Download RASCAL v4.2 Supplemental Training and User Manual

1.5 RASCAL – USER CONSIDERATIONS
1.5.1 RASCAL’s Early Phase Dose Projection Basis
The basis for this projection is that the dose would be received by an individual
standing outside continuously with no sheltering for the full four days. Persons
evacuated in a timely manner or sheltered in place will receive none or only a
portion of this projected 96 hour (hr) dose. Furthermore, this 96 hr time period,
given a release of limited duration, will include not only the early phase, with its
more urgent response considerations, but also the additional overlapping
intermediate and ingestion phases and their many response considerations,
including re-entry, relocation, return, and food protection actions respectively.
All phases should be considered early when responding to a real incident, and as
required when developing resources for supporting drill/exercise scenarios.
1.5.2 Initial Dose Projection Input Parameters
The need for an initial dose projection may occur quickly in a fast breaking event or
evolve over a period of time. RASCAL requires specific plant status conditions,
which may be hard to get in a timely manner, as well as meteorological information
which is more readily available, to produce an acceptable dose projection. Clues to
the plant’s condition, severity of the event, and potential impact on the GP, can be
obtained from the Emergency Classification Levels (ECLs) and Emergency Action
Levels (EALs).
The Nuclear Accident Reporting System (NARS) form provided by the NPP will
have the ECL and EAL classifications, as well as other needed early information,
including meteorological data, but may lack sufficient data to fully define all needed
RASCAL inputs. If the NRC’s Emergency Response Data System (ERDS) website
is operational, additional more instantaneous plant condition information should be
available.
In most instances however, it will be necessary to both make assumptions and
contact plant personnel in order to calculate early dose projection numbers. It is
suggested that “default” input parameters, based on pre-defined ECL and EAL
combinations and other likely plant conditions, be discussed and pre-established to
ensure that desired initial dose projections can be completed in as early of a time
frame as possible.
1.5.3 Dose Projection Output Results
RASCAL calculations are based on less conservative (but still conservative) more
up to date and accurate modeling equations. Therefore, dose projections
exceeding associated PAGs will occur at distances closer in toward the release
source than earlier versions of RASCAL. Though this will have the effect of
reducing the projected impacted area from what has been historically observed,
decision makers should resist the temptation to “add back” lost ground. This less
conservative calculation environment does not, however, similarly change or reduce
the importance of timely and effective decision making.
Version 4.2
March 28, 2013
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