ML17269A048
| ML17269A048 | |
| Person / Time | |
|---|---|
| Issue date: | 09/12/2017 |
| From: | Roy Mathew NRC/NRR/DE/EEOB |
| To: | |
| Mathew R | |
| Shared Package | |
| ML17181A349 | List: |
| References | |
| LTR-17-0257, NCP-2017-012 | |
| Download: ML17269A048 (30) | |
Text
NON~ONCURRENCEPROCESS COVER PAGE The U.S. Nuclear Regulatory Commission (NRC) strives to establish and maintain an environment that encourages all employees to promptly raise concerns and differing views without fear of reprisal and to promote methods for raising concerns that will enhance a strong safety culture and support the agency's mission.
Employees are expected to discuss their views and concerns with their immediate supervisors on a regular, ongoing basis. If informal discussions do not resolve concerns, employees have various mechanisms for expressing and having their concerns and differing views heard and considered by management.
Management Directive, MD 10.158, "NRC Non-Concurrence Process," describes the Non-Concurrence Process (NCP), http://nrcweb.nrc.gov:8600/policy/directives/catalog/md10. 158.pdf.
The NCP allows employees to document their differing views and concerns early in the decision-making process, have them responded to (if requested), and attach them to proposed documents moving through the management approval chain to support the decision-making process.
NRC Form 757, "Non-Concurrence Process" is used to document the process.
Section A of the form includes the personal opinions, views, and concerns of a non-concurring NRC employee.
Section B of the form includes the personal opinions and views of the non-concurring employee's immediate supervisor.
Section C of the form includes the agency's evaluation of the concerns and the agency's final position and outcome.
NOTE: Content in Sections A and B reflects personal opinions and views and does not represent official factual representation of the issues, nor official rationale for the agency decision. Section C includes the agency's official position on the facts, issues, and rationale for the final decision.
At the end of the process, the non-concurring employee(s):
Oconcurred
-~ontinued to non-concur D Agreed with some of the changes to the subject document, but continued to non-concur D Requested that the process be discontinued D The non-concurring employee(s) requested that the record be non-public.
~ The non-concurring employee(s) requested that the record be public.
D This record is non-public and for official use only.
¢his record has been reviewed and approved for public dissemination.
NRC FORM 757 U. S. NUCL EA R RE GULATOR Y COMMISSION t~~~~µ:: wu,r01n NON -CONCURRENCE PROCESS ~c P-- ;Ld1-o \ 2...
SECTION A - TO BE COMPLETED BY NON-CONCURRING EMPLOYEE TITLE OF SUBJECT DOCUME NT A0At.1 S ACCESSION NO
-..:1{1{ f{i;,punsc l.L'lti:r lLl Da\*id I .ochb.1wn Co ncerning l'a lo \"c*rde I .ice lhC .*\111c11dml'lll > I (J<1 a11d 21 )() \1 1. 1721-1!\ 703 DOCUMEN T SIGNER SIGNE f' TELEPHONE NO llrian I*.. Ho lian . .c\ I ) () 11 .J j ~* 1270 TITl E ORGANIZATION
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[ ___j DOCUMENT CONTRIBUTOR c:J DOCUMENT REVIE.\NEH [{ ] ON CONCURRENC E NON CONCURRING EMPL.OYE.E S SUPERVISOR John Lubinski TITl.E ORGANIZATION l)ivi ::. iun Di rector NRR DE
- -( ] 1WOULD LIKE MY
~__J N ON -CON C Uf~REN CE CONSIDERED AND WOULD LIK E A WRI TTEN EVALUATION IN SECTION 8 ANO C l l 1WOULD LIKE MY NON-CONCURR ENC E CONSIDERED . BUT A WRITTEN EVALUATI ON IN SECTIONS 8 AND C IS NOl
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NECESSARY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~--!
\!\'HE N THE PROCESS IS COMPLET E. I WOULD LIKE THE NCP FORM 17] PUBLIC l_J NON -P UBLIC REASONS FOR THE NON -CONCURRENCE. POl ENTIAL. IMPACT ON MISSION , AND THE P f~ O POSED ALTERNATIVES (use cont1nua11on pages or att~ ch Word doGUrnenl)
REASO NS !*OJ{ TH E :\ON-CO:\CL 'RR E'JC I*.: J>ropusr:d respon se to UCS j, li1i.:tua ll y incom:c:t :111d is not cn n, i,;1.::nt wit h :\ IH '
rcquir1.:111ents and the Commi ss io n's l\ilicy . T he staff did not fo ll ow th.; c111-r~* 1 1l gu ida nc1.: and ri.:quircrm:n ls tl:lTP 8-X. (jJ)( 's . l.O(lP '
I OC .\.)t i -l 6. 50J (J). 1\hi:n approv in g the lic<.:n sc amc ndn1enl s I*)<) and 200 for Pahl Vi:rdc l *nit .1 l:t°)(i AOT cxti:nsion ,;.
Sec att ad1cd f(ir dcta ikd <.: o mmcnt ~.
1'01 L N rl 1\L Jivll'M" T ON f\'IJSSJO~ :
T he appnwa l of the Palo Vi: rdc l:J)(j c111crgcric) a111cndrn1:11 t is inconsistent wi th th.: N IU ' \1i s~ ion . \/RC Visinn. N l< C Sali:ty Ubjcctivi:s. NRC Reg ul at o r~ E ll~ ctiv C' ncss St rategics, NRC Openness Strnti:gies, and the Principles of'(jom l Regulat ion.
The mnendmcnts t 19<l and 200) failed to pruvick reaso nable assurance of' pl ant sakty . In th e .:vent ol'ccn:1in ch:sig11 basi<; ac cid ent th i:
cu nst' (1 u,'. nccs wpuld sev crd~ in1p;ict pub Ii <: health and safi::t ~. and the cm iwn111cnt.
T l IE l'ROl'USED Al..TE R~ATI \.TS: Rev ise the rc ~ ponsc lette r to i!ddrcss thi: c1> m111 cms and c:u nccrn s.
The app roval (lf Pal u Ve rde Amendments undi:rmi ncs the credi bility ofNRC regu lation and intcrlcr..:s wi th the abilit y or s 1 ~1ff l o ens ure li c cn sec~ ma int ain mininrnm standard' e>f sa li::ty as prcscriht'd hy Ted111ical Spec ilications. Th.: approval oi" the l'a l<> \\:rd c licensing actio1b to extend e111 crgeney diesel gi:nerator allowed nu tagl' times by (J(J(J pi:rccnt is, in 111 y vic1*1. a 111aj0r failure of 1!J c agi:ncy: and demonstrates a fai lure to undcrstand and consistent I) implement regulatory prccedl'nt.
Lessons-learned must he developed and all staff mu st bi: trained to avoid future nun-eunsc rva1iv<: licensing actio1b .
SIGNATURE 1.JR C H)H M 7~ 7 \ 1 1 201 Si Use ADAMS Template NRC-006 (ML063120159)
NCP Attachment -Section A Mr. David A. Lochbaum Director. Nuclear Safety Project Union of Concerned Scientists P 0 Box 15316 Chattanooga . TN 37415
Dear Mr. Lochbaum:
On June 30. 2017 ,' you sent a letter to the U.S. Nuclear Regulatory Commission (NRC or the Commission ) in which you discussed regulatory decisions that the NRC has recently completed related to a loss-of-coolant accident (LOCA) coincident with a loss of offsite power (LOOP) .
Specifically , you referenced the NRC's decisions regarding the following :
- 1) the issuance of Amendment No. 200 2 for Palo Verde Nuclear Generating Station , Unit 3 (Palo Verde) to extend the allowed outage time for an emergency diesel generator (EOG) (Palo Verde EOG amendment)
- 2) the termination of the proposed rulemaking to decouple LOOP from LOCA 3 in accident analyses (LOOP/LOCA rulemaking)
- 3) an amendment request for Donald C. Cook Nuclear Plant, Unit No . 1 (D.C. Cook) to extend the allowed outage time for an EOG' (D .C. Cook EOG amendment)
You stated that, due to ambiguous NRC guidance, these decisions were contradictory. You recommended that the Commission direct the NRC staff to identify and correct guidance shortcomings . In response to your letter, NRC Chairman Kristine Svinicki sent you a letter.
dated August XX . 2017,5 and indicated that the NRC staff would send an additional letter with more information to address your specific concerns . I appreciate your perspectives and share your interest in ensuring that the staff makes sound regulatory decisions based on clear gu idance As you are aware . the NRC has a risk-informed regulatory framework 6 that considers defense-in-depth , risk insights , and safety margins. The NRC requires licensees to include Available in the Agencyw1de Documents Access and Management System (ADAMS) under Accession No ML17181A348.
2 The NRC issued Amendment No 200 at Palo Verde on January 4. 2017 (ADAMS Accession No. ML17004A020)
' The Commission approved the discontinuation of the LOOP/LOCA rule in the Staff Requirements Memorandum to SECY-17-0013 . dated April 21 . 2017 (ADAMS Accession No ML17110A512)
The licensee submitted the license amendment request for D C. Cook on May 28 . 2015 (ADAMS Accession No ML15149A412) 5 Available 1n ADAMS under Accession No. ML17200D011 .
' Examples of guidance that implements this framework indude Regulatory Guide (RG) 1.174 , Revision 2. "An Approach for Using Probabil 1st1c R isk Assessment 1n Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis" (ADAMS Accession No ML100910006); RG 1.177. Revision 1. "An Approach for Plant-Specific.
Risk- Info rmed Dec1sionmaking : Technical Specffications" (ADAMS Accession No . ML100910008): and RG 1 200. Revision 2. "An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities " (ADAMS Accession No. ML090410014).
D. Lochbaum principal design criteria as part of an application for a construction permit' The general design Commented (MRl] : This stmeme-1111 s 1101 consis1en1 w11h criteria (GDC) in Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix A , NRC current regulations such as JO CFR 50 Appendix A. 10 "General Design Criteria for Nuclear Power Plants ," or a plant-specific equivalent, as CFR 50.46, Palo Verde \J FS ,\R Chapters 6.8. and 15 11.c .
incorporated into the current licensing bases of the plant; establish minimum requirements for all los!; of coolant accidc.nt must he considered concurrent the principal design criteria for a proposed facility . These criteria establish the necessary with LOOP in-t:spective of its risL: significance *nus 1s a desip.n basis requirement ~ ote that th e NRC Cunm11ss1on design , fabrication , construction , testing , and performance requirements for structures , systems, rejected the decouple LOOP from LOC A nile mak mg efTon and components important to safety; that is. structures , systems , and components that provide Commented* [MR2Rl):
reasonable assurance that the facility can be operated without undue risk to the health and '='""""""_ _ . ===--"-""""""'='- -:
safety of the public. The NRC also requires plants to be able to safely withstand Ill *
- Commented [MR3Rl]:
IQ!t\'~~pabll)& ~d~ _* events that are described in each plant's Updated Final Commented [MR4]: Agree. But Generi c lcncr 80- '0 dnL"Ci fications until the cond ition can be met. It appears thal the remedial action Generic Letter (GL) 80-30 , "Clarification of the Term 'Operable' as it Applies to Single Failure cannot satisfy accident mitigation when plant is operating fo1 Criterion for Safety Systems Required by TS ," clarifies that the allowed outage time is a 62 days with only one emergency power source an<l if ii fail s temporary relaxation of the single failure criterion . As a result. when in a TS action statement, for a number of reasons. Therefore. the safe operating mock single failures of the remaining operable components are not required to be postulated . This is for licensee to ixrfom1 major repair of the EOG was dunnf the regulatory framework that the NRG uses to evaluate license amendment requests for
- shutdown condition .
proposed revisions to the allowed outage time in TSs. 1 Commented [MRS]: This tcmporruy relaxation only applies for the duration of the LCO thai was appro\'ed in 1he Palo Verde TS. {i.e., This means thar the temporary With regards to the Palo Verde EDG amendment decision, you stated that the NRG failed to rela~ation of N RC ~ rcquin:mcnts for sufficient indepcndt:ncc.
properly consider a single failure, as required by GDC 34 , "Residual heat removal ," and ' redundancy. and testability 10 pcrfonn their safet y functions GOC 35, "Emergency core cooling ," of Appendix A to 10 CFR Part 50 , along with a LOCA and a r assuming a sing.le failure is only for 10 days allowed by the LOOP . When the Palo Verde Unit 3 Train B EOG failed and the licensee entered the approved TS and does not apply when s1aff is rev1ewmg. a associated TS LCO , the licensee requested an extension to the allowed outage time to repair I LAR). Titc NRC staff ha' developed BTI' 8-8 for dc1cnnin1stic review of AOT extension~ (up 10 I .t days) the EOG. As discussed in GL 80-30, single failure of the operable Unit 3 Train A EOG is not required to be considered because the licensee had entered the TS action statement for the I>based on indusll)' requests for ~~(' ~ 1d~~~~~~~1 .,;,:* Il l i Commented [MR6RSJ:
Unit 3 Train B EOG . Further, the NRC staff assessed the impacts of the proposed change on GOC 34 and GDC 35 during its review , but acknowledges that it could have been more clearly I Commented [MR7RS]:
........... -=<> __ =-"----~-"""'--~- *-
documented in the safety evaluation . Nevertheless. the NRC staff did describe several of the i Commented [MRS): *nie roq11ircmen1 is 50 Ji> Sec above key factors leading to its decision in the Palo Verde case in the safety evaluation. including: discussion .
~-=~-*__,...._. . . . . __._._
J Commented [MR9]: No. This is nol rrue . The NRC
- 1) the identification of the root cause of the EOG failure
. approved the extension of an emergency diesel g.enera1or (EDG} allowed outage time from I0 days to 1 1 days 10 allo\\
- 2) the determination that the mode of failure was not common to the other EDGs 1 for continued troubleshooting and repair. Spccificall) . .~ [2]
1
- 3) the determination that a LOCA was not a significant contributor to the increase in risk LCommented [MRlOJ: Sc-c ahovc response and that the risk assessment met the acceptance criteria in RG 1. 177 l Commented [MRll]: NRC response 10 a 2.20t> 1>euuon filed in January 20 17 did not address inaccuracies in nsk I a~sessment. It .was ;us1 ignored by stating that it 1s a separate Additionally, the licensee proposed a significant number of compensatory measures (e .g.,
deployment of three portable diesel generators, use of one diesel generator-driven flexible I issue. Spccifi~d l y. staff did n01 fac1or lhc risk ctmtn ~u_-__:'.* (~j i Commented [MR12]: How can NRC make a statemen t coping strategies (FLEX) makeup pump, suspension of discretionary maintenance and protection of key equipment, and use of other administrative controls) that provided additional
! tha1 a LOCA was 1101 a significant contributor 10 the increase i in risk if the only operating diesel were 10 fail durin ~ dcsiµu
\~~.'.'..":cidenl ~~~.".'- ~00.'.'.1LOC.:~_7_:':1'.;'_".~* f!!~lcd **_ _1 41 Similar requirements exist for combined licenses. design certifications. standard design approvals . and Commented [RM13]: Con1pcnsa1ory measure ~ canno1 manufacturing licenses issued under 10 CFR Part 52 . mce1 dcs i~n ba.i;;.cs accident requirements
0 Lochbau m assurance that defense-in-depth and safety margins were maintained . Based on these key Commented [MR14]: 1*hcsc con1pcnsa101) 111c:isu rcs 1 ml~
factors , and in recognition that single failure criterion need not be addressed during this address LOOP and station Black u u1 sc.cnano:-. Thi .; doc..; 11n1 temporary situation for the Unit 3 Train A EOG . the NRC staff approved the one-time extension help for accident scenarios Acc1dc11t scenarios ca111m1 he met hy th e proposed compensatory measures hcc:rnsc of the allowed outage time for the Unit 3 Train 8 EOG . portahlc diesel generators and tle'< make-up pump"i canm 11 meet 1hc llCc1<lcn1 anal ys is assumpti o ns
.. -=-=",_,__-.....,.=---.--*--- -
Your letter compared the D.C. Cook amendment request . which was withdrawn by the _.__,...,.."'<-=<"""-.~.~~-
Comm~nted [MRlS): 11 look> like sialTand 'RC licensee,8 with the NRC staffs approval of the Palo Verde EOG amendment. You stated that a nianagcnu:nl :.tppro,*m g the ~uncndmcnt 1~ 1nh;rprc1mg the lack of clear guidance resulted in the NRC staff reaching contradictory decisions without 50 :t6 and GL 80-30 incom!:Clly objective factors leading to a consistent and repeatable decision . In a draft safety evaluation dated July 8. 2015,9 the NRC staff documented the basis for the planned denial 10 of the \\1hcn ;:1 licensee requests a c hange to the TS (cx1c11d the AOT). whether 11 1s u:mporary or pcmrnm.:nL ii doc ... m\t D.C. Cook EOG amendment request. In the draft safety evaluation . the NRC staff concluded mean thnt the h c:c nscc docs no1 ha\'<" In addn: ss tht* 'iingk that several key factors led to the decision to deny the D.C. Cook EOG amendment request , failur~ crucna The s1afTsti ll has lO ensure 1hat e \l cndin~
including : the AOT from JO days 10 62 days 1s safe and 11 meets all design b:is1s requir ement s This 1s to assure 1hn11 I J sp1!' ..: 1li~d
- 1) the licensee's inability to identify the root cause of the EOG failure acceptable fuel des ig n limit°' :md dl*sign cnnd1t1ons o f !hi.,_*
reactor coola.111 pressure boundary arc not C\CL"l."(.kd a ... ~\
rcsull of an11c1pa1ed opc:ra1tonal occurrences and (2) the core
- 2) the licensee's inability to eliminate the possibility of a common cause failure on the other
- 1s cooled and conr ai mnent i11tcg.n1y :md othe1 vital func11om.
EOG are mmnlamed in the event of 1Xtstu la1ed acc 1de111s lfd1e Cl1mpc11sutory 1ncasurc~~~1~~:.:.~,~ c1L*n 1 dt: f1."I [SJ
- 3) uncertainty as to whethe r the risk acceptance criteria of RG 1.177 were met. in part Commented [MR16Rl5):
because the licensee had not established the technical acceptability of its probabilistic Commented [RMl 7): *111e foo11101e **A ~ a r..:su\I of rh..:
risk assessment model in accordance with RG 1.200 wi thdrawal. the draft denial safc1y ev:llua11011 wa s OC' \'Cr finalized. did 1101 rcccn c nrnnaµcmcnl :ipprm al. :md dnes These key factors were sufficient for the NRC staff to deny the D.C. Cook request. During the rwt represent an ollkial agency pos 111on ~ rt11 ..; 1:-- rm course of the review. the NRC staff appropriately engaged the licensee in a discussion of the nh:orrect statcml*n t Also. 1his 1s 11 0 1 ;.1 dr:1H SI f ht: D( .. [6J licensee's ability to mitigate the consequences of several events. including a LOCA coincident Commented [RM18) :
with a LOOP. assuming a single failure of the operable EOG . In these discussions , the NRC Please note 1lm1 for lhc Palo Verde lir..;t I.A K. the s:u1fT staff sought to establish whether adequate defense-in-depth and safety margins existed to appron.'<i Amendment i\lo I QCJ fo1 21 da~ s for Ct1ntmucd rroubl esh oo1m ~ for ..:.f1111mn n cause and root ca use support the amendment request. However, the NRC staff mistakenly asked the licensee how it l'va lu atm ns 171 met regulatory requirements for this accident sequence and documented the failure to meet this accident sequence as a basis for denial in the draft safety evaluation. As discussed earlier, the Commented [RM19] :
This letter docs not specify L.. ey dc1enn1111s11c fac 1M-. 1hc licensee is not required to protect against a design-basis accident assuming single failure of the N R\ s1afT10 dL"fl)' the DC Cook request 1111.* d..:1cnnmi s11c operable EOG in accordance with GL 80-30. While the NRC staff may have misapplied the i.:oncl usions documcntt.."Cl in the SE stall.~
single failure criterion in the draft safety evaluation as a basis for denial, the staff appropriately T he staff's conclusion was based o n the follov.. mg [8) denied the D.C. Cook EOG amendment request based on failure to meet the other key criteria . Comm~nted [MR20Rl9):
As discussed above . the NRC staff consistently evaluated key factors to reach decisions for the Commented [RM21): No. This i.* not a mi.,ak* Please sec the ahovc response.
Palo Verde and the D.C. Cook requests. Additionally, plant-specific design differences. as well as utilization and capabilities of temporary equipment, were factors in the decisions. Thus. the 'Ille plant must be ahlc tn with stand a LOOP/UJCA '\hen NRC staff pointed to objective factors that resulted in different outcomes for similar licensee 0 1)1.!ralm ~ with only one cmer!!.enc~ diesel ~e nern1 m an 19J requests . Commented [RM22]: Sc<.' lhc commcnls ahm1; i\' K(
- h::1s neither rela'.\cd thl* rcquircmenls for acc 1d1..*n1s nor 1.~xcmp tcd You also discussed the Commission 's term ination of the proposed LOOP/LOCA rulemaking as th e licensee from ntit mcc11n p. th e requtrements fo1 acc1den1!.
Commented [RM23]: No The- staffh:L'i 1101 mi '>apphcd The NRC acknowledged the withdrawal of a license amendment request at O.C Cook (ADAMS Accession the sin~lc failure crneria and accident 111i1ip.:11ion No Ml15156A915) req uirements Avail able 1n ADAMS under Accession No ML15150A035 Commented [RM24]: II 1s m y op1nmn 1ha1 the staff
"' The NRC staff informed the licensee 1n a teleconference on May 30 . 2015. of rts intention to deny the D .C. Cook misapphcd the dc1cnn1111 s111: rcq11i rcm cn1 s for Pain Verde:
EOG amendment request. The NRC ottered th e licensee an opportunrty to withdraw the amendment request and approvul o fl\\ u I A.Rs. ht:.-c<1 usc of senior m anagC"1ncn1 the licensee form ally withdrew the amendment request by letter dated June 1. 2015 (ADAMS Accession directed the s taff lo approvi: lhe amcnd1m"1HS .. (see dc1ai h 111 No ML151548045) As a result of the withdrawal. the draft denial safety evaluation was never finalized . did not the DP<Js filed b~ RI \/ s mffand response filed frn D1: ... llOJ receive management approval. and does not represent an official agency position
D. Lochbaum an example of the NRC staff's inconsistent decisions in considering LOOP and LOCA events.
The proposed LOOP/LOCA rulemaking was not terminated because of safety concerns . The NRC published a Federal Register (FR) notice on June 20, 2017 (82 FR 28017), notifying the public that the LOOP/LOCA rulemaking had been discontinued because the current regulations (i e .. emergency core cooling system functional criteria ) provide adequate protection of public health and safety . During the review of the proposed rulemaking , the NRC staff determined that plant-specific risk insights were necessary in order to proceed with this rulemaking, and the staff did not agree with an industry proposal for a generic risk assessment. The industry then stated the proposed rule would be too costly to implement. With no plans for the industry to implement the rulemaking on a large scale and given the NRC staffs conclusion that safety would be maintained, the Commission approved termination of the proposed LOOP/LOCA rulemaking .
The NRC has guidance in place for each of the processes described above (i. e., rulemaking ,
license amendments, risk-informed decisionmaking) to address scope , purpose . regulatory framework , extent of public participation , use of risk information, and other factors . In addition ,
the NRC staff periodically reviews the adequacy of existing guidance as well as decisions that involve significant resources and/or differing staff views to determine whether updates to NRC guidance are necessary. The NRC staff believes that additional effort is needed to both clarify risk-informed guidance and enhance staff knowledge and use of that guidance . The NRC staff is in the process of responding to Commission direction 11 to update the Commission on the staffs use of risk information in decisionmaking activities. In this paper, the NRC staff plans to include a discussion of staff actions, and will ensure that the paper highlights the steps taken to ensure risk-informed requests to extend TS allowed outage times meet clear risk criteria with appropriate consideration of safety margin and defense-in-depth. In addition, as a result of two differing professional opinions (DP0s) 12 filed by NRC staff regarding the Palo Verde EOG amendments and ongoing staff discussions, the Office of Nuclear Reactor Regulation is taking several actions that had been recommended by the DPO review panel. The actions include evaluating guidance to determine if clarification is required for: (1 ) acceptability of long-duration completion times for one-time extensions and (2) maximum allowed outage times . even when supported with risk information , to limit the amount of time operation without single failure protection is permitted. Also , the staff will determine if clarification is needed for Branch Technical Position 8-8, "Onsite (Emergency Diesel Generators) and Offsite Power Sources Allowed Outage Time Extensions." 13 NRG approvals to extend the TS allowed outage times increase the amount of time when a plant does not fully meet single failure protection . The question is not whether the NRC process should allow this, but to what extent it should be allowed . Early versions of TS , with more limited operating experience and less advanced risk insights , conservatively held equipment allowed outage times to shorter timeframes (e.g., 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for an EOG). One would expect that with greater risk-informed knowledge and more plant-specific operating experience, the NRC is now better able to estimate a reasonable period of time for equipment to be allowed to be out of Commented [RM25]: I f siaff is tr}'mg 10 idc1111f)' RMTS service . Moving in that direction , the NRC recently issued amendments " for Vogtle Electric 4b as an exampl e of extending AOT s. plc~asc no te tha1 1t Generating Plant, Units 1 and 2, that modify the TS requirements to permit the use of allows only for 30 days e ve n fro m a ri sk-in formed principle risk-informed completion times, in accordance with Nuclear Energy Institute 06-og , This docs not j ustit) lh c NRC approval o f LA Rs fo r Pal o 1
Verde for 62 d~ ys . *111is lug.1c docs 110 1 make.* m uch sen se.
Revision 0-A, "Risk-Informed Techn ical Specifications Initiative 4b, Risk-Managed Technical Specifications (RMTS ) Guidelines." 15 These amendments allow the licensee to extend certain The bouom line 1s ri sl-.-infonncd mctJ1ods canno1 brmg bad, a lost o r inoperab le power source for ncc1dcnt mi 11µa11011. 1f
., Available in ADA MS under Accession No. ML17177A397 . th e only opcrnhlc power sour\.:.c fa ils. T ht* NRC staff has 10
'? DPO Case File for DPD-2017-001 and DP0-2017-002 (A DAMS Acces sion No ML17202G468 ) rccogni1..c 1ha1 plants arc ag.mg and com ponent s fai l.
" Available in ADAMS under Acce ssion No . ML113640138 "J11crcforc. is it s.afo for Pulo Verde to opcrall" al full powt"1
" Ava1lable in ADA MS atAccession No . ML15127A669 wi th reduced Safety marg in cmd defense-in- depth for 62
" Available in ADA MS at Accession No. ML122860402. days'? The c urrent determ im s1ic guidance sa ys **1'!0 -
D Lochbaum completion times based on the total risk presented by the current plant configuration and actions that may be needed to respond to emergent conditions. The NRC is in the process of reviewing several similar risk-informed completion time amendments for other plants , including Palo Verde. The staff will continue to consider defense-in-depth and safety margins in completing the NRC"s risk-informed safety reviews and determining whether a requested allowed outage time is too long. These principles, regarding appropriate use of risk insights, apply not only to the NRC"s licensing reviews but also to oversight programs, including the inspection and assessment of plant performance Thank you for providing your perspectives on these recent LOOP/LOCA-related NRC decisions.
I note that you have also provided additional , related views on the Palo Verde and D.C. Cook EOG amendments in several recent blog posts, which the NRC staff will further evaluate .
Again . I appreciate and value your views on these matters and I agree that it is important for NRC guidance to be clear enough to result in predictable and consistent outcomes. Likewise , I agree that it is important for NRC staff to clearly document its safety decisions . I expect that the NRC staff's response to the DPO Panel recommendations and the Commission's recent direction will yield improvements in the regulatory processes and guidance that you seek in your letter.
Sincerely, Bnan E. Holian, Acting Director Office of Nuclear Reactor Regulation
Incoming: ML17181A348 Resoonse: c hairman Letter ML172000011 ; NRR Letter M L17 2 14A 703 *via email OFFICE NRR/DORL/L PL4/PM NRR/DORULPL4/PM* NRR/DORL/LPL4/PM* NRR/DORULPL4/LA NAME MWatford Slinoam LReoner PBlechman DATE 7/20/17 7/27/17 7/27/17 7/20/17 OFFICE OTE" NRR/DORULPL4/BC
- NRR/DEJD* NRRIDRND*
NAME CHsu RPascarelli Jlubinski JGiitter (RFelts for)
DATE 8110117 814/17 818117 814117 OFFI CE NRR/DPR/D* NRR/DSSID* NRR/DORUD OGC-NLO NAME Llund (GBowman for) MGavrilas ABoland
- BMizuno DATE 814117 814117 8114117 819117 OFFICE NRRID!Al NAME BHohan DATE 81 117 Page : [l] Commented [MRS] Mathew, Roy 09/07 /2017 4:38:00 PM This temporary relaxation otily applies for the duration of the LCO that was approved in the Palo Verde TS. (i.e ..
This mean s that the temporary relaxation ofNRC requirements for sufficient independence. redundancy. and testability to perform their safety functions assuming a single failure is only for I0 days allowed by the approved TS and does not apply when staff is reviewing a LAR). The NRC staff has developed BTP 8-8 for deterministic review of AOT extens ions (up to 14 days) based on industry requests for NRC guidance document for perfom1ing major maintenance on line ra ther than shutdown. The temporary relaxation of requirements specified in BTP is based on the fact that licen sees perform major maintenance on the EDGs only once every 7-10 years to improve the reliability of EDGs.
The regulatory Position described in Regulatory Guide 1.93 . '"Availability of Power Sources" (Palo Verde licensing basis) states that If the affected source is restored within the time period specified in the plant-specific TS.
unrestricted operation may resume . Conversely. if the conditions for continued power operation are met. but the source is not restored wit hin the time period specified in the plant-spec ific technical specifications. the unit should be shut down .
Page : [2] Commented [MR9] Mathew, Roy 09/07/2017 4:54:00 PM No. This is not true. The NRC approved the extension of an emergency diesel generator (EOG) allowed outage time from I 0 days to 21 days to allow for continued troubleshooting and repair. Specifically. the license amendment No.
199 was issued for continued troubleshooting for identifying common cause and root cause eva luations. (Refer LAR ). Amendment 200 was approved for additional time (41 days) required to repair the EDGs to be functional and operable.
1 Page : .2 -: [3] Commented [MRll] Mathew, Roy 09/12/2017 4:52:00 PM]
NRC response to a 2.206 petition filed in January 2017 did not address inaccuracies in risk assessment. It was just ignored by stating that it is a separate issue. Specifically. staff did not factor the risk contribution from OPC design vu lnerabili ty at Palo Verde because the licensee has not comp leted the corrective actions. NRC risk assessment of OPC shows as risk significant (ADAMS Accession No. ML I 7223A066). The accuracy of risk assessment which concluded that the risk assessment met the acceptance criteria in RG 1.177 is in error.
Please note that David Lochbaum letter dated August 22. 2017 states "The NRC simply cannot make proper risk-informed deci sions by neglecting known and relevant risk factors. They have been lucky so far. I beg you and your office to compel the NRC staff to cease and desist its practice of neglecting known and relevant risk factors when making purportedly risk-infonned decisions before their luck runs out and someone gets harmed.
- Page : [4] Commented [MR12] Mathew, Roy How ca n NRC make a statement that a LOCA was not a significant contributor to the increase in risk if the only operating diesel were to fail during design basis accident such as LOOP/LOCA? The staff failed to consider all of the NRC requ irements before an amendment is reviewed. Otherwise. NRC must show that Palo Verde has received exemptions from certain regulations .
Page : [5] Commented [MR15] Mathew, Roy 0910112011 s:B;<ioPM]
It looks like staff and NRC management approving the amendment is interpreting the 50.36 and G L 80-30 incorrectly.
When a licensee requests a change to the TS (extend the AOT). whether it is temporary or permanent. it does not mean that the licensee does not have to address the single failure criteria. The staff still has to ensure that extending the AOT from I0 days to 62 days is safe and it meets all design basis requirements. This is to assure that (I) specified acceptable fuel design limits and design conditions of the reactor coolant pressure boundary are not exceeded as a result of anticipated operational occurrences and (2) the core is cooled and containment integrity and other vital functions are maintained in the event of postulated accidents. If the compensatory measures cannot provide sufficient defense-in depth and safety margins for mitigating accident scenarios. then temporary relaxation of the single failure criteria is not acceptable and the staff should recommend that amendment be not approved.
The Com mi ssion did not authorize the use of risk-based principles to approve the license amendment for Palo Verde AOT extension.
Page : [6] Commented [RM17] Roy Mathew 09/10/2017 5:47:00 PM I he l\>otnntc ** As a result of the withdrawal. the draft denial safety evaluation was never finalized. did not receive management approva l. and does not represent an official agency position.'" This is an incorrect statement. Also. this is not a draft SF.. The DC Cook SE was processed by DORL and EEEB staff (ML151548045 and ML I 5 I49A443 )
as official agency records. Also. both NRR and regional senior managers were briefed and approval were received for communicating the results to the licensee .
Page : [7] Commented [RM18] Roy Mathew 09/10/2017 5:56:00 PM Please note that for the Palo Verde first LAR. the staff approved Amendment No. 199 for 21 days for continued troubleshooting for common cause and root cause evaluations.
Page : [8] Commented [RM19] Roy Mathew 09/10/2017 6:07:00 PM This letter does not specify key deterministic factors the NRC staff to deny the DC Cook request. The deterministic conclusions documented in the SE states:
The staffs conclusion was based on the following:
(2) Neither the SDG nor any other power source (NDG and FLEX equipment) are credited in the accident analysis for accident mitigation.
(3) LOOP wi th LOCA and a single fail ure are the licensing and design bases requirements for CNP and the licensee has not demonstrated whether the CNP Unit I can mitigate the consequences of these requirements.
(4) Operating the plant for a period longer than specified in the NRC Branch Technical Position (BTP) 8-8. **onsite (Emergency Diesel Generators) and Offsite Power Sources Allowed Outage Time Extensions." is contrary to the requi rements specified in I0 CFR 50.36(c)(2). "Limiting Conditions for Operation." This BTP states that the EOG Allowed Outage Time shou ld be limited to 14 days to perform maintenance activities.
(5) The proposed operating configuration with on ly one ESF emergency power source do not meet the requirements of I0 CF R 50 .46 and the Cook Plant Specific Design Criterion 39. "Emergency Power." This is due to the fact that accident analysi s assumes one train of emergency AC power is available given a worst-case single failure for all Chapter 14 accidents. Exemptions from these regulations are required to extend the CT for CN P TS for 65 days and
.the licensee has not requested one in accordance with I0 CFR 50.12.
The staff finds that the licensee did not provide adequate assurance that the extended CT cou ld be utilized while maintaining adequate protection of public health and safety and common defense and security. Specifically. the li censee did not provide adequate assurance that the proposed compensatory measures including additional power sources will maintain the required safety functions during the proposed EOG CT extension period. Therefore. the staff concludes that there is not reasonable assurance that safe plant conditions will continue to be maintained:
therefore. the proposed changes are unacceptable."
Page : [9] Commented [RM21] Roy Mathew 09/10/2017 6:16:00 PM No. This is not a mistake. Please see the above response.
The plant must be able to wi th stand a LOOP/LOCA when operating with only one emergency diesel generator and if the only operable EDG fails or malfunctions. The regulations require that defense-in-depth and safety i11argins are maintained while pla nt is in operating mode .
Page : [10] Commented [RM24] Roy Mathew 09/10/2017 6:24:00 PM
It is my opinion that the staff misapplied the deterministic requirements for Palo Verde approval of two LA Rs.
because of senior management directed the staff to approve the amendments (see details in the DPOs filed by RIV staff and response filed for Director's decision on DPOs)
The NRC staff did not follow the staff guidance provided in NUR EG-0800, Standard Rev iew Plan. Branch Technical Position ( BTP) 8-8. "Onsite (Emergency Diesel Generators) and Offsite Power Sources Allowed Outage Time (AOT) Extension s." in that the license amendment No.
199 was iss ued for continued troubl eshooting. common cause and root cause eva luations and licensee amend ment No. 200 was issued for completing the extensive repair.
BTP 8-8 . specifies that the staff should not approve LARs for not more than 14 days. The 14 days was based on allowing licen sees to performed extensive maintenance on EDGs every 7 to 10 years to increase the reli ability of the EDGs.
Also. the current licensing basis for PVNGS TS Completion Time for electric power system is in accordance with Regulatory Guide (RG) I .93 , "Availability of Electric Power Sources." The staff did not review thi s licen sing basis requirements.
NRC FORM 757 U. S. NUCLEAR REGULATORY COMMISSION NCP TRACKING NUMBER NRC MD 10.158 (11-2016)
NCP-2017-012 NON-CONCURRENCE PROCESS SECTION B *TO BE COMPLETED BY NON-CONCURRING EMPLOYEE'S SUPERVISOR TITLE OF SUBJECT DOC UMENT ADAMS ACC ESSION NO .
NRR Response Letter to David Lochbaum Concerning Palo Verde License Amendments 199 and 200 ML17214A703 NAM E John W. Lubinski TITLE TELEPH ONE NUMBER Director (301) 415 -3298 ORGANI ZATION NRR/DE COMM ENTS FOR THE NCP REVIEWER TO CONSIDER (use continuation pages or attach Word document)
See attached SIGNATURE
/ /'XJ NRG FORM 757 (11-2016) / v y Use ADAMS Template NRC-006 (ML063120159)
Section B - COMMENTS FOR THE NCP REVIEWER TO CONSIDER The submitter provided specific comments on the document and I provided my responses to each in the attached.
The following is a central issue provided by the submitter:
Neither the Generic letter 80-30 nor 50.36 states that when a licensee requests a change to the TS in accordance with 50.90, staff does not have to consider single failure criteria. The temporary relaxation of single failure or other requirements only apply for the duration of the LCO that was already approved in the Palo Verde TS (10 days). To approve Palo Verde EOG AOT extension and relaxing requirements again for another 52 days, staff must evaluate the Palo Verde LARs using NRC deterministic guidance provided in BTP 8-8 which limits the AOT extensions to a maximum of 14 days, Palo Verde licensing basis which includes commitment to Regulatory Guide 1.93, "Availability of Power Sources," and applicable regulations such as Appendix A to 10 CFR 50, 10 CFR 50.46, and 10 CFR 50.36. The staff erroneously approved amendments without sufficient regulatory and safety bases how Palo Verde met the NRC guidance and requirements. The regulations and Commission's risk-informed Commission Policy require that it should meet the licensee meets regulations, defense-in-depth, and safety margins are maintained while plant is in operating mode in addition to the risk principles.
I provide the following comments for the reviewer to consider in response to this issue .
- 10 CFR 50.36(c)(2) "Limiting conditions for operation" states that limiting conditions for operation are the lowest functional capability or performance levels of equipment required for safe operation of the facility. It goes on to state that technical specifications for the limiting conditions must be established. These are established as limiting conditions of operation (LCOs) for specific equipment (note: the submitter refers to these as allowed outage times (AOTs)). Therefore, it is recognized that during an LCO, plants may not meet all design basis requirements. GL 80-30 provides additional information in this regard. GL 80-30 states, with respect to LCOs, that the specified time to action, usually called the equipment out-of-service time, is a temporary relaxation of the single failure criterion. GL 80-30 addresses the question that NRC may establish LCOs during which licensees would not meet design basis requirements if a single failure were to occur.
TSs for LCOs were established at initial plant licensing. When a licensee request an amendment to LCOs, the licensee is requesting a revised licensing basis with respect to the requirements of 50.36. The regulatory requirements for approving or denying the request are no different than for the initial LCOs. Therefore, staff can approve extensions to LCOs during which time the licensee would not meet design basis requirements if a single failure were to occur.
Licensing guidance, such as, BTP 8-8, is one way to meet regulatory requirements. However, it is not the only way. Licensees may proposal alternative approaches for meeting regulatory requirements. In doing so, I agree with the submitter that before approving an LCO extension the staff needs to ensure that safety is maintained. I believe the use of risk insights is appropriate in making this determination. When ensuring adequate safety margin and defense-in-depth , the staff needs to understand and evaluate the extent to which the plant can mitigate a design basis accident if a single failure were to occur.
Mr. David A. Lochbaum Director, Nuclear Safety Project Union of Concerned Scientists P.O. Box 15316 Chattanooga, TN 37415
Dear Mr. Lochbaum:
On June 30, 2017, 1 you sent a letter to the U.S. Nuclear Regulatory Commission (NRG or the Commission) in which you discussed regulatory decisions that the NRG has recently completed related to a loss-of-coolant accident (LOCA) coincident with a loss of offsite power (LOOP).
Specifically, you referenced the NRC's decisions regarding the following:
- 1) the issuance of Amendment No. 2002 for Palo Verde Nuclear Generating Station, Unit 3 (Palo Verde) to extend the allowed outage time for an emergency diesel generator (EOG) (Palo Verde EOG amendment)
- 3) an amendment request for Donald C. Cook Nuclear Plant, Unit No. 1 (D.C . Cook) to extend the allowed outage time for an EDG 4 (D.C. Cook EOG amendment)
You stated that, due to ambiguous NRG guidance, these decisions were contradictory. You recommended that the Commission direct the NRG staff to identify and correct guidance shortcomings. In response to your letter, NRG Chairman Kristine Svinicki sent you a letter, dated August XX, 2017, 5 and indicated that the NRG staff would send an additional letter with more information to address your specific concerns. I appreciate your perspectives and share your interest in ensuring that the staff makes sound regulatory decisions based on clear guidance.
As you are aware , the NRG has a risk-informed regulatory framework 6 that considers defense-in-depth, risk insights. and safety margins. The NRG requires licensees to include Available in the Agencywide Documents Access and Management System (ADAMS) under Accession No. ML17181A348.
2 The NRG issued Amendment No. 200 at Palo Verde on January 4, 2017 (ADAMS Accession No. ML17004A020).
3 The Commission approved the discontinuation of the LOOP/LOCA rule in the Staff Requirements Memorandum to SECY-17-0013. dated April 21 , 2017 (ADAMS Accession No. ML17110A512).
' The licensee submitted the license amendment request for D.C. Cook on May 28 , 2015 (ADAMS Accession No. ML15149A412) .
5 Available in ADAMS under Accession No. ML17200D011 .
6 Examples of guidance that implements this framework include Regulatory Guide (AG) 1.174. Revision 2, "An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis" (ADAMS Accession No. ML100910006); AG 1.177, Revision 1. "An Approach for Plant-Specific, Risk-Informed Decisionmaking: Technical Specifications" (ADAMS Accession No . ML100910008); and AG 1.200. Revision 2, "An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities" (ADAMS Accession No . ML090410014).
D. Lochbaum principal design criteria as part of an application for a construction permit. 7 The general design Commented [MRl]: 'This statement is not consistent with criteria (GDC) in Title 1O of the Code of Federal Regulations (1 O CFR) Part 50, Appendix A, I NRC current regulations such as 10 CFR 50 Appendix A, 10 "General Design Criteria for Nuclear Power Plants," or a plant-specific equivalent, as CFR 50.46, Palo Verde UFSAR Chapters 6,8, and 15 (i.e.,
incorporated into the current licensing bases of the plant, establish minimum requirements for all loss of coolant accident must be considered concurrent the principal design criteria for a proposed facility. These criteria establish the necessary with LOOP irrespective of its risk significance. 'This is a design basis requirement. Note that the NRC Commission design, fabrication , construction, testing, and performance requirements for structures , systems , rejected the decouple LOOP from LOCA rule making effort.
and components important to safety; that is, structures, systems, and components that provide reasonable assurance that the facility can be operated without undue risk to the health and
- Commented [MR2Rl]:
safety of the public. The NRC also re uires plants to be able to safely withstand Commented [MR3Rl]:
11*********lllllllJ1R}lven~ th?t '!r~ des_cri~ed in each p~ant's_ L)pd_a!ed Final Commented [U4Rl]: 'This is consistent It states that the Safety Analysis Report (i.e., design-basis accidents ; for example, a LOCA coincident with a plant must meet alJ regulations when not in an LCO.
LOOP with the assumption of a single failure) . Further, the NRC approved the technical No change recommended.
specifications (TSs) for each plant, which established the limiting conditions for operation
, Commented [MRS]: Agree. But, Generic letter 80-30 does (LCOs)-the lowest functional capability or performance levels of equipment required for safe not state that when a licensee requests a change to the TS, it operation of the facility . When a component described in the TSs is inoperable, the licensee does not have to consider single failure criteria for safety enters the action statement and is required to take action in a certain amount of time (i.e., the systems for mitigating LOCA. 10 CFR 50.36 (c)(2) states allowed outage time). The licensee can request an extension to the allowed outage time based that Limiting conditions for operation are the lowest r:::f1] .
upon an evaluation of plant-specific defense-in-depth , risk insights, and safety margins. Commented [U6RS]: GL 80-30 states the licensee I
peneric Letter (GL) 80-30, "Clarification of the Term 'Operable' as it Applies to Single Failure receives a temporary relaxation of the single failure crir.::r2]
'I Criterion for Safety Systems Required by TS," clarifies that the allowed outage time is a I
- Commented [MR7]: This temporary relaxation only
~empora~J~l?x_a!iQI'! gf _ttie_sJl'!g!e_f?i!UJ~ 12~~'1_0~._ As a resul!, ~h~Q Ln_a_i:s ?C_tis>Q i;tatement, ('. ** applies for the duration of the LCO that was approved C[3l single failures of the remaining operable components are not required to be postulated. This is Commented [MRBR7]:
the regulatory framework that the NRC uses to evaluate license amendment requests for proposed revisions to the allowed outage time in TSs. Commented [MR9R7]:
With regards to the Palo Verde EOG amendment decision, you stated that the NRG failed to I
Commented [Ul0R7]: This comment is addressed Gi section B comments. In addition, BTP 8-8 is aguidan1 ... [41 properly consider a single failure, as required by GDC 34, "Residual heat removal," and Commented [MRll]: The requirement is 50.36. See GDC 35, "Emergency core cooling ," of Appendix A to 10 CFR Part 50, along with a LOCA and a , above discussion.
LOOP. When the Palo Verde Unit 3 Train B EOG failed and the licensee entered the I Commented [Ul2Rll]: See above response.
associated TS LCO, the licensee requested an extension to the allowed outage time to repair ', I the EOG. As discussed in GL 80-30, single failure of the operable Unit 3 Train A EOG is not Cr5l
'I Commented [MR13]: No. 'This is not true. The NRC
~equire~ tq_ ~e q_O!J!)id~r~c! ~~C?l,JS,e_ the lice11see hE!cj ~ntere(j !he_TS f!CtiQI'! s.t?t~m~ri_t f~r J~e 1 approved the extension of an emergency diesel generair.::r6]
Unit 3 Train B EDG . Further, the NRC staff assessed the impacts of the proposed change on I GDC 34 and GDC 35 during its review, but acknowledges that it could have been more clearly I Commented [Ul4Rl3]: The information highlighted is documented in the safety evaluation. Nevertheless, the NRC staff did describe several of the I I
I I
addressing amendment 200 and not amendment 199. ..r:::r7l key factors leading to its decision in the Palo Verde case in the safety evaluation, including: 1, I Commented [MRlS]: See above response.
1, I II I Commented [Ul6Rl5]: See response above.
- 1) ~he identification of the root cause of the EOG failur~
- 1 ; I
.J ,,
Clsl
,,,, Commented [MR17]: NRC response to a 2.206 petition
- 3) ~he determination that a LOCA was not a significant contributor to the increase in risk Commented [Ul8Rl7]: This letter is not respon~~
either the referenced 2.206 petition nor the August 2 ... [10]
and that the risk assessment met the acceptance criteria in RG 1.1 17711 ,.
' Commented [MR19]: How can-NRC make a statement Additionally, the licensee p roposed a significant number of compensatory measures !(e.g., that a LOCA was not a significant contributor to the iLJiil deployment of three portable diesel generators , use of one diesel generator-driven flexible *' Commented [U20R19]: As discussed, the staff coping strategies (FLEX) makeup pump, suspension of discretionary maintenance and I
I '
considered the risk associated with a single failure anGLll I
protection of key equipment, and use of other administrative controls) that provided additional I Commented [RM21]: Compensatory measures cannot I meet design bases accjdent requirements.
I Similar requirements exist for comb ined licenses, design certifications, standard design approvals, and Commented [U22R21]: I agree that the compens a &
manufacturing licenses issued under 10 CFR Part 52. measures may not meet all design bases accident ... [131
D. Lochbaum assurance that ~efense-in-depth and safety margins r.vere maintained. Based on these key Commented [MR23]: These compensatory measures only factors, and in recognition ~hat single failure criterion need not be addressed ~ uring this address LOOP and station Blackout scenarios. This does not temporary situation for the Unit 3 Train A EOG , the NRC staff approved the one-time extension I help for accident scenarios. Accident scenarios cannot be met by the proposed compensatory measures because of the allowed outage time for the Unit 3 Train B EOG . portable diesel generators and flex make-up pumps cannot
' meet the accident ana1ysis assumptions.
Your letter compared the D.C. Cook amendment request, which was withdrawn by the Commented [U24R23]: I agree. Defense-in-<lepth aod licensee, 8 with the NRC staff's approval of the Palo Verde EOG amendment. You stated that a safety margin were considered in addressing the ri sk-lack of clear guidance resulted in the NRC staff reaching contradictory decisions without I I
infonned evaluation and not to meet regulatory requirements objective factors leading to a consistent and repeatable decision . In a draft safety evaluation with a single failure.
dated July 8, 201\5, 9 ~he r:JRC staff documented the basis for the planned denial 10 of the No change recommended.
D.C. Cook EOG amendment request. In the draft safety evaluation, the NRC staff concluded that several key factors led to the decision to deny the D.C. Cook EOG amendment request,
- Commented [MR25]: It looks like staff and NRC including: \ management approving the amendment is interpreting the 1 11 50.36 and GL 80-30 incorrectly. I
- 1) ~he licensee's inability to identify the root cause of the EOG failure When a licensee requests a change to the TS (extend Crl4ll 1 1
,\ Commented [MR26R25]:
- 2) the licensee's inability to eliminate the possibility of a common cause failure on the other I 1'
EOG .1
'1 Commented [U27R25]: This is addressed in my Section I \ B comments.
3} uncertainty as to whether the risk acceptance criteria of RG 1.177 were met, in part Commented [RM28]: The footnote "As a result of the because the licensee had not established the technical acceptability of its probabilistic 1 withdrawal, the draft denial safety evaluation was neCfiSl risk assessment model in accordance with RG 1.20Q Commented [U29R28]: I recommend this footnote be reworded to clarify the purpose of the draft safety evCfi61 frhese key factors were sufficient for the NRC staff to deny the D.C. Cook request. !During the Commented [RM30]:
course of the review, the NRC staff appropriately engaged the licensee in a discussion of the Please note that for the Palo Verde first LAR, the staCITTJ licensee's ability to mitigate the consequences of several events, including a LOCA coincident \
with a LOOP, assuming a single failure of the operable EOG. In these discussions, the NRC I\ Commented [U31R30]: This section is addressing the I\
D.C. Cook amendment, not the Palo Verde amendmeLJ18l staff sought to establish whether adequate defense-in-depth and safety margins existed to I
,, \
support the amendment request. However, the NRC staff mistakenly asked the licensee how it Commented [RM32]:
met regulatory requirements for this accident sequence and documented the failure to meet this 1* This letter does not specify key deterministic factors Cfi9l accident sequence as a basis for denial in the draft safety evaluatio~l [!.§ sli!>~u_S§~d- ~a_rtLe!, _tl:l_e_ I Commented [MR33R32]:
licensee is not required to protect against a design-basis accident assuming single failure of the 1' Commented [U34R32]: The letter does not need Lo operable EOG in accordance with GL 80-3d, ~_ti~e_ t!_l~ ~B9 _s!a_ff_n:i'!}'_h_9.~~ i:!lLS~Q~i~q !.h!l __
single failure criterion in the draft safety evaluation as a basis for denial, the staff appropriately
- I I include all of the reasons the staff planned to deny thCf20]
1' \ Commented [RM35]: No. This is not a mistake. Please denied the O.C. Cook EOG amendment request based on failure to meet the other key criteria;.
I\'
,, ' \
see the above response. um
~s discussed above, the NRC staff consistently evaluated key factors to reach decisions for the I 1'1' Commented [U36R35]: As noted in my Section B Palo Verde and the D.C. Cook requests. Additionally, plant-specific design differences, as well \\ 1' comments, plants are provided temporary relaxation C!22J II' '
as utilization and capabilities of temporary equipment, were factors in the decisions . Thus, the II' 1
Commented [RM37]: See the comments above. NRC has 1 I NRC staff pointed to objective factors that resulted in different outcomes for similar licensee , neither relaxed the requirements for accidents nor exei231 1\
requests. I I I Commented [U38R37]: See response above.
\1 LJ241 You also discussed the Commission's termination of the proposed LOOP/LOCA rulemaking as ' Commented [RM39]: No. The staff has not misapplied 1' \
the single failure criteria and accident mitigation .Ci25]
1\ I 8 The NRC acknowledged the withdrawal of a license amendment request at D.C . Cook (ADAMS Accession I\
Commented [U40R39]: As noted in my Section B I I No. ML15156A915) . comments, plants are provided temporary relaxation C[26J Available in ADAMS under Accession No. ML15150A035. ' I 10 The NRC staff informed the licensee in a teleconference on May 30, 2015, of its intention to deny the D.C. Cook Commented [RM41]: IL is my opinion that the staff I misapplied the deterministic requirements for Palo vG27]
EOG amendment request. The NRC offered the licensee an opportunity to withdraw the amendment request and the licensee formally wtthdrew the amendment request by letter dated June 1, 2015 (ADAMS Accession Commented [U42R41]: As noted by the submitter, these No. ML151548045). As a result of the wtthdrawal, the draft denial safety evaluation was never finalized , did not concerns have already been addressed in response to LJ28l receive management approval, and does not represent an official agency position .
D. Lochbaum an example of the NRC staff's inconsistent decisions in considering LOOP and LOCA events .
The proposed LOOP/LOCA rulemaking was not terminated because of safety concerns. The NRC published a Federal Register (FR) notice on June 20, 2017 (82 FR 28017) , notifying the public that the LOOP/LOCA rulemaking had been discontinued because the current regulations (i.e., emergency core cooling system functional criteria) provide adequate protection of public health and safety. During the review of the proposed rulemaking, the NRC staff determined that plant-specific risk insights were necessary in order to proceed with this rulemaking, and the staff did not agree with an industry proposal for a generic risk assessment. The industry then stated the proposed rule would be too costly to implement. With no plans for the industry to implement the rulemaking on a large scale and given the NRC staff's conclusion that safety would be maintained , the Commission approved termination of the proposed LOOP/LOCA rulemaking .
The NRC has guidance in place for each of the processes described above (i.e., rulemaking ,
license amendments, risk-informed decisionmaking) to address scope, purpose, regulatory framework, extent of public participation, use of risk information, and other factors. In addition, the NRC staff periodically reviews the adequacy of existing guidance as well as decisions that involve significant resources and/or differing staff views to determine whether updates to NRC guidance are necessary. The NRC staff believes that additional effort is needed to both clarify risk-informed guidance and enhance staff knowledge and use of that guidance. The NRC staff is in the process of responding to Commission direction 11 to update the Commission on the staff's use of risk information in decisionmaking activities. In this paper, the NRC staff plans to include a discussion of staff actions, and will ensure that the paper highlights the steps taken to ensure risk-informed requests to extend TS allowed outage times meet clear risk criteria with appropriate consideration of safety margin and defense-in-depth. In addition , as a result of two differing professional opinions (DPOs) 12 filed by NRC staff regarding the Palo Verde EOG amendments and ongoing staff discussions, the Office of Nuclear Reactor Regulation is taking several actions that had been recommended by the DPO review panel. The actions include evaluating guidance to determine if clarification is required for: (1) acceptability of long-duration completion times for one-time extensions and (2) maximum allowed outage times, even when supported with risk information, to limit the amount of time operation without single failure protection is permitted. Also, the staff will determine if clarification is needed for Branch Technical Position 8-8, "Onsite (Emergency Diesel Generators) and Offsite Power Sources Allowed Outage Time Extensions."13 NRC approvals to extend the TS allowed outage times increase the amount of time when a plant does not fully meet single failure protection. The question is not whether the NRC process Commented [RM43]: If staff is trying to identify RMTS 1
should allow this , but to what extent it should be allowed. Early versions of TS , with more 1 4b as an example of extending AOTs, please note that it limited operating experience and less advanced risk insights, conservatively held equipment allows only for 30 days even from a risk-informed principle.
This does not justify the NRC approval of LARs for Palo allowed outage times to shorter timeframes (e.g., 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for an EDG). pne would expect that Verde for 62 days. This logic does not make much sense.
with greater risk-informed knowledge and more plant-specific operating experience, the NRG is now better able to estimate a reasonable period of time for equipment to be allowed to be out of The bottom line is risk-informed methods cannot bring back service. Moving in that direction, the NRC recently issued amendments14 for Vogtle Electric a lost or inoperable power source for accident mitigation, if the only operable power source fails. The NRC staff has to Generating Plant, Units 1 and 2, that modify the TS requirements to permit the use of recognize that plants are aging and components fail.
risk-informed completion times, in accordance with Nuclear Energy Institute 06-09, Therefore, is it safe for Palo Verde to operate at full power Revision 0-A, "Risk-Informed Technical Specifications Initiative 4b, Risk-Managed Technical with reduced safety margin and defense-in-depth for 62 Specifications (RMTS) Guidelines.1' 5. These amendments allow the licensee to extend certain days? The current deterministic guidance says "NO."
Commented [U44R43]: This paragraph is providing 11 Available in ADAMS under Accession No. ML17177A397. examples of use of risk information to extend LCOs. It is 12 DPO Case File for DP0-2017-001 and DP0-2017-002 (ADAMS Accession No. ML17202G468). not citing these examples as justification for approval of the 13 Available in ADAMS under Accession No. ML113640138. Palo Verde amendment.
14 Available in ADAMS at Accession No. ML15127A669.
15 Available in ADAMS at Accession No. ML122860402. No change recommended.
D. Lochbaum completion times based on the total risk presented by the current plant configuration and actions that may be needed to respond to emergent conditions. The NRC is in the process of reviewing several similar risk-informed completion time amendments for other plants, including Palo Verde. The staff will continue to consider defense-in-depth and safety margins in completing the NRC's risk-informed safety reviews and determining whether a requested allowed outage time is too long. These principles, regarding appropriate use of risk insights, apply not only to the NRC's licensing reviews but also to oversight programs, including the inspection and assessment of plant performance.
Thank you for providing your perspectives on these recent LOOP/LOCA-related NRC decisions.
I note that you have also provided additional , related views on the Palo Verde and D.C. Cook EOG amendments in several recent blog posts , which the NRC staff will further evaluate.
Again , I appreciate and value your views on these matters and I agree that it is important for NRC guidance to be clear enough to result in predictable and consistent outcomes. Likewise , I agree that it is important for NRC staff to clearly document its safety decisions . I expect that the NRC staff's response to the DPO Panel recommendations and the Commission's recent direction will yield improvements in the regulatory processes and guidance that you seek in your letter.
Sincerely, Brian E. Holian , Acting Director Office of Nuclear Reactor Regulation
Incoming: ML17181A348 Response: c hairman Letter ML17200D011 ; NRR Letter ML17214A703 *via email OFFICE NRRIDORL/LPL4/PM NRR/DORULPL4/PM ' NRRIDORULPL4/PM' NRR/DORULPL4/LA NAME MWatford Slinaam LReaner PBlechman DATE 7/20/17 7/27/17 7/27/17 7/20/17 OFFICE OTE* NRR/DORULPL4/BC' NRR/DE/D* NRRIDRA/D*
NAME CHsu APascarelli Jlubinski JGiitter (RFelts for)
DATE 8/10/17 8/4/17 8/8/17 8/4/17 OFFICE NRRIDPR/ D' NRR/DSS/D' NRRIDORUD OGC-NLO NAME Llund (GBowman for) MGavrilas ABoland BM izuno DATE 8/4/17 8/4/17 8/14/17 8/9/17 OFFICE NRRIDIAl NAME BHolian DATE 8/ /17 I Page : [1] Commented [MRS] Mathew, Roy 09/07/2017 4:52:00 PM Agree. But, Generic letter 80-30 does not state that when a licensee requests a change to the TS, it does not have to consider single failure criteria for safety systems for mitigating LOCA . 10 CFR 50.36 (c)(2) states that Limiting conditions for operation are the lowest functional capability or performance levels of equipment required for safe operation of the facility. When a limiting condition for operation of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the technical specifications until the condition can be met. It appears that the remedial action cannot satisfy accident mitigation when plant is operating for 62 days with only one emergency power source and if it fails for a number of reasons . Therefore, the safe operating mode for licensee to perform major repair of the EDG was during shutdown condition.
I Page : [2] Commented [U6R5] Lubinski, John 09/13/2017 6:22:00 PM GL 80-30 states the licensee receives a temporary relaxation of the single failure criterion. Therefore, the licensee is not required to meet all regulations when also having a single failure.
I believe in determining safety impacts of the request, such as when evaluating risk insights, the staff does need to consider safety margin and defense in depth . Jn doing so, the staff needs to consider the level to which a plant can provide accident mitigation but not necessarily to the same level as when not in an LCO.
I recommend the third sentence of the next paragraph be modified to accurately address this point.
I Page : [3] Commented [MR7] Mathew, Roy 09/07/2017 4:38:00 PM This temporary relaxation only appli es for the duration of the LCO that was approved in the Palo Verde TS. (i.e.,
This means that the temporary relaxation of NRC requirements for sufficient independence, redundancy, and testability to perform their safety functions assuming a single failure is only for I 0 days allowed by the approved TS and does not apply when staff is reviewing a LAR). The NRC staff has developed BTP 8-8 for deterministic review of AOT extensions (up to 14 days) based on industry requests for NRC guidance document for performing major maintenance online rather than shutdown. The temporary relaxation of requirements specified in BTP is based on the fact that licensees perform major maintenance on the EDGs only once every 7-10 years to improve the reliability ofEDGs.
The regulatory Position described in Regulatory Guide 1.93, "Availability of Power Sources" (Palo Verde licensing basis) states that If the affected source is restored within the time period specified in the plant-specific TS ,
unrestricted operation may resume. Conversely, if the conditions for continued power operation are met, but the source is not restored within the time period specified in the plant-specific technical specifications, the unit should be shut down .
I Page : [4] Commented [U10R7] Lubinski, John 09/13/2017 6:32:00 PM This comment is addressed in my section B comments. In addition, BTP 8-8 is a guidance document for addressing one method of modifying LCOs and not a requirement for all LCOs.
No change recommended .
I Page : [5] Commented [U12Rll] Lubinski, John 09/13/2017 6:36:00 PM See above response.
No change recommended.
I Page : [6] Commented [MR13] Mathew, Roy 09/07/2017 4:54:00 PM No. This is not true . The NRC approved the extension of an emergency diesel generator (EDG) allowed outage time from 10 days to 21 days to allow for continued troubleshooting and repair. Specifically, the license amendment No.
199 was issued for continued troubleshooting for identifying common cause and root cause evaluations. (Refer LAR). Amendment 200 was approved for additional time (41 days) required to repair the EDGs to be functional and operable.
I Page : [7] Commented [U14R13] Lubinski, John 09/13/2017 6:37:00 PM
The information highlighted is addressing amendment 200 and not amendment 199. Also, this issue was addressed in response to a DPO on amendment 199.
No change recommended.
I Page : [8] Commented [U16R15] Lubinski, John 09/13/2017 6:38:00 PM See response above.
No change recommended.
I Page : (9] Commented [MR17] Mathew, Roy 09/12/2017 4:52:00 PM NRC response to a 2.206 petition filed in January 2017 did not address inaccuracies in risk assessment. It was just ignored by stating that it is a separate issue. Specifically, staff did not factor the risk contribution from OPC design vulnerability at Palo Verde because the licensee has not completed the corrective actions. NRC risk assessment of OPC shows as risk significant (ADAMS Accession No. MLJ 7223A066). The accuracy of risk assessment which concluded that the risk assessment met the acceptance criteria in RG l.177 is in error.
Please note that David Lochbaum Jetter dated August 22, 2017 states "The NRC simply cannot make proper risk-informed decisions by neglecting known and relevant risk factors. They have been lucky so far. I beg you and your office to compel the NRC staff to cease and desist its practice of neglecting known and relevant risk factors when making purportedly risk-informed decisions before their luck runs out and someone gets harmed.
I Page : (10] Commented [U18R17] Lubinski, John 09/13/2017 6:42:00 PM This Jetter is not responding to either the referenced 2.206 petition nor the August 22, 2017, letters. These are being addressed separately.
No change recommended.
I Page : (11] Commented [MR19] Mathew, Roy 09/07/2017 4:59:00 PM How can NRC make a statement that a LOCA was not a significant contributor to the increase in risk if the only operating diesel were to fail during design basis accident such as LOOP/LOCA? The staff failed to consider all of the NRC requirements before an amendment is reviewed . Otherwise, NRC must show that Palo Verde has received exemptions from certain regulations.
I Page ~ 2 -: (12] Commented [U20R19] Lubinski, John 09/13/2017 6:39:00 PM As discussed , the staff considered the risk associated with a single failure and a LOOP/LOCA in making its decision. The staff also considered the extent to which the plant could mitigate such an event. Also, as already noted, the plant is not required meet the single failure criterion with a LOOP/LOCA during an LCO.
No change recommended.
I Page : (13] Commented [U22R21] Lubinski, John 09/13/2017 6:43:00 PM I agree that the compensatory measures may not meet all design bases accident requirements when the plant also has a single failure. As noted, plants are not required to do so during an LCO.
No change recommended.
I Page : (14] Commented [MR25] Mathew, Roy 09/07/2017 5:13:00 PM It looks like staff and NRC management approving the amendment is interpreting the 50.36 and GL 80-30 incorrectly.
When a licensee requests a change to the TS (extend the AOT), whether it is temporary or permanent, it does not mean that the licensee does not have to address the single failure criteria. The staff still has to ensure that extending the AOT from 10 days to 62 days is safe and it meets all design basis requirements. This is to assure that (1) specified acceptable fuel design limits and design conditions of the reactor coolant pressure boundary are not
exceeded as a result of anticipated operational occurrences and (2) the core is cooled and containment integrity and other vital functions are maintained in the event of postulated accidents. If the compensatory measures cannot provide sufficient defense-in depth and safety margins for mitigating accident scenarios, then temporary relaxation of the single failure criteria is not acceptable and the staff should recommend that amendment be not approved.
The Commission did not authorize the use of risk-based principles to approve the license amendment for Palo Verde AOT extension.
I Page : [15] Commented [RM28] Roy Mathew 09/10/2017 5:47:00 PM The footnote "As a result of the withdrawal, the draft denial safety evaluation was never finalized, did not receive management approval, and does not represent an official agency position." This is an incorrect statement. Also, this is not a draft SE. The DC Cook SE was processed by DORL and EEEB staff (MLJ 5154B045 and ML15149A443) as official agency records. Also, both NRR and regional senior managers were briefed and approval were received for communicating the results to the licensee.
I Page : [16] Commented [U29R28] Lubinski, John 09/13/2017*6:48:00 PM I recommend this footnote be reworded to clarify the purpose of the draft safety evaluation . The intent of the sentence should be that the final Agency decision on the license amendment is only final when the person with appropriate authority signs the denial of the amendment request.
I Page : [17] Commented [RM30] Roy Mathew 09/10/2017 5:56:00 PM Please note that for the Palo Verde first LAR, the staff approved Amendment No . I 99 for 2 I days for continued troubleshooting for common cause and root cause evaluations.
I Page : [18] Commented [U31R30] Lubinski, John 09/13/2017 6:53:00 PM This section is addressing the D.C. Cook amendment, not the Palo Verde amendment.
No changes recommended.
I Page : [19] Commented [RM32] Roy Mathew 09/10/2017 6:07:00 PM This letter does not specify key deterministic factors the NRC staff to deny the DC Cook request. The deterministic conclusions documented in the SE states:
The staff's conclusion was based on the following:
"(l) The SDGs, NDG, and the compensatory measures are not able to supply power to the ESF loads for accident mitigation within the time constraints of the accident analyses assumptions (UFSAR Chapter I 4 requirements).
(2) Neither the SDG nor any other power source (NDG and FLEX equipment) are credited in the accident analysis for accident mitigation.
(3) LOOP with LOCA and a single failure are the licensing and design bases requirements for CNP and the licensee has not demonstrated whether the CNP Unit I can mitigate the consequences of these requirements.
(4) Operating the plant for a period longer than specified in the NRC Branch Technical Position (BTP) 8-8, "Onsite (Emergency Diesel Generators) and Offsite Power Sources Allowed Outage Time Extensions," is contrary to the requirements specified in 10 CFR 50.36(c)(2), "Limiting Conditions for Operation." This BTP states that the EDG Allowed Outage Time should be limited to 14 days to perform maintenance activities.
(5) The proposed operating configuration with only one ESF emergency power source do not meet the requirements of 10 CFR 50 .46 and the Cook Plant Specific Design Criterion 39, "Emergency Power." This is due to the fact that accident analysis assumes one train of emergency AC power is available given a worst-case single failure for all Chapter 14 accidents. Exemptions from these regulations are required to extend the CT for CNP TS for 65 days and the licensee has not requested one in accordance with 10 CFR 50.12.
The staff finds that the licensee did not provide adequate assurance that the extended CT could be utilized while maintaining adequate protection of public health and safety and common defense and security. Specifically, the
licensee did not provide adequate assurance that the proposed compensatory measures including additional power sources will maintain the required safety functions during the proposed EDG CT extension period. Therefore, the staff concludes that there is not reasonable assurance that safe plant conditions will continue to be maintained; therefore , the proposed changes are unacceptable."
\ Page : [20) Commented [U34R32] Lubinski, John 09/14/2017 5:54:00 AM The letter does not need to include all of the reasons the staff planned to deny the application. Also, as noted in my Section B comments, the third item listed by the submitter is not adequate justification for denial.
No change recommended .
\ Page : [21) Commented [RM35] Roy Mathew 09/10/2017 6:16:00 PM No. This is not a mistake. Please see the above response.
The plant must be able to withstand a LOOP/LOCA when operating with only one emergency diesel generator and if the only operable EDG fails or malfunctions. The regulations require that defense-in-depth and safety margins are maintained while plant is in operating mode.
\ Page : [22) Commented [U36R35] Lubinski, John 09/14/2017 5:57:00 AM I As noted in my Section B comments, plants are provided temporary relaxation from the single fai lure criterion during an LCO.
No change recommended.
\ Page : [23] Commented [RM37] Roy Mathew 09/10/2017 6:18:00 PM See the comments above. NRC has neither relaxed the requirements for accidents nor exempted the licensee from not meeting the requirements for accidents.
\ Page : [24) Commented [U38R37] Lubinski, John 09/14/2017 5:58:00 AM See response above.
No change recommended .
\ Page : [25) Commented [RM39] Roy Mathew 09/10/2017 6:22:00 PM No. The staff has not misapplied the single failure criteria and accident mitigation requirements.
\ Page : [26) Commented [U40R39] Lubinski, John 09/14/2017 5:58:00 AM As noted in my Section B comments, plants are provided temporary relaxation from the single failure criterion during an LCO.
No change recommended.
\ Page : [27) Commented [RM41] Roy Mathew 09/10/2017 6:24:00 PM It is my opinion that the staff misapplied the deterministic requirements for Palo Verde approval of two LARs, because of senior management directed the staff to approve the amendments (see details in the DPOs filed by RIV staff and response filed for Director' s decision on DPOs)
The NRC staff did not follow the staff guidance provided in NUREG-0800, Standard Review Plan, Branch Technical Position (BTP) 8-8, "Onsite (Emergency Diesel Generators) and Offsite Power Sources Allowed Outage Time (AOT) Extensions," in that the license amendment No .
199 was issued for continued troubleshooting, common cause and root cause evaluations and licensee amendment No . 200 was issued for completing the extensive repair.
BTP 8-8, specifies that the staff should not approve LARs for not more than 14 days. The 14 days was based on
allowing licensees to performed extensive maintenance on EDGs every 7 to I0 years t9 increase the reliabi lity of the EDGs .
Also, the current licensing basis for PYNGS TS Completion Time for electric power system is in accordance with Regulatory Guide (RG) 1.93, "Availability of Electric Power Sources." The staff did not review this licensing basis requirements.
I Page : [28) Commented [U42R41] Lubinski, John 09/14/2017 6:00:00 AM As noted by the submitter, these concerns have already been addressed in response to a DPO.
No change recommended.
NRC FORM 757 U.S. NUCLEAR REGULATORY COMMISSION NCP TRACKING NUMBER NRC MD 10.158 (11-2016)
NCP-2017-012 NON-CONCURRENCE PROCESS SECTION C - TO BE COMPLETED BY NCP COORDINATOR TITLE OF SUBJECT DOCUMENT ADAMS ACCESSION NO.
NRR Response Letter to David Lochbaum Concerning Palo Verde License Amendments 199 and 200 ML17214A703 NAME John W. Lubinski TITLE TELEPHONE NUMBER Director (301) 415-3298 ORGANIZATION NRR/DE AGREED UPON
SUMMARY
OF ISSUES (use continuation pages or attach Word document)
See attached EVALUATION OF NON-CONCURRENCE AND RATIONALE FOR DECISION (use continuation pages or attach Word document)
See attached TYPED NAME OF NCP COORDINATOR TITLE John W. Lubinski Director ORGANIZATION NRR/DE /
SIGNATURE--NCP coo~~ l DATE ct/a~-/(~
TYPED NAME OF NCP APPROV~
' TITLE Brian E. Holian Acting Director ORGANIZATION NRR
~---:__~~
SIGNATURE--NCP APPROVER DATr
'f 2-Sl 2At7 NRC FORM 757 (11 -2016)
Use ADAMS Template NRC-006 (ML063120159)
Section C- EVALUATION OF NON-CONCURRENCE AND RATIONALE FOR DECISION I agree with the replies by Mr. Lubinski to the specific comments provided by the submitter. In addition , I agree with the comments provided by Mr. Lubinski in Section B.
Below I have included my responses to each issue in the Summary of Issues.
Issue 1: The submitter states:
Page 2 of the response letter states "The NRC also requires plants to be able to safely withstand a set of low probability and high consequence events that are described in each plant's Updated Final Safety Analysis Report (i.e. , design basis accidents; for example, a LOCA coincident with a LOOP with the assumption of a single failure) ." LOOP/LOCA is design requirement that all operating reactors have to meet irrespective of its risk significance. The characterization of LOOP/LOCA as a set of low probability and high consequence event is neither stated in NRC regulations nor in Palo Verde licensing and design bases documents.
This should be either corrected or applicable regulations and Commission's directions which indicate that it is a low probability event should be provided.
Response: The sentence quoted from the letter above is correct with respect to the requirement that plants must meet all design basis criteria coincident with a single failure when not in an LCO. The intent of the sentence was not to qualify probabilities or consequences of design basis accidents. Therefore , I modified the sentence to remove this phrase (see revised wording below) .
Issue 2: The submitter states:
Neither the Generic letter 80-30 nor 50.36 states that when a licensee requests a change to the TS in accordance with 50.90, staff does not have to consider single failure criteria. The temporary relaxation of sing le failure or other requirements only apply for the duration of the LCO that was already approved in the Palo Verde TS (1 O days). To approve Palo Verde EOG AOT extension and relaxing requirements again for another 52 days, staff must evaluate the Palo Verde LARs using NRC deterministic guidance provided in BTP 8-8 which limits the AOT extensions to a maximum of 14 days, Palo Verde licensing basis which includes commitment to Regulatory Guide 1.93, "Availability of Power Sources," and applicable regulations such as Appendix A to 10 CFR 50, 10 CFR 50.46, and 10 CFR 50.36. The staff erroneously approved amendments without sufficient regulatory and safety bases regarding how Palo Verde met the NRG guidance and requirements. The regulations and Commission's risk-informed Commission Policy require that it should meet the licensee meets regulations, defense-in-depth , and safety margins are maintained while plant is in operating mode in addition to the risk principles.
Response: I agree with the comments provided by Mr. Lubinski in Section B. I disagree with the submitter's statement that the staff must limit an AOT extension based on deterministic basis. BTP 8-8 is guidance, not a requirement. The staff has used, and should continue to use risk-insights in evaluating such submittals. I have added to the letter a reference to NRR's "Action plan: Risk-Informed Decision Making Licensing Revisions," which has several actions to ensure clear and consistent application and documentation on the use of risk-insights, which includes an evaluation of the need to clarify guidance documents.
Issue 3: The submitter states:
Page 2 of the response letter states: "Nevertheless, the NRC staff did describe several of the key factors leading to its decision in the Palo Verde case in the safety evaluation , including:
- 1) the identification of the root cause of the EOG failure
- 2) the determination that the mode of failure was not common to the other EDGs
- 3) the determination that a LOCA was not a significant contributor to the increase in risk and that the risk assessment met the acceptance criteria in RG 1.177" The information is incorrect because amendment 199 was issued without identifying the root cause and common cause failure evaluations. The request for extending the AOT (first LAR) was for troubleshooting to identify/complete root cause and common cause failure evaluations.
In addition , the risk evaluations did not consider LOOP/LOCA scenarios and additional risk contributions from OPC design vulnerability since the Palo Verde has not completed the plant modifications for OPC protection. This was identified in a 2.206 petition filed in January 2017. Also, the NRC risk assessment identifies OPC issue is risk significant (ADAMS Accession No. ML17223A066). The accuracy of risk assessment which concluded that the risk assessment met the acceptance criteria in RG 1.177 is in error. David Lochbaum letter dated August 22, 2017 states "The NRC simply cannot make proper risk-informed decisions by neglecting known and relevant risk factors. They have been lucky so far. I beg you and your office to compel the NRC staff to cease and desist its practice of neglecting known and relevant risk factors when making purportedly risk-informed decisions before their luck runs out and someone gets harmed."
Response: I agree with Mr. Lubinski's response to individual comments with respect to these issues. The concerns regarding amendment 199 were addressed in response to a separate DPO on amendment 199. Regarding open phase, the agency is responding to this generic issue with NRC Bulletin 12-01 issued on July 27, 2012 , and with a plan to closeout this issue following inspections on individual plants. The Bulletin requires compensatory measures to be in place such as operator awareness and procedure modifications, to significantly reduce the risk associated with OPC until permanent measures are implemented.
Issue 4: The submitter states:
Page 3 of the response letter, footnote states "As a result of the withdrawal , the draft denial safety evaluation was never finalized , did not receive management approval , and does not represent an official agency position." This is a false statement. Also, this is not a draft SE. The DC Cook SE was processed and issued in accordance with NRR Office Instructions by both DORL and EEEB staff (See ADAMS Accession Nos. ML15154B045 and ML15149A443). These are official agency records. Also, both NRR and regional senior managers were briefed and approval were received for communicating the results to the licensee. These were documented in official agency records (emails and telephone conference calls).
Response: I agree with Mr. Lubinski's response to individual comments with respect to this issue. In response to the submitter's concerns, I removed a sentence from the footnote regarding "Finalization" of the safety evaluation as this detail was not necessary.
Issue 5: The submitter states:
Page 3 of the response letter states: "During the course of the review, the NRC staff appropriately engaged the licensee in a discussion of the licensee's ability to mitigate the consequences of several events, including a LOCA coincident with a LOOP, assuming a single
failure of the operable EOG. In these discussions, the NRC staff sought to establish whether adequate defense in depth and safety margins existed to support the amendment request. However, the NRC staff mistakenly asked the licensee how it met regulatory requirements for this accident sequence and documented the failure to meet this accident sequence as a basis for denial in the draft safety evaluation. As discussed earlier, the licensee is not required to protect against a design basis accident assuming single failure of the operable EOG in accordance with GL 80 30. While the NRC staff may have misapplied the single failure criterion in the draft safety evaluation as a basis for denial, the staff appropriately denied the D.C. Cook EOG amendment request based on failure to meet the other key criteria.
In DC Cook LAR review, staff followed all applicable NRC requirements and staff guidance, whereas for the Palo Verde amendment reviews (199 and 200) staff did not evaluate applicable NRC requirements, staff guidance, and licensing basis requirements as specified in Issue No. 2 specified above. The regulations and Commission's risk-informed Commission Policy require the licensee meets regulations, defense-in-depth, and safety margins are maintained while plant is in operating mode.
Specifically, DC COOK Safety evaluation conclusion states:
"(1) The SDGs, NDG, and the compensatory measures are not able to supply power to the ESF loads for accident mitigation within the time constraints of the accident analyses assumptions (UFSAR Chapter 14 requirements).
(2) Neither the SDG nor any other power source (NDG and FLEX equipment) are credited in the accident analysis for accident mitigation.
(3)LOOP with LOCA and a single failure are the licensing and design bases requirements for CNP and the licensee has not demonstrated whether the CNP Unit 1 can mitigate the consequences of these requirements.
(4) Operating the plant for a period longer than specified in the NRC Branch Technical Position (BTP} 8-8, "Onsite (Emergency Diesel Generators) and Offsite Power Sources Allowed Outage Time Extensions," is contrary to the requirements specified in 10 CFR 50.36(c)(2), "Limiting Conditions for Operation." This BTP states that the EOG Allowed Outage Time should be limited to 14 days to perform maintenance activities.
(5) The proposed operating configuration with only one ESF emergency power source do not meet the requirements of 10 CFR 50 .46 and the Cook Plant Specific Design Criterion 39, "Emergency Power." This is due to the fact that accident analysis assumes one train of emergency AC power is available given a worst-case single failure for all Chapter 14 accidents. Exemptions from these regulations are required to extend the CT for CNP TS for 65 days and the licensee has not requested one in accordance with 10 CFR 50.12.
The staff finds that the licensee did not provide adequate assurance that the extended CT could be utilized while maintaining adequate protection of public health and safety and common defense and security. Specifically, the licensee did not provide adequate assurance that the proposed compensatory measures including additional power sources will maintain the required safety functions during the proposed EOG CT extension period. Therefore , the staff concludes that there is not reasonable assurance that safe plant conditions will continue to be maintained; therefore, the proposed changes are unacceptable."
Response: I agree with the comments provided by Mr. Lubinski in Section B. The above discussion by the submitter is largely focused on the DC Cook submittal, which was not approved by the staff based on both deterministic and risk reasons . Amendment No.
200 for Palo Verde concluded that the one-time extension would continue to provide
reasonable assurance of adequate protection to public health and safety. As I noted in response to Issue No. 2, the staff is evaluating actions to ensure clear and consistent application and documentation on the use of risk-insights.
Issue 6: The submitter states:
Page 4 of the response letter states "One would expect that with greater risk informed knowledge and more plant specific operating experience, the NRC is now better able to estimate a reasonable period of time for equipment to be allowed to be out of service. Moving in that direction, the NRC recently issued amendments for Vogtle Electric Generating Plant, Units 1 and 2, that modify the TS requirements to permit the use of risk informed completion times, in accordance with Nuclear Energy Institute 06 09, Revision 0 A, "Risk Informed Technical Specifications Initiative 4b, Risk Managed Technical Specifications (RMTS)
Guidelines."
If staff is trying to identify RMTS 4b as an example of extending AOTs, please note that it allows only for 30 days even from a purely risk-based decision making. The Palo Verde amendments do not justify the NRC approval of for 62 days. This logic does not make much sense. The NRC staff has to recognize that plants are aging and components fail. Therefore, was it safe for Palo Verde to operate at full power with reduced safety margin and defense-in-depth for 62 days?
The current deterministic guidance and even risk-informed RMTS process says "NO." In addition, Lochbaum letters, OPOs, and 2.206, all points out the need for NRC to focus on safety to protect health and safety of the public rather than on economic pressures.
Response: I agree with Mr. Lubinski's response to individual comments with respect to this issue. The Risk Managed Technical Specifications reviews are mentioned in this letter to show overall staff progress in applying risk-insights. The 30-day limit on this program was deemed appropriate by staff, and does not limit a one-time extension that is submitted to the staff for a separate review.
In summary, in response to the noncurrence, I have made seven changes to letter:
- 1. I have modified the following sentence on Page 2 of the letter of the as follows:
The NRC also requires plants to be able to safely withstand a set of deterministic design basis accidents that are described in each plant's Updated Final Safety Analysis Report (e.g. a LOCA coincident with a LOOP with the assumption of a single failure).
- 2. I have modified part of the second paragraph on Page 2 of the letter as follows:
As discussed in GL 80 30, single failure of the operable Unit 3 Train A EOG is not required to be met while in the TS action statement for the Unit 3 Train B EOG .
The NRC staff considered the extent to which the licensee could mitigate a design basis accident coincident with a single failure of the Unit 3 Train A EOG in order to ensure that defense-in-depth and safety margins are maintained, commensurate with the expected frequency and consequences of challenges to the system , in accordance with RG 1.177.
- 3. I have modified part of the third paragraph on Page 3 to now read as follows:
The NRC staff mistakenly documented the failure to meet this accident sequence (a LOCA coincident with a LOOP, assuming a single failure of the operable EOG) as a basis for denial in the draft safety evaluation.
- 4. I have modified footnote number 1O to now read as follows:
The NRC staff informed the licensee in a teleconference on May 30, 2015, of its intention to deny the D.C. Cook EDG amendment request. The NRC offered the licensee an opportunity to withdraw the amendment request and the licensee formally withdrew the amendment request by letter dated June 1, 2015 (ADAMS Accession No. ML151548045).
- 5. I have modified part of the second paragraph and the associated footnotes on Page 4 to read as follows:
In addition, as a result of two differing professional opinions (DPOs) filed by NRC staff regarding the Palo Verde EOG amendments and ongoing staff discussions, the Office of Nuclear Reactor Regulation is taking several actions that had been recommended by the DPO review panel, as described in a risk informed decisionmaking Action Plan 13 . This Action Plan, which will be updated periodically, focuses staff on ensuring clear and consistent application and documentation on the use of risk insights. The actions include evaluating guidance to determine if clarification is required for: (1) acceptability of long duration completion times for one time extensions, (2) maximum allowed outage times, even when supported with risk information, to limit the amount of time operation without single failure protection is permitted, and (3) the appropriate use of large early release frequency in licensing and oversight. Also, the staff will determine if clarification is needed for other guidance documents (e.g., NUREG-0800, "Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR [Light-water Reactor] Edition," including Branch Technical Position (BTP) 8 8, "Onsite (Emergency Diesel Generators) and Offsite Power Sources Allowed Outage Time Extensions." 14 13 "Action Plan: Risk-Informed Decision-Making in Licensing Reviews ," dated August 11, 2017 (ADAMS Accession No. ML17219A346) 14 Available in ADAMS under Accession Nos. ML070810350 and ML113640138, respectively.
- 6. I have modified part of the last paragraph on Page 5 of the letter as follows:
I expect that the NRC staff's implementation of the risk-informed decisionmaking Action Plan in response to the DPO Panel recommendations and the Commission's recent direction will yield improvements in the regulatory processes and guidance that you seek in your letter.
- 7. I have added the submitter to the concurrence block of the letter to document the nonconcurrence.