ML20236T494

Discusses Final Status of Facility Human Engineering Discrepancy Mods,Per NUREG-0737,Suppl 1.All Mods Implemented W/Exceptions Noted on Encl Table 1.Nine Unit 2 Mods Scheduled for Implementation in 1988

ML20236T494
Person / Time
Site:	McGuire, Mcguire
Issue date:	11/20/1987
From:	Tucker H DUKE POWER CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
RTR-NUREG-0737, RTR-NUREG-737 NUDOCS 8712010306
Download: ML20236T494 (5)

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Duxe POWER GOMPANY L

P.O. Box 33189 CIIARLOTTE, N.C. 28242 i

HALD.TUGKER reLernown j

l vum enssammet (7o4) 373-4531 l

mootman reonverton November 20, 1987

,U. S. 7NucleargRegulatory Commission

.g s?Decumenticontrol Desk 1

W Washington, D.C.

20555

Subject:

McGuire Nuclear Station Docket Nos. 50-369, -370 Gentlemen:

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My letters dated March 29, 1984 and May 3, 1985 provide responses to NUREG-0737, Supplement I and included a schedule for completion of Control Room Review /HED Modifications.

By letter dated March 2, 1987 Duke provided an. implementation status report. The present status of our efforts is provided herein.

For McGuire Unit 1, there were originally planned 149 HED modifications. All have been implemented with the exception of those noted on Table 1 atteched.

For McGuire Unit 2, there were originally planned 158 HED modifications.

All have been implemented with the exception of those noted on Table 1 attached.

Nine HED modifications are ' presently scheduled to be implemented on Unit 2 in 1988 (2EOC4 refueling. outage).

The following discussion for certain HED modifications is provided:

HED M1-004A Duke letters dated March 2, 1987 and May 5, 1987 provided discussions relative to j

scope and schedule for this modification.

HED's M-1-0018 This HED was scheduled for the Unit 1 E004 (1987) refueling outage.

Implementa-tion had started during the first two weeks of the outage; however, work was halted due to the realization that coordination and scheduling efforts were not at sufficient levels to ensure the modification could be installed and tested in a safe manner and within the outage schedule.

The scope of the modification in-cludes wiring changes to the limit switch mechanism of over 80 safety related actuators, the installation in the Control Room of a new monitor light panel, and associated continuity testing and valve cycling to verify proper installation.

Due to our lack of timely review of the modification, the scope and coordination

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requirements were not known well enough in advance to properly plan and execute 4

the modification.

l The present Engineered Safety Feature (ESP) Monitor Light Panel will be restored to operable status. This panel is functionally adequate; however, the new monitor system involves a more efficient design as judged by the Control Room Review Team..

This Modification will be completed during the next Unit I refueling outage (IEOC5) and the next Unit 2 refueling outage (2EOC4).

HED M-1-517 This HED has been postponed until at least the 1989 refueling outages (1E006),

2E005) for the following reasons:

1.

The modiff. cations which implement the solution to this HED are comprised of two parts which are highly interrelated. The first part involves the rearrangement of valve switches and indications on control board MC-13.

This rearrangement la designed to provide a more logical layout of the present valve control switenes and indications associated with the six Moisture Separator / Reheaters (MSR's) and is the basis for the HED.

The second part, which is not a part of the HED solution, involves the replacement of the present auto / manual MSR control system with a better engineered system.

This control system will also have an Operator Interface Panel on MC-13 in addition to other possible impacts to the present valve controls and indications.

The Westinghouse retrofit system that is the basis for the existing modifications has been reviewed by Operations, Projects, and IAE engi-neers and lacks features necessary to justify the cost of the modifica-tions.

A new MSR control system is being developed. At this point in time it is unlikely the modification can be desigred for the 1988 refueling outages and it would be impractical to..aplement the HED portion knowing it would be changed again with the second part.

2.

All of the controls and indications associated with these modifications affect non-safety related components associated with the MSR's.

Control Room operation is typically limited to times during startup and shutdown and is controlled by operating procedures.

3.

A review of the benefit / cost ratio for this HED indicates that it was one of the lower ranked ones in the group of HED's accepted for imple-mentation.

4.

Replacement of the entire MSR control system may obviate the need for this particular HED.

HED M-1-192 Please refer to Duke letter dated May 5, 1987 for a discussion concerning this HED.

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HED's M-1-004B, -188, -520 1

These HED's involve the complete rearrangement of the Ventilation Systems' (HVAC)

Control Panel located outside the main control board area. McGuire's HVAC Control Panel houses controls and indications for the following ventilation systems on both units:

o VU - Upper Containment o VL - Lower Containment o VP - Containment Purge o VE - Annulus o VX - Containment Air Return and Hydrogen Skimmer o VA - Auxiliary Building o VF - Spent Fuel Pool Building o VC - Control Room The panel consists of control witches, flow indication meters, status lights, and annunciators.

Currently, the panel is approximately organized on a system basis, with controls in most cases better arranged than indications.

Demarcation and labelling has been improved to a reasonable standard.

Our primary concern with this modification lies in our inability to safety modify this control panel when viewed in the context of an operating plant.

The work involves a significant amount of reciprocating sawing, drilling, and weld repair and must be accomplished in extremely close proximity to controls and indication of operating components and systems.

In addition, the unwiring and determination of control board devices would have to be done in an extremely confined area behind and under the control panel.

As can be ascertained from the list of systems on this control panel, refueling outages do not present an appreciably better time to complete this work than with the unit (s) on-line.

On-line instal-lation has been definitely ruled out.

While it is recognized that the present control panel does not represent the best in human factors design, Duke has determined that the potential risk associated with implementation of these two modifications, far outweighs the benefits gained.

Duke engineers developed several alternatives that would reduce the risk and still provide measurable gains from a human factors standpoint. These alternatives were then reviewed -from a risk / benefit standpoint (in the context of an operating plant) and the conclusion was that none were acceptable.

Finally the need for enhancement of the panel from a HED standpoint was weighed against the alternative of implementation during a simultaneous shutdown of both units.

This option was ruled out on a cost / benefit basis.

This analysis is supported by the fact that during approximately four years of operational experience with the current panel there have been no significant problems due to human factors concerns.

Af ter careful consideration of all aspects of this situation we are cancelling these HED modifications in their entirety.

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In summary, Duke is providing this final' letter documenting the status of ~ HED modifications at McGuire.

By the end of the 1988 refueling outages, all planned HED's will have been implemented with one exception '(HED M-1-517).

This one has been postponed until at least the 1989 refueling outages. NRC will be notified of any changes to this schedule.

Very truly yours, Hal B. Tucker RLG/290/jgc xc: - Mr. W.T. Orders NRC Resident Inspector McGuire Nuclear Station Dr. J. Nelson Grace, Regional Administrator U.S. Nuclear Regulatory. Commission - Region II 101 Marietta Street, NW - Suite 2900 Atlanta, GA 30323 Mr. Darl Hood, Project Manager Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C.

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