ML18283A848

Encloses Proposed Temporary Changes to Environmental Technical Specifications. Includes Amendment to Operating License Change to Appendix B Technical Specifications Thermal Discharge Limits

ML18283A848
Person / Time
Site:	Browns Ferry
Issue date:	05/23/1977
From:	Gilleland J Tennessee Valley Authority
To:	Stello V Office of Nuclear Reactor Regulation
References
Download: ML18283A848 (14)

Text

U.sa~ NUCLL'AA ACC'>ULATOAV NAC I OIIMs 195 I2.70)

I C ISSION 0- R59 DOCKET NUMSCA

~C zq WP NRC DISTR)GUT)ON FoR PART 60 DOCKET MATERIAL FROM:

~u/

F I t. E NUM a E A D<TE Of DOCUMENT Tennessee Valley Authority '.5/23/77 Mr. Victor'tello, Jr, Chattanooga, Tennessee DATE RECEIVED Je ED Gilleland 5/26/77 Q.ETTEA 4OTO BIZ E D PROP INPUT FOAM . NUMGEA OF COPIES RECEIVED KOAI G INAL Ocopv DESCRIPTION UNCLASSIFIED ENCLOSURE

) ZIQ IUD a

Ltr e no torized 5/23/77... ~ . trans the

~

"foll'owing: I Amdt. to OL/change to Appendix B tech I I specsi.eeconcerning Thernal Discharge I

Limits ~ ~ ~ ~ ~ ~

ROBOT REMO1/g PLAI)T. NAIIE: (2-P) (2-P)

Browns Ferry Units 1-2-3 RJL ASST'

=.~Ran))

SAFETY FOR ACTION/INFORMATION IAS GNED AD:

BRANCII Cl)XEF:

PROJECT ) IANAGER:

LIC ~ '.

~ te PRO~ET se ill w se lw% e\

~ ~ I'i AP S ee

) GI.H//F

~

INTERNAL D IST R I BUT ION

.iES FILE SYSTEMS SAFETY +TQ SITE S EFJ~ Ss HRC PDR NEIHEt I~EH ~D~MC ERFIRO Al!AT+$TS X & E SC)IROEDER BEHAROYA E

~

DEa~c~g}LL~~

OFLD GOSSXCK & STAFF ENGINEERING IPPOLITO FRFIIULTECIL WIIIPC MACCARRY KIR10iI~OD CASE KNIG)IT LAR I IANAUER SI)WEIL OPERATICREACTOPS MEQIGL j IAQI.F.S PA< I LICKX S.TIJJ Q

'l~XCH PI)~0. FCT ) II'IiHAQEHFH REACTOR SAFE'I'Y 0)'1 RATTY 'F I CML BOY)) ROSS F.ISEN)l S.TEPP P, COI.LINS NOYAK SIIAO IUD

)IOUS CON ROSZTOCZY FiAER PETI'.RSOH C) IECK , DltTLI',R ~XX~ALYGL7 l11 I.T7. ~RItlES

) IF)e TI'.IRII S AT & I 3UHC)

S KOYIIOLT SALT7MAN ..COLLItlS R)i'I'III'.Ill. I~

EXTI:IINALl)ISTRIIIIJTION O'I'I IOI. NUMOIIR

).1'l)R. HAT IaAII: Bltpl)KIIAPItj tIAT LIIg TXC: I) I'.0 VXI ) I).)t I K SON 0) lttII,)

HAEC: IA )'l)R AS).)1 ~ COt) 11 0 I.TAN'1'S

>>1~3OiOI ACRE /)CYS 4H

~CPttfC/.'III:

I'I)IIM AII) I2 IIII

~ '

~

v~

yr

~+- ~ i Qgg 830 Power Building

=N~JESSEK V<L~ -'L 'CRl

.'H~5g r CHATTANOOGA. Tc.Ni'4KSSEK S740i May 23, 1977 TVA BFNP TS 83 Director of Nuclear Reactor Regulation HE Attention: Mr. Victor Stello, Jr., Director 26 lg77 Division of Operating Reactors U.S. Nuclear Regulatory Commission r Washington, DC 20555 K(KAYOING IIllIlKTFIL[ NIP Tennessee Valley Authority 50-260 50-296 In accordance with the provisions of 10 CFR Part 50.90, we are enclosing proposed temporary changes to the environmental technical specifications for the Browns Ferry Nuclear Plant unit Nos. 1 and 2 (Appendix B to Facility Operating Licenses DPR-33 and DPR-52), and the Browns Ferry Nuclear Plant unit No. 3 (Appendix B to Facility Operating License DPR-68). Enclosure 1 is a proposed change to Section 2.1 THERMAL DISCHARGE LLMTS that would approve a temporary increase in the discharge water temperature limits. Enclosure 2 provides justification for the requested temporary change. This matter has been discussed with members of your staff. Approval is requested by June 6, 1977, so the testing may proceed on schedule.

Very truly yo~s,

. E. Gilleland Assistant Manager of Power Subscribed an+swor o before me this~~~%ay of 977

~ totary Publ'c My Commission Expires D Enclosures cc: See page 2 t

77i530i01 An Eauot Opportunity Employer

Mr. Uictor Stello, Jr.

cc (Enclosures)

Mr. Tom Wombach Operating Reactors Branch No.

Division of Operating Reactors l

U.S. Nuclear Regulatory Commission Washington, DC 20555

Enclosure 2.0 .L.r~+TxLlG coiaxTro:Ls FO.L op"-LLATro;L 2.3. Ti/FPiRL DrSCF~GE LXVXTS Ehnitorin Peouirement Oh)ective The xmter temperature data collecteQ. by therJml monitoring n two"r; io te3e- 'he The purpose of thi s specification is to matered to the Browns Ferry meteoro-limit the thermal stress on, aquatic life 3.ogical. station. The meteoro3.ogical in Maeler Res rvoi r by operating Srowns station mill xeceive the data. and auto-Ferry Huc3.ear Plant so as to meet the matically record. the readings every 60 applicable eater quality temp rnture mLnutes. All, temperature data are tancLaxd,s of'he State of'labama. recoxded. on paper tape and maintained for xeco d:Keeping purposes. The 5-foot cLepth temLleratu e data which are used to S cification prevent e:cceeding the limiting condition vill be transmitted to the contro1 room The plant-induced. reservoir vater tempera- ancL %11 'be visually cLisplayed. for moni-ture at the 5-foot depth at the downstream toring purposes. The accuracy of the contro3. point shall not exceed. the water system nnd. the sensitivity of'he temperature measured, at the 5-foot depth thexmistor sensors are designed, to be of the upstream control monitor 'by more + 0.3~F and. 0.01F, xespectively-than th applicnb3.e ma'cimum temperature rise {currently 5 F~)nor shall th resex- ee thermal xxlnitors spacecL across the voir vater temperature measured nt the 5- reservoir in the vicinity of xivex'ile foot depth nt the downstream contz03. point 292.5 shall serve no th downstream con-exceed. the applicable ~~ imum ~ter tem- tro3.. R~ro monitors 3.0cated a'bove the perature (curxently 86~F~) due to the ~ plant, on locateQ, at about river mile

@discharge of the condenser cooli g >>ter. 297.6, ancL a second. 3.ocated. in thi" Xf this limiting condition io exceeQed, vicinity vill provide the upstream eater the plant operator shal3. ini~iate contr01 tempexeture data. The system is cLesignec.

measures.. The control measu-es oh&.3. be so that th downstream control monitors (1) to serve as b coup f'r on anothex and.

reduce the ~ote heat dischnrgecL to th similnl3y for the two upstream monitors.

reservoir anQ/ox (2) to recLu'st modifica- Th- locations of existing tempexature tions in the xeleases from TVA'o monitors are disp3.nyecL in Figure 2-3.-1.

Guntersvi3.1e nnd/or Hheeler Dnms to, increase the streamflow 'by the Brogans Xn the event th system descxibed is out Ferry plant. of service, an alternate method vill 'b employed three times a day (once each 0 sM.W~) to measure the river temperature

~ A p ~During a special diffuser performance at the 5-foot depth in the vicinity of study during the summer of 1977. {anti- the upstream and. downstream contro" cipated completion in June, l977), a monitors anQ. thus determine the tem-maximum temperature rise of 10 F and a pexnture rise and. the >mx9xn~ x iver CJ Ol maximum water temperature of 90 F, both vater temperature below the p3.ant Unpen 0 recorded at the 5-foot depth, will be such a method. mnQ.d resu3.t in nn imminent Sh 0 permitted. and substantia3. endangexmnt to the safety of'ex sonnet., thi" paragraph shall not nppQ-.

Buboes TVA, as n Federal agency, io recLuired 'by Sction 3l3 of the Fed r 1 Hater Pollution Control Act Amendmento of 1972 (P.L.92-500) nnd by Executive OrcLer 11507, "Preven-tion Contro3. nnd Abntenent of'ir and Hater Pollution ot Federal Fnci3.itieo," to m<<t applicable Federal,~ otnte,~ and, local water cLuality standards." On Zu3y 17, 3.9( 2 the

~

State of Alabama, adopted and. on Septc. ber 19, 1972, th Znvirormntnl Protection Agency

Enclosure 2 tification fo P d ETS Ch The following is a brief discussion of'he short-term field study that TVA proposes to conduct in order to verify plant discharge diffuser mixing.

TVA proposes to conduct a series of instream temperature and flow measurements during the summer of 1977 in Wheeler Reservoir near the Browns Ferry Nuclear Plant, using specially equipped boats. Although the period of testing may be several weeks long, the actual test time (total), is not expected to exceed approximately one week. The tests will evaluate the actual thermal mixing characteristics of the diffusers under preplanned conditions of river flow and plant operation consistent with system power generation requirements. The results of these tests wi3.1 be used to:

a. Assist the plant personriel in routinely operating the condenser cooling system of the plant in compliance with the thermal water quality standards and

b. Further refine theoretical methods and. mode3.s used in the design of future underwater diffuser systems being considered at new plants.

During initial phases of the tests measurements will be made of the diffuser performance under low and reverse flows in the river with the plant's condenser cooling system operating on cooling towers in the helper mode. During the final phase measurements will be made under the full range of river flows and while the plant is operated with the condenser cooling system in open mode (no cooling towers in service). During the study period records of temperature data from the boat 'surveys and from the system of installed reservoir monitors will be maintained.

Model verification is required by Section 4.1.1(b) Thermal Plume Mapping of the ETS'S, which states that TVA must "verify the accuracy of thermal plume models used in predicting environmental effects from the thermal releases from the Browns Ferry Plant." This proposed study should provide valuable information in evaluating the accuracy of thermal plume model predictions at Browns Ferry Nuclear Plant.

Due to the nature of this study, the present thermal discharge limits specified in Section 2.1 of'he ETS's may be exceeded. for short periods of time. Computer model predictions of mixed-temperature rise for the test program indicate that the maximum plant-induced heating will be 5.3.oF during one phase of the tests, but during the ma)ority of the test period, the plant-induced heating is expected. to be less than 3 F.

Although the actual plant-induced heating may be slightly different from the predicted values, TVA believes that a maximum plant-induced temperature rise 'of 10 F or a maximum plant-induced water temperature of 90oF in Vheeler Reservoir for such a short duration would only result in a few fish leaving the thermally-influenced area. Upon completion of the tests, the fish would be expected to return to the area. Such movements would have no 'significant impact on the Wheeler Reservoir fisheries resources. All other specifications and requirements related to thermal discharges from the Browns Ferry Nuclear Plant would remain in effect.

1 ENNESSEE VALLEY AUTHORITY CHATTANOOGA) TENNESSEE 374OI MAY 23 197?

TVA BFttP TS 83 Director of Nuclear Reactor Regulation Attention: Mr. Victor Stello, Jr., Director Division of Operating Reactors U.S. Nuclear Regulatory Commission Washington, DC 20555

Dear Mr. Stello:

In the. Matter of the ) Docket Nos. 50-259 Tennessee Valley Authority ) 50-260 50-296 In accordance with the provisions of 10 CFR Part 50.90, we are enclosing proposed temporary changes to the environmental technical specifications for the Browns Perry Nuclear Plant unit d'Ios. 1 and 2 (Appendix B to Pacility Operating Licenses DPR-33 and DPR-52), and the Browns Perry Nuclear Plant unit No. 3 (Appendix B-to Pacility Operating License DPR-68). Enclosure 1 is a proposed change to Section 2.1 THERKQ DISCHARGE L3ZKTS that would approve a temporary increase in the discharge water temperature limits. Enclosure 2 provides Justification for the requested temporary change. This matter has been discussed with members of your staff. Approval is requested by June 6, 1977, so the testing may proceed on schedule.

Very truly yours, A.eeg J. E. Gilleland Assistant ~tfanager of g

Power Subscribed aqd swo to before me this+3t~day od'977 6"n, Notary Public My Commission Expires > 7 Enclosures cc: See page 2 An Equal Oooortunity En>cloyer

Nr. Victor Sto11o, Jr. MAY 23 197$

cc (Enclosures):

Hx Tom Mombach Operating Reactors Branch No. 1 Di~ion of Operating Reactors U.S. Huclear Regulatory Commission Washington, DC 20555

f Enclosure 1 2.0 LIf!XVItiGCO'iDITIO:lS FOR OPZcbi IOH 2.1 Tiigc,!:AL DISCEBGE LD!ITS Ehnitorin Peouirerant OM Bc 1'v& The water temperature data col.3.ected by tha thawing. monitoring n two's tele-The pux'pose of this spacificatloxL is to metered to the Erovns Ferxy nmtcoro-1init the therma3. stress on aquatic 3.ife 1ogical station. The mataoro3.ogieal in lQ.aeler Reservoir 'by operating Brovns station vQ.l xeceive tha data and. auto-Ferry Nuclear P1ant so as to meet the matically record. th readings every 60 appl.ieab3 e vater gus.ity temperature minutes. A13. temperature data az e tandards of the State of Alabama. recorded. on payer t pa and maintained for record:3ceeping purposes The 5-foot depth temperature data which are used, to S acification prevent'exceeding the 3.imiting condition Vill. ba transmitted to the contro3. room The plant-induced, reservoir water tampa a- and vi13. be vism11y displayeQ. f'r roni-ture at the 5-foot depth e:h. the dovnstream toring purpos s. The accuracy of the contro3. point sha11 not exceed, the water system and the sansitMty of the temperature measured at tha 5-foot depth th rmisto sensors are designed to b-of the upstream control monitor 'by more + 0.3oF and. 0.01, F, respectively than tha applicable maximum temperature rise (currently 5OF-)nor shall the reser- Three thexma3. ~nito s spaced acxoss the voir watcx temp xature measured at the 5- reservoir in the vicinity of'iver xi3.e foot depth at the dovnstrem cont o3. point 292.5 shaU. serve as the downstream con-exceed, the app1.ieebla maximum water tem- txo3.. Wn xtonitors 1ocatad above the arature (currently 86OF") dua to the discharge of the condenser coo3.ing water.

.ply, 297-6, on locateQ, at about riv r mila and a second. 3.ocatad in his c

Xf this 1imiting condition is exceeded, vicinity will provide the upstream water the pl nt operator sha31 initiate control temperature data. The sys am is designee.

nea uxes.. The control measures shall be so that the downstream con rol xmitors (3) to serve as backup for on another and.

reduce the waste heat discharged to tha similar3y fox the tvo upstream monitors.

reservoir and,/ox (2) to xacLuast modifica- Tha locations of existing tempaxature tions in tha xeleasas frcmz TVA's monitors are clisp1ayed in Fiona 2 3.-1*

Guntersvi3.le and/or wheeler Hams to increase the streamf3ov 'by the Erovns 3:n th event tha system described, is out Ferry plant. of service~ an a3.ternate method will b etxp3.oyez'. three times a. Qay (once each sM.f ~) to measure tha rivex temperature

.~During a special diffuser performance at the 5-foot d,epth in the vicinity'f study during the summer of 1977 (anti- tha upstream and. downstream contro3 cipated completion in June, 1977), a monitors and, thus determine the tem-maximum temperature rise of 10 F and a perature rise and the maxf;arne vier maximum water temperature of 90oF, both water tezparature below the p1ant Uhan recorded at the 5-foot depth, vill be such a mathoQ. would. resu3.t in an imminent permitted. and. substantial endangerm nt to the safety of parsonna3., thi paragraph sha11 not appQ-.

Bases KVA, as a Federal agency, is recjuired 'by Swtion 33.3 of the Fade.a3. Mater Pollution Contro3. Act Amendments of 3.972 (P.I.92-500) and by Executi've psQar 13.507 "Preven-tion, Contro3. and Abatemant of Air an@ Mater PoU.ution at Federal Facilities, to meet applica'ble Fedexal, state, and. local, water quality standards. On July 3.7, 1972, the State of Alabama adopted and. on Septa=b r 19, 1972, the Znviroz~ntal Protection Agency

Enclosure 2 ificat f P d TS The following is a brief discussion of the short-term field study that TVA proposes to conduct in order to verify plant discharge diffuser mixing.

TVA proposes to conduct a series of instream temperature and flow measurements during the summer of 1977 in Wheeler Reservoir near the Browns Ferry Nuclear Plant, using specially equipped boats. Although the period. of testing may be several weeks long, the actua1 test time (total) is not expected to exceed approximately one week. The tests will evaluate the actua1 thermal mixing characteristics of the diffusers under preplanned conditions of river flow and plant operation consistent with system power generation requirements. The results of these tests will be used to:

a. Assist the plant personnel in routinely operating the condenser cooling system of the plant in compliance with the therma1 water quality standards and

, Further refine theoretical methods and. models used in the

b. reconsidered design of future underwater diffuser systems being at new plants.

During initial phases of the tests measurements will be made of the diffuser performance under low and reverse flows in the river with the plant's condenser cooling system operating on cooling towers in the helper mode. During the final phase measurements will be made under the full range of river flows and. while the plant is operated with the condenser cooling system in open mode (no cooling towers in service). During the s'tudy period records of temperature data from the boat 'surveys and from the system of installed reservoir monitors .

will 'be maintained.

Model verification is required by Section 4.1.1(b) Thermal Plume Mapping of the ETS'S, which states that TVA must "verify the accuracy of thermal plume models used. in predicting environmental effects from the thermal releases from the Browns Ferry Plant." This proposed study shou1d provide valuable information in evaluating the accuracy of thermal plume model predictions at Browns Ferry Nuclear Plant.

Due to the nature of this study, the present thermal discharge limits

'specified in Section 2.1 of the ETS's may 'be exceeded, for short periods of time. Computer model predictions of mixed-temperature rise for the test program indicate that the maximum plant-induced heating will be 5.1oF during one phase of the tests, but during the ma)ority of the test period, the plant-induced. heating is expected. to 'be less than 3 F.

Although the actual plant-induced heating may be'slightly different from the predicted values, TVA believes that a maximum plant-induced temperature rise of 10 F or a maximum plant-induced water temperature of 90 F in Wheeler Reservoir for such a short duration would only result in a few fish leaving the thermally-influenced area. Upon completion of the tests, the fish would be expected to return to the area. Such movements would have no significant impact on the Wheeler Reservoir fisheries resources. All other specifications and requirements related to thermal discharges from the Browns Ferry Nuclear Plant would remain in effect..

TENNESSEE VALLEY AUTHORITY CHATTANOOGA. TENNESSEE 37401 MAY 33 1977 TVA BFHP TS 83 Director of Nuclear Reactor Regulation Attention: kh. Victor Stello, Jr., Director Division of Operating Reactors U.S. Nuclear Regulatory Cotmaission Uashington, DC 20555

Dear Ih. Stello:

In the ifatter of the ) Docket Nos. 50>>259 Tennessee Valley Authority ) 50-260 50-296 In accordance with the provisions of 10 CFR Part 50.90, we are enclosing proposed temporary changes to tha environmental technical specifications for the Browns Ferry Nuclear Plant unit ~los. 1 and 2 (Appendix B to Facility Operating Licenses DPR-33 and DPR-52), and tha Browns Ferry Nuclear Plant unit No. 3 (Appendix B to Facility Operating License DPR>>68). Enclosure 1 is a proposed change to Section 2.1 THERMAL DISCHARGE LIHI S that would approve a temporary increase in the discharge water temperature limits. Enclosure 2 provides Justification for the requested tempozary change. This natter has been discussed with members of your staff. Approval is requested by Junc 6, 1977, so the testing may proceed on schedule.

Very truly yours, J. E. Gilleland Assistant ."fanager of Power Subscribed an/ sworn to before me t1da~3'%!ay of 977

~8 tery Public Hy Commission Expires d Enclosures cc: See page 2 An Equal Opportvnity Fmployer

Mr. Victor Stello, Jr. MAY 2,8 18'IIl:

cc (Enclosures):

kh. Tom Mombach Operating Reactors Branch No. 1 Mv1sion of Operating Reactors U.S. Nuclear Regulatory Commission Washington, QC 20555

Enclosure 1 2.0 LltGTIt'.G COi'i0ITIOsiS FOR OPZBAVIOig 2.1 THEPsÃL DISCKDGE LIi.'ITS Ehnito in Peouiremant Ob]ective The eater temperature data co3.3ected by the thenml monitoring network; is tele-The purpose of'his specification is to metered to the novns Ferxy mateox'o-3.imit the thermal stress on. aquatic life logica1 station. The meteoroid.ogical in LQ.eeler Reservoir 'by operating Broads station v'i3.1 xeceive the data and. auto-Ferry Rhtclear Plant so as to meet tha matically recoxd th readings every 60 applicable water quality temparatuxe minutes. All, temperature Qata are standard,s of the State of Alabama. xecorded. on paper tape and. maintained.

for xecoxd:1ceeping purposes Tha 5-foot depth temparatu e data vhich are used to S cification prevent 'exceeding the 3.imiting condition Mll be transmitted to the contro1 room The. plant-induced xeservoir eater tempaa- and. &11 be visually displayed for moni-ture at the 5-foot depth at the downstream toring purposes. The accuracy of the contro3. point shall not exceed the eater* system and. th sensitivity of the tempexature measured at, the 5-foot depth thermistor sensoxs are designed, to b-of the upstream control monitor by nore + 0.3~F and. 0.01 P, respectively.

than th applicable maximum temperature rise (currently 5~P~)nor shall-tha resar- 'Three thermal'. ~nito s spaced, across the voir vater temp rature maasureQ. ct the 5- reservoir in the vicinity of river wale foot depth at the dovnstra~~ control point 292.5 shall serve as the downstream con-exceed the applicaMe maximum ~ter tem- trol. Win monitors 3.ocatad above the p rzture (currently 86 P') dua to tha .plant, ona located. at about xiver mile

.%discharge of the condenser cooling wwter. 297.6, and. a seconQ. locat ct. in thi" If this limiting condition is exce cled., vicinity vill provide the upstream mter the plant operator shaU. initiate contro3. temperature data. The system is designee.

mea ures. The contro3. measures sha3.3.'he so that the do'mstream control nonitors (1) to serve as backup for on anothex and xeduce the waste heat discharged to tha similar3y fox the two upstream monitors.

reservoir and/ox (2) to xequ st nodifica- Th 3.ocations of existing temp x'.ture tions in the releases from TVA's nonitors are displayed in Figure Guntersville and/or %healer Dans to, 2-1-1-'n increase the stxcamflov 'by the Broads the avant th system described. is out Ferry plant. of sexvica, an a3:ternate method miH b-employad three times a. day (once each 0 sMft) to measure the river temperature

~pl

+During a special diffuser performance at the 5-foot depth in the vicinity'f study during the summer of 1977. (anti- tha upstream and. downstream control Q

cipated. completion in June, 1977), a monitors and. thus determine the tem-maximum temperature rise of 10 F and a p"xature rise and, th~ ma:duum river

~ 0) maximum vater temperature of 90 F, both eater temperature 'be.ov the plant- Uhan 0 recorded at the 5-foot depth, will be such a method vau1d resu3.t in an imainant 0

4 permitted. and. substantial endangexmant to the safety of parsonna3., thi" par graph "hall not appQ-.

Esses e

pe, as a Federal agency, is required 'by Swtion 33.3 of the Federz3. ]Tater pollution Control Act Amendments of 1972 (P.I.92-500) and, by Executive Order 11507, "Preven-tion, Control and Aba;temant of Air and hater PoU.ution at Federal Facilities," to meet applicab3.e Federal, state, anQ. 3.ocal mter quality standards. On July 17, 19(2> the State of Alabama adopted and. on September 19, 3.972, th= Znviroxmntal Protection Agency

Enclosure 2 ification for Pro osed ETS Cha The following is a brief discussion of'he short-term field study that TVA proposes to conduct in order to verify plant discharge diffuser mixing.

TVA proposes to conduct a series of instream temperature and flow measurements during the summer of 1977 in Wheeler Reservoir near the Browns Ferry Nuclear Plant, using specially equipped boats. Although the period of testing may be several weeks long, the actual test time (total) is not expected to exceed. approximately one week. The tests will evaluate the actual thermal mixing characteristics of the diffusers under preplanned conditions of river flow and plant operation consistent with system power generation requirements. The results of these tests will be used to:

a. Assist the plant personnel in routinely operating the condenser cooling system of the plant in compliance with the thermal water quality standards and

b. Further refine theoretica1 methods and models used in the design of future underwater diffuser systems being considered at new plants.

During initial phases of the tests measurements will be made of the diffuser performance under low and. reverse flows in the river with the plant's condenser cooling system operating on cooling towers in the helper mode. During the final phase measurements will be made under the full range of river flows and while the plant is operated.

"with the condenser cooling system in open mode (no cooling towers in service). During the study period records of temperature data from the boat 'surveys and from the system of installed reservoir monitors will be maintained.

Model verification is required by Section 4.1.1(b) Thermal Plume Mapping of the ETS'S, which states that TVA must "verify the accuracy of thermal plume models used in predicting environmental effects from the thermal releases from the Browns Ferry Plant." This proposed.

study should provide valuable information in evaluating the accuracy of thermal plume model predictions at Browns Ferry Nuclear Plant.

Due to the nature of this study, the present thermal discharge limits specified in Section 2.1 of the ETS's may be exceeded for short periods of time. Computer model predictions of mixed-temperature rise for the test program indicate that the maximum plant-induced. heating will be 5.1oF during one phase of the tests, but during the ma)ority of the

.test period, the plant-induced heating is expected to be less than 3 F.

Although the actual plant-induced heating may 'be slightly different from the predicted values, TVA believes that a maximum plant-induced temperature rise of 10 F or a maximum plant-induced water temperature of 90 F in Wheeler Reservoir for such a short duration would only result in a few fish leaving the therma1ly-influenced area. Upon completion of the tests, the fish would be expected to return to the area. Such movements would, have no significant impact on the 3/heeler Reservoir fisheries resources. All other specifications and requirements'related to thermal discharges from the Browns Ferry Nuclear Plant would remain in effect.

0

\