ML20206K083
| ML20206K083 | |
| Person / Time | |
|---|---|
| Issue date: | 11/25/1988 |
| From: | Ballard R NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Bunting J, Linehan J NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| REF-WM-1 NUDOCS 8811290262 | |
| Download: ML20206K083 (18) | |
Text
_ _ _ _ _ _ _-.
MEMORANDUM FOR: John J. Linehan, Acting Director i Repository Licensing Project Directorate, HLVM !
Joseph 0. Bunting, Chief Enginsering Branch, HLWM ,
FR0fi: Ronald L. Ballard, Chief Geosciences & Systens Performance Branch HLlet
SUBJECT:
UPDATE OF USER NEED STATENENT FOR HLW RESEARCH SUPPORT An inportant programatic fccus within the Division concerns NRC research needed to support the HLW licensing process. In 1984, the Division develo)ed a .
Research "User Need Statenent" that has served us well. However, tie changing '
scope of the HLW pregram and knowledge gained since that time suggests that an I updeted "User Need Statenent" is needed that addresses current licensing issues.
HLGP has the leed for cootdinating and prepat;ng an updated research user need staterEnt. We have developeo a prelininary draft of a new statenent that is based on the old one (Enclosures 1 and 2). At this point we need to incorporate i input from others in the Division. Therefore, I would like to obtain staff '
review of the preliminary draft. Each review should address specific changes 4
needed to develep the updated statenent. Also, all changes need to be related )
' to one or more elerents of our five-year plan. Coments are requested by COB on Decenber 6, 1988.
l David Brooks is coordinating this effort, and preparing a revised document.
Please provide bin with suggested changes to the current document as well as a "point of contact" by COB on December 6, 1988. As snon as a draft revision has been prepared, it will be distributed to the "point of contact" for coments ,
and we will ncet as necessary to develep a final draft to coordinate with RES.
If you have any ouestions, please call or see either re (X23455/5-H-1) or i David (X23457/5-H-12).
S/
Renald L. Ballard, Chief Geosciences & Systens Perfo.mance Eranch, HLWM l t
Enclosures. I As stated !
l cc: R. Browning
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RES SUM DISTRIBUTION-Central Files REBrowning DHLkH BJYoungblood, DHLkH RLBallard, HLGP JOSunting HLEN JLinehan, HLPli HLGP r/f N!!SS r/f DBrooks, HLGP OFC : : -
NAME : DBroo 11 : RBalfa d : : : : :
DATE : 11/ar/88 : 11/t';/88 : : : : :
'. ENCLOSURE 1 - Prolicinary DrafC of NMSS SteccOnt of HLU Rescerch Nceds !
I NMSS STATEMENT RES NEEDS NMSS STATEMENT OF HLW RESEARCH NEEDS l
i In order for the NRC licensing Staff to critically review and evaluate a DOE I license application for a deep geologic repository for high-level radioactive i waste, the staff of NMSS has the following needs for technical work which may i 1
apprcpriately be addressed by research programs. The areas of technical work ,
in HLW have been identified by the Itcensing staff based on its consideration '
of the findings required by 10CFR60, applying the lngic process described in l
4 Apperdix C of NUREG-C960. From the broader list of potential topics for .
technical work, these areas for NRC work were selected based primarily on the following criteria: l
)
- The technical work addresses highly uncertain phenomena or processes; f the work uses unconventional approaches to developing nodels or '
collecting data; the reseana is designed to confim studies that ore important to NRC's l 4
10CFR60 deteminations. !
The comprehensive set of general technical areas and specific technical I problems must be addressed by DOE in its technical programs to support its lj license application. The focus of the NRC technical work should be to assess j the capabilities, limitations, assumptions and uncertainties associated with: i Pethodologies for identifyirc failure modes and for quantitatively !
assessing risks associated with components of and with overall high-hvel !
, radioactive waste disposal systems; }
Methodologies for extrapolating short-term laboratory and field a
observations to long-tem pred'ctions for application in HLW )
- regulatory assessments.
I While the needs identified focus primarily on the information or capability ,
l that it needed to independently assess DOE's license application, NRC j 1 research progrants should be structured to provide interim results as they
- 1 become available to provide a basis for guidance to DOE during the prelicense I j application, site characterization phasa, f A, WASTE FORM AND PACKAGING
- 1. Identification and assessment of potential failure modes for waste f packages.
l The NRC requires a critical evaluation of waste package failure nodes to f j assess the perfomance objective of leng-ters containment of l 4 radionuclides (10CFR60,113(a)(1)(ti)(A)). The work nust permit l
. 1
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NMSS STATEhENT/RES NEEDS 2
application of results to the materials most likely to be con idered by 00E (currently, stainless steel containers) and the most likely weak point in the package (currently considered to be the container weldments).
Ilydrogen embrittlerent should be one of the failure modes that is analyzed. The product should be a report that identifies and critically evaluates potential waste package failure modes under the full range of repository environments and conditions.
A1;o, the final report should document the sensitivity of corrosion and mechanical properties to waste package fabr..ation processes. In particular, the report should identify and critically evaluate factors in waste package fabrication that may adversely affect waste package perfomance. These results should be presented in a femat that will pemit the licensing staff to efficiently review DOE fabrication design specifications as they may affect estimates of waste package reliability.
- 2. Assessment of Corrosion Rates The NRC staff has documented its position that pitting corrosion is a likely failure mode for waste package containers. The staff censiders work is needed to allow it to independently assess the rate of pit growth as a functicn of the age of pits. This work should also include tests to detemine whether heat flux (as well as temperature) influences the rate of pit growth. This infomation will help detemine the limits to which isothermal tests can be used to project pitting corrosion beh,vior in waste-package containers. The final report should assess whether pit growth is related to pit age and, where possible, include empirically derived relationships for rate of pit growth as a function of age in candidate container materials that are susceptible to pitting. In addition, the report should describe the extent to which the results of isothermal tests can be extrapolated as appruimations of pitting corrosion behavior under the full range of repository conditions. The report should also present the necessary criteria for when such extrapolations can be made reliably. Finally, the report should describe l the assumptions and limitations, as vell as laboratory protocols, for all predictive techniques evaluated and should include criteria that the staff could use to (1) formulate guidance to DOE on appropriate prediction techniques, and (2) review DOE data on pitting corrosion of high-level waste package containers.
- 3. Evaluation of Interactions Betwe n Waste Packages and the Repository Envircrrent NRC requires an identification and critical evaluation of the material's properties, and envi*ormental carameters that will have a significant l
f-pRELIMINAPY ORAFT NMSS STATEMENT /RES NEEDS f
influence on the interactions (che,atcal, physical and radiolytic) between !
l waste packages and the reposito.'y environment. This evaluation is '
needed in crder to conduct quantitative perferrance assessments 1
- (including sensitivity and uncertainty analyses) of waste package t containment and the rate of release of radionuclides after the containmert l fails. The work .aust address how container materials and their alteration !
products interact with the waste fom to cause its alteration and how !
these interactions could affect the release of radionuclidas (synergistic effects) . The final product should be a report that identifies the relative importance of properties and parameters that can have a i
significant influence on interactions between waste packages and the '
repository environment. ,
a 4 Laboratory Analogs of Leaching and Migration ,
i The staff anticipates that DOE may use laboratory analogs to model ;
) leaching of the spent fuel and high-level waste form (after failure of ,
containment). The licensing staff needs technical support that addresses ,
the extent to which laboratory analogs may be relied upon to assess '
leaching and near-field migration processes. The work must address the +
assumptions that must be made and limitations of using short-term,
! laboratory-scale experiments as analogs. The final report should identify a set of criteria that the staff could use in (1) forrulating '
guidance to DOE on appropriate laberatory-analog studies, and (2) !
i reviewing DOE data en spent fuel and HLW 1eaching and migration effects. l i
t B. REPOSITORY DESIGN AND ROCK MECHANICS
- 1. HLW Preclosure Safety Systems Analysis !
I NRC regulations specify general design criteria for the structures, f I
systems and components important to safety (both surface and subsurface) :
during the preclosure phase of repository development (10CFR60.131(b)). !
The licensing ittff must be in a position to independently assess the j preclosure safety analysis and requires technical support in develet.ing a [
methodology for analyzing pree.losure safety. The technical work must i l develop a systematic methodology that will identify and qualitatively l prioritize the structures, systems components and operations that are f
, important to safety. The final product shall be the full documentation [
l of the methodology and shall include a provision for technology transfer ;
i that will permit licensing staff to become familiar with the application >
j of the methodolocy.
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PRELIMINARY ORAFT NMSS STATEMENT /RES NEEDS
- 2. Coupled Interactions of Thermal-Mechanical-Hydrologic Systems Assessment of compliance with the performance objectives for containment (60,113(a)(1)(ii)(A)), radioruelide releases from the engineered system (60.113(a)(1)(ii)(B)), and radionuclfde ~ ele ses to the accessible 4
environment over 10.000 years (60,112) may require consideration of coupled themal-mechanical-hydrologic effects over time, particularly in the near-field. The final product of technical work in this area should be a report that identi.'ies and critically evaluates the coupled processes that may be important to meeting the above-cited repository perfomance objective. The report must identify the assumptions and limitations of the technical approaches used in the studies and should provide explicit reconnendations on how coupled processes may be addressed, including bounding and extreme analytical apr oaches that could be used, along with substantive criteria that the !! censing staff could apply in implementing the recomended approaches.
- 3. Rock-Mass Sealing The HMSS staff supports continutd work that ientifies significant material and fabrication parameters for sealing thafts, drifts and boreholes that might, if they failed, provide preh rred pathways for radionuclide migration or might Itherwise compromist long-tem repositcry perfonnance. The work should assess seal and plug performance under the full range of repository conditioes. The final report s.Nould identify and prioritize material and fabricatiot narameters that may be important to rock-mass sealing in different media. Technical information developed sheuld be seitable for use in review of DOE's proposed designs.
4 Testing Procedures for Rock Mechanics To assess the repository design with respect sc it; impact on the numerical performance objectives (60,113), the retrievability requ.'rement (60,11(b)), and the qualitative design criteria (60.131-60.135), the staff must be able to evaluate the mechanical, thermal and hydraulic propertiet of rocks. "e staff supports ongoing work to develop a set of standards for rock rechanical testing procedures. The standards will be used by the NRC licensing staff to develop guidance to DOE on acceptable testing procedures for the design and construction of geologic repositories for HLW. The standards must be developed and set by a National Standards comittee in time to support the findings required by 10CFR60.
a NMSS STATEMENT /RES NEEDS C. EARTH SCIENCES
- 1. Nctural Analog Studies i As part of its independent performance assessment capability, NRC must I have a basis for comparing laboratory study results with estimates of repository perfonnance over long time periods. Such information cannot be obtained from laboratory or in situ field tests, where the measurement period is instantaneous with respect to geologic time. Thus, ,
technical information is needed from natural settings and natural analog studies on In particular, processes thatstudies geochemical are being needstudied in the laboratory.
to be focused on natural settings where appropriate water / rock / physical-chemical conditions tht are relevant to geologic repositories prevail, and, for radionuclide-migration analop studies, where an appropriate source term is
, available. The final product should empiasize the similarities between E J the natural analog or setting and expected near-ard far-field repository environments and processes as observed under site conditions in the field or laboratory, and contain information concerning (1) colloid forreton and transport processes 2) the effects of organic complexation on ;
~
! radionuclide nobility; 3 the effects of oxidation state and redox '
kinetics on the mobility of redox sensitive radionuclides; and (4) the !
retardation processes that affect radionuclide transport. l
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- 2. Grour.dwater Chemistry Evaluation Over Time In developing the capability to independently assess waste package ;
performance and to evaluate radionuclide souece terms. NRC needs information on the evolution of groundwater chemistry as the result of l waste emplacement and the interaction between roch/ backfill / water. This i information will provide data concerring changes expected in the environment of waste packages for comparison to DOE project-produced i data. The technical work should include assessments of rock-surface i processes that are involved in the control of the mdox state of groundwater. Information is also needed on the kinetics of redox processes, which is important to the understanding of redox conditions of both pre-closure and post-closure groundwater and its effect on waste package stability and radionuclide nigration. The final products for each of these studies should be reports containing the basic data of the experimental work, documentation of the experimental procedures used, including all assumptions and limitations, and a set of criteria that can be used by the licensing staff to help evaluate DOE data, analyses and conclusions concerning the chemical evolution of groundwater over time in both the near field and the far field.
4 t
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PRELIMINARY ORAn NMS$ STATEMENT /RES NEEDS i
i (
- 3. Valence Effects on Radionuclide Transport i In order for NRC to provide guidance to DOE on the isolatit,n of waste, !
I technical u rk is needed on valence effects on radionuclide sorption and :
solubility. The technical work should include an assessment of the basic !
i behavior of redox-active elements such as technetium, neptunium and !
plutonium under appropriate repository conditions. Since uncertaint.V in !
- the results of analysis of radionuclide speciation at the low !
concentrations of interest introduces a large deqree of uncertainty into !
, estimates of radionuclide behavior, the technici work should contribute
] to understanding basic
- educed-technitium chemistry and the analysis of
?
speciation of other redox active radic elements at very low
- concentrations. The final product should be a ieport containing the l
- basic data of the experimental work, documentation of the experimental i' procedures used, including all assumptions and limitations, and a set of ;
criteria that can be used by the licensing staff to help svaluate DOE j data, analyses and conclusions concerning the isolation of waste. .
l
- 4. Backfill Mineralogy i 1 In order for NRC to provide guidance to DOE on the repository design, and
! to independently evaluate DOE's assessment of releases from the .
- engineered system, technical werk is needed in the area of backfill mineralogy. The technical work should include an assessment of the l
- physical changes in the backfill that may be expected as a result of [
i changes in backfill mineralogy over time and an assessment of the !
- changes in water chemistry that may result, as well as changes in j sorp.ive capability of the backfill materials. The final product should l l be a report containing the basic data of the experimental work, j documentation of the experimental procedures used, including all I
- assumptions and limitations, and a set of criteria that can be used by -
8 1 the licensing staff to help evaluate DOE data, analyses and conclusions concerning backfill perfomance.
- 5. Response of the Geologic Repository Operations Area to Strong Ground Motion j An independent evaluation of compliance with the safety aspects of the t J design criteria for the geologic repository operations area,10CFR60.E0
) through 10CFR60.134, with respect to the effects of strong ground motion 4
from near-field seismic events till require knowledge of the potential j magnitude and frequency of the vibratory ground motion that will be !
! generated. Although geologic repository operations area includes both j the surface facilities and the underground openingc, this study should be 5 focused on the effect of depth on the nature of the vib atory spectra with depth in a generali?ed rock media, the effect of the insertfon of a network of both vertical and horizontal tubular vo m in this media, and l boundary conditions between the voids and the me/fa. !
I l
PRELIMINARY DRAFT NMSS STATEMENT /RES NEEDS 7
- 6. Effects of Spatial Variability on Greundwater Flow and Radionuclide Transport Groundwater fic.w and iadionuclide transport are controlled by the highly variable pro p rties of natural geologic materials. NRC needs an awareness of the effects of that spatial variability on simulations and predictions of three-dimensional groundwater flow and radionuclide transport during site characteriz1 tion and perfomance assessrent. In addition, NRC needs the capabilit) to independently simulate those processes, incorporating important stochastic effects. Hydrogeolngic and geochemical properties which exhik.ft significant variability include hydraulic conductivity, gaochemical porosity reaction tems. Pr>, ducts dispersion, should retardation,)and include: (1 an avaluatien of the importance of perfomin stochastic analyses of three-dimensional groundwaterflowandradionuclIJetransportduringsit6 characterization and perfomance assessment; (2) techniques for predicting behaviour of large scale heterogoneous groundwater systens using measured field data and spatial variability; (3) techniques for estinating error and correction terms for state-o'-the-art non-stochastic models; (4) a comparison of different tectniques for incorporating three-dimensional spatial variability i.ito flow and transport models, including technioues under consideration by DOE and others.
D. SYSTEMS PERFORMANCE
- 1. Developvent of Independent Assessmert Pethodology for Evaluation of Total System Perfomance As part of DOE's HLW 'icense application. DOE must demonstrate that the pre-wasta-emplacement groundwater travel time along the fastest path of likely radionuclide travel from the disturbed zone to the accessible environrent exceeds 1,000 years (60.113(a)(2)), and that releases of ,
radionuclides to the acce p ible environment after pertarent closure are ;
limited to those permitted by the prorsed EPA standard (60,112). In analyzing the groundwater flow and radionuclide transpert, DOE will rely heavily on predictive modeling. In erder for GRC to independently assess DOE's analysis of crepitance with Part 60 and the EPA standards in its license application, NRC must also rely on predictive modeling, Thus, technical work is reeded by NRC to produce technically defensible nodels and computer cedes to predict groundwater flow, radionuclide transport, and geologic stability. It is essential that the models and cowes have a sound basis and are accepted by the earth sciences technical ecmuni ty. The final product will be a set of models and cceputer codes that cari be used to independently assess saturated /ynsaturated system performance in tuff.
t ENCLOSURE 2 - Lin;-in/lin;-out Ch ngos to I 1984 Stctcc:nt of Roccorch
' Nacds l
I WM NMS$ STATEMENT OF RESEARCH NEECS j 4 \
In order for the NRC licensing staff to critically review and evaluate a 00E license application for a coep geologic repository for hign-level racioactive waste. the staff of NM55 has the following noeos for tecnnical wors whten may '
appropriately be addre.' sed by research programs. The areas of technical wort in HLW nave been identified by the licensing staff based on its consideration of tne findings recutred by 10 CFR 60, applying the logic process described in Appendix C of NUREG-0960. From the broacer Itst of potential topics for technical =ctLinese areas for NRC work were selected based primarily on the !
fo11 cuing critetta:
o the technical wert addresses highly uncertain phenomena or processest a tne wort uses unconventional approaches to developing poeels or collecting datan o the research is designed to confirm studlet that are tr9ertant to NRC's *
- 10 CFR 60 deters 1 nations. -
Tha cowerehensive set of general technical areas and specific technical prooleas inust be todressed by 00E in tts technical programs to support its license application. The focus of tne NRC technical wort shouls be to assess the capabilities. Mmitations, assuestions and uncertainties associated with:
d v) o Methodologies for identsfying failure ecces and for cuantitatively assessingrisksassoa.iatedwithcoe$cnentsofandwithoveral%radicactive waste disposal systeest o Methodologies for estrapolating short tem laboratory ano f . eld observations to long tern predictions for application in NL d and LLW l regulatory assessments.
While the needs identified focus primertly on the information o r capability that is needed to independently assess 00E's license applicaticn NRC research programs should be structured to provi6e interia results as tney become availa'le o to provide basis for guidanca u 00E ouring the prelicense application, site c
- actertration phase.
A. Weste Fom and Packagine
- 1. Identification and assess a nt of :otential. failure sedes for waste packages.
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4 The NRC requires a critical evaluation o' waste packagt failure modes to assess tna perforNnce objective of long.<erm containment of radionuclides ,
(10CFR60,113(a)(1)(11)(A)). The work must permit appitcation of resuits to the uterials ecst likely to be considered by 00E (curnnti" 'nn,
- ;;n
- ::t ae+ stainless steel contsiners) and tne most likeiy, we:ak point in the package (currently considered to be the ccntainer weldments.)
Hydrogen emerittleranc should be one of the failure modes that is analyaed, The product snoulo be a report that identif tes and critica11e evaluates potenttal weste package fatture modes under the full range of reposttery environments and conditions. Also, . . . ( A p b " t3 " f e. P.4) ,
- 2. Asses 1N nt of ^ ; ;;' ; corrostoMM ' :- M ':r ::d:: ;;;;;
The NRC staff has docurented its position that pitting corrostoa is a likely fatture mode for waste package containers. The staf f considers work is needed to allcw It to independently assess the rate of pit growth as a functici of the age.cf pits. This work should also include tests to determine whether heat flux (4s well as temperature) influences ;he rate of pit growth. This inforNtion will help dettraine the limits .to which isntherN1 tests Can te used to project pitting corrGlion behavior in waste package containers. The final report should assess whether pit growth is related to pit ago and, where possible, include eepirically certved relationships for rate of pit growth as a function of age in
, caadidate centainer sterials that are susceptible to pttting. In addition, the report should describe the entent to which the results of isothermal tests can te entrapolated as approutstions of pttting correston tenavtor under the full range of repository conditions. The (
report should also present the necessary criteria for wnen such extrapolations can te Nde reliably. F% , . . . ( ggq[@
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- 3. Evaluation of interactions between waste packages ard tne repositor. I environment. I NRC requires an toontification and critical evaluation of the stor f als prepettles and 6nvironmental parameters that will here a significant influence on tr.e interactions (cheetcal, physical and radiolytic) tetween waste packages and the repository environment. This evaluation is neeced In eroer to conduct quantitative performnce assessments (including I l sensitivity and uncertainty analyses) of waste package containrent.ano the race of release of radionuclides af ter the containmnt falls. Tre wort i nst address how container materials and their alteratton procucts t
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Interact with the waste form to cause its alteration and how theso .-
interactions could affect the release of radionuclideg Ine fina product should be a report that identifies the relative importance of properties and paramtsrs that can have a significant influence on interactions between waste packages and the repository environavent.
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The staff anticipates that DOE may use laboratory analogs to mode) leaching of the spent fuel anc higr.. level waste form (after fallute of containm nt).: : : 2 n;2 ^ ^ ';-n'- t' n' _::' n ;. The itcensing staff needs technical support that addresses the extent to wnich labora*.ory analogs r4y be relied upon to assess leiching and near.f teld migration processes. The wort rust acdress tne assumptions that rust be maoe and limitations of using short. term, laboratory. scale experiments as analogs. The firal report shouhi identify a set of criteria that the staff could use (1) in forvulating guidance to 00( en approp-tate laboratory. analog studies one (2) in reviewing CCE cata on spent fuel and HLW leaching and migretton effects.
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- 1) fonralate guidance to DOE on appropriate prediction techniques, and 'QI e b* (2) review OCE data on pitting enrrosion of high level waste package centstrars.
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- fabrication processes. In particular, the report should identify and critically evaluate factors in isste package fabrication trst may j
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- t? review 00E fabrication design specifications as they may affect estimates i of waste package reliability, a
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l B. Repository Design and Rock Mechanics
. 1. 'HLW ProClosure $afety $ystems Analysis.
! NRC regulations speCify general design criteria for the structures.
- systems and components important to safety (both surf ace and subsurtre,e) j during the preclosure chase of repository devoleppent (10 CFR 60.131(b)).
i The licensing staff nuit be in a position to inacpendently assess the
- reclosure safety analysis ano requires technical support in developing a reth0Julogy for analyaing preclosure safety. The technical wort nust j
oevelop a systematic metnocology that will identify and quantitatively 4
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pfloritiIe the structures, systems, Coe9ceents and operations that are i
imortant to safety. The final product shall be the full cocumentaticn of i the M thodology and shall include a provision for technology transfer that will parait Itcensing staff to become femtliar with the application of the mthodology.
- 2. Ccupled interactions of thermal-mechanical. hydrologic systees.
Assessment of cog 11ance with the performance cNectives for containevnt (60.113(a)(1)(it)(A)). radionuclice releases from the engineerec system (60.113(a)(1)(11)(8)), and radionucitee releasis t1 the accessible environment over 10.000 years (60.112) my ref;utre consideration of coupled thermal-mechanical. hydrologic effects over time, particularly in the near. field. The final product of technic.81 work in this area shculd be 4 report that identifies and critically evt,luates the coupled processes that my be important to I.eeting the above. cited repository performance
, c6jective. The report mst identify the assumptions and limitations of .
the technical approaches used in the studies and shovid provice espiteit recossencations on hon coupled processes my N accressed, including
. Bounding and extreme analytical approaches that could be used. Along with substantive criteria that the licensing staff could apply in tspiesenting the recossenced approaches.
- 3. poca a ss sueling.
The hMS$ staff supports continued scrk that identifies significant storial and f abrication paramters for sealing shaf ts, crtf ts and boreMles that might, if they f ailed, provide preferred pathways for radionuclide migration or eight otrerNise ccepromise long. term repository perforsence. The work should alltts sdal atd plug perforirence under the 3
full range of reposttery conditions. The final report should identify ano 4
priorttlIn Nterial and fabriCatton parameters that rey be irportant to
! rock.asss sealing in different macia. Technical information develcsta should be suitable for use in review cf 00E's proposed designs.
l 4 Testing procedures for rock sechanics.
l To assess the repository cesign with respect to its 1spect on the nuserical performance cejectives (60,113), the retrievability requirement
'.60.11)(b)), and the qualitattve design criterta (60,13160.135), the staff mst to able to evaluate the t schanical, thermal and hydraulic properties, of rocks. The staff supports ongoing ork to develop a set of standards for rock mechanical testing procecures. The standarcs will te used by the NRC licensing staff to covelop guicence to DCC cn acceptable i
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6 testing procedures for the design and construction of geologic repositories for HLW. The standards must be developed and set by a National Standards coautttee in time to opport the ficcings required by 10 CFR 60.
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As part of DOE's NLW license appiteetion. DOE wat demonstrate that the pre. waste. emplacement grounewater travel time along the f astest path of gi
- likely radionuclide travel from the distu-ted zone to the accessible g environment exceeds 1.000 years (60.113(a)(2)). and that releases of
,, radionuclides to the accessible environmnt aftes ;,4rmanent closure are g, limited to those permitted by tne proposed EPA standard (60.1.2). In
- aalyzing the grourdwater flow and radionuclide transport. DOE will rely, b?
teavily on predictive accoling. tr. order for hAC to independently assess
} Iicense app 1tcation, hRC mst also rely on predictive modelin . Thus.
technical wort 1s needed by hRC to proeuce technically defens ble models 9 E and corputer codes to predict groundwater flow,emo radionuclide transpo It is esseatial that the models ano codes have a sound basis and are accepted 6y tre earth sc %nces technicel community. The final product will ce a set of models ah: computer ccdes ': ::L :^: M^^'t " " .
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] AM Nctural analog s nuies.
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As part of its independent serformance assessment capahtlity. NRC must
- have a basis for cosparing laboratory study results with estimates of repository perforssace over long tim periods. Such information cannot be obtainee from laboratory or in situ field tests, where the measuremnt l period is instantaneous with respect to geologic time. Thus, technical information is *eeded from natural sottings and natural analog studies on 4 processes that * *e being studied in the laboratory. In particular.
l geochemical stustes need to be focused on natural settings where
- appropriate water / rock /phyAical.cheetcal conditions that are relevant to
- geologic repositories prevet), and, for fadionuclide eigratton analog i studies, where an appropriate source term is available. The final produc.
Should esePasize the stallarities tetween the natural analtg or setting
! ano espected near. and f ar-fielo repository environments and processe ane contain infomation concerning (1) colloid formation and transpor.
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processest (2) the effects of organic coeclexan ton on rtolonuclice nott11tyt (3) the effects of oxidation state ant redom ti.tetics on tu rebility of redon sensitive radieruclidest ana 'a) the retardation processes that affect racionuclidt transpcrt.
1 Groundwater chemistry evaluation over time, In developing the capability to irdependently assess wasta, package performance and to evaluate radionuclide source teres. NRC needs information on the evolution of groundwater chemistry as the result of waste emplaceeent and the interaction between rock /backf tll/ water. This information will provide data concerfling changes expected in the environment cf waste packages for comparison to DOC project. produced data.
The tech'nical wort should incluoe assessments of rock. surface processes that are involved in the centrol of the redon state of groundwater. .
Information is also reened on the kinetics of redos processes, which is '
important to tht understenateg of redos conditions of both are. closure and '
post.dlosure grounowater and t'ts ef fect on waste package stability and, -
raoteruclide migration. The final products for each of these studies should be Jports contahing the beste data of the triperimental wort ,
cocusenenten of the emperimeatal procedures used, including all assumpt' ions and limitations. 4nd a set of Criteria that Can be used by the >
licensin; staff to help evaluate DOE cata, analyses and conclusions concerning the chemical evolution of groundwater over tire in ectn the near field and the far fielo.
). Valence effects en soration and solubility In order for NRC to p. ..ide guidance to DOE on the isolation of waste, technical work is needed on valefice ef fects on rcutonuclice sorption ano solub111ty. The technical work should include en assesssent of the baste behavior of redox. active eierenti, such as technetium. reptuntua anc plutcatum under appropriate repository ccacittons. Since uncertainty in the results of anelysts of radionve'ide spectation at the low cen.
centrations of interest introduces a large degree of uncertainty into estimates of radionuclide behavior, the technical wort should contribute to uneerstanding Msic reeuced.technittum cremistry and the analysis of Spec 14 tion of other redos. active resto elements at very low concentrations. The fine) product should be a report containteg the basic 3ata of the esperisontal wort, documentation of the esperimental procedures used. Inclueing all assumptions ano limitations, and a set of criteria test can to usec by the Itcensing staff to help avaluats 00E data, aralyses ano conclusions concervitng tre isolation of easte.
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4 34ckft11 mineralogy In orcsr for NRC to provide guidance to DCE on the repository cesign and to 1Nependently evaluate OCE's assessment of releases frot, the engineered system, technical wort is neeced in the area of backf t11 mineralogy, the technical work smould inciude an assessrent of the phy'atcal cN#nges in the backfill that rey be tapected as a result of changes in backft11 mineralogy over sim that may result, ano as as well an changes assessmntin of the changes sorptise capacity in water of thecMemistry) eack f t) materials. The final product should be a report containing the beste data of the esperimental work, documntation of the esperimental procedures used, tecluding all assuections and limitations, and a set of criteria that can be used by the licensing staff to help evaluate OCE data, aralyses and conclusions concerning backf tl1 performance.
M. Responte of the geologic repository operations area to strong ground
. nottin. ,
An indepencent evaluation of comoltanew wita the safety aspects of the cesign criteria fo* the geologic repository operations area.10 CF'160.130 througn 10 CFR 60.134. witn rescrct to the ef fects of strong ground mtton fece near field setsmic events will require knowledge of the potentia
- i magnitude and frequency of tre vibratory ground Mtion that util be I
' generated. Although geologic repository operettons area includes toth the surface facilities and the undergrouno openings, this study should be facused on the effect of cepth on the nature of the vibratory motion. The final prof Jct of a technical program in this rea should include an anal / sis of the ec4tftcation of the vibratory sectra with depth in a generalized rock medta, the effect of the instetton of a retw0rt of both vertical and norttontal tubular voids in this mote, and to"edary conditions tetween the votes and the media.
1
- d. Ef fects of spatial variability on grour.34 tar ficw and radionuclide transport Groundwater flow and radioevclide transport are controlled by the highly l variable properties of natural geologic mterials. NaC neees an awareness of the effects of that spettal variabiltty on simulations and predictions of three-disonstonal grcundwater flow and rationuc) tee transport auring site charactertration and performance assessment. In addition, his neegs the taabletty to independently sisulate those processes, tocorporating important stochastic effects.. Hydrogeologic and geocneetcal properties '
=Mich enhibit signiftcant variablitty include hydraulic conductivity.
porostty, dispers)Sn. r*terdation and geocnemical reaction terms.
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. 9 Products should include: (1)anevaluationoftheimportanceof f.
performing stochastic analyses of three-dimnsional groundwater flow and radionuclide transport during site characterization and perfora nce '
assessa nt; (2) techniques for predicting behavior of large scale heterogeneous groundwater syster.s using measured field data and spatial variability; (3) techniques for estimating error and correction terms for state-of-the-art non-stochastic models; (4', a comparison of different techniques for incorporating three-dimensional spatial variability into ficw and transport Ndels. including techniques under consideration by 0(,I and others.
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