ML20195J286

Forwards Itemized Responses to Open Items & List of Commitments in Response to NRC 871030 Insp of Corrective Actions Re Design Baseline & Verification Program

ML20195J286
Person / Time
Site:	Sequoyah
Issue date:	01/20/1988
From:	Gridley R TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
NUDOCS 8801270165
Download: ML20195J286 (7)

Text

TENNESSEE VALLEY AUTHORITY SN 157B Lookout Place January 20, ]988 U.S. Nuclear Regulatory Conmission ATTN: Document Control Desk Washington, D.C. 20555 Centlemen:

In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority ) 50-328 SEQUOYAH NUCLEAR PLANT (SQN) - DESIGN BASELINE AND VERIFICATION PROGRAM (DBVP)

On October 30, 1987, an NRC inspection team from the Office of Nuclear Reactor Regulation concluded a 1-week closecut inspection of open items associated with the TVA Division of Nuclear Engineering calculation effort and the SQN DBVP. The team reviewed the corrective actions taken by TVA co address 48 open observations originating in 8 previous NRC inspection reports (NRC Report Numbers 50-327, -328/86-27, 86-38, 86-45, 86-55, 87-06, 87-14, 87-2 7, and 87-31) .

The disposition of the DBVP open items are included in enclosure 1.

Enclosure 2 contains a list of connitments.

If you have any questions, please telephone M. R. Harding at (615) 870-6422.

Very truly yours, TENNESSEE VALLEY AUTHORITY

/.

R. G idley, D rector Nuclear Licensing and Regulatory Affairs Enclosures cc: see page 2 8801270165 880120 I PDR ADOCK 05000327 O DCD An Equal Opportunity Employer

U.S. Nuclear Regulatory Commission cc (Enclosures):

Mr. K. P. Barr, Acting Assistant Director for Inspection Programs TVA Projects Division Of fice of Special Projects U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. G. G. Zech, Assistant Director for Projects TVA Projects Division Of fice of Special Projects U.S. Nuclear Regulatory Commission Mail Stop 7E23 7920 Norfolk Ave.

Bethesda, Maryland 20814 Sequoyah Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy Daisy, Tent.essee 37379

9 ENCLOSURE 1 SEQUOYAH NUCLEAR PLANT (SQN) DESIGN BASELINE AND VERIFICATION PROGRAM (DBVP)

Observation D4.3-3 Steam Generator Access Platform Dasign NRC agreed with TVA's resolution; however, TVA needs to submit a commitment to perform postrestart additional walkdowns of the steam generator platforms and perform evaluations as required.

TVA Response TVA will perform walkdowns to collect as-built information for attachments to the unit 2 lower steam generator supports during the unit 2 cycle 4 outage.

The subsequent confirmatory structural evaluations will be completed before i the unit 2 cycle 5 outage.

Observation 3.17 - Solenoid Valve Mounting Support Variance The NRC team found TVA's approach acceptable, but TVA needs to submit a confirmatory letter when the calculations are issued.

TVA Response The calculation is complete and was issued under B25 871110 803.

Observation 4.8 - Containment Airborne Radiation Monitoring System Air Supply NRC agrees that TVA has adequately addressed this observation. However, Quality Information Request (QIR) Nuclear Engineering Branch (NEB)-86241 is not ccrrect. TVA needs to provide a schedule for correcting the QIR.

TVA Response The QIR was revised on October 13, 1987, and was issued under B45 871016 251.

Observation 6.3 - Inst rument Sensing Line Walkdown The NRC team finds the technical resolution of this item acceptable, but TVA needs to submit a revised response stating the corrective action taken, with a schedule for issuing the sketches as drawings.

TVA Response TVA will issue drawings for unit 2 phase 1 heating, ventilating, and air conditioning (HVAC) instrument lines by unit 2 cycle 4 refueling outage.

• Observation 6.14 - Project Evaluation of Electrical Failure Analysis for Procedure Sequoyah Engineering Project (SQEP)-12, Design Review Checklist The NRC team is closing the imposed voltage portion of this observation, but is keeping open the contact-to-contact isolation portion. TVA needs to revise the calculation to address breakdown between contacts of a given relay.

P TVA Response TVA is in the process of revising the calcuf ation. The calculation revision will be complete by January 27, 1988.

Observation 6.15 - Periodic Functional Test and Reset Timers TVA needs to submit to NRC a commitment to perform an integrated or overlapping test for the reconnected relays before restart and commit to perform periodic testing.

TVA Response Functional operability can be verified by out-of-circuit calibration of each relay followed by administrative 1y controlled and Quality Assurance inspector verified, lifting and relanding of electrical leads. This method of verification is endorsed by American National Standards Institute /American Nuclear Society (ANSI /ANS) 3.2-1982, "Administrative Controls and Quality Assurance for the Operational Phase of Nuclear Power Plants." Section 5.2.6, "Equipment Controls," states that temporary modifications such as lif ted electrical leads shall be controlled by approved procedures that will include a requirement for independent verification by either a second person or by a functional test that conclusively proves proper installation or removal of the temporary modification.

In addition, the twenty-two relays identified by this observation will be functionally tested in circuit before unit 2 mode 2. Maintenance Inst ruction (MI)-13.1.3 will be revised to include a functional test of these relays and a work request (WR) will schedule the performance of the MI. Performance of this functional test has been coordinated with Angelo Marinos, NRC Office of Special Projects.

Also as each MI for calibration of safety-related components is enhanced in accordance with TVA's Nuclear Performance Plan, a determination will be made i as to the feasibility of performing system functional testing following maintenanc e. When the test is determined to be practical, the enhanced procedure will include a functional test.

Observation 6.16 - HVAC Flow Switch Calibration Data Records and System 30 Surveillance Inst ruction Procedures TVA needs to submit to NRC a commitment to perform a system-level test of HVAC systems prerestart and to periodically perform surveillance testing on the interlocks and circuits of these systems.

TVA Response i TVA has evaluated the functions of 2-FS-30-200 and -207 and the generic issue of periodic testing. TVA agrees that 2-FS-30-200 and -207 should be periodically tested. Functional testing will be completed before mode 4.

Additionally, TVA will evaluate control loops identified by the Restart Test Programs (RTP's) Function Test Matrix as being validated by other than Surveillance Inst ructions (sis), to determine which cont rol loops should be added to the periodic test program. This evaluation will be completed postrestart, by June 30, 1988.

Acceptabilty of this approach is based upon RTP. Functional acceptability has been verified either by preoperational test or sis and the RTP ensured, through its evaluations, that there were no modifications or operational

-look-back issues that would invalidate the documented test results.

It should be noted that the reference to SQI-82 in your Inspection Report Nos. 50-327/87-31 and 50-328/87-31 was incorrectly identified. SQIs do not exist at SQN. We believe the correct reference to be System Operating Instruction (S01)-82. This is the operating instruction for running the diesel generators. TVA does concur that this operating instruction does not functional test these control loops. This instruction is only meant to provide the equipment operators with the appropriate instructions to operate the diesel generators. Also, the reference to S01-82 should have been part of observation 6.17 not observation 6.16.

Observation 6.17 - Diesel Generator Building Ventilation Fans Control Logic and SI Procedure TVA needs to submit to NRC a commitment to perform a functional test of the fans' control logic prerestart and to periodically perfo'em surveillance testing on this system.

TVA Response TVA has evaluated that the f unctions of 2-FS-30-448, -450, -452, and -454 do not have to be added to the periodic test program before restart, based on the evaluation performed under the RTP. These functions were evaluated under FAR-30 and RTP punch list closure form 2-PLC-30-8 in which WRs B100143, B100142, B100131, B100132, B100141, B100140, B100139, and 3100138 were issued to provide more thorough documentation of complete loop function than what existed in the original preoperational test. These control loop functional tests were completed between March and August, 1987. The referenced WRn were generated as a result of Condition Adverse to Quality Report (CAQR) SQP 871071 that was written as a result of this observation. These control loops functioned according to their design.

TVA concurs that these controls should be periodically tested. These control loops will be added to the periodic test program, postrestart as delineated in observation 6.16.

Observation 6.21 - Postaccident Monitoring (PAM) System The NRC team finds the restart and postrestart corrective action plans acceptable; however, TVA needs to specify what clarification will be submitted for the Final Safety Analysis Report (FSAR), section 7.5.2.

TVA Response The FSAR will be clarified to state that where PAM loops interface with the plant computer, analysis has demonstrated that postulated electrical failures in the computer will not degrade the PAM loops for unit 2. The FSAR will be revised in the 1989 update.

9 Observation 6.22 - Auxiliary Control Air (ACA) System TVA needs to address the NRC team's remaining comments regarding operating procedures that are in place to ensure that the fans restart in certain situations when the switch is in the P-Auto position and also that calculations are revised to reflect higher heat loads resulting from a recently revised Mechanical Engineering Branch calculation. TVA needs to submit a revised response.

TVA Response The scenario discussed in NRC Observation 6.22 involves loss of auxiliary control air (ACA) below the minimum required header pressure for less than 10 minutes. A system evaluation for all systems supplied by ACA has been performed and has determined that loss of ACA for a period of less than 10 minutes is acceptable (QIR NEB 87229, B45 871027 251; and QIR SQP-87-427, B25 870831 009).

In a recent inspection, NRC reviewed the above evaluation and questioned the control building heating, ventilation, and air conditioning (HVAC) logic on a loss of ACA. It was also determined that new heat loads generated from the Design Baseline Program had not been incorporated into the evaluation.

Review of the control building HVAC logic has been performed by TVA. It has been determined that on a loss of ACA to the operating control building HVAC train, a fault signal would be generated to start the standby train and stop the operat ng train. Assuming single failure of the standby train, loss of i

control building HVAC would result until operator action could be provided to reposition the handswitch in the main control room to start the operable unit. Abnormal Operating Instruction ( AOI)-10 Section C Loss of Auxiliary Air Train A or B, provides subsequent operator actions on loss of ACA.

Preliminary results of the control building HVAC calculations utilizing the higher heat loads generated from the design baseline effort indicate that sufficient time would not be available to take credit for operator action before abnormally high temperatures (104 degrees F) would be reached in two of the control building rooms. Nuclear Engineer Branch calculation SQNAPS4-009 (B45 880113 236) shows that the computer room, originally shown to exceed the 104 degrees F temperature, new is within the normal temperature limits.

Assuming total operator action time of 50 minutes to restore control building HVAC, the rooms that would experience elevated temperatures are the unit I auxiliary instrument room (106.2 degrees F) and battery board room No. 1 (113 degrees F) .

These conditions have been evaluated and are determined, as documented in the referenced QIRs, to be acceptable for the following reasons:

1. All equipment in the auxiliary inst rument room has been qualified to operate in the elevated temperature of 106.2 degrees F.

2. Equipment in the battery board room No. 1 is not safety related and is not required for safe shutdown of unit 2.

.s ENCLOSURE 2 List of Commitments SQN - DBVP

1. TVA will perform walkdowns to collect as-built information for attachments to the unit 2 lower steam generator supports by unit 2 cycle 4 refueling outage. Subsequent confirmatory structural evaluations will be performed before unit 2 cycle 5 refueling outage.

2. TVA will issue drawings for unit 2 phase 1 HVAC instrument lines by unit 2 cycle 4 refueling outage.

3. TVA will revise calculation PIR SQN-EEB86171, involving contact-to-contact isolation, by January 27, 1988.

4. TVA will perform in-circuit functional testing of the reset timers identified in observation 6.15 and revise MI-13.1.3 to include functional testing of these relays before unit 2 mode 2.

5. TVA will revise the appropriate instruction, to include periodic functional testing of 2-FS-30-200 and 2-FS-30-207, and will determine other control loops that need to be added to the periodic test program.

This action will be completed by June 30, 1988.

6. TVA will revise the appropriate instruction to include pr.riodic functional testing of 2-FS-30-448, 2-FS-30-450, 2-FS-30-452, and 2-FS-30-454. This action will be completed by June 30, 1988.

7. TVA will revise the FS AR section 7.5.2 in the next appropriate update, so that, where PAM loops interface with the plant computer postulated electrical failures in the computer will not degrade the PAM loop for unit 2.

8. TVA will perform functional testing of 2-FS-30-200 and 2-FS-30-207 before unit 2 mode 4.