ML20125B178
| ML20125B178 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 10/17/1979 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | Rubenstein L Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7910240484 | |
| Download: ML20125B178 (10) | |
Text
.-
. =..
f *.
O TENNESSEE VALLEY AUTHCRITY Cr4 AT' A NcOG A. T EN N ESSE E 37401 400 Chestnut Street Tower II October 17, 1979 Director of Nuclear Reactor Regulation Attention:
Mr. L. S. Rubenstein, Acting Chief Light Water Reactors Branch No. 4 Division of Proj ect Management U.S. Nuclear Regulatory Commission Washington, DC 20555
Dear Mr. Rubenstein:
In the Matter of the Application of
)
Docket Nos. 50-327 Tennessee Valley Authority
)
50-328 S. A. Varga's letter to H. C. Parris dated August 17, 1979, requested that TVA develop emergency operating instructions and train operators to recognize and mitigate an Anticipated Transient Without Scram (ATWS) event. Enclosed is a draft revision to the Sequoyah Nuclear Plant Abnor-mal Operating Instruction (AOI-1) for Reactor Trip.
This revision to A01-1 incorporates specific indications which must-be observed for reactor trip followed by mitigating operator actions in the event the trip does not occur. Operators are being trained to recognize and mitigate an ATWS i
event through the use of this operating instruction as part of TVA's operator training program.
Mr. Varga's letter indicated your review would include a site visit to determine the feasibility of implementing the proposed procedures through operator simulation of the steps.
In view of Sequoyah's fuel loading date of November 15, 1979, it is necessary to schedule your site visit as soon as possible.
Please get in touch with D. L. Lambert at FTS 854-2581 to make arrangements.
Very truly yours, TENNESSEE VALLEY AUTHORITY-T L. M. Mills, Manager Nuclear Regulation and Safety-Enclosure t D 10240 yh R
ENCLOSURE
~
't
- o. i i s
..g.
mi.. -,.., n. i r ' ' s
.. q q.
o.
m 4.s b
/ 18,
60) t... I.
14q s. t
..I t.e...
s S L h I' i t '...i.::: 0 qu.,'..'..'......'w'..-
U.
.')
- o
,.,4.*L.
,,, g _
[r. { en.<(-',*.
- g *% i.s.* { g 9 C, ] p.bm.
'. '. 3 4. e s. e. ).
s Ad"'.i n i G ! rO ; 1.VC b up 0 rViS O r IC
!!a i n.; e r.an c a Sun. c rviso r
...,.;..,,.,...O..
... ~ //
^0
- #. U P. J P ". c 2 '$ t Q 0 7 71.. ? r
- f...,J d.,3, g h.y. 9 A l....,.
4
..ia...
.1
- _.i..a,..
- t. i..
- t. v.
.e i..,.. i.. t -
Js.
.t.
.t.~,. j. t. i.. 3 1C Or. i t i c., S u;,e : ic:e an (_. ;
Qe.. I : t - / m r..a,.
S-
'e
_, _ lh til' 16 F... ;.i c l u t W IC
I I'
""E U 'N
- REACTOR TR1i' C'nlef Storal. coper Proop Te ;t Pro; ran Coo rdinator
()".....,
- ) :."..,,..
'4 Units 1 & 2-Ch e r i m i
- ,7,in c a r h.uii w' em i,U a rat e.;
Inn P run. int Shop
- -. ~. Tcaet.o r Eri;,Me r In s t '.. :n t Engin.c:
1:c ch.:ni c a l 21 r,i.nce St a f f Inde.:t ri al T.u 1.:no r IC Tl d i n [ll, C.'nl D T CO O rd } **.l t O ;
l'50 - ('h i c k
. u y.
..a ;, r : l'a i
..?
L Inii) f.C b.1
.'l V S.1" i C i
". *e2 o. n r....i.
)..o,.
, i.
o.
p((i p Ja..
; { l ; ? '...{;.
(k*
(' 9 t r;1.!
b^
](
e.
3 t.it i Mil O,*u 3
. !e 7
[, a f,x. jh d I,Y...e /gh..
_. l1
.1 e e V.
)..
s r ;; =- { c..--
%..e j.
tb
.P, i
i' ;, 1 c,:
r-of P P rc '
(" ' u;.1 O L, l N 1.ile f 9. r.*j '; <,
i(J
/.)
// y
-t
. - -.e.,--
a..,.
n
.n,
- -. -., s.i.,..-
.t.
e
.n..
.c.
. u.
Da.* n,
-.... Super ' c : den t, 5:: J 4
e.
i
- m... s e
i b
\\
3..,...
j
.,.,n,..
p-a_.
... ( (....-
'. f,s.0 '.
... - -. ::1.0. i '. : I 1, b;. i e w1 '."
.,s.: ' r,..acur);i u.;.ce r,
- p.,.
._u. v, /.t.a upe r 2 -
i I,.,..au L c:uin a t ut Ic c r :hteric.1r C:,0 r di n a t 7 r '
r,
.-- ;! m :n.'
r, CT-C.'.u.\\ S r c ! !
IU '. a A, p co v.ul:
g,.
'e, )
IU P P:wl " !.. ri r !:n:a.
P. r. n. h
.,.Q n v.
- 'o.
D. i t n 1:e.v i m d P. g.
1:,. v. t;o. l p.a e l
Its, s e d p g,.s m
3 9/H/78 All 2l25.y9 1
4
./... J..
"***-'.'ie..ia
. au.emee age a
e e
- u
.**=#
.ee.
. w. w
.,e g.
ii.
mea. - e a
e.
e
..*.h'
.. _.._. I..
..i._........___-
.The !.. t. p.*
o f t h I '4 j:.t ruct i.oa b
.i i: ' r
g t,, '*
un, i. t
.4 c 0 vi j Y.vv. 3 Reactor Trip Report Charts, etc., tc, be attached to trip report has not been determined yet.
1 N "
M. _/
f >~ 7/
s l
1
AOI-l - Units 1 !. 2 i
Page 1
.,f 5
Rev. 3 REACTOR TRIP.
I.
SYMPTOMS A.
T'ac reactor may be tripped by one or more of the following:
1.
Source r.me,e high flot. (10 s'PS, 1/2). Pinual b1A k abave P-6.
2.
Y n t e r:aed ia t.. range i.;gh flu.c (2', percent power, 1/2). P.anual bicek c'r nve I -10, 3.
Power raare high flux, low cetpoint (25 percent, 2/4).
.tna:.1 block a',uve F-10.
4 c vtr :-n p '.iit;b f:ta, hif, t.e t ;, t.. t (109 pere.nt, 2/4).
)
S.
her range M;;h ceut r ;o flux rate:
i a.
-Positive rate ($ percent of f ull poser in 2 seconds, 2/4).
l b.
Negative rate (5 percent of tull power in 2 seconds, 2/4).
6.
Overtemperature
- t. T. (2/4) 7.
Overpower t., T.
(2/4) 1 d.
Luw coolant flow, < 90 percent (1/4 loops when above P-6 setroint
)
of 35 percent power.
2/4 loops when < 35 percent power but above P-7).
9.
Undervoltage on 6900V unit RCP busses (4tl30 vults, 2/4) above P-7.
10.
Underfrequency on 6900V unit RCP busees (5h HZ, 2/4) above P-7 l!.
ilich pre:;6urizer pressure (2365 psig, 2/4) l 12.
Low pre:.uur!c.er pro:. ore (ldn5 p41g,, 2/4), above P-7.
13.
Pressurir.cr 5tch levo; (C; perecnt, 2/3), abcVe F-7 J.,
'U
.* r.
' '..uiw'r. : e r 'c lew til sM t e ti r.> ! r e ( dent utrb icv S/0 level s T. t..a t' ie: > fe dais.r Fl..w.2 3S t SC rated 4 ' u.u.
l ow, 1/2 or,one
<>'i'.i..J
$ Ji p;rce :t.cve
- t /.' o y
..e.
';/ u ).
1.h
- . e l.
S / s,.vwl ( 0 ;- pe r en:..! / 3.:.a a n y.ne.;/ J).
16.
Safety injection.
I 17.
Turbine trip, above P-/.
18.
. Manual trip, 1/.'.
]._.
.. l i -
u.
6116 ( h i.,,
l'. i n e vi 5 1
/g......,...
4 i,.
. C.... b ei.
.s
. t.. o '.
i.
A.
Turb.ne '.. ;, - ru.ctor Crip b.
Aux ! ! ; n ry [eedrian te r pi.mps :;ta r. on lo lo steam ;en.:rator icve l.
C.
Generator breakers trip, 6900V unft boarde auto transfer.
D.
Au toir.a t i c t, team du.1 p ac t ua t i on.
E.
Steam ger.erator teedwater regulator, regulator hypass, an'd.nain feed-water isolation valves close at 554*1' III. IM::EDI A"'i? OPEXA70is ACTION
{
A.
Verify reactor trip-rapid drop in nuclear power ( 10% initial power in 5 sec.).
l.
Emercency borate 100 ppm for each rod not fully inserted.
l Note: All rods in as indicated by IR?I and/or IRpI bottom lignts 1
2.
In the event a reactor trip signa 1 is r;enerated and tae reactor
)
- . rip breakers f ail to opca and allow the control rods to drop, the followine actions shall be initiated immediately:
l Note: An Anticipated Transient Without Scram (N:'JS) has occured a.
At t enp:. to manually trip the breakers cy placing, tne reactor irip switch in the TRIP position.
b.
If the above doen r.o t t rip the toda ia.r.ied iate l y d is pa tch soce-one tu the Ahn-V ani;.
.,aa r.! s A and a to tr.
tne breakers
. r : ve;
- r. i '.
5..
.". l i s.;i u d t bC donQ pcweriite ! !*. + + o n ' r..!
wirb.a :. i i... :...
If the control rods are not inserted by the above procedure, c.
actuate safety inl,cetion.
3.
Verify Turbine Trip - Srbine Steam Stop Valve closed.
If not:
1.
Use manual electrical trip switch 2
In the event of electrical Trip failure dispatch operator'to the turbine front standard to manually trip with the trip lever.
C.
De t e rn. ' w
.w to c coo ; in: sp r
.r.
..: a c us.
I.
Aux i, i :i ry fiordwtito r i% a p:3 r u.nl i n g".
D,e.'.nr..o.
- ,re ';G re an. '. a v e, withLa expoita. r..a
- i.
( l ')f 0-f4.iS
/
p...q. ).
( 24 -6i. pe rcen t i..* v o i ).
.-invg controt.iing to.>. 7,,.c.
4 Contaiament pre.,aure.ind temperatore a c c e a '. (-U. ! pu id -N. 3 puid)
(85-100'l'. uppe r co.np t rtment, I GO-120 i. Iower ec.npartment).
5.
Gene rator breakers open, 6.9-kV unit station sarvice transferred.
6.
Stean generator feedwater regulator, ter,ulator bypasr., and main iso-lation valves shut.
w e
e
s Avl va i. 1 & 2 Page 3 of 5 Rev. 3 C.
Announec, "kcactne Trip".
I';EC AUTI ON :
An t. o r. tic co. trol,.,rr nat.to im,i.. u e d
.n manaal un ess it is apparen the aa:o.r.at ic ac t ion has tailed.
1C a con:rol is placed on manun!, i; must be checked f requently for proper ope ra ; lo n.
IV.
SUBSEO.CC.'.T OPi.RATGk ACTICS A.
If :he reactor trip is a,. result of Lafety injection syotem actuecion, refer to E01-1, " Loss of Reactor Coolant'; E01-2, "Loas uf Secondary Coolant"; or E01-3, " Steam Genera:ce Tube Failure".
If the trip is a result of a power b;ackout, refer :o E01-5, " Station Blackout".
h.
W.rit-j prop,> r autosui.ie ac: ua:.on o f the noxi liary f ecavater sys;.ert.:
it) the :.wo no;.or d ris < '..cd or.c s team-drivea f eed pu/.ps ::a r ted,
( l '. level contru. vo ;ves open, ( 3) ;;ow tc cach atea:. Lencra:or at 440 gpm or being moculu:.ec ro,;.aintain levein at 33 percea;.
1.
If nnly one (1) mutor-driven aukiliary feedwater pu.::p is operable
- o deliver water to the. steam generators, the reac:.or coolant pumps should bc ttopped and MSiV's closed on loups without feedwater flow.
CA..... O..v a i.s : ine reactor coalant pur.ps shou,io, bc.u.oppco, only after,:
other auxili;.ry ' eedwai.er pumps cannot be La certain that s
placed in service and 1 minute af ter 'o-lo level is reached in any ateam generator.
'd.
Should any steu. generaor(s) have s: car., pressure indications ab-norcally low with respect to :he other stear., y,enerator(s), auxiliary feeowater flow to the steas generator (s) having the abnormally low pressures should be diver cd to the s: cam generator (s) having a hign pressure.
CAtjT;05 Be aware of 100 psi t.P safety injec: ion signal.
3.
Auxiliery feedwater uhould be contcolled to bring the a:eam p nerator
.cac.. :o the normal nu.ioad va.ue of 33 percer. uno to. seep. avg i
.ievcia e.
aiis,atly above the no-load value o;.
N,.
r., (..,e t.cmperature 3hould not be allowed to c below 547'F).
It une need for auxiliary icec.en:er is o
abacciatec with an accident discussed in one of :he de:atied ca.e g ney instructions, :ac procedure in those instructions should be :clicwed.
C.
',f :.hc main :ecdwate? :,ys tu.n f u avu llable, manua lly operate the r.ain f.:cd-wa t er sys tera an requ' red to.r.aiatain i,tca.n generator water a; 33 percent icsel.
1.
.'r.m.. f a r c ont r.i t o f a.e ::.a. : iced. eater pom,n, and the t.:ed ner cent.rol valvea tu maanal.
^
signal.
4ero the feedsater contesi 2.
Manually reset the feodwater isolation.
Open re.ain feedwa:er isolacion valve.
4 Vary feedwater pump speed and the fcccwater regulator bypass valve po-sition as required.
3
\\
/.01-i - Units i & 2 Pa y,e of 5
'V.
SU3sECUENT OPdkATOR ACTION (Cont.)
C.
5.
If Tovg cannot be main:cined.> 547? and/or level a: 3 H in ur.en:
transfer :o auxiliary feca-generators with main foedwater pumps, water pump control.
CAUTIOS:
Particular care must be taken to avoid recding wa:er to the steam generators too rapidly at cero 1 cud in orcer to avoid ccoling the reactor coolant below 547'F.
h?.e u core deccy hent is loi', rapid fecding of the s:eca gen-eratcra can cause large reductions in reactor coolant system tc:nperat,nre.
CAi.:TIOS : Rapid feeding of wat.:t into one steaa genera;or :ay result tn pressure dif f ercaces suf ficien: to ir.i te :e safety injection oy steam line high.G P.
D.
The stest; duup control should be :ronsfected to be main c:es,:. headt.:
p re s i,u re cont rol n.ude, and ti.c set pre.8sure adjusted to holc a stca pressure or i005 paig.
NOTZ
- n ordi;r to conne.ve ste.ca geaurator water, c '.., s e t pressure shauld not 1;e sd j urit ed b.'l w I Ut,*. pr,tg eve.. t hot.gn the reac;0r cc. l.iat t om,3e co t u r.
m. -j rine cons ce cat i y a have.% 7';. un:i;.
i.
. dec. era.ined that tc...a g.me ra t o r wa t e ; l e ve '. s in O' eta hic Sten.7, ;und '. t G d / e; HU l u n g,0 s s n. l l i. n
- a ba a re a;,vVe
[
20 percent icvel span on ;Le wide ranga 'e'.nl rec o rd e r.s.
E.
Verify the containment ventilation sys'te:n is notic.al. Three coolers operating in each compart. ment, upper and lower.
F.
Transfer NR45 to SR and IR.
G.
Verif y nor:aal pressurieur pressure of approxi.nately 2235 psia. Main:ain pressurizer level at 25 percent for rerc, load.
h.
As cain turbine >> pend approachar 1500 r/ min, verity aato start of bearing luba cil pon.ps.
As speed sproaches zero, n;ar: bec. ring oil litt p u.:. p s and place tuebine on turning gear when a;opped.
4 I,
Establish and maintair, ho; scandby canditions.
Re f e r tu G01 *, 'Plaat at Hot Standby with Xeno'n Present."
J.
I f a n ATk'S even t has occurrea, :) ring tne un;; to a colc cnutawn condition consisten: with techni:icistica specifica: ion 3.0.3.
K.
b' hen the.cause of the re ie t.,e t r i p has been de te rn....ed, couple:c :he deuctQr Irlp Repiirt, Appendix A.
i i
4
A. -l
!!.. I t s
.w.,.,,,. >
v.
IV.
SU'U.EQUE.?iT CPZRATOR ACTIO3 (cont.)
L.
If the cause of the reactor trip con be carrected. the olnnt may be returned to cperation. Pefer to G01-2, "Plar.t Startup From llot Standby to Minimun Load."
V.
DISCUSSION The reactor is tripped by deenergizing the control and shatdown rod drive mechanisms, thereby allowing the rods to drop, unimpeded, into the reactor core.
A reactor trip may be initiated autcmatically by the reactor protection system or maaually by the operator f rom the control room.
9
_3_
I l
i.
ADI-! - Ualts I r. 2 Appendix A s'a y: I ai J 17 e v. 3 RLisCTOR TRIP M PORT i i; i t W
%nc %r Trip do.
,a.
'.1 winated _
v:
no fiw
~
U. l' S,;
1 Operater T,rcur e.saip=ent ta!!ure,,
Safety Syste.a O t lie r __ __,
PI. ANT CONDITIor:S (Prior to Trip)
Rx Mode (1 thru 6)
Rx Pre:n u re Rx Power PR7. level Steam Flow Tava Feedwater Flcw PLAST O/0LUTION (Prior to Trip)
Starting Up Stutt ting Dowa Steady Operatton Sy.s t e rn Te s t Power Charge Other GENERATOR _
Sy nc h ron i.!<d Ye.
No.
Gu t p u t.
We
- 'o r T F : CATiu.S
- ?..an i a t r y
>b at U.c a l t h ?b p i c s I,a 0 a t Operating Supe r vi:,or a t
-u-
j;...
AOI-l - L'ni t s 152 Append 1.<
A Page 2 of 2 Rev. 3 ERIEF DESCRIPTION OF TRIP l
l 4
i A ITACH ThC FD. Ltri..... ( d..i r: s, ac. )
Unit Operator Assistant SE Shift Engineer e
+
.;