A method for testing materials by online irradiation in a heavy water reactor

Abstract

This invention discloses a method for testing materials via online irradiation in a heavy water reactor, comprising the following steps: installing a concave base and guide rod; installing the irradiated material and steel wire rope into the groove of the irradiation device; installing the irradiation device onto a designated VFD; conducting sample irradiation; dismantling the irradiation device; cutting the steel wire rope to remove the irradiated sample; cutting the remaining steel wire and storing it as waste; restoring the equipment to its original state on the designated VFD; and decontaminating the irradiation and shearing devices. The advantages of this invention are: it allows the irradiation channel to be opened during high-power operation of the reactor core, enabling the sample to be placed inside and irradiated for a relatively short period (usually several weeks or months) before being retrieved for analysis and testing.

Description

Technical Field

[0001] This invention belongs to the field of nuclear technology applications, specifically relating to a method for testing materials by online irradiation in a heavy water reactor. Background Technology

[0002] Heavy water reactors employ a pressure tube core design. The tube container is horizontally arranged, with the pressure tubes, serving as the pressure-bearing components of the primary loop, arranged in a square grid within the container. Coolant and moderator are arranged separately; coolant flows into the pressure tube from one end and out from the other, carrying away heat generated by fuel fission and nuclide decay. Both coolant and moderator are heavy water, and the fuel is typically natural uranium. The fuel structure is simple, with multiple fuel rod bundles usually loaded in series within a single pressure tube channel. Due to the relatively low residual reactivity, heavy water reactors require refueling during power operation. An upstream refueling unit pushes fuel assemblies into the core, while a downstream refueling unit receives the discharged spent fuel assemblies. Sufficient spacing is maintained between the pressure tubes to facilitate refueling operations. This spacing provides operational space for reactor control and protection systems. Heavy water reactors are designed with various control and protection devices, such as regulating rods, liquid zone control devices, mechanically controlled absorber rods, and shutdown rods. The control and protection devices of the heavy water reactor are all located in the moderator region outside the pressure tube, perpendicular to it. The active region of the heavy water reactor core is approximately Ф6m*6m. To achieve accurate measurement and control of the local power distribution in the core, a large number of neutron detector assemblies are arranged in the active region of the core. These neutron detector assemblies provide real-time signals to the heavy water reactor reactivity control and protection devices. Each neutron detector assembly has 11 channels for accommodating detectors. In fact, not all channels of each detector assembly on the heavy water reactor are occupied by detectors. Simultaneously, to facilitate core flux measurements during commissioning and operation, a movable fission ionization chamber channel is reserved at the center of each detector assembly. This channel is sealed at the bottom and directly connected to the upper end cover of the assembly's connection chamber, normally sealed with bolts. There are existing examples of material irradiation testing on heavy water reactors, but all of them used non-movable fission ionization chamber channels. Material loading and unloading must both be carried out during major overhauls. After removing the top cover of the assembly, specialized tools are installed for operation. Considering that some materials have short testing periods in reality, loading and unloading operations are not allowed between two adjacent major overhauls; therefore, the situation of online irradiation testing of materials needs to be considered. The movable fission ionization chamber channel provides convenient space for online irradiation testing of small-diameter materials.

[0003] Existing technology requires opening the irradiation channels during a reactor overhaul shutdown to place the sample into the reactor core, and then removing the core during the same shutdown. This technology is only suitable for samples that have been irradiated for more than two years for testing purposes. Summary of the Invention

[0004] The purpose of this invention is to provide a method for online irradiation testing of materials in a heavy water reactor, providing necessary irradiation testing conditions for certain isotopic materials before mass production.

[0005] The technical solution of the present invention is as follows: A method for online irradiation testing of materials using a heavy water reactor, comprising the following steps:

[0006] Step 1: Install the concave base and guide rod;

[0007] Step 2: Install the irradiation material and steel wire rope into the wheel groove of the irradiation device;

[0008] Step 3: Install the irradiation device onto the designated VFD;

[0009] Step 4: Irradiate the sample;

[0010] Step 5: Dismantle the irradiation device;

[0011] Step 6: Cut the steel wire rope and remove the irradiated sample;

[0012] Step 7: Cut off the remaining steel wire and store it as waste;

[0013] Step 8: Restore the device state on the specified VFD;

[0014] Step 9: Decontaminate the irradiation and shearing apparatus.

[0015] Step 1 includes:

[0016] Step 11: Remove the additional shielding block on the designated VFD in advance.

[0017] Step 12: Install two guide rods on the concave base.

[0018] Step 13: Remove the bolts on the upper cover of the designated VFD connection chamber.

[0019] Step 2 includes:

[0020] Step 21: Remove the cover plate of the irradiation unit's wheel chamber.

[0021] Step 22: Open the shielding door at the bottom of the irradiation device.

[0022] Step 23: Pass the steel wire rope through the lower flange of the irradiation device.

[0023] Step 24: Insert the upper end of the wire rope into the slot of the wheel groove.

[0024] Step 25: Rotate the grooved pulley counterclockwise to wind the wire rope into the groove.

[0025] Step 26: Install the radiator wheel chamber cover plate.

[0026] Step 3 includes:

[0027] Step 31: Use a 1.5T hand-operated hoist to hoist the irradiation device onto the designated VFD.

[0028] Step 32: Slowly lower the irradiation device and pass the two guide rods through the guide holes of the lower flange of the irradiation device.

[0029] Step 33: Continue to slowly lower the irradiation device until the lower flange of the irradiation device contacts the concave base.

[0030] Step 34: Release the lifting device and move the hand chain hoist to its initial position.

[0031] Step 35 involves connecting the drive power supply to the drive device and connecting the signal line to the control computer.

[0032] Step 4 includes:

[0033] Step 41: Use the control computer to rotate the groove wheel counterclockwise to insert the irradiated sample into the designated position inside the reactor core.

[0034] Step 42: Keep the irradiated sample within the reactor core to receive neutron irradiation, collect real-time core flux, evaluate the irradiation effect, and once the irradiation objective is achieved...

[0035] Step 43: Use the control computer to rotate the groove wheel clockwise to transfer the irradiated sample into the irradiation device.

[0036] Step 44: Close the shielding door at the bottom of the irradiation device and disconnect the drive power and signal connection on the irradiation device to prepare for transfer.

[0037] Step 5 includes:

[0038] Step 51: Use a hand chain hoist to slowly lift the irradiation device away from the concave base.

[0039] Step 52: After the lower flange of the irradiation device detaches from the guide rod, lift the irradiation device away from the reactor control structure platform.

[0040] Step 53: Connect the irradiation device to the receiving seat of the shearing equipment. The lower flange of the irradiation device and the upper flange of the receiving seat are connected by bolts.

[0041] Step 54 involves connecting the drive power supply to the drive device and connecting the signal line to the control computer to prepare for wire rope cutting.

[0042] Step 6 includes:

[0043] Step 61: Open the shielding door at the bottom of the irradiation device.

[0044] Step 62: Use the control computer to rotate the groove wheel counterclockwise to insert the irradiated sample into the shielded transport container.

[0045] Step 63: Cut the steel wire rope to allow the irradiated sample section to automatically fall into the shielding container.

[0046] Step 64: Use the control computer to rotate the grooved wheel clockwise to lift the wire rope a section.

[0047] Step 65: Close the top opening of the shielding container and close the shielding door at the bottom of the irradiation device.

[0048] Step 66: Open the shielding door of the shearing equipment and remove the shielding container.

[0049] Step 67: Transfer the shielded container holding the irradiated sample to the designated analysis station.

[0050] Step 7 includes:

[0051] Step 71: Install a new shielding container.

[0052] Step 72: Open the top opening of the shielding container and close the shielding door of the shearing equipment.

[0053] Step 73: Open the shielding door at the bottom of the irradiation device.

[0054] Step 74: Use the control computer to rotate the groove wheel counterclockwise to insert the irradiated sample into the shielded transport container.

[0055] Step 75: Cut the wire rope, allowing the cut section to fall into the shielded container.

[0056] Step 76, which is to repeat steps 74-75 until the cutting is complete.

[0057] Step 77: Close the top opening of the shielding container and close the shielding door at the bottom of the irradiation device.

[0058] Step 78: Open the shielding door of the shearing equipment and remove the shielding container.

[0059] Step 79 involves transferring the shielded container to the spent fuel receiving pool for storage.

[0060] Step 710 disconnects the drive power and signal connection from the irradiation device.

[0061] Step 8 includes:

[0062] Step 81: Install the bolts on the designated VFD connection chamber cover plate.

[0063] Step 82: Remove the guide rod.

[0064] Step 9 includes:

[0065] Step 91: Disassemble the irradiation device for decontamination. Wrap the last section of the removed steel wire rope in plastic wrap.

[0066] Step 92: Disassemble the shearing device for decontamination treatment.

[0067] Step 93 involves transferring the irradiation device and shearing device to a designated warehouse for storage.

[0068] The beneficial effects of this invention are that it can open the irradiation channel during high-power operation of the unit, put the sample into the reactor core, and after a short period of irradiation (usually several weeks or months), the sample can be taken out and sent for analysis and testing. Detailed Implementation

[0069] The present invention will be further described in detail below with reference to specific embodiments.

[0070] A method for testing materials by online irradiation in a heavy water reactor includes the following steps:

[0071] Step 1: Install the concave base and guide rod.

[0072] This includes: performing step 11 to remove the additional shielding block on the designated VFD in advance and installing the concave base.

[0073] Then, perform step 12 to install two guide rods on the concave base (the guide rods are bolted to the concave base).

[0074] Perform step 13 to remove the bolts on the upper cover of the designated VFD connection chamber.

[0075] Step 2: Install the irradiation material and steel wire rope into the wheel groove of the irradiation device.

[0076] This includes: performing step 21 to remove the cover plate of the irradiation unit's wheel chamber.

[0077] And proceed to step 22 to open the shielding door at the bottom of the irradiation device.

[0078] Then, proceed to step 23 to pass the wire rope through the lower flange of the irradiation device.

[0079] Then perform step 24 to engage the upper end of the wire rope into the groove of the wheel.

[0080] Next, perform step 25, rotating the grooved wheel counterclockwise to wind the wire rope into the groove.

[0081] Finally, perform step 26 to install the irradiation device's wheel chamber cover.

[0082] Step 3: Install the irradiation device onto the designated VFD.

[0083] This includes: Step 31, using a 1.5T hand-operated hoist to lift the irradiation device onto the designated VFD.

[0084] Next, proceed to step 32, slowly lowering the irradiation device and passing the two guide rods through the guide holes of the lower flange of the irradiation device.

[0085] Then proceed to step 33 and continue slowly lowering the irradiation device until the lower flange of the irradiation device contacts the concave base.

[0086] Next, perform step 34 to release the lifting device and move the hand chain hoist to its initial position.

[0087] Finally, step 35 connects the drive power supply to the drive device and connects the signal line to the control computer.

[0088] Step 4: Irradiate the sample.

[0089] This includes: Step 41, using the control computer to rotate the groove wheel counterclockwise to insert the irradiated sample into the designated position within the reactor core.

[0090] Next, execute step 42 to keep the irradiated sample within the reactor core to receive neutron irradiation, collect real-time core flux, evaluate the irradiation effect, and once the irradiation objective is achieved...

[0091] Next, in step 43, the control computer rotates the groove wheel clockwise to transfer the irradiated sample into the irradiation device.

[0092] Finally, step 44 is executed to close the shielding door at the bottom of the irradiation device and disconnect the drive power and signal connection on the irradiation device in preparation for transfer.

[0093] Step 5: Remove the irradiation device.

[0094] This includes: performing step 51, using a hand-operated hoist to slowly lift the irradiation device away from the concave base.

[0095] After proceeding to step 52 and the lower flange of the irradiation device detaches from the guide rod, the irradiation device will be lifted off the reactor control structure platform.

[0096] Next, perform step 53 to connect the irradiation device to the receiving seat of the shearing equipment. The lower flange of the irradiation device and the upper flange of the receiving seat are connected by bolts.

[0097] Finally, step 54 connects the drive power supply to the drive device and connects the signal line to the control computer to prepare for wire rope cutting.

[0098] Step 6: Cut the steel wire rope and remove the irradiated sample.

[0099] This includes: performing step 61 to open the shielding door at the bottom of the irradiation device.

[0100] Next, in step 62, use the control computer to rotate the groove wheel counterclockwise to insert the irradiated sample into the shielded transport container.

[0101] Then, perform step 63 to cut the steel wire rope, allowing the irradiated sample section to automatically fall into the shielding container.

[0102] Next, perform step 64, using the control computer to rotate the grooved wheel clockwise, raising the wire rope by a section.

[0103] Next, perform step 65 to close the upper opening of the shielding container and close the shielding door at the bottom of the irradiation device.

[0104] Next, proceed to step 66 to open the shielding door of the shearing equipment and remove the shielding container.

[0105] Finally, step 67 is performed to transfer the shielded container holding the irradiated sample to the designated analysis station.

[0106] Step 7: Cut off the remaining steel wire and store it as waste.

[0107] This includes: performing step 71 to install a new shielding container.

[0108] Then, perform step 72 to open the top opening of the shielding container and close the shielding door of the shearing equipment.

[0109] Next, proceed to step 73 to open the shielding door at the bottom of the irradiation device.

[0110] Next, in step 74, use the control computer to rotate the groove wheel counterclockwise to insert the irradiated sample into the shielded transport container.

[0111] Next, perform step 75 to cut the wire rope, causing the cut section to fall into the shielded container.

[0112] Then proceed to step 76, that is, repeat steps 74-75 until the cutting is complete.

[0113] Next, perform step 77 to close the upper opening of the shielding container and close the shielding door at the bottom of the irradiation device.

[0114] Next, proceed to step 78 to open the shielding door of the shearing equipment and remove the shielding container.

[0115] Next, proceed to step 79 to transfer the shielded container to the spent fuel receiving pool for storage.

[0116] Finally, step 710 disconnects the drive power and signal connection from the irradiation device.

[0117] Step 8: Restore the device state on the specified VFD.

[0118] This includes: performing step 81 to install the bolts on the designated VFD connection chamber cover plate.

[0119] And perform step 82 to remove the guide rod.

[0120] Step 9: Decontaminate the irradiation and shearing apparatus.

[0121] This includes: performing step 91 to disassemble the irradiation device for decontamination treatment, wrapping the last section of the removed steel wire rope with plastic sheeting.

[0122] Next, proceed to step 92 to disassemble the shearing device and perform decontamination treatment.

[0123] Finally, step 93 is performed to transfer the irradiation device and shearing device to the designated warehouse for storage.

Claims

1. A method for testing materials by online irradiation in a heavy water reactor, characterized in that, Includes the following steps: Step 1: Install the concave base and guide rod; Step 1 includes: Step 11: Remove the additional shielding block on the designated VFD in advance. Step 12: Install two guide rods on the concave base. Step 13: Remove the bolts on the upper cover of the designated VFD connection chamber; Step 2: Install the irradiation material and steel wire rope into the wheel groove of the irradiation device; Step 2 includes: Step 21: Remove the cover plate of the irradiation unit's wheel chamber. Step 22: Open the shielding door at the bottom of the irradiation device. Step 23: Pass the lower end of the wire rope through the lower flange of the irradiation device. Step 24: Insert the upper end of the wire rope into the slot of the wheel groove. Step 25: Rotate the grooved pulley counterclockwise to wind the wire rope into the groove. Step 26: Install the radiator chamber cover plate; Step 3: Install the irradiation device onto the designated VFD; Step 3 includes: Step 31: Use a 1.5T hand-operated hoist to hoist the irradiation device onto the designated VFD. Step 32: Slowly lower the irradiation device and pass the two guide rods through the guide holes of the lower flange of the irradiation device. Step 33: Continue to slowly lower the irradiation device until the lower flange of the irradiation device contacts the concave base. Step 34: Release the lifting device and move the hand chain hoist to its initial position. Step 35 involves connecting the drive power supply to the drive device and connecting the signal line to the control computer. Step 4: Irradiate the sample; Step 5: Dismantle the irradiation device; Step 6: Cut the steel wire rope and remove the irradiated sample; Step 7: Cut off the remaining steel wire and store it as waste; Step 8: Restore the device state on the specified VFD; Step 9: Decontaminate the irradiation and shearing apparatus.

2. The method for online irradiation testing of materials using a heavy water reactor as described in claim 1, characterized in that, Step 4 includes: Step 41: Use the control computer to rotate the groove wheel counterclockwise to insert the irradiated sample into the designated position inside the reactor core. Step 42: Keep the irradiated sample irradiated with neutrons inside the reactor and collect real-time core flux; Step 43: Use the control computer to rotate the groove wheel clockwise to transfer the irradiated sample into the irradiation device. Step 44: Close the shielding door at the bottom of the irradiation device and disconnect the drive power supply and signal connection on the irradiation device.

3. The method for online irradiation testing of materials using a heavy water reactor as described in claim 1, characterized in that, Step 5 includes: Step 51: Use a hand chain hoist to slowly lift the irradiation device away from the concave base. Step 52: After the lower flange of the irradiation device detaches from the guide rod, lift the irradiation device away from the reactor control structure platform. Step 53: Connect the irradiation device to the receiving seat of the shearing equipment. The lower flange of the irradiation device and the upper flange of the receiving seat are connected by bolts. Step 54 involves connecting the drive power supply to the drive device and connecting the signal line to the control computer to prepare for wire rope cutting.

4. The method for online irradiation testing of materials using a heavy water reactor as described in claim 1, characterized in that, Step 6 includes: Step 61: Open the shielding door at the bottom of the irradiation device. Step 62: Use the control computer to rotate the groove wheel counterclockwise to insert the irradiated sample into the shielded transport container. Step 63: Cut the steel wire rope to allow the irradiated sample section to automatically fall into the shielding container. Step 64: Use the control computer to rotate the grooved wheel clockwise to lift the wire rope a section. Step 65: Close the top opening of the shielding container and close the shielding door at the bottom of the irradiation device. Step 66: Open the shielding door of the shearing equipment and remove the shielding container. Step 67: Transfer the shielded container holding the irradiated sample to the analysis station.

5. The method for online irradiation testing of materials in a heavy water reactor as described in claim 1, characterized in that, Step 7 includes: Step 71: Install a new shielding container. Step 72: Open the top opening of the shielding container and close the shielding door of the shearing equipment. Step 73: Open the shielding door at the bottom of the irradiation device. Step 74: Use the control computer to rotate the groove wheel counterclockwise to insert the irradiated sample into the shielded transport container. Step 75: Cut the wire rope, allowing the cut section to fall into the shielded container. Step 76, which is to repeat steps 74-75 until the cutting is complete. Step 77: Close the top opening of the shielding container and close the shielding door at the bottom of the irradiation device. Step 78: Open the shielding door of the shearing equipment and remove the shielding container. Step 79 involves transferring the shielded container to the spent fuel receiving pool for storage. Step 710: Disconnect the drive power and signal connection from the irradiation device.

6. The method for online irradiation testing of materials using a heavy water reactor as described in claim 1, characterized in that, Step 8 includes: Step 81: Install the bolts on the designated VFD connection chamber cover plate. Step 82: Remove the guide rod.

7. The method for online irradiation testing of materials using a heavy water reactor as described in claim 1, characterized in that, Step 9 includes: Step 91: Disassemble the irradiation device for decontamination. Wrap the last section of the removed steel wire rope in plastic wrap. Step 92: Disassemble the shearing device for decontamination treatment. Step 93 involves transferring the irradiation device and shearing device to a designated warehouse for storage.