IR 05000327/1987014

Insp Repts 50-327/87-14 & 50-328/87-14 on 870302-13.No Violations Noted.Major Areas Observed:Assess Adequacy of Utils Design Baseline & Verification Program to Support Restart of Facility

ML20215B795
Person / Time
Site:	Sequoyah
Issue date:	04/30/1987
From:	Architel R, Imbro E Office of Nuclear Reactor Regulation
To:
Shared Package
ML20215B748	List: IR 05000327/1987014 ML20215B746
References
50-327-87-14, 50-328-87-14, NUDOCS 8706170454
Download: ML20215B795 (42)

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'U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR REACTOR REGULATION Division of Reactor Inspection and Safeguards j

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l lE Report Nos.:. -50-327/87-14,~50-328/87-14 50-327; 50-328  !

Docket Nos.:-

l Licensee: . Tennessee Valley Authority l 6N, 38A Lookout Place  ;

1101 Market S :

Chattanooga, TN 37402-2801 j

. Facility Name: Sequoyah Nuclear Plant, Units 1 & 2 Inspection At: Soddy Daisy, TN  !

Inspection Conducted: March 2-13, 1987

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Inspection. Team Members:.

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- Team Leader: R. E. Architzel, Senior Operations Engineer, NRR Mechanical Systems: F. Mollerus, Consultant, Mollerus Engineering In Nuclear Engineering J. Nevshemal, Consultant *- t Mechanical Components: A. V. du Bouchet, Consultant Civil / Structural: A. Unsal, Consultant, Harstead Engineering

. Electrical' Power: V.' Athavale, Electrical Engineer, NRR Instrumentation &-

Control: L. Stanley, Consultant, 'ytor In Operations: P. Holmes-Ray, Sr. Resident Inspector, Plant Hatch *

/M M Ralph'E. Architdel Team Leader Oh7

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[ Y Sh Eugene V. Imbro Ofl}

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Section Chief Special Inspection Branch

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LIST'0F ABBREVIATIONS ~

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.AFW Auxiliary Feedwater AI- Action Item 1 ASME ,American. Society of.. Mechanical Engineers 1

.CAQ Condition-Adverse to Quality J CAQ Condition-Adverse to~ Quality Report CCP Centrifugal Charging Pump

'CCS . Component Cooling Water System

'CEB Civil Engineering Branch C/R Commitment / Requirement ..

CVCS , Chemical and Volume Control System l DBVP- Design.. Baseline and Verification Program DIM Design Input Memorandum DNE~ Division.of Nuclear Engineering-EA Engineering. Assurance ECN Engineering. Change Notice EEB Electrical.-Engineering Branch '

ERCW- Essential ~ Raw Cooling Water System

'ESF Engineered Safety Features EQ Environmental Qualification FC Field Change Notice (Westinghouse)

FCR Field Change. Request j!

FSA Final Safety Analysis Report i HVAC Heating, Ventilation and Air Conditioning ;

IEEE Institute of Electrical and Electronics Engineers LOCA Loss of Coolant Acciden MEB Mechanical Engineering Branch MOV Motor Operated Valve NEB Nuclear Engineering Branch NRC Nuclear Regulatory Commissio NRR Office of Nuclear Reactor. Regulation NSS Nuclear Steam Supply System l PIR Problem Identification Report RIMS Records Information Management System

.SCR Significant . Condition Report '

SQEP Sequoyah' Engineering Procedure SQN Sequoyah Nuclear Plant SWBID System Walkdown Boundary Identification Drawing SYSTER System Evaluation Report TAC Temporary Alteration Control Form TVA Tennessee Valley Authority USQD Unreviewed Safety Question Determination WBN Watts Bar Nuclear Plant ZPA Zero Period Acceleration

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SEQUDYAH NUCLEAR POWER PLANT Design Baseline and Verification Program Inspection Report 50-327/87-14 & 50-328/87-14 March 2-13, 1987

- INTRODUCTION AND BACKGROUND The Design Baseline and Verification Program (DBVP) was developed by the Division of Nuclear Engineering (DNE) to resolve design control issues de-scribed in several TVA sponsored evaluations and audits and NRC inspection The Sequoyah Nuclear Plant (SON) Design' Baseline and Verification Program will i be used by TVA to provide an additional level of' confidence that the modifica- i l-tions to selected plant systems, implemented since receipt of the operating

! license, have not resulted in any violation of the plant's licensing basis. The program is described in the'" Program. Plan for the Engineering Assurance Inde-pendent Oversight Review for the Sequoyah Nuclear Plant Design Baseline and Ver P cation Program," dated May 9, 1986 and forwarded to the NRC as an enclo-su a to Mr. R. L. Gridley's letter dated June 27, 198 This report summarizes the results of-the fourth NRC inspection conducted to assess the adequacy of TVA's. Design Baseline and Verification Program (DBVP) to

' support restart of Sequoyah Nuclear Plan NRC inspection report 50-327/86-38'and 50-328/86-38 summarized the NRC's review of TVA's overall. DBVP plan and scope TVA's procedures for DBVP project review

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and engineering assurance (EA) oversight, TVA's preparation of system walkdown packages within the DBVP scope', and the NRC's preliminary review of TVA's design criteria for FSAR Chapter 15_ safety-related systems within the scope of the DBVP.

p NRC inspection report 50-327/86-45 and 50-328/86-45 summarized the NRC's review ofTVA'scompilationandimplementationofthe'~ commitment / requirement (C/R)

L data base, the design criteria which TVA prepared to support SON restart, and l

l the adequacy of EA's independent oversight review of C/Rs and design criteria.

l NRC inspection report 50-327/86-55 and 50-328/86-55 summarized the NRC's

[ review of the DBVP project's ECN review, the adequacy of the associated EA l:

l oversight, and review of the adequacy of TVA's actions regarding previous L findings identified during previous inspections of the DBVP and during inspection of the Gilbert / Commonwealth and TVA "3-system" design control reviews (Inspection Report 50-327/86-27-and 50-328/86-27).

A related NRC inspection (Report 50-327/87-06 and 50-328/87-06) was conducted to evaluate TVA's assessment of the technical adequacy of calculations, since this aspect was not evaluated by the DBVP projec '

, PURPOSE The purpose of this inspection was to evaluate the System Evaluation Reports-(SYSTERs) reflecting the DBVP's integrated assessment of the individual systems within the scope of the program, to assess TVA's resolution of-1-a

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i findings identified by the DBVP (including both restart decisions and )

corrective action adequacy), and to evaluate TVA's action for previous )

inspection finding ! INSPECTION ACTIVITIES ,

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.The following activities were generally performed by all team members: ]

(1) An overall assessment of the DBVP project's SYSTER review and the j associated Engineering Assurance (EA) oversight. The team compared its )

assessment with the project's findings, and reviewed the project's '

resolution of EA action items which documented deficiencies that were either not identified by the project's review or reflected programmatic concern (2) An independent NRC assessment of the SYSTER This effort included restart classification (pre- or post-restart) and corrective actions taken or proposed for the findings (tracked as " punch list" items) identified by the DBV (3) A review of the action taken by TVA in response to the deficiencies, un-resolved items, and observations previously identified in NRC inspection reports Nos. 50-327/86-27 and 50-328/86-27, 50-327/86-38 and 50-328/86-38, 50-327/86-45 and 50-328/86-45, and 50-327/86-55 and 50-328/86-5 (4) In addition, the team assessed TVA's evaluation of zero period accelera-tion (ZPA) loads at SQN. Previously, these had been discovered not to have been included in WBN piping analyse . SUMMARY OF FINDINGS The following paragraphs summarize the team's findings and conclusion Section 4.3 contains a detailed description of the inspection findings in each discipline. Observations are provided in Appendix A to this repor j 4.1 REVIEW OF DBVP PROJECT SYSTER EFFORTS TVA calculation SQN-0SG7-048 identifies those systems or portions of systems required to mitigate FSAR Chapter 15 Design Basis Accidents at the Sequoyah Nuclear Plant. The DBVP project evaluated these systems in accordance with Sequoyah Engineering Procedure SQEP-16, Procedure for System Evaluation and Development of System Evaluation Report. Thirty-five SYSTERs were developed and issued by the DBV The team inspected SYSTERs associated with the following system System 30A - Reactor & auxiliary buildings emergency ventilation system System 62 - Chemical and volume control (CVCS).

System 70 - Component cooling water (CCW).

System AP Emergency auxiliary AC powe _

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These systems were chosen for review by NRC based on a review of a draft for comment Reactor Risk Reference Document (NUREG-1150), which identified these systems as being major contributors to core melt probabilit A SYSTER contains a technical evaluation of the following items: ECNs, walkdown discrepancies, ONP generated drawing discrepancies, SCRs/NCRs, FCNs and TACFs. Only those items which pertain to the portion of the system and equipment required for FSAR Chapter 15 accident mitigation or safe shutdown of the plant have been included in the SYSTER evaluatio DBVP identified deficiencies are documented as punch list items. These items are also evaluated to determine if they constitute a condition adverse to quality (CAQ). If a CAQ exists, then the DBVP initiates a problem identification report (PIR) or a significant condition report (SCR), depending on the item's <

significance. The DBVP project has identified a number SCRs and PIRs, some of which are generic and identify the same deficiencies in different ECNs or systems. CAQs have also been identified relating to distinct technical issues which correspond to unique DBVP punch list item Sequoyah project and staff personnel (as opposed to DBVP project staff) are resolving the CAQs and punch list items which the DBVP project identified. The team was informed that the cognizant DBVP system engineer is actively involved in the resolution of identified punch list items. The Sequoyah staff are making determinations, on a punch list basis, of those items which must be assessed and addressed prior to restar A preliminary report addressing the results of Phase I (pre-restart) of the DBVP was issued during the inspection on March 5, 1987. The team reviewed this report. Several specific problems identified by the team with the characterization of DBVP findings are summarized in Observation 6.2 Overall, the DBVP review appeared to be thorough and competent. The DBVP effort resulted in numerous (approximately 10,000) punch list items. Many of these involve drawing deviations and inadequate tagging. The DBVP effort did not appear to have identified any substantial technical deficiencies. However, several important SCRs remain to be resolved. Categorization of the punch list items into restart or post-restart action items, :atisfactory resolution of the punch list items, and satisfactory completion of the associated aspects of the calculation review program, will substantially increase assurance that the systems will meet their safety objective .2 EA OVERSIGHT TVA's engineering assurance group overviewed the DBVP project's SYSTER effort, and wrote action items to identify deficiencies that the DBVP project had not identified any programmatic weaknessess in DBVP implementatio The EA reviews of the DBVP effort resulted in 48 EA-Mechanical action items during the course of the project. Three of these resulted from review of SYSTERs. The EA reviews did not result in any substantial technical deficien-cies in the mechanical area. A final report by EA was in preparation and not available for review by the tea '

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The civil / structural engineering assurance (EA) grcup overviewed the SYSTERS for the high pressure fire protection system, the containment spray system and s the residual heat removal system. EA reviewed the SYSTERS for these systems within the civil / structural scope of the DBVP program to confirm that ECNs and other change documents had been properly addressed, and that the SYSTERS had been prepared in accordance with the requirements of SQEP-16, Attachment 1, System Evaluation Report (SYSTER). EA concluded that the SYSTERS were prepared in compliance with SQEP-16, and that the SYSTER summaries incorporated the DBVP project's actions to address EA's action item concerns. However, EA noted that the adequacy of the SYSTERS was contingent on the resolution of a number of items on the civil / structural punch list, that relatively few punch '

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list items had been closed out at the time of the EA audit, and that the current disposition of punch list items was subject to review in accordance with revisions to SQEP-45, Control of Design Baseline and Verification Program Action Items. EA prepared five action items in the civil engineering area (C-54 through C-58) to document deficiencies identified during EA's SYSTER {

overvie The EA electric power group reviewed the SYSTERs for the auxiliary power system, vital power system, containment spray system and standby diesel generator system. This review generated 11 action items. One action item (EA-83) is of a generic nature, applicable to all disciplines. This action ,

item concerns a TVA internal memo (RIMS B01-861211-001) which improperly

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categorized all PIRs as post-restart items. This policy has been change TVA has committed to have the DBVP system engineer re-review all punch list ,

items and to perform a key role in concurring with restart vs. post-restart '

categorization. This is considered satisfactory resolution of classification issues arising from the management directive as it relates to DBVP decision making. EA otherw concluded that the SYSTERs were prepared in compliance with SQEP-1 l Overall, the team found that the DBVP and EA effort was thorough and competent, i and that DBVP concerns and issues have been properly translated into corrective action systems via punch list items, SCRs and PIR ;

4.3 NRC REVIEW 0F SYSTERS i

The team overviewed the DBVP project's review effort by independently evaluat- i

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ing a number of the SYSTERs the DBVP project had generated, and by comparing j the team's findings with the project's conclusions. Discipline-specific j summaries of the DBVP project's findings are discussed belo . OPERATIONS l

Operations activities during this inspection were limited to review of previous inspection findings and assisting other disciplines in evaluation of the SYSTERs.

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4. MECHANICAL SYSTEMS l The inspection team independently examined ECNs and SCRs contained in several of the mechanical-related SYSTERs. The main thrust of this review was on the functionality (spects of these ECNs and SCR *

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Systems selected for team review included the component cooling water, the chemical and volume control and ventilation systems. In addition, the mechanical systems review was extended to include the air conditioning system standby diesel generator system and fuel oil system. The latter two systems j were selected to complement the inspection team's selection of the auxiliary i

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power system for in-depth revie The inspection team's findings and those of DBVP did not identify any finding that would have a substantial adverse affect on safety system functionalit Most appear to have the capability to be resolved by further evaluation and )

additional documentation. The mechanical engineering evaluation contained in i the preliminary Phase I Summary Report by DBVP states that "The findings can be corrected and the underlying root cause rectified." The inspection team believes that adequate resolution of the DBVP and EA findings, open punch list items and the inspection-team's observations will provide a high degree of assurance that the safety functions of the mechanical systems have not been degraded since operating license issuanc EA-Mechanical reviewed the DBVP throughout the course of the projec During this period, they have issued 48 action items (M-1 through M-48), 3 of which resulted from the EA-Mechanical review of SYSTERs. Information provided to the inspection team indicates that EA has not found any substantial technical deficiencies in the mechanical discipline area. This substantiates similar findings by DBV During the inspection perioc the NRC team examined selected SYSTERs and related information for the systems This was done by identifying the ECNs in each SYSTER that were instrument in implementing a mechanical system or functional change to the system. These changes were then given a further evaluation by the tea ECN L5064 replaces CCS containment isolation hard seat check valves with soft seat check valves in order to reduce low leakage rates. The material, EPT, must withstand a high radiation environment and not deteriorate to increase leakage above the allowable rate following a postulated accident. The need to verify that the replacement valve seat material is satisfactory for the postulated LOCA environment was noted in a review of this ECN by EA. The SYSTER contained information that the valve material and the environmental conditions are the same that have been qualified for a similar application at Watts Bar. Formal documentation of the valve qualification for the Sequoyah valves is being tracked on the punch list for work after restart. This is a satisfactory approach to completion of this task. A review of the SYSTER for System 31, air conditioning, determined that ECN L5064 also changed the valve seat material for certain isolation valves in System 31 from hard, metallic seats to soft seats, again to reduce leakage. However, the evaluation for the System 31 does not address either the environmental conditions of this application or the suitability of the soft material. This is the basis for Observation The team also inspected the SYSTER for System 62, chemical and volume control system (CVCS). One modification to the CVCS involved removal of existing motor brakes and regearing of motor operators for certain isolation valves

. (ECNL6665). The brakes were removed because they could not be environmentally l qualified within the TVA EQ program. The valve operators were regeared to-5-

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slow down the valve closing speeds. Valve speeds were calculated and reviewed by the valve operator vendor. Punch list items remain open to electrically test and measure the speed of the modified valves. The inspection team noted that the SYSTER did not address whether the regeared valve speeds without brakes would satisfactorily prevent damage from closing impact. Correspondence received from the valve operator vendor during the inspection period stated that brakes are not required for 12 inch and smaller gate valves with valve operator speeds of 36 inch / minute or less. The valves in question meet these criteria, thus resolving the team's concer The team also inspected the SYSTER for System 67, essential raw cooling water system (ERCW). Included are 30 ECNs that were primarily nechanical system s

related changes. Two of the more significant ECNs (ECN L5415 and ECN L5009)

involved changes to system performance and are discussed belo ECN L5415 was issued to revise the ERCW flow rates as a result of pre-operational testing. The flow changes were primarily reductions, thus reducing the '

capacity to remove heat. Hewever, calculation B44860403009 has subsequently been produced to summarize and document the basis for flow requirements for the system that is contained in the drawings changed by ECN 541 ECN L5009 was issued to authorize the replacement of the ERCW system's 2-inch and smaller carbon steel piping and valves with stainless steel piping and valves. This ECN was in response to expected flow degradation due to corrosion product buildup in the small-bore carbon steel piping and test deficiencies ;

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described in preoperational Test Deficiency PT-631. The ECN is scheduled to be L partially implemented at restart. TVA considers partial implementation to be l satisfactory because the remaining small bore carbon steel ERCW piping is not l

excessively corroded at this time and surveillance test SI-566, which will be

) performed prior to restart and periodically thereafter, will adequately monitor for adequate flow to all components cooled by the ERCW system. This appears to be a satisfactory approach to long term implementation of the EC . MECHANICAL COMPONENTS In the mechanical components and civil / structural disciplines, the team re-viewed the system evaluation reports (SYSTERS) for the ventilation, chemical and volume control, essential raw cooling water, component cooling water, and stems. The team selected the SYSTER reviews for emergency 22 engineeringauxiliary changeAC power sy(ECNs) and two significant condition reports notices i (SCRs) for evaluatio Based on the team's review of the design modifications and corrective actions summarized in the SYSTER reviews, the team concludes that design modifications to safety-related piping, equipment and structures are in accordance with FSAR commitments and TVA's general design criteria. Observations Nos. 3.10 through 3.15 document the deficiencies which the team identified during the inspectio l

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The team reviewed the SYSTER reviews to confirm that:

(1) TVA's Civil Engineering Branch had properly analyzed design modifications to safety-related piping, equipment and structures with respect to rigor-ous piping analysis, pipe support design, pipe rupture analysis and structural design.

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(2) Civil / structural DBVP project had identified any additional corrective q actions required to bring these design modifications into conformance with ;

FSAR commitments and CEB's general design criteri l I

(3) CEB was scheduling design modifications and corrective actions in accor- 2 dance with the restart criteria detailed in Volume II of TVA's Nuclear Performance Plan for Sequoyah Nuclear Plan The team identified the following observations during the inspection: ;

Observation 3.10; Five field sketches used to reevaluate by rigorous analysis field-routed 3/8" sampling tubing which penetrated the steel l containment vessel were not signed by a preparer, and none of the sketches were signed by a checke Observation 3.11; The team asked CEB to retrieve the procurement and seismic qualification documents for the electrical board room and shutdown board room coolers to confirm that TVA procured and qualified the equipment to the required seismic Class I criteria. However, CEB could not retrieve the seismic qualification documents for the electrical board room cooler Observations 3.12 and 3.14; CEB installed restraints for two of eight removable, unmortared masonry block walls which serve as radiation barriers to protect adjacent ERCW piping from collapse of the walls during flooding. However, CEB could not retrieve the calculations which qualify the restraint design for the two block walls. This was not identified by the DBVP. The team found that such walls, in close proximity to safety-related equipment, were evaluated in some SYSTERs, such as the CVCS SYSTE .

l Observation 3.13; CEB's pipe rupture calculations for the west main steam valve room do not evaluate the valve room walls for main steam line break loads in conjunction with dead and safe shutdown seismic loads, as specified in the FSAR and the design criteria. CEB also used a concrete !

strength higher than the concrete strength specified in the FSA !

Observation 3.15; CEB's conclusion that zero period acceleration (ZPA)

loads on piping and equipment at Sequoyah Nuclear Plant have been ade-quately evaluated was examined by the team. One observation was identi-fied regarding CEB's reanalysis of pipe support no. ICCH-548. The team noted that TVA was using interim acceptance criteria in their evaluation of this suppor In addition, certain aspects of the calculation were not available for review, such as pipe lug load Based on the team's review of the design modifications and corrective actions summarized in the SYSTER reviews, the team concluded that TVA's civil engineer-ing branch (CEB) generally analyzed design modifications to safety-related piping, equipment and structures in accordance with FSAR commitments and CEB's general design criteri *

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4. NUCLEAR ENGINEERING The programmatic inspection by the team in the Nuclear Engineering discipline initially concentrated on a comparison of the SYSTER to the DBVP punch list items. The team's comparison of SYSTER 62 (CVCS) to the system pur.ch list revealed a group of 13 ECNs that were classified in the SYSTER as required for restart but were not listed on the punch lis Ccnversely, there were nine items associated with ECN's listed on punch list again required for restart which had not been evaluated in the SYSTER. The team determined the reason for the missing 13 ECNs was that TVA only opens a punch list item for those i ECNs found to be defective in some area. Conversely, this means that ECNs found to be complete (acceptable) in their description of the work required are not listed even though the actual work may not be completed. The tracking of the ECN required work was not being tracked by the DBVP punch list; however, the team was informed that the DBVP project was informed of all status changes for ECNs (pre , post-restart), and that the SQN project was responsible for tracking implementation of scheduled change The nine ECNs on the punch list but not evaluated as part of the SYSTER were part of an Addendum program. This program started after 10/5/86, which was an internal cutoff date for the DBVP to have itens evaluated. Although the original SYSTER is therefore limited in scope, reliance is placed on the Addendum to supplement the SYSTER and to support documentation of system acceptabilit Also, as part of the programmatic inspection of the SYSTER and punch list the team checked for consistency with respect to classification of an item as either pre- or post-restart implementation. For this, the team selected system 30A (ventilation). The team found items listed in the SYSTER as required for restart that were classified as post-restart on the punch list. This aspect of the inspection also uncovered several instances where punch list items had been downgraded from pre-restart to post-restart notwithstanding SYSTER statement The team found one reason for the downgrading was an internal TVA memo which provided an interpretation of the restart criteria based on the perceived importance of the concern as determined by whether the CAQ was classified as a PIR or SC For example, the memo stated that that all PIRs (Problem .

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Identification Reports) which had not been raised to an SCR (Significant Condition Report) should be classified as post-restart. The relationship of the directives set forth in this memo to the docketed restart criteria was i unclear. The team found instances within system 30A (ventilation) where the punch list item (entered for a PIR) was downgraded because the condition adverse to quality (CAQ) was only a PIR, but in fact an SCR had been written upgrading the PIR (Observation 4.7). Therefore, the team is concerned regarding the justification of the directives set forth in the memo to the docketed restart criteria and the application thereo The team reviewed the closure of punch list items as required by the procedure governing closure, which is SQEP-45. This procedure recognizes a controlling role for the system engineer. The team selected several punch list items which had been closed and inspected the recorded documentation. This revealed that the role of the system engineer was not clearly documented. The closure forms

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on file stated agreement by the system engineer per telecon. The system j engineer was unable to provide evidence of the telecon nor did the individual recall any of the telecons. Those responsible for the SYSTER also expressed-8-

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concern about the closure of punch list items because adequacy of the SYSTER assumes completion of certain items. For example, the following qualifying statements were included in the CVCS SYSTER; "The Punch List Report indicates that some punch list items have been closed. These punch list Items are reported below as closed, however, completion of these items has not been verified."

The inspection of the closure process has resulted in team concerns with the punch list item closure process, which documents verification of completion of required work and DBVP concurrence with the corrective action l The team inspected the EA effort and found that they in general shared the programmatic concerns mentioned herei Several EA action items have been initiated addressing the same areas of concern as the team. Thus, adequate resolution of the associated EA oversight action items will address the '

team's concerns in this are In summary, the team found that the DBVP SYSTER effort was on the whole technically sound. It was also observed that the breadth of the DBVP is limited and that it is identifying problems and transferring responsibility for completion of the actual work to other organizations. The relation of DBVP findings to restart criteria and punch list item closure were identified as areas of concern. These concerns will be re-examined during an inspection of DBVP corrective action . ELECTRICAL POWER ,

In the electrical power discipline, the team reviewed the system evaluation reports (SYSTERs) for the auxiliary power system, the ventilation system and for the component cooling water system. This included review of approximately 60 ECNs, two significant condition reports (SCRs), several problem identifica-tion reports (PIRs) and the documentation related to four closed punch list items in the AP system. The team also reviewed action items generated during EA's review of the SYSTERs and in addition, reviewed a sample work plan for cable pulling being performed for cables to be replaced pursuant to SQN's

"Ampacity" progra Based on the team's review of the design modifications and corrective actions summarized in the SYSTER reviews, the team concluded that the SYSTER review was adequate and results of this review were properly documented. The SYSTER process has generated a large number of punch list items. In accordance with ECN justification sheets, the adequacy of the modified systems for the restart of the plant depends on the proper resolution of selected punch list item The team's review of each SYSTER package covered a sampling assessment of attributes, such as justification of partially implemented ECNs for restart, correctness of classification (pre-restart or post-restart) of identified corrective actions, consistency in the SYSTER documentation and evaluation of effects of the engineered and non-engineered changes on the syste The team questioned the fact that the punch list was not a controlled docunect 1 and therefore credit taken for assumed closure of punch list items in assessing the adequacy of the modified system for restart may not be valid. TVA informed the team that although the punch list was not a controlled document, the-9- l

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documents which initiate changes to the punch list (SQEP 45 attachment forms)

are controlled. This resolved the team's concer The following paragraphs sumuarize the team's review on a SYSTER basi ]

Auxiliary Power (AP) SYSTER The boundary of this system includes the three phase power distribution system which supplies power to safety-related equipment during both normal and emergency conditions. The major system elements are the 6.9 kv shutdown boards, 480v shutdown boards, associated transformers and all motor control centers supplied by the 480v shutdown boards. This system does not include the standby diesel generato In this system the team reviewed approximately 40-45 ECNs and associated punch list items related to SQEP-12 and SQEP-14 checklists. The team identified several problems relating to walkdown finding resolution and inconsistencies and errors in the SYSTER. The DBVP project incorrectly classified electrical attributes as irrelevant for ECN-5298, and two punch list items addressing the same issue were classified differently (Observation 5.11). The NRC team was informed that the errors noted in the AP SYSTER will be corrected in an addendum to the SYSTER in the near futur The walkdown process has generated many punch list items. Some of these items identify a mismatch between the data shown on the drawings and the actual data obtained from installed equipment. The mismatches were noted in the equipment tag descriptions and in the ratings or settings of equipment, as discussed belo Various punch list items identify situations where the description on the name tags of the equipment does not agree with the description shown on design drawings. The team noted that the restart categorization for such items on the punch list is post-restart. The team was concerned with this classification and believes that the correction of identification tags of safety-related equipment should be accomplished before restart. The incorrect nameplate data could lead to a potential operator or technician identification mistake and improper action with a potential impact on the system operability. TVA noted that SQN-Operations policy had been to schedule corrective action for such equipment tagging items prior to restart. TVA informed the team that each punch list tag identification item will be revisited in the future to decide which items are required to be completed before restart of the plant (Observation 5.9).

Rating / setting mismatch: The walkdowns identified many cases where the ratings and/or settings of the installed equipment was found to be different than the values shown on applicable design drawings. The <

equipment involved included fuses, breakers, transformers, contactors, and relays. The team noted that a drawing deviation process (which only revised the drawing, considering the as-constructed condition to be correct) was used to resolve the differences. Engineering review (such as verification of values from the applicable calculations / specifications)

was not performed to verify the correct values. In many cases, the team noted that the installed ratings were lower than the values shown on the

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drawings, and in many cases, values from these drawings were used for the calculation efforts by DNE (Observation 5.10).

TVA informed the team that punch list items, including those already closed, written for tracking the drawing deviations will be reexamined to ensure the correctness of the corrective actio VentilationSystem(30)SYSTER In this SYSTER, the team reviewed the justification of electrical related ECNs for adequacy of the system to support accident mitigation and safe shutdown functions. The team review included ECNs 2945, 5183, 5370, 5415, 5422, 5872, 5882, 5883, 6529, 6547, 6553, 6597 and 6712. Of these, ECNs 5422 and 5872 will not be completed before the restart. ECN 5422 was issued to change the plastic blade axle bushings on dampers. All damper bushings have been replaced except for those of the diesel building ventilation syste The team was informed by the responsible system engineer that an unchanged bushing was acceptable since wear in the plastic will loosen the damper. This may cause a wobble in the damper during operation, but will present no problem in opening. The diesel building ventilation dampers are normally open and their safety role is also an .

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open position; therefore, changing the bushing after plant restart will not jeopardize the safety function. For ECN-5872, all components except the local hand switches were installed. The team was informed by the system engineer that these switches were not required for the safety function of this system; and therefore, installation can be accomplished post-restar The team noted that these justifications were not documented in the SYSTER packag The team's review of the ventilation SYSTER raised several concerns regarding post-restart classification of punch list items. These included post modifica-tion testing of the turbine driven auxiliary feedwater pump (TDAFW) room ventilation fan, verification of assumptions for the TDAFW pump room fan, and analysis of replacement cables for thermal requirements (Observation 5.9).

Component Cooling Water System (70) SYSTER The team reviewed the justification for electrical related ECNs-1690, 2890, 2983, 5457, 5591, 5731, 5746, 6310, 6209, 6231, 6553, 6648 and 6667. The team's review of the CCS SYSTER raised several additional concerns regarding post-restart classification of punch list items. These included post modification testing of replacement switches in ESF systems which were only '

bench tested, testing following removal of space heaters from motor operated valves, and verification of adequacy of electrical aspects (eg., voltage drop)

following replacement of a containment isolation valve motor (Observation 5.9).

The team also identified that a modification which deleted an electrical interlock to prevent improper paralleling of redundant division power feeds improperly assumed that adequate administrative controls were in place (Obser-vation 5.11).

4. INSTRUMENTATION AND CONTROLS The team reviewed System Evaluation Reports (SYSTERs) for safety-related ventilation systems 30, 30A, 31, and 31A, chemical and volume control system 62, and component cooling water system 70. Portions of the ventilation system

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instrumentation and control equipment were physically inspected by the tea During the revicw of DBVP program results, 22 individual punch list items among the 3 systems were examined in depth for their restart "yes/no" decision, their associated SQEP-12 Ech evaluations, and their SQEP-14 post-modification test requirement evaluations. Background material contained in the SYSTER l volumes for these three systems was also examined, and the preliminary summary report presenting the DBVP program results for each engineering discipline was reviewe In general, most of the instrumentation and control items described within the three SYSTERs that were reviewed by the team were satisfactor Each of the DBVP punch list "yes/no" restart decisions reviewed by the team was also satisfactory. However, one area of concern involved the technical resolution of individual punch list items by DBVP in that there were a number of instances where certain SQEP-12, SQEP-14, and SYSTER reviews did not appear to be technically adequate. For example, of 22 punch list items examined in some depth among the 3 reviewed systems, 4 (or approximately 18 percent) led to team observations regarding inadequate DBVP actions taken at various stages of the resolution process. Two out of five punch list items involving the ventilation .

systems had technical inadequacies as well as one each in CVCS and CCS. The !'

observations are discussed belo During this inspection, the team found that surveillance instructions did not exist for periodic test of certain engineered safety feature systems. TMs l omission was found at several places within the system 30 (ventilation) 6.d 31 (airconditioning) equipment. Replacement flow switches 2-FS-30200 and -207 l installed by ECN-L-5443 were not calibrated between 1981 and 1986, and the 1 initiation and interlock circuits used to actuate a backup fan when low flow I occurs for an operating fan had not been tested since the system preoperational .

test (Observation 6.16). The control logic for actuation of diesel generator i building ventilation fans and the automatic switchover between redundant fans also lacked surveillance instructions to assure the functional operability of this support system (Observation 6.17). Similar surveillance instructions did not exist for the instrumentation and control equipment of the 480 volt board ;

room and 6.9KV shutdown board room air handling units (Observation 6.19). 1 These instances support Observation 6.15 in MRC inspection report 86-55 which dealt with the lack of surveillance instructions for periodic test of pump control circuit The system 31 SYSTER and the mechanical summary report stated that no common cause failure exists that could cause both air handling units (and therefore the air conditioning system) to fail at the same time. However, the team believes that the four 480 volt shutdown board rooms (2A1, 2A2, 2B1, and 2B2)

may be susceptible to a common cause failure of the air handling units because of the close proximity of temperature sensors 2TE-313-333, -368, -324, and -359 located in the 6.9KV shutdown board rooms and the presence of an 85 F cutout in the control logic that deenergizes the fans serving the 400V shutdown board rooms on high temperatur I Similar high temperature cutouts exist for the 480 volt board room air handling units, where the setpoint had been changed by ECN 2614 from 85 to 100 F(which corresponds to the maximum range of the temperature switches). The DBVP review l noted that the functional adequacy of this setpoint change had not been i justified by an engineering calculation. The need for such high temperature

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cutouts in all such applications should be reassessed by TVA since the basic i design appears to be subject to common cause failure that could result in the j loss of some ventilation fans at a critical time (Observation 6.19). l The team spent considerable time examining the diesel generator building ventilation fan instrument and control circuits relative to the flow diagram, schematic diagrams, and physical installation drawings. The results of a 1977 preoperational test of the air handling units could not be confirmed because of numerous inconsistencies among these drawings. If a walkdown conclusion regarding labeling of air handling unit flow switches turns out to be true (that the ficw diagram, versus component ID tags, is in error), then this drawing, which is typically the top drawing for a system, will have been in error for over 10 year TVA is considering the performance of specific '

tests to demonstrate that the system does function as intended and also to identify which drawings need to be corrected (Observation 6.17).

During an Appendix R safe shutdown review, ECN-L-6308 was initiated to install a manual bypass switch in the control logic for an auxiliary oil pump pressure permissive in the centrifugal charging pump (CCP) control circuit which would allow the CCP to be started without oil pressure. The unreviewed safety question determination (USQD) stated that the CCP's could be started several times without oil pressure; however, this statement did not have appropriate supporting documentation. The CVCS SYSTER stated that the acceptability cf this change was provided in the SQN-DC-V-27.2 design criteria document. The team reviewed both the July 1986 and January 1987 versions of the design criteria, and could not find such a statement. The implemented hardware does not provide any lights or alarms to augment administrative controls; however, SI-708 does require that the position of the bypass switch be recorded every 28 days. However, no procedure exists to record the number of times that the CCP is started without auxiliary lube oil pressure present (Observation 6.18).

4.4 ZPA LOADS ON SEQUOYAH NUCLEAR PLANT PIPING AND EQUIPMENT TVA's review of the rigorously analyzed piping at Sequoyah Nuclear Plant (SON)

for the effects of zero period acceleration (ZPA) loads stems from TVA's determination that such loads were not assessed at Watts Bar Nuclear Plant (WBN). About five percent of the pipe supports evaluated for ZPA loads at WBN 3 require design changes. Although ZPA loads were also not assessed at .0QN the ZPA design loads at WBN are 1.6 to 1.9 times higher than the ZPA design loads at SQN $.e to the differences in response spectr The team reviewed Report CEB-87-01, Final Review of ZPA Effects on Sequoyah Nuclear Plant Piping, which summarizes the reviews which Impell, Bechtel and TVA conducted to assess the effects of ZPA loads on SQN piping. Impell reviewed the piping stress isometrics for the component cooling water system (CCS), ERCW system, and the EDS isometrics for the pressurizer relief s3 ste Impell also reanalyzed several TVA piping analyses. Bechtel selected five specific configurations to evaluate ZPA loads on equipment nozzles and the support restraints. CEB reviewed 15 piping analyses with piping similar to piping at WBN that had been identified as having significant ZPA loads, and evaluated 6 support configurations. The TVA CEB report 87-01 concluded that ZPA loads do not appear to be an issue at Sequoyah Nuclear Plant, since Impell, ,

Bechtel and CEB evaluated over a hundred " worst-cese" pipe support configura-tions without identifying any hardware inadequacie The team selected i

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several pirkg. analysis for re'iiew to arse'ss thew conclusions. One observation _

identified b 3 the team relating to TVA's evaluador' of nanger bank 1CCH-548 is that TVA is using interim restan crf %r.ia, to gaaHfy tite hanger t)ank, and also-could not provide calculations acriressing pipe lug loads or an evaluation of j associated concrete anchors. The team questidred T(A's use of interim crite-ia to justi'r acequacy of piping system desir,n for ZPA pfscts (Observation 3.15).,  !, {

i OBSE%ATIONS _.,

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,1 Specific t)ingings of individual NRC discipline insper, tors are categorized ar, j r ,

observttio.Q. The observations identified !,y each discipline of the NRC team s are provided bi Appendix A of this report. WA actions relating to individual future inspections on a observations selective basis. willIndividual be reviewed by the NRC observations may durf@be closid based on TVA'r, iesponse to this inspection report as appropriate. These observations elaborate on the general comments statcd in this report and in sgde cases provi.ie additioral comments not considered to be o? a general natur'e. 3 1!

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6.0 RE'!IEW OF PREV,IOUS INSPECTION FINDIf!CS

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Team review of TV,b. responses to the oeficiencies, uniesolved items and obser-vations documenten' ih NRC inspection ,repor::s 86-27, 86-38, 8C-45 and 86-55 is detailedir.A)pendixBtothisrepor I

' ' MEETINdSUMMARIES-REFERENCES ,

A summary of,the meetings held relating to the DBVP inspection and a list af references Mated to the series of design control inspections are provided in ,

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OBSERVATIONS-p .- b- j- p

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yf OACKGROUND

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The Observations identified by the: team during inspection 50-327/87-14 and J

S 50-328/87/14 are described by discipline in'the following section The dy ..

Q{k , report numbsrs used are a continuation of the numbering used for previous NR inspections of'the DBV IM MECHANICAL SYSTEMS b,Q g .q-Otiservation 2.8 - Valve Seat Material Qualification

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During the review of. the SYSTER for S'ystem 31, air conditioning, the inspection

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team observed that ECN L5064 chansMf, the valve seat material for certain

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...< isolation check valves in the system from hard, metallic seats to soft seats tin' order to improve maintainability'and reduce leakag However, the SYSTER and its supporting documentation do not address the envi-ronmental: qualification of this materf ah, which is a non-metallic sealing surface used for containment isolation. The inspection team noted that the

' component cooling water system SYSTER correctly evaluated a similar val.ve material change pursuant to' the same ECN. The System evaluation included an s assessment of material, radiation environment comparison with a similar t

qualified installation at.WBN, and a punch list entry to assure adequate formal documentation. A similar evaluation was not performed for the air conditioning

, system, where the valves and environmental conditions may be differen N 3,0 MECHANICAL COMPONENTS-Observation 3.10~ - Control of Field Sketches .4 1The essential raw cooling water (ERCW) SYSTER review of ECN L-6754 indicates that the ECN authorizes the re-evaluation of 3/8" sampling tubing which pene-

, J [' trates the steel containment vessel (SCV) to ctinfirm that the tubing and

) supports can withstand SCV movement due to a design _ basis accident (DBA).

TVA reevaluated the sampling tubing and associated supports. in calculation c'4 h: #

" Stress. Qualification and Support Loads for 3/8" Tubing Penetrations," dated June 20, 1986 (RIMS no. B41 860620 007). The calculation documents the rigorous A

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analysis ofLfour worst-case tubing / support3configurations which envelope the

"g- geometry detailed on 38 as-built field ske,tches. The team noted that five of

' the as-built field sketches were not sigied by a preparer, and none of the Lfield sketches were signed by a checker.' ,

' Observation 3.11 -

Electrical Board Room Cooler Seismic Qualification Document The ERCW SYSTER review of ECN L-5235 notes, in part, that the 1986 flow verifi-cation test for the electrical board and main control room HVAC equipment documented inadequate flow through the electrical board room coolers. No test a l

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deficiency was issued since the SI-566 test instructions indicated that the i electrical board room and shutdown board room coolers were not safety-relate However, design criteria documents SQN-DC-V-13.9.3 and SQN-DC-V-13.9.6 list the electrical board room and shutdown board room coolers as safety-related equip- .

ment. .In order to verify that TVA purchased and qualified this equipment to '

seismic Class I criteria, the team asked CEB to retrieve the procurement and l seismic qualification documents for the electrical board room and shutdown board room coolers. CEB accessed the procurement documents for the equipment, and these documents confirm that TVA purchased the coolers to seismic Class I criteria. CEB also accessed the seismic qualification documents for the shutdown board room cooler. However, CE8 could not access the seismic qualifi-cation documents for the electrical board room cooler, although CEB was able to provide the team with correspondence to indicate that CEB had reviewed these documents. The team noted that TVA issued a related PIR SQNCEB8705 on January 13, 1987 in response to NRC Potential Enforcement Finding 50-327,328/86-61-01 to address deficiencies in the storage and retrieval of quality assurance records <

for safety-related equipmen Observation 3.12 -

Retrieval of Seismic Qualification Calculations The ERCW SYSTER review of SCR SQNSWP8119R0 indicates that two of eight unmortared solid concrete block shield walls in the auxiliary building would not withstand the postulated flood load and might damage two adjacent ERCW lines. These walls serve as radiation barriers which can be removed to perform periodic maintenance. TVA prepared design criteria SQN-DC-V-1,1.1.1, Evaluation of Unreinforced Masonry Walls Constructed from Solid Concrete Blocks, in response to the hRC's Information Request on Category I Masonry '

Walls (NRC Bulletin 80-11). SCR SQNSWP8119R0 was issued after evaluating the existing walls with respect to the design criteri SQN-DC-V-1.1.1.1 requires, in part, that unmortared block walls be separately evaluated for the effects of flooding and the safe shutdown seismic event. ECN L-5532 authorized the design of of restraints for the two walls which could damage the ERCW piping. The Outstanding Work Items List (0WIL) indicates that the ECN is field complet The restraint design is detailed on TVA drawings 41N370-1, Rev. 4, and 41N370-4, Rev. 2. However, CEB cannot retrieve the calculations which qualify the i restraint design for the two block walls. All eight block walls are currently removed. As noted in Observaticn 3.14, the ERCW SYSTER did not evaluate ECN L-5532, although evaluation of this ECN was in scope for other SYSTER Observation 3.13 -

West Steam Valve Room Main Steam Line Break Evaluation The ventilation system SYSTER review of ECN L-6694 indicates that TVA prepared (

the ECN to initiate modifications to various piping systems to mitigate the l consequences of a main steam line break superheat condition in the main steam l valve vaults. TVA has subsequently concluded that ECN L-6694 can be cancelled, and is documenting the basis for this decision to the NRC. However, the team reviewed the pipe rupture calculations of record for the west main steam valve room, since these calculations would have been the basis for any re-evaluation of the valve room slab and walls if the ECH had been implemented. The team found that TVA did not prepare the pipe rupture calculations for the valve room l walls in accordance with FSAR and design criteria. Sheet 6 of FSAR Table 3.8.4-1, entitled Auxiliary Building West Main Steam Valve Rooms, specifies that main steam line break pressures and su conjunction with dead, live (as applicable)pport loads and safe be evaluated shutdcwn in seismic load A-2

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This load combination is reiterated in section 3.3.2.1 of design criteria SQN-DC-V-1.1, Design of Reinforced Concrete Structures, which TVA issued on May 1, 1970. However, TVA calculation " Auxiliary Building West Valve Room Pipe  !

Rupture," which TVA prepared in 1976 and stored in RIMS on July 16, 1986 (RIMS  !

no. B25 860716 308), does not evaluate the valve room walls for the effects of I main steam line break loads in conjunction with dead and seismic loads. CEB indicated that the pipe rupture loads are the dominant design loads. FSAR Table 3.8.4-1 also specifies allowable concrete stresses of 3000 or 4000 psi for the auxiliary buildin The team found that the calculation specifies a concrete design strength of 3000 psi for the west valve room, but uses a value l of 5000 psi for the pipe rupture evaluation. TVA indicated that a rational basis exists for the use of higher concrete strengths. A related Observation, CEB-11, Pipe Rupture Evaluation for Concrete, was identified in NRC inspection report 50-327/87-06, 50-328/87-0 Observation 3.14 - Evaluation of Masonary Block Walls The chemical and volume control system (CVCS) SYSTER review of ECN L-5537, indicates that the ECN added structural restraints to the unreinforced concrete masonry block walls that enclose the centrifugal charging pumps to enable the walls to withstand a seismic event without damaging the pumps. However, the SYSTER for the ERCW system does not evaluate ECN L-5532 (see Observation 3.12),

which authorizes the addition of structural restraints for two unreinforced unmortared concrete masonry block walls to protect adjacent ERCW lines. The team noted that the DBVP project does not appear to be evaluating unreinforced concrete masonry block walls in proximity to safety-related piping and equip-ment in a consistent manne Observation 3.15 -

Zero Period Acceleration (ZPA) Loads The team reviewed TVA report CEB-87-01, Final Review of ZPA Effects on Sequoyah Nuclear Plant Piping, which TVA issued on January 14, 1987. This report sum-marizes the reviews which Impell, Bechtel and TVA conducted to assess the effects of ZPA loads on piping and equipment at Sequoyah Nuclear Plant. The CEB report concluded that ZPA loads do not appear to be an issue at Sequoyah Nuclear Plant, since Impell, Bechtel and CEB evaluated over a hundred " worst-case" pipe support configurations without identifying any hardware inadequa-cies. The team also reviewed the 47K464-series piping isometric drawings for the component cooling system (CCS) that were used as the basis for piping analyses N2-70-3A and N2-70-14A to 25A, and asked CEB to review two pipe supports (100-599/601 and ICCH-548) with apparent ZPA loads greater than the design seismic inertia loads. CEB has confirmed the design adequacy of support ICCH-599/601.

On April 7, 1987 CEB provided the team with a copy of CAQR SQP870494, which CEB prepared on April 3, 1987 to document CEB's conclusion that the calcula-tions of record for the hanger bank which includes support No. ICCH-548 are not readily retrievable. CEB also provided the team with a preliminary copy of the calculation which reviews the hanger bank for the effects of ZPA load However, CEB did not provide the team with an evaluation of the pipe lugs which transfer the pipe axial load at support No. ICCH-548, or the embedded plates or concrete anchors which transfer the hanger bank piping and cable tray loads to the concrete slab. Moreover, CEB is using interim restart design criteria to evaluate the hanger bank for the effects of ZPA loads. Although the NRC has A-3

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authorized interim restart criteria for alternately analyzed piping and cable tray supports, this hanger bank supports both cable trays and rigorously analyzed pipin NRC acceptance of CEB's conclusion that ZPA loads at Sequoyah have been adequately evaluated remains an open item pending CEB's re-evaluation of the hanger bank for the effects of ZPA loads with respect to the default (post-restart) design criteri .0 NUCLEAR EtlGINEERIl4G Observation No. 4.7 - Classification of Pre-Restart Items TheDBVPpunchlistforSystem30A(ventilation)referstoitem5943whichis based on PIR-SQNEEB8671, Rev. 1. The PIR discussed the need for thermal calculations for cables that have been replaced due to NUREG-0588 concern The punch list item had been downgraded from the pre-restart category to ;

post-restart. The change in classification was based on TVA internal memo

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Kirkebo to Mason dated 12/12/86(801-861211-001). The team does not agree with the downgrading of this item because the concern satisfies the docketed restart criteria for a pre-restart classification. Additionally, the team found that the PIR had been reviewed and a Significant Condition Report (SCR) SQNEEB8793 (B25-870223-048) had been issued. The team was informed that an EA audit had identified several other instances of misapplication of the internal TVA memo in other systems (EA Action Item 83).

A similar problem was found for the DBVP punch list item 6521 (System 30A, ventilation),whichisbasedonPIR-SQNEEB8694. This item concerns indicators to be located in the main control room to show operation of vent fans located in the diesel generator and electrical panel rooms. These fans are required to operate at temperatures in excess of 120 F and an indication is needed to verify functioning of the fans when needed. The punch list item had been downgraded from pre-restart to post-restart. The classification change was also based on the TVA internal memo. The team found that during PIR review a decision was made to upgrade the item. Significant condition report SQfiEEB8728 was issued addressing this item, 5.0 ELECTRICAL POWER Observation 5.9 - Punch List Item Classification The following punch list items which related to SYSTERs for the AP, ventilation and component cooling water systems were classified as post-restart items. The !

team believes this classification is not correct and that these items should be completed before restar (1) Auxiliary Power System:

The DBVP walkdown process at Sequoyah plant has identified mismatches between the equipment's actual tag and the tag description shown on the :

drawings . Correction for safety-related equipment should be completed before restart to prevent introduction of errors and confusion in opera-tion and maintenance of the safety system Examples of mismatches are as follows:

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Punch list item #7774: 480 v ventilation board 2B1-B Compartment #9A, label reads " Vital Battery Room IV room fan"; the correct descript3on is

" Vital Battery Room III room fan."

Punch list item #8029: 480 v Ventilation Board 1B2-B Compartment #9D2 label reads "480 v Board Room Duct Heater"; the correct label is "480 v Board Room IB Duct Heater."

Punch list item #7785; 480 v Shutdown Board 2Al-A, Compartment #3B label reads "CRDM Cooler Fan 2Al-A"; the correct label is "CRDM Cooler Fan 2A" Punch list item #7764; Diesel Generator Board 2B-B, Compartment #3B label plate is blank; the correct label is DG 2B-B 480 v Elec. Heater" Punch list item #7786; 480V Shutdown Board 2Al-A, Compartment #3C label reads " Reactor Lower Compartment Fan CLR 2Al-A"; the correct label is

" Reactor Lower Compartment CLR Fan 2A."

(2) Ventilation System (30);

ECN-2945 changed the motors (from 1/3 to 1/2 HP) and the fan blade wheels for the DC and AC exhaust fans of the turbine driven auxiliary feedwater pump (TDAFWP) room. These fans are required to be operable to support proper operation of the TDAFW pumps. Adequate post modification testing of this modification was not performe Punch list items #5637 and #5639 generated for this testing were classified as post-restart items. The team believes that since continuous operation of TDAFW pump depends on operation of these fans, post modification testing to demonstrate that these fans can supply the required air flow under design conditions should be performed before restart of the plan ECN-L5370 replaced motors for the engineered safety features coolers for ;

EQ purposes. The DBVP noted that the feeder cables have not been analyzed for thermal requirements. PIR-SQN-EEB-8671R1 was generated, which resulted in a punch list item #5942. The team noted, during review of the punch list, that this item was classified as a post restart item rince it was a result of a PIR. TVA informed the team that improper categorization of PIR related punch list items had occurred due to misinterpretation of an internal DNE memo. Furthermore, the EA group had already identified ,

this issue (EA action item #83). The DBVP project stated that they will l revisit all punch list items which were related to PIRs and evaluate the restart category of each item on a case-by-case basi Punch list item #6723 identifies that the calculation (AB-30-14) for minimum air flow of the turbine driven auxiliary feedwater pump room (TDAFWP) ventilation fan should be revised to address verification of all unverified assumptions. This item was found to be classified as a post-restart item. The team believes that this should be accomplished before restart because the results of this calculation have been used for l post modification testing of this fan to justify adequacy of a supporting feature for the TDAFW syste ,

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(3) Component Cooling System (70)

ECN-L5591 changed the wiring of Westinghouse type W2 switches to monitor the neutral position contact. This modification was bench tested (per work plan 10114); however, the switch was not tested followirg installa-tion. Thus, the possibility of switch pin damage during installation may not be noticed. The team considers that testing with the installed switch should be performed before restart. Punch list item 3858 identified this concern and determined that the classification of this item is post-restar ECN-L5731 authorized removal of space heaters from the limit switch compartment for some motor operated valves. This modification disturbed the control wiring; however, some valves, such as RHR heat exchanger A inlet valve 2 FCV-70-2 and CCS heat exchanger B inlet valve 2 FCV-70-16, were not tested to demonstrate that these valves still perform their intended design function. The team considers that such testing should be completed before restart since the valves involved are components of safety systems. Punch list item 3797 identified the lack of testing, however shows this item was determined to be a " post-restart" ite ECN-L6783 replaced a 10 ft-lb torque motor with a 15 ft-lb torque motor for containment isolation valve 2-FCV-70-87. Punch list item #5315 was generated to verify the effects of this change on applicable electrical attributes such as voltage drop, feeder protection requirements, cable thermal requirements, etc., in accordance with the guidelines of the SQEP-12 (ECN review) checklis The team noted that this item has been classified as a post-restart item. The team considers that this analysis !

should be performed before restart because performance of this safety-related load is governed by these attribute '

Observation 5.10 - Design Verification of Drawing Changes The walkdowns identified many cases where the ratir.gs and/or settings of the installed equipment was found to be different than the values shown on applica-ble design drawings. The equipment involved included fuses, breakers, trans-formers, contactors, and relays. The team noted that a drawing deviation process (which only revised the drawing, considering the as-constructed condition to be correct) was used to resolve the differences. Engineering review (such as verification of values from the applicable calculations or specifications) was not performed to verify whether the as-constructed condition was as assume The team believes that a change in the data on the drawings may not adequately resolve the problem. TVA should verify the design, using applicable calcula-tions, such as the short circuit, loading, and coordination studies. The team reviewed four punch list items (6583, 6630, 6631 and 6664) which were completed, and found that the design had not been verified; only drawings were revise The team believes that lack of design verification may lead to situations where underrated and/or uncoordinated equipment may remain installed. This could l compromise the design function of safety systems. Punch list items reviewed by !

the team in assessing this observation were Nos. 6380, 6473, 6474, 6492, 6517, <

6536, 6537, 6549, 6550, 6552, 6555, 6557, 6558, 6559, 6562, 6564, 6565, 6566, l

6583, 6587, 6615, 6616, 6630 and 663 !

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.l Observation 5.11 - SYSTER Consistency f The following inconsistencies and errors were noted in SYSTER packages for the auxiliary power (AP) and . component cooling water system '(1) Errors ECN-5298(AP),SQEP-12, Attachment 2,designreviewchecklistcolumns5(a)

and 5(e) were incorrectly marked as irrelevant to this ECN (Note -8 of Attachment A). These checks are used for verification of electrical attributes, which include a determination of compliance with voltage drop and cable thermal requirements, respectively. Since this ECN re-routes the cables, attributes of these columns should have been verified from the applicable calculations (Ref: page 4-34 of the AP SYSTER).

ECN-6310 modified the electrical interlocking between the breakers of redundant train power feeders to component cooling water pump C-S. The USQD for this modification determined that since proper administrative procedures are in place, the two redundant power trains will not be paralleled due to a single failure. The team was also concerned with the personal safety aspects associated with removal of the electrical ;

interlocks, with the increased possibility of-operating the transfer switch under load. The modification removes the breaker electrical interlock,' leaving a mechanical interlock the only defense against improper paralleling. The team reviewed the installation of the modifica-tion and additionally noted that no administrative procedure exists which controls the operation of the transfer switch. The team also found that '

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this switch has a provision for locking by a padlock, which could prevent the unauthorized' operation of this switch. The team was informed by the ;

plant operators that although the' switch has provisions for locking, in the absence of an administrative procedure requiring locking, the locking provision is not use (2) Inconsistencies The restart categorization for punch list items 7797 and 8518 which resulted from a single PIR (SQN-EEB-86182) describing the same deficiency in Design Criteria DC-11.4.1, were different. Item 8518 is classified as a post re-start item and item 7797 is shown as a pre-restart item. For punch list items 8220 and 8221, the restart category shown on the punch list is post-restart, whereas that shown on the justification sheet for ECN-5591 appended to the SYSTER package.is pre-restar Table 2.1 of the SYSTER (pages 11 and'12), shows the status of the ,

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ECN-L5050 as partially implemented, but the justification sheet for this ECN (page 3-6) shows this ECN as fully implemented at restar .0 INSTRUMENTATION AND CONTROLS Observation 6.16 - HVAC Flow Switch Calibration Data Records and System 30 Surveillance Instruction Procedures l

ECN-L-5443, which provided environmentally qualified flow switches for the I

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emergency gas treatment room coolers, was described as being complete in the A-7

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-system 30 (ventilation) SYSTER. Punch list item 6962 requested calibration records for the 2-FS-30-200 and 2-FS-30-207 flow switches that had been missing from the installation work pla The DBVP electrical group reviewed and accepted the supplied instrument calibration data in mid-January 1987. The team reviewed this data with both DBVP and instrument craft personnel noting the following items:

(1) The vendor data included in the package was incorrect since the curves did not represent the sensor serial numbers listed on the calibration cards (291-1 instead of 292-1 for 2-FS-30-200 and 293-1 instead of 294-1 for 2-FS-30-207);

(2) Data initially supplied to Watts Bar for these sensors, which were subsequently transferred to Sequoyah, was used in the calibration data package rather than Sequoyah unique data. This approach introduced unnecessary confusion and complexity for DBVP and the team; (3) An extraneous and inapplicable copy of a calibration card for 2-FS-30-200 1 was included in the package for data taken on November 21, 1986, and

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(4) A circuit board serial number (889-1) was identified on the calibration card for 2-FS-30-200 rather than the correct sensor serial number (292-1).

The team did determine that sufficient data was included in the calibration data package (through cross-referencing of various identification numbers) to confirm that the desired setpoint values had been achieved for the installed flow switche The team subsequently reviewed the periodic calibration test procedure (SI-195)

for the model 12-64-3 Fluid Components flow switch used in HVAC systems 30 and 31, and emergency gas treatment system 65. No provisions were included in the surveillance instruction for calibration and testing of the flow switches used in system 30 (ventilation), and no sensor calibration records exist for these safety-related sensors over the 1982-1985 perio Since completion of the HVAC system 30 preoperational test, no system level surveillance instruction has been in place to test the various control logic interlocks developed by these sensor Observation 6.17 - Diesel Generator Building Ventilation Fans Control Logic and Surveillance Instruction Procedure DBVP walkdown of the diesel generator building ventilation fans and associated instrumentation disclosed that each installed flow switch was reversed relative to the configuration shown on flow diagram 47W866-9. Measurement of low flow from one fan is supposed to automatically actuate the backup ventilation fan for each diesel generator roo Punch list items 2164 and 2165 identified that 2-FS-30-452 and 2-FS-30-448 were reversed for the diesel generator 2A-A room and 2-FS-30-454 and 2-FS-300-450 were reversed for the diesel generator 28-B room. The walkdown team concluded, apparently based upon the flow switches physical location in the exhaust duct of the same numbered fan, that instrument tags were correctly placed and that the design flow diagram was in error. If this is true, this diagram has been incorrect for the past 10 A-8

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i years. The team was unable to confirm the validity of the walkdown team j conclusion from its own detailed review of mechanical, electrical, and physical ;

installation drawing j l

The team reviewed the flow diagram, control logic diagram, ventilation fan l schematic diagram, wiring connection diagram, mechanical arrangement drawing, and conduit routing drawing for the ventilation fans and discharge flow switches. Previous revisions of the flow diagram and control logic diagram l were examined for the 1976-1986 period to confirm that the design intent had not changed over this period. Pre-operational test data taken in 1977 indicated that the automatic switchover between ventilation fans had been implemented; however, the particular test method used contacts in the switchgear to simulate the low flow condition, and therefore was not sufficient to confirm that failure of one fan would automatically initiate the backup fan. A system level test is under consideration to confirm the operational functions of this .

syste l The team did confirm that the flow switches were subject to periodic calibra-tion, but noted that no testing instruction existed to confirm the actuation of the ventilation fans when the diesel generators are started or to confirm the automatic switchover interlock between the fans when a low flow condition is presen !

The team was informed that the control room flow diagram had been marked-up to reflect the conclusion reached by the walkdown team in accordance with instruc-tion AI-25, and that DNE was processing an FCR and ECN to change the flow diagram. During the inspection, the control room drawing was changed again to eliminate the walkdown team observatio At this time, the team has confirmed the following facts:

(1) Some design drawings are inconsistent with one another, such as the flow diagram, the mechanical arrangement drawing, and the conduit physical !

installation drawing; (2) The pre-operational test results cannot be confirmed through a detailed review of the design drawings; (3) There is no surveillance test instruction that addresses the starting of ,

the ventilation fans or their automatic switchover based on low flow j measurements. Demonstration of diesel generator operability in accordance !

with Technical Specification 4.8.1.1.2 does not explicitly mention the operability of the ventilation fans; however, the operability definition '

in the Technical Specifications does identify the need to assure that auxiliary equipment required for system functional performance is q available for service, and (4) A reverse image (opposite hand) note regarding installation details for fan discharge pressure switches on drawing 45N832-9 is not correct for rooms 2A-A and 2B-B.

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Additional field inspection data is required to resolve the present installa-

[ tion configuration relative to the design intent. This data should permit a determination to be made regarding the tagging of individual instruments, the A-9 1- 1

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correctness of individual drawings, and the operational effectiveness of the automatic switchover between the redundant fan Observation 6.18 - Centrifugal Charging Pump Auxiliary Oil Pump Low Flow Bypass Switch The auxiliary oil lubrication pump which provides initial lubrication to the centrifugal charging pump (CCP), is not safety-related or seismically qualified. An auxiliary lube oil low pressure switch provided an interlock to prevent manual actuation of the CCP. During an Appendix R fire protection review, it was determined that the CCP should be capable of manual actuation even if the auxiliary lube oil pressure was low. To overcome the existing low oil pressure interlock, ECN-L-6308 was initiated to provide a manual bypass switch in the control logi The USQD determination for this ECN contained a statement that Westinghouse had determined that the charging pump could be started several times without oil pressure. Under accident conditions, the CCP will be started with or without auxiliary lube oil pressure; however, the number of manual actuations of the CCP will be much greater than the number of SI signal actuations. Given the greater probability of CCP actuation without auxiliary lube oil pressure (because of the probability of the bypass being present) and the greater risk of CCP damage that would result, the team was concerned, however was unable to find any documentation that would substantiate the USQD statemen The CVCS SYSTER discussed the acceptability of ECN-L-6308 by stating that

" design criteria SQN-DC-V-27.2 documents that the CCP is capable of starting several times without oil pressure." Neither revision 0 (7/86) nor revision 1 (1/87) of this design criteria document provided such a statement. During the inspection, the team discussed this feature with the (Westinghouse) system engineers. Westinghouse appeared unwilling to document this claim, and has contacted the pump vendor to determine how many starts should be permitted without oil pressure being present at the CCP bearing In the SQEP-12 review of this ECN, the mechanical group did not identify any concern with the number of permitted manual pump starts without auxiliary lube oil pressure. Note 1 of the mechanical SQEP-12 review stated that ECN-L-6308 did not impact mechanical design and hydraulic design criteria. The electri-cal group's SQEP-12 review of this ECN stated that adding the bypass switch did not degrade the function or operability of the CCP's. In the team's opinion, neither of these SQEP-12 reviews by the mechanical and electrical groups was adequat The bypass switch is mounted on a CCP switchgear panel, but does not have any of the following provisions that could improve the effectiveness of administra-tive controls:

(1) Switch indication lights, locally or in the main control room; A bypass alarm light, locally or in the main control room; An annunciator in the main control room, or A local keylock for the bypass switc A-10

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Separately, the team reviewed existing Sequoyah administrative control proce-dures for this bypass switch. Procedure S01-62.1B,Section V, Precautions, step V requires that the auxiliary oil pump bypass switches be checked in their

" normal" position. TVA identified that SI-708 for Appendix R surveillances requires that the position of the bypass switch be recorded every 28 day However, there are no TVA procedures that would keep track of the number of CCP starts actually made without auxiliary lube oil pressure. The team does not agree that the present design is adequate to protect the CCP's from inadvertent damage, or to track the accumulated effects of starts during low oil pressure condition Observation 6.19 - 480 Volt Board Room Air Handling Unit Control Logic Each safety-related 480 volt board room is cooled by one 100 percent capacity air handling unit as shown on drawing 47W866-3. One temperature sensor is mounted on the wall of each 480 volt board room (2-TE-313-483 and 2-TE-313508, respectively), and controls the operation of two temperature switches in the fan control circuit. In the normal " process-auto-start" mode of operation, the air handling unit is actuated by one temperature switch at a 75 F rising setpoint, and is subsequently stopped by a second temperature switch when the temperature reaches 100 F or the temperature returns below 75 F. Similar temperature controls exist for each 6.9KV shutdown board room (2-TE-313-333,

-368,-324,-359), except that this high temperature fan cutout setpoint remains at its original 85 F design valu In 1979, ECN 2614 was initiated to change the high temperature setpoint for the 460 volt board rooms from its original 85 F value to the present value of 100 F. This setpoint change, which coincided with the maximum range of the temperature switch, was initiated when plant operating conditions prevented manual restart of the air handling unit after it had ceased to operate due to the actuation of the high temperature cutoff when the temperature of the space exceeded the 85 F set point. Punch list items 5293, 5318, and 5356 tracked this and other system 31 air handling unit control logic change Assuming that the high temperature limit is reached for an operating air handling unit (e.g. AHU 2A-A for train A safety-related equipment), the mechanical DBVP summary report took credit for the redundant standby air handling unit being available (e.g. AHU 28-B for train B safety-related equipment), and stated that no common mode failure existed that could cause both air handling units to fail at the same tim It should be noted that the SQEP-12 review of ECN 2614 stated that the acceptability of the revised high temperature setpoint (i.e., 100 F) had not been justified by a calculatio .

With respect to the cooling system for the 480 volt shutdown board rooms, the team identified that sensors 2-TE-313-333 and -368 were in close proximity on the wall of the 6.9KV shutdown board rooms. A high temperature condition at :

this location could concurrently disable the cooling for all of the Unit 2 480 l volt shutdown boards in rocms 2A1, EA2, 2B1, and 2B2, which are cooled by the redundant train A and B 6.9 KV shutdown board room coolers. TVA indicated subsequent to the inspection that this common caused failure may not be feasible because of standby features on the fans, depending on the positioning of hand switches. Consequently, the team questioned the DBVP position regarding no consen failure modes for safety-related ventilation equipment systems. (More redundancy exists for the 6.9 KV equipment in that some Unit 2 A-11

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' equipment is cooled by Unit 1 HVAC, and vice versa). -The team believes that essential air handling units could be rendered inoperable by unanticipated high temperature conditions in the 6.9KV shutdown board rooms. The high temperature cutout provision in the ventilation fan circuits appears to be a questionable design that'is subject to a common caused failur The mechanical DBVP sunmary report recommended that the high temperature control logic (for the 480v board room air handling units) be converted to provide an operating alarm. This recommendation would also eliminate the shutdown of each air handling unit based on high temperature. This recommended !

change was not identified in the Air Conditioning SYSTER, nor had it been j developed into a DBVP punch list item. The team believes that the various high 1 temperature interlocks should be thoroughly justified prior to restart to assure continued availability of the air handling unit Observation 6.20 - Preliminary DBVP Report _

The DBVP effort is currently summarized by TVA in a preliminary report issued on March 5, 1987. This report was reviewed by the inspection team. Several specific problems were noted by the team with the preliminary DBVP report:

(1) One of the four DBVP objectives was to assure that partially implemented, '

fully implemented, and unimplemented modifications did r.ot degrade a system to the point where it would be prevented from performing its safety functions. In several instances noted by the team, these evaluations were made from such a narrow perspective that an identification of interdis-ciplinary technical problems was not reached. An example of an incorrect evaluation is provided by the HVAC fan temperature cutout which was stated to be an acceptable design feature in the repor (2) The declaration that groups of 3 to 41 similar items identified by bBVP l represented " random" occurrences does not appear to be supported by data !

provided in the report. For example, page H2-5 listed missing qualification I data for Class IE motors, isolators, and relays that were stated to be an )

isolated situation. Pages H2-11 and H2-12 identified the need for i

additional test data covering 41 modifications and retest of 17 other l items for system operability. These items were identified as being random occurrences. A very large number of mechanical equipment condi-tions were listed on page H3-23, and were identified as random occurrence The team does not agree that such items represent either random or even isolated situation A-12

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APPENDIX B LICENSEE ACTION FOR PREVIOUS INSPECTION FINDINGS i

l The team reviewed the corrective actions taken by TVA to resolve the open deficiencies and observations identified in NRC inspection reports 50-327 and 50-328/86-27, 86-38, 86-45 and 86-55. Correspondence associated with these findings, including TVA responses, are tabulated in Attachment C. The fol-lowing are the team's comments on these item REPORT N0. 86-27 (Closed) Deficiency D3.1-1 -

Exhauster Installation Deficiency D3.1-1 indicated that TVA could not obtain the seismic qualification j documents for eight quick exhauster installations. NRC report no /86-55 and 50-328/86-55 summarizes TVA's actions to address this defi-ciency, which included documenting the adequacy of the exhausters, sampling additional installations and procedure revision The team reviewed TVA calculation " Component Analysis Resolution of Gilbert Audit Item #4," Revision 1, which TVA issued on May 17, 1986 (RIMS no. 841 860517 001), TVA calculation

"SQN Qualification of Control Air Tubing Supported from LCV's," which TVA ,

issued on March 25,1986(RIMSno.B41860325014), and TVA calculation

" Component Seismic Qualification Audit of Past Design Changes at Sequoyah,"

which TVA issued on June 16, 1986 (RIMS no. B41 860616 003). No problems were identified during these reviews and the particular exhausters are now considered qualified, therefore this deficiency is close (Closed) Deficiency D3.2-2 -

USQD Requirement Deficiency D3.2-2 detailed TVA's inability to retrieve seismic qualification documents for two existing valves with added extension operators and cover NRC report nos. 50-327/86-55 and 50-328/86-55 summarizes TVA's actions to address this deficiency. These included revision of interface documents, the ,

piping analysis handbook, and change control procedures to reverify the l validity of a USQD at ECN closure. The team reviewed Revision 1 to TVA '

calculation " Seismic Qualification of Remote Valve Operator Systems and Safety Related Valves (SCRSQNCEB8621)," which TVA issued on November 19, 1986 (RIMS J no. B41 861119 001). No problems were identified during this review. TVA's decision to evaluate the alternately analyzed piping and supports for the added mass of the extended valve operators after restart, as noted in Revision I to the engineering report for the SCR, has been submitted to NRC. Deficiency ,

D3.2-2 is closed for the purpose of the design inspectio l (Closed) Deficiency 03.2-3 -

Piping Flow Diagram Deficiency D3.2-3 identified a TVA piping flow diagram with a missing class boundary break. The team reviewed Revision 13 to engineering change notice (ECN) L-6784 (RIMS no. B25 870123 564). TVA issued Revision 0 of the ECN on August 25, 1986 to tabulate the system flow diagrams and piping physical drawings which required class boundary break clarifications or correction The team also reviewed 12 of the drawings identified on the ECN to confirm the B-1

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.i incorporation of ECN L-6784 on the drawings. Deficiency D3.2-3 is closed because the TVA review revealed that this was only a documentation item, and the applicable drawings have been revise '

(0 pen) Deficiency D3.3-1 -

Pipe Support Friction Design Deficiency D3.3-1 indicated that TVA had not considered friction forces for '

pipe support design. NRC report nos. 50-327/86-55 and 50-328/86-55 summarizes TVA's actions to address this deficiency. TVA is evaluating a sample of SQN ,

support designs in critical piping systems to determine the effects of friction !

loads. TVA will complete this evaluation by the end of cycle 4 operatio Deficiency D3.3-1 remains open pending completion of TVA's evaluatio t i

(Closed) Deficiency 4.3-1 - Evaluation of Structures for Reinforcing Bar Cuts The initial NRC inspection identified two cases where reinforcing bar cuts were not evaluated to determine structural adequacy. TVA, in response to this finding, has performed analyses to show that the structures with the reinforcing bar cuts are still adequate to carry the loads imposed on the The NRC team reviewed the following calculations and found the results 3 acceptabl SCG-1S31 10 - Rebar Cuts for Sleeve Placement in Reactor Bldg. Pressurizer Enclosure, Rev SCG-1S31 18 - Diesel Generator Building Rebar Cut Evaluation, Rev On a generic basis, TVA has initiated a corrective action program for rein-forcing bar cut control, as described in TVA memorandum from D.W. Wilson to R.C. Denny (RIMS No. B25 870115 001). The NRC team reviewed this corrective action plan which includes pre- and post-restart evaluations of various structures. The pre-restart portion of this program has already been completed ,

by TVA. The team reviewed samples of evaluations performed for this portion, '

as well as the complete progra The team concludes that TVA has an adequate program to address the generic aspects of reinforcing bar cuts and that the pre-restart portion has been adequately implemented. Therefore, this defi-ciency is close (0 pen) Deficiency D4.3-3 - Steam Generator Access Platform Design The initial NRC inspection identified that the steam generator lower supports were not evaluated for permanently attached platform loads added by an EC During the walkdown of these supports, TVA identified additional pipe supports that were attached to these steam generator supports which were not accounted for in the desig Westinghouse recently completed a reevaluation of the lower steam generator i supports using the walkdown information supplied by TVA. This reevaulation showed that these supports are structurally adequate to carry the additional loads. The results of this analysis are contained in a Westinghouse letter from L.L. Williams to R.C. Weir, dated 12/11/86 (RIMS No. B45 861219 601).

Although the effort by Westinghouse is complete, TVA is still performing evaluations to determine the structural adequacy of the lower steam generator B-2

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support attachments to concrete. This deficiency remains open pending i satisfactory completion of TVA's evaluatio (Closed) Deficiency 5.3-1 - Temporary Alterations using TACFs 1 This deficiency was related to the programmatic control of temporary modifica-tions. To resolve this issue, TVA has issued procedure SQEP-44, which de-scribes the method for controlling and handling of non-engineered temporary changes through Temporary Alteration Control Forms (TACFS) and Temporary Shielding Request Forms (TSRFs). The NRC team reviewed this procedure and found that it acceptably addresses the concerns identified in the previous inspection reports; therefore, this item is considered close ,

(Closed) Unresolved Item U5.3-3 - Motor Operated Valve (MOV) Thermal Overload Trip This item related to the verification of the trip settings of NOV thermal overicads to assure that premature tripping will not occur during accident l

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condition During review of SQN calculations at Knoxville (Inspection report 87-06), the NRC team reviewed calculation APS-003. This calculation was performed to evaluate heater sizing of thermal overloads for safety-related motor operated valve In this calculation, TVA has verified that the selected overload does not trip for 200 percent of the normal stroke time of the valve. This envelopes the longest travel time during degraded voltage conditions. As an !

example of the worst case, the team reviewed valve FCV-72-39, which in the degraded voltage condition has 79.3 percent of normal terminal voltage conditions. The team found that under these conditions, the valve stroke time increases to 150 percent, which is less than 200 percent. The team considers that TVA's use of 200 percent stroke time for avoiding premature tripping is a ,

conservative approach and therefore considers this item close l REPORT N0. 86-38 I

(0 pen) Observation 1.3 - System Interfaces on Drawings  !

This observation concerned the information related to "out of function" portions i depicted on system flow (mechanical and controls) diagrams. During system 1 walkdowns performed by TVA, the team noted that some "out of function" informa- l tion was not marked properly or treated in a consistent fashion. A similar !

situation was also noted in Observation 7.1 of NRC inspection report 86-3 ) l The TVA response to this observation, enclosed in a letter to the NRC dated February 27, 1987, states that "out of function" information on drawings will j be limited to the first "out of function" valve in-line. Although TVA intends j to delete most "out of function" information on future drawing revisions, their !

supplemental response to this item addresses significant enhancement of selected {

drawings provided such information is retained. In such cases, TVA will verify i the accuracy of the information on the drawing. This is considered an adequate ;

solution to the "out of function" issue; however, the following NRC questions !

relating to implementation of corrective actions remain: l What is the schedule of completion for revising the drawings to include correct information to the first in-line valve? j t

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I Which drawings will be included in this effort? I

) What controls are to be in place from now to the completion cf the corrective action effort?

This observation remains open pending satisfactory resolution of the questions identified abov I

'(Closed) Observation 5.1 - Walkdown scop This observation was related to a team concern regarding the incomplete a walkdown scope in the electrical and I&C areas. In response to this concern, the team was informed that electrical and I&C attributes were verified through various,other methods as described below and documented in a TVA letter (Gridley to Taylor) dated February 3, 198 Electrical terminations; Electrical terminations were reviewed by either o one or a. combination of the following methods; walkdowns, review of work plans, and review of the post modification testing.

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Cables; Cables were reviewed under the broad review of electrical e !

ment, including cables, under the Environmental Qualification (EQ) quip- !

progra Cables not covered by the EQ program were checked for quality level in accordance with the general procurement specifications. TVA is conducting an ampacity study to verify the adequacy of design attributes, such as basic ampacity and various applicable de-rating factors, for all

. safety-re' lated cable Cable trays; Civil Engineering branch is engaged in a program to verify the adequacy of cable tray supports. This program includes walkdown and calculation review, Junction Boxes; TVA reviewed junction boxes during the EQ program walkdown to ensure that the wiring, terminations and the physical barriers are well protected, such that the circuit remains intact during a design basis even Fuses; TVA has implemented a fuse verification program, involving review of the fuses to ensure that the proper size fuse was installed to achieve adequate circuit protectio Separation Criteria; This attribute has been verified by review of the

.workplans and as constructed drawings for modification Instrument Sensing Lines / taps / and root valves connections; Licensee actions relating to this aspect are addressed in Observation 6.3 belo The team believes that the above described actions undertaken by TVA should verify adequacy of the above attributes and completes the walkdown scope in the electrical and ISC areas. This observation is considered close B-4

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(Closed) Observation E.4 - Design Criteria This observation related to lack of an independent verification of the list of consnitment/ requirements (C/Rs) which Impell compile To resolve this issue, TVA's EA group reviewed approximately 325 documents out l

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of the 1600 (Impell's documents review consistedwhich weredocunients of 30,000 classified .by)Impell asthat EA noted notImpell applicable missed !

one document which should have generated a C/R. Upon ioentification of this i fact to the project, the project reviewed all 1600 documents and found 16 more i

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documents which contained C/Rs. The NRC team reviewed results of the EA and project reviews and concurs with the actions taken by TVA to resolve this issu Since all the documents which were classified by Impell as not applicable were re-reviewed by the project, the team's concern of missing C/Rs (by errors in Impell's work) no longer exists; therefore, this item can be considered close l (0 pen) Observation 6.3 - Instrument Sensing Line Walkdown i

This observation is closely coupled with Observation 5.1. The team reviewed a draft instrument line walkdown report. To resolve this issue, the DBVP I&C group has performed a supplemental walkdown to verify correctness of instrument tap connections, sensor lines and root valves. Over 200 instruments were inspected by DBVP in the walkdown, and two sense line differences not affecting system functionality were noted in the ventilation system area. Based on these results, the team recommended that all ventilation systems (30, 30A, 31, 31A, and 65) be walked down for the correctness of instrument sense line connec-tions. The team remains concerned regarding the accuracy, and potential consequences, of inaccurate information relating to instrument sensing lines for HVAC systems. This item remains open pending TVA evaluation of this Concer REPORT N0. 86-45 (0 pen) Observation Pipe Support Design Criteria Observation 3.4 noted that two design requirements specified in a Watts Bar procedure used to design and modify pipe supports at SQN were not included in the SON design criteria which TVA issued on June 23, 1986. The WBN design criteria has been revised through the years, and now contain requirements for design of stiff pipe clamps. NRC report nos. 50-327/86-55 and 50-328/86-55 notes that TVA's initial response to this observation was inadequate. TVA's revised response to item 1 of Observation 3.4 is still considered inadequate, as discussed below. TVA indicates that stiff pipe clamps are specifically addressed in section 2.2 of General Construction Specification G-43, Support and Installation of Piping Systems in Category I Structures. Section 2.2.1 of the specification notes that the torque values detailed on the support design drawings are to be used instead of the manufacturer's recommended torque values for certain vendor-supplied stiff pipe clamps. However, TVA revised the specification to incorporate this criterion on December 17, 1984. The team's concern is that TVA did not provide an estimate of the number or adequacy of j stiff pipe clamps installed at Sequoyah Nuclear Plant which may not have been j installed using provisions similar to those in the revised specificatio B-5

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l Also, TVA also did not indicate that these clamps were evaluated with respect to NRC Information Notice 83-80, which relates to pipe clamp TVA's revised response to item 2 of Observation 3.4 is also considered inade-quate. TVA indicates that Mechanical Design Standard DS-MS.2.6, Sleeves-Sizing, Sealing and Anchoring, specifies the design of load-carrying sleeves set in concrete walls or floors. However, TVA issued the standard on October 23, 1983. TVA should confirm that the load capacities of pipe sleeves installed at SQN prior to the issuance of the standard are adequat (Closed) Observation 5.5 - Commitment / Requirement Inclusion in Design Criteria !

for Auxiliary Power System

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This observation was related to the omission of some C/Rs from the design criteri TVA reviewed the missing C/Rs and concluded that C/Rs SQNEEBDRW 1077 and 1092 should be addressed in design guide documents. The design guide document will be issued by September 1,1987. In addition, C/Rs SQNEEBDRW 1017,1018, and 1019 should be addressed in the 125V vital power system design criteri TVA has revised design criteria SQN-DC-V-11.6 to include these C/Rs in a future revision of the applicable design documents. This is acceptable to the inspection team and therefore this item can be considered close (Closed) Observation 6.5 - EQ Requirements for Spare Parts During the team's review of design criteria documents, inconsistent wording was noted for EQ requirements for components and replacement parts. This observa-tion was reinspected in report 86-55. This item was closed on the basis of revised wording in a Design Input Memo which will change the text in the applicable design criteria documen (Closed) Observation 6.7 - Oil-Free Compressed Air Requirement The team identified a commitment regarding oil-free compressed air which was not incorporated in the design criteria. This item was reinspected during report 86-55 and left open pending incorporation of an appropriate change. The team closed this item based on revised wording in a Design Input Memorandum (SQN-DC-V-32.0-001) that will change the text in the design criteria documen (Closed) Observation 7.2 - C/Rs Related to Drilled in Anchors During the NRC review of commitments / requirements (C/Rs) data base items, it was determined that TVA did not evaluate those C/Rs that were related to drilled in anchors for inclusion into the design criteria prior to restar In response to this observation, TVA issued General Civil Design Criteria SQN-DC-V-1.0 on 12/5/86 to adequately document the capture of all restart C/Rs, including those relating to drilled in anchors. This design criteria identi-fies whether or not a C/R is a restart item and references a document where it is already considered for design. This action by TVA is acceptabl (Closed) Observation 7.3 - Revision of Design Criteria for Restart TVA commitment SQNCEB-CG 1170 stated that attachments to the reinforced masonry walls be made using through wall bolts, only. The TVA evaluation, which was B-6

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reviewed at the initial NRC inspection, showed that design criteria SQN-DC-V-1.1.1-had to be revised to capture this commitment. At the time of the inspection, TVA did r.ot have any plans for revising this particular design criteri In response to this observation, TVA revised the C/R such that a requirement to use only through wall bolts for masonry walls does not exist anymore (RIMS N B41 860806 256). Therefore, there is no need to revise the above mentioned design criteria. The team assessed TVA's decision regarding this C/R. There is no regulatory requirement or prescriptive technical reason to uniquely require the use of through wall bolts in masonary walls. Also, TVA has issued General Civil Design Criteria SQN-DC-V-1.0 to document where all C/Rs are captured. This response by TVA is acceptable to the NRC staff. This item.is close REPORT 86-55-(Closed) Observation 2.4 - Design Criteria vs. FSAR CCS Heat loads The inspection team found heat loads listed in the CCS design criteria are considerably less than those listed in FSAR Chapter 9.2. .TVA will include revised CCS and ERCW flow rates and heat loads in the 1988 FSAR Update. This item is closed (Closed) Observation'2.5 - Reactor Coolant System Design Criteria vs. Technical Specification (Four Loop Operation)

The team noted that Design Criteria SQN-DC-V-27.4 indicates that the plant can be operated with a minimum of two loops, while the Technical Specification states that all four loops are required for startup and operation. TVA will revise Design Criteria SQN-DC-V-27.4. This item is close (0 pen) Observation 2.6 - Flow Rate Assumption Used in Calculation Observation 2.6 noted that calculation SQN-60-0053 used the recommended vendor pump head curve and runout condition to calculate design pressure of the refueling water return line to the storage tank and observed that a system resistance curve or other justification should be the basis for the runout flow used in the calculation of design pressure. A revised calculation, given to the team during the recent inspection period, calculates the system resistance curve. However, it is based on administrative procedure to throttle the return valve to 75 percent closed in order to limit flow to within the original assumption and to limit calculated design' pressure. This feature provides approximately one-half of the piping system resistance used in the analysi The team considers that use of an administrative procedure is an inappropriate basis for design pressure. The observation remains ope (Closed) Observation Vent Condenser Heat Exchanger Flange Installations Observation 3.5 noted that TVA had used an apparent mirror image isometric to qualify a piping design modification that installed flances in the component cooling water 2" inlet and outlet lines and 3/4" relief line of the vent condenser heat exchanger for SQN Unit 2 boric acid evaporator package "B." In addition, thermal effects were omitted due to a coding error. TVA has revised the analysis isometric and reanalyzed the piping configuration to address B-7

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thermal load's. Revision 1 of the piping analysis documents a reduction in the magnitude of the upset thermal loads from 200 F to 120 F. Observation 3.5 is

closed, based on TVA's correction of the isemetric drawing and incorporation of thermal load (Closed) Observation Primary Containment Leak Rate Test Lines Observation 3.6 noted that TVA had unconservatively analyzed two 3/4" test lines with manually locked containment isolation valves which enable integrated leak rate testing of primary containment. TVA has revised the calculation to confirm the structural adequacy of the test lines. Observation No. 3.6 is closed.'

(Closed) Observation TVA-supplied Limit Switch Brackets Observation 3.7 noted that TVA had not documented the seismic adequacy of the.TVA-supplied bolts and brackets used for the optional installation of limit switches on valves. TVA has now documented the seismic adequacy of the TVA-supplied bolts and brackets. Observation'3.7 is closed.

(Closed) Observation Solenoid Valve Mounting Seismic Qualification Observation 3.8 noted deficiencies in the documentation and seismic qualifica-tion of a valve which was supported by control air tubing. TVA has adequately documented the seismic adequacy of the tube-mounted solenoid valve. Observa-tion 3.8 also noted that an incorrect piping isometric was used to evaluate an alternately analyzed piping configuration with a 70 lb. valve, and an apparent discrepancy between TVA's Sequoyah Alternate Analysis Review Program Descrip-tion SQN-AA-001, which postpones evaluation of large concentrated in-line weights in support for designs field routed piping until after restart, and TVA's Sequoyah Nuclear Performance Plan (Volume 2 - SQN), which indicates that the effects of motor and pneumatically' operated valves will be evaluated prior ,

to restart. Restart decisions regarding the alternate analyses review program t will be resolved by the staff as a separate issue. Observation 3.8 is closed for the purpose of this inspectio (Closed) Observation High Energy Line Break Designation Observation 3.9 noted that TVA had designated a-portion of CVCS piping in l SQN Unit 1 as a high energy line and had designated the corresponding segment l of Unit 2 piping as low energy. TVA has indicated that the Unit 1 piping is also low energy, and is revising the drawing. Observation 3.9 is close (0 pen) Observation 5.7 - Diesel Breaker Trip This observation identified an instance of a race between load shedding and diesel breaker closure in the diesel generator starting logic. This race was 3 introduced by a modification. TVA has issued Significant Condition Report (SCR {

SQN-EEB-86206-R0) to address this concern. Corrective action has not been l

determined at this time; therefore, this item remains ope !

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(Closed) Observation 5.8-DBVPReviewperProcedureSQEP-12 Checklist This observation was related to the fact that the DBVP project was taking credit for the work of other TVA pros ams for resolution of selected technical attributes of the SQEP-12 checklists without confirming that such attributes were properly addressed in the other programs. In addition, the DBVP failed to ,

provide a cross reference for such program To resolve this issue, TVA revisited all the checklists prepared by EEB and corrected the problem. All DBVP personnel involved in the preparation of EEB checklists were retrained. During the SYSTER inspection the NRC inspection j

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team reviewed some of SQEP-12 ECN checklists and found that proper cross references for other prograns, such as the " calculation program", have been .

made. The team also found that punch list items have been generated where i attributes could not be verified through such programs. This is acceptable to the team and therefore this item can be considered close (Closed) Observation 6.9 - Cable Design Criteria Temperature Limits This item concerned the inappropriate inclusion and incorrect values for EQ temperature requirements in design criteria SQN-DC-V-4.3 for power, control and signal cables. TVA has deleted the generic parameter values from the design criteria, and now refers users to the appropriate and governing environmental conditions control drawing and Environmental Design Criteria SQN-DC-V-2 (Closed) Observation 6.10 - Instrument Calibration Data Consistency This item concerned inconsistency in the documentation of several calibration test documents reviewed by the team. One item concerned the omission of recording as-found data for a calibration. The other item involved identifica-tion of setpoint tolerance ranges in the setpoint calculations. Regarding the as-found data, TVA determined that since the modification changed the equipment setpoints, recording of the as-found data was unnecessary, although the recording of such information is considered a good practice. The team agrees that this was a minor oversight which does not compromise the plant safety features. TVA identified the source of the instrument calibration tolerance as Environmental Qualification Binder SQNEQ-ITS-001. This item was closed based on TVA's commitment to revise SQN procedure Al-19, Part IV, to require referencing of source documents used to develop setpoints in the work plan (Closed) Observation 6.11 - Consideration of Non-Class IE Loads in a TVA Calculation This observation concerned TVA's cursory treatment of non-safety-related loads, such control rod drive mechanism cooling fan and containment lower compartment fan motors, in the analysis of the effects of these loads on the Class 1E 480 volt shutdown boards. TVA indicated that the calculation reviewed by the team (SQN-0567-038) addressed these loads on a concept level. TVA also addressed their rationale for leaving these cooling fans or until a phase B I

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containmtnt. isolation signed. Because these non-safety loads are used for normal hed removal, events which would only initiate a phase A isolation would not initiate containment spray or challenge the passive ice condensor system; therefore the normal containment heat removal equipment should not be disconnected. This item was closed as the identified loads were included and addressed in the revised TVA calculation 10 CFR 50.49b(2)-1, issued February 25, 1987. The revised calculation treated the non-safety related loads in a detailed fashio (Closed) Observation 6.13 - CCS Pump Discharge Pressure Switch Reset This item concerned the lack of basis for the reset pressure for an alarm annunciating a condition representing high pressure at pump shutoff flo This item was closed on the basis of United Electric pressure switch reset data reviewed by the team and a TVA commitment to perform a post-restart test to demonstrate that the alarm condition can be cleared as system pressure returns to its normal valu (0 pen) Observation 6.12 - Periodic Test of CCS Surge Tank Baffle Integrity The item concerned the lack of testing to verify that a common surge tank, which provides a surge volume for redundant trains of CCS, remained or was intact. TVA has performed a calculation to demonstrate that adequate net positive suction head for the pumps is maintained regardless of surge tank integrity. This item remains open pending TVA's completion of a draft test procedure to confirm the integrity of the baffle plat (0 pen) Observation 6.14 - Imposed Voltage Consideration During Failure liode and Effects Analysis This item concerned the TVA's not considering imposed voltage effects when evaluating ECNs for failure analysis. The DBVP electrical group will document an evaluation of these effects in a report to be issued by 4/30/87. This item remains open pending NRC review of this revie (0 pen) Observation 6.15 - Testing of 0.5 Second Time Delay Relays This item concerned TVA's failure to periodically test a relay in various pump start circuits which reset a load shed time delay for a loss of offsite power following a loss of coolant acciden This item remains open pending TVA's preparation of an improved periodic test program for safety-related Class 1E equipment, and completion of surveillance testing of the specific relay (Closed) Observation 7.4 - Project Review of Support Variance During the initial NRC inspection, team review of ECH 5298 and its supporting documents identified that two field change requests (FCRs) related to this ECN had the following deficiencies: FCR 455 required engineering calculations for its disposition, contrary to the DBVP project review which stated that no calculations were require B-10

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. FCR 565 was not evuluated in TVA document SWP 810528 033, contrary to the. q DBVP. project statement that this document contained the calculations ~for

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the' disposition of this FCR.- i The TVA response to this observation concluded that both of these NRC findings were isolated and'that the-checklist for.this ECN has been revised to indicate that calculations could not be found for both FCRs. These two items have been placed under PIR SQNCEB8639, which covers all missing calculations identified by the Design' Baseline and Verification Program. This response by TVA is ;

acceptable to the NRC staff.-  ;

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APPENDIX C-MEETINGS AND' REFERENCES-C.1 Meeting . Table C.1 provides a matrix of meeting attendance and principal persons contacted for the meetings conducted at Sequoyah Nuclear Plant site in Soddy Daisy, Tennessee. Other licensee personnel were also contacted. The-following paragraphs summarize the general purpose of these meeting Meeting 1: On March 2, 1987, the NRC held an entrance meeting. The NRC reviewed the inspection team's plans to inspect-TVA DBVP project's System Evaluation Reports andLfindings,' to evaluate TVA's engineering assurance over-

- sight of the DBVP, and to. assess the adequacy of TVA's corrective actions for previousiinspection finding Meeting 2: On March 9,'1987 a meeting was heldito discuss changes and plans

.for TVA's drawing control program,. including discussions of TVA's plans for determining which drawings will be maintained as Configuration Control

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Drawings

for SQH.-

Meeting 3: .0n March 12, 1987 a meeting was held during which TVA explained- ;

' DNE's' inter)retation of the restart criteria to be applied for SQN and J

' discussed t1e interrelationship of TVA's " condition-adverse-to-quality" (CAQ)

process within DNE and. restart decision makin Meeting 4: 'On March- 13, 1987, the NRC' held an exit meeting'to summarize.the results of the inspection team's effort ;

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Table C.1 - MEETINGS Name Organization Title Meeting Attended 1 2 3 4 REArchitzel USNRC-IE Team Leader X X X X SVAthavale USNRC-IE NRC-Electric Power X X PEHarmon USNRC-RII Resident Insp., SQN X X X ADuBouchet NRC-Consultant NRC-Mech. Components X X FJMollerus NRC-Consultant NRC-Mech. Systems X X AIUnsal NRC-Consultant NRC-Civil / Structural X X EVImbro NRC-IE Section Chief-Licensing X X LStanley NRC-Consultant NRC-Instr./ Controls X X MWBranch NRC-RII SQN Restart Coo X APCappozzi TVA-DNE Manager - EA X X X'

MPBerardi TVA-EA EA Oversight Ad X X X X AWLatti TVA-DNE-S&W Advisor DNE Mg X X RPSvarney TVA-EA Civil /Struct. Eng X JFCox TVA-DNE DVBP Mg X X'

BHall TVA-0NP Licensing-Sequoyah X X X X DGRenfro TVA-DNE Nuc. Eng X JvonWeisenstein TVA-DNE Team Leader EA ORT X AHRitter TVA-DNE Engrg. Assur. Eng X TGCarson TVA-DNE EA Reviewer-0perations X SAShuman- TVA-DNE Mech. Eng X SSlong TVA-0NP Walkdown Prog. Coo X EWSteinhauser TVA-DNE Mech. Disc. Eval. X JRRupert TVA-DNE Civil Disc. Eval. X WMMatejek TVA-DNE DBVP Advisor X X GBKirk TVA-0NP Comp. Lisc. Mg X X MTTonney TVA-DNE-S&W Advisor X X BMGore TVA-DNE Princ. Engr.Elec. Lead X RJFaubert TVA-DNE Reviewer X HBRankin TVA-ONP Mgr of Projects X KMJenison USNRC-RII Sr. Resident Insp., SQN X X JAKirkebo TVA-DNE Director X JEMaddox TVA-DNE Project Admin. Supervisor X FMcCoy US NRC-RII Section Chief - SQN X DSVassallo TVA-EA Senior C/S En X JEStaub TVA-DNE DBVP Elec. En X X JWSemore TVA-DNE Elec. Eng X DWFolks TVA-DNE Design Engr. Asso X t MCooper TVA-0NP Licensing-SQN X FMashburn TVA-0NP Nuc. Engr.-Compliance X LMNobles TVA Plant Mgr.-SQN X X DWWilson TVA-DNE Proj. Engr. - SQN X MRHarding TVA-0NP Site Lic. Mg X HLJones TVA-DNE DBVP Nuclear Eng X X X MJBurzynski TVA-0NP Licensing X ,

PRBevil TVA-0NP QA Specialist X KSWhitaker TVA-0NP Reg. Lisc. En X

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HDPeoples TVA DBVP Spec. Pro X PRWallace TVA-ONP Site Director's Office X ,

WSWilburn TVA-ONP Asst. to Maint. Sup X I JRobinson TVA Asst, to Mod. Mg X l l

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C ' REFERENCES (1) Inspection' Report 50-327/86-27.and 50-328/06-27, forwarded by J. Taylor letter dated April 22,'198 (2) ' Inspection Report 50-327/86-38 and 50-328/86-38, forwarded by J. Taylor letter. dated September 15, 198 (3) Inspection Report.50-327/86-45 and 50-328/86-45, forwarded by J. Taylor ;

letter dated October 31, 198 (4) Letter Requesting Additional Information Relating to Inspection Report-50-327/86-27 and 50-328/86-27, J. Taylor, NRC IE to C. C. Mason dated'

October 30, 198 (5) TVA. Response to Inspection Report 86-27 (Gridley to Grace), dated July 28, 198 '

(6) TVA revised response to Inspection Report 86-27, (Domer to Grace), dated December 31,.198 (7) TVA response-to Inspection Reports 86-38 and 86-45 (Domer to Taylor),

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dated February 3,198 i (8) TVA response to Inspection Report 86-55 and items Inspection Items remaining open (Gridley to Ebneter), dated April 198 (9) Inspection. Report 50-327,328/86-55, forwarded by J. Taylor letter dated February 3, 198 (10) Inspection Report 50-327, 328/87-06, forwarded by S. Ebneter letter dated a April 8,198 l (11).TVA Additional Information in Response to Inspection Report 86-27, !

(Domer to Taylor), dated January 30, 198 !

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