[Code of Federal Regulations]
[Title 40, Volume 22]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR192.20]

[Page 23-25]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 192--HEALTH AND ENVIRONMENTAL PROTECTION STANDARDS FOR URANIUM AND THORIUM 
MILL TAILINGS--Table of Contents
 
                        Subpart C--Implementation
 
Sec. 192.20  Guidance for implementation.


    Section 108 of the Act requires the Secretary of Energy to select 
and perform remedial actions with the concurrence of the Nuclear 
Regulatory Commission and the full participation of any State that pays 
part of the cost, and in consultation, as appropriate, with affected 
Indian Tribes and the Secretary of the Interior. These parties, in their 
respective roles under section 108, are referred to hereafter as ``the 
implementing agencies.'' The implementing agencies shall establish 
methods and procedures to provide ``reasonable assurance'' that the 
provisions of Subparts A and B are satisfied. This should be done as 
appropriate through use of analytic models and site-specific analyses, 
in the case of Subpart A, and for Subpart B through measurements 
performed within the accuracy of currently available types of field and 
laboratory instruments in conjunction with reasonable survey and 
sampling procedures. These methods and procedures may be varied to suit 
conditions at specific sites. In particular:
    (a)(1) The purpose of Subpart A is to provide for long-term 
stabilization and isolation in order to inhibit misuse and spreading of 
residual radioactive materials, control releases of radon to air, and 
protect water. Subpart A may be implemented through analysis of the 
physical properties of the site and the control system and projection of 
the effects of natural processes over time. Events and processes that 
could significantly affect the average radon release rate from the 
entire disposal site should be considered. Phenomena that are localized 
or temporary, such as local cracking or burrowing of rodents, need to be 
taken into account only if their cumulative effect would be significant 
in determining compliance with the standard. Computational models, 
theories, and prevalent expert judgment may be used to decide that a 
control system design will satisfy the standard. The numerical range 
provided in the standard for the longevity of the effectiveness of the 
control of residual radioactive materials allows for consideration of 
the various factors affecting the longevity of control and stabilization 
methods and their costs. These factors have different levels of 
predictability and may vary for the different sites.
    (2) Protection of water should be considered on a case-specific 
basis, drawing on hydrological and geochemical surveys and all other 
relevant data. The hydrologic and geologic assessment to be conducted at 
each site should include a monitoring program sufficient to establish 
background groundwater quality through one or more upgradient or other 
appropriately located wells. The groundwater monitoring list in Appendix 
IX of part 264 of this chapter (plus the additional constituents in 
Table A of this paragraph) may be used for screening purposes in place 
of Appendix I of part 192 in the monitoring program. New depository 
sites for tailings that contain water at greater than the level of 
``specific retention'' should use aliner or equivalent. In considering 
design objectives for groundwater protection, the implementing agencies 
should give priority to concentration levels in the order listed under 
Sec. 192.02(c)(3)(i). When considering the potential for health risks 
caused by human exposure to known or suspected carcinogens, alternate 
concentration limits pursuant to paragraph 192.02(c)(3)(ii) should be 
established at concentration levels which represent an excess lifetime 
risk, at a point of exposure, to an average individual no greater than 
between 10-4 and 10-6.

      Table A to Sec.  192.20(a)(2)--Additional Listed Constituents
Nitrate (as N)
Molybdenum
Combined radium-226 and radium-228
Combined uranium-234 and uranium-238
Gross alpha-particle activity (excluding radon and uranium)


    (3) The plan for remedial action, concurred in by the Commission, 
will specify how applicable requirements of subpart A are to be 
satisfied. The plan

[[Page 24]]

should include the schedule and steps necessary to complete disposal 
operations at the site. It should include an estimate of the inventory 
of wastes to be disposed of in the pile and their listed constituents 
and address any need to eliminate free liquids; stabilization of the 
wastes to a bearing capacity sufficient to support the final cover; and 
the design and engineering specifications for a cover to manage the 
migration of liquids through the stabilized pile, function without 
maintenance, promote drainage and minimize erosion or abrasion of the 
cover, and accommodate settling and subsidence so that cover integrity 
is maintained. Evaluation of proposed designs to conform to subpart A 
should be based on realistic technical judgments and include use of 
available empirical information. The consideration of possible failure 
modes and related corrective actions should be limited to reasonable 
failure assumptions, with a demonstration that the disposal design is 
generally amenable to a range of corrective actions.
    (4) The groundwater monitoring list in Appendix IX of part 264 of 
this chapter (plus the additional constituents in Table A in paragraph 
(a)(2) of this section) may be used for screening purposes in place of 
Appendix I of part 192 in monitoring programs. The monitoring plan 
required under Sec. 192.03 should be designed to include verification of 
site-specific assumptions used to project the performance of the 
disposal system. Prevention of contamination of groundwater may be 
assessed by indirect methods, such as measuring the migration of 
moisture in the various components of the cover, the tailings, and the 
area between the tailings and the nearest aquifer, as well as by direct 
monitoring of groundwater. In the case of vicinity properties 
(Sec. 192.01(l)(2)), such assessments may not be necessary, as 
determined by the Secretary, with the concurrence of the Commission, 
considering such factors as local geology and the amount of 
contamination present. Temporary excursions from applicable limits of 
groundwater concentrations that are attributable to a disposal operation 
itself shall not constitute a basis for considering corrective action 
under Sec. 192.04 during the disposal period, unless the disposal 
operation is suspended prior to completion for other than seasonal 
reasons.
    (b)(1) Compliance with Sec. 192.12(a) and (b) of subpart B, to the 
extent practical, should be demonstrated through radiation surveys. Such 
surveys may, if appropriate, be restricted to locations likely to 
contain residual radioactive materials. These surveys should be designed 
to provide for compliance averaged over limited areas rather than point-
by-point compliance with the standards. In most cases, measurement of 
gamma radiation exposure rates above and below the land surface can be 
used to show compliance with Sec. 192.12(a). Protocols for making such 
measurements should be based on realistic radium distributions near the 
surface rather than extremes rarely encountered.
    (2) In Sec. 192.12(a), ``background level'' refers to the native 
radium concentration in soil. Since this may not be determinable in the 
presence of contamination by residual radioactive materials, a surrogate 
``background level'' may be established by simple direct or indirect 
(e.g., gamma radiation) measurements performed nearby but outside of the 
contaminated location.
    (3) Compliance with Sec. 192.12(b) may be demonstrated by methods 
that the Department of Energy has approved for use under Pub. L. 92-314 
(10 CFR part 712), or by other methods that the implementing agencies 
determine are adequate. Residual radioactive materials should be removed 
from buildings exceeding 0.03 WL so that future replacement buildings 
will not pose a hazard [unless removal is not practical--see 
Sec. 192.21(c)]. However, sealants, filtration, and ventilation devices 
may provide reasonable assurance of reductions from 0.03 WL to below 
0.02 WL. In unusual cases, indoor radiation may exceed the levels 
specified in Sec. 192.12(b) due to sources other than residual 
radioactive materials. Remedial actions are not required in order to 
comply with the standard when there is reasonable assurance that 
residual radioactive materials are not the cause of such an excess.

[[Page 25]]

    (4) The plan(s) for remedial action will specify how applicable 
requirements of subpart B would be satisfied. The plan should include 
the schedule and steps necessary to complete the cleanup of groundwater 
at the site. It should document the extent of contamination due to 
releases prior to final disposal, including the identification and 
location of listed constituents and the rate and direction of movement 
of contaminated groundwater, based upon the monitoring carried out under 
Sec. 192.12(c)(1). In addition, the assessment should consider future 
plume movement, including an evaluation of such processes as attenuation 
and dilution and future contamination from beneath a disposal site. 
Monitoring for assessment and compliance purposes should be sufficient 
to establish the extent and magnitude of contamination, with reasonable 
assurance, through use of a carefully chosen minimal number of sampling 
locations. The location and number of monitoring wells, the frequency 
and duration of monitoring, and the selection of indicator analytes for 
long-term groundwater monitoring, and, more generally, the design and 
operation of the monitoring system, will depend on the potential for 
risk to receptors and upon other factors, including characteristics of 
the subsurface environment, such as velocity of groundwater flow, 
contaminant retardation, time of groundwater or contaminant transit to 
receptors, results of statistical evaluations of data trends, and 
modeling of the dynamics of the groundwater system. All of these factors 
should be incorporated into the design of a site-specific monitoring 
program that will achieve the purpose of the regulations in this subpart 
in the most cost-effective manner. In the case of vicinity properties 
(Sec. 192.01(l)(2)), such assessments will usually not be necessary. The 
Secretary, with the concurrence of the Commission, may consider such 
factors as local geology and amount of contamination present in 
determining criteria to decide when such assessments are needed. In 
cases where Sec. 192.12(c)(2) is invoked, the plan should include a 
monitoring program sufficient to verify projections of plume movement 
and attenuation periodically during the extended cleanup period. 
Finally, the plan should specify details of the method to be used for 
cleanup of groundwater.

[48 FR 602, Jan. 5, 1983, as amended at 60 FR 2867, Jan. 11, 1995]