ML17199F680
| ML17199F680 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 06/11/1985 |
| From: | Virgilio M Office of Nuclear Reactor Regulation |
| To: | Booher H, Edison G, Regan W Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML17199F679 | List: |
| References | |
| NUDOCS 8603130370 | |
| Download: ML17199F680 (15) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 June 11, 1985 MEMORANDUM FOR: 6. E. Edison, Chief FROM:
SUBJECT:
REFERENCE:
Purpose Technical and Operations Support Branch Planning and Program Analysis Staff, NRR W. Regan, Acting Chief Human Factors Engineering Branch Division of Human Factors Safety, NRR H. R. Booher, Chief Licensee Qualifications Branch Division of Human Factors Safety, NRR K. Black, Chief Nonreactor Assessment Staff Office for Analysis *and Evaluation of Operational Data M. J. Virgilio, Technical Assistant Technical and Operations Support Branch Planning and Program Analysis Staff, NRR TRIP REPORT fOR DRESDEN SITE VISIT Memorandum from M. Virgilio to G. E. Edison dated April 17, 1985 ENCLOSURE The purpose of this memorandum is to document the activities and findings of an NRC visit to the Dresden $ite on May 8 and 9, 1985.
Members of the NRC group for this visit included G. Trager (AEOD), A. Ramey-Smith (DHFS),
- 0. Persfoko (DHFS), and M. Virgilio (PPAS). This site vhit was conducted as a part of the short-tenn effort to detennine whether simple, low cost improvements can be identified and implemented to reduce the frequency of wrong unit/wrong train events occurring at nuclear power reactor facilitie~.
Additional background infonnation on this subject and a detailed plan of action for the short-tenn effort are presented in the referenced memorandum.
General Information
- The Dresden site is located nine miles east of Morris, Illinois -o~,the Kankakee River.
On the site are three reactors operated by Conmonwealth Edison Company, Dresden Units 1, 2 and 3. Dresden Unit 1 has been permanently shut down.
Dresden Units 2 and 3 are both General Electric NSSS BWR-3 with Mark I containments, each having a maximum dependable capacity (Net) of 772 MWe.
The architect/engineer for both units was Sargent and Lundy.
The construction for both units was United Engineers. Dresden Unit 2 was first placed into conmercial operation on June 9, 1970. Dresden Unit 3 was first placed into conmercial operation on November 16, 1971.
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- ~ l- *.. Site Visit Agenda The site visit discussions and tours were centered around three reported wrong unit/wrong train events that occurred at Dresden in 1984 and 1985.
The LER numbers for these events are 237-84-013, 249-85-005 and 237-84-012. During the site visit the NRC team inspected the location of the reported wrong unit/
wrong train events, superficially reviewed the procedures involved and discussed the events with the individuals involved, their supervisors and the Dresden Station Production Superintendent. Enclosure 1 provides a sequence of events for each of the LERs, a surrmary the licensee's follow-up actions for each event, observations from the NRC site visit tour and a sur1111ary of the discussion of each event with the individuals involved.
General Observations Dresden plant personnel stated that after several years of multi-unit operation, the station management perceived a need to improve the labeling and ident~fication systems. Accordingly, the floors surrounding components for Unit 2 were painted yellow and the floors surrounding Unit 3 components were painted blue.
Sound powered corrmunication systems for the Units were separated. In addition, large plastic labels were installed on most components.
At Dresden two administrative programs govern the evaluation of human errors; the PRO (professionalism) Investigation Program and the Potential Significant Event Investigation Program.
Implementation of *each program is governed by procedures that include provisions for determining the need for corrective actions such as hardware, procedural, and training improvements.
Two tag-out programs are utilized at Dresden to control breaker, valve and switch positions. In addition, monthly position/status checks are performed on certain essential support system components.
Some automated system and component status monitoring indication is provided in the control room, however, the plant design pre-dates the NRC guidelines on. status monitoring contained in Reg. Guide 1.47, nsypassed and Inoperable Status Indication for Nuclear Power Plant Safety Systems".
Training for Corrmonwealth Edison employees located at the site varies depending on their assigned.responsibilities. All non-licensed operators and other station personnel responsible for manipulating valves, switches and breakers in performance of their assigned duties receive. six months of training which includes system and component location, identification and labeling systems, proper methods of implementing tag-out procedu~es. and on-the-job training with other Dresden personnel. Isolation of sys*tems and components for maintenance is perfonned by these Operations Department personnel and confirmed by the maintenance personnel (Conmonwealth Edison Employees) before work corrmences. This is the case even when work is performed by contractor employees.
~-
.* Closeout Meeting The site visit was concluded by a meeting with the Production Superintendent and a Training Supervisor. Both individuals were asked what, in their opinion, were the overall causes leading to the wrong unit/wrong train events.
In the Training Supervisor's opinion labeling was most important and he felt that additional and improved labeling and identification systems would be helpful.
In the Production Superintendent's opinion additional conrnunication between shift personnel prior to performing plant evolutions (e.g., mode change, test, tag-out) was the most important factor and that improved conrnunications would reduce the number of wrong unit/wrong train events.
At the closeout meeting the NRC team expressed its appreciation to the Dresden site staff, in particular to the Production Superintendent whose cooperation in coordinating the tour and discussions made the site visit efficient, informative and productive.
Enclosure:
As stated cc: J. Funches T. Ippolito D. Beckham R. Gilbert
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M. J. V~lio, Tecitfiical Assistant Technical and Operations Support Branch Planning and Program Analysis Staff, NRR
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Review of Dresden Units 2 and 3 Wrong Unit/Wrong Train Events The Dresden site visit discussions and tour were centered around three reported wrong unit/wrong train events that occurred in 1984 and 1985.
The purpose of this paper is to provide a brief discussion of each event, a summary of the licensee's follow-up actions for each event and observations from the NRC site visit tour and discussions of each event with the individuals involved.
LER 237-84-013 Description of the Event The following event description was provided by the licensee to the NRC group during the site visit.
"On the afternoon shift of July 22 1 1984, Unit 2 was steady state at 747 MWe and Unit 3 was being prepared for startup following a*scram earlier that day.
A newly promoted Equipment Attendant (EA) was called in as extra to help with the Unit 3 startup. The EA had completed preparing a reactor feed pump (RFP) for operation and called the unit Nuclear Station Operator (NSO) to report the RFP ready for service. The NSO told him to go to the condensate pump room and prepare a condensate/condensate booster pump for service.
At this time, the NSO also told the EA that on his way to the condensate pump room he wanted him-to open the turbine electrohydraulic control (EHC) system valve FV-1.
The EA went to the Unit 2 instead of the Unit 3 EHC system and opened*:the FV-1 valve.
This resulted in a low EHC system pressure, causing a turbine trip and reactor scram on Unit 2 from 747 MWe.
11 Licensee's Investigation At Dresden most events that involve human error are evaluated to determine the cause and appropriate corrective action.
At Dresden these evaluations-~re called PRO (professionalism) investigations.
From the evaluation of the event the licensee determined that there were several contributors to the error.
The findings, conclusions and reco111rnendations of the PRO investigation are as follows:
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"The EA began employment on January 5, 1984.
He had not participated previously in any of the evolutions he was asked to perform.
His training included five weeks at the Production Training Center and about seven weeks of OJT.
The balance of his time was spent in on-site classroom training and associated plant tours. During his entire OJT training period, Unit 2 was operating and Unit 3 was in a maintenance outage. Shift supervision had told the newly promoted EA at the beginning of the shift that if he encountered any problems out in the plant while performing his duties, he should call and ask for help.
The EA had asked for and received help by phone from the NSO in order to prepare a RFP for service.
He said he felt hurried in receiving orders to prepare the.
condensate/condensate booster pump and open the FV-1 valve.
During his OJT he had been shown the FV-1 valve on Unit 2 and had a mental image of that valve.
When he erroneously went to the Unit 2 EHC unit, which is adjacent to the Unit 3 EHC unit, he verified the FV-1 tag notation, which was in large letters and overlooked the smaller "Unit 2 11
- This was his first shift working as an EA assigned to a unit.
He was called in as an extra EA for the start-up of Unit 3 and did not know the people on the shift and they did not know him.
He clearly understood that he was assigned to Unit 3 and all his work*that shift would normally be associated with Unit 3.
PERSONNEL INVOLVED Equipment Attendant -
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Nuclear Station Operator -
CONCLUSIONS
- 1.
There was no evidence of careless disregard for rules or requirements.
- 2.
The newly promoted EA received minimal shift management involvement or supervision.
- 3.
The root cause was assigning a person to do a task who was inexperienced.
- 4.
Human factor conditions regarding color coding, valve tagging and lighting were satisfactory.
RECOMMENDATIONS
- 1.
Newly promoted EAs should receive close shift supervision, especially when they are assigned a shift activity for the_
first time **
- 2.
Detailed briefings should be given before placing new EAs into stressful situations to ensure both proper understanding of assignment and method of accomplishment.
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- 3.
OJT should be expanded for an interim period of about 2 weeks in which the newly promoted EA works with and is backed up by an experienced EA prior to assuming the job.
- 4.
OJT should be conducted to ensure that personnel receite adequate training on both units (most training is now done on Unit 2) to avoid a "mind set" or preference regarding only one unit."
NRC Tour Observations As a part of the site visit tour the NRC team looked at the EHC System Valves FV-1 for Unit 2 and Unit 3.
The majority of the electrical and mechanical com-ponents for the Unit 2 EHC System are part of an assembly measuring approximately 4 ft (w) x 6 ft (1) x 6 ft (h).
FV-1 is located in the front center of the assembly approximately 5 ft from the floor.
The EHC system for Units 2 and 3 are located on either side of a passageway, separated by approximately 12 ft.
lhe base and floor surrounding the EHC assembly for Unit 2 is painted yellow, the base and floor surrounding the EHC assembly for Unit 3 is painted blue.
FV-1 is marked with a plastic tag measuring approximately 3 in x S in, with FV-1 in large letters and the uni~. number (Unit 2 or Unit 3) in smaller *letters.
NRC Discussions With Plant Staff During the site visit the NRC team met with the NSO and EA involved in the EHC system event discussed above.
When asked his opinion on the cause of the event the EA attributed his mistake to the training program's focus on Unit 2, and the fact that this was his first day on the job independently perfonning assigned tasks.
Other Observations Based on a review of the event, discussions with the individuals involved and inspection of the location where the event occurred the NRC team made_sever~l additional observations. Although these observations may not be direct'y related to this event they appear to be germane to the wrong unit/wrong train issue based on reviews of other wrong unit/wrong train events that have been reported to the NRC.
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- 1.
EA's as well as other shift personnel rotate through different assignments as well as different shifts. At Dresden there are six crews rotating through three working shift (graveyard, day and evening), training and time off. Within this rotation EA's serve in seven different assignments rotating at 3 day intervals (Unit 2 EA, Unit 3 EA, radwaste EA, etc.).
During any three day rotational assignment an EA may be asked to perform work outside his assigned *responsibilities for that three day interval.
- 2.
Although the floor surrounding a plant-unique component is color coded, there is no color coding scheme for labels, systems, or components.
Some components share identification numbers, FV-1 for example.
Although the label for FV-1 includes the Unit 2 or Unit 3 identi_fication on the label this is not the case for all labeled components in the plant. Tags for many Unit 2 and Unit 3 components are identical (i.e. have the same iden~ification number, same color). **Even though the unit designation was on the EHC valve tags, the EA stated that he saw FV-1, and opened the valve.
- 3.
There is no formal label maintenance program.
When missing or obscured labels are reported, repair orders are initiated by station personnel.
- 4.
Unless a caution or out-of-service tagout is involved, an EA's instructions are provided verbally.
An EA may be directed to perform tasks by different shift personnel (e.g. shift foreman, NSO, shift engineer), and priorities assigned to t.he different tasks are subject to change.
- ~
- 5.
There did not appear to be a formal program for determining schedules and assigning responsibility for implementation, although all of the PRO in-vestigation's recommendations had been implemented.
- 6.
Certain labels and tags include a functional description.of the component (e.g. bypass valve, discharge throttle valve). Others provide only a component identification number.
There did not appear to be a logical scheme to explain the difference.
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- 7.
Curbs surrounding components on both Units 2 and 3 were painted yellow to stand out as personnel hazards.
Yellow is also the color painted on the floor to designate Unit 2 components.
LER 249-85-005 Description of the Event The following event description was developed from the IE follow-up investiga-tion report and discussions with the licensee during the site visit.
Unit 2 was in the refuel mode with fuel in the ve_ssel and licensee personnel were preparing to conduct DOS 6600-5 "Bus Undervoltage and ECCS Integrated Functional Test for 2(3) Diesel Generator" on the Unit 2 emergency diesel generator.
Unit 3 was at or near full power and the Unit 2/3 (swing) emergency diesel generator was out of service for-routine maintenance.
Several shift fc)remen, 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 test.
On February 16, 1985, the outage lists had been made up from the lists in the procedure.
An equipment attendant (8-man) was assigned to m~ke 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 questioned the Unit 2 nuclear systems operator (NSO) and then proceeded to a differen~
assignment.
The NSO contacted a shift foreman and inquired about the test switch positions.
The reply was that the switches should be. opened and the NSO reflected this on the Caution tags. This is one of several errors tJlat led to
- the event because the Caution tags were to be only placed on the switches to enhance later identification.
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 06/03/85 5
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- of the test switches were not listed on the Caution tags. He*contacted a special shift foreman for the test, who provided a copy of the procedure DOS 6600-5.
When the EO opened the procedure, which contained portions common
- ~::~ ~~i~:.2c::~i!na:.::1:;:: :::::f~~ ~:.u;~:c:d:~.~*h:"~:~tc~:: ~::.:~::ch t of the switches on the tags and failed to notice that the locations were from the Unit 3 1i st rather tha.n the Unit 2 1 ist. Almost all components have identi-cal identification numbers, rather than identification numbers unique to Dresden Units 2 and 3.
The identification of wrong unit location was another significant contributor to the events and resulted in the Caution tags being placed on Unit 3 rather than Unit 2.
When the EO started placing the Caution tags and opening the switches he was met in the plant 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 EO.
They did not have a copy of the procedure 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 (Bu~.24-1) and Unit 3 (Bus 34-1) diesel geherator buses and concluded it was to prevent a perturbation on the Unit 3 side. They agreed to continue hanging the tags and followup on the question later. The SOS's use of improperly completed tags to verify correct placement was the third contributor to the event.
The hanging of Caution tags and opening test switches continued until the sixth and seventh tags were placed and the switches opened.
This caused control room alarm ~03-8, D-4, "4kV Bus 34-1 Voltage degraded~ to annunciate.
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 restored.
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 buildin~ wher~. he contacted the EO and the SOS who immediately closed the last two switch.es.
This cleared the alarm condition before the five minute time delay timed out.
A prompt review resulted in the removal of the Caution tags that had been placed and returning the test switches to the closed position.
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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 service.
Licensee's Investigation At the time of the site visit.the licensee had not yet completed its own evalua-tion of the event. A preliminary report on the potential significant event was prepared and issued on February 20, 1985. This report included a description of the event, a discussion of its safety significance and recommended actions.
The recommendations of this preliminary report are as follows:
"Corrective Actions The preliminary Station review of the event recommends the following acUons:
- 1.
Separate DOS 6600-5 and 6600-6 into separate procedures for Unit 3 and Unit 2.
- 2.
Place in the prerequisite of DOS 6600-5 and DOS 6600-6 a sign-off that the test cannot be performed until all three diesel generators are operable.
- 3.
Schedule manpower such that at most only two specific personnel will be in charge of the test to ensure better continuity and communication.
- 4.
Pre-printed caution card checklists will be included in the ECCS undervoltage test procedure to ensure that an accurate description of the undervoltage knife switches is included.
- 5.
An immediate review of this event will be held with all Operating personnel.
- 6.
An Operating Order will be issued to require that all personnel involved with a test or complex plan evaluation will discuss the activity in detail "face to face" before proceeding with the activity.
- 7.
A Pro investigation will be initiated on this event.
- 8.
Actions of the personnel involved will be reviewed directly by
- the Station Superintendent."
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NRC Tour Observations During the site visit the NRC team members were shown procedures, DOS 6600-5, 11Bus Undervoltage and ECCS Integrated Functional Test for 2(3) Diesel Generator" and OAP 3-8, "Caution Cards".
During the tour the NRC review team looked at the electrical busses and switches caution-tagged during the event.
From a superficial review of DOS 6600-5 we observed that the* pages for the Unit 2 and Unit 3 system alignments were uniquely identified by small letters at the top of each page.
However, this uniqueness appeared to be too subtle considering most of the component numbers for the Diesel generators and associated equipment were the same.
NRC Discussions With Plant Staff During the site visit the NRC met with the SOS and SSF involved in the diesel generator tag-out event discussed above.
When asked their opinion on the cause of the event the individ~als attributed their mistakes to misconimunication, lack of attention to details and procedural inadequacies.
Other Observations Based on a review of the event, discussions with the individuals involved and inspection of the procedures and the location where the event occurred the NRC team made several additional observations. Although some of these observations may not be directly related to this event they appear to be:.'germane to the wrong unit/wrong train issue based on reviews of other wrong unit/wrong train events that have been reported to the NRC.
- 1.
Although one of the proposed corrective actions is to separate this test procedure involved into plant unique procedures for Unit 2 and_Unit 3, other plant procedures remain combined two unit procedures.
- 2.
At Dresden administrative procedures are used to isolate and disable safety-related components. '
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Caution cards are utilized for a number of purposes including establishing plant conditions for tests. Out-of-service cards are used control plant conditions for maintenance. Although the out-of-service card procedure (OAP 3-5) specifically requires independent physical verification by a competent, qualified individual when removing or restoring equipment to service, the caution card procedure OAP 3-8 does not.
- 3.
A limited number of station procedures and logs are unit specifc and color coded.
Unit specific color coding of additional procedures is being considered by Dresden Station management.
- 4.
As in LER 237-84-013, components in Units 2 and 3 contain the same com-ponent designation.
In this case, the buses were specifically identified by Unit (i.e., 2253 for Unit 3 and 2252 for Unit 2), however, switch numbers on the buses were identical on both Units.
LER 237-84-012 Description of the Event The following event description was developed from discussions with the licensee during the site visit.
On July 9, 1984, with Unit 2 operating at 98 percent power, calibration of the main steam line log radiation monitoring system was in progress. The test equipment was connected to conduct a calibration of the c main steam line radia-tion monitor associated with RPS Channel A.
However, the Instrument Mechanic mistakenly turned the RPS Channel B low setpoint bypass switch to the off posi-tion. Since hydrogen additon.~as in progress, a low setpoint trip occurred in RPS Channel B.
The Instrument Mechanic was informed of the RPS Channel B trip by his assistant. The Instrument Mechanic then attempted to lower_the test signal on C mai~ steam line radiation monitor and remove his test equipment to avoid a Channel A trip and reactor scram.
Before the test signal could be lowered and test equipment removed, a voltage spike tripped the C main steam line which in turn tripped RPS Channel A and initiated a reactor trip.
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Licensee's Investigation The licensee's investigation concluded that the Instrument Mechanic was at fault by failing to follow the test procedure. The Instrument Mechanic was disciplined by receiving one day off presumably without pay.
NRC Tour Observations During the site visit the NRC team members were shown the surveillance test procedure.
During the tour the NRC review team visited the control room and examined the panel containing the test jacks and switches manipulated by the Instrument Mechanic during the surveillance test of the main steam line radiation monitors.
From a superficial review of the surveillance procedure, we observed that one procedure was utilized for three test conditions, Unit 2 with hydrogen addition on, Unit 2 with hydrogen addition off and Unit 3 (no hydrogen addition).
From our examination of the control; room panel we noted an apparent lack Of human factors planning for the surveillance testing and calibration of the main steam line radiation monitors.
As depicted in Figure 1, the instrument channel drawers were located above and to the side of bypass switches.
The drawers for instrument channels A and C (feeding into the A RPS logic) were located above the B and D instrument channel drawers (feeding the B RPS logic).
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. FIGURE l NRC Discussions With Plant Staff During the site visit the NRC met with the Instrument Mechanic responsible for the plant trip discussed above.
When asked his opinion on the cause of the event the mechanic attributed the mistake to confusion, a defective procedure (that requires the user to flip back and forth between vari~us sections and data sheets), and his lack of familiarity with the procedure (had only been performed by this individual once before).
In addition to procedural changes, the mechanic recommended that covers be placed over the switches to prevent inadvertent operation.
Other Observations Based on a review of the event, discussions with the individuals involved and inspection of the procedures and the location where the event occurred the NRC team made several additional observations.
- Although some of the observations may not be directly related to this event they appear to be germane to the 06/03/85 11 TRIP REPORT FOR DRESDEN
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wrong unit/wrong train issue based on reviews of other wrong unit/wrong train events that have been reported to the NRC.
- 1.
There was no PRO investigation for this event.
Because of previous human error events involving this individual and the more obvious circumstances of this event it was concluded that the Instrument Mechanic failed to follow procedures. Objectivity of the review appeared limited.
- 2.
Commonwealth Edison is beginning to become involved in the INPO accredita-tion program. It is anticipated that participation in the program will result in definitive qualifications and improved training and procedures for Instrument Mechanics.
- 3.
Although the instrument mechanic stated that the procedure was confusing, he-apparently was following the procedure correctly because he realized that an error occurred when he was informed of the Channel B trip instead of Channel A.
- 4.
This calibration had only been performed a total of six times since revi-sion of the procedure to account for hydroge~ addition. When.asked about training given the recent revision of the procedure, we were informed that someone who has performed this calibration before walks through the proce-dure with someone who is doing it for the first time.
However, the expe-rienced person is not always present when this inexperienced person is doing the calibration.
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