ML20115F471
| ML20115F471 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 10/14/1992 |
| From: | Wallace M COMMONWEALTH EDISON CO. |
| To: | Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| Shared Package | |
| ML20115F450 | List: |
| References | |
| NUDOCS 9210230104 | |
| Download: ML20115F471 (6) | |
Text
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1400 Opus Place
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Downers Grove, Illinois 60515 October 14,1992 Mr. A. Bert Davis Regional Administrator U.S. Nuclear Regulatory Commission Region lil 799 Roosevelt Road Glen Ellyn, IL 60137
Subject:
Request for Reconsideration of the Scheduled Byron /Braidwood Station Electrical Distribution System Functional Inspection NHC Docket Nos. 50-4141455 & 50-456/457
Dear Mr. Davis:
As you are aware, the Nuclear Reaulatory Commission is currently planning to conduct an Electrical Distribution System Punctional inspection (EDSFI) at Byron and Braidwood Nuclear Stations during the time period of February 22 through April 9, 1992. Commonwealth Edison Company (CECO) believes the performance of this inspection during this time frame will have an adverse impact on our company as outlined below, in addition CECO believes it can be shown that there is little safety significance associated with deferring or canceling the proposed EDSFI at Byron and Braidwood Stations. CECO is therefore formally apoealing the decision to conduct this EDSFi et Byron and Braidwood Stations as currently scheduled.
To gauge the potentialimpact of an EDSFl on Byron and Braidwood Stations, CECO examined th^ historic impact of the EDSFI conducted at LaSalle Station during the period of October 7,1991 through November 8,1991. Attachment A details the approximate person-day resources required to et;cport the LaSalle EDSFl.
CECO believes the resource requirements for the LaSalle EDSFl provide a reasonable estimate of the "esources required to support an EDSFI at Byron or Braidwood stations given the simi!ta age of the three plants.
As can be seen ir' Attachment A, the resources required during the inspection itself were 132 person-days fror.1 the LaSalle Station staff and 388 person days from the Engineering and Construction (ENC) organization. These resources were required during the inspection period. Assuming a similar impact on Byron and Braidwood stations, this would imply over 700 person-days will be required at Byrori and Braidwood Stations during the seven weeks of the scheduled inspection.
It is important to note that during this time frame both Byron and Braidwood Stations will have a unit in a refueling outage. An alternative schedule as proposed by your staff, beginning on January 11,1993, would result in the EDSFI being conducted during the Braidwood INPO evaluation and the Byron Refuel outage. This alternative will have negative effects similar to those described herein.
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ZNLD/2210/1
CECO normally plans its refueling outages at Byron and Braidwood stations such that the plant Technical Staff and Maintenance Staff are fully resource loaded.
This is done to maximize the contribution of these essential work groups to the efficient completion of the Jesignated work scope within the required time period. The performance of an EDSFi at Byron an.1 Braidwood Stations will therefore require a significant increase in resources beyond those already planned during the fully loaded resource schedule, or a redistribution of the resource allocation to accommodate the significant impact imposed by the conduct of these inspections during this time period.
The refueling outage is a period of high activity and reduced safety system availability which requires a significant level of management attention to ensure the safe conduct of these activities and the rninimization of shutdown risk. The managerial challenge presented by the conduct of these inspections during this time period will only serve to distract from this focus with no discernible net safety benefit.
CECO believes this will create an unnecessary ourden on our human resources given the limited benef!t to be derived from conducting the EDSFl at Byron and Braidwood Stations during the proposed time 'rame. As you are aware, CECO has implemented corrective actions at Byron and Braid vood Stations as a result of the four EDSFl's that have been conducted at the other CE Jo plants, as well as EDSFI's conducted throughout the industry. Attachment B details some of those corrective actions. Similar information was previously conveyed in a meeting with the NRC held 7
on September 23,1992. In addition, Attachment C details the actions CECO has taken or will be taking to address the five most significant EDSFI findings as noted in NRC IN 91-29. The implementation of these correct!ve actions in conjunction with the relatively low population and safety significance of findings at EDSFI's conducted at newer sites within the nuclear industry lead CECO to believe that there would be no safety significance associated with the deferral or cancellation of the currently scheduled Byron and Braidwood Station EDSFl beginning February 22,1992.
In summary, there is a known economic and/or safety impact associated with conducting the Byron and Braidwood inspections as currently proposed. In addition there appears to be no safety significance associated with deferring or canceling this same inspection. CECO is therefore formally appealing the decision by the NRC to conduct the Byron and Braidwood Station EDSFl as currently scheduled.
Sincerely, M. k <
KA fn. M. J. Wallace-Vice President of PWR Operations cc:
H. Miller J. Zwolinski R. Barrett Document Control Desk ZNLD/2210/2 o
Attachment A CECO Resources Required During the LaSalle Station EDSFI (Person Days)
LaSalle Station Staff 132 ENC Site 38 ENC Corporate 350 o
TOTAL 520 ZNLD/2210/3
Attachment B Corrective Actions Underway at Byron and Braidwood Station to Address EDSFlissues 1.
Roview 4 previous CECO EDSFl Electrical Complete questions and findings A$
2.
Review other utility results and IE Notices Ongoing for Byron /Braidwood applicability 3.
Identify relevant items and punchlist thc,se Ongoing that are applicable ( 120 electrical items) 4.
Review structural / mechanical items at other dngoing plants for applicability S.
Perform independent review and walkdowns of Complete Diesel Generator and Diesel Oil systems 6.
Perform new degraded voltage calculations Complete 7.
Perform a review of existing calculations on Ongoing affected systems and upgrade as required 8.
Perform new Electrical calculations in areas Ongoing were discrepancies were identified 9.
Perform untested contact study Ongoing 10.
Reviewed and reconciled / revised all 4 prior EDSFl Ongoing identified Mechanical / Structural System calculations as required ZiC D/2210/4
Attachment O (continued)
Corrective Actions Underway at Byron and
)
Braidwood Station to Address EDSFlissues 1
11.
Time delay relay population and function Ongoing identified, stations implomenting Calibration program during current Braidwood refuel outage 12.
Prepare white papers to address significant Ongoing issues.
13.
Review of previous Safety Related Ongoing Electrical Modifications on affected systems 14.
Review of Safety Related Alterations Ongoing 15.
Review and address any discrepancies found in 6ngoing the HVAC Calculations and UFSAR/ Technical Specification commitments 16.
Review UFSAR Section 8 against sits practices Complete 17.
Review IE Notices and Deviation Reports for Ongoing corrective actions
-ZNLD/2210/5
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Attachment C CECO Actions to Addross Generic Weaknesses identified IE Notice 9129 Supplement 1 for Byron and Braldwood Stations The following items were identified in NRC IN 9129 Supplement 1. CECO's actions to address these items are included.
1.
Undervoltage relay setpoints for degraded dd conditions (this issue was also addressed in Information Notice 9129).
New degraded voltage calculations were perf >rmed initially on a worst case all plant basis and followed up with division by divisloq calculations for each site. The resultant setpoints/ actions will be implemented on each unit during its next refueling outage.
2.
Interrupting capacity of f ault protection devices (see Generic Letter (GL) 8815. Electric Power Systems Inadequate Control Over Design Processes")
ELMS AC (Electrical Load Monitoring System) is used to monitor AC loading d an integral porilon of this program is tiis calculation of available short uit vanes as breaker interrupting ratin g. Deviations from acceptable Jos are flagged in the program. In addition, hand calculatlons are in olace h jemonstrate this coordination. These calculations include the case o" the Diesel Generator in parallel with the bus.
3.
Improper coordine.w.1 of fault protection devices (see GL 6815)
A calculation has been performed to address the short circult/ breaker / fuse coordination of the Safety Related 125V D.C. System. This calculation has verified the proper application of coordination devices in the system.
4.
Analysis of Emergency Diesel Generator (EDG) capacity to power safety related loads during postulated accidents (see GL 8815) i L
CECO has performed a calculation to demonstrate the Emergency Diesel Generator (EDG) Post LOCA loading.
5 EDG mechanicalinterfaces The supporting systems for the EDG (Air Start, Fuel Oil Storage and HVAC) have been reviewed and revised as necessary. In addition a review of the Diesel Generator, Diesel Oil, and HVAC systems has been performed.
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- ZNLD/2210/6 -
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