MODEL JC213 - PURE POLYETHYLENE
Description:
Pure polyethylene from John Caunt Scientific is often used as a moderator to
slow fast neutrons to thermal energies. To be most effective in these
applications it is important to maximise the hydrogen content and minimise
impurities that might absorb neutrons. High
purity, high density, high and ultra high molecular weight polyethylene is
readily available from John Caunt Scientific.
Chemical & Physical Properties:
Hydrogen: 14.28%
Density: 0.92g/cc
Options:
• Available machined into complex
shapes
• Cut to customer requirements
• It is also available in bricks, rods and pellets.
Uses:
• Reactor physics
• Around isotopic neutron sources
• To protect instrumentation from fast neutrons
MODEL JC2O1 - 5% BORON
POLYETHYLENE
Description:
The combination of polyethylene with its high hydrogen content and boron,
makes JC201 a very useful shielding material in areas of low and intermediate
neutron flux. The boron content attenuates thermal neutrons and reduces
the level of capture gamma rays, while the high hydrogen content thermalises
fast neutrons.
JC201 is a light weight material that can be machined and shaped with standard
tools or supplied cast to specification
Chemical & Physical Properties:
Hydrogen atoms/cc: 6.6 x 1022
Boron atoms/cc: 2.6 x 1021
Temperature limit: 82ºC
Density:
0.95g/cc
Hydrogen:
96% that of water
Options:
• Available as slabs, bricks, rods and pellets.
• Other dimensions / shapes on request.
• Can be supplied machined to close tolerances.
• Other boron loadings available on request.
• Self extinguishing version available (see model JC207).
Uses:
• Shielding personnel
• Neutron radiography
• In hot cells and accelerators
MODEL JC210 -
30% BORON
POLYETHYLENE
Description:
In reactor fuel handling and reprocessing, control of criticality is of
utmost importance. To ensure neutron isolation, materials containing very
high boron concentrations are used.
Model JC210 is a polyethylene loaded with 30% natural boron, which is very
effective in the capture of thermal neutrons.
Chemical & Physical Properties:
Hydrogen atoms/cc: 5.55 x 1022
Boron atoms/cc: 18.7 x 1021
Temperature limit: 82ºC
Density:
1.19g/cc
Options:
• Available as slabs, bricks, rods and pellets.
• Can be pre-shaped to customer specifications.
Uses:
• Criticality control.
MODEL JC2O2 -
LEAD LOADED BORATED
POLYETHYLENE
Description:
Lead Loaded Boron Polyethylene from JCS combines lead and boron in
polyethylene providing an effective shield against mixed neutron / gamma
fields. The hydrogen in polyethylene will thermalises fast neutrons.
The boron captures thermal neutrons and suppresses capture gamma rays. The
lead provides shielding against primary gamma rays.
Chemical & Physical Properties:
Boron Content:
1%
Lead
Content:
80%
Temperature limit:
82ºC
Density:
4.2g/cc
Lead Equivalence:
37%
Lead Equivalent Thickness: 18.8mm
Options:
• Available as sheets, rods or pellets.
• Other sizes and shapes can be made to customer specification.
• Other lead and boron loadings available on request.
MODEL JC215 -
LITHIUM-POLYETHYLENE
Description:
Gamma sensitive radiation detectors used near neutron sources need shielding
from both capture gamma-rays and the neutron source. A borated
polyethylene will attenuate the neutron flux but results in a 0.42MeV capture
gamma-ray. Lithium Polyethylene does not produce capture gamma-rays and is
therefore ideal for this application.
Chemical & Physical Properties:
Hydrogen atoms/cc: 5.44 x 1022
Lithium atoms/cc: 6.7 x 1021
Temperature limit: 82ºC
Density:
1.06g/cc
Options:
• Shields using enriched lithium 6.
• Pre-cast shapes and sizes on request.
• Other lithium concentrations on request.
MODEL JC207 -
SELF-EXTINGUISHING BORATED
POLYETHYLENE
Description:
JC207 from John Caunt Scientific is a self-extinguishing borated
polyethylene. Ideally suited for use as a shielding material in areas of
low and intermediate neutron flux, where there is concern about the level of combustible
materials.
Chemical & Physical Properties:
ASTM Test D-635: shows the material is self-extinguishing
ASTM Test D-2863: gives oxygen index of 30.2
Hydrogen content: 100% that of water
Hydrogen atoms/cc: 6.6 x 1022
Boron atoms/cc: 0.54 x 1021
Density:
1.4g/cc
Options:
• Available as sheets, rod, pellets or pre-cast to customer specification.
Uses:
• Power plants shielding hatches, ducts, sumps and stairwells..
MODEL JC227 -
BORATED FLEX / PANEL WALL SHIELD
Description:
High energy accelerators and fusion test facilities can produce high energy
neutrons. JC227 is designed to be fixed to walls, floors and ceilings to
reduce activation of concrete and cut down the overall radiation field.
Borated Flex / Panel Wall Shield is a self-extinguishing, lightweight material
with a high concentration of boron. The rubber-like material is easily
handled and can be cut to size using a sharp knife.
Chemical & Physical Properties:
Sheet
size:
1219 x 1219 x 7 mm thick
Weight:
12.3 kg per sheet
Hydrogen atoms/cc: 4.63 x 1022
Boron atoms/cc: 5.8 x 1021
Temperature limit: 82ºC
Density:
1.16g/cc
Uses:
• Fixing to walls to minimise concrete activation.
MODEL JC238 -
FLEX BORON SHEET
Description:
This is a fire resistant silicon based elastomer containing a high weight
percentage of boron. Model JC238 is used to attenuate thermal neutrons
around irregular shapes. It is extremely flexible and can be bent to a
radius of 6.4mm.
Chemical & Physical Properties:
Hydrogen atoms/cc: 2.7 x 1022
Boron atoms/cc: 23.2 x 1021
Temperature limit: 205ºC
Density:
1.64g/cc
Options:
• Standard sheets: 305 x 610 x 3.2 mm thick
610 x 914 x 3.2 mm thick
• Other sizes and thicknesses available on request.
Uses:
• Where a flexible protection against thermal neutrons is required.
MODEL JC259 - POLYCAST
Description:
Polycast is a dry mix material designed to be cast into closed
containers. It is field castable, providing excellent, low cost neutron
shielding, with a hydrogen content 6% greater than that of water. JC259
has 0.9% boron present to suppress radiation from capture gamma rays.
Polycast is mixed with water, it forms a strong solid material 30 minutes after
casting and can be poured in layers as each layer bonds to the previous one.
Chemical & Physical Properties:
Hydrogen atoms/cc: 7.10 x 1022
Boron atoms/cc: 0.58 x 1021
Temperature limit: 66ºC
Density:
1.15g/cc
Features:
• Field castable without special tools.
• Only requires water for mixing.
Uses:
• Walls.
• Roof slabs for cyclotron facility.
MODEL JC277 -
HEAT RESISTANT SHIELDING
Description:
High temperature resistance is often required for reactor shielding.
Model JC277 is designed to retain significant shielding properties up to 230ºC,
and maintains physical integrity to 1038ºC. JC277 is a rugged material
which can be shaped with standard power tools. It is completely non-combustible
and field castable. With three times as much hydrogen as concrete it is
well suited to attenuate the neutron flux from reactors.
Chemical & Physical Properties:
Hydrogen atoms/cc: 3.4 x 1022
Boron atoms/cc: 1.43
x 1021
Density:
1.68g/cc
Compressive Strength: 1000psi
Options:
• Available as dry mix for casting.
• Can be pre-cast to customer specification.
Uses:
• Penetration seal in reactor dry well.
• Cast into doors around primary coolant piping.
• Reduction of neutron background.
• Sacrificial shield wall.
MODEL JC237 - BORO-SILICONE
Description:
Boro-silicone is a fire resistant, heat resistant, self-extinguishing
elastomer which is available for field casting or pre-cast to
specification. It is hydrogen rich and will withstand temperatures of up
to 205ºC for long periods while retaining most shielding properties. It
has 1% added boron to give enhanced thermal neutron capture.
Chemical & Physical Properties:
Hydrogen atoms/cc: 4.49 x 1022
Boron atoms/cc: 0.94
x 1021
Density:
1.59g/cc
Options:
• Other boron concentrations available on request.
• Varied shapes and sizes, including pre-cast pieces to individual designs.
Uses:
• Reactor cavity neutron shielding plug.
• Biological neutron shield for coolant re-circulating lines.
• In-core instrumentation shield.
• Reactor fuel transport flasks.
MODEL JC243 - NEUTRON ISOLATOR
Description:
Model JC243 is a resin based material with a glossy surface for easy
decontamination. It will withstand temperatures of up to 177ºC and is
self-extinguishing. JC243 is supplied in pre-cast shapes, which makes it
ideal shielding material for areas where it is not necessary, or desirable, to contain
the material in stainless steel.
Chemical & Physical Properties:
Hydrogen atoms/cc: 5.03 x 1022
Boron atoms/cc: 2.88 x 1021
Temperature limit: 177ºC
Density:
1.55g/cc
MODEL JC244 -
NEUTRON ISOLATOR
Description:
Model JC244 is a field-castable, non-combustible material designed to be
cast by the addition of water into stainless steel or other protective
enclosures. JC244 will maintain 50% of its hydrogen at 177ºC. The
material is mixed in an ordinary cement mixer with the addition of water and
does not require heating.
Chemical & Physical Properties:
Hydrogen atoms/cc: 4.5 x 1022
Boron atoms/cc:
2.88 x 1021
Temperature limit:
177ºC
Density of Cast Material: 1.8g/cc
MODEL JC291 -
BORAL
Description:
Boral is a uniform dispersion of a boron carbide in aluminium. The resulting
sandwich has an exceptionally high cross-section for thermal neutrons and will
withstand temperatures up to 540ºC.
Chemical & Physical Properties:
Boron atoms/cc: 23.8 x 1021
Temperature Limit: 540ºC
Density:
2.5g/cc
Options:
• Available cut to size.
• Fabricated to customer shape.
Uses:
• Isolators in spent fuel element racks.
• Inner sections of reactor shields.
• Neutron curtains.
• Shipping containers.
MODEL JC258 -
NEUTRON SHIPPING CASKS
Description:
Neutron sources such as Cf, Am-Be and Pu-Be require transporting in specialist
shielding casks. Model JC258 is designed for this purpose. These
casks are designed to be moved by fork lift or overhead lifting device.
The casks are ruggedly constructed of heavy gauge steel, using Polycast JC259 as
the shielding material, which has an exceptionally high hydrogen content.
There is a central lead cup to shield against primary gammas and 0.9% boron to
absorb thermal neutrons and suppress secondary gamma dose. The casks can
be qualified as DOT Type 'A' shipping containers.
Dimensions:
| Cat
No. |
CASK |
Maximum Source Size for |
|
Shipping* |
Storage** |
|
Diameter
(mm) |
Weight
(kg) |
Cf-252
µg |
Am-Be or Pu-Be
Ci |
Cf-252
µg |
| 258 D |
457 |
125 |
30 |
13 |
0.4 |
| 258 E |
572 |
225 |
75 |
20 |
3 |
| 258 F |
686 |
320 |
150 |
N/A |
3 |
| 258 G |
838 |
615 |
375 |
N/A |
9 |
| 258 H |
1016 |
1360 |
1000 |
N/A |
32 |
| 258 I |
1219 |
2270 |
2500 |
N/A |
100 |
* Shipping limit is based on 10 mR/h at 1m
or 200 mR/h at cask surface, whichever is reached first.
** Based on 2.5 mR/h at cask surface.
Uses:
• Transport of neutron sources.
MODEL JC261 -
NEUTRON PUTTY
Description:
Neutron putty is non-hardening boron loaded putty with a high hydrogen
content. A 25mm thickness of JC261 will attenuate thermal neutrons by a
factor of approximately 105.
Chemical & Physical Properties:
Hydrogen content: 8.94%
Boron content:
10%
Temperature Limit: 45ºC
Density:
1.1g/cc
Neutron putty is available in 3.6kg cans.
Uses:
• Temporary neutron shielding.
• Collimation of neutrons.
• Blocking neutron streams.
MODEL JC240 -
CADMIUM SHEET
Description:
Cadmium sheet is often used for attenuation of thermal neutrons and, because
of its high cross section, it is effective even as thin sheets.
MODEL JC241 -
BORON CARBIDE POWDER
Description:
Boron carbide powder is available in fine powder with 68.3% boron
content. Bulk density after vibration is 52% of solid density.
MODEL JC001 -
BORATED WAX
Description:
Model JC001 is a wax with a 5% boron loading, often used for low cost
neutron shielding when lining doors or filling wells. Borated wax has a
density of 0.9 g cm-3 and a softening point of 70ºC.
Options:
• Other boron concentrations on request.
