ML13004A319
| ML13004A319 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 08/25/2010 |
| From: | Lawrence Criscione NRC/RES/DRA |
| To: | Banks M, Raspa R Advisory Committee on Reactor Safeguards, NRC/OIG |
| Shared Package | |
| ML130040225 | List:
|
| References | |
| FOIA/PA-2012-0259 | |
| Download: ML13004A319 (4) | |
Text
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From: Criscione, Lawrence Sent: Wednesday, August 25, 2010 11:31 AM To: Raspa, Rossana; Banks, Mark
. (b)(7)(C)
Cc: Zimmerman, Roy; McCrary, Cheryy; I
J
Subject:
Callaway Plant Concerns Rossana/Mark, Thank you for meeting with me yesterday. I'm sorry to have occupied so much of your time (it really did only take me 30 minutes when I met with 01).
The purpose of this email is to summarize my concerns regarding the October 21, 2003 Incident at Callaway Plant. Those copied are other people at the NRC whom I discussed the incident with recently or hope to meet with in the near future. I am not requesting any action be taken by anyone, but any advice or suggested course of action you might provide would be appreciated.
The facts of the incident which both Region IV and I agree on are:
Around 10:18, the reactor passively shut down due to negative reactivity added from a combination of a 50F temperature rise in the minutes following the turbine trip and the continual accumulation of transient Xenon-1 35.
" Following the shutdown of the fission reaction, reactor power was allowed to passively lower into the source range. Reactor power entered the source range around 10:39.
During this time the operators were busy raising letdown flow to 120 gpm, securing an Intake pump and placing Cooling Tower Blowdown in service. None of these tasks took priority over actively controlling the nuclear fission reaction in the reactor core.
For approximately 45 minutes (from 10:39 to 11:25) reactor power was in the source range with no SRNIs energized and the control rods at their Critical Rod Heights.
During this time the operators finished raising letdown flow to 120 gpm and secured an unnecessary Condensate Pump. I&C surveillances on two of the PRNI channels were also being performed.
At 11:25 a Main Control Board alarm annunciated when the Channel 2 SRNI energized. Following this alarm, 39 minutes (from 11:25 to 12:04) elapsed before the operators took any action to actively insert negative reactivity. During this time the operators swapped feed pumps from one of the turbine driven main feed pumps to the motor driven feed pump, commenced containment minipurge, spent three minutes closing out off-normal procedure OTO-NN-00001, and completed and commenced some I&C surveillances on the PRNIs. None of these activities took priority over inserting the control banks.
During the 106 minutes when the reactor was shutdown with the control rods at their critical rod heights (from 10:18 to 12:04) no formal calculation was performed to verify that Xenon-135 levels were sufficient to maintain the reactor subcritical. A Shutdown Margin Calculation was commenced at 11:42 and was not completed until 12:55.
Two off-normal procedures were performed during the morning of October 21, 2003:
OTO-BG-00001 for Loss of Letdown and OTO-NN-00001 for Loss of a Safety Related Instrument Bus. Neither of these off-normal procedures prevented the insertion of the control rods.
" There is no evidence that in 2003 anyone outside of the personnel in the Main Control Room was aware that when the control rods were inserted at 12:04 they were being inserted on a reactor that had been shutdown for 106 minutes. That is, no one outside
the Main Control Room was aware that the reactor had been allowed to passively shut down around 10:18 and the control rods had remained at their critical rod heights-for another 106 minutes.
- Both thel(b)(7)(C) have claimed in Quality Assurance documents and in sworn testimony to the NRC that they were aware the reactor would shut down following the turbine trip and that the passive shutdown of the reactor was not unintentional - that is, they claim they intentionally allowed the reactor to passively shut down and, without a formal calculation to back them up, intentionally relied on transient Xenon-135 to maintain the reactor subcritical while the crew completed ancillary tasks associated with the reactor shutdown.
Concerning the last bullet, if you accepi b)(7)(C) an,(b)(7)(c) claims (which I do not-I believe the passive reactor shutdown was inadvertent and UT'rUTM'lticed until 11:25) then the October 21, 2003 incident is an example of gross operator misunderstanding about conservative and safe reactor operation which warrants capturing and disseminating as Operating Experience.
This has not been done. Callaway Plant has not yet reported the details of the incident to INPO and the NRC has not yet released any communication concerning the incident.
Based on two.rami~rsations I had in 2007 with thel (b)(7)(C) who is now the (b)(7)(C) at Callaway Plant), I believe he was in the.Main Control Room at the time the first SRNIinstrument energized. Region IV did not interviewi(b)(7(c) as part of their investigation and made rnoatte ats to etermine whether or no was present in the control room. To my knowledgde (b)' 7
)(
j Jemails from October 21, 2003 were never requested by the NRC and there wa enyer ny attempt made to check Callaway Plant's "Observations" database to see I (b)(7)(c) laimed credit for a control room observation of the reactor shutdown.
Please note, that I have never claimed and I have never believed that in 2003 there was an orchestrated and coordinated conspiracy to cover up the inadvertent shutdown. Although I do believe it was intentionally covered up, it was not an orchestrated effort. My belief has always been that the Reactor Operator and Balance of Plant operator failed to recognize the reactor shutdown which occurred around 10:18. They failed to recognize this because of the level of activity occurring in the control room (e.g. the loss of letdown, being below the MTCO, etc.).
From 10:23 onward, the instrumentation the crew is used to referring to while at power (the secondary calorimetric computer point, the AT instruments, the PRNIs) was indicating approximately 2% power and stable. I believe the board operators failed to notice the lowering IRNI signal and did not realize the reactor was in the source range until they received an annunciator at 11:25. I believe that in the minutes after receiving this annunciator, all the personnel in the control room were aware that the reactor had inadvertently passively shutdown about an hour earlier and that they had failed to recognize it. At the time, it was not uncommon at Callaway Plant for the operating crews to neglect to document significant occurrences in the Corrective Action Program (this was noted by both INPO and the NRC during their inspections).
There was no orchestration of a cover up. There was no coordination. Everyone in the control room knew that the incident should be documented with a condition rpnort And Pvyrnn in hp control room privately hoped that neither th.(b)(7)(C) would chose to write a condition report. An. no one wrote one. And no one in the Outage Control Center was informed that the reactor was in the Source Range. Instead, the crew-without any orchestration - continued along their previous path of completing the ancillary tasks associated with the reactor shutdown. The Outage Control Center was informed that, since Electrical Maintenance was unlikely to repair NN1 1, the crew would be shutting down the plant
at noon. The crew continued performing the ancillary tasks, conducted a brief of the shutdown, and shortly after noon began inserting the control rods. They knew that everyone outside of the Main Control Room would assume that the reactor was being shut down by the only authorized method - inserting the control rods. It was only by accident that, more than three years later, I uncovered the incident and had the nerve to document it in the Corrective Action Program.
I have claimed and I still believe that, after I documented the incident in Callaway Action Request 200701278 in February 2007, there was an orchestrated and coordinated effort to cover up the incident. This allegation was part of RIV-2007-A-0093 which was never investigated.
My concerns are:
- 1. The interviews conducted during 01 Case 4-2007-049 were inadequate. In 208 neither Region IV adequately understood my concerns. During the interview of(b)(7)(c) n April 1, 2008, no one from the NRC had actual experience operating a reactor p *an.Few statements made b)7(c
- were challenged. The challenges which were made by the 01 investigator and the technical staff demonstrate that they did not have an adequate understanding of the concerns ave adequate knowledge of reactor plant operation to properly interrogate'(b)(7)(C)
I Please note I do not believe this was the result of any negligence, miscond or "wrong doing" on the part of NRC employees.
- 2. INPO's system for distributing Operating xperience has broken dow ith respect to hi vent. INPO assumes honesty. Th(b)(7 c who was the J
(b)(7)(C) at Callaway Plant was, and still is, involved in covering this incident up. The slidi icant details of the incident have not been shared with INPO or with Callaway Plant's own licensed operators. This event clearly meets the request which INPO made in SOER 07-01. And per Generic Letter 82-04 the NRC is relying on INPO to meet item I.C.5 of the TMI Action Plan (concerning sharing of OpE). However, this significant incident will not be shared voluntarily by Callaway Plant.
- 3. The NRC is reluctant to state whether or not we believe the passive shutdown of the reactor was intentional. As a member of the public, this is troubling to me. The NRC has the expertise, the right and the duty to consider the facts of the October 21, 2003 shutdown and decide whether or not the claims of the operators is believable. If we do not believe them, than we must address the fact that they lied to us. If we do believe them, then we must address the fact they demonstrated a gross misunderstanding of conservative reactor operation and determine what broke down in our operator licensing process to allow this to occur.
I appreciate that, in the absence of irrefutable evidence the operators are lying, there is not much we can do directly about the dishonesty of Callaway Plant's operators and management.
However, there is still much we can do if we believe they were dishonest. I am not requesting we do the actions below, but they are examples of how we could handle this issue if we decided it warranted more attention than it's been given:
The CEO of Ameren could be called before the Commission to answer for the operators' actions. The current CEO of Ameren has no nuclear experience and relies on his chain of command to as rorrinhs concerning Callaway Plant. Because of the involvement of the!'
7 )(C) jin covering up the incident, this system breaks down for the October 21, 2003 Incident. The NRC making a big deal about the discrepancies in the operators' testimonies will make it hard for the b)(7)(C) jof Callaway Plant to
continue to cover up this incident from Ameren. A 10CFR2.204 request from the NRC will likely cause Ameren to properly address this incident.
We can share the significant details of the incident with the broader industry. I have always assumed an Information Notice was the proper vehicle for doing this, but there may be better methods. Providing an honest accounting of the facts will make it hard for Callaway Plant to continue to cover up this incident from INPO and its own operators.
There is much to be learned from this incident and allowing Callaway Plant to cover it up is contrary to the nuclear Safety Culture.
It is incumbent upon us not to ignore this incident. If we believe we were lied to, we must address the dishonesty. If we actually believe the passive shutdown was conducted intentionally, we must address the severe flaws in our licensing of operators.
V/r, Lawrence S. Criscione Reliability & Risk Engineer RES/DRAJOEGIB Church Street Building Mail Stop 2A07 (301) 251.7603