ML20205D250

Forwards Revised post-restart Scope & Schedule for Design Baseline & Verification Program.Related Info,Including Statement of Util Commitments for Phase II & Justification for Excluding in-core Instrumentation Sys Encl

ML20205D250
Person / Time
Site:	Sequoyah
Issue date:	10/20/1988
From:	Gridley R TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
NUDOCS 8810270084
Download: ML20205D250 (12)

Text

F

• l!e .

Jr .. .

TENNECCEE VALLEY AUTHORITY ,

CHATTANOOGA. TENNESSEE 37401 SN 1578 Lookout Place o

08T 201968 ,

U.S. Nuclear Regulatory Commiss!'n  !

ATTN: Document Control Desk Hashington, D.C. 20553 Gentlemen:

In the Matter of ) Docket Nos. 50-327 s: Tennessee Valley Authority ) 50-328 SEQUOYAH NUCLEAR PLANT (SON) - POSTRESTART SCOPE AND SCHEDULE FOR THE DESIGN BASELINE ANO VERIFICATION PROGRAM (08VP) l Weferences: 1. Preselitation to NRC by TVA on July 21, 1988, "Phase II Design Baseline and Verification Program" -

'2. TVA letter to NRC dated May 12, 1937, "Stauoyah Nuclear Plant - Postrestart Scope and Schedule For The Design ,

Baseline And Verification Program (OEVP)"

In accordance with a TVA commitment made as a part of the reference 1 presentation, enclosure 1 provides the revised DBVP scope and schedule for phase II (postrestart) of SQN units 1 and 2. This information revised the program as outilned in reference 2.

TVA is utilizing lessons learned during the phase I OBVP as indicated in reference 1. This allows the DBVP processes to be optim12ed while ,

retaining the more valuable aspects of phase I efforts. Consistent with [

this position, the commitment to review change documents has been  ;

revised, phase II design criteria have been issued, and functional l walkdowns will be conducted. Overall program findings, corrective  ;

messures, conclusions, and recommendations will be summarized in a  !

phase II final report.

Enclosure 2 states and summarizes TVA's connitments for the phase II I OBVP. As the tabulation indicates, most of these commitments have f already been completed. The commitment to evaluate change documents has been revised in accordance with the reference 1 presentatiot.; existing l commitments address this item. Enclosure 3 inciudes a revision to the .

Issue date for the phase II OBVP final report to December 31, 1989. This  !

change is needed in order to incorporate the results of functional l walkdowns.  !

A K p 30 An Equal Opportunity Employer l

(

2 U.S. Nuclear Regulatory Commission OST 20 28 t

?

Enclosure 4 provides the justification for excluding the in-core instrumentation system (94) from the scope of the phase II effort. When ,

the reference 1 presentation was made TVA intended to include system 94  :

in the phase II OBVP. A recent review of commitments associated with  !

this systeia has indicated that it should not have been included in the  !

phase !! program.

TVA has reevaluated the benefits associated with updating and maintaining i the commitments / requirements (C/R) data base. Based on this review, TVA l has decided to archive the current C/R data base and rely on the i corporate commitment tracking system (CCTS) and the tracking and '

reporting of open item (TR0!) system to track commit. tents, and to rely on l formal engineering procedures to more effectively accomplish and coittrol i design document upd:,tes. The basis for TVA's position is described in i enclosure 5.

Please direct questions concerning this issue to J. H. Proffitt at '

(615) 870-7461. 3 Very truly yours, i TENNESSEE VALLEY AUTHORITY I l

' 9h

..Gridley,Manafer i Nuclear Licensing and Regulatory Affairs Enclosure cc: See page 1

. ~ . :n  !; y L .

-34 U.S. Nuclear Regulatory Commission 08T 20 m

'f Enclosures i cc (Enclosures): t Ms. S. C. Black, Assistant Director  !

1~ 3- for Projects 'i "1 TVA Projects Olvision '

U.S. Nuclear Regulatory Commission  !

One White Flint, North

• 11555 Rockville Pike l Rockville, Marylar.d 20852 ,

i Mr. F. R. McCoy, Assistant Olrector  :

for Inspection Programs .

TVA Projects Olvision l U.S. Nuclear Regulatory Commission '

Region II 101 Marietta Street, NH, Suite 2900 ,

Atlanta, G3orgia 30323 l

Sequoyah Resloent Inspector Sequoyah Nuclear Plant l' 2600 Igou Ferry Road' Soddy Dalsv, Tennessee 373 9  ;

i t

I l

f I i 1 >

I t

4 w

e .

g

? ENCLOSURE 1 POSTRESTART PHASE DESIGN BASELINE AND VEPIFICATION PROGRAM (DBVP)

SCOPE AND SCHEDULE INTRODUCTION The following discussion provides the information describing the postrestart phase of the OBVP (phase II). Specifically, it defines the actual systems that are included, the attributes of the phase I scope that are applicable, and a schedule for completion.

Phase II will establish the functional baseline for the safety-related systems or portions of systems as defined by table 1.

SCOPE i

The scope of the program is divided into design control activities and ,

baseline and verification activities.

Deslan Control i Implementation of improved design control practices that began in phase I will continue. The transitional design control system will continue to be used .

until all work initiated under this program is complete. Implementatien of l the permanent design control program began on March 31, 1988.

E)seline and Verification ,

A. Safe shutdown and accident mitigation (SS/AM) systems These systems or portions of systems were the subject of phase I. Work in phase II to complete thh, scope is as follows:

1. Po'trestart modifications and documentation corrections identified in phase I will be completed.

2. Postrestart configuration control drawings (CCDs) will be issuod.

B. Additional safety-related systems This scope includes the additional safety-related systems and the additional safety-related portions of the SS/AH systems defined by table 1. Calculation SQN-SQS4-0129 has been prepared to define the phase Il system boundaries.

1. Design Criteria / Design Basis The existing C/R data base has been used to develop new or to revise existing design criteria, as needed, to cover the system scope.

2. System Walkdown/ Test System walkdowns will be performed as needed to verify the functional configuration of the phase II systems. Equivalent means, such as functional testing, may be substituted for system walkdowns where appropriate. Olmensional data will be obtained from the waikdowns, as required, for inp1t to the CCD program.

Test reviews will not be performed as a part of the phase II OBVP.

The units I and 2 restart test programs adequately address the portions of systems 74, 77, 84, and 90 included in the phase IT scope (see table 1). Moreover, either a verification of functional operability or an in-service functional test will be performed for the phase II portions of systems 68, 78, and 79 (see table 1). Thus, phase II OBVP test reviews would be a duplication of effort, f

3. Evaluation of Engineering Change Notices (ECNs) Not Addressed in Phase I of the DBVP (Implemented ECNs Pertaining to Systems 79, 84, and the Phase II Portions of the Other Systems in Table 1)

Recent enhancements in the TVA design control process,'resulting in large measure from the phase I DBVP, make an independent plant change evaluation under the phase II DBVP an unnecessary dupilcation of effort. Th:re are four NRC commitments that meet the intent of the change document review:

1. NCO-87-0041-001 Complete ECN backlog closure en support of the 1989 Final Safety Analysis f.eport (FSAR) update

2. NCO-87-0041-003 Complete the FSAR verificition program

3. NC0-87-0184-003 Devclop CCOs

4. NCO-87-0184-002 Implement the permanent design control program (This program has been implemented.)

In conjunction with the walkdown effort discussed above, these four commitments considered collectively provide assurance that modifications are done consistent with the scope of the authorizing ECR and do not violate requirements stated in the associated safety evaluation, unreviewed safety question determination. Moreover, the commitments mandate that plant configurations be accurately shewn on CCOs and accurately depicted in the FSAR. Thus, it is concluded that these four commitments in combination provide a satisfactory basis for satisfying this phase II OBVP connitment, i

l

t i

The evaluation of change documents, other than those explicitly stated above, associated with these systems was performed during phase I  ;

under Sequoyah Engineering Project (SQEP) 26 (procedure for evaluating ECNs, field change notices, etc., not reviewed by phase I OBVP).

4. Final status report and corrective actions The objectives, results, and conclusions of this program will be documented in a final report for submission to the TVA vice president in charge of nuclear engineering. Based on review of the report, this .

individual will determine if the stated objectives of the program hava 1 been met or if additional actions are required.

Corrective actions required to resolve discrepancies identified in the phase II OBVP may require drawing changes, design basis document changes, and/cr licensing commitment changes. These findings will be i tracked by a punchlist data base and TVA's corrective action process (Nuclear Engineering Procedure (NEP] 9.1), as appropriate.

SCHEDULE The overall schedule for phase II is shown in exhibit 1. The program is scheduled to conclude with the issuance of the final report on or before December 31, 1989. Exhibit I depicts the interrelationships between the '

various phase II program elements and associated commitments.

ORGANIZATION A team to implement the phase II effort will be organized under the SQN l engineering project. Liaison within Nuclear Quality Assurance, Site -

Licensing, Nuclear Construction, and Nuclear Engineering organizations at SQN will be established and maintained.

ENGINEERING ASSURANCE (EA)

EA ovesiiW.'. af the phase II DBVP effort will be accomplished by the .

performance of 'achnical audit; of phase II activit.es to verify adequacy of 7 phase II DBVP and inte.iecing programs. A separate program plan will be  ;

prepared to define the scope and detalls of this activity.

PROGRAM PROCEDURES ,

Procedures required to assign specific responsibilities, define methods, and establish documentation requirements are being developed or revised, based on j phase I experience, i i

f

_ _ _ _ ~__

?

TABLE 1 PHASE II SAFETY-RELATED SYSTEMS SYSTEM NO NAME ___

68 Reactor Coolant System--Reactor Vessel Level Indication System (RVLIS) 74 Residual Heat Removal System--Cold Shutdown Capability 77 Waste Disposal System--Effluent Monitoring 78 Spent Fuel Pool Cooling System--Pumps, Heat Exchangers, and Associated Equipment 79 fuel Handling and Storage System--Fuel Handling Accident 84 Flood Mode Boration System--Entire System 90 Radiation Monitoring System--Effluent Monitoring i Note: Portions of systems 68, 77, 78, and 90 received phase I evaluations.

The phase II scope for these systems consists of the remaining safety-related portions a: described in +,he above table. The in-core instrumentation system (94) will not te included in the. phase II DBVP. See enclosure 4 for the justification.

EXHIBIT I 1/88 1/89 1/90 1/91 l

TRANSITIONAL SYSTEM PHASE OUT DESIGN PERMANENT SYSTEM IN EFFECT CONTROL GUN CLOSURE, 1989 FSAR UPDA_TE, CCD PROG IN IEU OF CHANGE 00C REVIEH (12/31/89)

POSTRESTART HOOS & DOC (10/1/89)

DEVELOP CCD'S FOR CONTROL ROOM AS-CONFIGURED ORAHINGS (CRADS)

PHASE I & II (12/31/89) l HALKDOWNS CRADS (10/1/89) 8 COMPLETE OC 7/29/83 FINAL REPORT 12/31/89 SCHEDULE OBVP SON UNITS I & 2 PHASE II l

)

i a

ENCLOSURE 2 PHASE II DBVP COMMITMENTS ORIGINAL COMMITMENT NUMBER DESCRIPTION OUE DATE STATUS NCO-86-0297-013 Extend DBVP to other systems 01/31/90 New date 12/31/89' NCO-66-0471-002 Complete phase II design 05/31/88 Cc.oplete criteria (superseded by items NCO-86-0471-006,

-007, -008, -009, and

-010)

NCO-86-0471-003 Submit phase II scope 03/21/87 Complete and schedule to NRC (superseded by NCO-87-0001-004)

NCO-86-0471-004 Perform phase II OBVP End of U2C4 New Date I walkdowns Refueling 10/01/89' Outage l NCO-86-0471-006 Complete phase II design 05/31/88 Complete l criteria for systems 74, 77, l 84, and 94 l NCO-86-0471-007 Complete phase II design 06/30/88' Complete criteria for system 90 NCO-86-0471-009 Complete phase II design 07/29/88 Complete c ' aria for system 79 NCO-86-0471-010 cv ete phase II design 07/29/88 Complete criteria for system 78 l

NC0-87-0001-004 Submit phase II scope and 06/21/87 Complete I schedule to NRC NCO-87-0184-001 Issue phase II OBVP final 10/01/89 New Date status report 12/31/89 8 NCO-87-0184-002 Implement permanent 03/31/88 Complete design control system NC0-87-0184 Develop configuration 12/31/89 On schedule control drawings NCO-87-0184-004 Perform phase II DSVP 04/01/89 See Note change document review 3 below and test evaluations This date was reviewed and schedule leproved because of the exclusion of system 94 from phase II.

8 This date has been revised in order to adequately reflect system walkdown findings in the final status report.

This phase II DBVP commitment has been revised, see enclosure 1. Items B.2 and B.3 for detall.

ENCLOSURE 3 REVISED COMMITMENT LIST TVA will issue the DBVP phase II final report by December 31, 1989.

~

ENCLOSURE 4 IN-CORE INSTRUMENTATION SYSTEM (94)

JUSTIFICATION FOR EXCLUSION FROM PHASE II DBVP System 94 consists of two subsystems: the flux mapping system and the in-cors thermocouple system. This system was originally included in the phase II OBVP scope, and an associated design criterion was issued. A review of the system boundary and associated commitments has shown that this system is outside the scope of the phase II program. The basis for this position is discussed below.

FLUX MAPPING SYSTEM This system prov' des a means of acquiring data used to verify raactor core parameters. The syster boundaries range from the initiating devices (moveable flux detectors) to the system output devices (strip chart recorders) and l include the thimble guide tubes, seal table rotary transfer devices, and drive ,

units. This system performs no active plaat safety function, but portions of '

the system meet safety-related design requirements to ensure that other interfacing safety systems are not degraded. These safety-related features (selsmic and reactor coolant system pressure boundary requirements) were i evaluated under the phase ! OBVP; therefore, no additional evaluation is l necessary.

IN-CORE THERMOCOUPLE SYSTEM The in-core thermocouple system was also originally designed as a non-safety-related data acquisition system. The boundarles of the prasently installed system range from the in-core thermocouples to the information readout in the main control room inclusive of the reference junction box and the process computer units. The original system requirements were changed as

• a result of NRC regulations stated in NUREG-0737, II.F.2, and regulatory guide l 1.97. TVA was committed to complete the upgrade of this system to class IE I

l requirements before restart following the unit 2 cycle 4 refueling outage.

Modifications will be performed by ECN L6189, which is currently unlmplemented, under the improved, permanent design control process, which began during phase I OBVP. A walkdown of the upgraded system cannot be performed until after the unit 2 cycle 4 refueling outage, which is inconsistent with phase !! objectives and schedule. However, upon implementation, ECN L6189 will be reviewed for completeness / closure in accordance with NRC commitments as discussed in enclosure 1, item B.3, which does satisfy phase II DBVP objectives.

~.

!' ENCLOSURE 5 BACKGROUND The concern of how to en;ure past commitments and requirements were incorporated when preparing design baseline documents was discussed with NRC.

TVA's solution was to establish the C/R data base as described la a December 31, 1986 letter to NRC (L44 861231 808). In thl: letter, TVA discussed how the C/R data base was to be developed and how it would be utilized in design criteria preparation to support the DBVP. As indicated in another letter to NRC dated February 27, 1987 (L44 8702227 805), the C/R data base was an enhancement tool for Jesign criteria preparation.

Based on the need to capture C/Rs on SQN before the start of the DBVP (mid-1986), the C/R data base was a useful tool. Continued maintenance and updating is, however, a duplication of effort based on the requirements in NEP-6.1, 6.2, 6.3, 6.4. 6.5, and 6.7. Specifically, NEP-6.1, attachment 1 "Checklist of Potential Effects on Design Documents"; section 3.5 of NEP-6.4 on plant modifications package requirements; and NEP-6.7, "Documents Update Process--Modifications," provide lists and specific requirements to address design documentation revisions in support of plant changes. Also, Program Manual Procedure (PHP) 0602.01, section 6.3, requires a response package, which contains such items as:

Impact on prior regulatory positions, documentation, regulations, TVA policy, procedures, or commitmants Allocations of resources, schedul e, and cost Moreover, section 11.1.2.7 of the SQN Nuclear Performan;e Plan (NPP) outlines the method of capturing and controlling TVA's commitments to NRC. The SQN Site Licensing CCTS was established to fulfill this commitment. In addition, section II.2.5.1 of the NPP discusses the use of the TROI system for improving the systematic flow and timeliness of corrective action implementation. These two tracking systems, in combination, will be a substantial impro'erent to the C/R data base in ensuring that commitments and requirements are appropriately captured in design documentation.

CONCLUSION The current C/R data base has served its intended purpose as an enhancement tool in design criteria preparation in support of DBVP. The C/R data base as it is now structured is also a duplicatien of the requirements delineated in specific NEPs, PHPs, and NPPs. Therefore, the C/R data base for SQN will be archived, and the processes described above will be utilized to trach and incorporate commitments in design documentation.