ML19322C810

Reg Guide 1.97,Revision 1, Instrumentation for LWRs to Assess Plant Conditions During & Following Accident

ML19322C810
Person / Time
Site:	Crane
Issue date:	08/31/1977
From:	NRC OFFICE OF STANDARDS DEVELOPMENT
To:
Shared Package
ML19322C797	List: ML19322C796 ML19322C799 ML19322C803 ML19322C807 ML19322C809 ML19322C810
References
TASK-TF, TASK-TMR REGGD-01.097, REGGD-1.097, NUDOCS 8001240572
Download: ML19322C810 (4)

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[s U.S. NUCLEAR REGULATORY COMMISSION August 1977 eneu f M. 4rV.J, REG U LATORY GUIDE q

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e OFFICE OF STANDARDS DEVELOPMENT o....r REGULATORY GUIDE 1.97 o

(NSTRUMENTATION FOR LIGHT-WATER. COOLED NUCLEAR POWER PLANTS TO ASSESS PLANT CONDITIONS DURING AND FOLLOWING AN ACCIDENT 4

whether the reactor trip and engineered safety-A. INTRODUCTION feature systems are functioning properly; (3) deter-mine whether the plant is responding properly to the Criterion 13. " Instrumentation and Control / of safety measures in operation;(4) provide information Appendis A. " General Design Crit:ria for Nuclear to the operator that will enable him to determine the Power Plants." to 10 CFR Part 50. "Licens? of potennal for breaching the barriers to radioactiwy Producuon and Utihzation Facihties." includes a re.

release: ($) furnish data for deciding on the need to quirem,ent that instrumentation be provided to take manual action if an encineered safety feature monitor sariables and systems for acadent condi.

malf uncuons or the plant is not responding effective-tion < as appropriate to ensure adequate safety, h to the safety systems in operation;(6) allow for ear.

Cnterion 19. " Con:rol Room." of Appendis A to

'l") inci:ation 'of the need to initiate action necessary 10 C FR Part f 0 includes a rcquirement that a control to protect the public and for an esumate of the team ":Irmid:d from w hich a:uons can be taken to magnitude of the impending thr:at; and (7) aid in m.:m:am :ne nuclear power unit m a safe condmon d::erm:ning the cause and consequence of the esent under acciden: condnions. includmp loss of-coolant for postaccident insesapation.

acadentt adioactnit}

At the car: of an accident. the operator canno:

ff' art 10 mcf ades Criterion M.

Monitorine Release-of Appendn A to 10Cf f "I"">' determme immediately what accident has oe-a ::auiremen: that means be prosid:a for monitorme Curred or n omm; and Sedu Cannd aba)$

etemphe.e. (nace contain$ -- ee-e, w,x h.mpic; r: n: r:<ponse. I,or this reason.

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- T m; components for recirculation 0: loss-of cooun.

the reactor in and certam safety actions (e.g..

a ;. den; fiu.d, efhuen: dneparce pa:hs. and the plant emergency core cochng actuauen.contammentisola-i a

em. iron for radioa:nuty that may be releaseu from uon, or depressunzanoni are desiened to b: per-pNulate.a, acad:ms formed automaucalb darme the miual stages of an a m dent Inamentan n k aho provided to mdicate Tm cuide describ ( a method acc:ptable to the mf rmaun abat plant pnameters required to N RC st iff for comphme with the Commissien's re-enable the operation of manually initiated safety-quiremenu to proud Instrumentauon to mo'rutor related systems and other appropriate operator ac-p.am.arubie< and e. stems durm. and follow mp an UM' fl acadent m a hpht water-cooled r,uelear power p!an:

I Ll The.Adsisory Commi: tee on Rea;:or Safeguards ha-m l

be:n c ansulted concernine this cuide and has concur-Esampics of serious esents that threaten safety if red in the regulatory pos'ition.'

condnions d:crade besond those assumed m the Final Safety A'nal)sn R' port are loss-of coolant acci-e B. DISCUSSION dents (LO(., Aq. reacuuty escursmns. and radioa:-

tnin releases. Such esents require that the operator r

r Monitored variables and s3 stems are used by the unders:and. in a short ume period. the state o.

operator m accident sur eillan:: te (li assist in deter-read mev. of engmeered safets features and their mmm; the nature o an acadent; ( ) ce: ermine potental for being challenged by an acticent in i

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To determine the important variables and the be used for both ac:id:nt and normal operation.

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> stems w hose values or status are needed by the Huaever, it is essential that instrumentation so up-

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'perat,orond. therefore the monitormg instrumenta.

graded does not compromise the accura:) and s:n.

J mn aceded by the operator a study (Ref.1) was sitivit> required for normal operation.

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made of a range of postulated ac:idents. The studs

.onc!ud:d that the followin: capabilities are most im".

It should be noted that in the safety analysis many ertant to ensuring that the power plant poses no parameters may be identined that w ill provide

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'hreat to pabh: saf:ty after an accident: reactor shut.

desirable, but less essential. informanon for the

'i W n. core cochng, contsinment isolation. and the operator. Any instrumentation used to measure these maintenance of containment pressure control.

less essential (i.e. " backup") parameters is outside i

Trimary sy'jjm pressure control, and a heat transfer the scope of this guide.

rath from the core to a heat sink. These vital

.apJbiliti h are designed to preserve the integrity of C. REGULATORY POSITION the barts:ts to radioactivity release (i.e.. the fuel clad-dine reactor coolant boundary, and containment)

1. For the postulated accidents listed in Chapter 15 of Regulatory Guide 1.70 (Ref. 2J. the applicant it is c?.sential that the reauired instrumentation be should perform d: tailed safety analyses necessary to capabl: of surviving the accident environment in determine the parameters to De measured and the in-a hich it n located for the len:th of time its function is strument ranges, responses, accuracies, and length of required. It could therefore' either be designed to time required to provide the operator with the infor-aithstand the accid:nt environment or be protected mation necessary to:

93 a local art Ocial ensironment. If the ensironment surround:ng an instrument component is the sam:

a. Assist in d:termining the nature of an acci.

a;: cent and normal eperating conditions te p.

dent.

in r;m:n' anon components in the mam control

b. Determine w h:ther the reactor trip and wmL in: irntrumentation components need no engineered safety.fcature sy stems are funct oning

a' en'. tronmental capability.

preperly, c Determine w hether the plant is respondine 11 n important t h.: t accident monitering in-properly to the safety measure. m operation.

rum:matmn ecmponent, and th::: mot.nts that d Determin: the potential for breaching the

.annot n:,e:atec in other than non-Schmi; harriers to radioactisit' releas:.

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. ten - I buddir e; 0; consen ainely des!gn:c for

c. Decide on the need to take manual actan if !

I m':ne:d seni:.

an encineered saict feat ure malfuncuons or the !

plant h not responding effe tneh to the saf:ts I Param:t.n seic ted fer accident moncormg can be s> stems in operauon. and

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.; tee w a to p:rmit r:iatn ely f ew m;truments to

f. Allow for earh indication of necessan acuen

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1. : essentia. informanon needed by the to protect the pubb'c and fer an esumate of th:

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rate for postac;ident monitorine. Further it is ma nitude of the impending threat.

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-.Jent tnat a hmued number of those paramet:rs

. containment pre,sure) be monitored by mstru-

'f h: cu:d: lines in Reference 1. alenc with th: !

era eu.:.ified to more strmgent environmenu.! re-guidehnes m Referen:: 3 deahn; with monitoring in-

.remeris and with ranges that estend to the mas-side in: power plant. may be used to make such mr" ulues that the sele:ted parameters can cuain analyses.

cnd:. u orst-case conditionst for example. a range for contamment pressure monitor estending beyond

2. The instrumentation ne :ssary to proside the I

'e d qn pressure of the comainment information noted m reculatory position i should be !

specified along with iustiGcation to show that the in. !

Wim.! power plant instrumentauon remaining strumentauon is adequate to provid: the operator i

- nona! for all ac dent condition' can prosid:in-with tne ne;enan information. The safety analvs:s

.auen records, and (with certam typer of m-should.proside the information necessary' to sc' lect ';

rumentH time history responses for many the appropnateqpe of accident monitonng instru-ar meten important to following the course of the m:nt: to specify the range. accuracy, transient l

.;ident. Therefore, it is prudent to select the re-response. emironmental and seismi: qualincations. !

.uired ;;cident menitoring instrum:ntation from the and insensitisity to sarrauons of energy supply: and l grmal peu er plant mstrumentation. Since some ac-to specify the method of recording, w h:n recordin.c is i Jenn impose s:ver operaung requirements on in-deemed necessary.

tumentauon components, it may be necessary to

. grade sen: mstrumentation compon:nts tc wnh.

3. A limited number of additional accident-

and tne more sescre operatin: conditions and to monitoring instruments should hase ranges that es-l e.nute greater vananons of momtored sariables tend to the maximum salues that selected parameters !

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; may n: associated with the accident if they are to can attain under worst case conditions. and the in. I

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l strumentation components should be qualified to

b. To the extent pra:tical, accident-monitoring in.

wihtand the nigher lese! of environmental condi-strumentation mputs should be frora sensors that Q i 'tions in which they will be recuired to function.These directly measure the desired variables.

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, parameters and associated maximum values to be

9. To the extent pra:tical. the same instruments i

meaa.ured by the instruments should include, but not should be used for accident monitoring as are used

. necenarily be IJnited to, the following:

for the normal operations of the plant to enable the l

E Containment pressure: 3 times design pres-operator to use. durm; accident situations [instru-3 sure fer concrete: 4 times design pressure for steel.

ments with which he is most familiar. Howese-where the required rance of accident monitoring irO

b. Radiation lesel inside containment: 10' rads strumentation results in a loss of instrumentation PCh

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c. Reactor coolant pressure: 3 times design pres-sensitivits in the normal operating range separatein.

sure.

struments should be used.

10. The accident monitoring instrumentation

d. Plan; radioactivity release rate through iden-tifiab!: release points: (plant dep:ndent) (range should be spe:ifically identified on control panels so dependent on maumum release rate postulated for a that the operator can easih discern that they are in.

nen release point).

tended for use under accident conditio.1s.

1. The accident-monitorine instrumentation II. Any equipment that is used for both accident should be qualified in accordance with Re;ulatorv m mt ring and nonsafety functions should be clas.

G uide 1.89. " Qualification of Class IE Equipment fo'r sified as part of the accident monitoring instrumenta-ti n. The transmission of signals from accident-N uc! car Pow er Plants..

monitoring cauipment for nonsafety system use instrumentation that is Seismic Catecon 1. as should be through isolation desices that are classified defined bs Reculatorv Guide 1. 9. " Seism'ic Desien as part of the accident-monitoring instrumentation ClaWfica'uon." shouid continue to function with'm and that meet the prosisions of the document.

the recuired accura:) following. but not necessaril}

durin;. a safe shutdow n earthcua A:.

12. Means should be prosided for ch:: Ling. with a high degree of co n fiden ce, the operational Inurumentation components and their mounts availabihty of each accident-monitorinc channel, in-

ha: anno: be located in other than non Ceismic cluding its input sensor. during rea::or operation.

Cate ory I buildings need no: me:: Seismw Categery This may ne accomplisned in various w a)s. for esam-l 1 ernera ple:

a. Bt per:urbing the monitored variable:

N Thee param:ters sele::ed for acciden:-

mencxing :nurumentation that pro'.id: tran icn; or

b. BI in:rodu:m: and s an inc. as appropnate. a t enc Mermation necessary for the operator te per-subunute' mput to thi s:nsor of the same nature as the measured s anable. er t o r r-m role should be recorded. Recorts of param::ers that proside information rele:cd to the

c. Bs cros9:heckm between channels that bear a know n' relationship to each other and that have ce:ermmation of radioactiuty release rates and to:al,;

readouts asailable.

radiea :nity reieases should be considered necessary.

l,s. S:nicing. testmg. and calibration procrams a ne a :ident-monitorinc instrumentation should be sp::!fied to mam:ain the capability of the shou;d b: cesigned so that a single tailure does not accident-monnored instrum:ntation. For those in-presen: the operator from accomplishing the objec.

struments u here the required interval betw een testing ines of re ula:on position 1.

wili be less than the normal time interval between NOTE: " Single failure...melud:s such events as aeneratm; station shutdow ns. a capabilitt for testine tne snortme or orencircuitmg of interconnecting durmc power operation should be provided.

signal or row er canles. It also includes singie credibie E.N CE PTION: "One-out-of tu o" ssstems are malfun uons or esents tha: cause a number of cons:-

permitted :o uolate the sincie failure crite'rion durinc eue.1uai componen:. moduk, or channei failur:3. Fer esarnp!:. :he oserheating of an amphfier module

channel bspass provided th'a

a:::p:able reliability c'r j operatio'n'can be otheruis: demonstrated. For exam-would b a " single failure' esen thouch seseral tran-pie. the bspass time interval required for a test, sis:or failures might result. Mechamea! damage to a calibration". or maintenance operation could be mode switch would be a " single failure" although several channels might become invohed.

shown to be so short that th: probability of failure of the a:tise channel would b: comm:nsurate with the

' The ac:ident-monitorine instrumentation chan-probability of failure of the "one-out of-two" nels tha: are redundant should be e!cetricalb in-sy stems during its normal mterval between tests.

depencent enercized from s:ation Class IE p$wer.

14. Whenever means for bypassing chann:Is are in-

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and phy sically separated. in a:Cordance with cluded in the design, the design should permit ad-Regula:ery Guide 1.75 " Physi:al independence of mimstratise control of the access to such bypass Eienti: Sy stems?

means.

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v lMTh design should permit administrative control plsing with the specified portions of the Commis-df *he a::ess to all setpoint adjustments, module sion's regulations, the method described herein will c

be used in the evaluation of submittals for construc-

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cal:bration adjustm:nts, and test points.

tion p:rmit applications docketed after September

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16. The accident monitoring instrumentation 30,1977.

d:si;n s;nould minimize the development of cond;-

tions inat w ould cause meters. annunciators.

REFERENCES i

ctders. alarms, etc., to give anomalous indi:at ons confusing to the op:rator.

1. Battelle-Columbus Laboratories, " Monitoring

17. 'T h: instrumentation should be desicned to Post Accident Conditions in Power Rea: tors,"

facilitate the re:ognition, io:ation, repla'ecment, BMI X 647, April 9,1973.

repair, or adjustment of malfun:tioning components

2. U.S. Nu:lcar Regulatory Commission," Standard or modules.

Format z.nd Content of Safety Analysis Reports D. IMPLEMENTATION for Nuclear Power Plants,' NUREG 75/094, Th: purpose of this s:: tion is to preside informa.

Regulatory Guide 1.70, Revision 2, September tion to applicants regarding the NRC staffs plans for 1975.

using this regulatory geidc.

3. BNWL 1635, "Te:hnologi:al Considerations in Ex::pt in those case. ir, whi:h the applicant Em:rgency Instrumentation Preparedness." May 1972.

preposes an a:::ptable alternative method for com-3 s.

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