IR 05000295/1997007
| ML20148G053 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 05/21/1997 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20148G042 | List: |
| References | |
| 50-295-97-07, 50-295-97-7, 50-304-97-07, 50-304-97-7, FACA, NUDOCS 9706050144 | |
| Download: ML20148G053 (21) | |
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U.S. NUCLEAR REGULATORY COMMISSION REGION lli j Docket Nos.: 50-295; 50-304 l l License Nos.: DPR-39; DPR-48 Report No.: 50-295/97007; 50-304/97007 Licensee: Commonwealth Edison Company - Facility: Zion Station, Units 1 and 2 Location: 105 Shiloh Boulevard Zion, IL 60099 Dates: March 12 - April 28,1997 'l
Inspectors: A. Vegel, Senior Resident inspector D. Calhoun, Resident inspector M. Bailey, Operator Licensing Examiner, Rlli G. Galletti, Human Factors Branch, NRR i
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Approved by: M. Dapas, Chief Reactor Projects Branch 2 i I
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9706050144 970521 PDR O ADOCK 05000295 PDR y , , .
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Report Details insoection Purnose The purpose of this inspection was to follow-up on the February 25 through March 7, 1997, NRC Augmented inspection Team (AIT) inspection of the improper control rod manipulation event. The AIT reviewed the operational performance and circumstances surrounding the improper control rod manipulation during the Unit 1 shutdown. The AIT inspection also included a review of the causes of the event and the corrective actions taken. The AIT inspection results were documented in inspection Report No. 50-295/97006 dated April 29,1997. The AIT follow-up inspection included the review of two other events which occurred during the inspection period, the Unusual Event (UE) on February 24, due to Technical Specification (TS) Limiting Condition for Operation (LCO) action requirements not being met for removing reactor coolant system loop "A" flow instrumentation from service, and the reactor coolant and residual heat removal system hydraulic transient event on February 2 This inspection was conducted to evaluate the events, including AIT findings, for regulatory compliance and to clarify issues as required. The inspection was not intended to duplicate the inspection efforts of the AIT. Where the term " inspectors" is used in this report, it may refer to the AIT inspectors, the inspectors in the follow-up inspection, or bot Summarv of AIT Findinas On February 21,1997, with Unit 1 operating at reduced power and Unit 2 shut down, the Unit 1 operations staff performed an unplanned unit shutdown in response to the expiration of a TS LCO action statement concerning the 1C containment spray (CS) pum Approximately 15 minutes prior to meeting the requirement to have the unit in a hot shutdown condition, the shift engineer (SE) directed the unit supervisor (US) to maintain the Unit 1 reactor critical following the turbine generator trip. Immediately following the turbine generator trip, the primary Nuclear Station Operator (NSO) inserted control rods in a continuous manner for 3 minutes and 48 seconds. With the reactor substantially subcritical and following a 55 second delay, the primary NSO withdrew control rods in a continuous manner for 1 minute and 45 seconds, with the intent of stabilizing reactor power at 0.025 percent. The primary NSO continuously withdrew control rods until he was directed to trip the reactor by the US. The US was instructed to trip the reactor by the SE because the 1C CS pump had not been restored and Unit 1 had to be in hot shutdown within the next six minutes in order to comply with Technical Specification The AIT concluded that the improper contrui rod manipulation occurred due to significant weaknesses in the licensee's operations program. The following is a summary of significant findings and conclusions of the AIT inspection effor _. . _._ _ -.. . _ _ . . . _ . _ . _ . _ _ _ . - . _ . _ . . _ _ . _ _ _ _ _ _ . _ _ - . _
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i The more significant root causes for this event included: 4 *- a total breakdown in command and control by operations supervision, i
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. e inadequate communications between operators, operations supervision, i ) operations management, and nuclear engineering department personnel, l l
* the failure of operations supervision, operations management, and plant l management to provide clear direction to the operating crew regarding the I planned shutdown, j
- * the failure to pre-plan the shutdown evolution, )
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j, e licensed operator training deficiencies, and ' ! * the existence of a number of control room distractions during shift activitie '
' Operations supervision did not properly exercise its oversight responsibilities for j
. ensuring that shift activities were conducted in a controlled manner and became focused on containment spray pump restoration activities and balance of plant
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: problems. As a result, operations supervision was unaware of improper control rod i manipulations.
+ l , Despite the almost continuous presence in the centrol room of operations and/or ! , plant management during shift activities, including the shutdown evolution, no , direction was provided to operations supervision to correct the command and control deficiencies, communication problems, lack of teamwork, and control room I distractions which collectively precipitated this event. This inaction by management conveyed tacit approval of the existing control room conditions to l operations supervisio ! - The actions of the primary NSO in continuously withdrawing control rods to ] re-establish power at the point-of-adding-heat (POAH) reflected a significant lack of
- understanding of reactor physics and proper control rod manipulations for a controlled approach to criticality. The actions of the primary NSO were also contrary to instructions in the plant startup procedur . Regarding command and control deficiencies
* The shutdown briefing was informal, poorly planned, and ineffectiv l
- Operations supervision did not provide any direction to the operating crew !
during the briefing regarding the decision point for proceeding to hot shutdown.
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Despite a number of control room indications and communications, operations supervision was unaware that the primary NSO had continuously , inserted control rods a total of 232 steps which placed the reactor in a , substantially subcritical condition, and then withdrew control rods 84 steps L m an attempt to re-establish power at the POA * Operations supervision failed to exercise their responsibility to minimize i: control room distractions with the potential to adversely impact the ability of ' operators to safely conduct plant evolutions.
i Regarding communications deficiencies: i
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i The SE did not provide clear direction to the US regarding his intent to keep } the Unit 1 reactor critical after the main turbine had been tripped.
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Operations supervision also failed to inform the operating crew of the intent to keep the reactor critica ;
* The primary NSO did not adequately communicate and seek resolution of i concerns he had with the actions directed by a specific step in the shutdown i procedure. The unit supervisor (US) also did not clarify the intent of this l procedural step for the primary NSO. This was one of the major contributing i
causes of the event.
[ * The qualified nuclear engineer, assigned to monitor the shutdown evolution, ] did not adequately communicate his concerns with observed control rod j manipulations to operations supervisio i
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On a number of occasions, the operating crew did not exercise proper three- , way communications.
. )~ * Ineffective communications between plant management, operations management, and operations supervision contributed to poor planning for the .' shutdown evolution.
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management in a timely manner, and licensee management did not
, effectively communicate expectations that the primary NSO, US, and shift engineer, involved in the shutdown, be removed from licensed duties.
f 7. Operations management did not appreciate the significance of the actions of the
primary NSO in continually withdrawing control rods in an attempt to take the reactor critical. This was evident in the deliberate decision by operations i management to return the involved licensed operators to licensed dutie ) 8. Immediate corrective actions were inadequate in that licensed operators directly 1 involved in the event resumed licensed dutie l
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* Operations supervision did not ensure that planned reactivity changes were
accomplished in a controlled manner and that the effects of these changes were
- understood and appropriately monitored.
.I i 1 The AIT identified a number of precursor events with root causes related to poor j communications, weak command and control, and poor reactivity management.
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Due to ineffective corrective actions in other cases, the licensee failed to correct { the underlying problems which contributed to these events.
. ' 1 The licensed operator requalification training program was deficient in that it did not i include training on shutdown evolutions that involve establishing and maintaining power at the POAH.
l 1 The overall level of knowledge among licensed operators pertaining to reactivity j management and reactor physics specific to plant response to a continuous control
rod withdrawal was adequate.
- l. Operations Conduct of Operations
) 01.1 General Comments a Licensee management and control room operators failed to demonstrate the
- necessary controls to ensure that the Unit 1 plant shutdown on February 21, was
performed in a controlled and deliberate manner. Contributing to the occurrence of the event were poor operator communications practices, inadequate pre-- evolutionary briefings, and the failure to perform reactivity changes in a
- conservative manner. Some of these same operator performance weaknesses also
contributed to the occurrence of two other events that occurred shortly after the
- February 21 event. The operators' failure to recognize TS implications when reactor coolant system flow instrumentation was taken out-of-service (OOS), and
! the initial lack of recognition of the significance of an unexpected hydraulic l transient during residual heat removal valve testing, reflected poor management
- . oversight and weak operations control of evolutions.
01.1 Imoroner Control Rod Manioulation Event
3 01. Evaluation of Ooeratina Crew and Manaaement Performance
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The inspectors evaluated the performance of the operating crews and management j during the event. The inspectors assessed the following facets of the licensee's operations program: command and control, communications, reactivity i management, procedure usage and adherence, and the implementation of corrective
! actions. The inspectors reviewed licensee administrative procedures, management
, directives, operator and licensee management statements pertaining to the j shutdown, training lesson plans, and corrective action documentation. In addition,
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. * the inspectors interviewed licensed operators, qualified nuclear engineers (ONEs),
training personnel, and licensee managemen . Command and Contrp1 The ir.spectors identified weaknesses in several activities which were significant conrhutors to the occurrence of the February 21 event. Specifically, the rWown briefing, the performance of the shutdown evolution itself, and the
.e. dous control room distractions all contributed to the operating environment which allowed the control rod manipulation error to occur.
' Shutdown Briefino Ine inspectors determined that both the SE and the US devoted the majority of their efforts prior to commencing the shutdown to reviewing and developing the 1C containment spray (CS) pump testing package and did not effectively plan the shutdown evolution. As a result, the US did not review the shutdown procedure in detail with the operating crew and did not discuss the shutdown strategy with the nuclear engineer The inspectors determined ihat although discussions were held between shift management and licensee management regarding the point to abandon 1C CS pump restoratico efforts, prior to the shutdown evolution, no clear course of action or management expectation for progression of the evolution was established. As a result, during the shutdown briefing, shift management failed to provide adequate direction to the crew regarding the point at which 1C CS pump restoration activities would be abandoned and the plant shut dow The inspectors determined that the shutdown briefing was informal, poorly planned, and ineffective. The inadequacy of the briefing contributed to the occurrence of the event. Shift management failed to properly focus on the shutdown during the briefing and devoted considerable resources to discussing how the plant should be brought back on-lin l.icensee procedures that prov.ded guidance on conducting thorough pre-evo!ution briefings were available but were not used. Zion Administrative Procedure (ZAP) 300-01, " Conduct of Operations," Revision 3, Section IV, defined infrequently performed evolutions as: " Evolutions whereby the performance frequency is greater than annually AND the evolution requires the coordination of two or more departments or three or more individuals AND has the potential to adversely affect reactivity control OR core cooling." In addition, the procedure required that a briefing be conducted prior to the start of the evolution. The inspectors considered the evolution of maintaining the reactor at the point of adding heat (POAH) as an infrequently performed evoluti7. The last time this evolution was conducted was December 199 ,
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brief to maintain the reactor at the POAH, as required by ZAP 300-01, is considered an example of an apparent violation of 10 CFR Part 50, Appendix B, Criterion V,
" Instructions, Procedures, and Drawings" (Escalated Enforcement item (EEI)
- 50-205/97007-01a).
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; Shutdown Evolution
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s I l Shift management failed to properly exercise supervisory and oversight ' responsibilities during the shutdown and became focused on containment spray
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pump restoration activities and balance of plant problems. As a result, the SE and US were unaware of significant control rod manipulations, even though control board indication of control rod movement was evident.
! Zion Administrative Procedure 300-01, " Conduct of Operations," Revision 3, i Section VI.A, requires that operations personriel SHALL be attentive to the
- condition of the plant at all times and that the SE SHALL maintain a broad i j perspective of operational conditions affecting the safety of the station as a matter L of highest priority at all time ,
l- l The failure of the SE to maintain a broad perspective on operational conditions ! { affecting safety, as required by ZAP 300-01, which was reflected in the failure to , l ! recognize significant control rod manipulations, is considered an example of an
- apparent violation of 10 CFR Part 50, Appendix B, Criterion V, " Instructions, l Procedures and Drawings" (eel 50-295/97007-01b).
! j The failure'of the US to be attentive to the condition of the plant at all times, as ) F required by ZAP 300-01, which was reflected in the failure to recognize significant {' control rod manipulations, is considered an example of an apparent violation of j 10 CFR Part 50, Appendix B, Criterion V, " Instructions, Procedures and Drawings" , j (eel 50-295/97007-01c). ] 3 i i Control Room Distractions .j i i ! The inspectors concluded that operations supervision failed to exercise their I , responsibility to minimize control room distractions with the potential to adversely J
- ' impact the ability of operators to safely conduct plant evolutions. The US and SE l l, allowed themselves to become too involved in activities that were not directly
' related to the unit shutdown, such as CS pump restoration efforts and the , resolution of balance of plant equipment problems. This resulted in operations
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j- supervision failing to exercise appropriate supervisory oversight.
' A contributing operator distraction during the shutdown was the excessively large i number of individuals in the control room. The high ambient noise le'rel in the control room, due to tha large number of individuals present, made coi;munications
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between operators at control board operating stations and communications l between operators and operations supervision difficult. This created a control room I i .
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. environment that was not conducive to conducting a controlled and orderly shutdow l
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Despite the almost continuous presence of senior plant and/or operations j management in the c ontrol room during shift activities, including the shutdown, no . direction was provided to operations supervision to correct the control room d distractions, which contributed to the occurrence of the event. This inaction by j
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management conveyed tacit approval of the' existing control room conditions to i operations supervisio j Zion Administrative Procedure 3OO-01 A, " Control Room Access and Conduct," f Revision 4, Section Vill.A, requires that all personnel conducting business in the , control room SHALL do so in a professional and courteous manner at all times. The ! procedure fu:Wr requires that control room business SHALL be conducted at a l
- location and in such a manner that neither on-shift licensed personnel attentiveness nor the professional atmosphere is compromised. The conduct of control room >
activities during the Unit 1 shutdown on February 21 in a manner that compromised on-shift licensee personnel attentiveness and the professional atmosphere is l considered an example of an apparent violation of 10 CFR Part 50, Appendix B, j Criterion V, " Instructions, Procedures and Drawings" (eel BO-295/97007-01d). ! Specifically, the US and SE were not attentive to ongoing control rod manipulatic,ns ! and the noise level in the control room compromised communications among the l shift cre !
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r 01. Ooeratina Crew Parformance - Communications The ' inspectors identified several instances of inadequate communications during shift activities involving operators, operations supervision and management, qualified nuclear engineers, and plant management, which directly contributed to the reactivay excursion even Communication of Manaaement Expectations Prior to the Shutdown Prior to the shutdown evolution briefing, senior plant management and operations management held a discussion regarding the plan to shut down Unit 1. Based on interviews with the involved managers, the inspectors determined that poor communications between licensee management contributed to the lack of understanding of the point to abandon efforts to restore the 1C CS pump to service. The failure of Unit 1 operations management to provide termination criteria for 1C CS pump restoration activities in order to assure pump activities did not interfere with the controlled shutdown of Unit 1, contributed to the event's occurrenc Communications in the Control Room During the shutdown evolution, with 15 minutes remaining before Unit 1 was required to be in a hot shutdown condition to comply with Technical Specifications, the SE approached the US and directed him to maintain the reactor critical after
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* i i tripping the turbine because he thougiit that testing of the 1C CS pump was nearly j !
complete and the pump would be returned to service shortly. The US then directed
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t the primary NSO to trip the turbine and esvablish power at or below the POAH per ! General Operating Procedure (GOP) 4, " Plant Shutdown and Cooldown." This ; ! directive, however, was not formally promulgated to the entire cre i 1 .
' in directing the US to maintain the reactor critical, the SE intended to keep Unit 1 in I ' Operational Mode 1 (reactor power greater than or equal to 2 percent) because he was concerned that if Unit 1 was placed in Mode 2 (core reactivity condition ,
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greater than or equal to zero and power level less than or equal to 2 percent), l Unit 1 could not be immediately returned to Mode 1 due to the inoperable status of
- - plant equipment. The SE's direction to the US was not clear and consequently, the i US thought that the SE was directing him to maintein the Unit 1 reactor at or below the POAH, i.e., in Mode 2, per GOP-4.
! : c As a result of his discussions with the SE, the US initiated actions per GOP-4.
! During implementation of the procedure, the US read Step 5.21.f of GOP-4 aloud to i ! ' the primary NSO. The NSO responded with a question regarding the intent of the procedural step; specifically, the NSO asked if he should drive rods in. Instead of f i answering the NSO's question or rephrasing the question, the US simply re-read ; l- the procedure step. Although the NSO was still unclear of the intent of the step, L he initiated a continuous control rod insertion. Zion Administrative Procedure ; 300-09, " Station Operational Communications," Revision 3, Section Vll.A.3, j h requires that if the receiver does not understand the communication, then the , receiver must promptly inform the sender and ask the sender to repeat or rephrase 5 the message. When the NSO did not understand the guidance from the US concerning driving in control rods, the NSO failed to inform the US to repeat or rephrase his guidance as required by ZAP 300-09. This is considered an example of an apparent violation of 10 CFR Part 50, Appendix B, Criterion V, " Instructions, Procedures and Drawings" (eel 50-295/97007-01e).
As the primary NSO continued to insert rods, the main control room board low rod insertion limit and low-low rod insertion limit annunciator alarms came in. The primary NSO announced each alarm as it was received. However, the US never acknowledged the NSO's announcement of the alarms and the NSO never confirmed the US's announcement of the alarms. Zion Administrative Procedure 300-09, " Station Operational Communications," Revision 3, Section Vll.A.3, requires that all operational communications SHALL use three-way communication ZAP 300-09 defined three-way communication as, "The technique of the sender issuing a communication that is repeated back by the receiver of the communication and confirmed by the sender to be the correct communication."
The failure of the NSO and the US to use three-way communications as required by ZAP 300-09 is considered an example of an apparent violation of 10 CFR Part 50, Appendix B, Criterion V, " Instructions, Procedures, and Drawings" (eel 50-295/97007-01 f).
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Communications of Manaaement Expectations in Resoonse to the Event ? After learning about the reactivity manipulation error on the afternoon of February 21, operations management decided to have the primary NSO, US, SE, and ONE report to the plant simulator the following day to recreate the event scenario. After reconstructing the event on the plant simulator, licensee management interviewed the individuals. Following these interviews, licensee . management discussed the significance of the event, the performance of the . . operators, and whether the operators should be removed from licensed duties. At . the end of this discussion, senior licensee management expected the operatore to .
' : be removed from licensed duties based on the operators' performance during the Unit 1 shutdown; however, this expectation was not specifically communicated to operations management. As a result, the operations manager decided to allow the SE, US, and primary NSO to continue performing licensed duties. -The SE and - primary NSO resumed on-shift licensed duties on February 23. The US was assigned as an extra licensed operator in support of the on-shift crew. All three individuals were subsequently relieved of licensed duties after senior licensee management became aware that the operators had been retumed to. shif The team concluded that operations management did not appreciate the significance of the actions of the primary NSO in continually withdrawing control .
rods in an attempt to take the reactor critical. This was evident in the decision by 'j
. operations management to return the involved licensed operators to licensed duties -l prior to determining root causes and implementing appropriate corrective action The licensee's failure to correct command and control, reactivity management, and communication deficiencies, exhibited by the SE, US, and primary NSO, and which were contributing causes of the February 21 improper control rod manipulation event, before returning the operators to licensed duties, is considered an example of an apparent violation of 10 CFR Part 50, Appendix B, Criterion XVI, " Corrective, Actions" (eel 50-295/g7007-02a).
01. Reactivity Manaaement The inspectors identified that during the shutdown evolution, the operating crew j failed to perform reactivity changes in a controlled manner and failed to adequately ! understand and monitor the effects of the reactivity manipulations. In addition, the ] qualified nuclear engineer assigned to monitor the shutdown evolution failed to provide adequate technical advice during the even Operatina Crew Performance - Reactivity Manaaement During the performance of the Unit 1 plant shutdown on February 21, the reactivity i management plan for the shutdown was not clearly understood by the control room i
, operators. As discussed in Section 01.1.3 of this report, the SE's direction to the US concerning maintaining the reactor critical was not clear. In addition, the SE's failure to communicate the shutdown plan to the entire on-shift crew contributed to the confusion over how the reactor was to be operated. Following the US's ,
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< direction to maintain the reactor at the point of addirN,6t (POAH), the primary
[ HSO questioned the US whether he should drive rods in. The US did not provide a '
clear answer to the NSO's question, but merely re-read the step of the procedure i . regarding establishing power at or below the POAH. After the turbine was
- manually tripped, the US read the step aloud regarding establishing power at or
! be?ow the POAH which the primary NSO acknowledged. Subsequently, the primary . NSO initiated a 3 minute and 48 second continuous control rod insertion. After the I control rod insertion was halted, the primary NSO observed that reactor power had
- decreased to below the intended power level. He subsequently informed the US <
- that he intended to withdraw control rods to re-establish power at the POAH. The i
pri nary NSO then initiated a continuous control rod withdrawal until the US directed him to trip the reactor. The US and SE were not cognizant of the .
- significant reactivity changes that were occurring due to the primary NSO _ !
L withdrawing rods after the excessive control rod insertion. The inspectors !
- concluded that the reactivity changes were not performed in a controlled manner.
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Licensee guidance for the performance of reactivity changes were documented in : several policies and procedures. For example, Operations Policy (OP) 96-05, "
" Reactivity Manipulations," Revision 0, specifically requires that the following *
actions be taken prior to any reactivity manipulations, including control rod ;
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manipulations:
* To ensure proper control of reactivity management and' to exercise I conservative reactivity management principles, concurrence from the US or another control room senior reactor operator (SRO) shall be obtained prior to any reactivity manipulation * The NSO shall state his desire to perform a reactivity manipul'ation, the .
reason for the manipulation, and the amount of reactivity to be adde * The SRO shall evaluate the reactivity manipulation request, ensure that it ' meets the need of the unit, ensure normal operating parameters will not be exceeded, then provide concurrenc ,
* For all evolutions that have potential reactivity effects,it is expected that a discussion will be held between the NSOs and SROs so that the evciution and strategy is fully understood by allinvolve The US and primary NSO failed to take the actions recommended by OP 96 05 prior to the control rod manipulation ' < in addition to the guidance provided in OP 96-05 concerning reactivity changes, operations administrative procedures also provided guidance on reactivity control Zion' Administrative Procedure 300-01, " Conduct of Operations," Revision 3, Section VI.A, requires that all planned reactivity changes be done in a controlled manner, that the effects of reactivity changes be known and monitored, and that any anomalous indication be met with conservative action. By excessively inserting control rods and then non-conservatively withdrawing control rods, the primary
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t , i i. . . , ; - NSO failed to perform reactivity manipulations in a controlled manner as required by + l ZAP 300-01. This is considered an example of an apparent violation of 10 CFR j' l Part 50, Appendix B, Criterion V, ." Instructions, Procedures and Drawings" (eel .! 4 50-295/97007-01g).. I t l Qualified Nuclear Enaineer (QNE) Interface with Ooerators - Reactivity Manaaement . f l- During performance of the plant shutdown, the ONE was providing technical l l oversight of the evolution. The ONE observed that due to the continuous control i
rod insertion by the primary NSO, the reactor was taken subcritical. Also, the ONE : ! noted the illumination of the rod insertion limit annunciators. At that time', the ONE < j informed the NSO that the reactor was substantially subcritical. The ONE
- - subsequently observed the NSO withdrawing control rods and informed the NSO j-
. ' that he was concerned with the excessive inward/ outward control rod '!
l manipulation. The ONE did not elaborate on the basis of his concern nor did he
- j pursue his concerns further with the NSO or other operations personnel. The NSO- {
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e- responded to the ONE by stating that he was also uncomfortable with his actions.
l Even though the NSO was uncomfortable with the excessive amount of rod j movement, he continued with the evolutio {> ! ! } Zion Administrative Procedure 300-018, " Reactivity Management Guidelines," - !- Revision 1, Section G.2.c, states that strict reactivity controls are required to " i minimize the potential for core damage, and that all plant personnel, particularly j
- operators, must stop and question unexpected situations involving reactivity, !
I critic 91ity, power level, or core anomalies. The failure of the primary NSO to stop . [ I and question the excessive rod manipulation as required by ZAP 300-01B is . l
- considered an exampliof an apparent violation of 10 CFR Part 50, Appendix B, i
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Criterion V, " Instructions, Procedures and Drawings" (eel 50-295/97007-01 h).
, Shortly thereafter, the SE approached the NSO and the ONE and inquired about j activities. The ONE informed the SE that he was concemed with the excessive ! control rod insertion and withdrawal manipulations. However, the ONE did not t communicate the technical basis for his concerns. Zion Administrative Procedure , 300-01B," Reactivity Management Guidelines", Revision 1, Section G.1.1, requires the ONE to implement the reactivity management policy by providing technical advice on assigned system and reactivity related matters. The failure of the ONE to ; provide technical advice for the excessive inward and outward control rod manipulations as required by ZAP 300-018 is considered an example of an apparent violation of 10 CFR Part 50, Appendix B, Criterion V, " instructions, Procedures and Drawings" (eel 50-295/97007-01i).
Reactivity Manaaement and Shutdown Trainino i The inspectors reviewed the licensee's operator requalification training program to determine how the licensee had implemented the requirements of 10 CFR , Part 55.59, "Requalification." ' i
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, The inspectors determined that prior to February 21, the US and the primary NSO 5 had not obtained operating experience in performing a plant shutdown and/or ! !' maintaining the reactor at or below the point of adding heat (POAH) as specified by . i 1.
Step 5.21.f of procedure GOP-4. Upon review of the licensed operator ! requalification program, the inspectors determined that no specialized instruction on reactivity management during shutdown evolutions had been conducted. In addition, no simulator exercises or evaluations addressing a plant shutdown to the POAH were performed during any requalification cycles within the last five year Licensee training personnel stated that the initial licensed operator training program addressed this evolution. In addition, the licensee stated that it was their expectation that licensed operators would maintain an appropriate knowledge level in regard to reactor physics through working experience and self-study. This absence of training was particularly noteworthy because reactivity management problems had occurred previously as discussed in Section 01.1.6 of this report. In addition, for 7 of 24 shutdowns performed during the last three years, operators maintained power at or near the POAH (Mode 2), for an extended period of time, before proceeding to either Mode 1 or Mode The inspectors concluded that the lack of training on maintaining the reactor at the POAH contributed to the occurrence of the reactivity management even . Evaluation of Procedures i i The inspectors reviewed operating procedures used during the Unit 1 shutdown to l
' determine if any procedure adherence or adequacy problems existed. The i inspectors did not identify any deficiencies with procedural adequacy; however, a significant problem was identified with procedural adherence. In addition, the ' inspectors concluded that inadequate operator reviews of the procedure used during the shutdown and the failure of the operators to take appropriate action when a i procedure step was not understood, contributed to the event's occurrenc Prior to performing the shutdown evolution, the SE and the US were distracted by i their involvement in restoration activities for the 1C CS pump and balance of plant equipment problems. Therefore, they were unable to adequately review GOP-4, " Plant Shutdown and Cooldown," which was to be used to perform the Unit 1 shutdown. Also, the primary NSO had not reviewed the procedure due to several turnovers of the secondary panel NSO. These turnovers prevented the primary NSO from reviewing the procedure because he could not be relieved of his duties by the secondary panel NSO in order to review GOP-4. Zion Administrative Procedure 300-01, " Conduct of Operations," Revision 3, Section IX.E, requires that the individual who is to perform an activity be responsible to adequately review the associated governing procedure. The failure of the primary NSO, US and SE to adequately review GOP-4 prior to performing the Unit 1 shutdown as required by ZAP 300-01 is considered an example of an apparent violation of 10 CFR Part 50, Appendix B, Criterion V, " Instructions, Procedures and Drawings" (eel 50-295/97007-01]).
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. Because GOP-4 was not reviewed, the NSO's subsequent question regarding the l intent of procedural Step 5.21.f, " Hold '#363, ROD MOTION CONTROL' switch IN '
to minimize dumping steam and establish power at or less than the Point of Adding ! Heat (2.5 x 10E-2% intermediate range (IR))," was not addressed until the ! shutdown evolution was in progress. Although the primary NSO was unclear -! about procedural Step 5.21.f, he initiated a continuous control rod insertion until power level reached .025%. At that point, the ONE informed the NSO that the ; reactor was substantially sub-critical. . Due to power drifting lower than .025%, the } NSO continuously withdrew control rods to re-establish power at 0.025%. In ! response to the rod withdrawal activity, the ONE informed the NSO that he was !
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concerned with the excessive rod manipulations. . The NSO replied that he was also uncomfortable with the rod manipulations. Zion Administrative Procedure 300-02, ,
"Use of Procedures in Operating Department," Revision 10, Section VI, requires j that lE an activity or evolution should not or cannot continue per the governing j procedure as written, THEN: Immedistely notify the responsible supervisor. The ;
failure of the NSO to immediately notify the responsible supervisor after : determining that the continuous control rod insertion and withdrawal should not : continue as specified by Step 5.21.f of GOP-4, which was required by ZAP 300-02, ) is considered an example of an apparent violation of 10 CFR Part 50,' Appendix B, l Criterion V, " Instructions, Procedures, and Drawings" (eel 50-295/97007-01 k). { l The inspectors reviewed procedural Step 5.21.f and concluded that the step, as l written,.was adequate to accomplish the intended result. However, the NSO's ' l actions to continuously drive control rods until a power level of 0.025% was l reached and his subsequent actions to withdraw control rods a significant number of steps to re-establish power at .025%, were not in conformance with the intent of the procedural step. The failure of the primary NSO to manipulate control rods to establish power level at the POAH as required by Step 5.21.f of GOP-4, is considered an example of an apparent violation of 10 CFR Part 50, Appendix B, Criterion V, " Instructions, Procedures and Drawings" (eel 50-295/97007-011).' 01. Event Precursors and Previous Corrective Actions The inspectors identified a number of precursor events with root causes related to poor communications, weak command and control, and poor reactivity management. Due to ineffective corrective actions, the licensee failed to correct the underlying problems which contributed to these event Bagptivity Manaaement Adverse Trend , On February 12,1996, the engineering manager issued a memorandum to the operations manager documenting a substantial increase in the frequency of reactivity management events at Zion. On February 28, the nuclear engineering supervisor (NES) generated problem identification form (PlF) No. 295-201-96-CAT 4-0489 documenting this adverse trend in reactivity management activities. The PlF screening committee classified the PIF as a Level 4, considering it to be of relatively minor significance. The PlF was subsequently issued closed based on immediate actions being satisfactory because
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i j i * i < l* discussions were being held between operations, training, and nuclear engineering _ , personnel.
. , On March 18, the regulatory assurance (RA) supervisor ~ directed that the PlF be - upgraded to a Level 3 which required a root cause investigation. During the same
- time, the assistant superintendent of operations (ASO) was directed to perform a
- - validation effort of the nuclear engineering department's concern. The ASO.
l confirmed the adverse reactivity management trend and documented the results of j- his validation effort, which included a number of recommendations in a letter, dated ! April 18,1996, to the operations manager. ' Upon receiving this letter, RA ! personnel improperly closed the Level 3 PlF on April 18.
. , in implementing the immediate corrective actions for the original PlF, the NES held
- several meetings between operations, engineering, and training personnel. As a
- result of these meetings, the nuclear engineers became more actively involved in
: startup activities, operators were trained on their responsibilities concerning i reactivity management, and nine reactivity management related topics were j identified for inclusion into licensed operator training programs. Three topics have
} been presented to date. The NTS was never updated to document these actions.
i Despite implementation of the above corrective actions, the licensee failed to affect j- an improvement in the declining trend in reactivity management activities. The { ' failure of the licensee to take adequate corrective actions to address the adverse
- trend in reactivity management activities, a significant condition adverse to quality, is considered an example of an apparent violation of 10 CFR Part 50, Appendix B, 1 Criterion XVI, " Corrective Actions" (eel 50-295/97007-02b).
1: 1 l NRC Violation for inadvertent Mode Chance i' On April 8,1996, the NRC issued a Notice of Violation, 50-304/96005-03, for an ( inadvertent mode change in January 1996 while performing an operability test for l one of the station auxiliary feedwater pumps. in the licensee's response to the , l violation, poor communications, weak command and control, and poor reactivity ! ( management were identified as root causes for the event. Although the licensee ; i implemented a number of corrective actions, which included discussing the " i circumstances of the event during licensed training and counseling operations - ; personnel involved in the event, the licensee failed to implement effective corrective actions to address all of the identified root cause Based on the recurrence of similar operator performance problems during the 1 February 21 event, including significant reactivity management problems, the inspectors concluded that licensee corrective actions were inadequate in addressing ; problems identified as a result of the January 1996 inadvertent mode change even The failure of the licenses to take adequate corrective action to prevent recurrence of command and control, communications, and reactivity management problems, identified as a result of an inadvertent mode change in January 1996, is considered ; an example of an apparent violation of 10 CFR Part 50, Appendix B, Criterion XVI,
" Corrective Actions" (eel 50-295/97007-02c). ;
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Inanoropriate Conthol Rod Manioulations Durina Unit 1 Startuo
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On January 28,'.1997, the station received a violation for inappropriate rod manipulations that occurred on September 16,1996. Although the licensee did not receive the report until January 28,1997, the inspectors had identified the same
, root causes for this event as the licensee did in its response to the April 8,1996, violation, which included weak command and control, ineffective communications, and a lack of sensitivity toward reactivity management. The Unit 1 operations manager discussed this issue with shift personnel as part of the licensee's immediate corrective actions. Although the licensee had not established long-term corrective actions due to the recent issuance of the violation, these root causes were emphasized at a management meeting in the Region ill office on October 7,
' 1996, and reiterated again as concerns during the resident inspectors' routine exit meeting on October 21,1996. The failure of the licensee to take adequate corrective action to prevent recurrence of command and control, communications, and reactivity management problems, identified as a result of inappropriate control rod manipulations during a Unit 1 startup, is considered an example of an apparent violation of 10 CFR Part 50, Appendix B, Criterion XVI, " Corrective Actions" (eel 50-295/97007-02d).
01.2 Limitino Condition for Ooeration (LCO) exceeded for Reactor Coolant System (BC.El Flow Instrumentation The inspectors reviewed licensee actions related to the removal of RCS flow instrumentation from service on February 22,1997, which resulted in an Unusual Event (UE) declaration on February 24. The inspectors discussed this event with licensee' operations personnel and management and reviewed applicable documentatio On February 22, at 'l:10 p.m., with Unit 1 in Operating Mode 3, Hot Shutdown, an out-of-service (OOS) was placed in support of planned work on the instrument sensing manifold for the loop "A" RCS flow detector,1F1-414. The OOS rendered all three RCS loop "A" flow instrumentation channels inoperable. The control room operators directing the placement of the OOS failed to recognize the Technical Specification (TS) implications for removing the instrumentation from service. This error unknowingly placed the unit into a TS 3.1." Reactor Protection Instrumentation and Logic," LCO action statement. Technical Specification 3.1 requires that RCS flow instruments be operable in Modes 1, 2,3,4 and 7. The TS required that if the minimum condition of one operable channel cannot be met, the plant is to be in hot shutdown within 24 hours and in a cold shutdown condition, Operational Mode 5, within an additional 24 hour On February 24, at approximately 7:00 p.m., the control room operators recognized that the TS requirements were not met for the RCS loop "A" flow instrumentatio The plant was already in_ Operational Mode 4; therefore, the unit coincidentally met the action statement to be in Hot Shutdown within 24 hours. However, the action statement requirement for the plant to be in Mode 5 within 48 hours was not me As a result, the SE declared an UE in accordance with the Nuclear Generating
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i i i l' Station Emergency Plan (GSEP). The licensee's immediate corrective actions
included tripping of the instrumentation channel input bistable relay to the reactor t protection system and continuing actions to place the plant in cold shatdown. Due , to increased emphasis on performing evolutions in a controlled manner, as a direct i ' result of the February 21 reactivity manipulation event, the evolution to place the
plant in cold shutdown was protracted. On February 25, at approximately
, 9:23 p.m., the plant was placed in cold shutdown and the UE was terminated. The
, plant had exceeded the LCO action statement time requirement to reach cold
- shutdown by approximately 32 hours.
i i The licensee determined that the causes for this event were weak procedures and . 1
' inadequate verification practices. Individuals in the operating organization did not l recognize the LCO entry because they were not required, by site procedures, to !
- verify that scheduled work had been classified in accordance with TS. An '
l opportunity for verification during the OOS process failed because the US used the j j Mode 3 Surveillance Checklist as a basis for determining LCO applicability, rather , than directly referring to the T The inspectors concluded that the failure of the control room operators to recognize the TS implications of removing safety-related instrumentation from service was indicative of a less-than-adequate operations staff knowledge of TS requirement In addition, this event demonstrated weak operating practices, including poor command and control, and training deficiencies, similar to those identified in the February 21 reactivity management even Technical Specification 3.1, " Reactor Protection Instrumentation and Logic," requires the RCS flow instruments to be operable in Modes 1,2,3,4, and 7. The TS allows two of three flow instruments to be inoperable for up to eight hours if the failed channels are placed in the trip mode.' If these conditions are not met, the unit is to be in hot shutdown within 24 hours and in cold shutdown within the following 14 hour The licensee's failure to comply with TS 3.1 and place Unit 1 in cold shutdown within 48 hours following all three RCS loop "A" flow instrumentation channels being rendered inoperable, is considered an apparent violation (eel 50-295/97007-03).
01.3 Hvdraulic Transient durina Residual Heat Removal (RHR) Valve Testing On February 25,1997, the licensee staff failed to recognize the potential significance of a hydraulic transient that occurred while performing RHR valve I testing. The inspectors interviewed licensee operations staff and management and ! reviewed applicable documentation, including Problem identification Forms (PIF) j 97-1047 and 97-107 i On February 25, during performance of surveillance test PT-2C-B-ST, Revision 4,
"RHR Suction Valve Leakage nnd Stroke Test", an unexpected 4% decrease in pressurizer level and RCS loose parts monitor alarms for both the upper and lower 17 i i
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core regions occurred. The control room operators and a senior operations ' supervisor, who had been assigned as a control room oversight manager, evaluated the transient and determined that it was caused by the alignment of the' RHR valves. Operations personnel did not recognize the occurrence of the transient as
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an abnormal condition, and as a result, they did not document i ~
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On February 26, a licensee site quality verification (SOV) inspector, who was in the : control room during the transient, initiated PlF 97-1047 to document the occurrence of the hydraulic transient event. The SOV inspector characterized the hydraulic transient as a " water hammer." The SOV inspector discussed the event with his supervisor, but the occurrence of the event was not communicated to - senior plant management. Senior plant management was not aware of the event until the NRC inspectors brought the event to their attention on February 2 Licensee immediate corrective actions included placing all RHR refueling surveillance tests on hold pending review and revision. The operations department representative responsible for oversight in the control room during the performance , of PT-2C-B-ST and the system engineer were assigned to review RHR system surveillance procedures. System engineers conducted a walkdown of the reactor coolant and RHR systems to ensure no damage had occurred as a result of the , potential water hammer. No equipment damage was identified during the walkdown. The licensee was in the process of developing iong term corrective actions at the end of this inspection period. These long term corrective actions were to include the training of operations personnel on recognizing unusual or unexpected plant response during the performance of tests and evolution The inspectors concluded that this event occurred due to the failure of the control ' room operators and senior operations department supervision to question and : investigate an unexpected change in plant parameters. The inspectors considered that the failure of the control room staff to communicate and address this potentially significant event was indicative of inadequate management oversight and poor operator performance. These weak operational attributes also contributed significantly to the occurrence of the reactivity manipulation error event on February 21,199 X1 Exit Meetina Summary The inspectors presented the results of the inspection to members of licensee management at the conclusion of the inspection on April 28,1997. The licensee acknowledged the findings presente The inspectors asked the licensee if any materials examined during the inspection should be considered proprietary. No proprietary information was identifie __ __ - _ . +
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i {* PARTIAL LIST OF PERSONS CONTACTED !
- - Commonwealth Edison Comoany
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J. Mueller, Site Vice President ! R. Starkey, Plant General Manager ! G. Vanderheyden, Operations Manager l B. Giffen, Systems / Component Engineering Manager 3 R. Godley, Regulatory Assurance Manager i T. Bergner, Training Manager i K. Hansing, Technical Specification Improvement Program Supervisor D. Bump, Unit 1 Maintenance Mant,ger
- M. Schimmel, Unit 2 Maintenance Manager j' K. Dickerson, Executive Assistant
! , . U.S. Nuclear Reaulatory Consmission R. Capra, Director, Project Directorate, Ill-2, NRR G. Grant, Director, Division of Reactor Projects, Region lli M. Depas, Chief, Reactor Projects Branch 2, Region lil A. Vogel, Senior Resident inspector, Zion Station G. Cobey, Resident inspector, Zion Station D.' Calhoun, Resident inspector, Zion Station -
* At exit meeting on April 28,199 INSPECTION PROCEDURES USED IP 71707 Plant Operations IP 61726 Surveillance Observation IP 62707 Maintenance Observation IP 37551 Engineering ITEMS OPENED, CLOSED, AND DISCUSSED Q1An 50-29C/97007-01a eel Failure to perform infrequently performed evolution brief 50-295/97007 01b eel Failure of shift engineer to maintain broad perspective on operational conditions affecting safety ,
50-295/97007-01c eel Failure of unit supervisor to be attentive to the condition of the plant at all times 50-295/97007-01d eel Failure to conduct control room activities in a manner that did not compromise on-shift licensed personnel attentiveness and professional atmosphere
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I 50-295/97007-01e eel Failure of a nuclear station operator to request the unit { supervisor to repeat or rephrase guidance that was not i 1 understood (
. 50 295/97007-01f eel Failure to use three-way communication
[ 50-295/97007-01g eel Failure to perform reactivity manipulations in a controlled 3 manner 50-295/97007-01h eel Failure to stop and question excessive control rod manipulation j 50-295/97007-01i eel Failure to provide technical guidance for excessive inward and l . outward control rod manipulations l l 50-295/97007-01) eel Failure to adequately review general operating procedure prior j i . to performing Uni: 1 shutdown ' ) 50-295/97007-01k eel Failure to inform responsible supervisor after determining that
continuous control rod insertion and withdrawal should not j continue as specified in the general operating procedure 50-295/97007-011 eel Failure to manipulate control rods to establish power at the ! j ' point of adding heat as required by the general operating ' procedure ! 50-295/9700742a eel Failure to correct command and control, reactivity . management, and communication deficiencies before returning ! operators involved in the event to licensed duties i' 50-295/97007-02b eel Failure to take adequate corrective actions to address the adverse trend in reactivity management activities L 50-295/97007-02c eel Failure to take adequate corrective action to prevent
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recurrence of command and control, communications, and
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! reactivity management problems identified as a result of the . { January 1996, inadvertent mode change ;
50-295/97007-02d eel Failure to take adequate corrective action to prevent
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recurrence of command and control, communications, and reactivity management problems identified as a result of f inappropriate control rod manipulations on September 16, 1 1996.
! 50-295/97007-03 eel Failure to comply with Technical Specification 3.1 action
statement requirements for inserable reactor coolant system ) flow instruments
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> . ! LIST OF ACRONYMS USED AIT Augmented Inspection Team ASO Assistant Superintendent of Operations Comed Commonwealth Edison Company CR ; - Control Room
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, CS Containment Spray i i eel Escalated Enforcement item GOP General Operating Procedure ! GSEP l General Station Emergency Plan INPO Institute for Nuclear Powers Operations IR Intermediate Range LCO Limiting Condition for Operation . LOCT Licensed Operator Continuing Training NES Nuclear Engineering Supervisor NRR Nuclear Reactor Regulation t NSO j Nuclear Station Operator . NTS Nuclear Tracking System ,
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OM Operations Manager OOS Out of Service OP Operations Policy PlF Problem identification Form ,
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POAH Point of Adding Heat 1 PT Performance Test i ONE : Oualified Nuclear Engineer 4 Rlli Region 111 ) RCS Reactor Coolant System ) RHR Residual Heat Removal
SAT Systems Approach to Training SE Shift Engineer SO Standing Order . ' SQV Site Quality Verification SRO Senior Reactor Operator TS- Technical Specification , UE Unusual Event US Unit Supervisor ZAP Zion Administrative Procedure ZIOPR Zion intensive Operator Performance Training Program ZNG Zion Nuclear Group . 21 }}