ML19318B605

Forwards Statement of Interim Policy,On Accident Considerations Under Nepa,For Publication in Fr.Statement Discusses Commission Position Re Including Considerations for Future EIS

ML19318B605
Person / Time
Issue date:	06/06/1980
From:	Harold Denton Office of Nuclear Reactor Regulation
To:	Dingell J, Hart G, Moffett T, Udall M HOUSE OF REP., GOVERNMENT OPERATIONS, HOUSE OF REP., INTERSTATE & FOREIGN COMMERCE, SENATE, ENVIRONMENT & PUBLIC WORKS
References
FRN-45FR40101, RULE-PR-50, RULE-PR-51 NUDOCS 8006270163
Download: ML19318B605 (13)

Text

. -

f A'M upISTRIBUTION K ENTPAL FILE DEisenhut FNRR R/F RVollmer AEB R/F SHanauer H0enton WKreger

.... g '. 90 EGCase WHouston Dross RMattson PFine AFerguson-NRR 405B The Honorable Gary Hart, Chairman BSnyder LKriesel Subcomittee on Nuclear Regulation

• BGrimes CPaul Comittee on Environment and Public Works PDR United States Senate SECY Washington, DC 20510

Dear Mr. Chairman:

Enclosed for your infbmation are copies of a Statement of Interim Policy, on Accident Considerations Under NEPA, which is to be published in the FEDEPAL REGISTER. This statement sets forth the Comission's position that its future Environmental Impact Statements shall include considerations of the site-specific envimnmental impacts attributable to accident sequences that lead to releases of radiation and/or radioactive materials, including sequences that can result in inadequate cooling of the reactor fuel and to melting of the reactor core.

Public coment on this statement is being invited during the 90 day period following publicatfor, in the FEDERAL REGISTER.

Sincerely, y,pT.';=GW

11. 3. Int:2.)

Harold R. Denton, Director Office of Nuclear Reactor Regulation

Enclosure:

Statement of Interim Policy cc: The Honorable Alan Simpson IDENTICAL LETTER SENT TO:

THE HONORABLE f!0RRIS X. UDALL, US HOUSE OF REPRESENTATIVES CC: THE HONORABLE STEVEN SYtif1S 1

THE HONORABLE JOHN 0. DINGELL, US HOUSE OF REPRESENTATIVES CC: THE HONORABLE CLARENCE J. BROWN THE HONORABLE TOBY f!0FFETT, US HOUSE OF REPRESEf}TATIVES THIS DOCUMENT CONTAINS CC: THE HONORABLE PAUL N. MCCLOSKEY, JR.

\\; w W

P0OR QUAUiY PAGES On 8006270 DSI:RP f h '(( M N YGC e HR nton

.s^

.t,

OSI:AEB' DSIkI N

RWHoust6n!cspWEr 'ege 6

'0FRef

.NR

'.~

o"'cc >

SURNAMEh.b/2[bb..

. b['-[ b-b[ [00*

' b[ *[bO'

' b[ '[SO' Y'

OTe>.

NIC FORM 318 (9 76) NRCM 0240 NU.S GovCRNMENT PRINTING OFFICE: 1979 289 369

, n

._r

,s 1$ $

G^al ' ' ' Ic;. *Ct ;I a;ulatory Cc missi:n

- E : -

U.S. *:acicar r

~~.:

tat: ant of *ntarin Policy T. '3:.Y : The Nuclear Regulatory Ccrmission (NRC) is revising its poli:y for ansidering the nore sevare Linds of cery low probability accidants that are

-hysically possible in envircc.antal i pact assessrents required by the

':3:icnal Environnental policy 'ct l'.E 0A ).

Such accidents are conmonly refer-red to as Class 9 accidents, follo..ing an accident classification schere nn; sad by the 't; sic 7ncegy Co: mission (preiecessor to NRC) in 1971 fo r

sepeses of i plenenting NEPA.

The " arch 23, 1979 accident at Unit 2 of the Three ile Island nuclear plant has erphasized the need for chances in NRC policies regarding the considerations to be given to serious accidants fren an environnental as well as a safety point of view.

This statement of interin policy announces the withdrawal of the proposed a.nex to Appendix D of 10 CFR Part 50 and the suscension of the rulenaking r

roceeding that began with the publication of that proposed Annex on December 1, 1971.

It is the Com. mission's position that its Environrental :rpact State-ments shall include considerations of the site-specific environmental iroacts attributable to accident sequences that lead to releases of radiation and/or radioactive raterials, including sequences that can result in inadequate cooling of reactor fuel and to nelting of the reactor core.

In this regard, attention shall be given both to the probability of occurrence of such releases and to f Frerosed as an Annex to 10 CFR Part 50, Appendix n, 35 FR 22851.

The Commis-sion's NEPA-irplerentina regulations were subsequently (July 18, 1974) revised and recast as 10 CFR Part 51 but at that time the Commission noted that "The Preposed Annex is still under consideration..."

39 FR 26279.

_t,.

~

.q

..t....,

_e ;

. - 3, 4 r.,,

s - s.

2

...,.._,x....c c... :

m..2

r.... i..e

"=r

'=..n r.-

c '..

v

=

t..,.. : _.,. e r...,

2, s

.......c..,..

n. 4.a c.s

-.tierations are in place.

2 ~ E S,:

c---':nt period eraires PESSES: The CO: mission intends the interin policy guidance cantained

'erein to be irrediately effective. Pc.iever, all interested persons who desire to subnit. ri: ten c rments or suc estions for consideration in con-sJ nection with this stitEcent sSculd send then to the Secretary of the Cc~nis-sion, U.S. "uclear Oegula tory Canaission, '.'ashington, D.C.

20555, Attention:

,oc. s.1og and dervice,-ranch.

FOR FURTHER I:,FORP.ATIO'! CC" TACT:

R. '..'ayne Houston, Chief, Accident Evalua-tion Erench, Office o f *.'uc1 car Reactor Regulation, U.S. !'uclear Regulatory Cc--i s s i on, ',!a s hi n gton, D. C.

20555, Telephone:

(301) 492-7323. F

~.

,e

... +

...c 7,,]Y-j.,

6 ; =.

'r-....'

e..

o.

~

i ':

'I.

It -

?5id to c rrcify a set of s tand3rdi:3d SCcidbnt 5 ' ~"~#: Ps 4

5.:ir. E".

_ tal ?:pGrts subnit'ed by 3f riicants for COnstruc; ion

. :rmits or :;2:stin; licenses for nuclear c.cer rsectors.

It also included a

r te- #

r cl assi fying eccid2'its accordirig to a ;qded scale of severity and

- cbability of occurrence.

• ine classes cf accidents tere defir,ed, ranging

'com trivial to very serious.

It directed that "fcr each class, exceot c' esses 1 and 9, the environ ental consequences shall be evaluated as indicated."

Class 1 nents e.ere not to be considered because of their trivial consequences, hereas in regard to Class 9 events, the Annex stated as follows:

"The occurrences in Class 9 involve sequences of postulated successive failures rore severe than those postulated for the design basis for protective systens and engineered safety features. Their consequences could be severe. Howiever, the probability of their occurrence is so sr.all that their environmental risk is extremely low.

Defense in depth (multiple physical barriers), quality assurance for design, nanu-facture, and cperation, continued surveillance and testing, and con-servative desien are all applied to provide and naintain the required high degree of assurance that potential accidents in this class are, and will racain, sufficiently renote in probability that the environ-nental risk is extrenely low.

For these reasons, it is not necessary to discuss such events in applicants' Environ ental peports."

A footnote to the Annex stated:

"Although this annex refers to applicant's Environnental Reports, the current assumptions and other provisions thereof are applicable, except as the content may otherwise require, to AEC draft and fir.al Detailed State ents."

During the public cor ent period that followed publication of the Annex a number of criticisms of the Annex were received. Principal arong these were the following:

~

~

.r*

~'

r 1

il;I*s SI,- en

'.C

. :. ' hat C'as: 3 ac;#: ~:

Is#'.. ' !I; I.,

P ;

5 ;il i ty

_'.a t t',ei r c:' I t c,se r :es i n I cf ;

• ~;'tal ris'.s.:ed not be discusied.

d)

Ji. 'c3.as gi/en as to Ec',

S c.l ien t a r.d n0 r~31 rCl i F i! o#

-dir.a:: ce ere'uents during plant c;eration should he ':,ctared ir,tc the ::s:-banefit analysis.

'5) The accidsnt assu ptions are nat ;5: e< ally apolicable to gas ::: led or liquid etal cooled eactcrs.

(5) Sa'ety and en'.iror ental risks are not essentially different considerations.

• 2f ther the 'tenic Ir.er:y Carmission nor the '.7C took any further action on this rul; aling e> cept in 197c '. hen 10 CFR rart 51 was pronulgated.

Over the intercening years the accident considerat!ans discussed in Environnental Irpact Stati ents for proposed nuclear po.-;er plants reflected the guidance of the Annex with few exceptions.

Typically, the discussions of accident consecuences through Class 8 (design basis accidents) for each case have reflected specific site cSiracteristics associated tith reteorology (the dispersion of releases of radicactive aterial into the atr: sphere), the actual population within a 50-mile radius of the plant, and scr.e differences between boiling water esactors (E"R) and,;ressurized vater reactors (F'.!P.).

Beycnd these few spec-ifics, the discussions have reiterated the guidance of the Annex and have relied upon the Annex's conclusion that the probability of occurrence of Class 9 event is too low to warrant consideration, a conclusion based upon generally stated safety considerations.

_a_

.. :7

+

~.

- ' : ' es: ::n s- : - if 2: :

3n

't7 ii 'I $: :1 '::ed

c' e a r -.ar -1

nt 2cci'ints, 3rti:f arly

?

't!

nich can 1:cd to :Se elting of the fuel incide a reactor.' The c 2 'a r.*.t es to thi s s tu dy..e re in ' eepir.c.i:h t 9:,-.en: and spirit of *:E?A to Siscicse" rele. ant in formation, Sut it is cbvic us that L.* ASH-laCC did not

'crn t"e basis for the corclusion expres red in the Annex in 1971 that the probability of occurrsnce sf Class 9 e'. ants..as too low to 1. arrant their (site-specific) consideration under *: EPA.

TFe Corc.ission's staff 'as, 5 : wever, identified in certain cases unique circunstances which it felt warranted nore extensive and detailed considera-tion of Class 9 events. Cne of these was the proposed Clinch River 3reeder Reactor Plant (CRERP), a liquid metal cooled fast breeder reactor very differ-ent from the nore conventional light water reactor plants for which the safety experience base is much broader.

In the Final Environmental Statenent for the CR8RP, the staff included a discussion of the consideration it had given to Class 9 events.

In the early site review for the Parry an site, the staff perforned an infornal assessnent of the relative differences in Class 9 accident conse-quences among the alternative sites.

(SECY-78-137)

In the case of the application by Offshore Pcwer Systens to nanufacture floating nuclear power,_ plants, the staff judged that the environmental risks 2

It is of interest that the Reactor Safety Study never refers to nor user the term " Class 9 accident" although this term is commonly used as loosely equivalent to a core nelt accident.

3 NUREC-0139, February 1977.

+

4

.~

.3 s'l) t r a r. : ' t. '

f ce

M.-w. r > t% :

.s:.;

=

4

'l' id}

s':-:':g -'

~ :' ai.

... c s s i # a -: i :;n

.ur.;-s t b ". s' 2 * - r

• S f:. :m Fich ::e -Tant #1 cats.

"-ce t"e staf#

.ers.to ' ail i e-Pasized its r.dus on ri:k.to TEE e ire - art ' cat did not find that the

.rctability of aL

tee ei t r.en: cc: c:ng in tb 3 first place was essentially-i iny;di fferent - than - for a lard-t e ssd plant.

In its ?s"3randum and Crder In e.

the :'atter of Off:tsee 5;.ee Syste.ns,' the C:--is sion concurred in the staff's

.judgnant. Thus, the EESctor Safety Study and '!?C experience with these ' cases has served to refocus attention on the need to re:-nphasize that environnental risk: entails both probabilities and consequences, a point that was made in the publication of the' Annex, but.as not given adequate dnphasis.

In July 1977 the NRC connissioned'a Risk Assessnent ?eview Group "to clarify,

}

the achievements. and linitaticns of the Reactor Safety Study." One of the j

conclusions of this study, published in September 1978, as NUREG/CR-0400,

" Risk Assessnent Review Group Peport to the U.S. Nuclear Regulatory Conmission,"

was that "The Review. Group.was unable to determine whether the absolute prob-1 abilities of accident sequences in UASH-1400 are high or low, but believes that the error. bounds on those estinates are in general, greatly understated."

i This-and other. findings of the ' Review Group have also subsequently been refer-

' redito in.Environnental Impact Statements, along with a reference to the 4

- Consission's policy statement on the Reactor Safety Study in light of the-i Risk Assessnent _ Review Group Report, published on January 18, 1979. The LConnission's ~ statenent accepted the findings of the Review Group,- both as to the Reactor: Safety Study's achievements and as to its limitations.

+

' Docket No. STN 50 437, Septenber. 14, 1979.

. d v

V 1

f w

d v

-1 4 =

t-r 1

- ~

y 9

y PT

... ~. - - -

1 e: ?.tr ta:

~ :r-C a :s'inc ett- :^:.

^-

tr s i t. :9.

P-e

=::

s e

"ar i a;;;r-an':

.o ecci ants et suce - :-n s, tu: rotad : Pat the e, scien:e i ':d

~r;- t"e i

'Srse ,ile Island sccident..as r.ot factcred into the disco:sion.

C D2r experience with past NEPA revie'.:s of accidents and the T"I accident i-cl'early leads -us to. believe that a yhange is needed.

Accordingly,-the propcsed Annex to Apperdix 9 of 10 CFR Fart 50, published on j

Decenher 1,1971, is hereby withdrawn and shall not hereafter he used by appli-cants nor by the staff. The reasons for the withdrawal are as follows:

i

-1.

The Annex proscribes consideration of the kinds of accidents (Class 9) that, according to the F.eactor Safety Study, doninate the accident risk.

2.

The definition of Class 9 accidents in the Annex is not sufficiently i.

precise to warrant its further use in-Cor.nission policy, rules, and regulations, nor as a decision criterion in agency practice.

3.

The Annex's1crescription of assumptions to be used in the analysis of

-the environnental-cons'equences of accidents does not contribute to

~ bjective consideration.

i

~

o 1

4 The Annex does not give adequate consideration to the detailed treatnent of neasures taken to prevent and to mitigate the consequences of acci-dents in the safety review of each application.

.The classification of ~ accidents proposed in that Annex shall no longer be used.

i

[

In 'its place ; die following interim guidance is given for the treatnent of--

j'

. accident risk considerations in NEPA reviews.

Accident Considerations in Future NEPA Reviews l

It~is the position of. the Connission. that its Environnental Inpact Statements, 1 pursuant: to Section 102(c)(i). of the National Environnental Policy Act of.1969 shall Linclude-a reasoned consideration of the envircnnental ri.sks (inpacts)

. attributable to accidents at the particular facility or-facilities within the scope!of each;such staterent.

.In. the analysis and discussion-of such risks, t-V L'

i' 'gr

. _, _..._ ; u.,,_

.' f

?:

. - J. / :a-

3

_--27

,e e

.a I' : < > : e r y e n.> i r r.

2rtal s':r:

- a "

' e,

c:

"g S i -

':Sr, M f :..rd..ater, 511 incl;de r;t ot be

.irts or accident secuences that 1 sad to re'easas 1 5

' -'ted to those that can reassnably Se expected to occur;

n-pl an t 3c c f _.2nt

q;ences that can lead to a saectrum of releases shall be discussid 2nd fiall include sequences that can result in inadequate cooling of reactor fuel and to melting of the reactor core.

The extent to thich ivents arising ~ron causes external to t' e plant v.hich are considered ;cssible ccr.tributors to the risk associated with the carticular plant shall also be discussed.

Detailed q:.antitative considerations that form the basis of probabilistic estinates of releases need not be incorporated in the Environrental Inpact State ents but shall be referenced tharein.

Such references shall include, as applicable, r3 ports on safety evaluations.

The environrental consequences of releases.; hose crobability of occurrence has been estimated shall also be discussed in probabilistic terns.

Such' consequences shall be characterized in terns of potential radiological expo-sures to individuals, to population groups, and, where applicable, to biota.

Health and safety risks that may be associated with exposures to people shall be discussed in a manner that fairly reflects the current state of knowledge regarding such risks.

Socioeconomic impacts that night be associated with emergency reasures during or following an accident should also be discussed.

The envircr. rental risk of accidents should also be conpared to and contrasted with radiological risks associated with normal and anticipated operational releases.

_a_

- 7

- u 5 -. _ ;

5 C;

mair. ~ce : i

' 3.:

E Pc:

"5 i-

' il

/ -.. -: n:r n: f :d:. -

" a c - ? u t i:v t: - wil l i e nti fy m l: r

=risinties in t: :

- : :F :t :

9::' stes.

On the other hand the Cc,7 ssion helie'.es that t'e :t3:e

'.f

'e i

Sr.is suf ficicn:iy ai/anced that a bs;inr.ing sbid ':- Ss

>de ir..te.se l

r f these ethodologies in the regulatory process,.3nd that sach use <.ill represent a constructive and rational for..ard step in t's di::harge of its responsibilities.

l It is the intent of the Ccraission in issuing this State :ent of Interin Policy that the staff will initiate treatrents of accident considerations, in accordance with the foregoing guidance, in its ongoinc ';E?A reviews, i.e.,

1 for'any proceeding.at a licensing stage where a Final Environrental Irpact i

1 Statenant has not yet been issued.

These new treatments, which will take j

into account significant site-and plant-specific features, will result in i

mre detailed discussions of accident risks than in previous environmental

)

'statenents, particularly for those related to cinventional light water plants at land-based sites.

It is expected that -these revised treatnants will lead

~

to. conclusions regarding the environmental risks of accidents similar to those that would be reached by. a continuation;of current practices, particularly for cases involving special circunstances where Class 9 risks have been con-

..sidered by' the sta ff, as-described above.

Thus, this change in policy is not. to be construed as any lack of confidence in conclusions regarding the i.

environnental risks of accidents expressed in-any previcusly issued Statenents, nor, absent a showing of_ sinilar special circumstances, as a basis for open-

ing, reopening or expanding any previous.or ongoing proceeding.

3: Commissioners Gilinsky and Bradford disagree with the inclusion' of the Lwith' an even-handed reappraisal _of the former, erroneous position on Class 9 precedi.ng two sentences.

They feel that they are' absolutely inconsistent

~

accidents.

.g.

F Y

7 J-w" 1

vW--t cP

• ri w v v- # 2-tWett 4-- + h 9-w-'s-9 T-

• -9--w

~

~

~.

7;7 5: - 4,3 :

~-

v

:r

ir

n

-ff_

2: :

':us m. f e r. s.

03ses fcr e uch. >;id ich a ri<al En.'cc sntal Statanent has already ':en it:

3' 5: -Le ti:n Ferrit stc;e but 'cr which the Operating License re.<ier. _._7e 'is '0t jet been reached.

In carryinn out this directive, the sta ff :':,1d u:.r.si, ;-r relevant site features, including,corulation d5nsity, associa:ed -lith 3c 'ient risk in corparison to such features at presently operating plants.

Sta ff s' auld also consider ti likelihood that substantive changes in c' ant design

'eatures which r,ay cor;ensate further for adverse site features ray be rcre easily incorporated in plants anen condt, uction has not jet progressed very far.

Environrental Reports cubmitted by applicants for construction p:enits and for operating licenses on or after July 1,1980 should include a discussion of the environmental risks associated with accidents that follo'z's the guidance given kerein.

Related Policy 'satters Under Consideration

!n addition to its responsibilities under NEPA, the

.P.C also bears responsi-bility under the Atonic Energy Act far the protection of the public health and safety fron the hazards associated with the use of nuclear energy.

Pursuant to this responsibility the Connission notes that there are currently a nunber of ongoing activities being considered by the Ccnmission and its staff which intimatel." relate to the " Class 9 accident" cuestion and which are either tha subject of current rulenaking or are candidate subjects for ruleraking.

'. - ^ ^

II :n.

hd 'r

, '.l i "0

~ ~. ;

~

1. ^

f m

c

1. "##nL*.I. *':v#se its r C t 2. " t s i 'l l'~"' -

i

' ' ' } # ** ',; -' 1 *; r T ' '.. '- r ; I ints.

nG.,

e

~.':

^

~'5'Y15YC;,,is the ?!!er tial CO' :':"Mn es o # C ass 3 scc ~ 'ti 5 E 7

p' Ger1C. S eP 3 e.

n August 197?, pursuant to the Comission't request, a Sitir; Oclicy FIk a-1.

?crce made reccr endations with respect to possible c%r.qss in

• 3C re5ctor siting policy and criteria, currently set forth in 10 CFR Fart 100

.s stated therein, its recor;.endations were nade to acconplish (among others) the following goal:

"To take into consideration in. siting the risk associated with accidents beyond the design basis (Class 9) by establishing population density and

]

distribution criteria."

(

This matter is currently before the Cormission, i

i shis and other recommendations that have been nade as a result of the investiga-tions into the Three Itile Island Accident are currently being brought together

.by the Cormission's staff in the forn of proposed Action Plans 9 Anong other matters, these incorporate reconmendations for rulenaking related to degraded core cooling and core nelt accidents. The Cornission expects to issue deci-l sions on these Action Plans.in the near-future.

It is the Comission's policy and-intent to devote NRC's major resources-to ratters which the Cornission i

believes will' make existing and future nuclear power plants safer, and to-6 44 FR 75167-7 cf. -t;UREG-0396, " Planning Basis for.the Development of State 'and Local Government Radiological-Energency Response Plans in Support of Light Water fluclear Power Plants," flovember 1978.

a.

" f:UREG-0625,." Report;of the Siting. Policy Task Force," August 1979.

.0 1 Draf t.!;UREG-0660,. " Action Plans Lfor Inplementing Recon ~endations of the

. President's. Commission and Other Studies of the TMI-2 Accident," Decenber 10,

'1979. S-

~

- preven ':.a recurrence of the kind of accident that occurred at Three Mile Island.

In the interim, however, and pending conpletion of rulemaking activities in the areas of emergency planning, siting criteria, and design and coerational safety, all of which involve considerations of serious acci-dent potential, the Conmission finds it essential to inprove its procedures for describing and disclosing to the public the basis for arriving at conclu-sions regarding the environnental risks due to accidents at nuclear power plants.

On completion of the rulemaking activities in these areas, and based also upon the experience gained with this statement of interin colicy and guidance, the Connission intends to pursue possible changes or additions to 10 C F: Dart 51 to codify its position on the role of accident risks under

'! E pA.

Dated at Washington, D.C. this day of 1980.

For the Nuclear Regulatory Commission Samuel J. Chilk Secretary of the Commission l

l-l

<.