IR 05000216/2003028
| ML17195A765 | |
| Person / Time | |
|---|---|
| Site: | Dresden, 05000216  |
| Issue date: | 04/02/1985 |
| From: | Chrissotimos N NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML17195A763 | List: |
| References | |
| 50-237-85-10, 50-249-85-09, 50-249-85-9, NUDOCS 8505020618 | |
| Download: ML17195A765 (12) | |
Text
U. S. NUCLEAR REGULATORY COMMISSION
REGION III
Reports No. 50-237/85010(DRP); 50-249/85009(DRP)
Docket Nos. 50-237; 50-249 License Nos. DPR-19; DPR-25 Licensee:
Commonwealth Edison Company P. 0. Box 767 Chicago, IL 60690 Facility Name:
Dresden Nuclear Power Station, Units 2 and 3 Inspection At:
Dresden Site, Morris, IL Inspection Conducted:
February 16 through March 28, 1985 Enforcement Conference At:
U.S. Nuclear Regulatory Commission, Region III, Glen Ellyn, IL on March 25,_ 1985 Inspectors:
S. Stasek T. M. Tongue C. D. Anderson Approved By: N~~~mos, Chief Reactor Projects Section 2C 1-J-85 Date Inspection Summary Inspection during the period of February 16 through March 28, 1985 (Reports No. 50-237/85010(DRP); 50-249/85009(DRP)).
Areas Inspected: Special resident inspection of recent personnel errors at Dresde The inspection involved a total of 68 inspector-hours onsite by three NRG inspectors including 12 inspector-hours onsite during offshift The Enforcement Conference involved a total of 44 hours5.092593e-4 days <br />0.0122 hours <br />7.275132e-5 weeks <br />1.6742e-5 months <br /> by 11 NRG personne Results:
Three violations were identified:
Violation of Technical Specifica-tions (paragraphs 2a and 2b); and failure to follow procedure (paragraph 2c).
~8~
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DETAILS Persons Contacted Commonwealth Edison Company Dresden Station Personnel
+'""D. Scott, Station Superintendent
'""R. Ragan, Operations Assistant Superintendent
+*J. Wujciga, Administrative and Support Services Assistant Superintendent
- J. Brunner, Technical Staff Supervisor J. Almer, Unit 2 Operating Engineer T. Ciesla, Unit 3 Operating Engineer
- M. Luoma, Q.A. Supervisor
+*R. Stobert, Sr., Q.A. Inspector
- D. Winchester, Q.A. Inspector G. Gates, Shift Control Room Engineer/Shift Technical Advisor R. Stasniak, Shift Foreman S. Styles, Shift Overview Superintendent G. Smith, Unit 3 Technical Staff Supervisor C. Segneri, Lead Test Engineer, Operational Analysis Department M. Schreim, Design/Quality Control Engineer, Station Nuclear Engineering Contractors Sargent & Lundy W. Chambers, HVAC Engineer D. Bianchini, Mechanical Project Engineer The inspectors also talked with and interviewed several other licensee employees, including members of the technical and engineering staffs, reactor and auxiliary operators and, shift engineers and foreme '""Denotes those attending one or more exit interviews conducted on February 22, 26, March 22, and March 28, 198 +Denotes those attending the Enforcement Conference held on March 25, 198 Corporate Representatives At The Enforcement Conference on March 25, 1985 B. Thomas, Executive Vice President D. Galle, Vice President and General Manager - Nuclear Station Division W. Worden, BWR Operations Manager B. Stephenson, Manager of Production D. Farrar, Director of Nuclear Licensing B. Rybak, Nuclear Licensing
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NRC Representatives At The Enforcement Conference on March 25, 1985 C. Norelius, Director, Division of Reactor Projects W. Shafer, Chief, Division of Reactor Projects - Branch 2 N. Chrissotimos, Chief, Division of Reactor Projects - Section 2C T. Tongue, Senior Resident Inspector - Dresden S. Stasek, Resident Inspector - Dresden C. Anderson, Resident Inspector - Dresden R. Landsman, Project Manager B. Berson, Regional Counsel W. Schultz, Enforcement Coordinator B. Stapleton, Enforcement Specialist D. Jones, Engineering Aide/Fermi 2 The resident inspectors performed an in-depth review of the following incidents that involved personnel errors which have occurred at Dresden during the period from January 4 to March 2, 198 The review involved independent evaluation by the inspectors of licensee actions concerning root cause evaluation and the corrective actions taken to prevent recurrenc Unit 3 High Pressure Coolant Injection System Room Cooler Found Inoperable On February 22, 1985, the Operations Department found the service water to the Unit 3 HPCI room cooler valved ou The valves affected were both the inlet and outlet manual isolation valves (3-399-344 and 3-399-345).
This caused the room cooler and, therefore, HPCI to be inoperabl Upon discovery, the affected valves were immediately opened and system operability restore An investigation in accordance with Nuclear Station Division Directive NSDD-A07 was undertaken by plant personnel to determine any past evolution that may have affected the status of valves 3-399-344 and 34 The Unit 3 logbook, Shift Engineer's logbook, and previous out-of-service requests were reviewe The last recorded manipulation of the valves was found to be September 1, 198 However, because of the operating characteristics of the room cooler, it was found that heavy condensation appears on the service water piping in and around the cooler when service water is properly valved i The licensee felt, because of the physical location of the cooler, which is located near the ceiling and directly above the entrance to the room, that dripping water would be noticeable to anyone entering the are Interviews were conducted with the different departments and the latest date determined for operability of the cooler, using the above criteria, was witnessed by electrical maintenance personnel working in that area on January 14, 198 The next documented date of indi-viduals working there again, was on January 23, 1985, when the HPCI operability surveillance was being performe No one involved at that time could recall any water drippin Therefore, the licensee
believes that station personnel, either misinterpreting the condensa-tion to be a leak from the cooler or to improve working conditions in the area, closed valves 3-399-344 and 345 without proper authorization during the period between January 14 and January 23, 198 Malicious mischief was ruled out during the course of the investiga-tion as a probable cause because of the physical location of the valve The cooler and its inlet and outlet valves are all located approximately 20 feet above the HPCI room main floor and are not easily accessibl Because the licensee's investigation revealed that the HPCI room cooler and, therefore, HPCI was inoperable from somewhere between January 14 and January 23 to the time it was discovered on February 22, 1985, Technical Specifications Limiting Condition for Operation (LCO) 3.5.C.l was exceeded by approximately 29 to 38 day This is considered a noncompliance caused by personnel error which, in this case, resulted in technical specifications being exceeded (50-249/
85009-0l(DRP)).
The following actions have been or are being taken by the licensee to prevent recurrence to either Unit 2 or 3 HPCI room coolers or to similar room coolers associated with other ECCS systems:
(1)
The affected valves were returned to service immediately and all similar valves on other ECCS room coolers for both units were inspecte No other misalignments were found.
(2)
All ECCS room cooler inlet and outlet valves are being locked and a temporary procedure change to reflect this is being added to the appropriate locked valve checklist (3)
These types of valves are to be added to the appropriate ECCS system specific operability checklist (4)
A verification of room. cooler operability is to be added to the appropriate Operating surveillance (5)
The event and above actions are to be discussed during the six week operator retraining progra (6)
Tailgate sessions were held with all departments reemphasizing the importance of contacting operating supervision prior to any valve manipulation (7)
Employed the services of Sargent & Lundy Engineering to conduct an analysis of the HPCI room heat balance without the benefit of the room coole The computer model with conservative assump-tions, showed that the temperature buildup in the room was slow enough to provide a significant period of time where the HPCI was still functional and alternate actions could have been taken.
- Unit 3 Torus Sample Line Found Open On March 2, 1985, the licensee discovered two normally closed torus (suppression pool) water sample valves ope These valves are located in the core spray system on the minimum flow line of the ECCS jockey pum The jockey pump takes its suction from and discharges (via its minimum flow line) to the B loop of core spray, downstream of the motor operated valv Torus water was found draining to the reactor building sump via a length of 3/8-inch tygon tubing which was connected to the sample lin Upon discovery, the valves were immediately closed and a chain and lock obtained to lock the valves in the proper positio The licensee then conducted an investigation to determine the cause of the misalignmen It was determined that at the time of discovery and during the previous five shifts, the 3B Reactor Building floor drain sump integrator log indicated an average per-shift pumpage of 489 gallon Prior to this, the average per-shift pumpage was approximately 211 gallon Following closure of the sample valves, the per-shift pumpage again returned to a lower rang A review was also done of the last sampling operation done at these valves and all similar samplings that were performed on nearby system At the com-pletion of the investigation, the licensee concluded that the torus sample valves were probably left open between Shift 3 on February 28 and Shift 1 on March No cause for the valves being open could be determine Torus water level was maintained at all time Rough calculations by the licensee indicate that a maximum of 40 gpm could blowdown through this flow path from the torus during a design basis acciden The water would then be contained within the reactor build-ing floor drain sump which isolates during an acciden Because there existed a direct flowpath from the torus (which is part of primary containment) to the secondary containment and the flowpath would have been in existence during a proposed accident situation, this is considered to be a noncompliance caused by personnel error which, in this. case~ resulted in Technical Specification 3.7.A.2.,
Limiting Condition for Operation, being exceeded (249/85009-02(DRP)).
The licensee has committed to take the following corrective actions:
(1)
The first isolation valve on the sample line for both Units 2 and 3 will be locked and added to the appropriate locked valve checklist (2)
Walkdowns of ECCS piping will be performed to determine other locations where similar problems could exis (3)
Procedural changes will be made to the Torus Water Drain Sampling procedures to require an operator be present to unlock and open the required valves to obtain the samples and to reclose and relock the valves afterwards.
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Loss of Undervoltage Protection on Bus 34-1 (1)
Preliminary Conditions Unit 2 was in the refuel mode with fuel in the vessel and licen-see personnel were preparing to conduct DOS 6600-5 "Bus Under-voltage and ECCS Integrated Functional Test for 2(3) Diesel Generator" on the Unit 2 emergency diesel generato Unit 3 was at or near full power and the Unit 2/3 (swing) emer-gency diesel generator was out of service for routine mainten-anc Several shift foremen, special shift foremen, nuclear system operators, equipment attendants, and equipment operators had been involved in preparation for the DOS 6600-5 test which had involved making up lengthy outage lists and Caution tags to be placed prior to the start of the tes (2)
Sequence of Events On February 16, 1985, the outage lists had been made up from the lists in the procedur An equipment attendant (B-man) was assigned to make out the Caution tags per the outage lists (two outages of about 85 tags each).
Since he was accustomed to seeing a valve or switch position listed on the tags, he ques-tioned the Unit 2 nuclear systems operator (NSO) then proceeded to a different assignmen The NSO contacted a shift foreman and inquired about the test switch position The reply was that the switches should be opened and the NSO reflected this on the Caution tag This is one of several errors that led to the event because the Caution tags were to be only placed on the switches for later identificatio Placing of the Caution tags started at about 8:00 am on February 16, 1985, by an equipment operator (EO) (non-licensed operator) who noted that the locations of the test switches were not listed on the Caution tag He contacted a special shift foreman for the test, who provided a copy of the proce-dure DOS 6600- When the EO opened the procedure and matched the switch numbers on the Caution tags with those in the proce-dure, he wrote the location of the switches on the tags and failed to notice that the locations were from the Unit 3 list rather than the Unit 2 list. Dresden Units 2 and 3 are nearly identical units thus, almost all components have identical iden-tification number This is another error that was a significant contributor to the events and resulted in the Caution tags being placed on Unit 3 rather than Unit When the EO started placing the Caution tags, he was accompanied by the shift overview superintendent (SOS).
The SOS noted that the tags were being placed on Unit 3 rather than Unit 2 and questioned the E They did not have a copy of the procedure
(3)
with them and through their discussion agreed that hanging tags on Unit 3 was probably due to the electrical cross-tie between the Unit 2 (Bus 24-1) and Unit 3 (Bus 34-1) diesel generator buses and concluded it was to prevent a perterbation on the Unit 3 sid They agreed to continue hanging the tags and followup on the question late This is a third error that contributed to the even The hanging of Caution tags and opening test switches continued to when the sixth and seventh tags were placed and the switches opene This caused control room alarm 903-8, D-4, "4kV Bus 34-1 Voltage degraded" to annunciat The special shift foreman (SSF), shift engineer (SE), and shift control room engineer/shift technical advisor (SCRE/STA) recognized that by procedure, the loads from Bus 34-1 would shed in five minutes if voltage was not restore The SSF, suspecting there may have been a problem with the outage placement, ran from the control room to the second floor of the reactor building where he contacted the EO and the SOS who immediately closed the last two switche This cleared the alarm comlltion before the five mjnnte time delay timed ou A prompt review resulted in removal of the Caution tags that had been placed and returning the test switches to the closed positio The errors were identified, the Caution tags corrected and properly placed and, the test was conducted as planned on the Unit 2 diesel generator after the Unit 2/3 diesel generator was returned to servic Evaluation of the Occurrence The licensee conducted an analysis of the effect of each switch being opened as the tags were place This analysis was reviewed by the inspecto The following is a listing of the results of each switch being opened and are listed by Caution tag numbers:
TAG
88
Prevented the start of the Unit 3 diesel generator on undervoltage (UV) on Bus 34, however, the diesel would have operated on opening of the supply breaker feeder from Bus-3 The UV function is anticipatory and has backup protectio Test switch could not be located, EO and SOS were to followu It turned out to be one of the differences between Units 2 and Verification only - no physical function involved.
91
93 (4)
Conclusion:
Prevented the automatic start of the Unit 3 diesel generator on opening of the supply breaker feeder from Bus-3 This is an anti-cipatory function and has backup protectio Disabled the second level (backup) load shedding from Bus 34-This action pro-tects the ECCS actuation ability while offsite power was available and the load shed that was suspected in the control room would not have occurre Was one of two switches required to give the control room alarm and start the five minute time Completed the circuit to give the control room alarm and started the five minute timer on degraded bus voltag This also would have prevented the ECCS logic from responding properly during the loss of offsite powe As a result of not properly following the procedure DOS 6600-5
"Bus Undervoltage and ECCS Integrated Functional Test for 2(3)
Diesel Generator" for the Unit 2 emergency diesel generator, Unit 3 low pressure ECCS systems were degraded for about four and one half minutes such that they could not have responded properly under a loss of offsite power conditio This condi-tion is considered noncompliance with 10 CFR 50, Appendix B Criteria V and XIV (50-249/85009-03(DRP).
It is noted that all systems would have responded as required to protect the plant provided offsite power was availabl (5)
Corrective Actions:
The licensee promptly commenced an indepth investigation in accordance with Nuclear Station Division Directive NSDD-A0 The immediate results of that investigation were provided to the inspecto The following is a summary of those actions:
(a)
Develop separate procedures by unit for those test This included the Unit 2 and 3 diesel generators as well as the Unit 2/3 diesel generator undervoltage test (b)
Require a signature step in each of the procedures that prevents starting unless all three diesel generators are proven operable.
(c)
Schedule manpower such that at most, only two specific personnel will be in charge of the test to ensure better continuity and communicatio (d)
Pre-printed Caution card checklists will be included in the ECCS undervoltage test procedure to ensure that an accurate description of the undervoltage test switches is include (e)
An immediate review of this event was held with all Operating personne (f)
An Operating Order will be issued to require that all personnel involved with a test or complex plant evolution will discuss the activity in detail "face to face" before proceeding with the activit The licensee has committed to have this order in place by April 1, 198 (g)
A "Professionalism" investigation was initiated on this even (h)
Actions of the personnel involved will be reviewed directly by the Station Superintenden The licensee reported the event in accordance with 10 CFR 50.72 and will submit a licensee event report, in accordance with 10 CFR 50.7 Three items of noncompliance were identifie.
Review of Additional Selected Licensee Event Reports Through direct observations, discussions with licensee personnel, and review of records, the following selected event reports were reviewed to determine that reportability requirements were fulfilled, immediate correc-tive action was accomplished, and corrective action to prevent recurrence had been accomplished in accordance with technical specification *LER 237/85-001 Unit 2 - Bus 23-1 Main Feeder Breaker Failure To Trip On January 4, 1985, during breaker differential relay testing by the Licensee's Operational Analysis Department (OAD), 4kV Breaker 2329 failed to trip as require The cause was found to be disconnected wires in the tripping logi A survey of similar relays was made (including those on buses 24-1, 34-1, and 33-1) and all were found intac A review of the breaker's work history revealed no work had been performed on it since the last OAD surveillance (March 8, 1983).
The licensee could not, therefore, make a determination as to why or when the wires were disconnecte The method of disconnecting was indicative of normal maintenance practices, and the licensee believed that no malicious intent was involved but that it was a personnel erro It was subsequently determined that breaker 2329 would have still tripped, if required, due to a differential fault.
LER 237/85-003 Unit 2 - Inadvertent Group 2 Isolation On January 29, 1985, with level transmitter 2-263-57B out-of-service and an intentional half group isolation signal present, level transmitters 2-263-57A, 2-263-58A,and 2-263-58B were taken out-of-service for modifica-tion testin When this was done, a full Group 2 isolation occurre The unit was in a refuel outage with all scrams jumpered out at the tim The licensee determined the cause to be a personnel erro The shift foreman failed to verify that jumpers were still inplace as they had been the day before to bypass the group isolation while this work was being performe Subsequently, the foreman recognized his error and realized that the jumper verification should have been don LER 249/85-009 Unit 3 - Torus Sightglass Upper Isolation Valve Found Open On February 5, 1985, an operator found the Unit 3 Torus sightglass upper isolation valve (3-1699-15) locked in the open positio Because the sightglass is constructed to a lower specification than the torus, this valve is classified as a primary containment isolation valve and, as such, is normally maintained in the locked closed positio However, no flowpath existed to secondary containment because the associated vent line was capped in response to an earlier incident which occurred on Unit 2 in October 198 Because the unit was operating at power at the time and primary containment was required by procedure, valve 3-1699-15 was still required to be locked in the closed positio The licensee subsequently determined that an operator had unlocked and opened the valve as part of taking a sightglass reading approximately one hour prior to it being found ope The licensee concludes that an error was made at that time where the operator, upon completing taking the sightglass reading, failed to properly reclose the valv Originally, the licensee did not believe the event to be reportable since no flowpath to the secondary containment atmosphere existed and the sight-glass is periodically leak rate tested (under static conditions) to acci-dent pressure However; following discussions with the resident inspector, it was determined that a licensee event report (LER) was required and would be submitte Personnel associated with this event have been reminded of the importance of returning these types of valves to their original position following completion of activitie LER 237/85-004 - Unit 2 Reactor Scram While Transferring RPS Power Supply On February 6, 1985, during the refuel outage, the Reactor Protection System (RPS) power supply for RPS Channel B was transferred from the RPS motor-generator (MG) set to its alternate suppl In the procedure (DOP 7000-1), a precaution is given that if the transfer is attempted while reactor pressure is less than 600 psig and the reactor mode switch is in Shutdown, Refuel, or Startup, a full scram would occur if condenser vacuum was less than 23 inches (Hg).
The resident inspector, following discussions with plant personnel, ascer-tained that to preclude the full scram, the 11 112 11 relays were normally blocked; however, this was not don The licensee has committed to write a procedure which better delineates the prerequisites to transfer RPS power to preclude any recurrenc LER 237/85-009 - Standby Liquid Control Operability Surveillance Not Performed Immediately On February 21, 1985, at 5:15 pm, while Unit 2 was in a refuel outage, the 2A Standby Liquid Control (SBLC) pump was taken out-of-servic Technical Specification 4.4.B requires that when this is done, the redun-dant component be demonstrated to be operable immediately and daily, thereafte However, SBLC pump 2B was not tested until February 23 at 4:30 am, approximately 35 hours4.050926e-4 days <br />0.00972 hours <br />5.787037e-5 weeks <br />1.33175e-5 months <br /> lat When the oversight was discovered, the pump was then tested and found to be operabl The licensee determined the root cause of this situation to be an error by operating personne The oversight was discussed with the Shift Engineer, Shift Foreman, and Shift Foreman Trainee who were on-shift at the tim Also, the incident was included as part of the six week operator training schedul The preceding LERs have been reviewed against the criteria of 10 CFR 2, Appendix C, and when the incidents described meet all of the following requirements, no Notice of Violation is normally issued for that ite The event was identified by the licensee, The event was an incident that, according to the current enforcement policy, met the criteria for Severity levels IV or V violations, The event was appropriately reported, The event was or will be corrected (including measures to prevent recurrence within a reasonable amount of time), and The event was not a violation that could have been prevented by the licensee's corrective actions for a previous violatio In summary, the foregoing list of events represents the basis for the concern related to the recent increase in personnel errors at Dresde This was discussed with the licensee during the exit meetings and the Enforcement Conference on March 25, 198 No items of noncompliance were identifie.
Inspector Evaluation The inspector ascertained that the licensee's investigation and evaluation into root cause determination and corrective actions designed to prevent recurrence were adequate in all cases.
11 Exit Interview The inspectors met with licensee representatives (denoted in Paragraph 1)
on February 22 and 26, and March 22, 1985, and at the conclusion of the inspection on March 28, 1985, and summarized the scope and findings of the inspection activitie The inspector also discussed the likely infor-mational content of the inspection report with regard to documents or processes reviewed by the inspector during the inspectio The licensee did not identify any such documents/processes as proprietar The licen-see acknowledged the findings of the inspectio.
Enforcement Conference The Region III staff met with licensee representatives (denoted in para-graph 1) for an Enforcement Conference on March 25, 1985, in the Region III offic The purpose of the Enforcement Conference was to discuss the recent increase in personnel errors at Dresde This included specific discussions on the Unit 3 HPCI room cooler isolation, the Unit 3 torus sample line being left open, the Unit 3 degraded EGGS undervoltage while testing Unit 2, plus a number of other recent personnel error The licensee provided a description of each of the events, immediate corrective actions, the analysis and long term corrective action In addition, the licensee provided an overall evaluation and a plea for merc The NRG representatives provided comments and questions on the licensee presentations and expressed concern about the potential seriousness and recent increase in the numbers of personnel error