We are pleased to announce the release of Phast v6.54 containing updates in a number of areas of the program as described in more detail below.

The key objective of this release is to make Phast compatible with Microsoft Vista. In doing this we have had to update a number of our third party components, which bring additional benefits provided by the third party developers’ own enhancements. These are described below.

Support for Microsoft Vista requires:

• Latest version of licensing component (FlexLM v11.5) resulting in licensing becoming more user friendly. We have also taken the opportunity to provide a license expiry warning

• Latest version of GIS Component (GeoMedia v6.1) which also includes:
  o Legend anchored in separate pane adjacent to the map with items grouped within tabs
  o Ability to select groups of objects using polygons as well as rectangles
  o Ability to assign name and description to coordinate systems
  o Display raster images as translucent and rotate them around a point
  o Improved control over shading and colouration of objects on maps
  o Extended support for raster image and GIS formats

We have also added a number of new features and enhancements which are described in detail in the Release Notes included with the release CD and download, and described briefly below.

Enhancements to discharge modelling
A number of features to increase the flexibility of the linking between discharge and other effects, to better represent cratered pipeline releases for instance;

• User defined Velocity Modification Factor for impinged releases
• Final Discharge Velocity maximum limit can be defined as Fixed or “Sonic”
• User defined Coefficient of Discharge
• Facility to define angle of release direction for impinged releases
• Ability to cap velocity for impinged releases

For In-Building releases the following enhancement has been added:

• Allow In-Building liquid releases to be treated as if they partially evaporate to compensate for lack of pool modelling within the building.

Improvements to Warehouse Model
This model predicts emissions from the combustion of pesticides or other warehouse materials, creating a “Warehouse Reference Mixture” based on combustion products. This is then dispersed using the appropriate Phast dispersion models. The improvements in v6.54 are:

• Ability to override pesticide molecular weight in case all the atoms cannot be specified in the structural material formula
• Specify warehouse area directly and allow it to be part of a larger building
• Allow flexible definition of the fire scenarios
  o Choose a PGS-15 fire extinction system which will then automatically generate the fire scenarios, with all the existing PGS-15 fire extinction systems pre-defined
  o Allow PGS-15 scenarios to be converted to User-Defined Scenarios so they can be edited
• Provide a new Overview Report showing the list of generated scenarios

Note: The Netherlands Commission for the Prevention of Disasters due to Dangerous Substances Directive PGS-15 provides guidelines for the storage of hazardous substances. See, for example, http://uk.denf.nl/services/technical_safety/Hazardous_substances_and_the_environment/PGS/.

Addition of “Plant Boundary” facility for use with free-field method
Currently if you select “Use Free Field Modeling” in the General Risk Parameters, the “Distance to site boundary”, also set in the General Risk Parameters, is used to decide if free field ignition occurs. In v6.54 we have added the facility to draw the site boundary on your map so that this can be used instead of the “Distance to site boundary” parameter. This feature is particularly relevant to the SAFETI^NL version.

Improved Societal and Individual Risk Ranking Reports
Additional detail is now available showing specific contributions to risk from:

• Individual Outcomes, e.g. Jet Fire, Pool Fire, Explosions, Toxic Effects
• Individual Weathers
• Individual Weather Directions

Other general enhancements
A number of more general minor enhancements have been included in v6.54 as summarised below:

• A method has been included to select short duration effects for immediate ignition, even for long-duration time varying releases. This enables an initial fireball, as well as a jet fire, to be modelled for immediate ignition scenarios for a pipeline rupture. Event-Trees have also been modified to allow for an initial fireball.
• An option has been added to include solar radiation in thermal radiation results. There is an existing weather parameter which defines the level of solar radiation to be used and a flag has been added to the flammable parameters in the radiation tab to select whether solar radiation should be included or not.

Changes to results
We do not expect to see any changes in results if using the same parameter sets. There are some new and some changed parameters in v6.54 as described above. However, if you read v6.53 studies into v6.54 or use the same parameters in a v6.54 model as in a v6.53 model and run the calculations, we would not expect to see any significant changes in the results.

We aim to record all enhancement requests and known issues and try to continuously deal with these, in combination with ever evolving requirements coming from our customers, regulators and the market. The selection of the development items included in this release has been driven directly by customer feedback. We have chosen the most requested features which we believe can be included in parallel with the key need addressed by the v6.54 release, which is support for Microsoft Vista, without extending the time required to deliver this update.