阅读说明：本技术 一种热室不锈钢壳体综合去污工艺 (Comprehensive decontamination process for stainless steel shell of hot chamber ) 是由 滕磊 王帅 王小兵 张永领 苏冬萍 江林志 罗婷 刘剑 但玎 吴勇 于 2019-10-22 设计创作，主要内容包括：本发明公开了一种热室不锈钢壳体综合去污工艺,包括以下步骤：1)、高压水射流去除表面松散污染：采用高压水清洗装置对热室不锈钢覆面远距离整体喷射去污,去除表面松散污染；2)、可剥离膜喷涂去除表面深度污染：待热室内水汽消散后,采用可剥离膜喷涂装置对热室不锈钢覆面的地面和墙面下部进行大面积去污,去除表面深度污染；3)、角磨机机械打磨去除深层污染：撕除地面和墙面上的可剥离膜,采用角向磨光机机械打磨热室不锈钢覆面去除深层污染。本发明所述工艺能够适用于辐射水平高、结构复杂且空间狭小的热室不锈钢壳体的去污处理,有效减少热室退役过程拆除的固体放射性废物量。(The invention discloses a comprehensive decontamination process for a stainless steel shell of a hot chamber, which comprises the following steps: 1) removing surface loose pollution by high-pressure water jet: adopting a high-pressure water cleaning device to carry out long-distance integral spraying decontamination on the stainless steel covering surface of the hot chamber to remove loose pollution on the surface; 2) and spraying a strippable film to remove surface deep pollution: after the water vapor in the hot chamber dissipates, a strippable film spraying device is adopted to decontaminate the ground and the lower part of the wall surface of the stainless steel covering surface of the hot chamber in a large area, so as to remove the surface deep pollution; 3) and mechanically polishing by an angle grinder to remove deep pollution: and tearing off the strippable films on the ground and the wall surface, and mechanically polishing the stainless steel covering surface of the hot chamber by using an angle grinder to remove deep pollution. The process provided by the invention can be suitable for decontamination treatment of the stainless steel shell of the hot chamber with high radiation level, complex structure and narrow space, and can effectively reduce the amount of solid radioactive waste removed in the decommissioning process of the hot chamber.)

1. A comprehensive decontamination process for a stainless steel shell of a hot chamber is characterized by comprising the following steps:

1) removing surface loose pollution by high-pressure water jet: adopting a high-pressure water cleaning device to carry out long-distance integral spraying decontamination on the stainless steel covering surface of the hot chamber to remove loose pollution on the surface;

2) and spraying a strippable film to remove surface deep pollution: after the water vapor in the hot chamber dissipates, a strippable film spraying device is adopted to decontaminate the ground and the lower part of the wall surface of the stainless steel covering surface of the hot chamber in a large area, so as to remove the surface deep pollution;

3) and mechanically polishing by an angle grinder to remove deep pollution: and tearing off the strippable films on the ground and the wall surface, and mechanically polishing the stainless steel covering surface of the hot chamber by using an angle grinder to remove deep pollution.

2. The comprehensive decontamination process for the stainless steel shell of the hot chamber according to claim 1, wherein the step 1) and the step 2) are both completed by the cooperation of a robot and a hot chamber manipulator, and the step 3) is completed by manual operation.

3. The comprehensive decontamination process for the stainless steel shell of the hot chamber according to claim 2, wherein the specific operation steps of removing the loose contamination on the surface by the high-pressure water jet are as follows:

A1) a spray gun of the high-pressure water cleaning device extends into the hot chamber through the hot chamber wall through hole;

B1) the operation robot enters the interior of the hot chamber through a shielding corridor door (1) of the hot chamber;

C1) operating a hot chamber manipulator to fix a spray gun of the high-pressure water cleaning device on a robot arm;

D1) setting parameters of a high-pressure water cleaning device and a robot, starting the high-pressure water cleaning device, and operating a robot arm to perform spray decontamination on the wall surface and the ground of the hot room;

E1) and after decontamination is finished, the operation robot takes down the spray gun of the high-pressure water cleaning device and withdraws from the interior of the hot chamber.

4. The comprehensive decontamination process for the stainless steel shell of the hot chamber according to claim 3, wherein the parameters of the high-pressure water cleaning device are as follows: the pressure is 40MPa, and the flow is 18L/min; the parameters of the robot are: the included angle between the robot arm and the wall surface and the ground is 65 degrees, and the distance is 200 mm.

5. The comprehensive decontamination process for the stainless steel shell of the hot chamber according to claim 2, wherein the specific operation steps of spraying the strippable film to remove the surface deep contamination are as follows:

A2) after the water vapor in the hot chamber is dissipated, operating the hot chamber manipulator, and wiping and cleaning the residual water on the ground of the hot chamber by using a water absorbing substance;

B2) operating a hot chamber manipulator, and arranging the strippable film spraying auxiliary tool at the lower part of the wall surface and the ground in the hot chamber;

C2) operating a hot chamber manipulator to clamp the strippable film spray gun;

D2) setting parameters of the strippable film spraying device, starting the strippable film spraying device, and operating a hot chamber manipulator to spray the strippable film;

E2) and after the spraying is finished, closing the strippable film spraying device, closing the shielding corridor door (1) of the hot chamber and opening the ventilation system in the hot chamber.

6. The comprehensive decontamination process for the stainless steel shell of the hot chamber according to claim 2, wherein the angle grinder mechanical grinding for removing deep contamination comprises the following specific operation steps:

A3) after the strippable film is dried to form a film, operating a hot chamber manipulator, clamping the strippable film spraying auxiliary tool, and tearing the strippable film from the wall surface and the ground;

B3) the working personnel enter the hot room to carry out pollution general survey on the hot room and mark out the point position with the pollution level exceeding the standard;

C3) and the worker adopts an angle grinder to mechanically polish and decontaminate according to the marked point positions.

7. The integrated decontamination process for stainless steel enclosures in hot rooms as claimed in claim 6, wherein a portable long rod dose rate meter is used to measure the radiation level in the hot room before the workers enter the hot room, and when the radiation level is reduced to a relatively safe level, the workers enter the hot room.

8. The integrated decontamination process for a hot chamber stainless steel housing of claim 6, wherein the polishing decontamination is performed while an auxiliary dust suction device on the angle grinder is turned on.

9. The comprehensive decontamination process for the stainless steel shell of the hot chamber according to any one of claims 2-8, wherein the robot surface is protected by a double layer of strippable resin material and transparent plastic cloth.

Technical Field

The invention relates to the technical field of nuclear facility decommissioning treatment, in particular to a comprehensive decontamination process for a stainless steel shell of a hot chamber.

Background

The strong and heat release chamber is used as a supporting facility for irradiation inspection of reactor materials, and is mainly used for irradiation inspection and determination of various thermal properties of various novel fuel elements and reactor materials, disassembly cutting processing of test element components and various irradiation devices, subpackaging of high-strength isotopes and the like. In order to avoid penetration and contamination of the building structure with radionuclides during long-term use, a stainless steel shell is usually designed as a cladding on the inner surface of the hot chamber.

As the reactor nears its design life, the hot cell will also face retirement after completing its historical mission. A large amount of radioactive operations are involved in the decommissioning process, a feasible decontamination technology is indispensable, and a set of good decontamination process can effectively ensure the radiation safety of the decommissioning activity. However, the decontamination of the hot cell housing is difficult at present, mainly due to the following:

(1) high radiation level, serious pollution and complex nuclide component

The hot chamber is used as a long-term radioactivity research working place, and directly cuts, packages, detects and the like irradiated fuel elements and various irradiation target pieces, in the operation process, radioactive particle scattering and acid-base corrosion cause serious pollution to a stainless steel shell, internal equipment, a ventilation system, a wall-penetrating pipeline and the like of a wall body of the hot chamber, and generally, the maximum pollution level of the surface of the stainless steel shell is more than 10⁵Bq/cm²This makes access to the personnel difficult and decontamination difficult to perform.

(2) The hot chamber has complex structure, narrow space and many limited decontamination operation factors

From the hot chamber structure, the wall body inside lining is confined stainless steel casing, has arranged equipment such as a large amount of wall pipes, cables on the casing, and the hot chamber space is generally comparatively narrow and small moreover, and the limited factor of decontamination process is more.

Disclosure of Invention

The invention aims to provide a comprehensive decontamination process for a hot-chamber stainless steel shell, which can be suitable for decontamination treatment of the hot-chamber stainless steel shell with high radiation level, complex structure and narrow space, and effectively reduce the amount of solid radioactive waste removed in the retirement process of a hot chamber.

The invention is realized by the following technical scheme:

a comprehensive decontamination process for a stainless steel shell of a hot chamber comprises the following steps:

1) removing surface loose pollution by high-pressure water jet: adopting a high-pressure water cleaning device to carry out long-distance integral spraying decontamination on the stainless steel covering surface of the hot chamber to remove loose pollution on the surface;

2) and spraying a strippable film to remove surface deep pollution: after the water vapor in the hot chamber dissipates, a strippable film spraying device is adopted to decontaminate the ground and the lower part of the wall surface of the stainless steel covering surface of the hot chamber in a large area, so as to remove the surface deep pollution;

3) and mechanically polishing by an angle grinder to remove deep pollution: and tearing off the strippable films on the ground and the wall surface, and mechanically polishing the stainless steel covering surface of the hot chamber by using an angle grinder to remove deep pollution.

The high-pressure water cleaning device, the strippable film spraying device and the angle grinder are all existing equipment.

In the invention, although the high-pressure water jet technology, the strippable film spraying technology and the angle grinder mechanical grinding technology are all the prior art, when the technology is applied to different fields, the process optimization and the parameter optimization are required in the concrete engineering implementation.

The invention is designed aiming at the characteristics of a hot chamber in the nuclear industry, the hot chamber not only has high radiation level, serious pollution and complex nuclide composition, but also has complex structure, narrow space and more limited decontamination operation factors; the existing high-pressure water jet technology, strippable film spraying technology and angle grinder mechanical polishing technology are applied to the decontamination treatment of the hot chamber, and the treatment sequence of the high-pressure water jet technology, the strippable film spraying technology and the angle grinder mechanical polishing technology is reasonably designed according to the characteristics of the hot chamber to realize the high-efficiency decontamination of the hot chamber.

The comprehensive decontamination process is reasonable, feasible, safe and reliable, and passes engineering practice verification for the first time.

Further, the step 1) and the step 2) are completed by the cooperation of a robot and a hot chamber manipulator, and the step 3) is completed by manual operation.

Further, the specific operation steps of removing the surface loose contamination by the high-pressure water jet are as follows:

A1) a spray gun of the high-pressure water cleaning device extends into the hot chamber through the hot chamber wall through hole;

B1) the operation robot enters the interior of the hot chamber through a shielding corridor door of the hot chamber;

C1) operating a hot chamber manipulator to fix a spray gun of the high-pressure water cleaning device on a robot arm;

D1) setting parameters of a high-pressure water cleaning device and a robot, starting the high-pressure water cleaning device, and operating a robot arm to perform spray decontamination on the wall surface and the ground of the hot room;

E1) and after decontamination is finished, the operation robot takes down the spray gun of the high-pressure water cleaning device and withdraws from the interior of the hot chamber.

Further, the parameters of the high-pressure water cleaning device are as follows: the pressure is 40MPa, and the flow is 18L/min; the parameters of the robot are: the included angle between the robot arm and the wall surface and the ground is 65 degrees, and the distance is 200 mm.

The parameter setting is summarized by the applicant through a large number of tests, and the applicant reasonably sets the parameters of the high-pressure water cleaning device and the parameters of the robot according to the structural characteristics and the radiation characteristics of the hot chamber, so that the thoroughness of high-pressure washing and the washing efficiency are ensured.

The pressure, the flow, the spraying distance and the angle are the most important parameters influencing the decontamination effect, and the parameters given by the invention are the optimal parameter combination obtained on the basis of 81 different parameter combination tests. If a certain parameter is changed, under the condition that other conditions are not changed, the overall decontamination effect is deteriorated, namely the pollution level after decontamination is increased, the amount of secondary radioactive wastewater is increased, and the economic cost is increased.

Further, the specific operation steps of spraying the strippable film to remove the surface deep pollution are as follows:

A2) after the water vapor in the hot chamber is dissipated, operating the hot chamber manipulator, and wiping and cleaning the residual water on the ground of the hot chamber by using a water absorbing substance;

B2) operating a hot chamber manipulator, and arranging the strippable film spraying auxiliary tool at the lower part of the wall surface and the ground in the hot chamber;

C2) operating a hot chamber manipulator to clamp the strippable film spray gun;

D2) setting parameters of the strippable film spraying device, starting the strippable film spraying device, and operating a hot chamber manipulator to spray the strippable film;

E2) and after spraying, closing the strippable film spraying device, closing the shielding corridor door of the hot chamber, and opening the ventilation system in the hot chamber.

The auxiliary strippable film spraying tool is an existing device and is matched with strippable film spraying equipment for use.

Further, the specific operation steps of mechanically polishing and removing deep pollution by the angle grinder are as follows:

A3) after the strippable film is dried to form a film, operating a hot chamber manipulator, clamping the strippable film spraying auxiliary tool, and tearing the strippable film from the wall surface and the ground;

B3) the working personnel enter the hot room to carry out pollution general survey on the hot room and mark out the point position with the pollution level exceeding the standard;

C3) and the worker adopts an angle grinder to mechanically polish and decontaminate according to the marked point positions.

Further, before the staff enters the inside of the hot room, the portable long-rod dose rate meter is used for measuring the radiation level in the hot room, and when the radiation level is reduced by a relative safety level, the staff enters the inside of the hot room.

And furthermore, an auxiliary dust suction device on the angle grinder is started while the angle grinder is polished and decontaminated.

The auxiliary dust suction device is in the prior art, is matched with an angle grinder for use, and avoids secondary pollution to the interior of a hot chamber caused by radioactive metal dust particles.

Further, the strippable resin material and the transparent plastic cloth are used for double-layer protection of the surface of the robot.

The robot can be effectively protected by the arrangement, and the radiation of the robot is reduced.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. the process provided by the invention can be suitable for decontamination treatment of the stainless steel shell of the hot chamber with high radiation level, complex structure and narrow space, and can effectively reduce the amount of solid radioactive waste removed in the decommissioning process of the hot chamber.

2. The process reduces the irradiated dose of the working personnel in the retirement stage, protects the safety of the working personnel and the environment, and has remarkable economic and social benefits.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:

fig. 1 is a schematic plan view of a heat chamber.

Reference numbers and corresponding part names in the drawings:

1-shielding porch, 2-concrete shielding wall, 3-floor drain, 4-hot indoor equipment, 5-stainless steel ground, 6-wall-penetrating pipeline and 7-peep window.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.