IR 05000482/1989017

Insp Rept 50-482/89-17 on 890626-0706.No Violations or Deviations Noted.Major Areas Inspected:Licensees Actions to Prevent & Respond to Loss of DHR as Described in Generic Ltr 88-17

ML20247M238
Person / Time
Site:	Wolf Creek
Issue date:	07/21/1989
From:	Bundy H, Seidle W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
Shared Package
ML20247M237	List: IR 05000482/1989017 ML20247M232
References
50-482-89-17, GL-88-17, NUDOCS 8908020004
Download: ML20247M238 (10)

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, APPENDIX ',

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y 2. A U.S. NUCLEAR REGULATORY COMMISSION.

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.g e REGION IV .

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$NRC'InspectionReport:, 50-482/89-171 Operating License: NPF-42'

' Docket:; 50 148 '

. Licensee: Wolf Creek. Nuclear Operating Corporation (WCNOC)

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P.O.' Box 411

'Burlington, Kansas 66839

,[ Facility Name: Wolf Creek Generating Station (WCGS).

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Inspection.At:/ WCGS,'Burlington, Kansas and Region IV Office , ,

Inspection Conducted:' June 26 through July 6, 1989 ~

L IInspector:- [ w 7d P1 Date Q.4. Bundy4 Reecte Inspector, Test Programs

• --Section,: Division of Reactor Safety

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. Approved: - ~>/b// 1 QW. C. Seidle, Ghief,/Tett Programs Section Date Division of-Reactor Safety

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' Inspection Sunnary

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-Inspection Conducte'd June 26 throuch July 6,:1989 (Report 50-482/89-17)-

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.Ar as Inspected: Routine, unannounced inspection . including licensee's actions to prevent and, if necessary, respond to loss of decay heat removal (DHR) as

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. described iri Generic Letter (GL) 88-1 Results:, The licensee's administrative controls, procedures, equipment, instrumentation, and training appeared to satisfy the-l expeditious action

< recommendations in GL 88-17. Licensee' actions in response to the programmed

enitancement recommendations in GL 88 '17 were not complete. In completing these-actions, the licensee should consider the inspector's comments with respect to

' additional training, procedure improvement, and instrumentation enhancemen ..

No violations or deviations were identifie >

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l -2-DETAILS Persons Contacted WCNOC

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• J. A. Bailey, Vice President Nuclear Operations

• F. T. Rhodes..Vice President, Engineering and Technical Support

• R. M. Grant Vice President, Quality

• 0. L. Maynard, Manager, Regulatory Services

• B.'Norton, Manager,' Technical Support

• C. E. Parry, Manager Site Quality

• M. G. Williams, Manager, Plant Support

• J. A. Zell, Manager, Training

• R. W. Holloway, Manager, Maintenance and Modifications

• J. M. Pippin, Manager, Nuclear Plant Engineering (NPE)

• T. F. Deddens, Outage Manager

• C. W. Fowler, Manager, Instrumentation and Control (ISC)

• B. McKinney, Manager, Operations T. O'Hearn, Manager, Plant Design Engineering

• N. Hoadley, Manager, NPE Systems

• W. M. Lindsay, Manager,' Quality Assurance

• D. G. Moseby, Shift Supervisor

• H. L. Stubby, Supervisor, Technical Training D. L. Fehr, Manager, Operational Training J. E. Gilmore, Supervisor, License Training C..R. Morris, Lead I&C Engineer

• S. Wideman, Licensing Specialist III NRC

• B. L. Bartlett, Senior Resident inspector The inspector also interviewed other licensee employees during the inspectio * Denotes those attending the exit interview on June 30, 198 . Licensee Actions to Prevent cnd Respond to Loss of DHR (TI 2515/101)

The purpose of this inspection was to verify licensee actions to prevent and, if necessary, to respond to loss of DHR during operaticos with the reactor coolant system (RCS) partially drained. Licensee actions were in response to reconnendations contained in GL 88-17. " Loss of Decay Heat Removal." Recommendations were made by GL 88-17 in two categories:

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expeditious ~ actions which should be implemented prior to. operating in-a reduced inventory condition, and

programmed enhancements which should be developed in parallel with

the expeditious actions and may replace, supplement, or add to'the expeditious action For purposes of future reference, the recommendations are briefly paraphrased below (to avoid confusion, the numbers are identical to similar items contained in GL 88-17):

Expeditious Actions (1) Discuss related events and lessons learned with appropriate plant personnel, provide training shortly before entering a reduced inventory conditio .i '(2) Implement procedures and administrative controls for containment

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closure in the event of loss of DHR event. This should be

' accomplished prior to entering a reduced RCS inventory condition for nuclear steam supply systems (NSSSs) supplied by Westinghous (3) Provide at least two independent, continuous temperature indications that are representative of the core exit conditions whenever the RCS is in mid-loop condition and the RV head is located on top of the R (4). Provide at least two independent, continuous RCS water level indications whenever the RCS is in a reduced inventory conditio Indications should be periodically checked and recorded by an operator.or automatically and continuously monitored and alarme (5) . Implement procedures and administrative' controls that generally avoid operations that deliberately or knowingly lead to perturbations to the RCS and/or to systems that are necessary to maintain the RCS in a stable and controlled condition while that RCS is in a reduced inventory condition; 'If avoidance of perturbations is impossible, compensatory measures should be take (6) ' Provide at least two available or operable means of adding inventory

. to the RCS that are in addition to pumps that are a' part of the normal DHR system (7) Istplement procedures and administrative controls that reasonably assure that both hot legs are not blocked simultaneously by nozzle dams unless a vent path is provided that is large enough to prevent pressurization of the upper plenum of the R (8) Not applicable to WCG (Applies to units with loop stop valves)

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Progransned Enhancements

'(1) Instrumentation Provide reliable indication of parameters that describe the-state of the RCS and the performance of systems nonnally used to cool the RCS for both normal and accident conditions. . At 'a minimum, provide the ..

following in the control room:

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(a).;twoindependent'RCSlevelindications; (b) at least two~ independent temperature measurements representative of the core exit whenever the RV head is located on top of th2 RV; (c) 'the capability of' continuously monitoring DHR system performance

'whenever a DHR system is being used for cooling the RCS; and-(d) visible and audible indications of abnormal conditions in temperature, level, and DHR performanc (2) Procedures Develop and implement procedures that cover reduced inventory operation, and that provide an adequate basis of entry into a reduced inventory condition. These include:

(a) procedures that cover normal operation of the NSSS, the containment, and supporting systems under conditions for which cooling would normally be provided by DHR systems; (b) procedures that cover emergency,' abnormal, off-normal, or the equivalent operation of the NSSS, the containment, and supporting systems if an off-normal condition occurs while operating under conditions for which cooling would normally be J provided by DHR systems; and (c) administrative controls that support and supplement the procedures in items (a), (b), and all other actions identified in this consnunication, as appropriat (3) Equipment (a) provide equipment of high reliability for cooling the RCS and avoiding loss of RCS cooling; (b) maintain equipment.available to mitigate loss of DHR or loss of l RCS inventory should they occur including at least one high pressure injection pump and one other system, e6th sufficient to keep the core covered; and i

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(c) . provide adequate equipment.for' personnel: communications

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involving ' activities related to the RCS or. systems necessary to =

maintain the RCS in a stable and controlled-conditio '

(4)' Analyses _

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. Conduct analyses to supplement existing information and develop a basis for procedures, instrumentation installation and response, and equipment /NSSS interactions and_ respons .g (5) Technical Specifications Technical Specifications that restrict or limit the safety-benefit of the actions identified in this letter, should be identified and appropriate changes.should'be submitte (6) RCS Perturbations-Reexamine Item,(5) of expeditious actions and refine operations as necessary'to reasonably minimize the likelihood of~ loss of DH ' Comments on the licensee's actions in response to GL'88-17 are provided

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, below.. The Attachment is a tabulation of related documents reviewed by the' inspector. When a document number is cited below', it will be the number assigned in the attachment. Also, in addition to reviewing the listed documents and interviewing appropriate personnel, the inspector walked down the'DHR instrumentation installed in the control room. It

- sh6uld be noted that the residual heat removal (RHR) system .is essentially the DHR system as discussed in GL 88-1 The inspector. reviewed' lesson plans (Attachment, Documents 15-19) and interviewed WCNOC trainers to ascertain licensee responsiveness to Expeditious Action (1). The training conducted was generally timely and responsive to'GL 88-17. The following comments were provided to licensee management for consideration in future loss of DHR training:

.No formal training of I&C and outage planning personnel pursuant to e GL 88-17 was conducted. Training for these individuals would be appropriate, particularly with regard to RCS perturbation * No specific training on reduced inventory operation for maintenance personnel was conducted prior to the last outage. However, mechanical and electrical maintenance personrel were subsequently trained as a

part of:the requalification program. Although mid-loop operation had been planned, it did not occur during the outage. Thus, the risk of

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loss of DHR was reduce " The lesson plans should include discussion of specific work which could ceuse RCS perturbation .

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Procedures related to loss of DHR are currently being revise Training on the' latest revisions should be conducted prior to entering a reduced inventory conditio With regard to Expeditious Action (2) and Programmed Enhancement (2), the {

inspector reviewed licensee procedures (Attachment, Documents 9-11), which i generally satisfied procedural commitments pursuant to the licensee's j responses to GL 88-17 (Attachment, Documents 1 and 2). Licensee -

. procedures require establishing containment integrity in accordance with f Technical Specifications prior to entering a reduced inventory conditio L The inspector provided the licensee with the following comments related to Procedure GEN 00-007 for consideration in the next revision:

GL 88=-17 recommends logging RCS water level cvery 15 minutes in a reduced inventory condition and core exit temperature every 15 minutes when operating at mid-loop if these parameters are not monitored and alarmed in the control room. The procedure requires logging these readings only every 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. These requirements should be teconciled with GL 88-1 *'

A caution statement concerning the number of successive RHR pump starts to correct air binding should be adde *

Precautions to ensure correct tygon hose installation should be adde * Include instrument calibration requirements under " Initial Conditions."

It should be determined that health physics personnel understand their duties in the event of containment evacuation without further procedural clarificatio Other procedure improvement comments were directed to the procedure coordinator for consideratio With regard to Expeditious Action (3) and Programmed Enhancement (1)(b),

licensee procedures reouire connecting at least two core exit thermocouple for control room monitoring. All thermocouple are monitored on a screen at the operator control console. The inspector noted that any changes should be easily detected by the operator. Also, thennocouples monitoring ano periodic printing capability is available at the subcooling monitor panel. This parel is not in the control room operators line of sigh Because the thermocouple do not have installed alarms, GL 88-17 implies that the readings should be logged every 15 minutes. As discussed above, the licensee's procedure requires logging every 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. Whereas the control room operator can continuously monitor these readings, a less frequent printout by the subcooling monitor might be justified, if continuous ,

control room operator monitoring is procedurally require i

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With regard to Expeditious Action (4) and Programed Enhancement (1)(a),

the licensee was relying on the RCS loop level indicator '(BB LI-53) and a temporary. level indicator consisting of a tygon hose backdropped with level reference marks. 'The shift supervisor stated that the tygon hose is continuously' monitored anytime the plant is ' operating at mid-loop. The inspector suggested;that a caution statement to this effect be added to the procedure. . It was noted that the licensee analyzed the total loo accuracy of BB L1-53 to be 0.5 inch. There are adjustable high and low alarms.in.the mid-loop range. This system appeared to be consistent with GL 88-17 short term reccamendation The lead I&C engineer described a proposed mid-loop RCE level instrumentation-system to the inspector. Installation is planned for the next refueling outage . To avoid adding additional taps to the RCS, connection to two RTD bypass manifold drain lines on Loop.I was proposed. Because of instrument inaccuracy caused by RHR flow. Loop 4 was dismissed from consideration for a tap. Each sensing line will be used by wide and narrow range instrument There will be dual indicators visible to the control room operator - one for the narrow range (mid-loop) and one for the wide range instrument The wide range instrument will read from 7 inches above the bottom of the hot leg to the bottom of the pressurizer. An existing. level instrument (LT 462) interfaces with the wide range instrument at the bottom of the pressurizer to provide cold pressurizer level readings. Consideration is being given to having dry legs on the level transmitter reference sides to assure conservatism. These. instruments appear 19 meet the intent of GL 88-17. The lead I&C engineer stated that they are planning on only low level alarms. The shift supervisor indicated a desire for a high level alarm also. The inspector observed that a high level alann would be prudent from an industrial safety standpoin With regard to Programmed Enhancements (1)(c) and (1)(d), installed instrumentation appeared to be generally adequate for monitoring an !

alarming DHR system performance. As discussed above, there was no audible core exit thermocouple alarm. RHR pump suction pressure is read on a local. gage. The lead I&C engineer stated that they intend to monitor all parameters related to DHR system performance on one computer scree i

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There were computer points for RHR pump current which have visual alarms and can be trended on recorders. The RHR pumps are monitored for noise by microphones patched into the communications system. The inspector understood i that the value of the system was. limited because of background noise and  !

suggested that. installation of noise monitors should be considered.

l Pursuant to Expeditious Action (5) and Programmed Enhancement (6), the licensee had procedural requirements to not allow any work which could l- perturb RCS operation at mid-loop. Also, the outage manager stated that this would be discussed in the preliminary scheduling meetings and prework briefings with operations. In addition, the planners coordinate with operations on equipment tagouts. As discussed above, the inspector

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recomended that examples of. work, which could perturb the RCS, be included

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in lesson plans. Further, the licensee should reconcile his response with GL 88-17 in that GL 88-17 discusses a reduced inventory condition and the licensee's procedure discusses only a less conservative mid-loop

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With regard to Expeditious Action (6) and Programed Enhancement (3),

licensee's procedures required one safety injection pump and one centrifugal charging pump to be available for alternate RCS inventory makeup. In accor-dance with the Technical Specification,-the safety injection pump was required to be tagged out at the breaker and handswitch. The shift supervisor

< ~ estimated it would take 15 minutes to place the safety injection pump in

. service if it were properly cleared. The available plant communications

. equipment appeared to support performance of Procedures GEN 00-007 and 0FN'00-015 which adequately' responded to loss of DHR event In response'to Expeditious Action (7), instructions and guidance h' ave been

' incorporated in Procedures GEN 00-007 and MPM M711Q-05 to prevent pressurization of the upper plenum of the R The inspector reviewed site specific analyses pursuant to Programed "

. Enhancement (4) which supported the procedural approach for preventing

. and/or responding to loss of DH The inspector reviewed drafts of revised Technical Specifications (Attachment, Document 22) prepared pursuant to Programed Enhancement (5).

Draft. revisions to the associated bases'were also reviewed. These revisions dealt with reduction in RHR minimum flow rate to 6 void vortexing and elimi-nation of the requirement for tagging open the safety injection pump -

breaker and bandswitch during certain reduced inventory conditions when the safety injection pump might be required for alternate RCS inventory makeup. The inspector understood that a Technical Specification change request to delete the RHR autoclosure interlock function will also be submitte No violations or deviations were identifie . Exit Interview The inspector met with the licensee representatives denoted in paragraph 1 on June 30, 1989, and sumarized the scope and preliminary findings of this inspection. The inspector continued the inspection in-office by reviewing completed RCS drain down procedures and proposed Technical Specification changes. No further significant findings were identifie Future inspection interests will focus on licensee completion of items noted in this report that were planned or in progress at the time of this inspection. The licensee did not identify, as proprietary, any of the materials provided to, or reviewed by, the inspector during this inspection.

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ATTACHMENT

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DOCUMENTS REVIEWED

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' Letter ET 88-0193, WCNOC to NRC, "GL 88-17 - Loss of DHR," dated December 23,:1988- Letter WM 89-0041,'WCNOC to NRC, "GL 88-17 - Loss of DHR," dated February 2, 1989 Memo NP 89-0271,' Engineering tb Distrib'ution " Scoping Meeting on Providing Two Independent RCS Level Indications in the CR for Reduced Inventory Conditions," dated March 3, 1989

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' Memo NS 89-0297, Consultant to Engineering, " Minimum Recommended RCS Levels to be Used in Determining Setpoints for. Permanent Mid-Loop. Level Monitoring System," dated April 21,'1989 Memo NP 89-0510 Engineering to Meeting Attendees, "UE WCNOC March 22,

.1989 Meeting in Kansas City on Mid Loop Operation," dated April 28, 1989 Letter ULNRC-1889, Union Electric to NRC, "Callaway Plant RHR Flowrate Reduction for Partial Drain Operation and Deletion of the ACI Function,"

dated January 6, 1989- Letter NRC to Union Electric Company, " Amendment No. 42 to Facility

< Operating License No. NPF-30," dated April 3, 1989 (Included Safety Evaluation Report)

I Memo OP 88-0187, Operations to Distribution, " Compliance With NRC Consnitment on Pressurizer Purge, Half-loop Operation, Loss of Shutdown

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Cooling, Energization/Deenergization of NB/NG/NK Busses Powering NK 25 Charges" Procedure GEN 00-007, Revision 10, " Mode 5 - RCS Drain Down," Approved November 15, 1988 10; Procedure OFN 00-015, Revision 6, " Loss of Shutdown Cooling (RHR),"

Approved November 8, 1988 11.. Procedure FHP 02-001, Revision 10 (Draft), " Refueling Procedure" 12. Procedure MPM M711Q-05, Revision 1, " Steam Generator Primary Nozzle Dam-Installation Removal," Approved October 29, 1988 13. Completed Procedures GEN 00-007, Revision 8, Approved February 3, 1988 GEN 00-007, Revision 9, Approved November 2, 1988 GEN 00-007, Revision 10, Approved December 5, 1988

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-2- GEN 00-007. Revision 10. Approved December 7, 1988 FHP 02-001 Revision 8. Approved December 23, 1988 14. Lesson Plan (LP) 031, " Loss of Shutdown Cooling During Half Loop Operations," Approved September 28, 1987 15. LP.058, Revision 003, "RHR System," January 4, 1989 16. LP 091, Revision 001, " Nozzle Dam Installation ar.d Removal," Approved September 15, 1988 17. LP 035, Revision 000, " Refueling Concerns," Approved September 23, 1987 18. LP 095, Revision 000, " Plant / Industry Events," Approved November 3, 1988 19. LP 035. Revision 001, " Refueling Concerns," Approved July 6, 1988 20. Surveillance Report TE:533595-1660, "Mid-Loop Operations Concerns," dated September 22, 1988 21. Sketch PMR 2937, " Proposed Midloop Instrumentation" 22. Draft' Technical Specification Changes: TS 3.4.1.4.2. TS 3.5.4, TS 4.9.8.1, and TS 4.9. " - - - _ _ _ . _ _ _ _ _ . _ _ _ _ . . _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _