ML20058N274
| ML20058N274 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 08/13/1990 |
| From: | BALTIMORE GAS & ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML20058N273 | List: |
| References | |
| NUDOCS 9008140012 | |
| Download: ML20058N274 (31) | |
Text
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- y. A1TACllMENT (1) ci ph.)q . .,n ? ' '
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- BG&E Letter dated August 13,1990 1
-License AmendmentRequest- i low Temperature Overpressure Protection - )
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t PROPOSED TECIINICAL SPECIFICATION CIIANGES , E .s ( i-l h
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m- REACTIVITY CONTROL' SYSTEMS i3/4.1.2 -BORATION SYSTEMS FLOW PATHS - SHUTDOWN LIMITING CONDITION FOR OPERATION _
~
3.1.2.1 As a minimum, one of the following boron injection' flow paths and one associated heat _ tracing circuit shall- be OPERABLE: a'. A flow path from the boric acid storage tank via either a boric-acid pump or a gravity. feed connection and charging pump to the
-Reactor Coolant. System if only the boric acid storage tank in Specification 3 l.2.7a is OPERABLE, or
~
i: b.- The flow path from the refueling water tank via either a a charging pump or.a high pressure safety injection pump
- to the l l Reactor Coolant System if only the refueling water tank in - a Specification 3.1.2.7b is OPERABLE--.
APPLICABILITY:- MODES 5 AND 6. ACTION:; _ With none of the- above flow paths OPERABLE, suspend all operations _ _
-involving CORE ALTERATIONS or positive reactivity changes'until at least I one injection path is restored to OPERABLE. status. ,;
l SURVEILLANCE RE0VIREMENTS 4.1.2.1. ~ At least one of the aboy'e required flow paths shall be L demonstrated OPERABLE: j
- a. At least once per 7 days by verifying that the temperature of ll p' the heat traced portion of the flow path is above the .
-j
+ temperature limit-'line shown on Figure 3.1-1 when a flow path 9 from the' concentrated boric acid-tanks is used. g b. At least once per 31 days by verifying that each valve (manual, y power operated or automatic) in the flow path that is not a' locked, sealed, or otherwise secured in-position, is in its correct position. H 321'Fandlm Selv.; 327"if, the required OPERAELE HPSI pump shall be in
~
pull-to-lock.and will not start automatically. Sc h; 327 f3 HPSI pump use wil1~ be conducted in accorlance with Technical , Specification 3.4.9.3. L L1 CALVERT CLIFFS - UNIT ) 3/4 1-8 Amendment No.145
D i REACTIVITY CONTROL' SYSTEMS. ; r CHARGING PUMP - SHUTDOWNL 4 LIMITING CONDITION FOR OPERATION ; 3.1.2.3 At:1 east one charging pump or.one high pressure safety injection- ! f u
-pump
- in the boron injection flow path required OPERABLE pursuant to
. Specification 3.1.2.1 shall be OPERABLE and capable of being ' powered from l-L an OPERABLE emergency bus._
l 3 APPLICABILITY: MODES 5 and 6. ACTION: With no' charging pump or high press';re safety injection pump OPERABLE, suspend ~all operations 11nvolving CORE ALTERATIONS or positive reactivity ; changes 1until at least one of the required: pumps is restored-to OPERABLE' -! status. -; SURVEILLANCE RE0VIREMENTS 14.1.2.3 No additional Surveillance Requirements other than those . required by Specification 4.0.5. .; t 1 P 4 k N221*F andleu Al.sz1Yand kn
- Belew- 327"Ti the required OPERABLE HPSI pump shall be in pull-to-lock and will not start automatically. Sci;w 327 T;, HPSI -l pump use will be conducted in accordance with Technical Specification 3.4.9.3. -
-CALVERT CLIFFS - UNIT 1 3/4 1-10 Amendment No. 145
.7
- Sg E $i . ,
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m. TABLE 3.3-3
- {flGJNEERED SAFETY FEATURE ACTUATION- SYSTEM INSTRUMENTATION'-
2 G , 9 NINIMUM TOTAL NO. ' CHANNELS CHANNELS ' ' APPLICABLE
- P FUNCTIONAL ~ UNIT OF CHANNfLS. . TO TRIP OPERABLE ~ MODES- ACTION - .t M
U l. SAFETY INJECTION (SIAS)9
. a. Manual. (Trip Buttons)' 2 -1 .2 - 1, 2, 3,L4 '6- '
l' i e 1,12, 3 ~ 5 a
- b. Containment Pressure - High- :
4 2 3 ;7*
~ t
- c. Pressurizer Pressure - Low .. 4 2.- 3 1,2,3(a) 17*
- 2. CONTAllflENT. SPRAY:(CSAS)
- a. Manual (Trip Buttons) 2 1 2 1,2,3,4- 6 :
t w b. Containment Pressure - High: 4 2 3 1, 2, 3 11 1 , I l w 3. CONTAlleIENT ISOLATION (CIS)# . I /. a. Manual CIS (Trip-Buttons)-- .2 1 2- 1, 2, 3, 4 -6 '
- b. Containment Pressure - High -4 2: 3 1,2,3 '7*. j E
& # Containment -isolation of non-essential penetrations is also initiated by SIAS (functional units.1.a and '
1.c). . 9 When the RCS temperature is:-. ' E (a) Greater than 350'F, the. required OPERABLE HPSI' pumps must:-be able to ~ start automatically .upon receipt of a SIAS' signal __ E - (b) Between~350 F and 327 F 0 8 M i ' ,;a.. transition region' exists where the OPERABLE HPSI pump _will D be placed in pull-to-loc down and restored to automatic status'on a heatup, D (c) Sc 6 327"i, the L required OPERABLE ~- .HPSI _ pump ! shall be in ' pull-to-lock and will not . start
- automatically.
M .311's an d /e.u _ i h - i.. .m.. 2 .ns ' _.%um. . Ism->. 4 +e- esq g (, --. **'WW W T'h W'#- TM V4-"v'=
- ' " " ' d-' 'WT'-' -8* Ws-85F" -
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t REACTOR-COOLANT SYSTEM-COOLANT' LOOPS AND COOLANT CIRCULATION HOT STANDBY LIMITING CONDITION FOR OPERATION l 3.4.1.2 a. The reactor coolant loops listed below shall be OPERABLE:
- 1. Reactor Coolant Loop #11.(#21) and at least une associated reactor coolant pump.
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- 2. Reactor Coolant Loop #12 (#22) and at least once 1 associated reactor coolant pump. j
~
- b. At least one of the above Reactor Coolant Loops shall-be !
in operation *. APPLICABILITY: MODE 3 ACTION: !
- a. With1 1ess than the above required reactor-coolant loops j
- 0PERABLE, restore the required loops to OPERABLE status within-72 hours or be in HOT SHUTDOWN within the next.12 hours,
- b. With' no reactor coolant loop in operation,3 suspend all _
~ operations involving'a reduction in boron concentration of the ,
Reactor Coolant Systen, and initiate corrective action to return the required loop to operation within one hour. !
.SURVEllLANCE RE0VIREMENTS- _
4.4.1.2.1 / At- least the above required reactor coolant oumps, if not in
. operation, shall be determined to be OPERABLE'once pe) days by _ i verifying correct? breaker alignments and' indicated power availability.
4.4.1.2.2 At least one coolir.y loop shall 'be verified to be in operation .
.and circulating reactor _ coolant QQonce pe_r 12 hours. !
-VW f ned6r tw/an/ pup) .cha//nd he .dcer6f avWi as 214 Qor%e. /ta
/ dan mame iy /m /hu a - 1 gh orno egpd&
&m4n 3D *F ,A o,d t't
'r /eu W,I uMn 6) /Aa.,rgw-w Q- wru a an.o a,ar y op a l a
fjj''*"RV? W or 9, t h .sov abua ,% su 9m . Tw '* All reactor coolant pumps may be de-energized for up to I hour (up
~L to 2 hours for low flow test) provided (1) no operations are permitted that would cause dilution of the reactor coolant system boron concentration, and (2) core outlet temperature is maintained at least 10 F 0 below saturation temperature.
i ! l
, , 1 CALVERT CLIFFS - UNIT 1 3/4 4-2 Amendment No. # ,55
. . . ._ - - ~ . _. . ._ _. _ _ .
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. ' REACTOR' COOLANT SYSTEM' Y ' COOLANT LOOPS AND COOLANT CIRCULATION:
SHUTDOWN LIMITING CONDITION FOR OPERATION 3.4.1.3 a.. ' At least two of. the coolant-l_ oops listed below shall be
'0PERABLE:
- 1. Reactor Coolant Loop #11 and its associat:d eteam a generator and at least one. associated reactor cooient-- .l pump.
-l
- 2. Reactor Coolan?. Loop #12 and its associated steam
. generator and at _least one associated' reactor coolant pump, l: 3. Shutdown Cooling Loop #11*,
- 4. Shutdown Cooling Loop #12*.
- b. At least one of the above coolant loops shall be in operation **.
1 E i APPLICABILITY: MODES 4***# and 5***#. ! i EUM:- 8
- a. With less' than the above required coolant loops OPERABLE, !
L initiate corrective action to return the required coolant loops h to OPERABLE status.within one hour or be in COLD SHUTDOWN l within.24 hours. e
. b.- With no coolant loop:in operation, suspend all operations
. involving a reduction-in; boron concentration of the Reactor <
. Coolant System and initiate corrective action to return the ,
required = coolant loop to operation.within'one hour. '
* - The normal or. emergency power source may be inoperable in MODE 5. i
** -All . reactor. coolant pumps and shutdown cooling pumps may be 't g . de-energized for up to I hour provided<(1) no operations-are- "
. - permitted that:would cause dilution of the reactor coolant system-boron concentration, and'(2) core. outlet temperature ic' maintained ,
0 at least:10 F below-saturation temperature. l
*** - A' reactor coolant pump shall not be started with the RCS temperature ?
-less than or eaual to 22 ' unless (1) the' pressurizer water level 17D is less than or' equal t inches, and (2) the secondary water J temperature of each steam generator is loss' than or equal to 30 0F L above the RCS te ssure i_s less j i than'or equal-t ature, sia..y p pl _:(3l nt th
- pe.cr ......... n er ege v:.:nt
,,,m,..... i,,-d fL- n!.. . ..::: cre t::p0r:ry rc:triction: :nd Orc Only
- v: lid for th: curr:nt shutdcur, : r.dition. Er.try into 20E 2 will
__.__._...n
' " gg __ .... ' 4_.,__ p .... u___ . . . a _ _a cl # SeeSkial estE[eptifk 7 1
0 CALVERT CLIFFS - UNIT 1 3/4 4-2a Amendment No. JE,145 l 1 i e p ->g cg g y w- ,,m , m -am. *--e--*I-* - u-
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REACTOR COOLANT-SYSTEM 3/4~.4.9 PRESSURE / TEMPERATURE LIMITS 3 ' REACTOR COOLANT-SYSTEM l; ' LIMITING CONDITION FOR OPERATION f j' L 3.4.9.1 The Reactor Coolant System (except the pressurizer) temperature and pressure shall be limited in accordance with the limit lines shown on ! Figure 3.4-2 during heatup, cooldown,' criticality, and inservic6 leak and i hydrostatic testing.with:
- a. A maximum heatup of: 1 Maximum Allowable Heatuo Rate RCS Temoerature l
# 0 F in any one hour period Ft F 00F in any one hour period F to 327 0F 4 0 0 L. 60 F-in any one hour period A 27 F I
- c
- b. -A-max 4 mum-cooldown-of-100 F-in-any-one-hour-peried-with-Tg9
- abcve 250 f-and-e-maximum eccid=n of 20 0 F in :ny en: hout
.. w ca n v u _. .ie g C ' '~ "_ ' '" '_a v g "y 'i w 4 ,.g O
- c. A maximum' temperature change of S F in any one hour period, M@ !
during hydrostatic testing operations above system design pressure.
,r
,F AJPLICABILITY: At all times. o ., ACTION:' ; LWith any_of-the above limits exceeded, restore the temperature and/or pressure to within'thel limit within.30 minutes; perform an_ engineering-evaluation to determine the effects of the out-of-limit condition on the '
~ fracture toughness properties'of the Reactor Coolant' System; determine ;
that the Reactor Coolant System remains acce) table for continued
- operations or be in at least HOT STANDBY wit 11n the next 6 hours and reduce the RCS T and pressure-to'less than 2000F and 300 psia, l 1 1respectively,wi8inthefollowing30 hours. '
' SURVEILLANCE RE0VIREMENTS 4.4'.9.1.1 The Reactor Coolant System temperature and pressure shall. be determined to be within the limits at least once per 30 minutes during ,
system heatup, cooldown, and-inservice leak and hydrostatic testing operations. 4.4.9.1.2 The reactor vessel material irradiation surveillance specimens i shall be removed and examined, to determine changes in material
-properties, at the intervals shown in Table 4.4-5. The results of these examinations shall- be used to update Figure 3.4-2.
-l ih m CALVERT CLIFFS - UNIT 1 3/4 4-23 Amendment No.145
ygi, l . s b.' A maximum cooldown of:
- L = Maximum Allowabic Cooldown Rate RCS Temperature p-
'100PFin any one hour period - > 250 F
~ 2@ Fin any one hoar period 250 F to 170 F-1@ Fin any one hour period < 170 F -
A ~
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Mser FM 76149.0 '
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Fi3URE 3.4 2a CALVERT CLIFFS UNIT 1 HEATUP CURVE,12 EFPY . , REACTOR COOLANT SYSTEhli PRESSURE TEMPERATURE LIMITS '! 250, _ - _ - HEATUP _
- i. , ,
, , . : - T SERVICE HYDROSTATIC TEST ;! _
-= =
=
2000 = ! =: ! -
- i :5
- - '? . ! i =
l l l t-
= LOW'iST 3 .
! 5 5 ' CORE 2: SERT' ICE : _f f CRITICAL
@ TEMPERATURE _n ,
_ f 5'i ' j' -
= 160 'F -
'i/ _- .-
5 1000 -
,5 - -
- j _ _ _
RCS TEMP. H/U RATE
/ _5- .:
f p5 '_ 70V TO 305T 5604/1 HR 7 ,5_/ __ 305T TO 327T s104/1 HR _5f ' 2:327 9 560T/1 HR 500 - i l 2 - -
= .- --
.i MIN. BOLgP' TEMP. 70 'F 1_ _
~
MAX PRESSURE _ FOR C OPERATION 1
^
. E' . -
0 10 200 300 400 00 600 INDI ED REACTOR COOLANT TEMPERATURECT 'Y l
/* The minimum boltup temperature is the temperature of the reactor vessel flange, not the coolant temperature.
CALVERT CLIFFS - UNIT 1 3/4 4-24 Amendment No.145
FIGURE 3.4 20 CALVERT CLIFFS UNIT 1 HEATUP CURVE,12 EFPY REACTOR COOLANT SYSTEM PRESSURE TEMPERATURE LIMITS ;
)
2500 i
- n. .i. .i...i.i .=_i F . a.l fi.d,_ii.i_-k._".lii.i.
7h...... . . E. . i i.E... - __.=_i. . I =_.1. I . f_idi.i._iiiil
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. L. '
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== lNSERVICE HYDROSTATIC TESTt;;;
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= . = . = _ _. =.- ._ i-..m
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< 22:=
=: = - - -
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- _t=E -- :=itEE:i tEEEE f=--{_ ! if f
' CORE CRITICAL:
=:= :=:np. n g-- *-- .
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g_ __/~~ f-r-- m ~ " - ~ ~ ~~~ ~
~ ~~
'I 1500 .=.-.'_ -
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_ . . _ . f 4-_j , ,' __, ._ _ g 4_ .g
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- LOWEST ~
e-- = f._._/ E;f _. ;
- g. E_ SERVICE .. ... %- . -
.__ _._ _ =. =: : :=/._-_ . - ~ ~
, _.-p_.
= TEMPER ATURE - -
- s----I
=160T
= : 3 _+ -
i/ =/ /;
.=
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- -' 7- RCS' TEMP. Hlu HATE i I.;:.:
. _. ,"m L -- -
-. g j 70T TO 313T 540T/1 HR f _
500 -
- --+-- /, - ,_
-e- >327T $60T/1 HR >
e--+
~. MIN, . BOLT,UP , TEMP. 70T. L
~+ ---
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f' l- ~
- 1 __ _ .. - n o: = !--
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.._ .- . MAXIMUM PRESSURE .a- . _ . , _
.' - r'
- 2FOR SDC OPERATION- -
.- . g._ . - . + _
- -- ^
._a_-.__i ..- - g - a g
( u 0 100 200 300 400 500 600 INDICATED REACTOR COOLANT TEMPERATURE T C'
- The minimum boltup temperature is the temperature of the reactor vessel llange, not the coolant temperature 3/4424
; ^
Fl2URE 3.4 2b CALVERT Cd*FS UNIT 1 COOLDOWN CURVE 12 EFPY I
< REACTOR COOLANT SYSTEM PRESSURE TEMPERATURE LIMITS 2 -
..I ::a s. .=:: .:r
. w.. . . . -:- n::
=. -: =
- : n -
, tt.
E E. .:5,,5
,~$.-
ru ::= ~h.n =n
'-_ INSLRVICE H YDROSTATIC TEST- _ _ !! :5 L..' ,
' -- ~ .: :; --
=m t: :4+: ,
-(
=_ i: i' 5 1:
.;::. ._. -~
.:=. W -::::n:::: -
- , q 2000
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r .- C' . .. . I 'Fr!.E i
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! i r == .:: n -3.;=:=.:.:
- - :u == - :
a ::: ::: ru %
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- == :n-
_-iOOLDOWNir._ 5: t=. t=:::x;-
' ; r ti - - -
= LOWEST 1
I' 1500 SERVICE
.f ! f
- N: 9
=E__ TEMPERATURE 1_ ': l' f f sg .g @ 4
= 160 'F "t:=i- ===t;
= :
=
5 .
.._: :=2#
_ ! 5
~~~~
--. f .-h hi::t-L -r p
L 1000 -
-.-Y_
5 '=~
.- C/D RATE
! RCS TEMP. :. 6
- - : = -
>250T $100T/1 HR
-_~ 5 / .:..-
I: - s20T/1HR :
$250T I
f - E!!E. _f _, ._
=
500 - r-3
=_ -
.. m .
== 6
~r MIN. BDLTUP -TERP. 70 'F1 .
E5d
^
L 5 = --
- +
M - ' UM PRESSUR E- .-- - l~ F S.DC OPERATION _ 0 f0 200 300 400 500 600 l-l- INDICATED. REACTOR COOLANT TEMPERATURE T C , *F 1. l l, l
. 1
- The minimum boltup temperature is the temperature of the' reactor -
- -- vessel flange, not the coolant temperature. i 1
l l j 1 CALVERT CLIFFS - UNIT 1 3/4 4-24a Amendment No.145 1 1
S FIGURE 3.4 2b CALVERT CLIFFS UNIT 1 COOLDOWN CURVE,12 EFPY REACTOR COOLANT SYSTEM PRESSURE TEMPERATURE LIMITS i 2500 i , . . 1 l; =.... .:: :=m =j . .. ........
. 1. l. .
J I .:# ..i =t==--d - . . ..= l., +
.j. := .= . . a =j. . . n== . .. . . ==p. .. . . . _r_= ;==
g ..{.. I
.: F. _. INSER,_VICE H. YDRO.S,_ TAT._IC TE_S.T. t %:n=_.] =._..)
E_H, =_. .4. --_ _. .t
- +. _ -
. ..n . 2 - _:: : .r.4 : _ . z.: _. . . . = _7 = =' ;----- -*=
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~-'== . n c f - : =_ .kn
= ~+. =
,- = r n.."__ "__.
- rt- . n1:
t__. :p . :b m;n =l=:= =:rf:= = ==: : :=t - - - + - 2000 - _
-j = _ , ,7_.
jz j_.= 7 . g. = ;_;ji . g_;p,,,, , , .._- - . . - . _g . __. _. =. . _ = _ .- xc+
.c - ___..: _a r : n+ = n t- i~ - - - - -
- . . . .:: 1 . ::.. : . .. : : .: n== =t==n==:= - 4 == -
4 , . .x .. . . _ _ . :: = = pi &='"~==::= ~~--
=-=====
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.i LOWEST = =F= L= ==C ""I " - ;O
! SERVICE!j5 *.IE51 f5 EEi555$3._~li"/Eihi'Eh!=RCOOLDOWNg
+
g TEMPERATURE" =: x==: :===; = i- :_.a:= : -- -
= _.
~:=:---r--- if.:.1t_-ft:t --r =_.=i..._=. * -
1500
- 160. _ d., m ___,t.=. ....F r ==t-----h, m
=. __ l_:r _ =.. . .~t =_= ==
- =_ _t._=_=.4 -
; =_ .-...e : =_. .*:-*t
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= - - + -
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..._t = h=_=_w_.=_ .=_
. . :' =.--. .:. ---=:= ~=.f._=.- s -rfn: -- _ .;-
%: 1000 . _ . _ . .__ .,.__
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/r6 =:=-~~:
.: =9.=_._n t =___~~~h=/2n-i==.4 = _ ==
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-++
.. >2504 5100T/1 HR
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-- :_ _.. =:-_-1:=-+r- / . _._
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e
- - - - - ---- +
u _.. , ==_ ;: <170T 510T/1 HR
-. _ u _ ;__._.,. _ g . __ _-} =_ ,.
500 _. _t... ..__+__.__.s_._ _ . . _ _+ =.L.._.. __4 _ - . . , . ..
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- .. .t_.. t :n=:trx ._ t_=.==___t=:_.=._=_t:_ :.==_ n_ _- w _
s ._
....._..__!.=....
#__1. __~.r_ _ _.
g___ ... --....... _ _ ....._.. m . ;_.. , . . _ . - . _ _ _ . _ i-EE.C_E ';;;.y_._E MIN. BOLTUP TEMP. 70 *F '"_ _ ; ,,~ . __
..n .__ __.=~~
~
- =t
*--"~ .
^~*~~-~ .- ;- -
- - = := ===M AXIMUM PRESSURE' - ~*r-- " -
2 -
= :: = = FO.R., .S.DC O,PER ATION - +- .r' - - * .---
- =_ t=_ = ...;.,_g__.,__;__ _._4_____n _ _ s.__..___.t tn__. .
_ q +--*- : _ .~
.,-_ _ u ~__ g = ,. _ _ = + =.;__;# _ .~
0 100 200 300 #30 500 600 INDICATED REACTOR COOLANT TEMPERATURE T C' The minimum boltup temperature is the temperature of the reactor vessel flange, not the coolant temperatore 3/4 4 24a
- ~ '7 :
^ ~~~ ' ' ~ ~
q REACTOR COOLANT SYSTEM n- 1 I O_VERPRisSUR PROTECTION SYSTEMS' LIMITING CONDITION FOR OPERATION :
.t 3.4.9.3 The following' overpressure protr . ion requirements shall be met:
a.- One of the following three ov6 >ressure protection systems - shall be in place:
- 1. Two power-o er te relief valves (PORVs) with a lift i setting S G psia or ;;
-- 2 . . A single PORV with a lift setting of-sw psia and a- t L* Reactor Coolant System vent.of 2 1.3 square inches,.or ,
- 3. . A Reactor. Coolant System (RCS) vent-2 2.6 square inches'. e
~
b.- : Two high pressure safety injec1! ion (HPSI) pumps' sh'all be E disabled by either removing (racking out).their. motor circuit _ . _ E i breakers from the electrical power supply circuit, or by_. 3 L locking shut their discharge valves. !
- c. The HPSI: loop motor operated valves-(MOVs)# shall be prevented: a from automatically aligning HPSI pump flow to the RCS by. _
1 l _ placing their hand switches in pull-to-override. ,
- d. No-more than one OPERABLE high pressure safety injection pump with suction aligned to the Refueling Water Tank may be used to inject flow into the RCS and when used, it must be under manual.
control; and one of the following restrictions shall. apply: ? 1. The total high pressure safety injection flow shall-be limited to s 210 gpm OR 2.' A reactor coolant system vent' of 2 2.6 square inches shall :
, exist.-
t APPLICABILITY: When the RCS temperature is 1 3270 F and the RCS is vented- , to.< 8: square inches. m . ACTION: I, a, 'With one PORV inoperable, either restore the' inoperable PORV to OPERABLE status within 5 days or depressurize and vent the RCS. L through a 1 1.3 square inch vent (s) within the next 48 hours; y ' maintain the RCS in a vented condition until both PORVs have .i been restored to OPERABLE status;
- b. With both PORVs inoperable, depressurize and vent- the RCS' i
- J l through-a 1 2.6 square inch vent (s) within 48 hours; maintain I the RCS in a vented condition until either one OPERABLE PORV l l
and a vent of 2 1.3 square inches has been established or both PORVs have been restored to OPERABLE status.
.l ? EXCEPT when required for testing. l l
CALVERT CLIFFS - UNIT 1 3/4 4-26a Amendment No. M ,145
# " " e-4 +- ee-- _ _ _ _ _ _ - _ _ _ . _ _ _ _ _ _ _ . - _ . _ _ _ _ . _ _ . _ _ _ _ ._.__.____ ___m__ . _ _ _
. " [ .
o -EMERGENCY CORE COOLING SYSTEMS-. SURVEILLANCE REOUIREMENTS j 4k5.2 Each ECCS subsystem'shall- be demonstrated OPERABLE *: I
- a. At least once per 12 hours by verifying that the.following valves are in the indicated positions with power to the valve .'
operators removed: ; Valve Number Valve Function Valve Position =
- 1. :MOV-659 Mini-flow Isolation Open
- 2. MOV-660- Mini-flow Isolation Open
~._3. . : CV-306 Low Pressure SI Open Flow Control
- b. At least once per 31 days by: 3
- 1. - Ve'rifying that_ upon a Recirculation Actuation Test Signal, the containment sump isolation valves open.
2; Verifying that each valve (manual, power ' operated or
- automatic) in.the flow path that is not locked. sealed,;or' f !otherwise secured in position, is in its correct position.
- c. By a visual inspection _which verifies that no loose debris (rags, trash, clothing, etc.) is present.in the con _tainment 1 which could be transported to.the containment sumpLand cause :
restriction of the pump suctions during LOCA conditions. This 1 W visual inspection shall be parformed:
- 1. For all accessible areas of the containment' prior _ to establishing CONTAIMENT INTEGRITY, and -
L. 2. - Of the areas affected within containment at the completion of containment entry when CONTAINMENT INTEGRITY is , established. *
- d. Within 4 hours prior _to increasing the RCS pressure above 1750 psia by verifying, via local indication at the valvs, that a CV-306 is open.
'cl.32Y'f and ltu Whenever flow testing into the RCS is required.at RCS temperatures
, "lew $O"F the high pressure safety injection-pump shall L rec rcu a e RCS water (suction from RWT isolated) or the controls of Technical Specification 3.4.9.3 shall apply. , CALVERT CLIFFS - UNIT 1 3/4 5-4 Amendmont No.145 ' {' -,
,. . .i g
r EMERGENCY CORE' COOLING SYSTEMS 0 ECCS SUBSYSTEMS,- T,yg < 300 F. LIMITING CONDITION FOR OPERATION E 3.5.3: As a minimum,1 o'ne ECCS subsystem comprised of the following shall be OPERABLE:
- a. One# OPERABLE high pressure safety injection pump, and b.- An OPERABLE flow path capable of taking suction from the refueling water tank on a Safety Injection Actuation: Signal and:
automatically' transferring suction to the~ containment sump-on a : ' Recirculation Actuation Signal. APPLICABILITY: MODES 3* and 4. L= ACTION:
- a. With no ECCS subsystem OPERABLE, restore at least one ECCS' i subsystem to OPERABLE status within'I hour or be,in COLD.
SHUTDOWN within the next 20 hours.. ,
- b. In the-event the ECCS is actuated and injects water into the . J,j Reactor Coolant System, a Special ' Report. shall- be prepared.and, '
submitted--to-the Commission pursuant to Specification 6.9;2 .
.within 90 days describing the circumstances of the actuation and the total accumulated actuation _ cycles,to date.:
SURVEILLANCE RE0VIREMENTS ,
.j 4.5.3.1 The ECCS subsystem sh'all be demonstrated <0PERABLE per the > l applicable Surveillance Requirements' of 4.5.2. ~i i
N 2 7 'f d ar d /t.u , F With pressurizer 0 pressurg17_501sia. 0 -l' nsition region exists
# Between.350 F and1327 F
-where the OPERABLE HPSI M.....ediM',a~t e pl ced.in pull-to-lock on-
-cooldown and restored to automatic st us on a heatup. e sw ,,27 0.
the requirr.d OPERABLE HPSI ump shall be in pull-to-lock an wi not start automatically. DeTo.f r?"") HPSI pump use will be conducte/. in accordance with echnical Specification 3.4.9.3. CALVERT CLIFFS - UNIT 1 3/4 5-6 Amendment No. Jf/Jfp,145
__ ~ _ _ _ ,<t
- r. -.
3/4.4 REACTOR COOLANT SYSTEM
- BASES- ,
13/4.'4.1 C00LAN1 LOOPS AND C(OLANT CIRCULATION The plant:is-designed to operate with both reactor coolant loops and 1 associated reactor coolant pumps,in operation, and maintain DNBR above
-1.195 during all normal operations and anticipated transients.-
[ I-
~ A single reactor coolant loop with its steam generator filled above the . low level trip setpoint provides sufficient heat removal' capability !
for core cooling while in M00ES 2 and-3; however, single failure 4 considerations require plant shutdown if component repairs and/or ' corrective actions-cannot be made within the allowable out-of-service ; R time. 4 In MODES 4 and 5, a single reactor coolant loop or shutdown cooling loop provides sufficient heat removal capability for removing decay heat; but single failure considerations require that at least two loops be I OPERABLE. Thus, if the-reactor coolant loops are not OPERABLE, this ' specification requires two shutdown cooling loops to be OPERABLE. The operation of one Reactor Coolant Pump or one shutdown coolin pump provides adequate flow to ensure mixing, prevent stratification' gand
. produce gradual reactivity changes during boron concentration reductions-in the Reactor Coolant System. The reactivity change rate associated. :
with boron reductions will, therefore, be within the-capability of operator _ recognition _and control. The restrictions on starting a Reactor Coolant Pump during MODES , and 5 with the RCS: temperature 1 3270 F are provided to prevent RCS l L pressure transients', caused by energy additions from the secondary system, which could exceed the limits of Appendix G to-10 CFR Par see B ses 4 . 9 (, h s d" ring
- n. ...: :::: y*te. .cw g :: g-"ym F
1
,,,e _ n- :r/fa 1 1000 c.p:g: . ,
..... ...d- ;
*T ow ng r a aoo v: /70/Ade };
'shUtdeenfor:t-le::t50d;I"bieh
- 1) restN etingitiie iater'v5 in the pressurizer ~ l a volume for the primary coolant to expand (2) intobyand{and restricting thereby provM
, starting of the RCPs to when the indicated secondary water temperature of . each. steam generator is less than or equal to 30 F 0 above the Reactor Coolant. System temperature, (3) limit th tial indicatad-. press of the ressuri o less than -- ^- Q on-or _ peet. . . . cn . . . . . k..:nt. 1 L 3/4.4.2 SAFETY VALVES MM L The pressurizer code safety valves operate to prevent the RCS from e being pressurized above its Safety Limit of 2750 psia. Each safety valve 3 b is designed to relieve approximately 3 x 105 lbs per hour of saturated steam at'the valve setpoint. The relief capacity of a single safety e ' valve is adequate to relieve any overpressure condition which could occur 1 during shutdown. In the event that no safety valves are OPERABLE, an operating shutdown cooling loop, connected to the RCS, provides overpressure relief capability and will prevent RCS overpressurization. During operation, all pressurizer code safety valves must be OPERABLE to prevent the RCS from being pressurized above its safety limit of l 2750 psia. The combined relief capacity of these valves is sufficient to y i CALVERT CLIFFS - UNIT 1 B 3/4 4-1 Amendment No. J//JJ/JE/E2,145
~
r ; g: a' REACTOR COOLANT SYSTEM it - BASES The minimum boltup ' temperature is the minimum allowable temperature at J pressures below 20% of the pre-operational: system hydrostatic test
~
s pressure. The minimum is defined as-the initial RT NnT for the' material . of the higher stressed region of the reactor vessel plus any effects for.. 1 L; irradiation per Article G-2222 of Section III of the ASME Boiler and : Pressure Vessel Code. The initial reference temperature of'the reactor' vessel and closure head flanges was determined using the certified- 3 material test: reports and Branch Technical Position MTEB 5-2. The , maximum initial RTy nT associated with the stressed region of the closure ~l head flange is -10 F. The minimum =boltup temperature: including- ; temperature instrument uncertainty _is -100 F.+-10 F --00F. However, for ; 0 conservatism, a minimum boltup temperature of 70 F is utilized. The design. basis events in the low temperature region assuming a water . solid system are: l A A RCP start with hot steam' generators; and, An inadvertent HPSI actuation with concurrent charging.
}
Any measures'which will prevent or mitigate-the design.basisLevents are. sufficient-for any-less severe incidents. Therefore, this section will discuss the results of the RCP start and mass addition transient ' analyses. Also discussed;is the effectiveness of a pressurizer steam bubble and a single PORV relative to mitigating the design basis events. The RCP start transient is a severe LTOP challenge for a water solid RCS, L Therefore, during water solid operations all 4 RCPs are tagged out of service. Anal sis indicates t t sient is ! uate ntr 1 ed- ! L p ac -res r c ons on ree p rame ers: initia pressur zer pressure 1 and-level, and the secondary-to-primary: temperature difference. With these restrictions in place and when decay heat level is low:(reactor has been shutdown 1 8 hours or longer), -the transient is _ adequately controlled : without the assistance- of the PORVs. Operating procedures require that during normal cooldowns, entry into MPT enable (3270 F and~ below) will' not , This restriction is not '
'koccuruntil8hoursafterreactorshutdown. intended to delay cooldown in situations considerations make expeditious cooldown prudent. If RCPs are restored ,
t in response to a loss of decay heat removal when decay heat loads are high and operator actions were either not-taken or ineffective, a single The inadvertent actuation of one HPSI pump in conjunction with one ; charging pump is the most severe mass addition overpressurization event. Analyses were performed for a single HPSI pump and one charging pump m assuming one-PORV available with the existing orifice area:of 1.29 in2 , o For the limiting case, only a single PORV is considered available due to t t single failure criteria. A figure was developed which shows the calculated RCS pressures versus time that will occur assuming HPSI and , charging pump mass inputs, and the expansion of the RCS following loss of I decay' heat removal. Sufficient overpressure protection results when the equilibrium pressure does not exceed the limiting Appendix G curve , pressure. Because the equilibrium pressure l CALVERT CLIFFS - UNIT 1 8 3/4 4-7 Amendment No. 145
o y _.. 4 s y;. REACTOR COOLANT SYSTEM;
, BASES MM .
exceeds endix G limit for full HPSI' flow, HPSI flow;is throttled
- to no more an 210 gpm indicated when the HPSI' pump is used for mass
. . addition. The HPSI flow limit includes: allowances for instrumentation uncertainty.. charging pump flow addition and RCS ex)ansion following loss of. decay heat removal. The HPSI flow is injected tirough only one HPSI loop MOV-to-limit instrumentation uncertainty, No more than one charging-pump (44 gpm) s allowed to operate in th PSI mass addition.
V 10 *f u Comparison e PORV discharge c ir181 e critical pressurizer i pressure of ~ ' psia indicates hat ade )rotection is provided by ! a' single PORNRCS temperatures een 0i 1en all mass input is ' limited to.380 gpm. HPSI discharge s mited to 210 gpm to allow for
, one charging pump and system expansion due to loss of decay heat removal.
L u To provide single failure protection against a HPSI pump mass addition ! L transient, the HPSI loop MOV handswitches must be placed in 1 L pull-to-override so the valves do not automatically actuate upon receipt ! L of a SIAS signal.- Alternative actions, described in the ACTION 'I ! STATEMENT, are to disable the affected MOV-(by racking out its motor. i , circuit breaker or equivalent), or to isolate .the affected HPSI header. 1 Examples of HPSI header isolation actions include; (1) de energizing and tagging shut the HPSI header isolation valves; . (2) locking shut = and - tagging all three'HPSI pump discharge MOVs'; and (3) disabling all .three HPSI pumps. q Three 100% capacity HPSI pumps are installed at Calvert Cliffs ' o Procedures will require that two of the three HPSI pumps be dit.abled (breakers racked out) at RCS temperatures less than or equal ta 327 0F and that.the remaining HPSI pump handswitch be ~placed .in pull-to-lock. 4 Additionally,'the HPSI pump normally in: pull-to-lock shall be throttled l L to less than.or equal to 210 gpm when used to add mass to the RCS. Exceptions are provided for ECCS testing and for res on LO As. , 321Y and .sf 1 A pressurizer steam volume and a single-PORV= wil pro e. a actory control of all mass addition transients with th exception of a spurious ;
. actuation of full flow:from e HPSI' pump. Over) sur ion'due to this- '
o transient will be precluded for temperatures"k.;w A7 . by disabling two L HPSI pumps, placing the third in pull-to-lock, an y t rottling the third pump to less than or equal to 210 gpm flow when it is used to add mass to the RCS.
. Note that only the design bases events are discussed in detail since the less severe transients are bounded by the RCP start and inadvertent HPSI actuation analysis.
u RCS temperature, as used in the applicability statement, is determined as follows: (1) with the RCPs running, the RCS cold leg temperature is the ; appropriate indication, (2) with the shutdown cooling system in operation, the shutdown cooling temperature indication is appropriate, ' (3) if neither tha RCPs or shutdown cooling is in operation, the core exit thermocoupits are the appropriate indicators of RCS temperature. CALVERT CLIFFS - UNIT 1 B 3/4 4-8 Amendment No. 145
~ %
;*. I
? k 4 4
s i EMERGENCY CORE COOLING: SYSTEMS- , BASIS . The trisodium phosphate dodecahydrate'-(TSP) stored-in dissolving baskets located in the containment basement is provided to minimize the' 4 possibility of corrosion cracking of certain metal components during . : operation of the ECCS following a LOCA. The TSP provides this protection by dissolving in the sump water and causing its final pH to be raised to 2 7.0. The requirement to dissolve a representative sample of TSP in a
- sample of RWT water provides assurance that the stored TSP will dissolve.
in borated water at the postulated post LOCA temperatures. ' The Surveillance Requirements provided to ensure OPERABILITY of each component ensure that as a minimum, the assumptions used in the safety analyses are met and the subsystem OPERABILITY..is maintained. .The-surveillance requirement for flow balance testing provides assurance that .. proper ECCS flows will be maintained in the event of a LOCA. Maintenance of proper flow resistance and pressure drop in the piping system to each- , injection point is necessary to: (1) prevent total pump flow from ) o exceeding runout conditions-when the system is in its minimum resistance l- configuration, (2) provide the proper flow split between injection points in accordance with the assumptions used in the ECCS-LOCA analyses, and : (3) provide-an acceptable level of total ECCS flow to all' injection ; points equal to or above that assumed in the ECCS-LOCA analyses. Minimum 4 HPSI-flow requirements for temperatures above 3270F are based upon small break LOCA calculations.which credit charging pump flow following an SIAS. Surveillance testing includes allowances for instrumentation and_ . system leakage uncertainties. The 470 gpm requirement for minimum HPSI j flow from the three lowest flow . legs includes instrument uncertainties 1 but not system check valve' leakage. The OPERABILITY of the charging 4 4 pumps and the associated' flow paths is assured by the Boration: System L Specification 3/4.1.2. Specification of safety injection pump total developed-head ensures pump performance is consistent with safety l analysis assumptions.6 $.:121*Fand/Lu i At temperatures se.cw M7 i, P I . injection flow is limited to less j p than or equal ~ to 210 gpm except in response to excessive reactor coolant , leakage. With excessive RCS leakage (LOCA), make-up requirements could L' exceed 210~gpm. Overpressurization is prevented by controlling >other parameters, such as RCS pressure and subcooling. This provides overpressure protection in the low temperature region. An analysis has been performed which shows this flow rate is more than adequate to meet core cooling safety analysis assumptions. HPSIs are not required to - - auto-start-when the RCS is in the MPT enable condition. - The Safety . Injection Tanks provide.immediate injection of borated water into the; t core in-the event of an accident, allowing adequate time for an operator to take action to start a HPSI. L i Surveillance testing of HPSI pumps is required to ensure pump operability. Some surveillance testing requires that the HPSI pumps H deliver flow to the .TS. To allow this testing to be done without increasing the potential for oveiressurization of the RCS, ;ither the RWT must be isolated or the HPSI pump flow must be limited to less than or equal to 210 gpm or an RCS nnt greater than 2.6 square inches must be l provided. p CALVERT CLIFFS - UNIT 1 B 3/4 5-2 Amendment No. Ef/Jpf/JJ/,145
m t , 5 ATTACIIMENTi2f f BG&E Letter dated August 13,1990 I.icense Amendment Request - Low Temperature Overpressure Protection i LTOP SYSTEM DESCRIPTION ; CALVERT CLIFFS NUCLEAR POWER PLANT UNIT 1 1.0 INTRODULTION On July 21,1977, a plant specific report on Reactor Coolant System (RCS) overpressure < l protection (LTOP) at low temperatures (Reference 8.1) was submitted to the NRC. That report detailed the administrative controls and hardware modifications which were necessary .l ' to protect Calvert Cliffs from an LTOP event for 10 effective full power years (EFPY). This document describes additional measures required to continue adequate 10 CFR Appendix O protection for 12 EFPY. It addresses the same issues as the 1977 report and therefore could be considered an extension of the original submittal. The focus of this description is not on the technical detail of supporting analyses, although some information is provided. Rather, a general overview of LTOP protective measures at CCNPP is presented. These measures (for 12 EFPY) supersede those established in 1977.
-Since no major modifications to systems affecting LTOP have been made, the important overpressurization events are the same as those postulated in the 1977 report; i.e., letdown isolation, safety injection (SI) pump start, charging pum i start, reactor coolant pump (RCP) start, and full pressurizer heater actuation. The re-ana ysis of these events is similar to the analysis discussed in the 1977. report,
.\
- 2.0 ' GENERAL APPROACII TO OVERPRESSURIZATION PROTECTION - !
BG&E's approach to LTOP is based primarily on the fact that the potential for L overpressurization of the RCS can be minimized by a combination of administrative L procedures and operator action. -flowever, because operator action cannot always bc l assumed, and because possible equipment malfunctions must be considered, BG&E has put in place additional controls to ensure adequate protection exists for all postulated events. : Analyses have been performed which demonstrate that a combination of administrative controls:and harJware modifications provide this protection. In general, this protection p includes the fcilowing:
- Procedural precautions and controls;
- Disabling of non-essential components whenever LTOP is required (below MPT enable temperature and RCS not vented); ;
- Maintenance of a non-solid system whenever practical; and,
- Use of the low relief setpoint in the PORV controllogic. 3 l
i 1 s
--_A-_.__--_____.-_-__-----
j . 7- a 9 ' ATTACilMENT (2F 1 3 I
^ 2.1 Design Criteria
'Ihe basic criteria to be satisfied in determining the adequacy of overpressure protection is that no single equipment failure or operator error shall result in a' violation of the pressure-temperature (P T) limits. This is in accordance with the l s criteria as originally stated in Reference 8.1. The applications of these criteria are ';
L addressed in Section 6.0, after the specific means of overpressure protection have 5 been presented. 2.2 ;1
- Basis for Pressure-Temocrature Limits The pressure-temperature (P-T) limits from which the heatup and cooldown curves (Technical Specification Figum 3.4-2a and 3.4 2b) were detived, were calculated per . '
the requirements of 10 CFR 50, Appendix G as supplemented by the Appendix G to Section III of the ASME Boiler and Pressure Vessel Code,1986 Edition. Pressure- . Temperature limits fcr 12 EFPY were calculated using Adjusted Reference
, , Temperatures developea frem the guidance of Regulatory Guide 1.99, Revision 2. In l addition, these P.T lirilts were corrected for pressure drops and for pressure and i temperature instrument uncertainties (Reference 8.2). -
i 2.3 - Basis for Low Pressure PORV Setnoint The low temperature PORV pressure lift setpoint ir based on protecting the most . l restrictive pressure of both the heatup and cooldown curves. The most restrictive pressure limitation is for the 10 F/hr cooldown at 70 F in the RCS.' The allowable pressurizer pressure (not including pressure instrument uncertainty) is 464.1 psia. A - a PORV setpoint of 430 psia is implemented in the field. This includes the "r r uncertainties (Reference 8.3) necessary for the protection of 464.1 psia in the pressunzer. ; 2.4 I}d for MPT Enable Temocrature and Pressure Setnoints The LTOP enable- temperature (MPT enable) has been developed using the 1 guidance fo'und in NRC Standard Review Plan 5.2.2, Revision 2 This 1SRP defines MPT enable as "the water temperature corresponding to a metal temperature of at a ' least RTNDT + 90 F at the beltline location (1/4 T or 3/4 T) that is controlling the-Appendix G limit calculations. MPT enable temperature was calculated accordingly - i by using specific heatup transients with changing thermal rates to accurately ! y . determine stress distributions. This method credits the soaking out of thermal
. stresses to meet the SRP criteria and is described in Reference 8.2. The MPT enable temperature for Unit 1 is 327 F.
-3.0 ' DESCRIMION OF ANALYFICALMODELS 1
1 Overpressurization analyses were performed as follows: The worst case overpressurization scenarios were identified for both mass and energy addition events; and i The effectiveness of the PORV to terminate an overpressurization event was J evaluated.
~ 1
.1
A*ITACilMENT (2) i
- u.
- De worst case events were identified and reported in Reference 8.1. . To determine the worst case events, solid water RCS conditions were considered his was/is a conservative assumption since the time delay in the transient due to a non solid system is climinated. Also, ;
all letoown ikw paths which could mitigate or terminate a particular overpressurization event ! were assumed isolated, he fotbwing subsections discuss the solid spien mass and energy input analysis, and effectiveness <;f the PORVs to mitigate an LTOP cvent. 3.1 RCS Mass Addition Anahsis
%c following mass addition events were postulated:
. Inadvertent High Pressure Safety Injection (IIPSI) pump start; .
L
- Inadvertent HPSI and Charging pump startt and,
. Inadvertent mismatch of charging and letdown Dow.
1 3.2 RCS Encrev Addition Anahsis ; The following energy addition events were postulated:
. RCS expansion following loss of shutdown cooling, includint steam generator heat addition; r
- Inadvertent pressurizer heater actuationt and,
. Energy addition from the steam generator secondary side to the RCS due to a :
start of any RCP when the steam generators are at a higher temperature than the reactor vesselinventory. ; Energy additions which are ci- stant with time include inadvertent pressurizer heater actuation and decay heat addition. Iland calculations were sufticient to model the ' resulting transients. 3.3 Effect of PORV Piotection De effectiveness of a single PORV was examined for (4 the RCP start transient, and (2) an inadvertent mass addition from a HPSI and chargJng pump. These incidents are considered the Design Basis Events as will be dis ussed in Section 4.0. o ; l- 3.3.1 For the RCP start transient, the analyses were performed to avoid opening a L PORV for normal operational transients, frutial saturated conditions are assumed in the pressurizer Assumptions include letdown isolation and no sensible heat absorption by the RCS component metal mass. Thesc : assumptions yield results which are considered the upper bound of. '
- anticipated RCS pressures.
l l 3.3.2 For the case of mass addition, the equilibrium pressure at which the IIPSI and !- charging pump deliveries, and expansion in the RCS due to loss of decay heat removal match the capability of a single PORY is determined. The complete ' range of operating pressures arid temperatures for LTCP are considered. Valve discharge rates are based on limiting thermodynamic conditions, L 3
A'ITACIIMENT (2) l i including critical (kiw effects. The backpressure at the discharge of the ! PORV is a maximum of 115 psia, based upon a quench tank rupture pessurc , of 100 psig. I 4.0 RESULTS OF ANALYSIS l i ne design basis events assuming a water solid system are:
. A RCP start with hot steam generators; and, ,
. An inadvertent HPSI actuation with concurrent charging.
Any measures which will preveut or mitigate the design basis events are sufficient for any of , the less severe incidei.'s. Therefore, this section will discuss the results (References 8.4 and 8.5) of the RCP start and mass addition transient analyses. l 4.1 RCP Start Transient The RCP start transient is a severe LTOP challenge for a water solid RCS. ! nerefore, during water solid operations all four RCPs are tagged out-of.senice. However, analysis indicates an RCP start transient is mitigated without the assistance of the PORVs by controlling initial pressurizer pressure and level, and the steam generator secondary to. primary temperature difference (delta T) when the decay heat level is low (reactor has been shutdown 8 hours or longer). Initial pressurizer. pressure cannot exceed 290 psia, initial pressurizer level must be less than or equal to 170 inches, and 8 it.ial della T must be less than or equal to 30 F. These limits are all ' indicated valui.., tellecting adjustment of analytical limits for instrumentation uncertainty. These controls ensure the PORV is not challenged for at least 10 : minutes after routine RCP starts, in addition, on a normal cooldown the unit will not enter conditions requiring L'IOP until the decay heat load is low enough to ensure loss of decay heat removal and RCP restarts after loss of flow do not challenge the PORV setpoint. Operating proccoures require that during normal cooldowns, entry - into MPT Enable (327 F and below) will not occur until 8. hours after reactor shutdown. However, if RCPs are restarted in response to a loss of decay heat removal, the PORVs may be required to mitigate the transient when decay heat load + is high and if o ierator actions are either r . taken or are ineffective. A single PORV . is capable of ac equately mitigating this transient. . 4.2 Inadvertent Safety Iniection Transient L r Starting one HPSI pump in wnjunction with one charging pump is the most severc ! mass addition overpressurization event. Analyses wcJe performed assuming one PORV available with the existing orifice area of 1.29 in . The entire LTOP pressure and temperature range was considered to determine limiting Guid conditions, including critical flow effects. The RETRAN code was used to provide an accurate ' calculation of the pressurizer liquid thermodynamic condition, ensuring an appropriate, conservative PORV flow model was used. From Figure 1, sufficient - overpressure protection results when the equilibrium pressure does not execed the t limitmg AppendixG curve pressure. Because the equilibrium pressure exceeds the Appendix G limit for full HPSI flow, HPSI flow is throttled to no more than 210 , gpm. The HPSI now limit includes allowances for instrumentation uncertainty ' (Reference 8.6), charging Dow addition, and RCS expansion following loss of decay heat removal. The HPSI now is injected through only one HPSI kop MOV to limit l , l
A*ITACitMENT (2) instrumentation uncertainty. No more than one charging pump (44 gpm) is allowed I to operate during the } IPSI mass addition, j 4.2.1 Three 100% capacity HPSI mps are installed at Cahert Cliffs.' Procedures will require that two of the hree liPSI pumps be disabled (breakers racked l out) at RCS temperatures less than or equal to 327"F and that the remaining ; liPSI pump handswitch be placed in pull to lock. Additionally, the HPSI ! pump in pull to lock shall be throttled to less than or equal to 210 gpm when ! used to add mass to the RCS. Exceptions are provided for ECCS testing ! and for response to LOCAs. These cases arc discussed in Sections 5.4.1 and 5.4.3. 4.2.2 Figure 1 is used to demonstrate that a maximum allowed liquid now oi .480 I pm through the PORV will result in a pressurizer pressure bek)w the i miaim. tim Appendix 0 limit of 464.1 psia. A total flow hmit of 380 gpm will i protect the :ninimum Appendix 0 limit for a range of initial RCS l temperatures from 70 to 327"F, and pressures from 50 to 400 psia. liPSI l How is limited to 210 gpm to allow for instrumentation uncertainty, charging flow, and RCS expansion following loss of decay heat removal. 4.3 Summary of Results A single PORY and the administrative controls described above will provide ; satisfactory control of all transients. Overpressurization due to the spurious actuation of full now from a HPSI pump will be precluded for temperatures at and below ; 327 F by disabling two llPSI pumps, placing the third in pull to. kick, and by : throttling the third pump when used to add mass to less than or equal to 210 gpm ! Dow through only one llPSI loop taotor operated valve. Lifting of the PORV on an E RCP start will be precluded by limiting the initial indicated pressurizer pressure to ' , less than or equal to 290 psia, the initial indicated secondary to primary tem wrature i delta T to less than or equal to 30 F, the indicated initial prepunzer level to ess than ; or equal to 170 inches when decay heat level corresponds to reactor shutdown for l more than 8 hours. Operating procedutes require that during normal cooldowns, i entry into MPT Enable (327"F and below) will not occur until 8 hours after reactor . shutdown. A single PORV is capable of adequately mitigating an RCP start in 1 response to a loss of decay heat removal when decay heat levels are high. Note that , only the design basis events are discussed in detail since the less severe transients are bounded by the RCP start and inadvertent HPSI actuation analysis. 5.0 PROVISIONS FOR OVERPRESSURE PROTECTION , Low temperature overpressure protection is provided at Calvert Cliffs by a combination of administrative controls and hardware provisions. The hardware provisions include the L incorporation of a dual setpoint capability in the PORV control circuitry and enabling the 1 PORVs during low temperature operations. Although the PORVs are the pimary means of protection, it is desirable to avoid challenging them. Therefore, maintenance of administrative controls is integral to overpressure protection. Disabling components when c unnecessary for plant operation will prevent their inadvertent actuation and therefore I minimize their potential for causing overpressurization. This section discusses specific - administrative and hardware modifi,:ations including procedural limitations for plant operation during startup, shutdown, surveillance testing, and RCS filling. ; 5
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A*ITACitMENT (2) 5.1. Administrative Measures his subsection discusses the administrative measures being taken to preclude RCS overpres6urization. 5.1.1 Maintenance of a Pressurizer Steam Volume Where RCS pressure, temperature, and other operating considerations permit, a maximum level of 170 inches will be mzintamed. Limitations which govern pressurizer operations are heatup and cooldown rates, spray valve,
. ,perature differentials, and pressurizer to hot icg temperature 4 xntials. A steam bubble may be formed and maintained as long as the
.:ssurizer operations do not exceed these limits. here is a general precaution in applicable procedures to instruct operating personnel to minimize the time in which the RCS is in a water solid condition.
5.1.2 De-activation of Non. Essential Components in general, any component capable of an energy or mass input which would result in RCS overpressurizatsn will be disabled when its operation is not essential to plant operations. The following are specific limitations: 5.1.2.1 Reactor Coolant Pumps - shall be disabled during water solid operations. A pressurizer steam volume (ensured by limiting pressurizer level to less than or equal to 170 inches indicated), initial pressurizer pressure (less than or equal to 290 psia indicated) and secondary to-primary delta T (less than or equal to 3(PF indicated) will be verified prior to operation of an RCP. Primary temperature is read using Shutdown Cooling System temperature indication in the Control Room or core exit thermocouples if shutdown cooling is not in operation. Steam generator secondary temperature is determined by using a hand held surface instrument at the steam generator (for example, at the steam generator-head, or steam generator shcIl between the tubesheet and head) or main steam line temperature if generating steam. Steam generator temperatures will be reduced to 220 F concurrently with allowing the RCS to be cooled by the shutdown cooling system. Operat ng procedures require that duiing normal cooldowns, entry into MPT Enable (327"F and below) will not occur until 8 hours after reactor shutdown. In addition, during solid water operations and during a cooldown below 150 F, all 4 RCPs are tagged out of se vice. 5.1.2.2 IIPSI Pumps .Two of the liPSI pumps are disabled and one is placed in pull to lock at RCS temperatures equal to and below 327 F. Also, the eight 1 IPSI kiop motor oxrated val.cs are prevented from operating automatically, typicaly by placing their landswitches in pull-to-override. This ensures that no SIAS can cause flow to the RCS given a single failure. In addition, when the RCS is solid and cold, either the llPSI header bolation valves (SI-654-MOV and SI 656-MOV) or equivalent valves in the IIPSI discharge flowpath are locked shut or univalent protection is provided by racking out and tagging the thid P. PSI pump breaker, Caution tags are used where operation of a pump or valve could result in RCS overpressurization. ( 6
l A'ITACllMENT (2) j i 5.1.2.3 Pressurizer heaters are disabled _and tagged during solid system operations, except as provided by procedure to allow drawing a i bubble, j r 5.1/2.4 Charping pumps that are not required during water solid operations are disabled and tagged. Typically only one c Si ng pump is required , to be operating under cold shutdown condit i a Whenever the RCS l is below MPT enable temperature and a H) LI pump is being used to l inject into the RCS for testing, at least two chargmg pumps shall bc l maintained in pull to. lock. , 5.2 Hardware Features ! 1 This subsection discusses the hardwaie mrovided to tratigate overpressurization events. High setpoint (2400 psia) PO RVs and Ccdc Safety Valves prevent overpressurization at temperatures above 327 F. At this temperature and below, the l low setpoint relief capabilitics of the system must be enabled. A discussion of this ; operation and related hardware considerations follows. l 5.2.1 Indication and Alarms An automatic computer activated high pressure alarm is set to alarm at an , increasing RCS pressure. The alarm is automatically enabled, by the plant ! cot.puter, whenever the RCS temperature is less than the MPT enable + temperature. This alarm provides audible and visual alarm on the control room panel and a typewritten message on the alarm typewriter. De pressure sensors used for this alarm function are PT103 and PTlatt. Each sensor loop provides a separate input to the computer. Additionally, a computer. activated high pressure alarm is manually set to alann at an increasmg pressure based on existing RCS temperature. By procedure, the plant operator resets this alarm to correspond with plant , conditions as RCS temperature changes. This alarm provides the plant operator with a Dashing display on the plant computer and is designed to provide threc alarm levels upon tcasing increasing RCS pressure; i.e.,
" warning,"" alert," and " critical." The pressure sensors for this alarm function are also PT103 and PT1031.
- 5.2.2 he mitigation system against RCS overpressurization at low RCS temperatures is based on the use of the existing PORVs (ERV-402 and >
ERV-404) enabled to provide relief capability at -low pressures. In .' conjunction with speific procedural controls, each PORV will provide sufficient and therefore redundant relief capacity to ensure that RCS pressure remains within the operating limit curves. The PORV low pressure setpoint will be 430 psia, which will be manually aligned when RCS . t temperature decreases to 327 F or less. Assurance of preventing inadvertent PORY actuation at RCS temperatures above 330'F is provided by the inclusion of a temperature interlock in the circuitry which prevents the low pressure setpoint from actuating the PORVs at RCS temperatures above MPT enable. The mitigating system is provided with separate ; id independent P T signals, bistables and power supplies to each POR' nis approach is consistent with separation and single failure criteria uset .a the original design of the plant. 7
L ! ATTACilMENT (2) ) J j 5.3 Summary of Oncration I The following discussion summarizes the sequence of events that ensures overpressure protection is available: 5.3.1- By normal plant cooldown procedures the RCS temperature and pressure arc , decreased to 330 F and 400 psia, respectively. An annunciator light will l come on to indicate that MPT cnable is required. Prior to cooling the RCS below 327 F, normal operating procedures will require the activation of the manual computer, generated high pressure alarm, the resetting of the hand switch to the "MPT Enable" position, checking that the PORY block valves 1 indicate 'open", disabling of two HPSI pumis by racking out their supply breakers,' placing the third HPSI pump in put .to-lock, and placing the 11 PSI , loop MOV handswitches in pull-to-override. When the PORVs are reset to the LTOP setpoint the annunciator window light will clear, indicatir4 that the i Iow temperature PORV mode of operation is in scivice. The setpoint of the plant computer high pressure alarm is manually adjusted as called for in - i procedures so that the operator will be alerted whenever RCS pressure approaches the operating hmits. Upon entering MODE 4, shutdown cooling may be used to cool the RCS. Steam generators must continue to be ccx) led ! to 220 F. RCPs are disabled by locking and tagging out their supply breakers at RCS temperatures less than 150 F. ; 5.3.2 During plant heatup, normal operating procedures will maintain the RCS' pressure below 400 psia until the RCS temperature is greater than 327 F. l . When the RCS temperaturs exceeds MPT enabic, normal operating ! procedures will require that the PORVs be reset to the normal (hig1) relief setpoint of 2,385 psig. At the same time, alarms will be deactivated by ! l procedure, and the temperature interlock will activate; thereby preventing ; the lifting of the PORVs at the low setpoint. Prior to exceeding 350 F, two HPSI pumps must be returned to automatic servic.:. . 5.4 Oncrating Guidelines 5.4.1 &nveillance and Component Testine r When ECCS system HPSI testingis required at RCS temperatures of 327 F ! and less, testing will be performed such that no new mass is introduced to the . RCS unless HPSI flow is throttled to no more than 210 gpm and a pressurizer , bubble exists or an adequate vent exists. When llPSI suction is taken from * , the shutdown cooling system, no limit is placed on discharge to the RCS since i L no new mass is being added, if addition of non. recirculated mass to the RCS in excess of 210 gpm is rec uired for tgsting, then the reactg coolant system must be vented through at cast 2.6 in for one pump or 8 in for multi pump testing. Testing of Safety Injection and CVCS system components (i.e., pumps, valves, automatic signals, etc. that are affected by LTOP controls will only be accomplished with a non.soh)d RCS. Such testing is only perf in accordance with approved procedures which establish adequate overpressure protection prior to component testing. No ECCS tcsting is allowed when water solid. I 1 e 8 , r
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A'ITACliMENT (2) 5.4.2 Reactor Filline Reactor coolant system lilling operations during a heatup are normally accom plished by using the containmert spray pum x which have a shutoff head t tat is well below the limiting pressure of the MPT curve. To collapse the steam bubble during a cooldown, a s'o:Wnarging pump is used. 5.4.3 LOCA Response In response to unidentified RCS leakage HPSI flow will be controlled to maintain pressuriter level and avoid overpressurization events. Depending on the size of the RCS leakage, flow greater than 210 gpm may be required. 5.4.4 Oncrator TIainiDS Operator training thrcugh required reading and/or on shift briefings will ensure adequate operator awareness of the latest approved LTOP controls. 6.0 DESIGN CRITERIA The design criteria for LTOP protection system were addressed in Reference 8.1. A brief discussion of the criteria follows: , 6.1 ' Oncrator Action t In each of the transient analyses, cperator etion was not credited for the first 10 minutes. De pressure alarms detailed in Section 5.2.1, in addition to other plant ; condition indications, will make the operator aware of the transient. 6.2 Sincle Failure A single failure must be considered in the overpressure mitigation system response to : an initiating event. 6.2.1 %c sensing / actuating / relieving system consists of two redundant and , independent trains. t 6.2.2 For the normal operational energy addition transient following an RCP start with a hot steam generator, the PORV setpoint will not be challenged for at ' I least to minutes if initial conditions for the pump start are satisfied, in this L case, failure of a PORV cannot result in overpressurization, since the valve ! setpoint is not challenged. Failure to satisfy one of the initial conditions may . result in opening one or both PORVs In this case, the PORV has sufficient : capacity to ensure the Appendix 0 limit is not exceeded. l 6.2.3 For the mass addition des!gn basis event (IIPSI actuation), a single PORY provides protection provided that 2 of the 3 IIPSI pumps are disabled and the l remaining purnp's flow is throttled, if we assume that the LTOP system l single failure is failure to throttic the llPSI while adding mass through onc HPSIloop motor-operated valve, then two PORW are available to maintain ,
~
l- the pressurization below Appendix G limits. l 9
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ATTACHMENT (2) ! i
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6.3 Seismic and IEEE 279 Design Criteria j Presently installed PORVs meet scismic criteria consistent with the basic objective of j preventing a potential LOCA pathway. Design of equipment added for o,*erpressure i mitigation is consistent with existing plant design criteria, and with the single failure criteria previously discussed. Design is such that (1) no additional risk of LOCA or other accident is imposed, and (2) design criteria of existing safety related systems are maintained, and these systems are not degraded. 6.3.1 In addition, the intent of scismic and IEEE-279 criteria is met for the operability and effectiveness of the mitigating system in that a single failurc ! which initiates an overpressurization event does not disable the mitigating system, t 6.3.2 Power is supplied to the PORVs from vital supplies designed to operate l during a scismic event and following loss of off. site power. Cable raceways i for this equipment are supported to withstand a seismic event. l 6.4 Testability t i ; The system is designed to be tested with a frequency that will ensure the system is ! operable when needed. !' 7.0
SUMMARY
l Overpressure protection is provided by a combination of hardware and procedural controls. Two are set to lift at 430 psia (protecting 464.1 psia in the pressurizer) for temperatures at l 5 and below 327 F. Alarms are provided to the operators to alert them to implement LTOP I' protective measures and to warn them when pressure limits are being approached. Components that can challenge MPT limits are disabled when not needed and m particular are disabled for water solid operations. Testing of components is controlled so as to , minimize any potential challenge to MPT limits and testing is prohibited during water solid operations.
8.0 REFERENCES
i 8.1 Letter from V. R. Evans (BGAE) to D. K. Davis (NRC), dated July 21,1977,
" Reactor Coolant System Overpressurization" ,
8.2 ABB Combustion Engineering Nuclear Power B MPS.90115, May 9,1990, P. J. Hijeck to Trevor Cook, "Calvert Cliffs 1 Reactor Vessel Pressure Temperature Limits Final Report t 83 Design Engineering Calculation I-90-196, Rev. O, "LTOP: Pressurizer Pressure low Pressure" 8.4 Memo from J. F. Williams to W. R. Boyd, NEU 90-536, July 17,1990, " Revised Unit 1 LTOP Operating Limits" 8.5 Memo from W. R. Boyd to B. S. Montgomery, NEU 90-620, August 10, 1990,
" Revised L'IDP Analyses for Energy Add; don Transient" g N l!
p 3' i; ,s..o A1TACitMENT(2) 4 h 1 i 8.6 Memo from W. R. Boyd to O. L Detter, NEU 90 526, July 18,1990, "Results of Revised Unit 1 LTDP Analyses
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5 I t 9 L t I I. W
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Figure 1 Calvert Cliffs PORV Performance. Liquid Discharge Equilibrium Pressure i Equilibrium Pressure - psia Initial pressurizer pressure - 400 psia i 500 490 - 480 - 470 - Minimum Appendix G pressure - 464.1 psia i
- 460 -
p/ ! 450 - . 440 ' l 430 - l l 420 l 380 390 -
-400 l Pressurizer inlet Flow gpm l
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