API RP 581 - 3rd Ed.2016 - Add.2-2020 - Risk-Based Inspection Methodology

3-36 API RECOMMENDED PRACTICE 581
represent typical costs to businesses of an injury up to and including fatal injuries. When assigning this value,
consideration should be given to the following:
a) any existing company standards for such calculations,
b) local medical/compensation costs associated with long-term disability,
c) legal/settlement costs, and
d) indirect costs such as increased regulatory scrutiny, loss of reputation, etc.
The costs associated with personnel injury are calculated using Equation (3.89):
FC = CA ⋅ popdens ⋅injcost
inj
inj
FC = CA ⋅popdens ⋅ injcost
(3.89)
f , prod f , inj
4.12.6 Environmental Cleanup Costs
Environmental consequence as a result of loss of containment can be significant and should be added to the
other costs including fines and other financial penalties. The methods presented here are based on the amount
of material spilled to the ground, the number of days to clean up the spill, and the environmental hazards
associated with the properties of the fluid released.
The cost of cleanup depends on where the release is likely to be spilled. For example, spills into waterways
will be much more costly than spills above ground. In addition, spills that work their way below ground will be
more costly than spills above ground. The environmental cost, envcost , in $/bbl, must be provided as an
estimate by the analyst.
Fluids that are released as a liquid per Section 4.1.6 are considered to have the potential for environmental
costs. Additionally, it is assumed that any liquid with a NBP less than 93 °C (200 °F) will readily evaporate and
thus the environmental costs will be negligible. If the release is likely to autoignite, the environmental costs
should not be included since the release will probably ignite and burn.
The fraction of the release fluid for remediation is a function of the evaporation rate. Estimates of release fluid
evaporation fraction, frac , as a function of the NBP is provided in Table 4.18. As an alternative, the
evap
following equation can be used to estimate frac :
evap
⎡
⎢
⎢
− + ⋅ ⋅ +
2
=
⎢
⎢
−3.5594(10)
⋅( ( 12
⋅ ) +
41)
⎢ 2331.1 203545
⎢+ −
⎢ ( C ⋅ NBP)
+ C
⎣
C ⋅ NBP + C
−3
7.1408 8.5827(10) (( C12 NBP) C41)
−6
fracevap
C NBP C
(( ) )
12 41 12 41
2
⎤
⎥
⎥
⎥
⎥
⎥
⎥
⎥⎦
(3.90)
where C
41
is a conversion factor that is equal to 0 when using the NBP in Fahrenheit (U.S. customary units)
and equal to 32 when using Celsius (SI units).
The spill volume of fluid that requires cleanup is calculated using Equation (3.91) for each release hole size
using the fluid liquid density, ρ (see Table 4.2), and the fraction of release that does not evaporate.
l