéité (4) d'arbre (7) de groupe motopompe primaire d'un réacteur nucléaire comportant au moins une garniture d'étanchéité selon la revendication 13. 14. Sealing system (4) for the shaft (7) of the primary pump unit of a nuclear reactor comprising at least one packing according to claim 13.
15. Groupe motopompe primaire d'un réacteur nucléaire comportant un système d'étanchéité d'arbre selon la revendication 14. 15. Primary pump unit of a nuclear reactor comprising a shaft sealing system according to claim 14.
1 6. Réacteur nucléaire à eau pressurisée comportant un groupe motopompe primaire selon la revendication 15. 6. A pressurized water nuclear reactor comprising a primary pump unit according to claim 15.
EP18729677.7A 2017-06-08 2018-06-08 Seal package face plate of a shaft sealing system of a reactor coolant pump Withdrawn EP3635749A1 (en)

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FR1755117A FR3067513B1 (en) 2017-06-08 2017-06-08 GLASS FOR SEALING A PRIMARY PUMP GROUP SHAFT SEALING SYSTEM
PCT/EP2018/065116 WO2018224633A1 (en) 2017-06-08 2018-06-08 Seal package face plate of a shaft sealing system of a reactor coolant pump

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JP3970270B2 (en) 2004-09-01 2007-09-05 三菱重工業株式会社 Non-contact seal and fluid machinery
JP5430389B2 (en) 2009-12-24 2014-02-26 京セラ株式会社 Non-contact type seal ring and shaft seal device using the same
FR3009125B1 (en) * 2013-07-24 2019-06-28 Areva Np ICE FOR SEAL TRIM FOR TREE SEALING SYSTEM

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US20200161009A1 (en) 2020-05-21
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FR3067513B1 (en) 2020-01-17
WO2018224633A1 (en) 2018-12-13
JP7160842B2 (en) 2022-10-25
JP2020522709A (en) 2020-07-30
CN110730990A (en) 2020-01-24
ZA201907913B (en) 2020-09-30

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