Often radiation employers need to assess how much shielding needs to be used in order to adequately protect their personnel from radiation or an evaluation needs to be performed to determine whether planned or existing structures are sufficient to provide the required degree of shielding.
RP Alba Ltd is able to perform a wide range of shielding assessments using bespoke software or calculational approaches dependent on the most suitable method for the scenario requiring modelling. The calculational approaches are often applied for X-ray shielding, neutron shielding, beta shielding and simple geometry gamma / photon shielding situations.
We have licensed copies of both MicroShield® v9.04 and MicroSkyshine® v2.11 which are ideal for modelling a wide range of situations where point kernel approaches are appropriate for photon & gamma radiation modelling. We have arrangements in place with supporting suppliers if even more complex modelling are warranted using alternative complex software such as MCNP or Attila.
MicroShield® is a comprehensive photon/gamma ray shielding and dose assessment program. It is widely used for designing shields, estimating source strength from radiation measurements, minimizing exposure to people, and teaching shielding principles.
MicroShield® 9.04 incorporates the International Commission on Radiological Protection’s latest Nuclear Decay Data library from Publication 107.
16 different source term geometries can be modelled using MicroShield® :
- Rectangular Area - Vertical
- Rectangular Area - Horizontal
- Cylinder Volume - Side Shields
- Cylinder Volume - End Shields
- Cylinder Surface - Internal Dose Point
- Cylinder Surface - External Dose Point
- Annular Cylinder - Internal Dose Point
- Annular Cylinder - External Dose Point
- Rectangular Volume
- Truncated Cone
- Infinite Plane
- Infinite Slab
In addition to being able to calculate dose rate results of both buildup and uncollided situations it is possible to source decay radionuclides to examine how dose rates change over time as daughter progeny are generated. It is also possible to investigate sensitivity of the results to time, source dimension, shield thickness, or distance and the amount of decay heat/energy can also be determined using MicroShield®.
MicroSkyshine® calculates the photon dose from sky scattered gamma ray radiation. Typical application would be to determine scattering from BWR turbine buildings, radwaste storage facilities, and waste disposal sites.
MicroSkyshine's® analytical method of solution is based on the use of “beam functions” for a point source.
14 different source term geometries can be modelled using MicroSkyshine®:
- Point Source In A Silo
- Vertical Line Source In A Silo
- Vertical Cylinder Source In A Silo
- Point Source Behind A Wall
- Horizontal Line Source Behind A Wall
- Horizontal Rectangular Area Source Behind A Wall
- Horizontal Circular Area Source Behind A Wall
- Vertical Line Source Behind A Wall
- Vertical Rectangular Area Source Behind A Wall
- Vertical Circular Area Source Behind A Wall
- Rectangular Volume Source Behind A Wall
- Vertical Cylindrical Volume Source Behind A Wall
- Horizontal Cylindrical Source Behind A Wall
- Point Source In A Rectangular Enclosure
Using MicroSkyshine® it is possible to decay the source terms to allow daughter progeny to be generated and through an iterative process it is possible to determine the variation of dose rates as the radioactive source term decays. This is of particular use when examination the evolution of radioactive waste disposal sites.
RP Alba Ltd has a range of shielding assessment services available depending on your requirements. Please contact us today to discuss your needs.
If RPA or RWA support services are being provided to you from RP Alba Ltd then access to our calculational approaches and our utilisation of MicroShield or MicroSkyshine software, when required to support you, are included in the service agreement.