ML20207N822
| ML20207N822 | |
| Person / Time | |
|---|---|
| Issue date: | 09/30/1987 |
| From: | NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | |
| References | |
| REF-WM-3 NUDOCS 8810190383 | |
| Download: ML20207N822 (22) | |
Text
)OM o
m 9
f m
ORAFT FOR COMMENT UNITEDSTATESNUCL$ARREGULATORYCOMMIS$10N DIVISION OF LOW LEVEL WASTE MANAGEMENT AND DECOMMISSIONING TECHNICAL BRANCH TECHNICAL POSITION PAPER ENVIRONMENTAL MONITORING OF LOW-LEVEL RACI0 ACTIVE WASTE DISPOSAL FACILITIES 8010190303 070930
^
\\
[@R PN')
-3 l p> 4,l.17 wM-3.
e
^)
.)
,s.c TABLE OF CONTENTS Page 1
INTRODUCTION...............................................
1 l
1.1 Background............................................
1
1.2 Purpose and Scope
1 2
ENVIRONMENTAL MONITORING PROGRAM OBJECTIVES.................
2 2.1 Primary Objective.....................................
2 2.2 Supporting Technical Objectives.......................
3 3
ENVIRONMENTAL MONITORING PROGRAM PHASES....................
5 3.1 Preoperational Phase..................................
5 3.2 Operational Phase.....................................
8 3.3 Postoperational Phase.................................
8 4
PATHWAY AND CONSTITUENT MONITORING.........................
9 4.1 Monitoring Specific Pathways..........................
9 4.2 Monitoring Constituent Leve1s..........................
19 5
OTH E R P ROG RAM COMP ON E N T S...................................
22 5.1 Quality Control Program...............................
22 5.2 Maintenance and Decommissioning of Monitoring Equipment 23 6
SUMMARY
24 7
REFERENCES.................................................
25 i
LLW ENVRNMNT MNTR BTP/$EPT 87
-)')
') )
1 INTRODUCTION 1.1 Backaround The Atomic Er.ergy Act of 1954 and the Energy Reorganization Act of 1974 give the U.S. Nuclear Regulatory Commission (NRC) the responsibility for licensing and regulating commercial nuclear facilities.
The Itcensing requirements for near-surface disposal of low-level radioactive wastes are in Part 61 of Title 10 of the Code of Federal Regulations (10 CFR 61). The NRC is also responsible for ensuring compliance with the provisions of the National Environmental PolicyAct(NEpA)of1969. The licensing requirements related to environmental protection are in 10 CFR 51.
With passage of the Low-level Radioactive Waste Policy Amendments Act of 1986, Congrsss improved procedures for the implementation of interstate compacts, subject to congressional approval, for the purpose of estabitshing and l
operating reolanal low-level radioactive waste sites. The NRC is aware that initial steps have been taken that will lead to the develooment of new sites' for such disposal. To provide timely assistance in this process, the NRC is issuing this technical position paper on environmental monitoring programs for near surface low-level radioactive waste disposal facilities utilizing shallow land burial.
l
1.2 Purpose and Scope
The purpose of this paper is to provide guidance, developed in accordance with 10 CFR 61, to applicants, licensees, and regulatory authorities with respect to the monitoring of low-level waste disposal facilities.
This document presents the Division of Low-Level Waste Management and Decommissioning (LLWN) T6chnical Branch staff'< opinion on technical requirements for site environmental monitoring.
It presents a rationale for the need and use of the types of monitoring suggested.
This guidance will facilitate interaction with the NRC in the design, construction, operation, and closure of new and existing 1
LLW ENVRNMNT MNTR BTP/ SEPT 87 F
u
,,. [
};
l) -
,l g.
(b) The licensee must have plans for taking corrective measures if migration of radionuclides would indicate that the performance objectives of Subpart C may not be met.
(c) 0! ring the land disposal facility site construction and operation, the licensee shall maintain a monitoring program. Measurements and observations must be made and recorded to provide data to evaluate the potential health and environmental impacts during both the construction and the operation of the facility and to enable the evaluation of long-term effects and the need for mitigative measures.
The monitoring system must be capable of providing early warning of releases of radionuclides from the disposal site before they leave the site boundary.
(d) After the disposal site is closed, the licensee responsible for postoperational surveillance of the disposal site shall maintain a monitoring system based on the operating history and the closure and stabilization of the disposal site.
The monitoring system must be capable of providing early warning of releases of radionuclides from the disposal site before they leave the site boundary.
In summary, supporting technical objectives encompassed in the above regulations are to:
(1) Characterize the site and processes affecting releases.
)
(2) Establish a statistical data base for environmental parameters.
i (3) Assess environmental impacts.
(4) Develop plans for taking corrective actions if the performance objectives in 10 CFR 61, Subpart C are not met.
i l
(5) Detect radiological and nonradiological nenhazardous releases from waste disposal areas before they reach the site boundaries.
i l
4 LLW ENVRNMNT MNTR BTP/ SEPT 87 l
i
'g
- \\
g.
t'he physical system and to add to the existing data base from which action levels are established. The preoperational monitoring program should be developed so that all media sampling devices are operating concurrently during the minimum one year period, regardless of whether certain devices were operating for site characterization purposes to support site selection.
To the extent practicable, preoperational monitoring stations should be located so that (1) they will not have to be decommissioned during site operations, (2) they will continue to provide useful data during the operational and postoperational phases of site life, and (3) preoperational and postoperational levels can be compared. Furthermore, the monitoring stations should not be located in disturbed areas that will affect the monitoring results.
Continuous media sampling for characterizing background levels of airborne constituents or direct gamma radiation is not necessary wnen the nature of potential releases from low-level radioactive waste disposal facilities is ceing considered. Discrete sampling is preferred for cedia that may be affected by random climatological events (e.g., surface-water quantity and quality). The minimal scope of analysis should include major radiological and nonradiological indicators, but may be more elaborate depending on site-specific conditions.
Existing data that are considered reliable can also be used to establish basaline conditions.
Action Levels An action level is defined as the concentration of a specific radionuclide or chemical indicator above which additional monitoring or some mitigative action is required. Action levels should be related to background concentrations or regulatory limits for the particular media.
The applicant should, when possible, test for parametric statistical characteristics so that proposed, statistically-based action levels are meaningful.
For instance, for constituents possessing parametric statistical characteristics, an action level might be set at two standard deviations above the background mean.
Nonparametric statistical analysis could also be employed to evaluate seasonality and/or natural trends of concentrations, both of which are important when setting action levels. Another means of setting action levels 6
LLW ENVRNMNT MNTR BTp/ SEPT 87
}
]
.s.
3.2 Operational Phase Operational monitoring should emphasize the measurement of short-term releases of radioactivity in quantities and concentrations that either present an immediate health and safety problem or create the likelihood of a future problem.
The staff anticipates that early in the operational phase of the site, most of the mon'.toring will be related to direct releases of l
radioactivity from incoming vehicles, waste <:ontainers, and handling equipment that may migrate off-site and impact the environment.
The monitoring program also should emphasize short-term releases caused by failure of the containment system.
In addition, any environmental monitoring that may be necessary in response to accidental releases from spills, container ruptures, fires, or other unanticipated events should be incorporated into a contingency plan.
Environmental monitoring that was initiated during the preoperational phase should be continued, on a periodic basis, to determine if background concentrations have been exceeded.
3.3 'Postoperational phase The postoperational monitoring plan should be based on information obtained during previous phases and include an optimal configuration of data collection stations or techniques necessary to detect radiological and nonradiological hazardous releases. A contingency monitoring plan should also exist during the postoperational stages in case significant migration of contaminants occurs.
I Initially, postoperational monitoring should continue at locations and frequencies specified during the operational phase.
If postoperational monitoring reveals that no significant releases are occurring, sampling frequencies and locations could be reduced. During site closure and early in the post-closure period, it will be necessary to monitor representative site media frequently to confirm or modify predictions about site performance made from the analysis of previous monitoring data, These include air samples and i
surface soil samples.
The sampling frequencies may be reduced for other media if there is no indication of radionuclide releases.
The staff considers it 8
LLW ENVRNMNT MNTR 87P/ SEPT 87
o.
The applicant should be capable of defining vertical and horizontal gradients throughout the affected saturated and unsaturated zones. These results will be necessary to design an efficient ground-water monitoring system for the opera-tional and postoperational phases.
Furthermore, these data will enhance the understanding of the hydrogeologic system at the site.
The applicant should sample, when possible, nearby residential, municipal, and industrial wells. The NRC staff notes that adequate well completion data for these wells are important to ensure knowledge of the monitored strata.
These wells should also be included in the ground-water monitoring plan and sampled.
Ground water monitoring facilities developed during the preoperational phase shculd be located so that they will continue to provide usable data during the subsequent phases of facility operation.
In addition to wells downgradient of the site, upgradient wells should be maintained to detect changes in background levels during the later phases of operation. As noted in 10 CFR 61, wells should be located so that early warning of releases of radionuclides from the disposal site is ensured before they leave the site boundary.
Thus, important release pathways should be monitored in the buffer zone.
Ground-water monitoring facilities should be designed so that information gathered during the cperational phase builds upon the information gathered during the preoperational phase Emphasis should be placed on short-term releases caused by spills and other unanticipated events. However, as disposal units becomo full and are closed, the NRC staff expects the emphasis to shift from short-term releases to longer-term releases caused by gradual failure of the disposal units. Thus, monitoring frequencies may be reduced in specific areas of the facility as long as compliance with the performance objectives can be demonstrated, and contaminant releases can be detected before they migrate offsite(10CFR61.53(c)).
Detection of a release should result in more thorough monitoring to assess environmental significance according to a corrective action plan outlined in the license appitcation.
Monitoring-locations should be maintained to the extent practicable so that data collection is as compatible with that collected during the preoperational phase as possible.
11 LLW ENVRNMNT MNTR BTP/ SEPT 87
o e
,e l
6-(
The emphasis during postoperational ground-water monitoring (encompassing closure, the period after closure, and long-term care) should be placed on the detection of long-term releases caused by the gradual failure of disposal units or other unanticipated (: vents, such as damaging weather conditions or inadvertent intrusion. As in operational monitoring, the applicant must increase the scope of the monitoring plan to assess the environmental impacts of possible contaminant releases, and if necessary, perform mitigative actions.
However, if postoperation&l monitoring indicates that isolation of the low-level radioactive waste has been adequately isolated, the sampling l
4 frequency may be reduced, provided compliance with the performance objectives
[
can be demonstrated.
The staff considers this to be an important aspect of the postoperational phase because it provides for eventual decreased monitoring during the long-term care period.
For example, if monthly ground-water sampling at a humid disposal site indicates that there has been no significant change for several years following closure the licensee could justify quarterly or bi yearly ground-water sampling. A licensee performing quarterly sampling i
at an arid site that yields acceptable results could possibly justify yearly sampling.
In both e.xamples, the licensee should analyze the ground-water samples for radiological and r.onradiological indicators such as tritium, gross alpha activity, gross beta activity, pH, and total dissolved solids, total L
organic carbon, or other indicator? expected to be in the waste stream.
o Soil Preoperational soil sampling will be performed during site characterization.
i Samples should be taken from surficial soils as well as at depths that reflect the site's stratigraphy. The staff recognizes that soil analysis costs can be prohibitive if the soil depth is very great.
The applicant, therefore, should sample material that is reasonably expected to become a migration pathway.
Naturally ocevrring radioactivity should be analyzed in addition to those chemical constituents that might affect site performance, for example, f
complexing agents present in the soll, i
During site operations, samples should be taken to detect surface contamination as a result of operations.
Soil sampling and testing should be done F
12 LLW ENVRNMNT MNTR ETP/ SEPT 87
e.'
$ ;., h.,
/
periodically at locations where contamination is likely and at locations near areas where waste has been buried. Accidents and nonroutine or positive release events may dictate more frequent sampling.
This monitoring should continue through closure.
Durir.g the postclosure period, soil sampling should include areas near the l
disposal t,its or cells -- far enough away, however, to ensure that the integrity of the disposal unit is not compromised -- as well as onsite areas remote from buried waste and in the buffer zone. The number of samples and 4
frequency of sampling may be gradually decreased during the postclosure period if laboratory results indicate no significant releases have occurred.
The staff anticipates that soil sampling will eventually be performed in response to an unanticipated event where the cover has been breached, or simply at very l
low frequencies to assess cell performance.
Soil sampling during the
(
p;.st-closure period should be performed so that disturbance to the site and vegetation is minimized to ensure that erosion does not become a problem.
o Surface Water and Sediments Because of siting requirements in 10 CFR 61, perennial surface water is not anticipated within the boundaries of the low-level radioactive waste disposal facility. However, it is important that nearby offsite surface water be monitored for two reasons:
(1) the monitoring could indicate surface contamination that is being removed from the site by surface runoff and (2)
(
perennial surface water downgradient of the site may be a manifestation of l
ground water that originates at or passes beneath the site.
If significant f
intermittent surface-water flow occurs on site, it should be included in the monitoring program.
l Ouring the preoperational phase, surface-water sampling locations should be selected upgradient of, adjacent to, and downgradient of the site in all sub-i watersheds to which the site may contribute. Nearby impoundments and surface-water drinking sources should be included in the sampling program.
Estabitshed sampling stations, constructed during the preoperational phase would ensure consistent sampling during subsequent monitoring phases.
[
f 13 LLW ENVRNMNT MNTR BTP/ SEPT 87
-.--- --... ---.- -.. O
' r" -
1.
Sampling of perennial surface-water sources near the site should be representa-tive of the flow regime.
Therefore, flow measurement should be part of the monitoring program.
Efforts should be made to sample epherc.eral water courses during runoff periods and to correlate the results with the results related to perennial water courses.
Samples should be analyzed for the same radiological and nonradiological constituents as those that are included in ground-water sample analyses.
During the operational monitoring plan, samples should be taken following extreme hydrologic events that result in large amounts of surface runoff from the site and following uncontrolled release -- spills, accidents, failures --
of radioactive or chemical materials.
Sample analyses should be the same as the ground-water sample analyses during the operational phase. Onsite surface-water sampling stations should be located in areas of runoff from active operations. For example, off-site runoff from truel. wash basins and temporary storage areas should be included in the monitoring prograin.
Snowmelt and large precipitation events that cause abnormal surface flows, temporary pending, spillovers and other such unanticipated events should prompt special or more frequent surface water sampling to determine if releases have occurred.
Surface water should be sampled during the pcstoperational phase at the same frequency as that during the oper tional phase.
Samples should be analyzed for the indicators determined during the previous monitoring phases.
Following site stabilization, sampling frequency may be reduced if there Are acceptable results. Positive results, on the other hand, would necessitate more frequent and rigorous sampling and analysis or, in the extreme, mitigative actions.
During all three phases, sediment samples from representative cross-sections of nearby surface-water courses should be taken and analyzed for the same radio-active and chemical constituents as those in soil samples.
Sample locations should be approximately the same as those for surface-water sampling.
Samples should be collected at various points and depths in the cross-section of the sediment profile. Samples from a discrete cross-section may be aggregated for radiological and chemical analysis.
14 LLW ENVRNMNT MNTR BTP/ SEPT 87
~
- 0.,
~
'o MeorologyandAirQuality A meteorological monitoring program should be established as part of the site charactert:.ation process, and should continue throughout the operational and postoperational stages.
Site-specific meteorological data should be collected for a minimum period of 1 year during the preoperational environmental monitoring period, unless the applicant can demonstrate that data from other meteorological stations represent conditions on site.
These da$a may include precipitation, temperature, wind spend and direction, etc.
The applicant must i
demonstrate 1at the seasonal variations noted in the characterization period represent his irical conditions. Thus, comparisons with past records should be made.
In addition to site-specific measurements, regional long term
[
meteorological data should be obtained from offsite sources such as the nearest National Weather Service station. These additional data are necessary ti supplement site-:.pecific records and to determine the extent to which they are representative of the prevailing climatological conditions.
P Along with surface temperature records, measurements of additional *meteorologi-cal parameters are needed to determine the water budget for the waste disposal site, as well as ground water Icvels and stream discharge. Measurements of the amount, rate ar.d type of precipitation are very important for estimating flow and potential contamination of surface and subsurface waters.
t Evapotranspiration, which can account for the largest component of outflow of precipitation, should be estimated using soil moisture measurements, pan evaporation, and meteorological conditions.
The fraction of precipitation in l
the form of snow and rainfall should be measured.
Evapotranspiration processes will typically move significant amounts of water from the near-surface environment into the atmosphere. Pan evaporation can be measured at the site to provide an upper bound on evaporation rates.
Additional supporting data for quantifying evaporative processes may be derived from measurements of temperature within the soil, solar radiation (insolation),
j soil moisture, matric potential, wind speed, and relative humidity or dew point.
4 J
i f
i f
l 15 LLW ENVRNMNT MNTR BTp/ SEPT 87 I
I
e.
- 4.,
' NRC has no authority to enforce against noncompliance with air emmission standards. However, tha license will most likely contain provisions whereby tne applicant is required to comply with applicable state and/or federal standards under the Clean Air Act.
Therefore, it is incumbent upon the appl? cant to establish ambient air quality levels early during the period of site characterization. Air quality parameters can include carbon monoxide, oxides of nitrogen, sulfur dioxide, hydrocarbons, ph6tochemical oxidants, and susoended particulates. Ambient levels constitute part of the data base for the disposal site.
Potential sources of nonradiological pollutants that might affect air qe.slity during disposal facility operations typically would be combustion emissions from transportation vehicles or power equipment operations, dust from trench excavations or backfill operations, and gaseous emanations from the decomposition of organic waste products.
During the preoperational phase, at least one continuous air sampler should be located downwind of the site in the most prevalent wind direction (as deter-mined during site characterization) sa that baseline air qualif.y conditions can be established. At least ene background continuous air sampler should be located a sM:ble distance upgredient of the most prevalent wind direction in an area that will remain undisturbed by site operations and that is not affected by other sources.
Air filters should be collected and analyzed for gross alpha and gross beta activities, and other indicators at a frequency adequate to evaluate air qua:ity changes. A composite gamma scan should be performed at least quarterly.
Air sampltrs should continue to be used during the site operational phase, although they may be repositioned depending on the analysis of climatological data.
During normal operations, air sampling should be performed regularly.
Nonroutine occurrences such as onsite accidents or extreme climatological events may mandate mcre rigorous sampling and analyses.
During closure activities, air sampling should continue as during site opera-tions. Once the site sur' ace has been stabilized after closure, routine air sampling may be reduced in frequency and number of sampling points.
For several y*ars durirg the postclosure observation period, at least one 16 LLW ENVRNMNT MNTR BTP/ SEPT 87
o.
continuous air sampler should be maintained near the site boundary downwind of the most prevalent wind direction.
Filters should be monitored for gross alpha and beta activity.
If the activity is high, the filters should be collected more frequently, and a composite gamma scan should be performed. Annual isotopic analysis of composite samples also should be performed.
If appropriate, O r sampling may be reduced during the institutional control
- period, o
,FJora and Fauna Flora and f auna may be potential pathways for human exposure. Also, the presence of certain species at or near a waste site may affect the ability of the site to contain the waste.
" < fore, because knowledge of preoperational ecological conditions n
t evaluate potential impacts caused by releases, monitoring of flo.
aad. una at or near the site should be a component of the menitoring program.
The purpose of an ecological monitoring program is to verify that, in the case of non-compliance with release criteria, the populations in the floral and faunal communities that have been identified as pathways to man have not been af fected in such a way that public health and safety are threatened. The preoperational monitoring program should identify those aspects of the ecological community that are "important" from the health and safety standpoint. Thus, for the purposes of this document, a species is important if:
(1) The species has been identified as a potential pathway to man.
(2) The species is a biological indicator of radiological and nonradiological constituents in the environment.
During the preoperational phase, vegetation should be collected in the vicinity of soil sampling locations an' from areas that may later be contaminated by Nigrating waste.
Sampling should include all major species of Vegetation i
17 LLW ENVRNMNT MNTR BTP/ SEPT 87
i 6-characteristic of the site that could become involved in the food chain and impact humans, or lead to other parts of the food chain.
The samples should be analyzed routinely for gamma activity and tritium. An adequate number of samples should be collected and analyzed so that baseline conditions are established. However, to distinguish between surface contamination and plant uptake, the sample should be washed before it is analyzed for plant uptake.
During the operational phase, sampling frequency may be reduced for shallow-rooted vegetation. The species of vegetation collected and the types of constituents analyzed in the sample should remain constant from year to year.
The operational phase monitoring program should be expanded later to f
include deep-rooted vegetation.
Leaves from representative deep-rooted species should be sampled annully beginning 5 years af ter operations begin.
They should be analyzed for at least gross alpha and gross beta activity and tritium. All vegetation samples that exceed action level concentrations established during the preoperational phase should undergo a complete isotopic analysis.
During the postoperdttonal phase, sampling and analysis of vegetation should continue as during the operational phase, though the sampling frequency will likely be lowered following acceptable analytical results.
A faunal inventory should establish the identity of the major terrestrial and aquatic organisms on or near the site that are determined to be pathways of radiological transport.
From this Itst, the important species should be identified and their quantitative abundances ascertained.
This inventory should be used to identify potential vectors and indicator species that are present, particularly in the case of an accidental release.
Representative samples of local livestock, dairy products, and game species should be taken and analyzed quarterly during the preoperational survey.
Analyses should include uma scans of sample portions known to accumulate contaminants. These samples can provide the basis for determination of environmental impacts and information on base level in potential vectors to man in the case of accidental release.
18 LLW ENVRNMNT MNTR BTP/ SEPT 87
r-Care should be taken to properly account for seasonal vr other dif ferences in the abundance of such species.
The inventory shoule; include species that migrate through the area.
In addition to wild sp'.cies, the survey should consider the locations and numbers of domesticated animals, especially dairy cows and goats.
The monitoring program for fauna should never involve the harvesting of rare, endangered or locally important species. Game animals should be sampled primarily during the hunting season for each species.
If these samples indicate the need for out-of-season sampling, approval should be obtained from the appropriate agency.
If an accident occurs, the applicant should sample the established vector species and determine whether they have been impacted by the contaminant release.
4.2 Monitoring Constituent Levels The site environmental monitoring program involves the analysis of two major constituent types:
(1) Detection of direct gamma radiation.
(2) Detection of radiological and nonradiological nonhazardous constituents released to the envf ronment from the facility or elsewhere.
Direct Gamma Radiation During the preoperational phase, continuous measurements of direct gamma l
radiation should be made at locations selected for air sampling and at various other locations on the site and in the site environs. Devices should ideally be located 1 m above the ground and at least 10 m from existing buildings.
l During the operational phase, monitoring of direct gamma radiation should continue. Measurement of direct gamma radiation during the institutional care period will be left to the discretion of the custodial agency.
19 LLW ENVRNMNT MNTR BTP/ SEPT 87
a b'
As part of the postoperational phase, a direct gamma radiation survey of the site surface will be conducted according to the acceptable frequency as described in the license application or for special cases.
Direct gamma radiation surveys should be conducted before the license is terminated or transferred and af ter major site disturbances such as trench subsidence or disruptive climatological events.
Radiological and Nonradiological Constituents The primary technical objective of a monitoring program at a low-level radio-active waste disposal facility is to monitor radiological and nonradiological nonhazardous species that may be released in order to:
(1) Determine the extent and direction of migration.
(2) Estimate whether (and when) such movement... n 2ch offsite areas.
(3) Estimate potential radiation doses from ground and surface water contamination.
(4) Identify, monitor and estimate potential radiation doses associated with other pathways.
(5) Identify whether contaminant release occurred as a result of gradual failure of the disposal unit or normal onsite operations.
A program for determining background concentrations of radioactive constituents should be initiated during the preoperational phase.
Pertinent literature and knowledge of the site area should be helpful in selecting specific constituents for which background levels will be determined. Seasonal and climatological variations must be considered.
During the operational phase, important radio-logical constituents in the waste form should be identified, and their signifi-cance with respect to hazard, volume, potential mobility, and half-life should be determined. This identification will enable the oetermination of background concentrations and the monitoring for radionuclide migration af ter waste 20 LLW ENVRNMNT MNTR BTP/ SEPT 87
s
$=
emplacement. During the operational and postoperational phases, radiological constituents identified as important should be monitored in all potential pathways (particularly soil and water). At a minimum, media should be analyzed for gross alpha activity, gross beta activity and tritium in water and vegetation. Gamma-ray spectrometry should be performed to characterize the principal gamma-emitting radionuclides present.
Isonradiological nonhazardous constituents in ground water should be monitored at a low-level radioactive waste disposal facility for three reasons.
- First, certain inorganic and organic species occurring naturally or introduced by waste emplacement, su:h as decontaminating agents, can form chemical complexes with radionuclides, potentially increasing radionuclide mobility.
Studies have shown that some organo-radionuclide complexes may persist and increase radionuclide mobility over significant distances.
It is necessary to understand what radionuclide complexes are being formed under the disposal site's geochemical conditions so that their migration behavior may be monitored. Second, the nonradiological constituents may themselves cause environmental impacts and therefore pose a public health problem.
- Third, changes in concentrations of nonradiological constituents could signify radionuclide release arid migration and can provide indications of off-normal performance.
It is appropriate to note that 10 CFR 61.56(a)(8) requires treatment to the extent possible of nonradiological hazardous constituents to Ilmit potential health effects. However, the staff considers it prudent to monitor for indicators of nonradiological hazardous releases for the above reasons.
During the preoperational phase, the soll and water at the site should be evaluated for the presence of chelating agents and known deleterious chemicals and background concentrations should be determined.
It is recognized, however, that monitoring every chemical parameter in every media that could potentially mobilize radioactive material or abet radionuclide migration is impracticable.
Therefore, a program for screening representative indicators of chemical constituents in the waste form should be developed that is based on the ability of the constituents to form chemical complexes.
Those constituents identified 21 LLW ENVRNMNT MNTR BTP/ SEPT 87
4
~ ;.'
i l
as significant in the preoperational and operational phases and in the waste form, respectively, should be monitored.
5 OTHER PROGRAM COMPONENTS 5.1 Quality Control program The applicant must provide a written Quality Control Program in the license application adequate to meet the requirements of 10 CFR 61.12.
It is stated in 10 CFR 61.12(j) that every application for a license to design, construct, and i
operate a low-level waste disposal facility is required te include a de-I scription of the Quality Control Program to be appiled to the determination of
(
natural dispsal site characteristics, and for quality control during design, construction, operation, and closure of the land disposal facility and the receipt, handling, and emplacement of waste.
The quality control requirements 61.12(j) are the bases for the development of such a program, and the QC plan for EM is considered to be an integral part of the overall program. NRC staff expect the QC Program to be implemented fully at the beginning of the preopera-
[
tional monitoring phase so that action levels are defined accurately. Although
(
not explicitly stated in 10 CFR 61, it is incumbent upon the applicant to ensure that an adequate Quality Assurance Program is implemented, including management organization, such that the QC Program is maintained.
This will provide assurance, to the licensing authority and intervenors, that the data collected on environmental conditions are defensible.
l l
The description of the QC Program with respect to EM should contain criteria which include, but are not limited to:
performance specifications for all I
sampling equipment; sampling instructions and procedures; control of measuring L
and test equipment; sample handling, preservation, storage and shipping; l
chain-of-custody procedures; performance specifications for all sampling i
equipment; calibration procedures; field checks; and the use of spiked, split, and blank samples. A procedures audit plan should also be included with the QC Program.in the license application.
22 LLW ENVRNMNT MNTR BTP/ SEPT 87
s n v 9
'5. 2 Maintenance and Oecommissioning of Monitoring Equipment Monitoring equipment should be maintained in operating order during its useful life. Manufacturers' recommendations for cleaning, refurbishing, and calibrating equipment should be followed. Monitoring fact 11ttes and equipment should be protected from damage from other site operations. Areas around monitoring equipment should be maintained so that natural or human factors (e.g., vegetative growth in the vicinity of a wind vane) do not bias sampling results.
Whenever practicable, monitoring facilities should be developed to be opera-tional during all phases of site life. However, it is likely that some monitoring facilities and equipment will have to be replaced during their life-time.
If decommissioning of monitoring facilities becomes necessary for any reason, it should be performed in a manner that is least disruptive to site performance or the local environment. This concept is especially important with regard to decommissioning of ground-water monitoring facilities. Wells and other facilities that penetrate the site surface should be completely re-moved, if possible, and sealed with grout cement to restrict contaminant migration.
If it is not possible to remove a particular facility, it should be plugged throughout its full extent and either capped in a manner that prevents infiltration along its external interface with surrounding soil, or preferably cut off below the site surface, capped, and backfilled to natural grade. Plans for doing this, along with a technical basis, should be developed at the time the system is designed.
Sealing activities should be compatible with applicable State requirements.
Complete decommissioning of monitoring facilities should be considered only when the facility is producing false or misleading data or no data at all.
Replaced facilities that are capable of yielding usable data should be retained as backup facilities in case of failure of the new facilities. When possible, a new facility replacing an old facility should be operational before the old facility is dismantled.
This will help ensure continuous data collection, 23 LLW ENVRNMNT MNTR BTP/ SEPT 87
f a
.e 6
SUMMARY
Components of an environmental monitoring program are described in 10 CFR 61.53. The purpose of this document is to provide guidance to applicants, licensees, and government entities for the development and implementation of such programs.
The primary objective of the environmental monitoring program is to determine compliance with the performance objectives in 10 CFR 61.41 and 61.44 Supporting technical objectives of the program are to characterize the site and processes affecting releases, assess vnvironmental impacts, establish a statistical data base for environmental performance parameters, detect radiological and nonradiological nonhazardous releases from waste di<posal areas before they leave the facility boundary, and develop remedial action plans when the performance objectives in 10 CFR 61, Subpart C are not met.
Environmental monitoring consists of three major phases:
preoperational, operational, and postoperational.
During the preeperational phase, a back-ground data base is compiled for radioactive and nonradiological constituents, appropriate action levels are determined, and remedial action plans are formu-lated.
Site monitoring for powr.;ial radiological and nonradiological releases is performed during the operational and postoperational phases, and if releases result in exceedance of action levels, remedial action plans are implemented.
The site environmental monitoring program consists of two major components:
detection of direct gamma radiation and detection of radiological and non-radiological constituents. Direct gamma radiation surveys should be conducted regularly during all three phases of the programs; or in specisi cases, such as before the license is terminated or transferred and after major site disturbances.
Radiological and nonradiological constituents should be sampled and analyzed periodically, and when migration is suspected, at a greater frequency and more comprehensively.
Specific pathways to be monitored during the three phases of facility operation are ground water, seil, surface water (including site runoff), sediments, air, and flora and fauna.
Important radiological and chemical indicators include tritium, gross alpha activity, gross beta activity, pH, total dissolved solids, total organic carbon, or other indicators ex,nected to be in the waste stream.
In addition, supplemental data 24 LLW ENVRNMNT MNTR BTP/ SEPT 87
,% =
+'
~
"n site-specific release mechanisms should be compiled which relate to ecology, o
meteorology, climate hydrology, geology, geochemistry, and seismology.
A quality control program should be developed and implemented to ensure the accuracy of all monitoring techniques and analy:;es.
Important components include maintenance and verification of monitoring equipment, documentation of field and laboratory procedures, checking and documentation of data fi'es and computations, and conducting an independent audit program.
Reporting requirements for the licensee include maintenance of permanent record files, preparation of periodic summary reports, and submission of all monitoring data and audit results to appropriate regulatory authorities (10 CFR 61.80).
Monitoring equipment should be maintained and decommissioned when necessary to ensure accuracy in data collection and to allow facility performance without disrup ton.
Equipment should be cleaned, refurbished, and calibrated according to the manufacturers' specifications.
Instruments should be protected from natural and human intrusion during the active life of the monitoring program.
When components of the monitoring system reach the erJ of their useful operating life or are no longer needed, they shoul6 be replaced or decommissioned.
7 REFERENCES Code of Federal Regulations, Title 10. "Energy," and Title 40, "Protection of Environment," U.S. Government Printing Of fice, Washington, DC, revised annually.
U.S. Department of Energy, 00E/LLW-13 Tg-1983, "Environmental Monitoring for Low-level Waste Disposal Sites," National Low-Level Waste Management Program, Washington, DC, 1983.
U.S. Geological Survey, "National Handbook of Recommended Methods for Water-Data Acquisition," U.S. Department of the Interior, Reston, Virginia,1977.
i 25 LLW ENVRNMNT MNTR BTP/ SEPT 87
,. o*
,,L Si Nuclear Regulatory Commission, NUREG/CR-1759, "Data Base for Radioactive Waste Management," Vol. 1, Washington, DC, November 1981.
--, NUREG/CR-4352, "Suggested State Requirements and Criteria for a low-level Radioac ve Waste Disposal Factitty," Washington, 0C, August 1985.
--, Regulatory Guide 4.15 "Quality Assurance for Radiological Monitoring Programs (Normal Operations) - Effluent Streams and the Environment,"
Washington, DC.
i l
26 LLW ENVRNMNT MNTR BTP/ SEPT 87
[
~