ST-HL-AE-1710, Forwards marked-up FSAR Pages Re Deletion of Containment Spray Sump Additive Tank.Requests NRC Review Changes as Soon as Possible to Avoid Impacting Project Schedule

Forwards marked-up FSAR Pages Re Deletion of Containment Spray Sump Additive Tank.Requests NRC Review Changes as Soon as Possible to Avoid Impacting Project Schedule

ML20203L994
Person / Time
Site:	South Texas
Issue date:	08/28/1986
From:	Wisenburg M HOUSTON LIGHTING & POWER CO.
To:	Noonan V Office of Nuclear Reactor Regulation
References
CON-#386-553 OL, ST-HL-AE-1710, NUDOCS 8609020123
Download: ML20203L994 (47)

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August 28, 1986 ST-HL-AE-1710 File No.: 012.188/G9.1 Mr. Vincent S. Noonan, Project Director FWR Project Directorate #5 U. S. Nuclear Regulatory Co' mission m Washington, DC 20555 South Texas Froject Units 1 and 2 Docket Nos. STN 59-498 STN 50-499 FSAR Changes Related to Deletion of Containment Spray Sump Additive Tank

Dear Mr. Noonan:

On June 18, 1986, Houston Lighting & Power Company (HL&P)-personnel had a telephone discussion with your Mr. P. Kadambi and several members of the NRC staff regarding elimination of the South Texas Project (STP) Units 1&2 sump additive tank from the containment spray system (CSS) design. The elimination of this tank will result in a minimum long term pH of the containment sump of 7.5 which is lower than the lower end of the pH range of 8.5-10.5 recommended in the Standard Review Plan (SRP). However, as explained below, the offsite 4 and control room accident doses were confirmed to be less than the allowable limits.

A reanalysis of the offsite dose was performed using current source term methodology (100% noble gases, 50% Halogens) and the lower sump pH.

During the ECCS injection phase, the containment spray was assumed to begin at the time calculated for the system to fill with water and begin spraying which is 2.34 minutes. The pH during this phase is the same as is currently evaluated in the FSAR (i.e. half of the flow at a pH of 8.0 and half at c pH of 9.0). At the end of the injection phase, the spray additive tank is isolated thereby maintaining a maxinam sump pH below 10.5.

Since the long term pH of the sump will be a minimum of 7.5 (rather thcn the SRP recommended limit of 8.5) after injection, this value was used to determine the maximum decontamination factor (DF) for elemental iodine removal by the sprays. The maximum DF was found to be 12.28 using the equation in Section III 4.c of SEP 6.5.2 (NUREG-0800). This DF was used as the point when elemental iodine renoval via sprays was assumed to stop (~.2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />).

Elemental iodine removal via plateout was assumed to continue until a total DF l of 100 (this includes the DF of 12.28 from spray removal) was reached.. In l

addition, particulate iodine removal via the sprays was assumed to continue l until a DF of 100 was reached on the particulate iodine concentration.

L1/NRC/ts 8609020123 860828 PDR ADOCK C500049G Qw dbd> Rl A PCR ki

ST-HL-AE-1710

-,11eusten Lighting & Power Comparty File No.: G12.188/G9.1 Page 2 The offsite and control room doses were confirmed to be less than the allowable 10CFR100 and 10CFR50, Appendix A (GDC19) limits. HL&P has concluded that the offsite doses and the spray effects on equipment qualification are acceptable. Therefore, the sump additive tank is_not required and will not be installed.

~

As a result of this design change, STP estimates a cost savings of approximately $400,000 in Engineering costs, $143,000 in hardware cost and

_$265,000 in construction cost for a total approximate saving of $808,000.

We request that the NRC review this change as soon as possible in order not to impact project schedule.

If you should have any questions on this matter, please contact Mr. M. E. Powell at (713) 993-1328.

Very trul ours, 4 O .

Y M

h. R. Wise burg Manager, Nuclear Licens g MEP/LRS/b1

Attachment:

Annotated FSAR Pages to Section 6.1.1, 6.1.3, 6.2.2, 6.5.2, 7.6, 15.6.5, Tables 6.4-2 and 7.1-2, Figures 6.5-1 and 7.6-9, and NRC Questions 22.11,~122.20, 312.07, 12 & 13.

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Houn n Lighting & Power Company ST-HL-AE-1710 File No.: G12.188/G9.1 Page 3 cc:

Hugh L. Thompson, Jr. , Director Brian E. Berwick, Esquire Division of PWR Licensing - A Assistant Attorney General for Office of Nuclear Reactor Regulation the State of Texas U.S. Nuclear Regulatory Commission P.O. Box 12548, Capitol Station Washington, DC 20555 Austin, TX 78711 Robert D.' Martin Lanny A. Sinkin-Regional Administrator, Region IV Christic Institute Nuclear Regulatory Commission 1324 North Capitol Street 611 Ryan Plaza Drive, Suite 1000 Washington, D.C. 20002 Arlington, TX 76011 '

Oreste R. Pirfo, Esquire i N. Prasad Kadambi, Project Manager Hearing Attorney U.S. Nuclear Regulatory Commission Office of the Executive Legal Director 7920 Norfolk Avenue U.S. Nuclear Regulatory Commission

, Bethesda, MD 20814 Washington, DC 20555 Claude E. Johnson Charles Bechhoefer, Esquire Senior Resident Inspector /STP Chairman, Atomic Safety &

c/o U.S. Nuclear Regulatory Licensing Board Commission U.S. Nuclear Regulatory Commission P.O. Box 910 Washington, DC 20555 Bay City, TX 77414 Dr. James C. Lamb, III M.D. Schwarz, Jr., Esquire 313 Woodhaven Road Baker & Botts Chap'el 11111, NC 27514 One Shell Plaza Houston, TX 77002 Judge Frederick J. Shon Atomic Safety and Licensing Board J.R. Newman, Esquire U.S. Nuclear Regulatory Commission Newman & Holtzinger, P.C. Washington, DC 20555 1615 L Street, N.W.

Washington, DC 20036 Citizens for Equitable Utilities, Inc.

c/o Ms. Peggy Buchorn Director, Office of InspLetion Route 1, Box 1684 and Enforcement Brazoria, TX 77422 U.S. Nuclear Regulatory Commission Washington, DC 20555 Docketing & Service Section Office of the Secretary i

T.V. Shockley/R.L. Range U.S. Nuclear Regulatory Commission l Central Power & Light Company Washington, DC 20555

P.O. Box 2121 (3 Copies) l Corpus Christi, TX 78403 Advisory Committee on Reactor Safeguards l

H.L. Peterson/G. Pokorny U.S. Nuclear Regulatory Commission City of Austin 1717 H Street P.O. Box 1088 Washington, DC 20555 '

Austin, TX 78767 J.B. Poston/A. vonRosenberg City Public Service Board P.O. Box 1771 San Antonio, TX 78296 Ll/NRC/ts Revised 5/22/86 i

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h. L A to S.IP FSAR c" fFod d3 ,

_PAGEI 0F LN (41*/c locatedflhe speg in +he FHBadditwe WCh 6 4cLnks mimtCunt.d information regcrding the selection, procurement, testing, storage, and gg g*F installation of nonmetallic thermal insulation, and demonstrating that the dudeg no leachabic concentrations of chloride, fluoride, sodium, ard silicate are pg comparable to the recommendations of RG 1.36, is contained in Section 5.2.3. p afen, C

The welding materials used for joining the ferritic base materials of the ESF conform to or are equivalent to ASME material specifications SFA 5.1, 5.2, 5.5, 5.17, 5.18, 5.20, 5.28, and 5.30. The welding materials used for l40 joining nickel-chromium-f ron alloy in similar base material combination and in dissimilar ferritic or austenitic bdse material combination conform to ASME material specifications SFA 5.11 and 5.14 The welding materials used for joining the austenitic stainless steel base materials conform to ASME material specifications SFA 5.4 and 5.9. The welding materials used for joining copper or copper-alloy base material conform to ASME Material 40 Specifications SFA 5.6 and 5.7. These materials are tested and qualified to the requirements of the ASME Code and are used in procedures which have been qualified to these sane rules. The methods utilized to control delta ferrite content in austenitic stainless steel weldments are discussed in Section 5.2.3.

The procedures utilized to avoid hot cracking (fissuring) during veld fabri-cation and assembly of austenitic stainless steel compenents of the ESF are the same as those used for the reactor coolant pressure boundary. There-fore, discussion of the procedures is found in Section 5.2.3.

Use of aluminum will be minimized in the Containment. Galvanized steel inventory is given in Table 6.1-2.

6.1.1.2 Composition, Compatibility, ity of Containment Sprav Coolants. The pH of the Contain n pray will be adjusted during the injection mode by the addition of a r weight-percent sodium hydroxide l3 solution to provide a minimum pH of .[A discussion of the NaOH addition design basis is provided in Section 6.2.2.2.2. 1r 7.; ;;;; ;;ill Oc ;;1u",.

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- t im %2 ';11  ;;;id S; s, vf 0.5 4v 10. 5c. l33 Iadiolytic decomposition of water will occur, but boric acid and sodium hy-droxide will not be affected by radiation. No pyrolytic decomposition of boric acia or sodium hydroxide is expected.

The vesr,els used for storing ESF coolants include the accumulators and the l3 refueling water storage tank.

The accunulators are carbon steel clad with austenitic stainless steel. l3 Because of the corrosion resistance of these materials, significant corro-cive attack on the storage vessels is not expected.

The accumulators are vessels filled with borated water and pressurized with nitrogen gas. The nominal boron concentration, as boric acid, is 2,500 ppm.

Fampics of the solutten in the accumulators are taken periodically for checks of horon concentration.

Annkom The refueling ster ctorage tank is a source of borated cooling water for injaction. The ;m;.i;.a2 baron concentration, as boric acid, is 2,500 ppm.

The tank cubicle is maintained above 50*F, thus ensuring that the boric j33 ,

u bt remains soluble, 6.1 .) Amendment 40

ATTACHMENT ST HL AE- 17s '

STP FSAR PAGE a_OF 30 In order to ensure materials compatibility during storage, the 94- to

}> iG 48: weight-percent sodium hydroxide chemical additive is contained in stain-less steel tanks.

The spray additive solution is not corrosive to the stainless steel compo-nents of the system with which it comes into contact. The spray and sump solutions will tend to severely corrode aluminum alloys, but will not at-tack stainless steel or Cu-Ni alloys.

6.1.2 Organic Materials Organic materials located inside the Reactor Containment Building (RCB) are limited to coating materials on painted surfaces, electrical cable insula-tion, and lubricating oils and greases. There are no significant amounts of other organic materials, such as wood or asphalt, located inside the RCB.

6.1.2.1 Protectiva Coatings Certain coatings that are in common industrial use may deteriorate in the post-accident environment and may contribute substantial quantities of for-eign solids and residue to the containment sump. Consequently, protective coatings used inside the containment have been tested'and selected to assure that they will withstand nuclear, chemical, and physical conditions of a DBA, as required by Regulatory Guide (RG) 1.54 and ANSI N101.2-1972. The tests are performed by independent laboratories and show that no signif-icant decomposition or radiolytic or pyrolytic failures will occur during a DBA. Inorganic zinc, epoxy, and modified phenolic systems are the most 29

) desirable of the generic types evaluated. This evaluation considers resis-tance to radiation, temperature, pressure and chemical conditions antici-pated during a loss-of-coolant accident (LOCA).

Steel and concrete surfaces inside the RCB with protective coatings can be grouped into three categories:

1. Major surfaces: This category includes large surfaces such as the containment liner, structural steel, large uninsulated equipment and equipment supports, pipe whip restraints, polar crane, and concrete surfaces receiving epoxy surfacer systems.

Coatings for major surfaces are selected in accordance with the require- l I ments of Section 4 of ANSI N101.2 and applied per RG 1.54, thus assuring 132 that .the majority of protective coatings inside the RCB will remain in- 29 tact in the post-accident environment.

6.1-3 Amendment 33

ATTACFMAENT STP FSAR ST-HL AE- 17/o, PAGE 3 OF 44, ,29 I

., 6.1.2.2 Cable Insulation. Cable insulation in the RCB is qualified to

} IEEE 383-1974 requirements and consists of 282,000 pounds of ethylene propy- l lene rubber (EPR), polyethylene (XLPE), and hypalon.

33 6.1.2.3 Oils and Greases. Significant quantities of lube oils used inside the Containment are located in the reactor coclant pumps, with ap-proximately 265 gallons per pump. Other pumps require only approximately I gallon of lube oil each or are grease lubricated and represent an insignif-icant amount, as noted below.

Oil-lubricated pumps 4 reactor coolant pumps 265 gallons / pump 2 reactor coolant drain tank pu=ps 1 gallon / pump 2 normal sump pumps 1 gallon / pump 1 equipment drain sump pump 1 gallon / pump Grease-lubricated pumps 3 Residual Heat Removal System pumps 33 All oils are contained in sealed reserviors and are not exposed to the out-side environment. When oil changes are effected, the used oil is drained directly into waste oil sumps outside the Containment prior to disposal.

In the event that small leaks might occur during operation, all pumps are equipped with drip pans placed and secured to prevent possible oil drops

) from coming into contact with adjacent piping or equipment.

6.1.2.'4 Decomposition Products. An insignificant amount of radiolytic decomposition in the reactor coolant pump lube oil will occur during opera-tion; however, the effect on oil properties, and the hydrogen generated by the reaction, are negligible.

Under DBA conditions, the Containment spray and sump water react with those surfaces coated with zinc-rich primer that are not epoxy topcoated. This reaction results in the generation of hydrogen. Further details are provid-ed in Section 6.2.5.

l 6.1.3 Postaccident Chemictry

r. G l

Following a DBA, the pH of the fluid inside Containment remains between 4h4' a gb 1444efollowing completion of c gstic injection by the Containment Spray 33 j

10.o ystem, as described in Section 6. 2.

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Amendment 33 6.1-5

STP FSAR ATTACHMENT ,

TABLE 6.1-1 ST-HLd Oft PAGE i AE4I 7/[o _

ENGINEERED SAFETY FEATURES MATERIALS Materials Employed for Safety Injection and Containment Spray Systems Components Component Material Ebm ct Highpeed Safety Injection, Iow Head Safety Injection, and Containment Spray Pumps:

Shaft A-276 TP 410 Impeller, Stage 1,' Flights A-240 TF 304 Hubs A-276 TF 304 Remaining stages A-296 CA40 Outer Barrel, .

Top Flange SA-182 F304 52 Top Cylinder SA-182 F304 Suction Nossle SA-182 F304 Bottom cylindar SA-358 TP304; Class 1. Welded Cap SA-182 F304

__g Residual Heat Exchangers Tube Sheets SA516 Gr. 70 with 304 stainless steel cladding Tubes SA249 Type 304 Heads SHELL SIDE SA516 Gr. 70 TUBE SIDE SA240 Type 304 33 Nossle Necks: SHELL SIDE SA-106-B(SMLS)

TUBE SIDE SA-312 Type 304 1

Shells: SHELL SIDE SA516 Gr. 70 ,

TUBE SIDE SA240 Type 304 i

Flanges: TUBE SIDE SA182 Gr. F304 f SA105

SHELL SIDE l

! Valves Containing Radioactive Fluids:  ;

Pressure-Containing Parts SA182 Type 316 or 304 i Seating Surfaces Stellite No. 6 or equivalent l Stems Type 630 and 410 or 17-4PH stainless Tonks_

Sp<n3 Add't6te Tand 6.1-7 SA

• TY" Amendment 52 l

ATTACHMENT STP FSAR ST-HL AE- /

PAGES OF  ;

TABLE 6.1-1 (Continued)

ENGINEERED SAFETY FEATURES MATERIALS Component  ;-

(Materiah Valves (Continued)

Containing Nonradioactive, Boron-Free Fluids:

, Pressure-Retaining Parts SA105, SA182 Type 304 or 316 Stems Type 630, 410 or 17-4PH stainless Relief Valves 33 Bodies SA351 Cr. CF8M All Nozz'es, i Discs, SA479 Type 316 or SA193 Spindles, and Guides Gr. 56 or Type 410 or 416 Stainless or Stellite or Inconel or Monel Bonnets SA351 Gr. CF8M or SA216 Gr. WCB Piping All Piping in Contact SA312, Gr. TP304, 304L, 316, or 316L; with Borated Water SA 376 Gr.

TP 304 or 316 52 SA 358 TP316L, CL.1 velded All Piping not in Contact A106 Gr. B with Borated Water SA106 Cr. B 2

Materials Emeloved for Electric Hydrogen Recombiners Outer Structure SA240 Type 304 33 Inner Structure Incoloy-800 Heater Element Sheath Incoloy-800 Materials Emeloved for Containment System Reinforcine Steel ASTM A615, Gr. 60 ASME - SA516 Gr. 60  :

containment Liner (Greater than 5/8" thick) 52 (5/8" and less thick) ASME - SA285 Gr. A 6.1-8 Amendment 52

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ATTACHMENT STP FSAR ST.HL AE # 7/b PAGE to 0F 44 1 l

8. The CHRS is designed to accommodate the Operating Basis Earthquake (OBE) l38 within stress limits of applicable codes and to withstand the Safe Shutdown Earthquake (SSE) without loss of function.

9. The CHRS and the RHRS are protected from the effects of missiles and pos- D8 tulated pipe ruptures without loss of safety function (see Sections 3.5 and 3.6) .

10. The CHRS is designed to permit periodic inspection of the system, 38 including important subsystems ar* components.

6.2.2.1.2 Containment Emergency Sump Design Bases:

1 The Containment emergency sump meets the following design bases:

1. Sufficient capacity and redundancy to satisfy the single-failure cri-teria. To achieve this, each CSS /ECCS train draws water from a separate l38 Containment emergency sump.

2. Capable of satisfying the flow and net positive suction head (NPSH) requirements of the ECCS and the CSS under the most adverse combination of credible occurrences. This includes minimizing the possibility of vortexing in the sump.

3. Minimizes entry of high-density particles (specific gravity of 1.05 or more) or floating debris into the sump and recirculating lines.

s

4. Sumps are designed in accordance with RG 1.82, proposed revision 1, May 38 '

1983.

6.2.'2.1.3 Fission Product Removal Design Basis: The Spray Additive  ;

Subsystem is:

1. Designed to. add sodium hydroxide to the Containment spray solution to remove iodine from the Containment atmosphere and ensure e-e&n4mune. equi-

"O librium sump solution pH of (12t yt T. G to 10. O .

2. Designed such that it will tolerate a single active failure.

3. Designed to accommodate the OBE within stress limits of applicable codes and.to withstand the SSE without loss of function.

4 Designed to assist in reducing offsite exposures resulting from a DBA to 138 less than the limits of 10CFR100 by rapidly reducing the airborne ele-mental iodine concentration in the Containment following a DBA.

38

5. Classified SC 3.

6.2.2.2 System Design Description.

6.2.2.2.1 Reactor Containment Fan Cooler System

Description:

The RCFC System is shown on Figure 6.2.2-4. The RCFC units are designed to remove heat from the Containment during both normal operation and accident conditions.

System operation and design requirements that are associated with the normal 6.2-32 Amendment 38

ATTACHMENT STP FSAR L AEg'7g water. The sodium hydroxide is added to the spray water until the spray additive tank is empt I or until +he RW ST water- reacre.s low- low levela

') tahichever occu rs v s r.

The CSS is actuated by a Containment 11-3 p'ressure signal. Manual operation 8

is not required during any mode of operation, but the ability to operate the system from the control room is provided. Descriptions of the actuation sys-tem are provided in Section 7.3. The setpoints .Se "5 :-t:- IGr are estab-lished at a level to prevent inadvertent operation of the system and yet provide assurance that the design pressure of the Containment is not exceeded.

InsertI A steam line break or LOCA ge erstes a SI s pial, which starts the DGs as des-Qgr, of cribed in Section 6.2.2.2.1. 4fith a LCC"f the ZSF load sequencers allow the

,pe taxi starting of the CSS pumps between 15 and 17 seconds following the,0C treaker.

ler rci If the Containment Hi-3 signal is not received by 17 seconds, the

'quenci starting of the CSS pumps is delayed to 40 seconds following the GC L m L::t eaeewee9- Af ter this delay period, receipt of a Containment EL 3 raignal starts 3gry op pe}the CSS pumps. The actuation of the CSS discharge valves to the spray headers food venc]Jandthevalvesintheoutletsoftheadditivetanksisdelayedonesecond I

following theA C Lie.kcr cle;ura after which receipt of a Containment H1-3 38 (stort of tFe . signal opens the valves; receiptWWhoolofLOOP +he HI-+he3volves signalopen Wmediafeg on (j$)p"'%theut  : t~r . :h: Cer - r: r: :: tree a e e:nre::ipt witha: the t:. - - - %

a loy for "C :::rting. The CSS - ::.17;; es: ; f :he Cor.::i..xc.:t, Ili4 aign:1 - ith: t 3:1:7 "

The transit time for the water to reach the last nozzle and for full spray to be developed is a maximum of 54.1 seconds following the starting of the CSS l44 pumps and opening of the CSS pump discharge valve. The CSS pump discharge 138 valve maximum opening time is fifteen seconds. l44 On actuation, approximately 5 percent of each spray pump discharge flow is diverted through each spray additive eductor to draw sodium hydroxide from the d tanks. This sodium hydroxide solution then mixes with the liquid entering the y pump suction, and the resulting spray solution is suitable for removal of ig iodine from the Containment atmosphere. e 6.2.2.2.2.1 Component Descriptions - Tables 3.2.A-1 and 3.2.B-1 lists ]38 safety classification, seismic category, and code requirements for the CSS and Spray Additive Subsystem components. The load combinations and transients to l38 which these components are designed are discussed in Section 3.9. Envi- .

ronmental, qualification of the components is discussed in Section 3.11. Sel3MC.

goalificaten is discossed in Section S.to.

The RWST serves as a source of borated cooling water for initial spray oper-ation and safety injection. During refueling operations, the RWST is aligned l38 to fill the refueling canal and the refueling cavity for refueling operations.

During normal operation, the RWST is aligned to the auction connections of the ECCS pumps and CSS pumps.

6.2.2.2.2.1.1 Containment Spray Pumps - The Containment spray pumps are the vertical centrifugal type, driven by electric motors. The pumps are designed to perform at rated capacity against a total head composed of Con-tainment design pressure, spray nozzle elevation head, line losses, and spray l38 nozzle pressure losses. Adequate NPSH is available with a minimum level in the RWST during the injection phase. A discussion of NPSH requirements is provided in Section 6.2.2.3.5.

6.2-35 Amendment 4/.

1

• ATTACHMENT ST.HL AE I7/As PAGE*$ OF M i

Insert 1 to page 6.2-35 With a IDOP, the ESF load sequencers delay sequencing of loads until closure of th'e DG breaker. Without a LOOP, the sequencers begin sequencing of loads onto offsite power inunediately, as discussed in Section 8.3.

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STP FSAR ATTACHMENT

~1 3o-32 7. s ST HL AEdF PAGE9 6.2.2. .2.1.2 Spray Additive Tanks - The stainles steel tanks contain a, '

cufficient (la m ) weight-percent of sodium hydroxide olution to bring the Ccntainment sump fluid to a minimum equilibrium pH of (1 : rb upon mixing with 38 tha borated water from the RWST, the accumulatore, and the reactor coolant.

This assures continued iodine removal and retention effectiveness of the Con-toinrent sump water during the recirculation phase. A blanket of pressurized nitrogen is maintained in the three tanks.

6.2.2.2.2.1.3 Syray Additive Eductor - Sodium hydroxide is added to the cprcy liquid by a liquid jet e.ductor, a device that uses the kinetic energy of a prsssurized liquid to entrain another liquid, mix the two, and discharge the riixture against a pressure head. The pressurized liquid in this case is the cprsy pump discharge, which is used to entrain the sodium hydroxide solution cnd discharge the mixture back into the suction of the spray pumps. The educ-tors are designed to limit the~ sodium hydroxide in the spray mixture to a maximum pH of 10.5.

6.2.2.2.2.1.4 Spray Nozzles - The CSS spray nozzles are distributed on spray ring headers located in the uppermost part of the Containment.in such an crray that the maximum volume of the Containment is sprayed. The spray noz-zico are hollow-cone type, with a 3/8-in-diameter orifice, and are fabricated from stainless steel. The nozzle atomizing capability is discussed in Se~ction 38 6.5.2.

6.2.2.2.2.1.5 Spray Headers - A plan view of the Containment spray hsrdars is shown on Figure 6.2.2-3. Spray nozzle location and orientation are also shown.

Th; STP ic pr;;idcd witht hur concentric Containment spray headers in :::M. ore provided.

-AG8c. Piping to the spray headers from the Containment spray pumps and valving crrcngement assures delivery of 100 percent of the required spray flow as-cuning any single active failure.

38 Tha spray pattern is determined using Spraco 1713-A nozzles. The spray hacders are located as high as possible in the Containment without allowing !38 interruption of spray pattern by impingement on the dome.

3 6.2.2.2.3 Containment Emergency S/ imp

Description:

The Containment emer- 5 gancy sumps are represented on the pipfng diagrams for the Safety Injection System (see Figures 6.3-1 through 6.3-7/) and are illustrated in Figure Q22.

13 i 6.2.4-2. There are three independent sumps to serve as reservoirs and provide suction to the ECCS and CSS pumps during the recirculation phase post-DBA. 38 l

l Ecch sump is stainless steel lined and is covered with a two-stage l ctesl-framed screen composed of:

! 1. Grating of stainless steel with a 4-in by 1-3/16-in. opening (80 percent open area),

l

! 2. Screen of stainless steel plate with 1/4-in.-diameter perforations at

! 5/16-in. center-to-center (58 percent open area). .

Tha sump assemblies are protected by a removable stainless steel cover. The 5 scrsen and stainless steel cover are bolted to the floor over the sump. The Q22.

sumps are located at Elevation -11 ft 3 in. The sumps are physically H 13 ,

6.2-36 Amendment 38 i

STP FSAR ATTACFDAENT ST HL-AE I 7'O -

PAGE to OF 4' separated from each other with no high-energy pipirg in the area. The floor g around the emergency sumps slopes away from them and toward normal sumps 5

) located in the area. The drains from the upper levels of the Containment Q22.13 Building do not terminate in the immediate area of the sumps.

The semp structures are designed to withstand the SSE without loss of struc-tural integrity.

Water entering the suction pipe at the bottom of the sump may contain a neg-ligible amount of small particles (less than 1/4-in in diameter). These particlescad[notclogthecontainmentspraynozzles(3/8-in. orifice diameter) which are the smallest restrictions found in any system served by 38 the sump.

At the beginning of the recirculation phase, the minimum water level above the Containment floor is approximately 3.6 ft. In accordance with RG 1.82, proposed revision 1, May 1983, the sump screens are designed to limit flow 38 velocities to 0,2 ft/sec. The velocity is limited to permit high-density particles to settle out on the floor and minimize the possibility of clogging -

the screens.

Most potential sources of debris are remote from the emergency sumps and are separated by shield walls or other partitions. Debris may be pieces of 38 piping, insulation, or concrete and paint chips. The possibility of debris reaching the sump screens is remote. Further, the possibility of paint chips peeling off has been minimized by requiring proper surface preparation and by painting large surface components such as the Containment liner, RCS supports,

) floors, and structural steel with coatings which have been qualified under DBA conditions.

insulation The insulation types used in the RCB are stainl ss steel reflective, blanket fibe(]' glass,fulhencapsulatedinorganicbulk, nd bulk sheathed in stainless steel. Most of 6e stainless steel reflective is used on the reactor vessel.

Mostoftheblanketfibe([glasstypeisusedonthepiping. Fully encapsu-

! lated inorganic bulk is used for some CCWS and SG blowdown lines. Bulk insu- 38 lation sheathed in stainless steel and bound with stainless steel straps is used on the CCWS supply and return lines to the RCFCs for antisweat purposes.

The Containment emergency sumps will be periodically inspected as delineated 5 l27 in the Technical Specifications. Q22.L3 6.2.2'.3 Design Evaluation.

> 6.2.2.3.1 Reactor Containment Fan Cooler System Performances: The design characteristics of an RCFC are given in Table 6.2.2-2 and represent the minimum required functional capability of the cooling unit. The.RCFCs are designed to meet these specifications. To assure the performance capability of the air cooling units, the manufacturers have developed analytical methods and models for design selection and for assessing the performance of the se-lected design. The analytical model used is presented herein.

The snalytical model simulates the heat and mass transfer process in a i cross-flow HX with extended surfaces or fins.

6.2-37 Amendment 38

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STP FSAP ATTACHMENT ST HL AE /*7 PAGE il OF ,

within the secondary shield wall and below the operating floor. For the Con-tainment volume outside the secondary shield wall, the mixing is accomplished

.,j as follows:

s

1. A portion of the supply air (2,000 fe / min per RCFC) is discharged outside the secondary shield wall, where it rises through various levels 38 to be finally picked up through the RCFC return air risers.

2. A major portion of the recirculated air is returned to the RCFC through the return air risers, which are located at the polar crane rail level.

The rising air with the action of the spray ansures mixing of the Con-tainment atmosphere above the operating floor.

Based on Containment spray and a mininum of three RCFCs in operation (total of 160,500 ft8 / min), the following is the sprayed voluce and rate of mixing of 32 each of the major Containment compartments:

The Containment dome compartment volume of 882,500 fts is considered a 138 1.

sprayed volume. 2 Q31

2. , The volume from the operating floor to the Containment spring line is 38 7 1,431,000 ft8, of which 1,425,400 ft is considered sprayed. 8

3. The region inside the secondary shield wall below El. 19'-0" consists of 281,500 ft8, of which 5000 ft8 is sprayed. Ninety-six percent of the p8 total RCFC flow is delivered to this compartment, resulting in an ex-change rate of approximately 61 volume changes per hour.

M'ost of the air flows upward through the grating at El. 19'-0" into the 38 loop compartments. A portion of the flow is through relief openings in the secondary shield wall due to pressurization.

4. The volume of the compartment inside the secondary shield wall including the refueling cavity between El.19'-0" and El. 68'-O is 232,000 f ts, of 38 which 219,600 ft8 is considered sprayed. This region vents approximately 94 percent of the air discharged to region 3 above. Most of this air rises and is returned to the RCFC System through the return air risers at El. 130 ft.

5. The volume of the compartment in the annulus space between El. 68' and b8

(-) 11'-3" is 734,200 ft8, of which 209,600 ft is 8 considered sprayed. r Air flow in this area is limited and is comprised of flov from inside the secondary shield wall and also from above El. 68' through grating. Ap-proximately 10 percent of the total RCFC discharge flow circulates through this region to the ring duct at El. 2'.

Figure 6.2.2-13 and 6.2.2-14 show the RCFC and related ductwork. Figures 38 6.2.2-6 through 6.2.2-12 illustrate the CSS spray coverage at var ous me 5F53

• g elevations in the , con.tainment."nW 62. h ondes CS-nmates OrM mh in 4%> t,^dmdu% vcy.or's idc>M,5 i abCNC -

6.2.2.3.5 Pump Net Positive Suction Head Requirements: The minimum available NPSH for the CSS pumps is such that an adequate margin is maintained between the required and the available NPSH for both the injection and recir-culation phases, ensuring the proper operation of the CSS. Recirculation operation gives the limiting NPSH requirements for the CSS pumps.

' 6.2-39 Amendment 38 1

. . , _ . . - _ _ - _ . yw c,, , . . , . ._,,_._-__v_., ..- , _ _ _ , , _ . - r,., ., , _ _ _ , , , _ _ _ , _ , . , ___ _ , - _ _ . , _ . , _ _ _ _m,_.,_.,..-r____

i

( ATTACHMEFTT r o c.a.a-s  %"{ftd,'g Spy h1w % RJu .

The spray mass flow rates for the various regions are as follows: '

Containment Dome Area -

29.840 lb/ min From Operating Floor (EL 68') 29.840 lb/ min To The Springline (EL 153')

• Inside The Secondary Shield 304 lb/ min Wall Belov El 19' gq Inside The Secondary Shield Wall 9,631 lb/ min '

Between EL 19' And EL 68' Including The Refueling Cavity Outside The Secondary Shield Wall EL 52' to EL 68' 6,818 lb/ min EL 19' to EL 52' 6,810 lb/ min EL (-)2' to EL 19' 2.352 lb/ min Below EL (-)2' 1,825 lb/ min l

1 al l

W e

r.-- - - . . . - - .,. ,

..._,-,___,-,,,,_____,-.-r-. , , . _ _ . . _ _ . . . . .___ ,._.._ . -

e STP FSAR ATTACHMENT ST4tt.AE 171,%

PAGE/J0F W The nozzles can be tested using the available air test connections. A special '

test tap is available to provide testing capability to ensure unrestricted flow.

The spray eductors are tested individually by opening the valves in the C3 miniflow lines and the valve in the eductor test line, closing the valve to the spray additive tank, and running the respective pump./ The operator ob-4 serves the eductor suction flow durine the test. fThe eductors have no movinn

• parts. FEacn of them liner. 6 Provided wi+h OL4 tow meter. Instvorvenhshon is cAlsoj O l eitCLble & sodly pump sottton eCi discharge prcSSaves anci distemrge,{

row d spray pump discharge isolation valves can be opened peri- 38 The mot odically for testing.

The spray additive tank isolation valves can be opened periodically for testing. The contents of the tank are periodically sampled to determine that the required solution composition is maintained.

Any abnormalities discovered during the surveillance testing will be corrected in accordance with the time requirements specified in the Technical Specifica-tions.

6.2.2.4.3 Environmental Qualification Test of Motors: Discussed in Sec-tion 3.11.

6.2.2.5 Instrumentation Requirements.

6.2.2.5.1 Containment Spray System: Instrumentation and associated log-ic circuitry employed for initiation of the CSS are discusced in Section 7.3. ,

Containment. spray injection is initiated either manually from the control room or on coincidence of two sets out of four Hi-3 containment pressure signals.

The spray actuation signal starts the spray pumps (start permissive is also required from the sequencer) and opens the discharge valves to the spray headers and the spray additive tank (SAT) outlet valves. Th; :::irexleti::t 38 (pher- af = pre; p::;ti;.. 1. omt at J L, ;;;;; 1 Iv31m .hich ;;;;ir;; th; init.

Ir6crf tistian =4ga-1 (1;. iv.) fium one RWST 1..m1 6&ousm166... Thi; 1:gi: e r-a =<t g -,7 the C ::: int:n ;;;p i;;1a;iva valv: 211c"ing the CCCC and CCS p__p: te tch:-

tier free th; Ceutoi...ca; .omy. The 1:r-1.,. l..el cig..1 f;;; cach r;rryq Ladditir; tank olvo . Its ;;.y. mil, vuilm; ;;17: ter ti::lly:_ l The following describes the instrumentation that is used for monitoring the system during normal and post-LOCA operating conditions:

1. Containment Emergency Sump Water Level - Each sump is provided with a level transmitter which gives control room indication through the 38 Qualified Display Processing System.

2. Refueling Water Storage Tank Level - Three level transmitters are provided with control room indication for each transmitter. An annun-ciator alarm is provided for high, low, low-low, and empty conditions.

The low-low signal is provided for automatic switchover to the recircu- 38 lation mcde of CSS and ECCS operationy and isoladon of. +He SAT oo+let VGNC6-6.2-42 Amendment 38

ATTACHMENT ST-HL AE- 17 PAGE/f OF Insert 2 to page 6.2-42 The recirculation phase of spray operation is actuated by the automatic recirculation signal, which is the SI signal concurrent with a low-low RUST level signal from the RWST level transmitter associated with the actuation train. This signal opans the containment sump isolation valves allowing the ECCS and CSS pumps to take suction from the containment sump. The RWST low-low level signal closes the Spray Additive Tank outlet valve for the actuation train. In addition, the low-low level signal from each SAT closes its respective outlet valve automatically, if not already closed in response to an RWST low-low level.

8 L1/NRC/ ins

i l I ATTACHMENT STP FSAR ST HL AE 17/o,

, PAGE M OFPI-

3. Containment Spray Pump Pressure - Each pump is provided with local suc-tion and discharge pressure indicator.

4. Containment Spray Pump Flow - Each pump is provided with a discharge flow 38 transmitter and control room flow indicator. An annunciator alarm is provided for low flow.

5 .- System Flow Testing Instruments - A local flow indicator is provided on l the line joining the eductor motive fluid outlet and the eductor suction

' line. A local flow indicator is provided on the recirculation flow line back to the RWST for testing the containment spray pumps.

6. Spray Additive Tank Level - Each tank is provided with a level trans- l38 mitter and control room level indicator. An annunciator alarm for high and low level is provided.

! 7. Spray Additive Tank Pressure - Each tank is provided with a pressure  ! 38 transmitter and a control room pressure indicator. An annunciator alarm for high and low pressure is provided.

1 SProg Additwe ToriKS we

8. (NitrogenSupplyHeaderPressure-jupplyheaderisprovidedwithalocal l 38 pressure indicator.

9. Containment Pressure : f T r;: :tr c - Six Containment pressure trans- <

mitters with control rcom indication provided through the Qualified Dis-play Processing System : d ; :; g s;; ;; indic. m ; are employed as di- 38

, verse instruments to indicate the effectiveness of the system in cooling the Containment atmosphere. Te*Per we ydie.o+ ion,al+woogn no9oli6ed, mcg also be used in detev mining +ee- cooling eMettke ness-

6.2.2.5.2 Reactor Containment Fan Cooler System

Instrumentation and associated logic circuitry employed for initiation of the RCFC System are '

discussed in Section 7.3.

The following describes the instrumentation that is used for monitoring the j system during normal and post-LOCA operating conditions:

, 1. Cooling Water Temperature - Each cooling water loop is provided with a

! temperature sensor. Temperature monitoring is provided in the control h2 l

room.

2. Cooling Water Flow - Each cooling water loop is provided with a flow

! transmitter and control room indicator.

s 3. Cooler Air Temperature - Each air cooler is provided with a temperature sensor on the inlet and outlet. Temperature indicators are provided in the control room.

i'

4. Fan - Each fan is provided with an indicating, differential pressure switch. The switch provides an annunciator alarm in the control room and -

38 is also monitored on the Emergency Response Facilities (ERF) computer.

t

5. Each fan motor assembly is provided with a vibration sensor and control l38 4 room alarm.

i 6.2-43 Amendment 38

(

,- -- w - ~ a - -

,g----.,-----,------e,-_ , - - , - - - - .------,c_, , - - - - - - - - - - . . _ , - - - - , _ - _ - - - , , _ _ - - - - - - , - - - , - - - - - ,

ATTACHMENT STP FSAR ST.HL AE- /?ler PAGE /bOFYi TABLE 6.2.2-1 CONTAINMENT SPRAY SYSTEM - DESIGN PARAMETERS INCLUDING SPRAY ADDITIVE SUBSYSTEM) ,

Conta'inment Spray Pump i Type Vertical centrifugal Quantity 3 Design pressure, psig 495 Design temperature, *F 300 0

Design flowrate, gal / min 1,900 Design head, ft 560 Eductors Quantity 3 Eductor. inlet fluid Borated water Operating' fluid Borated water Operating temperature 265 *F (Max) 30-32 Eductor suction fluid (12te-h wt % NaOH in H O solution 2

Suction fluid Specific gravity (12t: )s.1.339 - f. 3so 38 Operating temperature Temperature of spray additive tank w e l max / min 104*F/65* F accident 120*F Spray Additive Tanks

• Number 3 Total volume, gal 1,750 1

i l

i

• During normal conditions, there is a nitrogen gas blanket. During the accident, the tank pressure will fall below atmospheric pressure.

6.2-214 Amendment 38

STP FSAR ATTACHMENT ST.HL AE- 17/

PAGE17 0F

', TABLE 6.2.2-1 (Continued) 1 CONTAINMENT SPRAY SYSTEM - DESIGN PARAMETERS INCLUDING SPRAY ADDITIVE SUBSYSTEM)

Spray Additive Tanks (Continued)

Minimum required additive volume, gal h-3MC toob

".in d --N aOH concentration, wt % -Leseee 30-3 2.

Design temperature, 'F 200 External design pressure, psig 15 Internal design pressure, psig 100 Operating temperature, 'F ^Mi::::.

Plo<mol

^

..::ii..d (max / min) .

4104*F/65*F)8- 38 120*F Accident (mox)

Material Stainless steel b

6.2-215 Amendment 38

ATTACHMENT STP FSAR ST41L- -/7 PAGE OF

6.5.2.1 Design Bases. The design bases of the CSS for removing iodine ]

from the Containment atmosphere are: /

1. GDC 41, as related to Containment atmosphere cleanup.

2. GDC 42, as related to inspection of Containment atmosphere cleanup systems.

3. CDC 43, as related to testing of Containment atmosphere cleanup systems.

4. The CSS is capable of functioning effectively with the single failure of any active component in the system, any of its subsystems, or any of its support systems.

5. The CSS is designed to obtain adequate coverage of the containment volume in order to limit (in conjunction with other safeguards systems) the offsite thyroid doses to a limit less than that established by 10CFR100, '

using the assumptions in RG 1.4.

6. The spray nozzles are designed to minimize the possibility of clogging 3

and to produce droplet sizes effective for iodine absorption.

I

7. 5

7. The pH of the injection spray is in the range of (1 ::rh to 10.5. The 38 equilibrium pH of the Containment sump is (leter)_to 444FF

7. 5 10. O ,

6.5.2.2 System Design. The CSS design is discussed in detail in Section 6.2.2.

_}

Sodium hydroxide solution is added to the Containment spray solution to raise the pH of the spray solution and the sump solution to values consistent with 38 the above design basis #7. The effects of the increased pH levels are to increase the iodine removal capability of the spray and the iodine retention in the sump.

Before the refueling water storage tank is emptied, the Containment spray pump suctions are switched automatically to the Containment emergency sumps. AF +he Some

+ime +.he S AT ooHet voheer he iso!Oted.

i The number of nozzles and the nozzle spacing on each header is given in -

Section 6.2.2. A schematic of the headers illustrating the nozzle orien-tations is given on Figure 6.2.2-3. A description of the spray additive 38 system is provided in Section 6.2.2.2.2.

The total free volume of the Containment and the portion unsprayed are given in Table 6.5-2; the spray uniformly covers approximately 77 percent of the total Containment free volume. The regions covered by the Containment spray are discussed in Section 6.2.2.3.4.

ThesystemmeetstheredundancyrequirementsofanESFgystemandsatisfies 38 the system performance requirements despite the most limiting single active failure. Included in the performance requirements is consideration of maximum concentration and volumes for the post-LOCA Containment sump water sources.

The chronology of events for system operation is discussed in Section 6.2.2.

l 27 -

6.5-4 Amendment 38

s ATTACHMENT STP FSAR ST-HL-AE- D/D PAGEf 9 OF N.

6.5.2.3 Design Evaluation. The CSS is an ESF system employed to reduce  ;

pressure and temperature in the Containment following a postulated LOCA. For this purpose, subcooled water is sprayed into the Containment atmosphere  ;

, through a large number of nozzles from spray headers located in the l Containment dome.  !

l The large spray drop surface to Containment volume ratio enables the spray to effectively remove fission products postulated to have been dispersed in the 38 Containment atmosphere. (Radiciodine in its various forms is the fission product of primary concern in the evaluation of a LOCA.) The major benefit of the CSS is its capacity to remove iodine from the Containment atmosphere. To enhonte *aneetthis iodine absorption capacity of the spray, the spray solution is %7 adjusted to an alkaline pH which promotes iodine hydrolysis to nonvolatile forms.

According to the known behavior of elemental iodine in highly dilute solu- f3 tions, the hydrolysis reaction

~

I 2 + OH" g;? HIO + I proceeds nearly to completion (Ref. 6.5.2-1) at pH>8. The iodine form is highly soluble, and HIO readily undergoes additional reactions to form iodate.

The overall reaction is:

3I 2 + 3H 2O g:2E SHI + HIO3

? Values for the spray removal half-life of the elemental iodine in a typical Containment are on the order of minutes or less. Most of the iodine released to the Containment is assumed to be elemental form. The remainder is assumed to be in the organic and the particulate form. As discussed above, the 38 i Containment spray is very effective in removing airborne elemental iodine. No credit is taken for spray removal offoIganic,rr ; rticul te foraf of iodine.

l However, thethan particulate iodine iodine.

1d'5 was'etremoved by the spray, but at a rate much lower for elemental l Ele mevtol i 6.5.2.3.1 Containment SprayAIodine Removal Model: Containment spray io-I dine removal performance was determined using the spray model developed by Westinghouse Electric Corporation (Westinghouse). This model includes the ef-fects of spray drop-size distribution, droplet coalescence, and liquid phase mass transfer resistance. Its use results in conservative valu'es of spray iodine removal constants when compared with test results.

6.5.2.3.1.1 Method of Calculation - The elemental iodine removal capa-bility of the Containment spray is described in terms of individual spray droplets. The behavior of the aggregate spray is related to the behavior of the individual drops by means of a drop size distribution function. An advan- 38 tage to using this microscopic approach is the ability to derive the model from first principles. Thus, the model is free of scaling factors which would be required to extrapolate laboratory data to a full-size Reactor Containment.

i 6.5.2.3.1.2 Drop-Size Distribution - The drop-size distribution used in the model is based on data obtained from measurements of the actual size dis-tribution from the Spraco 1713A nozzle for a 40 psi pressure drop. 38 6.5-5 Amendment 38

ATTACHMENT STP FSAR ST HL AE- 17/O ,

PAGE GD OF P-Analysis of these drop-size measurements shows that the drop-size distribu- '

tion from this nozzle may be represented by a continuous-distribution func-tion, which is used as the input to the computer code. The spray drop sac. .

fsguaH on is sMoun in Fig ure 6. 5-2.

6.5.2.3.1.3 Condensation - As the spray solution enters the high-tem-perature Cont.ainment atmosphere, steam condenses on the spray drops. The 38 amount of condensation is easily calculated by a mass and energy balance of the drop:

a+a c " "'

T mh+ah = m'h g 4

where: .

m and m' = Mass of the drop before and after condensation, Ib m = Mass of condensate, Ib h = Initial enthalpy of the drop, Btu /lb i h and h g= Saturation enthalpy of water vapor and liquid, 8 Btu /lb l

The increase in each drop diameter in the distribution, therefore, is given by: .,

\

1 h-h M(dj "f . h4 v g where:

v f

= Specific volume of liquid at saturation, ft /lb e

I v = Sgecific volume of the drop before condensation, j ft /lb -

h = Latent heat of evaporation, Btu /lb f

h = Enthalpy of steam at saturation, Btu /lb d = Drop diameter before condensation, em d' = Drop diameter after condensation, cm l

The increase in drop size due to condensation is expected to be complete in a few feet of fall for the majority of drop sizes in the distribution. More

detailed calculations by Parsly (Ref. 6.5.2-2) show that even for the largest l drops in the distribution, thermal equilibrium is reached in less than half of the available drop fall height. The change in the drop-size distribution due l

to condensation was conservatively modeled by a step increase to the equi-librium size immediately after the drops emerge from the nozzle. ,,

l l

l Amendment 38 l

I 6.5-6

,c- - , . - . .---,,nn-,,,- , _ . , - , , _ . . , , , - - . - - - - , . . _ . - . - - . - , - - - . , , - - - - - - - - - . - - . - - -

ATTACHMENT 1 STP FSAR ST HL AE /7 o  !

PAGEJ/ OF affected most. This is expected since these sizes have the highest density of '

l drop population. Due to the considerably larger volumes of the larger diam- -~. 1 oter drops, however, the increase in the larger drop population is not very pronounced.

The resulting change in drop-size distribution is taken into consideration in the mass transfer model described below.

6.5.2.3.4 Mass Transfer Model: Containment spray system performance is cvaluated using a spray model developed by Westinghouse. The model considero the effects of spray drop size distribution, droplet coalescence, gas and liquid phase mass transfer resistance, drop trajectories, and condensation of eteam of drops.

The CIRCUS (Calculation of Iodine Removal in the Containment Using Spray) com-puter code is used to analyze the elemental iodine removal effectiveness of the Containment spray system.

The model used to determine iodine removal capability is the complete mixing model wherein the mass transfer resistance in the liquid phase of the drops is neglected, i.e., mixing within the drops is assumed to eliminate any concen-tration gradient. A description of the mathematical model is provided in Ref.

6.5.2-3.

6.5.2.3.5 Experimental Verification of the Model. To demonstrate that the model described above conservatively estimates actual spray performance, l38 the Westinghouse model was applied to the test runs made at Oak Ridge National '

Laboratory (ORNL) and Battelle Northwest Laboratorie:. Comparison of the results of these tests with the above-described spray removal model shows the spray removal model to be conservative in all cases.

6.5.2.3.6 Spray Performance Evaluatien.,

6.5.2.3.6.1 Sprav Iodine Removal During The Injection Phase: The spray iodine removal analysis is based on the censervative CSS parameters outlined in Table 6.5-2. The total Containment volume and sprayed volume are consis-tent with those values used for the LOCA offsite dose analysis described in Section 15.6.5. The Containment temperature and pressure used for this anal-ysis are consistent with the design values outlined in Section 6.2.

T.5 During the injection phase the spray solution pH is maintained between-(le;er) -

cnd 10.5 based on conservative parameters listed in Tables 6.5-3 and 6.5-4. 38 The elemental iodine removal constant for the CSS, using the model dyscribed above together with the parameters given in Table 6.5-2, is 4erschr 18 8 l -!n calculating ;he dcsign tasm radicicgical ceuoc3mmuu== fut Gm L^CA, ;het

-1 :catal iodine s;;c :1 cena;.ui of 20.3 is na; used. Instead, th:;

-g"4d-line: cf "cf. 6.3.2-4 ic felicx;d. It io .aa._;d ihot holf ef the car;;

in cuiviy vf iudium is . le acd to ;hm Cvuiaiummui oud half cf this irm- in 38 r diately plate eut un surfacc ir th: Centain :nt. TLm s=moiging cirir- 21, ala ental iodinc 1 :::uxcd subjec; tv . semvvol im.m of 10 hr s.

6.5-8 Amendment 38

ATTACHMENT STP

~[

the alKOUne conge.

At~the beginning of the injection phase, the sunp contains bor ted water which has a pH of approximately 5.5. As sodium hydroxide is added o the sump so-

! lutionbytheContainmentsprays,thepHquicklyincreasepto,(le:;;hdespite the addition of large volumes of borated water to the sump.,(e-- Ti " r 6.5-1)'.

d id i- k===A aa the see" rtic-- ' p : x::er; lict:d in Tahl. 6.~ 2. ""a i a ".-

p ::12:isa ;;pp:: d::::::'-in :ic; fac: (DF) of (1.i..) f;; th ^ $

vel ef ri x s :1 i; dine f::: d: C::::i= x: ::;;;ph::: hy :h :przye. S': . g ihr 07 I (la:; ) i; :::d:d" Usve N

-ft: 2 :: it'in: ::::::1 cre'it 1: tdx om..

+he most rion See Tuiole 6.6-3[, t-he minimom sump pH o+d 5

+ne end ofconservative,

+he inle etion oMurnp.e pho is T. 5( see Acp.re 6 The transfer of th4 sodium hydroxide solution from.5-1).the spray additive tanks to the Containment sump is,een complete at the end of the injection phase.g -he-e.

tr--inix; eedium h,J.;;id: cala*4-= fr c":d :: the e c-t ' n--t :p;_y; r 2 ~'2;'-

05: reci-ca1=*4a= p ehe - a._ insert X 38 At th; ;;j ;{ gh; inj--;{;; 7h : Q, 6.5.2.3.6.24n--4-ce1=*4aa *k-- .

actica fe the C:n::in; :t :p:27 ;" pr ir critch:d frer d. ;fu;11ag ;_:::q eto...; :::t (""ST) te th- C^-tri-_- .: _;p. Ini:i:11. 7 d: :::irnictir-',,,

5 7-: co-*.<m .n* 7..y mi11 k. .* .u :S (12 r) a-i d i; ;h; aini_ _ py ;;=,

.th: :: 7 eel" tie- d:: ;;ing d: :::- 7 tire: - ' per- rt::: in T d i: 6 . 5 3 .^,

f.ftc; th. .ume .ulusivu i.-y...i...e dur :::: t 2;;rc '- ::17 15^*F, dc ;

rrreind:: cf :he edi hydr. ide ;;1;;i:n 1: hir ':' rith d :::ir: let' ;a.,

p : 12tice hy th cd ::::. *;; cd :::: desiga ca;ur;; 22: th: :::i "

12:ica oy..y does uut sau ed p!! cf 10.5 d ;; .:ing 2: crr" r*4^-- ,

-per---t r in Td ic 5.5 1. f.f::: d : enafe .f ih. oys.y .udlii.. :; 2:^.,

Contain; n: is co-yl i , :h fin:1 :" r ;" ir 5:trer (leter) r a a n (_ :s,,

-Figer: 5.5-1)._. r_, .__

, "i:h

_ u_

th y!! eL;;; (1;;; ) ir 2: ;2p , 6: cirrr-trl 1 di-- ?",

..u um..... u . . ,

i 6.5.2.4 Tests and Inspections. The tests and inspections of the CSS are described in Section 6.2.2.4.

6.5.2.5 Instrumentatien Requirements. The instrumentation application of the CSS is given in Section 6.2.2.5.

6.5.2.6 Materials. The materials used in the CSS are discussed in Section 6.1.1.

6.5.3 Fission Product Control Systems l Refer to Sections 6.2.2 and 6.5.2 for a discussion of the CSS. Credit is l taken for the CSS as a fission product removal system.

l 6.5.3.1 Primary Containment. For discussion of the primary Containment l

structural and functional design and of the Containment systems, refer to the

! following sections:

Concrete Containment 3.8.1 l Containment Functional Design 6.2.1 l

Containment Heat Removal Systems 6.2.2 Containment Isolation System 6.2.4

$praq Icdine Partic.oloie Ehmevol: The particdlaM Cprag removal term was developed VSing tPC NMcC10legg descrilOtd in reference 6. 6.2.-6. j L-- r6.5-9 Amendment 38

. a- l

.W ATTACHMENT ST HL AE 171,b,,

PAGE

c fluid t- per ture chrce lgger, yon our s nn s i _ ,, a , -i; essmaedc 6.5-16 Amendment 38 ATTACHMENT  ; STP ST-HL AE 17/ 9 PAGE23 OF Pf-TABLE 6.5-4 i Input Parameters. rd ":: lt: :f .".21frir to Determine Maximum pH for Sump Solution and Spray I4igh H4thead safety injection pump flow, gal / min -1;;;;; Boo W Mead safety inject. ion pump flow, gal / min 4eeest 1900 viet Containment spray pumpaflow, gal / min Joseat. 4+90 i 5't0 Number of pumps in operation i+@H M4& head SI pump -leeest. 3 Leta Le4 head SI pump 12:en 3 Containment spray pump -leseat J 0 Eductor suction flow,, mew 4mune gol/niso ) inte # Sl =ini; :a leseat, hree Spray additive tank volume, each of +tm.ca, gal 1 steve.1995 sprog additive +onK volorve delivered core e("JdeC"w"ee,p 40 Concentration of NaOH in spray Phase, additive solution, wt. % 4etest. 32 aani S Nomber RWST deliv el s[ rake vokive ume, gal tonKs actinerohf 1eeew 359,2oo 38 ) RWST boron concentration, ppm leteat2500 Accumulator volume, each of 3, gol 4eeee4 877o Accumulator boron concentration, ppm 1-eteet. 1400 Reactor coolant system water mass. [ lb -letee, 626,0 00 Reactor coolant boron concentration, ppm -leteva-lo -Ti;; cfter initictie cf 'e^ th::t cerp ra1"*ic- r n;; rat:re 4 eps.e te 150*T, sin c agters i S Note : O) Flowrofe is o.t +he b inning of Cielurery and Flow -ote detreoses as -4,e level ConServadvely hfn. in Me tonk 4a ns. (2) Single follore l's + hat one Spraj QCiditive h2nk isola.fion volve Els to clo.te a& the erta of the inje c; tion paose.

• eet

1. "ith =^ t i :: fluid L , ratu : ch::: l',0*r, m u m ilen fic.

-i :: a:-- t 6.5-17 Amendment 38 STP FSAR ATTACHMENT ST HL AE-17/o PAGE;29 OF # Question 312.07 3 In order to independently evaluate the fraction of the containment volume covered by the spray we request the following information:

1) Provide plan and elevation drawings showing the fully developed spray patterns within the containment.

2) Indicate the sprayed and unsprayed volua.es within the regions identified in Section 6.2.2.3.4 and estimate the spray mass flow rate in each of these regions.

Response 0 lge 6.Z.2-6 6.2.2-6 See revised Section 6.2.2.3.4 fhad-newe j Figures ' . 3.3 ',' through 6.2.2-12. T)'e spt'ay massi flow rates r the pariouf regi s are ps follo s: , Containment Do'me Area / /  ? / ,29,840 lb/ min < i / ,, Frgm/ Opera [ingFloor(EL'68') 29,840 lb/ min Td The Springlin'e (EL .153') ' / ,/ /Inside The Secondary Shield , i 304 lb/ min Wall Below'El 19'.' ,' / 38 / , /Inside'IheSecondaryShieldWall 9,631lb/ min [ Between EL 19 And ZL 68' j Including ,The Refueling Cavity 'tside The Secondary Shield Wall / / o i / /  ! j EL 52' to'EL 68' / ,'6,818 lb/ min / EL,19' to EL 52' ' - / 6,810/lb/ min ' EL'(-)2' to EL 19' / , / 2,352'lb/ min Melow EL'(-)2' / / 1,I}25 lb/ min / [ , l i l l QER 6.2-28 Amen'dment 38 l i 1 ATTACHMENT STP FSAR ST HLAE- /7/ 4 PAGE360F W 1 l Question 312.12 l The ratio of spray additive flow to borated water flow determines the pH of l J the spray solution. Provide the magnitude of this ratio. What procedures will be used to verify (during pre-operational and routine testing) that the  ! two flow rates would indeed be maintained at this ratio?

Response

HI IThe dueto is desi ed so tha appr6xima ly 5 perce of the fl from ese is div ted for a ition of OH such th the resu ng spray x-g sp ay pu

. re d s not .ceed a pH 10.5. e Spray Ad ive Tank olation v ve N open automa cally on ontainmefi. iti8-3 pres re signal which als niti-i at Conta ent Spra System op(ration, an loses au3 ticallyj..cn th;':.

-had -" " th::, ich : .

dnh cr- =*- =*e 3 eleted. Me tank 2-- m.

N fM1"* Lf ::: efd.;tFr  ::: trai.- [ Lima i- df fici:n .. m - .,s f

\d - tim {ui.imoen- b ;, flu ;; ; riri- " c f 'derk a.t he end of cars Esrs+. l38 cepte+ed picn ever

^in' ction p ac cr w . %e 3ATfntents or s describ in See on6.2.2.4/,thespr educto can be te ed individu-

{ ally by ening t valves in he minif w and e ctor test es and run g ray pumps Each of esa li is provi with a fl the re ective met , and rumentati is also vailabl or spray mp suction nd dis- .

uring pre erational sting (des-O c rge pre ures and d charge ~ owrate.

ribed i Section 1 . .12.2) he educ r is veri ed to be o able by y pumpi the Spray Additive ank cont ts to the WST (via t mainiflow ine).

N,N Thi s part o the Cont terlock nment S ay System esting whi also veri s all c trols, al s, and , includin tank level nstruments on and 9 .

ation. ing perio testing, e Spray d-D arms an utomati valve a D -

ditive nk isola on valv is closed ile the o er portion of the e ctor pipin are test The allabili of this re ining sect n of ed tor tN ..

by drain g a small anrount of flu d from t tank Qd pi ng may'b confirm rough th sample 1 ne valve.

38

'a

• f Spray ado 11\ve % to bo<ated unter flow is adctressed in Secho routire o.rict 6 2. 2.2 2. See Seoio preoperafiorta.I o.nd 14. 2. I2. 2 (79) Er tesseg regu.irernenfs, respec&cIg.

l l

Q&R 6.2-29 Amendment 38

Y t

STP FSAR ATTACHMENT f

ST HL AEg PAGEal '

Question 312.13

) It does not appear that heat tracing is provided in the chemical additive tank, even though the NaOH solution may have a concentration greater than 30 weight percent. Provide your reason for the omission of heat tracing, or provide suitable design changes.

Response

30-32 4l*r The aOH o[ut in Spray / Addit e Tank is main ined be een c cen-tr io of#(1p:@ i t cent. e so ilfty mit for is co centt 38 ly(12'pp on s app xima r )". Spra Additiv anks ar locat in he ed bu ding the Fu Handl g Bui ing) the is main ined a ve 6 Fg eiq cema plan + crotion EEe SECtico 6 1. f. 2 dte -We sprog GddWVe CPemiSWp i

l l

l Q&R 6.2-30 Amendment 38

STP isAR ATTACHMENT ST HL AE 17/O PAGE 3pOF Ek4-Questio" 122.20

~ 'l For all postulated design basis accidents involving release of water into the Containment Building, estimace the time-history of the pH of the aqueous phase in each drainage area of the building. Identify and quantify all soluble acids and bases within the Containment.

Response

Fplow g des n ba s1 s-of coola ace ent, ha pH f the water the font nme e rgen- su is apidl rais abo 7.0 the ject of a so um dr ide lut nt ough e Co ainm t Spr Sys m. A he en of 76 ei ec on p se th accid t, t con inme su7p oluti pH i at or ao il mer) nd, st re ar no e nifi nt nts - addi onal luble 39 a ds ba s cate withi the ntai ent, e pH hould emai tabl t is alu . e es mated ime sto of th Cont nment ump uti H fo ovi a sig basis oss- -coo nt ac dent s sho in F.gure 5-1.

alwa al n e, el in ad ign b ir s ma 1 e ins e the enta ett, .he of th wa ri the C cai nt s pis(bre Ar ::r ' :: th- '.0" ue to he cond y de sate havin a sp ifie minimu pH 8.8. he ditio of sod by oxi xi solu on v pH wi the ontain nt " ray S tem be ecs t an 10. ,whi crea st is t e maximum s ay pH.

dur ng /

e/

inj ction.

)

See Secson 6 6.J. d.6.1 l

i Q&R 6.5-1 Amendment 43

ATTACHMENT l STP FSAR ST.HL AE 7/

1 PAGE33 F 4 TABLE 7.1-2 (Continued)

PLANT COMPARISON ALL OTHER SYSTEMS REQUIRED DIFFERENCES FROM FOR SAFETY COMANC!!E PEAK NUCLEAR STATI0'l

1. Switchover from Injection to IA. Comanche Peak uses 4 RWST Recirculation (Section 7.6.4) transmitters and a 2/4 coincidence logic to initiate the automatic switchover after an accident

• which generates an SI signal.

~

STP uses 3 level transmitters; each transmitter interfaces with one train of pumps (1/1 logic) to initiate the automatic switchover to recirculation (coincident SI signal required).-

IB. On Comanche Peak, only the RHR pump suctions are automatically switched from the RWST to the Containment sumps. Manual actions are necessary to transfer the pump suctions for the safety injection, centrifugal charging 44 and containment spray pumps from the RWST. On STP, because of the ECCS/ CSS pump suction design, all pumps are automatically switched We RL)ST low-low level sji nol to sump suction on RWST low-low Closes the Sprag Addi+ie lo^K level (coincident SI signal l

OOHet 6010 tion VGlVeS -

required). Only manual closure of the RWST outlet valves is needed thereafter, to back up the check valves also providedj

2. Containment Hydrogen 2A. Comanche Peak uses 2 analyzers Monitoring System (Section to monitor Containment hydro-7.6.5) gen concentrations in both units.

Four sample points are monitored in each Containment, with 2 points monitored by one analyzer and 2 points monitored by the other analyzer.

STP analyzers are completely separate between the units. "

Each unit has 2 separate analyzers, with each analyzer capable of monitoring 4 sample points (manually selected.)

l l

7.1-39 Amendment 44

ATTACHME T

^^gPFSAR 3f4 ST.HL A 8 PAGE 3 OF .

These normally open motor-operated valves have ESF monitoring alarms indi-cating a mispositioning with regard to their emergency core cooling function. 29

..) In addition, an annunciator system, as discussed in Section 6.3.5.5, is pro-vided to alert the operator when an accumulator discharge isolation valve is i closed when the RCS pressure is above the P-11 setpoint.

When the reactor is at power, except during the tests described above, these l43 valves are open and power to the valve operator is locked out. During plant shutdown, the accumulator valves are in a closed position. To prevent an inadvertent opening of these valves during that period, the accumulator valve breakers should be opened. Refer to Section 6.3.5.5 for discussion on power lock-out for these valves. Administrative control is again required to ensure l

that these valve breakers are closed during the prestartup procedures.

s 7.6.4 Switchover From Injection To Recirculation

'The automatic signal for switchover to recirculation from the injection phase during LOCA is derived from the Refueling Water Storage Tank (RWST) low-low l43 level signal coincident with the latched Safety Injection (SI) signal. This signal is provided by the Solid State Protection System (SSPS). The function-al logic diagram showing this feature is presented in Figure 7.6-9.

Open-closed status lights are provided on the main control board for each

, miniflow valve, Containment sump isolation valve, and RWST isolation valves. l43 The automatic switchover signal actuates the following ECCS components:

36

1. Close the high head and the low head SI pumps miniflow motor-operated

. valves (MOV) when the automatic signal is generated and the Main Control Board (MCB) manual switches for the miniflow MOVs are in the automatic position. Refer to Figure 7.6-4 for the logic diagram.

2. Open the Containment sump isolation MOVs when the automatic signal is generated and the appropriate signals showing closure of the miniflow 43 l valves are received. Refer to Figure 7.6-5 for the logic diagram.

, 3. Initiate alarm in the main control room to notify the operator that switchover has commenced.

l Further information regarding the switchover from the injection mode to the recirculation mode is given in Section 6.3.2.8. Also, during on-line test of 43 the automatic recirculation switchover signal, the test switchover signal is blocked as long as the RWST isolation valve is open. Interlocking between testing and closure of the RWST isolation valve (XSI0001 A, B and C) is pro-vided in the Safeguards Test Cabinets.

Additionally, the SIS includes an interlock which prevents the RWST isolation valves from being opened when the MCB manual switch is turned by operator 43 action to open unless the corresponding sump isolation valve is closed (See Figure 7.6-6).

7.6.4.1 Analysis of Switchover to Recirculation from Injection Phase During LOCA. This automatic feature assures that minimal operator action is required for 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> after an accident. This is further discussed in Section l43

, 6.3.2.8. Functionally, the switchover to recirculation from injection phase 99), age sdichover,&e Sprag addiNye Mk isolahon volves are closed by j +he sr lcu-Icw level St ddl Whed *MC MCB Stdtthes arc in -t+e octo poSL'hM l (refer io Figure 7.6-i4 b}me lopc7.6-5 atagramL Amendment 43 J

_ _ _ _ . _ _ . .__.___.___.m_._ _ _ . _ _ _ . _ . _ _ _ _ _ . _ . _ _ . . . _ _ _ _ _ _ _ _ _ _ _ _ _ _ . . _ _ .

ATTACHMENT

-STP FSAR ST HL AE 171O PAGEJ70F44 f 7.6.6.5 Volume Control Tank Low-Low Level Interlock. The Volume Control Tank (VCT) low-low level interlock uses the two VCT level transmitters to i sense low-low level and controls the two VCT outlet isolation valves and the two suction valves from the Refueling Water Strange Tank (RWST) to the charging pumps. These valves are shown on Figure 9.3.4-3 as XCV0113A, XCV0112B, XCV0112C and XCV0113B. This control system insures that the charging pumps always have a source of fluid during normal plant operation and protects them against loss of net positive suction head (NPSH) and consequent cavitation damage. Upon reaching the low-low level setpoint in the VCT, the RWST suction valve is opened and the VCT outlet isolation valve is closed, transferring suction from the VCT to the RWST. (This same action is performed upon receipt of the SI signal.)

The VCT low-low level interlock signal for each pair of valves is channelized into independent and redundant protection sets, to improve reliability.

Valves XCV0112B and XCV0112C are powered from Train C Class IE sources and receive the low-low level signal from LT-112 in Protection Set IV via actua-tion Train C. Valves XCV0113A and XCV0113B are powered from-Train B Class IE sources and receive their signal f rom LT-113 in Protection Set III via actua-tion Train B.

The logic diagrams for the VCT outlet isolation valves and RWST suction valves to the charging pumps are shown on Figures 7.6-12 and 7.6-13 respectively.

When the main control board switch is in the AUTO position, each RWST suction 43 valves is opened upon receipt of the low-low level signal (or the SI signal).

Each VCT outlet isolation valve is closed upon receipt of the signals; the interlock also prevents each VCT outlet isolation valve from closing.unless its corresponding RWST suction valve to the charging pumps is open.

7.6.6.6 Spray Additive Tank Low-Low Level Interlock. The spray additive tank low-low level interlock closes the tank's isolation valve when the fluid level is below a preset value. The purpose of this interlock is to preclude nitrogen (the tank cover gas) from being drawn into the suction of the con-acitive took. isolofion volve tainment spray pumps (via the eductor) . The spragwre preper 3 pray and Sump Fg-0150 receives 4Me' RWST towlow levet sgnal w The spray additive tank low-low level interlock signal for each valve is chan-nelized into independent redundant protection sets. Containment spray pump A ra~nd the tank A isolation valve are powered +4 erne. Train A Class 1E power sources; the valve is closed by the tank's Protection Set I level transmitter via actuation Train A. Similarly the B pu:np and valve are powered from Train j B sources; the valve is closed by the Protection Set III level transmitter (en l tank B) via actuation Train B. The C pump and valve are powered from Train C sources; the valve is closed by the Protection Set IV level transmitter (on i tank C) via actuation Train C.

The logic diagram for the spray additive tank isolation valve is shown on Figure 7.6-14. When the main control board switch is in the AUTO position, each valve is opened upon receipt of the containment spray actuation signal; the valve is the closed upon receipt of the spray additive tank low-low level i

l signal.

l I

! 7.6.6.7 CVCS Seal Injection' Isolation Valves Charging Header Pressure Interlock. The-charging header pressure interlock closes the CVCS l seal water injection Containment isolation valves when the Containment l

7.6-11 Amendment 2 45

A 4 i MLT1Et.N i ST-HL AE ill PAGE 3to0F RWST LEVEL CHANNEL BISTABLES

1) NORMALLY DE ENTRGIZED

2) ENERGlZED ON LO 60 SETPOINT PROCESS CONTROL 931 932 . 933 PROTECTION SET 13 BI 111 Bl tv BI RWST ISO. VALVE RWST ISO. VALVE RWST ISO. VALVE XSl0001 A CLOSED XSl00018 CLOSED XS10001C CLOSED T8 TB t ir u l' f t

I a a a a a a CLOSE SAT 130.

VALVE CS 0015 A h p --

h > --

h i --

y ir CLOSE SAT 150. CLOSE SAT 130.

VALVE CS00158 E E VALVE CS0015C MANUAL RESET PUSH BUTTON MANUAL RESET PUSH BUTTON M ANUAL RESET PUSH BUTTON C .

MCB MCB MCB ir 1r ir it ,, i r

p 1 ir ir it ir E E E ~E E E l i, i' TRAIN A TRAIN B TR AIN C ACTUATION SIGNAL ACTU ATION SIGNAL ACTUATION SIGNAL TO OPEN SUMP VALVE TO OPEN SUMP VALVE TO OPEN SUMP VALVE XS10016A AND CLOSE XS10016B AND CLOSE XSIOO16C ANO CLOSE MINIFLOW VALVES MINIFLOW VALVES MINIFLOW VALVES S10011 A. S10012A, S100118.S100128 $10011 C. SiOO12C.

S10013 A. S10014A St0013B, Gl00148 S10013C. $10014C LEGEND.

h TEST BUTTON A Ar:NUNCIATOR WINDOW (COMMON)

ACTUATION SIGNAL LAMP U' NITS 1 & 2 FUNCTIONAL LOGIC DIAGRAM SAFETY 1NJECTION SIGN AL FOR SWITCHOVER TO REClRC-ULATION SHOWING LO LO RWST LEVEL AUTOMATIC ACTUATION SIGNAL Ficure 7.6 9 _

,-n---o, - - - - - .,,,ww, , - , - - - --,--w-

ATTACHMENT ST HL AE-171C PAGE 3 70F 1^-

Figure 7.6-14 will be made available once it has been updated.

. ATTACHMENT ST.HL.AE r7/

STP FSAR PAGE 3Y;OF O

The Containment leak rate to the atmosphere used in the analysis is the design l45 basi leak rate which will be indicated in the Technical Specifications. For l27 the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following the accident, the leak rate is assumed to be 0.30 percent per day while for the remainder of the 30 day period the leak rate is assumed to be 0.15 percent per day. This Containment leakage is assumed to

• leak diret.tly to the environment.

The totg1 fase volume of the Containment has been calculated to be 3.58 mil- l45 l Fact of this volume is covered by the Contaitment. spray, while some lion ft .

is not. 'The major portion of the unsprayed volume is within the secondary shield wall below the operating f or. The unsprayed volume has been calcu-lated as approxiaately e40,000 ft l45 The transfer rate between the sprayed and unsprayed regions is assumed to be limited to the forced convection induced by the Reactor Containment Fan Cooler (RCFC) units. The namber of units assumed in operation and the total mixing

. flow are presented in Table 15.6-10. '1his assumed minimum ficwrate conserva-tively neglects the effects of natural convection, steam condensation and diffusion, although these effects are expected to enhance the mixing rate between the sprayed and unsprayed volumes. The majority of the RCFC air rup-ply, except a small portion discharged to the dome, is discharged to the space within the secondary shield wall, where it is relieved to the balance of the M Containment volume through the vent areas. The RCFC units are described more E fully in Sections 6.2.2 and 6.2.5. ,

p'oteoot) }@

For fission products other tisn iodine, the only removal processes considered cC-are radioactive decay and lestage. Iodine is assumed to be removed by radio ]

active decay and leakage, and elso by the Containment Spray System (CSS). They j effectiveness of the Containmen': spray for the removal of the iodine in the o Containment atmosphere and the model used to determine the iodine removal j i efficiency are discussed in Section 6.5.2. Only the elementalfiodine forms 6ee. ore l ass A spray removal rate of 18.6 52

' hr ped isto be effectively assumed, until the removed airbornt by alearstal the spray.iodine is reduced by a factor of

! 12.26 491 After this time, the spray removal rate is assumed to be zercy The sprays are considered Containment.

1. 1. 1. active only in the sprayed region Ye@M o of the(M*Ns"v"0+[a eo is 15.6.5.3.1.3 Containment Leakaat Doses-Dosesresultingdr'[nactivity reocHed leakage from the Containment have been calculated using the models presented in Appendix 15.B. The thyroid, whole-tody gamma an.1 skin beta doses are presented in Table 15.6-11 for the Exc1;sion Zone Boundary (EZB) distance of 1,430 meters and the outer boundary of tae Iew Population Zona (LPZ) at 4,800 meters.

15.6.5.3.2 ESF Leakage Contribution: A potential source of fission product leakage following a LOCA is the lestage from ESF components which are located in the Fuel-Handling Building (FHB). This leakage may be postulated to occur during the recirculation phase for long-term core cooling and Con-tainment cooling by sprays. The water contained in the Containment sumps is used after the injection phase and is recirculated by the ECCS pumps and the g45

,i Containment spray pumps.

15.6.5.3.2.1 Fission Product Source Term - Cince most of the radioiodine released during the LOCA would be retained by the Containment sump water, due to operation of the CSS and the ECCS, it is consetvatively assumed that 50 i

15.6-14 Amendment 52 l

_ .~ ..-__________.-._,_._.._._m _ _ _ _ _ _ _ _ _ . _ _ , , _ . . _ , _ , _ , _ , _ , _ _ _ _ _ . _ , _ _ _ ,_ , , _ _ _ _ _ _ _ __ _

ATTACHMENT STP FSAR ST HL AE-17/D  !

c PAGEM OF N '

percent of-the core iodine inventory is introduced to the sump water to be recirculated through the external piping systems. l45

)

Because noble gases are assumed to be available for leakage from the Contain-ment atmosphere and are not readily entraine'd in water, the noble gases are not assumed to be part of the source term for this contribution to the total LOCA dose.

15.6.5.3.2.2 Leakage Assumptions - The amount of water in the Contain-ment sumps at the start of recirculation is the total of the RCS water and the water added due to operation of the engineered safeguards, i.e., the ECCS and CSS. This amount has been calculated to be 512,494 gallons. This value is l45 conservatively low to maximize iodine concentration in the sump water.

The ECCS recirculation piping and components external to the Containment are designed in accordance with applicable codes and are described in Section 6.3. 45 The CSS is described in Section 6.2.2 and 6.5.2.

The maximum potential recirculation loop leakage is tabulated in Table 15.6-12. Each recirculation subsyster includes a high-head safety injection (HHSI) pump, a low-head safety injection (LHSI) pump, a residual heat exchanger, the Containment sump, and associated piping and valves. Thus three separate subsystems are provided for recirculation as well as for injection, each of which is adequate for long-term cooling.

Since three redundant subsystems are available during recirculation, leakage for any component in any subsystem can be terminated by shutting down the LHSI

and HHSI pump associated with that subsystem and by closing the appropriate pump suction and discharge isolation valves. , h5 Maximum potential recirculation leakages are indicated in Table 15.6-12. The f5 leakage rate assumed for dose calculat. ion purposes is conservatively twice the leakage rate given in Table 15.6-12.

The iodine partition factor applicable for this leakage is assumed to be 0.1. f5 15.6.5.3.2.3 ESF Leskage Doses - The iodine activity, once releassd to the atmosphere of the FHB, is assumed to be quickly transported by the venti-lation system through the exhaust filters and released to the environment at ground level. The iodine filtration efficiency is assumed to be 95 percent. l45 The offsite doses due to the recirculation leakage are presented in Table

[ 15.6-11 for the EZB of 1,430 meters for the initial two hour period and the

[

! LPZ outer boundary distance of 4,800 meters for the 30-day duration of the I accident.

2.3 15.6.5.3.3 Containment Purae/Centribution: In the event of a LOCA coin-cident with the containment supp mentary purge system in operation, the purge

, is assuned to be isolated within W-seconds following LOCA initiation. During norcal power operation, the containment supplementary purge system vents the 45 l containment at 5,000 ft S/ min. However, for this analycia the maximum flow l rate due to the pressure spike inside the Contairenent was used (88,900 ft /S min). The containment purge system is described in Section 9.4.

15.6-15 Amendment 4f

ATTACHMENT ST HL AE /7/O STP FSAR _ PAGE t/6 0F @/-

TABLE 15.6-10

)

PARAMETERS USED IN ANALYSIS OF LOSS-OFF-COOLANT ACCIDENT OFFSITE DOSES Parameter Core thermal power, MWt 3,800 Containment model 2 volume (spray and unsprayed)

Activity released to containment and available for leakage 1004 core activity noble gases Table 15.A-1 50% core activity l51 iodines Table 15.A-1 Form of iodine activity

' elemental 95.5%

organic 51 2pt particulate 2.5 %

Containment free volume, ft 6

total 3.58 x 10 5

unsprayed 8.40 x 10 .

Containment leakage rate, 4 per day 0-24 hours 0.30 1-30 days 0.15 Number of RCFC units operating 3.of 6 Mixing rate between gprayed and 160,500 unsprayed region, ft / min

rmt + - nt p eg 151 elemental,h{prsovalcoefficient 18.6 i organic, hr 0.0 particulate,hy'1 6.13 51 plate out, hr unsprayed - 7.06 sprayed .634 Assumed,6964 iodine DF elemental (Specy Steps of os DF of 12.28) -99e too organic particulate 100 15-6.33 Amendment 51

ATTACHMENT

' ST HL AE 1710 STP FSAR PAGE 4/ OF S TABLE 15.6-10 (Continued)

PARAMETERS USED IN ANALYSIS OF

~ LOSS-OFF-COOIANT ACCIDENT OFFSITE DOSES Parameter Spray additive delivery to Containment: 2.34 l51 time after initiation of LOCA, minutes Activity assumed mixed in Containment ,

sump water available for ESF leaka58 noble gases None iodines 50% core activity Table 15.A-1 ESF system leakage rate assumed, cc/hr Twice that of Table 15.6-12 45 Amount of water in which mixing of iodine occurs, gallons 512,494 Iodine partition factor for leakage 0.1 FHB filtration efficiency, percent 95 Supplementary purge rate, scfm 88,900 Time before isolation of purge, seconds 44e23 Meteorology 5 percentile Table 15.B-1 Dose model Appendix 15.B e

4 o

t l

% 15-6.34 1.:nondment 51

, m __- -,__ - .,p... y,. y -- -__, y -%_,p

_ ,__,, - , _ _ .,,m ,

ATTACHMENT STP FSAR 'fp71 TABLE 15.6-11 DOSE RESULTING FROM IARGE BREAK LOSS-OF-COOLANT ACCIDENT Parameter Containment Imakage Doses Exclusion Zone Boundary

• 0-2 hr 255 thyroid, rems 2 1.20S x 10 whole-body gamma, rems 2.1/9 skin beta, rems Low Population Zone

• 0-30 days 1.1R+$t 51 thyroid, rems 58.MG3 whole body gamma, rems 6.?tftk 10 skin beta, rems 4.;l# x 10' 3

ESF Leakage Doses Exclusion Zone Boundary

• 0-2 hr thyroid, rams 1 2.18 x 10,4 whole-body gamma rems skin beta, rems 6.81x10l4 1.94 x 10 Low population Zone 0-30 days thyroid gamma re:as 1 3.61 x 10,4 whole-body gamma, rems skin beta, rems 3.73x10{

1.3 x 10 Containment' Purging Dosen Exclusion Zone Boundary

• 0-2 hr thyroid, rems 17.00 whole-body gamma rems 9.2 x 10 skin beta, rems 6.6 x 10' Low population Zone 0-30 days .

thyroid, rems 51 t.

2.2 whole-body gamma, rems. 1.16 x 10'3 skin beta, rems 8.4 x 10' Total Doses Excl. inion Zone Boundary

• 0-2 hr , ,43

thyroid, rems b-GS x 10 2 whole-body gamma, rems 2 .df-Z.

skin beta, rems 1.k3CIS Low population Zone 0-30 days z y thyroid, rems 6.1B x 10 51 whole-body gamma, rems 0.68 skin beta, rems 0.43

• Exclusion Zone Boundary is at 1,430 m. Outer boundary of Low Population Zone is at 4,800 m.

15.6-35 Amendment 51

ATTACHMENT ST.HL- A E- l 7) O PAGEY3 0F 4G STP FSAR TA3LE 6.4-2 (Continued)

CONTROL ROOM DOSE ANALYSIS Results Whole-Body Skin Operator dose, 0-30 day period (rem): Thyroid Gamma Beta Containment leakage 13.h 1.5 1*

ESF leakage 1,63 5.0x10[55 3.1x10l4 4 Containment purging 0.036 5.4x10 8.2.t10 51 direct dose from Containment --- 0.11 ---

38 direct dose from cloud of --- 0.82 ---

released fission products Iodine filter loading --- 2.21x10,3 ---

Total 14.M 2.43 10.7

, cob 4

6.4 13 Amendment 51

-- g im y e -s--- -, w - .-p 9.- -

-w-__,---e_,--,-#-, , - - - - - - - - - - - - , - - . - , , , ,--.v-,-e - - - - - -

ATTACHMENT

/7/

STP FSAR ST RAGE HL4t AE,0F y 46 Question 022.11 The response to Request No. 022.5 assumes a maximum closure time for the supplementary containment purge subsystem (18-inch) isolation valves of 25 seconds. It is our position that the closure time for the valves should not exceed 5 seconds (see BTP CSB 6-4, Item B.l.f). Revise your FSAR accordingly.

Response

As part of the response to Request No. 022.5, two analyses were presented in order to demonstrate the adequacy of the Supplementary Containment Purge subsystem. These analyses were calculations of the radiological consequences of a postulated Loss-of-Coolant-Accident (LOCA) concurrent with operation of the Supplementary Purge Subsystem and analysis of the reduction in containment pressure resulting from the partial loss of containment atmosphere during the accident for ECCS backpressure determination. For both of these analyses, a total isolation time o ASEseconds was assumed. This assumed isolation time conservatively bounds the time required for valve closure, instrument delay, and diesel generator start (assuming loss of offsite power).

23 The Supplementary Containment Purge Subsystem motor operated isolation valve closure time, is 10 seconds or less while the pneumatic valves have a closure time of 5 seconds or less. The results of the analyses performed in response 53 to Request No. 022.5 have demonstrated the adequacy of the present Supplemen-tary Containment Purge Subsystem isolation valve design.

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Q&R 6.2-19 Amendment 53

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