Regulatory Guide 1.3
| ML13350A383 | |
| Person / Time | |
|---|---|
| Issue date: | 06/30/1973 |
| From: | US Atomic Energy Commission (AEC) |
| To: | |
| References | |
| RG-1.003, Rev 1 | |
| Download: ML13350A383 (12) | |
.!aRevision
1PU.S. ATOMIC ENERGY COMMISSION
REGULATORY
DIRECTORATE
OF REGULATORY
STANDARDS
Revision IJune 1973GUIDEREGULATORY
GUIDE 1.3ASSUMPTIONS
USED FOR EVALUATING
THE POTENTIAL
RADIOLOGICAL
CONSEQUENCES
OF A LOSS OF COOLANT ACCIDENT
FOR BOILING WATER REACTORS'
A. INTRODUCTION
S.'i'Cllil
50..;,I fI I('FR PlaII 50( eiliuir ls th:t each:1pl'icailll l a ,oittl t lrlic n pli ltm l ilil or olperaling 'ro',idtc an :!lhlvsis mtid evahaltion ol" the design andpl' ci; Iiiice of1 sitlicitlres.
anld Components ofihtc I:,,iility with the otive t" assessing the risk tolputllic h10:1t ll :aitd -:lfelv resl frm Im , oporation ol'thelaTilily.
"h" de:;ipi basis loss (of' coolant accidentl()C' A i5 )IliC ,I I p[st lat3ted accidents used 1oevaluate fil ade(l'iacv ofi these Sliltctures. s. andc..'tIIIpolt0elli s will lrespecl It tile public health safely.This Inidle -,i\'es :,ccepltble assumlptions lhat mavy beiseal ill eva\tial l- tihe radiological ctnsequcuces of' thisaccident for a boiling wlei leactor.
Ill soniLC CLasCs,ntiitsnltal site chlaractelrisltics.
plant dest;i featlres.
orothlr li' l tolls nav:y retqglire dilferetit asstinlotionls w\hichwiill ble Ctiside Led on anl illtividulial case basi
s. TheAdvisoty
('Cimmnitee Oil Reactor S:ile'quards hias been.consul ted con:ernini lt is guide altnd has conceturred in tlieregulatorvy pl ýili inl.
B. DISCUSSION
Arler reviewtitt a titinumber or" applicationls forconslitiet iin ,t nuits mnd opetating licenses for boilingwater reacolos.
tile AEIC Regulaltury staff hasdeveloped a rilniber ofl' appropriately conservalive al, ptinons.
bliscd on en&inecring juidpneni and onapplicable eXperimnenltal results fromn sa 'ty researchprogratus cndudcted by the AEC and(l tie nuclearindustryv.
that are used ti) evaluale calculalions of tlieradiological consequetces of1 various postulated accidelel s.This guide lists acceptable assumptions that may heu-sed to evalutate the design basis LOCA of' a BoilinlgWa enr Rcactor (IIWPR).
It should be shown tlhal tlhetc.,lose cotnsequences will be within the guidelines of I(I CFR Part 100.C. REGULATORY
POSITIONI. aIlle ,ssutllptiotis elatied I ll lte tcle:se o' l;ldia:lct iiiilellit l front1 th11 f0 I andl collt iilnltiill alle ;as I",lfows:
a. "\'i- t l >y-f'ive percent, of tile equilih)iilutn radioactive iodine invetn tory fromt mia\ iliintt!'uitl pow'er opeiatioi of thie core slhuhld IV JssI.niCId
1)he imtncdililely available I'Mti leakaue fioin the primar:iyv reactor conttaiinment.
Nine tV-mit percent ito this 2perceill is to Ile assulmled ito he ill tile 'orto of'ei nlenialiodine. 5 percent of' this 25 percent ill ilic ltOnn oIparticulate ioidine.
and -I p't.eent of this 25 percinti it!lhe l'orit of' orwanic iodides.h. One hluldred percent o1' the eqLlihibritinlt radioaclive nhble gas itnVentorny developed Ir'omllIltaxitiltilM
frill powver of' [lie %:oie should bleassumed it) lb ie tltedialtelv available lot hcakane It'oittle leactol Coll lailllltent.
c. The .os tf' radiolo-ical deca, during holdupinl thle conwaiintient or othet bujildimes should ble taketninto accounltI.
d. 'File reductiotn ill (hle alotii titt ' adioactive mtat.'rial
- ivailfable for leaka! ito the ehnvironineut bvCloln[;,ilmllelln Spray'. recirtuilaing filter ni olhiereneih:eered sai'eity ftatlres mtay be takelil itlno :icclittl, bill the atounit of' reduction ihi concrentiation ofradioactive materiils shotuld be evtlualed on :anildividual case ba:sis.e. Tile primary conllaitnitent should ble assumed toleak at the leak rate incorporated or tio hie incolporated in thie technical specifications f'or the duration ill' [lieaccident.
2 The shotild be assuiited ito passt"'l'iS guiidte is a revision Sate \l Giuide 3.2'lic on containni ent leakaee Iindcr atccid.nl conditio ot" I'e:ttlires protvidted to red ilce t' t':lkatpie of"radioalclive rtatlritits I'roll ItI" t'(l tnlit1inn n Will 11C he' eV3 litt 1 Lilt:nil individual case USAEC REGULATORY
GUIDES Copies of published guides may he obtained by reqcuest indicating the. divisions deilred to the US. Atomic Energy Commisvon.
Washington, D.C. 201545.Rcgulatnry Guides are issued in describe and make available to the public Attention;
Director of Regulatory Stalndards.
Comments and suggestion%
lotmethods accptablte to the AEC Regulatory staff of implementing specilit part- of itiproverienti In theta guidemý ace ancouragd and should be sent to the Secretary the regulations.
tO delineale techniques used by the staff in of the Commitsion, US. Atomic Energy Commission.
Washington, D.C. 20545.ealuating specific problems or postulated accidents, or to provide guidence to Attention:
Chief, Public Proo-redinga Staff.applkOjlnts.
Reoualo.yi Guides are not substitutes for regulations and compliance with them is not requited.
Mrthods and solutions different from those set out in The guides are itsuedt in the fortlowing ten broad divisior.:
the u.-ris will be acceptahle it they provide a basis for the findings requisite tothe llluance or osntinuance of a permit or licante by the Commission.
1. Power Reactors
6. Products2. Research and Test Reactors
7. 'Transrptortation
3. Fuels and Materials Facilities B. Occullationl HeialthPuhllshM
quiewi will hbe revi-id periodically, as aip!iogilate.
to accommodate
4. Environmental ard Siting 9. Antitrust Reviewcornrmenit
4nd in reflect new informatint, or experience.
S. Materials and Plant Protection tO, General
I *directly to the emergency exhaust system withoutmixing' in the. surrounding reactor building atmosphere and should then be assumed to be released as an elevatedplume for those facilities with stacks.4f. No credit should be given for retention ofiodine in the suppression pool.2. Acceptable assumptions for atmospheric diffusion and dose conversion are:a. Elevated releases should be considered to be ata height equal to no more than the actual stack height.Certain site dependent conditions may exist, such assurrounding elevated topography or nearby stnictures which will have the effect of reducing the actual stackheight. The degree of stack height reduction should beevaluated on an individual case hasis. Also. specialmeleorologicaI
and geographical conditions may existwhich can contribute to greater ground levelconcentrations in the immediate neighborhood of astack. For example.
fumigation should always beassumed to occur: however.
tlh- length of time that arumigation condition exists is strongly dependent ongeographical and seasonal factors and should beevaluated on a case-by-case basis." (See Figures I Athrough ID for atmospheric diffusion factors for anelcvated release with fumigation.)
b. No correction should be made for depletion ofthe effluent plume of radioactive iodine due todeposition on the ground. or for the radiological decayof iodine in transit.c. For the first 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, the breathing rate ofpersons offsite should be assumed to be 3.47x 10'cubic meters per second. From 8 to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following the accident, the breathing rate should be assumed to be1.75 x 104 cubic meters per second, After that until theend of the accident, the rate should be assumed to be2.32 x 10-4 cubic meters per second. (These values weredeveloped from the average daily breathing rate 12 x 107cm3/dayl assumed in the report of ICRP, Committee
11-1959.)
31n some c-ases, credit fur mixing will he allowed:
however.the amount of credit allowed will be evaluated on an individual case basis."Credit for an elevated release should be given only if thepitnt of release is (I) nire than two and one-half times theheight of any structure close enough to afrect the dispersion ofthe plume, or (2) located far enough from any structure whichcould have an efrect on the dispersion of the plume. For thoseIt\R's without stacks the atmospheric diffusion factorsassuming pround level release given in section 2.h. should be usedto determine site acceptability.
For sites located more than 2 miles from large bodies ofwater such as oceans or one of (the Great takes. a fumigation condition should be assumed to exist at the time of the accidentand continue for one-half hour. For sites located less than 2miles from large bodies of water, a fumigation condition shouldbe assumed to exist at the time of the accident and continue for4 hours.d. The iodine dose conversion factors are given inICRP Publication
2, Report of Comtmittee i1."Permissible Dose for Internal Radiation."
1959.e. External whole body doses should be calculated using Infinite Cloud" assumptions.
i.e.. the dimensions of the cloud are assumed to be large compared to ihedistance Ihat Ihic gamma rays and beta particles travel."Such a cloud would be considered atn infinite cloud fora receptor at the center because any additional (gammaandi beta emitting material beyond t(le clotuddimensions would not alter the flux of Igatmna raysandl beta particles to the receptor"
(Meteorology andAtomic Energy, Section 7.4.1.1-editorial additions made so that gamnma and beta emitting material could beconsidered).
Under ihese conditions the rate of energy.absorption per unit volume is equal to the rate ortenergy released per unit volume. For an infinite uniform cloudcontaining X curies of beta radioactivity per cubic meterthe beta dose in air at the cloud center is:D. = 0.457 EThe surface body dose rate from beta emitters in theinfinite cloud can be approximated as being one-half thisamount (i.e.. 01D- = 0.23 EOX).For gamma emitting material the dose rate in air at thecloud center is:DA= 0.507 E rXFrom a semi-infinite cloud. the gamma dose rate in airis:S=o.2s ExWhereD= beta dose rate from an infinite cloud (rad/sec)
DE= gamma dose rate from an infimite cloud(rad/sec)
EO = average beta energy per disintegration (Mev/dis)
Ei = average gamma energy per disintegration (Mevldis)
X = concentration of beta or gatnma emittingisotope in the cloud (curie/mr
3)f. The following specific assumptions areacceptable with respect to the radioactive cloud dosecalculations:
(I) The dose at any distance from the reactorshould be calculated based on the maximunmconcentration in the plume at that distance taking intoaccount specific meteorological, topographical, andother characteristics which may affect the maximiumplume concentration.
These site related characteristics
1.3-2 must be evaluated on an individual case basis. In the caseof beta radiation, the receptor is assumed to be exposedto an infinite cloud at the maxinmum ground levelconcentration at that distance from the reactor.
In thecase of gamma radiation, the receptor is assumed to beexposed to only one-half the ckud owing to tciepresence of' the ground. Tile maxinmm cloudconcentration always should be assumed to be at groundlevel.(2) The appropriate average beta and gamniaenergies emitted per disintegration, as given in the Tableof Isotopes.
Sixth Edition, by C. M. Lederer.
J. M.Hollander, I. Perhlan;
University ofCalifornia.
Berkeley:
Lawrence Radiation Laboratory:
should be used.g. For BWR's with stacks the atmospheric diffusion model should be as follows:(I) The basic equation for atmospheric diffusion from an elevated release is:exp(-h2/2Oz 2)VQ Tu y 0zWherex = the short term average centerline value of theground level concentration (curie/meter
3)Q = amount of material released (curie/see)
u = windspeed (meter/sec)
Gy = the horizontal standard deviation of theplume (meters)
[See Figure V-i. Page 48.Nuclear Safety, June 1961, Volume 2.Number 4, "Use of Routine Meteorological Observations for Estimating Atmospheric Dispersion,"
F. A. Gifford, Jr.)z= the vertical standard deviation of the plume(meters)
[See Figure V-2. Page 48, NuclearSafety, June 1961, Volume 2, Number 4,"Use of Routine Meteorological Observations for Estimating Atmospheric Dispersion,"
F. A. Gifford, Jr.)h = effective height of release (meters)(2) For time periods of greater than 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />sthe plume from an elevated release should be assumed tomeander and spread uniformly over a 22.50 sector. Theresultant equation is:2.032 exp(-h2/2oz2)x/Q =Wherex = distance from the release point (meters);
other variables are as given in g(1).(3) The atmospheric diffuision model' for anelevated release as a function of the distance from thereactor, is based on the information in the table below.TimeFollowing AccidentAtmospheric Conditions
0-8 hours See Figure 1(A) Envelope o1" Pastluill diffusion categories based oil Figure A7NI 'teorolog'
and Atomic I-netryo I tt(,1 ,assuming various stack heights:
vindspeed Ime ier/see;
uniform direction.
8-24 hours See Figure ItB) lEnvelope of Pasquilldiffusion categories:
windspeed I meter/see:
variable direction within a 22.5 sector.1-4 days See Figure I[C) Envulope of Pasquilldiffusion categories with the following relationship used to represent maximnnumn plume concentrations as a tumeltion of'distance:
Atmospheric Condition Case I40Y Pasquill A601'} Pasquill CAtmospheric Condition Case 250% Pasquill CPasqtill DAtmospheric Condition Case 333.3',` Pasquill C33.3% Pasquill D33.3% Pasquill EAtmospheric Condition Case 433.3!, Pasquill
1)33.3, Pasquill E33.3K- Pasquill FAtmospheric Condition Case 550r', Pasquill D501? Pasquill Fwind speed variable (Pasquill Types A. B. E.and F windspeed
2 memer/sec:
PasquillTypes C nid D windspeed
3 meter/sec)
variable direction within a 22.5" sector.4-30 days See Figure I(D) Same diffusion relations asgiven above- windspeed variable dependent on Pasquill Type used; wind direction
33.3"frequency in a 22.50 sector.11This model should be used until adequate sitemeteorological data are obtained.
In smote cases. avaitable information, such as meteorology, topography and geographical location.
may dictate the use of a more restrictive model toinsure a conservative estimate of potential offtsite exposures.
1.3-3 Ih. For BIWR's without stacks dhe almospheric diffusion inodel6,should be as follows:(I) The 0-8 hour ground level releaseconcentrations may be reduced b'y a factor ranging fromone to a nlaximum of three (see Figure 2) for additional dispersion produced by the turbulent wake of thereactor building in calculating potential exposures.
Thevolumetric building wake correction factor, as defined insection 3-3.5.2 of Meteorology and Atomic Energy1968, should be used only in the 0-8 hour period; it isused with a shape factar of 1/2 and the minimumcroms-sectional area ot the reactor building only.(2) The basic equation for atmospheric diffuision from a ground level point source is:x/0 =41U y ozWherethe short term average centerline value of theground level concentration (curie/rmeter
3)Q amount of material released (curie/see)
u windspeed (meter/sec)
O y =the horizontal standard deviation of theplume (nieters)
[See Figure V-I. Page 48,Nuclear Safrity.
June 1961, Volume 2.Number 4. "Use of Routine Meteorological Observations for Estimating Atmospheric Dispersion,"
F. A. Gifford.
Jr.]ID =the vertical standard deviation of the plume(meters)
ISee Figure V-2, Page 48.Nuclear Safety, June 1961, Volume 2, Number 4."Use of Routine Meteorological Observations for Estimating Atmospheric Dispersion,"
F. A. Gifford, Jr.](3) For time periods of greater than 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />sthe plume should be assumed to meander and spreaduniformly over a 22.5" sector. The resultant equation is:2.032X/Q =azUX*Whe rex = distance from point of release to the receptor;
other variables are as given in h(2).(4) The atmospheric diffusion model forground level releases is based on the information in thetable below.Ti meFollowing AccidentAtmospheric Conditions
0.8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Pasquill Type F, windspeed I meter/see, uniform direction
8-24 hours Pasquill Type F, windspeed
1 meter/see, variable direction within a 22.50 sector1-4 days (a) 40% Pasquill Type D. windspeed
3meter/see (b) 60% Pasquill Type F, windspeed
2meter/sec (c) wind direction sectorvariable within a 22.504-30 days (a) 33.3% Pasquill Type C, windspeed
3meter/sec (b) 33.3% Pasquill Type D, windspeed
3meter/sec (c) 33.3% Pasquill Type F, windspeed
2meter/sec (d) Wiind direction
33.3% frequency in a22.5' sector(5) Figures 3A and 3B give the ground levelrelease atmospheric diffusion factors based on theparameters given in h(4),I I A
10-3SELEVATED
RELEASEATMOSPHfERIC
DIFFSON FACTORSS,0-8 HLJUR RiEtASE TIME* .FIGURE 1VA)10-4S10-5 _......_ .....L ..÷ .7. -Vb.... .. ... .......10-4S- .d_........___.....I
-1 --*.102 103 10410Distance from Release Point (meters)1.3-5
- -o : -T -r----.-
... -.... ................
II .........
' --10-310-io2 iO3 o oDistance from Release Point (meters)z -6i
.% -'Np..1ATMC.-LEXMATF&ULEASt.
.kSH9R1C--D##ISMQ
FACTORS1-4.C)A'Y.R:1LASE
Tljfg.~FIGURE M()--t.................
.*10-10-5E001010... .. ..Ii i.. ..I '*1* [ ....-4-2I I " /'---S --------sk TfI1It40#
1tI------------
L- ..I ýi ISI.:zzjzz~~I~
VL~~I XA¶N.AIX-IIJpii:.i:F [ IxI '%71 ..1 1f-NI0l10-8102103Distance from Release Point (meters)1.3-7
- .. 4EUiVA"~bRIES
ATAMSW ON f-ORTtM..........
- S* .,. ..~4-110-5i10-IL -L.4 -4T V : J. _ _7jI x___I Iv. I4N.NINi-- -------7:'.I~w z..L.JI102103.1o4Distance from Release Point (meters)1.3-8 r, EtVAMD. RELEASEATMOSPHERIC
DISPERSION
FACTORSFOR .FUMIGATION
qONDITIONS
-ATMOSPHER
IC CdiNDITIONgS.
PASOUILL
TYPE FWINDSPEED
I METER/SEC
" F1GUHE It ......10-2i;h 60 ..... ..0C,,10-... ..... .. .............
i i:Tj .7 : i.....................................
,.. ..... .. ..-.I : aw~ H-F-9 WTNI,.A7-n LTL4-. 4--410-510-6102103104105Distance from Release Point (meters)3..9)
w ~K"i32.5 h----00u0racc5iFIGU^R'E
2 1 :T .I-._ ... .. ...M. :Ii-77 It* I-I..* I I* I0.50102St.ii 3; 1* I-i.1. iTd~36i102104Dlsnme from Structur (won W~0.-
I AU V .-- ._.-.- ..I~ AVARIOUS TIN ESF LC14HN CI TFIGURE V(A)L-18-24 hours .~10a3 10 10Distance from Structure Imeters)10-5 L102
-lA0TMOSERL~qIF
LLStOq Fibt~ .~ ~ .~... .. .. ..VARIOUS
TIMES FOULOWING
IAC Ir INT~ .~-.. FIGURE 3B) 300-8 hours....................
..43.............................
~~. ......ta .I JII. .... ......I. i4 -t103 10LLDit6Ic fromzz Stutr (meters