阅读说明：本技术 一种核动力船舶反应堆装卸料系统及装卸料方法 (Nuclear power ship reactor loading and unloading system and loading and unloading method ) 是由 顾颖宾 胡安康 林一 陈励志 孙建 王立陶 丁海 杜晓程 张筠如 于 2021-10-18 设计创作，主要内容包括：本发明涉及核动力船舶设计技术领域,具体公开了一种核动力船舶反应堆装卸料系统及装卸料方法,其中在装卸料过程中,装卸料箱置于反应堆舱的上方,燃料转运开口B与燃料转运开口A对中,屏蔽套筒的上端卡设于燃料转运开口B处,下端扣设于反应堆压力容器上的环形平台处。本发明采用转运的方式结合装卸料技术进行陆上处理,具有充分可实现性,配套设施可反复为多艘核动力船舶服务。(The invention relates to the technical field of nuclear power ship design, and particularly discloses a nuclear power ship reactor loading and unloading system and a loading and unloading method. The invention adopts a transfer mode and combines the loading and unloading technology to carry out land treatment, has sufficient realizability, and can repeatedly serve a plurality of nuclear power ships by matching facilities.)

1. A nuclear power ship reactor loading and unloading system is characterized in that: comprises a reactor cabin, a ship body related structure and a loading and unloading material box;

the reactor cabin and ship body related structure comprises a reactor cabin wall (101), a radiation shield (102), a top radiation shield cabin cover (103), a reactor pressure vessel (104) and a weather deck (106);

the loading and unloading bin comprises an outer peripheral wall (201), a shielding layer (202), an inner peripheral wall (203), an in-bin travelling crane (204), a travelling crane hook (205), a travelling crane gantry crane (206), a bottom radiation shielding hatch cover (207), a fuel assembly storage container (208) and a shielding sleeve (209);

the reactor bulkhead (101) is of a double-layer hollow structure, and a radiation shield (102) is filled in the reactor bulkhead;

a fuel transfer opening A is processed on the top surface of the reactor bulkhead (101) and is closed by a top radiation shielding hatch (103);

the reactor pressure vessel (104) is arranged on the inner bottom surface of the reactor bulkhead (101);

a ring of annular platforms (1041) are machined on the side wall of the reactor pressure vessel (104);

placing a fuel assembly (1043) within said reactor pressure vessel (104);

the pressure vessel top cover (1042) is buckled above the reactor pressure vessel (104);

a through weather deck (106) is arranged at the uppermost part of the top surface of the reactor bulkhead (101);

a cavity enclosed between the peripheral wall (201) and the inner peripheral wall (203) is filled with a shielding layer (202), and the whole body is enclosed into a loading and unloading box body;

an in-box crane (204) is fixedly arranged on the top surface of the inner surrounding wall (203);

a fuel transfer opening B is processed at the center of the bottom surface of the loading and unloading box body and is closed by a bottom radiation shielding hatch cover (207);

the temporary fuel storage container (208) is arranged on the bottom surface of the inner peripheral wall (203) and can be used for placing a fuel assembly (1043) to be replaced;

the outer diameter of the shielding sleeve (209) is smaller than the diameter of the fuel transfer opening B, and the inner diameter of the shielding sleeve is larger than that of the pressure vessel top cover (1042) so as to ensure that the pressure vessel top cover (1042) can be smoothly lifted out of the shielding sleeve (209);

in the material loading and unloading process, the material loading and unloading box is arranged above the reactor cabin, the fuel transfer opening B is aligned with the fuel transfer opening A, the upper end of the shielding sleeve (209) is clamped at the fuel transfer opening B, and the lower end of the shielding sleeve is buckled at an annular platform (1041) on the reactor pressure vessel (104).

2. The nuclear power vessel reactor loading and unloading system of claim 1, wherein: still including supporting ground-based transportation facility, supporting ground-based transportation facility include loop wheel machine, large-tonnage transportation flatbed (306).

3. The nuclear power vessel reactor loading and unloading system of claim 1, wherein: an opening deck (105) is arranged between the weather deck (106) and the top surface of the reactor bulkhead (101);

the size of the opening deck (105) is larger than that of the loading and unloading box body, so that the loading and unloading box body can be smoothly hung to the top surface of the reactor bulkhead (101).

4. The nuclear power vessel reactor loading and unloading system of claim 1, wherein: the weather deck (106) is a strong deck, and a hatch cover (108) is arranged to avoid damage caused by strength reduction of the weather deck (106) due to repeated cutting;

a hatch coaming (107) is arranged, matched with the hatch cover (108), and welded at a through opening of the weather deck (106).

5. The nuclear power vessel reactor loading and unloading system of claim 1, wherein: the weather deck (106) is a common through deck, and if the weather deck is not enough to support the large hatch cover, a cutting mode is adopted, and the through opening is sealed by repair welding after the loading and unloading are finished;

for supporting the large hatch cover, a hatch cover (108) and a hatch coaming (107) are arranged;

the hatch coaming (107) is matched with the hatch cover (108) and is welded at the through opening of the weather deck (106).

6. The nuclear power vessel reactor loading and unloading system of claim 1, wherein: and a guide rail bracket (109) is arranged on the top surface of the reactor bulkhead (101), is perpendicular to the top surface of the reactor bulkhead (101), and is used for guiding when the reactor bulkhead is hung into a loading and unloading tank.

7. The nuclear power vessel reactor loading and unloading system of claim 6, wherein: the height of the guide rail frame (109) is not less than 2m, and the top end of the guide rail frame is lower than the plane of the open-air clamping plate (106).

8. The nuclear power vessel reactor loading and unloading system of claim 1, wherein: an embedded groove is processed on the annular platform (1041), and radiation-resistant aging-resistant rubber is arranged in the embedded groove to ensure that the shielding sleeve (209) is clamped in and then sealed.

9. The nuclear power vessel reactor loading and unloading system of claim 1, wherein: and a shielding sleeve fixing clamping seat (211) is arranged on the bottom surface of the inner surrounding wall (203) and used for fixing a shielding sleeve (209).

10. The nuclear power vessel reactor loading and unloading system of claim 1, wherein: lifting lugs (210) are respectively arranged on the outer part of the peripheral wall (201), the bottom radiation shielding cover (207) and the top radiation shielding hatch cover (103) to ensure the safety and stability of lifting.

11. The nuclear power vessel reactor loading and unloading system of claim 1, wherein: a crane hook (205) of an in-box crane (204) is adopted to hoist the bottom radiation shielding cover (207), the shielding sleeve (209), the top radiation shielding cabin cover (103) and the pressure vessel top cover (1042), and a crane hook (206) is adopted to hoist the fuel assembly (1043).

12. A method for loading and unloading a nuclear power vessel reactor based on the loading and unloading system of claim 1, characterized in that: the method comprises the following steps:

s1, opening a through hole of an open deck (106) in a state that a ship is docked or is stopped;

s2, hanging the loading and unloading material box into the ship, accurately dropping the loading and unloading material box on the top surface of the reactor bulkhead (101) for fixing, and simultaneously ensuring that the top radiation shielding hatch cover (103) and the bottom radiation shielding hatch cover (207) are centered and can be opened;

s3, opening a bottom radiation shielding cover (207), and hoisting and moving the bottom radiation shielding cover to a placement area by using an in-box crane (204);

s4, opening a top radiation shielding hatch cover (103), and hoisting and moving the hatch cover to a placement area in a loading and unloading material box by using an in-box crane (204);

s5, hoisting the shielding sleeve (209) to the annular platform (1041) through the fuel transfer opening B and the fuel transfer opening A by using an in-tank crane (204);

s6, opening a top cover (1042) of the reactor pressure vessel, and lifting and moving the reactor pressure vessel to a placement area in a loading and unloading material box by using an in-box crane (204);

s7, hoisting the fuel assembly (1043) to be replaced away from the reactor pressure vessel (104) by using an in-tank crane (204), and moving the fuel assembly to a temporary fuel storage vessel (208) for storage;

s8, hanging a new fuel assembly (1043) into the reactor pressure vessel (104) by using an in-tank crane (204);

s9, hoisting the top cover (1042) of the reactor pressure vessel back to the original position by using an in-tank crane (204) and sealing;

s10, hoisting the top radiation shielding hatch cover (103) back to the original position by using an in-box crane (204) and sealing;

s11, hanging the bottom radiation shielding cover (207) back to the original position by using an in-box crane (204) and sealing;

s12, releasing the fixation of the loading and unloading material box, and lifting the loading and unloading material box to the land;

s13, closing the through opening of the weather deck (106).

13. The method for loading and unloading a nuclear power vessel reactor as claimed in claim 12, wherein: a crane hook (205) of an in-box crane (204) is adopted to hoist the bottom radiation shielding cover (207), the shielding sleeve (209), the top radiation shielding cabin cover (103) and the pressure vessel top cover (1042), and a crane exhaust crane (206) of the in-box crane (204) is adopted to hoist the fuel assembly (1043).

14. The method for loading and unloading a nuclear power vessel reactor as claimed in claim 12, wherein: if the loading and unloading are carried out in the dry dock (301), a gantry crane (304) or a floating crane ship (305) is used for carrying out the hoisting operation of loading and unloading the material box;

if loading and unloading are carried out at the ship docking wharf (303), a floating crane ship (305) is adopted to carry out the hoisting operation of loading and unloading the workbin.

15. The method for loading and unloading a nuclear power vessel reactor as claimed in claim 12, wherein: the loading and unloading bins are transported on land using large flat bed transport vehicles (306).

Technical Field

The invention belongs to the technical field of nuclear power ship design, and particularly relates to a nuclear power ship reactor loading and unloading system and a loading and unloading method.

Background

Compared with conventional power ships, nuclear power ships have the following obvious advantages: 1. the nuclear energy is used as clean energy, so that the problem of waste gas emission caused by petroleum product fuel can be effectively solved; 2. the nuclear power ship has strong self-sustaining capability, can be operated for years by filling fuel once, greatly avoids the situation of filling fuel at a port, shortens the non-operation time and improves the operation efficiency.

Once nuclear fuel needs to be replaced, accurate and safe design is inevitably needed for ensuring that leakage of nuclear waste gas and the like does not occur due to radiation damage of the nuclear fuel and extremely severe social influence possibly caused by nuclear pollution. Meanwhile, the shipboard nuclear facilities cannot have sufficient site conditions for arranging special spent fuel storage, loading and unloading sites like the onshore nuclear facilities, and compared with onshore nuclear facilities, particularly nuclear power stations, the consumption of the shipboard nuclear fuel is very slow, the shipboard nuclear fuel is usually replaced for years or even tens of years, and if a replacement material cabin is arranged on a single ship, the shipboard nuclear facilities are not economical.

Therefore, the combination of onshore assurance base loading and unloading sites for the replacement of marine nuclear fuel is a more operable solution.

Disclosure of Invention

The invention aims to provide a nuclear power vessel reactor loading and unloading system and a loading and unloading method, which are suitable for loading and unloading of a nuclear power vessel with a deck large opening condition and provide a new method and basis for all relevant designs based on loading and unloading of a vessel reactor cabin.

The technical scheme of the invention is as follows:

a nuclear power ship reactor loading and unloading system comprises a reactor cabin, a ship body related structure and a loading and unloading material box;

the reactor cabin and ship body related structure comprises a reactor cabin wall, a radiation shielding body, a top radiation shielding cabin cover, a reactor pressure vessel and an open deck;

the loading and unloading material box comprises an outer peripheral wall, a shielding layer, an inner peripheral wall, an in-box travelling crane, a travelling crane hook, a travelling crane exhaust crane, a bottom radiation shielding hatch cover, a fuel assembly storage container and a shielding sleeve;

the reactor bulkhead is of a double-layer hollow structure, and a radiation shield is filled in the reactor bulkhead;

a fuel transfer opening A is processed on the top surface of the reactor bulkhead and is closed by a top radiation shielding hatch cover;

the reactor pressure vessel is arranged on the inner bottom surface of the reactor bulkhead;

a ring of annular platform is processed on the side wall of the reactor pressure vessel;

placing a fuel assembly within said reactor pressure vessel;

the top cover of the pressure vessel is buckled above the reactor pressure vessel;

a through weather deck is arranged at the uppermost part of the top surface of the reactor bulkhead;

a cavity enclosed between the outer surrounding wall and the inner surrounding wall is filled with a shielding layer, and the whole body is enclosed into a loading and unloading box body;

an in-box crane is fixedly arranged on the top surface of the inner surrounding wall;

a fuel transfer opening B is processed at the center of the bottom surface of the loading and unloading box body and is closed by a bottom radiation shielding hatch cover;

the temporary fuel storage container is arranged on the bottom surface of the inner surrounding wall and can be used for arranging a fuel assembly to be replaced;

the outer diameter of the shielding sleeve is smaller than the diameter of the fuel transfer opening B, and the inner diameter of the shielding sleeve is larger than that of the pressure container top cover, so that the pressure container top cover can be smoothly lifted out of the shielding sleeve;

in the loading and unloading process, the loading and unloading material box is arranged above the reactor cabin, the fuel transfer opening B is aligned with the fuel transfer opening A, the upper end of the shielding sleeve is clamped at the fuel transfer opening B, and the lower end of the shielding sleeve is buckled at the annular platform on the reactor pressure vessel.

Still including supporting ground-based transportation facility, supporting ground-based transportation facility include loop wheel machine, large-tonnage transportation flatbed.

An opening deck is arranged between the weather deck and the top surface of the reactor cabin wall;

the size of the opening deck is larger than that of the loading and unloading box body, so that the loading and unloading box body can be smoothly hung to the top surface of the reactor bulkhead.

The weather deck is a strong deck and is provided with a hatch cover so as to avoid damage caused by strength weakening of the weather deck due to repeated cutting;

the hatch coaming is arranged, is matched with the hatch cover and is welded at the through hole of the weather deck.

The weather deck is a common through deck, and if the weather deck is not enough to support the large hatch cover, a cutting mode is adopted, and the through opening is sealed by repair welding after the loading and unloading are finished;

for the large hatch cover capable of being supported, a hatch cover and a hatch coaming are arranged;

the hatch coaming is matched with the hatch cover and welded at the through hole of the weather deck.

The top surface of the reactor bulkhead is provided with a guide rail frame which is vertical to the top surface of the reactor bulkhead and used for guiding when a loading and unloading bin is hung.

The height of the guide rail frame is not less than 2m, and the top end of the guide rail frame is lower than the plane where the open-air clamping plates are located.

An embedded groove is processed on the annular platform, and radiation-resistant aging rubber is arranged in the embedded groove to ensure that the shielding sleeve is clamped and sealed.

And the bottom surface of the inner surrounding wall is provided with a shielding sleeve fixing clamping seat for fixing the shielding sleeve.

Lifting lugs are respectively arranged on the outer part of the peripheral wall, the bottom radiation shielding cover and the top radiation shielding hatch cover so as to ensure the safety and stability of lifting.

And hoisting the bottom radiation shielding cover, the shielding sleeve, the top radiation shielding cabin cover and the pressure vessel top cover by adopting a crane hook of the crane in the tank, and hoisting the fuel assembly by adopting a crane waste crane.

The loading and unloading method for the nuclear power ship reactor based on the loading and unloading system comprises the following steps:

s1, opening a through hole of an open deck in a berthing or docking stop state of a ship;

s2, hanging the loading and unloading material box into the ship, accurately falling on the top surface of the reactor bulkhead for fixing, and simultaneously ensuring that the top radiation shielding hatch cover and the bottom radiation shielding hatch cover are aligned and can be opened;

s3, opening a bottom radiation shielding cover, and hoisting and moving the bottom radiation shielding cover to a placement area by using an in-box crane;

s4, opening the radiation shielding hatch cover at the top, and hoisting and moving the radiation shielding hatch cover to a placement area in a loading and unloading material box by using an in-box crane;

s5, hoisting the shielding sleeve to the annular platform through the fuel transfer opening B and the fuel transfer opening A by using an in-box crane;

s6, opening a top cover of the reactor pressure vessel, and lifting and moving the reactor pressure vessel to a placement area in a loading and unloading material box by using an in-box crane;

s7, lifting the fuel assembly to be replaced away from the reactor pressure vessel by using an in-tank crane, and moving the fuel assembly to a temporary fuel storage vessel for storage;

s8, hanging a new fuel assembly into the reactor pressure vessel by using an in-tank crane;

s9, lifting the top cover of the reactor pressure vessel back to the original position by using an in-tank crane and sealing;

s10, hoisting the top radiation shielding hatch cover back to the original position by using a crane in the box and sealing the hatch cover;

s11, hanging the bottom radiation shielding cover back to the original position by using an in-box crane and sealing;

s12, releasing the fixation of the loading and unloading material box, and lifting the loading and unloading material box to the land;

s13, sealing the through opening of the weather deck.

And hoisting the bottom radiation shielding cover, the shielding sleeve, the top radiation shielding cabin cover and the pressure container top cover by adopting a crane hook of the in-box crane, and hoisting the fuel assembly by adopting a crane waste crane of the in-box crane.

If loading and unloading are carried out in the dry dock, a gantry crane or a floating crane ship is used for carrying out the hoisting operation of loading and unloading the material box;

if loading and unloading are carried out at the ship berth wharf, a floating crane ship is adopted to carry out the hoisting operation of loading and unloading the material box.

The loading and unloading box is transported on land by using a large-scale flat-bed transport vehicle.

The invention has the following remarkable effects:

(1) the invention adopts a transfer mode and combines the loading and unloading technology to carry out land treatment, has sufficient realizability, and can repeatedly serve a plurality of nuclear power ships by matching facilities.

(2) The invention does not need to arrange a spent fuel treatment cabin on the ship, saves the capacity of the ship and avoids the excessive limit of the fuel treatment on the performance and the function of the ship.

(3) The design strength, the shielding mode and the like of the loading and unloading material box body are consistent with those of the reactor cabin, and the safety of the loading and unloading material box body is fully guaranteed.

(4) The shielding sleeve is additionally arranged before the top cover of the pressure vessel is opened, so that other equipment and components in the reactor cabin can be effectively prevented from being polluted and damaged by radiation.

Drawings

FIG. 1 is a schematic view of a reactor tank and a ship hull;

FIG. 2 is a schematic view of a loading and unloading bin structure;

FIG. 3 is a schematic view of an intermediate process of loading and unloading;

FIG. 4 is a schematic view of a material loading and unloading completion process;

FIG. 5 is a schematic diagram of onshore transport of spent fuel;

FIG. 6 is a schematic diagram of a land-based transportation facility.

In the figure: 101 a reactor bulkhead; 102 a radiation shield; 103 a top radiation shielded hatch; 104 a reactor pressure vessel; 105 an open deck; 106 weather deck; 107 hatch coaming; 108 a hatch cover; 109 a guide rail bracket; 1041 an annular platform; 1042 pressure vessel top cover; 1043 a fuel assembly; 201 peripheral walls; 202 a shielding layer; 203 inner wall; driving in a 204-box vehicle; 205 a crane hook; 206 travelling crane is spent; 207 bottom radiation shield hatch; 208 a fuel assembly temporary storage container; 209 a shielding sleeve; 210 lifting lugs; 211 sleeve fixing clip seats; 301 dry dock; 302 docking block; 303 a ship berthing wharf; 304 gantry cranes; 305 a floating crane vessel; 306 large-tonnage transporting flat car.

Detailed Description

The invention is described in further detail below with reference to the figures and the embodiments.

A nuclear power ship reactor loading and unloading system comprises a reactor cabin, a ship body related structure, a loading and unloading material box and a matched land-based transfer facility.

The reactor cabin and ship hull related structure comprises a reactor cabin wall 101, a radiation shield 102, a top radiation shield hatch 103, a reactor pressure vessel 104, an opening deck 105, an open deck 106, a hatch 107, a hatch cover 108 and a guide rail bracket 109.

The loading and unloading bin comprises an outer peripheral wall 201, a shielding layer 202, an inner peripheral wall 203, an in-bin travelling crane 204, a travelling crane hook 205, a travelling crane gantry 206, a bottom radiation shielding hatch 207, a fuel assembly storage container 208 and a shielding sleeve 209.

The ground-based transfer facility comprises a crane and a large-tonnage transport flat car 306. The crane is a floating crane ship 305 or a dock gantry crane 304.

Referring to the reactor compartment and ship related structure shown in fig. 1, the reactor compartment wall 101 is a double-layer hollow structure, and the interior of the reactor compartment wall is filled with a radiation shield 102. The material of the reactor bulkhead 101 is typically steel, and the radiation shield 102 is lead plate, boron-containing polyethylene, or other proven radiation shielding material.

A fuel transfer opening a is machined in the top surface of the reactor bulkhead 101 and is closed by a top radiation shielded bulkhead 103. The top radiation shield hatch 103 has at least comparable pressure and radiation resistance to the reactor bulkhead 101. Lifting lugs are arranged on the top radiation shielding hatch cover 103 to ensure the safety and stability of lifting.

The reactor pressure vessel 104 is disposed on an inner bottom surface of the reactor bulkhead 101. A ring of annular platform 1041 with an embedded groove is cast or welded on the sidewall of the reactor pressure vessel 104, and radiation aging resistant rubber is arranged in the embedded groove to ensure that the shielding sleeve 209 is sealed after being clamped. Within the reactor pressure vessel 104 is disposed a fuel assembly 1043. The pressure vessel top cap 1042 is fastened above the reactor pressure vessel 104, and the pressure vessel top cap 1042 is detachable and suspensible.

Above the top surface of the reactor bulkhead 101 there is a deck, wherein the uppermost layer is a weather deck 106.

The weather deck 106 is an uppermost through deck. If the weather deck 106 is a strong deck, hatch cover 108 is provided to avoid damage to weather deck 106 due to weakening of the strength of weather deck 106 caused by repeated cutting; if the weather deck 106 is a common through deck, the weather deck is in a cutting form for weak strength and insufficient for supporting a large hatch cover, the through opening is sealed by repair welding after the loading and unloading are finished, and the hatch cover 108 is arranged for supporting the large hatch cover.

The hatch cover 108 is selected from a hydraulic hatch cover or a hanging-off hatch cover.

The hatch coaming 107 is welded to the weather deck 106 at the through opening and mates with the hatch cover 108.

The guide rail bracket 109 is fixedly arranged on the top surface of the reactor bulkhead 101, is perpendicular to the top surface of the reactor bulkhead 101, and is used for guiding and limiting when a loading and unloading tank is hung. The height of the rail bracket 109 is not less than 2m, and the top end is lower than the plane of the open-air plywood 106.

One or more open decks 105 are provided between the weather deck 106 and the top surface of the reactor bulkhead 101. The opening of the open deck 105 is larger than the size of the loading and unloading box to ensure that the loading and unloading box can be smoothly suspended to the top surface of the reactor bulkhead 101. The open deck 105 may not be provided.

As shown in the loading and unloading box shown in FIG. 2, the cavity enclosed between the outer peripheral wall 201 and the inner peripheral wall 203 is filled with a shielding layer 202, and the whole body is enclosed into a loading and unloading box body. The peripheral wall 201 is made of steel, and lifting lugs 210 are arranged outside the peripheral wall to ensure the safety and stability of lifting.

An in-tank crane 204 is fixedly arranged on the top surface of the inner wall 203, a crane hook 205 is adopted to hoist the bottom radiation shielding cover 207, the shielding sleeve 209, the top radiation shielding hatch 103 and the pressure vessel top cover 1042, and a crane hook 206 is adopted to hoist the fuel assembly 1043. A fuel transfer opening B is processed at the center of the bottom surface of the loading and unloading box body and is sealed by a bottom radiation shielding hatch cover 207, and a lifting lug for lifting is arranged on the bottom radiation shielding hatch cover 207. The pressure resistance and shielding effect of the bottom radiation shielding cover 207 are at least the same as those of the loading and unloading box body.

The temporary fuel storage container 208 is disposed on the bottom surface of the inner wall 203, and can accommodate a fuel assembly 1043 to be replaced.

The outer diameter of the shielding sleeve 209 is smaller than the diameter of the fuel transfer opening B and the inner diameter is larger than the pressure vessel top cap 1042 to ensure that the pressure vessel top cap 1042 can be smoothly suspended from the shielding sleeve 209. The shielding sleeve 209 is made of steel or lead.

A shielding sleeve fixing holder 211 is provided on the bottom surface of the inner wall 203 for fixing the shielding sleeve 209.

In the loading and unloading process, the loading and unloading box is arranged above the reactor cabin, the fuel transfer opening B is aligned with the fuel transfer opening A, the upper end of the shielding sleeve 209 is clamped at the fuel transfer opening A, and the lower end of the shielding sleeve is buckled at the annular platform 1041 on the reactor pressure vessel 104, so that the equipment facilities outside the reactor pressure vessel 104 can be prevented from being subjected to radiation pollution in the loading and unloading process.

A nuclear power ship reactor loading and unloading method adopts the loading and unloading system to carry out ship nuclear fuel refueling, and comprises the following steps as shown in figures 3-6:

s1, in the state of berthing or docking stop of the ship, opening a hatch cover 108 or cutting an opening into the weather deck 106, wherein the opening can be used for hanging a loading and unloading material box.

S2, a loading and unloading box is hoisted into the ship through a floating crane ship 305 or a dock gantry crane 304 and accurately falls on the top surface of the reactor bulkhead 101 to be fixed, and meanwhile, the top radiation shielding hatch 103 and the bottom radiation shielding hatch 207 are ensured to be centered and can be opened.

And S3, opening the bottom radiation shielding cover 207 and hoisting the bottom radiation shielding cover to a specified placement area by using the crane hook 205.

S4, opening the top radiation shielding hatch cover 103, and moving the hatch cover to a specified placement area in the loading and unloading box 2 by using the in-box crane hook 205.

S5, the shielding sleeve 209 is hung to the annular platform 1041 through the fuel transfer opening B and the fuel transfer opening A by using the in-tank crane hook 205.

S6, opening a top cover 1042 of the reactor pressure vessel, and lifting and moving the reactor pressure vessel to a specified placement area in a loading and unloading bin by using a crane hook 205 in the bin.

And S7, hanging the fuel assembly 1043 to be replaced away from the reactor pressure vessel 104 by using the in-tank travelling crane 206, and moving the fuel assembly to the temporary fuel storage vessel 208 for storage.

S8, a new fuel assembly 1043 is hoisted into the reactor pressure vessel 104 by the in-tank traveling crane 206.

S9, the reactor pressure vessel top cover 1042 is lifted back to the original position by the in-tank crane hook 205 and is closed.

S10, the top radiation shielding hatch cover 103 is lifted back to the original position by the crane hook 205 in the box and is closed.

S11, the bottom radiation shielding cover 207 is hung back to the original position by the crane hook 205 in the box and is closed.

S12, the fixing of the loading and unloading box is released, and the loading and unloading box is hung to a large-tonnage onshore transportation flat car 306 through a floating crane 305 or a dock gantry crane 304 and is further transported to a corresponding spent fuel processing area.

S13, covering the hatch cover 108 or performing repair welding on the opening of the weather deck 106.

Loading and unloading are carried out in the dry dock 301 as much as possible, so that the ship can sit on a sufficient number of docking blocks 302 in a static state during loading and unloading operations; if the state of the ship can meet the loading and unloading requirements, the loading and unloading operation can be carried out at the ship berthing wharf 303.

If loading and unloading are carried out in the dry dock 301, a gantry crane 304 or a floating crane ship 305 is used for carrying out the hoisting operation of loading and unloading the material box; if loading and unloading are carried out at the ship berthing wharf 303, due to the fact that the loading and unloading work bin is heavy, the wharf quay crane is difficult to complete the lifting work, and the floating crane ship 305 is needed to carry out the lifting work of the loading and unloading work bin.

The loading and unloading bins are transported on land using large flat bed transport vehicles 306.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not intended to limit the scope of the present invention, which is defined by the appended claims.