Text

Proposed Tech Specs 3/4.7.K & 3/4.8.C Re Issues Resulting from Comeds Efforts to Reconstitute Design Basis of Chrs
	ML17187A799
Person / Time
Site:	Dresden
Issue date:	02/17/1997
From:	; COMMONWEALTH EDISON CO.
To:	;
Shared Package
ML17187A798	List: ML17187A797; ML17187A799; ML17187A800; ML17187A801; ML17187A802; ML17187A803; ML17187A804; ML17187A805;
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--~.* .ATIACBMENT C REVISEDTECHNICAL SPECIFICATIONS AND TECHNICAL SPECIFICATION BASES PAGES "1** 'i Page Number 3/4.7-16 3/4.7-17 J/4.8-5 B 3/4.7-5 B 3/4.7-6

(' ~-- *....

I* ,-'"; *"' -*.......... ~. -**~ CONTAINMENT SYSTEMS Suppression Chamber 3/4. 7.K

3. 7 - LIMITING CONDITIONS FOR OPERATION

4. 7 - SURVEILLANCE REQUIREMENTS K. Suppression Chamber K.

Suppression Chamber The suppression chamber shall be OPERA!3LE with:

1. The suppression pool water level between 14' 6.5" and 14' 10.5",

qs

2.

A suppression pool maxi water temperature of s °F during OPERATIONAL MOOE(s) 1 or 2, except that the maxi!l"um average temperature may be permitted to increase to:

a. s~ing testing which adds heat to the suppression

b. ~THERMAL POWER s1 % of RATED THERMAL POWER.

c. s~themains~~am line isolation valves closed following a scram.

3.

A total leakage between the suppression chamber and drywell of

_.. less than the equivalent leakage - through a 1 inch diameter orifice at a differential pressure of 1.0 psid. APPL! CABILITY: OPERATIONAL MOOE(s) 1, 2 and 3. ACTION* 1. With the suppression pool water level outside the above limits, restore the water level to within the limits DRESDEN - UNJTS 2 & 3 3/4.7-16 The suppression chamber shall be demonstrated OPERABLE:

1. By verifying the suppression pool water level to be within the limits at least once per 24 hours..

2.

At least once per 24 hours by verifying the suppression pool average water temperature to be :s:~F. except: ~

a.

At least once per 5 minutes during testing which adds heat to the suppression pool. by verifying the suppression pool average water temperature to be :s:@°F. l@I)

b.

At least once per hour whe_n suppression pool average water temperature is ~ @"£.by verifying: I l<fil.

c.

1)

Suppression pool average water temperature to be

s: @°F. and..

2) THERMAL PE>WER to be s 1 %

- -of RATED THERMAL POWER after suppression pool average water temperature has

exceeded Ql!F for more than 24 hours. L@

At least once per 30 minutes with. the main steam isolation valves closed following a scram and suppression pool average water tern rature > F. by verifying suppression pool average water temperature to be s~~ '{§) Amendment Nos. ~ I I. I

.. :-=....:.*.* *---- ~--.:-.... _ ~-~.*: . *:.~.:.:~_=}?.:::~~-.-.:~_:.:_._* *- CONTAINMENT SYSTEMS Suppression Chamber 3/4.7.K

3. 7 - LIMITING CONDITIONS FOR OPERATION

4. 7 - SURVEILLANCE REQUIREMENTS

- -I within 1 hour or be in at least HOT SHUTDOWN within the next 12 hours and in COLD SHUTDOWN within the following 24 hours.

2. In OPERATIONAL MODE(s) 1 or 2 with the suppression pool average water temperature >

F, except as permitted above, restore the average temperature to s@"F within 24 hours or reduce THERMAL POWER to s 1 % RATED THERMAL POWER within the next 12 hours.

3.

With the suppression po I average water temperature > °F during testing which adds heat to the suppression pool, except as permitted above, stop all testing which adds heat to the suppression pool and restore the average temperature to s@=F wjthjo @ 24 hours or reduce THERMAL POWER to s 1 % RA TED THERMAL POWER within the next 12 hours.

4. With.the suppression pool average**..

water temperature.>~ immediately place.the reactor mode switch in the Shutdown position and operate at least one low pre~sure coolant injection loop in the suppression pool cooling mode.

5.

With the suppression average-(j~o) water temperature*> °F, depressurize the reactor pressure vessel to < 1 50 psig (reactor steam dome pressure) within 12 hours. DRESDEN - UNITS 2 & 3 3/4.7-17

3. Deleted.

1.--

.* -~.,.

4. Deleted.*

5. At least once per 18 months by conducting a drywell to suppression chamber bypass leak test at an initial differential pressure of 1.0 psid and verifying that the measured leakage is within the specified limit. If any drywell to suppression chamber bypass leak test fails to meet the specified limit, the test schedule for subsequent tests shall be reviewed and approved by the Commission.

If two, consecutive tests fail to meet-the specified limit. a test shall be performed at least every 9 months until two conseci.Jtive tests meet the specified limit, at which time the 18 month test schedule may be resumed.

Amendment Nos. 152 & 147

CONTAINMENT SYSTEMS B 3/4. 7 ( BASES and de-inerted as soon as possible in the plant shutdown. As long as reactor power is below *1 s%

of RATED THERMAL POWER, the potential for an event that generates significant hydrogen is low and the primary containment does not need to be inert. Furthermore, th.e probability of an event that generates hydrogen occurring within the first 24 hours of a reactor startup or within the last 24 hours before a shutdown is low enough that these windows, when the primary containment is not inerted, are also justified. The 24 hour time frame is a reasonable amount of time to allow plant personnel to perform inerting or de-inerting.

3/4.7.K Suppression Chamber The specifications of this section ensure that the primary containment pressure will not exceed the design pressure during primary system blowdowh from full operating pressure. 1'""*e..f A> The suppression chamber water provid s the heat sink for the reactor coolant system energy release following a postulated rupture of the system. The suppression chamber water volume must absorb the associated decay a d structural sensible heat released during reactor coolant system blowdown from - Since all of the gases in the drywell are_ purged into the suppression chamber air space during a loss of coolant accident, the pressure of the liquid and gas . must not exceed the suppression chamber maximum pressure. The design volume of the suppression chamber, water and air, was obtained by considering that the total volume of reactor coolant is discharged to the suppression chamber and that the drywell volume is purged to the suppression chamber. An allowable bypass area between the primary containment and the drywell and suppression chamber is identified based on analysis considering primary system break area, suppression. chamber effectiveness, and containment design pressure. Analyses show that the maximum allowable bypass area is equivalent to all vacuum breakers open the equivalent of J ti 6 inch at all points along the seal surf~ce of the disk~. _;;;:-. *,.,~: ~*.. * - * * * >> *

Using the minimum or maximum water levels given in this specification (as measured from the bottom of the suppression chamber), primary containment maximum pressure following a design basis accident is approximately 48 psig,.which is below the design pressure. The maximum water level results in a downcomer submergence of 4 feet and the minimum level results in a submergence approximately 4 inches less.'* If it becomes necessary to make the suppression chamber inoperable, it is done in accordance with the *requirements in Specification 3.5.C.

OM~~< 2.4 ~11.."5 Because of the large volume and thermal capacity of t s ppress1on poo, the level and temperature normally change very slowly and monitoring these parameters is sufficient to establish any trend. By requiring the suppression pool temperature to be more frequently monitored during periods of significant heat addition, the temperature trends will be closely followed so that appropriate action can be taken. he re ement or an external visual->----. exammat1on o owing a event w ere potentially

loadings could occur provide ssurance age was encountered.

icular atten

ould be focu a on structural DRESDEN - UNITS 2 & 3 B 3/4.7-5
Amendment Nos.

150 & 145 . ~ *-

............ ~*.., .. -.... ***-**-£ -.. -~*

:?-~.:~~... :~~-~..... :~~~z~.. -

. Insert A to page B 3/4. 7-5 I.

safety/reliefvalve.discharges-or from Design Bcisis Accidents (DBAs). This. is the essential mitigative feature of a pressure-suppression containment that_

~0 ensures that the peak containment pressure is maintained below the

maximum allowable pressure for DBAs (62 psig). The suppression pool rnust also condense steam from the High Pressure Coolant Injection turbine system exhaust lines. Suppression pool average temperature, in conjunction with suppression pool water level, *is a key indication of the capacity of the suppression pool to fulfill these requirements.

".:..:_;=~~-[,r..:-:--:*. ~.. . -~..,..

CONTAINMENT SYSTEMS B 3/4.7 BASES v1c1mty o discharge since se are expecte .. :_:*: ~ -: '\\,.. *~ : ..... ~ ~* : ~:_:!.~~0-=:.~:,~*:..-"_<....... *.~~.,,._** -~ t" Under II power operating co amber w* an initial water temperature of 95°F result approximately 145°F: is peak temperature is low eno to provide tomplet~ co ensation via T-quenche (jevices. However, a maximum averages ression pool temperature f 75°F and approximat 2 psi of containment pressure is requir to assure adequate net p ttive suction pressure fo he ECCS pumps during es following certain anal d accidents. *No positiv containment pressure is sure adequate net positive uction pressure for the E S pumps after the first l. cessive steam condensi loads can be avoided if th peak emperature of the suppressio pool is maintained suffici tly low during any period safety relief valve operation for T-quenc r devices. Specifications ave been placed on the en lope of reactor operating conditi s so that the reactor can

depressurized in a timely anner to avoid the regime of potentia high suppression chambe oadings. In addition to th 1m1ts on,
temperature of the ppression chamber pool w er. operating procedures d ine* the action to be taken in the eve a safety or relief valve ina ertently opens or sticks op

. As*a minimum this action shall in ude: (1).use of all available eans to close the valve, (2 nitiate suppression p water cooli

(3) initiate reactor,shutd n, and (4) if*other safety or elief valves are used depress 1ze the reactor. their dischar e shall be separated from th of the stuck-open s relief alve to assure mixing and u
ormity of energy insertion to e pool.

. **~ '_.. *... In conjunction with the Mark I Containment _Short Term Program, a plant uniqL,i~. ~nalysis was_ *~: ~. performed which deni.onstrated_aJactor of.sa.fei'Y.~of at least.two for the.weakest-element-in the.:,.. suppre.ssion chahib~~. support system' and attached pi pi rig. The maintenance of a. dryw.ell- -~~o*:.'t:_;;_ :~-:.. *.: ...... *::.. ~-=:;-. ~:i.~:.:- -~-.. )

suppression chamber differential *pressure and a suppression chambe~ water level co_r.respondin*g to a downcomer submergence range of 3.67 to 4.00 feet will assure the integrity of the suppression chamber when subjected to post-LOCA suppression pool hydrodynamic forces.

-~. 314.7.l Suppression Chamber and Drvwell Spray Following a Design Basis Acddent (OBA). the suppression chamber spray function of the low ____,.* pressure coolant injection (LPCl)/containment cooling system removes heat from the suppression chamber air space and condenses steam. The suppression chamber is designed to absorb the sudden input of heat from the primary system from a OBA or a rapid depressurization of the reactor pressure vessel through safety or relief valves. There is one 100% capacity containment spray header inside the.suppression chamber. Periodic operation of the suppression chamber and drywell sprays may also be osed following a OBA to assist the natural convection and diffusion mixing of hydrogen and oxygen when other ECCS requirements are met and oxygen concentration exceeds 4%. Since the spray system is a function of the LPCl/containment cooling system, the loops will not be aligned for the spray function during normal operation. but all components required to operate for proper alignment must be OPERABLE. DRESDEN - UNITS 2 & 3 B 314.7-6 Amendment Nos. 152 & 147

. ::.......... ----~ *; - -. *- ... *~;;----~.-

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-~-~ :'-.. l-~.,;_-_s(.. ff-:;.~.. :.:~q~~;~ ::--~~-~~~~~4'.~-.-~tt*:~.. *-., ~:

.. --*....... *~-.

---~~... --:~

........ :~. - -*.-.:::t""":Y.:'.::~.--_::*-...::::~ .. ~~' '*,. Insert B to page B 3/4. 7-5 A limitation of the ;~ppression p~ol ~*~-erage.tempe~ature. i*~.-*;;"'Q1~i1;dt°ci:>>-":~--"'..,* * .:_ -}_}f:~=~v:.:*- - ensure that the containment conditions' assumed in the safety analys"es' 'are- '... *:.::::.' *- met.--*-This limitation subsequently ensures that peak primary containment --~:-~jj::::.};:.~ ~-;~- * - pressures and temperatures do not exceed maximum allowable values'** during a postulated OBA or any transient resulting in heat-up of the**'."'.. suppression pool. The postulated OBA against which the primary containment performance is evaluated is the entire spectrum of postulated pipe breaks within the primary,containment. Input to the safety analyses include initial suppression pool water volume and suppressior:i. pool *..

temperature. An initial pool temperat

__ ure of 95 °F is assumed for these.. analyses. Reactor shutdown at 110 °*F and vessel de-pressurization_ at a"*

pool temperature of 120 °F are also assumed for these analyses.*,:.The limit of 105 °t= at which testing is terminated, is not used in the safety *analyses because OBAs are assumed not to initiate during plant testing.

The suppression pool is also designed to quench the energy from*~:.':<:.:C:.~..::_c_.... - *,:~*c~--~:;, safety/relief valve discharges. *Thus, the safety analyses related to the - * '. --- - '*::*' *--~---.. *. - suppression pool must consider all accident scenarios that involve.. safety/relief valve actuation's. The limit for the suppression pool avera'ge temperature is set low enough to preclude local boiling due tc:l"-safetytrelief".'"~ *-~-~~:--::-_,.,..... ?*'-~:-; valve discharge via the T-quencher devices. In accordance with GE NEOO:- _. '*. 30832, local suppression pool temperature limits are not required because *

,_,::;.,e_"'Ii_;>:~:::~:.::.:,:._... -

the emergency core cooling system pump inlets are located* b"e1o'w'_'t6'e':,. *_

--.: .=:---- :~ -..

.,~l~~n ~ti!'":~*~=,~~h.f r~~ *,*.*.~;*. '.' c~,h;F'~.~~~ ;~:<~;;~~I~~:~~~~!~ The available net positive suction head may be less thanthat required*by*,s.*:-;~::*"-o:::~r.~~'~;.:----~-:-*=*-*;: the emergency core cooling system pumps; thus *there is dependency on~*: __.:'... -**" * '"~:--_ r~--***.. --4*~ * ' -*~-~~~,.. ~f--..*

I containment over pressure during the accident injection phase'.;'.--:*~~?T:7FF'. *'

"*~*,-:;,,..-;:-,- .'i.:* 'I. - ---~. :------ ~ -... ~;.* _~...:- \\.. ,.r,.* "i"*" - if_~*-**

~ *-* PLANT SYSTEMS UHS 3/4.8.C 3.8 - LIMITING CONDITIONS FOR OPERATION 4.8 - SURVEILLANCE REQUIREMENTS ... -* - C. -. Ultimate Heat Sink.,).;;-~,~i-~~s, *Jo;._*~-~~~*-_-.::,.;- ;. - '.,: C. Ultimate Heat Sink - *.-*'.. -.. *'-- *-:. *, * *,.,

t I

The _ultimate heat sink shall be OPERABLE with: ..:::-~ *: :* ~->_.. ;::::.-::~d~.*;<.**-*,.- *.. *c

1. A minimum water level at or above elevation 500 ft Mean Sea Level, and

2.

.q;.~rage water temperature of

-~ APPLICABILITY: OPERATIONAL MODE(s) 1, 2, 3, 4, 5 and*. ACTION: With the requirements of the above specification not satisfied:

1.

In OPERATIONAL MODE(s) 1, 2 or 3,.

- be in at least HOT SHUTDOWN within ..--~~ 12 hours and in COLD SHUTDOWN ":*: -~ '-~ within the next 24 hours.:_.~,~**-*.-.l:

-t-declare the diesel generator cooling '.

.

water *system inoperable and take the

.

ACTION required by Specific'ation

. 3.8.8.

3. In OPERATIONAL MODE*, declare the

. diesel generator cooling water system . - inoperable and take the ACTION required by Specification 3.8.8. The provisions of Specification 3.0.C are not applicable. The ultimate heat sink shall be determined A* *.OPERABLE at least once per 24 hours by-;,-* verifying the average water temperature and water level to be within their limits. ./ -. '". ~* .,_,:., **x: . J

--r:2~.. :;_~;~~~-;*_~[~~~~~;:;3~%.:::.~l::-~*..

.:~:. :_.;* :~.:-::...

.. -.... - "--:: :*. -*. -~,,,.. :--......, :-.. :.. When handling irradiated fuel in the secondary containment, during CORE ALTERATION(sl. and operations with a potential to drain the reactor vessel. DRESDEN - UNITS 2 & 3 3/4.8-5 Amendment Nos. 152 ~ 147 .. ~ *-

CONTAINMENT SYSTEMS 3.7 - LIMITING CONDITIONS FOR OPERATION K. Suppression CJ:lamber Thesuppression chamber shall be OPERABLE with: 1. The suppression pool water level *. .between 14' 6.5" and 14' *10.5",

2. A suppression pool maximum average
.:.. water temperature of.s 9 5 °F during OPERATIONAL MODE(s) 1 or 2, *except that the maximum average temperature

.may be permitted to increase to: I . a. *:s.105°F.during testing which . adds.heat to the suppressiO!l pool. I

b. *. s 110°F: with THERMAL..

. *.C.

POWER s 1 %.of RATED

.THERMAL POWER, ~**.. ~... s ;*20°F with the main steam line isolatio'n val~es closed following a scr~m*.. <3. *: A total leakage between ttie. * *... suppressio_n chamber and drywell of.. *. less than the: equivalent'leakage :.... through *a *1. inch ;diameter. orifice ai.a..... differential pressure *of l.O psid. *

APPLICABILITY:

.: *. * - OPERATIONAL MODE(s) *1,.'2 and i.

f

. **~... ~ ACTION: .. ~~.. ~.... _:,~

- ~;--:-_:;*}*.-.. l~.':
1.. With.the suppression pool,'!'later.'level

.*

outside*ttie above Hmits.".restore the..

Suppression Chamber 3/4. 7.K 4.7 - SURVEILLANCE REQUIREMENTS K. Suppression Chamber The suppression chamber shall be demonstrated OPERABLE: 1.. By verifying the suppression pool water level to be within the limits at least once per 24 hours.

2.

At least once per 24 hours by verifying the suppression pool average water temperature to be s95°F; except:

a.. At least once per 5 minutes during testing which adds heat to the suppression pool, by verifying the suppression pool average water temperature to be s-1 O 5 ° F.

b.

At *least once per hour when .. suppression pool average water .. temperature is <:: 95°F, by verifying:! . ~ )

Suppression pool average water temperature to be s 110°F, and I

2).THERMAL POWER to be ~*.1 %

of RA TED THERMAL POWER after suppression pool average

water temperature has*...

exceeded 95 °F for more than I

24 hours.

c. *At least.once per 30 minutes with

the main steam isolation valves

. closed following a scram and suppression pool. average water temperature > 95°F, by verifying

suppression pool average water
temperat0re to be s 120°F.

. ';-..-... ~. . ' *... :... - -~ ":.

~

..~. ' .~ 4:-

CONTAINMENT SYSTEMS 3.7 - LIMITING CONDITlo'NS FOR OPERATION

1 within 1 hour or be *in at least HOT
sHUTDOWN within the next 12 hours and in COLD SHUTDOWN within the following 24 hours.

'2.. *In OPERATIONAL MODE(s) 1 or 2 with

. the*suppression pool average water temperature > 95°F, except as..

permitted above, restore the average ~. I

temperature to ~95 °F within 24 hours
or reduce THERMAL POWER to ~ 1 %

RATED THERMAL POWER within the next -12 hours. ~- : * * ::*:3:

With the suppression pool average

. '.I ..

water*temperature > 105 °-F during testing which adds heat to the s.uppression pool, except as permitted
*.:;_ ***,:*.-.' aho.ve,"stop.all testing which adds heat

\\' *:*'.,to.the suppression pool-and restore the L*.. ave.rage, tern perature to ~ 9 5 ° F within.. 24 hours.or reduce THERMAL POWER to ~ 1 % RA TED -THERMAL POWER.

within. the.next* 12 hours.

4>. With.the suppression pool. average

.~.- * - <-**. J
<:water temperature :>1.io~F..

"' * * **.* **: > * * *

immediately place the reactor mode
* * *,....... ~ *
**.*." :**.:switch in.the ~shutdown position and
* *. *~*-

operate at least one low pressure -* * * * *., *--'.--~.:.. :*~. c.oolant inject.ion lo9p iii the-.sUppresSi6n *

*:.. '.-~ :'.poo_I cooling mode.

5:*.With._the' supp.ression pool average

.,, :.'***if *:z

~ *.. *, "water temperature > 120 ° F,. *

.,.*' : :.:de pressurize. the reactor.pressure vessel

~:::~..:<<.;:-<'C'~*to -C:::t-50 psig (reactor steam dome..
. :.. :;.. *;.' *. ~-: pressure) within* 12 hours. :*..:'
_ -_ ~

~..... -;i.-*~* !. **.*..,.* **** ;* -~*. *.*.. ..*_:--;*.* * ** ~~-:.:. ,* -~* -\\* '.: _:-~-:.....,_~~ .*.:*~:- t""-:..

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Suppression Chamber 3/4. 7.K

4. 7 - SURVEILLANCE REQUIREMENTS

3.

Deleted.

4.

Deleted.

5.

At least once per 18 months by conducting a drywell to suppression chamber bypass leak test at an initial differential pressure of 1.p psid and verifying that the measured leakage is within the.specified limit. If any drywell to suppression chamber bypass leak test fails to meet the specified . limit, the test schedule for subsequent tests shall be reviewed and approved .by the Commission. If two consecutive tests fail to meet the specified limit, a .test shall be performed at least every 9 *months until two consecutive tests meet the specified limit, at which time the 18 month test schedule may be. *

resumed.
~ \\. *~~.: ~;: "...... : *-=..... **. r: :*.. :*;'".

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_,-:::_<f'.--:',,;,'f:'~~*:-J.;"~:..:~ORESD.EN>~UNITS~2.& 3 *...::.:_.:*;~"'.*"*:..*.: --:3/4.7~11*. _,:. * * -~ Amendment Nos:

~~~t{i,;f~.~f
,~~1~~i~.~-'_~;~?~: '..f ".:~~-:-f~~~i1:~~h_ '.*,.<;. ~ :... *.. -.....

l ***

CONTAINMENT SYSTEMS B 3/4.7 BASES and de-inerted as soon as possible in the plant shutdown. As long as reactor power is below 15% of RATED THERMAL POWER, the potential for an event that generates significant hydrogen is low and the primary containment does not need to be inert. Furthermore, the probability of an event that generates hydrogen occurring within the first 24 hours of a reactor startup or within the last 24 hours *before a shutdown is low enough that these windows, when the primary containment is

not inerted, are also justified. The 24 hour time frame is a reasonable amount of time to allow

~la.nt personnel to perform inerting or de-inerting. . 3/4.7.K

:Sup'nressjon Chamber

,.. -The specifications of this.section ensure that.the primary containment pressure will not exceed the. -*design pressure duri~g primary* system blowdown from full operating pressure. . The ~uppression chamber water *provides the heat sink for the reactor coolant system energy

releas~ following a :postulated rupture.of the system. The suppression chamber w~ter volume must*

. : absorb the* associated decay and structural sensible heat released during reactor coolant system -.blowdown from *sa.fety/relief valve discharges or from Design Basis Accidents (DBAs). This is the

essential mitigative feature o*f a pressure-suppr.ession. containment that ensures.. that the peak
- *
containment pressure'is maintained below the maximum allowable pressure for DBAs (62.psig).

.* _/ T~e suppressio.n_pool must also condense *steam from the High Pressure Coolant Injection turbine . system exhaust lines. Suppression *pool average temperature, in conjunction with suppression pool

water level, is a key indication of the* capacity of the suppression pool to fulfill these requirements.

. Since all-of the gases in.the drywell are purged into the suppression chamber air space during a loss of" coolant *accident, the* pressure of the liquid and gas must not exceed the suppression .. *.: *chamber maximum pressure>.The design volume of the suppression chamber, water and air, was * .. *,*obtained by considering that the: total.volume of reactor coolant is discharged to the suppression.

' : **.,... chamber a_nd that the dryv1lell volume is purged to the suppression chamber.

~

.\\.: -* -::.* -* - ' -..
_:;~:~*::_;*_-Ah. ~llowable **i;y~ass *.a~ea,,b~t~*ek*~ the.primary c~ntainment and the drywell and suppression

. chamber is identified. based on.analysis considering primary system break area, suppression chamber effectiveness, arid :containment design pressure. Analyses show that the maximum allowable 'bypass area is.. equivalent lO all vacuum breaJ<ers open the equivalent of 1 /1 6 inch at all points along the seal surface of. the disk..

. i 1

'* -~

._'"',, r

~.. . :Using the minimum.or niaximunf:water levels given in this specification (as measured from the

bottom of the* suppression chamber),: primary containment maximum pressure following a design

,... :..

_f>asis**acci9enfis approxima~ely 48.psig, w.hich is below the design pressure. The maximum water
.-.. :,_. ~-~,.\\

1eVel resUlts.in ci*doW*ncOmer sUbni0fgence of 4 feet"and the minimum level results in*a ~J:::-:*-::.<-c* ~-. * .. subrriergenc"e.approximately.4.irwhes less:>lf it.becomes necessary to make the suppression ..,.:*._:-._,~*~,::~(,~: c.hamber inoperable, it.. is done in_.accorda_ncewithtl:te requ.irements in Specification 3.5.C. *

- An:iendment Nos. *

.,.. _.\\;:...' _.

.. t CONTAINMENT SYSTEMS B 3/4. 7 BASES Because of the large volume and thermal capacity of the suppression pool, the level and temperature normly and monitoring these parameters once per 24 hours is sufficient to establish any trend. By requiring the suppression pool temperature to be more frequently monitored during periods of significant heat addition, the temperature trends will be closely followed so that appropriate action can be taken. A limitation of the suppression pool average temperature is required to ensure that the containmen conditions assumed in the safety analyses are met. This limitation subsequently ensures that peak

primary containment pressures and temperatures do.not exceed maximum allowable values during a postulated OBA or any transient resulting in heat-up of the suppression pool. The postulated
OBA against which the primary containment performance is evaluated is the entire spectrum of

- postulated pipe breaks within the primary containment. Input to the safety analyses include initial suppression pool water volume and suppression pool temperature.* An initial pool temperature of .95 °F is assumed for these analyses. Reactor shutdown at 110°F and vessel de-pressuriz.ation* at a

pool temperature* of 120°F.are also assumed for these analyses. The limit of 105 °F at which
- testing is terminated, is not used in the safety analyses because OBAs are assumed not to initiate

. during plant testing.

- The suppression pool is also designed to-quench the e*nergy-from safety/relief ~alve discharges.

.

Thus, the safety analyses related to the suppression pool must consider all accident. scenarios that
involve safety/relief valve actuation's: The. limit for the suppression pool average temperature is set low enough to preclude iocal boiling due to safety/relief vcilve discharge ~ia the T-quencher.

devices. In accordance with GE NE00-30832, local suppression pool temperature limits are not required because the emergency core cooling system pump inlets are located below the elevation

Of the. quenchers.
The available 'net positive suction head mciy be less.than *t~at required by the emergency core

,.*cooling system pumps, thus there is dependency* on containment over pressure during the accident . injection phase.

_* 1n. conjunction with the Mark I Containment Short"Term Program, a plant unique analysis was performed which demonstrated a factor of safety of at least two for the weakest element in the suppression chamber support system and attached piping. The maintenanc*e of a drywell-

.-suppression chamber differential.pressure and *a suppression chamber water level corresponding to .**.-:a downcomer submergence range of.'3.67 to 4.:00 feet will assure, the integrity -of the suppression*

chamber when subjected ~o post-LOC~ suppression po~I hydrodynamic forces.
..... -...:... :~ *...,... '

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'= *.

~

CONTAINMENT SYSTEMS B 3/4. 7 BASES 3/4.7.L Suppression Chamber and Drywell Spray Following a Design Basis Accident (OBA), the suppression chamber spray function of the low pressure coolant injection (LPCl)/containment cooling system removes beat from the suppression chamber air space and condenses steam. The s~ppression chamber is designed to absorb the

sudden input of heat from the primary system from a OBA or a rapid depressurization of the reactor pressure vessel through safety or relief valves. There is one 100% capacity containment spray :header inside t!ie suppression chamber.

Periodic operation of the suppression chamber and drywell *sprays may also be used following a OBA to assist the natural convection and diffusion mixing of hydrogen and oxygen* when other ECCS requirements are met and oxygen concentration exceeds 4%. Since the spray.system is *a function of the LPCl/containment cooling sy~tem, the loops will not be aligned for the spray function during normal operation, but all components

required to operate for proper aiignment must.be.OPERABLE.

~*.. - '

. ~.

. ~. ~... . ~. - -\\~.. --. '.:.... :~ *:.:~ ~-. ~... -.;; *-*~- -, . "'?,: -~ ~.:. _ _..* _.r-. -~.

PLANT SYSTEMS 3;8 - LIMITING CONDITIONS FOR OPERATION C. Ultimate Heat Sink The ultimate heat sink shall be OPERABLE with:

1. A minimum water level at or above elevation 500 ft Mean Sea Level, and 2.. An average water temperature of

1
~95°F. *
APPLICABI LIIV:

O_PERATIONAL MODE(s) 1, 2, 3, 4, 5

and**.

. ' ACTION: ~.

_"With. the requirements of the.above
.:.~specification not satisfied:

. 1*. In OPERATIONAL MODE(s) 1, 2*or 3,* . be in at least HOT SHl,JTDOWN within

12 hours and in COLD SHUTDOWN within tht;i next 24 hours.*
* -* 2:.. In OPERATIONAL MODE(s) 4.or 5 *:

.declare the diesel generator *Cooling water system inoperable*and take the ACTION required by Specification *** '3.8:8.

3.

In OPERATIONAL MODE *,declare the '*_: diesel generator cooling 'water ~ystem'

.inoperable and take the ACTION*

required by Specification 3.8.8. The _::_*--. _:provisions of Specification 3.0:C.are - *.*:.*.. :not -?l.PPlicable.. - ~ UHS 3/4.8.C 4.8 - SURVEILLANCE REQUIREMENTS C. Ultimate Heat Sink The ultimate heat sink shall be determined OPERABLE at least once per 24 hours by verifying the average water temperature and water level to be within their limits.

ATTACHMENTD CALCULATIONAL LISTING DESCRIPTION PROPRIETARY STATUS

1. DRE 97~010 Dresden LPCVCore Spray Non-proprietory NPSH Analysis post DBA-LOCA - long term - Design Basis, Rev. 0 (att. G, reference l)

2. DRE.97-012 Dresden LPCI/Core Spray Non-proprietory NPSH Analysis post DBA-LOCA-short term - Design Basis/GE SIL 151 (att. G, reference 2)

' 3. DRE 96-0214 Minimum available Non-proprietory CCSW flow to maintain a 20 psi differential between LPCI and CCSW heat exchanger (att. G, reference 3) 4, GE-NE-T23000740-l Dresden Station Non-proprietory.

Nui::Iear Power Station Units 2 and 3 Containment Analyses of the DBA~LOCA based on long tenn LPCVContainment Coofing System* configuration of one

. LPCVContainment Cooling Pump and 2

ccsw pump. (att. G, reference 4) 5 *. Containment Pressure and Temperature. '*'*

Non-proprietory Analysis for Dresden NPSH Ev~luations -: 2

, CCSW pump flow of5400 gpm (att. G reference 5) *

. *~ : 6. Containment Pressure and Temperature Non*proprietory . Analysis for Dresden NPSH Evaluations:* l LPCVContainment Cooling Pump Flow of 5000 gpm. * ~ CCSW pump flow of5000. gpni (att. G;reference 6)

7. Containment Pressure and Temperature*..

Non-proprietory Analysis for Dresden NPSH Evaluations, . short.,.term (600 seconds) containinent... 2:'.

response, 4-LPCVContainment Coolitig * *: * )-

Piimp Flow of 5150 gpm per pump, 2-CS Pump Flow of 5800 gpm per pump (att. G;

reference 19) f

~'.'!"".<

~\\~ -

-.... --~-. REV. 0 0 0

r.

DATE 2/13/97 2/13/97 2/6/97 12/96 11/18/96 12/26/96 1128/97 '- ~-....

.r--_. '::i

- - ~~~;...
ATTACHMENTE REVISED UFSAR l*'"'.,

..:.... :~ ~';..

-t***

VOLUME 3,.

3 3

3

. *~

- -:3 _

'* __..i_,

.~: 3 3.-

. ~-- !. tJl'SAR CHANGE DFL 97011 SBORT-'l'EJUd/LONG-~ CONTAZNMENT PIUl:SSORE AND TEMP SECTION SECTION 6.0, LIST 'OF TABLES SECTION 6~0, J,IST OF .. FIGURES 6.2.1.3.2

- o :6
2.1, 3
2, 1 (new) 6.2.. 1.3.2.'2 (new)

'6.2.1. 3.-3 ~:t'.* 6

2 ; 1. 3
3.. 1
6. 2.1. 3 ;3. 3

~.*.. -*-t. :. :. '*, -~ .f PARAG~ N/A

N/A 1

N/A N/A .1, 3 to

a 1 to *4
1 to-.3.

... ~ PAGE 6-iv 6-v 6.2-19 6.2-19 6.2-24 6.2-25 6.2~26 . *6.2-27 . 6.2-27 .6.2-27 .6.2~28 DESCRIPTION/REASON FOR CHANGE Revised title of Table 6.2-3, added Tables 6.2-3a and 6.2-3b, deleted Table 6.2-6 and replaced Tables 6.3-17 . and 6.3-18 to reflect new containment temperature and pressure responses. Added Figures 6.2-19a, 6.2-19b, 6.2-20a, 6.2-20b, 6.2-20c and 6.2-20d to reflect new containment temperature and pressure responses *. Added a description to identify the short term and long term containment response to a Loss of Coolant Accident(LOCA). This change is a result of the Licensing Amendment to reevaluate LPCI and Core Spray pump requirements. Added subsection to identify discussion* for original containment short term response to a design bases accident. This change is a result of the Licensing Amendment to reevaluate LPCI and Core Spray pump requirements. Added new subsection which covers the new evaluation for the containment short term response to a-design bases accident (DBAl LOCA for minimum NPSH available. The discussion covers the worse case condition for the first 600 seconds of the accident. This change is a result of the Licensing Amendment to reev~luate LPCI and Core Spray pump requirements.*

Renumbered subsection to *6.2.1.3.2.3.to maintain consistency in the LOCA discussion *. Included statement that LPCI and core spray.will help remove the noncondensible gases during the first 10 minutes (paragraph 1).

In paragraphs 3 through 8,.referenc,es to the.original licensing basis for long term cooling were removed to reflect the current licensing basis being initiated for the long term DBA-LOCA. *This* current.basis reflects the worse case condition for LPCI and core spray operation and its acceptability. 'This change is a result of the Licensing Amendment.to reevaluate LPCI and Core Spray pump requirements. Subsection and.references *to the original licensing .basis for long term cooling were removed to reflect the current licensing basis.being initiated for the* long term DBA-LOCA. *This change is a result of the Lice~sing Amendment to reevaluate LPCI and Core Spray .pump requirements. Subsection and.references to the origin~! licensing basis for long term cooling were removed to reflect -the current lic~nsing basis being initiated for the long term DBA-LOCA. This change is a res.ult of the. Licensing Amendment *to reevaluate LPCI and Core Spray pump requirements. Subsection and references to the original licensing basis for long term cooling were removed to reflect .the current licensing basis being initiated for the long term.DBA.,.LOCA. This *change is a result of the Licensing Amendment to reevaluate LPCI and Core Spray pump requirements *

subsection*and *references to the original licensing

.basis for long term* cooling were removed l:o reflect the current licensing basis being in~tiated for the long term DBA-LOCA. This change.is a result of the Licensing Amendment to reevaluate LPCI and Core Spray pump requirements. I.

3 3 3 3.

3

3 3

3 U!'SAR C&ANCD: DJ!'L 97011 SBOR'l'-TJCIQ(/LONG-TZIQd CON'l'AXNMl!:NT PRESStJIU!! AND '1'!:MP 6.2.2.2 6.2.2.3.2 Table -~.2-3 .Table 6.2-3a... 6.. 2~3b .Table 6. 2-*6

.Table 6.2-7.

Table. 6~2-19 *.... _.,._ Table .6.2-20*

.i: ; *.

...:.._.~..:;.:_..::* .-*:.**:r** 8 & 11 7 N/A N/A NIA

F _,._.,

N/A

,f 6.2-59

.* 1 New

.l to.4 '1 N/A 6.3-77 "6. 3-78 Removed heat exchanger references to maximum suppression pool temperature of 170°F in Paragraph 8. This is bein9 removed since the current licensing basis being initiated for the long term DBA-LOCA sets this temperature at 176°F. In paragraph 11, unnecessary information on tube replacement for the LPCI heat exchanger is being removed to enhance the section description. The loss of 6% heat transfer addresses both plugged and replaced tubes. Added ECCS strainer design information for design consistency and to ensure incorporation into the UFSAR. This information was included in UFSAR pending change DFL-96140. Revised Table 6.2-3:which documented the original DBA-LOCA design parameters to reflect the design parameters from the new evaluations performed for the containment short term and long term responses to a DBA-LOCA, including minimum NPSH available. This change is a result of the Licensing Amendment to reevaluate LPCI and Core.Spray pump requirements. Added Tables 6.2-3a and 6.2-3b to reflect the design parameters from the new evaluations performed for.the containment short term and long term responses to a .DBA-LOCA, including minimum NPSH available. This change is a result of*the Licensing Amendment to reevaluate LPCI and Core Spray pump requirements. Deleted Table 6.2-6 as it relates to safety relief valve discharge device limitations (Section

6. 2.1. 3. 6. 4. 3) which were removed to reflect the current licensing basis being initiated for the long term DBA-LOCA.

This change is a result of the Licensing Amendment to reevaluate LPCI and* core Spray pump requirements. Added *containment cooling specifications for various LPCI and CCSW heat exchanger flows as related to the

new evaluations performed *for the containment short term and long term responses to a DBA-LOCA, including

.minimum NPSH available. The change to this*table initiated under VFSAR change DFL 96140 is being deleted with this design change *. This change is a result of the Licensing Amendment to reevaluate LPCI

and Core Spray pump requirements.

Initiated Tables 6.2-19a and 6.2-19b to reflect.the new suppression pool temperature and suppression chamber pressure responses evaluated for the .containment short term response to a design bases accident (DBA) LOCA for minimum NPSH -available. The discussion covers the worse case.condition.for the first *600 seconds of the accident.. This** change is a

result of the Licensing Amendment to reevaluate LPCI and Core Spray. pump requirements.* **

Initiated Tables *6.i-ioa, 6.i-20b, 6.2-20c and 6.2-20d to reflect the new suppression: pool temperature and suppression chamber pressure responses evaluated for the containment long term response to a design bases accident (DBA) LOCA for minimum NPSH available. The -discussion covers the worse case condition after 600 seconds into the accident. This change is a result of the.Licensing Amendment to reevaluate LPCI and Core Spray pump requirements.

Deleted the design description (Insert G) for NPSH

.. issued under DFL 96141 and added a new Insert G description* to identify the short term and long term

- - *containment response to a Loss of Coolant

~.: .*

.-:.<_~- Accident (LOCA)

This change is a result of the

,.. :~ -* ***., .:'.*.'**;;:z;~}'{Vt~:.\\;_.:*:r..:~i :;: *,.... ~ *::.: *::: '..:_-~_ * * * ~t:n~~~~i::~~=~t to reevaluate LPCI and Core spray ,._ ________..... ____________________...... ________..... ____________.._. __________...., __________________________________________....u

-~ :*-,

Ul'SAR CHANGE DFL 97011 SBORT-'l'ERM/LONG-TEIQ4 CONTJUNMENT PRESSURE AND TEMP 4 4 4 4-4 4 4 5 5

. '.~ -.. : ' *..

.~: 6.3.3.4.3.1 6.3.3.4.3.2 6.3.3.4.3.3 . 6.. 3

3.:4
3. 4
(New)

Table 6.3-17 Table 6.3"".'18 Figure 6.3-80 Figure 6.3-83 Figure 6.3-89 '9.2.1.3. .Table . :9.2-1.... .;, ~ *. All N/A All N/A All N/A All N/A N/A 'N/A N/A N/A N/A N/A'. N/A "N/A 'N/A N/A ~ 4 -. 9.2.2 N/A.. H/A ~-........ *.*' Deleted the description (Insert G) for NPSH issued under DFL 96141 and added new description (Insert G)to the subsection which covers the new evaluation for the CS/LPCI pump Post-LOCA short term response for minimum NPSH available. The discussion covers the minimum suppression pool pressure required to meet pump NPSH. requirements for the first 600 seconds of the accident. This change is a result of the Licensing Amendment to reevaluate LPCI and Core Spray pump requirements.

Deleted the description (Insert G) for NPSH issued under DFL 96141 and added.new description (Insert G) to the subsection which covers the new evaluation for the CS/LPCI pump Post-LOCA long term response for minimum NPSH available.

The discussion covers the minimum suppression pool pressure required to meet pump NPSH requirements for greater than 600 seconds of the accident. This change is a result of the Licensing Amendment to reevaluate LPCI and Core Spray pump requirements. -Deleted the description (Insert G) for ~SH issued under DFL 96141 and added new description to the subsection which* identifies the NPSK margin available. The discussion covers the pump NPSH requirements and the abilities to throttle the pumps to an acceptable operating condition. This change is a result of the Licensing Amendment to reevaluate LPCI and Core Spray pump requirements. Added new *subsection which identifies the.HPCI NPSH. This information was already in the UFSAR. and is not being changed by the Licensing Amendment to reevaluate LPCI and Core* Spray pump requirements. Deleted table reflecting original design.information. Deleted table reflecting original design 'information and replaced it with a table designating long. term throttling requirements. Deleted.figure reflecting original design information and reissued the figure with the current design information. Initiated a riew"figure reflecting t)le current design information. Initiated a new figure reflecting the current.design information. 'Added design information that*identifies the operation and location of.the.differential pressure control valve for the LPCI heat exchanger and the minimum CCSW flow of 5000 gpm for containment cooling. A change issued under DFL96140 identifying a different flow rate is being deleted by this change. This change is a result of the Licensing Amendment to reevaluate LPCI and Core Spray pump requirements. A change to the table initiated under DFL 96140 <identifying a flow: rate of 5600 gpm is being deleted

The table should only reflect containment cooling
service.water.equipment specifications..This change is a result of the Licensing Amendment to reevaluate LPCI and Core Spray* pump requirements.

f ,.. ~

- ~~--

.~ *** Jli~ii'!~z\\?;~*.~~:£-_ 7 "**.:{;~}fr, **.,... ?:;:~'*ct'.;...**...*. ;._ :....

~... . ~ :".-.. DRESDEN - UFSAR 6.0 ENGINEERED SAFETY FEATURES .LIST OF TABLES S4t"\\Mo.r-y of-Dres~e11 ~e..$u.LT5. 6.1-1 Fracture Toughness Requirements ~--~--~~~~-..:..----- 6.2-1 Principal Design Parameters of Primary Conta.iilment 6.2-2 Materials Used to Fill Drywell Expansion Gap 6.2~3 PMacimt:tm Containment Pressure and Peak Torus Temperature for Variou ~6.2-4 . 6.2-5 Combinations of Containment Spray and Core Spray Pump Operation - Mark I Containment Program Initiated Modifications Assumed Plant Conditions at Instant of Transient Listed for the Plant Unique Load Definition~ 6.2-7 Containment Cooling Equipment Specifications 6.2-8 Reactor Building Air Inleakage 6.2-.9 Principal Penetrations ofPrim;;iry Containment and Associated Isolation Valves 6.2-10 Locked Closed Containment Isolation Valves-* Unit 2 6.2-11 Locked *closed Containment Isolation Valves~ Unit 3 6.2-12 Incremental 30-Day Low Population Zone.Doses From ACAD Operation 6.3-1 6.3-2 6.3~3 . 6:3-4 . 6.3-5 6.3-6 Emergency Core Cooling System Summary Summary of Operating Modes ofEmergency Cqre Cooling Systems Core Spray Equipment Specifications.. ECCS Loading Sequence* LPCI Equipment Specifications. Maximum Expected Jet Pump Leakage Rate Driring LPCI Operation for Design Break* :. 6.3-7 HPCI Equipment Specifications 6.3-8 Total Pressures During Recirculation Line Break 6.3-9 Symbols and Subscripts Used for Blowdown Analysis 6.3-10 Important Experimental Quaptities : 6.3-11 Dresden Reactor Available ECCS Systems per Single Failure. 6.3~12 Dresden LOCA Analysis Results for ANF.9x9 Reload Fuel.. 6.3-13 Dresden 9x9 Limiting Break Event.Times., 6.3-14 ECCS Availability -,Small Break with Auxiliary Power 6.3-15 ECCS Availability - Small Break Without Auxiliary Power ~Q...\\e..."te. 6.3-16* ECCS Availability - Large Break with Auxiliary P.ower f ':.::::Bf !ii?:~ ~::*::~;;;z:z:ll§:@~r:~:3 LJ_et_e..~

control Roo~ HvAC System Component Leilige
6.5-1 Pressu~~.D~~._s.for SBGTS E~aust~ *.

'._2-3ct.

1<e.~.. ?~~Wl~~~*<~~t" <:o'l"thtn_~c..-c."t

,.,.,~l't' st.s

a. 2~3f,- * '.JkA_*:*;F-~c*k.iJ.:"-. e.~* ;He.A..°'r.T"rcvt.5--tie:~ * * ~o-.Te..

.... ~~. ::..'. i.. -=+i---------~----....... ---=====:-:----:---""".""""-"'- ~".\\~~c;.;"T * * * *** <:. :r&.faJ~.t1~~i~t~~~:~~r~{~"f_f.~*~:*t~{: ! -~.. :-.... "'

Figure 6.2-1 6.2.2 6.2-3 6.2-4 6.2-5 6.2-6' 6.2. 6.2-8 6.2-9 . 6;2-10 6.2-11 ..

6.2-12 6.2~13 6;2-14

.. 6.2-15 6.2-16. -. 6.2-17 6.2-18 6.2-19 .;,,6~2-20 6.2-21 . 6.2-22*.:* 6.2-25. 6.2-26 6.2-28 DRESDEN*- UFSAR 6.0 ENGINEERED SAFETY FEATURES LIST OF FIGURES General Arrangement of the Containment Systems Elevation View of Containment Plan View of Containment Suppression Chamber Section - Midbay Vent Line Bay Suppression Chamber Section~ Miter Joint Drywell Thermal Expa.nSion Typical Penetration Joint Resilient Characteristics of Polyurethane Containment Sand Pocket and Sand Pocket Drain System Dresdep Vacuum Breaker Assembly* Dresden Vacuum Breaker Sizmg Requirements

Pressure Suppression Piping; Unit 2. Drawing M-25 Pressure Suppression Piping, Unit 3, Drawing M-356 Recirculation Line Break -

Illustration Pressure Response - Calculations and Measurements Bodega Bay Tests -Vessel Pressure & Drywell Pressure for Break Area of 0.0573 ft2 _Bodega Bay Tests - Vessel Pressure & Drywell Pressure for Break Area of 0.0218 ft2 Comparison of Calculated &.Measured Peak Drywell Pressure** Pressure Response to Loss-of-Coolant Accident Temperature Responseto Loss-of-Coolant Accident

LOCA Sequence of Pnmary Events *.

Loading Condition Combinations for the Vent Header, Main Vents, Downcomers, and Torus Shell During a DBA Loading Condition Combinations for Submerged Structures During a DBA Loading Condition for Small Structures Above Suppression Pool During a

DBA Loading Condition Combinations for the Vent Header,' Main Vents, Downcomers, Torus Shell, and Submerged Struct\\ires During an IBA Loading Condition Combinations for the Vent Header, Main Vents, Downcomers, Torus *shell and Submerged Siructures During a SBA Pool-Swell Torus. Shell Pressure Ti-anSient at Suppression Chamber Miter Joint~ Bottom Dead Center (Operating Differential Pressure)

Pool-Swell Torus Shell Pressure Transien~ For Suppression Chamber

Airspace (Operating Differential Pressure)

Pool-Swell 'l'orus Shell Pressure Transient At Suppression Chamber Miter Joint~ Bottom Dead Center (Zero Differential Pressure) . Pool-Swell Torus Shell Pressure Transient for Suppression Chamber Airspace (Zero Differential Pressure)

6.2-31
DBA-Containment Pressure Response (Operating AP) *

-6.2-32

DBA Containment Pressure Response (Zero AP) 6.2-33
DBA Containment Temperature Response (Operating AP) 6.2-34 * *..
DBA Containment Temperature Response (Zero AP)

... _. 6.?:35 IBA *containment Presstire ~esponse .*.*? --~.*

~* *.'..*-.: *

6.2-36. !.* *
IBA *containment Temperature.Response

, ;::'..,. :~:.. -,~--6:2-~7

- *sB.A Containment Pressure Response_..;..*--.--------

) .;.,:~:;\\;;_: '..* "_ ~Ot> F~Gr.-.*.~~:2"'."_2oo-J z.oJ, 1 2.(>c.-~ ;u;j_ tto.~.a..~eJ.._. 1~*~,..7.. J*~(;'.~i~;i;::~p~-~.8&. ~~.2-~l~q_ ~_-lq&/;~ ~~e$ .1

--*--. **~* Insert for Page 6-v 6.2-19a 6.2-19b. 6.2-20a 6:2-20b 6.2-20c 6.2-20d ~. Short Term Suprcssion Pool Temperature Response. Case 6a2 - 60% Mixing Efficiency Short Tenn Suppression Chamber Pressure Response. Case 6a2 - 60% Mixing Efficiency Long Term Suprcssion Pool Temperature Response. Case 2al - High (100%) Mixing Efficiency Long Term Suppression Chamber Pressure Response. Case 2al -High (100%) Mixing Efficiency Long Term Suprcssion Pool Temperature Response. Case 2al - Low (20%) Mixing Efficiency

Long Term Suppression Chamber Pressure Response. Case 2al - Low (20%) Mixing Efficiency
. ~.....

... ~... -*. ' ~-... ,: I

- , *.' ~., -

'.,.,.,..... :-,*:J*:~-~-:.-*~-~;-:*:~t.', :~* '-. _---:~~:,_,~-._:.~~~i,:;~M-;~_~.... ~_.:,.... 't -r;.

-- ** ':; '. ** - _:r"r;.... ~-* r.. :i..: * "

~ ~-~-- :*

DRESDEN - UFSAR 6:0 ENGINEERED SAFETY FEATURES LIST OF FIGURES Figure 6.3-50. Blowdown Upper Downcomer Liquid Mass 6.3-51 Blowdown Lower Plenum Liquid Mass 6.3-52. Refill/Reflood System Pressure 6.3-53 Refill/Reflood Lower Plenum Mixture Level. 6.3-54

Refill/Reflood Core Midplane Entraj.nment 6.3"55
Blowdown.HOT CHANNEL Heat Transfer Coefficient

.* 6.3-56 Blowdown HOT CHANNEL Center Volume Quality - .. G.3-57* .Blowdown HOT*CHANNEL.Center.Volume Coolant Temperature . 6.3-58

Typical Hot AssemblyHeatup Results, 5 GWd/MTU 6.3-59

.Dresden MAPLHGR vs. Assembly Average Burnup

.
6.3-60.

Short Term Core Inlet Flow. and Pressure Transient 6.3-61 Core Response to *LPCI Alone 6:3-62 *

Core Axial.Power Distribution

. 6.3--63 . APED Multirod Cl:iF Data at 1000 PSIA

6.3-64 *'

MCHFR Transient for Recirculation Line Break

i6.3~65 Peak Clad Temperature.with One Core Spray Subsystem
6.3-'66 :

7 Peak Clad Temperature With Three LPCI Pumps.. *.. 6:3-67

core ~esponse to HPCI-LPCI (0.2.ft.2 Break Area) 6.3-'68

... Core Spray - HPCI System Performance (0.2 ft.2 Break Area) 6.3-69 *

<C.ore Response to ADS -

Core.Spray (0.05 ft2 Break Area)

*s.3~70. *
Core Response to ADS-: LPCI (0.025 ft.2 Break Area)
6.3-71
f'low.Rate.*Following S_team Line Break Inside Drywell_..
6.3-.72
Core Response to Steam Line Break Inside Drywell ~ Core Spray.
. 6,3-73.

Core Response to Steam Line Break*Inside Drywell - LPCI

6.3-7 4:: :

Core Inlet Flow Following Steam.Line Sreak Iriside Drywell .6.3~ 75 * . MCaFR Transient for-. Steam Line Break Inside Drywell

6.3-76.

. Rods Perforated vs. Liquid Break Size 6.3-77 .. Availability *AiialysUi - Small. Line Break* :*..

6.3-78
- .Availability Analysis -

Large Line Break ( r-cJl-.: 6:3~79 *

Peak Clad Temperature vs.' Liquid Break Size.

etf>u.' * :-. c_-;3<.857or---"!t'N~liri=1m=um=-i)Containment !>ressure b..¥aila91e and Gorttmnment.PFessYPe cz 'Reqtih cit io1 I amp 1H'SH Tor. ~ Ps H C 01t Gtkf'a..;llO/l * . 6."3-81 .

HPCI Pump Characteristics
-6.3-82.

Example HPCI Turbine Capacity Curves 6.4~ 1.

HV AC.System** Schematic D~am
~.

6.4-2..

*. Control Room Arrangement*

> 6.4~3 * *

. General Plant Layout.

'. ~ ~- .... 6.5-1

Di~~ of St~dby Gas.Treatment System

.., 6*.5-2..

charcoal*Cell Isometric.*. *:***"*-**. *. *

~-. ;6.5-'3. -.:.... ~*-. ;p~rforri:iance-Curve, Standby Ga.S*Trea~entSystem ExhaustFan . :.*. : :. *I.. ~ \\...... *! *** ~ ~ -

DRESDEN - UFSAR analyses to !*estore the margin of safety required in the original containment design. After completion of the Mark I Containment Program, it was determined that the water yolumes specified in the plant unique load definition 181 and the plant unique

analysis171 actually correspond to a downcomer submergence of 3.21 to 3.54 feet at zero differential pressure. An evaluation concluded that affected components were still Within the allowables established for the Mark I Containment Program191* This evaluation concluded that the present volume, corrected for the 1.0 psid
overpressure in -the drywell, does not adversely affect the existing analyses, and that the maximiim component stresses reported in the plant" unique analysis are still valid and mee~ the criteria ofNUREG-0661. See Section 6.2.l.3;6.2 for

~dditional diScussion of the Mark I acceptance criteria. Refer to Section 6.2.1.'3._6.4.2 for a description of the detirilS of the reevaluation. The ~pect~ of postulated break sizes with respect to reactor core response is

discussed in Section 6.3.3.2. *The following information covers the effects of a*

toe~ on the containment, with particular emphasis on the mpst severe break: the

doubled-ended rupture of one of the 28-inch-diameter recirCulation pump suction

.-:lines.: For the purpose of sizing the *primary containment, an instantaneous, *

.. *.* *:.. circlimferential break of this line was hypothesized. The LOCA involving the

=*.**,* *-~**

-~ :-~~~c1Jla~icin pumP, s~ction lin~ ~ould occur u~stream of point 1 on Figure 6.~-14. **=

."For the vessel 'blowdown~ the reactor was assumed to be operating at a full power of2527 MWt With the equalizer line valves between the recirculation. loops open, .. **,:even*though these valves.will be closed during power operation. Note that the ..* -~

equ8.lizer line and valves were removed from the Unit 3 recircUlation loops as
... - ** ~-* **! ~ * -*.desCribed.in.Section 5.4.1.*
~su~*g the equalize;*im'.~ valves are *open, the. flo~ area through the equalizer

.. lfue.must be considered m determining 'the total blowdown ijow area. The" totB.l

~-.blowdown flow area is equal to the sum of all parallel flow areas and is given by:

... ~--.., ~ . ::~~'-'. '.°:.* *As.= AR + AE; ~ NA:-;

-.where: : * * * *
~""

~*.: *:: -,*:** -,::. ~-* ~*_,---*-::~ ./'Y,~.. r\\if= Total eqUivaient break area (or blowdown flow area)

~*_,.* *.*.;~< -~~~:_~::~*-,*~~~,.;:~-,:~R*LF.~6~-.~~~ ~.fre-~tio~ llne =* 3.5,7 h2

. ":,-.-;: :< /._ *.....

2.

.**~~: ~;~:-~.~: *--*; *_.:_,AE =Flow area of eqlializerJine~_valve port= 1.48 ft. ~-~-:..

- ~.

~ -~* . '~?t~1eJ{£:~~;!;:if,(ii*,.};~~ri o_(~~~f :""I'~ ~~~ heal!~r ~ io -*..

.. -... *_.::.**:_-.;_-:~:-~:.-*.:-:"°'.*<.A~ ::_Fiow.area~of.a single jet pump nozzle= 0.057 ft2.. :: *

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Insert 1 for Page 6.2-19

'r.*-. - _. ~ In order to identify containment response to a Loss of Coolant (LOCA). accident, several analysis were performed. These analysis were performed to evaluate the containment short-term and long tenn pressure and temperature iCsponse following the Design Basis Accident (OBA) LOCA Short-tenn is defined as a time period from the beginning of the DBA LOCA to 600 seconds. There is no credit taken for operator actions during this short-term interval. Long-tenn is defined as a time period after short-term, namely from 600 seconds into the event, at which time the operator takes acti~ns to initiate containment cooling or to control pump flows .. *~:**~.:__:~~-. ~ R '"'I'". ~---*..

1 : * -~

-..,. ~ -~ DRESDEN -

UFSAR, Statement B may appear to contradict existing test data which shows as much as an 11-psi increase in peak drywell pressure due to prepurging. This apparent

disparity is attributable fo the effects of two phenomena discussed below.

A. Condensation on drywell walls: Due to the high ratio of drywell wall surface area to blowdown flow area, the effects of condensation reduced the peak drywell pressure in tests with cold drywell walls. Prepurging . eliminated any signifitallt surface conqensation, and higher peak drywell pressures resulted. The calculation of peak drywell pressure did not take. credit for surface condensation with or without prepurging. B. Liquid carryover into drywell vents: The calcuiation of peak drywell pressure assumes complete carryover of all liquid in the drywell into the

drywell vents which increases the peak drywell pressure. However, test data from the Humboldt Bay series of pressure suppression tests1121 reveal that carryover is more likely to be complete if the drywell is initially hot: Hence, the increased carryover would increase the measured pressure compared to a test with less carryover; i.e., one with rio purge. Hence, prepurging of the drywell does not significantly affect the peak drywell pressure so long ~ co~densation is neglected and

. complete liquid carryover is assumed for both the prepurged *and . nonprepurged cases.....

The pressufe and temperature responses of the. containment, as originally calculated using Moody's model, are shown in Figures 6.2-19 and 6.2-20. As can be seen -in Figure 6.2~19, the calculated peak drywell pressure is 47 psig, which is well below the design allowabl~ pressure of 62. psig.*

.Additional analyses of the containment pressure and temperature response to small . break accidents (SBA), intermediate break accidents (IBA), and the DBA were conducted as part of the Mark I Program. Refer to Section 6.2.1.3.6.4 for a description of.these. additional analyses.. On June 5, 1970, Dresden.Unit 2 experienced a .transi~nt which caused a safety . valve to open and fail.to reseat.. As a result, the containment atmosphere is

postulated.to have reached 320°F after approximately 1 hour.. A general casein which the containment wall is postulated io be 340°F has been analyzed to demonstrate the adequacy of the contamment. It was found that as a result of.

. thermal expansion of the drywell shell against the concrete walls of the containnient structure, the thermally induced loads for 340°F at 0.5 psig are the same as for the design condition of 281°F at zero psig.

At 340°F and zero psig the loads are slightly greater and result in a slight decrease in safety factor from 2:2 to
1.9.. -Therefore, it was concluded that the containment structure (design
temperature of 281°F) provides adequate safety margin.for the maximum steam superheat temperature of 340°F.

{,:."2. 1*.':>~2..?-**. .,.,~.

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Insert 2 for Page 6.2-24 6.2. 1.3.2.2 Containment Short~ Terni Response to a CDBA) LOCA for Minimum NPSH Available Various cases involving different pump combinations, pump flow rates, initial conditions and . assumptions were analyzed as shown in Tables 6.2-3, 6.2-3a and 6.2-3b. The short-term scenarios (0-600 seconds) that resulted in the minimum net positive suction head (NPSH) are described as follows:

. Four (4) LPCI pumps and two (2) Core Spray (CS) pumps for vessel makeup and no containment cooling up to 600 seconds following the DBA-LOCA with no operator actions required (Case 6a2 in Tables 6.2-3, 6.2-3a and 6.2-3b). This analysis was performed to detennine the short-term (0-600 seconds) suppression pool temperature and suppression.

chamber pressure response for a postulated break in the recirculation discharge line with all 4 LPCI pumps and 2 Core Spray pumps available for vessel injection and with the assumed

single failure of the loop selection logic which allows all the LPCI flow to be directed to the containment from the brokenloop. It was assumed that all LPCI flow was injected clirectly into the drywell "Two (2) LPCI pumps and one (l) Core Spray pump for ves~l makeup cmd no containment

~ling up to 600 seconds following the DBA-LOCA with no operator action required (Case 2al with 100%.thernial mixing in Tables 6.2-3, 6.2-3a and 6.2-3b). This scenario provides . the mirumum conditions for NPSH with the single failure of an.Emergency Diesel Generator, The GE computer Model SHEX-04 with decay heat based on the ANS 5.1, 1979 decay heat .model (Withoutadders) was used in each analyses. Analyses performed to benchmark analyses

with the SHEX-04 code to the Dresden FSAR analyses were performed. The benchmarking analyses included sen5itivity studies to quantify the effect on peak suppression po0l temperafure
due to differences between the updated analyses and the FSAR original analysis.

Variou; assumption5 were used in the analysis. These assumptions are included in Section

6.. 2.1.3.3.3. ~dditional assumptions for ~e short-term response are as follows:

.:i.

_. With a signal for LPCI initiation, Sll 4 LPCI pumps start vessel injection mode and
iriject directly* into the drywell (no flow to the vessel) at a flow rate of 5, 150 gpm per

' ;piimp for 6a2 and 5,000 gpm per primp for 2al during the first *ten minutes of this event.

.

After receiving a signal for CS initiatioll,' the 2 CS pumps start injecting into the vessel
at a flow rate of 5,800 gpm per pump for the first ten minutes of this event.

There is 60% thermal mixing efficiency of the break liquid with the drywell atmosphere for Case 6a2 and 100% thermal mixing efficiency of.the break liquid with the drywell . aunosphere for Case.2al. These.thermal mixings were chosen as appropriate for the conditions~represent~; *. As a result of th~ large LPCI injection directly into the drywell during the first ten minutes, a. significant red.uction in drywell pressure and temperature produced a reduction of pressure in the

suppression chamber: 0 The.results of this analysis are summarized in Case 6a2 of Table 6.2~3 and

. *. include the suppression pool temperature and suppression chamber pressure at 600 seconds (at . *, initiation.of operator actions):.figures 6:2-19a, 6.2-19b, 9.2~20a and 6:2-20b shows the

>*. si.ippression pool temperature and suppression chamber pressure responses. Various other
.. ~-. *",*'e.vaiuations were performed as~g different pump scenarios and mixing levels.. The results of

.. :*these are a.isolisted in Table6.2-3: Therestilts of the Case 6a2, 60% thermal mixing and Case

- :*,.. ; *.***2a1, *100%thermal mixing anaJ.y~,.which provide the mirumum.NPSH in the short term, are

~Jr* ' ~. * * * * .. ~. ~- -.. -- '..

<:if....... DREsnEN - tJFsAft 6~2.1.3 Containm~nt Lon. :.Term Res ~nse to~ Desi Basis Accide o.ncl cluP*n3 LPC.l:.. ca.nJ. Cd'C. Sf-~ injecl'io-t For n.c... f'ir~'t" Te.tt. wi 1n &LT~s.

A yses s owe t aft.er the blowdown.immediately *

following a p ulated recirculation line break, the temperature of the suppression chamber wa r would approach 130°F, and the primary containment system pressure wo d equalize at about 27 psig as discussed in Section 6.2.1.3.2. Most of the nonco ensible gases would be transported to the suppression chamber during blowdo However, soon after initiation of the coiitainment spray, the gases would re
bute between the drywell and the suppression chamber via the*

vacuum-breaker system as*the*spray redui::es drywell pressure. *.. The.core spray*systen:l would remove decay heat and sto~d heat from the core, thereby minjmiiing core h~tup and any metal-water reaction. The core heat is removed from the reactor vessel through the "broken recirculation line in. the form . of hot liquid. "This hot.liquid combines with liqUid from the containment spray and flows into the suppression chamber.via the drywell-to-suppression-chamber

connecting vent_pipes. Steam *flow would* be negligible. T.he energy tranSPorted to the suppression chamber ~ter.would ultimately be removed.from the primary containment system by the containment cooling heat-exchangers.

. To assess the long-term pressure and temperature respon.5~ of the prim8ry. . containment after the postulated l>lOwdoWii, and to demonstmte the adequacy and . £:.'4 rre.n "t redundBncy *o~ the core* and containment eooling systems~* an analysis was made of the

tion line break under various conditions of core and primary containment cooling. T e licensing basis long-term pressure and

. temperature response *of the ~ containi:nent was analyzed for tae ullewisg Aor;, ' *

cnnline es11iiiti1-:fo l(.cLl"1oc.ts. * ':Lo.c.l rtL"C~S~r\\~-;..~""~ c.o"-"*,TI01t~.

~~t:.R\\ 3 -+ . Operation of two core.spray~ foop~ and one or"the.two con~* mic:: """"-~ loops with two LPCI :pumps in service;. * .. Je_ld"°C.' B. c: 6.2-25. "\\ ~.. ..... ~.. ~*i-_..

.;.:~-:... ~'*.... :....

INSERT 3 for Page 6.2-25 For containment cooling after 600 seconds, two CCSW pumps providing flows evaluated at 5,000 gal/min, 5,400 gal/min and 7,000 gal/min per operating containment cooling heat exchanger were asswped to be in service at a cooling water temperature of less than or equal to 95 degrees F. LPCI and CS puplp flow rates were also evaluated for different values. Analyses were performed at these LPCI, CS and CCSW pump flows by GE using the SHEX computer code with current standard assumptions for containment cooling analyses, including the use of the ANS 5.1 decay heat model. Long term temperature is maximized and NP SHA minimized with a thennal mixing efficiency of 20%. All analyses cases (except 6al and 6a2 as described in Section 6.2.l.3.2.2) were performed assuming that during the first 10 minutes, two LPCI pumps and one CS pump are conservatively used for vessel makeup to provide the initial conditio~ for the long term cooling analysis. This assumes a single failure of an emergency diesel generator. At.10 minutes into the event, the operator shuts down one LPCI pump and aligns the other LPCI pump from the vessel injection mode to the containment cooling mode. At the same time, two CCSW pumps and one LPCI heat exchanger are lined up for long term cooling. The resulting. long-term containment cooling configuration consists of 1 LPCI primp, two CCSW pumps and one LPCI .heat exchanger. The various analyses used different pump flow rates and heat exchanger perfonIDmce values which were also evaluated for. the various flows. The evaluated heat exchanger performance values are identified in Table 6.2.3b. ~

Different initial containment condition5 were used for each combmation of p~p flow rates. Sensitivity

... cases were also analyzed to minimize the.suppression chamber pressure response. The sensitivity .parametersinclude heat sinks and the efficiency of.thermal mixing between liquid break flow and drywell atmosphere. Additionally, the input assumptions were cho5en to conservatively minimize the suppression chamber pressure and in the 'a' cases, iniJµmize the available NPSH. ~ . - Assumptions

14. Passive beat sinks in the dlywell, suppression cbambCr air space and suppression pool are conservatively neglected to maximize the suppression pool temperature. For the 'al' cases, heat sink inputs were developed based on the Dresden drywell geometry parameters which were compiled and used during the Mark I Containment Long Term Program and which are documented in GE Document 22AS743 and GE Document 22A5744, Containment Data, SeptembCr, 1982. The c:hywell and torus shell cond~nsation heat transfer coefficient is based on the Uchida correlation with a 1.2 multiplier. The inclusion of the heat sinks coDSel'Vlltively minimiu:s suppression cbambCr pressure.

lS. All Core Spray and LPCI system pumps have 100°/o of their horsepower rating converted to a pump
beat input which is added either to the RPV liquid or stippression pool water.

16. Heat transfer from the primal)' containment to the reactor building is neglected.

17. The effect of contaiDment leuage is negligiole considering that conservative input assumptions are used to minimiu: containment pressure.
The deSiio parameters determined by the evaluations for the various LPCI,. CS and CCSW flow rates,

.. including the sensitivity cases, are.shown in Table 6.2-3. The table includes the suppression pool temperanire and suppression cbambCr pressure at 600 seconds (at initiation of operator actions), the minimum suppression chamber pressure following initiation of containment '<dlywell and suppression chamber) sprays arid the suppression pool temperature and suppression chamber pressure at the time of peak suppression pool temperature. A comparison of~e results between the 'a' and the 'al' cases show

that the beat sinks have a negligiole effect on the suppression po0l temperature. As for the impact of the
suppression chamber pressure, the inclusion of the heat sinks resulted in a reduction of approximately 0.8

.psi at 600 seconds, 8nd a reduction of approximately 0.2 psi in the minimum*suppression chamber

.pressure following initiation of suppression chamber sprays. However, the heat sink effect on the*
suppression chamber pressure is negligiole at the time of peak suppression chainber temperature. The
- * * * :results demoilStrate that oni:e containment sprays are.initiated, the effects of heatsinks become

.insignificant *. ~ - ---.. . T1ie parameters.identified in the*evahiation performed for Case 2al (see.Table 6.2-3), 'Above nominal. . pump flow rate for LPCI pump (S,800 gpm) and CS (S,800 gpm) for first 10 minutes and nominal pump. flow for LPCI (S,000 gpm) and CS (4,SOO gpm) rate after 10 minutes -Containment Initial conditions to minimiu containment pressure,. chywell and torus shell heat sinks modeled', provides the minimum *

NPSH Figures 6.2~20a, 6:2-20b, 6.2-20c and 6.2-20d shows the suppression pool temperature and '

suppression chamber pressure rCspe>iises. This case provides the limiting condition for evaluating

available NPSH after iniwmon of containment sprays including available.NPSH at the time of th~ peak

. *

_. *suppression pool temperature. The analyses performed for Case Sal of Table 6.2-3 identifies.the _

-- maximum suppression temperature to bC 1760f'. These ~gn and operating parameters are such that they ellsure that plant safety margins are met ' * *. : * . The results ofihe new analysis indicate that the heat removal ~ility of the containment heat relnoval. _system remains sufficient to maintain containment integrity following DBA 's with a peak sui>Pression p<>Ol temperature of 1760f'. The consequences of this higher peak temperature have been analyzed and

found to bC acceptable: The results of the Case 2al analysis, which provides the minimum NPSH in the long term, are input to the gi-eater than 600 secondlong-temi position _of the*NPSH analysis in Section*

-. 6.3.3.4.3.2. -~. -. _: r._.:.... -~~--.. ~;_,. {-::;.. ~ -. -:'"~-- :*' 1- ,, ~*:; *: :'. _1 .-4,-

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~ -. : **~'.. - ' -~

...., ** * - :,r,_ .. -** - ~ \\ '* .. ~.. . ~ ~.* - ~- 1 . -.\\. \\. ___..,.., --::',~-*

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--*.. '...: ; --~. ':--:';<~--**.':..--- ;._';<<::.:). :'*:.. _~.:..
.. i:-*.

~*-.".. :.. ~ -:-\\.*,*:*....,_... f.. ""* - .:..:.f.": * * "t)f,~a;;:H1lss currently PJl:~:m-ic5iperation when the OD.~~ water temperature exceeds 7 5 .. ~- -- ~-

DRESDEN - UFSAR d energy from any metal-water reaction on the pool temperature were included Als the effect of heat from operating LPCI pumps was included. emperature was calculated considering an energy balanc containment c ing and core spray systems. The containment coo

g flow was assumed to enter.

containment at the discharge temperatur f the heat exchanger, and the co spray flow was assumed to enter t reactor at the suppression pool tempera

e. The combined flows (co nment cooling and core spray) would then drain back the suppression po, aving been heated by the decay energy, stored energy in tn ore, and an etal-water reaction chemical

-energy. The drywell temperature w hen en to be 5°F hotter than the exiting .flow. - determined from the amount from any metal-water re Using the drywel mperature, suppression pool temperature, d moles of gas in

the system, t system pressure was calculated assuming the ciry.;

suppressi chamber gases to be saturated. Also, it was assumed that e drvwell and s ression chamber wowd be at equal pressure. This is reasonable th ressure difference Ca.nnot exceed 4 feet of water ( 1.8 psi), the venl bmergence depth, after the initial reactor blowdow'n. Cooling Loop with Two LPCI Pumps The analysi resented here assumed that both of the core spray sy

operating follow*

the recirculation line break. Core spray sys not produce full flo until the reactor vessel pressure has de. eased to 90 psig. The anaiysis assumed at the systems commenced oper on 30 seconds cifter the recirculatiOn line brecik.*

s time is well *within the e calculated for -the vessel pressure to reach 115 psig....

This analysis also assUm.ed that onl WO 0

containment spray.cooling subsystems c
menced containment spray 400. seconds

.. after the recirculation line break. *T eat *changer associated with these two removal of.energy from the s ression chamber ter at this time. The flowrate .,.. LPCI.punips was assumed to.be ailable witn o CCSW pumps operating for J ;. fort~'s ~.on~tion_ is shown

Table 6.2-3, Case ~-

.. '. ~The -~culited ~ore. eatup ruid extent of metal-water reactio was found to be .... -*.*.-essentiallY.the s e as* for.operation of only one core spray syst as shown in . Figure 6.2~1. *. he-total *metal-water reaction was.calculated to be s than 0.1 %.

..,The pres e and-temperature response of the system is shown as Cun; a in

-i Figur,. _.... 2;19and 6.2-20,:*respectively~.* After the postulated blowdown, _tn

_ ~:ell .:.an /. uppression. ~~ber~pressures would _equalize at about 27 psig. Initiatio f , *,.:..... t:*,:..* __ * ** ;__, , e containment 'Spray would r~sult in quenching of the steam in the drywell an -~

.';.' _*.;~:.. '.

-:*.~:.-*---.~-. . ~6~2.>.

:.-~..

. *-* *~ DRESDEN - UFSAR

n a corresponding containment pressure reduction. Energy addition due to core cay heat would result in a long-term pressure increase to the maximum shown
Ta e 6.2-3. Thereafter, energy removal by the containment cooling heat exch wou *exceed the addition rate from all sources, resulting in decreasing contai ent pressure.

eration of One Core S For this analysis nly one of the two core spray systems was ass commence operatic 30 seconds after -the recirculation line bre The analysis also assumed that al our LPCI pumps in the containment co ing mode and all four CCSW pumps wo d *commence operation 400 seconds ter the recirculation

line break. The flowrate corresponding to these operatin conditions are shown in Table 6.2-3, Case b.

. Core heatup and the extent o ere found to be as discussed above for the two core spray ca. It is the same fi a single core spray sy$tem because *each of the *two indepen t core spray s stems are designed to maintain continuity of cooling in the event.o

LOCA, experimental results show that increasing *the flow above that dehve d by t single core.spray system does not appreciably change the heat transfer c a

ristics during spray cooling. Therefore, core heatup and extent of me -water reaction would be the same for one and two core spray pump operation. Iriitiation of cont~ment *spray cooli g wouid suit in quenching the steam in the drywell and in 'a corresponding re ction in con

ment pressure. Energy addition due to core decay heat would res
t in a long-term ressure increase to the ma-..:imum shown in Table 6.2-. The containment. essure and temperature are shown as Curve bin Figures*.2-19 and 6.2-20, respe ively.

6.2.1.3.3.3 Core spray and ntainmeiit spray operation for this analysis was. ssumed to be as discusse m Case A. The flowrates corresponding to these co* "tions are shown in Ta e 6.2-3; Case c. The results of this analysis were found o be the. same as pr erited for Case A.* The containment spray cooling flow use was identical .that analyzed in Case.A and the cooling characteristics of one d hvo

core sp y pump operation* do not change~.The containment-pressure and temp attire are shown as Curve c in Figures 6.2-19 and 6.2-20, respectively.

-_.~C~se D ~.: Operation df Orie Core Sprav Loop and One* LPCI.Pump

.-;_;-~
~ -.-

DRESDEN - UFSAR is analys~s assumed that only one ofthe two core spray systems commenc oper

n 30 seconds after the recirculation line break. However, only of the four LPC sin the containment spray mode and two CCSW ps were assumetj to com e operation 600 seconds after the recir tion line break. The flowrates corresponding hese conditions are show
able 6.2-3, Case d.

. Containment spray itself does not significantly affect the peak post-acci.dent pressure t:ise. It does, however, result in a somewhat faster depressurization.

immediately following the completion of the blowdown. The controlling parameter affecting the post-accident secondary pressure peak is the heat removal capability
of the containment cooling hea~ exchanger relative to the core decay heat production;'.*

r*; Additional analyses of the*short-term containment pressure and temperature .response to a SBA, IBA;. and DBA have.been conducted as part of the Mark I Program... Refer to Section 6.~.1.3.6.4 for.a description of.these analyses. 6.2.1.3.4. *Mark I Program De~cription for Reevaluation of Containment Respo~se to Hvdrodvnamic Loads . This s~bsection describe~ th~.analysis performed. to resolve new loadings identified after the original_ d~sign of the primary c;ontainment.1131 . The. first generations of.GE 'BWR nuclear steam supply systems are housed.in a containment structure designated as the *Mark I containment system. Dresden Units 2.and 3 utilize Mark I Containments; The original design of the Mark I containment. system considered postulated accident loads.previously associated with containment design*. These included pressure *and temperature loads associated.with a LOCA, seismic loads, dead weight loads, jet impingement loads, *hydrostatic loads due to water in the . suppression.chamber~ overload pressure.test loads, and construction loads. ln tii:'e CO~rSe *of,perforIIiing large-scale testing of an advanced design. pressure-s:uppression containment (Mark HI), and during in-pl~t testing of Mark I

.containillents~ riew suppression pool hydrodynamic loads, which had not been

. expfidtly:inch.~ded in the :origllial:fyiark"I containment desie;n.basis, were identified.

.
These addi tiona.l foads *result from *dynamic effects of drywell air and steam being rapidly.for.ced irito the.. suppressiOn:pool.(torus) *du~g a postulated LOCA and from

. ::~;f :~:;;;;;_ ~~::~.tl~~~~~IJf f~{?IiWi;,i~~~l:~i.~~~i':** :: :. __ -: ~;. _,,, *** *** * ,. *. ;.... l:

I**

DRESDEN -

UFSAR mass after drywell air carryover. The larger initial torus water mass has only approximately a 1°F effect on peak pool temperature. These effects result in a calculated increase in peak torus pressure of about 0.6 psi. For the IBA and SBA the peak drywell pressure increases by an equal amount. For the DBA, the increase in containment pressure increases the density ofthe vent flow which reduces the vent system pressure drop. This partially offsets the torus pressure increase and results in only a 0.3 psi increase in the peak drywell pressure. 6:2.1.3.6.4.3 Safetv Relief Valve Discharge Device Limitations ADI> IN5E.IT I FoR. Po-e_. 6. -z-+8 As*a result of studies of the instabilities in the condensation process previously described in Section 6.2.1.3.5.3 for the SRV discharge transients, it was determi ed that the magnitude of the SRV discharge-related loads is a function of the ty of discharge device used *and the suppression pool temperature. In the past, ramshead discharge device was used to direct the steam flow from ans into the . rus.. During the Mark I program, a T-quencher SRV discharge devi, :which

*inCludes perforated pipe sections, was installed on each SRV disch e line. The

. T-que cher device has been found to reduce substantially the hy odynamic .:.dischar loads in comparison to those observed for the other

charge devices.
Ref er to S ti on 5.2 for a descripti_on of the SRV discharge To preclude uns ble condensation and eliminate the c cern that SRV.

actuation at eleva... p'.lol t~:npera.tures.could result. severe vibratory pressure loads, a suppression _ c*l t~mp~rature limit has b establishf'!d.

To establish this limit, th
erence betwee he local and bulktemperature was

. determined.. Local temperat e denotes verage water temperature in the vicinity of the discharge device d repr en ts the relevant temperature which controls the behavior of the conde a

n process occurring at the pipe exit~

.The b:ulk temperature is a calcul ed v ue based on the total energy and mass .. release into the pool *. assumin he pool a s.as a uniform heat si.Ilk. Since bulk temperature is used in plan transient anal~ es, the difference between the bulk* and local values must be ecified so that the alysis can demonstrate operation within the prescribed r its... To determine th~erence bet~een bulk and local.co* "tions fQr the T-quencher device, the Mark I Owners Group relied on the in-plant t ~at Montkello.12s1 The. results indi 'ed that the difference between bulk and local mperature is 43°1" for the test out the RHR system.in operation and 38°F for ili tests with RHR operatio. The test with RHR was conducted with only one oop operating in recirculatiqn mode.. Note that RHR at Monticello is equiv~nt to LPCI.. ~"""C~.LJ~* ent cooling mode at Dresden. In.fate *1978, the Mark I *owners Group conducted an adjunct series of test *t the .* *,.,same facility. 1291 The purpo1>e-oftlie tests was to investigate methods to impr e

- thermal mixing 1n the suppression pool and to reduce 'the bulk to local pool
..*. :*~},
- - *..*. :j teiilp~rature diffefellce. These, methods include modifications.ofT-quencher design t-~i~~j:~:-~ii;I:(~~t:t*e/*t* ;-C.
G.

24 8

. :: '~ *-. : ' '

".,.--~

.. :. :_:-.. ~.. .. ~-. . ~ ~...,.. ~---------,*Dresden Station is equipped with safety/ relief valves (SRVs) to protect me reactor from overpressurization during operating transients. When the SR Vs open, steam released from the reactor vessel is routed through SR V discharge lines to the suppression pool where it is condensed. Extended steam-blowdown into the suppression pool, however, can create temperature conditions near the discharge location that can lead to instability of ' .the condensation _process. These instabilities can, in*tum, lead to severe vibratory - loading on containment structures. This effect is termed condensation oscillation. This is mitigated at presden Station by the *usage of quenchers at the end of the

SR V discharge lines, as well as restrictions on the allowable bulk* suppression pool water temperaturet in order to ensure that the local pool temperature stays within.

acceptable ranges. Technical Specification Section 3/4.7.K provides Limiting

conditions for Operation and Action requirements, regarding the. suppression
,.** chamber temperature. *..
.~By letter dated March 21, 1995, the BWR Owners' Group (BWROG)

. requested the NRC staff review and approve GE.report, NED0-30832 entitled, "El~mination ofLimjt on BWR Suppression Pool T~mperature." NED0-30832 ,,. presented a discussion of test data and analysis. that supports deletion of the . requirement to mamtain the local suppression pool temperature ~o °F below the saturatio~ temperature of the pool.during SRV discharge._* , Drecl~n h4.S. e.l1~rna.Tecl lhe lo~ suppression pool temp~ra~~ limits.. The test* data and analysis presented within NEDO-J0832 is applicable to Dre5den Station. The NRC.Staff Safety Evaluation Report (SER) 'approval ofNEI?0-30832, dated

August 29,'.1994, concluded that the ~nation of the local suppression pool. : *

. temperature limit is acceptable if the plant has emergency safety features pump

.inlet located below the:elevatfon of the quencher.* Because Dresden Station's pump inlet is below the elevation ofthe quencher, *NED0-30832 is applicable to *

.Dresden Station (see UFSAR Figures 1.2-7and 3*.8-17. The NRC ~found that _*the quencher device is effective in.maintaining the unstable condensation oscillation load to benign levels when the suppression pool is operated at _temperatures nearing saturation. ~*.,;** - ~' -. '.. -- ~. ..... ~. ... -.. ~-... : _:..

.".. ~~""* ;~**~:< -~~**.. :

-~*:...... ;:~.:..'-~~:.... ~~:~ *:*l-*~;--* *~.

r* ~ c ~. -~ -~:~:y_;** .,-:- *~-. -. -~ *. ~-.. * *- i ... -~~:::....._*

DRESDEN - UFSAR d the LPCI suppression.pool cooling mode discharge pipe configuration. The T-uencher was modified by adding a number of holes on the tips of one of the que cher arms. The LPCI system was modified by installing a 90° elbow. with a reduc* g nozzle, at the end of the ex_isting discharge lines. These modifications were in ended to promote mi.xing in the suppression pool during SRV dischara-. Test resu ts show a substantial improvement in pool mi.xing. The difference between b k and local temperature was reduced to approximately 15°F fo he test, with on loop of LPCI operating in the suppression pool cooling mo A plant-specific alysis was performed to determine the suppression ool

temperature limit or Dresden. Figure 6."2-39 shows the resulting l al pool temperature limit fi Dresden Units 2 and 3 as a function of reac r pressure.

Figure 6.2-39 shows th for all plant transients involving SR operation during which the steam flux thr gh the T-quencher perforations e eeds 94 lbm./ft2-sec, the suppression pool local t perature limit is 200~F. For 1 plant transients

involving SRV op*erations du *ng which the steam flux t ough the T-quencher

_ **perforations is less than 42 lb ft2-sec, the suppressio ool local temperature limit shall ensure *20°F subcooling.

rrhe Dresd~n :T-quenchers are subm ged in 9.17 et of 'vater corresponding to "18.53 p$ia. Th~ saturation temperatu psia is 224°F. Thus; to achie,*e

. 20°F subcooling the *focal *t~mperature a steam flux of less than 42 ... lbm./ft:!*sec is 204°F. . To"demonst~~tethat.ihe. local pool temp atu e. limit is satisfied, seven limiting transients involving SRV discharges w e anal~ ed.* Table 6:2-6 presents a summary of the transients analyzed d the co spending pool temperature.' *.'

results. Three of.the transients co ervatively ass *med the failure of one RHR loop, in addition* to the *single eq
ment malfunctio or operator *error which
initiated the event. This conse ative assumption exc
ds the current licensing basis for anticip;ited operatio transients. As noted in* able 6.2-6, the containment cooling heat.e
angerheat transfer rate as med in these analyses is 416.7 Btu/s~°F per.loop.
s was derived from the contain ent cooling heat
exchanger specification *
ch.states an overall heat transfer te of 105 x 106..

. Btu/hr is achieved giv

CCSW flow of.7000 gal/min at 95°F,.

LPG! flow through the heat eX anger of 10,700 gal/min at 165°F.

.Each of the SRV *scharge transients was ~alyzed assuming an init
temperature of 5°F, which is the Technical Specification pool tempera re -limit for
- normaI power. <:>Peration. The notes to Table 6.2-6 list other initial condi
ons and

. assumption induded in'.these analyses. ~. The *an: ~ ses of Table 6.2-G,.Case 2C,.normal depressurization at isolated hot , shutd.* n,-.sho,vs.a ni8Ximum-local pool temperature of 153°F. This demonstra that 1th no ~ys_tem°failures and in.. the' event ofa n6nmechanistic scram, de essurization_ otihe.reactor pressu.re'.vessel via SRVs at 100°F/hr results in loc _,:* * * '* ~ >~ *.. oLt"emperatures well belo~ the ;condensation stability limit shown in Figure * .. -~*. .~ ~. - ~ *'.. '". ~ ........ ~.. '

-, *-*~:.:.._._... ',', ~- - ~:._j,".. _:~. .. -~:*:.};.. *-:~---/~ *.*~~-. '.-~-~.. ~ '. .r**** .. *. ~-~.. -' --.. ~... -:

- .*~r=:=,u1... r 6 F-

,_........ ;*:?. . '.; ~*. .. -.-: \\:.... ~ -~-- ~** ~.. ~. ,:~*

--;. *~. DRESDEN - UFSAR Tab e 9-6, Case 3A, a SBA with one RHR loop available, results in a

1mum local.pool te ature of 180°F, which is below the condensati a ility limit of 204°F. The local to of maximum local

. temperature is 26°F. To ensure ade . e monitoring of the suppression pool tempe e, the SPTMS was in to monitor bulk pool temperature. The SPTMS is desc ion 6.2.1.2.8. 6.2; 1.3. 7 *containment Capabilitv 6.2.1.3.7.1 *

Potential For Hvdrogen Generation

... If,,as a result of a:Se\\~ere accident, Zircaloy in the reactor core was to be heated. above *about 2000°F. in the presence of steam, an exothermic chemical reaction would occur in which zirconium oxide and hydrogen would be formed. The correspondi:q.g energy release of about 2800 Btu per pound of zirconium . -. reacted, would be absorbed in the suppression pool. The hydrogen form*ed, howe,*er. "":*. *would *result.in* an increased pressure due simply to the added moles of gas in the 'fixed volume. Although very small quantities of hydrogen wo,uld be produced

during a DBA, the containment has the inherent ability to accommodate much larger amounts.**

The Dresden contai.nme~t is normally provided. \\vith an inerted atmosphere to

'._: *preclude the possibµity of a *hydrogen combustion event within the containment.

. ' '.fhe*~oxygen deficient atmosphere assures that hydrogen build-up due to metal~water,*reaction is.. not a con*cern.. : ..-

The.generati.on of~ignifi,~t quantities of hydrogen due to a metal-w~ter reaction from.high fuel cladding temperatures is prevented by assurance of adequate core*.*

. c;ooling. During.norinal operation, there 'are several systems, including feedwater

µid control rod drive (CRD), which add water directly to the reactor pressure vessel: .A reliable, aut,omatic means of cooling the core is provided :by ECCS. This; system is designed to provide adequate' cooling in accordance with 10 CFR 50.46 limits *assuming any single* failure in addition to loss of.offsite power. Refer to

.. :s.ection 6.3 for an eval?ation of th~ ECCS performance. ..*.:. F_9Howing'a: postulated LOCA, both oxygen and hydrogen may be produced by the

":... :,radiolyti~.decomposition:of primary coolant and suppression pool water.

.D~composition.would occur.due to the absorption.of gamma and beta energy -:.. :::~_.~:. :_~*'"

;.: _ :"'* *; :*. *releasE!d *by.fissiorLproducts.int_o reactor coolant and suppression pool water.

. c':',;:* ~'~?? *.. . -:. *. *~-.:.~\\~dicilysis*is :the.cinly :significant reaction mechanism whereby oxygen, the limiting ~-~~-*--., *;, ~~** *-.. *. <::,:.* '~::combustioD,,.reac;tant, is produced within the containment. Therefore, radiolysis is

::/_

.~'.::*i:r/:)::'.*:\\',~~;~i.'.:th~ _:pti_~ar.)*,*f~~us:.r~l~§,i:"'e '.t~*con,i_bu~t~~le gas control for.containme~ts with inerted

~llf ll;!l~J"l~~~'f ti~~-~~:*~~;,; ;;~ -~-~-s~ ~- ' > ' :~~

de.le. te.-. -

~ ~. ~ '....- DRESDEN - UFSAR Since the LPCI flo~ passes through the containment cooling heat exchangers, containment heat may be rejected during post-LOCA LPCI mode operaiion by starting the CCSW pumps (when sufficient electrical power is available) to provide . cooling to the heat exchangers. This results in the transfer of heat from the suppression pool to the CCSW system. During this mode of operation, suction is taken from the*suppression pool, pumped through the containment cooling heat exchangers to the reactor vessei, and back to the drywell via the postulated. break. When the cirYwell water level reaches the level of the containment vent pipes, the water flows through the vent pipes to the suppre.ssion pool.. Stagnant water conditions in the containment cooling heat exchangers (EPNs 2(3)-1503.:A&B) during standby conditions cause both pitting and corrosion of the 70-30 CuNi tubes.1341 This.has resulted in heat exchanger tube leaks and excessive *

equipment outage durations.. Various materials were evaluated for better corrosion

. resistance and AL-GXN was selected as the replacement tube material. A limited number of tubes will be replaced with AL-GXN tubes as tubes fail. (AL-GXN has . been accepted by ASME under Code Case N-438)..

DRESDEN - UFSAR Fibrous insiilation is a molded insulation used only on parts of the recirculation system and the 4-inch and smaller lines. The total amount of such material used in the drywell is only 0.16% by volume or 0.05% by weight of the suppression pool water. Any postulated accident would dislodge only a fraction of this *material. Miscellaneous items are expected to contribute a negligible volume of contaminates in comparison to the suppression pool water volume. Any particles contributed are expected either to be stopped by strainers if they reach that position or to be colloidal rust type particles which would have little or no effect on ECCS pump seals or bearings. As well as having limited contaminate sources, minimal probability of problems.. exist because of the circuitous path from the drywell to ECCS pump suctions. Particles. first must p~s through l x 1 'h-foot openings from the drywell to the 8-foot suppression pool downcomers. The downcomers are connected to large. spherical shells which are interconnected by 4-foot diameter pipes forming the inner suppression pool ring header. From this header, the path to the suppression pool is through 96 circumferentially spaced 24-inch diameter pipes which extend below the suppression pool water line.. The path then proceeds through four suppression pool suction strainers.located about _1h of the suppression pool water level height above' the suppression pool bottom..

From the.stralliers the path leads
into a 24 inch suction ring header and then to the _pump suctions. *This path is

.qUite circuitous,*providing many places to trap foreign objects and also spreadi.rig .the particles that do get through uniformly throughout the suppression pool vol~e. Larger pieces of metal will settle to the bottom of the suppression pool,. and.lighter.materials such as unibestos will float rather than be drawn into the

ECCS. p\\lmp fillets. _ *.

. The average water velocity in the suppression pool during ECCS equipment operation.is less than 0.1 ftJs *and ~s not.sufficient to transport particles (eXcept for .the smaller *pieces in colloidal suspension). However, during a postulated blowdown from the drywell to _the :suppression pool, there will be a less idealized situation.

The suppression pool water will be disturbed and a certain portion of materials will

'_*be near the* suction str8.iner5. **.The strainers are stainless steel.perforated plates .. with *.3f.i2 inch diameter *openings. Larger _pieces and part of longer pieces (of smaller diameter) will be *stopped and the strainer effective area will be somewhat reduced. . To account for this possibility, hydraulic performance of the ECC pump system is*

based on* 100% plugging of one of the four straiiiers with ft.&..iee ea oss...__ __ _

assumed across each of the remaining strainers. Therefore, more than a 33% extra strainer capacity is available. :This conclusion is conservatively based*on siniultaneous -operation of all ECCS equipment at full rated flow.

~--

~ a.."t 10,occar"'

Extended operation of all ECCS pumps is not required in order to satisfy long term deeay. hea~ removal requirements: Short term DBA~LOCA cooling analyses assume the.use.oftwo LPClpumps and one core-spray.pump, or two core spray
pumps, to' provide~adequate core.cooling.. However,.on a long-term basis, only one

. LPCI and:on~:core spray.pump are necessary.to provide required cooling to the 'conta.lnm.ent and the**core. *ThisJlow would require only one-eighth of the total *

. ~' *...

-:.'-/ <.. sere.en area.: Also, the'.suppression pool water is demineralized and does not ~ ":... ..:\\~L.:... :* __. _.. co~.~.:U~- ~.~,ec;~~~:~~~~~~:~:~~' ~he:_~=-~~~;:,~h~-~-li-~.-~l:pec~~~to remain es.se~tially -~ ~~~

. I J .. I I 1 DRESDEN -_UFSAR ~...,. :r..,. .~ ~ l

. **: : * **.,1..

. :*l

, *.r.

?:'.'.-:;/~.* :;*{: :;/U'*/.'.. ~

CONTAINMENT PRESSURE AND PEAJ(TORUS TEMPERATURE FOR VARIOUS COMBINATIONS 1.~')'11!:: 1 1:;,:'~!* ;*.,.. * ;.

.*.OF CONTAINMENT SPRAY AND COHE SPRAY PUMP OPERATION

?..{t:;:.~:~*4;;*:.;:\\~':\\;. ~*,:;'::_< *.

-* *--*~~~~~c t_\\.t I '. ~. l ) ~ ~. '

,. Containment Spray

. I . *.;(* ~ ,' ?'~*"..

Nu
: ; (> >. '. '* ::. * '*

of

~ 1, 'J' :~::: *. : Case 111

:.. Loops..

~ I ( -~ I'!./*;*~* !. ~

. ;.' ~I.

~ \\r ~ j r '\\.. '\\,

-:~: :~**

~- r' ; *: i'/'*. 1 ,h ': "t*. L', ~. f;.

*.. d -:

. *c.: n.

Noles: '*l i

,2.

j*. i :.. : Q/. 1 .1 .c~.* 2 .. 2 ..(~) *. .2 J 20,000 10,000* 5,0QO.. Core Spray Number or Loops Total

.Flow (gal/min) 9,o~o*

4,500. 4,500 . ccsw Number of Pumps Total Flow per HX (gal/min) 2 .14,000 \\: *5,600 'Y 3,500 Peak Torus Tern . (oF) 168 180 171 186 aximum Containment Pressure (psig) 6.5 4.5 7.2 8.6 7.6 9.4 I (Sheet 1 of 1)

"*l. l~)!;~;r;;11i**', '. ,i I ;

ht!J~1.'"*1tlp-*,,,j'~~\\~.(,l~{ j/~~.'-
- (.;~/; '

! r ) I

l~.t 1~~(.\\~f.W.~1~'.t::fir\\fk~~:t*'X.. ~

1 ": ~ ~i * *,:... "i1':',,:?F,~'i;*.* 11l..,~. )~,': ** .... \\,,._,..

Table s.i-3 FSAR ORES

'\\~~)i~ij'[f;'j;:~~~TAl~M~NT P;~SSURE AND PEAK T~RUS +EMPE~tuR£.FOR VARIOUS COMBINAllONS OF CONTAINMENT .'*:*;:.:*:*:.:r:~:*>*:.* '.. SPRAYANDCORESPRAYPUMPOPERATION J;:,;f.f.f ;~,;;,,.... *1, C.. '... *..

SUMMARY

OF DRESDEN CONTAINMENT ANALYSIS RESUL ts f *<> CASE~.* 1, 1a 1a 2 2a. 2a 2a1 2a1 3. 3a 3a 3a1 3a1 4 .4a 4a 4a1 4a1 S Sa

Sa
Sa1 Sa1 6a1 6a2
l!~ r

~?h ~~=~~:~~~~*:'.;.. ;.100 100 *20 100 1~0 20 100 20 100 100 20 100.20 100 100 20 100 20 100 100 20 100 20 100 60 ,. *-: Heat Sinks. no no no no no no yes yes no no no ves yes no no no yes yes no no no yes yes yes yes .**~1;1 Suppression Pool:.

. (;'{~. Temperatute ~ 600 1*4~ 149 148 150 150 1~0 149 148 '150 150 150 149 148 150 150 150 149 148 150 150 1so 149 148 149 149: -..._.. < sec 't0F) (At Initiation of operator actions) *
-;_: \\*: Suppression* '

.. ~: Chamber Airspace-~* * . ;;.i... Pres5ure at 600 sec 11.3 8.S 16.5 8.7 6.3 12.5 5.S 10.9 8.~ 6.2 12.3 5.5 11.0 8~7 6.3 12.S 5.S 10.9 8.7 6.3 12.5 S.S 10.9 2.e* 3.1

- *: * (pslg) (At Initiation of

'..,. operator actions) :- Minimum* "::,:*.;: Suppression. .. ~:*.* ~~l~=~~nr:=~:nof.6.9 4.S 2.7. 6.3 4~0 2.2 *3.6 1.9 6.2 3.9 2.0 3.5 1.7 6.3 4.0 2.4 3.7 2.0 6.4 4.0 2.4 3.7 2.0 NIA NIA Coil~ainment_ Spray 1': (Dsig). : 1

* *
Peak Long-term ;

r:_._.,

. *. * : Suppre5sion Pool 173. 173 173 173 173 173 172 173* 171 171 171 171 171 175 175 175 175 17S 178 176 176 17S 176 NIA NIA

;* Temoerature <°Fl.

1.: Suppression

Chamber Alr5pa~

., ': Pressure at time of

7. 2-4 9 3

7.3 4.9 3 Peak Suppression 4.8 2.9. 7.2 4.7 3.'1 4.7 3.1 7.6. 5.3 3.4 5.2 3.3 7.8 S.4 3.S 5.3 3.S NIA N/A , :* Pool Temperature Coslg) .t . *Temperature rounded up-actual temperature 172.1 °F .. A description of the containment analysis case specific assumptions are as follows: T,*

'GEllB lh mu e long-term this trend is reversed. After the drywell sprays reduce the drywell temperatlltE" belo the vessel liquid temperature, the break liquid heats up drywell temperature. Th fore a . ng efficiency results in reduced hearing of the drywell by the break. uid, which . minimizes su ression *~bcr pressure. Case* 3a are also evaluated with heat sinks. r these cases, which are . identified as Case.2al an as heat sinks. Both of these e 3al, the drywell shell, vent and torus shell are modeled are evaluated with high Table *3 identifie5 inpt*{ va!ucs (relative ucs) usCd to. minimize th~ SUppiession

c~ber pressUre response. Heat sinks use.v..,,_es 2al and 3al were developed based on the

. *.*;Dresden chy\\vell *and *to~ geometry -~- Which were compiled during the Marie I

_ **.Co~~ent Lo~g Tenn Prograin arid

~

**.. ~

.:C~e~specific -~oritirlnment.in

parameters for the differcn cs are summarized in Tables 6

-and7. \\Except as identifie clow and.iii Tables 6 and 7, the* *

- ues used in the analyses for

e. as. prevfously used in the analysis ~. ed in Reference J and

~-.** .~* CaJ*l-No~~untp~0Ral_'~~aa:oJCow~mentlnWaJ~o~ns.*.. * -¢ . In Case**1 it is assumed that the LPCI/Comaimnent Cooling pumps are operating at the nominal

.. *:p~p flow of 5000 gpDi per pump. and the cs*pump is opcratjng at the rated ~ump flow' of 4500 '

....

gpm throughout ~e event....-*

.. ~ :., .. ~.. Case. la.:.~.*Nominal_ :Pump :Flow Rizte.:.Containment.. Initial Conditions to. M"iniliuu

- .: *.Cont~inment.Pr~lire: :.* -:. *,. *...,:. *

~

~* :. !~.. :

-:E _...

<:. *.. :.-':"-.... _:::-.sam~:as-_Case*fi~--~~-;~~~~~v~*,hi~;~ons*are used to minimize ~on - *:*:.. / *:: -'~-~-~:._-:-; -~b~r:pre~s~.:'}his.case was anal~~ ~d.i:bo~.-.100% aJ1d 20% th~ miXmg efficiency.. .,_.,,*,,-.;:-_... *;.. ~*~*~;.... _:-* -~:;,,.,"':':'0a..~le. '.b.(-:3..:.*',J JJ.$~l"F--.to.:~::_,( ---~' '::

. "-'.~:- *..-,- -

i * ~:*- *.*. -~*:!...-

_

*.c....,-:-... --*~--.;:-.~~'.~.r:'.::;~->-,.~-~~--:?\\..,-~*>;:_

'._:-*~--:-::*.*.*..

,1-. ***

'. ;~.. I

I

Case 2 - Above nominal flow rate for LPCUContainment Cooling Pump and CS for fust 10 minutes and Nominal Pump Flow Rate after I 0 minutes - Nominal Contaiiiment Initial Condiiions .In Case*~ it is assumed that the LPCl/Containmcnt Cooling pumps are. operating with an above _nominal pump flow of 5800*gpm per pump and the CS pump is operating at an above rated pump

flow of 5800 gpm for the first* 10 minutes
It is assumed that at 10 minutes the operator reduces

'. 'the LPCI/Containment Cooli.ilg pump.flo.WS to the nominal flow of 5000 gpm per pump and the CS pump flow to the nominat'pump fiow of4500 gpin. (:ase la - Above nombtal purltp flow rate for LPCUContainment Cooling Pump and CS for . fu:st

10 min"wes. and Nominal Pump Flow Rate after.JD minutes - Containmmt Jniaal COndiJions to.M"mimke Containment Pressure Same as Case *2 except that conservative input assumptions* are useci to mjnjmin: suppresSion
>* -~ber presslirc~ This case was'analyzed with both 100% and20% thermal mixing efficiency.

~. - ~.:.-... '* -' -:;. ~ . ; :_*:.. Cmie' lal *~ Ab~ve nomin;u primpjlO~ rate for LJ'CuContainment Cooling Pump and cs for..

*. :; 'ji,;FJO. minutes ~d Nommal Plimp Flow Rate efter JO *minutes-~ Containmmt InitW

Condj.tions to Minimb:.e Containllll!nt Pressure, Drywell and Torus shell lleat sinks modeled
.,.*: _ *same as -Case 2a except.f:ba.t the d!ywell shell, vent* system, and torus shell are modeled as heat
.. sink$. This case *was mialyzed with both 100% and 20% thermal mixing efficiency.

v .,.f -; ***: -. . *_ * * * : '. *cas*e 3 -Above N~'ttwzal-Pump Flow Rate -Nonuiral Cont~ment lnit!aJ Conditions In Case 3 it is assumed that the LPCI/Contaimncnt Cooliilg pumps <M~ operating at the above

* ~ominal p~p flow ~f 5800gpm per pump ~

the cs pump is operating*~ the above nominal

:.",pump.flow of5800 gpro.thtoughoutthe event. :

f* ~:* **;:~* ** :.

- r;"

.,-,- *:.' ':: ~', ';.* ~!- ~ -.** :..;. :. 1.,. ~.... - '~

-~.(,...,;..,----.
~~-;:.. '.. ~Cas~ 3a.~*Above.Nominal Pump *now Rate - Contamment Initial *Conditions tD Kmimhe
--*: *.;/

>~con.tabz;;,~~{'p,:;;;u~~*, ** _:._*,c.C -~::. *.;:., -...~. ** -~~~\\~~:~>::~y:*:~}<}f> :~~-*.;;_;:'.> ;... ~< :< y

- ~-~~~~~y:~=~~~.-.~~:**~e"? :;xc~t ~

-~nservative ~ut assuinptions are. used to mini~!zt: ~ion

. :~:-:~*;;i}'..::'>-~':.-~~;clWJiber:,~sure.. "-~ case was analyzed with.both 100% and 20% thermal mixmg efficiency.

&~~ili;~~~\\~~:i~ 1 '~~f ~~~f '. ¥i~tki~~:;:- ~>j~serr ;.~~ C..

Case 3al - Above Nominal Pump Flow Rate - ContllinmenJ Initial CondiJions to M'znimiu >

Containment Pressure, Drywell and Torus shell ht!llt sinks modded Same as Case 3a except that the drywell Sh~ vent sy~ and toIUS shell arc modeled as heat sinks. This case was analyzed with both I 00% and 20% thermal mixing efficiency. . Case 4 - Above nominal/low rate for LPCI/Cantainment Cooling Pump and CS .. for fir.st JO minut<s and Nominal !'ump Flow Rate after 10 minutes -Nominal Containment Initial Canditil!ns In Case: 4 it is assumed that the: LPCI/Containmc:nt Cooling pumps arc operating \\\\ith an above nominal pump flow o~ gpm per pump and the CS pump.is. operating at an above r.ued pump flow of 5800 gpm for the fmt I 0 minutes. It is assumed that at JO minutes the operaiorieduces the.LPCl/Containment Cooling pump flows to the nominal flow of 5000 gpm per pump and the CS pwnp flow to . the nomi~.al pu~p flow of!4500 gpm. .J-:ase 4a -Above 11ominalpumpj1nw r'llJ~for LPCTIQ,ntainmOll CtJOling Plimp

an.d CS for Jim If! minutes aird_Nominal Pump Flow Rat~ after JO minutes-

, Con111inment lnirial Conditions to 1'1inimiu Containm~nt Ptasurr

skzi~ as C~e-4 ~~cep1 that comervatil'C input asS-~ons are usccf to minimize

, supp~ion clwnber prcSsure. Case 4al -A6o~ nominalpump flow ~for LPCIJCantainment Coaling ... _.... Pump and CS/or first 10 mm~a ~Nominal Pump Flaw Rau after JO.. ........ mmutu - Coittainment Initial Coluatiolu to Minlmiu Containmmt Preaure,

- */)rywe/l and To~ s/1d/ /1W, sinks ~tkkd *.

.. :--.-~... Same as Case 4~ except that the. c!rywcll. shell, vent system. and torus shell are . _:. *:, modeled as hcai sinks.*.* i:*.*

*.** c'..* c2se s :~

,,,,,.,;,,,,ijlaw b,fl,,. LPCTIOmtai..-ntCoolillg p_,.,;,1 a

.~ ~ 10 '

d Ju:... J~-'.,_,_Flo.., __ <<R-JO *. 11.r-=--1*

~* _-. ~ **' *.*,,... "" :: ";,,'()r Just. nanutes a:n J*a~

.. -~ w AUIC'.. J~ llfZ'lllta-4'fl"R>>UIM. . I...

<;onJtUnmmt In.iJiJll Contlilio_fS,.. ;.

"*:: *:'*.~.,,::.,:..:-.. *

.*.'::.'~**

-:**~**. :*;

~*/: : ;.;;,:.; :c*, -*,.In.Case ~ ~JS as.sumCd ~ LPCIJ'Cont11111!1h m Cooling J>UIDPS me opcmdng.

~~~;-~~fr{.~~;

.:::~ m ~~ti,~~ pump~ ~.~5890.FzlPcr~ and the CS.pump iJ

-~,~:.~*:,;~ ~ ~~ .micd ~flow OfS800 gpD>-for.1he ~ l~ minutm. It is ,.. ;:,,*;:-.-~4f ~,;;.. ~::~~,-assmned tbm at* ID.minutes. thd opcramrm:luccs the L'PCl/Coutaimncm CmliDg *

-~.,..;.,_~.: ;\\..:".=:.:/P~* ::_':*. :~*' *- :*.--,.;:.--:*._: -:~-~ *..:~* -:._:.,...

~ --:-*: :_

... -:. J. ~ *.. ~...* ~~~',:r~;~~:?~:'~:~;~zf:}nJ:mp.flows to*thC iuim;nat floi*orsooo. gpm per~ and the cs pump flow to ~lli~i~,;"~~t~J:s~;*z~~~~-l~~ii;f;;L~ej. '"'**'..**.**************. *** **..... * *

.Cue 5a -A/Jore nominal p;flow rokfw UCl/Cmdobutrod CoolUsg hmp and CS for fint 10 mlnuta Nomilud Pump Fklw llJZU llfter l~ minllla- . Cantainment IniJilll ContlitWfS to M~ CanJai:nnrenl Prasun I S ,.. ___ s -~ .. t.._.. ...:....~ ame as~ -.r ~carve mput-.._.t'wODB arc u:sg,a to mmsm1zc: suppzession. chamber pressure

I.

Cue Sal *-.Ah~;,e nominal pif. po,.. rrztefor LPCI/ConJizbant::nt Coollnc

Pump and CS for fnt 10 minutes tmcl Nominal P11111p Flow llllU q/la' 10 minutes-Contizizunent 1nitiJ Conditfbns"' KinJnriu Con~

Pr-salll'e, I Drytfld antl TOTUS shdl Mat1inla 1110dd!tl Same._. Case Sa e>ceept that c my..dhlicll, vent~ amllmus shell me

modeled m h=i sinks.
I *. -*

l~e..&;a.:l ~ *~a.2 ~ W"dhasignaimrLPCpnititiatjon.all4l.PCuCoutajnmcrrt~pmnps~ . ~ iD:jecticmmodo and ~dim:dy illm *' dlywc:D (no JlowtD tlm ~ ata1low .mieafSlSO gpmperpumpdUrmgtho&st 10 n1jii11fesQrthisevmt.

Aflernceivillg a.Jimrcs m.dia... 111o2 cs ptimps ~ ~

,m, tlm

vessel at a flow me ~5800 &Pm pc:rpump fbr1bD fiat JO JDimUr:s of this evait.

I For Case 6aJ ii is ~**is 100% ffauwl ~ duc;c:m:y of the bleak. liquid with the dryVidl For Case 6a2 it i ~that~ is.GO% fhemal nmina effic:icoey Oftbe ~ JUimd ...:..z. the "'--n h I. """. W.J ~ atmospJ:m.,, ~ *~ '. -. {... ...:.". :* ~>.

,,'};; \\:~~j,ii;,,.. :

CASE 1

:r\\ '~ ~ :* * '*
d;' ' *, *,
-,"\\'*'.**,.:. DECAYHEATMODEL ANS5.1

.~~~;\\;~f ;'~: .x.. *

,r:~ :t*.;*;)\\ ! 'TEMPERATURE ff)'- . eS

'YES 1

~: I*. ;f:*/_.';'

CASE 1a ANSS.1 ' 85 i YES CASE2 ANS5.1 85 YES Table 8.2-3a i<ey Parainetera for Containment Analyal*

CASE2a CASE38..

_.cAsE4a CASE2a1 *. cAsE3 CASE3a1

CASE4 CASE4a1 ANSs.1 ANS5.1 ANS5.1 ANS5.1 ANS5.1 85 85 85 e5.*

85 YES YES YES YES YES .. ).. ' ~ YES YES YES... YES YES YES _YES ('. ~*' .:~*-,.~r*\\~*;-;.. '..... ~.. :;i~** HEAT EXCHANGER K.:* , ~-~-:. *. . /{:~;,._; ';::;-.!- ;* VALUE (BTUISEC-0 f) ' 307.4 307.~.

.'.-:if:/~:fft.1f.:~-~~~ :*.
r:'.:~*ki;({'~:-::*'PRESSURE(PSIA).,

f; 15.85.. ;_ ~- 15.7

,~*.

r*r.:/** ;. . 307.4 3o7.4..,. . 325.4

m.4

. 2aa 288 . 15.85 15.n)'.~ ;.* . \\~.-*. .15.95. 15.70 '14.85 . 14.70. . -. 1.U5 .( 14.7Cf 1.4.85.. ; 14.70. 14.85.. 14.70 .* :,*, l'

.. *l.

l. 13s*._..'

150 135 ,150 .135 150

135.

.*150 20. 100 100 2o 100 20 100 r ** : CASES ANS5.1 85 YES YES 281.7 15.85 14.85 135 20 CASES. CASE 5a1 CASE 8a1 CASE 8e2 ANS5.1 ANS5.1 ANS5.1 85 85 85 YES YES - YES YES YES YES 281.7 NIA . NIA 15.70 15.70. 15.70 14.70 . 14.70 14.70 . 150 NIA NIA 100 NIA NIA

Case 2*1, 3.1, 4111, 5a1, and 8a2 n the same a cue 2a, 311, 4a, Sa, and 8a1 raspec:tlwly' except lh.t the dtywull lhell, vent syslam and tillnll lhell are modeled u heat sinks.

t -**Case 1*, 28, 2a1, 3a, 3a1, 4a, 4a1, Se and 5a1 n Miu.ted with 1~ mbdnil eftlc:lenc:y betwMn the lnak Oquld and ctrYw-n fluid and with 200A mbdng ellidency between the break llquld and drywall tluld.

Page 1

~.

i'.. . ~-* /. '\\.*

.TABLE 6.2-Jb
' *
Heat E~anger Heat Tnmifer'R&te
... :~Side Flow Rate

. <*- *~.(~WPump)_..

*........ o~M-.*_.~/"

.,.. : ~. --~. ;_ :~- ~ - ~: --~ **\\. :-_-_,... l.*7*000* (;'. ~.. -: -. . ~-* '. *.

'. ".::..~. -.

-~ . ;<;~~/(:' ?*~ ',.>*~* ;: y

~.: - !_,-*. -~~.. ~ *:~ ;>-.

-;~.' -

. *1 **

.K-Value * ' ~ B'IU/SEC-F'.. ::, '.

301.4 '.

-:*-1:.* ':
_~

I';' .Heat Transfer Rate (16S F Shell Side . Tcmpcniture, 9S F.Tube Side Preaure)

.1-1 _,

-:., :.... ~-.

~ : *,r*

":.*.* l *-

":.I

' ' ~ -'....... . ':'.~-\\ "." ;.'.:; __ '~* -. -~. ... ;;. ~<~*/*

.~ -v,.

"°"' "'t.-.... ::. ~t ~ :.. -, , \\

.',, i.. ~-~ ;.... ,~*. ~.,,

.I

> ~ I 1:._.;.; ~-..; *. .. ) : t ~ *: .. ~ . f'

.'1
DHESbEN ~ UFSAR Table 6.2-6

SUMMARY

OF DRESDEN U.NiT 2 AND 3 POOLTEMPERATURERESPONSE TO SRV TRANSiENTS .'1' '1 ** Nuniber of Maximum i,, ,._:.1',1.*.,.*..

~ '.

.. ~.

r:j;r~~\\:r:~i* :::l=*=;='.N=**=*~=,t=;=,~=*==*,=* =* =* ~s=a=* =n=v=a=t=. =i>=<>=w=c=r=. =s=p!:llt:;o:u=-i=o=u=s=.======~==========~========l;::;:o~=======T=========t SRVs Cooldown
Manuaily Rate Temperature Operied. *.

(°F/hr) (oF) 0 . 131 161 0 129 167

' '. -~~*. ~:. ;, :.' *. : '

~ *., '*"'...r:,;._:.

, l *

. ::'.~ ~:;<;:.~... .. 1~;**.:.:!j;*:..' ,c *...

1. *'.*

i * ~ * . r'. : ' ) .. ~.. isolation, two RHR loops.. ** .,1 1-..;.._~.:.-..;.._~-+-~~.,--~~~~'---'-~--'"--.;._~---'-....;._-+-~~'""""""~~~~~--.,....... -'-~---~~~~-+-~~~~~~~~-i-~~~~~~~~-t ~

!-* 2B 2c I,

Rapid. depressurization at** isolated hot shutdowil, one RHR loop*. SORV at isolated hoi shutdown, iwo RHR loops Normal depressuriza

n at isolated hot shu wn, two RHR

'258

i13 156 122 160 2'

115 153 loops :. '1----~~~~-t-~~~~-,,.._~~~~~--------+-------------+-~~~-~~--+----~--" ....... -~-+--~-~---'-i 3A* SBA-failure of shutdown

cooling mode, two RHR loops 5 ADS*
. 5.

2100 100 iBO 147 (Sh eel 1 of 4)

l

'~~ll!i~;::f ~,,,):.. ***.. ,,Y.. ~Cl~(tt:>~,-<<,"~' ~\\'Ii, Ji.~i,Ti;'4 ',:' ilj* :J:~*-.:..,,.., '.t'

I:) 'tJ( ",

J. I.i,. I "' ~ '. .. i:>r{E:sbEN ~~-DrsAR * ... :/. : N~tes.to Table 6.2: 1-6. 5, .* r operiitibn *at 102% of rated th~rlnal power-(2578 MWt). 1 . ' '~. . *.. h~ical S~eciflcatiori s*{~*ppr~~~ion pool' w~ter v~l~m~ (1 f2;203 fV'>. * ' *

.].

. has no initi~lv.elodly; '. , ** *:*,',*I.,* . r.. , i'*~,)'l!~;-':.f:~ :,... ;~~;4i: 6,. *;.Wetw~i'l.~nd drywell airsp s rtre at *~b*r~al ope~ati.~g ~onditions:. U~:1i(~~:G\\~; 1:j.*i~/~T:~l*1-?.( :* ;:.*; \\: * :* * *:

,"t:J:J:t 1{i)~~; >;.. 5: t_*: :\\;Normal aux~hary power is availall 1.

i./j:}.jj~~d{!~'::, 'Y)::f:.-': ::> **;

.:;;?:'.;;~:::.,.,.. "[*. *. 6:.:i:: :: :. OfTsite power-is assumed available for all

.1]\\,~'(if 2_( '.

':?. ':. ~ ~rni ~f aulo"1atiC operation of the i'lili1 t A uxilia r

.. 8.. !.
',l *~

-il . !*\\ .. *:ti{(*./_.:y: "~;9. . : Con~rol rod drive flow is maintained con

'.* \\o. *. SRV (manual, automatic; ADS) c

acilies are al 122.5o/o of ASME-rated no

, i*.'temperatures:*

!i.* 11: i2*.. .. 13. curve*(Ma.Y-\\Vltt) for containment ahalysis is used. is considered in th~ drywell o~ 'wetweli airsp'ace. s close 3 seconds after ~.Vt-second deiay for the isoiatiori signal. 1'hey are reactivated when

conservatively calculate m~imum pool
14..

perat~r actions are based on normal.ope~ator aclio1~ tinies and licei1sing basis delays during the give~ evenl. I,

1*

'1* . i,.. . i** ~.: I* \\ ( ... ~ *::.:~.: *........ ' . ~.:. ;:* l {.

~ ~-:.'

'~. . ~ '. :. : : ~ \\.,.. ~' '*' :;***.*. ' --~ . :' 'n" 1 1 1~s" n*.t'N.*.,.* -._. u' FS ... A. R*- ~.

.. 1 L

t ~- ~ ~' '".~,.. I, <* i7>;'- : Drywell fan coolers are initially.

ilable in SORV events and isolation evei to keep the clrywcll pressure.below the

'.*: 1' - ' :: high drywell pressure trip. setpoint Ii ~

1.: 18... ;_ The Abs system is modeled b~ fuily o-penin ve. SRVs 1n the A

' ' '. -: manually at a high suppression pool tempera tu

'J'he ADS system may be actuated

This assumption adds conservatism lo the

.* 20. .'The feedwaier temperature is taken . e actual temperature in the dwater system; However, for that portion of

feed water which is low-er than 17 1, the temperature is coriservatively as med to be 170°F*.

The service water temper re for the RHR heat exchangers is assumed constant 93°F, giving a heat transfer capacity of 127.4 Btu/, 1 per loop for shutdown cooli~g function, and 416.7 Btu/s-°F

21.

22.

. -LPCI discharge iine is dir.ected parallel io flow in the discharge hay. '. 23.

The hr flow mass and energy are.a~ded to flow through the quenchers fo~ SBA. cases_. This appro t makes the s of SBA cases more conservative because it maintains, a* "hot spqt'; around the quenchers at all tim I

--***--:-~-----*--** *--* *-

1.$~'.;:~k-i~;f:~:i:*r~>-:_.\\-.;:d.*~: __ : ** \\_

i*/,;i):"*l~f'iiJ-l.*.f,'.J.\\.'" '*',

;l~\\~!~fi1,.. ; ~,II*:','. in'i~*
'-..;"I:

! ' /

.i: .!.~~n;~}~~~~:;:;,,dbi,, * *.** r ~ *_. __ *

,.~*'._ *_.

- - i"*:11!.,;1.~:t:l~*'-'*J.~11,'l"1**'1i1J-!'.i

'::... ~~ - ~ -:* ~ *.1.

, ~

r.-

J....

t I *. I 'I**. DnESDEN :__ UFSAR ~~.,:;:.;~.;.;.:.;.....~~;;;,;..;.----*-*,~*--*--*-*---*-"~--------..;...-**--**-*,-*....... ----;.....--~-------*-**----~;.....~-;.....'....; __ ;_,~~~--------------------~--~--~~~:-1/'.

iif :,;'. -* ":,:'i., *-

_ *N,otcs lo Tablcf6.2-6 (Cohtii1\\.icd) !.*~ 1 il,,r', 'l~he ~ys~~ *~* term ina led w h~h t~~ pool iem peratu~ reach~s a fuaxim ufu a~d turns aroUnd, or whe ... ~-} *-

"dischar.

ac~ivities of the SRVs are over. - --

.~n ;*>.. ~7,.*.- * * ~ ~.
25.-~ :*:*.-*The operator w attempt to reclose-an SORV. Bas~d on 'availabl~ operating plan-t data prior

'the implementation of '-~;;'-: -.,.'-~the re~uirements 0 I Bulletin 80-25 (Reference 20), SO RVs have been shown to reclose - an average pressure of

>

: - : *-:,260 ps1g. The-lowest r _ osure pres_f?u~c r~corded was 50 psig, and t_his value is conse, atively assumed for this

<;~/~:-:.;f~,'_::':: ~~al~si,s:, : - _ 1 _.~

<'26.!: ' ' : The isolation condenser can be ac ted *by a high reactor pressure signal 1085 psla susiained for 15 seconds. -

'-'~,However; an addilionai 60-secoi1d del for its lube side outlet valve o ning is llssumcd to line up the condenser.for

_:-';/*_, ":";: ful_I operation. A total of 90,000 gailons is vailable from the cortd sale storage tank to supply the shell side water .*:*i;,; ;.:,inventory whenever needed. The isolation co enser has a de ned cooling rate of 252.5 x 106 Btu/hr.

.; r*.:; ~:f... ~\\ :.*.
~:(~ ;*;...

l ~;- \\.~'-: '. ';' ~ -;-1 ** I ~ ~:

~- 'll

'*. ~-., : : : '\\ .. -fi. ~ ~*-

-.f;. {: .. 1 * . ~. * *. DRES])EN. -UFSAR... **

-'l'Sbie 6.2-7 CONTAINMfilff COQLING EQUIPMENT SPECIFICATIONS
co~tainmeni C~oling Heat Exchange~..

I

" ~.. *. (2) CCSW inlet temp al to75 degrees F when* the plant is erating.to compensate for the reduce w, heat exchanger e low pressure ECCS net positive suction head ual heat exchanger performance is 98.6 ES BTU/hr.

~
1 **

. 1:... ~ ,, I( .. ~seN:C ~Me£ ~ Uk.ID.ER_ i>FL Cf b(4-{) . ~. ~. *--- -.:..~_;._~ . t -*.:. - ~

.!.\\, -*---;--,.,~-. - -.~ DRESDEN - UFSAR Table 6.2-7 (continued) CONTAINMENT COOLING EQUIPMENT SPECIFICATIONS Containment Spray Headers Drywell Spray Headers Number

Size*

No.. of nozzles (each) Type nozzle.* Suppression Chamber Spray Header .Number Size.** No. of nozzles

.*Type.

11 _--. ' 2 8 in. schedule 160 160 Fog jet. 1 4 iii. schedule 40 12 Fog jet

(Sheet'.2 of 2> *..

~.

FAX NO.: 18159422269

---~.-,-,.......... -**..................

I., I I I J ~ 213 am I~ 10 6-V _, UICA I aoo. t-------J.--...;f ___ --1-------1--------t------- j / .. ;.*,5;_- . :... "LL.:. >(!)

~

'I 'I I I I I

' I.,
Figure.6.2-19a - Short Term Supression Pooi Temperature Response

.--. -:'l I ~. ~. *_. ( .r *. /.: '- . ~-.. -*'. =_ +** =~

. ~ UJ *. a:. . a.... . 11111 D1llB .. llZ19f

,.:.,-;,.... : ~.
1

-I._,

1

.] ,1 Figure 6.2-t9b - SbOrt T~nn S~pp~i~n Cb,~ber Pressure llesponse * *Casie 6a2-6CJC'A>>.MiXm& Efficic:ncy. .. -: ;... ~ .... -* ~.' -:.,. :** i.*. . :.. *.*.. '~*..... -;\\_. -~ > **

.r.

.*f-

"-! ~* d:.-* DRESDEN 2/3 CXM' RESPCN;E TC SP TE1P ux:A ~~____:---...:i-_ _____ ~~--~----1~--~---ir-~~

300.*

n-'.' :* -- :200. r..-'"""._:---"""'.""'"--:---t------~__;,------+-------4------ U.,;

(!) **.

UJ 0 .:.1 -.. --~-. uJ s 1*00.

.~--'*

< ffi c,,... ~*

u.i**

.~.,. CM.t

0121M

. lOSUis

.. 1.*

<\\-7 -~.. ~:.*. ::-'.* :=;~: :.::*

-.~

.. ::.: <.'-.*~*

...f r**

I:*.. 100

., -../'*

..

1000 TIME.SECONDS 10.000
100,000

"~ '***- : -

::.~,:::: \\ii~~-~~~:ioa :-LOng Term Supi-ession *Pool Temperature Response.

-!"~--o~.--.. __, *"';, :> t1000.4) MiXing Efficiency ease 2a1 - High -'.:.. _~-!... . ".::.~~:: :Y ,~*~};;:~~:-{:* -~-~ ~ ~-:.' -~,--,~';:;'r:: '.;.'."""',::*:~::;_~*,_'~."':.. *....../.A*"'- ~.. -. ~ -:*.: ...,., :. ~..... . ---:-**~-*

DRESDEN 213 .am RE5Pcre TO l.OCA so*.,__......__;_ ___ ..J.-___ ,;__ __ _,_ ______ -+--------T----- ~ -:. *-- . ~ _.,_. ~ :. 0

io*

1000 10,000 °"* o~ lO!t* TIME SECONDS. '~~ '* -:~."~ r Figure 6.2-lOb.:: Long Term Supprmio~ Chamber Pressure Response. . : (1 QO~). Mixing *Efficiency ;

. "' *~ *~**:**.. *; ~'~:~'}+;~:<\\~:*!<:.~.*..
l

,_-<~* :.*:* :-": *=*.. J:(~-:..

100,000 ' Case 2al *- High .* \\ . i*

. :~. -:. DRESDEN 213

am* RESPtJEE m ux:A 5P TEf'P 3.00. r--------!-----------4--------+--------+-----

200.r--------+----..;...;..----i.___;,, _ _.;.. ____ i----------+-----~ s 100 :t-----~--+---....;,_---"-........ _ _;_ __ ~-------+---- ~ 0:: UJ .--~. UJ -~ '0._~_._.:.....i..........i.....i~..L....J"------___;;;._i _______ -J.. _________....i... ____ 10 100 1000 1~00 100.000 CM.I OlS 1051* 1lME SECONDS Figure 6.2.,lOc - Loni Term Supression Poof Temperatu~ Response. '* * *' (20o/c) u;.... ;...,. Effi

0

.... ~ Cl&:ney** *.. ;* ~' ":** Case2al~ / \\.. :.. *- ~.. -.. *-.**;:*::--~ --~--).:~ -:..*.

.~ -.;,

_:~'> __ ~~-~:.::-.-:* -.:. r; ~... ~.)t~.--~l::;~;~:'>-*::P; -" -:. ~..J...:.. *~~

.;:.2

... *_.:.7:": .. -.:.--.~:.. r-';, ~

.. CI.

0.. I UJ s en en UJ a:: Q.; DRESDEN 2/3 aM ~TO LOCA ~ PRESSl.RE ~**

~.~

.~

. 5fil
~
- ~

.. ~:

.~

t~
~
- - ~

, _____...:, _______ ~~~~-----:-~--~-----------i------------1r---""'.'----- r*.:.*.* \\~:;'. l

60.

- 3,'\\j 4'0.

I ~ I

~

I I

20.

. I

.o. I 10 ,1 \\ r .J ,1 1000 10,000 100,000

~~j

1~
-.~t~

r*:*:

- Jo....

!:~ -.. -<f.i ---~-.:_-:.. ~...., \\ 100,,.:. '~ *., Oii. 01*. TIME SECONDS

1051*
-c.. Figure 6.2-20d ;. Long Term Suppres.iioii Chamber Press.ire Response* Case 2al - Low (2.00A.) Mixing Effici.

'. ency ....... ;?.. :: .e~-~.'.**. r *~h .; ~>... -*.. ~- ;. -*~

~--~-"-'

.°"'~* --.: :-'"*~-

,J., .. :.:~.' '. ;. ":.;~ ~----~--~-.:.'-f ~~'~::_. ~--. i~-~~~~t~;, >. .-**:.,:... _**:~+ "~- -7.:: -'t*'.::<~*,;;.: ~ y'.

... * ** :... ~..., -~. DRESDEN - ti'"FSAR that could be accommodated without any clad temperature rise would be extended

from 0.2 to 0. 7 square feet. The 0. 7 square foot break is equivalent to a double*

ended rupture in an 8-inch line. For very large breaks the continued injection of feedwater does not influence the peak clad temperature curve so markedly. These breaks would cause the vessel to blowdown very rapidly with or without feedwater. The resultant core thermal transient would be terminated by flooding the inner shroud and since any feedwater flow would enter the vessel outside the shroud, f eedwater cannot be considered as part of the flooding capacity. Hence, the end points of curves C and D are at essentially the same peak clad temperature.

6.3.3.4.3 Net Positive Suction Head for ECCS Pumps emonstrate that adequate net positive suction head CNPSH) will be. available to the core sp. ray and LPCI pump:z::st all es, an analysis was performed based on the following degraded conditions:.

A. An indefinite loss of ite power. *. B. An. indefinite los!V<r:ne onsite diesel generator.

. /.

C. The ma:tim-gm service water temperatur~ - normally* the service \\\\"'a~er is at least °F cooler :than mmmum, which would" reduce *the peak pool ,/. ~

D. Th ma:timum pre-accident drywell temperature (150°F) and relative "dity (100%).. Normal operating con.ditions*are about 135°F/35Cie relative humidity which increases ~Sf.I by about 4 feet due to increased gas pressure resulting from the increased moles of noncondensible gases in the centainment. Even if. a sma1l leak preceded the accident, thereby increasing, thP. drywell temper,ature and relath*e h~idity, :the moles of noncondensible gas~ contallfed in the.primary containment would still be specified by the normaYconditions since venting of.these gases is not
allo~e.d. Thereforeyassum~d initial conditio~ ~e very. conservativ.e.

E. A minimum pre-accdent containment pressure (0 pSig) - normal operating pres ; e is CU?Tently 1.10 to 1.25 psig, and there are no circumstanc under which a* suba~ospheric pressure would occur. F. Accid actuation of containment sprays at rated flo~ - proceduTally th rater will actuate th~ sprays only' in the event of an abnormal containment pressure...

Therefore, actuation of the containment requires an operator**error. Actuation of ~e containment sprays I. l

_, Will rapidly reduce the/c:ontajnment pressure/. /

/.

0J-L q h07 S

- . *~i

... * ~./ G. _Containment gas J.e~e at the. rate of 57er day. ( .-.'. : *The results of the analy~ are summarized in Fi ' e 6.3-80 where the containme~ / pressure available is ;hown to always * @t pressureJeguir~ *.... !' - *ooe flow . n./!. v. IA 0 f,CI YI ~ .r ,.,~ r k, I' tr' Co! v.s /? '.:'fff,'.0lf 5:c1;'~} < : /;:l,,;~~*;:a~~ 's. 3-77 v ',_ '160 Ga -..

c-c--- -

\\

- ;. --,~'

i.
i': i..

"**t

. ~-....... DRESDEN - UFSAR

*--*****-..:.*******--*~*-** ****-** ----***

l

Additional analyses were performed to determine the available ~?SH for LPCI pumpds asdsumthinfigllvarious m unctions as defined m GE SIL 151. The analyses cons1 ere e
o owing L Cl pump operating configuratiollS;,*

I A. Case 1-T ee and four pump combinations injecting simultaneously 'l into.both r circulation loops With one brok~ *loop. B. ~ase 2 Three and fo~ pump comb~tl~~ injecting into one broken 1 loop. he break in this case* is assumed at the injection point ill the j re : ation loop, and no credit is ;a.ken for recirculation piping \\ . r istance. / Case 3 - Three and four pwµ-p'~ombinations injecting into the mtact I loop with the discharge valve open. **

i * *

/ following assumptions were made in the calculations: . I. /'... r \\ A..Torus water tempe~ture of 130°F was assumed and was considered to 1 . be the maximum emperature. aken.for the increase in torus level after the LOCA. I I

C. *Atmosph *c pressure about the suppressirm pooi and in the drywell was!
_ *taken t. e '14:7 psia.., *.

.:,./. I I D. *Re to~ pressu~e was iaken as 56 p5f~. -, *.* ._. /

_... * /. _,*....

E.*

he containment *coolliig heat ~changer bypass valve was. assumed open.. -. *

-/* F. LPCI design.flow*point 5350 gal/min \\\\'"as used.". ** .G~. Runout was. interp ed as *a point on.the flo~~* characteristic cun*e at. I which cavitation beca~e.the net positive SlJ:ction required e.~ceeds

.. the.available.1 J

. LPCL ~fJ ( DF-.~6 -06?:).* H. Thefsuctio alve isolates even if the.discharge valve* does not and, thu_t

will prev
t bacldlow through the. pump.

i ... The resuJ.ts oft ese analyses are presented in 'fables 6.3:17 and 6.3-18. A revieJ . of the data in cates only a few instances in which the required NPSH exceeds the * .. available -~H .. In ~. all co~ons for which-:i small deficit in re~d [

L NPSH *exj.sts involve _postulated failures or breaks wfuch prevent the reflooding df.

the. ves by the LPCI system. The most extrem6" case is a 3-foot deficiency in dne

**~"-' *:, c*_

,:ofthe ase 2 three-'pump combinations. The ~ence of a 2-psig pressm:

th~.

ell will offset this deficiency, and 2-psi the dryWell is one of th ** gna1s \\

* * :.., ;:.",:, *-_ *~

.. - :". w ch *initiates the ECCS.. *AfthoUgh ll pressure is taken as *a spheric, fch- ... ~::*:~.. '. : e breaks assumed.in the calculations ere will be an.estimated to 35 psigr** -.:;;:;'.~.. ~;~*'?'~ _.\\. -. *.. *the *~.;en and *suppression chambe. It is, *therefore, concluded ta conditio -:{:,_,:~,,-eY**~:** **,,..

will.ndt exist *wherein the NPSH
not be sufficient to prevent

".'itation.

*~..

~rii;5~~:~~t2~\\_. : ~.~

LHowever, ~e p~p. vend~.r._h~ nducted cavitatiori ~~* at p ts between 400

. *. *,.~--;*.-::.:~-h:.~.J'~_:::~~:,"... ~.. ~~-:-*and 6QQO:gal/mm 'Yl~*no ~t effect on*the:pump _m~ als after an hour f. ~ (!i --~ : --

Insert G on page 6.3-77

The evaluation of post LOCA NPSH for Core Spray and LPCI pumps was divided into two portions:

Short Term (less than 600 seconds-no operator action credited-vessel injection phase) Long Term (greater than 600 seconds-operator action credited-containment cooling phase) It should be ~oted that the 600 second mark for operator action was.. established per UFSAR Sections 6.2.1.3.2.3. as the time in which credit for manual initiation of containment cooling Can be taken.. . 6.3.3.4~.l

CS/LPCI PUMP Post-WCA Short Term Evaluation*.*

Ac8lculation was perfomied to evaluate LPCland Core Spray NPSH 'requirements in the short-term post-DBA LOCA Short-term is . _, *... *:considered the time.period from initiation of the Design Basis LOCA until .J 0 minutes post-aceident when operato~ action is credited. .. ***:. **" -J'he moSt limiting failures relating to Peak Clad temperature (PCT) wer~ * .. *considered: * .1)

SF-LPcl: *failure of a LPCI lnjectl~n Valve.
This case results in two (2) Core Spray pumps injecting*at
'maXimum flow 'with four (4) LPCI pumps running on minimum

. **flow onl)'... ~

- .*... :: 2f SF-DG: :Loss ~fa Diesel Generator * : *

.: This case restilts in two (2).LPClpull!ps and_one (1) Core Spray*:* . ** *. * *.

pump injecting af maximum flow.
The most.limiting. failure with regards to LPCI/CS pump NPSH; however,
js failure of the LPCI Loop Select Logic (SF-LSL). This scenario involves
the LPClpwnps injecting into a broken reactor recirculation ioop and is

~ :* '. Ciiscussed in deiail in GE SIL 151.

From a PCT perspective, this case is
. : * *, 'identiCal to the SF-LPCI case since *the net result of each scenario is two
,- * * :*. *..-:.* :core*sPll'.Y pmnps injecting in~o the core with no contribution from the

_ *.LPCl pumps. ~F-LSL is the NPS~ limiting scenario due to the LPqJCS .. *.'_',.'.. :*.* pumps* operating at the highest achievable flow rates, resulting in the.. . ~. ~i.. ::_ * *maxinium.pump-suction losses and NPSH requirements. Additionally, the.

..~~ *. __

'*.. * * * ;_/~,;;:":,.'.,LPCI:water escaping to the containment results in reduced containment . *;.,. ; ' -:~~:: ~;;.tf:?' and :suppression: pool presslires, which limit the available NPSH, See *.. <. *.:..:.,c:-*~<<*,*., :-.:*.;.:~.~; '.Secti<>.n.:.9~2.l.'3.2;7;:._ Both.the SP.;.LSL and SF-DG single failure cases ~. *. : ~

-~-:

,-:- ~ -.

-*-.. -.-.. ~,

were evaluated in the calculation. The SF-LPCI case is bounded by the SF-LSL case. The calculation uses the following inputs:

1. *Maximum LPCI and Core Spray pump flow conditions (un-thrott!ed system, reactor pressure at 0 psid), maximizing suction friction losses and NPSH required.. *
a.'Maximum.LPCI and Core Spray pump flows-Case SF-LSL CS I-Pump Maximum Injection Flow:

LPCI 3-Pump Maximum Inj~ion Flow:* LPCI. 4-Pump Maximum Injection Flow: 5800 gpm 16,750 gpm [5610111,140] 20,600 gpm

b. Maximtim LPCI and Core Spray pump flows-Case.SF-DG

cs.

I-Pump Maximum InjeCtionFtow:. 5800 gpm. .LPCI 2-PumP Maximum Injection. Flo~: 11,600 gp~ *

,_'. ~.:-- '.- "2. Increased clean, commercial steel suction piphtg friction losses by 15%.

.,to account for poten~ial.aging effects, thus m~g.suction losses.. -~**)*>:.;*.. *.. -. .. :3.. To acco~t for strainer plUgging, the mo~ limiting of the four torus* strainers is assumed 100% blocked, while the remaining three strainers ' *. -. are assumed cl~.

~>

... ~.;... ~.--. **. -. ~- -~

*. *_ /..

-~ ... **.!;:*:~~~:~*.. ;;~;.:<:' -:., ::_. *'. _<~ _ *.~: /" ::4. ContaiDment conditions used in the analysis are given in UFSAR

_:<'.-::.-~.:~ ::,.:**:.): <--~<::_/-.. ~-.'-- *:.- * * :*Section 6:2.1:3;2.3 which nlinimize NPSH available..

~-.. ... *: ::. **.. *,... :..:~ ,1' : .; -,.:_ -._:... < -:.:..-- **:

__
5: *-Initi81 suppressio~ pool.temperature is 95°F, which is the maximum allowable pool temperature under normal operating conditions. This

. -: *value is used as the initial pooi tempe~ture to maximize pool peak

: :: :.-<~ ** -__ : *. -~* * : -~. __ : -.. : -., -.. *... temperature, and is used as a minimum temperature during the LOCA

-_--, *:. *, ___ -*.-.:. ~. -. *-

to maximiie piping friction losses (maximum viscosity).

..( .. ~/ _* ~ .. _ :>c<~ _*,*. ::. 6. _*The miriimum Suppression poollevel elevation using a*maximum -

J:<.. : **: --_:_, :,

'.~-, : ~' ~drawdown of2.'l fLis491'5", (491.4 ft). LPCI and Core Spray. -~""' _'.:{*:~f?~'~.-_::_*-:~7-::'~'7-*j~- -~:~* *:puml>eenterlineelevation*is478.l ft. - : -

- - - -~~. -
      
      -::: ~**--~c:~.i:*~~::/;::~~~>~.~<--~*~*~ _.,~;.~- *'~* ~*.-:* -.~*-..

-~- <:: .. *. - *~ :< *. ..... ~..

:,:i.-*'-~-'-i'~.;~,*~',,'f,~~t-'!i(::).'-',*?:;c:!:""'i:<~'.~:~Y:.::~-:\\7; <The.suppression pool strainers have a 100%-elean head loss of 5.8 ft.

~-.... - *. ~-

. - '*..:.*.-)

8. NPSHR values at various LPCI/CS pump flows are taken from the vendor pump curves.

. The minimum suppression pool pressure required to meet LPCI/CS pump NPSH requirements was determined for both the SF-LSL and SF-DG single failure cases. The minimum pool pressure required was compared to the minimum pool pressure available post-LOCA for two cases: Case 6a2 with 60% thermal mixing used for SF-LSL containment conditions. Case 2al with 1000/o thermal mixing used for the SF-DG containment conditions. ~Ifthe pr~ssure*available is greater than the pressure required, then adequate ..

NPSH exists. If the available pressure is less than the pressure required, then the potential exists for the pumps to cavitate~ resulting in reduced
flows.

.. *.For: the SF-LSL case, no cavitation is expected to occur for the first 290

seconds post-LOCA During this time, the LPCI and CS pumps will r

deliver maximum flow of 5800 gpm per pump. Since PCT occurs at about ~*. 170 ~nds, the CS pumps will deliver adequate flow* to ensure no impact.

. on Pct.. After 290 seconds, the LPCI and CS pumps may cavitate,

- *.- resulting In reduced flows. The CS pump NPSH deficit reaches a . maximum of 10.0 feet at 533 seconds. Under these conditions for NPSH, Core Spray pump flow will reduce from -11,600 gpm (5800 gpm per pump)

at 290 seconds to abeut 10,200 gpm (5100 gpm per pump).* This.

_.... _* ;

represents the minirilum expected flow from the Core Spray pump for the

-. *.. : *. *.7.: :~:-

290 to 60.0 second interval. Figure 6.3-83a gives pool pressure, * *.

.....

_::*< -~-temperature,'*and LPCI & CS *pump required pressure for sever81 pump_

.*:.*,: *. :.<: *.:*,combinations over the short-term period for the SF-L.SL case.. ~ t.; '. .. As.~ted above, a potential exists f~r the LPCI and CS pumps to cavitat~* after the first 290 seconds post-LOCA However, as part of the original design.ofthe plant, the pump vendor performed a cavitation: test on a LPCI *

* *- *.. *-, *. * *.,.**. pump (a Quad Cities (RHR) pump was actually used). The Cavitation Test Report for Bingham 12x14x14xl/2 CVDS pump demonstrated no.

.... _* **. *: evidence of any damage to the pump components from cavitation with up --~. : : '~:* :;; =:~ *.*

- to one hour.of operation at' the cavitating condition.

~... ~ ~* *:... :.-. * '~-; ~.: -,~:*.. ~~--nus ~alysiswas r~viewed with ~espect to the C~re Spray ~ump ~d the '. -~.** *.. * *. : ' * '_::.results deiermined to be applicable. The rationale for this determination is . ' *,....... -: - -~ '* ~. ~

~.. ... ~ -. -. ***~. . :r* . :: : =----~* ->. Core Spray and LPCI are the same make and model pump (only impeller diameter is different. LPCI and Core Spray utilize the same impeller pattern, and therefore the same overall characteristics. All LPCI and Core Spray pumps have tested NPSHR curves that are essentially identical (within 1 % ). For the SF-DG case, adequate suppression pool pressure is available to satisfy LPCI/CS pump NPSH requirements forthe entire 10 minute period. That is, no LPCI/CS pump cavitation will occur, nor will any reduction take place from 5800 gpm for Core Spray and l 1;600 gpm for LPCI (5800. gpm per pump). Figure 6.3-83b gives pool pressure, temperature, and* LPCI & CS pump required pressure for several pump combinations over . the short-term period for the SF-DG *case.

LPCI/CS pump flow requirements are as follows:
- **For the SF-LSL and SF-LPCI cases, a two-pump Core Spray fl.ow of;;:::l.1:300 gpm up to the200 second mark results in a PCT of S2030°F,.

For the SF-DG:case, a two-pump LPCI flow of at least 9000 gpm and a single *core. Spray purrip flow of at least 5650 gpm are

required for PCT considerations.*
* *
Oruy a cof1:stant ~ominal total pump flow.of 9000 gpm is required

.

to achieve 2/3. core reflood in less t~ari 5 minutes. * *.

Therefore*; under the most.limiting single failures, the ECCS. will still

perform its function in _the short term.with no credit for operator action.

. 6.3.3.4.3.2 . CS/LPCI PUMP Posi~LOCA Long Term Evaluation .

The evaiuation exainined the Net Positive Suction Head (NPSH) available*
.. to theJ)resden'LPCI and Core Spray (CS) pumps aftenhe first 600
s~condsfolloWing a DBA LOCA for.several pump combinations.

. -~*:* :. :---.*i:.: :'* ...... If the. suppression pool. pressure avail ab I~ is greater than the pressure ....:, <: _.::>:.:;.::*.**_~: ~* *:*: * .*.. * : *.. required for adequate NPSH to the LPCI and CS pumps, then these pumps

".. ..{~i~~~';:;N:~;,/;, *,..-*

-~ ~-'.**-~. *. -.. have.adequate NP.SH for operation. *.If the suppression.pool pressure

- - ::~. -.:.;; :*,":..I: *--f~*-

-_ : _:.availab_fe: is less than-the pressure required by the pumps, then there.is in-.*. *

:~.:;-

..::_::;*'..'~:*\\ ':>.... - *. * *:<** ~-.. >.adequateNPSH for operation and potential.pump cavitation. In these

cases were run to establish the ability of the operator to throttle the pumps to an acceptable condition. A spectrum of pump combinations was explored to determine the bounding NPSH case for the LPCI and Core Spray pumps. It will be shown that the 4 LPCl/2 CS pump case is bounding for NPSH.

The calculation uses the following inputs:

l. Various LPCI and Core Spray pump flow conditions are evaluated (See table 6.3-i 8).

2. Increased clean, commercial steel_ suction piping friction losses by 15%

to account for potential aging effects, thus maximizing suction lpsses.

3.

It is assumed that at l Q minutes into the accident, operator action will be taken to ensure that the LPCI/CS pumps have been throttled to their

.rated flows.(5000 and4500 gpm respectively). Therefore, the pumps .. are attheir rated flows* at the time of peak suppression pool temperature (-20,000 seconds).

-. '4. To account for strainer plugging, the most limit_ing of the four torus
.* strainers is assumed 100% blocked, while the remaining three strainers

. are assumed clean. -5. :'°Initial suppression pool temperature is 95°F. This is the maximum . allowable suppression pool temperature under nonn81 operating . conditions. :,....... .6.

The,-.co~tainment. pressure andpres.sure responses provided in case.
2a(l}with 20%.rnixing as:shown in lJFSAR Section 6.2.1.3.2.3 are
* *.used.- *These.responses result in the boundi~g NPSHcase.

".7. *_ The.miriimum torus level elevation with a maximum drawdown of2. l ft.

is 491.4 ft.* Atthe time of peak suppression pool temperature, a recovery of Ll ft occurs, resulting in a net drawdown of 1 ft.

. *. * '" *_,: 8._.. The torus ~trainers hav.e a head loss of 5.8ft*@*10,000 gpm clean.

._.*.:. *..... \\ *9:* -iPCI~and.Core:Spray.p~p centerline elevatio~ is 478.1 ft..

.. '... _.._,: *.. ~ _,---... ':The.cai~ulati~n dete~ed the.~nimum su~pression pool pressure

.. :~*~: -

- : -*:.**-:;L*.=.~*>:f;.. :::*fequired tC? ~eet. pum.p'NJ>SHjequifements*for several ECCS pump .,. * * * ;_ -:,: :.*:combinations... The calculation shows that adequate NPSH exists to meet

* *c

.** * c**"- COre SpraY.PtiiiiP requiremetitS post,LOCAfof all ECCSpump , 1.*

f'.

"1 **

_ ~: ---.

combinations. However, potential exists for the LPCI pumps to cavitate at rated flows in the 4 LPCI/2 CS and 3 LPCI/2 CS pump scenarios. For these cases, throttling of the LPCI pumps to below rated flows may be required to ensure NPSH requirements are met. A minimum of 5000 gpm. total LPCI flow is required for containment cooling. Table 6.3-18 provides NPSH margin for throttled LPCI cases. Figure 6.3-84 gives the pool pressure and LPCI pump pressure requirements for several pump combinations over the long-term period. Operators have been trained to recogruze cavitation conditions and to protect their equipment by throttling flow if evidence of cavitation should occur due to inadequate.NPSH. The control room has indication of both discharge pressure and flow on each division of Core Spray and LPCI. The Emergency Operating Procedures (EOP's) also provided guidance to maintain adequate NPSH for the Core Spray and LPCI pumps. The NPSH curves provided in the EOP's utilize torus bulk temperature and torus * - bottom pressure to allow the operator to determine maximum pump or system flow with adequate NPSH. These curves are utilized as long as the core is adequately flooded. . 6.3.3.4.3.3 NPSHMargin

Figure 6.3-80 gives a graphical representation of the minimum required

containment pressure to meet NPSH requirements for both LPCI and Core.

Spray pumps. The _chart covers both the short-term(~ 600 seconds) and long-term(> 600 seconds) periods. The containment pressure response shown onthe chart, and covered in . UFSAR Section 6.2:1.3.2.3, *is for the following pump combinations over the short and long-term periods: ~ 600 sec > 600 sec 4 LPCI pumps/ 2 CS pumps Case 6al -60% them'lal mixing. _l LPCI pump/I CS pump* Case 2al-20% thermal mixing The LPCI and Core Spray required containment pressure on the chart is for

the following pump combinations and flows over the short and long-term periods:

--~ 600 seconds 4 LPCI pumps @ 5150 gpm each/ 2 CS pumps @ 5800 gpm each*.

> 600 seconds 4 LPCI pumps@ 2560 gpm each/ 2 CS pumps@
-.:._~:*... **

. ~:-.-~--.* 4~00 gprt?- each_ ~-;_~::~~i;:~~7: :~_, :'.. ~,...

-. "~

._. *.: * * '-_ At runout flows, the. Core Spray pumps have the potential to caVitate for* a .-.>~f**::c~(;,: 2

_-_>~:.*;*;*:*T-~\\~-,*-~i.*<; __ : -*s.~o~:~eri~d ~ftime (290 sec-600 sec) during the~ 600 second period.

. -~_:r *~-: -=* -:;:~ _.:~*--* *. ** --~.. *7 ** **: ~ . ~-:... ~~ ~:1~~~~~~~~~~0~11:;;: * ...*. : ~:.::*:_*_:-, r~3~-~ o~ 'f-._

-~.. _j?* This is acceptable per the discussion in UFSAR Section 6.3.3.4.3.1. Figure 6.3-80 also shows graphically the ability to throttle the Core Spray and LPCI pumps to an acceptable long term operating condition as discussed in UFSAR Section 6.3.3.4.3.2. . -;- f*.. '--~ :.: '.. *) ~*~* :. ;

.*."I. OF'l.. ~10tl . The valuation of post LOC twop

- Short erm (less than 600 sec phase)
.*
Long T (greater than 600 sec ds -operator action ere "ted - containment cooli phase)

It should be noted t the 600 5ec0nd mar for opei:mor action w lished per . ** IJFSAR Sections 6. .3.3 as the time in whi credit for manual initi ion of containment culation examines the et Positive Suction H d (NPSH) available to d Core. Spray (CS). mps in *the first.600. conds.following. a D

*
Specifi y, the GE SIL 15_1 was evaluated, which ostulates.a failure oft
e LPCI

..

Loop Sel logic. Such a failure
ults in 4 LPCI and 2. S pumps operating,
h the.
LPCI.pump injecting into a broken

. ctor recirculation loo (minimizing flow to r , for Peak C Temperature conside~ "ons). ".*Due to the high ows anticipated, the

.Spray' pumps*

y caVitate; resulting *1 reduced system flow.'* This reduced flow calculated and co pared to the. minimum ow required of the CS stem. This calculation * ... will be PC?rformed . g a reducer;i initial to. s temperature of 7 5 °F

2.psig:

-~ e minimum suppressi pool. pres5ure requir to satisfyLPCI and S punip NPSH _."re . rements

was-det

. ed under.short-term ost:..LQCA conditio . pr re reqtiired is greater the. pressure a. le, then the potential . - for the. ' .pump to *cavitate, resulting. reduced flows. A nu

um Core Spray sy mflow of
2_76 per.pump).is req "red for the first 200 s onds post-accid~t to ure the*

....... aµao>.below 2200°F whil a nominal Core Spray ow of 4500 gpm is q>table econds_.* . *

NPSH Requir

.(NPSHR) cur-Yes fo the LPCI/CS pumps provided on the ori vendor pump* es.* These NPSHR cu es represent the point which a 3% reduction

:* :.--*--pump develop~
has.oCc1lrred. Ca "on tests were perfo ed on this pump mqdel
by.~the vendor at
ous flow rates~ The t data indicates.that tli pump* remains stable_
: for ~several.feet *bel the-.NPSHR -value,:

"ch is* expected, b re the pump.head . collapses* (full caVitati f Based on th(dlow tes at which the pum were tested, it is .., :*'_-~*---+ &,,<*.:.. ossible.t~.. develop a uced *:NPSHR :curVe. hat represents the po t at *which.full

. ~ - *.*>>-~)~~::

_:{;~.:~ca **taiion ;has *.beeri *achi ed. -Thus, _gi~ 8: oWri set* of.conqiti~n (temp~ture, * ._ *. ~:*-~-~\\>:f... - ~-:- ~~~o u~~~ -~~~~:~~-<~;~;~~;,~ ::!!~E a~);~~~~:~~- p ; __, :,_s:--~l~ ~~~~~-~ wr.. et~rmi~~-:as :_

.**:S...,_-::_)'"~*.:X :.."'*.-. *. __ ",,>>_._ *::ASsumtdtjitial--ope -- *

g *pwrip flow-rate (m um pump flow).

"'*:~~~;; 1;1~~~~~1i~~~;tj~~~tr~~if ~f~:~~~itl~i'. :\\. ; : ". ~ ;

~ ' '

ne the suppression p 1 pressure required. t satisfy the pump's NPSH requirements
g the assumed p p flow and the
expected orus temperature at 2 seconds post-LOCA

. 3. Reduce pu p flo~ estimate until he pool pressure requ ed equals the minimum po 1 pre5sure available.

is at this. flow that the ump will be in full cavitati n and the total develop head (lDH) will dr off. Since
this drop-off i essentially vertical, pump curve will in sect the
*s flow, i.e.,.this is tti flow at which the em will operate.

Maxim m

LPCI. ~d Core Sp y pump flows used as follows. These fl ws were at.0 psid between the eactor and the.con

' '._ :: ** :*: Core S *ray* 1-Pump Maximu,n njection Flow

5800gpm 20,600 gpm

. ',.., >'. * * ~LPCI 4.,. ump Maximum Inject~ n Flow to Qroken loop.

< "*For*the purp~s of this evaluation, a pression pool pressur

-~'This is consistent "th the discussion pro "ded in Dresden UFS Section.6.3.3.4.3, in

. which the presenc of 2 psig in the d~ is expected since thiS is one of the signals which *initiates th~ E CS. This ~sumption i conservative based on he following: ' "\\. ~....... ':. _:;,... -~ ;~* 'The.. D~esden ** ost~LOCA coirtainm . :. :..~ ' *~. < .;'. -",;.* UFSAR Figure *..: 19) indicates an exp ed suppre5sioii pool "~ *~of >15_ psig at 20 . onds, arid >IO psig t 600 seconds.

.The Quad Cities po LOCA exJ>ected suppr
on pool pressure is 20 psig at
200 seconds and 600
5econds (Q Cities UFSARFigur *

-~ '-

~.

r ' > * ~ */ ~;'- ' . **,*.. ::.-:.:..-~**;.:--* ... _---:~---~,.~ .. ?:. -._;_~~.........:.....fD'-~__;,_;__;,.__~"""."'-'----~li------~-1 ~

*.... r."t'.
- ,,*'.*I

~*. *. .PA-Cfl:.(4( .B't.'1.. D r= L 1/0 I I

PFL Cf ?Oii Insert G to page 6 While no Dresden-specific sho term containment erature response

' reasonab estimate can be made ing the following existi perature profiles for Cities are aVailable d are considered "ve for use at Dresd based on plant similari *es with respect ent size, core power, d reactor operating p eters. The Quad Citi contairunent. response Quad Cities UFSAR 1 re 6.2-18) indicates. the ool temperature at 0 seconds is 144 °F, d at 600
- seconds is 14., based on a 90°F init pool temperature. T~ e values wen~ developed
ng original analysis t
ques, including the
Witt

. decay heat mode

no feedwater flow d no pump heat add. If
. corrected to a 95°F *tial pool temperature su~ng a one-to-ones rt-.

term temperature*rela *onship), these values ar conservative. .. " Therefor for the.purposes.ofthi tive Quad Cities.tempe

.'-.-will be use :._\\..

's *.- _.~.~... -- -... ~.

.. ;Jt is *assumed, t a reduction in init suppression pool te

' : '.corresponding r. reduction iii. the sh -term pool temperat

_-:cooling is not.
ve. 'Given this assum tion, therefore, for a reduced initial pool '

. temperature of 75°F. 15°F reduction from Q ad Cities values based n 90°F initial torus

temp.erature), the po temperature at 200 s conds post-LOCA *is 9°F, and at 600 econds is 132°F.. * *
14 LPCI pumps inje_
g into *both.reactor re *rculation
loops* si ultaneously, with one 1 p.broken. While it is e ected that this case m result in slightly *gherLPCI pump flow tes, a significant amo t ofwater:will be inject d into.

the reactor ough the intaet loop.. erCfore, any reduC:tio in Core Spray system ow.

. *due to -cavi
on 'below the minimu required flow will be de up by the LPCI w *
injecting into t rc;aclC?T.~ Therefore; ii* expected.that the P will not be challenged 1

-this case. :.':* ~... *._.... ~- *-"'.:;.... -- -~..:. ..,...:;~* . *.:~~t>C-. Jt--)tTl~Tf!.D UN'DE.R. PR- ~bl*' ,J .611:1 JJ FL-. *C(7 0 I/ . -~'

"i.

.-** r,-'

--~..

I--:.' :. ', --*: e~ . Insert G to page 6.3-7 ( 4of 6) It was determined that when six ECCS pumps are runnin LP and Core Spray pumps. to vitate. The LPCI pilmp NP deficit is relatively small

1 result in a negligible redu ion in flow due to cavitation < 100 gpm per pump).
The re ed flow at which the Core ray.pumps will operate in th rst 200 seconds was estimated be greater than 53 00 gp er pump, which is adequat to ensure the PCT remains belo 2200°F: The Core Spray p p reduced flow beyond 200 econds would be at least 5300 m per pump, which is er than the nominal 4500 m per pump required. Therefl e, it. is conduded that ad

. e NPSH exists to ensure he LPCl/CS P.umps can* perform heir safety function using a re of 75°F and a torus pressure o 2 psig. Tenn Evaluation

mum suppression pool pr ure required to ensure LP and CS pump protection

.was dete

ned under long-:term post-OCA conditions at the bo ding NPSH condition.

Since the s pression pool pressure r constant after 600 s nds (14.7 psia), the bounding NP condition. occurs at the ** e of peak suppression pool *emperature. If the pressure requir is less than 14. 7.psia,. then e pump NPSH requiremen have been met.. . If the required pr ure is greater.than 14.7 p then the potential exists fo the pumps to cavitate. In these *

ans, LPCI pump flows
be reduced to below-no *na1 values and new.cases were ru to establish the ability of operator to* throttle the p. ps to aii acceptable condition... Thi acc~table condition was:.'

ned by the following cite : e available is greater S pumps.

2) Ade uate containmenfco *n - the minimum co,ntanut~t *cooling flow analyzed i~ 5000 gpm. (LPCI.

ough a single.LPCI heat changer. If an accept le condition ~ot be achie by throttling, then cases. valving' reduced

suppr!!ssion p l teniperatures was eXJ>lored.

~:*..

-~*... ~

... ~---*~*** ~~7~~~~-~-~-1 ~ ..,_*:*: '.~**

- ><:f:~'!t,>~l~<... '.L~1T.i A::TE:P.*.-:: -~.iu*oE.fa.: *. J)FL **~b 1 ~(
~~~~~~~~~~;~1011_,*,

Vario pump combinations were explor to determine the bounding NPSH e for the LPCI an Core* Spray pumps. It was sho that NPSH for the LPCI/CS pumps LPCI/2 CS umps running is the bounding H case. This calculation is boundin . NPSH due to e of the following conservative in ts:

maximum long erm Suppression pool temperature ost-LOCA, thus maximizing the vapor pressure an minimizing NPSH margin
torus. pressure at ti of peak temperature. is atmosph. c, thus minimizing NP SH mar gm
- Technical* Specifications
- nimum _suppression pool level
eluding drawdown,

.minimizing elevation head an "nimizing NPSH margin increased clean, commercial stee uction fiiction l?sses by 15% to a ects* alysis was performed for the L I/CS pumps under* bounding, lo -term post-accident nditions with. atmospheric pres re in *the torus. Selecting inpu .. minimize NPSH giil,.'it *was.determined that the. tential exists for the LPCI and pumps to caviiate in Ost 'of the pump scenarios. Fort e cases,.throttling of the LPCI

pumps may be requir o ensure NPSH requirementS ar met. Specific cas.es involving throttled LPCI,pumps*wer uated to establish the ability o the operator to throttle the
pumps to an acceptable cond.*. n. The results of these cases wer follows:

~

- - .In,the'3 LPCI/2 Co~ Sp case, the single pump LPCI loo may need*

.. *to-be throttled. to'l)elo~ 50 m;.and containment heat remo d with the:2-pump loop. This *wilf

the LPCI heat exchanger recei s its rated LPCI flow. Alternatively, a PCI pump can be dropped to g.

th~ required NP_SH margin. ~ *In e *f LPCT/2 Core Spray case, an NPS deficit still exists after maximum

. thro
g.ofthe LPCI pump to 5000.gpiµ.* It determined that a reduction
.. : jn the p
suppression.pool temperature to 1

~ would result in positive .*

NPSH
n. *. This is.achieved* by maintaining
CCSW maximum inlet

.temperature o 75 deg F and a*torus water maximum i ~~ ~*:, :~_eg f. :*- ~ --.. :.<.>._-, ;_~. ~-- -~. There(oie, :at a reduced(suppress1 -.pbolpeak :temperatu;e of 160°F, it.is. under_ all postiLOCA-~:pump ~ comb1 io~. -positive NPSH margin.can be . thrOttlirlg the~~v~~~ble.L~(;:I PUmps!* --~.* ~~: * :

~*-* *~--~-* _

.. -.' _-.-.~.. ~ ... *-~*"?~}:.~~f ~~~~J~,~;:'\\f.;~;.;1j**:;~:'.'** ***.*.*. *

.Operators have been trained t ognize cavitation conditions to protect their equipment by throttling flow if e

ence of cavitation which would NPSH was ~ot available is observed.

e control room has mdication both discharge. essure and flow on each division of C Spray_ and LPCI. The Emerg Pro ures (EOP's) also provided guidan o maintain adequate NPSHfor Core Spray LPCI pumps. The NPSH curves

ded in the EOP' s utilize torus b temperatu and torus bottom pressure to allow _ operator to detennine maximum or system ilo with adequate NPSH. These curves adequately flood C/f-111Jc;p. /IV 11/ 4-TE.P

/./..A) J) C.R! DR ~614\\ DGLS.IE.P "13t'. OFl-j,01/.

r

.. ' -.. -.~ :- ' Attachment for UFSAR section 6..3..3.4..3 Page 6..3-77

[FL "16 - 06~

T~c: original TS Bases.3.7 A states that a full loop of suppression pool cooling (2 LPC!i1 CCSW) will. provide suffi_cient cooling that reliance on overpressure is not required to nzsure adequate NPSH.for the ECCS pumps. This case is less restri.ctive than the above analysis in that offsite power would need to be available to support the equipment lineup. The above analysis *demonstrates that in the most limiting scenario. NPSH requirements

can be met \\Vithout crediting overpressure. but with-little or no margin.
(.-

'*/ . ~. i * ~., ~.*..

t

-*1. -~..:.;*.

DRESDEN - UFSAR. During a LOCA, the* operator's concern will be *restoration of the vessel water level. The LPCI flow will be among the parameters closely monitored in the minutes immediately after the LOCA. The operator has several.motor-operated valves available to him in the main control room to adjust flowrates or even isolate flow paths. It is, *therefore, concluded that operator observation and response to flow

conditions will be completed shortly after the LOCA.

Because of the falling head characteristics of these pumps, the brake horsepower requirements are ne~ly constant from 4000 to 6000 gal/min. It is thus concluded that no overload-will occur for either the LPCI pumps or for the emergency diesel generators powering them in the event of a loss of offsite power. It is, therefore, concluded that for the conditions evaluated, no threat to *the

long-term cooling capability exists.
Hence; adequate NPSH is ensured at all times to allow continuous operation of the

.LPCI and core spray pump~ re:ted flue. h_ . (,,. 3. 3_ <-/. 3. </. *H?c: I NT-'S II The HPCI subsystem takes suction frOm the conoensate storage tank which

- remains cold throughout the plant cooldown so that the NPSH avail.able is unaff~cted by torus heatup*. If suction were taken from the torus, the maximum
.. torus water temperature would be less than 140°F *and the minimum ~~SH available would be 30 feet compared to the 21 feet required by the HPCI pump. * *

.. 6.3.4

Tests *.:u;a Insnections * *.

6.3.4.1 .: Core Sprav Subsvstem Provisions have 'been desigried into the core spray subsystem to tes~.the

- .. performance. of its.yarioU.s components. These. pro,.*isions and tests are summarized as follows:.
. : ~. :.. *-"
. : A... instrumentation Operational test of entire subsystem.
.Periodic subsystem tests using test lines.

B. Valves ~. : Preoperati~nal test of entire subsystem.

-*~**.-_.*;,9.~-*~Periodic subsystem tests using.test lines.
.. *
Test leak-off lines between isolation valves.

... *'*"*-'. 'Test drainline on pump side of outboard isolation valves.

. ;.':.~-. :.:.-.* * -Motor-operated valves can* be riercised independently..

r

-..~

- .-; ~*.

r '! --. lj' -~. ~' _,.I, ~.:. 10,370.*. 5,300 ': 6,920; . il,620... .. 5,30 10, 0 . NPSl*JR (fe7t" of waled . A nnc.l/or B C oiH.llor*D

, >EJG

' 37 37 39 30

32*

39 37 39 37 ../ .3~/' . () "*i NPSHA at 130°F Cf eel of waler) A ericl/dr ll C enc.I/or D

~4 41 34

.*: 41 36 41 41 34 41 34 41

36

\\ \\ I \\ I~\\. - - I 1 .. I' 1 '

'~. ' '*'I t~

~ ',.

,,;1:*' ... \\..-.

.. ~- * -. l l'

I

1..

i'.

J

.. - J..

1",'

I ... *.' 1,. -~ . ~. I . ~-.... \\' . i'. * *.* * :o*m~sDEN.:..:.. ursi\\Jf

'l'ablc *G.3-18 *

-~ l I L ~----*--

1 SYSTEM P§REQJtMi\\l'fCE Wl'l'H FOUR P.UMPS IN OPERATICJW----..

.. *.FOR CASE!S OUTLINED IN GE L ELEC'l'RIC SIL 161 ~ Cti*Pair, r*". ':' ~ I ... *.

NPSHR.

reel of waler NPSHA at.1ao°F (feet *or water) * \\ \\ \\ \\ \\

' 1. ".

n,oo.o. 33.9 \\ t

2. a.*..

4.

5.

6.

7.

2

10.,770

3 9;560 28 owing aSSl~mptions were d in lhe calculations

34.3 36.1. Design now, pu~p 1,0,700 gaVmin. 1 Rui10ut flow, pu

p'air: 12,000 galimin.

/ . NPSH calculated or greater pump flow in each case. i Friction drop.for NPSH calculation al flows other than de

obtained by square of flows fa~~dr.

1'o.rus waler temperature from GE process diagram 73

75.

Pressure above lorus 14.7 psia (reference Regulator uide 1.1). Strainer nearest pump is plugged (rererence GE 730E77fi). 'J ~ £-;:::::>LA-CE (..,; I !VE w TA-~LE {p. 3-18

.*. : *. ),:'.. :;;'" <.,,*

. */._.*.,. :. ... *I. I : ;

.I ; ~:- *

>.~ '\\ ~ :* -. ~ _,; *...l l! '( "*. ~. <.. i* 1' I _.. ! ;r: ~. \\.. . \\ ~ ' ,: NPSH margins with throttied LPCi flows:*., LPCI/CS Pumps (Li>Cf flow rates per pump). All CS flow rates @ 4500 gpm per DRESDEN~ UFSAR r,* Table 6.3-is l,. ~' *..

- .----------_..p_u~m~p_. _________..;,..,__ ____ Mi
ru_*m_u_m __

L_P_C_l_M_a~rg~in_*~(ft~) ____ ---T __ Mi "ru_*m __ um~--C~S_M ar~g~in~(~ft~)--~ 4/2 (2500) 10.6 6.6 3/2 (2500/5000)* 2.0. 6.6 I . 2/2 (2500) 12.4. 8.6

112 (5000)

,.;3.8 8.5

Two *pumps @ 2500, one pump @ 5000

(..- I .I. I (" I'\\

~

... f.*;*,"i'*

~'i.&:~f

'lrfB*

. ;<~)*~!: i ' '.:*:!{*~':/~~.'./ I n:: " 1 ~ j :,. * ~ :

-i.;
IS

, "t' .',',,:*I*; - tOlfAllftlUf PtllUURl itQUIRtbt * .. 1,,'. w/ NE. w +: /V-i-t 12 E... G. s-go

DRr!SDl!N STATION UNITS 2 & J MINIMUM CONTAINMENT PRESSURE AVAILAOLI! AND CONTAINMENT l'RESSURE

.. REQUlf{EO FOR PUMP NPSH . FIGURE 6.3-80

1~~*~';l,;;K1.i<. t ~~ 1,.. 7,i:) . £ f: I'.

~.

'.:. :1 > **:*;: .. ;*~.;::!.1:"),}.;:;:</:. 1 > :*:.~f ;,;* r'. J ::'

I : *
(-:'

.. :25' .i.:.*: ..:.,~ T :*.*

t,
r "'*~.,

'*i .~.. ',". ~*.. : >:* ~. \\

. 1*

(. "* . ~.:. 5 0 -5 10. ~- --~t .-;.. <. M~inlmurri Required containment Pressure2ror NPSH considerations Only (After 10 minutes: cs~ norrilnal flow, LPCI throttied to sooo gpm/Hx) ~: \\

\\

-~ ----* ~ - -- -~

100 1000 Peak.PCT Time (uc).

(<200 sec) 10 mlnutei Reflooci . (<300 sec) --Pool Pressure Avallable -Pool Pressure Required - Core Spray _._Pool Pressure Required* LPCI 10000

DRESDEN STATION UNITS i &3 100 000 MINIMUM CONTAINMENT PRESSURE AVAILABLE AND CONTAINMENT PRESSURE REQUIRED FOR PUMP NPSH FIGURE 6.3-80

(a) SF-LSL CASE SFUL LPCI and Core Spgy Pwq> Pleam9 Requirements 25 i s 15

l 1: *
E 10 i

0 u (b) 5 0 10 --~ Pllal..__ -c::.a 6A2 SJ!I. --6--LPO ~ "'-n*SIL 412 ~CS~"'--*Sll412 __._LPO ~ PNaan-Sll31'2 ~CS~"'-"'9-Sll31'2 ---PllalT~ / *-. ,,./. / ~ SF-DGCASE ~-- -~- _i;.-- 100 n.c-1 .... -\\ '\\ _\\ 150 140 130 ; 1 ! ii 120 ~ 110 100 1000 -SF.OO_LPCI and Core Spray~ Pressure Requiremi:nt5 25 20 '.ii :; ~ 15 e 1:

E 10 c: jj c:
O u

5 o.i-~~~....;..-'"~~~'--~~ 1~ ...... __...._...._...._......,......_~~~~....... ~~ ...... ~~...___.~................... _._..... 100 10 DRESDEN STATION UNITS2&'3 1000 SHORT 1ERM POsT-LOCA LPCI & CS PUMP PRESSURE REQUIREMENTS_ FIG,URE 6.3-83

:-:... 1 ~... ""'.: ~****
: ~ * *
t':~iU!1t!1:i~!:c: __ r~,:::,~,;;;:~~!1 j*,.--~ ---*
- ~~----
~ ;.';:'l:*::....':.;..C...... d.*~ -_~...

~

,..*.~

N

I. ,ii5i,~I."'.:! __ ,;_1"""'.!'""*.*_\\*;_;i*-*.:..;. --'-~:.-:_.-..:...,.-----=--'------....:.-.,.__....;... _________.;__......;.__; ___..;_ _________.....,,...___.-=--.;....:---...,...-----'-------~ .('" -,1:,..,

Lona term Poiit-LOCA.i-Pci Pump *Presslhe Requirements :-Thr~ttled Flows

:*.. 1* ~:~ }~[

. ~

. 1 J

-~l _*;.~;*:.. :~* ~.\\:.* .... _ ::.'..1.*..

'.: ;,, 4.00

'*.*i..r :,:;.'_ 1.** i:.:

i ;-."
.<p.::..>

. ;. \\ :~. -- , ; ::.! ::.1:'.3.-00 *r-:--:-"".;.;_~~-r---:- 1

-:--:i1-:--1-:1~1nt11::;::;;;:::::::'"-t7~:-'-r-:--1-1111t:t;;;;;~--..-'llli;;;;;:-r--1-1-t11ii

., ;.*, *~. v,.. l. r

----~---i-;...... J...,:.~---.....

..-1~1~:.-... ~ ~Pressure An Ila bl!' ' J".,

:.. '.~.: ~.00....:....:::__ ~4 LPCI
2 CS

. U-.+-:.+.V+-l......:;_;:....._...::....:.;~+--,;.._~__Jl--4--+-+.:..+:.+-k--~-~*"'""..... ~__;_-+-+-+.+.Wr-1 ~3 LPC1*2 CS -'~ -'.;.; '.:.::*:!":~ ~2 LPCI

2 cs

~i,...-,...

J ~~:-I--'-,:..;.;:.;.... -.-*..:...****-**1+. L-PC-.:....-1 *-2+-C-S___._+-.+.;;;_:. j+~-1-,...+-_..4~...;..*

.. ~"'" .* ~

,:-A'

,;,... -.... 4. L.---'-~-*-***

--i,~,.,,.*:

.,,.c,* F-~--+*~___.,_..,,._*-+.

i...--_*. +-,...-+~-!-. ~_;___--+-,,...;..~_-l-_;__+--1--1-4-+--l---I .. **1 :.~1.oo

.-2.o'o

. * ~3.oo

-5.00 100 '1;

.~~ *~~

~.....-------. ~. ..~~. -4~-, ~..... -- 1000

Tfm * (aec) 10000 DRESDEN STATION UNITS2&3 100000 LONG TERM POST~LOCA LPCI PUMP PRESSURE REQUIREMENTS
_/

FIGURE 6.3-84

~

rrt ~c::-

F.6'.~-8 3 F~.3-8Y' PageffabiefFigure No.

F 6.3-79 F6.3-80 F 6.3-81 'F6.342 6.4-1

6.4-l
- 6.+3 6.4-4

,......... :.6.4-5 ........,,.. 6.4-6 .... ~. . 6.~7 . :*6,4"1 .. 6.4-9 6.+10

6.+11

-.6.4-tl* ... :.~ . : >*--6.+13 ....... ~ .. '." *"T'6.~1.* ~ "... DRESDEN - UFSAR UST OF EFFECTIVE PAGES 0 ~THROUGH REVISION OlA 0 Revision 0 0 0 0 0 0 0 OIA

- OIA 0

0

o*

0 0

O OIA OIA

~ (Continued) Pageffable/Figure No. 7.2-1 i.2-l 7.2-3 7.2.... 7.2-5 7.2~ 7.2-7

7.2-1 7.2-9 7.2-10 7.2-11 7.2-12 7.2-13 7.2-14 7.2-15

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v - (,-: - ' ~ -*...... - -~ : ' ~ DRESDEN - UFSAR diagrams of the CCSW systems for Units 2 and 3 are shown in Figures 9.2-1 (Drawing M-29, Sheet 2) and 9.2-2 (Drawing M-360, Sheet 2),. respectively. The CCSW system provides coolirig water for the containment cooling.heat exchangers during both accident and nonaccident ~oriditions, as described in. Section 6.2.2. System piping is arranged to form two separate, two pump, flow networks (loops). Each pair of CCSW pumps takes a suction from the crib house via separate supply piping. Two CCSW pumps discharge into a common header which routes the cooling water to that loop's associated heat exchanger. At the

heat exchanger, heat is transferred from the low pressure coolant injection (LPC!)

-subsystem to the CCSW system~ and subsequently to the river. DUrlng normal plant operation, the CCSW system is not operating. Following an accident or other plant evolution which requires containment heat removal, the CCSW system is manually started. Each CCSW pump is rated at 500 hp with a service factor. of 1.15. The CCSW pumps are powered by normal ac or diesel generator ac power Additional CC um

orination is provided in Table 9.2-1.

"the. h'lc.n"'A.\\ " erb.."'t10"\\ IJ f *.

The CCSW umps eve op s cien ea o maintain the cooling water heat exchanger tu e side outlet ressure 20 si ater than the LPCI subsystem ressure 11 side.

. The aP is

maintained.b a differential pressure contro v v.

tamm ress differential prevents reactor water. leakage into the service water and thereby into

the river.f A,.... 11HM&.aft"(
o :f. *5-000 g,,,,.,. 1 s ll e '-e..55 c;tf' "t'"o hla.111"to1 "l

. C c.N1 t-o..,,,,,... e-'l t:: c..e O ~ I 'l a--* . ~.The.four CCSW pUinps are located in the turbine building. Two of the four CCSW.

*pumps.(pumps B and C) are located in a single, common watertight vault for flood.

protection:. To prevent'.the CCSW pump motors from overheating, the vault has ,/ *two vault coolers.. The cooling water for each cooler is provided from its respective

CCSW pump discharge line through a four-way valve. This valve also permits flow
reversal 'of the cooling water through these coolers to help clean the tubes. Refer to

..~ection 3.4 for a discussion of the flood protection features at Dresden. A ~o~tinu~us *fin of the CCSW system is.provided by.the servi~ water system or, in .:. the case. ()fa loss of power to the service water pumps,.the diesel generator coo~g

water system may be aligned to provide the continuous fill. This eliminates the
- .. *.. potential.:for water *hammer upon CCSW.system startup. The diesel generator
coolirig water system *is discussed in Section 9.5.5.

J' '.-

.The tr nit 2 ccsw loops. *aiso provide a safety-related source of service water to the
control room.air*conditioning condensers. Refer to Sections 6.4 and 9.4.1 for a description ofthe. control room ventilation system. *

.o.__

CC.SW o..,.tl~t-p; i"=';n3. Frotv1 e..l(..c.I, a."~ t! r. .. 9;2.1.3. Saf etv Ev8.luation .._ Conta.inrii.ent coofulg is not iminediately required foll~wing a design basis loss-of- ~-~ *;; :. -. :,. ::** -_*. ; ~ :. : *.* coolant,acciaent (LOCA). The required timing of the initiation of containment ---... *\\.. -~,*:. *:<.. -. -.,.. cooling functions by*ccsw is described in Section*6.2.2. One of the two heat ~;;:-_~*L*~~~<;:::'~. *,: \\. 7/::.'exc:hangers, two CCSW pumps; and one LPCI pump all in the same loop are the . :--* -.. __ ' =~~ -\\; ~-,. :~.. -_ ~ :. 'minim~ reqirirement.S-.for containment cooling.. . *--~~... -.. : *' ~.

- c.*1.'"
  - r
~-;

I INSERT D to page 9.2:-2 ain t 15 pressure-differ ntial at rated[P..... flow, the gpm during the limiti OBA LOCA wi a diesel ge erator failure with a ntainment cooling p p combination f 1 LPCl/2 C SW pump ne loop. L Vek"t-e_ n.~ C-~0.-'K /H. 1'tie._id

- ~-..::. _:' --

,:. -i* -~*.-~' ~-. ... ~**. .. ;: *.--:~; ~~~**;*:~~--;.....-:-..' !~:._ ....... :.1 .. -. -* -:*. :. ~.

\\).

~.,

DRESDEN.:....'UFSAR
.Table *9.2-1

l.

CONTAINMENT COOLING SERVICE* WATER EQUIPMENT SPECIFICATIONS \\ . -J. .:.*.. '-, ¥-"*** r...

z ~':

' *.* f,_

- *o:: ~r.. ~ ;.,.

~-..... f ~*~.-.:. ' .. *.z*.:.~.... ~;.. ~... *:--.~-.. -...,;. ... l_.,

- 1'

. ~.... . I*:; .,,:i: ....... " : ~ - -:.. -~ ***.:

INSERT E to Table 9.2-1
- . __ tj**

\\ ~ ,,.* *p. \\* -;- . TC-t '"*~ "c..*4.°"" ~e-

.. ~

e.. e._,c. u . t- **\\., ~ 11 ** ~J ('r-

.PFL Cfbl tJro

.. ::-*. ~-;.

' ~- ~. .Jiii l~ *. {V Vl -~. -.:-.:_.. :***. -.. *.... .. -..... ~... . : 7 ~

_ -. ::' *:~ -: _:.....

'. ~ ~. . ATTACHMENT F LPCI HEAT EXCHANGER PERFORMANCE ANALYSIS LPCUCCSW Heat Exchanger Performance Analysis As discussed in Section 52.7 ofthis report, the proposed performance of the LPCI Heat Exchangers are based on the following parameter~: LPCI minimum flow, 5000 gpm (See Section 4.2.5) _CCSW minimum flow, 5000 gpm (See Section 4.2.3) Maximum CCSW inlet temperature, 95 °F Maximum tube side fouling reistance, 0.002 °F-ft2hr(Btu Maximum shell.side fouling reistance, 0.0005.°F-ft 2hr/Btu .. Number of tubes *per heat exchanger, 2512 ( 6% of tubes are plugged) . Heat transfer area per heat exchanger, 9880 ft 2

in~ above conditioni;esult ill a heat t:ranSfer capability of7*1*x106 Btu/hrwhen the LPCi

.. inlet (suppression pool) temperature is 165_°F.

...* The heat exchanger heat transfer capability has been calculated by GE during the design

: ~ * * :.. basis reconstinition using aL~CI f.Iow of 10, 700 GPM and *a CCS.~ flow of 7000 GPM..
*."-.CalculatiOn OfU~: ***'..-' **_:\\ *

.*. The overall heat transfer coefficient, u, is' given by:* '

,~*.*"~***

~.,-.*:*~=-~ ***:****

** -.*. **)1_. -'

0 U~l/(R~ + Rf;s + Rf,t + Rfoul,s + Rfoul,t)

* ** Where:

Rw =tube (CCSW) metal wall resistance Rf,s = shell. side fluid resistance

Rf,t =:= tube side fluid resis~ce * *

..Rfoul;s = shell side fouling resiStance Rfoul,t ~ tu~ side fouling resistance *

..... *. * * &:/erence x values: * *.*

. '.. *.. *. :.;.. 0.00025 °F-f(-hr!Biii : '. Values of the abo~e thermltl resistance's. from 'Reference (25) are also sho~ above.

. : The refe~nce flow co~ditlons used* in the present analys~ ~e~.
10100 gpm LPCI flow for sheli side (:iLPCl/Cont. Cooling pumps)

,: -. -...,," ~-

165 'P L~I inlet temperature for shell !!ide

-~.-- *

** * ** 7000'gpm CCSWflow for.tube.side.(2-CCSW pumps).

~ * * * -~ ._*.-:-~--..

95 °F LPCI inlet temperature for tube side * *

~: -; r, . ' *'.:, *_,;~;.<,~* :~."~ :~:-~--~pproprl~~: ~~~~~ts. to the ~~is~~e-v~~e~: can b~\\n~~e -~~:ac~o~; fo~ ~e impact of differences in },_;;:!<.<~t~ -,_-/ fl~;-.~~-l!~t~:~i:i:~~;:~~:P-:~:~:.~~~~-Li~~~~~,~~?~~n~-~<~,~--;;.. _:... :.. - -~'.::_.. . --'~.*

- >**;;,-.',,,-<*~~
  
  :'::_::... _,_~::..:.-~hani:es_in*~r1s*au,e!o*chao~es_~o*tties~ell~i~eFiow-_: __ *.

'J '.:,. ~:.- :** - *~' -~

ATTACHMENT F LPCI HEAT EXCHANGER PERFORMANCE ANALYSIS The value ofRf,s is a reciprocal of the convective heat transfer coefficient. Namely,

Rf,s = l/hfr,s Where:*
hfr,s =convective heat transfer coefficient on shell.side

-. *, The ~alue ofhfr,s is calculated from*tiie following relationship -i,*, ** J

- - (. :, :;':*
- 'Where:.Nud = Nusselt number. *

..,.:. *.:kf= fluid thermal conductivity.. . :.. d =:' tube diameter ... Pr= Prandtl Numb~r = (µClkf) ,. Re= Reynolds Number= (pVmd/µ)

- .. p =fluid densicy

.. :. *.~. *

.. *µ = fluid viscosicy *' * ". -. *

-*_._-c~ = Spec~c heat*~;-.:**-* -~-.,*_*.. _--:~ _r..,.~.- -~-~~ .. *-~--- . :::.*_::.,,~For.Ws an~Iysis it is assumed that the effect of fluicf temperature change is negligible and the µiajor effect

*** L*. :is*: the effect of fluid*velocity.change. The~fore,.the major impact ofa reduction in p~p flow rate is the

.. ' *.. *. ::: ~: impact du~ to a. reduced fluid velocity'..This means thati( PumP flow.is changed then flow velocity is. ..-. :. '.*:?~;:-.*.,changed and the Reynolds number (Re) is changed. : ,z~:rfr~t~f;rti::~*,f :r:*~ilie df~ 00, ~i ~du~;* cm.;* :Re;.; ili~ mell ::de u.*.

*" '.* * * * * * *:.. hfr,s (new shell-side flo\\\\'.) = hfr.s(reference flowp (new shell-side flow/reference flow) * *
~*:*-

1 . **~::,_*.: * )~**_\\. ***.sin~e,Rf;s;,,,~.lhft::~ *.".>..,. 5 <)~;"' /'., *'

:. /*:.' *; *: <<~::.. ~-~:ili,s (ne:~heiI~sid~~ fl~~} '.~'_Rf,~ ~~};~c~: fl~~)** :c~~wshell-~id~ ~o~/referenc~ fl~~ )-0*6.

( 6) '::.*:~h~~~~-~-Ri~--~)10~~chan~~s*k:~;\\:~~ s~~~~}i~~~X.. :. *,. **: *., ~.-.:,_. **

_- ~;:-~u~ *o:f 'iJ}~~:*4*~~ip~~~;~~*c~~vecti~~'.h~~;:~f~-~;rfl~i~~.*,N~eiy~ :*.::.**.

. : *:c: *

Rt:t-=11b&,i*'. *,.. ;,-.. -. *~::::-'-:-~ ---_. *... *.:.**.

-~: * * -~

Wliere: *hfr.s~;.;,:co~~eCtiv~*he~transfercoefficienton.nibeside *

._.. /~?*\\~:.:>:::'..;;:._.*,::.>< '. ;* - *::'::... >;;-::*.. -.,'.

*;*r:....

*>'-* :~ne*.va1ue ofhfi:~t is calculated from_ the following relationship;.

t*;*.fo'.'*,:,,~"-.::i*~~~~~~~~*~.d~ ?(*': x *:.... *. ;. '*.. ; :.*. ' '.. ;. '.

....*.... *:. ::*~*.:,: -For:this analysis.it is again assunied tllat the.effect Qf~uid temperature is negligible and the major effect is .. *: * '*. /~:'{: 0 "* :"" i'.:; :::*;;**the effect of fliiiii veloc_it}'/ Therefore~the major impact of a reduction in pump flow-rate.is the impact due -. *.. ** <:~, <:~*.*:*~.,J:to*~:.t(> a reduted :fluid_velocity.'*'-Thi.S nieam thatifpump:flow :is changed then *flow velocity is changed and the. _,:*"J

ATTACHMENT F LPCI HEAT EXCHANGER PERFORMANCE ANALYSIS Rf,t (new tube-side flow)= Rf,t (referenc~ flow)* (new.tube-side flow/~eference flow)-0.s (7) . Using the above relationships and. the: following assumptions, the U for the proposed license amendment can be calculated. The impact of differences.m the flow conditions on Rw. Rfoul,s and Rfoul,t is negligible with the range of * .

flow conditions considered in the present analysis. *

-:-:::*:*~. *"*,. Rw=0.00025

. Rfoul;s = 0.0005.

' * *:Rfoul,t = 0.0023 . -.:.*:*. *:.';*: :,The fluid (convective heat transfer) resistances {Rf,s and. Rf,t) are affected by the flow rate only within the

. *.'.. -*. *_ *range of flow conditions considered in the analysis, neglecting temperature effects. Using the procedure,
.~_,:_ :calculating-the values ofRf,s and Rf,tfor different flow conditions described above, the following is
- ... ':* *,. *.>:calculated: "" *. '.

. ~:.'* *- :*~ ~:~_ -Rf,S. ~ 0.000988.* ~*:*.. * .. Rf,t = 0:001014

- . --~t".*~=:::*:~~'.L~*:*;:**.:/}<~*~~:~.~~~:-~*:*. :,:*.:;-**-:;:J~ i9z9Btu!hr~ tF.f!:

-* **"=-*1.._*,_*".*.- _s*:~'P ::>,.-~_.-. : I", .'~**.* :._.~_*:'***~ ._,.. ::-: -.....,...._;,_:.'*~CALCULI\\ TION OF PROPOSED K: _, *~\\:*<<*<~::_~:."~:.*~~,~-~~t-~~i~g~~*~e;~ pe~o;~~~;*~- is-~~d.in the-~c~~~~~t :~lys~ pefformed with GE's, .:1,..., SHEXcode. *The _defm1tton.ofK1s given below:* c . ~: . UA = i,955X 1~ Btli/hr ~ gf,

. --* *~ ' --

-~ "".521f1:h!~Ta), :'..-~-.* c ": **... *,* (I) * *

Where: - *

-: ::."~_:.Q -~.beirt.exchanger heat transfer rate..,~- ..*: /,':*,:: :_ __ -_** ~.T~.= inlet temperature on bot'fluid side (suppres5ion pool water)

~.*-:;~*>:.:_. :Tci =inlet temperature on c;:old fluid side.(seI"Vice water)

~.--:* ~ .~._~~:.<:-.. -~ ~* ... _-- ->" ~:~*~\\ :_: :.. --".:,*= - ~.*-;_ ~-~< -,- -. :* - -_*_*.* __ - .. *. >~*~;'>:*;:::-.'.:.~.j:_::::::~A, calcula~'?n proceduie"wbicfrisbBsed OD*8:parameter called beat excbangereffectiveness is used to

.~ *:.~ ~-

,,_ * :~::~~):'."':~* ~~culate tlte:heat e~ch~ger.performance-parame~,;l(. .. !.., ~.. ** * .. -Th~;*~~{ ~~~b~g~; ~;~~~~~~ *. e, is de~.e~*~ ~~;~~lowing way;*

j,.

-""~~~ ..... ~~ --~. .~

- * -~,

cf."

** ** * * <'., t ='actual heat transfer/maximiim possible beat transfer

'.*~~:-::.'-t!"~=,Y~Yf*~;---~ -:-<JL~~~-: ;:.'~~-~eai;~f~~.-~-~~-~~*~;at.~fer-~e~ the*b~-exc~ger.**N~ely,*this.

- .. ;.:c~:z*~'.~~ti;f~~~~~;!;~~'~f ~c~~i~:.:dJ 3m. b~~f~~.~h~ me fl~id ofW;.er fl~
,,:. *. ::: ~ :r:_~:;.~> :\\ * :~~-{. :, *

'./~*.::.:;_; _;,.. *::<>.:.rate* in_ the heat exchangeneaches the inlet temperature of the other fluid. Namely, this *

.... : ~.. --*~ .. :* :-. ~*:* -~ '.. ~- ~:' '

-.. :**~ "t*

AITACBMENT F LPCI HEAT EXCHANGER PERFORMANCE ANALYSIS (2) Where: Cp = specific heat of water

~min*= lower value between shell-side and tube-side flow rates.
From Equatioris ( 1) and (2) above, K can be_ ~alculated by the following equation:

(3) .. Accor~ing tp Refereii~e (4), the value o(& for shell-tube heat exchangers is calculated by:

:& =. 2* { 1+c+(I+c2)112*cI+exp["N(l +C2}

112]Y(I-exp[-N(l+c2) 112])}*1 .. *. '~ ~ ... ). ',: ; *~~ ~* '* *~~,*::_......I ' * -:.... -- '. ~*-.. ~.--........,..

1,

-. ~ . ~ '- Where:

* *: c *= w;,,;,;wmn,*

.N=UA/Wmin -and. . '. ~... _. (4): 'r:"

~ :*--~., _,:: :1'.;.::.. *..

-~ W~= itjgher value betw~en shell-side'and tube-side flow rates~ c : ~:.,, * . wajn ~ low,er_*v~ue between shell-side and tube-side flow rates. ~-..... ..u::. effective ovenill heat transfer cqefficient *

:A= tube surface area *

--~

.:. :* *-.:...'.: \\.
**thus, tbe.K-value c~ be cai~ulatedfor given shell-side and tube-side flow, using Eq~ati<:>ns'(3) and (4),. "

_ " ~- * -~:*:.<<. ohce the.value c;>fUKis detenriined.: _ ~. ~,*... Fo~ the evaluatio~ of the Dresd;m Heat exchanger K.:.value, the vaiue ofUA is first determined as ..... <:,._... -, :previously -~cussed. Then, the.K-value is calculated using ~uations (3) aQd (4), using the following

_,:*~.**:*. :::**. "L<>-.:*proposcid~~~-=.v'--.;*.:-.: --~~:*:~~~::>:-~:,'*~ / * * *. _-.__..:-:*. __ :.* * *.

. ~::"~-;-::::_:. > ** UA='2.079 x.10 Btu/hr~*C!f.(see previous discussion). . _ *-:_:~.;::-~~*.*..... *. ~~:_-* ~~-:**:~,?,_._._, .. **~ ~-.~.- ..::. :---.:. *.-. :: _. ~wmax'.,;,. 'sooo 8P1n*=*t:5 x--106 lb/hr .... *:~.. ".:* *. : : *' :::W..ilii -.;.*5000 gpm,.; 25 x*lp6 lb/hr : *. * .~.. - \\ ~; ** : *..- *.,..... *

_,...,*,'~
' ~ *

'_' *' 'I*. *.. -~-.; K=28t7Btu/seC-~.

';;:,.>".~~*~~---*~-r... --:.. -*..,,_,.. -*_::::~:;::,:::*... _

.;::.:.~~**.~***:_~:.*-.*_fr;*_,_*:.... ",;_,.--::*._.... -._ :_.: ..... :c-.,....,.

.'~'-'*.:..-.. *. 'Table F-2'beiowsWm1~stb~'res~its of the benchmark cases described above~ 'Table F-3 below'.

.* r

/..,,.. \\:sUmm;mzes the results ofthe_caicuJations to determine the K values for a long-term containment cooling

..,...,;o:-....,::-... : *. *
. : ;* _co~figliratlcni of ~ne (1 )LPCI-containment:cooling pump and two (2) CCSW pumps.
.;".,-*:.**: :*~*,_-:'>.".-:.:.*. :.;,,*.;:.>:* ?'***'..'*'." "'.... _._. *-...'.* :.:...,.. *..

-*.*_.:,:.:.,'.:,*.*.*~~;_:_'.:~ :.. :_::.~*.:.. ; : r: ::: :t:r ifiif~E,,+2sm;~r:~~~G.~ltHK¥M4JE =B.:f:N~lU'P~~l " :,, :

_- K Value
.. **GPM*,_-*
BTU/SEC- °F Heat Transfer Rate ( 165
°F shell side temperature, 95 °F tube..
side temperature
MBTU/HR

.,i'7,o -*.

ATIACUMENT.F LPCI HEAT EXCHANGER PERFORMANCE ANALYSIS 10700 7000 390.7 98.5

391.3 (Ref. (20))

98.6 (Ref. (20)) 5000 3500 249.5 62.87 249.6 (Ref. (20)) 62.89 (Ref. (20)) Shell side.flow rate Tube Side Flow.Rate K Value Heat Transfer Rate (165 JI LPCl/Containment (2 CCSW: pumps) "F shell side

Cooling.Pump) temperature, 95 "F tUbe side temperature
1-~~~....,..~....,..~~....,..~-+~~~....,..~.;.._~~....,..~....,..+-~....,..~~....,..~~..........,......,..-+~~~....,......,......:.~~~....,..---1

.:GPM

GPM

. BTU/SEC - VF MBTU/HR. .................................. ~ ............... ~ .............. ~ ............... ~ 5000 5000 281.7 71.0 'n,* -~7:_ -~.

1.

':.:>Dr_*_*~-~-~t~~~::.;-\\;:f:'::*~-. -~-*

~ ~.:..- - )'*,*.

*. ~ -

. *...... ___.\\'.:

_~;~:,'** *-

t

~,;,;~~~~f ~;~j;(

.

-~*:.;:~... :-::* c~-

. L

: ~.

r,:., -~'- *. . ~...... ~... -: -~-~',;. "v ~ -..... -J, *' -~' **

- - - - ."*-r***:* '<'".

-. -**.- r '":-*

- .*1 1*,... *

.:.~---. -. :.* ~*, "- -* -~ ~.,.. ":~.:.. '*,._;(" .. ~ ' ~.. ;... *. i*. --*-*~....

ATIACHMENT G NON PROPRIETARY REFERENCES

I.......... :

r.*
~: -*

.. ~ \\ .~: _'!"\\ -.*. '... ~ *:*. *_.. .\\,,_ ~ -. =-~*---

- .*-.:.~\\ _;~ -

/ 1 -* Reference l . '*1 ** - .f, '. .. ~ :."..

, *~*".: *:

i***.*-

"t*

-~..

.}}

ML17187A799

Text

SUMMARY

SUMMARY

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