ML20065S353

Responds to NRC Re Violations & Deviations Noted in Insp Repts 50-269/93-25,50-270/93-25 & 50-287/93-25. Corrective Actions:Piping Sys Will Be Modified by Installing Orifice Downstream of Potential Cavitation

ML20065S353
Person / Time
Site:	Oconee
Issue date:	05/12/1994
From:	Hampton J DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9405180181
Download: ML20065S353 (24)

Text

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Li l Duke Power Dimpany 1 W IIWW Oconce hiea:Ste Vke hesident I,'O Ebx 1G9 (h01)M3499 UI?ke Sencia. SCW79 (803)%3564 Fax i DUKEPOWER May 12,1994 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555

Subject:

Oconce Nuclear Site D > ket Nos. 50-269,-270.-287 Inspection Report 50-209,-270.-287/93-25 Reply to Notice of Violation By letter dated February 11,1994 the NRC issued a Notice of Violation and Notice of Deviation as described in inspection Report No. 50-269/93-25,50-270/93-25, and 50-287/93-25.

The inspection report covers the Service Water System Operational Performance Inspection that was conducted at Oconce from November 1 - December 14,1993.

A total of four violations were identified as a result of the inspection, with cighteen ,

separate examples requiring response. Two deviations were also identified, with live i separate examples requiring response. An extension request of sixty days was l submitted to the NRC on March I,1994 and approved by your Staff on March 22, 1994.

Pursuant to the provis!on of 10 CFR 2.201, I am submitting a written response to the violations identified in f.'1e above inspection Report. In addition, attached is the  :

response to the deviations that v:cre identified.

Very4ruly y'ours,I if' ' )hk i

s QlJ. kl ampton cc Mr. S. D. Ebncter, Regional Administrator U. S. Nuclear Regulatory Comm:ssion, Region 11 Mr. L. A. Wiens. project Manager Office of Nuclear Reactor Regulation Mr. P. E. liarmon / k Senior Resident inspector

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RESPONSE TO VIOLATION 'A'

• l A. 10CFR50 APPENDIX B, CRITERION XVI, " CORRECTIVE ACTIONS"

1. We accept this violation and agree that items I and 2 me examples of the violation.

Reasons for the violation are discussed below under each individual item.

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2. The corrective actions taken and the results achieved are discussed below under each individual item.

3, The correctisc actions that will be taken to avoid further violations are discussed below under cach individual item. Additional corrective actions, which will also serve to avoid further violations, were previously identified to you in our April 20, .t 1994 submittal in response to the potential programmatic weaknesses identified in. ,

the Scivice Water System Operational Performance Inspection report. As stated in our April 20, 1994 submittal the examples cited are not indicative of a programmatic weakness.

4. We are in full comp,. cc with this criterion.

ITEM 1.

Measures had not been established to assure that conditions adverse to quality had been corrected in that the evaluation of Condition Adverse to Quality Report, PIP 92-454, for a postulated water hammer within the Low Pressure Service Water piping downstream of the reactor building cooling units, did not address the water hammer effects on the ,

structural integrity of the piping. ,

R ESPONS E Oconce Engineering identified the potential for water to flash in the Low Pressure Service Water (LPSW) piping downstream of the discharge from the Reactor Building Cooling Units (RBCUs). Under worst case, design basis accident conditions, the pressure in the ,

piping could be subatmospheric. The high fluid temperature coupled with the low --

3 pressure could result in flashing of some of the LPSW in the discharge piping. Two concerns are associated with this flashing: the potential for this two-phase flow to cause pipe vibration which could threaten the integrity of the pipe, and the reduction in LPSW flow under two-phase conditions. PIP 0-092-0454 was written in September 1992 to address this situation. In response to this PIP, a calculation was performed (OSC-4922) ,

which assessed the potential reduction in flow under two-phase conditions and the LPSW hydraulic computer models were revised to conservatively model the reduction in flow.

The issue of pipe vibration was not explicitly addressed.

In December 1992. Duke power performed an internal review of the effectiveness of a ~I past technical audit of the LPSW system. During this effectiveness review,-it was identified and documented that the potential for two-phase flow to cause pipe vibration I

RESPONSE TO VIOLATION 'A' (and thereby threaten pipe integrity) was not explicitly addressed in the corrective actions for PIP O-092-0454. The review team recognized that LpSW discharecs from the RBCUs as subcooled liquid and exits the Reactor liuilding at a relatively coro ant cicvation. The piping enters the Auxiliary Building and then rises in elevation. Tuc piping exits the Auxiliary Building and enters the Turbine Building where the piping clevation drops down into the Turbine Building basement Door. Water in the LPSW pipe could Dash at the high point (in the Auxiliary Building) and condense at a lower clevation in the discharge piping (in the Turbine Building), where the pressure is higher. Flashing and the cavitation associated with the condensation of vapor will produce vibration loads on the piping and supports. Documentation does not exist that would indicate whether these loads were evaluated in the original design of the system. I Oconce's position on the findings of the effectiveness review team were documented in an October 1993 memo to file. In this memo. Oconce agreed that the potential exists for the two-phase now to cause vibration of the pipe. It was recognized that the potential transient loadings were not explicitly incorporated into the analysis that supports the piping design temperature and pressure. The potential consequences of this kind of transient loading is damage to hangers (support / restraints). Oconce has had instances '

where hangers have been pulled out of the wall due to water and/or steam hammer. In all cases, the piping has retained its pressure boundary integrity and remained operabic. '

It is possible that the LPSW lischarge piping from the RBCUs would be damaged and be pulled out of the wall,if exposed to these transient loadings during a worst case, design basis accident. 'lowever, it was the judgement of Oconce Engineering that the piping ,

would retain its integrity and remain operable.

Further review of this issue was initiated in December 1993. PIP 0-093-1031 was written, specincally on the pipe vibration and integrity aspect of this issue. The acceleration forces associated with the phase change and bubble collapse can be considered a type of water hammer, though water hammers are usually the result of transient conditions whereas the forces in the LPSW piping are steady state. An engineering evaluation (OSC-6020) was performed and it was determined that the forces would occur only in that portion of piping in the Turbine Building. Upstream of these forces, the piping is restricted from >

moving by passing through the Turbine Building / Auxiliary Building wall. Therefore.

any possible pipe break would occur in the portion of the LPSW piping in the Turbine Duilding as it travels down towards the basement noor.

Since any possible break would not occur inside containment, dilution of the boron ,

concentration in the Reactor Building sump is not a concern. In addition, since the break will not occur inside containment, containment isolation will not be affected. Since the potential break would occur in piping common to the discharge of all three RBCUs, a Dow imbalance would not be induced, it is possible that a slight change in.LPSW system pressure could icsult, depending on exactly where the break occurs. This could result in a slight change in LPSW Dow to the RBCUs and the Low Pressure injection (LPI) coolers. This would be accommodated for by adjusting the flow control valves for flow  !

through the LPI coolers, since the operators would act to maintain the required flows 2

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RESPONSE TO VIOLATION 'A' through the coolets. The metall effect on heat removal, if any, would be negligible.

The only safety-re)ited components in the vicinity of the potential break are air-operated flow control valves 1,2LPSW-251,1,2LPSW-252, 3LPSW-404, and 3LPSW-405. I f, during a postulated accident, these valves were operational to begin with, exposure to the water stream from a break could potentially cause the valves to fail open. These valves would not fail closed under these conditions (the valves are designed to fail open). .lf these air-operated throttle valves were unavailable for any reason, motor-operated valves 1,2,3LPSW-4,-5 would be used to throttic flow. The Turbine Building basement could be flooded at a rate up to 10,000 ppm due to the postulated break. As analyzed in the Oconce Probabilistic Risk Assessment. a flooding rate ofless than 10,000 gpm would not impact the ability of any safety related equipment to perform its function. Therefore, the LPI system and the RBCUs,in conjunction with the LPSW System, would continue to perform its required functions.

In conclusion, a PIP was written specifically on the pipe vibration and integrity aspects of this issue and an operability evaluation was performed. The piping would most likely retain its integrity, and even if it did not, all safety systems would continue to perform their required iunctions. A corrective action has been identified to modify the pipinn system by installinn an orifice downstream of the potential cavitation. The orifice will increase the upstream pressure and prevent the cavitation from occurring. A schedule for the implementation of this modification will be provided by 9/1/94. i ITEM 2.

Measures had not been established to assure that conditions adverse to quality had been corrected in that the evaluation to determine corrective actions for design study ONDS 327 and Problem investigation Report 92-084 concerning the postulated response of the liigh Pressure Service Water system to the maximum hypothetical carthquake did not include the consequences of spurious fire protection cornponent activations.

RESPONSE

The audit team recogniad Oconce's efforts to resolve concerns associated with the liigh Pressure Service Water (llPSW) system not being scismically qualific<l. This issue was evaluated as part of design study ONDS-327 and further evaluated in response to PIPS 0-092-0084 and 0-093-0695. liowever, the inspection report goes on to state that-  !

Oconec's evaluation on the scismic adequacy of the HPSW system failed to consider the 1 actuation of any of the system's fire deluge functions due to a scismic event. It is not clear that Oconce's licensing basis requires consideration of the potential actuation of the fire deluge functions during a scismic event. Duke has not been able to find any documentation of the intent of Duke Power design engineers and of the AEC (NRC) at the time Oconce was licensed. The changes occurring; in the design criteria and codes at the time, especially the seismic design criteria, apparently created some inconsistencies 3

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l RESPONSE TO VIOLATION 'A' When the overall design is reviewed on a comprehensisc basis, liowever, the original plant design was based on good judgement and sound engineering practices.

The spurious actuation of the fite deluge functions of I-IPSW, due to a scismic event, can be postulated. If the event were a scismic event only, the full operation of the llPSW-system would not adversely impact the safe shutdown of the plant, The two standby, 6,000 ppm IIPSW pumps would start as the Elevated Water Storage Tank level decreased to pre set limits. IlPSW would continue to provide its scaling and cooling function to the Condenser Circulating Water pumps. The effect on Low Pressure Service Water (LPSW) pump NPSil would be negligible since the I.PSW system would not be in its worst case configuration if,instead of a scismic event alone, the event were a LOCA with loss of offsite power and concurrent scismic event which ruptured all the compressed air systems, then there would be an impact on LPSW pump NPSil. The effect of full llPSW flow has recently been incorporated into Revision 5 of engineering calculation OSC-2280, "LPSW NPSII 3and Minimum Required Lake i etel.' The effect was to raisc the required lake ,

level 2 feet, from an elevation of approximately 784' to an cicvation of approximately 786'. This new, minimum lake level has been incorporated into the latest revision of SLC 16.9.7. No further corrective actions are necessary.

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l(ESPONSli TO VIOLATION 'B' i l

l B. 10CFR50, APPENDIX B, CRITERlON III, ~ DESIGN CONTROL ~ l

1. We accept this violation and agree that items 2 through 7 are examples of this violation. We do not agree that item I is an example of this violation. Reasons for the violation, and why we disagree with item I, arc discussed below under cach individual item.

2. The corrective actions taken and the results achieved are discussed below under each individual item.

3. The corrective actions that will be taken to avoid further violations are discussed below under each individual item. Additional corrective actions, which will also serve to avoid further violations, were f.reviously identified to you in our April 20, .

1994 submittal in response to the potential programmatic weaknesses identilled in the Service Water System Operational Performance inspection report. As stated '

in our - April 20. 1994 schmittal, the examples cited are not indicative.of a programmatic weaknc3s.

4. Though some of the corrective actions will be completed earlier, full compliance with the criterion will be achieved by 6/1/95.

ITEMl.

The NPSil of the Low Pressure Service Water pumps was not adequately considered as a design input in that calculation OSC-5019 was accepted by the licensce's engineering personnel with inadequate NPSil.

RESPONSE

The NPSil of the Low Pressure Service Water (LPSW) pumps has been adequately considered in engineering calculations. Worst case plant configuration was assumed along with the worst case design basis accident of a LOCA with concurrent loss of offsite power (LOOP) and worst case single failure. In addition,it was conservatively assumed that a catastrophic failure of all the instrument air systems occurred at the same timc as the LOCA/ LOOP. The instrument air systems are not safety related and were not scismically _

designed. Air-operated valves in the LPSW system fail to their safe position, which is open for several large system loads. If the instrument air systems did not fail, existing -

administrative limits on lake level would ensure adequate NPSli to the LPSW pumps during a worst case design basis accident with single failure.

When engineering analyses determined that a complete loss ofinstrument air, during the accident conditions desciibed above, could result in inadequate NPsil to the LPSW pumps, procedural guidance was developed to ensure the operators would quickly regain control of systern load demands. The completion of these operator actions in a timely 5

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IRESPONSE TO VIOLATION Y manner (20 to 30 minutes) leduces system demand, and thcicfore pump flow, to a point where NPSil is adequate. The pump manufacturer was immediately contacted to evaluate pump performance under conditions of inadequate NPSil for a limited period of time. The manufacturer's evaluation, documented in the supporting engineering calculations, determined that the LPSW pumps can withstand operation with inadequate NPSil for the limited period of time they would be exposed to these conditions. ' The impeller inlet would be subject to cavitation damage, but this is generally a long term effect and 20 minutes is not a significant time period for this wear.

In conclusion, engineering analyses have appropiiately evaluated and documented the acceptability of this condition for a limited period of time. Procedural guidance _ for operators has been developed and administrative controls have been placed on lake level.

No other actions ate planned or necessary.

ITEM 2.

Measmes established to assure design basis are correctly translated into procedures were inadequate in that no procedural controls existed to assure the Low Pressure Service Water's pump Dows inputted into the hydraulic computer model for the Low Pressure Service Water system remained valid during quarterly testing of the Low Pressure Service Water pumps.

R ES PONSE We agree that formal procedural controls do not exist to assure that the Low Pressure Service Water (LPSW) pump flows inputted into the hydrevlic model remain valid during quarterly testing. Ilowever, during every refueling outage, a full system now test is performed on that unit's LPSW system. Pump flow rates are recorded over a range of header pressures for a number of different system load configurations. This is in comparison to quarterly ASME Section XI testing which is performed over a limited pressure range. Following the flow test, the data is analyzed and 'used to re benchmark the LPSW hydraulic flow models. This periodic re benchmarking provides information on pump performance over time. The re-benchmarking also provides information on the potential degradation of flow through various loads due to raw water induced fouling. j If the re-benchmarking indicates a degradation in pump and/or system performance, then the hydraulic models of LPSW system performance during a worst case, design basis ,

accident are re analyzed. While the full system now test data on pump performance is

-not collected and analyzed as often as quarterly ASME Section XI data, it is recorded over a much broader range of pressures and Dows and is, therefore, more useful for ensuring the flow model remains valid.

Responsibility for both design basis and testing has recently been combined into the same systems engineering groups. As part of the expectations for these new groups, system engineers have responsibility for ensuring all design basis functions, as defined in 6

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RESPONSE TO VIOLATION B engineering calculations and other design documents, are appropriately validated through testing. Quarterly perfmmance test procedures will be revised to include an action step for the system engineer to review the results of the test before test procedure completion is documented. The test procedures for LpSW and other select systems, which do not have clear test acceptance criteria for pump performance, will be revised by 9/1/94.

Synem engineers will compare quarterly pump test data, along with full system flow test data, against computer models and other calculations to ensure Ihe validity of design basis analyses.

ITEM 3.

The mersures applied to the selection of Belzona as a suitabic material for application to-the Unit 2 Reactor Building Cooling Unit tubes were inadequate in that the commercial grade evaluation. CG D-2021.01-01-0001, did not consider t he Ihermal (temperature) and hydraulic (pressure) changes Belzona would experience due to accident conditions.

R ESPONSE During the commercial grade evaluation of Belzona, an analysis of the Reactor Building Cooling Unit (RBCU) application was performed. This analysis was a " static" analysis at " normal" conditions. By inspection of these results and comparison with published product specifications and peak LOCA conditions,it was judged that the material would' withstand the " static ~ conditions (pressure, temperature, borated water spray) of a LOCA.

Ilowever, no consideration vas given to the steep temperature ramps imposed by a LOCA '

(though local ramps may be much less severe than the bulk average ramp). Similarly, no consideration was giveu to material degradation due to temperature or pressure changes during normal operation.

The installation of the Belzona is such that it has a free surface. llence, thermal stresses would not be expected to exist or would be very low (localized only). llence, only the pressure changes wouhl be expected to contribute to the cyclic loadings. Normal Low Pressure Service Water (LPSW) pressures in the RBCU's tend to be fairly constant, changing a little over time with water temperatme, lake level, and other loads (such as Low pressure injection Coolers during other unit RFO's). llence, the magnitude of the alternating stresses would be small Ovith large periods) and the time to potential fatigue failure would be long.

There is a wide history of favorable industrial experience with the material. This favorable expericace also tends to make any application oriented analytical work oflesser importance.

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Belzona (or a similar product) is the only truly practical means of repairing any minor l leakage of the RBCU coils. The joints are brazed and are in close proximity to each  !

other. Any attempts at either solder or brazing repair would most likely weaken or 7

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RESPONSE TO VIOLATION 'B' destroy adjacent joints. Ilence, Belzona-like products are the only practical products to use. Belzona itself typically has superior performance specifications compared to similar products. Also, Oconce has had good experience with previous Belzona repairs, most notably, the 'D' heater drain pump.

An effort is currently underway to obtain dynamic material propertv data and to analyze Belzona for usage under cyclic loading and LOCA conditions. This evaluation will be completed by 12/16/94 and will further clarifv where Belzona can be used. Also, a modification to replace the RBCU cooling coils has been completed on Unit 3 during the U3EOCl4 refueling ourage, is currentiv underway on Unit I during the UIEOCI5 refueling outage, and will be performed on Unit 2 during the U2EOCl4 refueling outanc.

ITEM 4.

The design basis of the Emergency Circulating Cooling Water system was not adequately.

translated into design documents in that the calculations supporting . Emergency

. Circulating Cooling Water decay heat removal capability did not include numerous aspects of the design that would reduce that system's decay heat removal capability.

RESPONSE

Calculation OSC-2349, "CCW Intake Piping Degassing in the ECCW Mode," was intended to determine water level in the CCW intake piping, as a function of time, following a Station Blackout (SBO) event. The maximum analyzed flow rate of 30,000 ppm is adequate to address the SBO transient. It was'never the intention of this calculation to analyze the LOCA/ LOOP scenario. We intended to analyze this scenario in a separate calculation. Calculation OSC-5670, " Required Number of CCW Intake Flow Paths ," has been developed to address degassing issues for flow rates up to 90,000 gpm which me possible during a LOCA/ LOOP cvent, in addition, using a site corrected atmospheric pressure of 14.0 psia in OSC-2349, instead of the 14.7 psia.actually used, would have an insignificant effect on the analysis. No other actions are planned or necessary on OSC-2349.

Calculation OSC-2346, ~ECCW System Performance Evaluation,"_did not accoun_t foi condenser tubes plugged with Amertap balls or condenser tubes taken out of service due to plugging. Based on the large number of condenser tubes (16,960 per condenscr) and -

the relatively small number affected (approximately 700 or less than 4.5%) the effect on the analysis is insignificant. Using a site corrected atmospheric pressure of 14.0 psia in OSC-2346,instead of the 14.7 psia actually used, would decrease the maximum allowable temperature by 5.5 degrees F to 163.1 degrees F. OSC-2346 calculates a maximum temperature of 145 degrees F; therefore, the maximum allowable temperature is not exceeded.

OSC-2346 assumes a total ECCW minimum flow rate of 4,500 gpm per unit or 13,500 8

RESPONSE TO VIOLATION Y

. gpm total tailrace flow for all three units. Oconce test data given in PT/1,2, or 3/A/0261/07, " Emergency CCW System Flow Test.' yicki a condenser flowrate of at least 20,000 gpm for each unit, versus the required value of 13,500 gpm. Furthermore, the three units display similar condenser flow rate values. This indicates that unit specific condenser piping configurations do not adversely affect the assumption of an approximately equal flow split among the condensers.

OSC-2346 does not presently account for outgassing of the CCW, which may decrease the heat transfer capability of the condenser. A preliminary analysis has been performed on the potential for outgassing of CCW to disrupt siphon. The preliminary analysis has demonstrated that significant margin exists and siphon will not be impoired. A formal revision to calculation OSC-2346 will be compleled by 10/1/94.

ITEM 5.

The design basis of the Circulating Cooling Water system's capability to withstand loss of Lake Keowcc was not translated into any design document.

R ESPONS E ,

The appropriate level of design documentation does not exist on the Condenser Circulating Water (CCW) system's ability to withstand a loss of Lake Kcowec. However, the Oconce FSAR does state that the CCW system intake canal contains an underwater weir that is designed to trap approximately 67 million gallons of water in case ofloss of Lake Keowec. The trapped water in the intake canal would be pumped through the condensers to remove decay heat and recirculated back to the intake canal. Due to the -

influx of warmer water into the intake canal, the temocrature of the water at the suction of the CCW pumps could increase, even though significant heat loss to the atmosphere is expected. Also, any evaporation or leakage would decrease the water inventory in the intake canal while any rainfall would supplement the water inventory. .The water '

inventory would be supplemented by fire trucks or other portable sources as part of recovery efforts, as necessary. The required time frame for these recovery efforts is likely to be on the order of several days or longer, but this has not been analyzed in detail.

We have begun engineering calculations to analyze the heatup of the intake canal water and the potential water inventory losses (due to leakage, evaporation, etc.) during a postulated loss of Lake Keowcc event. The effects of increased temperature and decreased water inventory on the CCW system, and any system being served by CCW during this scenario, will be addressed. The appropriate design documents will be revised as a result of these analyses. The analyses will be completed and design documents revised by 6/1/95.

ITEM 6. ,

RESPONSE TO VIOLATION 'IP T.he design basis of the Low Picssure Service Water system's capability to function as described in Case B of Abnormal Piocedure AP/1/A/1700/13, " Loss of Condenser Circulating Water Intake Canal / Dam Failure, Step 5.5.1, was not translated into any design document.

RESPONSE

Design documentation does not exist on the Low Pressure Service Water (LPSW) system's ability to function during a loss of Lake Keowee. We have begun engineering calculations -

. to analyze the range of nowrates and heatup of LPSW. The time to reach the maximum allowable LPSW system temperature,in order to meet the NPSil requirenrnts for the LPSW pump in this mode of operation, will be determined. If necessary, appropriate changes to the Abnormal Procedures and other documents will be made. The analyses will be comr)leted and desien documents revised by 6/1./95.

ITEM 7.

The design basis of the Safe Shutdown Facility Auxilimy Service Water System's capability to remove decay heat was not adequately translated into design documents in that a minimum flow less than required by 23 gpm per steam generator pair was established in calculation OSC-4171.

RESPONSE

Calculation OSC-4171, Rev. 2 recognizes that a 400 gpm indicated flow rate could potentially be less than the minimum flow rate required 'o prevent heatup of the Reactor Coolant system (RCS)if the 400 gpm indicated now rate was maintained. However, the calculation assumes that RCS instrumentation (Tcold) would alert the Standby Shutdown

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Facility (SSF) control room operator to increase or decrease the SSF Auxiliary Service Water (ASW) flow raie provided to an affected unit as needed to achieve hot shutdown conditions in the RCS. This is consistent with established operating procedurcs.

Establishing a 400 ppm initial SSF ASW flow rate would be successful since the SSF control room operator will adjust flow, if necessary, based on RCS parameters.

Though the original method used to feed an affected Unit's steam generators during an SSF event would have been successful, an improved method of feeding steam generators was implemented as part of modification NSM-52882 in April of 1994. Revision 3 to OSO4171 was created to support this NSM and, as part of this revision, an explicit allon. ace for potentialinstrument loop crror was included. No other actions are planned .

or necessary.

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RESPONSE TO VIOLATION 'C' l

l C. 10CFR50, APPENDIX B, CRITERION V. "lNSTR UCTIONS, PROCEDU RES, 1 AND DRAWINGS"

1. We accept this violation and agree that items I through 5 are examples of this violation. Reasons for the violation are discussed below under each individual item.

2.- The corrective actions taken and the results achieved are discussed below under cach individual item.

3. The corrective actions that will be taken to avoid further violations are discussed below under each individual item. Additional corrective actions, which will also serve to avoid further violations, were previously identified to you in our April 20, 1994 submittal in response to the potential programmatic weaknesses identified in the SWSOPI report. As stated in our April 20,1994 submittal, the exampic.s cited are not indicative of a programmatic weakness.

4. Though some of the corrective actions will be completed earlier, full compliance with the criterion will be achieved by I1/l f94.

ITEMl.

As of December 14, 1993, a prescribed procedural activity affecting quality did not contain appropriate acceptance criteria for determining that the activity had been satisfactorily accomplished. Procedurc EDM-101, Engineering Calculations / Analysis, Section 2.4.4 did not establish a definitive length of time for revising calculations following design changes; thus, allowing calculation OSC-3233, Safe Shutdown Facility's Service Water flydraulic Model, and OSC-2030. Standby Shutdown Facility 1-leating Ventilation and Air Conditioning Load Calculations, to not be updated for years after design changes affecting those calculations were implemented.

RESPONSE

Section 2.4.4 of EDM-101 requires that all other documents affected by the revision to-a ca!culation be appropriately revised in a " timely manner". We agree the engineering calculations OSC-3233 and OSC-2039 were not updated in a timely manner. The amount-of time allowed to make a " timely revision" is normally much less than that taken for  ;

revising OSC-3233 and OSC-2030.

Calculations OSC-3233 and OSC-2030 have since been revised to incorporate the changes made to the SSF Systems. EDM-101 will be revised to clarify management expectations on the amount of time allowed to update calculations by 9/l/94.

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RESPONSE TO VIOLATION 'C' ITEM 2.

As of December 14,1993, a prescribed procedure did not contain appropriate acceptance criteria for determining that an important activity affecting quality had been satisfactorily accomplished in that no Gow instruments existed to confirm 200 gpm was being provided to each steam generator or 400 ppm to an un-isolated steam generator by the Auxiliary Service Water pump as directed by Emergency Procedure EP/l,2,3/A/1800/01, Section 502.

R ESPONS E Changes to the Emergency Operating Procedure (EP/1,2,3/A/1800/01) incorporated guidance on establishing certain now rates to SG(s) when feeding with the Auxiliary Service Water (ASW) pump. This guidance was incorporated based on feedback from Training Center personnel and licensed operators. it was incorrectly believed that flow instruments were available to allow the operator to properly establish these specified Dows. As documented by this item, flow instruments are not available which would allow the operator to establish these specified flows. Ilowever, the operator was also referred to the Loss of Main Feedwater AP (AP/l,2,3/All700/19) which provides guidance for feeding SG(s) using the ASW pump. This guidance instructs the operator to maintain Reactor Coolant System pressure and temperature constant, which is the main concern.

Consequently, even though the operator could not have veriGed flows as speciDed in the EOP, the Loss of Main Feedwater AP would have provided guidance to allow the proper use of this pump in feeding the SG(s).

A revision to the EOP is underway which will include the removal of specific Gow nuidance for the ASW pump. The reference to the Loss of Main Feedwater AP will remain and the operator will feed the SG(s) in accordance to the guidance provided in that AP. Training will be completed on the procedure revision and the revision will be issued by 10/1/94.

ITEM 3.

As of December 14,1993, drawings affecting quality were not adequately prescribed in that the Keowcc Turbine Generator Cooling Water system drawings, K FD-100A-1.1 and K FD-100A-2.1, did not indicate the existence of an additional valve downstream of valve  ;

2WL-3 for Unit 2; the supply line to the air compressor coolers was interconnected to the 13 inch main piping for Unit 1; the piping downstream of valve WL-76 was copper for both Units; or a consistent piping class break in the supply line to the generator thrust bearing coolers for both Units.

RESPONSE

The Keowce now diagram drawings were created by design study ONDS-258 in June 12

RESPONSE TO VIOL ATION 'C' 1

i 1992. ONDS-258 was created to upgrade the design documents for Keowec and to create now diagrams for the safety related mechanical systems. Following the initial release of the drawings, several minor errors were identified and corrected. During the Service Water System Operational Performance inspection, additional errors were identified for -l drawings KFD 100A-l.1 and KFD 100A-2.1 (Unit I and 2 Turbine Generator Cooling Water System). PIP 0-093-0986 was initiated to address these items. Due to the number ofidentified denciencies, the corrective action is to re verify the drawings by walk down.

All identified errors will be corrected on the drawings by 7/1/94.

ITEM 4.

In November 1993, an activity affecting quality was not performed in accordance with '

prescribed pincedures in that a condition adverse to quality report associated with a broken coupling on the Keowcc hydroelectric station's Unit 2 turbine guide bearing oil cooler was neither processed as an upper tier adverse quality repott nor did it reccise a <

written operability evaluation.

R ESPONSE On 10 28-93, MP/2/A/2000/25 was performed on the Turbine Guide Bearing Oil Cooler.

During performance of the procedure, the soldered joint immediately downstream of the cooler was broken. Pip 0-093-0926 was written on 10 28-93 to document the probicm and discuss operability. The PIP was processed as a lower tier report and, while operability of the Keowcc unit was assessed and determined to be operable, no formal operability statement, using NSD-203, " Operability Determination", was issued.

We recognize that the PIP should have been processed as an upper tier report and a formal operability evaluation should have been performed. In response, PIP 0-093-0994 has been written to resolve the questions concerning the parameters under which the Turbine Guide Bearing Oil Cooler may be isolated and the unit remain operabic.

Management expectations have been clarified on when a PIP should be processed as upper tier versus lower tier. The operability evaluation will require testing when the lake temperature is high, typically late August. The evaluation will be completed by ll/1/94. >

ITEM 5.

In November,1993, an activity affecting quality was not performed in accordance with prescribed procedures in that a safety related work order,93077640, for performing the triennial inspection of Keowcc hydroelectric station's Unit 2 turbine guide bearings oil cooler per MP/2/A/2000/25 specified a housekeeping zone higher than 3.

RESPONSE

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~ . . .-. . -_ ... - - - -- -_ -. . . _ . - . . . . - ~

RESPONSE TO VIOLATION 'C' We agree that the work order was not performed in accordance with prescribed l procedures. Oconce Nuclear Site Directive (SD) 1.4.1 section 3.1 states," Cleanness Zones  !

I,11, and ill are for maintaining internal cleanness of Qa Condition i systems and components. Zone IV is for area cleanness in the vicinity of QA Condition I systems and components. Zone V is for area cleanness for other station areas."

Keowce personnel were cognizant of the fact that much equipment at Keowce was.

designated as QA Condition I, safety related. SD 1.4.1 section 3.2.3 references locations outside the Auxiliary and Reactor Buildings, but still within the Protected Area fence.

This contributed to the impression that clean zone ill was for Oconce Nuclear Station equipment only. For that reason, clean zone IV was used.

Predetermined (preventative maintenance) work orders and their associated procedures will be reviewed and, if necessary, revised. to ensure correct clean zone assignment by 10/1/94. In addition, refresher training will be conducted on Site Directive 1.4.1 for Kcowee Station personnel by 8/l!94.

14

• ' * " ^ ^ _, , .,_ f*'~ " ~ -

~ ;-

RESPONSE TO VIOL ATION 'D' 11 10CFR50, APPENDlX 11, CRITERION XI. " TEST CONTROL " I l

1. We accept this violation and agree that items I through 4 are examples of this  !

- violation. Reasons for the violation are discussed below under cach individual item.

2. The corrective actions taken and the results achieved are discussed below under cach individual item.

3. The corrective actions that will be taken to avoid further violations are discussed below under each individual item. Additional corrective actions, which will also serve to avoid further violations, were previously identified to you in our April 20, 1994 submittal in response to the potential programmatic weaknesses identified in the Service Water System Operational Performance inspection report. As stated in our April 20, 1994 submittal, the examples cited are not indicative of a -

programmatic weakness.

4. Though some of the corrective actions will be completed earlier, full compliance with the criterion will be achieved by 8/1/95.

ITEM l.

A test procedure did not include adequate provisions for test instrumentation in that in proceduie PT/1/A/ 0261/07, Change 8, August 8,1991, Emergency CCW System Flow ,

Test, a 2,000 gpm deviation in the test instrumentation used was not accounted for in the acceptance criteria.

RESPONSE

We agree that potential test instrumentation error was not properly accounted for. The method used for measuring the flow rate for the Emergency Condenser Circulating Water (CCW) System Flow Test involves a measurement error of up to approximately 2,000 gpm. The most recent test results for cach Oconec unit have beca reviewed to determine whether a 2,000 gpm measurement error would have affected the acceptability of the test results. This review indicated that the minimum flow required for decay heat removal after a station blackout (plus excess now of several thousand gpm) was avaibhic, even with a 2,000 gpm penalty. Therefore, failure to consider the flow measurement error during these tests did not have an adverse effect on safety.

A detailed analysis of the flow measurement error associated with the Emergency CCW system flow test will be completed by 7/1/94. The results of this analysis will be used to '

revise the test procedure lo incorporate the appropriate flow measurement error by 8/1/94.

15 i

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_m ._ __ __ . - _ _ - . - _ _ - . _ _ _ _ - . _ _ _

RESPONSE TO VIOLATION 'D' ITEM 2.

The post-construction Rushing procedure for the Safe Shutdown Facility's discharge lines to all the steam generators did not contain Rush velocitics or acceptance criteria based upon filter, turbidimetric or chemical analyses.

R ESPONS E A post-construction " fill-and-drain" was performed on the Standby Shutdown Facility (SSF) Auxiliary Service Water ( ASW) system. Ilowever, the actions performed did not meet the requirements contained in the piping specincation at that time, for flushing newly installed piping systems. The velocitics achieved during the " fill-and-drain ~ were not sufficient to meet the flush criteria.

A reverse now test of each unit's SSF ASW supply piping will be performed to verify that an open flow path will be available during an SSF csent. A modincation to add piping has been installed to allow demineralized water to be nushed from the Emergency Feedwater (EFW) system back through SSF ASW piping A reverse now test will be performed instead of a forward now test because it is undesirable to pump lake water from the SSF ASW supply piping into the steam generatois. The 'B' motor driven EFW pump will be used to pump dcmineralized water from the upper surge tank through that Unit's corresponding SSF ASW supply piping. A 500 gpm Dow rate will be established during the nush to ensure that adequate Rush velocitics will be achieved. 500 gpm was chosen because it is the maximum allowed now rate through a Unit's SSF ASW supply header during an SSF event. Water samples will be taken during the flush to verify that the SSF supply piping Dush is adequate. The test is will be performed on Unit I during the current UI EOCI5 refueling outage (scheduled to be completed June '94), on Unit 2 during the U2EOCl4 refueling outanc (currently scheduled to begin September '94), and on Unit 3 during the U3EOCl5 (currentiv scheduled to begin May '95). In addition, the existing pipe speci0 cation will be reviewed, and if necessary revised, to ensure adequate guidance is omvided for properly flushing piping systems hv 8/1/94.

5 ITEM 3.

Periodic Safe Shutdown Facility Auxiliary Service Water pump operability test; -

PT/0/A/0400/05, was not performed under suitable environmental conditions in that the pump was preconditioned in step 12.2 by venting the pump just prior to its being started masking any air entrapment that would affect pump performance.

RESPONSE

We agree that venting the pump just prior to its being tested couhl potentially mask air entrapment that could affect pump performance. The Standby Shutdown Facility (SSF) l Auxiliary Service Water (ASW) pump has been vented as a good practice whenever the i

! 16

RESPONSE TO VIOLATION 'D' I pump is returned to service after a maintenance period and prior to performance testing.

This is consistent with Table 4.1-2 of Oconce's Technical Specifications, which requires i that the high pressure injection pumps and low pressure injection pumps be vented prior to testing. Since the nF ASW pump is at a low point in the system, any air which comes out of solution in the piping will tend to move away from the SSF ASW pump towards the high point in the piping system. Littic or no air is expected to come out of solution in the piping surrounding the SSF ASW pump since the pressure at the SSF ASW pump is greater than atmospheric pressure and will be capable of holding more dissolved air in solution than the same water held at atmospheric pressure. Therclbre, littic or no air is expected to accumulate inside the SSF ASW pump.

To further insure that a pump will operate as required. . testing procedures will be revised to climinate venting of the SSF ASW pump and other select pumps immediately prior to a performance test. The procedures will be revised by 9/1/94.

ITEM 4.

The preoperational test program to demonstrate that systems and components would perform satisfactorily in service and meet the icquirements contained in applicable design documents for the Safe Shutdown Facility's service water system was inadequate in that the now control capabilitics to the steam generators and the flow distributions among the three service water pumps (Auxiliary Service Water; Heating, Air Conditioning and Ventilation; Emergency Diesel Generator Cooling Water) when operating simultaneously as assumed in numerous design calculations was not performed.

RESPONSE

The preoperational test performed on the Standby Shutdown Facility (SSF) service water pumps (Auxiliary Service Water (ASW), HVAC cooling water, and diesel generator cooling water) was not an integrated test. Currently each of the SSF service water pumps are tested individually to demonstrate operability. Motor-operated valve testing is also performed per Generic Letter 89-10 to demonstrate vahe operability. Other components, such as the diesel generator, are tested individually, as well. Ilowever, an integrated system test demonstrating Dow control capabilitics among all three SSF service water '

pumps simultaneously, has not been performed.

A periodic, integrated system performance test involving all three SSF service water pumps has been developed. SSF ASW pump Dow is through the pump minimum now l line and test line. Flow rates through the SSF ASW test line were chosen to match flow rates required during an SSF event. The test has recently been conducted and has i successfully demonstrated integrated system performance. This integrated test will bc performed periodically.

17

RESPONSE TO DEVI ATION 'A' A. DURING Tile 1993 SERVICE WATER SYSTEM OPERATIONAL PER FOR M A NC E I NSPECTIO N CON DUCTE D AT OCON EE, FOU R ITEMS WERE IDENTIFIED TilAT DEVIATED FROM OCONEE'S WRITTEN RESPONSE TO GENERIC LETTER 89-13.

1. We accept this deviation and agree that items I through 4 are examples of this deviation Reasons for the deviation are discussed below under each individual item.

2. The corrective actions taken and the results achieved are discussed below under each individual item.

3. The corrective aedons that will be taken to avoid further deviations are discussed below under each individual item.

4. Though some of the corrective actions will be completed earlier, all corrective actions will be completed by 10/l/94.

ITEMl.

A periodic testing program had not been established for the testable Kcowcc service water system heat exchangers or the Standby Shutdown Facility's testable cmergency dicscl generator heat exchangers.

R ESPONS E Oconce's January 1990 response to GL 89-13, Action 11 states that a heat exchanger test program for testable, safety-related heat exchangers has been established. In Oconce's response to GL 89-13, Low Pressure Service Water was the focus. PIP 4 094-0192 was written to document the omission of Keowcc service water systems. Additionally, item number 93-02-6B, from the Electrical Dist ribution System Functional inspection identified

-the need for heat exchanger testing. Modifications are currently under development to facilitate testing. We will provide a revised response to GL 89-13, Action 11 along with a schedule for impicmentation of the modifications and testing by 9/1/94.

The Standby Shutdown Facility's emergency diesel generator heat exchangers ate utilized monthly and service water flow and diesel temperatures are monitored to ensure they are within manufacturers specifications. On a quarterly basis, the now is veriGed via a periodic test procedure. Oconec considers this an " equally effective program" to ensure satisfaction of the heat removal requirements. Per NRC recommendation for a GL 89-13 testing program, an " equally effective program" can be utilized by the utility to ensure' satisfaction of the heat removal requirements of the service water system.

i 18 I

R ESPONSI! TO Dl!VI ATION 'A' ITEM 2.

All raw water systems were not reviewed for stagnant or intermittent now under ONDS-252 in that Keowce service water cooled systems were not included.

RESPONSE

ONDS-252 is a design study which senes as the initial planning for the organization of a long term plant monitoring program. The purpose of this program is to assure the functional integrity of the raw water systems are maintained. Oconce's January 1990 response to GL 89-13, Action Ill (Inspection and Maintenance Program) stated that ONDS-252 would review the entire raw system of the plant to determine where water is stagnant or subject to intermittent flow. Once a complete " picture" was obtained, a monitoring / inspection program would be developed and implemented. In Oconec's response to GL 8913, Low Pressure Service Water was the focus. PIP 4 094-0192 was written to document the omission of the Keowec service water systems. We recognize that Keowcc service water should have been included and we will provide a revised response to GL 8913, Action ll1 by 9/l/94.

ITEM 3.

The training and procedures review programs established for service water systems were not adequate in that these reviews never identined that there were no now indicators in the Auxiliary Service Water discharge lines to the steam generators, no emergency procedure addressed inadequate Low Pressure Service Water now and there were no operating procedures for Keowcc service water systems.

RESPONSE

Changes to the Emergency Operating Procedure (EP/l,2,3/A/1800/01) added guidance on establishing specified flows to SG(s) using the Auxiliary Service Water (ASW) pump.

This guidance was added based on feedback from Training Center personnel and licensed operators. It was incorrectly believed that now instruments were available to allow the operator to properly establish these specified flows. The now rates specified in this guidance were identical to those speciDed in other portions of this section of the Emergency Operating Procedure (EOP). Therefore, this change to the EOP was not a.

philosophy change, nor did it require any equipment to be operated differently than previously required by the EOP. The intent of this change was to respond to feedback based on procedure usage and provide more complete guidance on establishing Dow.

Consequently,it was deter mined that this change did not require a plant validation. This-determination was in error. 'llowever, requiring these specified flow rates, where no flow -

instrument existed, did not preclude the establishment of proper ASW flow to the SG(s).

The Loss of Main Feedwater AP (AP/1,2,3/A/1800/01), which is icferred to in the same step which required these now rates, does provide adequate guidance for establishing 19 i

. - -. . . . - . ._ .. - ~._- _ . - . - - - - .. . -_-

RESPONSE TO IEVl ATION 'A' SG(s) feed using the ASW Pump. This AP states that the flow rate should be controlled so as to maintain Reactor Coolant System pressure and temperature constant, which is the overriding concern.

A revision to the EOP is underway which will include the removal of specific flow guidance for the ASW pump. The reference to the Loss of Main Fecdwater AP will remain and the operator will feed the SG(s) in accordance to the nuidance provided in that AP. Training will be completed on the procedure revision and the revision will be issued by 10/1/94.

~ In the event of a loss of Low Pressure Service Water (LPSW) flow, or degraded LPSW flow, the LPSW licader Aill Press Low statalarm would be received. The alarm response guide directs the operator to perfm m AP/l,2.3/A/l800/24, Loss of Low Pressure Service Water. As now stated in this procedure, the purpose is to provide guidance in the event that LPSW is inadvertently lost or degraded. Procedural guidance is provided to diagnose the cause of the loss g degradation, and mitigate the event. Operator training continually emphasizes the need to consult alarm response guides to determine proper actions in response to alarms received. This process of referring to the alarm response guides will ensure that the operator is properly referred to the Loss of Low Pressure Service Water AP. Current procedures are adequate and no additional procedures are needed.

Operating procedures have been created and approved for the following systems at Keowcc and include the procedure numbers and approval dates:

- Unit No. I Thrust Bearing Oil llcat Exchanger (OP/1/A/2000/047)- 02 04-94

- Unit No. 2 Thrust Bearing Oil llcat Exchanger (OP/2/A/2000/047) 04-94 Unit No. I Generator Air Coolers (OP/l/A/2000/048)- 02-04-94

- Unit No. 2 Generator Air Coolers (OP/2/A/2000/048) + O2-04 94 The procedures for the identified systems include an enciosure for a valve alignment checklist. This checklist includes all valves required to operate the system including the

~

throttled discharge valve with instructions for positioning it to the normal throttle position.

ITEM 4.

Numerous service water systems were omitted from the Self Initiated Technical Audit

~

including the Auxiliary Scrvice Water system, the Standby Shutdown Facility's service water systems, the Keowcc service water systems, the condenser cooling mode _ of the Cliculating Cooling Water system, and the recirculation mode of the Circulating Cooling _

Water system.

20

RESPONSE TO DEVI ATION 'A'

RESPONSE

in 1987,a Self-initiated Technical Audit (SITA) was conducted of Oconce's Low Pressure Service Water (LPSW) system to assess its operational readiness and functionality. A SITA takes a focused,in-depth look at a particular system versus a broader, but less in-depth review. A SITA also looks at the interfaces the particular system in question has with other systems. For example, during the LPSW SITA. Emergency Condenser Circulating Water (ECCW) to the suction of the LPSW pumps was studied, along with liigh Pressure Service Water (liPSW)10 the CCW pumps. It was never the intention of this particular audit to cover the Auxiliary Service Water System, the Standby Shutdown Facility's service water systems, the Kcowcc service water systems, the condenser cooling mode of the CCW system or the recirculation mode of the CCW system.

Duke Power's January 1990 response to Generic Letter 89-l.1. Action IV (Confirmation of Licensing 11 asis) states that a SITA had been completed on the service water system at Oconee in 1987. The system referred to in that statement is the LPSW system, since 1,PSW is (bc nuclear safety-related service water system, it was not intended to refer to all service water systems at Oconce. We will provide a revised response to Action IV of Generic Letter 89-13 by 9/l/94.

21

RESPONSE TO DEVI ATION 'B' B. OCONEE'S WRITTEN COMMITMENTS ASSOCI ATED WITil STATION BLACKOUT (SBO) INDICATED TilAT REGULATORY GUIDE l.155 WOULD BE FOLLOWED. CONTRARY TO Tills STATEMENT, A TEST PROCEDURE FOR DEMONSTRATING TilAT SYSTEM READINESS REQUIREM ENTS WERE M ET, WAS INADEQUATE IN TilAT Tile TEST ACCEPTANCE CRIT ERI A DID NOT ASSURE THAT A 4-HO U R INVENTORY OF lilGil PRESSU RE SERVICE WATER COOLING WWFER -

AS ASSUMED IN Tile SBO EVENT WAS AVAILABLE FROM Tile i MINIMUM ALLOWABLE ELEVATED WATER STORAGE TANK LEVEL.

1. We accept this deviation. Reasons for the deviation are discussed below.

2. The coricetive actions taken and the results achieved me discussed below.

3. No further corrective actions me planned.

4. All corrective actions have been completed.

DETAILED RESPONSE:

Oconce's Station Blackout (SBO) submittal discussed gravity now cooling of the Condenser Circulating Water (CCW) pumps from the Elevated Water Storage Tank (EWST) for up to four hours so the CCW pumps could be restarted immediately upon restoration of offsite power.  :

The EWST would provide gravity flow cooling to the CCW pumps foi 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. This capability is tested annually, using PT/0/A/250/38 " Elevated Water Storage Tank Drain Test." At the time of the Service Water System Operational Performance Inspection, the test procedure contained several weaknesses:

1. The calculation in the procedure for determining the capacity of the tank, in minutes, should have used Ihe minimum fulllevel of 90,000 gallons,instead of the actual initial EWST level.

2. Stricter controls should have been placed on re-performing the test if the original test failed due to leakage of the check valves on the Iligh Pressure Service Water (llPSW) pump discharge.

3. The procedure should have directed the test performer to notify the operating manager when the calculated HPSW Gow rate exceeds 375 gpm, not 500 gpm.

A PIP (0-094-0307) was written on these procedure weaknesses and the procedure has been revised. Past test procedures have been retrieved and the recorded data has been 22

RESPONSE TO DEVI ATION 'B' ,

P' reviewed. This review indicated that the identined weaknesses do not change the conclusion arrived at upon completion of each test. None of the tests would have failed due to using 90,000 gallons in the calculation instead of the initial volume. None of the test.s needed to be re-performed due to check valve leakage.

Following a four hour SBO event, plant recovery would be per AP/1,2,3/A/1700/.I 1," Loss of Power.' This procedute provides direction on restarting a CCW pump. Even ifIIPSW gravity flow from the EWST to the CCW pumps was not maintained for four hours, the ability to immediately restart a CCW pump upon restoration of offsite power would not be adversely impacted. Without continual llPSW now, air inicakage could result in the formation of soids in the high points of the CCW inlet piping. 1lowever. even if this occurred, extensive Gli and venting actions would not be required prior to starting a CCW.

pump because the pumps (and their impellers) are located underwater. Restart;ng a CCW pump would simply push the air through the pipe. In addition, the surge lines on the CCW piping near the inlet to the condenser would provide a relief path for any air 4 that was swept through the pipe. Any air that was swept past tac surge lines would be carried through the condenser and out the CCW discharge piping to the lake. Upon restoration of power, the llPSW pumps would also be restarted ar d would provide forced scaling and cooling now to the CCW pumps. Gravity flow from .he EWST to the CCW pumps is no longer needed once power is restored. ,

i In conclusion, the weaknesses originally identified in PT/0/A/250/38 han hen corrected.

In addition, even if IIPSW gravity flow from the EWST to the CCW pumps did not las,. 1 the full four hours, the ability to immediately restart a CCW pump upon restoration of power would not be adversely impacted. No other actions are planned or necessary.

l 3

~l 1

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