摘要:
An electrode probe for measuring the electrochemical potential of a surface at a location of interest in a boiling water reactor. The probe has a monolithic sensor configuration built into a single stainless steel mineral insulated (MI) cable. This monolithic sensor can be used as a switch to detect when the appropriate concentration of dissolved hydrogen required to provide IGSCC mitigation is present at any location inside the reactor. Using the sensor switch, it is possible to in situ instantly determine the minimum hydrogen level required to reach the IGSCC protection potential. The sensor configuration consists of a metal/metal oxide/ZrO.sub.2 sensor and a noble metal sensor in a combination wherein the outer sheath of a mineral insulated cable acts as the conductor for the noble metal and the central conductor of the MI cable acts as the conductor for the metal/metal oxide/ZrO.sub.2. The metal/metal oxide/ZrO.sub.2 sensor acts as a reference electrode in the BWR environment (i.e., at constant pH) and the noble metal sensor acts as a hydrogen electrode which responds to the dissolved hydrogen content in the BWR water.
摘要:
Method for controlling the amount of metal atoms deposited into an oxide layer present on a metal surface, which metal atoms increase the corrosion resistance of metal when present in the oxide film, wherein the metal surface is submerged in water at a selected temperature within the range of about to 200° to 550° F.; and a solution of a compound containing the metal which increases the corrosion resistance of the metal surface when present in the oxide film is injected into the water. The compound decomposes at the selected temperature to release atoms of the metal which incorporate in the oxide film at a desired loading.
摘要:
Method for controlling the amount of metal atoms deposited into an oxide layer present on a metal surface, which metal atoms increase the corrosion resistance of metal when present in the oxide film, wherein the metal surface is submerged in water at a selected temperature within the range of about to 200° to 550° F.; and a solution of a compound containing the metal which increases the corrosion resistance of the metal surface when present in the oxide film is injected into the water. The compound decomposes at the selected temperature to release atoms of the metal which incorporate in the oxide film at a desired loading.
摘要:
A method for ensuring the distribution of noble metal in the reactor circuit during plant application without measuring the reactor water for noble metal content by chemical analysis. The method involves the measurement of electrochemical corrosion potential in an autoclave or a high-flow test section that is connected to the reactor water circuit through sample lines downstream of the injection port, preferably the point in the reactor circuit which is furthest from the injection port. If the noble metal flows into the autoclave or test section at these distant points in the reactor circuit, then the noble metal will deposit on the test specimens inside the autoclave or test section. After the noble metal has been injected for a predetermined duration, the electrochemical corrosion potential autoclave or test section is exposed to hydrogen water chemistry conditions and the electrochemical corrosion potentials of the specimens inside the autoclave or test section will be measured to determine the extent of their catalytic response. A good catalytic response indicates that the noble metal has reached the locations upstream where electrochemical corrosion potential is being measured.
摘要:
A system and method of injecting a chemical into a high pressure process stream without pumps or other active components. The system utilizes the differential pressure created by resistive losses of downstream components within a high pressure process stream. A bypass side stream is taken from an upstream pressure location and returned to the downstream side of the resistive inline process component. The chemical solution vessel is pressurized by the higher side of the pressure differential. The solution then passes through a flow controlling capillary tube exiting on the lower pressure differential side into the bypass stream. The high flow rate chemically diluted bypass stream then returns to the process stream at the lower differential process stream tie-in. The chemical solution is isolated from the process water pressuring the vessel by a movable separating device preventing mixing of the two fluids. The vessel can also be pressurized by gas.
摘要:
Composite particle comprising a zinc containing compound such as zinc oxide and a noble metal such a platinum, and process for fabrication thereof. The particles facilitate simultaneous controlled introduction of the zinc and noble metal species into a nuclear reactor.
摘要:
A method for mitigating crack growth on the surface of stainless steel or other alloy components in a water-cooled nuclear reactor wherein a solution or suspension of a compound containing a noble metal is injected into the coolant water while the reactor is not generating nuclear heat, e.g., during shutdown or recirculation pump heatup. During shutdown, the reactor coolant water reaches temperatures as low as 120.degree. F., in contrast to the water temperature of 550.degree. F. during normal operation. During pump heatup, the water temperature reaches 400.degree.-450.degree. F. At these reduced temperatures, the rate of thermal decomposition of the injected noble metal compound is reduced. However, radiation-induced decomposition also occurs inside the reactor. In particular, the noble metal compound can be decomposed by the gamma radiation emanating from the nuclear fuel core of the reactor. The noble metal compound decomposes under reactor thermal and radiation conditions to release ions/atoms of the noble metal which incorporate in or deposit on the oxide film formed on the stainless steel and other alloy components. As a result, the electrochemical potential of the metal surface is maintained at a level below the critical potential in the presence of low levels of hydrogen to protect against intergranular stress corrosion cracking.
摘要:
The present invention relates to a compound of the formula: ##STR1## wherein (a) A is independently selected from --SR.sup.1, --NR.sup.1 R.sup.2, --PR.sup.1 R.sup.2, --Si,R.sup.1 R.sup.2 R.sup.3, or --SnR.sup.1 R.sup.2 R.sup.3,R.sup.1, R.sup.2 and R.sup.3 are each independently selected from alkyl, cycloalkyl, alkylcycloalkyl, arylalkyl having from 1 to 20 carbon atoms or aryl, substituted aryl, or where R.sup.2 and R.sup.3 together form a heterocycle group, having from 4 to 20 carbon atoms, andn is an integer from 1 to 5;(b) Y is selected from a direct bond or --CR.sup.4 R.sup.5 --, wherein R.sup.4 and R.sup.5 are each independently selected from hydrogen, or alkyl group having 1 to 20 carbon atoms or R.sup.4 and R.sup.5 together form a cycloalkyl group having 4 to 20 carbon atoms;(c) Z is aryl or substituted aryl; and(d) X is halogen, sulfonate, carboxylate, phosphate, carbonate, sulfate, or MD.sub.m wherein M is boron, phosphorous, arsenic, antimony or silicon, D is fluorine, chlorine, bromine or iodine and m is 2, 3 or 4. These compounds are useful as synergistic corrosion inhibitors for metals. These compounds are also useful as bacteriostats, antifungal agents and as deicing agents as surfactants.
摘要:
Composite particle comprising a zinc containing compound such as zinc oxide and a noble metal such a platinum, and process for fabrication thereof. The particles facilitate simultaneous controlled introduction of the zinc and noble metal species into a nuclear reactor.
摘要:
A ceramic sensor is disclosed that includes a ceramic tube having a closed end and an open end, and a metal sleeve having open first and second ends. The ceramic tube is formed of stabilized zirconia. The metal sleeve extends about the open end of the ceramic tube and is sealingly joined thereto at a contact region by a brazeless bond resulting from hot isostatic pressing. A mixture of metal and metal oxide powders is provided within the ceramic tube adjacent the closed end, and a conducting wire extends from the mixture of metal and metal oxide powders to the second end of the metal sleeve.