ML20105A525

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Responds to NRC Re Unresolved Items Noted in Edsfi Rept 50-219/92-80.Corrective Actions:Adequacy of Voltages at safety-related Ac motor-control Ctr Control Circuit Equipment Will Be Analyzed by End of Feb 1994
ML20105A525
Person / Time
Site: Oyster Creek
Issue date: 09/09/1992
From: J. J. Barton
GENERAL PUBLIC UTILITIES CORP.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
C321-92-2241, NUDOCS 9209170064
Download: ML20105A525 (8)


Text

J . l i

.- j GPU Nuclear Corporation G,, G Nuclear o

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rsee Forked River, New Jersey 08731-0368 609 971 4000 Writer's Direct Dial Number

C321-92-2241 September 9,1992 U. S. Nuclear Regulatory Commission Attn Document Control Desk Washington, D. C. 20555 Gentlemon:

Subject:

Oyster Creek Nuclear Generating Station Electrical Distribution Functional Inspection IR No. 50-219/92-80 Unresolved Inspection Items In your letter (dated July 9,1992), you requested that we provide a schedule for the resolution of the inspection items rnd any actions taken or planned to enhance the functionality of the electrical distribution system. We have enclosed' two attachments which satisfy ' your request. Please note that our response to the Notice of Violation (92-80-01) was sent by a separate letter.

Attachment A delineates our proposed actions and schedule for addressing the

. ten unresolved items identified in the inspection report. Attachment B provides additional information on our actions or comments to those areas which you l identified as a concern or weakness.

The sichedule for addressing the unresolved items and comments was developed with

- the consideration of multiple aspects of GPUN activities. Each item was assessed

-with respect to its safety significance and integrated into the total work scope for GPU Nuclear. The estimated completion dates incorporate priority and resource availabilities. GPUN nas a long term program associated with electrical analyses of Oyster Creek and THI Unit 1. The actions associated with the Electrical Distribution Functional Inspection serve as a subset of this total program.

15609; 92o9170064 920909 -lg DR ADOCK 0500 )

GPU Nuclear Corporation is a sut.udwy of Genera' Puboc Utomes Corporation /

u .

If you have questions on this letter or our response to the Notice of Violation, please contact Tom Blount (609 971-4007) or David Jerko (201 316-7976).

V y truly yours, J. J. a ton Vi e resident and Director _

Oy 'tm Creek k

Attachments JJB/DGJ cc: Administrator, Region I HRC Resident Inspector Oyster Creek NRC Project Mcnager l

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Attachment A Inspection Report No. 50-219/92-80 GPUN Proposed Actions and Schedule For Unre.e'ived items Item: 92-80-01 Notice of Violation - Safety related comgonents not functionally tested GPUN response: The response to the NOV is provided by separate letter, m

Ltem: 92-Q0-J2_ Edmagy of MCC Control Circuit Voltage GPUM response: The adequacy of voltages at safety related AC motor control center control circuit equipment will be analyzed by the end of February 1994.

Jtem: 92-80-03 Adecuacy of Voltage to AC Components GPUN response: The adequacy of voltages at safety related /C equipment terminals down to the 120VAC level will be analyzed by the end of August 1994.

Item; 92-80-04 BFP Start on Augiliary Transformer GPUN response: Starting of the Reactor Feed Pumps is controlled by administrative procedures which require the downstream valves to be closed when the pumps are started. The reduced pumping load will limit the motor starting time to values less than the degraded grid relay timer settings. But in order to -

provide additional documentation of motor starting capability, a study will be completed by the end of February 1994.

Item: 92-80-05 Adequacy of Voltage to DC Components GPUN response: The adequacy of voltages at safety related DC equipment terminals will be analyzed by the end of March 1994.

Item: 92-80-06 Adeq.uacy of DC Short Circuit Protection GPUN response: The DC short circuit duty of cencern is associated with DC Jistribution Center C and its downstream panels. Should the static battery charger contribution exceed 500% of full load current as suggested, there is still more than adequate margin 1 between available fault current and equipment ratings. An evaluation will be performed to determine the available short circuit contribution of our particular static chargers and if needed, the calculation will be updated by the end of February 1994. Please note that the MG set short circuit contribution used in our calculations was 750% of charger rating not 75%.

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,ltemi92-80-07 Adequacy of HVAC Temperature Control to 4ky and 480v Switchaear Rooms GPUN response: GPUN will provide guidelines for monitoring room temperatures and establish the maximum allowable room temperatures for the 4kV and 480V switchgear rooms. These guidelines will be provided by the end of April 1993, ite : 92-80 Me_qu_a_cy of EDG Battery liydrogen LeyeLduring Normal Operation GPUN response: An engineering evaluation was completed on 6/12/92. The resulting data indicated no detectable hydrogen in any vent opening of the battery boxes in either diesel unit. Based on this asses'; ment no further action is considered necessary.

Jtem: 92-M-@_ Seismic _!Lualification of C Battery Room Heater GPUN response: The electric heater for Battery Room C was installed to maintain a minimum temperature of 65 F dry bulb during winter outages of the plant. An evaluation of the seismic qualification of the heater will be completed by the end of October 1992.

Jtem: 92-B_0-10 lL_equacy d of TS Minimum Battery Voltage to Start tiot EDG GPUN response: An engineering evaluation to collect and review data available on the EDG battery low voltage concerns is expected to be completed by the end of September 1992.

Ltem: 92-80-1L Mequ.a_cy_gf Coordinatjon between ApS Breakers and F_us_es GPUN response: An evaluation will be conducted to determine the appropriate tripping and melting / clearing times for the associated breakers in the DC power panel and the fuses in the ADS _

circuits. This evaluation will be completed by the end of February 1993.

4 4 Attachment B Inspection Report 50-219/92-80 GPUN Additional Actions or Connents NRC comment;. The de control power for the switchyard consists of a single battery and battery charger. The absence of a program to periodically test the battery to verify its continued operability to provide power for its design period (48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />) is an area of potential concern. (page 6. section 2.1)

GPUfLrftigonse: Discussiens are in progress between GPU Nuclear and Jersey Central Power & Light to address general maintenance and housekeeping activities in the switchyards. The discussions will lead to an action plan being developed to address concerns such as equipment maintenance, general housekeeping and tours by plant operations.

NRC comme'1t: Two cases were identified in which valve bus voltages had been incorrectly selected from a previously prepared analysis of distribution voltages. The failure to identify the correct bus voltage in the;e two cases was of minor safety significance because the voltages used in the calculation (from the wrong bus) were more limiting than the correct voltages. The licensee committed to correct the calculation and to review .all other loads reassigned in the same modification. (p.10, sec. 2.4)

GPUN resDonse: GFUN is in the process of addressing the concerns associated with NRC Generic Letter 89-10 for motor operated valves. The calculation reviewed during the EDSFI was an interim calculation prepared to address GL 89-10 supplement 3 concerns on operability of certain M0V's. This calculation will be updated along with other studies as part of the overall __

response to GL 89-10. Other electrical equipment will be evaluated in response to unresolved item 92-80-03.

NRC comment _;. The EDG cold starting load limitation was not clearly defined in the licensee's analyses and, in one case (Calculation 5250-003), specifically omitted. Even though the loading requirements identified were well within the EDG rating, this limitation is necessary to properly evaluate future load additions. The team concluded this item to be a weakness in documentation and not a safety concern. (pgs.10,11, sec. 2.5)

GPUN response: The EDG cold starting load limitation will be evaluated and calculations will be revised as necersary by the end of October 1993.

NRC comment: The major loads on the EDG were revised by the licensee from the original automatic loading schedule. Consequently, only one core spray booster pump starts automatically. The team noted that the FSAR had not yet been revised to reflect this modification. (p. 17, Sec. 3.1) l

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. G PUN.' r.e_a.qDiel The Core Spray System is a low pressure emergency core cooling

- system which consists of two independent subsystems. Each ,

subsystem contains two main pumps and two booster pumps (one 1 primary and one backup) which can receive emergency power from

-their own respective diesel generator.

A 13R modification locks out the backup booster pump if the primary booster pump on the same electrical division is running.

A change was made to the FSAR (Section 6.3.1.3.3.C) to reflect this modification; bowever, changes were not made to Tables 8.3-1 and 8.3 A Plant FSAR Update was initiated during the inspection and the appropriate change will be incorporated in

-Update 7 (December 1992).

NRC comment: Marinite board, originally installed to enhance cable separation and protection, was found in a number of cases to be ' loose, missing, or damaged. The licensee acknowledged the -

team's concern and committed to repair the identified board y deficiencies, . inspect for similar deficiencies, and conduct L periodic reinspections. (p.20, Sec. 4.1)

GPUN response: . A Material Non-Conformance Report was generated to address the

~immediate concern of- the damaged M-board in _480 volt switchgear room. Disposition of this MNCR included cPrection

.of the deficiencies by-issuing a work request. A Job Order was then issued and-the scope was expanded to include directions-for the replacement of the M-board. The work is scheduled to

- be completed by the end of September I?:-2.

A deviation report _was initiated _to :

-Perform a root cause analysis of the'M-Board problem.-

Completion is expected by the end of September 1992.

- Conduct a plant walkdown of major plant areas where the M-board is expected to'be installed. Guidelines will be provided to. identify possible M-board Ldeficiencies.

Completion of walkdowns is expected by the end of September 1992.

Review the results of the walkdown to establish the need .

to expand the inspection to other plant areas._ Identify the deficient M-board locations. Completion is expected -

by the end of October 1992.- ,

4

- Planned Additional actions include:

Provide guidelines in procedures and engineering specifications on how to maintain the M-board installations. Completion is expected by the end of netober 1992.

Training will be provided to plant personnel to educate and enhance their swareness about the need to maintain the M-board in its as-installed configuration.

Completion is expected by the end of November 1992.

The need for documentation of future M-board installations was reviewed and it was determined that periodic walkdowns would be more appropriate. This periodic walkdown inspection program will be established to identify M-board deficiencies which may occur over time. Completien of the program is expected by the end ,

of October 1992.

NRC comment: Tra inm identified that the duty cycle for ELG-2 battery had at be n established. TS section 4.7.B was not clear in that the cucy cycle rating was not specified. The licensee committed to establish the EDG battery duty cycle and to submit _ the appropriate TS amendment request. (p.21, sec.

4.2.1)

GPUN response: The duty cycle for the EDG-2 battery will be determined and the need for a Technical Specification Change Request will be evaluated by the end of August 1994.

NRC comment: The team identified that neither the generic procedure nor the PMs provided good acceptance criteria for testing breaker instantaneous trip elements. The team considered this to be a weakness. The licensee initiated actions to incorporate acceptance criteria in.new and existing PMs for the MCCs.

(p. 22,-sec. 4.2.4)

GPUN response: Motor Control Center Preventive Maintenance Procedure A100-SME-3915.01 is presently being- revised. This revision includes the acceptance criteria for fixed and adjustable instantaneous trip elements; it is expecced that it will be issued for use by the end of September 1992. All new and revised PM tasks are being developed using the acceptance criteria in accordance with the revised procedure.

The PM task upgrade activity to address this concern will continue over an extended period of time due to the significant number of tasks involved. In addition, major enhancements to extend the scope beyond the instantaneous trip tests will oe included. Completion is expected by the end of

December 1994.

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. NRC 'commin11 The calculations initiated as a result of the design basis reconstitution program were good and presented in a comprehensive manner. However, the status of old and superseded calculations was not clearly annotated to prevent potential design errors. (p. 33, sec. 5.8)

Sfl)N re H9D191 The Technical Functions Division prepares calculations using Procedure 5000-ADM-7311.01 (EP-006). This procedure provides general guidelines for the documentation of computer and manual calculations.

Prior to revision 3-01, EP-006 provided no guidance for engineers doing new work to be familiar with previous calculations and overtly void, supersede or revise previous calculations when appropi. ate based on the currently ongoing calculation activities. In 1990, Section 4.5 of EP-006 was revised to include a note:

The originator of a calculation shall review or be aware of previous calculations for the system for which the calculation is being completed. These previous calculations will be voided, superseded, or revised as appilcable.

By this change, the Technical Functions Division has already initiated corrective action to improve the performance in this area.

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