ML101900404

Review of the Ground Water Protection Program at the Fort Calhoun Nuclear Power Station, Tsd #08-015, Revision 01

ML101900404
Person / Time
Site:	Fort Calhoun
Issue date:	05/24/2008
From:	Scott D Radiation Safety & Control Services
To:	Office of Nuclear Reactor Regulation
References
FOIA/PA-2010-0209 TSD #08-015, Rev 01
Download: ML101900404 (32)

Text

,RDIATION SAFETY & CONTROL SERVICES, INC. BSCA Technical Support Document REVIEWOF THE GROUND WATER PROTECTION PROGRAM ATTFHE FORT CALHOUN NUCLEAR POWER STATION TSD #08-015-Revision 01 Originator: ~1'3 DavkJ'91ýtt -LE.F."k

)~ Date: 2I~~

Reviewer:

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TSD##08-015 Revision 01 Page 2 of 32 Table QfContents, -[- .i.:. ...... . ......

.  :. .r I. Ev'alu'ation of:'FCS' Completion of "Action 1"items of the NEI Groun Water o..Progamj 4 .Protecti Qbjctie 1 ofthe NEI Ground Water Protection Program: Site Hydrology and'.

G l . . . ......"

QbjectiVeJ12 of t. e NEI Ground Water Protection Program:. Site Risk Assess.ment .5 ObjectIive 13'6f the~ NEI Grouind Water Protection Program: On-Site Ground Water '

"Mon '*' "

Qbj-ctive 14 of the NEI Ground Water *-Reme Protection Program: - ation Process 6*

Objective 1.5 of the NEI Groutnd Water Protection Program: Record Keeping 7.......

11. Evaluationi of FCS' Completion of Tasks Prescribed in Sectio6n 5.0 of the EPR.I Gro'uiidWater Protection Gu~idelines for Nuclear Power Plants ("Locating, Installing and T .sting Ground W ater M. .o.nitoring Wells") ...... _! * .... . ... 77...........

Section 5.1 of thie EPR Ground Water Protection Guidelines Data Quality Objectives.

for Well Drilling ........................................ ............ 7 Section 5.2 of the EPRI Ground Water Protection Guidelines: Well Installation C onsideration

• s. .7......................

.............. ....................................................... ...... ... 7 Section 5.3 of the EPRI Ground Water Protection Guidelines: Monitoring Well Construcii6on ....... .S t n .5.. 1tI n................................

d.. .... 8 SGectrion :w5.4 of the EPRI GroundlWater Protection Guidelines:Maintenance Program

.OrM itoring Wells .................. ........... ... . . 8 111. Update ofiheFCS Sit Conceptual 'Model.tinG ......... -'..--. ......... 9 es...........

IV,. Review of ConstuctionoPhotos .. . 12 V. Review and Evaluation of Reports Containing Pre-Operational GroundsWater and CG eolog ic D ata ............... .... ........... ............................. ....;............... 13......................

13 Design Basis Documtent PLDBD-CS-54 aC 1 Seismic Cr.iaC13 rti eria ... t.ring... ell."-.........

Desig~n-Basis Documhenit PLDBD-CS-54: Geotechnical ........................ 14

'Final'Salfety Ainalysis Report, Section 2:. Site and Environs..................... 15 Section.-. 2 of the FSAR - GeneralrDescription of Site and Environs ..... am........ 15 K Section 2.3' gofthietSARo Topography .. .....: ..... .... ........................... 1'5

.- Section 2.5 of the FSAR e Meteorology ...................................................... ..... 15 Section 2.6 of the FSARu- G eology...................... ......................... .............. ..... ...

1...

15

. section

- 2.7 of te FSAR - Hydrology ........ .. . . . ........ ....... ...... .....16 16.

Section'2.7.2 of the FSAR - Ground W ater a-......

. . ..... .... ._............ ... 16 .

16.....e.

Section 2.10 of the SAR - Environmental Radiation Monitoring 17 17.................

Final Safety Analysis Report, Appendix B: Site Environmental Studies .... 17 Updated Safety Anialysis Report, Appendix C: Foundation Studies, D~ames and Moore~

... ................... ......... -....... ...... 18 Updated Safety Analysis Report, Section 2.6: Site andcEnvirons m........... - Geology ... 18 Updated Safety Analysis Report, Section 2.7: Site 'ad Environs - Hydrology 18 VI. 'Review and Evaluation of Hydrogeologic Reports.for*theCharacterization of Site "Geology and Ground Water Since FCS Became ;Operational.. _* ..... ........... 18

• J~' 'K~~~Ž _____

TSD# 08015 Revision :01 Page 3of32

• Hydrogeologic Investigations Report, FortCalhoun Power Station, Water Treatment Sludge Disp6sai Area; SCS* Engineers, June, 1995......................+..18

• Hydrogeoloogic Assessment Report, 0PPD Nuclear Power Generating Station, Fort Calhoun, Nebraska, Teracon ConsultantsIInc*, December 14, 2007 .... ........ 19 o Ground Water Gradients ........................................ 19 o Strontium -90 ........... .... ............................................................................. 21 o Hydraulic Conductivity Testing..;.:.. ..... ....... .........,.............. ............ 22 VII. Evaluation of Regional Hydrdgeological Characteristics in Reports Published by they U.S. Geo16gical Surv',ey and theNebrsaDptmn of..Natural.,Resourc'es ....... 22

• Geology of the Omaha'-Coucil Bluffs.Area, Nebraska-Iowa,: iUSGS. Pr'fession'aI Paper 472,;Robert D. Miller, 1964 ............................ ...... 22 K econnaissance of Ground Water Quality in the. Papio-Misisou'ri River Natural Resources District, Eastern Nebraska, USGS Water-:Resources Investigations 94-4197, IM. Verstraeten and M.J. Ellis, 1995........................................... ..... 23

• 2006.Annual Report of the Missouri Tributaries: Basin; LB962, Nebraska .

Department of Natural Resources .................................. 24,

• Nebraska Data Bank Interactive Maps, Nebraslia Department of Natural Resources ................................................................ 24 VIII. Evaluation of the Priority'fidex for Selected'SSCs Containing Radiological M aterial .................. ........ 2..5..................................

................ 25, IX. Summnary of Recommendations .................................. . . .......... 29 X . Referenced R eports .... .................................................................................... 30.

List of Tables Table 1: Recommended: Revisions to Priority Factor Scores ..... . .......... 25 List of Figures Figure 1: Existing and Proposed*Monitoring Wells: ..... .............. ..... 32

TSD # 08-015 Revision 01 2Pa~ge4of 32 Review of the Ground Water Protection Program Fort Calhoun NucleartPower Stati~on.

Fort Calhoun, Nebraska This report~evaluaites severai elements of t he ground water protection rogram for Fort CalhouniStation (FCS)., The elements reviewed include those outlined in Radiation.-

Safeyi' and Control Sepc (RSS) Proposal toPCS dated Octobler 31,2007, in which the scopeof the propos.edconsuling* seryices w ribed.

Evaluation of FCS' Compnletion of "Actionl1"Items of F.

the NEI Ground Water Protection Program O 1.1 of the NEI Ground Water Protection Program:

-bjective S Wite CHdroliog and Geology" a) With. thecompletion of constmction of an array of monitoring wells within the indstral reain August 2007 (1 erracon Consultants, Inc., 2007) and measurement of ground water levels iin Septmber, October and November *CS~has characterized the stratigraphy of the area.andgbegun th process of determining ground water flowi Th~e ~~di'h~ anbe expected to vary seasonally, and seealmr graiets quarters of monitoring data wil.I be required to understanid the rangge6ngrounod water flow characteriistcs- Hydraulic conductivity testig was completed in each of the new monitoring: wells pt MW-8).w gw com*l"V fi:e'ch 6f"the b) This reportdocuments a reyew ofthe 2007 Terracon Consultiats report and earliei reports of environmental studies of FCS, including sections of the Final Safety Anailysis Report (FSAR) and Updated Safety Analysis Report (USAR) (see Section V).

c) One possible pathway for ground water to migrate from on-site't6 off-site locations haszbeen identfiedi: discharge o ground water from the site to the MisssouriRiver and subsequent flow downsteam. SiSte ground water wrthithe radius of influence of the rproduction well supplying wa~ter to th~e reverse osmosis treatment plant ("RO well") is

'capýtured by that well and used for on-site process water. Much of that water

.ultimately leaves the site in the form of steam or water vapor.

)The Fort CalhounGround Water Protection Plan (GWPP) has been reviewed to evaluate its conformance withthe acceptance crlteria tpscribe*1 by tie Nuclear Energy Institute Ground WatierProtection Program. The NEI document stipulates that each ground water protection program should estalishi the fequency at which

'the site conceptual model is reviewed. Periodic rev'ie is required to assure that new information that may b*e dveloped pertinent to the o:cur*c*ce and monit6oring of ground water contamination is' icorporated into the cit delad the

TSD #08-015

'Revision01 Page.5.D0f32 ground water protection.plan. The FCS GWPP specifiesgthe-frequency of review of the Site Conceptual Modelin Section 6.7 of SO-G- I18 . .

e) The.FCS FSAR should be updated toreflect the hydraulic gradients, hydraulic conductivities and ground waterflow velocities determined during the August 2007 hydrogeologic investigation off the site. The FSAR should also be revised to indicate the apparent seasonal reversal of ground water gradients near the Missouri River.

phenomenon

.This was'doc .umented both by Terracon Consuiltants .(2007) and by SCS Engineers (1995) in thei. report of closure ofthe water treatment sludgeidisposal area, Objective 1.2 of the NEI Ground .Water Protection: Program:

Site Risk Assessment a) FCS has evaluated each' structure, system or component (SSC) and work pr.ctice.that could reasonably be' expected to contain lice.nsed material and for which theres is .

credible mechanism for release.of the materialto ground water (seethe evaluation of Priority Indices for each' SSC in Secto III)on ..

b) Leak detection methods for each SSC and work practice that contain licensed material for which there is a credible mechanismfor0release of the material to ground wateri are considered in determining the "Priority index" for each SSC or work practic. ,In the section "Current FCS Groundwater Protection Status", the FCS GWPP m* tJntionis

" the existence of leakage monitoring plans for ih'e spent fuel pool, transfer can*land' thereactor cavity.yIn addition, Item 4 of Phase Hll Initiatives 'i the GWPP discus.iss identification of leak tdetection methods; appropiate for each SSC.or work practice, such as operator rounds, engineermgmispections;,,

radiation monitoring systems, integrity tests, NDE- methods and ground water "

monitoring, should also be"iincluded in the GWPP.:

c) Potential enhancements to leak detection,. ystie: toprografns are discussed in the FCS GWPP (Phase IIl Initiatives, Item 5).

d) Potentialenhancements to prevent spills or.leaks from reaching ground water are discussed in the FCS GWPP (Phase HII InitiajtivesItem 6).

e). The site process for tracking corrective actions is*i*esumably the Condition Report' process, but it is not specifically discussedtin the FCS GWPP. The process for .'

tracking corrective actions at IFCS should be clearly defined in the GWPP:

f) Long-term programs zto perf6rm preventative maintenance and surveillance to, minimize the potential for inadvertent release oflicensed: materials to grounnd water.

due to equipment failure are discussed in the ECS GWPP, Phase IjInitiatives; items:

A IIl and A12 and Phase IlIInitiatives,-Itermi C2.

'TSD # 08-015 Revision 01 Page 6 of 32

g) The frequency for periodic reviews of SSCs and work practices is discussed in the FCS GWPP (Phase Ill Iitiatives, Itemr8).

Objective 1.3 of the NEI Ground Water Protection Program:

,On-Site Ground Water Monitoring.

a)'Monitoring wells have been, constructed down-gradient of some portions of the plant.

'The wells were drilld acrdance with the FCSdociument:,"Data Quaiity.

Objectives for WellDrii i'Evaluation of the"ground water gradfientsmeasured

.during the 2007 inetgto eel ground water flow directions not fofrmerly anticipated in some areas of the plantindustrial area, Additional monitoring wells are

-recommended in 1ocationss now revealed to be down-gradient of potential sorcs of release of radiological material to the environment (see Section VI).

b) Monitoring wells have been placed near SSCs that have therhighest potential for inadvertent releases to grod water: Howvever, because of ground :nanticipate water gradients In some areas of the plant, additional wells are reco9mmended~, as noted above.

c)., Sampling and ng analytial senstivity requirements, are  :

discussed inItem 9 of Phase IllInitiativesoff the GWPP .'

d) The FCS GW~PP, estaiblishes a formial, writteni prga o long-term g~round water

.monitoring. Detailsas to the specific *wellsto be monitored, analytes, sampling frequency, nmiiniuf detectable concentrations, data-quality . "data managemnent process should be provided.

The GWPP discusses review o f station or contract laboratory *CS  :

analytical

.,capabilities (Item 9 of Phase Ill Initiatives).

.f).he FCS GWPP discusses establishment of a long-term progam4fr preventative m.ainten"ance of ground water monitoring wells (Item 9 .oftPhase*I I nitiatives) g): The FCS GWPP discusses establishing,th rqec o eidcrve of the ground water monitoring program (Item 9 of Phase IlIIlnitiati*es). <.

Objective 1.4 of the NEI Ground Water Protection Program:

Remediation Process a) ItemnD~2 of Phase TV Activifties in the FCS GWPP requires that a determiniation be~,

made as to when ground water clean-uip activities are needed. Iterj 1 ~I ofPhase Ill Initiatives of the GWPP requires establishment of writen procedures outlining the.

TSD # 08-015 Revision 01 Page.7 of-32.

.decision making process for*iemediation of leaks, spills or other instances of inadvertent releases to grundwater.

d The.GWPP could stipulate that no investigation

.of impacts to ground w'ater is neededfor 'leals or spii*i. that occur inside and are contaired within structureswhere there is nDocredib*e niechanisnv for rel*ase *6f radionuclides to the environment.

b) The FCS GWPP discusses evaluation of the piotentialfor detectible levels of licensed material resulting from planned releases of liquids anddairbortieiiterials being identified by the ground water monitoring program*(Items 23 and 24 of Phase III Initiatives).

c) The FCS GWPP discusses theneed to evaluate decommissioning impacts resulting from remediation activities durinig the operating lifeof the plant, or the absence thereof (Item 12 of PhaseJIiInitiatives).

Objective 1.5 of the NEI Ground WaterProtectionProgram:

Record Keeping a) The FCS Ground Water Protection Plan establishesa record keeping .prograpm to meet the requirements of01 QFR 50.15(g). Aspects ofithis program are discussed in Items A6, A14 and Al 5 of the Phase I nitiatives anditems 19, 20 andJ21 of Phase ii "

Initiatives ofthe GWPP.

II. Evaluation of FCS' Completion of Tasks Prescribed in Section 5.0 of the EPRI Ground Water Protection.

Guidelines for Nuclear Power Plants ("Locating, Installing and TestingGround Water Monitoring Wells")

Section 5.1 of the EPRI Ground Water Prqotection Guidelines:

Data Quality Objectives for Well b lling i FCS has prepared a document titled: "Data QualityObjec*ives'for Well Drilling". That' document adequately describes the data quality objectives*frddrillihng *ntorig wells and should be incorporated into the GWPP for FCS.

Section 5.2 ofthe EPRI Ground WaterProtection Guidelines:

Well Installation Considerations 5.2.1 ConfigurationMainagement for Well Drilling

TSD # 08-015 Revision 01 Page 8 of 32' The construction details for*o*ntoring wellsdri'lledin 2007 are'documentedin well logs proyided.by Terracon Consultants (20) hs rle n19 r documented inwell logs provided by SCS.Engineers (1995). FCS may find it usefult tosuurnmarize in a database the pertinent details of each w includitn, g total deptli, diameter,.*screehed~ interval, elevation of top 'of casing and water level, These parameters should be summarized for all site wells.

5.2.2 Pemnitting Requirements for Well Drilling, Terracon Consultants (2007).notes that the monitoring wells dlled in 2007 were, constructed in accordance'with Title 178, Chapter12 of the Nebraska Adrinistrative Code.

5.2.3 Well Location Well locations were determined based upon the ~site conceptual model and the FCS "document: Data Quality Objectives for Well Dirilling".

5.2.4 Samnling Accessibility FCS Monitoring wells dilllednin 2007 and 1995 are 'twoinches.in diameter>.This is a comnmon welI'diameter and'iis large enough toacmmdt submersible pump

--for sarnpling'2 Section*5.3 of the EPRI Ground-Water Protection Guidelines:

,Monitoring Well Construcftibn ." .

Drilling and construction of monitoring wells in 2007 and 1995 "were completed un.der' the6 supervisipnlof qualified geosientists. The geologic materials pnetr*ated during drilling were sampled and loggedtod allow determination offocal stratigrfphy.*All wells drilled during both'of these campaigns conformn with recognized staidards such'as STM D5092-02. Thewells'drilled in 1995 were noted by SCS Engineers to have been drilled by*,a State of Nebraska Licensed Drilling Contractor. . " .

Both.Terraaco'n Consultants (2007) and SCS Engineers (1995) estimated linear gound

,Water flow velocities atth'e site. SCS Engineers based their:estimates on hydrauli

conductivities determnine&dy. Dames and Moore (9l£68). Teicon Consultanits based their estimates onhydr~aulicconductivities they determinied from slug testscompleted in.

te&monitoring wells drilled in 2007.

Secib on-:5.'4of the EPRI Ground Water Protection Guidelines:

Maintenance Program for Monitoring Wells.

Monitoring wells:constructed in 2007 and 1995 have proper surface completions that' provide secu'rity from vandalisn and protection from infiltration of surface water. The

TSD # 08-015 Revision 01 Page 9 of 32 FCS GWPP includes a requirement to establish a maintenance program to insure the continued integrity of monitoring wells (Item 9 ofPhase'ili Initiatives).'

lll Upate of the FCS Site ConceptUalIModel The Missouri River is:a large perennial stream that is the primary surface drainage featute in the vicinity of FCS. The river is also the site of regional ground water discharge.

Because of its location on the flood plain of the river, the topography in the area of the power.plant is flat.; The resulting hydraulic gradieit within the unconsolidated sediments in the.flood plain is also relatively flat. This loiw hydrauiic gradient, combined with Kmoderate hydraulic conductivity of the generalli~y:ne -gained alluvial aquifer material, results in relatively slow ground water flow velocity beneaththe site.

Land use within theflood plain adjacent to FCS is agricultural. A bluff located aapproximately 2,5.00 feetsouthwest of the river rises aaew: hundred feet and is up-gradient from the.ýplant; A few residences are.located on thtebluff. NoWiatgeh*rahawals, of ground water that would divert flow off-site:,exiistnear the plant. A sufrface-water municipal supply drawing from the :Missouri River is located upstream o;bf-FCS in the .

nearby town of Blair, Nebraska. This municipal suppsySystemi is thesource of potablef-p

• water for E'S. The water supply for the City ofO rruahiis: also drawn!from the Missouri River, about 20 miles downstreamfrom FCS..

Process water for FCS is purified in a reverse ,osmosisS'(RO) treatmentipiant. The source of water to the treatment plant is a production well located at the northwest cormer of the old:warehouse. Testing during construction of the well determined that it is capable of producing approximately 500 gallons per minute (gpm). The production well was in service as of August 2007, continuously pumping about 200 gpm.

The radius of influence of the "RO well" hasnot beendetermined quantitatively, but can be assumed to be several hundred feet. Waterlvlsimeasured during the fall of 2007 in some of the newly constructed monitoring well witin the, restricted area indicate a direction ofground water flowt4owardthe RO well. Water: levels in Septenberand early October showed'the flow directiohnto.be to the southwest (toward the RO well),-.

throughout: all of therestricted area., In late October and Nov.emberý the' ground water flow .direction within approximately 600 :feet of the RO we0l continued tobe toward the southwest,,.but;at distances greater than about 600&feet*from the well,. thedirectioniw.  :

reversed to flow to thiehnortheast (toward the Mi ssouriRiver) .

Section 2.5 ,ofthe Final SafetyAnalysis Repoi0t orCS notes that370,to 715percent of the local annual pfecipitation falls in showers andthuinderstorms that-.occuri duiring the eried April throu gh: September. This pattern ofr*!fral*itis:reflectedjin ground !waterlevels.

measured at FCS. Water levels measured in site wells on September 10 and 1:1, 2007 were approximately three eet higher than those measured inrithe same wells on, November 30, 2007,(Terracon Consultants, 2007).

TSD #08-01-5 Revision 01 Page 10 of 32 The observed ground water gradients in the restricted area suggest that during the spring, summer and early'fall,*w<heni most precipitationoccurs and ri'er flow is relative*y high, bank storage is recharged by river flow and the direction of ground water flow near the river is away from the channel (toward the'sou~thwest on the soth side of the river). 'As' river flow recedes during the late fall and winter, bank .storage is reducedandground .

water near the'ri'ver reverses to flow toward the river. A eeslo gon ae

.gradients near theriver was also'documented by SCS Engineers in 1995.

The effect on ground water flow of pumping the RO well is superimposed on the effect of river flow. At distanicesfrom the well less'than about 600 feet, the RO well continually induces ground water flow toward it. At greater distances from the well'witlhin the

..industrial area of theplant, theeffects of low river stage, during th late fall and winter predominate to icausea reversal of ground water flowtoward the river. .The hinge line along which the in ground.water

)revesal flowdirrection occurs appears to bel. ,

approximately 600 feet from itheRO well. 'This distance*i* the presumed radis of. K: .

influence of the well within therestricted area.,

Contaminants that may be released to the ground water at FCS would be tr.anspoted in the direction of ground water flow. The apparent seasonal reversal of flow dir*ctions under the northeastern portion o fthe restricted area, between .location th of approximately monitoring wells lMW-2A and 2B and the river; will complicate the transport of contamiiantstln this area. .MW-2Aand 2B are also located'within the area whriere plant pre-construction p*lf*s show a swal. formerlyexisted. The hyd:raulic

,properties of the sements'filling this former drinage fyontrast significntly with-those ofthe adjacent  : and may-affect goiuindwater flow in the area.,

Nopotenitial receptors of ground, water contamination exist within the restricted area.

Contaminants may:be ccaptured by the pumping' R well-southw."est of the restricted area".

w produces approximately 200 gpm from a a faquifer whoseshapeis approximately circular s in ground water drawn into the well *would be' diluted with water from some sectors, within itszone of influence that are.not impacted,,

and the net concentration of contaminants in the well discharge wouldlikely be lower thantihe l]evel in theintercepted contaminant plume.

The unconsolidated sediments that underlie the plant can be groiiped generally into tw units: an upper finegrainedsanidyclay with silt approximtely: 20 to 50.feet thick, and.an underlying fine to coarse s*and ith 'some gravel. Thilo'wer un to the y .itextends

,relatively d "flat-lyi'ng carbonate bedrock'surface at-a depth of approximately 70ioJ5 fet below grade. Both unCODSOlIdat'd units are water bearing, but the deeper unit has higher hydraulic conductivity. The*depth to ground 'water ranges fromabout 15 to feet ei2 below' ground suface. Solution cavities have been identifiedwyithin the upper portion of the carbonate bedrock, but the water-bearing characteristics of this unit have not been investigated at FCS.

TSD #08-015 Revision 0.1 Page 11 of 32 Tritium is the most likely:piant-i~lated raidionuclide to bedetected inground water at FCSb*beause of its relatively, high inventory within primar*i* ooling water and its lack' of

.retardation bysopto to soil. Other pla~nt-related radionuclides that are less mobile; within the environment, but are also present in primary, cooling water and have been-.'

detec .td A grud wteraaother nuclear power statonsofsimilar design~, include: r90,

,Cs-.1:37,Co-60, Fe-'55, and Ni 63,.

Virtually no tritium has been detected in ground:waIter samples collected in September and November 2007. Strontium-90,0'as-detected in the shallow wells of both theeMW-3.,.

and:MW-4 monitonng wellclusters in November. However, Sr-90 was not detected in t~hese wells during the next samipling rounid in: ýMarch 2008. No ~plant-related radionuclides have beendetected in the deeperm onitornng wells. The soiurce of Sr-90 in MW-3S and MW-4S.in.No0embei2007,is not clear Ciiontinued quarterly sampling of these wells and analysis forSr-90 miay suggest that th&eNoyember'results were false positive or may provide'ar indication of the source of this radionuclide. The ground water flow, gradients and xrelated contaminant flow paths in the area where strontium was detected: in November 2007 Ihave been shown to vary seasonally. The seasonal reversal of flow gradients in the area of wells MW-3S'and MW-4S may influence the local ground water quality.

Potential sources of ground water contamination at FCS include the spent fuiel pool (SFP), the safety. injection:refueling water~tank (SIRWT), unlined concrete sumps (including those in rooms 21, 22 and 23 at the lowest elevation of the primary auxiliary building (PAB)), and the radioactive effluent (radwaste) pipeline from where it exits the turbine building undergIround toits point of dischage undergr6oud in the cooling water discharge tunnel.

Releasesoof radioactiveAliquids from a*ny of these potential sources would occur at or near the ground surface. Accordingly, *hefirst water-bearing unit to be impacted would bethe fine sandy silt layer. Because pumping of the RO well induces a ground water flow gradient that is opposite to the inferred natural gradient toward the Missouri River and because flow gradients near the river apparently reverse seasonally, the existingarray of.

monitoring wells does not allow sampling the flow paths down-gradient from these potential contaminant sources in all flow conditions. FCS may consider adding a few shallow ýmonitoring wells to the array to eliminate these apparent data gaps.

The vertical ground water flow potential in the areaof the SFP, SIRWT, and PAB was determined in 'October 2007 anid was generally downward across most of the restricted area. Because of-its,1ldcation within the floodplain ofalargeiver and proximity to the river bank where ground water typically discharges, the vertical flow potential for ground water inthe :vicinity.,of the radwaiste pipeline.is likely upw*rd much of ýthe time.

However, during periods of high iver ,stagethis vertical flow potential is-likely reversed.

TSD # 08-015~

Revison 01

~Page~ 12' of 32 Several hundred gallons of!primarywater overflowed the SIRWT and were released to the ground during one event in the, id-1980s. Although remediatioin ofvsurfacesoil was completed, the, clean up was basedupon surveys for gamma-emitting radionucides. A substantial ,volume of tritium likely impacted the so~il and~ground water dluring this event.

Some of that tritium myea suspended b p rces th soilwithithe vadose zone above the water tableinthe area of the spill.Seasonal rises in ground water level mnay remobilize aportion of that suspended tritium an contribuite to residual

-ground water contaminlation.

..The SIRWT* is aniundergiround cocretne.tank with a. coated carbon .stee*liner,.

....Undetected leaks, to theadjahave developed vep around penetratins and.

racksin the concrete walls. Becuse the concentration6of tritium in thewater within the tank is on the order of several tens ofm;"illions of"pCi*Leven veysliow'leks could result in asiggnfificant impact to ground water.

L'eakage between the concrete walls and stainless steel linerof the SFP has been moiitorcd for several >years in an installed leak-off coll*ction system. Until February 2005,, the: rate of leakage ws a few quarts per d. the leakag rate increased to amaximum of nearly 300 quarts perday.' Since June.2006, the.

.rate has decreased to 3*ori4quarts per day. Although the water collected: theleak-off collectiOnsysternhas been confirmed to.be' fromnthe SFP, the, cause'of thisobserved ponditlon., s not know n.::*::  : . .. . ** :*,.i,,'.*......! *.:":7,* :,; .4.;:::..::* -

.Reote in spetion of the SFP liner with a submersible camera did not, idetif any suspected k. offsystem w ear icompleted njecting a measured volume of de-ionized water into four ports located ithe liner above the normal water level in the SF1 The. injectedi water was recovrd over.a 2 and revealed that the leak-off ystem is comprised of two inter~conmnecte systems.

Results of the testing su'gest that the SFP leak-off system is intat and capable of identifying The and captu.rig leaks from the SFP.

m haniss'.'hcapaioulie Tlhe mechanismsby wh.h or uiades mght be released to the environmentfrom other potential soucssuh aunl.inedconcrete sumps, within the PAB or from the :radwaste discharge pipeline, are more obvious. The crystallincs r of concrteteis? ,'

ocucture approximatelyA 5 percent e is known to be serm-permeable to water concrete jand (anddtitium). Cracks in the sump concrete or pipe penetrations *,ithinthe bottomn or

walls of the sumps would increase the potentialfor leakage of radioactive fluids that the sumps accumulate. Stress corrosion cracks in the walls of the stamless steel radwaste.

pipeline, or failure of welds atjoints and fittings, would result in release of concenfrated radioactive liquids to the adjacent soil.

IV. Review of Construction Photos.

TSD #.08-015 Revision 01 Page 13 of 32 A total of 62 photographs, of various phases of plan* C0onstruction were reviewed to identify features pertinent to ground water conditions at the site. The photos confirm. the following:,

• Prior'to construction of the plant,theisite was used for crop cultivation'

• Pre-construction topography was geherally flat over the.inldu strialarea 'ofthe: site, with a slight downward gradient to the northeast, toward: the Missouri River.

A photograph dated Februf3, 19609"isows virtualiy continuous ice covering the reach of the MissouridRiver shown in the plato:'

Soils exposed by construction excavation (to a maximum depth of approximately twenty feet)arefineigrained: .

• No cobblebr boulder-sized clasts are visible in the'eposed sediments.

• Stratification of the exposed, sediments -appears to be horfizontal, indicating the .

presence of flood-plain alluvial deposits. '.

" Excavation deeperthan appiroximately fifteento' twenty feet encountefed the water table and required dewatering to proceed deeper.

" A dense network Of piles was'installed to the b*drock surface beneath all Class t structures, including the reactor contaimenftbuilding, primary auxiliaay buildng' and cooling water intake structure. Installation.oifthese piles, and subsequent'treatment of the surrounding soils by yibroflotatio'n-ncreased the dn ts 'sity I ,.

altered their hydroge&glgic characteristics.

A water-filled swale is visible in the area of the plant on several early Constructi on photographs. The swale is located parallel to and approximately-250 feet southwest-(inland) from the current channel of the Missouri River. The swale rmarks the remains of .a former, channel of the river which"is separated from thencurrentchannel by accretionary sediments deposited by1theeriver. The swale on the photos terminates toP.the east and west of thei present industrial-reaof'the -plant, buta hmap by Dames and Moore'(Plate 3)i'n Ap endix C of the USAR shows the swale to .have been continuous beneath the area now occupied by the reactor containment and primary auxiliary "building before plant construction began. The sediments filling this swale

,may have hydraulic properties that, contrast,wth*those of the adjacent sediments. If so, the presence of this feature may affect the periodic reversal of ground water flow gradients. measured in this.portion. of the site and could potentially influence-.he transport!fof gr idwatercontamminants released in'the area.

V. Reviqw. and Evaluation of Reports Containing Pre`

Operational Ground Water and, Geologic Data Design Basis.Document PLDBD-CS-51: Seismic Criteria This document contains very little geologic data relevant to ound water. Instead, it is focused on determinmng seismic criteriasuch as the'history of seismiciof the regin surrounding FCS, the agnitude'of the largest probableagroundmovement resulting from'

TSD # 08-015 Revision 01 Page 14 of 32 an eahquake and deteination of the response acceleration spectra. A study of he tpossible, existence of faults was made during the geologic irivestigation of the area- of tlhe.:.

andlrecent sedimens oftflheý

.,,Site. No faultingwas fo)uniin the*eunconsolidatedPleisitoceneacthetybsinc Missouri-iRiver low landsi*d no seismic th***ginning Of tsignfcant

,.the:Pleistocene Epoch 2 million yaiasbeforepresent.

Design~Basis Document PLDBD-CS-54: Geotechnical Thisdboument also contains very little geologic data relevant to grourd ater. PLDBD-CS-54 primarily discusses requirements for foundatondeign, which must t PLDoBD-account-the physical characteristics of the site, mcluding eismology and geology. The geology is dscribed as "consistingof alluvial deposits.65 to 75 feet thick. Bedrock is mostlyilimestone andekxhibits little relief. A number .of solution cavities were found to exist in the upper 15 feet of the bedro.ck."

."The upper 20 to 50 feet of natural soilskare predominantly silty sands and sandy silts.

The lower soils consist of sanld with interbedded gravel lenses*.' The relativly loose upper soils were not consildered suitable for support of heavilyloaded foundations or foundations of'settl~ement-sensitive structures. The denser lower soils and bedrock were considered suitable for support of heavy foundation loads without detrimental .

settlem-ent." The FCS site conceptual model is consistent with this nformation-.

The: ground water level at the 'site is typically 10 to 12 feet below ground surface. It'Is generally near riv.erleYel and varies with it." These depths to ground water are"ess~thalh the 15 to 20-foot rangel that was measured in the ffallof 2007-.rGround-wte d are

'deepernow presumably becausettee plant grade was raisedbyaddition o fill din ant

construction. -

Section.vI of PLDBD-CS-54 states that .. ccause consolidation ooffine-gramed soilslike those found at Fort CalhounStation. *This could result'in sett*fei tf structuressuipported on spread footings'. This possibili " shouIld be examinedbefore hge lowering of the water table beneath1anystructu*e". C,.s lass'I.

striictures such.as the reactor containme..nt'and imary auxiliary buildig air founded

• n pilesandwould not be subject to potential' settlement due to dewatering of soils.'. .

However, the old warehouse is not founded on piles and is likelysupported on spread footings: This structureis adjacent to the "RO well", a pt pumps approximately 200 gallons per minute to the reverse osmosis system providing treated make-up water to the plant, Pumping of the well of dew'ateredsi creates a mass:lists*a in the shape of a conecentered on the well. TheR0 wel1reistration wr a diadw drs..oil of the static water level in the well from 18 to 20 feet, at a pumping rate of 500. gallons

.pe miuteAsumig tese at reflect ~current operating cond~itions, it se~ems unlikelyi that the two feet of induced water-level drawdown would pose a significant risk of soil' settl 'ent that would damage the'foundation, of the nearby old **ehus

TSD #08-015 Revision 01 Page 15 of 32 FinalSafety Analysis Report, Section 2: Site and Environs

• The following sections of the FSARcontain some information pertinent to ground water protection at FCS. Brief descriptions of the relevant content are provided below.

Section .2.2.of the FSAR -GeneraIDescription of Site and Environs This section presents an overview of the location, size and land use of the FCS property.

The FCS site conceptual model is consistent with the contents of this section.

Section 2.3 of the FSAR ,-Topography',

This section describes the: flood plain 'of the Missouri River in the vicinity of FCS, the bluff at the southwestern extent of the flood plain and the variation of land surface elevations across the site.

Section 2.5,:of the FSAR - Meteorology Description of the meteorology of the site provides some insight into the variability of river flow and ground water levels at FCS. The localcimate is characteriZned by warmft.

summers and cold, dry, winters, with marked variation intemperature and rainfall from year to year. Air approaching from the west looses most of its moisture on the windward side of the Rocky Mountains. As a result, no significant amount of rain or snow reaches the state from the Pacific.

The source of moisture for..Nebraska is the Gulf of Mexico, The remoteness of this source contributes to the wide variation in rainfall from year to year. The prevailing wind direction from May through December is from the south-southeast. Relatively dry winds from the north-rnothwest predominatethroughout the remainder of the year.,

Section 2.6 of the FSAR Geology -

This section describes the regional and local geology, including the geologic history since the early Paleozoic Era and the glacial history of the Missouri valley. During the, Pleistocene Epoch, when the iuterior of the continentwas covered-by continental glaciers, Nebraska was' occupied by oiilythe firstt*w6 o four major ice sheets. Nebraska anid westernIowa were not covered by the later continentat glaciers, but during advance and retreat of nearby ice sheets wind-blown deposits ofine s6and and siltf:accurulated to thkiknesses:of as much as 100feet. Thhese' deposits,'kown- asloess, form. the steep-sided hills and bluffsofeastern Nebraska and western:Iowa.-

TSD # 08-015 1.Revision 01 Page 16 of 32, Unconsoli datedse'd imeuts at the site generally range* from, 65, to 75 feet in*thickness. The

.soilsare typically interstratifiedanddcross-bedded.. 'The beds ;chmnagei*r-grde. gra:

laterally sorapidly tath nobed lithologic correlation is ,possibleffnoibdriiigt'borng.

The boring data indicate that the upper 20 to 50 feet of s6il areredominantly silty sands and tle lower beds c osffine-sandswi ;oc~casinal iterb~edo Thie.FCS site conceptual model is consistent with the inf6orantion in thi"s ection. -

Section 2.7 of theFSAR - Hydrology Six dams upstrearm of ECS controlflow in the utpper Missouri River. The closest'is Gavin Point, approximately f50 miles upstrea*n at the South Dakota- Nebraskaborder.

.Because of the large' watershed between the Gavin Point Dam and FCS, the dam has relatively little effect on dyt -dday river flow'at FCS.,There areno dams onthe liver

'downstream of the plant. The design peak flood stage attheeplant is an elevation of 1004.2ofeet above mean sea level. . -,

Section 2.7.2 of the FSAR - Ground Water Movement of ground waterunderi-the uplands'southwest of FCS istowardaand into the Missouri River trench. The' FSARnotes that the occurrence of spring~s alongthe base of bluff confirms henmovement of ground water away from thehillsand toward the the riv . " ',  :: ., , S.

Ground water: levels inmeasured in borings at the site in July and August 1966reveal that ground water gradients are nearly flat, with only a gentle slope to ardthe river. The'

,water 'tablew~as approximately 10 feet below land surface:. Ground wat!er lvs were noted.to0vary with river levels!., The rate of ground Water flow in the alluvial soils varies with permeability but is very low because of the low hydraulic gradients. Th'e temperatureof ground water measured in August 1966 was 540 1andd it was noted that no large seasonal',anratins in temperature can be expected.

The coefficient of permeability (hydraulic conductivity) was reported to vary from 0.55 to 3 feet: per day (1.8 E-4to 1.1 E-3 centimeters per second) in' the upper siltysaiind.In the lower fine to coarse sa" d and gravel, the permeability Was noted tobe as 'high as 20 ft/day (7. E-3: cm/sec). "Th hydraulic conductivities determeiye ................

• in i

200,7.are an ,order of magnituideor.more higher ithan the values noted in*the FSAR. These-

higheruvalubes may reflect the.vertical and lateral vanability in soil texture across the site.

mgtest was conducted byDames and Moore in 1966 on a est w*,ll at the plant ite at arateeof 7.00 gallonsi per minute, The maxim*m*idrawdown in watlevelr was reported tobe 21 feet and the radius of influence was*estimated , 0 t 1, fe

'The Isoils 'at: the site were noted to5 be~ in direct. hydraulic'Co6nnection witlh the Missouri River., Akfadius of influence of approximately 600feet 5for the RO 'well pumping at about 200 gpm us .consistent with the noted radius of influence oofthe 1966 test well 'pumping at 700 gpm.. .

________________________ K ________________

TSD # 08-015 Revision 01 Page 17 of 32 The FSAR section on ground 'waterconcludes ,by stating that "the hydrologic character of the, site.,and- surroundingz area aind the ptern of ground water flow are such that iaccidental discharge of radioactive fluids. inito ground water would have no *adverse effect o6n existing & pot'ential ground water '.Suchfluids ,would percolate slowlyiin the direction of the Missouri Ri-,er",

--W-hile this statement is-valid relative, to dose, *isiifitafeit'co-n"cenafti-ns of ra'idioloIical material were to be found in ground water beneath FCS,' thefinding would damage :he:

-credibility of plant-manageieintand' strain public confidence. The'NEI Ground Water-Protection;Initiativ~e.acknoieges this risk' and *seeks to' minze it.by improving the detection, management and communication ofincidents, ofiround wate'r:ontar*ination by radiological material atrall:nuclear power plants.

Section 2.10 of the FSAR-EEnvironmenttalRadiation Monitoring The FSAR notes that the average concentration of tritium'in 1 well water samples in early, 1969, prior to plant .operation,.was 550 picocuries per liter (pCi/,L, and in 6 surface water samples the concentration was 1,000pCi/L. In those same samples the average concentration of strontium-90 was 0.1 pCi/L in well water and ,1.3 pCi/L in surface water.

The higher concentration of Sr-90 in surface water is of interest, inwview of the resultsof ground water sampling in Nviyember 2007 which found anomalous levels of Sr-90 in monitoring wells MW-3Aard*MW-4A. Strontium 90 was notsdetected in these wells during :theý subs equent sampling round inlMarch 2008. If surface water from the Missouri River were the source of the elevated levels of Sr-90 detected in ground water from these wells, one should expect that Sr-90 would also be detected in wells close to the river, inlding MW-5A. and MW-6. iN'o Sr-90 was. detected in'*"*

incluwas these wells. Additional quarterly sampling and analysis to confirm or refute the presence of Sr-90 inMW-3A and MW-4A is warranted, as discussed below in Section V*I.

Final Safety Analysis Report, Appendix B: Site Environmental Studies Appendix B ofrtheFSAR updates the initial comprehensive site in'vestigation. cnducted by Dames and Moore'in 1967, which included field explorations, laboratory tests, geologic and hydrologic'studies engineering seismology and recomnendations for foundation design and installation. Updates to the initial report of site investigations were required because some of the information was superseded due to changes in design criteriapand additionalTiformation acquired durinegineering stu.dies and further site

.investigations. Appendix B, provides. abri ef description f the principal'updates, and pertinent references.

TSD # 08-015 Revision 01 Page 18 of 32 Solution cavities were foun[din the limestone bedrock:.'Therefore, a more extensive . estigat,. fhehbedrock: was performed andia speciali tchnique for;.

pile installation was devised. '

., The values of the ~design eatquake an~d.;maximumn hypothetical earthquake ~

factors were increased to 8 'and 1i7 percent o5f gravity, re'spectively, in~ accor~dance with recommendations ofihe U.S. Coast aid*Geodetic Survey.f..

0.The earthquake response spectra were revised due to the change in earthquake factors.

S P).Ptential liquefaicton* othesoilswas found torequire consideration.-

• Di-scsiion*

u f the I yahgh waterevelof the MissourilRiver oof 1008.8 feet iithe t plantsitewasifnied andrevised.; -

Updated Safety Analysis Report, Appendix C: Foundation Studies, Dames and Moore Appendix Cof tthe USAR discii*sses foundation studies for the Class I structures at the site. Muiicfof the report"*i cuseson investigation of solution cavities identified in the limestone,bedrock during initial soil boring work. The FCS site conceptal mnodelis consistent'with inforiation petining to site geology provided in*the USAR, Appendix C.

Updated Safety Analysis Report, Section 2.6: Site and Environs

-Geology This section is identical to Section 2.6 in the FSAR, discussed above.

ýUpda ted Safety Analysis Report, Section 2.7: Site and Environs vHydrology This section is essentially the same as Section 2:7 ,in the:ESAR, discussed above. -

VI. Review and Evaluation ofHyd'rogeologic Reports for the Characterization of Site Geology and Ground Water Since FCS Became Operational h P e

• Hjydrogeolo~gic investigations Report, Fort Calhoun Power Startion, Water Treatment Sludge D isposalArea, SCS\

En ginekers, June, 1~99,

TSD #08-015 Revision 01 Page 19 of 32 This investigation was undertaken to close the landfill area containing sludge from the FCS water treatment plant. Three 2-inch diameter moinitoring wells were drilled and sampled for the investigation. No analyses for radioactive materials were completed on soil or ground water samples. Background levels of several metals were found in ground water samples from the monitoring wells, but SCS Engineers concluded that ground water at the site was not impacted by disposal of sludge in the landfill.

Ground water, flow beneath the site was found totbe controlled by the Missouri River.

During high rivers tages the flow was away from the river, and during low river stages the flow was toward the river at calculated velocities of less than 0.08 feet per day.

The local and regional geology described by SCS Engineers is consistent with descriptions in PLDBD-CS-54 and the FSAR: Water levelmeasurements made during ithe 1995 investigation show that ground water levels at FCS were lowest in March and highest in June. this condition reflects the yearly cycle of precipitation for the region noted in the FSAR.

Hydrogeologic Assessment Report, OPPDNuclear Power Generating Station, Fort Calhoun, Nebraska, Terracon Consultants, Inc., December 14, 2007 o Ground Water Gradients Terraco*n Consultants, Inc. drilled thirteen monitoring wells in: or near the restricted area of FCS in August, 2007. The wells are in locations that were presumed to bewithin the down-gradient flow path of contaminants that potentially could be released from SSCs containing radioactive fluids.i The wellswere constructed in accordance with industry best practices. Water table and potentiometric surfce contour mapstonstructed based upon water levels measured i* the new wells indicate ground water flow directions different from the directions presumed prior to construction of the wells.

Two conditions at FCS produce ground water flow gradients that areqopposite to those originallypresumed, Construction of a productioonwell that continuously pumps approximately 200 gallons per* inute to ther everse osmosis system providing treated make-up water to the plant was completed in December 2005. Operation of the "RO Well" began in 2006. Pumping of the RO well induces drawdown of ground water levels in its vicinity and, in the area between the welland approximately the turbinei building, a reversal of the seasonally normal flow gradient toward the Missouri River. The generally southwestern ground water flow direction inthis area will likely persist as long as continuous pumping of the RO well is maintained.

The vertical componentrof the ground water gradient at FCS is slightly downward beneath most of the industrial area of the plant. *his condition is also contrary to what might be expected within an alluvial aquifer? adjacenttoalarge river,twheregound water

TSD # 08-015 Revision 01 Page 20 of 32 4generally flows upward and toward the channel to discharge to the river. The gradients meaisured by Terracon Consultants to be slightlydownwardn ad toward the southwest are induced by pumping of the RO well.

-*The Missouri River is in hydraulic connection with ground water in the alluvial aquifer within its floo drlain, Duingperiods of relatively high river stage, which cc~ur generally,:

from April through September when precipitation is greatest, river water recharges the nearby alluvial aquifer and induces ground water flowp- gradients outward from the river channel. These gradients reverse seasonally, during periods oflower river stage, The'se

.reversals i ground watergradients are documented by Terraconr'Consuiltants in the report of their 2007 investigation, and by SCS Engineers in their 1995 investigation report, The pumnping rate from the RO well and the stage of tlieMissouri River at the plant site should bemonitored daily sand tracked over time. .These data can be compared' with ground water levels to further characterize the timing and position 6f seasonal changes in ground water< gradients. and flow direction near the river. A more tho6rough description of these periodic changes willhelp in understanding the mechanism for transport of contaminants that may be released to the ground water system.

Ground water gradients measired across the industrial area of FCS reveal that with the current array of monitoring wells there are a few unanticipated gaps in the bility to monitor potential releases to ground water in the flow paths down-gradient from some sources of radioactivewanliquids. Specifically, other than monitoring rig wellsnMW-lA wellsMW-I A ading andI speB,.

B, thereareno on the down-grdient (southwest) side-of the radwaste building, spent fuelpool and safety injection refueling water tank.

While it appears that potential releases from these sources would be captured by pumping o&fthe RO well, dilution may make it difficult to detect those releases in the RO well discharge. Shallow monitonng wells at two locations near the exterior southwest walls of the radwaste building woutld provide a means to more easily and precisely detect a release from these potential sources. Figure I shows the locations of two shallow monitoring wells prposed on the southwest side of the radwaste building for this purpose.

Finally, the legends and notes 'foir Eigures 6F and 6H in the Terracon Consultants report should be revised. Thiesefigures are contour maps showing the potentiometric surface and ground water gradients based upon water levels measured in deep monitoring wells at FCS on October 31 and November 30, 2007.'The legends and notes for these two "

figures mistakenly identify the elevations plotted on the maps ais water table elevations measured in shallow wells, Figures 6F and 6H should be revised to eliminate the inconsistency between what is described in the legends and notes and what is actually portrayed on the maps. In their memo dated May 6, 2008, Terracon concurs with this recommendation and will provide revised figures,

5. 5.i TSD # 08-01.5 Revision 01 Page 21 of 32 o Strontium-90.

Analysis of ground waters amples collected from foiirteen nonitoring wells in

November, 2007 detected5 Sr-90 in*two shal1ow wells

IMW3A and'-MW-4A. No strontium was detected in deep monitgring wells. During the subsequent sampling round in March2008 Sr90 was not detected'in these~or any other monitoring wellsi. Although

,the conffentrations detectedin November 2007 (0.972 and 2.81 pCi/IL respectively)!are below the U.S. EPA maximum contaminant level for* Sr-90 of 8.0 pCiIL, detection of this

.lparit-related radionuclide suggeststha a release to groundwater from an .SSC containing.

radioalctive liquids may have7occurred.

As noted in Section 2. 10 of the FSAR, an average concentration of O.1 pCi/L of SPr-was, deAected in eleven ground water samples at FCS be.* een November 1968 and Junie

.1.969, before the plant became operational. Dung that same period,: an average of 1.3

.:pCi/,L of Sr-90 was measured in six surface water samples at the plant site.. Because ground water within the alluvial aquifer near: the river is recharged by surface water,,

during periods of high river stage, and.significantly higher-leyels of Sr-90 have been.

m:measuied in surface ,water.relative to ground water at FCSjst seems Possible that the sourc5 e, of strontium detected in ground water samples, frorm MW-3A and MW4A may be

the Missouri River.

The. source of strontium-90 inthe river may be liquid radio6ctive effluent routinely dischaýged from FCS. An additional less likely source cobuld;be fallout from nuclear' we.apons testingthat has been eiodedby streams throughout ýthe drainage basin upstream of thie plant. Deposition of fallout effectively ended during the 1970s, when atmospheric testing of weapons was banned internationally. Strontiur-90*has undergone more than a half-lifeeof decay since that time.

However, if the source of strontium-90 in MW3-3A and MW-4A is the Missouri River, it would be reasonable to presume that strontium would also be detected in other monitoring wells ,closer to the river.~ No6 strontium has been detected in wells MW-5A, M=W B: and MW-6,. which are located between MWs 3A and 4A and the river. The source of Sr-90 in these wells is undetermined and is difficult to explain because no Sr-W90

• was.detected in the subsequent sampling round. Strontium 90 shouldbe analyzed for in argroundwater samples for seeral additional sampling runds todetermine if the

.vlues6reprted, inNovember 2007. were falseposti ayticalresults or iftheycan be i-eprodiced. Determining the source ofthe s is a matter of importance, not only.

i

• to identify any potentially ongoing leaks~mSSCs

• t al b. auseireso bn ....f its

."sourcbe(if the analytical results are confirmed) will likely be required.:at it*etime of plant decommissioning.

.Monitoring Well"MW-8 The iextk ofthe Terracon Consiltants report explains t.hat the s6il boring in which monitoring well MW-8 is completed encoiutered refusal on a concrete slab 1i7; feetbelow grade. The .geologiclg for MW-8 indjicates.that the total depth of the well is 16.5 feet.

below grade and the screened zone is completed in lean ilay. Tables 1 3,3 and 4 of the

TSD #08-015 Revision 01 P.age 22 of 32

' report nOte that MW- .wadr II October 31 and November 30, 2007.

I{yrdogeq o rlog ~oiles n F~igures 7A anid 7B of the Teacon r o~d show that the elevation of the water table in early5and late Octobe** 2007 wa's'sbelow*leottom of

... . ...... "xybelo

.as iv h,'"b6ttom of Table 2 of thereport indicates that ab'out one fot of water was mea

sured in M'..W-8 on

..October 8, 2007. This4 water was very likely infiltrated si*[#*lmoisturie that moved from the grouind surface downw~ard through the unsaturated zone, be*&ame peched on top of the concrete slab and drained laterally*very slowlyb'ecause of tie relatiavely low-permeability leari.clay in the formation at that depth. For this reason,.the water level measured in MW-8 on October 8 and the small volume of water. sampled from the well on that date

'and on November 1, was not *epresentative of the elevatiohnJfthe water table"'*r of "4

.",ground water quality in the shallow aquifer: inits vicinity. ,

Because MW-8 is not deep enough to intersect the water table during most times of the

.,year and'hecause of ?the mechanism by which perched'watr canoi ,retaine#dwithin the

..wel;wate lyevels nmeasured in the well and water samples collected fro mthe well are not prpesentative of conditions in the adjacent shallow qifer and are misleading.MW* 8 should be permanently abandoned by pumping it' full of grout. ,'4attermpt shouildbe made.to dill a replacement shallow monitoring w ell approxinately 25 feet deep adjacent to MW-8 ' '

,6.Hydraulic Conducivity Testing i.tepr*petation

... of the. sug test data provided in the Terracon Consultants rePor reSulted in

• vai of hydrauliic hls c-onductivity 'thatappeared to be inconsistentwith . the work ofother '

investigators (Dames'and Moore, 1968; Freeze and Cerry, 1979). In their memo dated May 6,2008, Teacon Consultantsjustified theirinterpretations based upon tihe fact' that

.th* tests were) conducted in stratified sediment who6se hydraulic properties vary vertically and'laterally and that the tests .measurie t'hose nly a small radius surrounding the test well.esuetoeppris.whno VII. Evaluation of Regional Hydrogeological Characteristicsin Reports Putblished by the U.S.

Geological Survey and the Nebraska Department of

.Natural Resources4 4444

~~~~. . ........ . ...... 44.<444 .  :..:"

o- Geology of the Omaha-CouncilBluffs.Area, Nebraska-Iowa,

'USGS Pro fessionalI Paper 472, Robert D. Miller,' 1964 The FCS plant site *s near'but notwithin the study area of this professional paper. The report provides.adetailed :description of the stratigraph>' 4 of the study area and the geologic history oftheregion. The principal geologic units of i*he area are the glacial

TSD #=08-015 Revision.'01, Page .23 of 32 sediments and alluvium of the Missouri River Valley, *dposited'during the Pleistocene and RecenvEpochs. These units overlie bedrock;;which is limestone ofPennsylvanian agein the area ofFCS.

This report: also discusses' the engineeinfg.properties of the various sediments deposited in:the stuidy area, and gives insight as*towhyfully penetrating piles founded on the bedrock srfAce-were used, for the fouindationof Class I structures at FCS. The types and thicknesses of soil found at FCS are not capable of supporting the plant design l*adswith friction: piles. The FCS.slite conceptual model is consistent ~with the information provided in,this professional paper. -

o Reconnaissance of Ground Water Quality in the Papio-i 6 Missouri River NaturalResour esEitrt, Eastern

'Nebraska, USGS Wate~r-Resources Investigations 94-4 19'7,,

LM. Verstraeten and M.J. Ellis, 1995 This, paper reports the results of sampling and analysis of ground water from a totail of 62 ir.rigation, municipal supply, dorestic andindustrial wells completed in alluvial aquifers and the Dakota sandstone aquifer located in the Elkhorn, Missouri and PlatteRiver .

Valleys within the study area of the report. Therepor*evaluates the effects of cropland applicationof fertilizers and herbicides on ground water quality within the study area.

Sample results include levels of nitrates, herbicides, metals, majorions and a few radionuclides. Introductory sections provide brief descriptions of the climate, soils, geology; and hydrogeology of theregion, based ipon other reports of state-wide scope.

The site conceptual model for:FCS is consistent with the information in thlese sections.

Water'fromall principal'aquifers, exceptthe Dakota aqu4ifer, had detectable l*vels of -

herbicides'. The rýeport- notes that where th'yruicgain favors lossbf surface, water, to.ground water, the detection of herbicides in water from wells along thebanksi of the.Platte River indicates that the river could act as a line source of herbicides to the local, aquifer.

This finding.has significant implications for theFCS site. First, it points out that seasonal recharge of ground water by river water (demonstrated by local reversal of ground water flow direction) is observed in the alluvial aquifer of the Platte River Villey.: This condition has also been documented in the alluvia aquifer of the Missouri River at the FCSsite,.arand apparently is a common occurrenceIinialluvial1aquifers near the major rivers within the Papio-Missouri River Natural Resources District (NRD).

Second, the finding confirms that contaminants iii river water can be trnported to nearby"ground Water in the alluvial aquifers i th* e NRD. As noted in Section 2. 10 of the FSAR thie pre-constructiorn average!concenrtiationof s*ontium-90 in riverwat er at'FCS was J1.3 pCi/I and in ground water was 1A pCi*L. Therefore, the finding of Verstraeten

TSD # 08-015 Revision 01 Page 24 of 32 and Ellisisuggestsa'Th chanism that imiglt~expainm the detection of anomalous levls of, stront~ium-90 in' EGS moioigwlsM -AadM-W-4A in Novemfber, 2007.

However,it. should be noted thtatno strontium was detected in other wells near the river (MW-5A,5 and MW-6) during the same sampling event or inmn wells dufring the subse.quent saipling M in arch 26* 8. Additional quarterly sampling and analysis for Sr- ,

90 is recommended to further investigate its source in monitoring wells at ECS. 2006 Annual Report of the Missouri Tributaries Basin LB962, Nebraska Department of Natural R~esources This report includes text and a series of basin-wide figures showing the distribution of such features as surface water bodies, annual precipitation, till deposits bedrocki-colgY, saturated:thickness of uconsolidated aquifers, transmissivity, specific yild, wa*r..tble Selevation.rgistered wellocations and selectegrounwater hydrraphs The era annual'precipitation at Omah islistedrgeoo T**the s is os30.ihes.e basin described as complex d totheglacial origin of the recent sediments. . . ..

Treport s ha ansmissivity of the.sediments in most areas of the basin have values less than 20,000 gallois per day, per foot of aquifer width This is a limitin-g value  ;.

that most. of the sedim nisnthe s basin do"not exceed. As-suing a saturated thickne.s of a'60feet at FC Shiswould correspondtoan average valiep of I*than45feetper day for hydraulic i Section 2.7.2'ofthe FSARstats that the hydrauli;c .

conductivity of'the upper silty sands at FCS raiges from 0.5 to 3 feet per day, and that of the lower fine to co'arse sand and gravel Is as high as 20 feet per day.~ Therefore, the two references corroborate one another on this finding and are not contradictory. ..

Thisreporfuhe s tt it f October ,2005,

,ere 3,697 registered water

'veils basin the;ii san tha*rigationw,-is listed as the largest consumer of ground water, with approximately !*600 irr igation wells in the basin. Amap oh -p ,we]!s :in the Missouri Tributaries Basin shows no wells the immediate vicinityof FCS Nebraska Data Bank Interactive Maps, Nebraska Department of Natural Resources,>~

The Nebraska DNR maintainsi a data bank of interactive maps on their website. Various layers of data can be added to.a base map ofany ar.ea of interestin the state. Data layers inclue soil type, aerial photos on multiple dates, elevations, wa]ter bodies, roads and registered ground water wells.

Aerial photographs clearly show th~e land usemin'ithe vicinity of FCS and itschangeo tm Wells r*egistee d to OPPD and a sumaryof their registrati io ationcan.also me Wcelssdo the interactive mapof the FCS site.. .. "p"re gistrtioi {WI*7';in :'naio:

beaccessed.

. N' *<*)'"'"'

TSD # 08-015 Revision 01 Page 25 of 32 VIii. Evaluation*of thelPriority Index for Selected SSCs ContainingRadio log gical Material

The.following table summarizes FCS' scoring of0the priority factors used to calculate a

ý,pfiority. index for SSCs containi*g, radiological material, and suggested revisions for selected priority factors. T&ýerev'ised priority ind"icesjrange from 15:for the steam

generatorblowdown -system, to 76 for the-spent fuel-pool-leak detection *system.

Table 1.

Suggested Revisions to Priority FactorScoring.

System Priority Factor OLD New Reason foruRevised Score*

Score Score Condensate History 1 1 work practice Condition 0 0 Design 2 2 Pre-release detectibn 2 .2 Inventory 1 2. PWR secondary system.

Hazard  ! l Mobility 3 3 Post-release detection I I Priority Index. 211 24 Radwaste History 1 .1 sumps Condition 3 Design 3 3 Pre-release detection 3 3

. Inventory 3 3 Hazard 2 2 Mobility, 3 3 Post-releasedetection 2 2:

Priori Index 69,69

.Fuel*transfer History 1 1

canal drain Condition 3 3 "

Design 3 3 Pre-release detection 3 3 Inventory 3 31 Hazard 2 2 Mobility. 3 3, Post-releasedetection 2 2

.... _ Priority

• n*dex: 69 6 Steam Hi-4story

. 0 0

TSD # 08-015 Revisiobn 01 Page 26 of 32 System Priority Factor OLDr New Reason for Revised Score Conditin .Score Score generator Condition1 jIowdown Design .0 0 Pre-release detection 1 2 Contained before release to th nvironment.

Inventory 1 2 PWR secondary system.

Hazard .,,

Mobility 3 3 Post-release detection 1 1I Priority Index 8 15 Componenit 1Histor 2 2 cooling wat~er Condition I I Design 0' 0 Pre-releaise detections 2 2 Inventory I I Hazard I 1 Mobility 3 3 Post-release detection 1 I Priority Index 21 21

~Containment History I 1 sunip piping Condition 3 3

,Design 2 2 Pre-release detection 3 3 Inventory' 2 2 Hazard 2 2 Mobility 3 3 Post-release detection 2 2 Priorit Index 69 69

,Discharge History 1 I header Condition 3 3 Design 2~ 3 Single-walled steel subsuirface pipe3.

Pre-release detection 3 3 rInventory 2 2 Hazard 2 2 Mobility 3 3 Post-release detection 2 2 Priori Index 56 63 Condensate History 0 0 storage tank Condition I I

'Design, 0 2 Single-walled steel tank with

___ containment.

"__........secondary

TSD #08-015 Revision 01 Page 27 obf 32 System Priority Factor, OLD- Ne Reasonfor:Revised Score

____.__...____.___ Score" Score Pie-release detection 1':2-:.Contained befbe'releaset0o the environment.

Inventory 1 2 PWRsecondary system.

Hazard 1 Mobility 3 3 Post-release. detection Priority Index 8 24 Raw water History 1 3 Known recurring in-leakage.

piping Condition 1 1 Design 2 2 Pre-release detection 3 3 Inventory 2 2 Hazard 2 2 Mobility 3 :3 Post-release detection 2 2 Priority Index 44 56:

Spent fuel History 2 3 Known ongoig!g leak.

pool Condition 2 3 .. Unknown"condition, probable

.,liner corrosion or faile'dweld.

Design 0 0 Pre-release detection 2 2 Inventory 3 " 3 Hazard 2 2 Mobility 7 3 3 Post-release detection 2 2 TPriority Index 42 56 SPF leak-off History ' 3 3

• system Condition 2 :2 Design. . 2 3P High probabilit*yfor soil::or, Pre-release detection 3 3% ground water contamination Inventory 3 3 fofllowing initia4 leak 6r spill1 Hazard 3 3 .

Mobility 3 :3.

Post-release'detection' 2 2

._ _ Priority index 76 ": ",8" "

Sa~fet~y.` History 1 1 injection, Condition 3 3-piping Design 3 ;3.

Pre-release detection 3 3 Inventory 3 3

,, _ _ _ Hazard 2 2 ,, .... .,_..-. ........

\~

TSD # 08-015

" Revision 01 Page 28 of 32 System, Priority Factor. OLD New Reason for Revised Score Score~ Score Mobility 3 3 Post-release de~tection 2 2 Priority Index69 6 Safety History * . 2 2 injection Condition 1 1 refueling Design 2 '2.

water tank Pre-elease detection 3 3 Inv~entory3 Hazard 2 :2 Mobility ~ 3 3 Post-release detection 2 2

_________Priorit Index56 5 SFP History,,.< 2 2 cooling/IX: Condition 1 1.

Design 0 0 Pre-release detection 2 2 Inventory 3 3 Hazard 3 3 Mobility 2 3 High mobility (H1-3).

Post-release detection I I

.:Priority Index 31 ý35 Turbine History'1 1 building'- Condition 0 1 Good condition, no known sump leaks.

Design.... .... 1 3 Unlined concrete sump.

Pre-release detection 1 .. 3 Undetected until in the environment.

Inventory ~

HazardI Mobility ~ 3 3 Post-release detedtion 1 2 First detectegd at on-site monitoring station.

Priority Index 13ý .39 Discharge HistoryŽ 3 ~3

• tunnel pping Condition 3 3.

Design 2 .3 Singe-wall steel subsurface pipe.

Pre-releas& detection 3 3.

• Inventory* 2 2

________Hazard 2 2 ____________

TSD # 08-015 Revision 01 Page 29 of 32 System Priority:Factor' OLD New, ' Re ason for Revised Score

_____M bliy_

_________ .________,-Score: "Score ____ ____ ____ ____

Mobility. ~ 3 3 Post-releaseidetection, 2 2.

______Priority Index 69 75.1 IX. Summary of Recommendations

1. Drill an additional. two shallow monitoring wells near the southwest exterior wall of the radwaste building, in locations recent testing has shown are down-gradient of the spent fuel pool and safety injection refueling water tank., These SSCs are potential sources of release to the: environment of radioactive liquids. Figure 1 shows the locations of the proposed shallow wells.

2. Permanentlyabandon MW-8 by pumpung1i full ofgrout.andattempt.to drill-a deeper replacement well to approximately 25- feet below.grade near the location of MW-8.

3. Monitor daily the rate of pumpingRthe RO well and-the stage of the Missouri River at the FCS plant site. These dta should be tracked over time and compared wyith griound water :levels to further characterize thetiming and position of seasonal changes ingrond water gradients and flow direction: near the river. A more thorough description-of these periodic changes will help in understanding the mechanism for:transport of contaminants that maybe released to the ground water system.

4. -Summarize the construction details:for all wells at FCS, to provide easy access to this informationfr*0on-going use. The details to be summarized should include:

total well depth, diameter, screened interval, and elevations of the top of casing

. iand a representative 'water-level.

5. Update, the Final'iSafety- Analysis Report for FCS to reflect the hydraulic gradients, hydriaulic conductiv'itiesj ground water flow ve ocities and theseasonal reversal of ground water gradients near the river determined by recent testing at the site.

6. Clearly define teprocess for tracking corrective actions in the FCS. GWPP.

7. Provide inthe FCS GWPP details regarding hlich specific wells to monitor, their, sampling 'fequency,' analytes, minimumi detectable concentratons; data' quality ,

objectives and a management scheme for the monitoring data.

8. Incorporate in the FCS GWPP the document "Data Quality Objectives for Well Drilling". . . -:

N V TS D # 08-01 5:

Revision 01 Page 30 of, 32.

X. Referenced Rep orts A slug test method for determining hydraulicconductiwty of unconfined aqifers with completely or partially penetrating wells, Bouwer, H. and R.C. Rice, 1976, Water

'Resources Research, vol. 12, no. 3, pp.i423-428.

2006 Annual Report of1 the Missouri Tributaries Basin, LB962, Nebraska Department of Natural Resources Data Quality Objectives for Well Drilling, Fort Calhoun Station Design Basis Document PLDBD-CS-5 1, Seismfiic' Criteria, Fort Calhoun Station Design Basis Document PLDBD-CS7 54, Ge'technical, Fort Calhoun Station, '

EPRI Gr'oundwater Assessment for OPPD Fort Calboun Site, April, 2007 .

FyAnalysis Report, Section 2,Site and Environs, Fort Calhoun Power Station De.ce*eber 1971..

.Fin-'al Safety Analysis Report, Appendix1B: Site Environmental Studies, Fort Calhoun Sta~tion Geology of the Omaha-Council Bluffs Area, Nebraska-Iowa, USGS Professional Paper

.472, Robert D. Miller, 1964 Groundwater, Freeze, R. Allan, and Cherry, John, A., 1979, Prentice Hall Inc.

Groundwater Monitoring Well Results for 3rdQuarter 2007, Fort CalhounPobwer Station Groundwater Monitoring Well Res for* 4

Quartoerl 2007, Fort Calhoun Power Station Groundwater Protection Guidelines for Nuclear Power Plants, ElectricePower Research Institute, November, 2007 Grotdwcater ProtFecton Plan 2006 Through Decommissioning, R3, Omaha Public Power.

District,,Fort Calhoun Station . .. . 4 ".K Hydrogeologic Assessment Report, OPPD Nuclear Power Generating Station, Fort Calhoun, Nebraska, Terracon Consultants, Inc., December 14,:2007 Hydrogeologic Investigations Report,*Fort Calhoun Power Station, Water Treatment Sludge Disposal Area,i Omaha7Pubic Power Distcrit,.SCS Engineers, June 29, 1995'

'Indu~stry Ground Water Protection Initiative -FnlGui dance Document, Nuclear Energy

~Intiut,u~t,2007

TSD# 08-015 Revision .01 Page 31 of 32 Nebraska Data Bank Interactive Maps, Nebraska De artment of Natural Resources Reconnaissance of Ground Water Quality in the Papio-MissouriRiver Natural. Resources District, Eastern Nebraska, U.SGS Water-Resource.Investigations 944197, LM.

Verstraetenand M.J. Ellis, 1995 SO-G--t8, Standing Order: Site..GroundWaterotction Program-,Fort Calhoun Station, Unit-No. 1.

Tgeracon. Memo, May 6,,2008: RadiationISafetf& Corfrot Services Response to Terracon's Hydrogeologic Asse6ssment Report, Dated*December 14, 2007.

,Updated-Safety Analysis Report, Appendix C, Foundation Studies, Fort Calhoun Station, Damies and Moore, January 30,`1968 Updated Safety Analysis Report, Section 2.6: Site and Environs - Geology

.Updated Safety Analysis Report ,Section 2.7: Site and Environs -. Hydrology

TSD # 08-01 5 Revision 01 Page:32 of 32 N

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