Page images
PDF
EPUB
[blocks in formation]

DETAILS OF INVESTIGATION

Background

Fermi 2 Nuclear Power Station achieved its first reactor criticality on June 21, 1985. On the evening control room shift of July 1, 1985, Fermi was in the process of a startup to 5% power. The control room personnel consisted of a Shift Supervisor, Assistant Shift Supervisor, Senior Reactor Operator, Reactor Operator, Reactor Engineer, Shift Technical Advisor (STA), STA in training, and a Shift Operations Advisor (SOA). The reactor operator, who was not experienced at operating the Fermi 2 reactor, was to continue the control rod pull started on the afternoon shift. The NRC Senior Resident Inspector who followed plant operations, was scheduled to leave for Washington, DC, at noon on July 3 to attend the July 10 Commission hearing and vote regarding a Fermi 2 full power license.

Chronology of Events

On July 1, 1985, at approximately 11:00 p.m., DECO Reactor Operator William KLINE, took over the already in-process reactor startup procedure at Step 38. KLINE was advised by the previous reactor operator to expect criticality at approximately Step 156. KLINE was performing his first rod pull to criticality on the actual Fermi 2 reactor. His only other experience had been in the Fermi 2 simulator. When KLINE began withdrawing the first group 3 rods, he did not observe the procedure instruction to pull from 00-04, but rather he withdrew 10 group 3 rods to position 48. On the eleventh group 3 rod Step 56, KLINE and the STA in training, John DEWES, noticed the increasing neutron count on the source range monitors. KLINE immediately began to insert the misaligned rods and directed the STA in training to summon the Shift Supervisor, David ANIOL, and the Reactor Engineer, Barry MYERS. ANIOL, who was in the Shift Supervisor office, came out to the 603 panel and directed KLINE to continue inserting the eleven group 3 rods to their proper position. MYERS was advised by the STA in training of an out-of-sequence criticality and he proceeded to log the premature criticality in the Reactor Engineering Log (Exhibits: 1, pgs. 6-15; 2, pgs. 8-15; 3, pgs. 6-9; 4, pgs. 18-29).

ANIOL contacted the Operations Supervisor, Eugene PRESTON, and advised him of the operator error to include a statement that the reactor had not achieved criticality. Contrary to his sworn testimony given to OI, ANIOL did not consult the SOA, STA, or the Reactor Engineer for input to that reactor criticality decision. PRESTON requested that ANIOL prepare a Deviation Event Report (DER) documenting the incident and granted approval to continue the rod pull to achieve a planned startup. ANIOL did prepare a DER, however, he did not document the operator error in his Shift Supervisor Log, nor did he advise the Lead Reactor Operator, Stephen BURT, of the incident; therefore, the operator error was not documented in the Reactor Operator's Log. During the same evening shift, sometime after the rod pull incident occurred, ANIOL became aware of the fact that the Reactor Engineer, MYERS, had entered a premature criticality in the Reactor Engineering Log. ANIOL advised MYERS that his log was incorrect and the reactor had not been declared critical. Based on ANIOL's suggestion, MYERS altered the Reactor Engineering Log to read, "the count rate began to increase on one of the SRM's as if we may have

[blocks in formation]

been critical (Exhibits: 3, pgs. 6-9; 4, pgs. 19-29; 5, pgs. 14-17; 6, pgs. 9-13; 7, pgs. 7-10; 8, pgs. 8-13; 9, pgs. 8-13; 10, Reactor Engineer Log; 11, DECO NSS Log; 12, DECO NSO Log)."

On July 2, 1985, at approximately 6:00 a.m., PRESTON arrived at the Fermi 2 site and obtained the already prepared DER from ANIOL. ANIOL advised PRESTON that he should be aware of the Reactor Engineering Log entry of criticality. At 7:00 a.m., during the shift turnover meeting, PRESTON advised the Assistant Manager, Nuclear Production, Robert LENART, of the out-of-sequence rod pull error; however, he did not mention the Reactor Engineering Log entry. At 8:00 a.m., during the DECO staff meeting, PRESTON gave the DER to the Assistant Plant Superintendent, Gregg OVERBECK, who read the DER and stated to PRESTON that he would address that DER during the Corrective Action Review Board (CARB) meeting following the staff meeting. At the morning CARB meeting, OVERBECK was cognizant of the dissenting opinion by reactor engineering regarding criticality, and therefore, he assigned reactor engineering the task of analyzing the rod pull event to settle the criticality issue. Concurrently, several other corrective actions relating to operator actions and verification were instituted. No one from the DECO staff cognizant of the operator error, advised the NRC Resident Inspectors of that incident on July 2, 1985 (Exhibits: 4, pgs. 24-27; 9, pgs. 18-25; 13, DECO DER, dtd 07/02/85; 15A, pgs. 3-4; 16, pgs. 5-13).

On July 3, 1985, reactor engineering advised Operations that a decision had been reached as to criticality. A meeting was convened with Plant Operations Managers LENART, OVERBECK, PRESTON, DECO Nuclear Consultant Leo LESSOR, and from reactor engineering, Hari ARORA, Jon THORPE, and Melvin BATCH. THORPE made reactor engineering's presentation, which stated that based on computer models, a review of the source range monitor charts, and his "detailed knowledge of how the core is loaded and the worth of the control rods at the peripheral locations as opposed to the anterial locations, the reactor was, in fact, critical." LENART's nuclear consultant, LESSOR, a former Plant Manager at the Cooper Nuclear Power Station in Nebraska, stated:

"In my opinion, you were critical...just from my experience of
looking at these charts back in Nebraska, I was just almost certain
that especially after interviewing the operator and what he said, I
just pretty well knew what the results were going to be.... It
really doesn't make that much difference, the error. You pulled 11
rods in error, the seriousness of the event is the same, you did not
stop. But as a minimum, you better go right over and talk to the
resident inspector and make him aware of what happened."

LENART stated in an interview with OI, that his gut feeling was that he agreed with LESSOR, but did not express that opinion at that review meeting. Contrary to reactor engineering and LESSOR's advice, OVERBECK defended his operating staff and reiterated that the reactor had not been declared critical and he believed the reactor engineering analysis was inconclusive. LENART and OVERBECK made a decision to ask reactor engineering to perform an additional analysis, and meanwhile, to officially advise the NRC Resident Inspector, Michael PARKER, of "the operator error and that we had the meeting that was held on July 3, and that the issue of criticality was still an open issue, and there was further analysis going to be done in that regard." LESSOR, not agreeing with LENART's decision, requested that PARKER also be advised that

[blocks in formation]

the DECO position on criticality was not unanimous. LESSOR stated, during an interview with OI, that had the NRC Resident Inspector queried him as to the rod pull error, he would not have supported the DECO position, but rather would have confirmed the reactor criticality based on his reading of the SRM charts (Exhibits: 9, pgs. 25-34; 9A, pgs. 16-20; 14, pgs. 9-14; 15, pgs. 6-16; 15A, pgs. 5-8; 16, pgs. 13-20; 16A, pgs. 9-25; 17, pgs. 18-19; 17A, pgs. 6-12; 18, pgs. 7-12).

LENART's decision on the DECO "management position" with regard to premature criticality was admittedly not the conservative approach. LENART stated:

"From this particular incident in question, the most conservative, after everything was done and over with, the most conservative approach to take with regard to taking a management position and erring on the conservative side is to say it went critical." LENART, rationalizing why he chose the non-critical decision, stated: "It was also recognized by me to some degree the significance of that internally and externally, and with regard to any immediate subsequent actions it really didn't make any difference. In other words, if on the 3rd that had been the position of that meeting, it wouldn't have made any difference with regard to the plant conditions, personnel, or anything else. And therefore, before that was made, I felt the prudent thing to do was to make sure that there weren't any mistakes. It's the same old case, you know. It is always difficult to get an accurate and complete retraction of something that has already been stated. It was a judgment call on my part with the information I had available from experts, both from an Operations viewpoint and the Reactor Engineering viewpoint. I weighed all of those and made the decision that I did."

OVERBECK's account of the July 3 meeting and discussion of what to advise the NRC Resident Inspector also revealed DECO management having a problem in deciding how to describe the event. OVERBECK states:

"Because there was a discussion at the end of our meeting on
the 3rd, well, we've got to go tell the Resident Inspector. What
are we going to tell him? Are we going to tell him it's critical
or not critical? The decision was made, supported by Bob LENART,
to tell him that the reactor was not critical, but that we still
had a controversy between our Reactor Engineering people and our
operators, and that we are going to go back and do some more
evaluation. That's exactly what he was told (Exhibits: 15A,
pgs. 12-14; 16A, pgs. 15-16)."

In the early afternoon of July 3, 1985, shortly after the Senior Resident Inspector (SRI), Paul BYRON, who was following plant operations, left the Fermi site, PARKER was requested to attend a meeting with OVERBECK and PRESTON. At that meeting, he was advised the rod pull error had occurred and that criticality was not achieved, although reactor engineering was reviewing the event. In addition, PARKER stated that the impression given was that they would get back to him if and when the Corporate position on criticality had

[blocks in formation]

changed. When OVERBECK discussed the notification to PARKER on July 3, he stated it was the direct result of:

"Clearly the fact whether the reactor was critical or not
critical. The more we got into it, the more we did the
evaluation, the more we found out, boy, we really blundered
here. We didn't make a simple mistake, we made a big mistake."

Although the element which elevated the operator error to the threshold of NRC notification was apparently the potential reactor criticality. DECO's notifi cation of the criticality implied that there was a consensus within the DECO organization that the reactor had not achieved criticality and failed to mention there was disagreement among DECO personnel as to the reactor criticality decision. That notification did not provide the dissenting opinions of the nuclear consultant, LESSOR, or the Nuclear Engineer, THORPE, both of whom had significantly more experience and knowledge in startup and nuclear reactivity, respectively, than any of the DECO operations management present at the July 3 meeting. PARKER stated that he and OVERBECK discussed civil enforcement action resulting from the operator error and recalled that OVERBECK stated "the event could be sensitive to licensing because it involved an operator error (Exhibits: 9, pgs. 34-37; 16, pgs. 18-21; 16A, pgs. 22-32; 19, pgs. 1-2; 19A, page 2)."

Following the afternoon meeting with OVERBECK and PRESTON, PARKER telephoned Reactor Engineer Supervisor, ARORA, to verify that reactor engineering was conducting an analysis. ARORA confirmed reactor engineering's assignment, but did not relate the fact that reactor engineering's John THORPE had already performed an analysis and informed operations personnel of the suggested criticality. PARKER subsequently contacted NRC Region III, Nicholas CHRISSOTIMOS, and advised that DECO had notified him of the reactor operator error, and that reactor engineering was reviewing for reactor criticality. PARKER did not pursue the incident further due to other pressing matters and expected that DECO would keep him apprised of any developments regarding reactor criticality (Exhibits: 18, page 12; 19, pgs. 1-2).

Also on the afternoon of July 3, LENART met with Dr. Wayne JENS, DECO Vice President of Nuclear Operations, to advise him of the rod pull error. stated to JENS:

"We had earlier in the morning had a meeting in which this
subject was discussed with regard to whether the reactor
did or didn't go critical. There were differences of opinion
in that meeting, and that I wanted him to be aware of that fact;
and I basically told him because, you know, I thought it would
be oh, from a PR standpoint, a sensitive issue, and told him
what the game plan was: reactor engineering was to go back and
do another analysis, and that there would be further results."

LENART

Dr. JENS corroborated his discussion with LENART, and when asked if he perceived a necessity to get back with LENART on this issue, JENS stated:

"I talked to the head of our Nuclear Engineering Department,
and I asked him to see if he could get the matter resolved
because reactor engineering reported to him. I asked him to

[blocks in formation]
« PreviousContinue »