[Code of Federal Regulations]
[Title 40, Volume 24]
[Revised as of July 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR191]
[Page 6-17]
TITLE 40--PROTECTION OF ENVIRONMENT
CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
PART 191_ENVIRONMENTAL RADIATION PROTECTION STANDARDS FOR MANAGEMENT AND
DISPOSAL OF SPENT NUCLEAR FUEL, HIGH-LEVEL AND TRANSURANIC RADIOACTIVE WASTES
Subpart A_Environmental Standards for Management and Storage
Sec.
191.01 Applicability.
191.02 Definitions.
191.03 Standards.
191.04 Alternative standards.
191.05 Effective date.
Subpart B_Environmental Standards for Disposal
191.11 Applicability.
191.12 Definitions.
191.13 Containment requirements.
191.14 Assurance requirements.
191.15 Individual protection requirements.
191.16 Alternative provisions for disposal.
191.17 Effective date.
Subpart C_Environmental Standards for Ground-Water Protection
191.21 Applicability.
191.22 Definitions.
191.23 General provisions.
191.24 Disposal standards.
191.25 Compliance with other Federal regulations.
191.26 Alternative provisions.
191.27 Effective date.
Appendix A to Part 191--Table for Subpart B
Appendix B to Part 191--Calculation of Annual Committed Effective Dose
Appendix C to Part 191--Guidance for Implementation of Subpart B
[[Page 7]]
Authority: The Atomic Energy Act of 1954, as amended, 42 U.S.C.
2011-2296; Reorganization Plan No. 3 of 1970, 5 U.S.C. app. 1; the
Nuclear Waste Policy Act of 1982, as amended, 42 U.S.C. 10101-10270; and
the Waste Isolation Pilot Plant Land Withdrawal Act, Pub. L. 102-579,
106 Stat. 4777.
Source: 50 FR 38084, Sept. 19, 1985, unless otherwise noted.
Subpart A_Environmental Standards for Management and Storage
Sec. 191.01 Applicability.
This subpart applies to:
(a) Radiation doses received by members of the public as a result of
the management (except for transportation) and storage of spent nuclear
fuel or high-level or transuranic radioactive wastes at any facility
regulated by the Nuclear Regulatory Commission or by Agreement States,
to the extent that such management and storage operations are not
subject to the provisions of part 190 of title 40; and
(b) Radiation doses received by members of the public as a result of
the management and storage of spent nuclear fuel or high-level or
transuranic wastes at any disposal facility that is operated by the
Department of Energy and that is not regulated by the Commission or by
Agreement States.
Sec. 191.02 Definitions.
Unless otherwise indicated in this subpart, all terms shall have the
same meaning as in Subpart A of Part 190.
(a) Agency means the Environmental Protection Agency.
(b) Administrator means the Administrator of the Environmental
Protection Agency.
(c) Commission means the Nuclear Regulatory Commission.
(d) Department means the Department of Energy.
(e) NWPA means the Nuclear Waste Policy Act of 1982 (Pub. L. 97-
425).
(f) Agreement State means any State with which the Commission or the
Atomic Energy Commission has entered into an effective agreement under
subsection 274b of the Atomic Energy Act of 1954, as amended (68 Stat.
919).
(g) Spent nuclear fuel means fuel that has been withdrawn from a
nuclear reactor following irradiation, the constituent elements of which
have not been separated by reprocessing.
(h) High-level radioactive waste, as used in this part, means high-
level radioactive waste as defined in the Nuclear Waste Policy Act of
1982 (Pub. L. 97-425).
(i) Transuranic radioactive waste, as used in this part, means waste
containing more than 100 nanocuries of alpha-emitting transuranic
isotopes, with half-lives greater than twenty years, per gram of waste,
except for: (1) High-level radioactive wastes; (2) wastes that the
Department has determined, with the concurrence of the Administrator, do
not need the degree of isolation required by this part; or (3) wastes
that the Commission has approved for disposal on a case-by-case basis in
accordance with 10 CFR Part 61.
(j) Radioactive waste, as used in this part, means the high-level
and transuranic radioactive waste covered by this part.
(k) Storage means retention of spent nuclear fuel or radioactive
wastes with the intent and capability to readily retrieve such fuel or
waste for subsequent use, processing, or disposal.
(l) Disposal means permanent isolation of spent nuclear fuel or
radioactive waste from the accessible environment with no intent of
recovery, whether or not such isolation permits the recovery of such
fuel or waste. For example, disposal of waste in a mined geologic
repository occurs when all of the shafts to the repository are
backfilled and sealed.
(m) Management means any activity, operation, or process (except for
transportation) conducted to prepare spent nuclear fuel or radioactive
waste for storage or disposal, or the activities associated with placing
such fuel or waste in a disposal system.
(n) Site means an area contained within the boundary of a location
under the effective control of persons possessing or using spent nuclear
fuel or radioactive waste that are involved in any activity, operation,
or process covered by this subpart.
[[Page 8]]
(o) General environment means the total terrestrial, atmospheric,
and aquatic environments outside sites within which any activity,
operation, or process associated with the management and storage of
spent nuclear fuel or radioactive waste is conducted.
(p) Member of the public means any individual except during the time
when that individual is a worker engaged in any activity, operation, or
process that is covered by the Atomic Energy Act of 1954, as amended.
(q) Critical organ means the most exposed human organ or tissue
exclusive of the integumentary system (skin) and the cornea.
Sec. 191.03 Standards.
(a) Management and storage of spent nuclear fuel or high-level or
transuranic radioactive wastes at all facilities regulated by the
Commission or by Agreement States shall be conducted in such a manner as
to provide reasonable assurance that the combined annual dose equivalent
to any member of the public in the general environment resulting from:
(1) Discharges of radioactive material and direct radiation from such
manage ment and storage and (2) all operations covered by Part 190;
shall not exceed 25 millirems to the whole body, 75 millirems to the
thyroid, and 25 millirems to any other critical organ.
(b) Management and storage of spent nuclear fuel or high-level or
transuranic radioactive wastes at all facilities for the disposal of
such fuel or waste that are operated by the Department and that are not
regulated by the Commission or Agreement States shall be conducted in
such a manner as to provide reasonable assurance that the combined
annual dose equivalent to any member of the public in the general
environment resulting from discharges of radioactive material and direct
radiation from such management and storage shall not exceed 25 millirems
to the whole body and 75 millirems to any critical organ.
Sec. 191.04 Alternative standards.
(a) The Administrator may issue alternative standards from those
standards established in Sec. 191.03(b) for waste management and
storage activities at facilities that are not regulated by the
Commission or Agreement States if, upon review of an application for
such alternative standards:
(1) The Administrator determines that such alternative standards
will prevent any member of the public from receiving a continuous
exposure of more than 100 millirems per year dose equivalent and an
infrequent exposure of more than 500 millirems dose equivalent in a year
from all sources, excluding natural background and medical procedures;
and
(2) The Administrator promptly makes a matter of public record the
degree to which continued operation of the facility is expected to
result in levels in excess of the standards specified in Sec.
191.03(b).
(b) An application for alternative standards shall be submitted as
soon as possible after the Department determines that continued
operation of a facility will exceed the levels specified in Sec.
191.03(b) and shall include all information necessary for the
Administrator to make the determinations called for in Sec. 191.04(a).
(c) Requests for alternative standards shall be submitted to the
Administrator, U.S. Environmental Protection Agency, 1200 Pennsylvania
Ave., NW., Washington, DC 20460.
[50 FR 38084, Sept. 19, 1985, as amended at 65 FR 47325, Aug. 2, 2000]
Sec. 191.05 Effective date.
The standards in this subpart shall be effective on November 18,
1985.
Subpart B_Environmental Standards for Disposal
Sec. 191.11 Applicability.
(a) This subpart applies to:
(1) Radioactive materials released into the accessible environment
as a result of the disposal of spent nuclear fuel or high-level or
transuranic radioactive wastes;
(2) Radiation doses received by members of the public as a result of
such disposal; and
(3) Radioactive contamination of certain sources of ground water in
the vicinity of disposal systems for such fuel or wastes.
[[Page 9]]
(b) This subpart does not apply to:
(1) Disposal directly into the oceans or ocean sediments;
(2) Wastes disposed of before November 18, 1985; and
(3) The characterization, licensing, construction, operation, or
closure of any site required to be characterized under section 113(a) of
Public Law 97-425, 96 Stat. 2201.
[50 FR 38084, Sept. 19, 1985, as amended at 58 FR 66414, Dec. 20, 1993]
Sec. 191.12 Definitions.
Unless otherwise indicated in this subpart, all terms shall have the
same meaning as in subpart A of this part.
Accessible environment means: (1) The atmosphere; (2) land surfaces;
(3) surface waters; (4) oceans; and (5) all of the lithosphere that is
beyond the controlled area.
Active institutional control means: (1) Controlling access to a
disposal site by any means other than passive institutional controls;
(2) performing maintenance operations or remedial actions at a site, (3)
controlling or cleaning up releases from a site, or (4) monitoring
parameters related to disposal system performance.
Annual committed effective dose means the committed effective dose
resulting from one-year intake of radionuclides released plus the annual
effective dose caused by direct radiation from facilities or activities
subject to subparts B and C of this part.
Aquifer means an underground geological formation, group of
formations, or part of a formation that is capable of yielding a
significant amount of water to a well or spring.
Barrier means any material or structure that prevents or
substantially delays movement of water or radionuclides toward the
accessible environment. For example, a barrier may be a geologic
structure, a canister, a waste form with physical and chemical
characteristics that significantly decrease the mobility of
radionuclides, or a material placed over and around waste, provided that
the material or structure substantially delays movement of water or
radionuclides.
Controlled area means: (1) A surface location, to be identified by
passive institutional controls, that encompasses no more than 100 square
kilometers and extends horizontally no more than five kilometers in any
direction from the outer boundary of the original location of the
radioactive wastes in a disposal system; and (2) the subsurface
underlying such a surface location.
Disposal system means any combination of engineered and natural
barriers that isolate spent nuclear fuel or radioactive waste after
disposal.
Dose equivalent means the product of absorbed dose and appropriate
factors to account for differences in biological effectiveness due to
the quality of radiation and its spatial distribution in the body; the
unit of dose equivalent is the ``rem'' (``sievert'' in SI units).
Effective dose means the sum over specified tissues of the products
of the dose equivalent received following an exposure of, or an intake
of radionuclides into, specified tissues of the body, multiplied by
appropriate weighting factors. This allows the various tissue-specific
health risks to be summed into an overall health risk. The method used
to calculate effective dose is described in appendix B of this part.
Ground water means water below the land surface in a zone of
saturation.
Heavy metal means all uranium, plutonium, or thorium placed into a
nuclear reactor.
Implementing agency means:
(1) The Commission for facilities licensed by the Commission;
(2) The Agency for those implementation responsibilities for the
Waste Isolation Pilot Plant, under this part, given to the Agency by the
Waste Isolation Pilot Plant Land Withdrawal Act (Pub. L. 102-579, 106
Stat. 4777) which, for the purposes of this part, are:
(i) Determinations by the Agency that the Waste Isolation Pilot
Plant is in compliance with subpart A of this part;
(ii) Issuance of criteria for the certifications of compliance with
subparts B and C of this part of the Waste Isolation Pilot Plant's
compliance with subparts B and C of this part;
(iii) Certifications of compliance with subparts B and C of this
part of
[[Page 10]]
the Waste Isolation Pilot Plant's compliance with subparts B and C of
this part;
(iv) If the initial certification is made, periodic recertification
of the Waste Isolation Pilot Plant's continued compliance with subparts
B and C of this part;
(v) Review and comment on performance assessment reports of the
Waste Isolation Pilot Plant; and
(vi) Concurrence by the Agency with the Department's determination
under Sec. 191.02(i) that certain wastes do not need the degree of
isolation required by subparts B and C of this part; and
(3) The Department of Energy for any other disposal facility and all
other implementation responsibilities for the Waste Isolation Pilot
Plant, under this part, not given to the Agency.
International System of Units is the version of the metric system
which has been established by the International Bureau of Weights and
Measures and is administered in the United States by the National
Institute of Standards and Technology. The abbreviation for this system
is ``SI.''
Lithosphere means the solid part of the Earth below the surface,
including any ground water contained within it.
Passive institutional control means: (1) Permanent markers placed at
a disposal site, (2) public records and archives, (3) government
ownership and regulations regarding land or resource use, and (4) other
methods of preserving knowledge about the location, design, and contents
of a disposal system.
Performance assessment means an analysis that: (1) Identifies the
processes and events that might affect the disposal system; (2) examines
the effects of these processes and events on the performance of the
disposal system; and (3) estimates the cumulative releases of
radionuclides, considering the associated uncertainties, caused by all
significant processes and events. These estimates shall be incorporated
into an overall probability distribution of cumulative release to the
extent practicable.
Radioactive material means matter composed of or containing
radionuclides, with radiological half-lives greater than 20 years,
subject to the Atomic Energy Act of 1954, as amended.
SI unit means a unit of measure in the International System of
Units.
Sievert is the SI unit of effective dose and is equal to 100 rem or
one joule per kilogram. The abbreviation is ``Sv.''
Undisturbed performance means the predicted behavior of a disposal
system, including consideration of the uncertainties in predicted
behavior, if the disposal system is not disrupted by human intrusion or
the occurrence of unlikely natural events.
Waste, as used in this subpart, means any spent nuclear fuel or
radioactive waste isolated in a disposal system.
Waste form means the materials comprising the radioactive components
of waste and any encapsulating or stabilizing matrix.
[50 FR 38084, Sept. 19, 1985, as amended at 58 FR 66414, Dec. 20, 1993]
Sec. 191.13 Containment requirements.
(a) Disposal systems for spent nuclear fuel or high-level or
transuranic radioactive wastes shall be designed to provide a reasonable
expectation, based upon performance assessments, that the cumulative
releases of radionuclides to the accessible environment for 10,000 years
after disposal from all significant processes and events that may affect
the disposal system shall:
(1) Have a likelihood of less than one chance in 10 of exceeding the
quantities calculated according to Table 1 (appendix A); and
(2) Have a likelihood of less than one chance in 1,000 of exceeding
ten times the quantities calculated according to Table 1 (appendix A).
(b) Performance assessments need not provide complete assurance that
the requirements of Sec. 191.13(a) will be met. Because of the long
time period involved and the nature of the events and processes of
interest, there will inevitably be substantial uncertainties in
projecting disposal system performance. Proof of the future performance
of a disposal system is not to be had in the ordinary sense of the word
in situations that deal with much shorter time frames. Instead, what is
required is a reasonable expectation, on the basis of the record before
the implementing
[[Page 11]]
agency, that compliance with Sec. 191.13 (a) will be achieved.
Sec. 191.14 Assurance requirements.
To provide the confidence needed for long-term compliance with the
requirements of Sec. 191.13, disposal of spent nuclear fuel or high-
level or transuranic wastes shall be conducted in accordance with the
following provisions, except that these provisions do not apply to
facilities regulated by the Commission (see 10 CFR Part 60 for
comparable provisions applicable to facilities regulated by the
Commission):
(a) Active institutional controls over disposal sites should be
maintained for as long a period of time as is practicable after
disposal; however, performance assessments that assess isolation of the
wastes from the accessible environment shall not consider any
contributions from active institutional controls for more than 100 years
after disposal.
(b) Disposal systems shall be monitored after disposal to detect
substantial and detrimental deviations from expected performance. This
monitoring shall be done with techniques that do not jeopardize the
isolation of the wastes and shall be conducted until there are no
significant concerns to be addressed by further monitoring.
(c) Disposal sites shall be designated by the most permanent
markers, records, and other passive institutional controls practicable
to indicate the dangers of the wastes and their location.
(d) Disposal systems shall use different types of barriers to
isolate the wastes from the accessible environment. Both engineered and
natural barriers shall be included.
(e) Places where there has been mining for resources, or where there
is a reasonable expectation of exploration for scarce or easily
accessible resources, or where there is a significant concentration of
any material that is not widely available from other sources, should be
avoided in selecting disposal sites. Resources to be considered shall
include minerals, petroleum or natural gas, valuable geologic
formations, and ground waters that are either irreplaceable because
there is no reasonable alternative source of drinking water available
for substantial populations or that are vital to the preservation of
unique and sensitive eco systems. Such places shall not be used for
disposal of the wastes covered by this part unless the favorable char
acter is tics of such places com pen sate for their greater likelihood
of being dis turbed in the future.
(f) Disposal systems shall be selected so that removal of most of
the wastes is not precluded for a reasonable period of time after
disposal.
Sec. 191.15 Individual protection requirements.
(a) Disposal systems for waste and any associated radioactive
material shall be designed to provide a reasonable expectation that, for
10,000 years after disposal, undisturbed performance of the disposal
system shall not cause the annual committed effective dose, received
through all potential pathways from the disposal system, to any member
of the public in the accessible environment, to exceed 15 millirems (150
microsieverts).
(b) Annual committed effective doses shall be calculated in
accordance with appendix B of this part.
(c) Compliance assessments need not provide complete assurance that
the requirements of paragraph (a) of this section will be met. Because
of the long time period involved and the nature of the processes and
events of interest, there will inevitably be substantial uncertainties
in projecting disposal system performance. Proof of the future
performance of a disposal system is not to be had in the ordinary sense
of the word in situations that deal with much shorter time frames.
Instead, what is required is a reasonable expectation, on the basis of
the record before the implementing agency, that compliance with
paragraph (a) of this section will be achieved.
(d) Compliance with the provisions in this section does not negate
the necessity to comply with any other applicable Federal regulations or
requirements.
(e) The standards in this section shall be effective on January 19,
1994.
[58 FR 66414, Dec. 20, 1993]
[[Page 12]]
Sec. 191.16 Alternative provisions for disposal.
The Administrator may, by rule, substitute for any of the provisions
of subpart B alternative provisions chosen after:
(a) The alternative provisions have been proposed for public comment
in the Federal Register together with information describing the costs,
risks, and benefits of disposal in accordance with the alternative
provisions and the reasons why compliance with the existing provisions
of Subpart B appears inappropriate;
(b) A public comment period of at least 90 days has been completed,
during which an opportunity for public hearings in affected areas of the
country has been provided; and
(c) The public comments received have been fully considered in
developing the final version of such alternative provisions.
[50 FR 38084, Sept. 19, 1985. Redesignated at 58 FR 66414, Dec. 20,
1993]
Sec. 191.17 Effective date.
The standards in this subpart shall be effective on November 18,
1985.
[50 FR 38084, Sept. 19, 1985; 50 FR 40003, Oct. 1, 1985. Redesignated at
58 FR 66414, Dec. 20, 1993]
Subpart C_Environmental Standards for Ground-Water Protection
Source: 58 FR 66415, Dec. 20, 1993, unless otherwise noted.
Sec. 191.21 Applicability.
(a) This subpart applies to:
(1) Radiation doses received by members of the public as a result of
activities subject to subpart B of this part; and
(2) Radioactive contamination of underground sources of drinking
water in the accessible environment as a result of such activities.
(b) This subpart does not apply to:
(1) Disposal directly into the oceans or ocean sediments;
(2) Wastes disposed of before the effective date of this subpart;
and
(3) The characterization, licensing, construction, operation, or
closure of any site required to be characterized under section 113(a) of
Public Law 97-425, 96 Stat. 2201.
Sec. 191.22 Definitions.
Unless otherwise indicated in this subpart, all terms have the same
meaning as in subparts A and B of this part.
Public water system means a system for the provision to the public
of piped water for human consumption, if such system has at least
fifteen service connections or regularly serves at least twenty-five
individuals. Such term includes:
(1) Any collection, treatment, storage, and distribution facilities
under control of the operator of such system and used primarily in
connection with such system; and
(2) Any collection or pretreatment storage facilities not under such
control which are used primarily in connection with such system.
Total dissolved solids means the total dissolved (filterable) solids
in water as determined by use of the method specified in 40 CFR part
136.
Underground source of drinking water means an aquifer or its portion
which:
(1) Supplies any public water system; or
(2) Contains a sufficient quantity of ground water to supply a
public water system; and
(i) Currently supplies drinking water for human consumption; or
(ii) Contains fewer than 10,000 milligrams of total dissolved solids
per liter.
Sec. 191.23 General provisions.
(a) Determination of compliance with this subpart shall be based
upon underground sources of drinking water which have been identified on
the date the implementing agency determines compliance with subpart C of
this part.
(b) [Reserved]
Sec. 191.24 Disposal standards.
(a) Disposal systems.
(1) General. Disposal systems for waste and any associated
radioactive material shall be designed to provide a reasonable
expectation that 10,000 years of undisturbed performance after disposal
shall not cause the levels of radioactivity in any underground
[[Page 13]]
source of drinking water, in the accessible environment, to exceed the
limits specified in 40 CFR part 141 as they exist on January 19, 1994.
(2) Disposal systems above or within a formation which within one-
quarter (\1/4\) mile contains an underground source of drinking water.
[Reserved]
(b) Compliance assessments need not provide complete assurance that
the requirements of paragraph (a) of this section will be met. Because
of the long time period involved and the nature of the processes and
events of interest, there will inevitably be substantial uncertainties
in projecting disposal system performance. Proof of the future
performance of a disposal system is not to be had in the ordinary sense
of the word in situations that deal with much shorter time frames.
Instead, what is required is a reasonable expectation, on the basis of
the record before the implementing agency, that compliance with
paragraph (a) of this section will be achieved.
Sec. 191.25 Compliance with other Federal regulations.
Compliance with the provisions in this subpart does not negate the
necessity to comply with any other applicable Federal regulations or
requirements.
Sec. 191.26 Alternative provisions.
The Administrator may, by rule, substitute for any of the provisions
of this subpart alternative provisions chosen after:
(a) The alternative provisions have been proposed for public comment
in the Federal Register together with information describing the costs,
risks, and benefits of disposal in accordance with the alternative
provisions and the reasons why compliance with the existing provisions
of this subpart appears inappropriate;
(b) A public comment period of at least 90 days has been completed,
during which an opportunity for public hearings in affected areas of the
country has been provided; and
(c) The public comments received have been fully considered in
developing the final version of such alternative provisions.
Sec. 191.27 Effective date.
The standards in this subpart shall be effective on January 19,
1994.
Appendix A to Part 191--Table for Subpart B
Table 1--Release Limits for Containment Requirements
[Cumulative releases to the accessible environment for 10,000 years
after disposal]
------------------------------------------------------------------------
Release
limit per
1,000
MTHM or
other
Radionuclide unit of
waste
(see
notes)
(curies)
------------------------------------------------------------------------
Americium-241 or -243........................................ 100
Carbon-14.................................................... 100
Cesium-135 or -137........................................... 1,000
Iodine-129................................................... 100
Neptunium-237................................................ 100
Plutonium-238, -239, -240, or -242........................... 100
Radium-226................................................... 100
Strontium-90................................................. 1,000
Technetium-99................................................ 10,000
Thorium-230 or -232.......................................... 10
Tin-126...................................................... 1,000
Uranium-233, -234, -235, -236, or -238....................... 100
Any other alpha-emitting radionuclide with a half-life 100
greater than 20 years.......................................
Any other radionuclide with a half-life greater than 20 years 1,000
that does not emit alpha particles..........................
------------------------------------------------------------------------
Application of Table 1
Note 1: Units of Waste. The Release Limits in Table 1 apply to the
amount of wastes in any one of the following:
(a) An amount of spent nuclear fuel containing 1,000 metric tons of
heavy metal (MTHM) exposed to a burnup between 25,000 megawatt-days per
metric ton of heavy metal (MWd/MTHM) and 40,000 MWd/MTHM;
(b) The high-level radioactive wastes generated from reprocessing
each 1,000 MTHM exposed to a burnup between 25,000 MWd/MTHM and 40,000
MWd/MTHM;
(c) Each 100,000,000 curies of gamma or beta-emitting radionuclides
with half-lives greater than 20 years but less than 100 years (for use
as discussed in Note 5 or with materials that are identified by the
Commission as high-level radioactive waste in accordance with part B of
the definition of high-level waste in the NWPA);
(d) Each 1,000,000 curies of other radionuclides (i.e., gamma or
beta-emitters with half-lives greater than 100 years or any alpha-
emitters with half-lives greater than 20 years) (for use as discussed in
Note 5 or with materials that are identified by the Commission as high-
level radioactive waste in accordance with part B of the definition of
high-level waste in the NWPA); or
[[Page 14]]
(e) An amount of transuranic (TRU) wastes containing one million
curies of alpha-emitting transuranic radionuclides with half-lives
greater than 20 years.
Note 2: Release Limits for Specific Disposal Systems. To develop
Release Limits for a particular disposal system, the quantities in Table
1 shall be adjusted for the amount of waste included in the disposal
system compared to the various units of waste defined in Note 1. For
example:
(a) If a particular disposal system contained the high-level wastes
from 50,000 MTHM, the Release Limits for that system would be the
quantities in Table 1 multiplied by 50 (50,000 MTHM divided by 1,000
MTHM).
(b) If a particular disposal system contained three million curies
of alpha-emitting transuranic wastes, the Release Limits for that system
would be the quantities in Table 1 multiplied by three (three million
curies divided by one million curies).
(c) If a particular disposal system contained both the high-level
wastes from 50,000 MTHM and 5 million curies of alpha-emitting
transuranic wastes, the Release Limits for that system would be the
quantities in Table 1 multiplied by 55:
[GRAPHIC] [TIFF OMITTED] TC11NO91.000
Note 3: Adjustments for Reactor Fuels with Different Burnup. For
disposal systems containing reactor fuels (or the high-level wastes from
reactor fuels) exposed to an average burnup of less than 25,000 MWd/MTHM
or greater than 40,000 MWd/MTHM, the units of waste defined in (a) and
(b) of Note 1 shall be adjusted. The unit shall be multiplied by the
ratio of 30,000 MWd/MTHM divided by the fuel's actual average burnup,
except that a value of 5,000 MWd/MTHM may be used when the average fuel
burnup is below 5,000 MWd/MTHM and a value of 100,000 MWd/MTHM shall be
used when the average fuel burnup is above 100,000 MWd/MTHM. This
adjusted unit of waste shall then be used in determining the Release
Limits for the disposal system.
For example, if a particular disposal system contained only high-
level wastes with an average burnup of 3,000 MWd/MTHM, the unit of waste
for that disposal system would be:
[GRAPHIC] [TIFF OMITTED] TC11NO91.001
If that disposal system contained the high-level wastes from 60,000
MTHM (with an average burnup of 3,000 MWd/MTHM), then the Release Limits
for that system would be the quantities in Table 1 multiplied by ten:
[GRAPHIC] [TIFF OMITTED] TC11NO91.002
which is the same as:
[GRAPHIC] [TIFF OMITTED] TC11NO91.003
Note 4: Treatment of Fractionated High-Level Wastes. In some cases,
a high-level waste stream from reprocessing spent nuclear fuel may have
been (or will be) separated into two or more high-level waste components
destined for different disposal systems. In such cases, the implementing
agency may allocate the Release Limit multiplier (based upon the
original MTHM and the average fuel burnup of the high-level waste
stream) among the various disposal systems as it chooses, provided that
the total Release Limit multiplier used for that waste stream at all of
its disposal systems may not exceed the Release Limit multiplier that
would be used if the entire waste stream were disposed of in one
disposal system.
Note 5: Treatment of Wastes with Poorly Known Burnups or Original
MTHM. In some cases, the records associated with particular high-level
waste streams may not be adequate to accurately determine the original
metric tons of heavy metal in the reactor fuel that created the waste,
or to determine the average burnup that the fuel was exposed to. If the
uncertainties are such that the original amount of heavy metal or the
average fuel burnup for particular high-level waste streams cannot be
quantified, the units of waste derived from (a) and (b) of Note 1 shall
no longer be used. Instead, the units of waste defined in (c) and (d) of
Note 1 shall be used for such high-level waste streams. If the
uncertainties in such information allow a range of values to be
associated with the original amount of heavy metal or the average fuel
burnup, then the calculations described in previous Notes will be
conducted using the values that result in the smallest Release Limits,
except that the Release Limits need not be smaller than those that would
be calculated using the units of waste defined in (c) and (d) of Note 1.
Note 6: Uses of Release Limits to Determine Compliance with Sec.
191.13 Once release limits for a particular disposal system have been
determined in accordance with Notes 1 through 5, these release limits
shall be used to determine compliance with the requirements of Sec.
191.13 as follows. In cases where a mixture of radionuclides is
projected to be released to the accessible environment, the limiting
values shall be determined as follows: For each radionuclide in the
mixture, determine the ratio between the cumulative release quantity
projected over 10,000 years
[[Page 15]]
and the limit for that radionuclide as determined from Table 1 and Notes
1 through 5. The sum of such ratios for all the radionuclides in the
mixture may not exceed one with regard to Sec. 191.13(a)(1) and may not
exceed ten with regard to Sec. 191.13(a)(2).
For example, if radionuclides A, B, and C are projected to be
released in amounts Q<INF>a</INF>, Q<INF>b</INF>, and Q<INF>c</INF>, and
if the applicable Release Limits are RL<INF>a</INF>, RL<INF>b</INF>, and
RL<INF>c</INF>, then the cumulative releases over 10,000 years shall be
limited so that the following relationship exists:
[GRAPHIC] [TIFF OMITTED] TC11NO91.004
[50 FR 38084, Sept. 19, 1985, as amended at 58 FR 66415, Dec. 20, 1993]
Appendix B to Part 191--Calculation of Annual Committed Effective Dose
I. Equivalent Dose
The calculation of the committed effective dose (CED) begins with
the determination of the equivalent dose, H<INF>T</INF>, to a tissue or
organ, T, listed in Table B.2 below by using the equation:
[GRAPHIC] [TIFF OMITTED] TR20DE93.009
where D<INF>T, R</INF> is the absorbed dose in rads (one gray, an SI
unit, equals 100 rads) averaged over the tissue or organ, T, due to
radiation type, R, and w<INF>R</INF> is the radiation weighting factor
which is given in Table B.1 below. The unit of equivalent dose is the
rem (sievert, in SI units).
Table B.1--Radiation Weighting Factors, wR\1\
------------------------------------------------------------------------
wR
Radiation type and energy range \2\ value
------------------------------------------------------------------------
Photons, all energies........................................... 1
Electrons and muons, all energies............................... 1
Neutrons, energy < 10 keV....................................... 5
10 keV to 100 keV..................................... 10
<ls-thn-eq>100 keV to 2 MeV........................... 20
<ls-thn-eq>2 MeV to 20 MeV............................ 10
<ls-thn-eq>20 MeV..................................... 5
Protons, other than recoil protons, <ls-thn-eq>2 MeV............ 5
Alpha particles, fission fragments, heavy nuclei................ 20
------------------------------------------------------------------------
\1\ All values relate to the radiation incident on the body or, for
internal sources, emitted from the source.
\2\ See paragraph A14 in ICRP Publication 60 for the choice of values
for other radiation types and energies not in the table.
II. Effective Dose
The next step is the calculation of the effective dose, E. The
probability of occurrence of a stochastic effect in a tissue or organ is
assumed to be proportional to the equivalent dose in the tissue or
organ. The constant of proportionality differs for the various tissues
of the body, but in assessing health detriment the total risk is
required. This is taken into account using the tissue weighting factors,
w<INF>T</INF> in Table B.2, which represent the proportion of the
stochastic risk resulting from irradiation of the tissue or organ to the
total risk when the whole body is irradiated uniformly and H<INF>T</INF>
is the equivalent dose in the tissue or organ, T, in the equation:
[GRAPHIC] [TIFF OMITTED] TR20DE93.010
Table B.2--Tissue Weighting Factors, wT \1\
------------------------------------------------------------------------
Tissue or organ wT value
------------------------------------------------------------------------
Gonads.................................................. 0.25
Breast.................................................. 0.15
Red bone marrow......................................... 0.12
Lung.................................................... 0.12
Thyroid................................................. 0.03
Bone surfaces........................................... 0.03
Remainder............................................... \2\ 0.30
------------------------------------------------------------------------
\1\ The values are considered to be appropriate for protection for
individuals of both sexes and all ages.
\2\ For purposes of calculation, the remainder is comprised of the five
tissues or organs not specifically listed in Table B.2 that receive
the highest dose equivalents; a weighting factor of 0.06 is applied to
each of them, including the various sections of the gastrointestinal
tract which are treated as separate organs. This covers all tissues
and organs except the hands and forearms, the feet and ankles, the
skin and the lens of the eye. The excepted tissues and organs should
be excluded from the computation of HE.
III. Annual Committed Tissue or Organ Equivalent Dose
For internal irradiation from incorporated radionuclides, the total
absorbed dose will be spread out in time, being gradually delivered as
the radionuclide decays. The time distribution of the absorbed dose rate
will vary with the radionuclide, its form, the mode of intake and the
tissue within which it is incorporated. To take account of this
distribution the quantity committed equivalent dose, H[Tau]([tau]) where
is the integration time in years following an intake over any particular
year, is used and is the integral over time of the equivalent dose rate
in a particular tissue or organ that will be received by an individual
following an intake of radioactive material into the body. The time
period, [tau], is taken as 50 years as an average time of exposure
following intake:
[GRAPHIC] [TIFF OMITTED] TR20DE93.011
for a single intake of activity at time t<INF>0</INF> where
H<INF>T</INF>(t) is the relevant equivalent-dose rate in a tissue or
organ at time t. For the purposes of this part, the previously mentioned
single intake may be considered to be an annual intake.
[[Page 16]]
IV. Annual Committed Effective Dose
If the committed equivalent doses to the individual tissues or
organs resulting from an annual intake are multiplied by the appropriate
weighting factors, w<INF>T</INF>, and then summed, the result will be
the annual committed effective dose, E([tau]):
[GRAPHIC] [TIFF OMITTED] TR20DE93.012
[58 FR 66415, Dec. 20, 1993]
Appendix C to Part 191--Guidance for Implementation of Subpart B
[Note: The supplemental information in this appendix is not an
integral part of 40 CFR part 191. Therefore, the implementing agencies
are not bound to follow this guidance. However, it is included because
it describes the Agency's assumptions regarding the implementation of
subpart B. This appendix will appear in the Code of Federal
Regulations.]
The Agency believes that the implementing agencies must determine
compliance with Sec. Sec. 191.13, 191.15, and 191.16 of subpart B by
evaluating long-term predictions of disposal system performance.
Determining compliance with Sec. 191.13 will also involve predicting
the likelihood of events and processes that may disturb the disposal
system. In making these various predictions, it will be appropriate for
the implementing agencies to make use of rather complex computational
models, analytical theories, and prevalent expert judgment relevant to
the numerical predictions. Substantial uncertainties are likely to be
encountered in making these predictions. In fact, sole reliance on these
numerical predictions to determine compliance may not be appropriate;
the implementing agencies may choose to supplement such predictions with
qualitative judgments as well. Because the procedures for determining
compliance with subpart B have not been formulated and tested yet, this
appendix to the rule indicates the Agency's assumptions regarding
certain issues that may arise when implementing Sec. Sec. 191.13,
191.15, and 191.16. Most of this guidance applies to any type of
disposal system for the wastes covered by this rule. However, several
sections apply only to disposal in mined geologic repositories and would
be inappropriate for other types of disposal systems.
Consideration of Total Disposal System. When predicting disposal
system performance, the Agency assumes that reasonable projections of
the protection expected from all of the engineered and natural barriers
of a disposal system will be considered. Portions of the disposal system
should not be disregarded, even if projected performance is uncertain,
except for portions of the system that make negligible contributions to
the overall isolation provided by the disposal system.
Scope of Performance Assessments. Section 191.13 requires the
implementing agencies to evaluate compliance through performance
assessments as defined in Sec. 191.12(q). The Agency assumes that such
performance assessments need not consider categories of events or
processes that are estimated to have less than one chance in 10,000 of
occurring over 10,000 years. Furthermore, the performance assessments
need not evaluate in detail the releases from all events and processes
estimated to have a greater likelihood of occurrence. Some of these
events and processes may be omitted from the performance assessments if
there is a reasonable expectation that the remaining probability
distribution of cumulative releases would not be significantly changed
by such omissions.
Compliance with Sec. 191.13. The Agency assumes that, whenever
practicable, the implementing agency will assemble all of the results of
the performance assessments to determine compliance with Sec. 191.13
into a ``complementary cumulative distribution function'' that indicates
the probability of exceeding various levels of cumulative release. When
the uncertainties in parameters are considered in a performance
assessment, the effects of the uncertainties considered can be
incorporated into a single such distribution function for each disposal
system considered. The Agency assumes that a disposal system can be
considered to be in compliance with Sec. 191.13 if this single
distribution function meets the requirements of Sec. 191.13(a).
Compliance with Sec. Sec. 191.15 and 191.16. When the uncertainties
in undisturbed performance of a disposal system are considered, the
implementing agencies need not require that a very large percentage of
the range of estimated radiation exposures or radionuclide
concentrations fall below limits established in Sec. Sec. 191.15 and
191.16, respectively. The Agency assumes that compliance can be
determined based upon ``best estimate'' predictions (e.g., the mean or
the median of the appropriate distribution, whichever is higher).
Institutional Controls. To comply with Sec. 191.14(a), the
implementing agency will assume that none of the active institutional
controls prevent or reduce radionuclide releases for more than 100 years
after disposal. However, the Federal Government is committed to
retaining ownership of all disposal sites for spent nuclear fuel and
high-level and transuranic radioactive wastes and will establish
appropriate markers and records, consistent with Sec. 191.14(c). The
Agency assumes that, as long as such passive institutional controls
endure and are understood, they: (1) Can be effective in deterring
systematic or persistent exploitation of these
[[Page 17]]
disposal sites; and (2) can reduce the likelihood of inadvertent,
intermittent human intrusion to a degree to be determined by the
implementing agency. However, the Agency believes that passive
institutional controls can never be assumed to eliminate the chance of
inadvertent and intermittent human intrusion into these disposal sites.
Consideration of Inadvertent Human Intrusion into Geologic
Repositories. The most speculative potential disruptions of a mined
geologic repository are those associated with inadvertent human
intrusion. Some types of intrusion would have virtually no effect on a
repository's containment of waste. On the other hand, it is possible to
conceive of intrusions (involving widespread societal loss of knowledge
regarding radioactive wastes) that could result in major disruptions
that no reasonable repository selection or design precautions could
alleviate. The Agency believes that the most productive consideration of
inadvertent intrusion concerns those realistic possibilities that may be
usefully mitigated by repository design, site selection, or use of
passive controls (although passive institutional controls should not be
assumed to completely rule out the possibility of intrusion). Therefore,
inadvertent and intermittent intrusion by exploratory drilling for
resources (other than any provided by the disposal system itself) can be
the most severe intrusion scenario assumed by the implementing agencies.
Furthermore, the implementing agencies can assume that passive
institutional controls or the intruders' own exploratory procedures are
adequate for the intruders to soon detect, or be warned of, the
incompatibility of the area with their activities.
Frequency and Severity of Inadvertent Human Intrusion into Geologic
Repositories. The implementing agencies should consider the effects of
each particular disposal system's site, design, and passive
institutional controls in judging the likelihood and consequences of
such inadvertent exploratory drilling. However, the Agency assumes that
the likelihood of such inadvertent and intermittent drilling need not be
taken to be greater than 30 boreholes per square kilometer of repository
area per 10,000 years for geologic repositories in proximity to
sedimentary rock formations, or more than 3 boreholes per square
kilometer per 10,000 years for repositories in other geologic
formations. Furthermore, the Agency assumes that the consequences of
such inadvertent drilling need not be assumed to be more severe than:
(1) Direct release to the land surface of all the ground water in the
repository horizon that would promptly flow through the newly created
borehole to the surface due to natural lithostatic pressure--or (if
pumping would be required to raise water to the surface) release of 200
cubic meters of ground water pumped to the surface if that much water is
readily available to be pumped; and (2) creation of a ground water flow
path with a permeability typical of a borehole filled by the soil or
gravel that would normally settle into an open hole over time--not the
permeability of a carefully sealed borehole.
[50 FR 38084, Sept. 19, 1985. Redesignated and amended at 58 FR 66415,
Dec. 20, 1993]