IR 05000445/1989090

Insp Repts 50-445/89-90 & 50-446/89-90 on 891218-26.No Violations or Deviations Noted.Major Areas Inspected: Licensee Actions to Prevent & If Necessary,Respond to Loss of DHR as Described in Generic Ltr 88-17

ML19354D832
Person / Time
Site:	Comanche Peak
Issue date:	01/08/1990
From:	Bundy H, Seidle W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
Shared Package
ML19354D831	List: IR 05000445/1989090
References
50-445-89-90, 50-446-89-90, GL-88-17, NUDOCS 9001220229
Download: ML19354D832 (11)

Text

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ca - s qf'C" -APPENDIX - O ' y' t lF ^ ' U.S. NUCLEAR REGULATORY. COMMISSION ~ o - .

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. < , . - , > - , , I , M 'NRC Inspection Report: ;50-446/89-90 CPPR-127.- 50-445/89-90 Construction Permitsi CPPR-1261

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' ' Licensee: TU Electric Skyway' Tower: , , , N ,, ~ 752b j .# e c

Jacility Name:. Comanche Peak Steam Electric Station (CPSES)y ="

- ' . ilnspection At:i CPSES, Glen Ro:;e, Somervell County, Texas % ' v;. .e , " ' tInspection Conducted: December 18-21, 1989, onsite n. : ~ December 22 and 26, 1989', in-office ' - >v Inspector: _ M 1//g/':70 ' H.--F. Bundy, Reactor Inspector, Test Programs-Da'te ' ' , Section, Division of Reactor Safety t . .

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l W. C.'Seidle9 Chief, Test Programs Section Date ' K' - Division of-Reactor. Safety - s: . L-Inspection Sumary v , g, , . Inspection Conducted During the Period December 18-26, 1989 (Report 50-445/89-90) ! ' -

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gAreaI$spected:hRoutine,unannouncedinspectionoflicensee'sactionsto PA 1 prevent and, if necessary.. respond to loss of decay heat removal (DHR) as . y described in Generic Letter (GL) 88-17 for CPSES, Unit 1.

, . LResults: The procedures and administrative controls were well written and.

' responsive to GL 88-17. The lesson plans prepared pursuant to GL 88-17 were - comprehensive. The training observed was effectively presented and well received.

t The_ simulator scenario was responsive to the' training objectives. The installed' + instrumentation appeared to;be-sufficient to meet the expeditious action requirements of GL 88-17 and was user friendly. The instrumentation proposed -, sin response to programed enhancement recomendations appeared responsive to GL-88-17. The licensee has made' a comitment to install this instrumentation < , prior-to the end?of the first refueling outage. The inspector identified the

following concerns regarding the licensee's response to GL 88-17: ~

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L..,. - g; . y, ", .-2- .l t>< , x , The' licensee was unable to demonstrate the effectiveness of the hot leg

" ' vent-path through the detensioned reactor vessel (RV) head (0 pen Item 445/8990-01) The curve, "Available Time for Containment Closure vs. Decay Heat Generation !

! Rate," in Procedure IP0-010A was incomplete (0 pen Item 445/8990-02) t '

Appropriate instructions were not included in Procedure IPO-010A for , monitoring residual heat removal-(RHR) p(0 pen Item ump' motor current durin transient reduced inventory operations 445/8990-03)g a

-There was no procedural' requirement, in accordance with a prior commitment, to require refresher training and briefings for certain- ] categories of personnel prior to entry into reduced inventory operation l (0penItem 445/8990-04) L a L No violations or deviations were identified.

' . Inspection Conducted During the Period December 18-26, 1989 (Report 50-446/89-90) l

, l Area Inspected:- No inspection of CPSES, Unit 2 was conducted, i L l' L , ! 4<

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' p DETAILS: - , ' ,, 1. - Persons Contacted ' , ' TU Electric! f . ~ '

• D. Devinef Deputy Director - Quality Assurance (QA)

.D. Stonestreett, Manager - Outage Planning , J.. Walker, Manager - Operations / Engineering Training J. Ellard;< Simulator Training Supervisor . . J. B. Soileau, Maintenance Training Supervisor J. McInvale, Unit-Supervisor. Operations ,

• J. Brau, Supervisor 0perations Support

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• J. Smith, Plant Operations _ Staff

' ' N. Terrel, Supervisor - Technical' Support . .

• S. Palmer,. Stipulation Hanager

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• B. Layton,' Mechanical-Supervisor - Operations Support Engineering _
• J. Meyer Principal Engineer -' Operations Support Engineering

- K.l Pointer,: Licensing Engineer .

• V.' Smith, RHR System Engineer - Technical Support

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• F. Dunham, QA Interface Coordinator
• T.'A. Hope', Site Licensing-

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• 0. L. Thero, Consultant o

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• W. D.' Johnson, Senior Resident Inspector H,
• S. Bitterg Resident Inspector - Operations

E R. V. Azua, Reactor Inspector - Region IV - - 'The inspector also-interviewed other licensee employees during the ~ inspection.

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• Denotes those. attending the exit interview on December 21, 1989.

2.

Licensee Actions to Prevent and Respond to Loss of DHR (TI 2515/101) , a.- ' Recommendations contained in GL 88-17 ' l . , The purpose of this inspection was to verify licensee actions to prevent and, if necessary, to respond to loss of DHR-during l operations with the reactor coolant system (RCS) partially drained.

Licensee actions were in response to recommendations contained in GL-88-17, " Loss of Decay Heat Removal." Recommendations were made by GL 88-17 in-two categories: ., L

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' Expeditious actions, which should be-implemented prior to

operating in a reduced inventory condition, and Programed enhancements, which should be developed in parallel

with the expeditious actions and may replace, supplement, or add to the expeditious actions.

Fct purposes of-future reference, the recomendations are briefly paraphrased below and the numbered-recomendations 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 condition.

(2) Implement procedures and administrative controls for containment 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 ' Westinghouse.

(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 RV.

. (4) Provide at least two independent, continuous RCS water level indications whenever the RCS'is in a reduced inventory ' condition.

Indications should be periodically checked and recorded by an operator or automatically and continuously monitored and' alarmed.

(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 the RCS is in a reduced inventory condition.

If avoidance of ^ perturbations is impossible, then compensatory measures should be taken.

(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 systems.

(7) Implement 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 i; ,m x, /M '. -5- , - (8)uNotapplicabletoCPSES.

(Applies to units with loop stop-valves) Programmed Enhancements ' (1) Instrumentation ' Provide = reliable indication of parameters that describe the i state of the RCS and the performance of systems normally used to .! cool the RCS for both normal and accident conditions. At a l e minimum, provide the following in the control room: ! (a) Two. independent RCS level indications; I (b) At.least two independent temperature measurements representative of-the core exit whenever the RV head is located on top of the 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 performance.

(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 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 communication, as appropriate.

(3) Equipment (a) provide equipment of high reliability for cooling the RCS and avoiding loss of RCS cooling;

?$? .; u... ! gil,p ~-{ . A y-6- . ' '_(b)' Maintain equipment available to mitigate loss of DHR or

- loss of RCS-inventory should they occur including at least one high pressure _ injection pump and one other system, each ,1 sufficient to keep the core covered; and ' - (c) Provide adequate equipment for personnel communications involving activities related to the.RCS or systems ' necessary_ to maintain the RCS in a stable and controlled l condition.

' le > t ,(4) Analyses . y Conduct analyses to supplement existing information and develop a basis for procedures, instrumentation installation and i / response, and equipment /NSSS interactions and response.

' , i$< -(5) Technical Specifications Technical Specifications that restrict or limit the safety i , ' benefit of the actions identified in this letter, should be i " identified and appropriate changes should be submitted.

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(6). RCS Perturbations R . Reexamine Item (5)'of expeditious actions and refine operations-l .,, as necessary to reasonably minimize the likelihood of loss of.

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Licensee's Actions In Response to GL 88-17 Recommendations , The inspector's comments on the licensee's actions in response to < -; , GL 88-17'are provided below. -The attachment is a tabulation of j 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 theElisted documents and interviewing ._ -appropriate personnel, the-inspector walked down the installed DHR - p, equipment and instrumentation. Because the plant was operating at y mid-loop during this walkdown, the inspector was 'able to directly L assess the licensee's DHR monitoring capabilities.

It was noted that the newly' installed wide and narrow range level indications were reading within a_ tenth of an inch of each other. Also, the Tygon i f ' hose indication was within a fraction of an inch of the wide and

narrow range indications.

It should be noted that the RHR systen is L essentially the DHR system as discussed in GL 88-17.

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, L Descriptions of the CPSES installed RCS level instruments, which are responsive to Programmed Eniecement (1)(a) and Expeditious Action (4), are provided by Docum c.tc 1 and 2.

They consist of l narrow range (30-inch span) and wide range (150-inch span) control L room indicators, a heated junction thermocouple (HJTC) system with a [ range from near the top of the RV head to the upper core alignment

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-7-plate and control. room indication, an'd a Tygon hose sight glass with the level sensing leg connected to a loop 4 hot leg drain line. As

discussed above, the inspector verified the accuracy of these instruments while-the~ plant was operating at mid-loo). Also, the wide and narrow range instruments should be reliable in t1at the transmitters are tied into separate flux. thimble guide tubes. Either instrument can actuate a low level alarm on the control board.

The licensee responded to Programmed Enhancement (1)(b) and Expeditious Action (3) by_ requiring two core exit thermocouples (CETs)'to be in service as a prerequisite to reduced inventory operation in accordance -with1 instructions in Document 5.

Document 5-requires setting the associatedplantcomputer(P-2500)alarmsat140*F. Document I requires that these alarms will be set approximately 10'F higher than the stable RCS-temperature being maintained.

In resolving this - discrepancy, the licensee-should consider the consequences of a possible; inadvertent mode change if the.present setpoint is exceeded.

In-Document-1, the licensee takes credit for the HJTC system as a ' backup to the CETs. -Information provided to the inspector indicated that the: accuracy of the HJTC system for temperature indication was approximately 125'F. Therefore, the HJTC system would only be reliable-for indicating temperature trends.

Prior to enhancing DHR monitoring and alarm capabilities pursuant to recommendationsforProgramedEnhancements(1)(c)and(1)(d),the licensee performed vortex testing in accordance with Document 6.

The inspector reviewed-the test results-and discussed them with the ' principal engineer. The planned enhancements are discussed in Document.4. They include the following: Increased resolution for control board indication of RHR flow at ' low flow rates Control room indication of RHR pump suction pressure including

audible alarm Control room indication of RHR pump motor current with audible

alarm Consideration was also given to installing noise monitors, because the testing indicated that noise level changes were reliable indicators of excessive air entrainment. -However, this was not pursued by the licensee because of perceived difficulties in properly calibrating noise monitors for operator use.

Existing RHR system instrumentation included the following: Control board indication for pump discharge pressure and flow

Local indication of RHR pump suction pressure, miniflow, and

motor current <

, . ;. t.. ,. y i , -8- - The inspector concluded that the above monitoring capabilities constitute an acceptable response to' recomendations in GL 88-17.

The control board instrumentation configuration was excellent. The , - licensee comitted in Document 4 to installing the improvements prior to the end of the first-refueling outage for Unit 1.

The inspector . reviewed the following procedures which were developed pursuant to therecommendationsinProgrammedEnhancement(2):

• l Document 5 IP0-010A Document 7 ABN-104A

Except for the open items and concerns discussed below, the above procedures appeared responsive to Expeditious Actions (2) and (7), andProgrammedEnhancement(2).

In responding-to this item, the licensee, with the exceptions discussed below, was also responsive to

the training recommendations in Expeditious Action (1). The

' procedures were found to be generally of high quality. The inspector noted that Procedure-IP0-010A required a manual valve for flow control-at mid-loop. This was to prevent a high flow vortexing loss of DHR as postulated by Document 12 in the event of loss of electrical power or air to the automatic flow control valve.

The. inspector did have the following concerns: In Procedure-IP0-010A, Step 2.1, leaving the RV head detensioned

with the nuts removed was listed as one of three-options for providin5 a hot leg vent path prior to installing the first steam generator nozzle dam. This did not appear to be a viable vent path and.the licensee was unable to provide an analysis to support this method. Resolution of this issue will be tracked as Open Item 445/8990-01.

Attachment 7, "Available Time for Containment Closure vs. Decay

Heat Generation Rate," curve in procedure IP0-010A was blank.

Completion is necessary to satisfy the recommendations of Expeditious Action (2) and, therefore, will be tracked as Open Item 445/8990-02.

Step 5.1.13 of Procedure IP0-010A should have a requirement to , s-monitor RHR pump motor current during draining to mid-loop.

Also, Step 5.1.16 NOTE should require periodic monitoring of RHR pump motor current during draining of steam generator tubes.

' Inclusion of appropriate RHR pump motor current monitoring instructions in Procedure IP0-010A will be tracked as Open Item 445/8990-03.

A comitment in Document I to require, in a procedure, refresher

training (including related loss of DHR events) and briefings for maintenance, planning, work control, and test personnel, prior-to entry into reduced inventory operation was not incorporated.

Although it was not a part of the commitment, this training was ! _ _ _ _ _ _ _ _ _ _ _ _

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< L - m , required by Procedure IP0-010A for operations personnel, as appropriate, pursuant to Expeditious Action (1) recomendations.

L Inclusion'of_this training requirement in a procedure for the other categories of personnel will be tracked as Open Item 445/8990-04.

' In further followup on the licensee's actions pursuant to the recomendations in Expeditious Action (1), the inspector interviewed ' training management personnel, and reviewed Documents 8-11 together h with the associated class schedules. The inspector found the lesson plans-(LPs) were excellent and the scheduling was timely. The simulator scenario reviewed was responsive to the training objectives.- The inspector attended a GL 88-17 lessons learned presentation for instrumentation and control personnel, which was expertly-presented and well received. The inspector observed that planning and work control personnel were participating in the ,. maintenance department training. However, the maintenance training l' supervisor stated that beginning in 1990, planning and work control ! personnel would be trained with the technical staff. The inspector

comented that management should verify that' GL 88-17 training I continues for this category of personnel.

l The inspector observed that previous loss of DHR events were not covered in the LP-currently aeing presented to operations-personnel.

However, they were covered in a draft revision to the LP, which the . training manager ~ stated would be ' presented. in the next cycle.

l With regard to Programed Enhancement (3) and Expeditious Action (3), ! the licensee appeared to have sufficient equipment procedurally ! controlled to provide for cooling the RCS, avoiding loss of DHR, and i RCS inventory makeup. The sources of alternate inventory makeup were -) one centrifugal charging pump and one safety injection pump. The

< procedure allowed the pump motor breaker to be racked out if the i pumps were'otherwise available.

With regard to Programmed Enhancement (4), the analyses to support procedural requirements and installed equipment and instrumentation interactions.were, in general, either appropriately referenced or ! provided by the site vortex testing. Open Items 445/8990-01 and -02

-discussed above address further analyses for closure.

' Pursuant to Programed Enhancement (5), the licensee changed Technical Specification (TS) 4.9.8.2 to allow a reduction in RHR flow rate from 3800 to 1000 gpm when in Mode 6.

This will satisfy minimum , cooling requirements and minimize air entrainment during reduced i inventory operation. Deletion of the RHR suction valve autoclosure interlock was under consideration. No other TS changes relating to loss of DHR-were being considered.

> With regard to Programmed Enhancement (6) and Expeditious Action (5), the licensee's comitments in Document I were generally satisfied by i - - = - - - -- - - - - -. .. _ _ _ _ _ _, _. _ _ _ _ - - _ _ - _

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However, there is a commitnent in Document I that outage . planning procedures will require a review of planned activities prior to er.tering a reduced inventory condition to determine if they could " . perturb the RCS or reduce the. reliability of DHR systems, support t ' systems, associated monitoring instrumentation, or designated. recovery equipnent. Because these procedures had not been issued, it was impossible to verify satisfaction of this commitment. This item will be pursued in a future inspection.

No violations or deviations were identified.

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Exit Interview .u The inspector met with the licensee representatives denoted in paragraph 1 on December 21, 1989, and summarized the scope and preliminary findings of this inspection. The inspector continued the inspection in-office-by reviewing Documents 6 and 13-18. Questions were discussed with Mr. John Meyer of TV Electric on December 26, 1989..No further significant findings were identified. The licensee did not identify as proprietary any of the materials provided to, or reviewed by, the inspector during this inspection, i , ! , l l l l-l - .' L .. . - .

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ATTACHMENT y DOCUMENTS REVIEWED - , y.. dt .I'. . Letter TXX-89041, TV Electric to-NRC, "CPSES Response to GL 88-17 - Loss .. of.DHR," dated February 10, 1989 . . - "

. ' ' * 2L Letter TXX-89282, TU Electric to NRC, "CPSES' Updated Response to GL'88-17," dated June 1, 1989 l 3.- Letter, NRC to TU Electric, " Comments on TU. Electric Company Response to-r . GL 88-17 with. Respect to Expeditious Actions for Loss of DHR for CPSES."

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dated June. 27, 1989 s . 4 '. - Letter-TXX-89804, TU Electric to NRC, "CPSES Updated Response to , GL 88-17," dated November 20, 1989 - 5.- Procedure IP0-010A, Revision-1, " Reactor Coolant System Midloop , Operations" ' ' ! 6.

Procedure IP0-TP-89A-1-, Revision 0,:"RCS Midloop.0perations/ Vortex Testing"- } , 7.

Procedure ABN-104A, Revision 3, "RRR System Malfunction" !

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LessonPlan(LP)LO41".B90.0P1.LP,"MidloopOperations" , 9.

" Simulator Exercise Guide'LO44.B90.N01.LP001.01, "Midloop Operations" 10. LP IC31.089.IR1.LP, "Quaiter 4 Seminar" ! 11. LP.MM31.089.1R1, "INPO SOER 88-03 - Reduced Inventory Operation Events" 12. Lotter TXX-89719. TU Electric to NRC, "CPSES Potential Loss of RHR - SDAR: CP-89.-023 (Final-Report)," dated September 25, 1989

, , .13. Design Control Authorization (DCA) 82613, Revision 3, " Add Level Transmitters to'RCS to Monitor RCS Level During Midloop Operation" 14. DCA 81350, Revision 0, " Specifies Technical Data for New Level Transmitters 1-LT-3615A and 1-LT-3615B" 3" 115., DCA 82334, Revision.0,f" Specifies Technical Data for New Level ' Indicators 1-LT-3615A and.1-LT-3615B" 16. DCA 83016, Revision 8, "Provides Circuitry for Low Level Alarms from RCS Level Indicators 1-LT-3615A and 1-LT-3615B" 17. DCA 84502, Revision 4, "Provides Installation Details for Level Transmitters 1-LT-3615A and-1-LT-3615B" , 18. ~DCA 92519, Revision 0, "Provides Low Level Alarm Setpoints for Level Indicators 1-LI-3615A and 1-LI-3615B"

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