IR 05000409/1979018
| ML19262B922 | |
| Person / Time | |
|---|---|
| Site: | La Crosse File:Dairyland Power Cooperative icon.png |
| Issue date: | 10/18/1979 |
| From: | Boyd D, Foster J, Ridgway K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML19262B920 | List: |
| References | |
| 50-409-79-18, NUDOCS 8001170077 | |
| Download: ML19262B922 (10) | |
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U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT
REGION III
Report No. 50-409/79-18 Docket No. 50-409 License No. DPR-45 Licensee: Dairyland Power Cooperative 2615 East Avenue South La Crosse, WI 54601 Facility Name:
La Crosse Boiling Water Reactor (LACBWR)
Investigation At: LACBWR Site, Genoa, Wisconsin Investigation Conducted:
September 11-12, 1979 Investigator (: '
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K. R. RidgWay
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Reviewed By: y.E.Norelis
/o -/ $.- 7 7 Assistant to the Director hfWGyd D. C. Boyd, Chief
/O- /S -77 Reactor Projects Section 3 Investigation Summary Investigation on September 11-12, 1979 (Report No. 50-409/79-17)
Areas Investigated:
Special, announced investigation of Licensee Event Report 79-16, bypassing of low flow safety circuit during reactor startup on September 7-9, 1979; review of pertinent records, observation of control room conditions, interviews of personnel. The investigation involved 28 inspector-hours by two NRC personnel.
Results: Of the areas investigated, two items of noncompliance with NRC regulations were observed (1) infraction; failure to energize the low flow scram circuit during startup, (Paragraph 8) and (2) infraction; failure to perform a timely review and corrective action for a previous incident report (Paragraph 9).
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REASON FOR INVESTIGATION
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On September 9, 1979, the licensee, Dairyland Fower Cooperative, reported to NRC Region III (RIII) by telephone that the forced circulation system low flow safety circuit (low finw scram) switches had been on bypass since startup on September 7, and during low power operation (less than 17) until discovered on September 9, 1979. This investigation was conducted to determine the cause of the incident and review corrective actions taken or proposed to prevent recurrence.
SUMMARY OF FACTS Following notification by the licensee, NRC personnel visited the Lacrosse Boiling Water Reactor (Lt.CBWR) site on September 9-12, 1979. During this period an investigation was performed of the low flow scram bypass involving interviews, rcview of operating logs, station procedures, incident reports, and a discussion of proposed corrective action with the licensee.
Review of the station logs for the time period indicated that from 1035 hours0.012 days <br />0.288 hours <br />0.00171 weeks <br />3.938175e-4 months <br /> on September 7, 1979 until 0820 hours0.00949 days <br />0.228 hours <br />0.00136 weeks <br />3.1201e-4 months <br /> on September 9, 1979, the low flow scram switches were in the bypass position. Station startup pro-cedure requires that these two switches be in the normal position during this time period. A review of the operating logs indicated that the reactor was in a startup condition at this time and had operated at low power levels indicated to have been approximately 0.1% at 8 o' clock on September 9, 1979. Actual power level at the time when the low flow scram was discovered to be in the bypass condition, 0820 hours0.00949 days <br />0.228 hours <br />0.00136 weeks <br />3.1201e-4 months <br />, may have been slightly in excess of this figure, as the reactor was gaining power during this period.
See Exhibit I.
Interviews were held with all immediately involved station operators.
The operator who performed the initial part of the startup procedure indicated that he had apparently missed a step in the startup procedure which required that the low flow scram switches (Nos. 34 and 35) be placed in the normal position.
The operator stated that he had been interrupted at least once during performance of the procedure, and he believed that he must have omitted this step inadvertently. No check list or hold points were included in the startup procedure to preclude omitting the step in the startup procedure.
Interviews with succeeding operations shif ts indicated that these personnel had logged keys 34 and 35 in the operations log as being in the bypass condition without recognizing that this reflected a safety system which should not be in the bypass condition. Operators indicated that they had not made the connection between the Nos. 34 and 35, and the low flow scram system, these being two switches which are infrequently used.
It was also indicated that in many cases succeeding shifts do not review the preceeding shift's log.
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A review of procedures indicated several procedural deficiencies which
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have been highlighted by this incident, including lack of a startup check list, and some procedures which lack instructions to return bypass switches to the normal position once the procedure or surveillance is accomplished.
A review of previous incidents indicated that there had been a similar in-ident on May 7, 1978, when the same switches, Nos. 34 and 35, were found to be in the bypass condition just prior to reactor criticality.
As re,uired by station procedures, an incident report and review by the statiot operating reactor committee was performed for this incident.
However, the incident did not receive a timely review as it took some seven months to receive review and approval, and the corrective action was apparently not adequate to prevent recurrence of the incident.
Discussions were held with licensee personnel concerning proposed cor-rective actions to assure that a similar incident would not occur in the future. These corrective actions included initiation of startup check lists, hold points being placed on certain procedures for shift supervisor review and approval, a requirement for an operating log review sign-off by shift personnel, the logging of bypassed switches by system name rather than system number, and a review of procedures to determine whether they should be revised to include normalization of a switch which is required to be placed in the bypass condition during the procedure. The licensee also advised that they would con.ider utilization of a color code for various bypass switches. These s rrective actions appear adequate to provide assurance that a similar.ncident will not occur.
Two items of noncompliance were des 31oped during the investigation.
These items are related tc 1) a site procedure violation, 2) untimely and inadequate corrective action taken on a previous occurrence. This incident received considerable local media coverage.
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DETAILS 1.
Personnel Contacted R. Shimshak, Plant Superintendent
- J. Parkyn, Assistant Plant Superintendent G. Boyd, Operations Supervisor L. Kelley, Security and Fire Protection Supervisor R. Cota, Shif t Supervisor P. Moon, Shift Supervisor J. Gallagher, Shif t Supervisor S. Buck, Plant Operator R. Christians, Plant Operator P. Crandall, Plant Operator D. Kabachinski, Plant Operator J. Papierniak, Plant Operator D. Stalsberg, Plant Operator D. Wandschneirer, Plant Operator G. Whynaught, Plant Op rator M. Wilchinski
- Denotes person present at the exit interview.
Subsequent to the r
exit interview, Mr. Shimshak was contacted by telephone to confirm commitments to corrective actions.
2.
Introduction The Lacrosse Boiling Water Reactor (LACBWR), licensed to Dairyland Power Cooperative, is located approximately one-half mile south of the city of Genoa, Wisconsin, on the Mississippi River. The facility, a Boiling Water Reactor desigr.ed by Allis-Chalmers Company, has been in commercial operation since November, 1969.
3.
Scope This investigation was performed to review the occurrences during the reactor startup initiated on September 7, 1979, and focused upon the bypassing of the low flow reactor scram switches. The investigation was initiated to determine the causes for this incident, and review proposed licensee corrective actions.
4.
Background LACBWR has been provided with twenty-seven key lock bypass switches located on control benches D and E, to facilitate safety circuit and control rod testing and to bypass certain scram circuits until the scram relays are energized during reactor startup. The keys to the switches are, by procedure, controlled by the Shift Supervisor and are issued only as required for specifically approved operations.
When the locks are in the normal position, the keys are removed and 1945 023-4-S
stored in a locked key cabinet.
Only two bypass keys are in bypass position during normal reactor operations; the intermediate level neutron monitoring channels 3 and 4.
All bypass keys but the above two are connected to one annunciator on the control panel which remains on (alarmed) until all bypasses are removed. Thus, during a reactor startup the annunciator remains on until the turbine is synchronized to the power grid at approximately 25% reactor power.
The forced circulation low flow scram prevents reactor startup with less than 30% forced circulation flow. To protect a fluid piston bearing, the forced cirulation pumps have also been provided with interlocks that prevent operation at less than 40% flow. Thus, when the pumps are started, the flow is immediately increased to 40%, and if the forced coolant pumps are tripped off, the flow will drop below 30% and the reactor will be shutdown by a trip of the low circulation flow safety circuit.
Bypass key locks are provided on the low flow scram to permit safety circuit and control rod tests during shutdown with the forced coolant pumps off.
Duringnormalstartupandafterprerequisitesystemsareoperging, a position check of the bypass keys is required by procedure.-
At this time the forced coolant low flow bypass switch should be in the
" normal" position with the key removed. After the forced coolant pumps are started, and the control rod drive charging pumps and control rod drive system are on, nine bypass keys are still in the bypass condition to permit startup and heatup with the turbine and condenser isolated.
On September 5, 1979, the reactor was shutdown to repair a forced coolant pump discharge bypass valve packing leak. After the repairs and other work, including safety circuit and control rod tests had been completed, the reactor was taken critical at 2 p.m. on September 7, 1979. During the startup and using the startup procedure, the operator failed to normalize and remove keys 34 and 35 for the forced coolant low flow scram circuit. Following each shift change, the bypassed circuits were accurately recorded in the turbine operator r.? cords by number as being in the bypass condition.
That is, for tu six shift changes following the startup, keys 34 and 35 were noted in the log as being bypassed. During this time the control rods were very slowly withdrawn by procedure, to precondition the fuel following a cold reactor shutdown.
Heatup was also delayed to maintain eessel temperature differences within required limits.
On the morning of September 9, a shift supervisor noted and questioned why keys 34 and 35 were still in the bypass condition, and they were 1/
I.ACBWR Operating Manual, Vol. I, Integrated Plant Operations, Plant Startup,Section II, Revised April, 1978.
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promptly placed in the normal position. The highest reactor power level attained during this period was recorded in the operator's log as being 1/10th of one per cent reactor power.
Failure to normalize the forced coolant low flow scram during operations is in violation of Technical Specifications limiting safety system setting, 4.0.2.2, Table 4.0.2.2.1-1 and Figure 4.0.2.2.1-1.
In accordance with Technical Specification 3.9.2.a.(6) the licensee notified RIII by telephone of this event at approximately at 1:25 p.m.
on September 9, 1979.
5.
Visit to Site On September 11-12, 1979, RIII personnel visited the LACBWR site, reviewed plant operating procedures, operations logs, incident reporcs and other pertinent documents, interviewed management and operations personnel, and held discussions of possible corrective actions with licensee management.
6.
Control Room Tour The LACBWR control room was visited by RIII personnel, and particular attention was paid to the location of keys 34 and 35, which controlled the forced coolant pump low flow scram safety circuits. These keys are located on a control bench, and are adjacent to several switches controllin various safety systems. When a switch is in the bypass s
condition a red light located above the switch is illuminated. The key itself is attached to a black plastic identification card which gives the name of the system controlled by the key and a number which designates the key's location.
From observation of the control switches, it was apparent that the system designations located on the black plastic cards attached to the keys were not inmediately visible to operations personnel, although the key switcher and annunciator lights were in the central location and should have been easily visible. Two of the keys, those inserted during normal plant operation, do not have the identified plastic cards attached to them.
7.
Review of Records During the site visit, RIII personnel reviewed the LACBWR operation log, shift log, a draft incident report reflecting the bypass of the low flow scram switch, a written statement by the operator who had begun the initial reactor startup, flow charts indicating the flow in the forced coolant system, a quality assurance audit dealing with corrective actions, operations review committee meeting minutes, and reactor operating procedures.
Information gathered from the operations log as to the power level of the reactor at times and dates during the startup are reflected in Exhibit I.
Review of the plant operations procedures indicated that no startup check list had been provided for.
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Failure to provide a check list for startup operations was considered an example of an inadequate procedure, in that procedures were not adequate to prevent omission of one step in the reactor startup procedure. This is contrary to the recommendation for startup checklists in ANSI Standard 18.7 (1972) to which the licensee is committed in Technical Specification 3.8, Procedures. While the Standard itself recommends such checklists rather than making them a requirement, LACBWR commitments indicate that they would comply with the recommendations contained therein. The lack of a startup checklist was considered as a significant contributor to this incident, and directly related to the noted noncompliance with plant Technical Specifications As such, a separate item of noncompliance will not be issued.
It was noted that ANSI Standard 18.7 (1972) also contains a recommenda-tion for a shutdown checklist. This item was not reviewed during the investigation, is considered on open item, and will be inspected during a future inspection (011-79-10).
8.
Interview of Operators All available LACBWR operating personnel involved with the operations conducted during the September 7-9 reactor startup were interviewed by RIII personnel.
These interviews, combined with the review of procedures, indicated that many of the safety circuit keys are in bypass condition during reactor startup, and that various operating problems took some of the attention of operators during the September 7 startup.
Several other safety circuit keys are in near proximity to keys 34 and 35 on the control desk, and by practice these are scanned by the operator designated as the turbine operator, and logged by system number.
An interview of the reactor operator involved with the initial startup indicated that he recalled being interrupted or distracted from the startup procedure, which as previously noted did not involve the use of a check list.
(A typed transcript of a statement supplied by this operator to LACBWR is attached as Exhibit IV.) he was unable to explain the oversight of not removing keys 34 and 35 from the bypass condition. Apparently, this procedural step was missed.
This constitutes a violation of the LACBWR Operating Manual, Vol. I, Integrated Plant Operations, Plant Startup,Section II.
Interviews with succeeding shift personnel indicated that they assumed that prerequisite actions had been performed prior to bringing the plant to its (then) current status. As the preceding shift did not advise them of any abnormal conditions, they indicated they did not pay particular attention to the safety circuit switches.
The operators stated that they had logged keys 34 and 35 as being in the bypass condition but had not recognized that 34 and 35 represented a safety system required to be in operation during that operation i945'026
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mode. They advised that keys 34 and 35 were infrequently utilized and their function was not easily recognized.
Operators stated that they logged the keys as bypassed almost automatically, by scanning the board and r.oting the key numbers bypassed.
These comments were confirmed by the review of the operations log, which clearly indicates that the keys were logged in the bypass condition, and does not contain any additions or deletions.
It is apparent from the statements of the operators during the interviews that the key switches were visible, but the significance cf their being in the bypass condition was not apparent to the operators at that time.
Operators indicated to RIII personnel that their own review had revealed that several reactor tests do not include steps for key removal after the completion of reactor testing, that each succeeding shift operator is not required to review the operations log, and that each shift supervisor does not check the position of the bypass keys personally.
Operators were questioned as to whether they were aware of a previous incident in which the same two keys, 34 and 35, were found to be in the bypass condition just prior to reactor criticallity. With one exception, all of the operators interviewed indicated that they could not recall such an incident, or reading an incident report reflecting such an incident.
9.
Review of Previous Incident A record review and discussion with the RIII project inspector indicated that a similar incident had occurred on May 7, 1978, and was found to be recorded in LACBWR incident report, DPC-78-31.
During this incident, the same keys, 34 ani 35, we re not normalized, but in this case the condition was recognized immediately prior to the reactor reaching criticality. The RIII project inspector had been notified of this incident and it was determined, on the basis of the discovery and correction of the condition prior to criticality, that a Licensee Event Report to RIII was not required.
During this investigation, LACBWR personnel were not able to provide a final copy of DPC-78-31 while the investigators were on site.
A draft report of this report and minutes of the December 13, 1978 Operation Review Committee, reflecting review and approval of the incident report were reviewed. A copy of the finalized report was subsequently transmitted to RIII.
(See Exhibit III)
It was apparent from this review that DPC-78-31 had not received a timely review in that the date of the Operations Review Committee reflecting signoff and approval of this incident report took place some seven months subsequent to the incident.
The operators inter-viewed during this investigation were apparently unaware of the incident, and if it had been discussed with operators, they did not 1945 027
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recall such a discussion.
It is also noted that this previous incident was in all respects similar to the incident at hand, and if adequate correction action had been taken to the initial incident, it is probable that the present incident would not have occurred.
The noted corrective action for DPC-78-31, that of discussing proce-dures with the involved personnel, was therefore not adequate. This is considered to be a violation of Administrative Control Procedure, 17.1, Incident Report and to 10 CFR 50 Appendix B, Criterion XVI, which requires the prompt evaluation and correction of conditions adverse to quality.
A review of audit report 79-01, which reviewed incident reports and corrective actions, indicated that numerous incident reports, including 78-31, had not been finalized, signed or distributed.
10.
Proposed Corrective Actions On the basis of the review of procedures, control room tour, and interviews with operators, conclusions regarding the causes for the incident at hand were discusssed with licensee management personnel, and their proposals for corrective action were reviewed.
Licensee personnel advised that they had determined that a procedure check list for reactor startups was required, and on the basis of discussions with RIII personnel, indicated that they would put in place procedures for the review and initialing of the operations log by oncoming shift personnel, the logging of bypassed key switches by system name rather than by system i.+..ber, a review of and possible revision of test procedures and check lists to insure that they contain a step for normalizing the positions of any bypass switches, and additional training for the operators to emphasize the importance and use of the key switches.
Licensee personnel advised that they would take under consideration a possible color coding scheme to designate which key switches should be in the bypass position for a particular mode of reactor operation.
These corrective actions were considered by RIII personnel to be adegoate, and should provide assurance that a similar incident would not occur in the future. To confirm the RIII understanding of these commitments an Immediate Action Letter was sent to the licensee on September 17, 1979. This letter is attached as Exhibit II.
Attachments:
1.
Exhibit I - Power Level During Reactor Startup On September 7-9 2.
Exhibit II - In,ediate Action Letter dated September 17, 1979 3.
Exhibit III - Copy of finalized version of DPC-78-31 4.
Exhibit IV - Typed transcript of operator statement
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POWER LEVELS LACBWR REACTOR STARTUP SEPTEMBER 7-9, 1979 (from operating log)
DATE TIME POWER LEVEL COMMENTS 9/7 0750 control power turned on
9/7 1035 control rods charged, keys 34 &
35 should be normalized 9/7 1445 commence reactor startup
9/7 1513 reactor criticality
-10 9/7 1600 2.5 x 10 3,p, 9/7 2400 7 x 10-10,,p, 25 x 10 amps 9/8 0800 9/8 1600 50 x 10 %
-3 9/8 2400 20 x 10
%
9/9 0800
.1%
9/9 0820 uys 34 & 35 observed, normalized
as required 9/9 1600 23%
9/9 2400 30%
1945 029 Exhibit I Page 1 of i
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s>m ma4 UNITED STATES 9,
NUCLEAR REGULATORY COMMIS510N f
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SEP 171979 Docket No. 50-409 Dairyland Power Cooperative ATTN:
Mr. F. W. Linder General Manager 2615 East Avenue - South La Crosse, WI 54601 Centlemen:
This refers to Reportable Occurrence No. 79-16, dated September 10, 1979 concerning the failure in administrative controls which permitted the low flow scram protection circuit to be bypassed during startup and low power operation between September 7,1979 and September 9,1979.
We understand based on commitments made during our investigation of this incident on September 11 and 12, 1979, that you will take the following actions:
1.
Before the next reactor startup:
Develop and implement startup checklists requiring operator a.
sign off on procedural steps and include a " hold point" re-quiring the Shif t Supervisor's approval and sign of f before initiation of control rod withdrawal.
b.
Revise Administrative Control Procedure, ACP 02.3, to:
(1) Require the Reactor Plant Log to be initiale? by each operator indicating that he has reviewed the plant status; (2) Require that the status of safety circuit bypass keys be recorded in the Reactor Plant Log by system name rather than key number.
2.
Before the next safety circuit surveillance test, review and revise as necessary *.he tent procedures and checklists to require the re-turn to normal of any safety circuits bypassed during the test.
3.
Conduct operator training to reemphasize the safety significance of safety circuit bypass and the importance of double checking the status of safety equipment.
1945 030 Exhibit II page 1 of 2 79ypptp8 L6
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Dairyland Power Cooperative-2-SEP ! 7 p7q
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If our moderstanding of your planned action, as described abr-te is not in accordance with your actual plans and actions, plasse contact this office immediately.
Sincerely, James C. Kappler Director cc:
Mr. 1. E. Shinshak, Plant Superintendent Central Files Reproduction Unit NRC 20b FDR Local FDR NSIC TIC Anthony toissan, Esq.,
Attorney J. J. Shea, NRR
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Exhibit II
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page 2 of 2 1945 031 i
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LACBWR INCIDENT REPORT
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1.0 Report No. DPC-78-31
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2.0 Facility La Crosse Boiling Water Reactor (LACBWR)
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3.0 Date and Time of Incident May 7, 1978 0 1540 4.0 Incident Subject Violation of approved Operating Procedure 5.0 Component that Failed None (Operator Error)
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6.0 Similar Occurrences None 7.0 Operating Conditions at Time of Incident In the process of performing a reactor startup (LACBWR Operating Manual, Volume I, Section 2.1.2, Step (11), the reactor was not critical.
Condition 2 startup.
8.0 Description of Incident With the plant in Operational Condition 4, Cold Shutdown, at around 9:30 a.m., the Maintenance Supervisor and Shif t Supervisor were in the lA Forced Circulation Pump (FCP) Cubicle listening to the pump motor as it had been making an unusual amour.t of noise.
The Control Room Operator was in contact with them by radio, and they decided to try running the pump at oifferent speeds to listen to any change in sound that may occur.
After several speed changes, they wanted the speed run up to 1100 RPM with the discharge valve closed.
Because of design, the pump speed cannot be increased past 80% while the reactor is in the scrammed Condition 4, Cold Shutdown, so the scrams had to be reset.
The pump speeds were varied as required and returned to minimum.
At this time, the keys were turned to normal and control power off, but lef t installed because an electrician was due in to take IRD readings.
Keys 34 and 35 should have been taken out at this time, but because of the incessant number of phone calls and everything else that was going on, they inadvertantly got lef t on the console and then were turned to bypass during the reset of scrams for reactor startup.
Exhibit III pa ge 1 of 2 1945 032 gog$
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LACBWR.'NCIDDIT REPORT NO. DPC-78-31 - (Cont' d)
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9.0 Immediate Evaluation, Corrective Action and Results The insertion of low flow bypass keys numbers 34 and 35 were noticed by the oncoming Shif t Supervisor at 1540 and were turned to normal and removed.
Rod withdrawal had commenced but the reactor was not yet critical.
Criticality was achieved at 1549.
10.0 Permanent Corrective Action The operator and his Shif t Supervisor were remir.ded of the importance of following procedures.
The operator who placed the keys in bypass prepared the " Description of Incident" The incident was reviewed portion of tinis incident report.
and discussed with the NRC compliance inspector that because of the discovery a reportable occurrence was not necessary.
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$ "Y R.
E. Snimshak, LACBWR..sperintendent RES : GSB: abs DISTRIBUTION:
SRC ORC (ltd.)
II. Nestingen K. Ridgeway File R5G Reviewed by ORC:
12/8/78
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(Date)
1945 033
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Exhibit III page 2 of 2 2-
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On SepterLar 7th I conducted a Rx start up apparently with keys 34-35 in the bypass position. They were evidently left in that position on a previous watch to mine.
I was not aware of aay tests having been conducted needing (their) use, and I did not make any special note of their position.
During the start I definately remember checking the key switches that were needed to be in bypass and normal according to the procedure. The only possible reason I can think of missing the fact the 34-35's were in bypass is that they are listed at the end of the step in the procedure and that I was possible distracted from what I was doing (I can remember starting the step to check the key twice) before I completed it and when I returned to the procedure then started the next step.
Individual "A" 1945 034 Exhibit IV Typed Transcript