ML20115E811

Proposed Tech Specs Re Increase in Refueling Water Storage Tank & Accumulator Boron Concentration

ML20115E811
Person / Time
Site:	Comanche Peak
Issue date:	10/19/1992
From:	TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:
Shared Package
ML20115E749	List: ML20115E746 ML20115E811
References
NUDOCS 9210220136
Download: ML20115E811 (52)

Text

_ . _ _ _ . _ _ . - . _ _ _ _ _

Attachment 3 to TXX-92469

}

Page 1 of 9 i *EACTIV:~1 CONTROL SYSTEMS l.

j BORATED WATER SOURCE - $HUTDOWN I

i LIMITING CONDITION r0R OPERATICN 1

3.1.2.5 As a mini.wm. cne of the following borated water sources shall te

! OPERABLE:

a. A boric acid storage tank with:

j 1) A minimum indicated borated water level of 10% when using the i boric acid tranafer pump, i-

) 2) A minimum indicated borated watc* level of 20% when using the j gravity feed connection,

3) A minimum boron concentration of 7000 ppm,- and A) A minimum solution ter.perature of 65'F.

t; .

Tne refueling water storage tank (RWST) with:

l

1) A minimum indicated borated water level of 24%,

f 2)

, A minimum boron concentration of h m._and

3) A minimum solution tempers u-e of 40** - '

4 I ADPLICAE!LITY: MOEE5 5 and 6.

i ACTION:

Witn no borateo .ater source OPERABLE, suspend all optrations involving CORE i ALTERATIONS or positive reactivity changes, r

, SURVEILLANCE RE0V! CEMENTS

~

e 4.1.2.5 The above reovired borated water source shall be demcastrated OPERABLE.

a. A;>1 east once per 7 days by:

t

1) Verifying the boron concentration of the_ water,

. 2) verifying the indicated borated water level, and>

3) veri'ying_the boric acid storage tank solution temperature -nen L <

it is.tne source of borated water.

t

b. At least once per 24 hou s by verifying the RWST temperature when it -

( 'is the source of borated water and.the outside air temperature is.

less than 40 F l-9210220136 921019

PDR ADOCK 05000445 P PDR i

~

COMANCHE DEAK,,- UNIT 1 3/4 1 -

Attachment 3 to TXX-92469 Page 2 of 9 i

REACTIVITY CONTROL SYSTEMS BORATED WATER SOURCES - OPERATING

{ LIMITING CON 0! TION FOR OPERATION 4

3.1.2.6 4

as required by Specification 3.1.2.2:As a minimum, the following boreted wat

a. A boric acid storage t&ak with

1)

A minimum indicated oorated water level of 50%.

2) ,

A minimum boron concentration of 7000 ppe, and

} 3) A minimum solution temperature of 65'F.

5 b.

1 The refueling water storage tank (RWST) with:

1)

A minimum indicated borated water level of 95%,

2)

,.2600 A boron concentration between ppa and ,

i

3) x A minimum solution temperature of 40'F, and El 6/00

4) A maximum solution temperature of 120'F. #

APPLICABILITY: MODEE 1, 2, 3, and 4.

ACTION:

a.

With the boric acid storage tank inoperable and being used as one of the above required borated water sources,. restore the tank to OPERABLE the ntxt 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and status borated within 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />sMARGIN to a SituTDOWN or be in at leastto HOT STA equivalent at least 1.3% ak/k at 200*F; restore the borte acid storage tank to

OPERA the next 30 8LE status within the next 7 days or be in COL 0' SHUTDOWN' with hours.

5.

With-the RWST inoperable, restore the tank to OPERABLE status within J hours or be in at least HOT STAND 8Y within the next 6hourE*ad'ac'5"u'o""""'atha"**'a'3 h "-

r COMANCHE PEAK - UNIT 1 3/4 1-12 Amendrnent No. 5 4

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Attachment 3 to TXX-92469 Page 3 of 9 Eu!RGENC* :CRE CCOL:'40 3 5'Eu5

3/4.5.1 ACCUMULATORS COLO LEG INJECTION LIMITING CONDITION

CR ODERATION

~

1 3.5.1 Each c ol .: 'eR 'njection accumulator snail De 0;ERABLE with

a. The cisenarge isolation valve open with power ?emoved, t.

An indicated torated water level of between 3?', and 61'.

gg -

c. A boron concentration of between ppm, and j d.

An indicated cover-pressure of between 623 and 644 psig. - R 600 APDLICABILITY: MO:E5 1, 2, and 3*.

ACTION:

a.

aith ore co!c leg :njection accumulator inopercole, except as a result of t closeo isolation valve or the boron concentration outside the reovirec .alues, restore the inoperable accumulator to OPERABLE status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> or te in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and recsce pressuricer pressure to less than 1000 psig witnin the following 6 nours.

t.

With one cold leg injection accumulator in; s eable oue to the isolaticn ,alve being closed, either immed' 'ely open the isolation

,alve or te in at least HOT STANDBY within hours and reduce press ri;er cressure to less than 1000 psig ithin the following o nours.

c.

With the :.; req concentration of one cold leg injection accuniulator outsice 19e requireo limit, restore the bocca concentration to within d

the eecu ec limits within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be is at least SCT 5'ANDBY aithin t*e next-6 hours anc reduce pressuri:e* oressure to less than 1000 psig ithin the following 6-hours.

SURVEILLANCE REOUIDEMENTS 4.5.1.1 Each cold 'eg infection accamulator shall be cemonstrated 1 OPERABLE:

a. At less; : ace ter 12 mours by:

1) Verifying the indicated borated water level and nitrogen cover pressure in the tan (s, and

• Pressuricer pressure above 1000 psig.

~

C:MANCHE DEAK - UNlT 1 3N $-1 I

i Attachment 3 to TXX-92469 Page 4 of 9 EMERGENC CCIE COOLING S <5TEMS 3/4.5 4 REFUELING WATER STORAGE N*.K LIMIT'% 00NDITION r0R OPERATION 3.5.4 Tne refueling .ater storage tank (RWST) shall be OPERABLE with:

6. I minimum indicated borated water level o L b.

gg A boron concentration of between h d @of borof.,

c.

A minimum solution tempetature of 40'F, and d.

A 6cc A maximum solution temperature of 120'F.

l APPLICABILITY: MODES 1, 2, 3, and 4.

ACTION:

ce in 30 following it least hours. H01 5TANOBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> anc in CO ur or 1

i i 1

J 50RbEILLANCE REQUIREMENTS 1

4.5.4 The RWST shall be demonstrated OPERABLE:

a.

At least once per 7 days oy:

1) i Verifying the indicated borated water level in the tank , and 2)

Verifying the boron concentration of the water.

b.

At least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> by verifying the RW5i temperature when the outside 120'F. air temperature is less than 40'F or greater than COMANCHE PEAK % UNIT 1

^ + 3 19 4

Attachment 3 to TXX-92469 Page 5 of 9

3/a.9 _ REFUELING ODERAT CNS 1

l _3 /4. 9.1 BORON CONCENTRATION R

i LIMITINGCON0!TIONFOROP{ RATION 3.9.1_ The beron concentration of all filled portions of the Reactor Coolant ,~

System and th'e refueling cenal shall be maintained uniform and sufficient to ensure that the trore restrictive of tne following reactivity conditions is met; either

a. A K,ff of 0.95 or less, or j b.

A boron concentration of greater than or equal to 7 #00 1 pm.

• Additionally, either valve 1C5-8455 or valves 1C5-8560. FCV-111B, 105-8439 1C5 8441 and 1C5-8453 shall be closed and secured in position. ,

APPLICABILITY: MODE 6.

ACTION: '

4 a.

1 With the reouirements a. or b. of the above-not satisfied, immediately suspend all operations involving CORE Al.TERATIONS or positive reacti-

. vity enances and initiate and continue boration at greater than or

} noual to 30 gpm of a solution containing greater than or equal to 7000 ppm boron or its equivalent until K,ff is reduced to less than j or equal _ to 0.95 or the boron concentration is estored to greater than or equal to Q ppm, whichever is the more restrictive.

! b.

t If either valve 1C5-8455 or valves 1C5 8560. FCV-111Br 105-8439,_

1C5-8441 and 1C5-8453 are not closed and sec; red in position, immeciately suspend all operations involving CORE ALTERATIONS or

, positive paths. reactivity changes and take action to isolate the dilution Witnin 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, verify the more restrictive of 3.9.1.a or

{ 3.9.1.D or carry out Action a. h ove.

SURVEILLANCE _REQUIDEMENTS

4. 9.1.1

cetermined The more prior to

restrictive of the above two reactivity conditions shall be 4

a.

Removing'cr unbolting the reactor vessel head, and

) b.

Withdrawal of any=con insyrted position " +rol rod in excess of 3 feet ~from its fully

& r. the reactor vessel.

i 4.9.1.2

' canalshallti$determinedbychemicalanalysisatleastonceper72 t

4. 9.1. 3 t

and 105-8453 Either valve 1C5-4455 or valves 1C5-8560 FCV-1118,_1C5-8439,1C5-8441 shall be verified closed.and secured in position by mechanical stops or by removai of air or electrical power at least-_once per 31 days to verify that dilution paths are isolated.

l l *During initial fuel

i. canal is not applicable provioed the refueling canal level is verifie i

below the reactor vessel flange elevation at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

i

. COMANCHE PEAK ~ - UNIT _1 3/4 9-1

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i Attachment 3 to TXX-92469 Pagg 6 of 9 kEACTIVITY CONTROL SYSTEMS BASES l

q MODERATOR TEMPERATURE COEFFICIENT (Continued) i involved subtracting the incremental change in the MDC associated with a core i condition of all rods inserted (most positive MDC) to an all rods withdrawn condition and, a conversion for the rate of change of moderator density with temperature at RATED THERMAL POWER conditions.

transformed into the limiting End of Cycle Life (EOL) This MTC value value.

of the MDC was then The 300 ppm surveillance limit MTC value represents a conservative value (with corrections for burnup and soluble boron) at a core condition of 300 ppe equilibrium boron EOL MTC value. and is obtained by making these corrections to the limiting concentration i The Surveillance Requirements for measurement of the MTC at the beginning

, and near the end of the fuel cycle are adequate to confirm that thir HTC remains within its limits since this coefficient changes slowly.due principally to the reduction in RCS boron concentration associated with fuel burnup.

~

3/4.1.1.4 MINIMUM TEMPERATURE FOP CRITICALITY This specification en*ures that the reactor will not be made critical i

with the Ocactor Coolant System average temperature less than 551'F. This limitati i

<< wired to ensure: (1) the moderator temperature coefficier.t is rito its normai - e, red temperature range, (2) the trip instrumentation is within m ang range, (3) the pressurizer is capable of being in an OPERABLE status with a steam bubble, and (4) the reactor vessel is above its minimum RT NDT temperature.

3/4.1.2 BORATION SYSTEMS The Boron Injection System ensures that negative reactivity control is

' available during each mode of facility operation. The c.amponents required to-perform this function include:

(1) borated water sources

' (3) separate flew path'., (4) boric acid transfer pumps, an d(2) (5)charging pc.nps, an emergency power supply from Pr.,d8LE diesel generators.

WiththeRCS%veraget'emperature.above200'F,aminimumoftwoboron injection flow paths are required to ensure single functional capability in

the event an essumed failure renders one of the flo.e paths hoperable. The boration capability of either flow path is sufficient to provide a SHUTDOWN MARGIN from expected operating conditions of 1.6% Ak/k after xenon decay and cooldown'to 200'F. The. maximum expected boration capability requirement l

oce-'s at EOL from full power equilibrium xenon ennditions and requires L

! 15,iu0 gallons of 7000 ppm borated water from the boric acid storage tanks or 70,702 gallons of @ ppm borated water from the refueling water storage tank (RWST).

Lgg COMANCHE PEAK - idIT 1 B 3/4 1-2 1

Amendment No. 6

Attachment 3 to TXX-92469 Page 7 of 9 1

, REACTIVITY CONTROL SYSTEMS BASES ,

BORATION SYSTEMS (Continued)

With the RCS temperature below 200'F one Baron Injection System is acceptable without single failure consideration on the basis of the stable 1

reactivity condition of the reactor and the addition &1 restrictions prohibiting CORE ALTERATIONS and positive reactivity changes in the event the single Doron Injection System becomes inoperable.

The limitation for a maximum of two charging pumps to be OPERABLE and the requirement to' verify one charging pump to be inoperable below 350*F provides assurance that a mass addition pressure transient can be relieved by the operation of a single PORV.

' The limitation for minimum solution temperature of the borated water sources are sufficient to prevent boric acid crystallization with the highest allowable j boron concentration.

The boron capability required below 200'F is sufficient to provide a

SHUTDOWN MARGIN of 1.3% Ak/k af ter xenon decay and cooldown from 200*F to 140*F.

This condition requires either 1,100 gallons of 7000 ppe borated water from the bor e acid storage tanks or 7,113 gallons of(!Ogg;ppe borated water from the A YOO As listed below, the required indicated levels for the boric acid storage

tanks and the RWST include allowances for required / analytical volume, unusable

^

volume, measurement uncertainties (which include instrument error and tank tolerances, required as apnlicable), system configuration requirements, and other volume.

4

Tank MODES Ind. Unusable Required Measurement System Level Other Volume Volume Uncertainty Config. (gal)

(gal) (gal) (Cal)

RWST 5,6 24% 45,494 7,113 4% of span 1,2g3,4 57,857 N/A 9EE 45,494 70,702 4% of span N/A 357,535*

. Boric 5,6 y lut 3,221 1,100

Acid 5,6 6% of span N/A N/A

& 201 3,221 1,100 6% of span 3,679

Storage (gravity feed) N/A Tank 1,2,3,4 50% 3,221 15,700 6% of span - N/A N/A i

The OPERABILITY of one Boron Injection Systes during REFUELING ensures that this system is available for reactivity contro1~while in MODE 6.

1

• Additional volume required to meet Specification 3.5.4.

r COMANCHE PEAK - UNIT 1 B 3/4 1-3 4 Amendment No. 5

- --y ..,m.-~+ - , - , .

._ ~ _ _ . _ _ _ _ _ _ _ . _ _. . _- -_.

4 Attachment 3 to TXX-92469 Page 8 of 9 d '

!  !"ERGENC< :: E :: LING SfSTEMS BASES 1

ECCSSUBSYSiEMS(Continued)

I to be inoperable below 350'F provides assurance that a mass addition pressure t transient can be relieved by the operation of a single PORV. l The teQuirement to remove power from certain valve operators is in accore-i ante failurewith Branch Technical Position 1C58-18 for valves that fail to meet single considerations.

coard, Power is removed via key-lock switches on the control i

j The Surveillance Requirements provided to ensure OPERABILITY of each

component ensures that at a minimum, the assumptions used in the safety analyses are met and that subsystem OPERABILITY is maintained.

Surveillance Requirements

far throttle valve position stops and flow balance testing provide assurance .

that proper ECCS flows will be maintained in the event of a LOCA.

cf proper flow resistance snd pressure drop in the piping system to eacnMaintenance injection point is necessary to:

. (1) prevent total pump flow from exceeding runout conditions when the system is in its minimum resistance configuration, (2) provide the proper flow solit between injection points in accordance =ith the assumDtions used in the ECCS-LOCA analyses, and (3) provide an acceptable level of total ECCS flow to all injection points equal to or above that assumed in the ECCS 10CA analyses.

F4. 5. 4 REFUELING WATER STORAGE TANK '

The OPERABILITY of the refueling water storage t rk (RWST) as part of the

• 4 ECCS ensures that a sufficient supply of borated water is available for injet-e tion b the ECCS in the event of a LOCA. The limits on RWST minimum volume and DoronToncentration ensure that:

(1) sufficient water is available within i

containment to permit recirculation cooling flow to the core,-(2) for small

break LOCA ano steam line breaks, the reactor will remain subcritical in the cola conoition following mixing of the RWST and the RCS water volumes with all control rods inserted except for the most reactive control assembly, (3) for large break LOCAs, the reactor will remain suberitical in the cold condition

• following mixing of the RWST and the RCS water volumes with all shutcown and control rods fully withdrawn, and (4) sufficient-time is available for the

. operator to take manual action and completo switchever of ECCS and containment spray suction. suctiots,to the containment-sump without emptying the RWST or losing

{ 1 l The reolrhed indicated level includes a'4 percent measurement uncertainty an unusable volums of 45,494 gallons and a required water volume of 428,437

-gallons.

A,&

also ensure The limits on indicated a long-term pH value of water volume and boron concentration between of the RWS and 10.5 for the solution j

retirculated within containment after a LOCA. .This pH band minimizes the i evolution corrosion on of fodine systems mechanical and minimizes 2nd components. the effect of chloride and caustic stress t

, COMANCHE PEAK - NTT 1 P$" en _ _ _

_ _ ___._ _. . . . _ _ _ . _ . _ - _ . ~ . _ _ _ _ _ . _ ._ _ _ _ _ _ _ _ _ . _ .

4 b Attachment 3 to TXX-92469 Page 9 of 9 4

i i

a 3/4.9 REFbELING CP,ERATIONS i

1-1 BASES i  !

i 3/4.9.1 PORON CONCENTRATION

• 1 r The limitations on reactivity condit' ns during REFUELING ensure that:

l (1) the reactor will remain suberitical during CORE ALTERATIONS, ano (2) a >

j uniform boron concentration is maintained for reactivity control in tne water volume having direct access to the reactor vessel. +

, These limitations are consistent in the safetywith analyses, the initial conditions assumed for the boron dilution incident  ;

The value of 0.95 or less for K,ff includes a i

' 1% Ak/k conservative allowance for uncertainties. Similarly, the boron '

(~~ allowance of.50 ppm boron.__concentrai.lonvalueofG@@g>ppmorgreaterincludesa The locking closed of the required valves during pq gg refueling of the filled portion of the RCS.theThis operations precludes possibility of uncontrolled boren dilutic" action prevents flow to the RCS of ,

unborated water by closing flow paths from sources of unborated watir.-

i ,

3/4.9.2 INSTRUMENTATION 4

l The OPERABILITY of the source range neutron flux monitors ensures that reoundant monitoring reactivity condition of capability the core. is available to detect changes in the l  !

3/4.9.3 DECAY TIME The minimum requirement for reactor subtriticali.

irradiated fuel assemblies in the reactor vessel ensur prior to movement of I

es that sufficient-time has elapsed to allow the radioactive oecay of.the short-lived fission products,

safety analyses. This decay time is consistent with the assumotions used in the i

. 3/4.9.4 CONTAINMENT BUILDING PENETRATIONS j The requirements on containment building penetration closure and OPERABILITY i ansure that a release restricted.from leakageoftoradioactive the environment. material within containment will be The OPERABILITY.and closure '

restrictions"are fuel element'rbpturesufficient'to based upon the restrict lack ofradioactive containmentmaterial-release

_ pressurization- from.a ,

potential while in the' REFUELING MODE.

3/4.9.5 COMMUNICATIONS 3

L The requirement for communications capability ensures that refueling i station personnel can be'promptly informeo of significant changes in the

.f acility status or core reactivity conditions during CORE ALTERATIONS.

4 1

COMANCHE PEAK'; UNIT;1 B 3/4 9-1

• I 4

1 i ENCLOSURE 1 TO TXX-92469 i

j Westinghouse Safety Evaluation,

., " Plant Operation at a  !

Modified Primary Coolant Chemistry pH Regimen,"'

SECL-92-235 4

1 a

I i .

l 4

t t

r c., g4w g up. -r- ..- U---- cre--+- ,- , . ~ - , - ,--..ws.,r., -, ,, w~,r--,-e---,-, r

, . ._ - . - - - . . . . - - - - - -- ~.

-me . - - - - - - -

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ll l

SECL-92 235 - =1 4

Li i ,

Customer Reference No(s). 4 N/A~

i -

L. -W _ eninghouse Refem No(s).

I - SECL&030 ,

WESTINGHOUSE

, SAFETY EVALUATION CINCK LIST l

4

1) NUCLEAR PLANT (S) Cort'anche Peak Units I and 2 -

[ ,

i 2)- CHECK LIST APPLICABLE TO: Plant Operation aj a Modified Primary Reactor Coolant Chemistry i pH Regimea '

i 3)

The written safety eveluation of the revised procedare, design change or modification required by '

10CFR50.59 has been prepared to the extent required and_is attached. If a safety evaluation is not-j reqvited or is incomplete for any reason, explain op Page 2. Parts A ~and 8 of this Safety Evaluation-Check List are to be completed only on the basis of the safety evaluation performed.

! GECK LIST - PART A -

( '

j 3.1) Yes.A. No_ A cnange to the plant as described in the FSAR?

i 3.2) Yes_ No_X. A change t' procedures as described in the FSAR7!

j 3.3) 'Yes_ No_X. A test or experiment not described in tha FSAR?

3.4) Yes_ No_X. A change to the plant technical specifications (App - 2 A to the Operating License)? '

l

4) CHECK LIST a PART B (Justification for Part B answers must be included on page 2.)-

a .

4.1) Yes_ No_X., Will the probability of an ' accident previously evaluated -ia the FSAR be

uct;ased?

4.2) Yes_ No.X. Will the consequences of an accident previously evaluated in the FSAR be -

increased? ' ,

1 4.3) Yes No_X. May the possibilityof an accident which is different than any already evaluated

! in the FSAR be created?

4.4) Yes_ No_X. Will the prohbilityof a malfunction of equipment important to safety previously evaluated in the ESAR be increased?

i '4.0 - Yes_ No_X. L Will. the ' consequences of a malfunction of equipment important -to safety

. previously evaluatei in the FS AR be increased?

• 4.6) _Yes _, No_X_' May the possibility of a malfunction of equipment -importani to safety different

' than any already evaluated in the FSAR be created? '

{ 4.7; Yes No_X_ Will the margin of safety as defined in the bases to any technical spe dcation be redt.ced?

I

, Page 1 of 9

s

f. SECL 92 235 t:

i If the answers to any of the above questions are unknown, inCcate under 5) REMARKS and explain i- below.

If the answer to any of the above questions in Part (3.4) or Part B cannot be answered in the negative,~-

i ' the change review requires an application for license amendment in accordance with 10 CFR 50.59 (c)

! and submitted to the NRC pursuant to 10 CFR 50.90.-

i I 5) REMARKS: '

f The answers given in Section 3. Part A, and Section 4, Part B_, of the Safety Evaluation Checidist, are i- based on the attached Safety Evaluation.

j Reference document (s):~

l

[ .

~*

FOR FSAR UPDATE-'

f I

Sutiva: 5.0  !'ege : Tables: 5.2 Tigures; i

i I-Reason for / Description of Change.

'- The lithium and boron concentrations will need to be updated to reflect the revised chemistry ,

control program.

l' 4

SIGNATURES-i.

b 4 Prepared by (Nuclear Safety): T. J. Kitchen Y. s G8t Date: )- E ~f P..

f Independently Reviewed by: ~ R.- H. Owoc .

Date: hcF-9A Nuclear Safety Manager: - M. J. Proviano N /th a m r- Date: k 'l- T v.

1 t

j Page 2 of 9 t

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SECL-92 235 Comanche Peak Units 1 and 2 Plant Operation with Modif A Reactor CoJant pII Regimen

1.0 Introduction

This evaluation addresses the potential safety impact of operating Comanche P primary coolant pH chemistry regimen. Westinghouse developed the concept the eactor coolant to help minimize the build-up rate of ex core radiation n field 4

radiation exposure of plant personnel. He modified primary reactor coolant chem minimize the rate and quantity of corrosion products that will deposit on the re reactor coolant, at temperature, is controlled by adjusting the lithium concentration wit concentration in accordance with die " Lithium-Boron Chemistry Control Program', presen This evaluation assesses the impact of the proposed changes to the reactor co primary and auxiliny system materials. Steam generator primary to seconda 5

are assessed. His evaluation supports the operation of Comanche Peak Units I and 2 w coolant chemistry on the basis that the change does not involve an unreviewed safety

, 2.0 Regulatory Basis Chapter 10 of the Code of Federal Regulations, Section 50.59 (InCFR 50.59) allo authoriring operation of a nuclear power facility the capacity to initiate certain chang s, tests, :nd change, test, or experiment if it does not involve an unre specifications incorporated in the license, it is, however, the obligation of the licen of these changes, tests, or experiments to the facility to the extent that such c Reactor coolar.t system chemistry is discured in Subsection 5.2.3.2.1 of pH limits for power operatiot's are given the Coma

. The Table 5.2 5 of the FSAR.

these records shall include a written safety valuation which provides ate the ba change, test or experiment does not involve an unreviewed safety question.

3.0 Evaluation it is the Westinghouse position that a modified lithium control program will provid of the coolant pH during power operation. This program is in accordance wi for optimization of primary system pH presented in the EPRI PWR Primary Wate Revision 2 (Reference 1). Coolant pH is controlled based on the average .,. For tempe this evaluation, T., is assumed to be 591 A'F '310.8'C). Since, the actual T.

nominal T,,, may vary slightly from the it has been determined that T, :an vary i 5'F without having a significant effxt o application of the modified chemistry program pc -nted below. He attachment c which illustrate the following modified lithium-boron c..vnistry control program.

At the beginning of cycle oueration, boric acid b added up to 2500 ppm boron at T., isoxidation.

Zircaloy maintained at a mininum of 6.9 to minimize crud deposits on fuel and to m i

l i

Page 3 of 9 4

l SECL-92 235 l

After the lithium concentration at T,, has been reduced to 2.210.15 ppm at pH greater or equal  ;

to 6.9, lithium is maintained constant at 2.2 0.15 ppm until the pH at T,, reaches the 7.2 to 7.4 i range.

The pH at T,., is maintained in the 7.2 to 7.4 range until the r i of the operating cycle, nod 1 that lithium variations have greater effect on pH at lower boron concentrations. The lium concentration required to maintain this constant target pH is controlled within A 0.15 ppm lithium.

Operation in the chemistry regime, described above, is acceptable for system chemistry and corrosion control.

. It should be noted that PWSCC laboratory test data for Alloy 600 have identified a potential increase in PWSCC initiation during exposure of some specimens to 3.5 ppm lithium for an extended period. Due to lack of supporting data, these corrosion data have not been characterized as statistically significant. However, 3 elevated pH control of reactor coolant with lithium concentration above 2.2 ppm for extended periods is not recommended. Exposure to lithium concentrations at and above 2.2 ppm should be kept to the minimum time necessary for mdatenance of recommended pH control, that is pH at T,, greater than or equal to 6.9.

Since operation at Comanche Peak with concentrations above approximately 1600 ppm boron requires greater

, than 2.2 ppm lithium for pH control, the impact on steam generator tubing PWSCC has been assessed, and plant specific fuels and materials reviews have been performed.

3.1 Steam Generator Component Materials Comanche Peak Unit I has Model D4 steam generatore that are tubed wi6 mili anneded (M A) AJiny 600 tubing that is full deptn rolled into the tubesheets. Comanche Peak Unit 2 hr., Model D5 steam generators

that are tubed with thermally treated Alloy 600 tubing that is hydraulically expand-d into the tubesheet.

Primary water stress corrosion cracking (PWSCC) 1.s an intergranular cracking process that can affect Alloy

~

600 nuclear steam generator tubing. Extensive research into the nature of PWSCC in recent years has established that PWSCC requires high tensile stresses that are greater than the annealed yield stress. Areas of cold work and relatively high residual tensile stresses can occur in the Unit I steam generators in the transition region between the rolled and unrolled region of tubes in the sinall radius U-bends. The residual stresses in the hydraulically expanded tubesheetjoints of the Unit 2 steam generators are considered to be.far -

less than that of rolled tubesheet joints. Moreover, the Unit 2 thermally treated tubing is considered to be more resistant to PWSCC than MA tubing.

l Although the kinetics of PWSCC initiation may be influenced by microstructure /ce npositional aspects of the J.nay 600 material and/or by environmental factors of the primary water, research continues to identify high tensile stress as the sing!e most important parameter affecting PWSCC. Stress is considered more imporunt than the other PWSCC factors involving microstructure or environment. Reduction of residual tensile stress in MA Alloy 600 tubing can reduce or eliminate the initiation of PWSCC, For this reason, the Comanche Peak Unit 1 steam generators were shotpeened prior to sta-tup to ameliorate the effects of re ual tensile ; tresses in critical regions within the steam generators. Shotpeening is an established method for introducing surface compressive stresses over a shallow depth on the inner surfaces of the roll expanded tubes such that the residual roller induced tensile stresses are, in effect, eliminated at the surface of the shotpeened area. Field experience indicates that shotpeening is effective in minimizing PWSCC initiation, if performed prior to operation.

, Page 4 of 9

SECL-92 235 Additionally, the Row I and Row 2 small radius U-bends at Comanche Peak I were thermally stress using an in situ heat treatment method. The effectiveness of this process was verined in the Westinghouse in work performed with partial support from the Electric Power Research Institute (E These processes to ameliorate residual tensile stresses in hfA tubing in expansion transitions and in radius U bends are of demonstrated effectiveness.

For MA Alloy 600 tubing, Westinghouse and EPRI studied the resistance to PWSCC in the lab highly struned/ highly stressed split tube " reverse U bends" (RUBS) of Alloy 600 tubing spec variations, or proposed variations, in the lithium hydroxide concentration. This work is an outgrowth lithium modification studies associated with ALARA considerations in the primary system. Studies of PWSCC initiation have been repetitively conducted at lithium concentrations of 2.0, 3.5 and 7.6 baseline boric acid concentration of 1200 ppm boron. He definitive te,.ts have been conducted at 330"C (626*F) with representative dissolved hydrogen concentrations.

4

Since certain MA heats of Alloy 600 are relatively resistant to cracking in all of these environments, atte

! has been focused only on two less resistant heats. One of these heats, Heat 96834, was espe by EPRI to exhibit a low resistance to PWSCC initiation when mill annealed at 1700'F. He other heat is a Westinghouse heat Heat 1019. For these two susceptible MA heatt, an extensive data base indicates tha there is no statistically significant difference in PWSCC crack initiation times for the various lithium concentrations cited.

4

' More recently, these tests have been extended to higher boron levels (1800 ppm B) and to lower lithiorn lavel: (0.56 ppm L!). The tcsult: continue to show the absence of a statistically significant effect of lithi boron chemistry on the PWSCC initiation kinetics for MA specituens of the same two PWSCC-sensit heats, discussed above. Rese very went results have also been disseminated through the indu Since the single most important factor in PWSCC initiation, residual tensile stress, has been addres Comanche Peak Unit i steam generators, the resulting enhanced resistance to PWSCC initiation can expected to be retained for the proposed modified coolant chemistry operation.

In addition, the modified chemistry program is not expected to have an adverse effect c . the Unit 2 s ger.erator tubes which is manufactured from thermally treated Alloy 600 material. Hermally treate is considered to be more resistant to PWSCC than MA tubing. Also, the lower residual stress fields in hydraulically expanded tubesheetjoints would not be expected to act as an bitiator to PWSCC in t of the modified themistry conditions.

3.3 Steam Generator Primary-to-Secondary Leakage The increase in potential for corrosion of the steam generator tubesheet and tubes causi by prim secondary leakage of lithium hydrox.ide into the sludge pile and crevices, and the potential for interference in the detection of primary-to-secondary side leaks, has been assessed and is addressed as follows:

3.3.1 Potential Corrosion Euects A primary-to-secondary leak would result in the transport of both lithium hydroxide and boric acid from the primary system into the secondary side of the steam generator. The potential for accelerated corrosion conditions is judged to be negligible. The quantity oflithium introduced into the secondary side of the ste;m Page 5 of 9 J

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l SECL 92 235 generator with leakage less than the Technical Specification leakage limit has been estimated to be minimal. l A primary-to secondary leak would result in the ingress of substantially larger quantities of boric acid than  !

lithium hydroxide to the secondary side of the steam generator. Use of boric acid has been shown to inhibit 1 steam generator tube denting and stress corrosion cracking. As a result of the expected low rate of ingress .I and the known corrosion inhibition capabilities of boric acid, primary-to-secondary leakage of reactor coolant I containing elevated lithium is judged not to contribute to secondary-side corrosion issues.

3.3.2 Detestion of Primary-to-Secondary Leaks i The occurrence of fission-product radionuclides and radioactivated species in steam generator blowdown 4

samples is used to measure the presence and rate of primary-to-secondary leakage. The presence of small concentrations of lithium in the blowdown samples is not expected to affect the detection and measurement of these radionuclides.

3.4 Primary Side Leakage The potential effects of primary coolant leakage or plant components have been assessed for the subject chemistry control program. This evaluation assumes that the corrosive effects of reactor coolant system leakage at less than Technical Specification limb on low alloy carbon steel, consistent with the requirements of Generic Letter 88-05, have been addressed at Comanche Peak. It is Westinghouse's engineeringjudgement that primary leakage within allowable Technical Specification limin with the higher boron concentration is not expected to deleteri:r.:!y r.f.ht pican integrity'.

3.5 Balance of RCS Components Materials and Auxiliary Systems Engineering assessments have beca performed in order to survey the potential consequences of the modified lithium control program on the reactor coolant system component:. The following Nucicar Steam Supply System (NSSS) components were assessed:

Control Rod Drive Mechanism

. Reactor Coolant Pump and Seals

• Piping

• Valves

• Pressurizer Reactor Vessel and Internals The assessments concluded that no known corrosion concerns were identified relative to the components as -

a result of the chemistry program, with the exception of the CRDM penetrations. For the CRDM penetration, the investigation into the potential for primary water stress corrosion cracking is ongoing due to the recent inspection results of the CRDM penetrations in European PWR plants. More detailed evaluations and mitigation studies are being performed for domestic plants. As a part of the evaluations, key factors affecting PWSCC, i.e., stress, environment, and material, are being compared betweea the European and domestic plants. '

The key environmental factor identified thus far, is the operating temperature of the reactor vessel head, where the CRDM penetrations are located, Existing data indicate a temperature of 560*F for Comanche Peak, as opposesi to 590*F for the European plants. Assuming all other factors are equivalent, PWSCC susceptibility for the CRDM penetrations at Comanche Peak would be reduced relative to the European plants j Page 6 of 9

f SECL 92 235 5ecause of the lower operating temperature. Preliminary review of the evaluation on the other factori als appears to be favorable.

In conclusion. since the time period during which the lithium ccacenJation is above 2.2 ppm is minim implementation of the modified lithium control program. described abou, is not expected to have an effects on the balance of RCS component materials. Assessments of the tuxiliary systot also concluded tha operation with the modified coolant chemistry program is not expecttd to have an adverse effect on the Chemical and Volume Control System, the Safety injection System, the Residaal Heat Removal Sy Boron Recycle System, or the, Spent Fuel Pit.

3.6 Fuel Cladding Corrosion Westinghouse has observed satisfactory in-reactor cladding performance, that is, acceptable corrosion with lithium concentrations between 0.2 and 2.2 ppm at moderate power levels (4-7 kw/ft, core average li power) for fuel rod average burnups to 60 GWD/MTU. _ Further, through September 30,1991, Westinghous has extended cycle operating experience with 77 operating cycles in whk.a carly cycle lithium leveh have exceeded 2.2 ppm for limited periods as a result of following the pH 6.9 :oordinated boron / lithium mode of reactor coolant system chemistry operation. Visual refueling surveillanco has been performed in 63 of these cycles, and no adverse effects on cladding corrosion or any other aspect of fuel performance have been reported. Operation within the extended boron concentration range (up to 2500 ppm) would be only for relatively short period of time. Thus, operation with the modified lithium program is judged to have no

• • rse impact on the corrosion behavior of the Zircaloy-4 clad < ling at Comanche Pa A. 2

4.0 Assessment of Unrevimed Safety @estion i

i Oneration of Comanche Peak with the modified primary coolant chemistry pH regimen has been evaluated

• using the guidance of NT 4 C-125 and does not represent an unreviewed safety question based o justification.

1.

i Will the probability of an accident previously evaluated in the FSAR be increased?

No.

Operation of Comanche Peak at a modified primary coolant chemistry pH regimen is not

expected to have an impact on reactor coolant system components. The modified chem program is not expected to affect the resistance to PWSCC nor impact the integrity of Zircaloy fuel cladding. The chemistry control program, defined above, is consistent with the EPRI Coolant Chemistry Guidelines (Reference 1) and is not expected to have an impa on the balance of RCS component materials or auxiliary systems, t

2.

Will the consequences of an accident previously evaluated in the FSAR be increased?

No.

The consequences of an accident previously evaluated in the FSAR are not increased dus to the modified coolant pH. The modified Lithium Boron Correlation helps to minimize-the rate of build-up of ex-core radiation fields and thus reduce the operational radiation exposure of plant personnel. The response of the plant when subjected to postulated eccident conditions has not changed.

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l Page 7 of 9 J

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RECL 92 235 3.

i - May the possibility of an accident which is different than any already evaluated in the FSAR be increased?

No. As noted above, the modified chemistry program is consistent with the EPRI Coolant Chemistry Guidelines No new accident scenarios ire identified.

. 4.

i Wil' te probability of a malfunction of equipment important to safe *y previously evaluated in the FSAR be increased?

No.

The modified chemistry program does not introduce any new equipment nor alter the design of existing equipment. Re modified chemistry program is not believed to affect the inte.~rity of the steam generator tubing, as it is not expected to increase the occurrence of PW5CC. The chemistry control program is consistent with the EPRI Coolant Chemistry

' Guidelines (Reference 1) and is not expected to have an impact on the balance of RCS component materials or auxiliary systems.

5 Will the consequences of a malfunction of equipment important to safety previously evaluated in the FSAR be increased?

No. De consequences of an accident previously evaluated in the FSAR are not increased due to the modified coolant ; H. The modified Lithium Boron Correlatica helps to minimize the rc or tmila-up cf ex core radiation. fields and tbus raduce the cpamional radiation e::posure of plant personnel. The modified chemistry program will not adversely affect de fuel c' adding luegrity, and therefore will not result in an increase in the assumed levels of fuel failure for accident scenarios involving steam release to the environment. The response of the plant when subjected to pcstulated accident conditions has not changed.

} 6.

May the possibility of a malfunction of equipment important to safety different than any already evaluated in the FSAR be created?

No.

As noted above, no new equipment is introduced and existing equipment is not adversely affected by the modified chemistry program.- Modified coolant pH is not expected to affect the resistance to PWSCC. No new failure mechanisms have been introduced.

)

7.

Will the margin of safety as defined in the bases to any technical specification be reduced?

No.

The margin of safety with respect to primary pressure boundary integrity is prc,vided, in part, by the safety factors included in the ASME Code, and is not reduced. The modified

' chemistry program does not require a change to the Technical Specifications nor does it l prevent inspections or leakage monitoring capability requir:d by the Technical Specifications.

5.0 Conclusion Operation of Comanche Peak Units 1 and 2 with the modified primary coolant chemistry pH regimen is not expected to have an adverse effect on pri: nary pressure boundary integrity and does not represent an i

unreviewed safety question in accordance with 10 CFR 50.59 criteria.

Page 8 of 9

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SECL-92-235 I

1 6.0 References 4

1.

EPRI NP 7077 Project 2493, PWR Primm. Water Chemistry Guidelines: Revision 2 November 1990 f

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!- ENCLOSURE 2 TO TXX-92468 I NUREG-0800

- Standard Review Plan Section 6.5.2 Rev. 1 - July 1981 l

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N U R EG-0800 l (Formtriy NUREG 75/087) I e

@/psoggs ) U.S. NUCLEAR REGULATORY COMM; OFFICE OF NUCLEAR REACTOR REGULATION

%, ...../

e 6.5.2 CONTAINMENTSPRAYAIAFISSIONPRODUCTCLEANUPSYSTEM REVIEW RESPONSIBILITIES f

Primary - Accident Evaluation Branch (AEB) 4 Secondary - Chemical Engineering Branch (CMEB)

1. AREAS OF REVIEW The AEB reviews the contair. ment spray and spray additive system to determine the 2 fission product removal effectiveness of the system whenever the applicant claims a containment air cleanup function for the system. The following areas of the applicant's Safety Analysis Report (SAR) relating to the fission product removal and control function of the containraent spray system are reviewed by the AEB:

1. Fission Product Removal Requirement for Containment Spray Sections of the SAR related to accident analyses, dose calculations, and fis-sion product removal and control are reviewed to establish whether fission product scrubbing of the containment atmosphere for the mitigation of offsite doses following a postulated accident is claimad by the applicant. This review usually covers Sections 6.2.3.1, 6.3.2.1, and Chapter 15 of the SAR.

2. Design Bases The design bases of such containment spray systems are reviewed to determine whether they reflect the requirements placed upon this system by the assump-tions made in the accident evaluations of Chapter 15.

3. System Design The descriptive information concerning the design of the spray system, including any subsystems and supporting systems, is reviewed to familiarize the reviewer with the design an6 operation of the system. The review includes:

. Rev. 1 - July 1931 USNRC STANDARD REVIEW PLAN l Standard review plans are prepared for the guidance of the office of Nuclear Reactor Regulation staff responsible for the review of I applications to construct and operate nuclear power plants. These documents are made available to the public as part of the i i Commission's policy to inform the nuclear industry and the general public of regulatory procedures and policies. htandard review i plans are not substitutes for regulatory guides or the Commission's regulations and cornpliance with them is not required. The I ttandard review plan sections are keyed to the Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants. l Not all sections of the standard Format have a corresponding geview plan.

Published standard review plans wD be revised periodically, as appropriate. to accommodate comments and to reflect new inf orma-tion and experience. ,

1 Comments and suggestions for improvement will be considered and should be sent to the U.S. Nuclear Regulatory Commission, j Office of Nuclear Reactor Regulation, Washington. D.C. 20565. i

,, . - .- -- - . . - . - . . . . - ~_ . -

.I '

.. _a.

e The descriptive information-contained in SAR Sections 6.2, 6.5.2.2, 6.5.2.4, 6.5.2.5, and 6.5.2;6 to establish the basic design concept,-

i the-systems, subsystems,.and. support systems required _to carry out the iodine scrubbing function of the: system, and:the' components and instrumentation employed-in.these systems. -

[ b.

The process.ano instrumentation diagrams of SAR-_Section:6.5.2 or~6 2.2,-

whichever contains the relevant'information, 3 t.

4 c.

Layout drawings (plans, elevations, isometrics) of the-spray distribu-

{ - tion headers, from SAR Chapter 1.0 and Sections 6.5.2 or 6.2.2; d.

Plan of views and elevations of the containment layout in Chapter _1.0 the'SAR, _

?

! e.

j Process and instrumentation diagrams ~of any_-ventilation' systems ~~ opera-2 tional in the postaccident environment.-

4. Testing and Inspections _

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j .Section16_5.2i4oftheSARHisreviewedto-establishthedetailsNfthe i preoperational test _to be performed for syst(m verifiedtion and the' post-i operational tests and inspectionsito be perfomed.for verification of the!

continued status.of readiness of-the spray system.

,- 5. Technical SpecificatiLos .

(' At:the operating license stage,:the applicant's proposed = technical speci- #-

fications in Chapter 16' of the Final Safety- Analysis Report (FSAR) are reviewed

. requirements.

to establish permissible outage times and. surveillance 4

i A secondary review is. performed by the Chemical _ Engineering B anch:(CMEB) and

! the results are:used by the' AEB to complete the overall= review of the contain-

. ment-spray system <

I -CHEB reviews the chemical additive storage: requirements 2

.and areas as indicated below.

to AEB- for use in the. SER writeup.'The results_-of CMEB's -analysis are transmitted p

l- d L In a'dition, AE8 will' coordinate other branches evaluations ~that interface with-

the review of the containment spray system as_follows

CMEB reviews metallic 1

[ materials compatibility and organic material decomposition ' including formation

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F L of' organic iodide:as:part of its primary review responsibility'for SRP-Sections 6.1.'1 and'6.1.2. The Containment Systes Branch (CSB) reviews thei . '

F L heat removal and hydrcgen mixing ~ function of the containment sprayisystem and:

-the containment 1 'mp design as part cf its primary review responsibility.forz SRP Sections 6.2.1 and 6.2.5. The-acceptance criteria for. the review and the L

methods .of application are contained in the referenced -SRP section~ of- the-

[; corresponding primary branch ~as stated above. -

l -II.

ACCEPTANCE CPITERIA The AEB acceptance the-following' criterim are based-on meeting-the relevant requirements of-regulations:

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- 6.5.2-2~ Rev. 1 - July 1981 '

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4 A. General Design Criterion 41 (Ref.1) as related to the containment atmos-phere cleanup system being designed to control fission product releases-to the environment following postulated accidents.

B. General Design Criterion 42 (Ref. 2) as related to the containment atmosphere cleanup system being designed to permit, appropriate periodic inspections.

C. General Design Criterion 43 (Ref. 3) as related to the containment atmos-phere cleanup system being designed for appropriate periodic functional

testing.

Specific criteria necessary to meet the relevant requirements of GDC 41, 42, i and 43 are:

1. Design Reauirements for Iodine' Removal Furction The containment spray system should be designed in accordance with the ANSI requirements of Reference 4. As used in this SRP sect'on, the term

" containment spray system" incluaes the spray system and the spray addi-tive sur m as defined in Reference 4.

a. Systs .ar ation The containment spray system should be designed to be initiated _ auto-matically by an appropriate accident signal and to be transferred automatically from the injection mode to the recirculation mode to assure continuous operation ur.til the design objectives of the system have-been achieved. In all cases the operating period should not be less than 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. In addition, the system should be capable of operation in the recirculation mode, on demand, for a ceriod of at least 1 month following the postulated accident,

b. Coverage of Containment Volume In order to assure full spray coverage of the containment volume, the following should be observed:

(1) The spray nozzles scould be located as high in the containment as practicable to reaximize the spray drop fall distance.

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(2) The layout of the spray _ nozzles and distribution headers should be such that the cross-sectional-area or the containment covered by the_ spray is maximized and that'a nearly. homogeneous distribu-tion of spray in the containment volume is produced. Unsprayed regions in the upper containment and, in particular, an unsprayed annulus adjacent to the containment-liner should be avoided wherever possible.

(3) In designing the layout of the spray nozzle positior.s and orien-tations,.the effect of the postaccident atmosphere should be considered, including the- effects of postaccident conditions that result in the maximum possible atmosphere density.

6.5.2-3 Rev. 1 - July 1981

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3 c. Promotion of Containment Mixing: ,

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Because the effectiveness of the containment spray system depends on 3

L a well mixed containment atmosphere, all-design features enhancing postaccident mixing should os considered.1 Where necessary, forced- M p air ventilation should be provided to avoid stagnant air; regions.-

d. Spray Nozzles The nozzles.used in the containment spray system should be of a design  ;

that minimizes the possibility of clogging while. producing drop' sizes

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effective.for iodine absorption. The nozzles should not have internal' moving parts such as swirl vanes, turbulence promoters, etc. LThey

should not have orifices or internal restrictions which would narrow

the flow passage to less_than_1/4-inch diameter. . Detailed information ,

L

.on the drop size distribution for the nozzle, such as a histogram, l should be prov'ied. Designations:such as " average," "mean," andy j " median"_ numbers.do not provide suf ficiently detailed-information to- -

i s

permit an independent ' evaluation:of- the- performance of the nozzle.. ,

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[ e. Injection Spray Solution U

The partition of iodine between.-liquid _and gasiphases:is enhanced:by-

• 4 the rikalinity of the solution. The spray: system s_hould be designed- _

such-that the sprayisolution maintains- the highast porsible pH,"within j

mat"ial r >mpatibility_ constraints. . This requirementrisEsatisfied; by a spray pH in the range of 8.5 to 10.5. .A minimum l partitioning _

i

' of iodine between liquid and' gas phs.;esihas also been= demonstrated: p" i

for boric acid solutions with trace. levels of impurities (Ref. 5).

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! In this case, pH requirements-are determined solely'by material 3 compatibility constraints,-which'are_ reviewed-by CMEB. Iodine:

scrubbing creditL is given for spray solutions whose chemistry, including any additives, has been demonstrated to be effective-for.

j-iodine absorption and retention _under postaccident: conditions. Both 1 i theoretical and experimental ~ verification- are required, L The spray __ solutions shown in Table.6.5.2-1 have"beentshownito'be-1-

effective-for removal;of elemental iodine. . Acceptable values for:

! -the instantaneous elemental iodine partition coefficient"ftr these-spray'. solutions. ara also shown~in' Table'6.5.2-1. Reference 6 provides i-information on spray solutions that are effective-for removal of-1 organic iodides.

Table 6.5.2-1 Spray Solutions and Acceptable

[ iPartition Coefficients-D i Spray-solution r i- Dartition coefficient '

i' sodium hydroxide-in boric 'see Figure 6.5 2-1; ph_ values

[  : acid solution- are assumed a room temperature I '

hydrazine (50 ppm t 5) 5000

) boric acid (1500-2500 ppn boron)- 50

!. water (plain or demineralized)- 100 trisodium phosphate (added to see Figure 6.5.2-1; same pH

-sump during recirculation mode). dependence _as sodium hydroxide- l solutions: I 6.5.2-4 Rev. 1 - July 1981-e

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f. i Containment Sump Mix _ing The containment sump should be designed to promote mixing of emergency core cooling system (ECCS) and spray _ solutions. Orains to the engineered

safety features (ESF) sump should be provided for all regions of th?

containment which would collect a significant quantity of the spray solution. Alternatively, allowance should be made for " dead" volumes in the determination of sump pH and the quantities of additives injected.

g. Containment sumo and Recirculation Spray Solutions The pH of the aqueous solution collected in the containment sump after completion of injection of containment spray and ECCS water, and all

" additives for reactivity control, fission product removal, or other purpose, should be maintained at a level sufficiently high to provide assurance that significant long-term iodine re evolution does not occur. Long-term iodine retention is calculated based on the expected long-term partition coefficient. The instantaneous iodine partition coefficients given in Table 6.5.2-1 and Figure 6.5.2-1 may be used in the absence of suitable data for equilibrium iodine partition coefficients. Long-term iodine retention with no significant

' re-evolution may be assumed only when the equilibrium sump pH, after mixing and dilution with the primary coolant and ECC3 injection, is above 8.5. This pH value should be achieved at the onset of the spray recirculation mode. The material-compatibility aspect of the long-term sump and recirculation spray solutions is reviewed by the CHEB.

e

h. Storage of Additives The design should prov;oe facilities for the long-term storage of all spray-additives. These-facilities Jhould be decigned such that i

' the additives required to achieve tCe design objectives of the system are stored in a state of continual readiness whenever the eactor is critical-during the design life of the plant. The storage facilities

should be designed such that freezing precipitation, chemical.. reaction,-

and decomposition of additives are prevented. For NaOH storage tanks, heat tracing of tanics and piping is required whenever exposure to temperatures below 40"F is predicted. An inert cover gas.should be provided for solutions that may deteriorate as a consequence of expo-sure to air.

i . Single Failure The system should be able to function effectively and mea

• all the i above criteria with a single failure of an active compont N the spray system, in any of its st _ systems, or'in any of its support systems. The system is considered functional with respect to iodine removal if it is capable of delivering the design spray flow rate with the additive concentration within the acceptable range as' deter-mined above.

2. Testing Tests-should be performed to demonstrate that the spray systems, as installed, meet all design requirements for an effective iodine scrubbing i

function. Such tests should include preoperational verification of:

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6.5.2-5 Rev. 1 - July 1981 l

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! a. freedom of the containm:n't spray piping and nozzles from obstructions, >

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! - b, capability of the system to deliver the' required spray flow, and I

, c. capability of the system to deliver the required spray additives within

the specified range of concentrations. For ansystem whose performance is sensitive to the as-built piping layout, such as a system, the. testing should be performed at full flow.~ gravity feed l

3. Technical Specifications

} The technical s)ecifications should specify appropriate limiting conditions.

l for operation (LCOs), tests, and inspections:to provide assurance that '

the system is capable of its design function whenever the reactor is criti-p cal. These spacifications should include:

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a. The operability requirements for the system, including all active and passive devices, as a limiting condition for operatini. (with-

. acceptable outage times). The foll; wing should be specifically f included:

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containment spray pumps, f-additive pumps (if any),

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~a dditive mixing devices (if any),

valves and nozzles, er i

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additive quantity and concentration in the additive storage tanks,

. and i -

nitrogen or other inert gas pressure in the additive storage i- tanks.

b. Periodic ins;,ection and sampling of the c'ontentsfof +he additive tanks 9 to confirm that the additive quantity aad concentrations are within

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the limits established by the-system design._ '

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c. Periodic testing and exercising of the active components of the system i and verification that essential piping and passive devices ~are free 4

of obstructions.

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III. , REVIEW PROCEDURES-i The reviewer selects and emphasizes aspects Lovered' by' this SRP section a's -

appropriate for-a particular plant. The judgment of which areasineed h 'e.given attention and emphat,istin the review is based on-a:dctermination that toe material presented is similar. to that recently- reviewed on other plants-or- that items:

of;special safety _ significance are' involved. The review of the fission product:

removal f nction of the containment spray ~ system follows the procedure outlined

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below.

L_ The reviewer determines whetner the containment spray.systcm is used for fission E

product removal purposes._ Chapter 15 of the-SAR should be reviewed to establish whether'a fission product _ removal fur.:. tion for the containment spray system is assumed in accident-dose evaluations. If the containment spray system is not.

6.5.2 Rev. 1 - July 1981 i

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! .used for dose mitigation purposes,-no _further_ review is required by the AEB.  !

The CSB reviews the heat removal and hydrogen mixing aspects of_the containment spray system.

If the contrinment spray- system is designed to re' duce: the concentrations of - .i L fission products in-the containment, th( capability of the system to function-

}: effectively asta fission product removal system _is reviewed.- If,_as a result 4

of the review, >ystem modifications are'requ; red, the AEB reviewer will advise  :

3 the CSB of the _ required modifications for integration with any other requirements  ;

placed on the containment spray system._ This.is a coordinating review function.

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1. System Design b Review ~of_the system design includes an examination of the components-and r

. design features necessary to carry out the iodine scrubbing function, j incloc'ing:

i a. Spray Chemistry The forms of iodine for which spray removal: credit is claimed in- the accident analyses-(SAR Chapter 15) are established. Containment spray

systems may be designed for removal of iodine in the elemental

form' l (i.e. vapor), in the form of organic compounds,.and 1 the particulate i- form. -

L e i The systems or subsystems required to carry out the iodine scrubbing i function of the containment spray, such'as.the spray % st e , recircu-.

i lation systen., spray additive system,- and_ water sour a are identi' led.

[

The design of the systems-involved is reviewed in orats 'o:-

L (1) Determine'the chemical' additive and to ascertain the effectiveness -

i cif the additive for elemental and organic iodintumoval by j comparison with additives of-proven effectiveness.(see acceptance e

criteria in subsection -II) or by- review of theoretical; and.Experi-mental- verifications; supplied for _new additives.

l (2) Ascertain that the range:of additive concentrationsLis within' I the limits listed in the-acceptancescriteria' of subsection II 7

above,or that adequate justification'is-supplied for the iodine removal and ' retention- ef fectiveness for the range of concentra-tions encountered. The concentrations ;in the storage facility,

~

p i the chemical addition lines, the spray solution; injection, the I containment sump solution, and the recirculation spray solution

!- should be examined. The extremesJof the additive concentrations

! should be determined with the most adverse:combinationTof-ECCS,

, spray, and. additive pumps (if,any) assumed to be operating, and-

+

i- a single active failure of pumpster valves? shculd-be considered.

l The AEB' reviewer coordinates this review aspect with the CMEB which reviews the-s'torage of?theispray additives under subsec-4: tion III.1.f.

The~AEB reviewer consults with the CMEB to' verify that the spray and l sump water solutica -stability, and-the' corrosion,= solidification, L and precipitation behavi_or-of the chemical additives, have appropriately

[ been taken into considerati'n o for'the range of' concentrations encountered.

l

[

-6.5.2-7 Rev._1 - July 1981 L

1

s

! , b. - Systen Operation The time and method.of system initiation, including _ additive addition, Lis reviewed to confirm that>the acceptance criteria of subseJtion II above are_ met.- Automatic initiation of spray and spray additive flow, without mechanical. delays or manual overrides, is. required.- Credit ,

for immediatt initiation is assumed if the system can be shown, by

+ test, to deliver the. spray solution through the nozzles.within 90 seconds, post-LOCA. For those systems where the spray solution is delivered after 90 seconds, post-LOCA, credit for spray removal of iodine will be assumed to commence upon-the time of actual flow; through the nozzles. The'systet operation should be continuous until the iodine removal objectives-of the system are met. If a switchover ,

i fron the injection to a recirculation mode of operation is_ required during this time period, the reviewer should confirm that all require-ments listed in the acceptance criteria,=particularly those concerning j spray coverage and solution pH, are met during the recirculation phase.

Manual switchcVer from the injection mode to the recirculation mode

j. during the first 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> following the initiation of the spray _ system operation is not acceptable.

L i.

c Spr_ay Distribution and Containment Mixing l

The number and layout of the spray headers used to distribute the' spray flow in the containment are reviewed. The reviewer verifles that the layout of the headers assures coverage of_ essentially the entire cross section of the containment with spray, under minimum spray flow conditions. The effect of the high temperature and pressure

• conditions in.the containment on the spray dro f

be taken into account in determining the-area covered plet' trajectories should by the-spray.

The layout of the containment and forced. ventilation systems (safety-

grade) operating after the LOCA are reviewed to determine if_any areas of the containment free volume'are not sprayed. The mixing rate due to f natural convection between the sprayed and

unsprayed regionsiof the containment, provided that adequate flow area exists between these

!- regions,.is assumed to be.2 turnovers of the unsprayed-region (s) per-p hour, unless other rates are justified by the applicant; itls also t assumed that forced air ventilation systems ^ designed to operate in

[ the-postaccident environment move air at 50% of their_ design' flow-rates.

'. The containment may be considered'a single,-well mixed volume

' provided the spray covers regions comprising at least 90% of the con-tainment volume and provided a ventilation system.is available for adequate mixing of any unsprayed compartments.

~

d. Spray Nozzles a

4' 'The design of the spray nozzles is reviewed to confirm that_the spray 1

nozzles are not subject to clogging from debris entering the recircu-1ation system through the sump _ screens.-

e. Sump Mixing The mixing of the spray water containing._the chemical additive arid

. ment water without additive (such as spilling ECCS coolant) in t% contain- -)

_ sump.is reviewed.

The areas of the containment which are exposed i

6.5.2-8 Rev.1 - Juiy 1981

~tothe,spraytutarewithoutdirectdr$instotherecirculationsump (such as the refueling cavity) are considered. The-reviewer confirms' that the required sump-concentrations-are achieved-within the appro-priate time intervals. The long-term s!"np pH should be reviewed in .

regard to iodine re-evolution, using tbs criteria given in subsec-tion II.1.g above.

The equilibrium partitioning of iodine between the sump liquid and the containment atmosphere is examined for_the extremes of the additive l

concentrations determined above, in combination with the range ofE temperatures possibleiin the containment-atmosphere and the sump: solu--

tion. The minimum iodine partition coefficient (H) deter.nined for these conditions forms =the basis of the ultimate iodine decontamination factor in the staff's analysis described below. See Reference 7 for a theoretical examination of iodine partition coefficients.

f. Storage of Additives The design of the additive storage tanks is reviewed by CMEB-to estab-lish whether heat tracing is required to prevent freezing or precipi-tation in the tanks. The reviewer determines whether-an inert cover gas is provided for.the tanks to prevent = reactions of the additive-with air, such as the formation of-sodium carbonate by the reaction of sodium hydroxide and-carbon dioxide. Alternatively, the_ reviewer  !

e verifies by a conservative analysis that an inert cover gas is not.

required.

g. Single-Failure The system schematics are reviewed by-inspection postulating single failuresofanyactivecomponentinthesystem,includinginadvertent operation of valves that are not locked open. The review is performed with respect to the iodine removal function, considering ;onditions that could result in too fast as well as _too slow an additive-injection. _.

2. Tecting At the construction permit. stage, the containment spray concept and.the ,

proposed tests of the system are reviewed to co1 firm the-feasibility of-verifying the design functions by appropriate' testing. At the operating iicense stage, the proposed tests of the system and its components are reviewed to verify that the tests will' demonstrate that the system,< as  :'

installed,;is capable of performing, within the bounds established in the description and evaluation of the system, all functionstessential'for effective iodine removal following postulated accidents.

3. Technical Specifications The technical specifications are reviewed to verify-that the system, _as designed, is capable of meeting the desigt. requirements and>that it r mains -

in a. state of readiness whenever the reactor is c;1tical._

a, ' Limiting Conditions for Operation (LCO)

The LCOs should require the operability of the containment spray pumps, i all' associated valves and. piping, the spray additive. tanks including.

6.5.2-9 Rev.- 1 _ July 1981-y

the appopriate quantity of additives, and any metering pumps or mixing devices,

b. Tests Preoperational testing of the system, including the additive tanks, pumps (if any), piping, and valves is required, as discussed above.

In particular, the preoperational testing should verify that the system, as installed, is capable of delivering a well mixed solution containing all additives with concentrations falling within the design margins assumed in the dose analyses of Chapter 15 of the SAR, Periodic testing and exercising of all active components should include the spray pumps, metering pumps (if any), and valves. Confirmation that passive components, such as all essential spray and spray addi-tive piping, and any passive mixing devices are free of obstructions should be made periodically. The contents of the spray additive tanks should be sampled and analyzed periodically to verify that the concen-trations are within the established limits, that no concentration gradients exist, and that no precipitates have formed.

4. Evaluation

~

A calculation of the iodine removal effectiveness of the system is performed to establish the degree of iodine dose mitigation by the containment spray following the postulated accident. The mathematical model used for this calculation reflects the preceding steps of, the review. The analysis and 4

assumptions are as follow - 4 a.

The amount of iodine assumed to be released to the containment is 50% of the core iodine inventory. This has the composition of 95.5%

elemental, 2.5% particulate, and 2.0% organic. The amount of iodine airborne inside containment depends upon plate out on interior contein-ment surfaces, removal by the spray and action of other engineered safety features present, radioactive decay, and outleakage from the containment.

b.

The removal of iodine from the containment atmosphere by the spray is considered a first-order remo'eal_ process. The removal coefficients A (lambda) for each form of iodine (i.e., elemental, particulate, and organic) for each of the sprayed regions of the containment is computed by the methods such as the digital computer code SPIRT (Ref. 6). Removal coefficients representing time-dependent elemental iodine wall plate-out are also calculated. The coefficients for spray removal and wall plate-out are summed for elemental iodine. The removal lambdas are used as input parameters into a computer model used for dose calculation. In contrast to previous practice, the coefficients so calculated do not have an arbitrary maximum allowable value when used in conjunction with the assumption of 50% of the core iodine inventory initial'y airborne.

c. The maximum elemental iodine decontamination factor, DF, for the containment atmosphere achieved by the spray system is determined from the the equation (Ref. 4):

6.5.2-10 Rev. 1 - July 1981

N DF=1+[V C H

I

where

J

. H = equilibrium iodine partition coefficient Vs = v lume of liquid in containment sump and sump over flow Vc = containment net free volume less V, j The maximum decontamination factor for plain water, boric acid 4

solutions, sodium hydroxide and hydrazine additive systems is DF, = 200

! DF is defined as the initial iodine concentration in the containment

! atmosphere, obtained when 50% of the core iodine is instantaneously j- released, divided by the concentration of iodine in the containment j atmosphere at some later time.

The effectiveness of the spray in removing elemental iodine shall be presumed to end at that time, post-LOCA, when the maximum elemental iodine DF is reached. Because the removal mechanisms are-significantly different (and slower) for organic and particulate iodines, there'is i no need to limit the DF allowed in the analysis for these iodine forms.

IV. EVALUATION FINDINGS The staff's evaluation of the iodine removal effectiveness of the containment spray system should include the following parameters, which are-used in the thyroid dose calculations of a postulated loss-of-coolant accident:

overall first-order removal constants (per hour) for ele.nental iodine,. A , i

for organic iodine A2 , and for particulate iodine, A3 ,

the effective spray volume, V_(ft3),

t the' maximum decontamination factor for elemental iodine,-DF.

i

After the AEB reviewer determines that the containment spray and spray additive

! system is effective for iodine removal, the following can be reported in the j~ staff's safety evaluation report (SER):

The staff concludes'that the containment _ spray system as a fission product-cleanup system is acceptable and meets.the relevant require-ments of General Design Criterion 41, " Containment Atmosphere Cleanup,"

General Design _ Criterion 42,~ " Inspection of Containment Atmosphere Cleanup Systems," and General Design Criterion 43, " Testing of_Contain-

-ment Atmosphere Cleanup Systems." This conclusion is based on the ,

fo! lowing:

The concept upon which the proposed system is based has been_ demon-strated to be effective for iodine absorption and retention under postaccident conditions. The proposed system design is an acceptable 6.5.2-11 Rev. 1 - July 1981

T t

application ofsthisiconcept.

e The_ system provides suitable redundancy in enmponents and features such that itt safety function can. bel _ accom plish'ed assuming'a single = failure. 1The staff concludes that-the-I- system meets the requiremen;s of General Design Criterion 41.

L i- The proposed pre-operational tests, post-operationalftesting and t

~

surveillance, and proposed limiting conditions ~of: operation for th9-spray system provide adequate'3ssurance that the: iodine scrubbing i

function of the containment spray system will meet or exceed the .

effectiveness assumed in the accident evaluation and, therefore, 4

meets the requirements of General _ Design: Criteria 42'and 43. '

+

F V. IMFLEMENTATION ,

~

j The following pro,' des ;uidance to' applicants and licensees regarding tto staff's-j t

plans fer using this SRP section, .

I Except in those cases in which the applicant proposes an acceptable alternative-method for complying with specified portions of the Commission's--regulations, the method described herein will be used by the staff in its evaluation of'

j. conformance with Commission regulations. '

l.

VI, REFERENCES

1.

10-CFR Part 50, Appendix A, General Design Criterion 41, " Containment Atmosphere Cleanup."

2, j 10 CFR-Part 50, Appendix A,. General Design Criterion 42, " Inspection of _ dI ~

Containment; Atmosphere Cleanup-Systems."

j 3.

10 CFR Part 50, Appendix A, General' Design Criterion 43=, " Testing of Containment Atmosphere Cleanup Systems." ,

! 4. ANSI /ANS Standard Criteria." 56.5-1979,. "PWR and BWR _ Containment Spray System = Design '

r 5.

) D._L.-Reid, B. M. Johnson, and A. K.,Postma, "Research onlRemovalxof' Iodine by Containment Sprays _Containing. Trace Levels of.Hydrazine," Battelle~

Pacific Northwest Laboratories,1 June 1979.

6. 'A..K. Postma, R. R. Sherry, and P. S. Tam,'" Technological Bases fer!Models

{

of Spray _ Washout of Airborne Contaminants in Containment Vessels,"

NUREG/CR-0009.

7.

L. F. Parsly, " Design Considerations of Reactor ContainmentLSpray Systems--

i- Part IV._" Calculation of Iodine Partition Coefficients," 0RNL-TM-2412, Part IV, Oak Ridge National Laboratory (1970).

i- .

i 5

i-4 .

1 6.5.2-12 Rev. 1 - July:1981-t

-- - - , . , . , , , , . - -,, . _ . ,.,w 3 ., , . - - yy s r ,-,,,y, ,- gep..-++-g.y4-r ,+=#g y 9 99 y -g*

4 L

5000

/

l J

4

! l

1

. 1000 l I 4 i I d

~ I_

, -l 2 500 l

.s

.2

/ .

4 t i 8  ;

8

'z

'B b

100 s

I I

50 4

5 6 7 8 9 .10 11 Spray pH Fig. 6.s.2-1 Partition Coefficient.vs. Spray pH I For Solution Containing i Sodium Hydroxide (Ref. 4) 6.5.2-13

' l Rev. 1 - July 1981 l

l

. 1 1

8

.l q

3 f

1 L

ENCLOSURE 3 TO TXX-92468 NUREG-0800 Standard Review Plan Section 6.5.2 1

Rev. 2 - December 1988 4

1

'e J

J 4

4

?

I I

t i

I f

4 I

t-I

NUREG.0000 (Formerly NUREG.75/067)

,. / *\ U.S. NUCLEAR REGULATORY COMMISSION -

I

+ i'M,i STANDARD REVIEW PLAN

/ OFFICE OF NUCLEAR REACTOR REGULATION l e.ee*

l 6.5.2 CONTAINMEn'T FDRAY AS A FISSION PRODUCT CLEANUP SYSTEM REVIEW RESPONSIBILITIES Primary - Chemical Engineering Branch Secondary - P O +. Systems Branch Raolation Protection Branch I. AREAS OF REVIEW The containment spray and the spray additive or pH control systems are reviewed to

' determine the fission product removal effectiveness whenever the applicant claims a containment atmosphere fission 7toduct cleanup function for the systems. The following areas of the applicant's safety analysis report (SAR) relating to the fission product removal and control function of the containment spray system are reviewed.

1. Fission Product Removal Requirement for Containment Spray Sections of the SAR related to accident analyses,. dose calculations, and fission product removal and control are reviewed to establish whether or not fission product scrubbing of the containment atmos-phere for the citigation of radiological consequences following a postulated accidant is claimed by the applicant. This review usually covers sections in SAR Cha- ters 6 and 15. ,

4

2. Desian Bases i The design bases for the fission product removal function of the containment spray system are reviewed to verify that they are consis-tent with the assumptions made in the accident evaluations of SAR Chapter 15.

, Rev. 2 - December 1988 USNRC STANDARD REVIEW PLAN Standard review plans are prepared for the guidance of tte Office of Nuclear Reactor Regutetion staff responsible for the review of app (mtions to construct and operate nuclear power plants. These documente are made oveliable to the public as part of the Commission's policy to inform the nuclear industry and the general public of regulatory procedures and policies. Standard review plane are not substitutes for regulatory guides of the Commisalon's regulatione and compliance with them le not required. The

/ standard review plan sections are keyed to the Standard Format and Content of Sefety enetyens Reporte for Nuclear Power Plants.

Not sit sections of the Standard Format have a corresponding review plan.

(:d. Published standard review plane will be revised per6odically, as appropriate, to accommodate comments and to reflect new informa-tion and emperience.

' Comments and suggestione for 6mprovement will be considered and should be sent to the u.S. Nuclear Regulatory Commiselon.

Office of A ,cleet Reactoe Regulation. Washington. D.C. 20tiG6.

3. System Duian . - -

~~

The information on the design of the spray system, including any subsystems and supporting systems, is reviewed to familiarize the reviewer with the design and operation of the system. The informa-tion includes:

a.

The. description of the basic design concept; the systems, sub-systems, and support systems required to carry out the fission product scrubbino function of the system; and the components and instrumentation employed in these systems.

b. The process and instrumentation diagrams.

c. Layout drawings (plans, elevations, isometrics) of the spray distribution headers, s

d.

Plan views and elevations of the containment building layaut.

4. Testino and Inspections The system description is reviewed to establish the details of the preoperational test to be performed for qvstem verification and the postoperational tests and inspections to be performed for verifica-tion of the continued status of readiness of the spray system.

5. Technical Specifications #

h At the operating license stage, the applicant's proposed technical V specifications are reviewed to establish permissible outage times and survei.llance requirements.

In addition, the reviewer will coordinate other evaluations that interface with the review of the containment spray system as follows: any chemical additive storage requirements, materials compatibility of ~the long-tena containment sump and recirculation spray solutions, and organic material decomposition including formation of organic iodides as part of SRP Sections 6.1.1 and 6.1.2, the heat removal and hydrogen mixing function of the containment spray system and the containment sump design as part of SRP Sections 6.2.2 and 6.2.5. The acceptance criteria for the review and the methods of application are contained in the referenced SRP sections.

II. ACCEPTANCE CRITERIA The acceptance criteria for the fission product clear.up function of the contain-ment regulatinns: spray system are based on meeting the relevant requirements of the following A.

General Design Criterion 41 (Ref.1) as it relates to containment atmosphere cleanup systems being designed to control fission product releases to the reactor containment following postulated accidents.

\

6.5.2-2 Rev. 2 - December 19P9 4

~

? .. .. ~

3 B. General Design Criterion 42 (Ref. 2) as it relates-to c6Titsinment atmosphere cleanup systems being designed to permit appropriate periodic inspections.

j C. General Design Criterion 43 (Ref. 3) as it relates to containment atmosphere j cleanup systems 'being designed for appropriate periodic functional testing.

Specific criteria necessary to meet the relevant requirements of General Design

' Criteria 41, 42, and 43 include: -

1. 0_e_ sign Requirements for Fission Product Removal The containment spray system should-be designed in accordance with the

. requirements of Reference 4. except that requirement

far any spray addi-tive or other pH control system in this reference need not be followed.

l

! a. System Operation 9

The containment spray system should be designed to be initiated automatically bv an appropriate accident signal-and to be transferred automatically fiom the injection mode to the recirculation mode to i ensure continuous operation _until the design objectives of the system have been achieved. In all cases, the operating period should not be 4 less than two hours. Additives to the spray solution may be initiated ,

manually or automatically, or may be stored in the containment sump to be dissolved during the spray injection period.

( b. Coverage of Containment Building Volume j -

In order to. ensure full spray coverage of the containment building

~

volume, the following should be observed:

! (1) The spray nozzles should be located as high in the containment building as practicable to maxi _mize the spray drop' fall distance.

(2) The layout of tw spray nozzles and distribution headers should be such that the c. mss-sectional area of the containment building i covered by.the spray is as large as practicable and that a nearly homogeneous distribution of spray in the containment building

space is produced. Unsprayed regions in the upper containment building and, in particular, an unsprayed annulus. adjacent to the cantainment building liner should be avoided wherever possible.

' (3) -In designing the. layout of the spray nozzle positions and orien-4 tations, the effect of the post-accident atmosphere should be considered, including the effects of post-accident conditions that result in-the maximum possible density of the containment atmos-phere.

c. Promotion of Cortainment Building Atmosphere Mixing f(

l-\-

Because tF effectiveness of the containment spray _ system ' depends on

=a well-mixed containment atmosphere, all design features enhancing post-accident mixing should.be considered. l b

6.5.2-3 Rev. 2 - December 1988 i

a b --

4

d. Spraj Nozzles - --

The nozzles used in the containment spray system should be of a design that minimizes the possibility of clogging while prcducing drop sizes effective for iodine absorption. The nozzles should not have internal moving parts such as swirl vanes, turbulence promotf:rs, etc. They should not have orifices or internal restrictions which would narrow the flow passage to less than one quarter of an inch in diameter.

e. Spray Solution l

The partition of iodine between liquid and gas phases is enhanced by the alkalinity of the solution. The spray system should be designed so that the spray solution is within material compatibility con-straints. Iodine scrubbing credit is given for spray solutions whose chemistry, including any additives, has been demonstrated to be effer-tive for iodine absorption and retention under post-accident conditions.

f. Containment jump Solution Mixing The containment sump should be designed to permit mixing of emergency <

core cooling system (ECCS) and spray solutions. Drains to the engineered safety features sump should be provided for ail regions of the containment which would collect a significant quantity of the spray solution. Alternatively, allowance should be made fer " dead" volumes in tl.e determination of the pH of.the sump solution and the quantities of additives injected. A ,

)

g. Containment Sump and Recirculation Spray Solutions -

The pH of the aqueous solution collected in the containment sump after completion of injection of containment spray and ECCS water, and all additives for reactivity control, fission product removal, or other purposes, should be maintained at a level sufficiently high to provide-assurance that significant long-term iodine re-evolution does not occur. Long-term iodine retention is calculated on the basis of the expected long-term partition coefficient. Long-tenn iodine retention may be assumed only when the equilibrium sump solution pH, after mixing and dilution with the primary coolant and ECCS injection, is above 7 (Ref. 5). This pH value should be achieved by the onset of the spray recirculation mode.

h. Storace g Additives j The design should provide facilities for the long-term storage of any l spray additives. These facilities should be designed so that the additives required to achieve the design objectives of the system are stored in'a state of continual readiness whenever the reactor is crita ical for the design life of the plant. The storage facilities should be designed to prevent freezing, precipitation, chemical reaction, and decomposition of the additives. For sodium hydroxide storage tanks, heat tracing of tanks and piping is required whenever exposure to l

L l

6.5.2-4 Rev. 2 - December 1988 8

temperatures below 40'F 1s predicted. An inert-cover gas should bT" provided for solutions that may deteriorate as a consequence of exposure to air.

i. Single Failure The system should be able to function effectively and meet all the criteria in subsection 11 with a single failure of an active compo-nent in the spray system, in any of its subsystems, or in any of its support systems.

2. Testing _

Tests should be performed to demonstrate that the containment !? ray system, as installed, meets all design requirements for an effective fission product scrubbing function. Such tests should include preoperational verification of:

c. freedom of the containment spray piping and nozzles'from obstructions,

b. capability of tM system to deliver the recuired spray flow, and N

c. capability of the system to deliver spray additives (if any are needed) and to achieve the sump solution pH specif M in the SAR. For a system whose performance is sensitive to the as 0. lt piping layout, such as a gravity feed system, the testing shot.l be r eformed at full flow.

3. Technical Specifications The technical specifications should specify appropriate limiting conditions for operstion, tests, and inspections to provide assurance that the system is capable of performing its design function whenever the reactor is cri-tical. These specifications should include:

a. The operability requirewnts for the system, including all active and passive devices, as a limiting condition for operation (with accept-able outage times). The following items should be specifically included: conteinment spray pumps, additive pumps (if any), additive mixing devices (if any), valves and nozzles, edditive quantity and concentration in additive storage tanks, and nitrogen (or other inert gas) pressure in additive storage tanks,

b. Periodic inspection and sampling of the contents of ad,.'.cive storage tanks to confirm that the additive quantity and concentrations are within the limits established by the system dtsign.

c. Periodic testing and exercising of the active components of the system and verification that essential piping and passive devices are free of ob'structions.

Acceptable method for computing fission product removal rates by the spray system b a given in subsection Ill.4.c. " Fission Product cleanup Models."

(

(

6.5.2-5 Rev. 2 - December 1988 8

i i

l i

While granting credit for containment spray removal of firs 16n products in the ') ,

i calculations of accident doses, the acceptance criteria of containment leakage ,

. in SRP Section 6.2.1.1. A and the acceptance criteria of the engineered safety i

feature atmosphere cleanup systems in SRP Dection 6.5.1 should still be met.  ;

4

!!!. REYlEW PROCEDURES  ;

j The reviewer selects and emphasizes aspects covered by this SRP section as i appropriate for a particular plant. The judgment-of which areas need to be -

! given attention and emphasis in the review 's based on a determination of 4

whether the material presented is simil.sr to that recently reviewed on other plants and whether items of special safety significance are involved. l j The reviewer determines whether the containment spray system is used for fis:'on

, product removal purposes. SAI Chapter 15 should be reviewsd to establish whether j a fissicn product removal fur.ction for the containment spray system is assumed in 5 accident dose evsluations. If the-containment spray system is not used for miti-

! gating radiological consequences, no further review is required under this SRP

(- section, if the-containment spray system is used for mitigation of radiological-doses, then the review of the fission product removal function of the containment spray system follows the procedure outlined below.

1. System Desion l Review of the system design includes an examination of the components and

{ design features necessar: to carry out the fission product scrubbing func- lm

! tion,-including. '

i )

a. Spray Solution Chemistry l .

i >

l The foms of iodine for which spray removal credit is claimed in the

• l accident analyses (SAR Chapter 15) are established. Containment spray l systems may be designed for removal of iodine in the elemental form, i in the form of organic compounds, and in the particulate form. Spray.

! removal credit for other particulate fission products.is also.

i. established.

!- The systems or. subsystems required to carry out the fission product  :

scrubbing function of the containment spray are identified, such as -

l t':e spray system, recirculation system, spray additive. system, and water source. The design of the systees involved is reviewed.in order to:

i-

,_ (1) Ascertain the effectiveness of any chemical additive'for iodine

removal and retention.

. (2) Arcertain that the amount of additive is sufficient to meet--the-acceptance criteria of subsection II or that adequate-justifica-

. tion is supplied for the iodine removal-and retention effective-ness for the range of concentrat ans encountered.' The concentra-

, tions in the storage facility, the chemical addition lines, the

, spray-solution injection -the containment-sump sulution, and the recirculation spray solution should be examined. The extremes T

6.5.2*6 Rev. 2 - December 1988 e

__ _ _ ._ .~ _ ..

of the additive concentrations should be determined with the most advere.e combination of ECCS, spray, and additive pumps (if any) assum^1 to be operating, and considering a single failure of active components in the systems or subsystems.

The reviewer verifies that the stability of the containment spray and sump solutions and the corrosion, solidification, and precipitation behavior of the chemical additives have appropriately been taken into consideration for the range of concentrations encountered.

t; . System Operation The time and method of system initiation, including chemical addition, l is reviewed to confirm that the acceptance criteria of subt.ect;on Il I are met. Automatic initiation of spray is reviewed under SRP Sec-4 tion 6.2.2. The system operation should be continuous until the fission product removal objectives of the system are met. The reviewer should confirm that all requirements listed in th' scceptance l

criteria, particularly those concerning spray cove' rage and sump solu-tion pH, are met during the recirculation phase. Switchover froo the injection mode to the recirculation mode following initiation to the spray system operation must be automatic to prevent damage to the spray pumps through loss of swtion.

c. Spray Distribution and Containment Mixing f The number and layout of the spray headers used to distribute the

(" spray flow in the containment space are reviewed. The reviewer verifies that the layout of the headers ensures coverage of essent-ially-the entire horizontal cross-section of the containment building with spray, under minimum spray flow conditions. TL.e effect of the

' post-accident high temperature and pressure conditions in the con-tainment atmosphere on the spray droplet trajectories should be taken into account in determining the area covered by the spray.

The layout of tl,e containn nt building is reviewed to determine if any areas of the containment free space are not sprayed. The nixing i

rate attributed to natural convection.between the sprayed a.id unsprayed regions of the containment building, provided that adequate flow exists between these regions, is assumed to be two turnovers of

, the unsprayed region (s) per hour, unless other rates tre justified by the applicant. The containment building atmosphere may be consid-l ered a single, well-mixed space if the spray covers regions compris-ing at least 90% of the containment building space and if a'ventila-tion system is available for adequate mixing of any unsprayed compartments,

d. Spray Nozzles l The design of the spray nozzles is reviewed to confirm that the spray nozzles are not subject to clogging from debris entering the recircu-lation system through the containment sump screens. l l

f b- 6.5.2-7 Rev. 2 - December 1988 h

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e. ContainmentSuq_titxin' --

J The mixing of the spray water containing any chemical additive and water without additive (such as spilling ECCS coolant) in the con-tainment sump is reviewed. The areas of the containment building l that are exposed to the spray but are without direr:t drains to the recirculation sump (such as the refueling cavity) are considereo.

The reviewer confirms that the required sump solution concentration.

are achiev*d within the sppropriate time intervals. The pH of the sump solution .N eld : reviewed in regard to iodine re evolution, using the critirri;? gMa in subsection II.1.g and the procedure in subsection III.4.c.(2).

f. Storage of Additivess The design of any additive storage tank is reviewed to establish l whether heat tracing is regul'c0 to prevent freezir,g or precipitation in the tank. The reviewer determines whether an itert :over gas is provided for the tank to prevent reactions of the additive with air, such as the formation of sodium carbor, ate by the reaction of sodium hydroxide and carbon dioxide. Alternatively, the reviewer verifies by a conservative analysis that an inert cover gas is not required.

g. Single Failure The system schematics are reviewed by insoection postulating single failuresofanyactivecomponentinthesystem,Includinginadvertent Sj operation of valves that are not locked open. The review is performed with respect to the fission product removal function, considering conditions that could result in fast as well as slow injection of the spray solution. -

2. Tecting At the constructiot, permit stage, the containment spray concept and the proposed tests of the system are reviewed to confirm the feasibility of verifying the design functions by appropriate testing. At the operating license stage, the propt, sed tests of the system and its components are reviewed to verify that the tests will demonstrate that the system, as installed, is ce able of performing, within the bounds e;tablished in the-description and evaluation of the system,.all functions essential for effective fission product removal following postulated accidents. l

3. Technical Specifications The technical specifications arc reviewed to verify that the system, as designed, is capable of meeting the design requirements and that it remains in a state of readiness whenever the reactor is critical.

a. Limiting Conditions for Operation The limiting conditions for operation should require the operability of the containment spray pumps, all associated valves and piping, the t ,

v 6.5.2-8 Rev. 2 - December 1988 1

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h- appropriate quantity of additives, and any metering pumps or mixTiig devices. J

b. Tests  !

Preoperational testing of the system, including the additive storage tanks, pumps (if any), piping, and valves, is required. In parti-cular, the preoperational testing should verify that the system, as i nsta*. led is capable of delivering a well-mixed solution containing all additives with conccntrations falling within the design margins assumed in the dose analyses of SAR Chapter 15.

Periodic testing and exercising of all active components should include the spray pumps, metering pumps (if any), and valves. Con-firmation should be mde periodically that passive cort.ponents, such as all essential spray and spray additive piping, and any passive mixing devices are free of obstructions. The contents of the spray additive storage tanks should be sampled and analyzed periodically to verify that the concentrations are within the'estabilshed limits, that no concentration gradients exist, and that no precipitates have formed.

4 Evaluation The fission product removal effectiveness of the system is calculated to establish the degree of dose mitigation by the containment spray system

(- following the postulated accident. The mathematical model used for this

(" calculation should reflect the p-eceding steps of the revicw. The analy-

, sis and assumptions are as follows:

a. The amounts of fission products assumed to be released to the containment space are obtained from Regulatory Guide 1.3 (Ref. 6) or Regulatory Guide 1.4 (Ref. 7), as appropriate. The amounts of fis-sion product airborne inside the containment building depend upon plate-out on interior surfaces, removal by the spray and action of other engineered safety features present, radioactive decay, and outleakage from the containment building.

b.

The removal of fission products frori the containment atmosphere by l the spray is considered a first order removal process. The removal coefficient A (lambday for each of the sprayed regions of the con-tainment ib computed. Removal coefficients representing time-dependent wall plate-out are also calculated. The coeffic'ents for spray removal and wall plate-out are summed. The removal lambdas t

are input parameters of a computer model for dose calculation.

c. Fission Product Cleanup Models The reviewer estimates the area t f the interie: surfaces of the i containment volume flow ratebuilding which of the system could be (assuming single washed failure , by the the aver-spray) system age drop fall height and the mass-merin diameter of the spray drops, e a

6.5.2-9 Rev. 2 - December 1988 l- <

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from inspection of the information in the SAR. Th'eeffectivenessoE a containment spray system may be estimated by considering the -)

chemical and physical processes that could occur during an accident in which the system operates. Models containing such considerations are reviewed on case-by case bases. In the absence of detailed models, the following simplifications may be used:

Experimental results (Refs. 8, 5, and 11) and co nputer simulations of the chemical kinetics involved (Ref. 10) show that an important factor determining the effectiveness of sprays against elemental iodine vapor is the concentration of iodine in the spray solution.

Experiments with fresh sprays having no dissolved iodine were observed to be quite effective in the scrubbing of elemental iodine even at a pH as low as 5 (Refs. 9 and 11). However, solutions having dissolved iodine, such as the sump so1Ltions that recirculate after an accidene, may revolatilize iodine if the solutions are acidic (Refs. 5 and 10). Chemical additives in the spray solution have no significant effect upon aerosol particle removal because this removal process is largely mechanical in nature.

(1) Elemental iodine removal dur.i g raying of fresh *,olution During injection, tne removal of elemental iodine by wall deposition may be estimated by '

A,= K,A/V '

)

Here, tion, AA*is the wetted surface area, V is the containment build-is the first-or ing net free volume and K.. is a mass-transfer coefficient.

Allavailableexperlmental"datiareconservativelyenvelopeaif K , is taken to be 4.9 meters per hour (Ref. 11, page 17).

Duringinjection,theeffectivenessofthesprayagainst elemental iodine vapor is chiefly determined by the rate at which fresh solution surface area is introduced into the containment building atmosphere. The rate of solution surface created per unit gas volume in the containment atmosphere may be estimated as (6F/VD), where F is the volume flow rate of the spray pump.

V is the containment building net f.ree volume, and 0 is the 1 mass-mean diameter of the spray drops. The first-order removal coefficient by spray, A,, may be taken to be 6Kg TF As

• VD where the tim k@ of fall of the drops, which may be estimated by theis the gas p ratio of the average fall height to the terminal velocity of the mass-mean drop (Ref. 14). The above expression represents a first-order approximation if a well-mixed droplet model is used for the spray efficiency. The expression is valid for A s

t 6.5.2-10 Rev. 2 - December 1988 -

- - - = . - - - _ _ - - - - - - . - --= - . - - . . -

t i

' ~

values equal to or greater than ten per hour.~ ' is to be A

limitedto20perhourtopreventextrapolation8eyondthe i

existing data for boric acid solutions with a pH of 5 (Refs. 8

and 11). For A values less than ten per hour, analyses using l amoresophistilatedexpressionarerecommended.

(2) Elemental iodine removal during recirculation of sump solution The sump solution at the end of injection is assumed to contain fission products wa:hed from the reactor core as well as those removed from the containment atmosphere. The radiation absorbed

] by the sump solution, if the solution is acidic, would generate

hydrogen peroxide (Ref. 12) in sufficient amount to react with 4

both todide and iodate ions and raise the possibility of ele-4 mental iodine re evolution (Ref. 5). For sump solutions having

. pH values less than 7. molecular iodine vapnr should be conserva-tively assumed to evolve into the containment atmosphere

(Ref. 15).

Information on the partition coefficients for molecular iodine

, can be found in References 15,16, and 17. The equilibriom

partitioning of iodine between-tht sump liquid and the containment atmosphere is examined for the extreme additive concentrations

! determined in Sectio. III.1.a.(2), in combination with the range i

of temperatures possible in the containment atmosphere and the sump solution. The reviewer should consider all known sources l

4

[-

(

and sinks of acids and t,ases (e.g. , alkaline earth and alkali metal oxides nitric acid generated by radiolysis of nitrogen l and water, alkaline salts or lye additives) in a post-accident containment environment. The minimum iodine pa-tition coefficient determined for these conditions forms the basis of he ultimate

iodine decontamination factor in the staff's analysis described

, in subsection III.4.d.

! (3) Organic iodides It is conservative to assume that organic lodides are not removed by either spray or wall deposition. Radiolytic destruction of iodomethane may be modelled, but such a model must also consider

radiolytic production (Ref. 18). Engineered safety features

{ designed to remove organic iodides are reviewed on a case-by-case basis.

~

(4) Particulates The fh st-order removal coefficient, A p for particulates may be estimated by A 3hFE P * 'fW

' where h is the fall height of the spray drops, V is the contain-ment building net free volume F is the spray flow, and (E/0) is.

the ratio of a dimensionless collection efficiency E to the-6.5.2-11 Rav. 2 - December 1988 4

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1 l- avert e spray drop diameter D. Since the reibn1 of particula't7 mater al depends markedly upon the relative-sizes of the ')

particles and the spray drops, it is convenient to combine param-eters that cannot be known (Ref. 13). It is conservative to assume (E/0) to be 10 per meter initially (i.e., 1% efficiency for spray drops of one millimeter a to one per naeter after the aerosol.in diameter),

mass has been changing depleted by abruptly a

l factor of 50 (i.e., 98% of the surpended mass is ten times more readily removed than the remaining 2%).

. d. The iodine decontamination facter, OF, is defined'as the maximum j iodine concentration in the containment ats.osphere divided by the concentration of iodine in the containment atmosphere at some time

'; after dt. contamination. OF for the containment atmosphere achieved by the containment spray system is determined from the following-equation (Ref. 4):

V, H -

0F=1+ y

, C i

where H is the effective iodine partition coefficient, V is the l volumeofliquidincontainmentsumpandsumpoverflow,AndV c is the containment building net free volume less V,.

The maximum decontamination factor is 200 for elemental iodine. The effectiveness of the spray in removing elemental iodine shall be pre-sumed to end at that time, post-LOCA, when the maximum elemental iodine DF is reached. Because the removs1 me:hanisms for organic iodides and particulate lodines are sigaificantly different from and 4} -

slower than that for elemental iodine,<there is no need to limit the OF for organic lodides and particulate iodines.

l IV. EVALUATION FINDINGS The reviewer verifles that sufficient information has been provided'by the applicant and that the review and calwiations support-conclusions of the i fo1% wing type, to be included in the staff's safety evaluation report:

L

' The concept upon which the proposed system is based has been demonstrated to be effective for fission product removal and retention.under post- l accident conditions. .The proposed system design is an acceptable appli-cation of-this concept. The system provides suitable redundancy in components and features so that its safety function can be accomplished assuming a single failure. -l The proposed preoperational tests, postoperational test'ng and surveil-lance, and proposed liraiting conditior,s for operation of the spray system provide adequate assurance that the fission product scrubbing function of l the containment spray system will meet or exceed the effectiveness assumed

-ir. the accident evaluation. ;l l

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6.5.2-12 Rev. 2 - December 1988

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f The staff concludes that the containment spray syn'em as a fission prIduct cleanup system is acceptable and meets the requirements of General Design l Criterion 41 with respect to the iodine renoval function following a post-ulated loss-of-coolant accident, General Design Criterion 42 with respect

, to the capability fcr periodic inspection of the system, and General Design

! Criterion 43 with respect to the capability for periodic testing of the system.

V. EPLEMENTATION The following guidance is provided to applicants and licensees about the staff's l 1

~

plans for using this SRP section. i I

Except in those cases in which the applicant proposes an acceptable alternative '

method for complying with specified portions of the Comnission's regulations, the method described herein will be used by the staff in its evaluation of j conformance with Commission regulations. j Implementation of the acceptance '-iteria in subsection !! a'nd the review procedures in subsection III is t follows: .

d

1. Op6 rating plants and applicants for operating licenses pending at the date of issue of this revision need not comply with the provisions of this l revision, but may do so voluntarily.

2. Future applicants will be reviewed according to the provisions.of this revision, i D VI. REFERENCES

1. 10 CFR Part 50, Appendix A, General Design Criterion 41, " Containment Atmosphere Cleanup."

2. 10 CFR Part 50, Appendix A, General Design Criterion 42, " Inspection of Conteinment Atmosphere Cleanup Systems."

3. 10 CFR Part 50, Appendix A. General Desi Containment Atmosphere Cleanup Systems."gn Criterion 43, " Testing of

4. ANSI /ANS 56.5-1979, "PWR and BWR Containment Spray System Design Criteria," American National Standards Institute, Inc.

4 5. C. C. Lin, " Chemical Effects of Gamma Radiation on Iodine in Aqueous Solutions," Journal of Inorganic and Nuclear Chemistry, 42, pages 1101-1107 (1980).

6. U.S. Nuclear Regulatory Commission, Regulatory Guide 1.3, " Assumptions Used for Evaluating the Potential Radiological Consequences of a Loss-of-Coolant Accident for Boiling Water Reactors."

7. U.S. Nuclear Regulatory Commission, Regulatory Guide 1.4, " Assumptions Used for Evaluating the Potential Radiological Consequences of a Loss-of-Coolant Accider.t for Pre:surized Water Reactors."

f(~ ~

6.5.2-13 Rev. 2 - December 1988

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d m n e

8. R. K. Hilliard, A. K. Postma, J. D. McCormack, L. F. Cofeman, and ~)

C. E. Lunderman, " Removal of lodine and Particles From Containment Atmospheres - Containment Systems Experiments", Pacific Northwest Laboratories Report, BINL-1244. February 1970.

9. 5. Barsali, F. Bosalini, F. Fineschi, B. Guerrini, 5. Lanza, H. Hazzini, and R. Mirandola, "RemovC cf Iodina by Sprays in the PSICO 10 Model Containment Vessel", Nuclear Technology, 2a, pages 146-156 (August 1974).

10. H. F. Albert, "The Absorption of Gaseous Iodine by Water Droplets".

U.S. Nuclear Regulatory Commission Report, NUREG/CR-4081, July 1995.

4

11. A. K. Postma, L. F. Coleman, and R. K. Hilliard, " Iodine Removal from

-Containment Atmospheres by Boric Acid Spray", Pacific Northwest Laboratories Report, BNP-100, July 1970,

12. A. O. Allen, The Radiation Chemistry of Water and Aqueous Solutions, i Van Nostrand, New York (1961).

13. A. K. Postma, R. R. $herry, and P. 5. Tam, Technological Bases for Models of Spray Washout of Airborne Contaminants in Containment Vessel, U.S. Nuclear Regulatory Commission Report, NUREG/CR-0009, October 1978.

- 14. G. B. Wallis "T 9 an InfiniteMedIum,heTerminalSpeedofSingleDropsorBubb1_es1

" International Journal of Multiphase Flow,1, pages 491-511 (1974). , g

~ '

15. E. C. Beahm, W. E. Shockley, C. F. Weber, S. J. Wisbey, iiid V-H~ Wing, .

"Cmbtry and Transport of Iodine in Containment", U.S. Nuclear Regula-tory Commission Report, HUREG/CR-4697, October 1986.

16. J. T. Bell, M. H. Lietzke, and D. A. Palmer, " Predicted Rates of Formation of Iodine Hydrolysis Species at p'H Levels, Concentrat. ions, and Temperatures Anticipated in LWR Accidents, NUR'!G/CR-2900, October 1982.

17. J. T. Bell, D. O. Campbell, H. H. Lietzke, D. A. Palmer, and L. H. Toth.

" Aqueous Iodine :hemistry in LVR Accidents: Review and Assessment",

NUREG/CR-2493, April 1982.

18. E. C. Beahm, W. E. Shockley, and O. L. Culberson, " Organic Iodide Formation folling Nut bar Reactor Accidents", NUREG/CR-4327, December 1985'.

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6.5.2-14 Wev. 2 - December 1988 L

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i ENCLOSURE 410 TXX-92468 f

4 NUREG-1346 i Technica'i Specifications l South Texas Project. Unit Nos.-1 and 2 License flos. NPF-76 and NPF-80 .

l Title Psge and Page 3/4 5-10 1

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NUP.EG-1346 i~  ! /

ControgsdPS- . ,, e i  !

Technk:al Specifications l

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Sout, Texas Project I

! Jnh Nos.1 anc 2

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Docket Nos. 50-498 and 50-499 i

5 l 9 Appendix "A" to  ;

b License Nos. NPF-76 and NPF-80 n

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h t U lssued by the 2 U.S. Nuclear Regulatory l e Commission 6

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EMiRCENCY CORE Cu0 LING SYSTEMS 3/4.5.5 RIruttlNG WATER STORAGE TANK l

LIM 11Mg_Reli10N TOR OPEDAT1DL l _

l 3. 5. 5 The refueling water storage tank (RWST).shall be OPERABLE with:

a. -

-A minimon' contained borated water volume of 458,000 gallons, and f b.

A boron. concentration between 2500 ppm atd 2700 ppm.

f APPLICABILITY: MODES 1, 2, 3, and 4 i . -

ACTION:

- With the RWST Inoptreble, restore the tank to OPERABLE status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> <or' b& in at least following 30- hours. HDT STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the SURVEILLAyrE REOUIREMENTS .

4.5.5 The RwST shall be demonstrated OPERABLE at least once per 7 days b ':

a.

Verifying the contained borated water volume in the tank, and'

b. Verifying the boron concentration of the water.

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A SOUTH T(XA5 - UH1151 & 2 3/4 5 e-4c t o.- on *c@' 'o***~ --

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ENCLUSURE 5 TO TXX-G2468  ;

1 Federal Register 48 FR 14870 Vol. 48 N067 e

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" (.4870 Tederal Redster / Vol. 48 No. 67 / Wednesday. April 6. tota / Rules sLnd Rerelations esnsegusaces? twy understanding sornet procedures of the O* flee of Nut!ss.t esi the stateewns uans the Ccasesion (1) A punir administredvs c.hange t6  ;

ss. m e ,,e w i m e..ws u la, Rsactor her *2ncn. a copy of which wi!) todalcal specifica tions: for example, e bepiated a e,c o mssiu m u.

' a.m. io se.:.,e consistucy n's'Me"'Ph' **Jt2"La Nu $ H=- S'a*b a' *' "**^ 'P' c$ ""a =-

m se o e. st - c . rum =,ies of Amendments hat An corneda M u wror or a change b Mr. Hart Tm Est.stor e undmtand.r.g is Contidered Ilkely To lavolve amenciatun.

cor ett. As you bow. tLs prevalon peas to everrule the boldzg of the U.S. Coart of SignLfiunt Haze S Considuations An (11) A change that constitutes sa Appuls for the thsmet cf Colan.ble to $hoUY Ilsud Baw addjtjonal udtation, restriction, or , ,

esunH Nurjest Ress story Comunca. Ttat 1.Inless the specific c!rcumstances of a control not presently induded in the i case intohed the tentar.4 of todoacnve license annendment request, when technjeal specdficauena: for example. a kinto pe from the damased Tt.ree MUe more stringent survedlance requirement.

measured agamst the standards in

• C iU for a nudear aower reactor, a ee se on t$eLos : on as

• M7 then pur'a=='ia the proc'di u ia V #* d(ang)e resulting from a nuclear reac e,m,ed e tat,se amnme.% ni.e rome into ef'ect. It coujd prove impesoble to I h a preposed amendment to an con niosding. a no fue ammbun c.orrect ar y overwhts of fact or errors of operathg Ucense for a facdJty !! censed significan0y cL&rere from those found Ivdgwnt. Therefore. the Cocun.soon has an previously acceptable to the NRC for a uder l 60.21(b) or I $0.22 or for a

' obbssbon when essesttr:3 the bealth or testing faciuty wiu hkely be found to previous core at the facibty in queston safe y traphesucas of an amenciment bsvit involve eigndcant beauds us involved, TWs anumes that no invs ersible connevenen,io tase, that cajr sign $ cant cbugn are made to 6e those troend:nents that clearly take se considerathna,if operation of the sMca.nt basards lasues will take effect fagtyty in accordance with the propond " " E ' "" " for th' chrdcal pner to e pubbc beant.3 M. fPan W). el S. # # "UI h#"}'" 8" O' "" 0g O' spec @ cations, est the analytical

"' methods used to demonstrate -

(ih k '6 ant nlaxatfon of the conformann we se teen cal In light of tl e Conference Rtport and criter. + 8Pecmcations arairerulauens an not coUoquie' quoted above. the 'o e3tsbush safety hmits.

(11) A . c Acanirelaxadon of the Mgnmeant changed, and that NRC has i

Corrasm wisbes to note that it wtD make suce "est ordy those amendments bem for fimiting aMety system settings or umiting conditient for opersbon.

pnmap'found

• • • 'Pl*D such mdods that cle atly raise ne e,.. Scant basards iv A rehe' f grankd upon

(!!!) A significant relaxauon in hmiting issues wiU take effect prior to a pubbe con &Uons for operaden not de(mo)nstradon of acceptable opue heanns "It will do this by providn3 in fra an opusung rutncum est was i accompanied by compensatory changes l $0 02 of the rule that it will review conditons, or ac?!ons that maintain a impond because acceptable operston proposed amendments with a view as to was not yet demonstrated. TNs assumes whether they insolve irrnversible commensurate level of safety (euch as aDowing a plant to operate at full power that thu operating restnction and the consequences. in this regard, example dunns a penod in whJch one or more criterte to be appued to a request for (111) makes clear that an amendment safety systems are not cperable). rebelhave been estabbshed in a prior which allows a plant to opmta at fall tv) Renewal of an operanns licensa, nview and thatit is justded in a power caring wtuch one or non safer / ,

v) Fer a nua. lear power plut, an er.usfactory way that the criteria have systems are not openble would be been mal trested in the same wty as other increase in authorized maximum core power leval. IV)UPon satisfactory completaon cf esamples considind hiely to lavolve a - (vi) A change 11 techrdcal signifiennt basarcs consideration in that construction in connection with as specifiestions or other NRC #pprovaj operating facility, a reDef granted from it is !!kely to meet the critaria in i 50.92 involvirg a sign 2ca:.t unroviewed an opunting natriction that was of the rule. cesstion. Imposed because the construction was EnaUy It is once egelnimportant to safety) vt! A change in plant operation not yet cumpleted satisfactortJy. nJa is note that the examples do not cover all de(:lgned to improve safety but which. Intended to involve only restrictiona possible examples and may not be due to other factors in fact allows plant where it is justifled that constvetion representsuve of allpossible concerna, operst en with eafe'y margins As new trArmation is developed. the has been completed satisfactorily.

!gni!!cantly reduccd frem those . (vt) A change which either may result Cocmission will rafine these samples beheved to have been present when the in some increase to the probability or and add new examples. in keeping with beanse was issued.

the standr.rds in i 5052 of the interim conseqt ences of a previously analyzed final nale-end. If necessary,it will P' ' accident or ma reduce in some way a tghten the standards themselves. Con d Y b*! j sa e margin ut where the results of the hane are, clearly within all The Commission has left the pro nd Slgumcast Hatards Considmtions Are rule intact to the extent that the r Wed Below meptahtuta wnh nepecuo the states standards with respect to the system or component specified in the Unless the specific circumstances of a meaning of "no algnificant staards Standard Review Plan: for example, a Ucense amendment request, when . change msulting from the application of censideration." Tne standeeds in the meascred against the standards in interim f.nalrule are substantially a smallrefinement of a previously und 6 50.92. lead to a contrary conclusion calculadonal model or design method, idenucal to those la the prtvosed rule, then, pursuant to the procedures in though the attendant language in new (vti) A change to ranks a Ucense I 50S1, a proposed amendment to an conform to changes in the regulauona.

! 50 92 as well as in l 50.58 has been operaung Ucense for a facility licennd revssed to make the deterrn! nation where the licenu change rnults in vny under i 50.2t(b) or i 50.22 or for a testep minor changes to facilltv opersbons es sf ar to ute and understand.To facility willlikehr be found 4 involv nc clearly ta keeping with the regulauons, sup; lenient the standards that an being signlHeant hazards considerausna. if incorperated into the Com=]selon's (vill) A change to a license to ref)tet a operation of the facility in accordance minor adjustment in ownership shans regulsuons the ruidance embodied in with the proposed amendment involves

. the examples wd3 be referenced in tha among co-owners alteady shown la the only one or more of the.foUowing: licensa.

.