IR 05000327/1987064
| ML20149N002 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 01/08/1988 |
| From: | Architzel R, Imbro E NRC OFFICE OF SPECIAL PROJECTS |
| To: | |
| Shared Package | |
| ML20149M997 | List: |
| References | |
| 50-327-87-64, 50-328-87-64, NUDOCS 8802290370 | |
| Download: ML20149N002 (30) | |
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-t a U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR REACTOR REGULATION Division of Reactor Inspection and Safeguards Report Nos.: 50-327/87-64,50-328/87-64 Docket Nos.: 50-327; 50-328 Tennessee Valley Authority Licensee:
6N, 38A Lookout Place 1101 Market S Chattanooga, TN 37402-2801 Facility Name: Sequoyah Nuclear Plant, Units 1 & 2 Inspection At:- Knoxville, Tenne:,see Inspection Conducted: October 26-30, 1987 Inspection Team Members: .i. Architzel, Senior Operations Engineer, NRR Team Leader:
Mechanical Systems: F. J. Mollerus, Consultant, Mollerus Engineering In Mechanical Components: A. V. du Bouchet, Consultant A. I. Unsal, Consultant, Harstead Engineering Civil / Structural:
S. V. Athavale, Electrical Engineer, NRR Electricel Power:
Instrumentation & L. E. Stanley, Consultant, Zytor In Control:
h Nf23f87 Date Ralph E. Architzel"
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Team Leader l
l C Y Eugene V. Imbro Nh /h 'Date
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Section Chief Team Inspection Appraisal and Development Section #2 (
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Special Inspection Branch 8802290?70 080223 7 DR A00CK 050 l
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LIST OF ABBREVIATIONS AFW Auxiliary Feedwater CAQ Condition Adverse to Quality CAQR Condition Adverse to Quality Report CCP Centrifugal Charging Pump CCRIS Calculation Cross Reference Information System CCS Component Cooling Water System CEB Civil Engineering Branch DBVP Design Baseline and Verification Program DNE Division of Nuclear Engineering EA Engineering Assurance ECN Engineering Change Notice EEB Electrical Engineering Branch ERCW Essential Raw Cooling Water System FSAR Final Safety Analysis Report G/C Gilbert /Comonwealth HVAC Heating Ventilation, and Air Conditioning LOCA Loss of Coolant Accident MEB Mechanical Engineering Branch
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NEB Nuclear Engineering Branch NEP Nuclear Engineering Procedure NRC Nuclear Regulatory Comission PIR Problem Identification Report QIR Quality Informatien Report RIMS Records Information Management System RLCA R. L. Cloud Assoc'!ates SCR Significant Condition Report SQEP Sequoyah Engineering Procedure SQN Sequoyah Nucicar Plant TVA Tennessee Valley Authority U500 Unreviewed Safety Question Detennination N
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SEQUOYAH NUCLEAR POWER PLANT Design Calculation Review Program Inspection Report 50-327/87-64 & 50-328/87-64 October 26-30, 1987
, INTRODUCTION AND BACKGROUND The design calculation review program was developed by the Division of Nuclear Engineering (DNE) because past audit findings and other reviews have shown that the design basis for TVA's nuclear power plants have not been adequately docu-mented by supporting calculations or that such calculations, if perfomed, may no longer be retrievable. This program augmented the Sequoyah Nuclear Plant (SQN) design baseline and verification program (DBVP) by including a technical -
adequacy review of supporting calculations, a feature not included in the DBV TVA established an electrical calculation program to correct various problems with electrical calculations identified first by INPO in 1985 and later con-This program was firmed through NRC, Gilbert /Comonwealth and DhE audits.The Electric Engineering Bran later expanded to other engineering branche (EEB) used the services of Sargent and Lundy to help review the existing calculations and to establish a new calculation program. This program was developed to address identified problems such as inadequate documentation, inadequate control, and out-of-date and missing calculation Short-term program objectives were to define a minimum set of essential calcu-lations required to support the SON design bases; then establish procedures and guidelines to generate, control, revise, and maintain the essential calcula-tions to support the restart of SON Unit 2. Long-term objectives are to generate, verify, control, revise and maintain all nonessential and essential calculations and procedures in the post-restart period and to train TVA person-nel regarding the procedures and policies needed to meet the long-term objective The NRC conducted two previous inspections of the design calculation review program and documented the results of these inspections in reportsTVA has responded 327, 328/87-06, and 327, 328/87-27 (References 10 and 18)*.
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to the observations identified in these reports (references 4, 20, and 21). PURPOSE The purpose of this inspection was to review TVA's corrective actions associ-ated with their in-house calculation review program. Regarding the calculation review program, this inspection principally addressed closecut of previous inspection findings, although some effort was made to assess the status of the
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The team also reviewed TVA corrective actions associated with NRC ooservation docurrented in previous NRC design control inspection reports, including previous inspections of the DBV )
- References are listed in Section C.2 of Appendix C
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l l RESULTS OF NRC INSPECTION The following paragraphs characterize the team findings and conclusions in eac discipline. The inspection results detailing the team's review of licensee action on previous inspection findings for the design calculation review and the DBVP are provided in report Appendices A and B, respectivel The team found that TVA had completed the calculation review program for the most part in the Electrical, Mechanical, and Nuclear Engineering Branche The adequacy of the Civil Engineering Branch calculation review program rem an open issue which will be further evaluated by the NRC Office of Special Project The team also noted that the EA technical review of the calculation program remained an active effort, and appeared to have enhanced the qu of the program effort .1 MECHANICAL ENGINEERING BRANCH Reference 19 describes the calculation review effort being conduc Mechanical Engineering Branch (MEB). This calculations and a review of all calculations for technical adequacy.These have been effort detemined that there were 111 missing calculations.MEB cond regenerated.and contracted with Stone & Webster Engineering Corporation to c nical adequacy review of the remaining MEB calculations, including regenerated missing calculation Five unacceptable calculations were identi-calculations in the sample of 77. fled in thehave These remaining MEB subsequently calculations re been Completion revise Report SQTCR 008-1, Revision 0).The team was informed possibleeffectsinheating, ventilation,andairconditioning(HVAC),which was still under evaluation during the inspectio During team discussions with EA regarding the EA technical review, the inspec-
tion team was infomed that EA inspected 19 MEB calculations and that EA was
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satisfied with the technical adequacy in this sampl will be through scheduled programmatic audits of MEB.
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The inspection team determined that HEB's plan to review for missing calcula-tions and conduct a review of all calculations for technical adequacy was complete; that unacceptable calculations have been corrected and reissued; that exception sheets have been issued for the 13 remaining unverified assump-tions, which have been dispositioned as post-restart and scheduled for confir-matio The team considered that TVA action to address closure of NRC Observations MEB-8 and MEB-10, discussed in Attachment A, was required prior restart.
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. i 3.2 NUCLEAR ENGINEERING BRANCH Reference 19 describes the Nuclear Engineering Branch (NEB) calculation review effort. It is similar to the MEB effort and includes a review for missing The inspection calculations and review of all essential NES calculation These have been team regenerate detemined that there were four missing calculations.The technical a There were 30 unacceptable calculations, 21 of 395 essential calculation which were essential. These were corrected without any effect on hardwar The inspection team determined that EA inspected 2; NEB calculations and Follow-up EAthat EA was satisfied with the technical adequacy in this sampl activity will be through scheduled programatic audits of NE The team detemined that NEB's calculation review program was completed with no remaining pre-restart corrective action .3 ELECTRIC ENGINEERING BRANCH Electrical Engineering Branch (EEB) identified 576 essential calculations All calculations had during the conduct of the calculation review progra been regenerated except several that related to cable installations, class 1E timer accuracies, instrument accuracies and justification Work of contact was in progress to contact to complete the isolation between IE and non-1E circuit remaining calculations, update existing calculations (which included addressing the impact of DBVP and NRC inspection findings), confim the validity of unveri-fied assumptions and revise calculations for ongoing design change A portion of TVA instrumentation and control calculations are assigned to the EE These safety-related calculations include instrument loop setpoint accuracy deteminations for enviror, mental qualification purposes and the recent inclusion of time delay relay setpoints. A number of instrument setpoint accuracy calcula-tions reviewed by the team used an acceptable methodology and were considered satisfactory. No time delay relay calculations were available for review during the inspections; however, there should be no technical difficulty in perfoming these calculations in an adequate manner. A large portion ofThe these time delay team agreed relay setpoint calculations will be completed pre-restar with each of TVA's post-restart decisions for certain time delay setpoint calculation A number of safety-related process setpoint calculations for balance of plant f
instrument loops have been perfomed by NE8 and MEB. The team determined that During several such calculations performed by NEB were technically adequat this inspection, considerable improvement was noted for setpoint calculations perfomed by MEB. As a result, TVA's establishment of such process setooint values was considered technically adequate by the tea The team also discussed with the EA oversight group those instrumentation and l control calculation problems that had been identified by In EA eachduring theircorrec-instance, l
technical reviews of the calculation review program.The team concurred with l
i tive actions taken by TVA were satisfactory to E EA's assessment and individual resolutions.
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During this inspection, the team foundThis that workthe will EA be techn been implemented or agreed to between EEB and the auditors.During the completed before restart. calculations had been revised and other calculation progres .4 CIVIL ENGINEERING BRANCH
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3. Rigorous Piping Analysis and Pipe Supports The Civil Engineering Branch (CEB) calculation review program in the rigorous piping analysis area was originally based on the recommendations for corrective action contained in CEB sumary report "Evalua 1987(RIMSNo.B41870130013).
In response to the recomendations contained in that report, CEB retained Gilbert /Comonwealth (G/C) to select and reanalyze five rigorous piping analyse to assess the adequacy of CEB's analyses of record for these piping subsystems G/C sumarized the results of their review 13,1987 in Report
[ records No. management infomation 2689 "Sequoyah Un Rigorous Analysis Review," dated MayThe report confimed the technical adequacy system (RIMS)No. 841870519250).
of CEB's five rigorous piping analyses with respect to Sequoyah Nuclear Pla licensing comitments and design criteria, but identified numerous technical issue CEB then asked R.L. Cloud Associates (RLCA) to review th implications of G/C's findings.in Report No. P154/03/87/001 19, 198 "Initial Asse Review of SQN Unit 2 Rigorous Piping Analysis," dated May CEB concurrently evaluated G/C's findings and documented that review in CEB Peport No. 2689 "Sequoyah Unit 2 Rigorous 28, 1987.Analysis Review / Preliminary Response to Gilbert /Comonwealth," dated May TVA docketed the interim status of CEB's corrective action program in the rigorous piping analysis area inOnaSeptember submittal to the NR 1, 1987. TVA
- Technical Adequacy Report," dated June 1, 198 presented the criteria which CEB is using to regenerate pipeduring However, support calcu tions to the NRC (Heeting Sumary dated September 4,1987).the team the week of October 26, 1987, CEB's evaluation of the conclusions and recomendations con issues of the RLCA and TVA report CEB's pipe support calculation regeneration program had regenerated 4,165 5,804 pipe support calculations by October 29, 1987, pipe support calculations to be regenerated before restart of Sequoyah U The NRC's Office of Special Projects is overviewirg TVA's corrective actions for CEB's calculation review programs, therefore activities during this inspec-tion were limited to assessing the status of completion of CEB's calculation review progra . ,
EA's technical review of the calculation review program in the rigorous piping analysis area are documented in Audit 87-09 (Technical), "DNE Calculation Review Effort Audit Report," dated February 10, 1987, and a followup EA Audit 87-09 (Technical), "DNE Calculation Review Effort Evaluation of Responses for Deficiencies 87-09-01 through 87-09-06 and Response to the Identified Concerns," dated April 24, 198 In addition to the reviews which EA documented in audit 87-09(T) and the followup to that audit, EA also reviewed several pipe support calculations which the DBVP identified as missing and which CEB regenerated as part of CEB's The results of EA's review were pipe support calculation regeneration program. documented in the "Supplem Report /SQN Unit 2/DBVP," dated September 29, 198 As an additional followup to audit 87-09(T), EA reviewed 26 pipe support calculations during the period September 14 - October o.1987 that had recently been regenerated as part of CEB's pipe support calculation regeneration program. During the inspection EA indicated that a draft report sumarizing the results of EA's review was in progres During discussion with the team EA stated that they would review the planned CEB report which evaluates the conclusions and recommendations of the RLCA and TVA reports (addressing potential generic deficiencies in the rigorous piping analysisarea).
3. Civil / Structural In the civil / structural area, the team concentrated its effort on reviewing TVA
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corrective actions associated with previous NRC inspection findings (See The team also held meetings with CEB and EA engineers to Appendices A and B).obtain information on the status of the calculation efforts f Nuclear Plant.
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During a team meeting on October 26, 1987, CEB statedOf that there346 these, are calcula-1740 l
essential calculations Asinofthe thecivil / structural inspection, area. calculations had been 146 missing tions tvere missin regenerated. Twenty-four remain to be generated before restart and 76 to be
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I generated after restar CEB is also continuing their efforts on technical l
adequacy reviews performed for miscellaneous structural steel and conduit and HVAC duct supports. At the time of the NRC inspection, TVA had not reached a conclusion on the overall technical adequacy of the civil / structural calcula-
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The team also met with TVA EA to detemine whether they are performing inspec-tions on the technical adequacy evaluations performed by CEB. EA has advised the NRC team that in the civil / structural area EA was waiting the outcome of the integrated design inspection recently conducted by the NRC to determine a plan of action for their review. At the the time of this NRC inspection EA l
was not perfoming any reviews on the technical adequacy evaluations in the civil / structural are The NRC's Office of Special Projects is overviewing TVA's corrective actions for CEB's calculation review programs, therefore activities during this
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j inspection were limited to assessing the status of completion of CEB's calculation review progra . OBSERVATIONS FROM DESIGN CALCULATION REVIEW PROGRAM INSPEC Specific findings of individual NRC discipline inspectors were cate
"observations."
in the inspection reports and in some cases provide relating TVA actions additional to coments individualnot considered to be of a general natur observations were reviewed by the NRC. Individual observationsSelected were closed items,on the basis these reviews and TVA's responses, as appropriat noted as confirmatory items, remain open pending TVA confinnation that the indicated action has been complete Results of these reviews by the NRC team are provided in Appendix A of this repor . REVIEW OF PREVIOUS DBVP INSPECTION FINDINGS The team consisted of individuals who had previously participated in a series The team reviewed TVA's of design control inspections of TVA's DBVP for SQ respceses to the deficiencies, unresolved items, and observations documented in the following previous NRC inspections associated with the DBVP:
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
- 50-327/86-55 and 50-328/86-55
50-327/87-14 and 50-328/87-14
50-327/87-31 and 50-328/87-31 Details about that review can be found in Appendix B to this inspection repor . MEETING SUMMARIES - REFERENCES A sumary of the meetings held during the inspection and a I
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Appendix A LICENSEE ACTION FOR PREVIOUS CALCULATION REVIEW PROGRA Report No. 87-06 (Closed) Observation GEN-1 - Substantiated Condition for a CAQ This item addressed a team concern with proposed revisions to the DNE corrective action procedur The team reviewed Nuclear Engineering Procedure (NEP) 9.1, "Corrective Action,"
Revision 2, dated June 30, 1987. NEP 9.1 was issued with a revised definition of a condition adverse to quality (CAQ). The new definition states:
Conditions Adverse to Ouality (CAQs)
Adverse conditions within the scope of the Office of Nuclear Power
Quality Assurance and limited Quality Assurance programs including nonconforming material, parts or components; failures; malfunctions; deficiencies; deviations; hardware problems involving noncompliance with licensing comitments, specifications, or drawing requirements; abnormal occurrences; and nonhardware problems such as failure to comply with the operating license, technical specifications, licensing comitments, procedures, instructions, or regulation A statement that unsubstantiated conditions are not defined as CAQ's, which was in the definition contained in the Nuclear Quality Assurance Mancal, was not incorporated in the NEP 9.1 definitio Revision 2 of NEP 9.1 also provided for implementation of a Problem Identifica-tion Report (PIR) system within DNE to document problems and potential problems that are not CAQs, Project engineers, branches, and DNE staff organizations are directed (procedure section 1.1.1) to implement a PIR system to handle non-CAQs that previously would have been handled with an NEP 9.1, Revision 0 PIR. Attachment 10 of procedure NEP 9.1 provides a fom for handling PIR The team noted that Sequoyah Engineering Project has implemented a PIR process through Sequoyah Engineering Procedure (SQEP) 61, "Handling of Conditions Adverse to Quality Reports (CAQRs) and Problem Identification Reports (PIRs),"
Revision 0, dated February 23, 1987. The team reviewed SQEP 61, noting that the SQN project had in fact implemented a PIR process in advance of DNE direc-l
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tion requiring such a proces These actions adequately address the concerns noted by the team; therefore, this observation is close (0 pen) Observation MEB-3 - Water Hamer Observation MEB-3 noted, in part, that CEB had not fomally documented an evaluation of the main feedwater system piping at Sequoyah Nuclear Plant with respect to water hamer forces arising from a postulated line break in the turbine building. TVA had not justified not issuing the feedwater water hammer
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analysis when it was identified by engineering as a licensing comitmen During the inspection, CEB was still reviewing the main with a revised response to Observation MEB-3 when this review has been complete Observation MEB-3 will be forwarded to the NRC's Office of Special Projects for review and dispositio (0 pen) Observation MEB-6 - Component Cooling Water System Des','gn Pressure During this inspection period the team re-reviewed the recalculation of the componentcoolingwatersystem(CCS)designpressure(B448 After further discussions reasons noted previously in References 10 and 1 with TVA, the team detemined that a satisfactory resolution should include the following attributes: A design pressure calculation based on:
a static head produced by the surge tank water level at the high end (a) of the nomal level control range, (b)
the lowest pump flow (highest total dynamic head) that can occur for any nomal operating mode of the CCS, and (c) the lowest expected operating coolant temperature, TVA should show by calculation that CCS pressure variations meet the requirements of Paragraph 102.2.4 of the Power Piping Code B31.1.0-196 The team considered that events such as closure of the nomal surge tank vent and increase in surge tank pressure to its relief valve setpoint plus accumulation can be considered pressure variations provided the event meets the spirit of the phrase "occasional periods of operation for short periods" contained in 831.1.0-1967 and is not pemitted to be a normal mode of operatio . TVA should conduct a review to determine if all components meet the calculated design pressur The team noted that the final safety analysis report (FSAR) presently states in l
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for a greater flow and less total dynamic head than that associated with pump l
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shutoff, then the FSAR should be revised and the Office of Special Projects notified before restart of TVA's intent to revise this portion c' the FSA The This observation remains open pending a confirmatory letter from TV team considered that these actions should be completed prior to restar (Closed) Observation MEB-8 - Inconsistent Equipment Qualification Temperature 844 870716 007) that The team reviewed a recent TVA calculation (RIMS N shows a calculated peak temperature that is in agreement with the plant's A-2
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environmental data sheet peak temperature of 110'F for the turbine driven auxiliary feedwater pump location. Therefore, the observation has been close (Closed) Observation MEB-9 - Unverified Heat Load Inputs This item had been left open during the previous calculation inspection (Refer-ence 18) pending verification of the regenerated calculations by EA. The team reviewed a letter detailing EA followup review (Capozzi to Chandley, RIMS N BOS871016004). EA has verified that the calculations were complete, issued and were all included in the Stone & Webster Engineering Corporation technical adequacy review Task Completion Report SQTCR.008-1, Revision (Closed) Observation NEB-1 - Emergency CCS Pump Net Positive Suction Head The team reviewed calculations and analysis that address the three parts of this observation: Crane Wall Penetration Seals. The observation noted that operability of the emergency core cooling systems (ECCS) requires maintenance of water inventory in the containment sump. In the sump level calculations. TVA had assumed the crane wall electrical and mechanical penetrations below the 693 feet elevation were sealed and did not allow leakage of sump water. Recent calculations (B45 871026 426) show that, even for a catastrophic failure of foam seals, sump water levels remain above both small and large break loss of coolant accident (LOCA) safety limit . Small break LOCA Sump Water Temperature. The observation noted that the temperature assumed for the small break LOCA calculation,190'F, may not be conservative since less ice melt would occur. More recent analysis contained in OIR MEB82272 (RIMS No. 845870826259) showed that contain-ment spray will always be actuated prior to switchover of the low pressure safety injection pumps to the sump and that temperatures will be approxi-mately 105'F at time of switchover. Factors limiting the sump to less than 190'F include reduced decay heat at switchover and the capacity of the RHR and containment spray heat exchangers to remove decay hea . NUKON Insulatio The observation expressed a concern that NUKON insula-tion used on pressurizer loop seals and debris from unqualified coatings could cause block of the sump screens and that the 30% blockage factor assumed in the calculations was unverified. Subsequently, excerpts from a proprietary report from Westinghouse Electric Corporation. WCAP-11534, dealing with screen blockage by dislodged NUKON insulation and coatings, were reviewed by the team. The report concluded that adequate net positive suction head will be maintaine Based on the adequacy of the infonnation made available to the inspection team during this inspection periud, the observation has been close (Closed) Observation EEB-1 - Battery and Charger Sizing The team noted several errors in the battery and the charger sizing calcula-tion, such as failure to address in-rush currents, worst case leading and margins for load changes due to design modifications. The installed capacity of the system was found to be lotter than the calculated capacity. TVA tried to A-3 l
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justify a lower capacity for the installed system by changing ba life from 80 to 89%.
to the operations department, nor was TVAit addressed included this in the appropriate observation by sections of the FSAR and technical specification taking the following step TVAhasrevisedcalculationSQN-CPS-004(Revision 2)usingSargentandLundy computerized calculation software program "Electrical Load Monitoring Syste TVA infonned the team that this software is DirectCurrent"(No.ECB77). However, because the software is proprietary based on IEEE-485 guidelines.TVA relied upon Sargent and Lundy for soft perfonn an !n-house (TVA) quality assurance revie The team reviewed the revised calculation, which used an inverter loading o 17.5 kva (versus nameplate rating of 20 kva), motor in-rush currents, a worst case loading of the de syste This made the batteries was found team's concerns to beFSAR regarding the same as the installed and technical size.changes moo specification However, the team was concerned that any changes in the values of parameters ustd in the calculation, such as loading of the inverter loads due to design changes, human errors, equipment failures or poorTVA informed th maintenance may render the installed capacity inadequate. te In addition. TVA has developed possibilities described by the tea procedures to TVA revise battery and charger sizing calculations infonned the team that since the inverter loading is for any futur design change administratively limited to 15 kva and the inverter loading used for the calculation is 17.5 kva, each battery (having two inverters co has 5 kva excess capacit will adequately handle future design changes and therefore considers this observation close (0 pen)ObservationEEB-2-BreakerCoordination This observation was related to an error in the corrective action taken by T to resolve breaker coordination problems for the 480 V diesel generator and essential raw cooling water (ERCW) system board the error would have been identified during field implement corrective actio The team noted that this ECN describes correct the coordination problem.the proper corrective action and th The team reviewed the impact of post-restart post-restart of Unit 2. completion and noted that the loss of one board shutdown capacity; therefore, completion of the corrective actions af restart of Unit 2 is acceptabl pending a CCTS comitment to complete the corrective actio (Closed) Observation EEB-3 - 120 V AC and DC Solenoid Voltage This observation related to inadequacies of voltagr drop calculation SQN-CPS-001, which did not address effects of harsh environment temper on field cable resistance, added resistance due to e l
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The calculation was with the "pig tails" of electric conduit seal assemblie ,
also inconsistent regarding location and description of unverified assumption:.
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TVA has resolved this concern by addressing all the above items ,
calculation it acceptabl (Revision 9).In addition. TVA retrained personnel regarding the requiremenl of Nuclear Engineering Procedure 3.1, "Calculations," relating to unverified assumption The above actions by TVA were considered acceptable by the team, therefore, this item is considered to be close (0 pen) Observation CEB-2 - Structural Steel Sizing Calculations (0 pen) Observation CEB-3 - Structural Steel Details (0 pen) Observation CEB-4 - Platfom Steel Calculations and Drawings (0 pen) Observation CEB-5 - hvisions to Steel Platfom Calculations (0 pen) Observation CEB-6 - Seismic Loads for Steel Platfoms CEB-2 through CEB-6 raised various concerns about the structural In oroer to Observations adequacy of the steel platfoms at the Sequoyah Nuclear Pla SQN 8711 to require reanalysis for various platfom To detemine the structural adequacy of platfoms, CEB selected six platfoms to be reanalyzed. Three of these platforms were located in the auxiliary All buildin The other three were selected from the reactor buildin platforms were walked down to obtain as-built information, which was laterl The team reviewed TVA calculations (RIMS (
in the computer reanalysis.which contained the reanalysis of the auxiliary building i No. 825 870926 805) The team agreed with the TVA approach to
platfom at elevation 724'-3". l determine structural adequacy of the platfoms with the following exceptions: 1 l
TVA used 0.0 pounds per square foot live load inThe theteam reanalysis considersof the that
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steel platform when combined with seismic loads.TVA should isl load, other than foot traffic, on such platforms during plant operatio (2) TVA qualified certain connections by torsional tests performed on tests These connec- ,
tions at TVA's Singleton Materials Engineering Laborator l were extensive in nature and only partially reviewed by the team (RIMS i
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No. 846 870904 001). Since these tests are not standard tests and are not covered in the AISC code, the team considered that TVA should ensure ,
that the test results are valid, for example, by having an independent l review of the testing performe (3) TVA concluded that the bending stresses in one beam exc stress before limit restart for those cases where the FSAR stress requirements wculd be
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I These actions are considered confirmatory item )
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. . j As a part of the corrective action for SCR SQN CEB8711, TVA also perfomed walkdowns on five randomly selected miscellaneous steel features and five structural steel elements. These walkdowns were perfomed to detemine whether there were any configuration changes or attachment loads that were not considered in the original design. The walkdown of the five miscellaneous steel features did not identify any significant attachments or any configura-tion differences. The walkdown of the five structural steel elements showed that two elements, the auxiliary and control building roof framing, had some attachment loads. Reanalysis of these elements by TVA has shown that they are adequate to carry the attachments. The conclusions reached by TVA on miscellaneous steel and structural steel walkdowns were acceptable to the tea (Closed) Observation CEB-11 - Pipe Rupture Evaluation for Concrete The team's review of CEB calculation PWP 840920 705 showed that concrete and reinforcing steel allowable stresses were exceeded for pipe rupture loads without any technical justification. In response to this observation CEB issued CAQR SQP870183 and perfomed a finite element analysis of the slab in ouestion to show that it is structurally adequate to withstand the pipe rupture loads. The TVA calculation (RIMS No. 825870519300) that contains this analysis was reviewed by the team and found to be acceptabl As part of the generic implications of this observation TVA reviewed the 47E235- series environmental drawings and detemined that certain areas had differential pressure loads of up to 1.4 psig. This review is documented in a TVAcalculation(RIMSNo.B25870821490). CAQR SQF870151 was written to This evaluate those areas which were found to be affected by these pressure evaluation (RIMS No. 825 870831 463) showedThe thatteam these elements reviewed thisare struc-calcula-turally adequate to carry the pressure loads.The team considers this observation to tion and found the results acceptabl be close Report No. 87-27
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(0 pen)ObservationMEB-10-LossofStationACPowerCalculation This observation concerned lack of a calculation or other basis which TVA's substantiated the adequacy of HVAC during a loss of station ac power.
I submitted response (Reference 20) was considered inadequate by the tea During the inspection, TVA acknowledged a commitment to maintain hot shutdown following a loss of station ac power for a two-hour period. The licensee stated that this capability is achieved by adequate vital battery capacity and l
operation of the turbine driven auxiliary feedwater pumps and associated I valves. The team reviewed an analysis and HVAC calculat %ns (tlIMS N B44 870716 007) demonstrating adequate turbine driven au d iary feedwater pump
'The team capability during the two-hour period of loss of ac powe considered these actions adequate; however, this item was left open pending submittal of a revised response to the NRC documenting these actions.
l (Closed) Observation NEB-2 - Wide Range Containment Pressure Transmitter TVA calculation SON NAL4-002, Revision 6 stated that containment wide range pressure transmitters PT-30-310 and PT-30-311 had a range of -5 to 460 psig, an A-6
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accuracy of +/- 10.98 psig, and did not have a use specified in plant emergency procedures. The items remaining to be resolved during this inspection were:
(1)therequiredinstrumentaccuracy;(2)useofthesetransmittersinplant emergency procedures, and (3) their possible replacement with more accurate instrument stated that the required AninternalTVAmemorandum(RIMSNo.B45870904255)
acc.uracy determination and the use of these instruments in operating procedures would be established post-restart. Since the wide range transmitters were identified in hth NUREG-0737 and NRC Regulatory Guide 1.97 Revision 2, and TVA's comitment to implement Regulation Guide 1.97 is after restart, the team agreed with this post-restart categorization. The teamDuring was also informed that the inspection the search for an improved transmitter would continu on October 29, 1987, the post-restart action items for these Hence,transmitters were this item entered into the TVA Corporate Comitment Tracking Syste is close (Closed) Observation EEB-6 - Turbine AFW Time Delay Relay Setpoint This item identified an automatic auxiliary feedwater (AFW) pump start time delay in excess of design criteria requirement CAQR SQF 870086(RIMSNo.B05870605306) was initiated in June 1987 to address this issue. The CAQR proposed changing relay R5 to be a 25 second maximum time This relay in the turbine-driven AFW logic delay rather than 60 second AFW design controls the steam supply switchover from steam generator 1 to criteria SQN-DC-V-13.9.8 and FSAR section 15.2.8.1 recuired that AFW flo provided to at least two intact steam generators This time within delay value was60chosen seconds following a to avoid loss of normal feedwater flo inadvertent lifting of main steam safety and relief valves during operational transient In October 1987, CAQR SQF 870086 was revised to justify continued use of the 60 secord R5 time delay rela However, the team observed that this CAQR revision did not identify that the existing plant relay setpoint was in conflict with TVA requirements stated in both the design criteria document and the FSA subsequently revised the CAQR to identify the post-restart changes needed in the design criteria and the FSAR. The overall time interval for valve move-ment and time delay relay operation is approximately 95 seconds, rather then the 60 seconds stated in the FSAR. Because total loss of AFW for 10 minut has been accepted, as stated in the FSAR feedwater line break analysis, the team agreed with TVA that the documentation changes could be accomplished post-restar (0 pen) Observation EEB-7 - HVAC Temperature and Flow Process Safety Limits l did not The team had noted that a TVA calculation (RIMS N B44 860819 004)
establish process safety limits for HVAC temperature and flow safety-related TVA subsequently issued a completely new HVAC setpoint calcula-measurements.
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' tion (SQN-30/31-0053-FSG-WVC-080887) that did provide both setpoint values and This new calculation established
process safety limits for these measurements.the setpoint value at 90 p l
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previous calculation setpoint value of 50 percent, and should provide an
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earlier indication to the plant operator of HVAC fan failure or perfonnance degradatio For the fifth vital battery room heater control (0-TC-31-498 and -499), TVA determined a 71*F increasing setpoint with a lower process safety limit of 40'F. This latter value was taken from the environmental qualification docu-ment, but the team noted that it is in conflict with another TVA calculation (SON-CPS-004 revision 4), where a minimum battery room temperature stated for battery operabilit *F the team considered that the calculation should be revised to sho minimum valu (Closed) Observation EEB-8 - Setpoint Accuracies for hYAC Temperature and flow Instruments The previous MEB calculation for HVAC setpoint accuracies (RIMS No. B44 860819 004) had numerous inconsistencies for instrument ranges relative to 40*F minimum and 104*F maximum temperature limit This calculation has been superseded by calculation SQN-30/31-D053-FSG-WVC-080887 (RIMS No. B44 87 006), which corrected each of the observed discrepancie close (0 pen) Observation EEB-9 - Containment Electrical Penetration Overcurrent Protection SCR-SQN-EEB-8676 identified a concern regarding continuous overcurrent trip settings that were used to protect the circuits of containment penetration assemblies Nos. 52 and 53. The conductor size used for these electrical The calculated maximum allowed penetrations was No.12 American wire gage. current through these condu IEEE-317-198 TVA selected the next larger available trip setting of 20 arperes, which will allow the 16 ampere continuous current to be exceeded without the excessThe team fel current being detected in the 16 to 20 ampere rang allowed current, in excess of 16 amperes, may result in reduction in the life and/or leak sealing capacity of the penetration assembly. TVA perfonned calculations using vendor's test data to prove that these penetrations canThe carry 33.3 amperes safely without raising conductor temperature to 90' team reviewed this calculation and noted that value of the ambient temperature The team at the penetration :ssemblies was incorrectly assumed to be 71* noted that the maximum ambient temperature was 120'F, asFurther shownTVA's on environment calcu-drawings, Chapter 3 of the FSAR, and the vendor report.lation did not generation that arises from increases in penetration operating terperatur The team performed alternate calculations using the manufacturer's temperature of194'F(90*C). The team calculated that the maximum allowable current will be above 25 ampere On this basis the team does not consider resolution to be required prinr to restar Although this calculated value for the maximum current was greater than the 20 amperes setting of the breaker, the team stfll questioned the licensee's The team approach because it did not correctly address temperature effec A-8
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I ambient and changes in the resistance of the conductor due to changes in t mperature, including an assessment of heat dissipation which considers factors such as the geometry of the penetration assembly and HVAC. The team closed this item for inspection purposes. If TVA's revised calculation i indicates that the allowable current is less than 20 amperes, the Office of Special Projects should be informed. This item will be kept open pending a Corporate Comitment Tracking System comitment to revise the calculatio '
This revision need not be completed prior to restar (0 pen) Observation EEB-10 - Pump Start Time Delay Relay Setpoint Calculations The team had previously identified that no time delay setpoint calculations had been prepared by TVA for both the 15 to 25 second and 0.5 second time delay relays used in pump start circuits for the ERCW, CCS, and AFW systems. TVA has subsequently revised procedure PM 86-02, "Method For Electrical Calculations,"
to specifically list a time delay relay category in the set of required calcu-i lations. In addition. TVA has identified 38 specific time delay relay applica-tions requiring setpoint calculations, and has designated 12 of these as post-restart. The team reviewed each of these 12 post-restart applications,
and independently concluded that TVA's designation was correct. As a result, the technical aspects of this issue have been satisfactorily resolved. This item remains open pending TVA correspondence confiming entry of these post-
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restart calculations into the TVA Corporate Comitment Tracking System.
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(0 pen)ObservationEEB-11-ComponentC6olingSystemSetpointCoordination CCS flow alam accuracy values were discussed between EEB and MEB, but justifi-cations for selecting particular values were not documented in an MEB calcula-tion (RIMS No. B44 870602 001). TVA has subsequently stated that the flow alam ;
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- setpoints are not essential for safe shutdown of the plant; consequently. TVA plans to complete demonstrated accuracy calculations for these alam setpoints postarestart. The team agrees with the technical aspects of this planned action; however, this item remains open pending confimation by TVA that the comitment to accomplish the accuracy calculations has been entered in the CCT (0 pen) Observation CEB-13 - Regenerated CEB Pipe Support Calculations Observation CEB-13 noted that CEB's calculation for pipe support H10-635 demonstrated that the pipe support failed when friction forces were considered, but CEB did not document this deficiency on the calculation cover sheet or in the CAQR which CEB subsequently prepare In addition, the CEB calculation for pipe support H10-1219 did not include a themal check of the pipe support, but CEB did not note this as an unverified assumption on the calculation cover sheet or on CEB's pipe support calculation log. During this inspection the team noted that Bechtel had regenerated the calculation for pipe support H10 635, and was regenerating the calculation for pipe support H10-121 Regeneration of essential pipe support calculations is required before restart ;
of SQN-2. Observation CEB-13 remains open until TVA issues the calculation to qualify pipe support H10-1219 and provides the NRC with a letter confiming completion of corrective action (Closed) Observation CEB-14 - Engineering Assurance Acceptance of CEB's Corrective Action Prograrr for Rigorously Analyzed Pipe Supports A-9
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Observation CEB-14 indicated that Engineering Assurance (EA) acceptance of CEB's program to identify and regenerate missing pipe supports was prematur This was because CEB had not addressed the generic implications of the findings from CEB's design verification of 201 of the 791 pipe support calculations TVA's response which the DBVP identified as missing and which CEB regenerate to Observation CEB-14 noted, in part, that EA would review any significant
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I changes to the pipe support regeneration program, The team confimed and that EA haswculd overview CEB's had respon-implementation of the progra sibility to review and approve the following Civil Engineering Branch
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i instructions, which formed the basis for CE8's pipe support calculation ,
regeneration program:
CEB-CI 21.80, "Program Plan for Calculation Regeneration of Pipe Supports (1) on Rigorously Analyzed Category I Piping - Sequoyah 2," Revision 1, dated August 28, 1987 CEB-DI 21.81, "Generation and Control of Rigorous Analysis Revision Problem 1, dated Connec-(2) tivity Diagrams for Category I Piping: Sequoyah 2."
August 28, 1987 CEB-DI 21.83, "Functional Verification of Supports for Rigorously Analyzed
"
l (3) Category 1 Piping: Sequoyah 2 " Revisian 2. dated August 28, 1987 (4) CEB-DI 21.85, "Generation of Pipe Support Design Data: Seouoyah 2."
Revision 1, dated September 4, 1987 (5)
CEB-DI 21.87, "Review and Regeneration of Calculations for Supports on Rigorously Analyzed Category I Piping: Sequoych 2 " Revision 1, dated
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3eptember 4, 1987 CEB-CI 21.88, "Control of Input and Output from the SQN Hanger (6) Tracking Subprogram of Calculation Cross Reference Infomation System,"
- Revision 0, dated July 15, 1987 CEB-CI 21.89, "Modification Priorities for Pipe Supports Revision on Rigorously 0, dated August 20, (7)
Analyzed Category I Piping - Sequoyah Unit 2,"
i 1987 As indicated by the above, EA has maintained an active oversight role in monitoring the corrective action program for rigorously analyz d pipe support Observation CEB-14 is close (Closed) Observation GEN-3 - Unverified Assumptions This observation addressed the team's concern that no administrative program or procedures were in place that delineated the requirements forteam TVA informed the verification of i
' unverified assumptions in TVA's calculation progra verbally during previous inspections that all unverified assumptions contained in "essential restart" calculations for SQN will be verified before the plant l would be restarted.
l TVA infortred the team that a program for verification of unverifiedThis progr
assumptions was initiated on June 5, 1987. Nuclear Engineering Pr i
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log implemented by the Calculation Cross Reference Infomation System (CCRIS).
The team reviewed Revision 1 of NEP-3.1, noting that section 4.1.1 of this procedure directs the lead discipline engineer and assistant branch chief to trackcalculationscontainingassumptions(requiringlaterconfirmation)
through the CCRIS or a calculation log. For SQN Unit 2 calculations, all disciplines were directed by the Manager of Nuclear Engineering to resolve all unverified assumptions by August 31, 1987. TVA informed the team that NEP- programatic controls will be revised to include requirements for timely closure of unverified assumptions. The team noted that each discipline had already developed their own tracking program for tracking unverified assumptions. The team found these measures taken by TVA acceptabl Therefore, this observation was close '
(0 pen) Observation CEB-15 - Technical Adequacy of Miscellanecus Structural Steel Initially, CEB reviewed 54 features to detemine the technical adequacy of miscellaneous structural steel at Sequoyah Nuclear Plant. Considering the
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findings of this review, the team was concerned that this initial sample size was not large enough to represent the total population of miscellaneous structural stee l
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In order to resolve this observation, TVA increased their sample size to review 38 more missing calculations which were recently generated. TVA will also select 60 equipment support calculations, which will be reviewed to detemine
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i whether the appropriate vendor loads have been utilized in the design. TVA stated that this effort would be completed by November 30, 198 The team did not perform a technical review of this effort by TVA. However, the conversations held by TVA engineers showed that TVA is preparing an interim acceptance criteria which would be used to qualify miscellaneous structural steel items. The team stated that any interim c.1teria which deviates from the f
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comitted FSAR structural steel stress limits should be submitted to the NRC for review and approval.
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Although the team agrees with the sample size which TVA selected to detemine the technical adequacy of miscellaneous structural steel, this item will be kept open pending a confimatory letter documenting completion of this effor The team considered that work relating to this observation should be completed i
prior to restar (0 pen) Observation CEB-16 - Conduit and HVAC Duct Support Calculations CEB's review of recently regenerated calculations (five conduit and four HVAC i
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duct support calculations), identified numerous discrepancies between the calculations and the associated design criteria. TVA perfomed this review as ,
part of their technical adequacy review of CES calculations. The team reviewed the CEB findings and concluded that the regenerated calculations lacked com-
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plete and adequate analysis. Also, 9 e contract personnel used to regenerate l
- i these calculations were apparently nut fully aware of the applicable CEB design t l criteria and TVA standard practices, i
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In order to resolve the technical issues raised by the TVA findings. TVA has written CAQRs SQT870626 and SQT870843 to pe fom evaluations of the design of A-11
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During the NRC inspe conduit supports. HVAC ducts and HVAC duct support tion, this effort was still ongoing for the HVAC ducts and duct support l Team meetings with TVA engineers revealed that certain allowable stresses (as stated in Sequoyah design criteria SQN DC-Y-13.10), were exceeded for conduits and clarps. The team stated that any interim criteria that deviates from FSAR requirements should be submitted to NRC for review and approva Regarding contractor efforts, CEB issued instruction Cl-21.53 (RIMS No. B41 870916 007)
which clarifies the duties and responsibilities of each TVA or contractor designer in the development of design calculations. CEB also has I sent each employee a memorandum emphasizing the need to improve the quality of j This observation remains open pending completion of TVA work CEB calculation on HVAC duct and duct supports, and review by NRC Office of Special Project l
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Appendix B LICENSEE ACTION FOR PREVIOUS DBVP INSPECTION FINDINGS The team reviewed the corrective actions taken by TVA to resolve the open
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deficiencies and observations identified in NF.C inspection report Nos. 50-327 and 50-328/86-27, 86-38, 86-45, 86-55, 87-14, and 87-31, which examined the DBVP. Correspondence associated with these findings, including TVA responses, The following are the team's coments on these are tabulated in Attachment ;
item !
Report No. 86-27 (0 pen) Deficiency 04.3-3 - Steam Generator Access Platform Design The initial NRC inspection identified that the steam generator lower supports were not evaluated for permanently attached platfom loads added by an EC During the walkdown of these supports to determine platfom loads, TVA identi-fied additional pipe supports that were attached to these steam generator supports which were not accounted fcr in the original desig Westinghouse has recently completed a reevaluation of these supports using the walkdown infomation to show that the supportsThe areattachments structurally of adequate these supportsto
carry the additional loads (B45 861219 601).to concrete were reanalyz Westinghouse evaluation. The calculations by TVA, B25 8711120 452, showed that the attachment stresses are within FSAR requirements. TVA also evaluated the crane wall for the additional loads obtained from the Westinghouse analysis. This calculation, B25 870903 454, showed that the crane wall is adequate to carry these additional load During the NRC inspection, TVA engineers stated that the walkdowns perfomed on the steam generator supports were not in accordance with the TVA Quality Assurance requirement They also stated that these walkdowns will be perfomed again (post-restart) using the TVA Quality Assurance requirement This observation was kept open pending a Corporate Commitment Tracking System comitment to perfom these walkdown Report No. 86-38 (0 pen) Observation 6.3 - Instrument Sense Line TVA performed a walkdown of approximately 200 instrument sensing lines for a l
technical adequacy verification of the instrument process sensing lines rela-I Based on the TVA walkdown results, the tive to Sequoyah drawing requirements.
j team recommended a more complete walkdown o' HVAC safety-related instrument connections. TVA subsequently performed an additional walkdow A large
number of HVAC instrumentation discrepancies were documented. The team was satisfied with the technical depth of this TVA re-review. During this process, TVA a number of instrurent sense line "as-built" sketches were prepare indicated that a review of technical adequacy for these sketches was in process, and that when completed, these sketches would be converte fomal TVA drawing submission of a schedule for completing these HVAC instrurentation drawing ;
B-1
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Report No. 86-45 There are no observations which remain open for inspection purposes for inspec-tion report 327,328/86-4 Report No. 86-55 (Closed) Observation 6.12 - CCS Surge Tank Baffle The CCS surge tank has an internal baffle plate to provide independence of the TVA conducted CCS surge tank leakage tests which two redundant water volume In derronstrated the integrity of the baffles in the Unit I and 2 tank addition. TVA has comitted to perform a periodic test of the surge tanks at 10 These actions were considered year intervals (RIMS No. S53 871028 895).
satisfactory by the tea (Closed) Observation 6.14-ImposedVoltages During previous hRC inspections, the team had comented S)ecifi-Change Notice and Field Change Notice Documents," was result from postulated failures at the electrical terminal board con within a cabine review has been superseded by SQEP-13 for the design control transition perio This new procedure does not require the use of checklist questions for a design change evaluatio Instead. TVA has issued several docurents that provide guidance for ECN and field change notice evaluations, as follows:
(1) Nuclear Perfomance Plan, Volume 2 Procedure 0604.04, Revision 1 dated June 30, 1987, "Evaluation of (2)
Changes. Tests, and Experiments" for the unreviewed safety question determination (USQD) evaluation in accordance with 10 CFR 50.59 Revision 1, dated August 14, (3) Training Program Material EGT024.001
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1987, "USQD Evaluator Certification Training" to provide training information for USQD evaluators The team noted that single failure analysis requirerr.ents, including aSince consider-ation of internal cabinet failures, were described in these documents.
j the purpose of an s imposed voltage analysis is to assure that any single cabine failure cannot prevent accc3plishment of protective functions when require the documentation provided by TVA appeared adequate to cover the team's con-l cer A second aspect of this observation concerned TVA's the accep.This ability of relay
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contact-to-contact calculation did not address electrical the electrical isolation (RIMSvoltage breakdown No. B43 870803 capability of 905).
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adjacent relay contacts where one contact is used in a Class 1E TVA subsequently deter- circuit and other contact is used in a non-Class IE application.
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I mined that the NEMA breakdown voltage is a mintmum of 2200 volts (2 times rated voltage plus 1000 volts) in each instance where contact-to-contactTV isolation has been used at Sequoyah.
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would be revised to reflect that contact-to-contact and coil-to-contact isolation between IE and non-lE circuits on qualified Class IE switching devices such as limit switches, relays, and circuit breaker auxiliary switches is analyzed considering the maximum credible voltage and current faults in the (
non-1E circuit. The team considered these actions adequate, therefore this j item is close l (0 pen) Observation 6.15-PeriodicfunctionalTestandResetTimers Half-second reset timers in four safety-related pump motor circuits had not been subjected to periodic calibration or system functional tests. TVA cali-brated the reset timers by disconnecting their wiring leads, but did not perfom either an in-circuit system functional test or an overlapping test to confirm correct operation of the Class 1E circuit TVAhastakenaposition(RIMSNo.B43860930901) that only those modifica-tions involving concurrent loss of offsite power and a loss of coolant acci-dent are a pre-restart activity based on an April 20, 1983 NRC Power Systems Branch memorandum. This memorandum stated that a loss of offsite power subsequent to a LOCA was not a design basis event since it did not significantly contribute to the probability of core mel However, the team considered that this TVA position is in conflict with their comitment to the periodic test criteria specified in IEEE Std. 338-1971 and NRC Regulatory Guide 1.22 as described in FSAR sections 7.2.3 and 7.3.2. Since the nonconcurrent loss of offsite power and a loss of coolant accident
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reset timer circuits are installed in the same Class 1E circuit with other '
portions of the pump motor actuation controls, the omission of systems l
functional or overlapping tests for the reset timers could cause an j unmonitored degradation of the pump motor Class 1E circuits. Moreover, the
' team noted that, although TVA may have a valid point regarding whether or not the plant design must address nonconcurrent loss of offsite power and a loss of coolant accident, because these circuits are installed at SQN they will be '
in effect for a certain fraction of poctulated events. In light of this possibility, the te,w considers that testing should verify the entire circuit on either an integnted or overlapping basi ,
Report No. 87-14 (Closed) Observation 3.13 - West Steam Valve Room Pain Steam Line Break
- Evaluation
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Observation 3.13 indicated that CEB did not prepare the pipe rupture calcula-
tions for the valve room walls in accordance with the FSAR and design criteria.
' On June 4, 1987 CEB issued RevP, ion 1 to CAQR SQP870183 to specify the i
required corrective action powrenort. However, CEB has completed the
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corrective actions required to veriiy the structural adequacy of the valve i room walls. The team reviewed the following CEB documents:
! (1) Two proposed amendments to the FSAR i (2) Sequoyah Nuclear Plant Concrete Evaluation Report, dated February 6, -
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i (3) QlR NEB 87111, dated March 26, 1987, which transmits NEB-generated pipe break design pressures in the west main steam valve room to CEB ,
(4) CEB calculation "Auxiliary Building West Yalve Room Pipe Rupture " Revi-sion 1, dated August 21,1987(RIMSNo.B25870821489)
(5) CEB calculation "Roof Slab El. 729.0 Auxiliary Building," Revision 3, dated August 19,1987(RIMSNo.B25870821488)
(6) CEB calculation "Cumulative Attachment & Rebar Cut Evaluation - Structural Wall.e " Revision 1. dated August 19,1987(RIMSNo.B25870821487)
CEB also indicated that design criteria SQN-DC-V-1.3.3.1, "Additions After November 14, 1979 - Reinforced Concrete Structural and Miscellaneous Steel "
will be revised consistent with the proposed FSAR amendrents. The team considered these actions adequate; therefore, Observation 3.13 is close (0 pen) Observation 6.16-HVACFlowSwitchCalibrationDataRecordsand System 30 Surveillance Instruction Procedures Section 9.4.5.4 of the Sequoyah FSAR states that the electrical components, switchovers, and starting controls of the diesel generator building ventilation and heating systems are tested initially and periodically. The team noted that surveillance procedure 501-82 does not provide assurance that the HVAC system is operating properly because it does not exercise the starting controls or train-to-train switchover interlocks. The team considered that TVA has not prepared nor perfonned an appropriate surveillance instruction that would satisfy the FSAR comitment; hence, the team was unable to resolve this concer (0 pen) Observation 6.17 - Diesel Generator Building Ventilation fans Control Logic and Surveillance Instruction Procedure This observation identified drawing errors in logic diagrams and noted that the control circuits were not tested in accordance with FSAR comitments. TVA has committed to correct the mechanical and control logic diagram inconsis-tencies with electrical wiring diagrams prior to restart; however, TVA has not prepared nor perfonned surveillance instructions to test the HVAC controls and interlocks as comitted in the FSAR.
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(Closed) Observation 6.18 - Centrifugal Charging Pump Auxiliary Cil Pump Low Flow Bypass Switch TVA installed a two position bypass switch for fire protection purposes which permitted the centrifugal charging pumps (CCPs) to start without initial oil
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pressure whenever the switch was placed in its bypass position. Westinghouse
' letter TVA-87-796, dated September 18, 1987, stated that one or two such starts would be acceptable provided that a minimum oil pressure of 10 psig was rain-tained. TVA prepared an analysis of vibration measurements taken for each CCP over the past two years which indicated that no bearing degradation or wear was i evident even though 21 individual pump starts occurred without auxiliary oil
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pressure. Consequently, TVA concluded that additional administrative controls 1 r !
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r were not required for the CCP's. The team agreed that the vibration data !
supported TVA's conclusion; hence, this item is close '
Report No. 87-31 (Closed) Observation 3,16 - Valve Motor Operator Orientation Observation 3.16 indicated that MEB had prepared problem identification report (PIR) SQN-MEB-86-127 to document differences between the installed orientation and the piping physical orientation of ten component cooling water system (CCS)
valve motor operators. However, MEB did not request a potential generic To address this deficiency, MEB revised PIR condition evaluation for the PI SQh-MEB-86-127 to request a potential generic condition evaluation and CEB revised the calculation "Sumary of Analysis N2-PIR-MEB-86127-MISC." (RIMS N ) to evaluate the generic implications of the PIR. DNE will revise Nuclear Engineering Procedure 9.1, "Corrective Action," to require that justification for determining that a generic review is not required be docu-mented on the CAQR. Observation 3.16 is close (0 pen) Observation 3.17 - Solenoid Valve Mounting Support Observation 3.17 identified two installed variances to a typical solenoid valve mounting support detail which lacked seismic qualification calculations. To
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address this deficiency, TVA was generating a calculation package that will qualify the instrument line support variances to current (default) or Unit 2 restart criteria. TVA indicated that the calculation package will be generated before restart of Unit 2. Observation 3.17 remains open until TVA confinns that an acceptable calculation to qualify the instrument line support variances
- has been issue (0 pen) Observation 4.8-RadiationMonitoringSystem TVA provided the team with revised Quality Infomation Report (QIR) NEE 86 241 RI(B45871016251) that concludes the corrective action need not be perfonned prior to restart since: The sample line isolation valves that serve a containment isolation i
function will close upon loss of ai . The fact that the system has not been specifically designed to remain functional when subjected to a safe shutdown earthquake was determined l
' accepteble in Section 5.2.4 of the Sequoyah Safety Evaluation Report, NUREG-0011. March 197 The team considered that TVA had adequately addressed inconsistencies regarding QIR NEB 86 241, and that that system design was consistent with that accepted f by NRC during initial plant licensing. Therefnre, a post-restart classification was appropriat This item remains open pending a CCTS comitment to complete l
the corrective actio (Closed) Observation 6.20 - Preliminary DBVP Report The team was concerned that a large nurnber of mechanical walkdown findings were designated as random occurrences in the preliminary DBVP report. The issued B-5 ,
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redesignated the mechanical walkdown findings DBVPreport(RIMSB25870529010) This redesignation was as 'of a limited extent", rather than being "random."
acceptable to the team; hence, this item is close (0 pen) Observation 6.21 - Post-Accident Monitoring TVA's electrical separation design criteria document. SQN-D The existing Sequoyah design does not fulfill ing PAM-1 and PAM-2 channel Full implementation of these separation comitments for the PAM-1 channe accident monitoring instrumentation in accordance with NRC perio The team reviewed TVA's preliminary plans for the interim and the final imple-mentation of physical separation and electrical isolation of the PAM-1 and In the interim plan, high impedance resistor temination PAM-2 channel networks would be added within the R26 and R27 termination cabinets to isolate each PAM channel from the process compute fied Class IE isolator to each PAM-1 channel to satisfy the FSAR separ criteria comitment. technically satisfactory; however, these plans remain to be documented as a formal comitment incorporated into the Corporate Comitment Tracking Syste (0 pen) Observation 6.22 - Auxiliary Control Air System A postulated design basis event could cause the temporary loss of one auxiliary control air system because of a lack of physical separatinn of safety-related auxiliary control air piping inside containment relative to high energy line A postulated single failure during this Forevent could approximately break (crack) source also eliminate the redundant auxiliary control air syste .5 minutes after the design basis accident, safety-ritated auxiliary controlAir press air would be lost to HVAC damper and instrument load gradually restored to the affected auxiliary control air system once its containment isolation valve closed automatically on low pressur TVA has examined The team reviewed the licensee's evaluation for this even the impact of this scenario on the HVAC systems 30 and 31; emergency gas treatment system; auxiliary building gas treatment system; auxiliary feedwater and main stream control valves; containment butiding vacuum relief isolation valves; transfomer room ventilation system; control building air conditioning; 480 volt shutdown board room ventilation; and shutdown board TVA also determined that safety-related ventilation fans room ventilatio either continue to operate or will automatically restart at 7.5 minutes when auxiliary control air would be fully restored to the affected trai The team questioned two aspects of this analysis; namely, a determination of the time required for operator action based on higher heat loads in the 480 volt shutdown board rooms than those assumed by TVA, and a review operating procedures used by the control room operator for the ventilation systenThe team s process-auto control switches. operator will adequately respond during the post allowed for operator action is not too prompt fless than 30 minutes).
B-6
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(Closed) Observation 7.5 - Punchlist Accuracy The DBVP cunchlist was generated to track and resolve concerns resulting from FCN reviews, system evaluation ieviews, NRC inspections and internal EA over-sight reviews. Each of these concerns was identified by a unique punchlist numbe . The forms which control the list (SQEP 45-Attachment 2 Forms) provide a description of the concern, proposed corrective action, schedule for correc-tive act5on such as post-restart or pre-restart, status of implementation of the corrective action and a short explanation if the item was categorized as a post-restart item. NRC team review of ;;unchlist items revealed that the These errors were related to one or more factors punchlist had many errors.such as incorrect schedule category, incorrect status of corre incorrect definition of corrective action to resolve the punch 11st item, errors relating to problem description, incorrect data on SQEP-45 attachment 2 foms, absence of such forms, and editorial errors. To resolve this concern TVA initiated the following action Regarding the timeliness and accuracy of the control and processing of changes, the DBVP project issued DBVP Directive DBVP-D-87-008, dated August 5, 1987. This directive requires the punchlist changes to be classified as administrative changes, implementation status changes, or technical change Technicul and implementation status changes require review and approval by the The punch-responsible system engineer and discipline evaluation supervisor. lis the requirements of SQEP 45 and Directive D-87-008 have been tre TVA stated that these actions, together with those required by previously issued DBVP Directives 87-12. 06, and 07, greatly improved the consistency and correctness of the punchlist data base.
(
The team considered that the above steps taken by TVA to resolve concerns l regarding punchlist errors acceptable; however, the team was concerned with their irrplementation. EA informed the team that they had reviewed approxi-
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mately 333 valid punchlis 'tems and verified that the directions of the above directives were followe- properly. Considering the extent of implefrentation reviews performed by the oversight effort the team concurs with the review results and considers this item closed, i
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APPENDIX C MEETINGS AND REFERENCES C.1 MEETINGS Table C.1 provides a matrix of meeting attendance and lists principal persons contacted for the meetings conducted during the inspection. Other licensee personnel were also contacted. The following paragraphs summarize the general purpose of these meeting Meeting 1: On October 26, 19B7, the NRC held an entrance meeting. The NRC reviewed the tEcm's plans to inspect the calculation review program and to assess the adequacy of TVA's corrective actions for previous inspection finding Meeting 2: On October 28, 1987, a meeting was held to discuss the interim status and the results of the inspection as of this dat Meeting 3: On October 30, 1987, the hRC held an exit meeting at the plant site to summarize the results cf the inspection team's effort Table C.I - MEETINGS Title Meeting Attended Nama Orcanization 1 2 3 X X X REArchitzel NRC-NRR Team Leader X X SVAthavale NRC-NRR NRC-Electric Power X NRC-Mech. Components X X X AduBouchet NRC-Consultant X X NRC-Consultant NRC-Mech. Systems X FJMollerus X X X AIUnsal NRC-Consultant NRC-Civil / Structural X X LStanley NRC-Consultant NRC-Instr./ Controls X X X EFGoodwin NRC-0SP Tech. Assistant X X APCapozzi TVA-DNE Manager - EA-EA MPBerardi TVA-EA EA Oversight Ad X X TVA-ONP-DNLRA Licensing-Sequoyah X X X BHall X RJames TVA-DNE Civil DES X
PBNesbitt TVA-DNE Electrical DES DBVP Eng. Mg X X DLKitchel TVA-DNE RTHolliday ONSL-KLS Nuclear En X X X X
TCPrice TVA-DNE Design Basis Mg X X X
PKGuha TVA-DNE Asst. Br. Ch. - EEB X X X WPennell TVA-DNE Mgr., E&TS LJones TVA-ECB Acting Mgr., ECB X X Alenyard TVA-ECB Section Supervisor X X DGRenfro TVA-NEB Principal Nuc. En X X JCKey TVA-SQEP Asst. Proj. En X X GLNicely TVA-EEB Sr. Elec. En X X KDKeith TVA-NEB Sr. Nuc. En X X X TVA-CEB Asst. Chief Civil En X X RDHernandez TVA-CEB Sr. Geotech. En X X X SDStone X X FEDenny TVA-EA Sr. Lead Auditor X X
DLWilliams TVA-DNLRA Acting Manager X JPLittle TVA-PEB Sr. Mech. En X X X X FAKoontz, J TVA-NEB Asst. Branch Chief X TVA-SCEP Asst. Lead En X X PRWasher JARoop TVA-EEB Sr. Elec. En X LWBoyd TVA-MEB Sr. Eng. Specialist X C-1
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C.2 REFERENCES (1) Inspection Report 50-327/86-27 and 50-328/86-27, fomarded 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) TVA response to Inspection Report 50-327/87-06and50-328/87-06(Domer to NRC) dated July 2, 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),
dated February 3, 198 (8) TVA response to Inspection Report 86-55 and other Inspection Items remet 1g open (Gridley to Ebneter), dated April 22,19C/.
(9) Inspes: ion Report 50-327, 328/86-55, forwarded by J. Taylor letter dated February 3, 1987.
l (10)InspectionReport 50-327,328/87-06, fomarded by S. Ebneter letter dated April 8, 198 (11) TVA Additional Infonnation in Response to Inspection Report 86-27, l
(DomertoTaylor),datedJanuary 30, 1987.
! (12) Engineering Assurance Oversight Review Report, "Sequoyah Nuclear Plant-
!
Unit 2 Design Baseline and Verification Program," EA-0R-001, issued l
April 29, 198 (13) Sequoyah Nuclear Plant - Design Baseline and Verification Program Unit 2 Phase 1 Report, dated May 29, 198 (14) Inspection Report 50-327, 328/87-14, forwarded by S. Ebneter letter dated June 4, 1987.
j (15) TVA response to Inspection Report 50-327, 328/87-14 (Gridley to NRC),
dated July 16, 1987.
l (16) TVA revised response (Observation 5.7) to Inspection Report 50-327, l 328/87-14 (Gridley to NRC), dated September 1,198 (17) TVA letter relating to control and processing of changes to the punch list (Gridley to NRC), dated August 20, 198 C-2
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s.. 6 (18)InspectionReport 50-327,328/87-27, forwarded by S. Ebneter letter dated August 24, 198 (19) TVA letter addressing SQN-DNE Design Calculation Efforts (Gridley to NRC),datedJuly 31, 198 (20) TVA response to Inspection Reports 87-27 (Gridley to NRC), dated October 21, 198 (21) TVA letter addressing revised commitment date for interface guidelines (Gridley to NRC), dated November 20, 198 (22) TVA letter is response to findings identified during the final NRC inspection of the DBVP (Gridley to NRC), dated October 27, 198 \
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