Composite thermal insulation and radioactive radiation shielding

• US 5,814,824 A
• Filed: 08/22/1996
• Issued: 09/29/1998
• Est. Priority Date: 11/15/1995
• Status: Expired due to Term

• Current Assignee: Electric Power Research Institute Incorporated, Exelon Generation Company LLC (Exelon Corporation), Sargent & Lundy LLC, Transco Products Inc.
• Original Assignee: Electric Power Research Institute Incorporated, Commonwealth Edison Company (Exelon Corporation), Sargent & Lundy LLC, Transco Products Inc.
• Inventors: Polak, Frank P., Olson, David E., Hamby, Peter N., Wolbert, Edward J., Alpha, Bruce J., Risley, Bryan L.
• Primary Examiner(s): NGUYEN, KIET TUAN
• Application Number:
  US08/701,388
• Time in Patent Office: 768 Days
• Field of Search: 250/515.1, 250/506.1, 250/517.1, 250/518.1, 250/519.1, 376/272, 220/611
• US Class Current: 250/515.1
• CPC Class Codes: G21D 1/02 Arrangements of auxiliary equipment
• CPC Class Codes: Y02E 30/00 Energy generation of nuclear origin
• CPC Class Codes: Y02E 30/30 Nuclear fission reactors

Abstract

The present invention relates a composite insulation and shielding article and a method of permanently installing the composite article onto a system to provide at least radioactive shielding. The composite shielding for permanently reducing radioactive radiation emanating from a system comprises at least one inner layer, at least one outer layer, and a shielding layer between said inner and outer layers, said shielding layer comprising a shield material that reduces said radioactive radiation.

Claims

1. A composite shielding for reducing thermal transfer and radioactive radiations emanating from a system, said shielding comprising:

at least one first supporting layer and at least one second supporting layer;

a shielding layer comprising a shield material that reduces said radioactive radiation, wherein said shielding layer is located between at least one first supporting layer and at least one second supporting layer;

at least one inner layer and at least one outer layer such that said first and second supporting layers are located between said inner and outer layers;

at least one first thermal insulation layer located between said inner layer and said shielding layer comprising a low thermal conductivity material a microporous mineral fiber-based material;

a plurality of second thermal insulation layers located between said shielding layer and said outer layer comprising a metallic reflective material, and

said shielding being adapted for installation next to said system.

2. The shielding of claim 1 further comprising:

at least one first barrier layer between said first supporting layer and said shielding layer; and

at least one second barrier layer between said second supporting layer and said shielding layer.

3. The shielding of claim 2 wherein said barrier layers form an enclosure that substantially encases said shielding layer.

4. The shielding of claim 2 wherein said first and second barrier layers comprise a high-temperature flexible material impervious to fine particles.

5. The shielding of claim 4 wherein said flexible material comprises components selected from the group consisting of chrysotile asbestos, glass wool, ceramic fibers, silica mineral fibers, silicate mineral fibers, aramids, metal fibers and combinations thereof.

6. The shielding of claim 2 wherein said barrier layers comprises silicon impregnated in a material selected from the groups consisting of silica mineral fibers, silicate mineral fibers, aramids, metal fibers and combinations thereof.

7. The shielding of claim 1 further compromising at least one first thermal insulation layer is located between said system and said shielding layer.

8. The shielding of claim 7 wherein said first thermal insulation layer and said shielding layer has a thickness ratio of about 2:

1.

9. The shielding of claim 1 wherein the shielding layer comprises a shield material selected from the group consisting of high atomic weight materials, high hydrogen-containing materials, high boron-containing materials and combinations thereof.

10. The shielding of claim 1 wherein the shield material is selected from the group consisting of lead, uranium, depleted uranium, tungsten, alloys of lead, tungsten, uranium, depleted uranium and combinations thereof.

11. The shielding of claim 10 wherein said shield material is lead.

12. The shielding of claim 1 wherein the shield material is a selected from the group consisting of polymers, hydrated materials, concrete, borated materials and combinations thereof.

13. The shielding of claim 1 further comprising an in-plant insulation effectiveness of from about one up to about ten times the true half value for Cobalt 60 isotope.

14. The shielding of claim 1 wherein said shielding withstands seismic levels of at least up to about 7 G.

15. A composite shielding for permanently reducing thermal and radioactive radiation emanating from a system, said shielding including a plurality of component layers comprising:

at least one inner layer comprising a metallic reflective material;

at least one first thermal insulation layer adjacent to said inner layer, said first thermal insulation layer comprising an insulation material selected from the group consisting of low thermal conductivity materials, metallic reflective materials and combinations thereof;

at least one first supporting layer adjacent to said first thermal insulation layer;

at least one first barrier layer adjacent to said supporting layer;

a shielding layer adjacent to said first barrier layer, said shielding layer comprising a shield material that reduces said radioactive radiation;

at least one second barrier layer adjacent to said shielding layer;

at least one second supporting layer adjacent to said second barrier layer;

at least one outer layer adjacent to said second supporting layer, said outer layer comprising a metallic reflective material;

said shielding layer having a plurality of shielding surfaces, said shielding surfaces being coated with an oxide layer;

said first and second barrier layers forming an enclosure to substantially encase said shielding layer and prevent chemical and galvanic interaction between said shielding layer with said metallic reflective component layers and the system.

16. The shielding of claim 15 further comprising at one second thermal insulation layer between said second supporting layer and said outer layer, said second thermal insulation layer comprising an insulation material selected from the group consisting of low thermal conductivity materials, metallic reflective materials and combinations thereof.

17. The shielding of claim 15 wherein at least one of said first and second supporting layers comprise a metallic reflective material.

18. The shielding of claim 15 wherein said first thermal insulation layer comprises a microporous mineral fiber-based material.

19. The shielding of claim 15 wherein at least one of said first and second barrier layers comprise a flexible material selected from the group consisting of chrysotile asbestos, glass wool, ceramic fibers, silica mineral fibers, silicate mineral fibers, aramids, metal fibers and combinations thereof.

20. The shielding of claim 15 wherein at least one of said first and second barrier layers comprise silicon impregnated in a material selected from the groups consisting of silica mineral fibers, silicate mineral fibers, aramids, metal fibers and combinations thereof.

21. The shielding of claim 15 wherein said shield material is selected from the group consisting of high atomic weight materials, high hydrogen-containing materials, high boron-containing materials and combinations thereof.

22. The shielding of claim 21 wherein the shield material is selected from the group consisting of lead, uranium, depleted uranium, tungsten, alloys of lead, tungsten, uranium, depleted uranium and combinations thereof.

23. The shielding of claim 21 wherein said shield material is lead.

24. The shielding of claim 23 further comprising an in-plant insulation effectiveness of from about one up to about ten times the true half value for Cobalt 60 isotope.

25. The shielding of claim 24 wherein said first thermal insulation layer and said shielding layer has a thickness ratio of about 2:

1.

26. The shielding of claim 21 wherein the shield material is selected from the group consisting of polymers, hydrated materials, concrete, borated materials and combinations thereof.

27. The shielding of claim 15 wherein said shielding layer and said first and second supporting layers are positioned adjacent to said first and second barrier layers such that the distance between said shielding layer and said supporting layers is between about 0.0625 to about 0.125 inches.

28. The shielding of claim 15 wherein said shielding withstands seismic levels of up to about 7 G.

29. A method for reducing thermal transfer and radioactive radiation emanating from a system, said method comprising the steps of:

providing a composite shielding in a plurality of segments, wherein each segment comprises a plurality of sections, said composite shielding comprising;

at least one thermal insulation layer;

at least one supporting layer;

a shielding layer comprising a shield material; and

at least one barrier layer adjacent said shielding layer;

said shielding being adapted for installation next to said system;

providing longitudinal lays onto each section for mating said sections together;

providing spacing limitations between said shielding layer and the supporting layers adjacent to said barrier layers for preventing fretting and generation of shield material powder during steady state vibration.

30. The method of claim 29 wherein the composite shielding is provided on a permanent basis to the system.

31. The method of claim 29 further comprising the step of providing solid stainless steel end pieces at terminal ends of the composite shielding.

32. The method of claim 29 further comprising the step of providing fasteners for securing said segments together.

33. The method of claim 29 further comprising the step of providing a circumferential lap at one terminal end of each segment for mating said segments together.

34. The method of claim 29 further comprising the step of the distance between said shielding layer and said supporting layers between about 0.0625 and about 0.125 inches.

35. A composite shielding for reducing radioactive radiation emanating from a system comprising:

a shielding layer having a surface coated with an oxide layer comprising a shield material that reduces said radioactive radiation between inner and outer layers;

at least one first barrier layer adjacent to said shielding layer;

at least one second barrier layer;

said shielding layer disposed between said first and second barrier layers;

said first and second barrier layers forming an enclosure that substantially encases said shielding layer;

at least one supporting layer adjacent to at least one of said barrier layers.

36. The shielding of claim 35 wherein said shielding layer is located between at least one first supporting layer and at least one second supporting layer.

37. The shielding of claim 35 wherein said barrier layers comprise a flexible material selected from the group consisting of chrysotile asbestos, glass wool, ceramic fibers, silica mineral fibers, silicate mineral fibers, aramids, metal fibers and combinations thereof.

38. The shielding of claim 35 wherein said barrier layers comprise silicon impregnated in a material selected from the groups consisting of silica mineral fibers, silicate mineral fibers, aramids, metal fibers and combinations thereof.

39. The shielding of claim 35 wherein the shielding layer comprises a shield material selected from the group consisting of high atomic weight materials, high hydrogen-containing materials, high boron-containing materials and combinations thereof.

40. The shielding of claim 35 wherein the shield material is selected from the group consisting of polymers, hydrated materials, concrete, borated materials and combinations thereof.

41. A method for permanently reducing radioactive radiation emanating from a system, the method comprising the step of providing a composite shielding comprising:

least one inner layer;

at least one outer layer;

at least one shielding layer between said inner and outer layers, said shielding layer having a surface coated with an oxide layer;

at least one first barrier layer adjacent said shielding layer;

at least one second barrier layer adjacent said shielding layer and opposite said first barrier layer; and

at least one supporting layer.

42. A composite shielding for reducing thermal transfer and radioactive radiations emanating from a system, said shielding comprising:

a plurality of segments wherein each segment comprises a plurality of sections, each of said sections having longitudinal laps for mating sections together, each of said sections comprising;

at least one thermal insulation layer;

at least one supporting layer;

a shielding layer comprising a shield material; and

at least one barrier layer adjacent said shielding layer wherein spacing limitations arc provided between said shielding layer and the supporting layers adjacent to said barrier layers for preventing fretting and generation of shield material powder during steady state vibration;

said shielding being adapted for installation next to said system.

43. The composite shielding of claim 42 further comprising fasteners for securing the segments together.

44. The composite shielding of claim 42 wherein said thermal insulation layer comprises a thermal insulation material selected from a group consisting of low thermal conductivity materials, metallic reflective materials and combinations thereof.