CN204189465U - A kind of neutron source safety can - Google Patents

Abstract

The utility model relates to a kind of neutron source safety can, this safety can comprises tank body and container containing (7), described tank body upper end has opening, the middle and lower part of described container containing (7) is inserted in tank body from tank body opening, bottom and the periphery of described container containing (7) are equipped with moderation of neutrons layer, be arranged with neutron absorption layer outside described moderation of neutrons layer, the outer of neutron absorption layer is arranged with gamma shield.Safety can of the present utility model, by adopting the mode of MULTILAYER COMPOSITE protection, achieving the shielding of seed source and absorbing the gamma-ray shielding produced in the process of neutron, the harm effectively preventing neutron from producing staff and the public and damage; Barrier propterty is excellent, and structure is reliable.

Description

A kind of neutron source safety can

Technical field

The utility model belongs to radiation-protection equipment field, is specifically related to a kind of neutron source safety can, for solving neutron shield problem.

Background technology

Along with the development and application of nuclear energy technology, there has been purposes widely in increasing neutron source apparatus field such as material flaw detection, well logging, activation analysis in physics, biology, chemistry, medicine, engineering, petroleum prospecting, nuclear industry and commercial production, and the radiation safety brought thus and protection question also become more and more important.Because the penetrability of neutron is extremely strong, stronger radiation damage can be produced to human body, environment, instrument and equipment etc., the normal work of what degree was serious directly threaten human life's safety and instrument and equipment, so shield well neutron source, avoiding occurring radiation safety problem, is the effective means making neutron source serve the mankind better.Generally extremely more low-yield by light element slowing down fast neutron to the shielding of neutron, re-use the materials such as boron, lithium, cadmium and absorb, lower the object of the outer neutron dose of shield to security level to reach.This neutron source safety can adopts the MULTILAYER COMPOSITE shieldings such as Moderation of the fast neutrons layer, neutron absorption layer and gamma shield, effectively can shield thermal neutron, fast neutron and gamma-rays that neutron source produces, effectively prevent neutron irradiation from producing radiation hazard and damage to Job personnel and the public.This neutron source safety can NEUTRON PROTECTION structure has that barrier propterty is excellent, structure is reliable, be applicable to the advantages such as the larger environment of the temperature difference, has good physical property and mechanical property simultaneously, has good application value in radiation protection field.

Utility model content

For the defect existed in prior art, the utility model provides a kind of neutron source safety can, and this safety can shield the neutron in tank and the gamma-rays produced in the process of absorption neutron, and effective anti-staff and the public are endangered and damage; Barrier propterty is good, and structure is reliable.

For reaching above object, the technical solution adopted in the utility model is: provide a kind of neutron source safety can, this safety can comprises tank body and container containing, described tank body upper end has opening, the middle and lower part of described container containing is inserted in tank body from tank body opening, the bottom of described container containing and periphery are equipped with moderation of neutrons layer, and be arranged with neutron absorption layer outside described moderation of neutrons layer, the outer of neutron absorption layer is arranged with gamma shield.

Further, described moderation of neutrons layer is Boron-containing-PE layer, and described neutron absorption layer is cadmium layer, and described gamma shield is lead layer.

Further, gap is provided with between described Boron-containing-PE screen layer and container containing inwall.

Further, described Boron-containing-PE screen layer adopts bonding connection with cadmium layer.

Further, described cadmium layer adopts bonding connection with lead layer.

Further, described tank body comprises outer wall and bottom, and described outer wall and bottom form obturator.

Further, the both sides of described tank body are provided with carrying ring.

Advantageous Effects of the present utility model is:

(1) the utility model is by adopting the mode of multilayer proofing, realizes neutron and is absorbing the gamma-ray shielding produced in the process of neutron; Prevent neutron irradiation from producing radiation hazard and damage to Job personnel and the public.

(2) the utility model neutron source safety can, barrier propterty is excellent, structure is reliable; Be applicable to the environment that the temperature difference is larger, there is good physical property and mechanical property simultaneously.

Accompanying drawing explanation

Fig. 1 is the structural representation of the utility model neutron source safety can.

In figure:

1-bottom 2-outer wall 3-carries ring 4-Boron-containing-PE layer 5-cadmium layer

6-lead layer 7-container containing

Embodiment

Below in conjunction with accompanying drawing, embodiment of the present utility model is described in further detail.

As shown in Figure 1, be the neutron source safety can that the utility model provides.This safety can comprises tank body and the container containing 7 that upper end has opening, and the middle and upper part of this container containing 7 is inserted in tank body by the opening of tank body, has neutron source in container containing 7.Here container containing 7 is stainless-steel tube, selects stainless material to be 0Cr18Ni10Ti, and inside surface is easy to cleaning and decontamination.

In order to carry out slowing down to the neutron in container containing 7, the bottom of container containing 7 and periphery are equipped with Moderation of the fast neutrons layer.This Moderation of the fast neutrons layer can adopt Boron-containing-PE layer 4, and the effect namely playing slowing down can also have good absorption to the thermal neutron produced after slowing down.Certainly, Moderation of the fast neutrons layer of the present utility model is not limited to Boron-containing-PE layer, as long as have the overlayer of slowing down effect to fast neutron.

In order to better absorb the thermal neutron after slowing down, the outer of Moderation of the fast neutrons layer is arranged with neutron absorption layer.This neutron absorption layer adopts cadmium layer 5.Certainly, the utility model is not limited only to cadmium layer, as long as have the overlayer of absorption to thermal neutron.

In order to shield absorbing the gamma-rays produced in the process of neutron, the outer of neutron absorption layer is arranged with gamma shield.This gamma shield adopts lead layer 6.Certainly, the utility model is not limited to lead layer, as long as the overlayer shielded gamma-rays.

Although the effect that lead layer shields gamma-rays is fine, there is certain toxicity, so be provided with the airtight clad of stainless steel outside whole screen layer, to ensure tightness and impermeability, to guarantee that poisonous substance can not enter in the environment of surrounding.Wherein, tank body comprises outer wall 2 and bottom 1, and outer wall 2 and bottom 1 adopt argon arc welding to be welded into obturator.Should welding technology be noted when welding, ensureing that deflection meets the demands, noting the protection to screen layer in this external welding process, avoid the destruction of causing screen layer because local welding temperature is too high.

In order to ensure because ambient temperature change causes during Boron-containing-PE deformation and can not destroy tank structure, reserved certain interval between Boron-containing-PE screen layer and inwall.

For the ease of carrying, the both sides of tank body are equipped with carrying ring 3.

For the ease of cadmium layer 5 and Boron-containing-PE screen layer 4 connection between the two, glue can be adopted to be adhesively fixed.

For the ease of lead layer 6 and cadmium layer 5 connection between the two, glue is adopted to be adhesively fixed too.

Be described the selection of each protective layer below: primary shield comprises Boron-containing-PE layer, cadmium layer and lead layer, outermost layer is that stainless steel is coated.Because the atomic mass of neutron is close with the atomic mass of hydrogen atom, therefore, when in fast neutron and shield during hydrogen nuclei generation elastic collision, the easiest by its energy transferring to hydrogen nuclei off-energy, thus be slow neutron and thermal neutron by Moderation of the fast neutrons.In shield, hydrogen content is more, then slowing down effect is stronger, and in the hydrogen content of relatively more conventional neutron shielding material, tygon hydrogen content is the highest, is shield the best moderator of fast neutron.After fast neutron is thermal neutron by slowing down, thermal neutron need be absorbed with shielding material thermal neutron absorption cross section being produced greatly and not to high-energy gamma radiation, just can reach the object shielding fast neutron completely.Because boron has higher thermal neutron absorption cross section, be the good absorption agent of shielding thermal neutron containing boron material.In conjunction with the strong absorption characteristic that polythene material has the slowing down effect of fast neutron and boron atom pair thermal neutron, this safety can selects the anti-neutron Boron-containing-PE of 8% Boron contents, and the shield effectiveness of protection americium-beryllium (241Am-Be) neutron source and californium-252 (252Cf) neutron source fast neutron is high.In addition, Boron-containing-PE has that intensity is high, even density, acid-alkali-corrosive-resisting, neutron shield superior performance and be convenient to the features such as machining, is applicable to the screen layer of protection tank body.This safety can selects cadmium plate as neutron absorption layer, and select stereotype as gamma-ray screen layer, cadmium has excellent neutron absorption capability, and lead has excellent gamma ray shielding ability.Because plumbous and cadmium and compound thereof have certain toxicity, whole screen layer is outer airtight coated by stainless steel, prevents from working the mischief to operating personnel in lead and cadmium entered environment.

Neutron source safety can of the present utility model is not limited to above-mentioned embodiment, and those skilled in the art draw other embodiment according to the technical solution of the utility model, belongs to technological innovation scope of the present utility model equally.

Claims (7)

1. a neutron source safety can, this safety can comprises tank body and container containing (7), described tank body upper end has opening, the middle and lower part of described container containing (7) is inserted in tank body from tank body opening, it is characterized in that: bottom and the periphery of described container containing (7) are equipped with moderation of neutrons layer, the outer of described moderation of neutrons layer is arranged with neutron absorption layer, and described the outer of neutron absorption layer is arranged with gamma shield.

2. neutron source safety can as claimed in claim 1, it is characterized in that: described moderation of neutrons layer is Boron-containing-PE layer (4), described neutron absorption layer is cadmium layer (5), and described gamma shield is lead layer (6).

3. neutron source safety can as claimed in claim 2, is characterized in that: be provided with gap between described Boron-containing-PE screen layer (4) and container containing (7) inwall.

4. neutron source safety can as claimed in claim 3, is characterized in that: described Boron-containing-PE screen layer (4) adopts bonding connection with cadmium layer (5).

5. neutron source safety can as claimed in claim 4, is characterized in that: described cadmium layer (5) adopts bonding connection with lead layer (6).

6. the neutron source safety can as described in any one of claim 1-5, is characterized in that: described tank body comprises outer wall (2) and bottom (1), and described outer wall (2) and bottom (1) form obturator by welding.

7. neutron source safety can as claimed in claim 6, is characterized in that: the both sides of described tank body are provided with carrying ring (3).