ML20216F674

Requests Enforcement Discretion to Permit One Time Testing of safety-related Logic Circuits While Plant in Mode 1 Power Operation & Addl 24 H Beyond 24 H Permitted by TS 4.0.3 to Complete Testing.Ts Amend Request Will Be Submitted

ML20216F674
Person / Time
Site:	Wolf Creek
Issue date:	09/05/1997
From:	Warren C WOLF CREEK NUCLEAR OPERATING CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20216F677	List: ML20216F674 ML20216F691
References
GL-96-01, GL-96-1, WO-97-0093, WO-97-93, NUDOCS 9709120068
Download: ML20216F674 (8)

Text

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W@ NUCLEAR LF CREEK OPERATING C Clay C. Wanen  !

l Chef Operating OWer September 5, 1997 l

WO 97-0093 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station Pl-137 Washington, D. C. 20555

Subject:

Docket No. 50-482: Request for Enforcement Discretion Regarding Compliance with Technical Specification Surveillance Requirements 4.8.1.1.2.g.2)c)2),

4.8.1.1.2.g.3)d) and 4.8.1.1.2.g.4)d) for the Emergency Diesel Generators Gentlemen:

Pursuant to Section VII.c, of the " General Statement of Policy and Procedure for NRC Enforcement Actions," (NUREG-1600), Wolf Creek Nuclear Operating Corporation (WCNOC) requests that the Nuclear Regulatory Commission (NRC) exercise enforcement discretion regarding compliance with Technical Specification Surveillance Requirements 4.8.1.1.2.g.2)c)2), 4.8.1.1.2.g.3)d) and 4.8.1.1.2.g.4)d).

On September 4, 1997, as a result of reviews undertaken in response to Generic Letter 96-01, " Testing of Safety Related Logic Circuits," and information received from another plant, WCNOC determined that existing surveillance testing did not completely verify all of the above Technical Specification surveillance requirements. Technical Specification 4.0.3 was entered at 1906 CDT on September 4, 1997, for the missed surveillances, WCNOC is requesting Enforcement Discretion to permit one-time testing of these contacts while the plant is in MODE 1, Power Operation. Additionally, WCNOC is requesting an additional 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> beyond the 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> permitted by Technical Specification 4.0.3 to complete this testing, fi 9709120060 970905 ll l JQ' PDR /

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A WO 97-0093 Pago 2 of 2 T i This-request for enforcement discretior was . verbally discussed with the NRC Region IV ' Of fice and- Office of Nuclear Reactor Regulation on Septenber 5, 1997, and subsequently verbally approved.

If-you should have any questions regarding this request, please contact me at (316) 364-8831, extensic, 4100, or Mr. Richard Flannigan at extension 4500.

Very truly yours C1 y C. Warren CCW/jad Attachment cci E. W. Merschoff (NRC), w/a W. D. Johnson (NRC), w/a J. F. Ringwald (NRC), w/a J. C. Stone (NRC), w/a

. Attachment to WO 97-0093-1Page 1 of _8 REQUEST FOR ENFORCEMENT DISCRETION REGARDING CCHPLIANCE WITH TECHNICAL SPECIFICATION SURVEILLANCE REQUIREMENTS = 4. 8.1.1. 2.g. 2) c) 2) , -1

. 4.84 1.2.g.3)d) and 4.8.1=.1.2.g.4)d)," EMERGENCY DIESEL GENERATORS" Ai Technical Specification or other License Condition that will be Violated

) The following Technical Specification surveillance requirements have not been adequately demonstrated: j Technical Specification 4.8.1.1.2.g.2)c)2) requires that each Emergency Diesel

~

Generator (EDG) be demonstrated operable, at least once per 18 months, during.

shutdown, by verifying on an actual or simulated loss-of-offsite power (LOOP) -

signal that the EDG auto-starts f rom standby conditions and - energites the auto-connected shutdown loads through the shutdown sequencer.

, Technical Specification 4.8.1.1.2.g.3)d) requires that each EDG be-  !

demonstrated operable, at least once per 18 months, during shutdown, by verifying on an_ actual or simulated Safety Injection Actuation Signal that each EDG auto-starts f rom the standby condition and the of f site power source energizes the auto-connected (accident) loads through the LOCA sequencer.-

a Technical Specification 4.8.1.1.2.g.4)d) requires that each EDG be demonstrated oper_able, at least once per 18 months, during shutdown, by verifying on a simulated LOOP in conjunction with a simulated Safety Injection Actuation -Signal the each EDG auto-starts from the standby condition and energizes the emergency busses with permanently connected loads within 12 seconds, energizes the auto-connected emergency (accident) loads through the h0CA sequencer.

B. Background and Circumstance Requiring the Request for Enforcement

. Discretion On September 4, 1997, as a result of reviews undertaken in response to Generic Letter 96-01, " Testing of Safety Related Logic Circuits," ar.d information received from another' plant, Wolf Creek Nuclear Operating Corporation (WCNOC) determined that existing surveillance testing did not completely verify all of the above Technical Specification surveillance requirements.

Specifically, it was discovered that certain relay contacts that open have not been tested during performance of surveillance procedure, STS KJ-001A/B,

, " Integrated Diesel Generator Safeguards Actuation Test Train A/B." The

! contacts in question are actuated by relays K1102, K4102, Klll7, K4117, K1118 and K4118. The current testing process implemented through STS KJ-001A/B has not demonstrated the function of the contacts because there are other contacts 4

in series that could also be open.

The relay contacts provide a blocking / time delay function for start of the Component Cooling Water (CCW), Essential Service Water (ESW) and Motor Driven 1 Auxiliary reedwater pumps (MDAfWP) . On a loss of offsite power the CCW, ESW, and MDAFAP are shed from the safety busses and then loaded in sequence to the EDGs. The contacts blocking / time delay function assure that no matter. what the start demand is for the pumps, they are not started until the parallel contacts of the-load sequencer close to start the pump at the required time increment.

The functionality of the relays has been demonstrated during prior performances of procedure STS KJ-001A/D, for example, relays K1102 and K4102

-have successfully actuated load shed and tripped the NB bus normal feeder breaker,- relays K1117 and K4117 -have successfully actuated valves - EFHV-42 and ,

EFHV-40 and ' relays Kll18 and K4118 have successfully actuated ECHV-59 and EFHV-60. However, testing of the specific contacts should 'be _ conducced to provide complete _ testing and absolute assurance that load sequencing will function as designed.

Attachment to WO 97-0093 Page 2 of 8 Technical Specification 4.0,3 was entered at 1906 CDT on September 4, 1997 for mise $ed syrveillances. Technical Specification 4.0.3 allows the ACTION requ'irements to be delayed for up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to permit the completion of the surveillance when the allowable outage time limits of the ACTION requirements are less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. However, Technical Specification 4.8.1.1.2.g requires that the surveillance testing be performed once every 18 months during shutdown.

WCNOC is requesting Enforcement Discretion to permit one-time testing of these contacts while the plant is in MODE 1, Power Operation. Additionally, WCNOC is requesting an additional 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> beyond the 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> permitted by Technical Specification 4.0.3 to complete this testing. The testing of these

_ contacts at power will be performed in accordance with specific procedures approved for this purpose.

A preliminary cause for this condition is an error made during the initial development of the surveillance procedure in that these contacts were not recognized as requiring testing. WCNOC has initiated the proper corrective action documents to research the root cause, determine corrective actions to prevent recurrence, and investigate generic aspects of the event.

C. Safety Evaluation Design Bases function:

The standby power supply for each saf ety-related load group consists of one diesel generator complete with its accessories and fuel storage and transfer systems. It is capable of supplying essential loads necessary to reliably and safely shutdown and isolate the reactor. The diesel generators are electrically isolated from each other. Power and control cables for the diesel generators and associated switchgear are routed to maintain physical separation.

Ratings for diesel generator sets are established in order to satisfy the requirements set forth in Regulatory Guide 1.9. The diesel generator loads are determined on the basis of nameplate rating, pump pressure and flow conditions, or pump runout conditions. The continuous rating of the diesel generator is based on the maximum total load required at any time. The Load Shedding and Emergency Load Sequencing (NF) System removes selected loads from the Class 1E bussem under degraded bus voltage conditions or upon the presence of a safety injection signal and actuates equipment fed from these busses in a prede t e rmined sequence following degraded bus voltage conditions or in the presence of a loss-of-coolant accident (LOCA).

The load shedding portion of the NF system removes selected loads under degraded voltage conditions on the 4160 volt Class IE busses. Loads are then actuated in programmed intervals by the sequencing portion of the system such that the voltage of the busses does not fall below 75 percent of rated voltage and the frequency does not fall below 95 percent of rated frequency. All of the non-Class IE loads supplied by the Class IE busses, with the exception of the non-vital instrument busses, are shed automatically upon the presence of a safety injection signal; these loads must be manually re-energized, if required. In the event preferred power is lost following a LOCA, the load sequencer will function to shed selected loads and automatically start the associated standby diesel generator. Load sequencers then function to start the required Class IE loads in programmed time increments.

The contacts in question are actuated by relays K1102, K4102, K1117, K4117, K1118 and K4118. The relay contacts provide a blocking / time delay function for starting of the CCW, ESW, and MDAFW pumps. On a loss of offsite power the CCW, ESW, and MDAFW pumps are shed from the safety busses and then loaded in sequence to the ED3 s . The contacts assure that no matter what the start l

Attachtnent to WO 97-0093 Page 3 cf 8 domand is for the. . purnps, they are not started until the required time increment.

Irnpact on ' Nuclear Safety:

For the relay contacts associated with the ESW and CCW pumps, testing will be accomplished by actuating slave relay K645A/B and verifying that the blocking contact on relays K1117, K4117, K1118 and K4118 change state.

For the relay contacts associated with the MDAEW pumps, testing will be accomplished by isolating the relays (K1102, K4102) from their normal power supply by lifting leads, and actuating the rvlay using a portable power source to verify the contacts change state for the specified tirne period. During the test f or the "A" MDAFW purnp the leads f rom relay K1102 that shed N90112, "NB01 Normal Feeder Dreaker," must be lifted to preclude tripping this breaker.

Adverse effects of improper conduct of the test could result in tripping NB0112, "ND01 Normal Feeder Breaker," but are mitigated by implementation of .

existing plant off-normal procedures. This activity will be administratively controlled to ensure removal and restoration are safely accomplished.

The integrated EDG and Engineered Safety Features Actuation test is performed during shutdown because of a potential that this surveillance could cause

. pe rt urbat ions to the electrical distribution systems that could challenge continued steady state operation and, as a result unit safety systems. The testing proposed to be done at power does not duplicate the integrated EDG and Engineered Safety Features Actuation test and will not cause any perturbation to the electrical distribution systems that could challenge steady state operation or unit safety systems.

Probabilistic Safety Assessment (PSA) Evaluation:

A quantitative probabilistic evaluation was performed to estimate the impact of performing the subject testing in Modo i versus performance in Mode 3.

Uning both Modo 1 and Mode 3 plant operation as starting points, the impact on plant risk associated with performance of the subject testing was considered.

For both Mode 1 and Mode 3 plant cperation, the relative increase in risk over the baseline CDP value (no equipment out of service) due to removing plant equipment from service for the short test duration was nearJy identical. This would be expected as the equipment being removed from service for testing has the same type of functional impact for postulated initiating events in both plant operational modes.

The likelihood of experiencing transient related plant conditions, such as an inadvertent safety system actuations or a plant system alignment failure, is qualitatively considered to be slightly greater, to some incremental degree, during a plant shutdown and startup evolution than for continued at-power operation. While some very minor annual CDP reduction would be experienced by operation in Mode 3 instead of Mode 1 for a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period, on a qualitative basis it is considered that this reduction would be offset by the increased likelihood of experiencing an event of the type that might present a challenge to the relay contacts in question prior to performance of the testing.

Theretore, performance of the subject testing in Mode 1 is not risk significant.

D. Unreviewed Safety Question Determination and No Significant Hazards Consideration Evaluation In accordance with 10 CFR 50.59 and 10 CFR 50.92(c), WCNOC's evaluation of the proposed enforcement discretion for an unroviewed safety question and no significant hazards consideration is as follows:

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Attachment to'WO 97-0093 Page 4 o.f 8 -

1. The proposed _ request for enforcement discretion does not involve. a significant increase in the probability or consequences of an accident or a,alfunction previously evaluated.

This request for enforcement discretion does not change the function or performance requirements- for the Load Shedding and Emergency Load Sequencing System as described in the _ Updated Safety Analysis Report - (USAR) and the i Technical Specifications. Testing these relays at power will . not cause any degradation in system performance, nor will it increase the number of 6 challenges to equipment _ assumed to function during an accident situation. The -

testing ..will require related equipment - to be declared inoperable for the duration of each test,- but these durations will be much less than those allowed by the applicable Technical Specification Action Statements. Further, the enforcement discretion prevents an unnecessary unit shutdown which could

. result in.a reactor - transient and . a unwarranted challenge of the safety-related systems. Future testing will be performed in accordance with the

. requirements specified in Technical Specifications.

Thus, the request for enforcement discretion will not result in an increase in the consequences of, or an increase in the probability of, occurrence of any accident or safety-related equipment malfunction. *

2. The proposed requec.t for enforcement discretion does not create the possibility of a new or different kind of accident from any accident previously evaluated.

The Load Shedding and Emergency Load Sequencing System will continue to perform in a manner consistent with the assumptions in the USAR. No new scenarios, transient precursors, failure mechanisms, or limiting single failures are introduced. There will be no adverse effects or challenges imposed on any safety-related system as a result-of this request. Therefore, the possibility of a new or different kind of accident is not created. *

3. The proposed request for enforcement discretion does not involve a significant reduction in the margin of safety?

The purpose of this request is to allow WCNOC the ability to perform a one-time partial test of the subject Load shedding and Emergency Load Sequencing System relay contacts while .at power. This will demonstrate complete compliance with Technical Specification 3/4.8.1 without having to shutdown the unit. This activity will not affect any system or component setpoints or safety limit settings associated with the Load Shedding and Emergency Load Sequencing System. No new accident scenarios, transient precursors, failure mechanisms, or limiting single failures are introduced. There will be no adverse effects or challenges imposed on any safety-related system as a result of this. request. This request-for enforcement discretion will not result in a significant reduction in the margin of safety. ,

Therefore, WCNOC has determined that the requested enforcement discretion does not: involve a significant increase in the probability or consequences of an accident or other . adverse condition over previous evaluations; create the possibility of a new or different kind of accident or condition over previous evaluationst nor involve a significant reduction in a margin of . saf ety.

Therefore, the requested enforcement discretion meets'the requirements of 10 CFR 50.92(c), and does'not involve a significant hazards consideration.

In conclusion,-based on the safety evaluation discussed in Section "C," WCNOC believes that the activities associated with - the enforcement discretion request -satisfy ~ the requirements of 10 CFR 50.59 and 10 CFR 50.92(c). j Accordingly, no- significant hazards consideration is justified and nc

-unreviewed safety question exists. -j

4 Attachment to WO 97-0093 Page 5 of 8 E. Environmental Evaluation

' This request for enforcement- discretion meets the eligibility criteria .for cate'gorical exclusion set forth in 10 CFR 51.22(c) (9) as specified below

1. Involves no significant hazards consideration As demonstrated in Section "D" of this letter, the request does not involve any significant hazards consideration.

2. There is no significant change in the types or significant increase in the I amounts of any effluents that may be released offsite g The request does not involve a change to the facility or operating procedures that would cause an increase in the amounts of effluents or create new types of effluents. The request for enforcement discretion does not involve changes >

to any instrumentation setpoints, _ system operating parameters, or system accident mitigation capabilities, nor does this request affect the probability of any event initiators. Thus, the - request does not reduce the margin of safety to any licensed design parameter.

3. There is no significant increase in individual or cumulative occupational radiation exposure The request would not adversely affect the operation of the reactor, and would not affect any system that would affect occupational radiation exposure. The proposed change does not create additional exposure to personnel nor af fect levels of radiation present. The enforcement discretion request will not result in any increase in individual or cumulative occupational radiation exposure.

Based on the above, it is concluded that there will be no impact on the j environment resulting from the request, and that the- request meets the i criteria specified in 10 CFR 51.22 for a categorical exclusion from the 3

requirements of 10 CFR 51.21 relative to requiring ' a specific environmental assessment by the Commission.

F. Compensatory Actions Both EDGs have been successfully demonstrated operable and the applicable testing procedures will be revised to include testing of the subject contacts every 18 months during a shutdown condition.

-During the testing the following compensatory actions will be in place:

1. WCNOC will follow its protected train philosophy and only one train will be worked on at a time.

2. No work will be ongoing in the Switchyard; System Operations will be notified to maintain maximum grid stability.

G. Justification for Noncompliance Duration

- -WCNOC is' requesting a _ very short noncompliance period of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for a nonrecurring event. The additional 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, beyond the 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowed by Technical Specification 4.0.3, is requested in order to-allow enough time to prepare procedures and complete testing on the subject contacts. The request, if granted, would allow WCNOC the-ability to perform testing of these contacts at power to demonstrate compliance with Technical Specification Surveillance Requirements 4.8.1.1.2.g.2)c)2), 4.8.1.1.2.g.3)d) and 4.8.1.1.2.g.4)d),

, without having to; change plant status from Mode 1 to shutdown. Enforcement discretion will preclude an unnecessary plant transient and the system realignments associated with a plant shutdown.

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Attachment to WO 97-0093 Page 6 of 8 H. Plant Safety Review Committee Approval The . request for enforcement discretion and its basis were reviewed by the WCNOC Plarit Safety Review Committee (PSRC) prior to the request being made to the NRC. The PSRC reviewed and approved with this written request.

I. Justification for Submitting a Request for Enforcement Discretion In accordance with NUREG-1600, " General Statement of Policy and Procedures for NRC Enforcement Actions,"Section VII, " Exercise of Discretion Subsection "C," Exercise of Discretion for an Operating Facility:"

"For an operating plant, this exercise of enforcement discretion is intended to minimize the potential safety consequences of unnecessary plant transients with the accompanying operational risks and impacts."

The during shutdown requirement for these surveillance is intended to prevent unnecessary challenges to the plant and its systems during integrated EDG and Engineered Safety Features Actuation System (ESPAS)tecting. The testing of these contacts will not result in any EDG or ESFAS actuations, but only test proPr functioning of the specific contacts. Testing performed during the previous refueling outage adequately established other EDG and ESFAS actuation circuitry. The testing proposed to be done at power would not duplicate these tests in scope or potential impact to the plant.

For the current situation, both EDGs are operable, and the plant is in MODE 1 near 100% power.

WCNOC has submitted 1moroved Technical Specifications for review to the NRC.

A review of our submittal confirmed that adoption of the Improved Technical Specifications would not have obviated the need for this request for enforcement discretion.

J. Mark-up Pages for Emergency Technical Specification Amendment Request WCNOC will submit a request for an emergency technical specification amendment associated with this Request For Enforcement Discretion. The proposed technical specification changes are shown on the attached markup pages.

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