[Federal Register Volume 85, Number 44 (Thursday, March 5, 2020)]
[Notices]
[Pages 12917-12920]
[FR Doc No: 2020-04546]

-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

[EPA-HQ-OAR-2002-0050; FRL-10006-13-OAR]

National Emission Standards for Hazardous Air Pollutants
(Radionuclides), Availability of Updated Compliance Model, CAP88-PC

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of Availability.

-----------------------------------------------------------------------

SUMMARY: Pursuant to section 112 of the Clean Air Act, as amended, the
Environmental Protection Agency (EPA or Agency) is announcing the
availability of Version 4.1 of the CAP88-PC model. This version may be
used to demonstrate compliance with the National Emission Standards for
Hazardous Air Pollutants (NESHAPs) applicable to radionuclides. CAP88-
PC is approved for this use by the EPA. Version 4.1 includes a number
of improvements from previous versions, including Version 4.0. The most
significant of these changes from a user perspective are the
implementation of a new Wix installer technology that enhances
compatibility with Windows 10 and future Windows updates, an update in
the number of included radionuclides and the data for these
radionuclides, and a change in the manner in which reports are printed.

FOR FURTHER INFORMATION CONTACT: Brian Littleton, Office of Radiation
and Indoor Air, Radiation Protection Division (6608T), U.S.
Environmental Protection Agency, 1200 Pennsylvania Avenue NW,
Washington, DC 20460; telephone number:<PHONE_NUMBER>; fax number:
(202) 343-2304; email address<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this action apply to me?

    You may be potentially affected by this action if you are subject
to the requirements for radionuclide NESHAPs found in 40 CFR part 61,
subpart H. This subpart applies to Department of Energy (DOE or
Department) facilities.

B. How can I get copies of the model and other related information?

    Docket. The EPA has established a docket for this action under
Docket ID No. EPA-HQ-OAR-2019-0050. Publicly available docket materials
are available either electronically through www.regulations.gov or in
hard copy at the Air and Radiation Docket in the EPA Docket Center
(EPA/DC), EPA West, Room B 102, 1301 Constitution Avenue NW,
Washington, DC. The EPA Docket Center Public Reading Room is open from
8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal
holidays. The telephone number for the Public Reading Room is (202)
566-1744, and the telephone number for the Air and Radiation Docket is
(202) 566-1742.
    2. Electronic Access. You may access this Federal Register document
electronically through the EPA website under the ``Federal Register''
listings at http://www.epa.gov/fedrgstr/.
    3. EPA website. You may download the CAP88-PC model and
documentation from the EPA's website at https://www.epa.gov/radiation/cap-88-pc.

II. Background

    On December 15, 1989, the EPA promulgated the National Emission
Standards for Hazardous Air Pollutants (NESHAPs) under section 112 of
the Clean Air Act to control radionuclide emissions to the ambient air
from a number of different source categories [54 FR 51654, December 15,
1989 (Docket EPA-HQ-OAR-2002-0050-0028)]. Subpart H of 40 CFR part 61
is one of the source categories covered in the 1989 final rule.
Facilities owned and operated by the DOE are regulated under subpart H.
The Department administers many facilities across the country,
including government-owned, contractor-operated facilities. Some of
these facilities handle significant amounts of radioactive material
that could potentially be emitted into the air in various chemical and
physical states. The purpose of subpart H is to limit radionuclide
emissions (not including radon) from the stacks and vents at DOE
facilities so that no member of the public receives an effective dose
equivalent of more than 10 millirems

per year (mrem/yr) or, in SI units, 0.1 millisievert per year (mSv/yr).

III. CAP88-PC Model for Demonstrating Compliance

A. CAP88-PC History

    The EPA is today announcing the availability of Version 4.1 of the
CAP88-PC model for use in demonstrating compliance with the
requirements of 40 CFR part 61, subpart H. CAP88 (Clean Air Act
Assessment Package-1988) is a set of computer programs, databases and
associated utility programs for estimation of dose and risk from
radionuclide emissions to the air. CAP88-PC implements, on the personal
computer platform, modified versions of the AIRDOS-EPA and DARTAB codes
that were written in FORTRAN 77 and executed in a mainframe computing
environment. CAP88-PC provides for dose and risk assessments of
collective populations, maximally-exposed individuals and selected
individuals.
    The original CAP88-PC software package, Version 1.0 allowed users
to perform full-featured dose and risk assessments in a DOS environment
for the purpose of demonstrating compliance with 40 CFR 61.93(a); it
was approved for compliance demonstration in February 1992.
    CAP88-PC Version 2.0 provided a framework for developing inputs to
perform full-featured dose and risk assessments in a Windows
environment for the purpose of demonstrating compliance with 40 CFR
61.93(a). Version 2.0 was approved for compliance demonstration in
1999. Version 2.1 included some additional changes compared to the DOS
version and the previous Windows Version 2.0. The changes included the
addition of more decay chains, improvements in the Windows code error
handling and a modified nuclide data input form. The CAP88-PC User
Guide provides a summary of the changes incorporated into Version 2.1
relative to Version 2.0.
    CAP88-PC Version 3.0, released in 2006 (71 FR 8854, February 21,
2006), was a significant update to Version 2.1. Version 3 incorporated
dose and risk factors from Federal Guidance Report 13, ``Cancer Risk
Coefficients for Environmental Exposure to Radionuclides'' (FGR 13) in
place of the RADRISK data that was used in previous versions. In
addition, the CAP88-PC database, the user interface, input files and
output files were modified to accommodate the FGR 13 data formats and
nomenclature. Page 9 of the CAP88-PC Version 3 User's Guide describes
the modifications incorporated into Version 3 relative to Version 2.1.
    CAP88-PC Version 4, released in 2015 (80 FR 7461, February 10,
2015), was a significant update to Version 3. While keeping the
fundamental model unchanged, modifications were made to add
flexibility, enhance stability of the code, and make it easier for the
user to use while also improving the quality assurance of the modeling.
The most significant of these changes from a user perspective were the
incorporation of age-dependent radionuclide dose and risk factors for
ingestion and inhalation (the use of which is specified by the user),
the increase in the number of included radionuclides, and a change in
the file management system used by the program. Those modifications
produced a significant improvement in speed and stability for Version 4
relative to Version 3 and eliminated the solution approximations used
in Version 3. The EPA also implemented an extensive testing and
documentation program for CAP88-PC Version 4 to address user concerns
with past versions. This enhanced documentation allowed for greater
compatibility with user software quality assurance programs. The total
number of nuclides available in Version 4 was increased from the 825 in
Version 3 to 1,252. The maximum number of nuclides that can be included
in any single case was increased from the 256 in Version 3 to 500 in
Version 4.
    CAP88-PC Version 4.1 incorporates the following changes to Version
4.0:
    (1) Dose and risk coefficient data have been updated to the values
supplied by Oak Ridge National Laboratory with the Dose Coefficient
Data File Package (DCFPAK) Version 3.02 (addition of internal dose
information for 151 isotopes; updated information for isotopes in vapor
or gas forms; and additional risk information for many isotopes);
    (2) The ability to print from the Reports tab has been removed
because of incompatibility of certain characters in the reports with
some printer drivers. Printing reports can be done by opening the
report files in any word processor or text editor. The new button opens
the location of the report files;
    (3) The synopsis file now provides the adjusted fractions of milk,
meat, and/or vegetables produced in the assessment area, if CAP88-PC
adjusted them to account for population;
    (4) Enhancements to the user interface code have been made to
increase performance and/or maintain compatibility with the DCFPAK
Version 3 data;
    (5) The installer system has been updated for better compatibility
with Windows;
    (6) Migration utility updates have been made to migrate data from
Version 3 to Version 4.1 formats; and
    (7) The user interface has been updated to provide automatic
conversion of Version 4.0 datasets to Version 4.1.
    In summary, Version 4.1 enhances and completes the updates
initiated under CAP88-PC Version 4.0 and incorporates compatibility for
newer operating systems.

B. CAP88-PC Model Summary

    All versions of CAP88-PC use a modified Gaussian plume equation to
estimate the average dispersion of radionuclides released from up to
six sources. The sources may be either elevated stacks, such as a
smokestack, or uniform area sources, such as a pile of uranium mill
tailings. ``Plume rise'' can be calculated assuming either a momentum
or buoyant-driven plume. Assessments are made for a circular grid of
distances and directions for a radius of up to 80 kilometers (50 miles)
around the source. The Gaussian plume model produces results that agree
with experimental data as well as any model, is fairly easy to work
with and is consistent with the random nature of turbulence. Site-
specific information on population location and meteorological
conditions is provided to CAP88-PC as input files developed by the
user. The formats for these input files have not changed from the
original mainframe version of the CAP88 code package.
    CAP88-PC Version 4.1 is a modification intended to improve
usability, enhance the modeling methodology, update the dataset
formats, and provide a more maintainable code base and documentation
set for the future. Version 4.1 provides age-dependent dose conversion
factors and lifetime risk factors and uses a code architecture that
conforms to more recent coding standards and data formats. The data
updates include adoption of the ingestion and inhalation age and
particle size dependent dose and risk factor data supplied by Oak Ridge
National Laboratory in the DCFPAK Version 3.02 model,\1\ and age-
dependent ingestion and inhalation rates from the EPA.
---------------------------------------------------------------------------

    \1\ https://www.epa.gov/radiation/tools-calculating-radiation-dose-and-risk.
---------------------------------------------------------------------------

    The CAP88-PC Version 4.1 software was developed using a structured
software engineering methodology that included adoption of a defined
software

architecture, rigorous source control, independent verification of
source code as it was being implemented, multiple phases of testing,
and configuration control of the documentation and the code as
development progressed.
    To conform to Windows 10 security requirements, and to improve
usability, case-specific input and output data files are now stored by
default in the user's Windows profile folders, rather than in the
application's Program Files folder.
    CAP88-PC Version 4.1 input datasets can be stored in their own
folders, as subfolders of the Datasets folder. As an example, for the
Modtest dataset included with the Version 4.1 distribution set, the
folder holding the dataset and all associated data files and reports
would be located at c:\Users\xxxx\Documents\CAP88\Datasets\Modtest.
Datasets are recommended to be put into their own folders, because
using this data storage structure will simplify use of the code and
management of case data. Reports are always stored in the same folder
as the dataset. Population and wind files can be stored with the
dataset or in the default Population/Wind folders. However, CAP88-PC
Version 4.1 will preferentially use the population and wind files
located in the dataset. This improves sharing of dataset information
between organizations and simplifies configuration management of cases
because all pertinent case records (input and report files) are stored
together. A user can send a dataset, its population and wind files, and
its reports to another user, who can open them, using CAP88-PC Version
4.1 or any text editor, confident that the proper files are being used.
    As was the case with Versions 3 and 4.0, Version 4.1 is not
backward compatible, and datasets generated using Versions 3 and 4.0
cannot be used directly by Version 4.1. This is the result of many
factors, including the addition of age-specific data and the inclusion
of many more nuclides than in previous versions. However, both Versions
4.0 and 4.1 include a dataset migration utility that upgrades many
Version 3 datasets to the applicable Version 4.0 or 4.1 format. The
migration utility runs on first use and is also available on demand
from the Tools>Options drop-down menu. The migration utility will move
Version 3 database files, input dataset files, population files, and
wind files from the format used with the 9 December 2007 release of
Version 3 to their respective Version 4 formats. The folder locations
of the Version 3 files being migrated and the locations for the Version
4 files being generated are selectable by the user or the utility will
select the default locations for those files.
    The overall principle of the Version 4 architecture was to optimize
the code by performing data manipulation in the user interface and
computational functions in FORTRAN. CAP88-PC Versions 4.0 and 4.1 have
accomplished this by having the user interface collect the user input
data, read the associated databases, generate the dose and risk factors
from the DCFPAK data, then build and write the case dataset. The user
interface also handles all program interactions with the file system.
The FORTRAN computational sub-system now performs all decay and ground
surface buildup calculations along with all the air dispersion,
deposition, intake, dose, and risk calculations. The only file
manipulation performed by the FORTRAN sub-system is reading the dataset
files and writing report files. The data system used in CAP88-PC
Version 4.1 has access to information for all 1,252 radionuclides,
including those for which internal dose and risk factors have been
added in to DCFPAK Version 3.02.

C. Validation of the CAP88-PC Version 4.1 Model

    The CAP88-PC Version 4.1 program is a well-established and
validated code for the purpose of making comprehensive dose and risk
assessments. The Gaussian plume model used in CAP88-PC to estimate
dispersion in air is one of the most commonly used models for
dispersion modeling. It produces results that agree with experimental
data as well as any model, is fairly easy to work with, and is
consistent with the random nature of turbulence. Version 4.1 has not
modified the basic Gaussian plume algorithm used by the AIRDOS module
of CAP88-PC, and comparison cases between Versions 4.0 and 4.1 have
been run.
    The EPA's Office of Radiation and Indoor Air (ORIA) has reviewed
the testing report submitted by the contractor and verified the results
through independent testing. The report can be found at https://www.epa.gov/radiation/cap-88-pc.
    As part of the software testing, the user interface was extensively
tested. The testing verified that the interface only accepted:
    (1) Positive distances less than or equal to 80 kilometers (km) for
receptor distances;
    (2) Non-negative release rates;
    (3) Annual precipitation amounts between 0.01 and 500 centimeters
per year (cm/yr);
    (4) Annual ambient temperatures between -100 and 100 degrees
Celsius ([deg]C);
    (5) Lid heights between 25 and 10,000 meters (m);
    (6) Non-negative source heights, and positive source diameters or
areas;
    (7) Non-negative heat release rates, exit velocities and fixed
plume rises; and
    (8) Agricultural fractions that summed to unity.
    All issues identified with the interface have been resolved and
closed. Seven test cases were developed to test the capabilities of
CAP88-PC Version 4.1. Six of these cases involve the calculation of
dose and risk to an individual or population at the location identified
by the model as that of the maximally exposed individual (MEI) or
specified by the user. The testing objectives for these six cases
include the following verifications:
    (1) Dose factors agree with those calculated using the DCFPAK 3.02
from Oak Ridge National Laboratory to 1% or less;
    (2) Values of Chi-over-Q ([chi]/Q) agree within 1% with those
calculated using CAP88-PC Version 4.0, including but not limited to the
direction of the MEI (the calculated values for [chi]/Q showed good
agreement between Versions 4.0 and 4.1 in all directions);
    (3) Air concentrations and deposition rates (where applicable)
agree within 1% with those calculated using CAP88-PC Version 4.0; and
    (4) Results for dose rates and risks agree within 5% of independent
calculations; the 5% criterion was used here to allow for differences
caused by different modeling methods.
    The objective of Test Case 7 was to verify the CAP88-PC Version 4.1
calculations of the air concentrations and working levels for radon-
only are consistent with Version 4.0.

D. Limitations of the CAP88-PC Model

    Like all models, there are some limitations in the CAP88-PC system.
While up to six stacks or six area sources can be modeled, all the
sources are modeled as if located at the same point; that is, stacks
cannot be located in different areas of a facility. The same plume rise
mechanism (buoyant or momentum) is used for each source. Also, area
sources are treated as uniform. Variation in radionuclide
concentrations due to complex terrain cannot be modeled. Errors arising
from these assumptions will have a negligible effect for assessments
where the distance of exposed individuals is large compared to the
stack height, area or facility emissions.

E. Use of CAP88-PC Version 4.1 for Compliance Purposes

    In the same manner as CAP88-PC Version 4.0, Version 4.1 allows the
user to incorporate the age-specific dose conversion factors and intake
rates contained in DCFPAK Version 3.02. The code allows the user to
select the ingestion and inhalation dose conversion and intake rates
from the age groups modeled in DCFPAK Version 3.02: infant (100 days
old), one-year old, five-year old, ten-year old, fifteen-year old, and
adult. However, the addition of this capability does not change the
requirements for compliance to the NESHAPS Subpart H requirements.
These are clearly stated in 40 CFR part 61 Subpart H. The ability to
allow the code base to include age-dependency does not impact or imply
changes to the compliance demonstration.

F. Summary of Changes for CAP88-PC Version 4 to Version 4.1.

    Version 4.1 of CAP88-PC is an update from Version 4.0, and a
significant upgrade from earlier versions. CAP88-PC Versions 4.0 and
4.1 not only added significant features, but also redesigned the
interface to give the user a more standard experience. The entire user
interface module was re-written for Version 4 using VB.Net, the
Microsoft.Net Framework Version 4, and the Visual Studio 2010
development environment, in order to better comply with updated code
standards in Windows 7, Windows 8.1. and Windows 10. Specific changes
from Version 4.0 visible to the user in Version 4.1 include:
User Interface
    (1) The Print button on the Reports tab has been replaced with a
button that opens the folder holding the report files which may then be
printed using a word processing program;
    (2) Some labels in the user interface have been modified for
clarity;
    (3) The capabilities for migrating datasets from previous versions
of CAP88-PC have been improved, including automatic conversion of
Version 4.0 datasets to Version 4.1.
Reports
    (1) Some report headers have been modified for clarity;
    (2) The Agricultural Data in the Synopsis report now prints the
values for the fractions of vegetables, milk, and meat from the
assessment area used in the calculation, which may have been adjusted
by CAP88-PC from the input values.
Data
    (1) The dose and risk coefficients have been updated from DCFPAK
2.2 to those in DCFPAK 3.02 provided by Oak Ridge National Laboratory;
    (2) Internal dose and risk coefficient factors for 151 more
radionuclides have been added;
    (3) Additional risk coefficient data has been added for more
radionuclides and chemical forms beyond the additional 151;
    (4) Inhalation coefficients for radionuclides with special chemical
forms, such as iodine, have been added.
Error Handling
    CAP88-PC Versions 4.0 and 4.1 contain an internal error logging and
tracking system. In the case of internal code errors, the code will
write errors to a file in the Message Log folder located in the same
folder set as the folder containing the datasets. Sending this file to
the EPA representative will facilitate troubleshooting.
On-Line Help System
    CAP88-PC Version 4.1 includes a context-sensitive help system that
is accessible during operation. The on-line help system is a hypertext
version of the traditional user manual; the traditional user manual is
included as part of the release distribution package in pdf format.

    Dated: February 26, 2020.
Lee Ann B. Veal,
Director, Radiation Protection Division, Office of Radiation and Indoor
Air.
[FR Doc. 2020-04546 Filed 3-4-20; 8:45 am]
 BILLING CODE 6560-50-P