ML17191A733

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Forwards Summary of 980529 Dresden Mgt Meeting on Scrams & Handout Provided by Commonwealth Edison During Meeting
ML17191A733
Person / Time
Site: Dresden  Constellation icon.png
Issue date: 06/16/1998
From: Grant G
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To: Kingsley O
COMMONWEALTH EDISON CO.
References
NUDOCS 9806220359
Download: ML17191A733 (32)
v • d • e


Text

I June 16, 1998

  • Mr. Oliver D. Kingsley President, Nuclear Generation Group Commonwealth Edison Company ATTN: Regulatory Services Executive Towers West Ill 1400 Opus Place, Suite 500 Downers Grove, IL 60515

SUBJECT:

DRESDEN MANAGEMENT MEETING ON SCRAMS

Dear Mr. Kingsley:

The NRC staff met with Commonwealth Edison and Dresden Nuclear Power Station management on May 29, 1998. This management meeting was open to public observation. contains the associated meeting summary. Enclosure 2 contains the handout provided by Commonwealth Edison during the meeting.

In accordance with Section 2. 790 of the NRC's "Rules of Practice! Part 2, Title 10, Code of Federal Regulations, a copy of this letter and its enclosures will be placed in the NRC's Public Document Room.

Docket Nos.: 50-237; 50-249 License Nos.: DPR-19; DPR-25

Enclosures:

1.
2.

Meeting Summary Meeting Handout See attached Distribution DOCUMENT NAME: G:\\dres\\dre05298.sum Sincerely, Original signed by Geoffrey E. Grant, Director Division of Reactor Projects To receive

  • copy of thl* document, Indicate In the box *c* = Copy without ettechment/encloeure "E" = Copy with ettechment/encloeure "N" = No co OFFICE Riii NAME Lerch:co DATE 06/iS /98 9806220359 980616 PDR ADOCK 05000237 p

PDR

e cc w/encls:

M. Wallace, Senior Vice President D. Helwig, Senior Vice President G. Stanley, PWR Vice President J. Perry, BWR Vice President Distribution:

SAR (E-Mail)

D. Farrar, Regulatory Services Manager I. Johnson, Licensing Director DCD - Licensing M. Heffley, Site Vice President P. Swafford, Station Manager F. Spangenberg, Regulatory Assurance Manager R. Hubbard N. Schloss, Economist Office of the Attorney General State Liaison Officer

  • Chairman, Illinois Commerce Commission Project Mgr., NRR w/encls C. Paperiello, Riii w/encls J. Caldwell, Riii w/encls B. Clayton, Riii w/encls SRI Dresden w/encls DRPw/encls TSS w/encls DRS (2) w/encls Riii PR2R/en PUBLIC 1 w/encls Docket ile w/encls GREENS IEO (E-Mail)

DOCDESK (E-Mail)

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May 29 Management Meeting Summary:

Public Meeting Summary Dresden Management Meeting The meeting was focused on the* recent scram (or reactor trip) history for both units at Dresden involving four automatic scrams and one manual scram in the past 6 months. Dresden Unit 2 experienced automatic scrams on December 23, 1997, January 13, 1998, and April 20, 1998.

Dresden Unit 3 experienced an automatic scram on April 9, 1998, and a manual scram on

.May 16, 1998. The number of scrams in a 6-month period far exceeded industry goals.

However, of more importance was the fact that each scram contained preventable elements involving poor performance in some aspect of the licensee's program. The purpose of the meeting was to understand the specifics of each of the scrams, the root causes, and the steps Commonwealth Edison (ComEd) was taking to avoid future unnecessary scrams.

The licensee presented information on each of the scrams and ComEd actions contained in the applicable handout in Enclosure 2. The licensee's presentation concluded there were three main root causes for the scrams involving: poor materiel condition, time spent in a half scram condition, and weaknesses in the utilization of industry experience. Of note was that since 1991, Dresden station had not actively participated in the BWR owners group scram reduction initiative.

Additionally, the licensee pointed out that Dresden station entered the half scram condition over 150 times per month for normal surveillance testing.

The licensee presented a discussion of corrective action plans for each of the areas. In the area of materiel condition, improvements completed during the most recent outages on each unit were*

discussed including: work on the offgas system involving the steam jet air ejectors and hydrogen recombiners, installation of three-element control and modification to the 28 feedwater regulating valve internals on Unit 2, and multiple actions with inlet drain line piping, lube oil cooler tubes, valve repairs, and switch upgrades on the high pressure coolant injection system. However, the licensee acknowledged* additional actions were still needed in materiel condition and also discussed planned future improvements, including a schedule for completion of those improvements.

  • During the discussion, the NRC staff questioned many of the licensee's actions and the licensee, in tum, provided appropriate responses. The NRC staff also pointed out the importance for Dresden of establishing a sustained period of successful plant performance. Achievement of this goal had obviously been impacted by the scrams.

Partial List of Attendees:

C. Paperiello, Regional Administrator, Riii J. Caldwell, Deputy Regional Administrator, Riii G. Grant, Director, Division of Reactor Projects. Riii M. Ring, Chief, Reactor Projects Branch 1, Riii K Riemer, Senior Resident Inspector, Dresden D. Roth, Resident Inspector, Dresden B. Dickson, Resident Inspector, Dresden Commonwealth Edison

0. Kingsley, Chief Nuclear Officer J. Perry, BWR Vice President D. Helwig, Senior Vice President M. Heffley, Dresden Site Vice President P. Swafford, Station Manager R. Freeman, Engineering Manager F. Spangenburg, Regulatory Affairs Manager D. Winchester, Quality and Safety Assurance Manager S. Barrett, Operations Manager R. Fisher, Maintenance Manager Commonwealth Edison
  • Management Meeting Handout

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May 29, 1998

Agenda

  • Introduction
  • Materiel Condition *
  • Conclusion M. Heffley P. Swafford R. Freeman M. Heffley 2

Reactor Trip Review

  • History *
  • Three Main Root Causes
  • Dresden Today

- Utilization of Industry Experience

- Time in Half Scram

  • Corrective Actions *
  • 3

History

Contributors Materiel Condition-OPEX..

Time in Half Scram Design-OPEX-Time in Half Scram Materiel Condition-OPEX-Ti.me in Half Gr 1 Design Issues Materiel Condition-Human Error Materiel Condition Reactor Trips Automatic Trips At Power LPRM Spike Concurrent with 1/2 Trip Valving in of Sensitive Instrument Faulty HF A Relay Concurrent with 1/2 GR 1 Design Error in New Aux Current Transformer Installation NGG Interfaces Manual Trips at Power

  • Excessive Leakage Through Cross Around Relief Valve 5

Contributors Materiel Condition Human Error

  • Failure of Automatic Bus Throwover on New Main Power Transformer Three Automatic Trips While Shutdown
  • Repositioned Wrong APRM Mode Switch
  • SDV Hi Hi Due to Valve Failure
  • Channel Spike Due to Noise Between APRM-9 6 and Flow.Comparitor Drawers 6

u Three Root Causes

  • Utilization of Industry Experience
  • Materiel Condition 7

Weak Utilization of Industry

. Experience *

  • Participated in BWROG Scram Reduction Initiative Until 1991
  • Sporadic Implementation of Vendor Recommendations (SILs and TILs)
  • Industry Best Practices Not Fully Utilized
  • Line Ownership of OPEX Review
  • Incorporation of Experience Into Work Packages
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8

Prolonged Time in Half Scram

  • Materiel* Condition Frequently Extends Time in Half Scram
  • Industry Practices for Half Scram Reduction Not Utilized

.e 9

Materiel Condition

  • Deficien.cies and Corrective Actions Detailed in Russ Freeman's Presentation 10

Corrective Actions Utilization of Industry Experience

  • Incorporate Industry Experience Into Work Packages
  • Line Concurrence for Industry. Experience Dispositions.
  • Train Personnel in OPEX Retrieval 11

Corrective Actions Tinie In HalfScram

  • Contingency Work Packages, Procedures & Parts for Key Half Scram Surveillances
  • Implementation of Industry Practice of Bypassing Instrument to Reduce half Scram Duration
  • Installed Chart Recorders to Detect False Actuations
  • Identified Components That Result in Excessive Half Scram Durations (e.g., EHC Low Pressure)
  • Evaluating Non-single Failure Proof Components For Upgrade to 2-out~of-3 Logic
  • Evaluating Divisionalization for Instrument Racks 5 and 6
  • Evaluating Mounts for Sensitive Instruments 13

Conclusions

  • Behind in Utilization of Industry Experience
  • Behind in Application of Scram Reduction
  • Recommendations
  • Important Improvements Have Been* Made, But Materiel Condition Challenge.s Continue
  • Management Will Continue to Address Issues 1.4

Materiel Condition

  • Key Systems
  • D2Rl 5 and D3P02
  • Future Improvements
  • Summary Assessment 15

Key Systems Continuing Materiel Condition Issues:

-.Offgas

- Control Rod Drive System

- Unit 2 Feedwater Level Control System *

-High Pressure _Coolant Injection 16

Off gas

  • Completed Actions

-. SJAE/Recombiners

- Replaced Unit 3. Catalyst Contaminated Piping

  • Results

- Steam Dilution Modification

-* Unit 3 Trains Operated in Parallel

- Hydrogen Analyzers Functional

-. Unit 3 Crosstie Removed 17

Control Rod Drive

  • Completed Actions Scram Solenoid Pilot Valves Full Core Scram Testing Control Rod Drive Mechanisms.and Pumps HCU Manual Valves and Accumulator Alarm Reduction On-Line Maintenance
  • Results Reduced Reactivity Management Challenges (HCUs Improved)

CRD Pump Reliability Off-Line Scram Testing 18

Unit 2 Feedwater Level Control

  • Completed Actions

- 2B FW Regulating Valve Internals

- Condensate Booster (CB) Recirculation Valve

- Automatic CB Recirculation Valve *Control

- Dynamic FW Regulating Valve Gain Adjustments

- Automatic Post-Scram Reactor Water Level Control 19

High Pressure Coolant Injection

  • Completed Actions

- Inlet Drain Line Piping

- Lube Oil Cooler Tubes

- GSLO System Safety Related Upgrade

- Inlet/Exhaust Drain Pot Magnetrol Switch Upgrade

- 2301-3 Valve Repair

  • Results

-*Unit 3 HPCI Unavailability Remains Higher Than Unit 2

  • GSLO Condenser Level Cop.trol Problems 20

D2Rl5 Materiel Condition Improvements

  • Eliminate Operator* Challenges HCU Valves and CRDs Moisture Separator Drain Tank Valves Condensate Demineralizer Service Units Feedwater Level Control System HPCI Injection Valve and Steam Supply Valve
  • Improve Performance and Reliability 2B Core Spray Pump Volute ECCS Suction Strainers 24/48 vdc Batteries and Chargers Generator H2 Cooler HPCI Drain Pot Line and Lube Oil Cooler LPCI 22B Valve and 2A LPCI Heat Exchanger

-. SBM Control Switches Vertical Extraction Steam Bellows Drywell Insulation and Coolers 21

D3P02 Materiel Condition Improvements

  • Eliminate Operator Challenges CRD Main Control Room Alarms
  • Improve Performance and Reliability FW Heater Trim and Bailey Level Control HPCI Packing/Oil Leaks; Check Valve, Switches; Gland Seal*

Level Switches CRD Flange 0-Ring Condenser Tube Leaks Second 3/8" Hole in Reboiler Line 3B Offgas - Crosstie Modification 22

. Future Improvements

  • 1 Year Improvement Plan

- Maintenance Rule a(l) Systems

- SHIP

-. Control Room Challenges

- Operator Work Arounds

  • Performance Measurement

- SHIP Report

- Maintenance Rule.Report 23

24

. Future Improvements

- Unit 3 Turbine Control Valve 02/99 2301-46 Valve 07/31/98

- Turb. Main Terminal Box

  • SBM Switches 09/30/98

-* 100 Switches each Unit D3R15

  • 3B LPCI Pump/Motor Vib.

. D3R15

  • RR MG Brush Replacement Mod. D3R15

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Summary Assessment

  • Overall Materiel Condition Improving

- Several Long Standing Problems Corrected

- Materiel Condition LERs Reduced

. * - 1 Year Plan Focusing on Key Systems to Improve Reliability and Reduce Operator Challenges and Work Arounds

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Concluding Remarks Scram Frequenc)'

  • Addressing Common Contributors to Increase Reliability Material Condition
  • Improving
  • Additional Action Required 27
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