ML19352A502

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Comments on Draft ATWS Procedures for Facility.Util Should Review ATWS Analyses & Submit Revised Procedures
ML19352A502
Person / Time
Site: McGuire, Mcguire  
Issue date: 10/22/1979
From: Thadani A
Office of Nuclear Reactor Regulation
To: Birkel R
Office of Nuclear Reactor Regulation
Shared Package
ML18025B195 List:
References
FOIA-80-587 NUDOCS 8104170147
Download: ML19352A502 (2)
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NUCLEAR REGULATORY COMMISSION

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_E WASMNGToN, D. C. 20S55 k..v f gt!

NOTE TO:

R. A. Birkel

SUBJECT:

OPAFT ATAS PROCECURES FOR MCGUIRE NUCLEAR STATION The following are our cor=ents on the draft AT45 procedures for McGuire Station:

1.0 Symotoms i

1) The procedure does not identify the initiating event. For example, would all rod bottom lights illuminate if the initiating event is loss of offsite power.

ii) The operator is not given any aid in knowing what the symptoms of AT45 events might be.

Further the symptoms would depend on initiating event.

I.t seems to me that they ought to carefully look at at least the following three events:

a) Loss of Main Feedwater b) Loss of Offsite Power c) Stuck Open PCRV fii) The first item of importance is that the operator recognize that scram action was talled for but did not occur.

2.0 I rnediate Actions 2.1 Automatic - These statements don't say anything about an ATAS. As a matter of fact, item 2.1.? may not occur at all if the scram breakers don't coen. This section should discuss other automatic signals such as auxiliary feedwater actuation and emergency enee cooling system actuation.

2.2 Manual - What is the time frame for these actions.

0 Item 2.2.3 - For what ATdS events would T decrease to 546 F for f'"Cediate action.

Why is there no discussion of auxiliary feedwater and HPSI actuation.

These systems are critical during AT4S events. The auxiliary feedwater system is needed 1 : mediately and the flow should be verified.

3.0 Subsecuent Actions provide time frame for these actions:

3.1 How can the operator verify tnat tnese parameters are normal. What is tne operator to do if these parameters take on acnormal values as would ce One case during an ATWS event.

81041701 y

ET211979 R. A. Birkel 3.-2 Can this instruction be accomplished for loss of offsite power event.

This comment applies to several subsequent instructions.

3.8 What is the rol.e of this statement during an ATWS7 General Comment. After reading this procedure, I came to the conclusion tnat people who wrote this' procedure probably don't have a good understanding of ATWS events.

I recommend that you ask the utilities to:

a) review ATWS analyses, b) combine procedures for those ATWS events where sucn combination is warranted by similar required actions (I believe two er three procedures should do it),

c) keep in mind the comments on the draft procedure, and d) submit a revised set of procedures.

(hb}..YV

A. Thadani

Enclosure:

cc:

S. Hanauer T. Speis l

S. Varga R. Baer M. Srinivasan i

K. PareIewski H. Vander Molen l

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Dtntz Powrn COMP.O.*'T Powen Berr.orro 4a2 SocTu Caracz Srazzr. CaAarorrz. N. C. asa4e

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Septemoer 25, 1979 su'

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m.e u Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Censaission j

'4ashington, DC 20555

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Atten:1on:

Mr. R. L. Baer, Chief l

Light 'Jacer Reactors Project 3 ranch No. 2 i

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l Re: McGuire Nuclear Station l

Uni:s 1 and 2 l

Docket Nos. 50-369, 50-370 l

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Dear Mr. Denton:

1 Your letter of August 17, 1979, transmitted interi:a requirements for AT4S which sust be satisfactorily 1:nplemented to support issuance of an operating 1

l license. The basic requirements were to:

1) Provide emergency procedures to provide for operator recognition of and propse response to an AT4S event, and
2) Provide operator training :o assure proper inplementation of these pro-cedures.

The emergency procedures, in general, at McGuire consist of a general reac:or

rip procedure and a series of specific transient and accident procedures.

In order to address AT4S concerns it is our intentien to revise the reac:ce trip procedure to include specific indications which =ust be observed for a reactor ::1p followed by necessary ni:1 gating operator ac:1ons in the event a trip does not occur. The specific ::ansient procedures which require a I

reac:or : rip v111 also be revised to refer the operator to the reac:or

rip procedure if an AT4S event is identified. At: ached for your review is a draft ecpy of :he revised reactor trip procedure.

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Mr. Harold R. Denton, Director September 25, 1979 Page Two It is eur intention to provide the necessary training to assure operator familiarity with the above ATWS provisions. If there are questions regarding this matter, do not hesitate to ccatact us.

l 7exh truly yours, a m a. A William O. Parker, Jr.

GAC/sch Attachment 9

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E?/1/A/SC00/01 3UKZ PC'JIZ CCMPANY

.%:GUIZI NUC'ZAR STA!!::N h

)g REACTCR TRI?

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-l-1.0 Sv=ocess l

1.1 Any Alarm on Reac:c: Trip Tirs: Out ? anal.

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4 1.2 All : d bc:::= 11gh:2 are ill*

  • m:ed.

hf,7 1.3 Nuclea !:st:*.:nencacice indicati=g a rapid decrease in Neutron YY t

l flux.*

1.4 If :here is c: a rapid d: p is nuclear power and :he cen:::1 : ds 'are l

inserted, then dis is an "A=:icipated Transian: "Jidcut Scram" so:

event.

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2.0 I==edia:e Action 2.1 Aue:matic 2.1.1 All rods d::p is:: core.

2.1.2 Turbine-Genera:Or ::1p.

2.1.3 7eedvater Isola:10: when Tavg decreases== 364*T.

2.1.4 Steam Ou=ps Arm-Actuate and/c ?CR7 lif.

1 2.2 ym-uni l

l NOTI:

Do set place systa=s in =anual unless =isepera:1:n in au: ma:i 13 apparent.

2.2.1 If all ::ds do so: d::p is:o :he :::e then:

2.2.1.1 Ma-um'17 : rip :he reae:::.

2.2.1.2 If a react:: ::1p has ac: ye: cccurred, :he: asually

1p :he F.C se 3krs. locally.

2.2.1.3 If a reac::: ::1; has no: ye: occurred, i= media:ely ac:ua:e safe:7 infec:ie:

2.2.1.4 If a reae::: : rip has ac: yet ec urred, p'. ace de C::: 'ol Red 0:1re la=k Selec::: S ".:d i:..anual and inst?: ::ds.

2.2.2

!! turbine genera::: did ne: ::ip, :he::

2.2.2.1 F.2=ua117 ::ip :::51:e f :s C ::::1 Rec = or ' cally a: de :::51:e.

2.2.2.2 2f a turbine ::ip has no: ye: =c:urred, :he place i

2EH Cc=:::1 in =anual, and manua'.'.y ci:se de " eve :::

7alres.

2.2.3 25 Feedva:e: !sela:1:n does ::: occur whe: : avg decreases :=

.c :. *.,

..e e

2.2.3.1 C1:se de =ais f eedva:e: regula ":g valves and de, bypass s

d& M va., res.

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i 2.2.3.2 If feedvater isola:1cn has not yet occurred, the sais yeedvace: Con:21=menc Isol. Valves.

2.2.3.3 If feedva:e isolation has see yet occurred, manuan y Qp trip the feedvacer pumps.

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2.2.4 If steam dumps fail to arm-actuate and/or PORV's fail to 114:,

han:

g 2.2.4.1 Check sceam pressure =ede se::ing at 1090 psig and pla.:e y

.,/ [ [

in pressure mode centrol.

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.e 2.2.4.2 Close an ?CRV =anual leaders and place PCR7 selec:::

e-s.;

svi:ch in sanual. Regulate ?CRV's to =aiscain steam

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pressure as desired.

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2.2.5 Secure all boren dilution operacions.

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f 3.0 Subsecuent Acti:n

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c 3.1 verify ?::. level, NC Pressure, charging and lecdevn flow, Tavg, S/C

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levels and S/G ? essures are normal.

-Y 3.2 If any pressurize: PCR7's open en high pressuri:e pressure, ensure reseating at 2315 psig decreasing.

NOTI: If PCR7 fails to close and pressure is less than 2315 psig, then cicsa the associa:ed PCR7 isolatica valves.

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Ensure the CISystem is feeding :he Staam Ge erators. If not, =anually 3.3 v

e start the seco driven CA Fumps.

3.4 Anncunce occurrance ever plan: paging system.

3.5 Note :he cause of :he ::1p en the firs: cu: panel before reset:ing :he alarm.

3.5 If an : ds are not funy inser:ed, borate 130 ppm for each :=d sec inser:ed per CP/1/A/5150/09 (3c: n Cc=ce:::ati:n Cent:ci).

3.7

sf er NR-45 :s one source range cha==e1 and c=e inte==edia:e range channel for indica:ica. Ensure a segative pe:1cd and decaying : ust ra:e.

3.3

  • ' en the cause of :he ::1p has been fecer=ised, vi:hdrav :he shu:fe e.

banks per CP/1/A/5150/08 (Red Can:::1).

3.9 7erify no lead p::. pressure and level are res:sred and =ais:ained (2225 psig and 23:: respec:ively).

3.10 Salac: "2eset" en :he hiisture'Separa:c: Rehea:e: Panel.

3.11 ::ansfer Aux. S:a2= Supply to. Main 5:ea= by spening 1AS-12 (7:1: 1.Mn.

5:s. to Aux. S:n. Edr. Cen:::1 !alec scla:1:=) and cl=se 1AS-9 (Uni: 1 "C" E::. 31eed :s Aux. S:s. Edr. Isolati:n).

3.12 ::ansfer s:e2= du=o cen:::1 :o :he "?: essure" cds and adjus: ::::::ller as :acessa:7 :s a1= tai: Tave 337'y (appr:xi=a:ely 1090 psig).

_3 CAUT!CN: Insure ?:17.ary and Se===dary Syste=s have stabil1:ed before going to pressure =cde.

h f kh, 3.13 Secure any exesss C de=sa:e 3cos:e: ? =ps a=d Hocueil Pu=ps.

3.14 Place Au:s 5:ar: Defea: svi::hes of Aux. Tesdva: : ?. ps A & 3

/;

o.,efes:,,.

.s 3.15 7erify vol.: a C:::::1 Tank level is baiss =ais:al=ed.

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3.16 Rese: ?.171ux at Shu:dow: Ala= vher. =au:::= flux decreases belev sa:pois:.

3.17 No:1fy Che=ist:7 to eb:ais a NC Sysca= bc::= sa=ple and perf:=

a rezc:ivi:7 b='=-ee calcula:1:= and =ais:ais a shu:deve :argis equal :s : grea:e :ha= 1.5%.ik/k-par CP/C/A/51CC/06 (Reac:ivi:7 3alance C41 tla:1:=).

3.13 Notif7 Plas: Manage, or Superi=:e= dent of Cpera:1 s pe.

Sca:ic: Diree:ive 3.1.5 (Reasens f:: No:ifyi=g :he Manage: ::

1 Superin:endent of Opera:1:ss).

3.19 if 1: is desired to supply Auz. 5:aa= f::= :he Ele :ric 3c11ers, place :he boilers is operati = per CP/1/3/s250/073 (Ilec::1:

3o11ers).

3.19.1 As 115-120 (Aux. Ilec. 21. A & 3 to AS ' sol.) is opened sievly th:::.le elesed 1AS-12 (Uni: 1 SM :: AS Edr. Cc=:. I:le: 1 sol.).

3.20 Take a ual ese:: 1 and ci:se :he f=11:vi:3 valves:

1C7-32 (5:aa= Ce=. lA F-*J C ::::1) 1C7-22 (5:aa= Cec.13 70'4 C:::::1) i 107-20 (Staas Ce:.1C C'4 C ::: 1)

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.e e,,. (5:ea= we. sm e

e ::::1) e i

l 1C7-104 (3:ea= Gen. lA F**J C ::: 1 3 pass C ::::1) l 7

1C7-103 (5:ea= Cec. 12 707 C ::::1 3 pass C::::01) 7 1C7-106 (5:ea= Gen. ic 7 W C ::: 1 3ypass C:::::1) i

  • C7-107 (3:ean Gen. 13 ?!*J C::::: 1 3 pass Cc: ::1)

)

7 2.21 lese: !:ai: A & 3 Feedva:e

!sc*2.1:=.

2.22 ?:si:ics :ha f 011:vi g valves:

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.e.., s e s e..

9 :. n,,

(.n.

e~_. e.a.....~.,.. eje s,.4, 9,,

  • e., a: a 1

13 Aux. Teedva:a Nc::le Is:1.)

Ope 107 '25-3 (S/C

  • A C7 :: CA N ::le :s:1.)

1 Cp e: 1CI-1f1-A (C7 Ie pert. $ ?*.;*J "O 3/C 1A Au. It ed*44 :2

)

i N:::14 '.s :1. )

i l

i

+

m S/G "3":

Cpen 1C7-127-3 (5/G 13 C7 :s CA No::la : sol.)

/Np Cpe= IC7-133-A (C7 Temper 1:3 71cv :s S/G 1.3 Aux. Teodwa#

Pf

! sol.)

04 S/G "C":

Open ICT-123-3 (S/G IC C7 :s CA No::le Isol.)

Open 1C7-115-3 (C7 Tempe:1=g 71cv :s S/G IC Aux. 7eedva:e ! sci.)

S/G "G":

Cpen,1C7-129-3 (S/G D C7 :o CA No::le Isol.)

Open 1C7-157-3 (C7 Temperi g 71ev := S/G D Aux. 7eedva:e Scl.)

3.23 Star a Teodwater ? =p per CP/1/A/5250/01 (Cc=dessa:e a:d Feedva:e System) and secure Auxiliary Teedva:e per CP/1/A/5230/C2 (Au-r* " m:7 Feedva:e Systa=) whe: desired and =ais 4 ired s:aam ge: ara::: levels a: :o 1:4d values ( 25%).

3.24 If a: A"*4 has occurred, bri=g :he pla=: :===1d shu:dev: vi:his 30 h urs.

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3.25 De: :=ise :he cause cf :he reac:or trip and cor:ee:

he pr:' les.

o If restart is desired, refer :s CP/1/A/61CO/05 (leae:Or Trip Recovery). If shu devn is :ecessary, refer :s CP/1/A/6100/02 (CO:::c111=g ? :cedure f : C=i: Shutd:-m).

3.25 Af:e: the : u== ra:e has decreased to.5 decade telev :he

" Source la ge ?.igh Flux Lavel a: Shu:dev " alar = se: poi::, the shu:d:.m ha=ks =ay be isser:ed if desired.

i 5

I

DISTRICUTION:

G CEC i 1979 s

tiOTE TO:

C. Stahle FR0:1:

Ashok Thadani He have revict:2d the ATils cecrgency operating procedure submitted by TVA' on October 17, 1979.

The enclosed corrents on this procedure are written in such a canner as to misimize the TVA effort required to develop accep-table ATils prosedure(s).

I recomend that you request the Operator Licens-ing Cranch to review the proposed TVA procedure and our co.monts.

If requested, we will be pleased to discuss these coments with TVA.

AshokeThadani Reactor Systens Cranch Division of Systems Safety cc: AT11S Task Force S. llanauer T. Speis S. Varga

'3 5'

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D M SS:RSB AThadani 8'104170665 l

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REVIEW 0F ATWS PROCEDURES FOR SEOUOYAH PLANT A.

e notoms

~

1 The procedure lists the parameters which cause the reactor to scram, but does not describe the actual indications available to the operators in the control room which would make him aware thac an AT}.i event has j

occurred.

These ATWS symptoms v.ould depend on initiating event and, therefore, they ought to be evaluated for at least the following three key events:

Loss of Main Feedwater loss of Offsite Power Stuck Open PORV In making the evaluation it is important to show for each event what symptoms would indicate to the operator that : cram action was called for but did not occur.

B.

Automatic Action 1.

This section does not address how the automatic actions relate to ATWS.

Some of the automatic actions (e.g., turbine trip) may not even occur after an ATWS. This should be specified in more detail in the procedure.

2.

Why is automatic actuation of HPSI not included in this section of the procedure?

C.

Immediate Ooerator Action 1.

The procedure should specify critical indications available to the operator consistent with the initiating event and assumption that the reactor trip has not occurred.

~

~ 2.

The imediate actions that the operators have to take after ATWS has occurred and an attempt to manually scram the reactor from the control room has failed should follow two parallel paths. While one operator should continue the operation of manually scramming the reactor by trip-ping the breakers powering the control rod drive MG sets, the other operator should initiate the other actions leading to safe shutdown of the plant. The procedure should reflect that the actions described in sections A.2.b and A.2.c and those described in sections B.1 and B.2 are to be performed simultaneously.

Section B should require sequential actuation of turbine trip, all auxiliary feedwater pumps, and high pressure safety injection system.

(See Figure 1).

3.

Describe the actions taken by the operator when he discovers, during the verification of reactor coolant system status (section C), that the conditions are not within the prescribed limits. What is the impact of loss of offsite power on availability of those signals to the operatcr.

What is the shutoff head of the HPSI pumps? What provisions are taken to prevent pump damage when HPSI is operating against the RCS pressure which is higher than the shutoff head of the pump?

D.

Subsequent Operator Action 1.

What is the time frame for these actions?

2.

What criteria are provided to verify that:

a. The auxiliary feedwater system is providing the necessary flow to the steam generators,
b. The HPSI is providing necessary flow to RCS.
c. The containment heat removal is being accomplished, if the containment colditions are outside the normally specified valves.

, 3.

What additional procedure does the operator have to follow in order to bring the plant to and maintain in a cold shutdown condition after an ATWS? For example, wha,t boron concentration should be maintained in the RCS.

W t

4

SUBSEQUEilT ACTI0 tis Event & Action Transient Failure to Immediate Opera-Verify RCS, Steam Long Term Sequence Initiated Scram tor Actions Generator, Contain-Shutdown Symptoms Symptoms Two Operators ment Parameters Values General time t

t t

t t

g j

2 3

4 Sequence Operator #1 l

Manual Scram If outside specified Describe spect Attempts limits, describe the actions to br(

i operator actions, plant to a col siiutdown cond(

Operator #2 tion and main:

Assure that tain that condition.

j a) turbine tripped b) all AFWS provid-ing flow c) HPSI providing flow (shut off head) i in that order.

What, if any, is the impact of stuck open PORV.

4 Figure 1.

Generalized Approach to be followed for writing ATWS procedure (s) t I

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