IR 05000298/1997012

Insp Rept 50-298/97-12 on 970708-0905.Violations Being Considered for Escalated Ea.Major Areas Inspected:Evaluation of Licensee Performance Re Recognizing Documenting & Correcting Conditions Adverse to Quality

ML20217F166
Person / Time
Site:	Cooper
Issue date:	10/03/1997
From:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
Shared Package
ML20217F159	List: IR 05000298/1997012 ML20217F154
References
50-298-97-12, NUDOCS 9710070383
Download: ML20217F166 (13)

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ENCLOSUM U.S. NUCLEAR REGULATORY COMMISSION

REGION IV

Docket No.: 50 298 License No.: DPR 46 Rooort No.: 50 298/97 12 Licensee: Nebraska Public Power District Facility: Cooper Nuclear Station Location: P.O. Box 98 Brownville, Nebraska Dates: July 8 through September 5,1997 Inspector: Mary Miller, Senior Resident inspector Approved By: Elmo Collins, Chief, Branch C Division of Reactor Projects ATTACHMENT: Partial List ot Persons Contacted List of Inspection Procedures Used List of items Opened, Closed, and Discussed List of Acronyms

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9710070383 971003 PDR ADOCK 05000298 G pag t

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EXECUTIVE SUMMARY Cooper Nuclear Station NRC Inspection Report 50 298/97 12 The NRC performed a specialinspection at the Cooper Nuclear Station f acility. The special inspection evaluated the licensco's performance concerning recognizing, documenting, and correcting conditions adverse to quality.

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Qocrationg

• Although discharges of hundreds of gallons of water to the Z-sump had been observed in February and April of 1997, the licensee f ailed to recognize, until July 1997, that volumes of water in that sump greater than approximately 250 gallons would result in standby gas system inoperability (Section O2.1).

• Operators failed to issue a problem identification report (PIR) when an unexplained

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alarm was received twice during a surveillance test. This alarm had been received

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in past surveillances and was, therefore, expected, but not explained or understood (Section 07.1).

• Inspectors noted increased instances of problem identification, and determined this to be examples of some improvement in the licensee's implementation of the PIR process (Section 07.2).

MA!ptenance

Inspectors identified a significant problem in that the heat exchanger test program f ailed to detect a degraded heat exchanger. At the end of the inspection, the licensee had not formulated or implemented corrective actions to address the program (Section M7.1).

• The licensee f ailed to recognize that blockage of the residual heat removal heat exchanger tulms could be safety significant, and f ailed to document the as found condition of the heat exchanger Considerable NRC intervention was required to ensure the safety significance was addressed (Section M7.1).

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RepstLQttails j ,

i Summarv of Plant Status l

4 This report was conducted to evaluate the licensee's effectiveness regarding identification- l l and correction of conditions adverse to quality. During this inspection period, the plant a. operated at 100 percent power, with the exception of a forced shutdown on July 29 to j repair torus to-drywell vacuum breakers. The plant returned to full power operation on

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August 5,1997. _ '

, l. Operatiosa i  !

02 Operational Status of Facilities and Equipment '

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O2.1 Vulnerability to Flood Standbv Gas Treatment Lines with Water t, -

a. Scooe (71707)

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inspectors reviewed documentation and conducted interviews regarding the findings

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sump).

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a-b. Observations and Findinos F i

Condensation from the standby gas treatment and condenser off gas systems drains j to a sump (Z sump) belov :Se elevated release point. In 1994,it was recognized-that the Z-sump pumps did not have vital power._lf a significant volume of water

(approximately 250 gallons) were to be introduced into the Z sump with the pumps ,

. not operating, it would overflow into the standby gas treatment system and occlude i flow to the elevated release point, in 1994, an emergency procet.ure was  ;

j. developed to temporarily connect vital (diesel) power to these sump pumps should !

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l -there be a loss of offsite poweri The procedure requires approximately 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> to implement.

4 On February 12,1997, after an automatic isolation and trip of the off gas system, the Z sump pumps ran for 1.6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. This amount of run time indicated that approximately 4800 gallons of water had drained to the sump. During the May  ;

L 1997 outege, the offgas holdup line drain was found blocked. Water introduced

into the line would not drain to the sump. The missing water volume was not addressed. The PIRs for these two occurrences did not address the potential to occlude the standby gas treatment lines, which would result in standby gas

treatment system inoperability during a loss of offsite power, in addition, the

[ source of water was not identified and eliminated. The licensee identified that,

! historically, several cases have occurred in which large volumes of water were

unexpectedly discharged to the Z sump.

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.2 On July 13,1997, following an unexpected trip of the off gas system, Z sump

, pump running times indicated that about 5200 gallons of water were removed from

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the Z sump (PIR 2 22086). The licensee determined that the standby gas system remained operable because water did not enter the system. The licensee reported this as a condition outside of the design basis. On July 15, the control room crew questioned the operability of the Z sump. Troubleshooting for a clogged drain line

) was laconclusive (PIR 2 22079).

On July 21, af ter the off-gas system had been restarted, the licensee performed Procedure 6. SUMP.101 to verify Z sump operability. After it was estimated that

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about 1200 gallons had been injected into the off-gas system without the pumps starting, the licensee questioned the missing water and isolated the off gas system.

Approximately 1200 gallons were released to the sump and subsequently pumped

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out. The licensee again reported the event according to the requirements of

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10 CFR 50.72 (PIR 216251). The plant continued power operation during these

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occurrences.

Licensee Event Report 50-298/97 010 described the event and described the 4 vulnerability to standby gas treatment system operability if water entered the standby gas treatment lines on a loss of offsite electrical power. The licensee

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determined that an amount greater than 250 gallons introduced into the sump after a loss of offsite power would result in the standby gas treatment system being inoperable.

The licensee did not properly evaluate the occurrences of large volumes of water entering the Z sump. These occurred on February 12,1997, during the refueling

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outage in April 1997 and on July 13,1997, in these instances, the source of water

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was not identified and actions were not implemented to prevent plant operation with water accumulating in the offgas holdup line. The failure of the licensee to

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recognize and correct the accumulation of water in the offgas holdup line and the adverse effect on the standby gas treatment system is an apparent violation of 10 CFR Part 50, Appendix B, Criterion XVI, which requires that significant conditions adverse to nuality be identified and corrected with actions to prevent recurrence (APP VIO 50 298/97 012 01).

c. Conclusion Altbnugh discharges of hundreds of gallons of water to the Z sump had been observed in February and May of 1997, the licensee f ailed to recognize until July 21,1997, that the volumes of water greater than approximataly 250 ga;lons would result in standby gas system inoperability.

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07 Quality Assurance in Operations Activities 07.1 Enihet to Question Unexclained Alarm Durinn Main Steam Safely _ Relief Volvo Testino a. insocction Scone (61720 The inspectors observed testing of the main steam safety relief valves, b. Observations and Findinns On May 21,1997, the inspectors observed operators perform Surveillance Procedure 6. ADS.201, " ADS Manua! Valve Actuations," Revision 0.1 c1. The inspector noted that, during the surveillance, Alarm 0 31/D 2, " Relief Valve Accumulator Low Pressure," was received and immediately cleared while testing Relief Valves MG RV 718 and 71C. The inspector also noted that the alarm i response procedu6e was not reviewed by the operators either time the alarm was received. After the surveillance was completed, the inspectors questioned the

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operator performing the surveillance as to why the alarms were received for only two accumulators. The operator responded that he did not know why the alarms were received, but he did note that the alarm immediately reset and did not think it was a problem.

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On May 29, the inspectors questioned plant management as to why a PIR was not

, written to document and determine the cause of the unexplained alarm. On June 6, PIR 2 22894 was written, which stated that the cause of the alarm should be determined and, if the alarm should be expected, that information should be added to the procedure to state this. The concern was further described as a programmatic problem with the surveillance procedure not identifying an expected alarm. The operator's f ailure to question the alarm was not identified as a condition in the PIR. Administrative Procedure 0.5, " Problem Identification and Resolution,"

Revision 10 c2, Section 15.2, requires, in part, that all personnel are responsible for reporting problems that are, or potentially could be, conditions adverse to quality.

Procedure 2.0.1, Revision 32c1, " Plant Operations Policy," Step 16, requires that, if an alarm cannot be explained or understood, it shall be documented as a PIR.

Procedure 2,0.3, Control Room Access, Conduct and Staffing Requirements,"

Revision 21, Step 8.2.6.3, states that control room operators shall respond to abnormal control room panel indications and alarms in a timely f ashion and take prompt action to determine the cause of and correct abnormalities.

During a discussion on July 9,1996, the operators stated that the alarm had been discussed during the control room brief, and considered an expected alarm, since

- the alarm had occurred during similar testing in 1995. Plant annunciator records corroborated this assertion. The operators acknowledged that a more questioning attitude may have been appropriate, i

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~4-The failure of the licensee to evaluate and resolve as necessary the cause of the relief valve accumulator low pressure alarm is an apparent violation of 10 CFR Part 50, Appendix B, Criterion XVI, which requires, in part, that conditions adverse to quality be identified and corrected (APP VIO 50-298/97012-02).

c. Conclusions

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! Operators f ailed to issue a PIR when an unexplained alarm was received twice during a surveillance test. This alarm had been received in past surveillances and was, therefore, expected, but not explained or understood.

07.2 Cstrective Action Proaram a. Lrignection Scope (71707)

Inspectors reviewed performance indicators, b. Observations and Findinns Performance indicators showed that PIR generation had increased from about 240 per month in 1996 to about 295 per month to date in 1997. Resident inspectors noted that the number of problems identified had generally increased. This represented a stronger questioning attitude, c. Conclusions I

inspectors noted increased instances of problem identification, and determined this to be examples of some improvement in the licensee's implementathn of the PIR process, which implements problem identification requirements of 10 CFR Part 50, Appendix B, Criterion XVI.

11. Maintenance M7 Quality Assurance in Maintenance Activities M7.1 Failure to Reccanize Residual Heat Removal B Heat Exchanaer Tube Plunaina as a Condition Adverse To Quality a. Inspection Scope (617261 _

Inspectors observed heat exchanger cleaning, reviewed the PIRs and licensee activities, ar held discussions with plcnt staff to address residual heat removal heat exchanget tube mud plugging.

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5-b. Observations and Findinaji l

b.1. bijyre to Reconnire Mud Plunaina as Potentia"v. Safety Sionifican.1 As documented

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in inspection Report 50 298/97 05, on April 22,1997, the inspectors observed the licensee removing significant amounts of mud from the Residual Heat Removal Heat Exchanger B. Inspectors found that the licensee was not recording the as found condition or assessing the safety significance of the heat ext. hanger and had not l taken steps to identify the condition as a problem. After NRC questioning on April 22 and 23, PIR 2 04147 was initiated to address the concern. Considerable

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NRC involvement was required before the licensee performed an adequate operability assessment of the heat exchanger.

b.2. Heat Exchanner Dearaded But Not inonerable The operability evaluation concluded that the heat exchanger may not have been able to perform it's design basis function at a (design basis) r> /er temperature of 90'F. However, river ternperatures had reached a high of only F3*F during the prior summer and, therefore, under actual conditions experi";,ced, the heat exchanger would have been able to perform it's safety function, b.3. PIR 2-04147 Did Not Address the Failure to RecDanize Mud Pluaaina as a Condition Adverse to Quality PIR 2 04147 was assigned a condition adverse to quality tracking number (CAO 97 0742) and closed in engineering on May 7 when the safety significance evaluation was completed, The evaluation concluded that the as found condition of Residual Heat Removal Heat Exchanger B was normal and that the preventive maintenance frequency used for cleaning activities was optimal The evaluation further concluded that no condition adverse to nuclear safety or unexpected condition exited.

The CAO evaluation also concluded that, since it had been determined that no condition adverse to quality existed, nu corrective actions were required. At a May 13 meeting 61 Region IV, the licensee discussed their plan to improve their ability to recognize problems, and the associated initiatives that were to be implemented.

On June 5,1997, the inspector questioned why CAO 97 0742 had been considered complete and closed by engineering, and noted that the failure to recognize the issue had not been documented or addressed in corrective actions. The truining department had not scheduled or received requests to address the issue of problem recognition. No training had been performed, b.4. Failure to Perform Test on Heat Exchanaer A Prior to Outane Residual Heat Removal Heat Exchanger A was also cleaned in preparation for eddy current inspection. Less mud was found in the tubes, it had been cleaned during the prior outage. The licensee had waived the scheduled performance test, since cleaning would be preformed during the outage.

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On April 28, when the licensee recognized that a commitment to test the heat exchanger had been missed, PIR 2-04175 was initiated. As a corrective action, a tracking item was initiated to review testing commitments to ensure other commitments were not missed. As of September 5, no action on this item has taken place. j b.5. Second PIR for Heat Exchanner B Mud Plunnina Failed to Address Lark of Problem Reconnition After inspector questioning on June 6 9, PIR 2 23058 was issued, noting that the residual heat removal heat exchanger cleaning was not stopped to assess as found conditions different than expected. This PIR was then transferred to maintenance, a root cause of inadequate control of r .ntractors was identified, and the PIR closed on July 28,1997, Corrective actions addressed the need for maintenance rather than engineering to control contractors performing plant work.

No actions were documented in the PIR to correct the concern that engineering had not recognized that mud in the residual heat removal heat exchanger could degrade the design basis function of the component.

b.6. Narrow Corrective Actions to Control Contractors The corrective actions for PIR 2-23058 did not evaluate the extent of condition of the stated root cause, inadequate control of engineering contractors. An August 1997 quality assurance audit of engineering concluded that engineering's control of contractors was deficient. The PIR had taken action only to correct engineering contractors performing in plant work. Technical review work was not addressed, b.7. One Hour Trainina Class on Preservation of As Found Conditions The inspector noted that approximately one hour of continuing training for engineers had been developed after the inspectors June 6 discussions. It was implemented in mid-June. The inspector observed the class, which collected student input on the Ottributes of component testing and the maintenance program, and then collected more input on the methods of alternately cleaning and testing the heat exchangers on an every other cycle basis versus cleaning both during one cycle. The class provided no clear answers or judgments concerning appropriate standards or lessons learned on test program adequacy, preserving evidence, or documenting as-found conditions.

The inspector noted that the student training materials stated that the heat exchanger would have performed it's design basis function, contrary to the conclusions of the operability evaluation. The engineering manager confirmed that this statement was in error, b.8, Emilure of the Service Water Test Proaram to identifv Dearaded Residual Heat Bgmoval Heat Exchanaer The licensee performed testing of the service water system to verify the design basis function of the systems and components. The licensee had performed heat exchanger performance tests every other outage for each heat exchanger. Each heat exchanger is cleaned and inspected en alternate outages.

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Inspectors noted that the service water testing program had not predicted the degradation of the heat exchanger and had allowed the heat exchanger to significantly degrade. Inspectors also noted that the licensee did not change the scheduling of heat exchanger testing to perform more than one performance test per two cycles, until prompted by NRC inspectors in July 1997. At that time, the maintenance manager added the performance test to the forced shutdown schedule, but did not inform engineering. The licensee did not perform the test as scheduled during the most recent shutdown.

The licensee did not identify or document the testing program as inadequate, although the engineering manager stated during discussions with the inspector on September 3 that he questioned the adequacy of the test program, b.9. Generic Letter 8913 ResnonE2 The Tcer.see's response to Generic Letter 8913 dated January 29,1990, stated it was a summary of actions taken and planned by the Nebraska Public Power District (District) to comply with the guidance provided in Generic Letter 8913 and to provide further assurance that the Cooper Nuclear Station service water system would function as designed. The response stated that the surveillance program provides for flow tests once per operating cycle to ensure the service water system and the associated required safety related components meet or exceed the post LOCA design flow requirements.

In response to the requirement to conduct a test program to verify the heat transfer capability of all safety related heat exchangers cooled by service water, the District stated that it currently verifies the heat transfer capability of residual heat removal heat exchangers and other heat exchangers. In addition to verifying heat transfer capability, the District verifies design service water flow rates to all safety related components in the service water and residual heat removal service water booster systems. This program demonstrates that cornponents are not significantly degraded by fouling or obstructions.

The response stated that by the end of the 1991 refueling outage, enhancoments would be completed to revise applicable heat exchanger performance evaluation procedures to require trending to ensure flow blockage or excessive fouling accumulation did not prevent the performance of safety related functions. These enhancements also included formalizing appropriate procedures to adjust heat exchanger test results to design heat removal rates with calculations.

Regarding routine maintenance programs, the present frequency of heat exchanger inspections varies from once per cycle to once every three cycles. These frequencies have been established through operating experience and have proven to be adequate. Regarding confirmation that maintenance practices involving the service water system are adequate to ensure that safety-related equipment cooled by the service water system will function as intended, it was determined that these procedures provide sufficient technical guidance for pump and heat exchanger maintenance.

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The District also stated that the plant design considerations supported the intent of 10 CFR Part 50, Appendix B, Section XI. This section requires that a test program be established to demonstrate that structures, systems, and components will {

perform satisf actorily while in service. Additionally, the test program will be i priormed in accordance with written test procedures which incorporate the requirements and acceptance limits contained in applicable design documents.

After discussions with inspectors on August 24, the plant manager directed that the PIRs concerning *.he residual heat removal heat exchanger mud plugging be re-opened and thcroughly reviewed. As of the September 5 exit meeting, the PIRs had not been re opened, but had been assigned to the issues management team.

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The failure of the licensee to recognize and properly address the safety significance of residual heat removal heat exchanger mud plugging, an inadequate heat

- exchanger testing program, and the control of engineering contractors is an apparent violation of 10 CFR Part 50, Appendix B, Criterion XVI, which requires that significant conditions adverse to quality be corrected and the root cause be identified and corrected with actions to prevent recurrence (APP VIO 50 298/97012-03L c. Conclus'2n1 Inspectors identified a significant problem in that the heat exchanger test program f ailed to detect a degrar,ed heat exchanger, and the licensee f ailed to recognize that the testing program ha.t failed to detect heat exchanger degradation. As of September 5, no changes to the testing program have been made to correct the program.

The licensee failed to recognize that mud plugging of the residual heat removal heat exchanger tubes could be safety significant and f ailed to document the as-found condition of the heat exchanger. Considerable NRC intervention was required to ensure the safety significance was addressed, inspectors identified that 25 days after a May 13 meeting with the NRC to discuss corrective actions to improve problem identification, no activities or training requests had been documented or performed to implement the corrective actions.

Two PIRs concerning heat exchanger mud plugging were closed on May 15 and July 20 without identifying or correcting the failure to recognize the problem.

The corrective action for plant work contractor control was narrow in that additional engineering contract control problems were later identified by a quality assurance audit.

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M8 Miscellaneous Maintenance issues M8.1 -Multiple examples of inadequate problem it 7tification and corrective action were dxumented in recent inspection reports. Lese concerns provide additional examples of the licensee's failure to properly identify and resolve conditions adverse to quality and are additional examples of Apparent Violation 298/97012-02.

Althot'gh, for some of the issues, the problems in the plant have been corrected, the licensee failed _to_ recognize, document, and correct root causes of significant conditions adver 9 to quality.

(Ocen) URI 97007 01 Failure to correct degraded condition of torus to drywell vacuum breakers. '

(Ocen) URI 97007-01 Third example of returning a Technical Specification gaseous offluent radiation monitor to service without proper sample lineup.

(Open) URI 97007-01 Failure to properly resolve service water booster pump breaker antipump device failure.

(Ocen) URI G7007 01 Failure to correct violation of closing the secondary containment hatch without use of approved procedures.

(Ocen) URI 97007 01 Inadequate corrective action for unauthorized modification of '

emergency diesel generator muffler bypass valve controls.

(Ocen) URI 298/97007 01 Repeated cycling of diesel breaker timing relay before surveillance measurement obtained.

V. Management Meetinas X1 Exit Meeting Summary.

The inspectors presented the inspection results to members of licensee management at the exit meeting on September 5,1997. The licensee acknowledged the findings presented.

The inspectors asked the licensee whether any materials examined during the inspection should be considered proprietary. No proprietary information was identified.

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e ATTACHMENT SUPPLEMENTAL INFORMATION PARTIAL LIST OF PERSONS CONTACTED licenggg D. Buman, Engineering Support Manager P. Caudill, Senior Manager L. Dewhirst, Licensing Engineer F. Diya, Design Engineering Maneger C. Gaines, Maintenance Manager 1 R. Gardner, Operations Manager M. Gillian, Corrective Action Program Supervisor M. Halo Radiation Protection Manager B. Hourion. Licensing Manager J. Lonti, Pert rmance Analysis Manager D. Me Isen, Lionsing Engineer O. Olaori, Plan + Engineering Manager M. Peckh:, n, Plant Manager

'P. Graham, Vice President, Nuclear

'J. Pelletier, Senior Engineering Manager NI1R

'E. Collins, Chief, Project Branch C

'C. Marschall, Project Engineer, Project Branch C

' Attendees via teleconference INSPECTION PROCEDURES USED IP 37751: Onsite Engineering IP 71707: Plant Operations IP 92901: Followup Plant Operations IP 92902: Followup - Maintenance IP 92903: Followup Engineering IP 92700: Onsite Followup of Written Reports of Nonroutine Events at Power Reactor Facilities

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ITEMS OPENED, OPENED AND CLOSED, CLOSED, AND DISCUSSED

Opened 298/97012-01 APP Failure to identify the source of large volumes of water VIO entering the Z sump and failure to prevent recurrence 298/97012 02 APP Multiple examples of not identifying or correcting conditions VIO adverse to quality (Sections 07.1 and M8.1)

l 298/97012-03 APP Failure to recognize sl9nificant degradation of Residual Heat t VIO Removal Heat Exchanger B and inadequate evaluation and

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corrective actions (Section M7.1)

Discussed 298/97007 01 URI Failure to correct degraded condition of torus to drywell

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vacuum breakers 298/97007-01 URI Third example of returning a Technical Specification gaseous effluent radiation monitor to service without proper sample lineup 298/97007-01 URI Failure to properly resolve service water booster pump breaker antipump device failure 298/97007 01 UR; Failure to correct violation of closing the secondary conteinment hatch without use of approved procedures

298/97007 01 URI Inadequate corrective action for unauthorized modification of emergency diesel generator muffler bypass valve controls 298/97007-01 URI Repeated cycling of diesel breaker timing relay before j surveillance m 2surement obtained

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