ML20197B004
| ML20197B004 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 10/30/1978 |
| From: | Gilleland J TENNESSEE VALLEY AUTHORITY |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7811010073 | |
| Download: ML20197B004 (197) | |
Text
!
TENNESSEE VALLEY AUTHORITY CH ATTANOOG A, TENNESSEE 374o1 830 Power Building October 30, 1978 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555
Dear Mr. Denton:
In the Matter of the Application of
)
Docket Nos. 50-327 Tennessee Valley Authority
)
50-328 The environmental review for the Sequoyah Nuclear Plant was initially conducted by TVA pursuant to a lead agency agreement with AEC. A draft environmental statement (DES) was prepared by TVA, transmitted to the Council on Environmental Quality (CEQ), and made available to the public on October 19, 1971.
In accordance with the lead agency agreement, TVA responded to all AEC concerns in the final environmental statement (FES) and consulted with the AEC in the preparation of the FES, which was submitted to the CEQ and made available to the public on February 13, 1974. The environmental state-ment evaluated the environmental impacts resulting from operation, as well as f
construction, of the Sequoyah Nuclear Plant units 1 and 2.
On July 30-31, 1974, a hearing was held in Chattanooga, Tennessee, to decide whether, in accordanca vi+'
he applicable requirements of Appendix D of 10 CFR Part 50, the 1.icense should be issued. The conclusions of the Atomic Safety and.
Board were as follows:
(1) That TVA's environmental review purs.
HEPA (1969) was adequate and (2) that Section 102(C) and (D) of NErt.
1969) and Appendix D of 10 CFR 50, Section B have been complied with. Since the operating license hearing, there have been some minor changes in the project that result in very minimal changes in impacts addressed in the FES.
TVA has conducted a reassessment of the environmental aspects of the changes to the Sequoyah Nuclear Plant. Enclosed are the results of this review. Enclosure 1 is a description of the changes, Enclosure 2 contains referenced tables and drawings, Enclosure 3 is an environmental assessment of the changes, and Enclosure 4 is a copy of TVA's " Tritium Management Considerations for Pressurized Water Reactors (PWR's)" which is included for infm.aation only.
781101co73 7
s\\
An Equal Opportunity Employer
. Mr. Harold R. Denton, Director October 30, 1978 TVA's review indicates that the environmental impact of operation of the Sequoyah Nuclear Plant, as modified since 1974, will be somewhat less but approximately the same as described in the FES.
Based on our reviev, TVA has determined that no supplement to the Sequoyah Nuclear Plant FES is necessary. Furthermore, the FES and information discussed in this submittal fully assess the environmental impacts of operation of the Sequoyah Nuclear Plant.
If you desire, we vill be happy to meet with you at your convenience to discuss these changes.
Very truly yours, It C-31
['4J. E. Gilleland Assistant Manager of Power Enclosures
(
l t
.,,....., _..,,..,,, _,,. -. _,., _,., -.... ~,
,.,..m
, - _., ~,,, -.., - -,... _
c.-
m...,. _,,,..
i l
Description of System Changes i
Notes: (1) Referenced tables and figures (drawings) are included as Enclosure 2.
(2) An environmental assessment of these changes is included as Enclosure 3.
l l
P-1.0 Addition of Condensate De=ineralizers (Reference FSAR Sections 10.L.6 and 10.k.8)
The original plant desi n allowed no provisions for treatment of 6
steam generator blevdown when the steam generators vere operated with primary-to-seconda.ry leakage. The design was =odified so potentially radios.ctive steam generator blevdovn could be treated by reverse os=osis units and an auxiliary vaste evaporator.
"te radioactive vastes recovered frc= treatment in the reserve es=osis syste= could then be concentrated during auxiliary vaste evaporator processing and packaged for shipment to an NRC-approved offsite burial facility. After this design modification was made, generic problems with steam generater vater chemistry vere identified. Upon the reco==er.dation of Westinghouse, T/A subsequently decided to e= ploy all-volatile treat =ent for Sequoyah !?uelear Plant.
T/A determined that with all-volatile treatment of the steam generators, condensate de=ineralizers should be added to protect the system against instrusion of impurities due to condenser leakage. As the condensate de=ineralizers vould also have the capability for treating stea generater blevdown, the reverse os=osis-evaporator syste= discussed above vould no longer be needed. The condensate desineralizers vill be operated in a
=anner to minimize the transfer of condenser leahage and primary-to-secondary leakage to the feedvater system. This practice vould ensure that radioactive =aterials released in steam generator blevdevn to the reservoir are minimized and should result in lover quantities of radio-active materials in liquid effluents, thus providing a consequent reduction in radiological doses to downstrea reservoir users.
Figure 1.0-1 (included at the end of this discussion) shows the routing of steam generator blowdown. The blowdown first enters a flash tank, where j
it is cooled as about one-half of the liquid entering the tank ia converted' to vapor. The vapor is recovered by sending it to a heater in the secondary system. The liquid is normally routed to the inlet header of the condensate demineralizers, so that liquid is processed whether the demineralizer is in bypass or full-flow operation. The liquid may also be routed to the condenser hotwell, from which it is pumped to the condensate demineralizer This rou. is employed only when the demineralizers are in full-flow operation. The liquid may also be sent to discharge via the cooling tower blovdown line. This route vill normally be used only during startups. Flow to discharge vill be' terminated manually when radioactivity is detected, and a radiation monitor vill terminate the discharge automatically at a specified radioactivity concentration if it has not been terminated earlier by operator action. Upon termination of discharge, the blovdown flow is diverted to the condensate demineralizers.
I j
When a unit is operated with primary-to-secondary leakage, the l'
deminernlizers remove not only the radioactive materials in the steam generator blowdown, but also those materials that are carried over with the steam and are dissolved in the condensed steam. When
'the demineralizers are regenerated (with sulfuric acid and sodium hydroxide), the radioactive materials are removed into the spent
regenerant liquid. If activity in the spent regenerants is below specified limits,- the spent regenerants can be discharged to the cooling i
i tower blevdown line. If the gross radioactivity is above specified limits, the regenerants are processed in the condensate demineralizer vaste evaporator. Most of the radioactive material is retained in the evaporator concentrates. The distillate, which is to be discharged to the cooling tower blevdown line, would contain less than 1/1000 of the radiciodines and less than 1/10,000 of the isotopes other than radiciodines that leaked from the primary system into the secondary system.
The condensate demineralizer system can handle any blowdown flow rate up to 120 gpm. This limit is imposed by the design of the blevdown piping. During periods of operation with condenser leakage or primary-to-secondary leakage, the blevdown rate vill be maintained at or near the maximum. At other times, lover rates will be employed.
Condensate demineralizers are employed to treat all or part of the condensate pumped from the condenser hotwells. As described above, i
most of the steam generator blowdown is treated by the condensate demineralizers also. The principal constituent of both of these streams is ammonia, used in trentment of secondary system water. Both streams also contain corrosion products from the condenser, steam generators, and system piping. During operation with condenser leakage, impurities contained in the condenser cooling water vill be present in the condensate.
During operation with primary-to-secondary leakage, the steam generator blowdown and, to a lesser extent, the condensate contain
- fission and corrosion products and boric acid from the primary system.
Impurities in the influent to the condensate demineralizers vill be in the forms of suspended particles and dissolved materials. The demineralizers vill act as filters in removing suspended particles,and dissolved ionic impurities vill be removed by ion exchange. The desineralizers are regenerated periodically vith sulfuric acid and sodium hydroxide.
The regeneration process removes the impurities that have been accu =ulated in the desineralizers. Regenerant vaste solutions vill be discharged to the cooling tower blevdown line when the radioactivity content is belov specified limits. It is expected that in normal operation, radioactivity vill be much lover than specified limits.
Table 1.0-1 (included at the end of this discussion) shovs expected quantities of ammonia and other constituents discharged annually as condensate demineralizer regeneration vastes. The data in this table are based on the assumptions that the denineralizers are opera'. on a full-flow basis at the maximum condensate system pH of 9.2.
A description of the condersate cleanup system is given in section 10.L.6 of the Sequoyah Nuclear Plant Final Safety Analysis Report.
i
TABLE 1.0-1 SUMitARY OF ADDED CHEMICALS AND RESULTING END PRODUCI CHEMICALS FOR CONDENSATE POLISil!NG DEMINERAllZERS Chemical Treatment Est. Max. 5 Waste End Pesulting End Product Source Chemical Annual Use Product Avg. Annual Mean Daily and Waste Products)
Pounds Chemical Pounds (5)
Pounds (5)
Sulfuric Acid 303,725 50 -2 297,525 815 (11 5 0 )
4 2 4 Sodium Hydroxide 142,100 Na*
81,710 225 (Ha0H)
Na*
1.911 5.4 Sodium Sulfite 5,400 (Na 50 )
50 -2 4,115 11.3 2 3 4
Annonia 44,835 Nil 44,835 154 4
(NH4)
Carbop)tes (3)
C0 (3)
(3)
(C0 3
3 Metallic Salts (4)
(4)
(4)
(4)
I Based on full-flow operation of condensate polishing demineralizers for 292 days / year at pH 9.2.
2 Based on one sodium sulfite soaking of each CDSV resin bed per year (12 total for plant),
Dependent on magnitude of air inleakage.
4 Dependent on magnitude of primary to secondary leak and/or condenser tube leak.
5 Assumes 25% of chemicals have been disposed of as solid radvaste.
w Vapor to
+ To Condensate Demineralizer
- Cecondal/ System sten 31 cW ~ -.\\!
Flash
_To Ccnden:c.te Deminemlizers v,,,,,,,,
Gene: acor:
Lig:.: 7 Ted.
~ ~ ^ ~ ~ ~
via Conden:er Hotvel3 L.
+ To Discharge (Cooling Tover 31 ordo-n}
i i
Fig r C1,0-1 Stec.= Generator Blo.nicvn Treatment
2.0 Addition of Radvaste Evaporator (Reference FSAR Section 11.2.3)
In order to have capability for processing condensate demineralizer vastes in the event both units are operating with primary-to-secondary leakage, TVA has installed an additional evaporator in the liquid radvaste system at Sequoyah Nuclear Plant. This forced circulation evaporator vill be rated at 30 gpa. This additional evaporator may l
also serve as a backup to the auxiliary vaste evaporator.
l Of course, procedures for the release of radioactive materials to the environment vill be established and controlled by the technical specification issued for Sequoyah Nuclear Plant and, additionally, all applicable regulations (e.g.,10 CFR Part 20,10 CPR Part 50, and 10 CFR Part 50, Appendix I) must be met, i
~...
t 3.0 Sodium Hypochlorite System (Reference FES pp. 2.5 14, and 5, and FSAR Section 9.2.2.6 Amend. 53)
Because aerolein is no longer an approved clamacide, it has been eliminated from the biocide treatment system at Seqyoyah.
This section is a description of the changes resulting in the~ elimination of acrolein as a clamacide, and the replacement of aerolein with sodium hypochlorite.
3.1 INTRODUCTION
For the purpose of this discussion, the following is presented to define exactly what is meant by each term:
f Constituent
- Definitions 1
1 i
H001 (Hypochlorous Acid)
)
)
0C1 (Hypochlorite Ion)
) Free Chlorine
)
IDI,C1 (Monochloramine)
) Combined
) Total NHCl (Dichloramine)
) Available
) Residual NC1 (Nitrogen Trichloride) ) Chlorine
) Chlorine 3
]
l i
- 0rganic chloramines (R-NCl) were not considered.
i 1
1
-,. _.... -.u _ _--.. _ _ _ - _ _ _.,-.. _._..
.._......._.-._..,.._u_..___..
~..
i
-i 3.2 CHEMICAL TREATfENT PROGRAM-In order to minimize the effect of Asiatic clam infestation and algae and slime growth in critical plant systems using rav vater for cooling purposes, the following procedures vill be followed at the Seqyoyah nuclear. Plant. The chemical to be used is sodium
~
hypochlorite. This chemical vill be produced onsite and vill have a concentration of 8 percent (est.).as available chlorine.
3.2.1 SLItE AND ALGAE' CONTROL'IN THE CONDENSER CIRCULATING WATER SYSTEM TVA is primarily concerned with controlling slime and algae growth in the main condenser circulating vater system. Injection points are provided for sodium hypochlorite (a) upstream of each unit's main condenser, and (b) at a point as close as possible to the inlet of each unit's cooling tower The follo91ng chemical treatment methods using sodium hypochlorite vill be applicable to the condenser circulating water system.
. - - ~,,.. - - -
-. -.. ~ ~
- ~. -
3.2.1.1 closed Mede Operation No chlorination is proposed until after sufficient operational monitoring is conducted to determine if chemical treatment is necessary.
.3.2.1.2 Open or Helper Mode operation Chlorine Treatment:
Two 30 minute periods of chlorination per unit per day
. Inject' sodium hypochlorite at the injection point upstream of main condenser.
One unit at a time Both units to be treated on a daily basis Never chlorinate each unit simultaneously Estimated Chlorine Dosage:
l'.5 mg/l Na0Cl Effective-Treatment Level Required:
To maintain a free chlorine residual at the condenser outlet
... -. -.., _.. ~,. _. _. _.....,
.. _., _ _...... ~ _. ~. _.. -... -.. _ _..
3.2.1.3 Cooling Tower Trestment Chlorine Treatment:
With the planned " shock" chlorination of the CCW system during operation in the helper mode it is not anticipated that chlorination of the cooling towers vill be required. However, in the event that slime buildup does occur in the tover, provisions have been made to periodically chlorinate individual towers if necessary.
However, TVA vill not chlorinate the towers simultar.cously.
T 3.2.2 ASIATIC CLAM CONTROL In order to minimite the effect of Asiatic clam infestation in critical plant systems using rav vater, the following procedures and design criteria are applicable.
Asiatic clama can be controlled with low-level applications of chlorine as sodium hypochlorite during the clam spawning season of May to October. Chemical treatment using sodium hypochlorite shall begin within three weeks after the plant
~
rav vater supply temperatures reach 62 to 65 F, usually in.
late May or early June and shall end shortly after water temperatures fall below 62 F,_upually in late October.
Chlorine residuals shall be maintained at all time in the range of 0.6 to 0.8 mg/l as total residual chlorine during the chlorination period for each system.
Plant systems fer which chemical treatment using sodium hypochlorite vill be provided includes raw cooling water, raw service water, essential raw cooling vater, and high-pressure fire protection systems. A more detailed discussion of the injection points is provided in the next few paragraphs.
.g
.-....,.._... -,... _.,. ~... _... _ _. _... _ _.... _
t 4
3.2.2.1 Righ-W essure Fire Protection (EFTP) Systen Sotirm hypochicrite shall be injected into ee.ch of the two 8-inch headers (qualified) and into the lh-inch co=sce discha ;;e header of the 5?7? streiners (ncn-t q alified).
- In aidition to the prina y injection ;cint devnstrean of the nonqualified strainers, sodiu. hypochlorite stall he i
periodically injected at the upstreen side of ea.:h E?7?
strainer. Tne lines used to fey! these secenisry injection i
points shall ner:117 te valved clos +d and shall te used cnly e
in the event of excessive sline and tigae ryevth in the 4
r strainer. Strainer ba.ekvash flev shall be nar;usily ter:Insted durir.g these periods to prevent the dis: barge of chlorinated vater to the river. Injectien of sodiun. 7pechlorite at *be prinary injection pcint shall als.o be nanually terrinated when hypochlorite is aided upstrean of the strainers.
i Codiun hyp -chlorite shall he injected during test s and flushing of the EP'? systen. Mring the chlorinatien period (s) (cla spav.ing sessen) of the rav :acling vater syste s, ~*/A vill I
establish a snall conticac2s flev throur,h all.Ajer fire l
protection headers except those fire protectien systens or a
parte thereof Ordina-ily nct exposed to rav vater, that is, f
a,. eP.ed Eter Or P Ced L7 50."JUy,
i e. e a eb N e a
i k
i J
->-e
<=
r, e
c,-
a,- rw
~e-V wr-wv +
-w v
-~r,"
- ~
.- -.- ~..
injection of sodium hypochlorite at the fire pumps is not required during a. fire, but may not necessarily be' curtailed during a fire. When a fire has been 4
extinguished and when power is available to the injection feed pumps, injection shall resume until an adequate residual chlorine level is established in the system.
Two injection feed pumps are required. One injection feed pump shall'be manifolded and used to treat both of the 8-inch headers (qualified); whereas, the second feed pump will be used to treat the lk-inch header (nonqualified) and the manual injection lines upstream of the strainers.
Estimated HPFP flow for testing is 5000 gpm. Ectimated small continuous flow through' major headers is less than 1 gpm.
3.2.2.2 Rav Cooling Water (RCW) System and Rav Service Water (RSW) System Water enters the RSW and RCW systems from the CCW intake conduits i
through a common 36-inch header. Sodium hypochlorite shall be injected at two injection points on the 36-inch header that supplies water to the five RCW pumps and the three RSW pumps.
One injection point shall be located on the unit 1 side as close as possible to the strainer A,20-inch suction line takeoff. The second injection point shall be located on the unit 2 side
)
(opposite end) as close as possible to the strainer D 20-inch i
1 suction line takeoff.
l 4
1
The RCW and the RSW systems vill be treated continuously for two 3-veek periods per year. Continuous treatment during the entire clam spawning (six months) period mcy be required if periodic treatment does not result in effective control.
If problems occur in the HPFP system, consideration vill be given to continuous treatment with sodium hypochlorite of the RSW system. As a result, additional injection points vill be required immediately upstream of the RSW system pumps in the turbine building. Space in the hypochlorite building shall be allocated for at least three additional injection feed pumps.
Estimated RSW flow per two units total is 1500 gym.
Estimated RCW flow per unit is 29,000 gpm.
The RCW vater to be chlorinated enters the RCW system from the CCW intake conduits, flows through the RCW system, and then discharges into the CCW discharge conduits downstream of each unit's main condenser. The RSW system discharges at various l
l points, but ultimately flows to either the turbine building station sump or into the yard drainage system.
l l
l
3.2.2.3 Essential Rav Cooling Water (ERCW) System The ERCW system vill be treated continuously during entire clam spawning period.
s 3.2.2.3.1 ERCW Pumps at (old) Intake Pumping Station (IPS)
The ERCW pumps (old) at the IPS will remain in service for unit 1 operation until the new ERCW pumping station is completed for units 1 and 2 operation. Four temporary injection points have been installed' in the ERCW pump discharge header by Construction personnel. One injection point has been provided downstream of each pump (A-A, C-B, F-B,
- and H-A) which serve strainers lA and 2A for header A and strainer 1B and 2B for header B.
The backwash from each strainer (lA, 1B, 2A, 2B) discharges into the yard drainage system which flows to the yard drainage pond.
The equipment already in operation in the field vill be sufficient to chemically treat the (old) ERCW system at the IPS until the (new) ERCW pumping station becomes functional.
- ~ ~ ~ * " ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
~
4 The old ERCW system pumps in the intake pumping stntion vill operate during unit 1 operation until the new ERCW pumping station is complete. The old ERCW system pumps vill be removed from service prior to unit 2 operation.
3.2.2.3.2 ERCW System Pumos at (new) ERCW Pumping Station Sodium hypochlorite shall be injected primarily into the common header immediately downstream of each of the four ERCW strainers. Each of four primary injection points shall have a corresponding feed pump.
In addition to the primary injection points, each of the feed pumps can also discharge to the upstream side of each ERCW strainer. The lines used to feed these secondary injection points shall normally be valved closed and shall be used only in the event of excessive slime and algaa growth in the strainer. Strainer back-vash flow shall be manually terminated during these periods to prevent the discharge of chlorinated water to the river. Injection of sodium hypochlorite at the primary injection point shall also be terminated when hypochlorite is added upstream of the strainers.
Estimated normal ERCW flow per unit is 17,000 gpm.
Units 1 and 2 ERCW flows into a common h8-inch discharge header that ultimately drains to the cold water channel.
=
h.0 Descrintion of ERCW Intake Pumping Station (Reference FES p. 2.6-5, and FSAR Section 9.2.2'.2.2 Amend. 28)
A description of the ERCW system at Sequoyah Nuclear Plant can be found in section 9.2.2 of the FSAR for this plant. A flow diagram of the new ERCW system is included as Figure h.0-1, additional flow, control, and logic diagrams for the ERCW system are shown in the FSAR in Figures 9.2-11 through 9 2-13, Figures 9.2-15 through 9.2-19, and Figures 9.2-20 through 9 2-24, respectively. Tables 9 2-27 and 9.2-27a present the pump design data for the pumps housed in the intake structure (condenser circulating water intake pumping station) and ERCW pumping station, respectively. The location and arrangement c' the equipment in the intake structure can be found in Figures 1.2-lh through 1.2-17 while similar information for the ERCW pumping station is shown in Figure 1.2-18 and Figures 1.2-22 through 1,2-24.
General information relating to' both of the subject pumping stations is summarized in section 1.2.2.8 of the FSAR. CCW pump design data can be found in section 10.h.5.2.
The intake structure located at the land end of the intake channel vill be used for ERCW supply prior to unit 2 operation. Supply water for the ERCW pumps flows into the intake channel under a skimmer vall from the river, enters the intake structure through trash racks and traveling water screens into the CCW pump pits, and then flows into the ERCW pump pits. Under nor:hal opers. tion prior to commencement of unit 2 operation, a flow of 579,000 gr,m per unit for three CCW pumps plus two ERCW pumps vill be seen aeross three of these trash racks and traveling water screens. Assuming equal division of this flow between
_._-. ~.,
,... ~., -. _... -...., _. _.. _ _ _ _. _... _ _._
. ~...
- - ~
s these three intake sections,: velocities of 1.3h,1.19, and 2.31 feet per second vill be realized across'the trash racks, in that portion of the intake section between the trash racks and traveling vater screens having minimum flow area, and across the traveling water screens, repsectively, with minimum normal reservoir level of El 675 0'.
The new ELCW pumping station, which will be used'for two-unit plant operation, is located within the plant intake skimmer structure and has direct communication with the main river channel for all reservoir levels including loss of downstream dam. Supply water for the ERCW pumps enters the pumping station through four trash racks leading into four 9' -by-9' square conduits having invert El 625', passes through four traveling water screens, and flows'directly into each corresponding ERCW pump pit from which two ERCW pumps take suction. Under normal operation, one ERCW pump in each of the four pits vill operate at a flow of approximately 8130 gpm. This vill result in velocities of 0.27, 0.23, and 0.55 feet per second across the trash racks, in the square conduits (upstream of the screens), and through the traveling water screens, respectively.
i m,
e.~
,,.,,..,,... -, -. -,,...., ~ -,
,,... - -,., ~.. - -, -., ~,,,,.,,,..,
,. -,...,,,,,... ~. ~..... _.,...
--,e e
e.,-~e.,...r,
-