ML20058C701
| ML20058C701 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 11/19/1993 |
| From: | Hebert J Maine Yankee |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| JRH-93-236, MN-93-104, NUDOCS 9312020541 | |
| Download: ML20058C701 (8) | |
Text
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g {* %,?4' un MaineYankee RELIABLE ELECTRICITY SINCE 1972
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. EDISON DRIVE e AUGUSTA. MAINE 04330 * (207) 622-4868
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November 19, 1993 MN-93-104 RH-93-236 ip F
UNITED STATES NUCLEAR REGULATORY COMMISSION f
-Attention: Document Control Desk I
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- Washington, DC 20555
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References:
(a) License No. DPR-36 (Docket No. 50-309)
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(b) USNRC' Letter to Maine Yankee dated September 19, 1991 - NRC Electrical Distribution System Functional Inspectic Team Report No. 50-309/91-81 (c) Maine Yankee Letter to USNRC dated October 23, 1991 (MN-91-147)
Response
to NRC Partial Electrical Distr!bution-System Functional Inspection Team Report (d) Maine Yankee Letter to USNRC dated April 2, 1992 (MN-92-34)
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Subject:
Status Update - NRC Partial Electrical' Distribution System Functional Inspection Report No. 50-309/91-81 Gentlemen:
In early 1991, an NRC Team conducted a Partial Electrical-Distribution System I
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Functional Inspection (EDSFI) 'at Maine Yankee. Reference (b) reported the results-i of the inspection. Maine ~ Yankee responded to the Inspection Report with Reference
- (c) and updated the status with Reference (d).
j In anticipation'of the upcoming follow-up EDSFI, we have. updated Attachments A, B and C to Reference (c) to reflect the status of issues as of November 15, 1993.
This updated issues summary is attached.
.Should you have any questions on the attached information, please contact us.'
Very truly yours,
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9312020541 931119 James R. Hebert, Manager P
DR-ADOCK 0 309 Licensing & Engineering Support Department WBD/ jag
- Attachments c:
Mr. Thomas T. Martin Mr. J. T. Yerokun Mr. E.-H. Trottier.
a Mr. Patrick J. Dostie -
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1 ATTACHMENT 1
Priority and Schedule for Comc.-itments Made during EDSFI (As response to specific issues in the Inspection Report) f The matrices which follow document Maine Yankee's response to the specific issues raised in the NRC EDSFI Team Report. The issues are listed (as description) in roughly the order as presented in the report.
Sub-Item Numbers were assigned for ease of cross-refeience and tracking purposes; these numbers should not be confused with Request Numbers assigned and tracked during the course of the actual inspection.
Description is a restatement of the issue documente-in the report.
The Status / Comments column includes status information and/or actions taken.
During the course of the inspection, Maine Yankee actively maintained an issues tracking document, "EDSFI Inspection Request Tracking System". The document was used to assure that each issue perceived by Maine Yankee was documented and responded to.
Where appropriate, Maine Yankee committed to appropriate follow-up items. Although the attached matrix differs in format, saquence, etc., from that developed during the inspection, we have attempted to reflect all of our prior commitments associated with these unresolved open items in Attachments A and B.
The " Scheduled Completion" dates listed on the attachments are our current plans for completing a particular item.
Maine Yankee views these items as licensee initiatives which are subject to change without prior notice to the NRC. An asterick
(*) in the Scheduled Completion column indicates that the item has been rescheduled to a date different from that provided in a previous response.
A "[" in the left margin is indicative of a change in the Scheduled / Completion column or the Status / Comments column since the previous response.
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4 ATTACHMENT A Page 1 of 3 NRC EDSFI AUDIT FINDINGS
SUMMARY
NRC REPORT NO. 50-309/91-81 OPEN ITEM NUMBER DESCRIPTION _
PLANS.
SCHEDULED COMPLETION STATUS / COMMENTS 01 Calculations addressing the Conduct 120 V ac/125 V End of 1995 Inspection Team found no evidence voltage drop to limiting 120 V dc voltage studies.
Refueling of inadequate' voltage at the loads t
ac/125 V dc components were not
- Outage, nor that the systems could not available.
perform their safety functions.
02-1 Battery charging procedure Resolve minimum voltage Complete Resolution of NRC concern provided acceptance criteria not requirement for battery by MN-91-147.
i consistent with battery sizing test discharge, calculation.
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02-2 The effects of minimum voltage Revise battery sizing January 1994*
loads not addressed in battery calculation MYC-104.
sizing calculations.
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03-1 No f'ormal inverter. sizing Develop inverter sizing End of 1995 To be completed concurrent with
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calculations have been prepared.
calculation.
Refueling 120 V ac/125 V de voltage studies.
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Outage
- See Open Item number 01.
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03-2 Issue updated loop End of 1995
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power supply one line Refueling 2
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diagram.
Outage
- 04-1 125 V dc and 120 V ac short Complete and issue End of 1995 circuit and coordination studies coordination studies.
Refueling Outage are not available.
04-2 40% higher trip current levels Incorporate proper trip End of 1995 for de breakers not taken into characteristics in Refueling Outage
, account in informal dc curves.
coordination studies.
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ATTACHMENT A Page 2 of 3 NRC EDSFI AUDIT FINDINGS
SUMMARY
NRC REPORT NO. 50-309/91-81 j
OPEN
- ITEM SCHEDULED.
NUMBER DESCRIPTION
' PLANS COMPLETION STATUS / COMMENTS 05-1 No mechanical interlock to Place breaker 7T8 in Complete Technical Evaluation No. 211-91 prevent inadvertent closure of its diconnected issued and breaker racked down as 7T8 exists.
position.
of August 2, 1991.
J 05-2 No mechanical interlock Review plans to Complete Resolution of NRC concerns identification on one-line en.ure mechanical provided by MN-91-147.
diagrams.
interlocks properly reflected.
05-3 No mechanical interlock to Revise administrative Complete Breakers are locked 0FF.
prevent inadvertent closure of procedures to lock Procedure revision has been emergency bus MCC tie breakers.
MCC 7A/8A and 7B/8B issued.
tie breakers in OFF position.
05-4 Need to preclude use of 120 V Install spare battery Complete The installed spare inverter and ac/125 V dc tie breakers in the charger and inverter.
battery charger greatly reduces
- future, the need to cross-tie 120 V ac/125 V dc buses.
05-5 Resistive type faults were not Review resistive type Complete Resolution of NRC concerns addressed.
faults for auto-provided by MN-91-147.
transfer switches.
05-6 Need for automatic transfer Review need to LSI-M-Complete Associated check valves evaluated switches should be addressed.
11, 21 and 31 auto-during the 1992 outage. Automatic transfer switches.
transfer switches will be retained based on the resultant use of valves LSI-M-II. 21 and 31.
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O ATTACHMENT A Page 3 of 3 NRC EDSFI AUDIT FINDINGS
SUMMARY
NRC REPORT NO. 50-309/91-81 OPEN-ITEM SCHEDULED.
NUMBER DESCRIPTION PLANS COMPLETION STATUS / COMMENTS 06 Is the EDG tachometer self-Issued DCR to correct Complete Updating prints as part of design powered?
In energizing a dead documentation errors.
package was not done under PA bus, how do you know frequency?
81.
07 Actions to resolve EDG field Complete actions 2 &
For DG-1A and 18, action 2 was breaker and wiring Part 21 3 of CMS 4-12-24 for:
completed satisfactorily. Action issues were not complete.
DG-1B Complete 3 has been completed for both DG-1A Complete EDGs.
08 The extent of tornado Update the FSAR to Complete protection for the switchgear reflect the extent of room ventilating equipment as tornado protection discussed in the FSAR is not for switchgear room clear.
ventilating equipment.
09 EDG Instrumentation Specify and initiate Complete Calibration.
a calibration frequency for EDG instruments.
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ATTACHMENT B Page 1 of 2 NRC EDSFI AUDIT FINDINGS
SUMMARY
NRC REPORT NO. 50-309/90-80
.m OPEN ITEM-SCHEDULED NUMBER.
DESCRIPTION PLANS COMPLETION STATUS / COMMENTS 90-80-01 Sufficient motor data not Establish a schedule Dec. 1993 Thermal damage curves provided, available to verify if AC to draft a motor Preliminary coordination curves-overcurrent protection is overload protection and Relay Data Base completed.
conservative.
setpoint manual, Need final review.
which will provide the setpoints and setpoint bases as a reference manual.
90-80-02 The existing DC short circuit Modify electric cable Complete calculations show a fault run from batteries current of 13,000 amps but the 1&3 to buses 1&3.
DC breakers are only rated for 10,000 amps.
Complete DC short Complete circuit analysis and DC voltage study to reflect modifications.
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ATTACHMENT B Page 2 of.2 NRC EDSFI AUDIT FINDINGS
SUMMARY
NRC REPORT NO. 50-309/90-80
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OPEN ITEM SCHEDULED NUMBER DESCRIPTION
' PLANS COMPLETION /
STATUS / COMMENTS-90-80-03 The AC short circuit calc. did
- 1. Determine interrupting Dec. 1993 not consider variations from duty of breakers under nominal 345 KV.
worst case conditions.
- 2. Evaluate interrupting Dec. 1993 duty for 4160 volt breakers fed by 115 K','
Systems.
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- 3. Establish permanent Complete
- Required replacement of resolution of JC0 for transformer X24.
4160 volt breakers.
90-80-04 The DG loading calc. failed to Evaluate effects of Complete The scope of additional evaluate the effect of voltage dips on monitoring will focus on multiple starts on individual contactors, starters, and voltage level versus time at motor control center loads, control relays during Motor Control Centers during Thermal overload protection worst case accident starting and sequencing of could also be affected.
loads. Perform required loads.
In addition, the sample i
diesel testing during MCC starter circuits will be next outage.
monitored to determine the response to the contactors to dips in voltage which result for the load sequencing.
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ATTACHMENT C Page 1 of 1 NRC EDSFI AUDIT FINDINGS
SUMMARY
NRC REPORT NO. 50-309/91-01 OPEN.
ITEM SCHEDULED NUMBER DESCRIPTION PLANS COMPLETION.
STATUS / COMMENTS 91-01-01 The short circuit available at
- 1. Replace all unit Complete the terminals of several substation safety related 480 volt transformers with circuit breakers exceeds the higher impedance interrupting rating of the transformers breakers.
during the next refueling outage.
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- 2. Develop and Complete
- Breaker replacement accomplished' install new in conjunction with MCCB program.
breakers for MCC 7A and 8A.
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