EIS-0113_Section_11 - Hanford Site

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" T 7 1936
9 h, !VISION
Seddon 4.4.1, Surface W.ttel. page 4.12. p.ngraph 2
kialts of flood studies in the Cold Cr ea k watershed (Skaggs and Walter, 1981)
.Indicate that a potential for flooding. of po rtio ns of the seta exists. AS
3.5.6.7
p ro posed, it appears that several facilities my be placed in an awes of the
Cold Crank fl aodplalo, which could be Inundated by se veral feet of water.
Based an an examination of t he Skaggs and WAlttr y report,. It appears that the
Magnitude of flooding on Cold Creek May m underestimated,The prolabie
Maxine, plead (PMF) was estimated In the report to have a magnitude of SS,=
cubic felt per '"i'md (Cie) at the site where the drainage Aral is About lit
.square miles. Revin of hitteriC flood 0. As for Arid regions of Wishingtan ant
Ore... with similar climate$ and weather patterns indicates that a flood of
this nagnituda his occurred on a aired with a drainage an, of about 13 sq..,
Allen, touted lass than 150 mites from the sat on.
In recognition of the fact that the Cold Crick basin could have different
flood-producing ermeterlatics N
fr ee the stre am that pro duced the historic
maxi man discharge, It Is nevertheless iraortant,tlat the We represent an upper
bound of fiood,p,stential for a Dartlwlar strew. It appears that this upper
bound is not well-defined for Cold creak.
3,5,6.7
In adcitl.V, maaaas water levels .111 be tncr ... N as . result of increased
PMF discharge arc way Also be Increased by site loatien in the flood plain.
The amount of Increase in water level cue to flew plain constriction has not
been discussed In the DEIS. On the basis of tnpngraphlc and 0.oss-..mtional
exemlhatidn of the site area, surface facilities May be subject to floodteS tad
may constrict the flow ma it the flood pla'r_. Thismay "t .the water.
levels Associated with major floods; .this + asedlevel and'its potential
- helicon should be discussed in she "e . Feral EIS.-
Section 4.4.2. Groundwaar. pane 4.18 at.ure 4:B
:.:T 7
19 36
10 VISION
variations may ruse Incrus all sediment loads fn the Columbia River and Its
tributaries, resulting in possible channel migrations; These passible adverse
conditions are discussed In al p ' convent A2 Of NRC's comments on the draft EA
far Manned (NRC, I"S.) add should be considered in the defense waste Final
EIS.
Appendix 5, Section 3:2. Radionuclide Releases to Accessible Envlronang rope
S:b para9rooh 2 -
Frwe discussions to the MIS, It Is unclear whether the drier-clinace scenario
is considered representative of either the N p locena (recent) climate at .Hanford
or of conditions drier than at present. As smec log-nomal probability density
functions for annual groundwater recharge wan described for O p en drier and
wetter climate scearlos over the next 10,000 years. The drier climate
scenarl. was assumed to be,* a ..of an annual recharge of 1.5 on, whereinthe
value for the vector cliate 'dVd run was assmed to be 5,0 u.
DOE-RL
If It Is intended that the drier Climate sciarlo is representative of recant
conditions, what Is the basis For the assumed Albino annual recharge of 1.5 em? 3 .5.2.52
On pages A.l9.md 4.20 it is stated that the annul Avers, recharge Tram
precipitation on the 200 Areas plateau has VOL been established to date, but
two sets of IysiAnor. messier ... are expected se re salve teals question Mthln
4 to & years. It was also toted that WE ex p ects twat the value will Ifs
within the range of 0.5 to 5-.0 ce/yr named on data to date.
3.2.1.3
1, O..u, with seo.M to futere cli ma te scenarios, the Final EIS should
contain a discussion that mows clearly defines and dlff.renti ate. betw een the
terms "drier^ versus •wetter:° Al se, mire in'olvi dhdutd of included about
uncerta'nties in assumed values for r ange And Median values of
annual
r.IM"a for t he Hanford Site. - - -
A,mndh S. Seattle. 5.5 R.Oults t page 5 . 24 Eara,a M1 9
3.5.2.46
leobO.ds indicate a. potential for n ,rAtidV of waake free the Mat area I. the
;Mating cmeserc'ai low-level vast. facility st:atec n . to. aoukhwast ...her
of the 200-E area. ThIS no adversely impact groun pvater monitoring activities
i.ocinted wish that facility.
Aep.nd4, R. Section R.g Other Surface Floetl lase Vote R.92 pI.agraph 1
Disposal alternative W2, aadd In some reseecn alternative M1 and 03 (page 'a,
Eseeutiva Suwary), , present disposal so .... Its s m ! i ar to the burl al of
high-level waste In a shal'.er lend dfsrosa: site. All or some of the
high-level add low-1 evil wa stes would at sn.11.e depths below the gnmd
surface. Consequently, the vast. to be sub}etc to near-surfaro natural
Phen om ena.
I
3.5.6. 1 1 The draft EA fee the or., ...6 dis posal of sigh-level wastes at Hanford
concluded, hid the NRC acres, that proolaclal eatastrophie flooding associated
Mtn the aelttng pMSa of g1.ciAti.V .pule at likely oat ur during the
10,000-year isolation aerioo. However, ether consequences of either
significantly wee re ar or cooler cllnatic trends could result in Adverse
AbOronnenbt conditions at the Hanford Site, I .r e.aaple, future C11oW,
It Is stated that the comecalte release-ratio/probability curves. shn the: the
In-placetabiliIation and disposal altar Athee e'M the reference a'.ternttiVe
met the EPA standard at the 99.9 percentile. This conclusion Is not
adequa te ly supported.
%,elficsily, n er the next 10,000 years.. it is as sumed that a drier climate
a M. t. n e times n e probable than a wetter clite ma scenarid (0.9. i.
01 r'. COTbined r p r:bal,01tyx r 1,0), No basis for this assum p tion is given ant no
ro)evant referencros are Cited in the .pduhdix. This a ..,I.n bias es the
results of the composite release curves (Figure SAC) in favor of a drier
Citrate with its fwpllnHOet of reduced recharge, fnfiltratfon, add
contaminant transport Tne rationale for assigning such a high drobldflity to
dryer Citrate sectaries should be explained in greater detail.
3.5.6.3