ML20212F264
| ML20212F264 | |
| Person / Time | |
|---|---|
| Issue date: | 12/09/1986 |
| From: | Lainas G Office of Nuclear Reactor Regulation |
| To: | Bernero R Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20209E138 | List: |
| References | |
| FOIA-87-10 NUDOCS 8701090625 | |
| Download: ML20212F264 (3) | |
Text
r .
- UNITED STATES g
)4
- E NUCLEAR RESULATORY COMMISSION WASHINGTON, D. C. 20555
- December 9,1986
\ ...~
MEMORANDUM FOR: R. M. Bernero Director Division of BWR Licensing FROM: Gus C. Lainas Assistant Director Division of BWR Licensing
SUBJECT:
POST-ACCIDENT OFFSITE DOSES FROM ELEVATED VENTING OF NOBLE GASES DURING A SEVERE ACCIDENT
References:
(1) Memo from Gus C. Lainas to Robert M. Bernero,
" Post-Accident Offsite Doses from Venting Noble Gases During Severe Accident," September 25, 1986; (2) Memo from Frank J. Congel to Marvin W. Hodges,
" Post-Accident Doses Offsite--Additional Information," November 13, 1986; (3) " Graphs for Estimating Cloud Gamma Doses," by C. A. Willis, McDonnell Douglas Astronautics Co., 1969; 1969; This is a supplement to our memorandum of September 25, 1986 (Ref. 1) which described post-accident offsite doses from noble gases released at, or near ground level. Our objective herein is to show the effect on the whole body dose as i1sult of an elevated release relative to ground release.
Enclosure 1 presents the expected whole body radiation doses as a function of distance for a near ground (10 meters) release and for an elevated release point (100 meters). As in Reference 1 these plots assume release of 100% of the noble gases from a 3412 MWt LWR, a one hour holdup in reactor prior to release, and a 5 hour5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> release period. Estimated 95 percentile doses for corresponding ground and elevated releases are also shown. The 95 percentile
- estimate is based upon the variability of meteorological conditions and release start times end should be interpreted as follows: Given the release-assumed in the calculation, the likelihood of the dose being less than the indicated value is 95% for a person who would remain stationary under the plume at the downwind location.
l The graphs are based on calculations using the MACCS code and were provided by Sarbes Acharya (References I and 2). We believe that an extrapolation of the MACCS results would tend to overestimate the doses within 1/2 mile from the elevated source release point. Accordingly, we have modified the estirnates i using reference 3 to obtain the values shown at distances less than 2 miles from the release point for the elevated release case.* As the graphs indicate, l
Contract: F. Skopec, RSB, x29468
- 5. Acharya disagrees with our modification and estimates that the curve would not turn over as we have shown but would rather parallel the slope of the grcund release curve. s 34 e/o TNL&1 Gos y
- a d
the effect of an elevated release relative to a ground level release is to reduce the expected dose by about an order of magnitude at 1/2 mile, and by about a factor of 2 at 3 miles.
The graphs assume a one hour holdup or decay within the reactor enclosure prior to release to the atmosphere. Greater delay before release can lower doses substantially. For example, an inreactor holdup time of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (instead of the one hour used in the calculations) can reduce doses one mile from the release point by as much as a factor of 30.
Both graphs plot doses for positions downwind from the release point.
Variations in doses can also be significantly affected by location, distance and meteorological conditions. The range can include near zero doses for people that are not exposed to the plume (i.e., cross or upwind, or evacuated).
'Gus C. Lainas, Assistant Director Division of BWR Licensing
Enclosure:
As stated cc w/
Enclosure:
W. Houston M .,
RSB Members
. ENCLOSURE 1 so .
. = = m wm mu=u m man 7 a r
1 ; - = r
, =
tr d5 e
b
+ = Oijj -1 -. . -
FIGURE
_= ,
. .:_=_. _ . _ _ . _ . . . _
-- EXPECTED WHOLE BODY RADIATION DOSE (REM), ==-
i; -
s un n; : f ! i 1 i FROM RELEASE OF 100% N0BLE GASES
=
DN$lh1M
Zf?! L (1 HOUR DECAYED AND 5 HOURS DURATION OF THKei - RHi 4? Ici ?!25
MjM WW~~~~7222 RELEASE) FROM 3412 MWt LWR VS. DISTANCE E 2_ =**
~ ~
3-- -
NOTES: '
a 1. Graphs assume one hour holdup and decay prior to release. Greater delay in release can produce ;
lower doses (e.g., as much as a factor of about '
30 at one mile for 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> of inreactor holdup comparedtoonehour). --
i
~
2
- !? !MUlm=-p = r en z .f;g : =l 2. Dose estimates are based upon MACCS computer p
- TZ ---====== ygJPii =
e 7, ==gg;;
j 4 e
~
- CRAC and CRAC2) metecode orological sampling calculations models. using 'revised (relative to Ej s_ --r- = , = At distances less than 2 miles from the release b '50 Hiii point estimates for elevated releases have been
!..??
=
19 iEN4 *i:
8,!
Z
'l n
m:
355! modified in accordance with Reference 3.
====; iii
___ i_hiPC T
N,'
- sa t== -
- 3. The likelihood of exceeding the n=
3
= ~; " estimated 95 percentile dose is less e == L-~ than 5% given release of 100% of .
a ~~T noble gases as specified above, for a '
p'
- :h; <> person who would remain stationary at g]
a downwind location under the plume. N (00 : m L
w m W'
" l0
- m- = =o .aee= e s 8
= --
d.__ W i n: n
,.= e e -
s # i=L ESTIMATED 95 PERCEiTILE d L=
- C l
g ., g; p e@ g -a,
- ~ ~ ~~ ~ ~ ~ ~ ~ ~ ~
' , GROUND LEVEL RE. EASE 10 METERS
" ~~ -~ ~~
'j; g5 a z 2a ---
i e / co :
== g f -
- __._ w ':
gg a m d y e a m -
===z+ 2 m 'Ii g -
ESTIMATED 95 PERCENTILE ;
M -His p=M=;;
4ua1g
,M1 g d2;
=-
49
=
L
=
bg =
5 =W fE m 1,, == ==-= =
M
=~ -- -
EL_EVATED RELEASE 100 METERS
- -- - j!- !g< 5;
,!p T--.=:=
-== -
Mi sd 2.o ii! jfi EE (r ~8 U=- * ~ *
-~+ 4a+-- 2- ::
t
- =; :== :-g =
- ei l
_ - g wg p
t; o a =Ei = =
-;; I a
=
,em ummej 1
g; , - g.
~
__ m w:
g; obu -- m-w i u , , a ,
w?
- ag , 1 1 i
- = s , L ,, i' ,
W
% N "
d , i i G !
Ea F >
X %M
~
i n' 1 : i ,
X ,e j 93 . i i y ()
d 10 mu .- r=
y 1 = lm .
=
m d L, % ki d m - % , =. m h g J,. == s:- m z =- m < =$ ' :. : s mz r-y- = m .m e=mz 2
- Ci cs = n m
- s w WW -=
n a & ? a i- d h- d k a as i n iL WM ie? e A ~ -
-d
~
e s s =
7 l
g a_ a_ x_-- 1_ .-_ .---
-m w=. -ss .
$ Q(m x .
- i. GROUND LEVEL RELEASE 10 METERS == ==
l ,gu .-- __
a = = 2 m v u- w; : 1 W--
m u x ,
e g w v x m ~a x
=
3It ET =
W _~ m -
ngl m 81 m~~ a 54 +=
. i _ i = ; = -E l EE 2-- ? ? El :
fi 1 ='
fi- FE Z Ei. . =5
"=
l5:
~' ~ ~ ~
jZ: 5 5 ig lQ dd l 5 $$ 5k :: 55 55 : AA 55 55 b1. 3[ 5hJ :E= h 5 5 -
NE
= 1 = 5- - - -
~ '--~
sEi! !! ii! !!Dil !I 5! 5 $$ 2 53 55l !!! ET I bM = t O. 22 - 2- ---
E 855EI5I ELEVATED RELEASE 100 METERS 5 -
Q y =
q; 3( W. . . ,
.a ,. ,
_i , .
- DISTANCE FROM RELEASE POINE (MILES), =
_ , , _ l I l Ill i I I Iil i I I IIl i I I II! I I I IIt I I I II: 1II I i k
6 l - i a -3 4 5 6 7'8 9 to 11 12, 15 14 r
l e ,
October 7,1986 O
. LICENSEES: BWR OWNERS' GROUP FACILITIES: ALL BWR PLAhT5
SUBJECT:
SUMMARY
OF SEPTEMBER II, 1986 MEETING ON GENERIC REQUIREMENTS FOR BkR CONTAINMEriTS A meeting between the BWR Owners' Group (BWROG) and the fiRC was held ir. l Cethesda, Maryland, or September 11, 1986. The purpose of the meeting was for the I:FC te present to the BWROG a set of strawman gene-fc requireraents being cu sidered by the NRC for the purpose of enhancing BWR containment performance ir severe accident conditions. The BWROG was to present the results of its partilel stud) using ticrthern States Power Company's Monticelle plant as reference BWR with Mark I containmer.t. A list cf meeting attendees is rr. closed (Encicstre I).
The f;FC presented th( current staff thinking as sunrr.arized in the enclosed vugraphs (Enclosure 2). Mr. Robert M. Bernero it. formed the BWROG that the Verment Yankee study for cor.tainment enhancement: in response to cor:cerns cxpressed by the Governor of Vermont will neatly dcvetail intc the f:RC considerations cf suitable generic requirenents.
The BWFOC rive a presentation of it: position on its pcrallel study (Encicscre 3). They r.6ve concludet thet emergency procedure guidelines, revisior. 4 (EPG-4) shculd be implemented by EWP owners. However, the issues cf hydroger.
control, drywell spray enhanceraents, containment venting, and core debris ranagerer.t were beir.s referred te liuclear Utilitics Management ard Humar.
Resources Corarittee (NUVARC) for generic application to all light water reacters. -
/.t the conclusion of the meeting, Mr. Bernero proposed e second technical exchange meeting with BWR00 raid November 1986, prior to staff briefing to CRGR scheduled for November 19, 19Ef..
original signed by Mohan C. Thadani, Proiect Maragcr Generic Requirements for BWR Containments Encicsures: _77 0/o As stated cc: w/ enclosures: Central Files D[lI.
See next pages DMuller/GLainas Distribution 0GC-Bethesda NRC/ Local PDRs for BURS EJordan/BGrimes HDenton/RVollmer RBernero/RHouston C '
DBL PDs, BCs and PMs ACRb (10)
BWR Licensees ar.d cc lists PD#2 R/F/MThadani g:[ gg 7/ hgM ,_
l FC- TD'BL':TDf2: : : : : :
l.-...:--....-----.:.....----.--:-------.....:....--------:.....-----..:----------..:......
l1AME :MThadani: Ik : : : : : :
l-----:- .-----....:...-........:---.........:.....------ :--.....-----:-----.------:--------..-
'3 ATE:/0/2/86 : : : : : :
~
s e
, Enclosure il NRC-BWROG MEETING ON
~
CORTATtXEC REQUIREMENTS SEPTEMBTR'T1,1986 NAME AFH LIATION R. Eernero NRC/ DBL H. Derter. NRC/NRR C. Reed Comor. wealth Ediscn Jctr Raulstor. Ter.nessee Valley Authcrity Vincent Boyer Philadelphia Electric Corrpar,3 Richard Diederict Philadelphia Electric Ccrip ny James C. Carter IT Corp /IDCOR Edward Hoherd Ecsten Edisor R. E. Skavdahl General Electric Jotr.. F. Fulter Boston Edison Corrpany T. E. Linders New York Power Auttcrity J . A'. G ray , J r. New York Power Autterity S. D. Floyc' Carolina Pcwer & Light Ccapr; A. P. Cutter Carolina Pcwer & Light Cor,pany H. V. Keiser Pernsylvar.it Pcwer & Light Compar.y Briar FcCaffre) Long Island Ligrting Cortpan)
Charlet Caveric Lors Island Lighting Corrper.y L. T. Gucwa Gecrgia Powcr Corpeny S. H. Chestut Georgia Power Ccmpary J. R. Langley Gulf States Utilities /HCOG Terr 3 Picker. Northern States Power Kevir. Mcitzclav Gereral Electric Ccmpny -
Dear. Houston NRC/ACRS Staff Farcut Eltawila NRR/DSR0/ RIB Jir Deoder.s Gulf States Utilities Certpar,y Dernis E. Hacking Enercon Services /HCCG Wayr.e Hodges NRC/ DBL /RSE l L. G. Hultran NRR/ DEL /PSE t.r.gelc F.arinct NRR/ DEL
- 5. W. Wilczet, Jr. Niagara Mohawk -
fruce A. Prestor Power Supply & Ergineering & Const.
Richarc F. Murray Power Supply & Engineering & Ccr.st.
FictacI 7. l'ay TenneSiee Valley Authority - EFN Woody Stroup Enercen Services Pat Pcwcll Washington Public Power Supply Syster Lynn Connor Doc-Search Associates Larry Gifford General Electric John Stang NRR/BWRd/ Lacrosse Prcject Manager l- Ihomas S. Rotella NRR/ DBL /BWDa Big Rock Poir.t PM l Raman Pichumani NRR/ DEL /F0B l Donald R. Hoffirar Cleveland Electric Illurninatinc l Vernon L. Rooney NRR/ DBL /BWC2 l John Larkins OCM/LZ
! Kazimieras Carrpe NRR/ DBL /PSB Gerald E. Gears NRR/ DBL /PDf2 l
l l
~2~~- . - - . __.
NAME AFFILIATION Jack Kudrick KRR/ DEL /PSB -
Jay Thayer Yankee Atomic R. J. Lodwick Verr.cnt Yankee Stephen P. Scttlt: Yankee Atonic Electric David E. Wagner NRR/ DEL /BKD3 Donenic B. Vassallc NRR/ DBL /FCE Daniel R. Nuller NRR/ DEL /PD2 John A. Zvolirski NRR/ DBL /BKD1 Paj Abitch NRR/ DEL /BKD1 Jact Denchtt NRR/ DBL /BllC1 E. G. Adensar. NRR/CEL/BKL3 Earl Pase Detroit Edisor Phill?p L. Paull Vermcr.t Public Service Dept.
G. Tarrant VT Dept. Pub. Service N. V. Ecwarcr KUTECH C. L. Reic' Bechtel Ower M. Scott Southern Co. Services G. D. Leir.ts NRR/ DBL Eve Fotopoulcs SERCH Licensirit, Bechtel Akire Orctc The Tokyo Electric Pcwer Tetst Imzi TEPIC Sant Bc fit NRR/ DBL /PSE Mchar. C. Thadar.i NRR/ DEL /BKD?
Kathleer E. Shct Newman & Hcitzinger David Wilter Iowe Electric Lignt and Fcwer Stepter. Pt.lcrcy Devenrue Dor. Lewis - Mississippi Pcher & Light Pabl Leech NRC/BWC e
EN CLo S upE tt; DISCUSSION OF A GENERIC LETTER ON BWR CONTAINMENT PERFORMANCE ,
SEPTEMBER II, 1986 i.
ROBERT M. BERNER0, USNRC P
t
. . , y s
~
GENERIC LETTER ON BWR CONTAINMENT PERFORMANCE THE SETTING: PLANT EVALUATIONS UNDER THE SEVERE ACCIDENT POLICY STATEMENT THE KEY REGULATIONS: GDC 16 AND GDC 50 THE SUBJECTS: 37 BWRS WITH PRESSURE SUPPRESSION CONTAINMENTS THE METHOD: A GENERIC LETTER OF REQUIREMENTS TO IMPLEMENT
. CHANGES BASED ON GENERIC EVALUATION i
-- . _ - - - - _ _ . _ - - - - - - - - - - - - - - - . -- . - - - ,- - - - - -- ,-, --e--. -- ,-- - - ---
2 NRC SEVERE ACCIDENT -
POLICY STATEMENT
~
e THE MOST COST-EFFECTIVE OPTIONS FOR REDUCING THIS VULNERABILITY SHALL BE IDENTIFIED AND A DECISION SHALL BE REACHED CONSISTENT WITH THE COST-EFFECTIVENESS CRITERIA 0F
'THE' COMMISSION'S BACKFIT P'0LICY AS TO WHICH OPTION OR SET OF OPTIONS (IF ANY) ARE JUSTIFIABLE AND REQUIRED TO BE IMPLEMENTED.
e IN THOSE INSTANCES WHERE THE TECHNICAL ISSUE GOES BEYOND CURRENT REGULATORY. REQUIREMENTS, GENERIC RULEMAKING WILL BE THE PREFERRED SOLUTION.
IN OTHER CASES, THE ISSUE SHOULD BE DISPOSED OF THROUGH THE CONVENTIONAL PRACTICE OF ISSUING BULLETINS AND ORDERS OR GENERIC LETTE,RS WHERE;. MODIFICATIONS ARE JUSTIFIED THROUGH BACKFIT POLICY, OR THROUGH l PLANT-SPECIFIC DECISION MAKING ALONG THE LINES OF THE INTEGRATED SAFETY ASSESSMENT PROGRAM (ISAP) CONCEPTION.
r-P
, , , , - - - . - - , - - , . - , , +----.,---,--...-_--e--, -_> -,mo ,m ,, - - --- , w.-- , a-,--.e..- , - - - ,w- mw--, ee r v---- - - - - -
~
' ~
.. . 3 GDC 16: ,
CRITER10N 16 - CONTAINMENT DESIGN. AN ESSENTIALLY LEAK-TIGHT BARRIER AGAINST THE UNCONTROLLED RELEASE OF RADI0 ACTIVITY TO THE ENVIRONMENT AND TO ASSURE THAT THE CONTAINMENT DESIGN CONDITIONS IMPORTANT TO SAFETY ARE NOT EXCEEDED FOR AS LONG AS POSTULATED ACCIDENT CONDITIONS REQUIRE."
t em I
i i
l l
l
. 4 GDC 50: ,
CRITER10N 50 - CONTAINMENT DESIGN BASIS. --AS REQUIRED BY SECTION 50.44, ENERGY FROM METAL-WATER AND OTHER CHEMICAL REACTIONS THAT MAY RESULT FROM DEGRADATION BUT NOT TOTAL FAILURE OF EMERGENCY CORE COOLING FUNCTIONING, (2) THE LIMITED EXPERIENCE AND EXPERIMENTAL DATA AVAILABLE FOR DEFINING ACCIDENT PHENOMENA AND CONTAINMENT RESPONSES, AND (3) THE CONSERVATISM OF THE CALCULATIONAL MODEL AND INPUT PARAMETERS."
e O
O P
. . - _ _ , , . _ _ , . . ~ _ _ _ _ *.. _ . . .. . ** PEII*
- I* _ ElI_ * -
5
~ ~ ~ ~
U.S. BOILING WATER REACTORS e 24 BWR 2/3/4 WITH MARK CONTAINMENT .(ALL LICENSED) e 9 BWR 4/5 WITH MARK II CONTAINMENT (7 LICENSED) e 4 BWR 6 WITH MARK III CONTAINMENT (3 LICENSED) h P
~
G INSTITUTIONAL PROCESS l
e CLOSURE OF SEVERE ACCIDENT ANALYSIS FOR CONTAINMENT ,
NO FURTHER ANALYSIS UNLESS EXCEPTION IS TAKEN e SPECTRUM 0F OPTIONS RULEMAKING 50.5LIF LETTER FOLLOWED BY ORDER GENERIC LETTER FROM DIRECTOR NRR OR DIRECTOR DBWRL e PROCESS CHARACTERISTICS
- BASEDONT5CHNICALWORKAVAILABLE,IDCOR,SOURCETERM, l PLANT SPECIFIC WORK, NUREG-1050, NUREG-1150 t
l -
OPEN TO PUBLIC FOR COMMENT AND PARTICIPATION h
- t t': t
- e -E e
l
.g.....-... . . . . . . .... . _ . . . . . . .
~~ 7 A BWR - MARK I FOR REFERENCE BEFORE e CORE MELT FREQUENCY: 1x10-4/YR A FULL SPECTRUM OF SEQUENCES INCLUDING BLACK 0UTS e CONTAINMENT CAFABILITY: UNCERTAIN AND VARIABLE BUT ASSUME 1 OUT OF 2 CORE MELTS GIVES FAIRLY LARGE RELEASE AFTER e CORE MELT FREQUET::Y: 1x10-4/HR IPE FOR FRONT END MAY REDUCE BUT NO CREDIT IS TAKEN HERE e CONTAINMENT CAPABILITY: SUBSTANTIAL ASSURANCE THAT CONTAINMENT WILL MITIGATE CONSEQUENCES, DEGREE VARIABLE FROM PLANT TO PLANT BUT 1 OUT OF 50 CORE MELTS GIVING A FAIRLY L
- LARGE RELEASE SHOULD BE REPRESENTATIVE P
- ~
8 l
l
.- HYDROGEN CONTROL PROPOSED REQUIREMENTS e CHANGE TECH. SPEC. AT END OF OPERATION FROM 24-HOUR ;
ALLOWANCETO12-HOURALLOWANCEOFNON-INERTEDONERATIONAI REDUCED POWER e PERMIT 12-HOUR PERIOD AT REDUCED POWER WITHIN THE OPERATING CYCLE TO SEARCH FOR UNIDENTIFIED LEAKAGE RATIONALE ,
e DEINERTING TYPICALLY TAKES 4-8 HOURS e LEAKAGE INSPECTION AND MINOR REPAIR CAN BE REASONABLY ACHIEVED IN 4-8 HOURS
~
I e REDUCED POWER (36 33%) SUBSTANTIALLY' REDUCES SHORT-LIVED FISSION PRODUCT INVENTORY AND DYNAMICS OF POSSIBLE ACCIDENTS l
e I
P
.r .. - _ _ - . .__--.____r___ ._. . - _- ,
- 9 !
DRYWELL SPRAY PROPOSED REQUIREMENTS
~
j 1
e REDUCE DESIGN SPRAY RATE (CHANGE N0ZZLES) TO ABOUT 10% OF PRESENT VALUE e PROVIDE AC-POWERED BACKUP WATER SUPPLY FOR SPRAY AND AC-INDEPENDENT WATER SUPPLY, AVAILABILITY BY REMOTE MANUAL OPERATION OR BY SIMPLE RELIABLE PROCEDURE DESIRABLE ,
e MAKE ALTERNATE WATER SOURCES AVAILABLE TO COOL CORE DIRECTLY e 90/10 MODE OF RHR 0PERATION RATIONALE
, b
~
e WATER SUPPLIES AND EQUIPMENT ARE ALREADY AVAILABLE FOR LOWER FLOWS e LOWER. FLOWS PROVIDE ALL BENEFITS EXCEPT LOW sd T DECAY HEAT REMOVAL AND DO NOT RAPIDLY FLOOD CONTAINMENT e ASSURED DRYWELL SPRAY SUBSTANTIALLY REDUCES PROBABILITY AND SIGNIFICANCE OF DRYWELL FAILURE OR SUPPRESSION POOL BYPASS d O Weenus mea e e ., as . gopoemmenhe 9 ese S ese . e--- -_-- -- me e se e ese e .g me p . , . . . . . , . , , ,o
, , , , , - , , - - - - , , , . - - , - , n-, --- - - - , - - - - - -
10 j
PRESSURE CONTROL PROPOSED REQUIREMENTS ,,
e RELIABLE CAPABILITY TO VENT WETWELL AT EPG PRES,S.URE LEVEL WITH OR WITHOUT AC POWER. FOR VENTING WITHOUT AC POWER MANUAL PROCEDURE IN ADVANCE MAY BE USED IF NITROGEN PURGE IS AVAILABLE e VENT OF 18-INCH DIAMETER OR GREATER DESIRABLE 9
e ABILITY TO VENT SLOWER SEQUENCES THROUGH STANDBY GAS TREATMENT SYSTEM .
e BURST RESISTANCE DUCTING IN REACTOR BUILDING TO MINIM 12E COMPLICATIONS RATIONALE e RELIABLE VENTING PREVENTS UNCONTROLLED OVERPRESSURE FAILURE WHICH'CAN CAUSE CORE MELT e VENTING WITH DRYWELL SPRAY GIVES GREAT ASSURANCE OF RELEASE MITIGATION
. 11 CORE DEBRIS PROPOSED REQUIREMENTS ,
)
e ASSURE RETENTION OF WATER AT LEAST 3 FEET DEEP IN TORUS ROOM IF TORUS LEAKS ENTIRE CONTENTS DESIRABLE e CONCRETE CURBS OR OTHER BARRIERS WHICH WOULD RETARD DEBRIS ATTACK OF DRYWELL SHELL e AVOID LOSS OF RECOVERY SYSTEMS FROM WETTING BY TORUS ROOM WATER RATIONALE ,
e DRYWELL FAILURE BY DEBRIS ATTACK IS MADE LESS LIKELY AND LESS SIGNIFICANT BY DRYWELL SPRAY AND VENTING e RETENTION OF TORUS WATER ENSURES DEBRIS QUENCHING AND SHOULD FACILITATE ACCIDENT RECOVERY i
f V
f
... .... . ... =.
^ -
.. = .. . . ... . .
CHRONOLOGY e 1986: MEETING WITH BWROG/LDCOR PROPOSED A GENERIC '
JUNE LETTER, 16, PRESCRIPTIVE SOLUTION, BY BdCKFIT ,
1986: VERMONT YANKEE COMMITS TO GOV. KUNIN TO DO A s JUNE SPECIAL 6 30, 0-DAY CONTAINMENT STUDY ,
o JULY 25, 1986: BOSTON EDISON COMPANY BOARD DECIDES TO FIX PILGRIM CONTAINMENT e AUGUST 19 1986: BWROG EXECUTIVES VOTE TO FUND AND CONTINUE DIALOGUE 6N THIS WITH NRC, CONTACT NUMARC ABOUT BWR VS PWR e SEPTEMBER 11, 1986: MEETINGWITHBWROGTOCOMPAREBACKFiT NOTES AND STRAWMAN GENERIC REQUIREMENTS e SEPTEMBER 11, 1986: MEETING WITH VERMONT YANKEE TO REVIEW CONTAINMENT STUDY i e SEPTEMBER 23, 1986: NRC/IDCOR MEETING ON BWR/ MARK 1 ANALYSES e SEPTEMBER 23, 1986: ACRS SUBCOMMITTEE ON CONTAINMENT PERFORMANCE TO DISCUSS HARPERS FERRY WORKSHOP RESULTS AND BW CONTAINMENT GENERIC APPROACH e SEPTEMBER 24, 1986: ACE: SUBCOMMITTEE ON CLASS 9 ACCIDENTS TO DISCUSS BWR/ MARK 1 ANALYSES AND SEVERE ACCIDENT PROGRAM e NOVEMBER 19, 1986: CRGR REVIEW OF DRAFT GENERIC LETTER ON BWR CONTAINMENT REQUIREMENTS (T0 BE PUBLISHED FOR COMMENT) e DECEMBER 17, 1986: ISSUE DRAFT GENERIC LETTER ON BWR CONTAINMENT REQUIREMENTS FOR PUBLIC COMMENT e april 1987: ISSUE FINAL GENERIC LETTER ON BWR CONTAINMENT -
REQUIREMENTS P
> , , - , , - - - - e n,,-
, ,,,.--,_n----
~
-? . EtJ CunuRE #3
~.
SEVERE ACCIDENT CONTAINMENT POLICY
' INDUSTRY EVALUATIONS 1
4 i SEPTEMBER 11, 1986 BETHESDA, MD,
E se
~
OBJECTIVES: .
o PRESENT RESULTS OF IDCOR/BWROG 8 UTILITY EVALUATIGIS OF PROPOSED SEVERE ACCIDEllT CONTAINMENT POLICY ELEMENTS
~
o DISCUSS CONCLUSIONS REACED BY UTILITIES
CONCLUSIONS - BWR EXECUTIVE MEETING
)
o AUGUST 19 MEETING - 20 0F 23 BWROG UTILITIES REPRESENTED o CONTINUE CONSTRUCTIVE DIALOGUE WITH NRC o AGREEMENTS:
COMMIT T0 IMPLEMENTATION OF REVISION 4 TO EPGS NUMARC CONTACTED TO CONSIDER SEVERE ACCIDENT CONTAINMENT ISSUE AS A GENERIC INDUSTRY ISSUE CONTINUE WORKING WITH NRC TO BETTER DEFINE ISSUES FOR RESOLUTION PROPOSE TO BWROG SEVERE ACCIDENT INSIGHT
-REVIEW 0F EPG REV. 4 l
l
t 9 IDCOR/BWROG/ UTILITY EVALUATIONS:
o WIDE VARIATION IN ESTIMATED COST o EVALUATIONS PERFORMED ON SMALL NUMBER OF PLANTS o OBJECTIVES APPEAR GENERIC - EllHANCEMENTS APPEAR PLANT SPECIFIC o QUALITATIVE ASSESSMENTS OF BENEFITS AND NEGATIVE IMPACTS PERFORMED We .
s
- - ~ - - - - ~ - -,, - ,
~
ELEMENT I - HYDR 0GEh OBJECTIVE: PREVENT HYDR 0 GEN COMBUSTION CAUSED FAI LURE REQUIREMENTS:
A. 0XYGEN CONTROL (MARK I AND NARK II)
B. HYDROGEN CONTROL (MARK III)
IDC CR/BWROG EVALUATIONS:
o 0XYGEN CONTROL BY NITROGEN INERTING ADEQUATE FOR MARK I AND MARK Ils, o LIMITING THE TIME DEINERTED UNDER REVIEW.
O MARK III HYDROGEN CONTROL BEING ADDRESSED BY HYDROGEN. CONTROL 0WNERS' GROUP (HC0G).
l
i 1
HYDIOGEN CONIROL CITERS GROUP S11UGEGY TO ADDRESS SENERE N APD STATIN BIJGXFr
< s MEETING Wrs 1EE NRC W SENERE pnesfTS BE"rmmg s
SEP5MBER 11, 1986 1
v - - - -- - ,, , ---- .,,.-, .,,, - , n -.---- - - - -- - . - -,-- - -.-,- - --- n. - - ,
BACKGRut2O
- E::tablished HCOG Progres to address Hydrogen Rule requirenents for
" Degraded Core Accidents".
- Quarter Scale Testing Program
- Analytical effort
- Station Blackout as a hydrogen generation event (HGE) within the context of recoverable degraded cores is an issue being addressed.
- Current HOOG evaluation indicates that SBO is not a credible HGE
- HCOG responding to NRC questions
- %e need for an independent power supply.for igniters in the event of an SBO identified by the NRC in'the context pf Sekre Accidents.
i 1
0 e
a~
t l l
1
's a :
r ,
BOOG Pa20 SAL 100G to supply the design criteria for a backup power supply to the hydrogen igniters.
- Backup power supply need not be safety related
- Identify impact of addressing Severe Accidents on the design of a backup power supply.
- Ntzrber of igniters required in the event of an SBO
- Make use of existing data base and criteria
- Additional testing, only if necessary, to follow cmpletion of current Test Program - end of this year Responsibility of individual Mark III Owners with support of HOOG as required.
- Define backup power supply source
- Define associated costs
- - Meet and discuss with the NRC the details of the design, costs,
- and benefits of a backup power supply to the igniters l
- Decisicm and timing for proceeding
,-r
ELEMENT 2 - SPRAYS GJECTIVE: SPRAY WATER TO:
~
- 1. QUENCH DEBRIS (PRIMARY)
- 2. SCRUB AEROSOLS (SECONDARY)
- 3. LNER PRESSURE (SECONDARYJ I4. COOL VULNERABLE EQUIPMENT (SECONDARY)
REQUIREMENTS:
- 1. SPRAY IN DRYWELL
- 2. BACKUP WATER SOURCES AND PUMPS
- HOSE CONNECTIONS
- USE OF FIREPAINS IDCOR/BWROG EVALUATIONS:
o TYPICAL SPRAY CAPACITY 5 - 10,000 GPM/ HEADER o CONCEPTS CONSIDERED o CONNECTION TO H0SE STATIM IN REACTm BUILDING l - APPR&IMATE FLN PROVIDED 200 GPM
- - DES NOT PROVIDE SPRAY 4
.- ELEMENT 2 - SPRAYS (Continued) o CROSS TIES FROM DIESEL FIRE PUMPS TO RHR
- APPROXIMATE FLCW PROVIDED 1/2 0F FIRE ,
PUMP RATING
- CLOSE OFF APPROXIMATELY 70% T N0ZZLES T0 ACHIEVE SPRAY o FLOW RATES IDENTIFIED APPEAR ADEQUATE o DEBRIS QUENCHING DOES NOT REQUIRE SPRAY o POTENTIAL BEllEFIT/ RISK WARRANTS FURTHER STUDY O
de e
ELEMENT 3 - PRESSURE f'
OBJECTIVES: 1. AVERT IJNCONTROLLED OVERPRESSURE FAILURE
- 2. CONTROL RELEASE PATH (SCRUBBING)
REQUIREMENTS:
- 1. SUBSTANTIAL CAPABILITY TO VENT WETWELL
- 2. REMOTE / RELIABLE CONTROL OF VENT VALVE
- 3. ABILITY TO RECLOSE VENT IDCOR/BWR0G EVALUATIONS:
o C0llCEPTS CONSIDERED o UPGRADE DUCTING AND STANDBY GAS TREATMENT SYSTEM (SBGTS) TO CONTAINMENT DESIGN PRESSURE CAPABILITY
- NOT FEASIBLE TO UPGRADE SBGTS 0 HARDPIPED BYPASS AROUND SBGTS ,
o HARDPIPED DEDICATED VENT l
l 0 COSTS ARE C(MPARABLE FOR HARDPIPED (PTICNS i
l
ELEMENT 3 - PRESSURE (Continued) o VENT SIZING UNDER REVIEW o ATWS Ms m @@Cu o DHR 5" #g%-
o NEGATIVE IMPACTS NEEDING FURTHER REVIEW o SECONDARY CONTAINMENT CONTAMINATION O DELIBERATE RELEASE 5
I
- ELEMENT 4 - CWE DEBRIS OBJECTIVE: REDUCE LIKELIHOOD E FAILURE BY DIRECT ATTACK .
REQUIREMENTS:
- 1. USE PRACTICAL DEBRIS RETARDING BARRIERS
- 2. CWSERVE SUPPRESSIm POOL WATER AS A QUENCHING POOL IDC m/BWR03 EVA LUATI WS:
o DRYWELL o CONCEPTS CONSIDERED PLUG IN PEDESTAL OPENING INCREASE SUMP SIZE INSIDE PEDESTA L CURB QJTSIDE PEDESTA L OPENING CURB AT DRYWELL LINER / FLOOR JUNCTION ADDITIWAL PEDESTAL OPENINGS TO PROMOTE EVEN DISTRIBUTION o NEGATIVE IMPACTS LOCA CMSIDERATIONS SEISMIC INTERACTI WS ALARA CmCERNS
"[ -
ELEMENT 4 - CORE DEBRIS (Continued) c QUA LITATIVE BENEFIT LOW DEPENDENT' ON ANALYTICAL M(DELS OF DEBRIS -
MOBILITY WHICH ARE VERY UICERTAIN o WETWELL o MCST PLANTS CURRENTLY HAVE CAPABILITIES TO HOLD WATER IN TORUS CHAMBER OR PROVIDE PROTECTIm TO CRITICAL EQUIPMENT IN C mNER R0WS o QUALITATIVE BENEFITS LOW o N0 NEGATIVE IMPACTS o NO FURTHER STUDY WARRANTED l
r ELEMENT 5 - TRAINING AND PRIEDURES
@JECTIVE: ENSURE TERATCRS ARE READY TO USE PLANT FEATURES TO BEST ADVANTAGE IN SEVERE ACCIDENTS REQUIREMENTS:
- 1. C LEAR SYMPT 0i BASED STRATEGIES (INTEGRATED)
- 2. REMOVAL OF UNNECESSARY INHIBITIWS
- 3. TRAINING /PREEDURES IDCOR/BWROG EVALUATIONS:
o REV. 4 IMPLEMENTATION BY AL1 UTILITIES C WSISTENT WITH PREVI OJS PGT-TMI COMMITHENT o PROPGE REVIEW 0F REV. 4 WITH INSIGHTS FRm SEVERE ACCIDENT STUDIES l
i
4
.I CONCLUSIONS - BWR EXECUTIVE MEETING o AUGUST 19 MEETING - 20 0F 23 BWROG UTILITIES REPRESENTED -
o ~ CONTINUE CONSTRUCTIVE DIALOGUE WITH NRC o AGREEMENTS:
COMMIT TO IMPLEMENTATION OF REVISION 4 TO EPGS NUMARC CONTACTED TO CONSIDER SEVERE ACCIDENT CONTAINMENT ISSUE AS A GENERIC INDUSTRY ISSUE CONTINUE WORKING WITH NRC TO BETTER DEFINE ISSUES l FOR RESOLUTION PROPOSE TO BWROG SEVERE ACCIDENT INSIGHT
. REVIEW 0F EPG REV. 4 We'
=
9 I
+ - - - .-, . - - - - . , , . - . - . , - . - - . - - , . -n-------.. --- -.-- --
/
EhcRbsonClobc Boston. Massachusetts 02 07 Te'ephore 617 929 2000 Decembe r 29, 1996 Donnie Grimsley, Director FREtiDOM OF lNr'ORMAlk)M Division of Rules & Records ACT REQUEST U.S. Nuclear Regulatory Commission ~
Washington, D.C. 20555 ["/
h /g/ .p Re: Freedom of Information Act Request
Dear Mr. Grimsley:
7-Pursuant to the Freedom of Information Act. 5 U.S.C. 552 ey. seq., I hereby request that you provide me with copies of the following documents:
All NRC documents relating to the Public Service Co. Of New planning Hampshire's zone at Seabrook. proposed reduction of the emergency That would include summa ries of meetings with the applicant, discussions with Brockhaven National Laboratory on its review of Seabrook studies and other relevant material.
I would also like any documents on changes to containment that NRC is considering for General Electric plants generally, and to Pilgrim and Vermont Yankee in particular.
All documents regarding the inspection of Pilgrim I since its shutdown in April.
In the event that the search and reproduction fees involved in complying with my request do not exceed the sum of $25.00, I would be grateful if you would send me copies of the documents requested along with your statement of search and copying charges. In the event that those fees do exceed the som of $ 25.00, I would be grateful if you would inform me of the total charges :.
advance of fulfilling my request.
_hj 9{'
m_.
E Mr. Donnie Grimsley December 29, 1986 Page two.
Thank you in advance for your anticipated cooperation in this matter. I shall look forward to
' receiving your response to this request within 10 days of car receipt of it.
Si cerely, Larry Tyb Globe Staff 1
I I
l
{
t i
e