ML20055H829
| ML20055H829 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 07/16/1990 |
| From: | Jeffery Grant YANKEE ATOMIC ELECTRIC CO. |
| To: | Jocelyn Craig NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| BYR-90-92, LR-90-006, LR-90-6, NUDOCS 9007310002 | |
| Download: ML20055H829 (25) | |
Text
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. YANKEE ATOMICELECTRIC COMPANY
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580 Main Street, Bolton, Massachusetts 01740-1398
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July 16, 1990 BYR 90-92 LR 90-006 U. S. Nuclear Regule. tory Commission Document Control Desk Washington, DC 20555 Attention:
John W. Craig, Director License Renewal Project Directorate Division of Reactor Projects - III, IV, V and Special Projects Office of Nuclear Reactor Regulation Referenecs:
(a) License No. DPR-3 (Docket No. 50-29)
(b) Letter, NRC to Yankee Atomic Electric Company, June 8, 1990 (c) Letter, NRC to Yankee Atomic Electric Company, June 15, 1990
Subject:
Pilot Evaluation Report License Renewal of Yankee Nuclear Power Station Dear Mr. Craigt Per References (b) and (c), NRC requested additional information regarding the " Yankee Nuclear Power Station Pilot Evaluation Report for Plant License Renewal," YAEC-1710, and the " Methodology for Identifying Potential. Fluid Component Age-Related Degradation at the Yankee Nuclean. Power Station,"
YAEC-1727P, which describes a rule-based computer pt.ogram, CoDAT, that is used by Yankee in its pilot evaluation report.
Our responses to the questions contained in each referenced NRC letter are attached ( Attachments 1 and 2).
At the June 20-21, 1990 meeting 'oetween NRC and Yankee regarding the pilot study evaluation, NRC also requested Yankee's position regarding any further review of the pilot evaluation report or CoDAT.
While we believe that the pilot evaluation has provided an excellent forum for focusing both the industry and NRC on license renewal, we also believe that any differences that still-exist between the pilot evaluation methodology and that of the license renewal rule can be readily resolved through our license renewal application. Therefore, Yankee requests that subsequent to acceptance of the attached responses that no additional staff review be conducted on the pilot evaluation report.
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We'also request that at this time, no further review of CoDAT be conducted.
We will inform you at a later date should we decide to have CoDAT. reviewed j
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1 Yasdnee anspeine to et Cm en Pilot Report (veEC-1714 Cosament # Category WRC Cosoment YAEC Respense i
1 Clerity The reeutts of VAEC's review of sefety injection system comporunts ligptementetion of the EMARC nethodology was difficult in severet areas tabuteted in Attactueent E to the report ere not cleer. The steps and which hos teed to confusing reoutts. Changes heve been ande end further topic applied in Attachment E are not consistent with the utpupC WUPLEX i,
.as are plamed in conjunction with the proposed methodelegy asethodology discussed in Attachment A of YAEC Wo. 1710.
This revisions outlined in the April 24, 1990 NummeC tetter to WEC.
discrepancy should be empteined.
2 Effective The rationete and the basis should be provi*d for eliminating Lic+ feces ensst ensure the votidity of the decision to disposition e Programs c
-7.s and structures frase further considerations for license compenent on the basis of effective progasses. Deses justifying such a reneuet and for which credit is teksn beesume of ongoing programs and decision will be en integret port of ticense reneuet doeveentation. The rewirements.
For those ongoing programs and rewirements when entent to advich such booes are developed wilt
- pend upon the considered as port of estetytished effective program (s) for senseing component (s) and program (s) involved. Such beses doctasetetion will be aging, the beels for prestseing thet the programs address ett retevent provided, in saamery feehion, in the license reneuat a3splication.
oging mechanisms and dess adetion processes and that they ere effective for timely mitigetion of aging degradetion should be provided. When credit is taken for eliminating ports and components from further consideration for License reneuel on the basis thet they are routinety replaced, then criterie for estabtishing reptocessent intervat(e) should be described. The documentation should be an integret element of an established effective program for monoging aging. The licensee should assure thet those decisions are votid decisions for extended life considerations.
3 screening Secause the Yankee screening process is booed on the proposed utsamec currently, Yankee hos reviewed the systems and structures emetuded from sethodology, iAst modifications to the Yankee screening process for further license reneuel consideration in the pilot report against the structures, systems and components and specificetty to the components definitionet criterie being adopted in the mumpet NUPLEX Screening in the sofety injection system have been made te accoesnt for the sunhWC leethcdology. As a reeutt of this review, five addit 5cnet structures resolution of comments on their proposed screening methodology?
heve been recteesified and may now roupsire further review for license Page D 1 July 13, 1938 i g
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2 Yardree Bosponse te K Cements en Pitet esport (TAEC-1793)
YAEC Response WRC Comment
_ fm # Category-renewel. The charpt in the NURARC uuPLEX Screening seethodology will not '
considerably effe-t the overoll screening reeutts reported for the
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safety injection system in YAEC-1710. Nowever, %e criterie chenyt will now atlow seat SI cogenents to be dispositioned teufer Sdetop 2b rather than 5thstep 2c.
The current set of Yankee systems and structures regJiring further review for license renewet is considered *o be raservative.
4 Screening The pilot application does not address cobte wrap or barrier YmPS did not install cable wraps for Appendix R.
As irmicoted in the'
. penetrations. The report should identify how these items will-be Pilot Study, cables themselves will be addressed in a seperste report. :
Cable wraps, if any, would be addressed for the affected cables in the handled by the renewet process.
cable report.
Nowever, berrier eenetratform will be. eweluoted seperately..
5-Definitions A rumber of terms or phreses teed in the report require definition or soth industry aM mRC have created numerous terne and phrases dich nose smiform th*inition. EPRI is currently working on a tererinotopy guide -
greater explanetton. These terms include:
which sey provide a uniform basis for license renewat terms.
a). potentially significant age-related degradetion (pope fli) b) property managed (pose fif) c)~ as necessary (pege fli) d) effectively meneses age-related degradotion (pose 2) e) undesirebte effect (pope 8) f) functional requireemnts are property addressed (page 18) g) breekdown (page 20) h). potentist aging degradet!an mechanism (pose 27)
July 13,'1990
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- Yasdeer meaponse to MC Cameuunts an Pilot Saport (vaEC-1799)
YAEC Response NRC Comment Comunent # Category
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mo. However, it is recognized that other plant systeam eruf structures o
Screening Did the study evettrte 30P SSC dose age-reteted feltures may chattense werrant consideration of aging tseyond the scope of ticense renomet for the fisictions of the ofety related $$C7 the following reosons: key transient initletoes, personnet sefety, and :
plant economics. Yonkee specific risk studies and industr, emperience ullt deters!ne the focus and entent of review.
The Pilot Report on the St System uns: prepored..to provide a 7
Documenti. tion Witt there be evolustion reports, simiter to the SI System Repert. on demonstration of the screening process for a typical plant system. This other YNPS systems? If yes, dat is their schedute?
is only one port of the overett License reneunt progree es.shown on Figure 1. Similar reports for other systems are not planned.
Does the Yankee program for the management of age-related degradetion The Yankee License Renewel Progrsun does address the identified elements 8
Effective Programs include, (i) detection 'of degradetion, (ii) preventive maintenance, to the extent necessery. This approach is consistent with the revisions '
(iii) trending of parameters useful to monitor degradotion, and fiv) being made to the NummRC NUPLEX Screening feethodology.
record keep!ng? Describe how these elements have been incorporated into the lessons tearned on the pilot system w as.
9 Screening The pilot apptication, when addressing age-related degradation of The review of piping compenents tooks et the degradation mechanisms thet '
can tapect the pressure boundary functions of integrity, flow poth, and It piping appears to focus on the capability to maintain integrity.
does wt adequately address aging related effects on piping 'dich heet transfer capability, as applicable. We agree that the report is-result in increased pressure drops due to possible diameter reduction not eteer in this regard.
and piping corrosion. Describe what programs are in place to assure adequate NPSM. will be avellable dJring the - reneust tefut.
- Also, The piping with the SI system uns not shoun to be susceptible to any deseribe those prograus ' currentty in ptace that assure that aging deeradetion that uoutd signif feentty fagsmet the fIou poth fisietlen.
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. Yesdese saapunse to siac comments en Pilot emport (YmEC-1718)
' tAEC Response NRC Comumt Comment # ' Category effects for att fluid systems over the additionet license reneust Nowever, for systems susceptible -to microbiologicelty influenced corrosion or generet corrosion,' the flow path fwiction may be iemocted period will not result in flowrotes below those assumed in the pter t and adegante NPSM could be an foeue.
safety onetysis.
10 Effective pee 7 of the electrical system couponents have been etirineted from EO is one program conside%s effective for license renount. : The EO -
further evaluation because they are stated to be tsider ef fective (EG) program was establisheJ to quotify electrical eg.ripment _ reprired to Programs remain functionet niuring and/or efter destys basis events, and located programs or surveittance and maintenance procedures. so discussion of in envirorments whiJe would be significantly more severe (es e result the nature of the EQ programs was previoed. In particuter, we neticed of design basis events) than their nornet envircreents.. Ittherent in the no discussion of how those w,~.a.;s that were enty qualified for the EQ Program is an evolustion of aging to doctsment the abitity to fwiction life of the plant would be addressed. Although the proce&res are listed by name and title none of. the proce&res were provided.
throughout its qualified life. A review of the EO Program is currently -
Althwgh the criteria to be oppt'ed in determining the ef fectiveness of being completed to determine if the eastified (Ife can be demonstrated the piecedires in detecting age-related phenomeno are discussed, no through the license renouet period. the study will ensure thet ett EO a.;s - are eastified for the license renemet period.
If example s weee given to ittustrate how the peccedures were applied in cm making 3e determination. Also, we note that although the w..;s qualification throughout the entire license reneuet period. is not needing further evetuation howe been identified, the actuat evolustions documentable, the c a.; will be reptoced prior to its and ' of are stattd to be beyond the scope of the subject report. Describe how quotified life, as regsfred by the EO program.
these corcerns will be addressed in the two ticense reneuet reports.
Additionet discussion relative to establishing the basis for screenfra -
decisions is provided fr; the response to ra== ant No. 2.
Se: tion 3.3, the scope of systems and structures should etso cover Systems and structures containing ews reesired for desting with 11 Scope tii sse strtetures and sv,~.E.;s included in ATWS, PTS or Station ATWS, Station glockout,. and fire protection heve been included for further License reneust review in G A A with the new screening gl.ctout events and evolustions. Describe hou these events were criteria being adopted by the casent suPLEX Screening seethodategy.~ It ~
factored into the screening process descrioed in this report..
July 13, 1990.
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- Yar6ee sampasse to EEC Cemeents en Pitet esport (TNEC-fTS0)
YAEC Weaponse ssRC Comment C-
.t #'. Category is tsicteer from the comment es to uhet aspect of pts, es it applies to _-
the screening of systees and structures, is being gsestioned.
In section 3.3.2, the report identified the evetuation factors, but did screening s@ step 1e (now eliminated by the definitionet approach) was 12 intended to conservettwety identify systees and structures potentfeity not identify the specific acceptance criterie for these factors. State how the applicable acceptance criteria in F3AR, SitP, and SEP would be important t3 ticense renewat so that they could be poseed on to Sabotep Ib for further screening, gecause of this. two-step systeet(structure ~
used in your evolustion.
screening process, brood-based criterie, in which the system or structure merely had to be identified in a porticuter ~ anotysis or licensing document, were used.. The definitionet approach to identifyiew systems and structures for ticense renewet being adopted by the IIUpgWC IIUPLEX screening feethodology eliminates the above two-step screening process.
The stressors identified in section 3.3.2.7 and referred to en gege 20 Live and deed design toeds are est age-reteted degredation stressors.
13 Clarity do not reflect deed and live design toeds. Also on page 21, you stated only cyctic toeding could be considered as en age-reteted degradetion l
that the detelted analysis"and the siapte examinettons were beyond the stressor. This witt be addressed under fatigue.
scope of this report. Provide eterifications on thes two issues.
Sectico 3.4, rhe inferimetion used to judge the increase in radiological As stated in the response to Comment slo.12, sdssteps te and 1b were : -
14 Screening heetth and safety risk to the pihtic'would be sceful to the stoff in ' eliminated by the adoption of the definitionet screening esproech in the evetusting the screening process. Provide the specific criterie used.
RetRItC IgJPLEX. screening Stethodology.
Therefore, the critstion in '
garstion no longer applies.
July 13, 1990-
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.s, Yardtoe Aeepense to K Comments en Pilot Report (TEC-1719) 6 Comment # ' Category.
NRC Comment YAEC Response
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15 system Section 3.4, this section states " age-reteted degradetion of a system The turbine generator system is a terge 'and complex system idile, does Interaction or structure is considered potentietly significant to plant safety if rot pose a risk to the heelth and safety of the pi, tic, wit, the the fatture of. the system or structure contributes to increesed exception of turbine missite concerns.
Emaninettens of rett.;ing radiological heetth - and safety rlsk to the public.
However, the ews are routine with spec.ific guidelines provided by the turtpine licensee must consider the potential-interaction of one component with generator manuf acturer(s), WRC, and inetustry. Systeun interactione and -
another as a result of its fat ture.
Attachment D esserts that the risks associated with systems contelning stored energy are ret des adation of the tus uine generator system is not significant for considered to require !! cense renewet review if not currently covered plant safety and need not be considered For license renewel. gecause by regulations. Many of these issues are addressed in the response to.
the turbine generator consists of targe rotating components uhose Comment me. 6.
fatture could demoge equipment needed to protect the radiotegical heetth and safety of the ptblic, age-retated degradetion of the turbine generator system and its effects sust be considered. Are there other systems or structures that have large anrnrits of stored energy and could, Lyon failure, interact. 6*th other components to increese the I
It is risk to the radiological health ani! safety risk of the public?
not cteer how the aging ef fects on tc'"ne missite probability were taken into accotrit and uhat the basis for elimination is. Describe how these issues are addressed in the subject reports.-
16 screeaing Attachment D esserts that the teek monitoring system is not significent ' 7% leek monitoring system is used to perform the deity vapor contel'ner to plant safety. The staff does not agree with this conclusion because air an belance for determining containment teekage, os recpsired by.
teek monitoring is : intended to detect the potential toss of the ' plant tr.:h iicet specifications.
The containment pressure betridery pressure boundary integrity of components.
If the teek monitoring portion of the teek detection system is significant to plant safety and system becomes isiretiable because cf age-reteted degradation, the regJires further review for License renewal (included as port of the pressure boundary integrity could be lost without any edwence warning.
vapor container pressure boundary).
The ISC portion of the teek Are there other system or components that monitor the plants condition monitoring system will also receive further review for ticonee renewet -
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Yardese sempanse to enc Comments en Pilot mayort (YaEC-1T1e) 7
- Comment # Category MRC Comment YAEC Response that are considered not significant to plant safety?
to ensure continued retlebility of deity containment.teskase monitoring.
17 Screening In Section ~ 3.4.3, the licensee esserts thec the Meeting Age-related degradstion of the SteenvCondensete System and the uRY SteauvCondensate System - and Non-Return. Vetve -(NRV) -Enctosure Enclosure Ventitation Systems may teed to their failure. Neuever, their Ventitation Syste% ore excluded front evolustion because their fatture feiture does not significantly ~ affect plant safety.
The would be detecteJ in a time frame that would allow the plant to be shut SteesVCondensate system provides heeting steen to the SIT Tank, which doun, before the need for a manuel or automatic plant trip. Are the is maintained between 120F - 130F in eccorderse with plant technicet meterlats in these systems susceptible to age-releted degradotion that specifications. A toss of this system would result in a very slow could lead to sudden catastrophic felture?'
dem in 51 Temperature dich would be readily identified. The NRW-Enctosure Ventitation System is ured to maintain the DRV enclosure above '
freezing in the winter. Loss of this system would result in a decrease f
in NRY Enclosure temperature dich is eleo reedity' detectable.
Additionally, even if these systems did have a catastrophic feiture, l
' it would not adversely impact the plant's ability to safety shutdoun.
i 20 Effective Section 3.5, - an established effective program sunt have, as Established effective programs must have, to the entent necessary, the :
Programs appropriate,'the elements of trending, record keeping and maintenance' elements of trending and record keeping. Replacement and mainterance j
in addition to those listed in the bottom buttet (o) of page 15 of the are included under the items listed in the 2nd buttet on page 15. Short-l report. An acceptable alternettve for short-tived components would be lived 4es are not believed to be e license renouel ' leeue. '
a replacement that is based on demonstrated conservative life Conservative life essessments bened upon industry date or trending of assessment.
failure rates can provide the bests for continuation of ~ current practices.
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YAEC Response NRC Comment Consent # Category In the first peregraph of page 16, you stated that component-specific - As emplained in the response to comment 7, the _ Pilot geport only.
19 Scope evaluations are beyond thel scope of 'the report..
State if addresses the screening of -
as. Besed on screening reoutts, some component-specific evaluations hese been or are being perfonned and how components will require further evetustion to deterurine if ac Severet evetuotions are in progress, the results of which necessary.
you are handling the results of these evetustions.
allt be summarized in the License genovel Application.
Trending, record keeping, and maintenance, es_ appropriate, are integr1st Section 3.5.2, the criteria used for established effective replacement, 20 Effective or inspection program appears to be missing such key elements, as ports of an established effective program. The focus, houever, is to Programs trending, record keeping and maintenance. -In addition, examples of establish that activities performed ensure etsuponent finctionstity, addressing age-related degradetion to the extent necessery. The above.
specific criteria for determining the need for corrective action should mentioned eleserts, partletty or uhotty, contribute to establishing a be provided. Pleese discuss how the above concerns are factored into component's program os effective.
tne screening process at Yankee.
The peregraph on structural components on page 20, states that ther As emptsined in Section 4.5.4, Assessments were performed for: (a 21 Scope will be evetusted for generic degradation. Mouever, this report seems-concrete, (b) structuret and miscellaneous steel, (c) architecturet to focus only on concrete ome as (Attachment K).
State how you items, and (c) support components. Attachment K use provided as an example of a structural essessment.
plan to address the steet components.
22 Screening Section 3.5.3, in addition to the focused watkdown of structuret The need of or plans for in-situ meesurements or testing have yet to be estabt shed.
components, are there any plans for insitu seesurements and testing of Walkdowns possible degradetion sites? If yes, discuss the current plans, if no, -
state the basis for the conclusion that they need not be done.
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9J Yanhoe asapense to Egilt temeents en Pilot asport (YaEC-1713).
YAEC Response NRC Comment Cosament # Category-23 E f factive
' Section 4.1, aging-degradetion essessments shoutd be sigiptemented with screening eseesses the capabitIty of p! ant programs to amnese age Programs plant procedures for SSC evetustion. ISC ocysipsont and some electriest related degradation. In many comes, the bases sigiporting the screening.
- w. s any be evolueted as groups, or assessment will recastre further development.
componen;s and fluid system w es sub-systems. Atso, eti apptfeable ptant procedures, estabtished programs, ongoing regulatory regJirements, and applicable codes and standLrds should be identified in the report and tPeir effectiveness in managing age-related degradation described.
26 Documentation Section 4.2, when wilt the staff receive the results of the screening A summary of the screening and ewelustion reeutts will be provided in:
s.; tewet the License Renewei Application. The results of tfm fatigue anetyees process on the remaining plant fluid systems requiring om review? In addition, how will the staff be informed of the types of will stso be provided. Att stgiporting reports and analyses will be sveltabte at Yankee for mRC review.
plant changes made to correct deficiencies in amnoging age-degradetion for those components which are identified at the end of the screening process? The staff has a similar concern regarding fatigue evetustions discussed in the report.
YAEC Report 1727P (page 4) provides the following justification for the 25 CoDAT In Section 4.2.4, YAEC suggests that. only six compone-t are potentietty subject to age-related degradation. The licensee has uped elimination of the mentioned degradstion nochenismo:
a rule-based computer expert system, CODAT, to determine whether components are subject to age-related degradetion. In Appendix 4, the
- 1) Thernetty Induced Strees Retamation was eactuded by WP-5461 itself -
ticensee has described 14 mechanisms that were considered in the because of the operating temperatures (700 F) rewired to sagsport strees evetuation. Four mechanisms identified in EPRI-NP-5461 were excluded.
relaxation.
Why were they excluded?
- 2) Irradiation Incksced Stress Releration, es steted in uP-5461, occurs 2
only in a very high fluence environment (> 6x10" n/cm for fluences >
1 new). Since the reactor vesset, sesociated sigiports, and internets -
are the only components that are egoced to very high fluences and these c y a.;s are not within the scope of components evetuated Ipy CogAT,
'trredletion Induced Strees Retametion can be eliminated as a potentist July 13, 1990 Pageit9
I Yardtee temperse to MC Cements en Pilot Supert (TAEC-1718)
^ 19 Comment # Category NRC Comment VAEC #eeponse i
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oge-related degradation machenism for ett other components evolunted by CoDAT.
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- 3) Swelling has been experienced only within fuel etements. _ since.
CcDAT is not used to evolunte 'any core Internets Swetting can be eliminated as a potentiel age-related degradetion machenism for~ ett other components evetuated by CcDAT.
- 4) Plastic Deformation has been eliminated as a potentist ege-reteted degradation mechanism because Yankee's construction code, Aust g31.1 -
1955, established design limits that preclude reoching a meteriot's, l
yield point.
-I 26 CcDAT The system, meteriet, and envirorumental characteristics for each The types of infor1metion avaltable and used to perform the component component that were used es irput into CODAT should be avaltable for screening evetustions are described in YAEC Report.1727P.
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audit by the staff.
- information styporting CaDAT witt, be avellable et Yankee for NRC review. Verification of the data is in progress.
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l 27 CcDAT The licensee indicate < CODAT does not evaluate fatigue or degradetion For att active coursonents, it was esstamed that the weer and gelling associated with component operations (i.e., general weer and mechanical deg adetion mechanisms would occur. ' Plant progrens will provide the degradetion of ptops and volves). Now were these mechanisms evetuated basis for maneging these mechanisms.
l' for the pilot systema l
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. Fatigue is addressed outside of screening by the following:
1)
A detailed evaluation of usSS components.
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YAEC Response mRC ra==mt Comment # Category '
2) system reviews and walkdowns to identify locations susceptilde-to high cycle fatigue.
The licensee has not discussed the use of maintenance, falture and The pilot system screening woe a binning process to identify those 20 Effective The review of -
' inspection records to determine whether mechanical or fluid components components which are best maneged by effective progress.
Programs and systess are experiencing ege-related degradation, nes the ticensee plant experience is an integret port of our maintenance ewetustion evaluated its saintenance, falture and inspection records to determine - process d ich assesses the ability to manage age-reteted degradetion.1 whether any components or systems have been experiencing age-related See response to Cosenent No. 20 for additionet discussion on issues related to effective programs.
degradation and how was this foi.tored into the pilot system report?
29 Screening Table 4.2 doesn't clearly identify cable troys as an item for Cable trays are considered a structurat sapport cogenent which was reviewed as port of the review of plant structures.
evolustion. Address this staff concern.
30 Effective Section 4.3.3 'Ef fective Program Review' provides examples of I&C OP-4634 provides specific acceptance criterie for pressure evitch The licensee operation. If the switches did not operate at the correct pressure components subject to an ef fective progrant other than EG.
Programs has stated that one effective program is contained in procedure OP-4634 during testing, ISC st@ervision is required to be notified and the
- switch adjusted and/or replaced. Periodically checking the switches and which functionetty checks and, if necessary, adjusts the trip and reset -
points of certain SI actuation switches. Unless the results of OP-4634 adjusting them to meet the acceptuice timits is an effective program.
are adequately trended and specific action taken if certain criteria In this case, t ending does not meesurably add to etyaipment retlebility.
are not met, the stated program may not be effective. Programs or Trending, hoeseve*,13 utilized where appropriate.
. procedures such as these may have to be revised to incorporate trending and corrective action measures.
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YAEC Response MRC Comument
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,t # Category In the various tables throughout the report, there are columns entitled The forset was indeed confusing. Changes have been ande and further 31 Clarity "not stbject to effective prograse or same other simiter title improvements are plamed in conjwiction mitt, the proposed utsenAC IEAPLEX -
beginning with anot".
The "yes" and "no" respenses associated with. Screening 90ethodology revisions.
these re sometimes. difficult to interpret because of the negative title.
32 Clarity Also, in many of the tables, a dash (-) replaces a yes or no response. 'see response to comment #31.
It is not made clear why a yes or no response is not applicable, and in some cases, a component may have a yes or no response while an identical or simitar component has a desh. Clarification is necessary, especiatty in Attachments 0 through G.
The heeting boiler vent stack uns eliminated at tne systeeWstructural-33 Screening In the Attachment C Table,_ structures such as the heeting boiter vent stack are eliminated (Step 1a) because they do not contribute to plant levet under Step 1a. We subsequently picked it to during review at the safety. The staff assumes that a review to assure its failure wilt not c
_ a levet.
The originot methodology and criteria mere ' not affect any safety-related eaulpment has been completed es port of the ' explicit in this eree, however, the proposed changes to the mulgutC NUPLEX Screening feethodology cleerty require review of att non-sofety.
elimination process. Describe the process used ty the licensee to structures or components idiose felture could directly impact safety reach the specific conclusion for the above component.
related components.
34 Screening In Attachment D, the circulating water system and equipment floor The circulating water system uns assumed to' felt in the flooding ;
drainage system (EFDS) are elleinsted (Step Ib) based on. their. anstysis and was determined to have no impact on safe shutdoun of the degradation not be!M significant to plant safety. From a flooding plant. Likewise, no credit uns taken for the floor drain system in the standpoint, it is not cleer why they shculd be elimineted. This is flooding anetysis. Therefore, its failure etso will not prevent safety.
especie11y true for the EFDS. Itany ftcoding ano1yees may be based or; shutting down the pfant.
the ability of the EFDS to handle ? specific minimum flow rate and to July 13, 1990 Pageif12
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Yestee Bospense to MC Comments an Pilot Report (VMC-f719)
' YAEC aeopense Cceament i ~ Category
~
~ NRC Comment prevent beckflow into certain erees.' Aging effects on the EFDS piping cause flow redactions uhich couid effect flooding anstyses
- moy
' (removat rate and beckflow), and the operability of certain chect;-
- valves could also affect flooding analyses. Further Justification for
-eliminetton should be provided to address the stated staff's concern.
Section 4.3.3 Lists a rum 6er of general attritutes of an effective The distinction between the three attributes are as follows:
35 Effective program to assure ' continued instrismentation and control ~ sm -a Programs operability. Among those listed attributes are, checking for worn " checking for. worn ports" Looking for the physical siers of end>-
component mechanical weer.
ports, observation and visuet inspection.' It is not eteer that there Is e distinction between these three attributes and whether specific '
guidance and criteria are given for each. Pteese clarify how each of "vistat inspection" Looking for signs of potentist-environment induced degradation.. For these attributes specifically contributes to an effective program.
exemple, corrosion or pitting; or the presence of moisture or dirt that could Leed to degradation.
" observation" Looking for signs of - abnonnet instrument operation.
Also in Section 4.3.3,'It is indicated that certain instrumentation and The comments were not meant to lepty insufficient program effectiveaeos.
36 Effective The programs have cteerty demonstrated effectivenwas over the life of..
Programs control. components - are streedy covered by en effective program.
Further discussion is _ then provided irksicating that ordiancements to the plant. Momever, it was recognized that enhancement in the areas of fonnalized dote collection and documenting generet' conditions may be existing programs are being considered to increase emphasis on the Justified in some cases. leplamentation of the seethodology provides a following:
pretiminery aseosoment of the capability of plant programs to proeide n
. Assessment of component generet condition and signs of...
the beefs for managirg ege-related degradetion Adring the rensuel 1.'
July 13, 1993
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Yanitme 8sepense teMC Cameents en Pilot Saport (YMC-1718)
YAEC Response WRC Comment C-
,t # Category abnonent operation.
period. Yankee furt V reviews the _. -.:s and programs to amoure continued effect M ness. Erdienced trending and date cettaction rotated to ISC compone.sts will be included in the overett plan, as necessory.
2.
Data cettection fcc trending.
It" appears -that the programs as they exist today, may not. be sufficiently effective in controtting or detecting age-related Provide more degradstion of instrumentation and controt components.
details regarding these enhancements and how such ergiancements will be-made rather than just considered.
caution will be exercised to assure that designs,, applicetions,
~37 Screening Section 4.4.1, caution snould be exercised in evolusting components such as cables, penetrations, relays, etc. on a generic basis. Because stressore, and environments typical for the a..; are considered to w
assure that ett components within the evetustion witt be bo m foe. '
designs, applications, stressors, and environment on which they operate may dictate what aging mechanisms are operative and importantly, uhat witt be the rate of their degradotion, if any?
Section 4.4.3 describe how the " erosion" of the MOV bodies (an aging section 4.4.3 discusses the review of effective programs forf the '
38 Effective mechanism) is addressed in the periodic ftmetionet testing procedures.
Emergency Electrical Power System. mn evetuation for erosW. of MOV Programs How are aging mechanisms at verlous degradetion sites within the MOV vetve bodies was performed using CoDAT and is represented 'n Attac E of the draft Pilot Evetustion geport (refer to sec' son 4.2.3).
boundary addressed in the YWPS procedJre?
Witt Cables will be evolueted on a generic basis to the extent possible.
The 39 Screening Table 4.1, the cable group has been categorized as conductors, cables be evolueted genericatty? If so, will th e include insutsting cable has two main functions: (1) to conduct electricity and (2) to isolate the electricity from its surrounding environment.
Thus,'the' meteriets or just the conducting portion (current carrying conductors)
Insulating meditan will be addressed relative to the second function.'
of the cable systems?
July 13/ 1990
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Coussent # Category '
IHtC Comument YAEC Response
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40 Effective In Section 4.4.3, YAEC states that the acceptability of a request for The diagnostic testing program that will be. implemented on motor '
Programs renewal of a plant license will depend,-In part,' on the degree of. operated velves (MOWS) Witt include att MOWS thet are respaired to meet -
confidence existing in the rapahitity of ~ ' plant components performing. Generic Letter 89-10, ' Safety Related Motor Operated velve Testing and ;<
their safety functions. With respect to actor-operated velves (Movs),
Surveittance* guidelines.
the report states that a program wilt be laptemented in accordance of Generic Letter 89-10, " Safety-related Motor-operated Velve Testing and Surveittance." One espect of the Program that will be considered is its scope.
The report states that " critical plant MOVs will be included in a diagnostic testing program..This stated scope of the program appears to be more restrictive than that recommended by the staff in Generic Letter 89-10.
- 1 Effective Section 4.5.3 discusses estabtished - effective replacement,.. The enhancements sugge.ed are associated with fonnetization of existing Programs refurbishment, or inspection programs.. The License indicates that the. routine inspection practices and possible follow-up exams of specific programs for the screenuett house er::t seat pit may need eYee-.t.
areas.
The emancements for these structural components will need additionet review.
42 Screening Identify the criteria to be used in the Masonry Watts Survey Program Masonry wells within the scope of IEg 80-11 for Yankee are currently discussed in the test paragraph of page 38.-
Inspected each outage for signs of cracking or degradation. The scope J
?= covered by this program are defined by the plant's current ticensing basis. Depending on the finst criteria used for deteristnieg systems and structures for license reneust, additionet wells may be added to the existing inspection program (f.e, included as port of IES 80-11 welkdowns).
-Page h 15 July 13, 1990
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16 Yaptoe asepense to ERC rm==mmssts an Pilot Report (TAEC-1719)
YAEC Response
-WRC Lamment Comment # Category The structuret esseeement of support components (reference Comment 21) -
' 43 screening on page 39, you identified sipport components es port of the aging degredation revieu.
Provide a specific 'tisting of the support consider the following:
. compments considered in this ef fort.
-.Structuret steet (Including Solting,-Welds,'and Sese Pietes)^
- Spring Supports
- Pre-engineered Pipe Sapport Itans
- Light-Gage feetet (i.e., (Jnistruts)
- Solid Ltbricants
- Conduits
- Electricot Somes
- Raceweys
- Conduit Clasps
- Instrument Rocks
- Instrument Penets
- Pouer Penet Bones snubbers are routinety inspected and refurefehed or reptoced in-accordance with an established progree. ' As such, they are not included -
in the essessment.
stateriets for the support components are es follows:
a.
Structuret steet:
+ Shapes, ptetes, and hers - ASTM.37 or A36~
+ Botts - ASTM A307, A325, or A193,t. ede 57
+ Structuret Tubing - ASTM A500, Grade 6 '
.+ Weld filter metet - AWS E60KK or E70NX July 13, 1990
-Pageh16 N
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Yartoe Rompense to K Cauments on Pilot esport (VAEC-1MO)
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Comment # Category HRC Comument YAEC Response b.
Spring supports and pre-engineered pipe segport items - carbon steel and staintees' steel (Grinnell standard or equivatent).
Light-gege metet'- teu carbon strip steel (Unistrut rconderd or.
c.
equivalent).
d.
Solid tthricants (Lthrite or fluoropold).
l e.
Instrument racks are fabricated frem structuret steel and tight-(
gage metal.
1 l'
I f.
Penets, bones, conduits,. receways, and conduit clamps are fabricated from comunercial quality carbon steet.
44 Screening on page 40, you addressed the plant welkdom. Clarify if this plant The plant walkdown refers to att structures determined to require a Wa diw.
welkdown applied to the entire plant or just to the safety-injection component review for license renouet. The Pilot Report specifically system.
aMressed the preliminary results for three structures housing Safety injection System components.
45 Screening /
Section 4.5.5. and Attachment L provide some results of the plant. The results of the welkdoun have not been finalized. The majority of Walkdowns ustkdown. However, you do not identify action items to be taken for actions required, however, are in the eree of corrective maintenance.
the various findings. Provide the action recomumended by your finet Some conditions worrent further evaluation to determine the optiansa -
evaluation.
method of repair and need for fottou-te examinettons.
.Pageh17 July 13, 1990 r
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- t-Yardtee Response to IEC Comments on Pilot Report (YAEC-1710) l 18.
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Ccament # Category NRC Comment ~
YAEC Response 46 Screening Attachment C does not specifiestly identify the control room and the The intake structure ' at ' Yankee is' the screerusett house 'eAlch ums intake structure. State if these structures will belong to port of.
reviewed. The control room is considered port of the turbine building your evaluation scope and if yes, indicate where they are identified.
which also was reviewed.
4F Screening Attachment D identifies 70 out of % systems and structures. as - Admittedly, the falture "not detectable" concept is very confusing. The:
potentially significant to plant safety.
It lists the systems and way it was used in the Pilot Report (YAEC-1710) meant thet feiture could '
I structures in whics. f al tur~e is not detectable. YWPS reasoning in - not be detected in a time frame which would practude a plant trip or an addressing why failure cannot be detected should be provided.
undesired result.
It was never implied that the failure was
" undetectable".
The criterion containing the "not detectable" concept has now been eliminated due to the adoption of the definitionet aW
' in the IAJMARC NUPLEX Screening methodology.
l
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48 Effective Based on the analysis described in the Attachment D, can it be prestmed The cogonents in the systems and structures identified by a "Y" in the'.'
Provaums that YWPS will include, as port of the established effective program, test column of Attachment 0 will be reviewed to deteratine coverage by att systems and structures identified as "Y" in the test column?
effective programs (i.e., provided the cogonents are first determined in Steo 2a to be laportant to system safety function).
l 49 Effective' In Attachment E, five out of 392 components with potential age-related Yankee conservatively deferred any assessment of programs associated.
l Pr3 grams degradetion mechanisms have been identified.
Staff comments aruf with pressure botmdery integrity t.mtil af ter the Cc0AT review was concerns that Irwolve step 2g of the NUMARC-NUPLEX methodology are performed in Step 2C.
In fact, rummerous programs are in place that -
clearly reflected in the Attachment E table. seost of the components of address the operability of the SI system components and entensive In-
.Page I 18 July 13, 1990 '
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i Yasse Response to K Coununts en Pilot mayort (YAEC-1710) 119 Ceaumont # Category
'mRC Coimeent YAEC Reepense
-the SI system are not subject to e refurbishment, ' reptocement or : Service Inspections ore perfonned.
Inspection (RRI) program, yet many of them are considered important to system safety functions and port of the RCs pressure bomdery. A The process used to identify the potentiel age-related degradetion -
description of the process for. identifying - the. potentist aging-machenisms is contained within YAEC Report 1727P.
degradation mechaniss:s for the five components should be provided.
50 Scope in Attachment G,
the listing of degradetion mechanism excludes Att system components that have en operability ftsution ere asessmed to
'" fatigue," "weer," and " creep". It is e derstood that " fatigued will esperience weer. Plant progrees associated with these congenents will be evaluated seperately. When and were evolustion for "iseer" and provide the basis for identifying and monitoring the progression of
" creep" will be mode 7 weer.
As identified in YAEC Report 1727P, creep has been eliminated as e -
potentist ege-related degradation mechanism et the Rowe piare. Creep.
was eliminated because the operating temperatures regJired to etyport. -
creep are higher than those associated with the operation of etI systems et the towe plant.
A discussion of fatigue is provided in the response to Cesument me. 27.
51 CoDAT On page G-1, how were the 28 specific degradetion mechanisms The 28 specific mechanisms were established. by reviewing industry established? Were enteriets. stressors, and envirorumentet interactions documents such es, EPRI's NP-5461 report titled, ust Component Life considered in establishing the degradation mechanisms? A listing of Estimation: staterials Deeredation.
Twelve besic meteriet these mechanians should be included in the report.
ctessifications and ' twelve dif ferent process fluids were used ~ to -
describe the plant operating environments. Additionally,'ptent system.
chemistries and operating conditions were evaluated to detemine their.
lupact on the potentist for age-reteted degradotion. This infonmotion
- Page # 19
-July 13, 1990
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artee Desponse to WC Comments en Pilot Report (YAEC-1710).
20 ~
YAEC Reepanse NRC Cannent C -..t # Category uns presented briefly in Attachmer t G of our draft sedunittet aruf.is discussed in greeter detait in YAEC soport 1727P.'-
As indicated on Page 32, the 43
-.:s have not been eliminated but:
In Attachment M, provide the bases for the elimination from review of 92 Effective witt be further evaluated.
the 43 out of 168 IEC s.;s susceptible to age related degradation Programs for which there are no established effective programs for managing aging?
As indicated on Page 37, the 25 cousmnents have not been etiminated but
!n Attachment I, provide the basis for the elimination from review, the 53 Screening will be further evolunted.
25 out cf 99 EEPS components susceptible to age-related degradation for which there are no "estabtished effective programs" for emnoging aging?
Evetustions of the NST and RSS ere in progress outside the scope of 54 Evatustions
!n Attachment E, you indicated that further evaluations will be screening. The results of these evetustions will be summarized in the performed for the NST, RSS and SFP. State when these evetuations Witt License reneuet application. Detailed reeutts witt also be.sveitstde be completed and if you plan to provide the evolustion results for staff review. The same infor1metion should be provided for the boric at Yankee for NRC review.
acid evaluation identified in pages 11 and 12 of this attachment.
Degradetion due to contact with pressesster that'mey contain corrosive Testing at. Yankee hos shown groundseter to be benign as described in 95 Screening /
elements, werrants ' identification of methods of monitoring and - YAEC-1710 (Attachment K).-
Structures ing such effects.
The' assessment provided in Attachment E provides information to assist in Attachment K, description is needed of dat 151 programs and NDE 56 Effective In tne plant walkdooms booed on oweitable industry infonastion. Any NgE activities were used to derive the conclusions presented.
Programs July 13,'1990
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Yodee tempanse to K raments en Pilot suport (19EC-1799) -
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1 21 Coment # Category Mtc Comment YAEC Response Alch may be esysired to address specific structure concerns wilt he ' -
detailed in follow-up evolustions.
57 Screening /
In Attechnent it, reports on neutron and geene heating and irradiation ~ Calculations were performed to show thet neutron ord gemune heeting and Structural effects on concrete, and on boric acid teskoge erosion of concrete are irradiation effects on concrete are within acceptelde limits. " Theeel promised. When witt these reports be eveitable?
results will be = w ired in the RSS report atens with consideration of boric acid teekage.
58 Screening /
Alkati-silica reaction is not limited to certy In the life of the Alkall-silica reaction is not believed to be a. concern 'for 2 the Structural structure. A rather limited took at structures was taken by tooking aggregates used in the construction of the Yankee structures...
only at two reedity accessible futty or portially sr-tumerged structures.
Since degradation from such chemical' reactions of aggregates can be distribute througri the entire structure, it is not cteer. dat IIDE
. technique was employed to reach this conclusion.- Are the fomdation mots free of this problem, and how was this determined?
59 Screening /
Chapter 5, Inspection, is an important section of the report, yet it is See resperse to Comment 856.
Structuret significantly abbreviated. Detailed results of the inspection progree is necessary for the staff to complete its review.
i
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l Yankee's Response to NRC Comments On CODAT At:the June 20-21, 1990 meeting between NRC and Yankee-regarding license renewal activities, NRC requested that Yankee include a written basis for key _ decision parameters used in the CoDAT reportLlogic diagrams (in lieu of listing the reference and page' number-that provide the-basis)is to Yankee intends to-develop a more detailed written bas the CoDAT report.
The followingJinformation is provided in response to NRC comments on CoDAT:
NRC Question a)
Table 2, pg. 7 - Boric Acid should be included as a separate environmental parametcr since it plays an important role in corroding carbon steel components when boric acid leaks and comes in contact with carbon steel components.
Yankee Response Boric acid can corrode carbon steel components from-the outside as-a result of system leakage and from the insidetas a result of interactions with systems that normally contain boric acid.
Corrosion.
resulting from boric acid leakage, is addressed by periodic plant inspections as identified in our response to Generic Letter 88-05.
This form of boric acid corrosion or wastage is best identified by performing visual examinations of susceptible locations-and is not. predicted by the expert' system-CoDAT.- However, CoDAT does perform a review for boric acid corrosion for systems which can contain boric acid.
It accomplishes this review by checking the decision' parameter called " Chemicals Added To System" (see Table 2 of YAEC 1727P) _ for the value of boric acid, as well as other types of acids.
The questioning process is shown on the General Corrosion logic diagram'(see success path " ISSUE 25").
NRC Question b)
Section 7.1, pg. 14 - Not all alloying elements in low alloy steel decrease general corrosion-rates, e.g.' chrome in concentration less than 5% produces an increase in the corrosioa rate of steel when immersed in sea water.
Yankee Response ~The basis for the assumption given in Section 7.1 is contingent on the scope of fluid environments found at Yankee.
Clarification of the scope of fluids for whicn this assumption applies will be included in Section 7.1.
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..e Yankee's Response to NRC~ Comments on CoDAT oNRC Question c)
Section 7.4, pg. 15
-Impurities can be introduced to the steam system through
. condenser leaks-and this can cause intergranular attack corrosion.
Yankee Response' It is' recognized that impurities can be introduced-into the boiler feed system by a
way of condenser leaks.
These impurities can lead to conditions that support IGA when the impurities are allowed to concentrate, as they will around the steam generator i
includes moisture separators:and a blzwhich-
. tubes.< However, steam system design owdown system, assures that impurities in the steam j,
are minimized, consequently preventing, IGA.
,1
- In the first decision squ(Single--
Erosion Corrosion NRC Question d)= Attachment-12, are-"yes" Phase) to the question "is the component fluid stagnant?" should produce _"no-issue" and "no" should require-further Westioning.
In erosion / corrosion pH is an'important factor and should be included.
Yankee Response _We agree _that answering 1 the first question "yes" should' produce'"no' issue" and the;
'l diagram has been revised accordingly.
We also agree that pH'is a very important factor when determining'the rate of erosion / corrosion but not when determining' its notential, which is the purpose of d_
CoDAT..
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