IR 05000002/1993003
| ML20036A845 | |
| Person / Time | |
|---|---|
| Site: | University of Michigan |
| Issue date: | 04/30/1993 |
| From: | Barger J, Cox C NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20036A839 | List: |
| References | |
| 50-002-93-03-EC, 50-2-93-3-EC, EA-93-069, EA-93-69, NUDOCS 9305170078 | |
| Download: ML20036A845 (7) | |
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U.S. NUCLEAR REGULATORY COMMISSION j
REGION III
Report No. 50-002/93003(DRSS)
Docket No.50-002 License No. R-28 Enforcement Action No.93-069
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Licensee:
University of Michigan
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Facility Name:
Ford Nuclear Reactor r
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Enforcement Conference At:
Region III Office, Glen Ellyn, Illinois
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Enforcement Conference Conducted: April 26, 1993 Inspector:
bb70 kl!//'3 C. Cox /
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Approved By:
[]) / ed bgNem k / 3D
J. W. McCormick-Barger, Chief Date'
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Non-Power Reactor Section i
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Enforcement Conference Summary Enforcement Conference on April 26. 1993 (Report No. 50-002/93003(DRSS))
Areas Discussed: The circumstances surrounding the March 24, 1993, overpower event.
Included in the discussion were the accuracy of Inspection Report No.
50-002/93002(DRSS), in which this event was discussed in-detail, root causes, and the short and long term corrective actions.
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9305170078 930510 PDR ADOCK 05000
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DETAILS i
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Persons Present at the Enforcement Conference University of Michiaan i
J. Nowack, Research Advisor, Office of Vice President, Research R. F. Fleming, Director, Michigan Memorial-Phoenix Project
R. R. Burn, Nuclear Reactor Laboratory Manager G. M. Cook, Assistant Manager for Reactor Operations
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M. Driscoll, Radiological Safety Officer
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Nuclear Reaulatory Commission
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H. J. Miller, Deputy Regional Administrator, Region III i
J. Lieberman, Director, Office of Enforcement C. D. Pederson, Chief, Reactor Support Programs Branch, Division of Radiation Safety and Safeguards (DRSS), Region III R. W. DeFayette, Director of Enforcement and Investigation Coordination Staff, Region III
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J. L. Caldwell, Chief, Non-Power Reactors Section, Operator Licensing Branch, Nuclear Reactor Regulations (NRR)
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B. A. Berson, Regional Counsel, Region Ill
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J. W. McCormick-Barger, Chief, Emergency Preparedness and Non-Power
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Reactor Section, DRSS, Region III T. S.
Michaels, Project Manager, NRR T. D. Reidinger, Senior Inspector, DRSS, Region III C. R. Cox, Non-Power Reactor Inspector, URSS, Region III
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Enforcement Conference An Enforcement Conference was held in the NRC Region III office on i
April 26,1993. The purpose of.the conference was to discuss the circumstances surrounding the March 24, 1993, overpower event. An inspection of the event was conducted from March 25-26, 1993,- and the inspection findings were documented in Inspection Report 50-002/93002(DRSS), which was transmitted to the-licensee on April.13, 1993.
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The conference agenda included: (1) a discussion of the sequence.of events, the apparent violations, and concerns identified in the inspection report; (2) the. licensee's root cause analysis and corrective actions; and (3) an information exchange to assist in determining the appropriate Enforcement Action, including escalating or mitigating circumstances. A copy of the licensee's presentation is attached.
Included in the attached presentation are the licensee's comments to
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Inspection Report 50-002/93002(DRSS).
The licensee took two exceptions to Inspection Report 50-002/93002(DRSS)
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during the licensee's presentation. The first exception involved the i
second opportunity. to identify an operator's knowledge weakness
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i described in the inspection report as an event that took place in February 1993 involving the Assistant Manager for Operations.
The
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inspection report's description was in agreement with information obtained by the inspectors through interviews with two licensed
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operators.
However, the licensee was able to reconstruct an event in January 1993 which the two licensed operators later agreed, via a signed
document at the enforcement conference, was the actual event they were
attempting to remember during the interviews. The major difference between the event in the inspection report and the event presented at the conference was that in the January event, the Assistant Manager for Operations was not aware of the event and did not leave the operators to figure out for themselves how to adjust the linear level ion chambers.
- The event in the inspection report was used as an example of an opportunity for management to identify the knowledge weakness demonstrated by the senior operator during the overpower event.
If the
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event the operators were trying to describe to the inspectors was the t
event in January, it still demonstrated that the senior operator from
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the overpower event lacked understanding of power level instrumentation adjustments.
In the January event, another assistant manager was
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informed of the event which provided the licensee's management an
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opportunity to identify the knowledge problem that led to the overpower event on March 24, 1993.
The second exception identified in the licensee's presentation was the statement in the inspection report that the junior operator during the overpower event realized that the reactor was at 2.3 megawatts before calling the off-shift senior reactor operator but was reluctant to raise the issue based on his experience of being chastised by shift
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supervisors when questioning their actions.
Based on a review of the interview information, a more accurate description would be that the
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junior operator thought that reactor power may have been at 115% and
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stated that to the senior operator. The senior operator stated that the Assistant Manager for Operations would arrive soon and then the problem could be resolved. Our interview notes indicate that the junior operator still stated that he was reluctant to raise the issue based on previous experiences.
Inspection Report 50-002/93002(DRSS) was revised
to provide the more accurate description.
I At the conclusion of the conference, the licensee was informed that they
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would be notified in the near future of the final Enforcement Action.
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Attachment: As stated l
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as necessary to establish 2 MW actual power with the linear level setpoint between 95% to 105%. While Step 5.36 of OP-101 was not clear on stating that the linear level setpoint be adjusted at 1 MW before raising power, the step combined with the expected level of operator knowledge should have prevented the overpower event.
By not reviewing OP-101 prior to starting the reactor, the operating crew failed to follow Step 5.1 and Step 5.36.
The failure to follow those two steps of OP-101 are apparent violations of Technical Specification 6.4.1 which requires that written procedures for reactor startup shall be followed (50-002/93002-02a and -02b).
Another contributing factor to the event was an apparent reluctance by the operators to request help when a question arose and a reluctance by the console operator to challenge the shift supervisor when the console operator recognized something was wrong. When the question arose about at what power level the linear setpoint should be adjusted, they chose to proceed to 2 MW indicated power.
It appeared that based on his past performance, the shift supervisor was afraid to seek help from his management. Before calling the off-shift SRO, the console operator informed the senior operator that he thought that the reactor was at 115% but he was not sure. The senior operator wanted to wait until the Assistant Manager for Operations arrived to resolve the issue.
The junior operator did not pursue the issue since he was uncertain about the power level and also indicated in his interview that he was reluctant to pursue the issue based on his experience of being chastised by shift supervisors when questioning their actions.
Interviews with other operators indicated that some of the less experienced operators may have felt intimidated by the senior operators at times.
Communications between the shift supervisor and the console operator was another contributing factor. After calculating the 86% setpoint from the calorimeter, the shift supervisor asked the console operator if he should lower the linear level setpoint to 86%. The console operator was taking logs at the time and thought the shift supervisor was asking about the 95% to 105% band at 2 MW steady state.
He answered no, that the band was 95% to 105% Then the shift supervisor asked at what power level were the ion chambers adjusted. The console operator replied that most shift supervisors adjusted the chambers at 2 MW. The console operator also indicated in the interview with the inspectors that at times in the conversation it was not clear if the shift supervisor was discussing linear level setpoint adjustments or linear level ion chamber
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adjustments which also contributed to the confusion.
Based on the overpower event, it appears that some of the corrective actions taken for several events identified in 1992 were not effective in preventing the occurrence of the overpower event.
For example:
o Not following or reviewing procedures and poor communications were contributing factors for the fuel handling violation in 1992. As a result, Step 5.1 was added to OP-101 but this was one of the two i
steps not followed in the overpower event.
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o Another event on July 22, 1992 involved operators leaving the Shim Range Defeated Scram Interlock in a by-passed position.
Contributing to that event was a human factors problem regarding a step on the Startup Checklist which involved a number of operator actions.
That step led an operator to overlook the action for returning the interlock to active, but initialling the one step as complete.
The corrective actions from that event included reviewing all of the operating procedures to identify steps involving a number of actions that should be reduced to several smaller steps. After the overpower event on March 24, 1993, Step 5.36 in OP-101 was identified as needing a revision that should have been identified by the review initiated by the July 22, 1992 2 vent in that the step contained several operator actions that should have been contained in separate steps.
o In response to the weakness identified in December 1992 by NRC operator examiners, the Reactor Manager wrote a memorandum to his operating staff explaining the power indications, how they
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interacted, when to adjust the linear level setpoint., and when to adjust ion chambers to maintain operating bands. All licensed operators signed a required reading sheet indicating they had read and understood the memorandum. One operator interviewed did not recall reading the memorandum and if the two operators involved in the overpower event had understood the memorandum, the even+
l should not have occurred. The Reactor Manager did not incorporate the operating concepts described in his memorandum into OP-101 i
" Reactor Startup" which, had the startup procedure been changed, may have also precluded this event.
Another concern identified by the inspectors was that there was two l
prior opportunities to identify the operators' power level indications
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knowledge weakness demonstrated by the overpower event.
The first i
opportunity, as discussed above, was when the NRC operator examiners
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identified the generic weakness in December 1992. The other opportunity t
was in February 1993 when the shift supervisor from the overpower event was on shift and became confused on how to lower the linear level setpoint while. maintaining the 95% to 105% band. The shift supervisor,
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the assigned console operator, and an operator trainee were discussing
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methods to adjust the linear level setpoint when the Assistant Manager
for Reactor Operations entered the control room. The operators i
requested guidance.from the Assistant Manager for Reactor Operations.
However, the Assistant Manager for Reactor Operations responded that the
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operators needed to be able to figure that problem out for themselves then left the control room without following up. These two
opportunities identified a lack of knowledge level expected of licensed i
operators and that licensee management failed to take effective
corrective actions to address the knowledge level problem.
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In reviewing the different operating limits for the power range
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instrumentation, the inspectors identified a concern regarding the non-conservative approach che licensee was taking in waiting to adjust the
safety channel ion chambers at the 2 MW level.
The licensee was
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i routinely starting up with all the ion chambers left in an equilibrium
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xenon position from the previous shutdown. Therefore the ion chambers
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would read a power level lower than actual power because the xenon free safety and control rod positions would shadow the ion chambers from more
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neutron flux.
The safety channels provide a high power scram with a
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setpoint of 2.4 MW. With the two safety channel ion chambers reading lower than actual power, then the actual power that would result in a high power scram would routinely be greater than the 2.4 MW during startup. The setpoint would not be 2.4 MW until the safety channel ion
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chambers were adjusted at the 2 MW level to maintain a required 1.9 MW to 2.1 MW operating band. To address the concern about the non-
conservative approach on adjusting the ion chambers, the licensee
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modified its procedures to instruct operators to adjust the ion chambers i
a 1 MW. The Office of Nuclear Reactor Regulation (NRR) will review the
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safety significance and generic non-power reactor aspects of the non-
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conservative approach the licensee uses towards adjusting the ion chambers. This question will be tracked as an unresolved item (Unresolved Item No. 50-002/93002-03).
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Interviews with the operations staff identified a concern in the method by which the facility kept track of SR0 on-shift time in maintaining SR0 licenses active.
10 CFR 55.53(e) states that for test and research reactors, the licensee shall actively perform the functions of an operator or senior operator for a minimum of four hours per calendar quarter. With the exception of staff SRO, the FNR did not track on-
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shift time for licensed operators. The facility assumed that licensed.
operators on shift assignments would receive at least four hours in the control room and did not track the distinction between operator or senior operator time. Therefore, the licensee was unable to readily e
determine if all the SR0s had maintained their licenses active by i
performing the functions of a senior operator for a minimum of four hours per calendar quarter. Review of shift logs indicated that licensed console and supervising operators were required to sign the log respectively for each reactivity manipulation performed. The log entries made a distinction between a reactor operator and senior reactor operator. The question arose as to whether an SR0 could count time
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spent as a reactor operator towards the four hours needed to maintain his/her SRO license active. To resolve the immediate concern, the
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licensee provided six hours of remedial training to all SR0s with questionable license status in accordance with 10 CFR 55.53(f). NRR will review the specific question and generic non-power reactor aspects
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concerning counting reactor operating time towards minimum SRO on-shift time to maintain an SR0 license active. This question will be tracked as an unresolved item (Unresolved Item No. 50-002/93002-04).
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4.
Exit Interview (30703)
J The inspectors met with the licensee representatives denoted in Paragraph I at the conclusion of the inspection on March 26, 1993. The inspectors summarized the scope and results of the inspection and discussed the likely content of this inspection report.
The licensee acknowledged the information and did not indicate that any of the
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information disclosed during the inspection could be considered
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proprietary in nature.
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