Text

Supplemental Response to Generic Letter 2006-02, Grid Reliability and the Impact on Plant Risk and the Operability of Offsite Power.
	ML061780425
Person / Time
Site:	Columbia
Issue date:	06/15/2006
From:	Oxenford W; Energy Northwest
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	GL-06-002, GO2-06-092
	Download: ML061780425 (22)
	v • d • e

9ENERGY NORTHWEST People. Vision- Solutions-P.O. Box 968

Richland, WA

99352-0968 June 15, 2006 G02-06-092 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, Maryland 20852

Subject:

COLUMBIA GENERATING STATION, DOCKET NO. 50-397 SUPPLEMENTAL RESPONSE TO GENERIC LETTER 2006-02, "GRID RELIABILITY AND THE IMPACT ON PLANT RISK AND THE OPERABILITY OF OFFSITE POWER"

Reference:

Letter dated April 3, 2006, from WS Oxenford (Energy Northwest), to NRC, "Response to Generic Letter 2006-02, 'Grid Reliability and the Impact on Plant Risk and the Operability of Offsite Power"'

Dear Sir or Madam:

On April 3, 2006 Energy Northwest submitted, pursuant to 10 CFR 50.54(f), the referenced response to Generic Letter (GL) 2006-02. Submittal of the requested material was a collaborative effort between Energy Northwest and the Bonneville Power Administration (BPA) and the responses were compiled in accordance with a mutual non-disclosure agreement.

The response contained information designated as Critical Energy Infrastructure Information and was therefore submitted pursuant to 10 CFR 2.390 and the guidance in Regulatory Issue Summary (RIS) 2005-26 as Sensitive Unclassified Non-safeguards Information which should be withheld from public disclosure.

Subsequent to submittal of the referenced GL response, your staff contacted Energy Northwest and requested that some or all material be declassified in order to be consistent with industry responses.

In response to the staff's request, BPA and Energy Northwest reviewed the GL response and determined that portions of the response could indeed be made available for public review in order to honor the staff's request. That information available for public disclosure is contained in the enclosure hereto.

fWJ23

IL SUPPLEMENTAL RESPONSE TO GENERIC LETTER 2006-02, "GRID RELIABILITY AND THE IMPACT ON PLANT RISK AND THE OPERABILITY OF OFFSITE POWER" Page 2 There are no commitments being made to the NRC by this letter.

Should you have any questions or desire additional information regarding this matter, please call Mr. GV Cullen at (509) 377-6105.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the date of this letter.

Respectfully, WS Oxenrd Vice President, Technical Services Mail Drop PE04

Enclosure:

Supplemental Response to Generic Letter 2006-02, "Grid Reliability and the Impact on Plant Risk and the Operability of Offsite Power" cc: BS Mallett - NRC RIV BJ Benney - NRC NRR NRC Senior Resident Inspector/988C RN Sherman - BPAI 399 WA Horin -Winston & Strawn

r 7 SUPPLEMENTAL- RESPONSE TO GENERIC LETTER 2006-02, "GRID RELIABILITY AND THE IMPACT ON PLANT RISK AND THE OPERABILITY OF OFFSITE POWER" Enclosure Page 1 of 20 The following provides the NRC Questions contained in Generic Letter (GL) 2006-02 in italicized print along with EnergyNorthwest (EN) response.,

I. Use of protocols between the NuclearPower Plant(NPP)licensee and the Transmission System Operator(TSO), Independent System Operator(ISO), or Reliability Coordinator/Authority(RC/RA) and the use of analysis tools by TSOs to assist NPP licensee in monitoringgrid conditions to determine the operability of offsite power systems under plant Technical Specifications (TS).

GDC 17, 10 CFR Part50, Appendix A, requires that licensees minimize the probabilityof the loss of power from the transmissionnetwork given a loss of the power generatedby the nuclearpower unit(s).

1. Use of protocols between the NPP licensee and the TSO, ISO, or RC/RA to assist the NPP licensee in monitoring grid conditions to determine the operabilityof offsite power systems underplant TS..

NRC Question 1(a):

(a) Do you have a formal agreement orprotocol with your TSO?

EN Response:

Response not for public disclosure.

NRC Question 1(b):

(b) Describe any grid conditions that would triggera notification from the TSO to the NPP licensee and if there is a time periodrequiredfor the'notification.

EN Response: . -

Response not for public disclosure.

NRC Question 1(c):.

(c) Describe any grid conditions that would cause the NPP licensee to contact the TSO. Describe the proceduresassociatedwith such a communication. If you do not have procedures,describe how you assess grid conditions that may cause the NPP licensee to contact the TSO.

EN Response:

The primary procedures that require Columbia Generating Station (CGS) to contact Bonneville Power Administration (BPA) pertaining to grid conditions are titled "ABN-ELEC-GRID" and "ABN-GENERATOR." The plant output is to the 500 kVgrid network. 1Offsite power is provided to the plant by the 230 kV and

SUPPLEMENTAL RESPONSE TO'GENERIC LETTER 2006-02, -"GRID RELIABILITY AND THE IMPACT ON PLANT RISK AND THE OPERABILITY OF OFFSITE POWER"'

Enclosure Page 2 of 20 115 kV grid networks., The conditions for entry intprocedure "ABN-ELEC-GRID" that require subsequent action for CGS to contact BPA involve conditions:

where CGS has indication or information that the current 500 kV system condition is degraded,.and cannot be immediately restored,'the current 230 kV

-voltage supply to CGS is less than the required limit and is not immediately..

- !restored to TS limits orthe current 115 kV voltage supply to'CGS is less than the required limit and is not-immediately restored to TS limits.

The conditions for entry into procedure "ABN-GENERATOR" and subsequent action for CGS.to contact BPA'involVe 'conditiohs.where CGS'detectS Main

,Generator,Power Oscillations or,other generator abnormalities.

Activities that involve a plant-startup; slhutdown;:down'powai or*plant scram are controlled byprocedure that require CGS to 'crnmmunicate with BPA as these activities result in changing CGS-loading on the.230 'kV\'grid 'network or affect CGS support of the:500 kVgrid'network., .

NRC Question I(d):

(d)Describe how NPP operatorsare trainedand tested on the use of the" proceduresor assessinggrid conditions in question 41(c).,

EN Response:

Training is conducted for CGS operators on assessing grid conditions using the procedures described in question 1(c). .The training primarily includes classroom procedure training. Simulator training is also conducted for power restoration.

For further details, see response to question 3 (f).'

NRC Question 1(e):

(e) If you do not have a formal agreement orprotocol with your TSO, describe why you believe you continue to comply with the provisions of GDC 17 as stated above, ordescribe what actions you intend to take to assure compliance With GDC 17.

EN Response:_

EN has a formal agreement with BPA.; The agreement is do6umented in Letter:

Agreement 04TX-1 1739, signed October 2004. Thus, this question is not applicable.

NRC Question ().,: :, .

( If you..have an existing formal interconnection agreement or protocolthat ensures adequate communication and coordinationbetween the NPP licensee

SUPPLEMENTAL RESPONSE TO GENERIC LETTER 2006-02, "GRID RELIABILITY AND THE IMPACT ON PLANT RISK AND THE OPERABILITY OF OFFSITE POWER" Enclosure Page 3 of 20 and the TSO, describe whether this agreement orprotocol requiresthat you be promptly notified when the conditions of the surroundinggrid could result in degraded voltage (ie.,; belof;w TS nominal trip setpin-t value requirements; including NPP licensees using allowable value in its TSs) or LOOP aftera trip of the reactorunit(s)..:. . -.

EN Response: , i.

The existing formal interface agreement;, between BPA'and EN ensures communication. between.CGS and.BPAat Muiro Control Center and Dittmer

..;i.;Control Centeriwhen the conditions. f.thesurrounding grid could result in degraded voltage., Notification is triggered-at an alarm level above the nominal trip setpointvaluprequirementsWhen eitherthe~degraded ,Voltage real time or the predicted leyels..based on the c6htingencies [see response.to Question 2(a)]

are identified.- In addition;, there -is a Dispbtch6r Standing Order that re'quires immediate notification from BPA to'CGS :anytime the-PNSC notifies BPA of any affected reliability of.the offsite sources to CGS.

NRC Question 1(g): '. -,

(g) Describe'thelow switchyard voltage conditions that would initiate operation of plant degraded voltage protection.

EN Response:

Response not for public disclosure.

2. ,*Use of criteriaand methodologies to assess whether the offsite power system will become inoperableas a result of a trip of your NPP.;'%

NRC Question 2(a): .

(a) Does your NPP's TSO use any analysis tools, an online analytical "

transmission system studies program, or other equivalent predictive methods to determine the grid conditions that would make the NPP offsite power system inoperableduring various contingencies? If available to you, please provide a brief~descriptionof the analysis tool.that is used by the TSO.. "

EN Response:

Response not for public disclosure.

SUPPLEMENTAL RESPONSE TO GENERIC LETTER 2006-02,."GRID'RELIABILITY AND THE IMPACTON PLANT RISKAND*THE OPERABILITY, OF OFFSITE POWER'",.

Enclosure Page4 of 20 -

NRC Question 2(b):-

(b) Does your NPP's .TSO,use an analysis tool as the basis for notifying the NPP

-licensee when such a condition is identified? -If not, how does the TSO determine if conditionson the grid warrant NPP licensee notification?

EN Response:

BPA and PNSC use the previously described analysis tool as a basis for reporting predicted grid voltage conditions with potential impact to CGS station service. .For actual.degraded voltage conditions, an alarm-has been established

to -alert Munro Control Cehter.(respoisiblefor.230rk\/fsystem).that voltage at the

.-- Ashe bus"(ard on.the 230 kV ie line) that'serves*0CGS'is' beloW the alarm level and that action ýshould be'taken immediately:t0-restore.caability; .LikewiSe, if the PNSC (responsible for the :reiiability.function 'of thesystem) *itedmines that

. predicted voltage'at the Ashe bus would be below the"alarm level due t 'certain analyzed contingencies (such'as CGS-post trip),':the PNSC will notify BPA to initiate action to restore required grid capability. The Munro Control Center notifies CGS of the predicted condition, including the predicted voltage levels, for-CGS to determine if.the offsite source is capable of perforrming its TS 'required function.

NRC Question 2(c):

(c) If your TSO uses an analysis tool, -wouldthe analysis tool identify a condition in which a trip of the NPP would result in switchyard voltages (immediate and/or long-term) falling below TS nominal trip setpoint value requirements (including NPP licensees using allowable value in its TSs) and consequent actuation of plant degraded voltage protection? If not,' discuss how such a condition would be identified on the grid. .

EN Response:

Response not for public disclosure.,.

NRC Question 2(d):

(d). If your TSO uses an analysis tool, how frequently does the analysis*t*ol program update? .

EN Response:

Response not for public disclosure.

SUPPLEMENTAL RESPONSE TO GENERIC LETTER 2006-02, "GRID RELIABILITY AND THE IMPACT ON PLANT RISK AND THE OPERABILITY OF OFFSITE POWER" Enclosure Page 5 of 20 NRC Question 2(e):

(e) Providedetails of analysis tool-identified contingency conditions-thatwould triggeran NPP licensee .notificationfrom the TSO.

EN Response:

Response not for public disclosure.'

NRC Question 2(f): ,' . ' . .

(f) If an interface, agreomentexists-between .the TSO and the NPP licensee, does it require that:the.NPPlicenseebe'notifiedofpeio'ds when the.;TSO is unable to determine if offsite power,voltage :and.capacity could be inadequate? if so, how does the NPP,-licenseeideterrnine'thattheoffsitepower would remain operable when such a-notificationis received? .

EN Response: ... .. - -

Response not for public disclosure.

NRC Question 2(g):

(g)After an.unscheduledinadvertenttrip of the NPP, are the resultant switchyard voltages verified by procedure to be bounded by the voltages predictedby the analysis tool?

EN Response:

Verification that actual post trip grid voltages are bounded by the predicted voltage is not currently in our agreement with BPA or in our procedures to.

perform. Ifthe voltages following an unscheduled trip of CGS are below the degraded voltage relay setpoints; the actual system voltage alarms Will be initiated and corrective action taken., However, correlation between theactual and predicted voltage level would require a post trip verification action by BPA.

The actual SCADA data for the time period preceding the plant trip and loading of the offsite power source and the analysis obtained oh a 10 minute interval may not correlate unless grid conditions are in a relatively steady state condition prior to the plant trip or grid event. Although the predicted voltage can be rerun with the reconstructed grid configuration, SCADA data, and grid load flow conditions just prior to the trip, the accuracy of this reconstructed grid state and its predicted condition to actual post trip voltage has not been verified by CGS.

SUPPLEMENTAL RESPONSE TO, GENERIC LETTER 2006-02, -."GRID'RELIABILITY AND THE IMPACT ON PLANT RISK AND THE OPERABILITY OF OFFSITE POWER"'

Enclosure Page 6 of 20 NRC Question 2(h): .

(h) If an analysis tool is not available to the NPP licensee's TSO,'do you know if there are any plans for the TSO to obtain one? if so, ýwhen?

EN Response: ....

" . . .- ... "' " . . ::* . : . : "I;*: *

Analysis tools are utilized by BPA. This question does not apply.,-

NRC Question,2(i): -- .* ' > ' : < .

(i) If an ahalysis tool is not available,,doesvour-TS0 peurorm periodicstudies to verify that adequate offsite power capability;including adequate NPP post-trip switchyard voltages (immediate and/orlong-term); will be available to the NPP licensee over the projected timeframe of the study?

EN Response:. * . .. , . . .

Response notResp for public t.r disclosure.

cdislosure. ' " , -.. . ,"

NRC Question 2(i)(a): .

(a) Are the key assumptionsand parametersof these periodic studies translated into TSO guidance to ensure that the transmission system is operated within the bounds of the analyses?.--.

EN Response:

Response not for public. disclosure.

NRC Question 2.)(b):

(b) If the bounds of the analyses are exceeded,.does this condition triggerthe notification provisions discussed in question 1 above? .

ENResponse:. . ..

Response not for public disclosure.

NRC Question 2(i): f

(")If your TSO does not use, oryou do not have access to the results of an analysis tool, or your TSO does not perform and make available to you periodic studies that determine the adequacy of offsite power capability,please describe why you believe you comply with the provisions of GDC 17 as stated above, or describe what compensatory actionsyou intend to take to ensure that the offsite

SUPPLEMENTAL RESPONSE TO GENERIC LETTER 2006-02, "GRID RELIABILITY

AND THE IMPACT ON PLANT RISK AND THE OPERABILITY-OF OFFSITE POWER" Enclosure Page 7 of 20 power system will be sufficiently reliable and remain operable with high:

probabilityfollowing a trip of your NPP.,

EN Response: - , . " "

BPA uses analysis tools and makes results available to CGS., CGS complies with provisions of GDC 17 as described in the licensing basis for CGS.

3. Use of criteriaand methodologies to assess whether the'NPP!s offsite power system and safety-relatedcomponents will remain operable when

switchyard voltages, are inadequate.",. *. ' '

NRC Q uestion 3(a):.v,.- , N:'*..i*'i:**\ ,,,,-,,**..','-:.,.. *-:'.i*1 ::" .. "." . ..

(a) If the TSO notifies the NPP operatorthat a trip of the NPP, or'the loss of the most criticaltransmission line orthe largestsupply to the grid would'result'in switchyard voltages (immediate and/or long-term) below TS nominal trip setpoint value requirements (includingNPP licensees using allowable ilalue in its TSs) and would actuateplant degraded voltage protection,:is the NPP offsite power system declared inoperableunder the plant TSs? If not, why not?*' .

EN Response: ..

Response not for public disclosure.

NRC Question 3(b):.

(b) If onsite safety-related equipment (e.g., emergency diesel generatorsor' safety-related motors) is lost when subjected to a double sequencing (LOCA with delayed LOOP event) as a result of the anticipatedsystem performance and is.

incapable of performing its safety functions as a result of respondingto an

1emergency actuation signal during this condition, s the equipment considered inoperable? If not, why not?

EN Response:.

Double sequencing or what is referred toas a LOCA with delayed LOOP'is not considered in the CGS licensing basis. The plant is not designed or analyzed for double sequencing scenarios involving starting ECCS pumps responding to' -7,;'

LOCA auto start signals, load shedding the ECCS due to delayed LOOP, then re-starting the ECCS when' vital bus' sou'rce selection logic is satisfied and the vital bus is re-powered.'An engineering evaluation has not been performed on double sequencing. However, the plant is designed to minimize the potential of de-energizing the ECCS pumps,; if a delayed turbine trip should occur. A fast transfer design between the normal auxiliary supply breakers and the 230 kV offsite supply breakers assures that if the ECCS pumps are running, they will

1L SUPPLEMENTAL RESPONSE TO GENERIC LETTER 2006-02, "'GRID RELIABILITY AND THE IMPACT ON PLANT RISK AND THE OPERABILITYF OF FSITEPOWER"'

Enclosure Page 8 of 20 continue to operate and not trip off and restart upon energization by the 230 kV source. Further, due to the degree of independence between the 500 kV and the 230 kV and 115 kV transmission grids, a plant trip is -highly unlikely to result in a loss of the offsite power sources causing a-delayed LOOP. If on site'safety related equipment is lost (i e., incapable of performing safety function(s) in

.accordance with applicable TS) then.this equipment: is declared inoperable.

NRC Question 3(c):. ," .. . .

(c) Describe your evaluation of onsite safety-related eqUipmient-to determine

- .whetherit will operate as designed during the condition describedin question 3(b~). . ~2c EN ..

Response: ... .. .::...... ,.r- =.. .. ,..,,... . ....

EN Response: ... r '-*.

An engineering evaluation has not been performed on double sequencing.

NRC Question 3(d): , ,

(d) Ifthe NPP licensee is-notifiedby.the -TSOof other grid conditions that may impair the capability or availability of offsite power, are any plant TS.action*

statements entered? If so, please identify them.'

EN Response:

If CGS is notified by BPA of other grid conditions that may impair the capability or availability of offsite power to CGS, compliance with TS LCO 3.8.1 would be "

evaluated, and if appropriate, Required Actions and Completion Times would be followed. "

NRC Question 3(e):

(e) If you believe your plant TSs do not require you to declare your offsite power system or safety-related equipment inoperable in any,of these circumstances, explain why you believe you comply with the provisions of GDC 17 and your plant TSs, or describe what compensatory actions you intend to take to ensure that the offsite power system and safety-related components will remain ope6rable

__..when switchyard voltages are inadequate... .. - - :

EN Response:

Except as noted in the responrse to Question 3(a) and 3(d),,plant operators at

CGS would conservatively declare offsite power systems or safety related.

equipment inoperable in accordanie with 1LCO 3.8.1 if any of the previously postulated circumstances occurred resulting in the inability of these systems to

. perform their design.safety functions.I CGS complies with provisions of GDC 17 as described'in the licensing basis for CGS.

SUPPLEMENTAL RESPONSE TO GENERIC LETTER 2006-02, "GRID RELIABILITY AND.THE IMPACT.ON PLANT RISK AND THE OPERABILITY OF OFFSITE POWER" Enclosure Page 9 of 20 NRC Question 3(f): . I P (f Describe if and how NPP operatorsare trainedand tested on the compensatory actions mentioned in your answers to questions 3(a) through (e).

EN Re EN Re Training is conducted for NPP operators on the procedure "ABN-ELEC-GRID,'

Technical Specifications, PPM 1.3.66 (Operability Determination), and Plant Procedure Usagein the following .areas:.!.-......

.".. . . . . . . . . . . *. . , " ,. .7 ., ..... *

" Loss of Off-Site Electrical Power

" Station Blackout Recovery 0 Operability Determination -

" Technical Specifications . "- . -

CondUct-of'Oliertitons -

Plant operators 'are trained in the use of the "ABN-ELEC-GRID", procedures per the 2-year training plan. The compensatory actions are contained within -

procedures at CGS. Evaluated simUlator scenarios are the primary method of testing to assure that operators have sufficient skiIand knowledge.

4. Use of criteria and methodologies to assess whether the offsite power system will remain operable following a trip of your NPP.

NRC Question4(a):- -,-'........... ,

(a) Do the NPP operatorshave any guidance or proceduresin plant TS bases sections, the final safety analysis report,or plant procedures regardingsituations in which the condition of plant-controlledor -monitored equipment (e.g.;, voltage regulators,auto tap changing transformers,capacitors,static VAR, compensators, main generatorvoltage regulators)can adversely affect the operabilityof the NPP offsite power system?, If so, describe how the operators are trained.andtested on the guidance andprocedures.:

l l;-...!-----=

E_~

Ne¶ Response not for public disclosure.,

a':. -

NRC Question 4(b):-.:~---

(b) If yourý TS bases sections, the final safety analysis report,and plant procedures do not provide guidance regardingsituationsin which the condition of plant-controlledor -monitored equipment can adversely affect the operabilityof the NPP offsite power system, explain why you believe you comply with the

t.

SUPPLEMENTAL RESPONSE TO GENERIC LETTER 2006-02, "GRID RELIABILITY AND THE IMPACT ON PLANT RISK AND THE OPERABILITY OF OFFSITE POWER"'

Enclosure Page 10 of 20 provisions of GDC 17 and the plant TSs, or describe what actions you intend to take to provide such guidance orprocedures.

EN Response:

CGS complies with provisions of GDC 17 as described in the licensing basis for CGS.

II. Use of NPP licensee/TSO protocols and analysis tool.by TSOs to assistNPP licensees in monitoringgrid conditions for considerationin maintenancerisk assessments.

The Maintenance Rule (10 CFR 50.65(a)(4)) requires that lic'einsees iassessand manage the increase:inrisk that may result from proposedmaintenanceactivities before performing them. -

5. Performanceof grid reliabilityevaluationsas -partof the maintenance risk assessments requiredby 10 CFR 50.65(a)(4).

NRC Question 5(a):

(a) Is a quantitative or qualitative gridreliabilityevaluation performed at your NPP as part of the maintenance risk assessmentrequired by 10 CFR 50.65(a)(4) before performing grid-risk-sensitivemaintenance activities? This includes surveillances,post-maintenancetesting, and preventive and corrective maintenance that could increase the probabilityof a plant trip or LOOP or impact LOOP or SBO coping capability,for example, before taking a risk-significant piece of equipment (such as an EDG, a battery, a steam-drivenpump, an alternateAC power source) out-of-service?

EN Response:

Quantitative risk evaluations are performed via the Sentinel program which is a risk evaluation tool based on a blended approach of deterministic as well as probabilistic assessments. Certain grid conditions will require input to the Sentinel program for risk assessment, (e.g., loss of one or more TR-S offsite power sources, severe weather, 500KV grid stability threatened). These are proceduralized in PPM 1.5.14, "Risk Assessment and Management for Maintenance/Surveillance Activities." In addition to the Sentinel analysis,,..

qualitative evaluations are performed by review of the BPA OASIS website which posts upcoming grid maintenance activities ensuring that plant grid risk activities are planned around the BPA work. This approach to maintenance complies with 10 CFR 50.65(a)(4).

SUPPLEMENTAL RESPONSE TO GENERIC LETTER 2006-02,-"GRID RELIABILITY AND THE IMPACT ON PLANT RISK AND THE OPERABILITY OF OFFSITE POWER" Enclosure Page 11 of 20 NRC Question 5(b):

(b) Is grid status monitored by some means for the duration of the grid-risk-sensitive maintenanceto confirm the continued validity of the risk assessment.

and is risk reassessedwhen warranted?.If not, how is the risk assessed during grid-risk-sensitivemaintenance?

EN Response:

Response not for, pubklIc disclosure.. . : ,:. x'."': . "

NRC Question 5(c):

(c) Is there a significant variationin the' stress'on'thegrid;irithe vicinity of your NPP site causedl by.;esasonal,!oads'or'maintenance activities associatedwith critical transmission elements? Is there a seasonalvariation (or,the potential for a seasonalvariation)in the LOOP frequency in the local transmissionregion? If the answer toeitherquestion isyes,: discuss the time of year When the variations occur and their magnitude..:,.

EN Response:

Response not for public disclosure'. ."

NRC Question 5(d):

(d) Are known time-related variationsin the probabilityof a LOOP at your plant site consideredin the grid-risk-sensitive maintenance evaluation? If not, what is your basis for not considering them?

EN Response:

The CGS LOOP frequency used in the PRA does not consider time-related variations mainly because there is no reliable data. Columbia's PRA was developed consistent with NUREG/CR-5496 which does not consider.time-.

related variations. Risk management actions associated with certain potentially risk significant planned maintenance activities assure that performing' maintenance when grid stress conditions could be potentially high is avoided.

For example, prior to and during the performance of potentially risk significant maintenance on an emergency diesel generator, procedures require contacting BPA for the status of grid conditions to assure adequate capability of the offsite circuits.

SUPPLEMENTAL .RESPONSE TO GENERIC LETTER 2006-02,. "GRID RELIABILITY AND.THE IMPACT:ON PLANTRISK AND THE OPERABILITY OF OFFSITE POWER"'

Enclosure Page 12 of 20 NRC Question 5(e:.

(e) Do you have contacts with the TSO to determine currentand anticipatedgrid conditions as part of the grid reliabilityevaluation performed before conducting grid-risk-sensitivemaintenance activities?. -

EN Response:

The Dittmer or Munro Control Centers are contacted, as appropriate, when grid-risk-sensitive maintenance activities are first scheduled:.,CGS requests that near grid BPA activities are minimized. during these.times.' BPA'posts'maintenance activities on their OASIS website'with at leasta 4.5-daylead time:, This website is reviewed weekly by the CGS Unit Coordinators..ii.Phone 66,n'imunications from

.BPA provides follow-up to the website information. Any activities which may impact CGS are evaluated against plant activities to ensure the risk'is.

understoodand manageable per procedure PPM -1.3.76 andWCI-4"'Online Work

..Control Process."- Contingency plans would document requirements for periodic communications to BPA during the grid-risk-sensitive-maintenance activities.

NRC Question 5(f):

(f) Describe any formal agreement orprotocolthat you have with your TSO to assure that you are promptly alerted to a worsening-gridcondition'that may emerge during a maintenance activity.'

EN Response:

Response not for public disclosure.

NRC Question 5(g):

(g) Do you contactyour TSO periodicallyfor the duration of the grid-risk-sensitive

, : '*I - ,r - - '.

m aintenanceactivities? - .-.

EN Response::

BPA is periodically.contacted for the duration of the grid-risk-sensitive

maintenance activities as determined by plant operators as part of any'-

contingency plan that is in place for the activity in accordance with procedure PPM 1.3.76.

NRC Question 5(h):.

(h) If you have a formal agreement or protocol with your TSO, describe how NPP operatorsand maintenancepersonnel are trained and tested on this formal agreement orprotocol.

SUPPLEMENTALRESPONSE TO GENERIC LETTER 2006-02,* "GRID RELIABILITY AND THE IMPACT.ON PLANT RISK AND THE OPERABILITY OF OFFSITE POWER"'

Enclosure Page 13 of 20 EN Response: .

No formal training is conducted onthe Letter-of Agreement with BPA: Aspects of the Letter of Agreement are implemenrted thrbugh various plant procedures and department instructions. Training on these procedures is part of Operations training. A copy of the Letter of Agreement is kept in the Control Room.

NRC Question 5(i):

(i) if your gridreliability.evaluatiorf,performied.aspart of the maintenancenrisk assessment requiredby. 0 .'CFR 50,65(a)(4), does not cOnsldefb orrelyon some arrangementLfor)-commuhication-withthe .TSO; explain why ybubelieve you comply with 10, FR5065(a)f4)..7 *--:. "

EN Response: *. ' , , . .'-- .:.:; ,"- .* .

Communications with :BPA are a part of CGS's maintenance risk assessment process. This. question does not apply.

NRC Question 5(i):

') If risk is not assessed (when warranted)'basedon continuing communication with the TSO throughoutthe duration of grid-risk-sensitivemaintenance activities, explain why you believe you have effectively implemented the relevantprovisions of the endorsed industryguidance associatedwith the maintenance rule. -

EN Response: "

Continued communications during grid-risk-sensitive maintenance activities is part of CGS's maintenance risk assessment process. This question does'not apply.

NRC Question 5(k):.

,(k) With respect to questions5(i)and 5(), youmay, as an alterative, describe what actions you intend to take to ensure that the increase'in risk that may result from proposed grid-risk-sensitiveactivities is assessedbefore and during grid-risk-sensitive maintenance activities,respectively.

EN Response:

Energy Northwest has no 'alternative response to questions 5(i) and 50).

SUPPLEMENTAL RESPONSE TOGENERIC LETTER 2006-02, ."GRID RELIABILITY AND THE IMPACT ON PLANT RISK AND THE OPERABILITY OFOFFSITE POWER".'

Enclosure Page 14 of 20

6. Use of risk assessment results, including the results of gridreliability evaluations,in managing maintenancerisk, as -requiredby 10 CFR

50.65(a)(4)..

NRC Question 6(a): .

(a).Does the TSO coordinate transmissionsystem maintenance activities that can have an impact on the .NPP.pperation.

with -the NPPoperator?.

i _

EN Response: -. -

In addition to posting B PA maintenance activities on-a website45 days in:

advance of the scheduled work, BPA communicates upcoming maintenance activities directly to the CGS Unit Coordinator. This communication occurs through periodic meetings, the OASIS web site, or via telephone in advance of, the activity. This allows time;for the -CGS Unit Coordinator.to make changes to the scheduling of activities or to ask BPA to reschedule'activities that may conflict wýith'CG-Swo'rk. -

NRC Question 6(b): .

(b) Do you coordinateNPP maintenance activities that can have an impact on the transmission system with the TSO?

EN Response:.

The CGS Unit Coordinator contacts the appropriate BPA Control Center when maintenance activities that can impact the grid are initially scheduled. BPA is requested to not perform discretionary grid risk activities .for-the duration of the activity.

NRC Question 6(c):

... (c) Do you considerand implement, if warranted,the rescheduling.ofgrid-risk-sensitive maintenanceactivities (activities that could (i) increasethe likelihood of

.,a plant trip, (it) increase LOOP probability,or (iii) reduce LOOP or SBO coping

capability)under existing, imminent, or worsening degradedgrid reliability conditions?, . .. ,'* .

EN Response:

An initial qualitative evaluation is performed when CGS work is scheduled. Grid risk sensitive work is-not scheduled.coincident with BPA grid risk sensitive work per procedure WCI-4. If degraded grid conditions exist or are imminent, grid-risk-

,sensitive maintenance activities would be postponed until grid conditions are returned to normal. Additional evaluations-are performed using the Sentinel risk assessment program which uses a variable (HRELOSP) to evaluate an

71 - . IN SUPPLEMENTAL RESPONSE TO GENERIC LETTER .2006-02, "'GRID RELIABILITY

AND THE IMPACT ON PLANT RISK AND THE'OPERABILITY OF OFFSITE POWER"$

Enclosure Page 15 of 20 increased potential for a loss of station power due to certain grid conditions, (e.g.,

loss of one or more TR-S offsite 'power sources, -evere weather, or 500 kV grid stability threatened)- .

NRC Question 6(d): -

(d) If there is an overriding needto performgrid-risk-sensitivemaintenance activities underexisting orimminient conditddhs of degradedgrid reliability,or continue grid-risk-sensitivemaintenance when grid conditions worsen, do you implement appropriaterisk management actions? Ifso, describe the actions that you would take. .(These actions could include alternateequipment protection and compensatory,measuresto:Iinit or tnirniMuze.nik.) ......-

EN Response: *

,m'c: . . ..

3.;I~7 . .. * . k. -

Contingencypians'woUld b* ptit" Ilcetoehsu'e actibisare taken t6 minimize the risk.; :For-example,, isk~sensitiVe6activities Would be stopped or postponed, safety and important to safety equipment would be protected.- Plant-procedure PPM :1.3.76, "Integrated Risk Management" contains requirements for managing risk sensitive work.

NRC Question 6(e):

(e) Describe the actions associatedwith questions 6(a) through 6(d) above that would be taken, statewhethereach action is governed by documented .

procedures and identify'the procedures,and explain why these actions are effective and will be consistently accomplished..

EN Response:

The specific actions are described in -responses to 6(a).through 6(d) above.

These actions are implemented through approved procedures as indicated.'

Management oversight ensures these actions will be effective and consistently,'

accomplished. Discrepancies will be identified and resolved via CGS's corrective action program. -

NRC Qu'estion"6(f):- -'-

(f) Describe how NPP operatorsand maintenance personnel are trainedand tested to assure they can accomplish the actions describedin your answers to question 6(e).

EN Response:

Through the use of the systematic approach to training, the training needs of items 6(e) above have been identified to include the following:

SUPPLEMENTAL RESPONSE TO GENERIC LETTER 2006-02, "GRID RELIABILITY AND THE IMPACT ON PLANT RISK ANDTHE OPERABILITY OF OFFSITE POWER"'

Enclosure Page 16 of 20 Operators are training on conduct of maintenance activities as part of their OJT/OJE qualification checklist. Training on procedure use and Conduct of Operations provides the operators guidance on implementing procedures requiring communications and coordinationwith BPA for activities that could impact grid reliability. Additionally,,ltheyare trained in risk ýmanagementand the requirements of PPM 1.3.76.

-Shift Managers receive additional work management arid risk management training in.theirOJT/OJE qualificationchecklist.

. Maintenance personnel receive training on the electrical distribution system and transformer yard Specific.procedures'(Qualificatiorn ELEX).

Work Control personnel have an Indoctrination Checklist to document training and procedure review per WCI-5 Work Control Indoctrination:arid Training.

Testing is accomplished through the use of wrdttenrxarn (initial training'-

exams and requalification cycle examinations) and evaluated, dynamic simulator

ý.

scenarios.: Training'effectiveness evaluations 1 -*-cnducted based on the SAT

.. process which takes into consideration plant perfonjinance'data,"la'nrt assessments, the operating experience program, and the corrective action

-,program. Training needs identified using'the above data`are integrated into the training program through the CRC and TAG processes.

NRC Question 6(g):

- (g) If there is no effective coordinationbetween' the NPP Operatorandthe TSO regardingtransmissionsystem maintenance or NPP maintenance activities, please explain why you believe you comply withthe provisions of 10 CFR

50. 65(a)(4).*,-

EN Response:

Effective coordination is maintained., This question is not applicable'.

NRC Question 6(h):

(h) If you do not considerand effectively implement appropriaterisk management actions during the conditions describedabove, explain why you believe you.,

effectively addressedthe relevantprovisions of the associatedNRC-endorsed industryguidance.

EN Response:

Appropriate risk management is implemented effectively. This question is not applicable. . ...

SUPPLEMENTAL RESPONSE TO GENERIC LETTER 2006-02, "GRID RELIABILITY "AND THE IMPACT ON PLANTRISK AND THE OPERABILITY OF OFFSITE POWER" Enclosure Page 17 of 20 NRC Question 6(i): . -

(i) You may,.as 'an alternativeto questions 6(g) and 6(h) describe what actions

,.you intend to take to ensUre that the increase in risk that may result from grid-risk-sensitive,maintenance activities is managed in accordancewith 10 CFR 50.65(a)(4).

EN Response: . . ."

SEN has no alternative response to*questions 6(g) andt6(h).

EN~~,

alentv, has. no, a Ill. Offsite power restorationprocedures in accordancewith 10 CFR 50.63 as developed in Section2ioflRG -. 1155. ,:... .. A ..... .

Pursuantto 10 CFR.50.63 th.e NRC requires that each NPP licensedtoo"'peratebe able to withstandan SBO for a specified durationand recoverfrom the SBO.

NRC RG 1.155 gives licensees guidance on developing theirapproachesfor complying with 10 CFR 50.63... '

7. Proceduresfor identifying localpower sources that could be made available to resupplyyour plantfollowing a LOOP event.

Note: Section 2,, "Offsite Power," of RG 1.155 (ADAMS Accession No. ML003740034) states:! ,

Proceduresshould include the actions necessary to restoreoffsite power and use nearbypower sources when offsite power is unavailable. As a minimum, the following potential causes for loss .

of offsite power should be considered:

Gridundervoltage and collapse

Weather-inducedpower loss S. Preferredpower distributionsystemn faults that could result in the.

:loss of normalpower to essentialswitchgear buses NRC Question 7(a): , I (a) Briefly describe any agreementmade with the"TSb'-to idd'ntify local power sources that could be 'made available to resupply power to your plant following a LOOP event. .

EN Response:

Response not for public disclosure.

SUPPLEMENTAL: RESPONSE :TO GENERIC LETTER 2006-02,' "GRID RELIABILITY AND THE IMPACT, ON PLANT RISK AND THE OPERABILITY OF OFFSITE POWER" .

Enclosure Page 18 of 20 NRC Question 7(b):..,

(b) Are your NPIP operators trained and tested on identifying and using local power sources to resupplyyour plant following a LOOP event? If so, describe

,how. - -

EN Response:

There are no local offsite AC power sources and transmission lines of sufficient capacity that-are under the direct-control of EN.:;AIl offsite'power sources-and

...transmission lines are under the control :of BPA. Therefore, there is no training of

.,operators to identify local-powersources to resuppil9 'the CGS following aLOOP event,.-However, operators are trained to coordinat-"WiithWBPAtb implement' offsite power.restoration. -The.alterrfate sources ofitheloffsite power has been pre-established by BPA in the letter.agreeme.it, asidescribed in response to question

.one ormore7(a) above. When BPA has restored the offsite power availability from ofthese designated sourcesthe restoration is ,coordinated with BPA

...to resupp!y the plant. These actions are-controlled by proce'dures and plant operators are trained in these procedures.. . -. -

NRC Question 7(c): , " - .. -

- - (c) ffyou have not establishedan agreementwith yourplant's TSO to identify local powersources.that could be made availableto resupply power to your plant following a LOOP event, explain why you believe you comply with the provisions of 10 CFR 50.63, or describe what actions you intend to take to establish compliance..

EN Response:

Response not for public disclosure.

IV. Losses of offsite power caused by grid failures at a frequency of equal to or greaterthan once in' 20 site-years in accordancewith Table 4 of Regulatory Guide 1.155 for complying with 10 CFR 50.63 Pursuantto 10 CFR 50.63, the NRC requires that each NPP licensed to operate be able to withstandan SBO for a specified duration and recover from the SBO.

NRC RG 1.155 gives licensees guidance on developing their approachesfor complying with 10 CFR 50.63.

SUPPLEMENTAL :RESPONSE TO GENERIC'LETTER 2006-02, "GRID RELIABILITY SAND THE IMPACT'ON PLANT.RISK AND THE OPERABILITY; OF OFFSITE POWER" Enclosure Page 19 of 20

8. MaintainingSBO coping capabilitiesin accordancewith .10CFR 50.63.

NRC Question 8(a):,

(a) Has your NPP experienced a total LOOP caused by grid failure since the plant's coping duration was initially determined under 10 CFR 50.63?

EN Response: : iw ". ,. - , . '. ,

The CGS coping,.duratior..was ,determined using data in-Table 8A-1.of the FSAR

..andthe methodoo providbd.in Chapter. 3 ofNUMARC 87-00 .ahd submitted on the docketvia'letteriG02-89-062ý in April 1 989:ofrom-the,'submittal in accordance with 10 CFR'50z63,;0GS is~designated as'AC.:Power Design, Characteristic group

.P1. Since this initial AdLtrmination,:CGS. hasnit experienced.a total LOOP caused by gridfailure:(grid centered,.LOOP).,-, ;:- "

-.. I ..- ,* .L-',*-II " , ;': ":, : .. .' :

As noted in the :response to TI12515/156,; Se6tion! B. 10 CFR 50.63, Station

'Blackout (SBO),,CGS has reported one plant centered LOOP which occurred during a refueling outage on May14,11989#(refer to LER 89-'01 6).

NRC Question 8(b):

(b) If so, have you reevaluatedthe..NPP using the guidance in Table 4 of RG 1.15.5 to determine if your.NPPshould be assigned to the P3 offsite power design characteristicgroup? .

EN Response:

CGS has not experienced a total LOOP caused by grid failure (grid centered LOOP) and has not performed a re-evaluation using the guidance in Table 4 of RG 1.155 to determine if assignment to the P3 offsite powerdesign characteristic

-group is~appropriate.z NRC Question.8(c):

(c) If so, what were the results of this reevaluation,and did the initially determined coping duration for the NPP need to be adjusted?

EN Response:

CGS has not experienced a total LOOP caused by grid failure (grid centered LOOP) and has not performed a re-evaluation using the guidance in Table 4 of RG 1.155 to determine if assignment to the P3 offsite power design characteristic group is appropriate.

SUPPLEMENTAL RESPONSE TO GENERIC LETTER 2006-02, "GRID RELIABILITY OF OFFSITE POWER"'

AND THE IMPACT ON PLANT RISK AND THE OPERABILITY Enclosure Page 20 of 20 '- . -'

NRC Question 8(d):" - .

(d) If your NPP has experienced a total LOOP caused by grid failure Since the6 plant's coping duration was initially determined under 10 CFR 50.63 and has not c been reevaluatedusing the guidance in Table 4 of RG 1.155, explain whyyou believe you comply with the provisions of 10 CFR 50.63 as stated above, or describe what actionsyou intend to take to ensure that the NPP maintainsits SBO coping capabilitiesin accordance with 10 CFR 50.63.

EN Response:.

- CGS has not experienced a total LOOP caused by grid failure since the plant's coping duration was initially determined under 10 CFR 50.63 and has not

,performed a reevaluation using the guidance in Table 4 of RG 1.155.:' CGS's current licensing basis (CLB) for SBO capabilities remain in compliance with 10 CFR 50.63. Changes to CLB are controlled by procedures that require evaluation of the changes to determine if compliance with NRC regulations is

-affected. The CLB change process procedures also require one-over-one review and plant management approval. The robustness of this process ensures that the SBO coping capabilities are maintained in accordance with 10 CFR 50.63.

NRC Question 9:..-

9. If you determine that any action is warrantedto bringyour NPP into compliance with NRC regulatoryrequirements,including TSs, GDC 17, 10 CFR 50.65(a)(4), 10 CFR 50.63, 10 CFR 55.59 or 10 CFR 50.120, describe the schedule for implementing it.

EN Response:

EN has determined, that in consideration of GL 2006-02, compliance with NRC regulatory requirements, including TS, GDC 17, 10 CFR 50.65(a)(4), 10 CFR 50.63, 10 CFR 55.59 and 10 CFR 50.120 is maintained at CGS and no actions' are warranted.

Text

9ENERGY NORTHWEST People. Vision- Solutions-P.O. Box 968

Richland, WA

99352-0968 June 15, 2006 G02-06-092 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, Maryland 20852

Subject:

COLUMBIA GENERATING STATION, DOCKET NO. 50-397 SUPPLEMENTAL RESPONSE TO GENERIC LETTER 2006-02, "GRID RELIABILITY AND THE IMPACT ON PLANT RISK AND THE OPERABILITY OF OFFSITE POWER"

Reference:

Letter dated April 3, 2006, from WS Oxenford (Energy Northwest), to NRC, "Response to Generic Letter 2006-02, 'Grid Reliability and the Impact on Plant Risk and the Operability of Offsite Power"'

Dear Sir or Madam:

On April 3, 2006 Energy Northwest submitted, pursuant to 10 CFR 50.54(f), the referenced response to Generic Letter (GL) 2006-02. Submittal of the requested material was a collaborative effort between Energy Northwest and the Bonneville Power Administration (BPA) and the responses were compiled in accordance with a mutual non-disclosure agreement.

The response contained information designated as Critical Energy Infrastructure Information and was therefore submitted pursuant to 10 CFR 2.390 and the guidance in Regulatory Issue Summary (RIS) 2005-26 as Sensitive Unclassified Non-safeguards Information which should be withheld from public disclosure.

Subsequent to submittal of the referenced GL response, your staff contacted Energy Northwest and requested that some or all material be declassified in order to be consistent with industry responses.

In response to the staff's request, BPA and Energy Northwest reviewed the GL response and determined that portions of the response could indeed be made available for public review in order to honor the staff's request. That information available for public disclosure is contained in the enclosure hereto.

fWJ23

IL SUPPLEMENTAL RESPONSE TO GENERIC LETTER 2006-02, "GRID RELIABILITY AND THE IMPACT ON PLANT RISK AND THE OPERABILITY OF OFFSITE POWER" Page 2 There are no commitments being made to the NRC by this letter.