ML20215H695

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Recommends That Commission Approve Publication of Subj Amends to 10CFR50 Re Codes & Stds for Nuclear Power Plants & Technical Info in Effective Form (Encl D of SECY-75-283)
ML20215H695
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Issue date: 11/03/1975
From: Minogue R
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ML20215H685 List:
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FOIA-87-136 SECY-75-283B, NUDOCS 8705050148
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(M U y"h6 t uwa UNITED STAf tS November 3, 1975 NUCLEAR f1EGULATO AY COMMISSION , SECY-75 283B CONSENT CALEND AR ITEM For: The Commissioners From: Robert B. Minogue, Director, Office of Standards Development {'

Thru Executive Director for Operations o b'

Subject:

REVISION TO SECY-75-283 - PROPO9ED  ;

AMENDMENTS TO 10 CFR PART 50: D0 DES AND STANDARDS FOR NUCLEAR P0k'ER PLANTS AND TECHNICAL INFORMATION ,

Purpose:

Approval of publication of the subject amendment in effective form.

Issue Modification of proposed rule in view of

. comments received supplemented by expanded discussion of the impact and value af proposed amendment.

Discussion: At Policy Session 75-41, July 24, 1975, the Commission approved in principle but requested revisions of SECY-75-283. On August 18, 1975 a correction notice, SECY-75-283A with suggested revisions was submitted to the Commission for a f f i r ma t io n a t a Policy Session. Four Commissioners approved SECY-75-283A, however one Commissioner requested more rationale with regard to impact /value of the proposed action.

An expanded discussion of the impact and value associated with the proposed amendment is included in the revised Enclosure "F".

Specific revisions are as folloss:

, Contacts

- A. Taboada, SD 443-6927 SECY NOTE: This paper must be used in conjunction with SECY-75-283.

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The Commicsioners -3 *

1. Paragraphs (g)(5) and (c) of Inclosure ";"

of SECY-75-283 were r e v i .s e d to addreis the basis to be used by cae Co==1331 for evaluating licensee ceterminatic'.=

that conformanca with Ce e requireme;ts for inservice inspection is imprac cal. .;eae ya;es ". ave c. o t oeen eaaa;ed iroc cae aabmi aica in dICY-;i-loSA.

.. r.c.cn.r: 7' was .0difico to provide note .u : nc. . .

a. aa ; c. e ..nticipated impact /value of taa proposec amendmeat and includes discussicna a: (a) cricerla to be used for judding 1= practicality to be found on pages > and 7 (0) anticipated downtine associated with augmented inservice inspection requirements on pages 13, 14 and 15, (c) radiation exposure due to the proposed chanae on page3 15, 16, and 17 anu (d) the e x t s.n t to whica requirements are likely to change based on past experience beginning or.

page 7 and including Table 1 Following the publication in the Federal F agis ter of the proposal to is .o this amendment tc 10 CFR Part 50, numercus licensees have indicatac a desire to use it in Lieu of the present rule and are proposing to procure ecmponants o r. nis basis. SkR is delaying actica on these prcposals pending final Commission action on the matter.

Hence, prompt consideration la desirable.

Recommendation: That the Commission:

1. Approve publicatica of tce subject amendments to 10 CTR 2 art 3" in effective form (Enclosure "3" c: :.0T-75-2a3).

_.--____..-____.._.--_ _ _ _ _ __._-_ _ _ - - - _ _ - _ . _ - _ - - _ . - . _ _ _ _ _ . _ _ _ _ _ _ ____ __ _ __ __ _.. _ _.-.- ____---___ _ .____.____ ____a

O The Commissioners - 3-

2. Note; t

(a) The notice of ruie making (Zaci; ara "5 of 3ECY-75-233) wi.1 ae p u b l ; 2 c. e . . .a the FEDEAAl REG;57EA to became effec:ive 30 cays ef:er ?ua.;ca:.;..,

('a ) Ina: : .e scalf aas es;ar::nec taa: ; c. . . _

a%end ents are i n a ; 3 r. i f i c a n t fr;: : .J 30:ncpoin; af an"ircaner.:ai impa;;.

Therefora, pursuant to 5 51. 5 (c ) ( 3 / a:

he Commission's regulations, no anvironmental impact atate:ent, c.ejattva declara: ion, or environmenta.

i= pact appraisal need be preparad; (c) That the JCAE will be informed; and (d) That a public announce:ent will be issued (Enclosure "E" of SECY-75-253).

Coordination: The Offices of Nuclear Reactor Regulation, Inspection and inforcement, Exocutive Legal l Director, and Public Affairs concur in tha reco=mendations of th.s paper.

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/ N . n~*\ ri Ro b e rt- 8. Min;;ue, Lircator Office of Standards Oevelopment

Enclosures:

1. Pages 14 and 15 of Enclosure "D" of SECY-75-283

, 2 Enclosure "F" Expected Impact of I:ple=enting Proposed Amend =ent

?UJE: Car.ission conscr.ts cr ccrrcr.ta a.Tuld be pr:viax. c.; r.c Cth:c f :t.a

! Secret.iry by closo cf busir.csa, bxinemsy, :tve; w 12, IM5.

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DISTRIBUTION NO. OF COPIES Secretary 5 Chairman Anders 4 Commissioner Rowden 2 Cornissioner Mason 3 Cornissioner Gilinsky 2 Commissioner Kennedy 3 Exec. Dir. for Operations 2 Asst. Exec. Dir. for Operations 1 Congressional Affairs 2 Public Affairs 2 General Counsel 3 Inspector & Auditor 2 Exec. Legal Director 2 Administration 3 Policy Evaluation 2 Planning & Analysis 1 Nuclear Roactor Regulation 2 Reactor Licensing 3 Technical Review 1 Standards Development 5 Inspection & Enforcement 3 AS&LBP 2 AS& LAP 2 l

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(iii) The initial inservice tests of pumps and valves for assessing operational readiness and systo: pressure tests conducted during the first 20 months shall comply wita chose l l

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requirements in editions of the code and addanda in effect no more than 6 months prior to thc. start of acility co c.are.4.

operation.

(iv) Inservice tests of pumps and valves 10r assesa;ng operational readiness and syste: pressure tea:a ccaducca. 4 ,. c . n ,;

successive 20-month periods throughout ene service life of tha facility shall comply with those require =ents in editions o;*

the code and addenda in effect no more than 6 :onths p rior to the start of each 20-month period.

(v) For an operating facility whose operating licanse was issued prior to July 1, 1975, the provisions of paragraph (g)(4) shall become effective after January 1, 1976, at the start of the next regular 40-month pertoa of a series of suca periods beginning at the start of facility coenercical operation.

(5)(1) The inservice inspection progran for a facility shall be revised by the licensee, as necessary, co = cec the requirements of paragraph (g)(4).

(ii) If a revised inservice insp ec t ier, p ro g ran f o c a facility conflicts with the technical speciiica: er, . iot :he facility, the licensee shall apply to the Co :ission far scendment of the technical speci!Lcations to coalce: tac c <. c . a . . 21

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e s specification to the revised p rogra=. This application soall be aab-mitted at least 6 months before the start or the period durtag whien the provisions becomo applicable as determined by paragraph (g)(4).

(iii) I _f the licanace ha. ceters;ned that aant reaa .

with certain code requtrament 1. 1:3ractical l o r e. . s 12:1.;;3, the 11:ensou shall nottfy tha 00n=tasion and suenic in!arna:ia3 j to support his_ determinations.

l (iv) '4he r e an exa=tnation or cost requirement by the as;.

or addenda is determined to be impractical by the licensea and is 2

] not included in the revised inaervice inspection program as permitta, by paragraph (g)(4), the basis for this detur=ination shall be

demonstrated to the satisfaction of the Commission not later than 1

12 :onths after the expiration of the initial 120-month period of l operation from start of facility coc= arc.41 operation and each subsequent 120-month period of operation curing which the exanination or test is determined to be impractical. '

(6)(1) The Commission will evaluata determinatiors undar i

paragraph (2)(5) that code requirceents are 1: prae:1:ai a r. , tay j grant such relief as it determinaa is authoric.:d vr et;l

_l .a w a n c.

not endanger life or property se ene es: man defocaa .t.  : cur.:y i

! and is otherwise in the public interest s t v i n .: . . t. e e c n a i d o :* . i s n

{ to the burden upon the licenseo : hat e a t. i d rosatt if tha re-l quirceenen were imposed on the factitty.

(11) Iha Commi nion may require the iiconaca to follow

{ aa audmented inservica inspeccion prograt Jar systa:s and l componenta for which :ha Cc::taato dae a t,. a t adcad assurance 3

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of structural reliastittf 14 c. a c e s s a r y .

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1 ENCLO....Z "F" EXPECTED IMPACT OF IMPLZMENTING PRO?OSED AMENDMINT P

A. Proposal to chance :1c Sas14 for car 1hlixhin? s i f e ' . v-datos for referenced c:Jes aac stancara, .) v r ; '. a : . -  : .u i h

i= pie =entation : :es to O .- dec%et dato ist : ' ' : . . . qe ..

i construction y e r .i t 17 ..

ten rather than :he coc c r . . . _.

porst: isaua ea:a The revised ru.e ;, cts.es ; .. e procurcsont of =ajor reactor cooiar.L a y 3 s .- componcr.:. in conformance wi.h f

standard industry practtcom proven effective by severai decades of expertsaco. This change, which was unanimously  !

endorsed by comacators, would elininate an extremuly i

difficult administractvc activity imposed 'y a the extating rule, that res uires suaatantial effort by utilitieu, i

primo contractors and NAC porsonr. 1 without any not  !

improvement in the loval of safety. By avoiding the j need for updating (rapostedly witr. each reviaton of the Codo rules) the purchade orders anc cesign baat.  ;

of a plant, the impletantation of :he sc. cod critoria i I

of Safety Analysis Reports will bc great"y . facilitatea f

and unified without tho acod for acondments co tacse '

i reports. Such changas enaulo result in considerable e c .4 -

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savings in endineering anc processtr.; ol . censen . (a scinate

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i cost up to a million dollars per year) for hoch the '

licensees and the government, and wou;u clininace 0 .e  !

source of unr.acessary delays in licenstag aac p;aa; ochedules. Suca changea should not modigy che leve, c

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safety incorporated in :he cesign of caesa plancs since the resulting condic10aa of cae plant ec ;. aenca saau;c l not be significantly afie: ec. Section ":1 cf the A s .v.2 Boiler and Pressure Ve.sel Code is a very =scure code (first edition 1963) and changes included in the Cwde i

revisions have generally seen in the nature of minov  !

upgrading of 4atety requirements. ilowevur, if any r.ew requirement acopted by the Coce was determined by tne NRC acaff to be essential to safety, such requiremer.t i

would be imposed, in any event, carough the backfit '

rule (Section 50.109). t B. Proposal to requfra periodic upda: tag o! intorvice inspection pro?ra 1 for operatin? !1 cili:iaA Section 50.55a adopts inplementat.on req.1:a:4nta ist '

Section XI, " Rules for Inservice inapectica of Nuc. ear Power Plant Componenta", of the A3ME Ccee, .i t a c e this Code does not specify imple=entatica te;..t6ser.ca.

However, Section 50.554 presently only reqaires

- 2a 2nclosure "Fd l

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inspection programs for nucioar plant s whose cona t r ac c ion permits were issued after January 1 1971 and the c.rrent rulo requirca conformance only to tac inservice ir.,we.;aa provisions (Section X ) c: the ASME 2:11er anc .*rus,ete Vossel Codo in offec: 5 acnths prior to c .' a aa:e of Lasuo of the con.cractier permit.

This sectica is d e f i c i a c. t i t. :nat it reaults in a variability a a t r..; o c ;;c a p ro grams because the regu.a;;ca does not provice ic: accating new requiromonta of the Codo au revised editions and addenda are published, thus, permitting oldar plants to use static inspection programs which vill 'acco:s obaolote over the 40 year life of the plant while c ;.o never planta are using more recent Code editions. The proble: 14 further compounded in as :uch as Suction XI of the A3ME Codo, which is amended de-t- ,

annually, is a relatively new (first edition issued La l t

1970) and dynamic code and has u nd e rg o r.o a;;nificant improvements in recent addanda. Further, Section X1 to expected to have several complace new subsectienz l added in forthcoming aadenda, extending inapocciot.s to additional components in nuclear powcr planta chat l

are considered 1:portant to safety.

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b The premise that updating inspection progra== is ne;essary is supported by the videly recognized need for impravement.

in inservice examination techniques specified by Se:t.an X;,

as evidenced by taa nuserous studtes unscrway in th..

i field by NRC, ZRDA, EPR1, WRC, anc cthors. The ASM; I

, Code committee recogn;;e4 :nis need for in>reve.tenc, I

i in ncndestructive exa:Ination technology and such i=provements, up;n Jeview and evaluation, are expec;ed i

i to be incorporated into cha Code as expeditiously aa I l i is practical.

l Since Section 50.55a does not provice guidance for 1

) inservice inspection o! nuclear plants for which I construction pur:tts were issued prior to January ;, it71, s

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! a problem exists in determining iha appropriato inserviec I (

i inspection require: ants for 70 s ch plants. To datu, i r the rogulatory practice has been to require inservise  !

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inspection of such older plants on an ac hoc basis, i 1

i through provisions in tas license tocan.:21 apecifications

that, at the time such technical specit. cations werc i

prepared, reflected the current availac'.e state of ene

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! inspection technology.  ;

f When deemed necessary, nacificaciana er .ccatiana t; 1

l inservice inspection requirementa for a reactor, have l

been imposed by NRC, also on an ad noc oasia. Suen an b

approach leads to the acn-uniformity of inservica f inspection pro; rams.

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  • 4 i . The proposed a=cndment, which has been supported by L i

all utility reprenontatives of t..e A8 E subconnittea i on Inservice Inspection, would require lleenneca ta update their inservice in.pection programs in a s y ;, ; e .7,a t t e  ;

j manner by adding to such progra:s those e:< a:I n a t ic a and costing require:en;- Laciudad ir. ;he new Coco a!1: . c.i 4 l

l and addenda approvod by anenacent to the regula;1one, Such program modifications would bu =ade on'y at . l reasonable periodic intervals of 40 conths. F u r t h u .' .

i since certain inspection requirements may be imprac ical ,

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i to implement for older plants, inspections woule be t

! required only to the extent practical wit.ain the 1

limitations of dosign, geometry and macoriala of 4

q construction of the cc poaants. Decorcinations that examination or testing p rovisions are imprectical wcula s

i be made by the licenseo and subject to approval by :;RC I

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through revisions of the license technical specifications.

j These determinations would be reviewud attor osch ten j

year inspection interval in the 11ah a .' now dovolopmenc4 I

in the field of inspection techniquea an. rathoda r available at that tico.

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j The criteria that will be used by the NRC stall for l Judging practicality of applying a Code revision to  !

l an operating plant would he based on a review of taa

$ above stated limitation. ..s 14cattfied weth cae I

original plant do41gn and wich due coas tco ra tion gi /en

, to potential for radia:1on exposure :o the peraonne.

1 involved. As in other licensing mat:ces, decorni..a;tana of practicali:y ay che regulatory staff would nocosai; ate  ;

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matura judgnent, experience, and knowledge of the '

i specific situation. An examination requirement for a  ;

4 j component would be considered impractical ift s

! 1. the component requiring examination is inaccosutblo.

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2 modification of struccuras or components or ,

s j redesign of systems would ba necoasary to enabic 1 l b

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such examination (except for minor changes such  :

r as removal of insulation or attaching instrumor.cs).

3. properties of materials of construction or  !

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design of the component would not parmit saanin;!.;  !

examinations. I u

i Inclosure "/"

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t 4 the examination would result in a signtiicant increaso in the overall radiation exposure to cae i

j inspection personnal anc remotely operable i..sjectica l

equipment of existing deat;ns cannot be applics to perfor: che examinat.on.

For unique ..tus: ion., cae proposec rule proviaaa lac oxcmpting requiremun:. lor which compliance may res..;

in an undue burden w;;aou; a significant incraase in safety or far adding requirements if necessary to ausure structural reliability where safety considerations are overriding. Such decisions as made by the staff are subj ec t to =anagement review, and, as always, the  ;

licensee may appeal scaff decisions to NRC management and the Commission.  ;

Types of Chango1 Decuring .n See:1on XI. A3.d.E Codo The more significant past ruvisions to Section X1 oi che ASME Code and the impact of these revisions on ongoing inservice inspection programs are sunnarised in Table '.

Although new Lode revisions obviously cannot be deter =ined in advance, a basis exists for predicting the extonc and i probable impact of such revisions in viow of cur knot. edge i

of the membership of the Codo co: it tuu r e s p o a J i h l'e for these revisiona, the contents of past adcunda approvad by the Code consitte and the subject .t:er presently being considered for incorporation into tha Coeu. .

, Enclosure "F"

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  • A major constraint on changes to cne As.it Coce resulca i

! from the representative membership of the Code committee i

l which prepare and approve the Code rules.

The present Coce committee responsible for new a c d e s : c.

of Section XI (!nservica :nspection) consia:4 cf twenty-one experts, all actively working . t. :he nuclear ficid, cha: are representatives of 7 utilicies, 5 nuclear secam syscem suppliers, 2 archi:ect-engineering organtaa;;cas, 2 insurance underwriting companies, 3 regula:ory agencies (including NRC), a:1d a supplier of inspection services. Such a membership assures recognition of new safety issues which may develop as well as screening of unproven inspection techniques. NRC participation provides tae committee with an advance NRC reaction to proposed chsages and an opportunity for NRC to request changes to the Code based on needs for consistency with approved NRC criteria, standards and regulations.

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NRC also receives, through its participation, advan:e  ;

notices of the proposed Code changes that permit 1 appropriate action to be taken in a ti=cly nanner.1.

order to avoid unj us tifiabic or inadequate rev;sicas.

Past addenda to the inservice inspection Code, summarized in Ta' ale 1, as well as provisi;as in preparation are considerec indicative of the nature of future changes which may Se expected in the ASMC Code. These changas fall into the following generai categories:

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1. The addition of components and systens not previously included in Section XI The initial version of Section XI included only the reactor coolant pressure boundary. Subsequently, other systems nd components important to safety have been added as planned. These additions have included requirements for examination of ASME Class 2 and Class 3 co=ponents anc lor ; eating c2 pumps and valves. In the course of preparatio:

are subsections for containments, conponent su;perts, and core internals. *'i

  • t h t he addicion of these requirements all of the major acd;tions plannec for i

light-water reactors should be comp'eted. ,

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2nclosure "F" i

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, , 2. Test procedures and requirements which were "r2vioua;y I

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identified in Section XI only in teneral t e r r.s i

Major procedural sections are being developed :hrough l experience and research that are expected to concr:bute j significoncly to the safety of these systems. For l exa=ple, Appendix I, added in the Sunner 1973 Adcenc,

gives cetailed.=ethod for ultrasonic examina
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of welas in Jerritic vessels that provides a

, quantic;;1va characterization of flaw geo=etria= co l perc;t improved evaluation of the consequences of 1

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such flaws. Also adced in the Su==cr 1973 Addenda J

a were new revisions for evaluation of indications in j

vessels anc for =cchods of repair of-vessels. These i

j provide rules for aceton to be taken when flaw s

j indications are detected during inspections and for j permitting continued service after proper evaluations

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i, and remedial actions have been taken. These revisions have been identified by utility members of Section XI J.

as major advancements in avoiding potential plant e

downtime.

i 3. Specific changes in the details of the Code su:a as  !

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inspection schedules, designations of areas anc I  !

1 componenta to be inspected and type,_ex: ant and l fre'quency of examinations t l

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Such chan;es, in general, result from experiencas '

} in apply . a; the Code or reflect aavances in the J 4 i  :

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state-of-the-art and have =inor impact on the overall inservice inspection programs but coull 1

result in reductions of inspection times, cost, and in radiation exposures. In time, the bul4 of the changes to cae Code should fall into this category.

4 New inspection me: hods t

Although no new examination methods have been acdec to the Code to date, several advanced =ethods are

being developed which have the potential for'i=provec flaw detection capability or as a = ore efficient substitute for existing techniques. Such =ethods 1
  • are expe.cted to be added to the Code at.the I

i appropriate stage of develep=ent. Also, in this

category are the addition of existing techniques to i

resolve new problems. For example, the Code rules '

t include the addition of requirements for examination of steam generator tubes based on procedures using l.

q eddy current testing methods.

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Value of Updating Inservice Inspection ?ro; rams '

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{ Through the proposed change in the regulation, needed i

inspection require =ents would be added to all operating i j plants in a syste=atic and ti=ely =anner which would l I

contribute to the maintenance of integrity of nuclear i

i power plant components at~ct.a level intended to protect-

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the public health and safetysand environmental co=patability commensurate with their impact, instead of the presant ad hoc practice, which has been applied on a non-unaform basis. Thus, all operating plants would be required to have unifor=, co prehensive, nationally stansa.edized, inservice inspection programs based on current and proven examination and testing provisions (to the degree that these provisions could be applied). This w'ould prevent the situation, presently permitted by the Regulations, of allowing the application of provisions of the Code that become obsolete and are replaced by improvecents during the entire service lifetime of the plant.

The systematic examination and testing of components a

during routine shutdowns should detect at early stases conditions that, if left uncorrected, could develop into maj or saf ety problems as well as unplanned plant i

outages and lengthy downti=e for repairs and additicnal inspections. For example, the detection of wastage in steam generator tubes of p ressurized water reactors precipitated corrective action that not cnly has <

1 prevented an unsafe condition but probably has_avoicad the need to replace the steam generators, a ca or l l

maintenance problem.

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! The application of i= proved testing techniques will result in more definitive character 1:ation of flaw indications, which combined wich'new analytical =etsods i being adopted by the Coce, should result in core

! quantitative and reliable assessments of the potential consequence of these flaws. This shoulc pr: vide i greater confidence and permit more flexibility in corrective action, as well as significantly reduce the need to repair components. For example, through tha use of new rules of the inservice inspection code, a significant flaw-indication in the Pilgri= reactor 4

L vessel was carefully characterized and, although larger than permitted by.the standards of the construction code, was deter =ined to be well under the size considered unsafe. Acceptable continued operation of the vessel 4 avoided considerable reactor downtice and unnecessary expense to the licensee and the public.

i I= pact on plant operating and downtime It is the judgment of the staff as well as most = embers 4

of the Section XI Code Committee, including all utility members (according to the chairman of this co==ittee)-

that, on balance, the proposed change would significan:1y 13 - Enclosure "F" 4

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a L decrease the potential for plant downtine. Normal inservice inspection operations are perf ormed durin.;

regular refueling operations or other major mainten.ince outages which presently require approximately twice the ti=e needed for inservice inspection. The addi:1on of inspection requirements not previously _ncludec L ..

the Code is not expected to increase downtire since such inspeccions would be independent of other operactons and could be conductec concurrently with present . inspection operations at refueling and/or caintenance outages.

To date, we are aware of no case where planned inservice inspection has resulted in unscheduled downtime.

In further support of this judgment is the trend to establish alternatives for inspection require =ents in the older Code editions which have caused unexpected problems or were excessively' time consuming. The

! application of the latest Code edition has been esticated by Commonwealth Edison to require less tnspection time than the original license technical specification i

requirements and with co: parable results.

A major saving in downtime and cost should result-in the event that a major component failure is averted by the periodic inspections. A single-failur'e requiring an

unscheduled outage could easily result in core plant 4

e 14 - Enclosure "F"

L downtime and cost-than that resulting from inspection .

for the entire life of a plant. If located in advaace, an incipient failure may be repaired in an orderly manner during regular outages. For example, replacing a pipe section normally takes less than one week an'i could easily be accomplished during a nor=al outage which takes approximately six weeks.

Radiation exposure due to inservice inspection Occupational radiation exposure due to normal inservice inspection is not considered a problem at this ti=e.

The radiation exposures in light water plants over the past 5 years attributed (l) to inservice inspection was on an average 3 to 5% of-the total exposure reported per reactor. The average exposure received

by individuals due to inservice inspection was well

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i below the limits allowed by 10 CFR Part 20. For 1

j example, in 1974 the average exposure was 1.5 REX whereas 1.25 REM is permitted per quarter. Radiation

~

exposures as a result of additions to the Code should be trivial since most changes will apply to nonradioactive components, whereas most exposure results from inspection of the reactor vessel and the reactor coolant pressure boundary which are radioactive. Inspection requirements-I (1)

NUREG - 75/032 Occupational Radiation Exposure at Light Water Cooled Power Reactors 1969-1974, June 1975 l - 15 -

Enclosure "Fd

. . . . .= _ . .. - - .-.

for these radioactive components have been in Section1XI -

since its inception and are presently being. reevaluated by the Code committee in light of the radiation exposure- problems that result.

j Since the radiation exposure levels are expected to increase as plants get older and. radioactivity builds j

l up in components, a concern exists that, in the future, the available number of qualified examiners may receive radiation exposures at an unacceptable rate. For this

reason, the Code approved draft of the Winter 1975

) Addenda provides an alternative inspection program which i

permits at an earlier date in the service life, the front loading of inspection operations and a stretch-out of inspections at the later dates to minimizing radiation

.1 exposure. Also, remotely operable inspection equipment has been developed for the inspection of the closure heads, flanges, nozzles and belt line regions of reactor vessels and for inspection of pipe welds and stea=

i

.; generator tubes. It is expected that other equ1p=ent 4 for such purposes will undoubtedly be developed as

the need arises.

An objective of inservice inspection is to prevent 1

failures that could lead to nigh radiation exposures i

such as have resulted in the cases of ?WR steam generator 1

tube failures and SWR pipe cracks. The operations l l

. I 16 a -

Inclosure F" a

r wT y , - , m- - ,- ,.w--t-e- , - - . ---e- -e.,--,--.--+.,e---

f

'~ associated with cleanup, repair, and maintenance 4_ of such failures in radioactive systems are inherently more time consuming than inspection operations, and

radiation exposure is proportionally increased.

Economic Impact of ISI Because the proposed regulation would requira the adoption of Code changes for examination and ces tin;;,

but not major changes such as plant redesign and structural modification, the impact of these regulations I generally would be small. For example, the Code revisions could result in additional maintenance work to prepare co=penents for inspection, additional

examinations as required by the Code and possibly.

t l new equipment for performing the inspections. The I

i costs of such changes are typically not excessive.

Even such major inspection operations as (1) the eddy current testing of the tubes in a PWR steam generator tubes or (2) the ultrasonic examination

of the (approximately 50) pipe welds in the pump bypass lines of a BWR, are estimated to cost less than $20,000 each for the extent of inspection that the Code woulc normally require in a forty month period (costs include l
  • 17 - Inclos'ure " F

i

+, . .

.i_

l component preparation and set up operations). As a comparison the estimated cost for normal inservice inspection based on 1972 Addenda of the Code is approximately $200,000/ year.

As noted above, since the inservice inspection Coac is written specifically to pernit inspections durin; nor=al plant outages, costly outages for inspection should not result fro the adoption of new Code revisions.

On balance, expenses resulting from new Code requirements should be offset by the increased safety and improved availability afforded the plant, as well as the economic benefits expected to result from the inplesentation of' these programs. For example, repair of the Pilgrim vessel or replacement o f - the stea: generator tubes in PWh would involve millions of dollars. Further, an unscheduled shutdown due to failures that require rapiirs could cost I

hundreds of thousands of dollars per day.'

s t , The staff believes that licensees are ace {uately_

i protected against undue impact on plant availability and cost as a result of the proposed a end:ent. The proposed a=endment will not r equire plant modificati2ns i

or redes'ign, and special plant outages, and new Code Y

Y t

15 - Incloaure "F" a

e. ; .

provisions will be applied only to the degree practical.

Further, the proposed rule has provisions that commit NRC to consider the overall impact of Code changes and the economic burden en the licensees and the paal c prior to imposing such provisions on a facility.

~

s 19 -

Enclosure "F"

6 -

/,

  • TABLE

-} SIGNIFICANT ADDITIONS TQ SECTION XI ASME CCDE EXISTING IN AangNDA ADDENDA CHANGE IMPACT ON Is! paocgAM linter 1971 minor scheduling revisions that provide slight redaction more flexibility

ummer 1972 editorial revisions none

' inter 1972 new section requiring examination extension af of class 2 components excainaticas

.ummer 1973 Appendix I standardized ultrasonic small incr2ase examination procedure addea for reactor vessel major standards for evaluations of potential ma; or examination results for vessel reduction belt line region a

major revision to section on potential maj or methods for repair of vessels reduction inservice testing of pumps and slight increase over valves added Tech. Spec. reqts.

Appendix for evaluation of flaw potential reduction indications .

inter 1973 review procedure for visual none examination - referencesSection V revisions added to 74 edition none new section added requiring slight increase -

inspection of Class 3 components .

linter 1974 in.)ection of core support structure small reduction welds

unmsr 1974 method of characterizing flaw clarification indications revised standards for evaluation of ex- potential racuccion amination results for welcs in vessels, dissimilar metal welds, bolting and cladding ummer 1975 paragraph permitting pipe co be none exempted from ISI Preservice examination requirements small reduction for control rod crive housing revised method of characcarizing clarificaticn flaws l

t -

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