ML20006F939

From kanterella
Jump to navigation Jump to search
Summary of ACRS Containment Sys/Structural Engineering Subcommittee 890912 Meeting in San Francisco,Ca Re Development of ACRS Paper on Containment Design Criteria for Future Plants Based on Present Knowledge
ML20006F939
Person / Time
Issue date: 09/26/1989
From:
Advisory Committee on Reactor Safeguards
To:
Advisory Committee on Reactor Safeguards
Shared Package
ML20006F940 List:
References
ACRS-2663, NUDOCS 9003010374
Download: ML20006F939 (45)
v • d • e


Text

- - -

g7mgrp en e a b

D4TEISSUED: 9/26/89 I

kOR M

yy.

,hlN p

ACBS JOINT SUBCOMMITTEES MEETING

SUMMARY

/ MINUTES FOR CONTAINMENT SYSTEMS / STRUCTURAL ENGINEERING SEPTEMBER 12, 1989 SAN FRANCISCO, CALIFORNIA.

,t

-t

[

PURPOSE The ACRS Subcomittees on Containment Systems and Structural Engineering

' held a joint meeting on September 12, 1989 in San Francisco, California.

The purpose of this meeting was to continue the discussion'in regard to-the development of an ACRS paper on containment design criteria for future plants based on present knowledge. A copy of the meeting agenda and selected slides from the presentations are attached. The meeting.

began at 8:30 a.m.~and adjourned at 5:15 p.m., and was held entirely in open session. The principal attendees were as follows:

1 I

ATTENDEES ACRS INVITED SPEAKERS D. Ward, Co-Chairman P. Hamond (Private Consultant)

C. Siess, Co-Chairman B.Sugnet(EPRI)

J. Carroll, Member T. Kress (ORNL)

I. Catton, Member H.Townsend(GE)

W. Kerr, Member F.Silady(GA)

P. Shewmon, Member R.Budnitz(FRA)

L C. Wylie, Member

[

D. Houston, Staff NRC/RES B. Hardin REVIEW DOCUMENTS

-There were no formal documents to be reviewed at this meeting. The ACRS effort on this subject is in response to a Staff Requirements Memorandum L

dated July 28, 1988, which was written following an ACRS meeting with the Consnission on July 14, 1988.

DESIONATED ORIGINAL 9003010374 890926,

h Certified By as a

is acas

leh m

, =

Containment Systems / Structural Engineering Meeting Minutes September 12, 1989 i

ACTIONS, AGREEMENTS AND COMMITMENTS The joint Subccmittees agreed to schedule two additional meetings on' this subject with invited speakers:.(I) October 17, 1989 at the Hyatt RegencyatO' Hare,Rosemont, Illinois,and(2) December 13, 1989 at the Phillips Building, Bethesda, Maryland.

DISCUSSION j

In opening coments, D. Warc indicated that the purpose of this ACRS t

activity was to promote the development of a comprehensive new set of containment design criteria (if appropriate) on the experience and knowledge gained over the past 30 years.

He noted that no such programs seem to have jelled within NRC or industry to develop these criteria.

C. Siess coninented that while this was a joint meeting, it should not be interpreted as putting toc much emphasis on the structural capacity of containments.

l.

P.Hammond(PrivateCcnsultant)indicatedthatpresentcontainment standards result in a very expensive box that is incompatible with a complete prevention policy or a complete containment policy.

He ex-l pressed a belief that all present containments could be made invulner-able at relatively minor costs. He proposed three essential require-ments and one highly desirable requirement for future plants, as fol-lows:

1 (1) New containments should be developed and proof-tested to achieve assurance of zero release or radioactivity under any credible reactor accident.

(2) Public awareness and credence in these containments should be built by public proof-of-performance demonstrations, using tracers.

l (3) Any new installation should be required to use the new containment type.

l l.

,?

..,: 3 m.

P-

,'I Containment Systems / Structural-Engineering Meeting Minutes. September 12, 1989 I

-(4) Within-such containments the NRC should give the reactor owner great freedom to build and operate his plant as he sees fit, subject only~ to the containment limits. However, even an advanced

" passively-safe" reactor should still be contained, because it is _

unproven and-because public confidence is essential.

Mr. Hammond also discussed the characteristics of present containment-vent systems and objectives for a chill-vent system. He indicated that thiswouldbeapassivesystem(rupturedisc)thatwouldcondenseall vapors, trap all particulates, absorb all radioactive gases and allow free passage of air and hydrogen only. This chill-vent system would adhere to_his proposed requirement stated above in regard to achieving zero release of radioactivity.

B. Sugnet (EPRI) discussed the efforts by EPRI in the advanced light water reactor (ALWR) program and their requirements document to treat severe accident issues. The ALWR design bases were shown conceptually as three elements:

licensing design basis, risk evaluation basis and perfomance evaluction basis.

He also discussed the three key elements for severe accident protection and the ALWR top-level probabilistic criteria in terms of core damage frequency ($ E-05) and public safety (25 Rem at 0.5 miles, cumulative frequency less than E-06).

L Mr. Sugnet next discussed the philosophical bases for containment k

criteria and supplemental criteria for beyond the licensing design basis.

He indicated that a rugged containment should be required.

He discussed structural criteria which were being studied to apply to the l

licensing design and risk evaluation bases.

He also indicated that EPRI L

was opposed to the concept of containment venting on technical and L

philosophical bases.

T. Kress (ORNL) discussed his personal opinion on containment criteria.

He indicated that requiring a containment was a good idea but faulted

E., J a.;

5.;.

Y Containment Systems / Structural Engineering Meeting Kinutes September 12, 1989 i

present criteria in three areas:

(1)choiceoftheDBA,(2) arbitrary

[

specificationoffissionproductsourceintocontainment,and(3) lack j

of credit for engineered safety systems. He believed that enough was known about severe accident threats to containment that one could, L

quantify the maximum loads and design a containment with some factor of safety. He proposed that most containments would meet the "no failure" criteria if the zircaloy cladding were replaced with a ceramic material.

He then discussed the need for a containment with the MHTGR.

He re-viewed the various fission product barriers with this design and the possible sources of fission products that might be released under accident conditions.

If one could produce high quality coated fuel (fractional defects less than about E-06), a containment would not be needed.

For any plants with containments, he proposed performing a leak test prior to each start-up.

H. Townsend (GE) reviewed the NRC policy statements which recomend that future plants be safer than current ones and that a balance be provided between prevention and mitigction.

He also stated that public opinion would require a plant with passive typo responses and capable of zero releases (no evacuation). He discussed the ABWR design in regard to core and containment features to prevent or mitigate a severe accident.

For severe accidents, he indicated that GE believes venting for contain-ment overpressurization protection has merit. The current ABWR vent system was described as a passive system (rupture disc). He indicated that present containment structures are conservatively designed with current code practice.

Thus, the present codes with design certification are adequate.

F. Silady (GA) reviewed the MHTGR approach to containment design and the generic applicability for future plants. He indicated that the criteria must be given in direct statements of acceptable consequences or risks to the public or the environment, must be independent of plant design and must be quantifiable. He next discussed licensing basis event (LBE)

s.

e Containment Systems / Structural Engineering Meeting Minutes September 12, 1989 definitions and a summary of the LBE selection method. He discussed the MHTGR in some detail and presented the design criteria in regard to vessel system chemical attact and transfer of vessel heat to the ulti-mate heat sink.

He discussed the generic approach to containment system design'and the applicability of the MHTGR approach to other reactor types.

He presented the insights gained through application of this approach in terms of challenges, barrier dependency, functions per-formed, and support systems.

R.Budnitz(FRA)'presentedhisnotionsonhowtoselectcontainment performance criteria. One key ground rule was that not withstanding any other argument, the containment must have some specified mitigative characteristic with some factor of reduction (10-30) of the amount of offsite deses compared to a design with no containment. He indicated that the regulators should choose a fanily of beyond design basis accidents (BDBAs)foranalyses. An analysis of uncertainties and sensitivities would be essential. He proposed that the analyses be performed realistically and that the regulators add appropriate conser-vatisms. He indicated that his-proposal was intended to be an outline cf logic, not a finn proposal on what to do. He believed that public opinion would always require a containment around a reactor no matter how safe they may be said to be. He further indicated that designers must have some options to keep the cost of nuclear plants competitive.

B. Haroin (NRC/RES) discussed briefly some of the containment perfor-mance criteria under consideration for ALWRs. These focused on some measure of defense-in-depth in a qualitative rather than quantitative manner. Mr. Hardin also believed there is a timing effect for the attenuation of fission products. He indicated that the staff is still assessing the need for a generic rule for ALWRs and the issue of debris coolability.

During the discussion, the Subcommittee Members expressed various comments and concerns as follows (random order):

...,j s.

.1 t

Containment Systems / Structural F

Engineering Meeting Minutes September 12, 1989

-(1)

J. Carrol] commented that making containments smaller should not be a major objective since such would restrict the ability to perform maintenance.

(2)

D. Ward asked P. Hammond,'in regard to the chill-vent system, if J

this would become plugged by the condensation and freezing of

[

discharged steam. Mr. Hammond indicated that the aggregate in the filter would be sized in such a way, larger sizes on the bottom, as to assure flow paths.

(3)

In response-to questions by W. Kerr and C. Siess, W. Sugnet in-dicated that EPRI would not propose to use large low-pressure containments for any of the ALWRs and that EPRI would require a containment even if core melt frequency were shown to be IE-06.

(4)

In response to questions by I. Catton, H. Townsend indicated that GE had allowed the suppression pool temperature to go to 212'F, not the local saturation point, before venting so that flashing of the pool would not be expected, p

(5)

W. Kerr, I. Catton, P. Shewmon, and J. Carroll expressed objectiuns I

to the use of a rupture disc to activate the vent system on the basis of technical and philosophical issues.

n (6)

I. Catton questioned F. Silady in regard to their ability to provide a steel vessel with an emissivity of 0.8.

l (7)

In response to a question by W. Kerr on how believable small numbers are in PRA studies, R. Budnitz indicated that he did not believe real small numbers.

These tended to be of the order of IE-08 and smaller.

e

~

7

..-O.

~

Containment Systems / Structural l

Engineering Meeting Hinutes-September 12, 1989

-NOTE:

Additional meeting details can be obtained from a' transcript of this meeting available in the NRC Public Document Room, 2120 L Street, N.W., Washington, D.C. 20006,(202)634-3273, or c6n be purchased from Heritage Reporting Corporation,1220 1

L Street, N.W.

Suite 600, Washington, D.C. 20005,(202) 620-4888.

I i

i

)L 4

l

t-

' ' ' '{

Revisedt

-9/8/89 3.-

ACRS JOINT-SUBCOMMIT!EE MEETING CONTAINMENT SYSTEMS / STRUCTURAL ENGINEERING SEPTEMBER 12, 1989-SAN FRANCISCO, CA

-TENTATl[EAGENDA-Cortainment Desian Criteria for Future Nuclear Plants A.

Subcommittee Chairnten Remarks D. Ward / -

8:30 a.m.

C. Siess, ACRS Ihv1TED SPEAKERS B.

Phil Hammond (Private Consultant) 9:00 a.m.

  • 10:00 --10:15 a.m.

C.

Bill Sugnet,-EPRI 10:15 a.m.

D.

Tom Kress, ORhL 11:15 a.m.-

l 1

        • LUNCH ****

12:15 - 1:15 p.m'.

E.

Hal'Townser.d. GE 1:15 p.m.

i F.

Fred Silady, GA 2:15 p.m.

        • BREAK ****

3:15 - 3:30 p.m.

G.

Bob Budnitz, FRA 3:30 p.m.

l H.

Subcommittees Discussion 4:30 p.m.

I.

Adjournment 5:30 p.m.

7.-

g :-

Q ?,

l

-AN APPROACH TO NEW CONTAINMENT STANDARD 3-

^^

by R. Philip Hammond t

i.

OUESTIONS TO BE ANSWERED

1. WHAT'S WRONG WITH PRESENT CONTAINMENTS?
2. ESSENTIAL FOR PASSIVE SAFE REACTORS?
3. WHAT FUNCTIONS FOR CONTAINMENTS?
4. WHO SHOULD CONTROL DESIGN?
5. WHAT STANDARDS YvlLL BE NEEDED?

i ENVIRONMENT FOR ORIGINAL CONTAINMENT STANDARDS

1. AEC GOAL: A NEW SOURCE OF ENERGY
2. SAFETY BASED ON CONSERVATIVE DESIGN AND FAITH
3. LARGEST CONCEIVABLE REACTOR 350 MWe
4. REACTOR DATA CLASSIFIED, PUBLIC TRUSTED EXPERTS

m,y ll,-

g:4 :

i r-THE PATH OF TOTAL ACCIDENT PREVENTION j~

1. NEW ANALYSIS REVEALS NEW FAILURE PATHS h
2. EACH NEW PATH REQUIRES A NEW 'FfX" 2
3. INTERACTION OF FIXES MAKES IMPROVEMENT UNCERTAIN
4. TOTAL PREVENTION INHERENTLY UNPROVABLE THE PATH OF TOTAL CONTAINMENT
1. THOUSANDS OF FAILURE PATHS LEAD TO SIMPLE SET OF ACCIDENT STATES THAT THREATEN CONTAINMENT
2. ACCIDENT STATES CAN BE DIRECTED, CONTROLLED AND UMITED BY ENGINEERING DESIGN r
3. CONTAINMENT ESSENTIALLY A SIMPLE BOX. DESIGNED TO RECEIVE FINAL ACCIDENT STATES
4. PERFORMANCE AND REUABluTY CAN BE PROOF TESTED
5. TOTAL CONTAINMENT INHERENTLY PROVABLE AND CREDIBLE

..c j;,,

1 ELEMENTS OF A NEW CONTAINMENT STANDARD 1 WITHSTAND ANY REACTOR ACCIDENT

2. ZERO LEAKAGE OF RADIOACTIVITY
3. PUBLIC PROOF OF PERFORMANCE
4. REOUIRED FOR ANY NEW REACTORS, EVEN PASSIVELY SAFE TYPES
5. OWNER FREE TO MODIFY WITHIN THE DOME
6. OLD CONTAINMENTS MAY OPTIONALLY BE UPGRADED, THEN RECEIVE SAME FREEDOM CHARACTERISTICS OF PRESENT VENT SYSTEMS
1. CONTAINMENT USUALLY KEPT PRESSURIZED
2. ONLY EXCESS PRESSURE IS VENTED
3. FILTER SYSTEM DESIGNED TO DELAY OR CONTROL RELEASE 4, FILTER OPERATES AT AMBIENT TEMPERATURE
5. KRYPTON AND XENON NOT TRAPPED

^'*'l,

,*7 o

. - BASIC DESIGN FACTS

1. MOST RADIOACTIVITY RELEASE MODES VANISH IF CONTAINMENT IS UNPRESSURl7.ED
2. QUENCHING AND CHARCOAL TRAPPING TECHNOLOGY PROVEN AND INEXPENSIVE
3. ONCE ACCIDENT BEGINS, DIVERSE EVENT CHAINS LEAD TO ONLY A FEW WELL KNOWN CONDITIONS
4. POST. ACCIDENT CONDITIONS CAN BE MANAGED AND CONTROLLED BY ENGINEERING DESIGN CHILL VENT SYSTEM OBJECTIVES
1. PREVENT ANY APPRECIABLE PRESSURIZATION
2. ABSORB ALL ENERGY RELEASED IN STORED MEDIUM
3. CONDENSE ALLVAPORS
4. TRAP ALL PARTICULATES
5. ADSORB ALL RADIOACTIVE GASES i
6. FREE PASSAGE FOR AIR AND HYDROGEN ONLY
7. PASSIVE IN OPERATION 8

U

g J.x i

4'.

/ \\ -

=

Weether proesedam and gelses y..... 5

/ Ineutetion 3

- Activeted charooel = 40 T 4

~ l I

i su Bs P

I

. A temperstiss

- 960 T insulation and cover chilled betalt i

rock or equivalent

(~ -80'F)

l

, p Building Containment quem

..e -.'

.,j Rupture l #D*

L E:

1 Refrigeration plant

(

/

(con be underpound)

/

_ Weggyest c

e ete e GW9 l

~,;

'E 4

w Utmty / EPRI Presentation to ACRS Subcommittee on-Containment Criteria 4

W. R. Sugnet September 12,1989 s

4 Advances Lwn pmeram Utillty / EPRI I

Presentation Outline

Background

- ALWR Design Bases ALWR Treatment of Severe Accidents Containment Criteria

- Philosophical Basis Investigation of Supplemental Containment Design Criteria Screening of Events to be Considered Approach to Supplemental Containment Design Requirements Advanced LWR Procram

w n

', r. '

.rl1 UtlHty / EPRI

].

t SEVERE ACCIDENT PROTECTION l

l Th'ee Kev Elements?

1. Design to meet applicable Regulatory Requirements -

covers licensing design basis j

provides significant margin

2. Emphasize core damage prevention l

target core damage frequency, s to E 5/ reactor year 1

provide addnional preventive features to protect utilhy investment

3. Analyze dominant SA sequences to show sufficient margin:

conservative design (e.g., containment design pressure) investment protection features (e.g., increased RCS inventory) plant features that aid in SA mitigaton (e.g., cavrty area'arrangementilooding: RCS vent valves) realistic, mechanistic evaluations including non safety related tf equipment Advanced LWR Prtwam l,

l' L

l-uuiriy i spRi ALWR Top-Level Probabilistic Criteria Core Damana Freauenev

. In add 6ca to meeting all other licensing design basis requirements, mean annual CDF s 1 x to E 5 Pub!!c Safety

. Beyond meeting other licensing design basis requirements, site boundary (0.5 mi.) whole body dose shall be less than 25 Rom for accident sequences whose cumulative frequency (mean value) exceeds 1 x 10 E -6 per reactor year Advanced LWR Pmoram L

l e-l '.. '..

gae I

i' Utility I EPRI

-]

.1 CONTAINMENT CRITERIA

)

Advanced L WR Pmaram Utility / EPRI Philosophical Basis for Containment Criteria A rugged containmentja recuired Prevent release of radionuclides in a core-damaging aa:ident where significant fission products are released from the fuel Provide margin in light of imperfect knowledge of accident progression and plant response This rationale remains valid, even in light of today's improved understanding of accident behavior

\\

The pertinent issue is whether today's knowledge can be

/

used to improve upon the design critoria that have previously been applied Advanced LWR Pmoram

.. ~

~.. - - -

e}
  • e

> e.

i is i

UtilMy / EPR -

)

Current Situation -

Initiating Event plus Core Damage Single Failure Event

^

Be avior LOCA L 'N B hav t TID 14844 L

Advanced L WR Pmoram )

UtilMy / EPRI Areas for Further Consideration l

Initiatina Event plus Core Damage ll SingTe Failure Event l

l TH Consider DBA Behavior Conditions LOCA Potentistly l

Beyond DBA l..

Radio-Revloed Consider nuclide Lloonsing

  • - Conditions Behavior Approach More Realistic than TID 14844 Advanced LWR Prooram l

\\

e, l

l s.,

1 t

\\-

Utility i EPRI i

Containment Criteria Seyond LDB l

Supplemental deterministe containment crheria being

{

conskjered

. Structuralctheria I

Time based performance targets Critona based on conettenal probabilny of contariment failure may be counterproductive, and are not being pursued further Advanced L WR Pmaram Utilfly / EPRI Approach to Consideration of Supplemental Containment Criteria 1

l Cannot design for all imaginable scenarios Must define a way to screen core damage accidents,

  • e taking socount of preventive measures Arrive at a reasonable suboet of event sequences to l.

be addressed in supplomontal design erneria i

Develop parameter ' envelope

  • from the selected subset, using best estimate analysis methods, realete assumptone Advanced LWR Pmaram

..a

~

4 r

l 1

Milhy I f.PRI Co6tainment Challenges / Preventive Features Phenomenon Atwn Desian Feature Hycrogen Detonaten

. Size Containment to Dilute Hydrogen l

. Containment Strength for Burn

. ControlSystem,if necessag Direct Containment Heating RCS Depressunration Capabiley

. Cavny Design l

Debris Con'act wth

. PedestalDesign Containment Shell Overpressun2ation Due

. Provide Dobns Cooling with To Core Concrete Attack Cavity /Drywell Flooding Basemat Penetraten

. Provce Debns Cooling with Cavity Drywell Flooding j

. Adequate Concrete Thokness t

AdvancedLWR Prwsm I

wii.,, mi _

Screening Criteria Being Studied Composne deterministic / probabilistic screening orneria being evaluated based on: a preventive measures in ALWR Requirements, and b) ikelihood of event seque ice. This would result in a subset, for design consideraten, along the 1ollowing lines; i

Coro damage has occurred RCS has been depressurged Coro debris penetrates RPV after time _

Coro debris is flooded and cooled within time _

Hydrogen is generated and bums if flammable e

Containment heat removal function is successful, or is recovered by time _

Advanced LWR Proptam l

1

)

i i

I UillNyi EPRI Structural Criteria Being Studied

)

Licanalna Dealan Ramla (LDR) i

. Continue to use the limiting LOCA. main steam, or feedwater line break as event that determines LDB pressure 4emperature Ptlak Evaluation haala (RER) f

. Establish criteria which provide predictable structural response under

  • envelope
  • pressureSemperature loading, where containtnent shell will remaln en the elastic range except for local condnions i

. Impose via owner design specification the ASME Code desion tulos for steel (Subsection NE) and concrete (Subsection CC) containment vessels; However:

l Permh higher allowable stresses for steel shell vessels and 5

lower load f actors for concrete containment design, consistent with the lower probability of the severe accident event Advaved L WR Pmtam UtilMy / EPRI Structural Criteria Being Studied Staal Prannura Vanaal

LDB. primary membrane stress design to Service Level A RES. primary membrane stress design to Service Level C L

Mainforced Concreta Vanne!

ASME Subsection CC

(-

LDB ' abnormal

  • factored load ocuation. design whh load factor of i

1.5 on DBA pressure and temperature loading terms

[Capachy.1.0 D + 1.0 L + 1.5 P(LDB) + 1.0 T(LDB) )

REB ' abnormal

  • f actored load soustion. design with load f actor of

(

1.0 on

  • enveloping
  • pressure and tempemture loading terms

[Caphelty.1.0 0 + 1.0 L + 1.0 P(REB) + 1.0 T(REB))

Advased LWR Param l

I

\\

l

l t

i AN OPINION i

on CONTAINWENT CRITERIA for j,

i ADVANCED REACTORS i

i i

T. S. KreSS, Manager ORNL Severe Accident Programs

)

i i

Presentedto ACRS Subcommittees on Containment Systems and Structurni Engineering 1

Son Francleco, colli.

1 Sept.12,1989 r

l l

l L

3...-

p i

i IN MY OPINION, THE.PRESENT CRITERIA HAS THREE MAIN FAULTS:

1

1. CHOICE OF DESIGN BASIS ACCIDENT i
2. " ARBITRARY" SPECIFICATION OF FP SOURCE INTO CONT.
3. CREDIT FOR ENGINEERED SAFETY FEATURES 7

9

I BEUEVE WE HAVE PROGRESSED IN OUR UNDERSTANDING 0F A2 APPR0ACH TO SEVERE ACCIDENTS TO THE P0lHT THAT WE NOW AT i

LIAST HAVE IDENTIFIED ALL THE THREATS TO CONTAINWENT (ALTHOUGH THE ABILITY TO QUANTIFY THEW IS NOT AS GOOD AS IT SHOULD BE)

  • BLOWDOWN STEAW

- vessel bottom head I

- reactor cavity

  • FISSION GASES 1
  • THERWAL ADDITIONS
  • WCCI
  • OTHERS (seismic; fires; missiles; tomadoes; etc.)

POINT 4 WE SHOULD BE ABLE TO QUANTIFY THE MAXIMUM LOADS AND DESIGN THE CONTAINMENT TO NOT Fall WITH SOME FACTOR OF SAFETY 1

ll,..

i i

IF ASSURANCE'CAN BE GIVEN THAT CONTAINMENT DOES NOT FAIL, THEN CAN CONFIDENTLY STATE THAT ACCIDENT CONSEQUENCES WILL BE NEGLIGIBLE f

DO NOT HAVE TO QUANTIFY FAILURE FREQUENCIES OF ACTIVE COWPONENTS i

l ACCURACY IN THE SPECIFICATION OF SOURCES OF fps INTO CONTANWENT CAN BE REuXED l

t PROBABLY CAN DO AWAY WITH NEED FOR EWERGENCY RESPONSE PMNS BUT:

MUST PAY MORE A7 TENT 10N TO:

- look HgMness

- Confoinmenf IsolaHon

- PonefraHon seal failures L

l

l..

2-i i

~

i CONSIDER THE FOLLOWING THREATS TO CONTAINWENT THAT ARE NOT j

COVERED BY THE PRESENT DESIGN BASIS ACCIDENT FOR CONTAINWENT:

  • ENERGETIC FCis
  • WCCI
  • HPME/DCH f

THE COMMON CULPRIT IN ALL OF THESE IS

  • ZlRCALOY WE COULD (PROB 49LY) ASSlRE THAT MOST PRESENT CONTAINMENTS i

H'OULD MEET A "N0 FAILURE" CR/TERIA If WE REQUIRED THE SISTEWI/C REPUCEMENT Of ZlRCALOY CUD FUEL WITH A FUEL THATIS CERAMIC B4 SED.

l l

1 -

j

.. F.. :,

3 i

FOR AN MHTGR, THE BARRIERS TO FISSION PRODUCT RELEASE CONSIST OF:

l.

t THE FUEL KERNAL

~

THREE CONCINTRIC COATING LAYERS :PyC (2); SIC (1 THE FUEL COWPACT WATRIX L

THE GRAPHITE CORE STRUCTURE AND RERECTORS c

i EE ?EACTOR C00LO'T SYSTEM i

EE ?.EAC70? 3' LTNG (OR CONTA!NVENT/ CO J

L 1

?

.,{',

h IN SUWWARY, THE CRITUtiA l AW PROPOSlHG IS SIMPLL

1. EQUIE DUDCARI DETERMAT10N OF WAXIWUW LOAD CDWOMATIDN

}

THROUGH DETDtMISTic ACCSDR SEQUD4CE ANALYSIS. DDELOP UNCDtTAINTY DISTRIBUTION.

j i

?

2. DESIGN CONTAINWENT VOLUWE AND STRD6GTH TO MTHSTAND WAXIUUW j

LOAD C0WBINATION MTH A REASONABLE FACTOR OF SAFETY AT SOWE SPECHD ASSURANCE LEVEL BASED ON THE AB0YE UNCDtTADUY DISTRIBUTION.

3. SPECIFY SDSl40 DESIGN EQUIREWENTS ON PROSAgil2nIC BASIS
4. REQUIRE LEAK TESTING PRIOR TO EACH START UP
5. REQUIRE DEFENDABLE WECMANISTIC DETDtWINATION OF CHARACTUtlSTICS OF SOURCE TUtW TO CONTAINWENT (CNEW FORKS; ADt0 SOL QUAN11TES) l
6. SPECIFY NORWAL IIAK T10NTHESS UNDER WAX. LOAD CONDm0NS AT THE ASSURANCE LEVEL SPECinED M [1] SUCN THAT WRN ALL Rs NTRODUCED INTo CONTAMWDU SafULTAME00 SLY AT TlWE OF PEAK MtESSURE A SPECRD SAFITY CRITUtlA (og 10CFR100 or PAGe) tS OT.

l

.]

p.

n.

.a.

..u-.-.

~a

',i,:

i,

'g s

L I

i e

I l

.A r

f t

i 1

e I

i i

I i

  • ~

L 5, -

'[-* Z G

e Z

a:

UA v

t M

w w

s

'./

xu e ze ZM Z.

W $. m#

v e en e =

V E

7 4"

i C%

A

.-E

~ < e3 in r

'/.

' V.'

m m

g k.

f, %

V g,-

b==

e A

me M

g g-Z.

  • .g e

W e

s W

W Amme Y N,

.U.f K.

r..

M-m 8-eums I

Zf Zg O

Q

.a v.-

n N

HZ 7s 7r z_.e gE 4

r W

g. U W

w 4

$4 N

F-E h.

o U

e

,,a.,--.-.,.n

- + -.- -

,, + -.

--,--e

CONTAINMENT DESIGN CRITERIA MEETING 7-BACKGROUND 4

11 S NRC POI. ICY REQlIIRES FIITURE Pl. ANTS IIE SAFER TIIAN CURRENT Pl. ANTS Proviile balance lief wecn prevention anil niitigation PRA requirmt l

Satisfy NRC severe acci< lent. require inents j

U S ALWR REQlilREMENTS PROGRAM (Evolutionary Plants)

Capability of prevent /mit.igate severe aceitlcnt.s

<10

/YR CDF (internal / external)

<25 REM for events >10 ~Iyr 1

WORI.D PUHLIC OPINION Fut.ure plants must xhibit passive like responses No evacual. ion desired AI.WRs MUST MEFT EXPECTATIONS FOR FUTURE Pl. ANTS IIIT:ArltS1

l

'.'e r

er e

i 6

)

i f

i em i

W emy M

+

L;

.r -

i V

  • e g

o 9=

F *

.b k

' est.

6 y

C Z:

w 6*

/.

m y*

v.

~

m n

I M.

{-

G e.

me -

4 n w a

c C

ge 6

^

. Z.

~

r=

y*.

v.

b M

,e esa gg,,

C e,,

s w

e,e ad g

y y

w p.,

6 --

C W

v==>

N.

3b

.h

.5

[

7.

5' i

x:

L a-e R

  • w-=

??

L o

C y.

u g,

l-

  • ~

w.g Z

y L = w E,

y as 6

6

.v v

e V. Wv C C C

l

  • ==
  • /

c

~

E f""

Z-O C

Z 4

If:

Q

==

w C

<4 g

  • =

v.

g a;

e V-

. 5

~L 4

e

~

  • C i-y%

v;.[.;

O.

O

>=.

l"<

O

^

~

L

-w A

m.

C L

g, f,,,

6

  • =

g g

C V

.=

=

C w

Z, M

C=

~

C v.

g

c. $

l C'

Z 56.5:

.~

O C

C C

u 2 v.

4' a * >==

C f

t==

I Y

'c

.C *

  • u:-

C C

4 p.

v;

1. u M._g y, 3 d u..g E 4i M

0 C

e, C

w

.~.

v C

p C

- w -

c g

C O ' ' - ~

c C o.c d

C W.

Oc-(

b t

b c

0 6 e

l E =-

a.se c

'y S

a es sI 5 $ $

% b5.~5 Z

o e !- a. a. -

=

ozu m

C 6

O

<.4 I

I I

I

<E I

I I

n

=

~

SEVERE ACCIDENTS f

CONTAINMENT OVERPRESSURE PROTECTION EI'RI A1,WR Re<piirement s silent. on Containmerit. Overpressure l'rolcelion ItWR operating yelant EI'Gs idculified venting for cert ain circumstances Cont.ainmen1 overpressure protcetion virt ually precluvics offsite releases exceeding "?5 REM for severe accielculs On lialance, GE tiiinks overpre ssure-protect. inn vent lias merit.

AllWR overpressure proscetion reviewed willi NUMAltC severe accident working group anil llWR owners group Executive oversiglit coinmitIcc - feat ure elesiraliility l

acknowledged col' In ing avlopt df5>r llWR ConIaisimceil.s IIFI':ACRs4 i

t - _ _. _. _ _ _ _ _ _ __ _, __

i-.

+

e.

,+,-

+

mw~,.... -

e

.,e,e+,

..m..,,,

s-,,-[

..n.

.n..

a -.

s

-~

______.a w a ~.

n n.,.u..w,

.s i

i.-

t 1

i e.

i 6

I C.'

M

'c 2-

+ v en n

i v.

v

.t.

L.,

1 i.

~

1 k

8

.~

1 L

w i

'A k

E C

A 9 j

=

4 is:

r C

7,

,E, n

u j

w M

C* v.

i

. W s

ato P-w.

. be p

p T, -

T.

e

~

~

- v.-

~

i

./.

,4 v,.

.v v.

i Z

u" l

+-,

o

./

C O

i<,,

f,,,

p V;

C v.

~

e i

7.'

y-L L =

l V.

r'~

..C. %

a v.

6 6

t g

C L

(

~

Y 6

e.

1 e

P g

y O

M e

>-=

9

.i y'

c

>=

w C

.M c

M >**. y

==.

%..=

r,m v.

y*

y*

~

b

= =. = =. = -

,m y-1 w.

w y

' y

'O',,'

t v.

E L

7.

C C

.<i e t

v. -

c.

L m

/s

~

..Z p.

g w

s 1

e p

p w

". ". ' O G

L L.

t o

L C

C 6 s

6 O

Q

. k i.

C.

y L e

)

C M

.V-

  • r,'

f-i L

Q

~

W w

'88 Z

y y e.

0 L

  • e=

4 i O Z.

I h 'z g

cb

~

C w

~

C Z

~

g g

($

C c$L E [-

1 r 'E b Z

U vs w

v.

x v v v v.

c

<=

e u

w-u u

e s

u e-.-

u g "%

C 7

c.,

.~.s cO

~

,L, K

$.. =K C,

a.

M k 4

A t..

=

g Z

w

'e*

w a

he W.iB e

1 O

o g,,

B 8

DM.m ga.B A

I w

w l

g n

g n

a n

?.

(.

O w

w 8

8""

6 l

i i

i

i i

4

9. -

}

4.,

i 1

i i

n

.t i

)

.J.

v..

.s.

n a

. ~.

e k

=

..ti :

O s

a

=

t1 -

b i

s

-c C

C

=

v.

~v ' O L

a L

c, w

v.

. v, C

M t

~

w a

=

F

.L r'

L

  • g a

7 g

.[s L

1

<=

v a

C O

't""

=

v C

C e

s L

7,.

C

~

s.

f.

C "ll V.

a L

L O

L e.-

r.-

~

C C

M 4

.L C

y b

'C e

4.

H v.

C L

.s L.

c V

y C

a C "

Q<

C g

=,. y,

==

a/

M >.

p.4 u

t 0

L

~

,L L,

c.-

L u

.L 0 #,

T v.

"j.

r Z

t"""

g

(.

y r-

==

y-C,',:

Z A

)

b L c

L

.C r.

r*

4 b

c g-6 b

C D

v.

v.

M G-W 3

0 g,,.-

U L

L D

w

v..-
  • /

~

e Q

v.

r,'

=

R c

e y

e-C

+

v*

O

  • =

g

%.F cC O

Tf.'

l 'M O L O

M

. v, k

V.

~

.n v.

o

~.

v O

v.. G g, c g

e C-

==

.o eL E*

e.E 5 t

E. c

.=

~

~

.a V,

k g

v.

e C

C v, '

y O

.C a

k.

m.-

v.

u

-cw y

v*

v.

L O

6

,e C p

L m%

v.

= s O

c

,=

c g

6 y

ep

. f.

6 e.

d:

O.

5 g,,

=

C

=

.e

.a.

g C.,

'3 w

=

p L

C-L w

{

~%

G 5 y

n l

{

l 5

Ed I

m

~

['

G

-w m

,a.,... -.,,. -,

..,._,..,,w,..-.n,._,_n.,.

,-n,---,

?..

CONTAINMENT DESIGN CRITERIA

SUMMARY

G overn men t/U tili t i es/ Ve n d ers/A - E's all working toward innproveel passive plant designs Current Containment design metliods seem adequal.c and allow f8cxibility for innovation to tical with severe accidents t

y Certification process for specific designs again allows rapid and flexible consideration of unique design features without the burden of extensive rule making.

4 Current Containment. Design Codes t

with design certification is adequate lift:A(~I68 4

O O

g

-->-q w

y N

e

  • +.r-a er-w'w-

..--u.

w w

r a.gr yr--.,y--w-=wec-e---w...

.e----+

-wm i wwe4-,e. e e -vweiv.

(

I US-DOE MMGR FROGRAM

]

~

G e

MHTGR sat-t-IY APPROACH TO CONTAINMENT SYSTEM DESIGN CRITERIA PRESENTED TO ACRS SUBCOMMil Itis ON CONTAINMENT SYSTEMS AND STRUCTURAL ENGINEERING SEPTEMBER 12,1989 I

i F. A. SILADY MANAGER, REACTOR SYSTEMS ENGINEERING i

i

+ ATOMICS GENERAL i

(

)

l

{DIVS10.CARot.j558 1 11-SEP-89

~

a-it,.o m..

=m--e-EMa

.ns- -

9 e se e

i 1 H

IE!

w R

r w

a x

Y E

wt x

=

m R

m 5

=

.~ a ;,+ y; o

c.o x

s' 2

E

!!.. i';

i{

W $

Ei !!!

M 2

_._, m _ _ q !!..!.[.{i!! ".. '[.li.. j!

W E

W g

g

-d I

vs C3 a.C l

's

-=

w I

g5 W

=

i d

5l E slg I

'= l

~

m g(g, s.

!a.

Il l

g g,

m l

/',t M=

l r.m

=5

= Eof

/

8 8"

2

,,,,L,,,hiililiiiiliiii ii i i liii i liih i.

7.

l E

r r

r 7

r e

r l

n e

e a

e a

e e

a L

WVIA INV1d U3d A3N3flD3Wd NV3W I

m a

E~

$h z,

e 1..

+

, ~;

(

lUS-DOE MHTGR PROGRAM

]

SUMMARY

OF LBE SELECTION METHOD

1. DEFINE REGION BOUNDARIES
2. COMPARE ASSESSMENT RESULTS TO REGION DOSE LIMITS 3.

IDENTIFY AS AOOs FAMILIES OF EVENTS iN APPENDIX 1 REGION 1

THAT, WERE IT NOT FOR DESIGN SELECTIONS MADE, COULD l

EXCEED ALLONABLE RELEASE LIMITS

4. EVALUATE THE CONSEQUENCES OF A00s REALISTICALLY t

l 5.

IDENTIFY AS DBEs FAMILIES OF EVENTS IN 10CFR100 REGION THAT, WERE IT NOT FOR DESIGN SELECTIONS MADE, COULD EXCEED ALLO #ABLE RELEASE LIMITS j

i L

l l

1 GENERAL l

T atomics

(

J r

[Dw510.CAROt]65 21 11-SEP-89 J

v

, ;]

g.

[

lUS-DOE MHTGR PROGRAM

]

~

SUMMARY

OF LBE SELECTION METHOD (CONT) i 6.

ALSO EVENTS WITH UPPER OR LONER BOUND FREQUENCY IN REGION 7.

EVALUATE THE CONSEQUENCES OF DBEs CONSERVATIVELY 8.

IDENTIFY AS EPBEs THE DOSE-DOMINANT FAMILIES OF EVENTS IN PAG REGION 9.

EVALUATE THE CONSEQUENCES OF EPBEs REALISTICALLY

10. COMPARE ASSESSMENT WITH NRC SAFETY RISK GOALS
11. ASSURE THAT RESIDUAL RISK IS NEGLIGIBLE

+ GENERAL-ATOMICSJ k

[DIVS10. CAROL}65 22 11-SEP-89

v j s' 1111TGR RADIOtlUCLIDE CotiTAlliffETIT SYSTE!!

SCIIEf1ATIC OF ItET. EASE BARRIERS REACTOlt DUILDITIG Primary lie PRIf1ARY COOLAllT PRESSURE BOUllDARY Leaks IIcavy rietal

/

UCO, Tho "t""i"^ti 2

Circula ting Activity 4

Plateout

/' /

/

Core L

3,

{,l fs b kY*h TNJ!

1[elease SIC Lif k OPyC FUEL ELEllETIT l

s Steam Induced IWashoff Vap.

I Cotidensa tinn Deposition Settling Ile Purification 1

I I

I I

I i

Y t

1 4

EXCLUSIOtt AREA I

k ventina Buildilx1 Leaks

)

+

-~

~

n

-x-w

=ee mr

_,--wc x,,m.-,4 s

m

.s.

m

. m.

v

=

MHTGR SAFETY RELIES ON THREE BASIC FUNCTIONS l

RETAIN RADIONUCLIDES IN C0ATED PARTICLES i

1 I

REMOVE CONTROL CONTROL CORE HEAT HEAT GENERATION CHEMICAL ATTACK l-839(l 6)

A 4

10-19-88 Ng N a

f lUS-DOE MHTGR PHOGRAM

]

e GENERIC APPROACH TO CONTAINMENT SYSTEM DESIGN l

l e*

1. DETERMINE QUANTIFIABLE DOSE AND RISK UMITS FROM i

TOP-LEVEL REGULATORY CRITERIA.

l

2. EQUATE DOSE AND RISK UMITS WITH ALLOWABLE ACTIVITY I

RELEASES FROM SITE.

3. IDENTIFY THE TOTAL RADIONUCUDE SOURCE l
4. DEFINE TOTAL REQUIRED CONTAINMENT SYSTEM RETENTION AS THE DIFFERENCE BETWEEN RADIONUCUDE SOURCE AND ALLOWABLE l

RELEASE TO THE PUBUC.

l l

i 1

i

+ GENERAL ATOMICS) 1

(

[PARWE]15 1 11-SEP-89 l

(

lUS-DOE MHTGR PROGRAM ]

GENERIC APPROACH TO CONTAINMENT SYSTEM DESIGN (CONTINUED) 9

5. IDENTIFY THE PHYSICAL BARRIERS BETWEEN THE RADIONUCLIDE SOURCE AND THE PUBLIC
6. ALLOCATE TOTAL REQUIRED RETENTION BETWEEN BARRIERS.

i

-ACCOUNTING FOR CREDIBLY BOUNDING BARRIER CHALLENGES

-RECOGNIZING INHERENT CHARACTERISTICS OF EACH BARRIER l

-CONSIDERING OTHER DESIGN TRADE-OFFS / REQUIREMENTS l

7. SELECT CONTAINMENT SYSTEM BASED ON ABOVE.
8. DEMONSTRATE ADEQUACY OF SELECTION WITH DESIGN BASIS EVENTS CHALLENGING RADIONUCLIDE RETENTION.

+ ATOMICS GENERAL y

1emuqu 2 n-sce-a,

l f

lUS-DOE MHTGH PROGRAM

\\

1 INSIGHTS GAINED THROUGH APPLICATION OF APPROACH TO MHTGR

'l i

e SINCE APPROACH IS MECHANISTIC, IT IS MORE USEFUL WITH SIMPLER DESIGNS WHICH ALLOW EASIER MORE ACCURATE CHARACTERIZATION OF RISK AND RELEASE MECHANISMS e CONTAINMENT REQUIREMENTS MUST BE BASED ON A SPECTRUM OF j

CHALLENGES TO RADIONUCLIDE RETENTION AND CONSIDER THE i

MULTIPLE RELEASE BARRIERS THAT MAY EXIST e CONTAINMENT REQUIREMENTS SHOULD NOT BE BASED ON AN l

AUTOMATIC ASSUMPTION OF BARRIER INDEPENDENCE e CONTAINMENT REQUIREMENTS SHOULD CONSIDER ALL OF THE FUNCTIONS PERFORMED BY A PARTICULAR DESIGN SELECTION (E.G., THE CONTAINMENT BUILDING MAY SUPPORT CORE HEAT I

REMOVAL, PREVENTING CORE MELT, AS WELL AS RETAIN RADIONUCLIDES GIVEN CORE MELT) i i

o CONTAINMENT REQUIREMENTS SHOULD CONSIDER " SUPPORT SYSTEMS" AS WELL AS " FRONT UNE" SYSTEMS IF THEIR FUNCTION IS REUED UPON

+ GENERAL I

ATOMICS).

(

i

[eautp3 4 u-stP-89 j

? I' 7 I

,e I

o-e I

I i

I"

$0B BUDNITTE NOT10hlt ON beow TO *LLLtt CONTAINhr[NT PERFORh*MCE CRITERI A HQyV TO EEttCT coNTitMMt'u? PERFORMAWft CRITERIA a'

CROUND rut tt-

1) Critene should tehe the form eh ROBERT J. BUDNIT2 e deGn.iion of e terge nimese* to be deo.gned e

i ege. net 3

en acceptobie disent en ennt,el frecuency for the e

defines *terge reiseee*

r Future Rueuern Anecietu. lat.

2000 Center Street. Suite all

- 6 2)

Analye.e should be taahaus w+th twiem opeutned emnese.

terteiey, Centemie 94704

  • l'**-
3) Cenewvetism shouad be eeded by requietwo *et the end*, se y

make the amount end therector of the toneerwetism as aaplicit se lessible, September II.1999 el Notwithstanding any other orgument tenteenment/confhessient gmal have some specifeed mitigetave therectenetecs...

perneps some sposaned facter of reducteen (*eseres nutigelsen letter') of emount of offsite dose (espected weauel sempered to situation with no containment /confenoment like e fastee of ID or 30.

. -. -.. -.. ~

3 4

E"Att'ATf'JN AcatNET THE fp!Tf MA.. A FtVE.ETEP PPottet STEPL Reehm - W a r- -

M**-

n... a.... An.m..* t anaA. i A spuifk

  • design'. indudir's e postuteted contem.

Each ODBA showed represent a group of essadent ment /conGnoment design. 'e being sensedered.

e s

eseuences, but not be the 'weret* emeng that group =

more likely, something that is 'typesel* of the group Each SDB A showed esertsee one er more hoy espects of e

STEP 1:

Requietore cheese e fem.ly of BDBAe ability to cope unth LOOP ebility to cope with large LOCA perfeemence during spesiGed bypees esenene STEP 2 Proponente snelyse each 8084 reelistically Au geospe of ooevences eheund be espresented by at e

least one SOB A. unises tetel annual frequemer of a g,eu,.e below eeme denned easted like <1 E.7 to 1 E.8 STEP 3:

Reguietere odd venous eeneervetism.

For esemple, for a snedem large PWR, DOSAs suisht M STEP 4:

Active oystemer design must reiset menirnum eekebility entene e

opeoGed lege.LOCA seguence e

LOOP wsthout nieteen bleetwet e

LOOP w6th stetten biochest e

LOOP with ATWS

$TEP $:

Reestte era compared with regv6etery entene e

emes.LOCA with failum to ow8' shoes' 8e N"

o trone.no weth goes of conteensnent hast re#' eve 3 e

spouGod bypees in high-pressum/le*. pressure piping e

1 or 2 steem.genereter tube reptise esenonse o

etc.

...m.

~.-

o..-

.?

g f I' g

6 l

e 9

t sygp t

_....ag. _

m-U12,2; Penannant ahnuldJnalytt_A&ch bORA an enalia.

l

[galte as fannikle ta *S!but the falla*ine-l These sentervatisme would be embedded h foguiettwee er segutetery '

f e

utident progreseien guidente, f.aemplee might be toeviresnente le le Appendie Kl that e

timing espette. in. vessel end es.veneet the enoireis ravet neume some tembination of the someaugt L

e usume 20% emeiner conteinmeat/sennaement solume

[

o

...aebte intnneit minisetive featurn e

l then ett.ier (w meybe 20% lugw peonwe else than

-}

actual) e eveilable (octival mitiget6te strategies.

including both hardwe'se and operator ettient e

enume 13% less ultimate pressure espeb51ty then settsel a

realistic tente.nment lesee y

t i

e

,eeses teniainment pertarmente o

enume as% 8ergw hydvesea retenee then estems -

e seef.etit eeurte term 1

)

e enume 29% 4erger oewog poet pseseuse in eeneen.

j ment /tennnesnant then estuel 1

0-Unt*rtainty enefreio end sensativity onelysis era enentiel.

i j

e enounio 20% mese pertinesente snetter from esse eenesese Interactione 3

0 If ettseent reopense mises on active systems, see discusseen of voisebHity entene ($TEP 4).

{

e eseume $0% fnere necesa produite est reigesed then i

estuel e

Anolyste must mese conservative eseumotions whenever e i

technetaliosue tennet be snelysed test etitelly, j

i

  • Attual* meene "best eetimele by eno6yses'. and neede to be t

defined prosately ter eMh portmenet - temetemos nadien.

temetimes mean, etc.

t t

s l

?

I ADVANTACEE OF APPROACM m

Entana rar actiwa emarmuupent statama e

nowies ensivoie el phenomeno ii e

Caneereotieme empiesetty added in speaant passes 4.

Independent of other entene. tegulatere must insist that estive tentainment systems releed on in e

Cntene are sleet, and steer 6y linked to seguestery reopense to wenous BDBAe setisfy certain entane for *h gh* reisebility on demand, including hereh p,ebebilistic appeseth eNotwo *de nunsmie" appseesh to

')

poet.< ore demage environmente.

eseuence groupe of sufAssently low probabihty 11.

Cntene eheutd be specific to each system.

DIRADVANTACER OF APPROACH l

PRA. booed aseident (seeveney esteWestone ese tdghly Ill.

For enemple, the requietore might sheen to reevice o

a mensmum failuso probability of < 0.01/ demand for oproyo, <0.001/ demand for peel heet eschengere, etc.

e Selection et 90BAe is jisegemental o

Defbution of *everes naalgetion faster

  • emnet he done 1

. seredully l

l

Retrieved from "https://kanterella.com/w/index.php?title=ML20006F939&oldid=4661440"