IR 05000373/1997008
| ML20149F029 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 07/17/1997 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20149F020 | List: |
| References | |
| 50-373-97-08, 50-373-97-8, 50-374-97-08, 50-374-97-8, NUDOCS 9707220012 | |
| Download: ML20149F029 (21) | |
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U.S. NUCLEAR REGULATORY COMMISSION REGION lli l
Docket Nos:
50 373; 50-374
' License Nos:
Report Nos:
50-373/97008(DRS); 50-374/97008(DRS)
Licensee:
Commonwealth Edison Company Facility:
LaSalle County Station, Units 1 and 2 Location:
2601 N. 21st Road
. Marseilles, IL 61341 Dates:
April 28,1997 - June 20,1997 (
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inspector:
E. Duncan, Reactor Engineer
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Approved by:
M. Ring, Chief, Lead Engineers Branch Division of Reactor Safety
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PDR ADOCK 05000373 G
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EXECUTIVE SUMMARY LaSalle County Station, Units 1 and 2 NRC Inspection Report 50-373/97008(DRS); 50-374/97008(DRS)
Enaineerina The inspector reviewed Unresolved item 50-373/374/97004-04 regarding a residual
heat removal (RHR) heat exchanger waterhammer concern. The inspector determined that concerns regarding waterhammer on division 2 of the residual heat removal service water (RHRS$N) system had been previously identified by the licensee due to a high vertical piping loop unique to division 2. However, the licensee did not consider the effects of design lake levelin a subsequent evaluation of the potential consequences of a worst case waterhammer event until after questions were raised by NRC inspectors. As a result, the licensee failed to recognize that division 2 of the RHRSW system was inoperable from initial plant startup. This was an example of an apparent violation of 10 CFR 50, Appendix B, Criterion XVI, " Corrective Actions." (Section E1.1)
As discussed in inspection report 50-373/374/97004, the inspector determined
that the licensee failed to identify that the Unit 1 and Unit 2 division 1 RHRSW heat exchangers were susceptible to tube voiding and waterhammer. During this inspection, the inspector concluded that a detailed evaluation was required to demonstrate that the division 1 RHRSW system was operable, which was an example of an apparent violation of 10 CFR 50, Appendix B, Criterion XVI,
" Corrective Actions." (Section E1.1)
The inspector reviewed modifications planned by the licensee to address the
division 2 RHRSW system waterhammer issue. No concerns were identified.
(Section E2.1)
The inspector observed testing of the RHRSW keep-fill system modification and
identified numerous problems including poor test scheduling and preparation, weak coordination of resources, improper use and approval of overtime, unclear backshift engineer expectations, and inadequate communications. (Section E4.1)
The licensee's prompt investigation report regarding RHRSW keep-fill system post-
modification testing problems failed to clearly identify that Technical Specification requirements regarding overtime approval were not met and failed to identify issues regarding the roles and responsibilities of a backshift engineer. (Section E4.2)
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Report Details Exercise of Discretion Two examples of an apparent violation described in Section E1.1 of this report are based upon activities which satisfy the appropriate criteria in Section Vll.B.6, " Violations involving Special Circumstances," of the " General Statement of Policy and Procedures for NRC Enforcement Actions" (Enforcement Policy), NUREG-1600, and a Notice of Violation (NOV) is not being issued for this apparent violation. In particular, significant NRC eaforcement action was recently taken against LaSalle County Station for a service water sealant intrusion event for which the licensee's corrective actions encompass the root causes for the violation under consideration, and the licensee voluntarily entered an extended shutdown on both units to address wide ranging performance problems which encompass the causes for the apparent violation discussed in the report. In addition, actions specified in Confirmatory Action Letter (CAL) Rlll-96-008B effectively prevent the licensee from starting up LaSalle County Station without NRC approval.
Ill. Enaineerina El Conduct of Engineering E1.1 Residual Heat Removal Service Water (RHRSW) System Waterhammer Concern a.
Inspection Scope
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The inspector reviewed Unresolved item 50-373/374/97004-04 regarding a RHRSW system waterhammer concern on Unit 1 and Unit 2.
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Observations and Findinas Backaround As discussed in NRC inspection reports 50-373/374/96011 and 50-373/374/97004, the inspectors identified that the RHR heat exchanger tubes were at an elevation 30'-3" higher than normal lake level and 40'-3" higher than design lake level. As a result, the inspectors postulated that the heat exchangers could be susceptible to tube voiding as a result of an event which caused lake level to decreace from the normal level of 700 feet to the design level of 690 feet, or due to boi!ing in the RHR heat exchanger tubes during a design basis event, in either case, once the RHRSW system was manually initiated, the inspectors were concerned that a void in the tubes would rapidly collapse, resulting in a
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waterhammer which could rupture the heat exchanger and render the system inoperable.
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i The licensee responded during the inspection that a waterhammer would occur as l
postulated. At the end of that inspection, the licensee had not determined the l
consequences of a worst case waterhammer event. Subsequently, the licensee formally responded to the inspectors' concern in a letter dated December 20,1996.
In that letter, the licensee provided the following additional information:
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Division 1 I
Due to the physical configuration of the Unit 1 and Unit 2 division 1 RHRSW
.sys em, tS only location within the system where the postulated waterhammer t
event could occur, under certain circumstances, was in the upper elevation of the RHR heat exchanger tubes. For example,if prior to starting the RHRSW pumps, the l
RHR heat exchanger tubes were heated up due to suppression pool heatup, which
would occur during a loss of-coolant-accident or safety relief valve (SRV)
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blowdown, tube voiding could occur. In addition, the situation would be worsened if the lake level decreased from the normal level to the design level following a failure of the nonsafety-related dike.
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To evaluate the effects of the postulated waterhammer on the division 1 RHRSW system, the licensee conducted the following evaluations:
General Electric (GE) performed a study which developed waterhammer
pressure pulses resulting from a worst case waterhammer in the RHR heat l
exchanger tubes. GE concluded that the bounding waterhammer pressures which could occur in the RHR heat exchangers were acceptable.
Sargent and Lundy (S&L) performed an evaluation which providad further
confirmation of the adequacy of the RHR heat exchangers following a postulated worst case waterhammer in the RHR heat exchanger tubes.
S&L performed additional evaluations of the piping, equipment, and supports l
for a postulated worst case waterhammer event in the RHR heat exchanger tubes. These evaluations concluded that the stresses in the system piping, i
valves, penetrations, strainers, pumps, and supports were acceptable.
l The inspector obtained the evaluations performed by GE and S&L. These r. valuations have been forwarded to the Office of Nuclear Reactor Regulation (NRR)
for further review.
10 CFR 50, Appendix B, Criterion XVI, " Corrective Actions," requires that
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measures shall be established to assure that conditions adverse to quality, such as
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deficiencies, are promptly identified and corrected and that in the case of significant conditions adverse to quality, the measures shall assure that the cause of the l
condition is determined and corrective action taken to preclude repetition.
l As discussed in inspection reports 50-373/374/96011 and 50-373/374/97004, and
as described above, from initial plant construction to 1996, the licensee failed to l
identify that the Unit 1 and Unit 2 division 1 RHRSW system was susceptible to
tube voiding and waterhammer as a result of an event which caused lake level to j
decrease from the normal level of 700 feet to the design lake level of 690 feet, or l
due to boiling in the RHR heat exchanger tubes during a design basis event. In
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addition, because detailed evaluations were required to demonstrate that division 1 of the RHRSW system v'as operable under the above conditions, this was an j
example of an apparent violation of 10 CFR 50, Appendix B, Criterion XVI (50-373/374/97008-02a).
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However, because this violation satisfied the criteria in Section Vll.B.6, " Violations invo'ving Special Circumstances," of the " General Statement of Policy and Procedures for NRC Enforcement Actions" (Enforcement Policy), NUREG-1600, a Notice of Violation (NOV) is not being issued.
Division 2 The physical configuration of the Unit 1 and Unit 2 division 2 RHRSW system also allowed for a waterhammer event to occur in the RHR heat exchanger tubes similar
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to division 1. However, the division 2 piping had a large verticalloop with a maximum elevation (733'-6" on Unit 1 and 735'-3" on Unit 2) higher than the RHR
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heat exchangers (730'-3") and significantly higher than normal lake level (700 feet)
or design lake level (690 feet). This loop existed to provide a straight run of piping j
necessary to ensure the accuracy of flow mecsuring instrumentation.
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To evaluate the effects of a postulated worst case waterhammer event on division 2 of the RHRSW system, the licensee performed additional evaluations.
However, in this case, the licensee's evaluations failed to demonstrate that the piping and piping supports could withstand a postulated waterhammer at the design lake level of 690 feet. As a result, a keep-fill system with crosstiec to both the nonsafety-related service water (WS) system and the diesel generator cooling water (DGCW) system was designed for division 2 of the RHRSW system to maintain the piping system full and eliminate the potential for a waterhammer to occur when the system was started following a design basis event.
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The inspector reviewed the licensee's response regarding the susceptibinty of division 2 of the RHRSW system to a waterhammer event and determined that waterhammer events had been observed and identified by the licensee previously.
In addition, the inspector determined that pressure transient data had been recorded as part of special testing conducted to evaluate the waterhammer issue. Following that testing, procedure changes, including the installation of a temporary hose to provide makeup to the Unit 2 division 2 RHRSW system prior to surveillance testing, had been implemented to minimize the waterhammer consequences.
Unresolved item 50-373/374/97004-04 was opened pending further NRC review.
Inspector Review During this inspection period, the inspector reviewed the configuration of div sion 2 of the RHRSW system in detail, and conducted interviews to evntuate the waterhammer issue, including the licensee's identification of t' ! problem and planned corrective actions. The inspector developed the following chronology of events:
05/04/90 LaSalle Special Test (LST) 90-49, "RHR Service Water Pressure Transient Study," was et,nducted to record and evaluate the pressure
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transients in the Unit 2 division 2 (2B) loop of the RHRSW system during system startup and to investigate alternate startup methods to mitigate the waterhammer transient. The following results were obtained:
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Using the normal startup method in which the RHRSW
discharge valve was opened after the RHRSW pump was started, the maximum recorded pressure in the RHRSW system was about 200 pounds per square inch gauge (psig).
Using an alternate startup method, in which the RHRSW
system discharge valve was partially opened before the RHRSW pumps were started, the maximum recorded pressure in the RHRSW system was only about 100 psig.
Note: This testing was performed at normallake level (about 700 feet) and failed to account for the effects of design lake level (690 feet).
05/08/90 LaSalle Operating Procedure (LOP) RH-05, " Operation of the RHR Service Water System," was revised to mitigate the observed waterhammer effects as follows:
Procedure steps were revised to open the division 2 RHRSW
system discharge valve, wait 5 to 6 seconds after receiving dual position indication, start one RHRSW pump, and then after flow indicated greater than 3000 gallons per minute (gpm), to start the other RHRSW pump.
A precaution was added which required that the division 2
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q RHRSW system discharge valve should indicate dual position fo3th open and closed lights illuminated) for 5 to 6 seconds prior to starting an RHRSW pump to avoid waterhammer damage to the system.
05/09/90 Action item Request ( AIR) 373-251-90-00072, "Waterhammer in the Division 2 RHRSW System," was generated to track a long-term engineering resolution for the division 2 RHRSW system waterhammer issue.
07/31/90 AIR 373-251-90-00072 was updated to discuss the results of LST-90-49. The update also stated that the issue was to be discussed at an 8/6/90 technical review committee (TRC) meeting.
08/06/90 TRC meeting discussed the division 2 RHRSW system waterhammer
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issue. During the meeting, it was suggested that a special test be
performed to crosstie the WS system with the RHRSW system as a keep-fill system.
l 10/25/90 LST-90-105, "RHR Service Water Pressure Transient Monitoring i
During System Startup," was conducted which crosstied the WS system with division 2 of the RHRSW system to evaluate a keep-fill crosstie.
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The licensee's evaluation of LST-90-105 test results concluded that no significant transients were noted and that a permanent crosstie
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should be an effective method to prevent severe pressure transients
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during RHRSW system startup.
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i 10/26/90 AIR 373-251-90-00072 was updated to reflect the following:
The suggestion in the 8/6/90 TRC meeting to crosstie the WS
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uystem with the RHRSW system.
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l LST-90-105 was completed on 10/25/90 and demonstrated
that a WS system crosstie was an effective method to prevent L
severe waterhammer transients.
11/05/90 TRC meeting discussed the results of LST-90-105. A decision was made to submit a modification request to install a permanent WS system crosstie.
l 11/27/90 AIR 373-25190-00072 was updated to reflect the following:
The results of LST-90-105 were discussed at the 11/5/90 TRC
I-meeting.
A WS crosstie modification request was on the 1/22/91 senior
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02/07/91 S&L letter (Chron 162880) was received oy Comed regarding the results of an S&L study which evaluated the division 2 RHRSW system waterhammer issue. The following important points were noted in the letter:
l Waterhammer was measured with transient pressures of up to
200 psig.
An alternate startup method in which the RHRSW pumps were
started after the discharge valve was partially opened reduced the maximum waterhammer pressure to 100 psig.
The root cause was a vertical loop in the divir. ion 2 RHRSW
system piping.
Potential corrective actions included a piping re-route to lower
the height of the verticalloop or a keep-fill modification from the WS system.
The RHR heat exchangeis were also reviewed and determined
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to be acceptable since the top of the RHR heat exchanger l
tubes were less than 31'-7" higher than lake level.
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Note: Design basis lake level was not considered in the S&L evaluation.
02/14/91 AIR 373-251-90-00072 was updated to reflect that the modification i
request was not discussed at the 1/22/91 SMRC meeting, but would l
be placed on the agenda for the next SMRC meeting.
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03/04/91 Internal Comed letter (Chron 163763) recommended that LaSalle
continue to implement the alternate system startup method (opening the division 2 RHRSW discharge valve just prior to RHRSW pump operation) which would easily and cost-effectively eliminate the i
possibility of waterhammer without additional funding.
Modification options were ec.ommended to not be investigated any l
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l 07/01/91 AIR 373-25190-00072 was upiated to reflect the following:
The keep-fill modification request was presented to the SMRC.
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The SMRC cancelled the modification request since the
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alternate RHRSW system startup method had significantly reduced the pressure transients experienced during system startup, and since this method had been implemented there had been no further instances of system damage due to waterhammer.
AIR 373-251-90-00072 was closed.
02/11/93 Problem identification Form (PlF) 373-201-93-00111 was generated to document a loud waterhammer which occurred when the 2B RHRSW system was started, followed by a metallic clanging noise in l
the RHRSW system piping and heat exchanger.
02/17/93 PIF 373-201-93-00111 was closed. The following actions were
documented:
The RHRSW system wac walked down for leaks or damage.
- None were identified.
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A work request was generated to inspect the 2B RHRSW
backwash strainer during refueling outage L2R05.
Work requests had been previously written to inspect the 2B
RHR heat exchanger and 2B RHRSW system flow element during L2R05,
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07/14/93 A memorandum from R. Ayer, LaSalle System Engineering, to J. Schmeltz, LaSalle Station Manager, discussed RHRSW system i
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waterhammer, in that memorandum, the following information was noted:
The Unit 2 division 2 loop of the RHRSW system was
susceptible to waterhammer due to a vertical loop of piping.
However, the 18 loop and both division 1 subsystems did not have piping above 734' and therefore were not likely to be
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susceptible to waterhammer.
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Note: Design lake level effects were not considered.
On 2/11/93, a severe waterhammer occurred when the 2B
RHRSW system was started to support an RHR heat exchanger differential pressure test which may have caused damage to the 2B RHRSW system backwash strainer tube assembly.
On 6/30/93, another waterhammer occurred while performing
a differential pressure test. (Note: the licensee was unable to provide this PlF to the inspector and the inspector was unable to determine any additional information regarding this event).
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These two events indicated that further corrective actions
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were necessary. The following actions were recommended:
Testing to identify additional procedural methods to i
alleviate the waterhammer problem.
Re-opening the investigation for a long-term engineering
resolution to the problem.
08/31/93 LST 93-063 was performed which monitored the effectiveness of a j
keep-fill crosstie from the service water (WS) system to the RHRSW i
system. Testing results were similar to those obtained on 10/25/90.
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10/18/93 LOP-RH-05 was revised to add steps to fill the 2B RHRGW loop prior to startup. These steps consisted of connecting a temporary hose between a WS system test tap and the RHR heat exchanger inlet drain valve to fili any voided piping in the 2B RHRSW system.
11/16/93 PIF 374-200-93-01347 was generated to document a loud waterhammer which occurred when the 2B RHRSW system was manually initiated without filling the loop in accordance with the revised LOP-RH-05 procedure.
l PIF 373-200-93-0134701 was generated to track completion of l
corrective actions from PlF 374-200-93-01347.
I 12/01/93 The licensee completed an investigation of PlF 374-200-93 01347.
l The following findings and corrective actions were documented:
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Procedure LOP-RH-05 was not written in such a manner as to
make it clear that the crosstie fill was required at all times
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unless waived by the shift engineer.
The reactor operator in charge of starting the 2B RHRSW
system assumed that because of a note in his turnover, the system was already filled.
No material condition problems were identified during
walkdowns by operations and system engineering personnel j
following the waterhammer event.
Caution cards were added to the Unit 2 "C" and "D" RHRSW
j; pump control switches to indicate a required crosstie fill until i
LOP-RH-05 was revised.
The event was discussed with the operating crew and upper
- station management.
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PIF 374-200-93-01347 was closed.
01/04/94 LOP-RH-05 was revised to more clearly identify filling requirements for the 2B RHRSW system.
[e 01/10/94 PlF 373-200-93-0134701 was closed.
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08/14/95 TRC meeting discussed the 2B RHRSW system waterhammer issue.
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The TRC meeting notes documented the following:
Unit 2 had a unique piping arrangement on the division 2
RHRSW system that had resulted in a number of severe
waterhammer transients.
The problem had been minimized by procedural controls and a
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manual keep-fill process which was an operator workaround.
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TRC approved a solution which permanently crosstied the WS system to the RHRSW system (ER9500167).
i TRC determined that the proposed crosstie was the most cost-
effective solution and approved the change as a modification for installation in 1997.
09/03/96 NRC System Operational Performance Inspection (SOPI) began at LaSalle to assess the operational performance of the RHRSW system.
l 09/18/96 NRC inspectors questioned a potential waterhammer in the RHR heat
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exchangers documented as Comment 20, " Potential for RHRSW System Waterhammer," in NRC inspection report 50-373/374/96011.
Specifically, the inspectors were concerned that since the top of the
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RHR heat exchanger tubes were greater than 32 feet above the l
design lake level of 690 feet, tube voiding, which could result in a l
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severe waterhammer transient, was possible.
09/24/96 NRC SOPl team exit meeting held. Unresolved item 96011-19'was
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opened to track the RHR heat exchanger waterhammer concern.
09/26/96 PIF 96-2824, "1B and 2B RHR Heat Exchanger Service Water Piping
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j Potential for.Waterhammer," was generated to identify a problem j
regarding a potential waterhammer at design lake level due to the verticalloop in the division 2 RHRSW system piping.
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PlF 96-2825, "RHR Heat Exchanger Tubes Potential Waterhammer,"
was generated to identify a problem regarding a potential
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waterhammer at design lake level in the RHR heat exchangers.
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09/27/96 As documented in NRC inspection report 96011, the licensee responded to Comment 20. In that response, the licensee described procedural steps in place during startup_and shutdown of the RHRSW j
system including discharge valve and RHRSW pump operation
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sequence.
The response also stated that as a conservative measure Unit 1 and Unit 2 had been shutdown and the waterhammer issue was being j
investigated to ensure that the RHRSW system was operable prior to unit restart.
12/17/96 The licensee contacted the NRC Operations Center in accordance with 10 CFR 50.72, "Immediate Notification Requirements for Operating Nuclear Power Plants," and reported that division 2 of the RHRSW system was outside its design basis due to concerns regarding the consequences of a worst case waterhammer transient.
01/16/97 Licensee Event Report (LER)96-020, " Potential Waterhammer Concerns of Residual Heat Removal Service Water System Division 2 Piping," Revision 0,.was submitted to the NRC.
The inspector reviewed the information documented above and concluded the following:
Concerns r3garding waterhammer on division 2 of the RHRSW system had
been identified prior to May 1990.
The licensee failed to adequately consider the effects of design lake level
during an evaluation of the RHRSW system waterhammer consequences prior to NRC questions on September 20,1996.
- Actions to fill the Unit 2 division 2 RHRSW system prior to routine
surveillance testing, although not performed to meet surveillance acceptance criteria, were pre-conditioning activities since the actions enhanced the
l testing results by mitigating the waterhammer transient and would not normally be conducted prior to initiating the RHRSW system during an event.
The initial modification plan to provide a crosstie from the WS system alone
was inadequate, since this system could not be relied upon to be available during a loss-of-offsite-power (LOOP), or a seismic event.
Corrective Actions
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The inspector determined that the licensee had planned or completed the following corrective actions to address the waterhammer concern A keep-fill system was installed on division 2 of the RHRSW system for Unit
1 and Unit 2 to ensure that the RHRSW system would remain filled and pressurized under all plant conditions.
The RHRSW system was selected for a design review prior to startup. This
review was being conducted to verify adequate design implementation, that there was a documented analytical basis for the design, that no important design features had been overlooked, and that the design provided for the necessary functional operating requirements. The licensee planned to resolve any additional waterhammer problems identified prior to startup.
The licensee planned to review systems important to safety and systems
utilized within the action steps of the emergency operating procedures (EOPs) to identify and correct any similar waterhammer problems, c.
Conclusions The inspector determined that significant concerns regarding waterhammer on division 2 of the RHRSW system due to a high vertical piping loop had been previously identified by the licensee...owever, the licensee did not adequately consider the effects of design lake level during an evaluation of the consequences
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of a worst case waterhammer event until questions were raised by NRC inspectors on September 20,1996.
10 CFR 50, Appendix F,, Cnterion XVI, " Corrective Actions," requires that measures shall be esta )lished to assure that conditions adverse to quality, such as deficiencies, are prompt!y blentified and corrected and that in the case of cignificant conditions adverse to quali.y, the measures shall assure that the cause of the condition is determinsd an J corrective action taken to preclude repetition.
l As discussed in inspection report 50-373/374/97004, and as described above, from initial plant construction to 1996, the licensee failed to identify that the Unit 1 and Unit 2 division 2 RHRSW system was outside its design basis, a significant
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condition adverse to quality, and take appropriate corrective actions, which was an example of an apparent violation of 10 CFR 50, Appendix B, Criter;on XVI
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(50-373/374/97008-02b).
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However, because this violation satisfied the criteria in Section Vll.B.6, " Violations involving Special Circumstances," of the " General Statement of Policy.and j
Procedures for NRC Enforcement Actions" (Enforcement Policy), NUREG-1600, a
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l Notice of Violation (NOV) is not being issued.
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. Engineering Support of Facilities and Equipment
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j E2.1 RHRSW Keeo-Fill System Modification Review a.
inspection Scope l
l The inspector reviewed the licensee's keep-fill modification installed on the Unit 1 and Unit 2 division 2 RHRSW system.
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Observations and Findinas The inspector determined that to address the waterhammer events on division 2 of the RHRSW system, the following modifications were completed:
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The installation of two crossties to division 2 of the RHRSW system to
ensure that it is kept filled and pressurized. One crosstie was from the WS system, while the other was from the diesel generator cooling water -
(DGCW) system. Two crossties were required because the WS system is
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nonsafety-related and therefore cannot be relied upon in the event of a l
LOOP, or seismic event. The DGCW system is safety-related, but does not normally operate continuously. It operates whenever the emergency diesel generators (EDGs) are running. Therefore, the crosstie from the WS system would maintain the RHRSW system filled during normal plant operating conditions, while the crosstie from the DGCW system would maintain it filled during a LOOP.
The installation of a division 2 RHRSW system low pressure alarm in the
control room.
The installation of an interlock to the control logic of the division 2 RHRSW
system backwash strainers to permit automatic initiation of the backwash cycle only if the RHRSW pumps are running.
The inspector reviewed the modification packages associated with these design modifications, as well as the design drawings which addressed the changes. The inspector concluded that the design modifications were acceptable to correct the waterhammer problem. No concerns were identified.
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Conclusions l-The inspector concluded that design modifications to address the division 2 RHRSW
system waterhammer issue were appropriate. No concerns were identified.
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E4 Engineering Staff Knowledge and Performance E4.1 RHRSW Keeo-Fill System Post-Modification Testina Observations a.
Insoection Scoce The inspector observed the performance of post-modification testing following the addition of division 2 RHRSW system keep-fill modifications on Unit 1.
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Observations and Findinas On April 29,1997, the inspector observed the performance of modification test 9600195 following the installation of division 2 RHRSW system keep-fill modifications on Unit 1. During the testing, the inspector noted the fol!owing:
The testing was considered " critical path" work although the two test
engineers performing the test could not explain why this was the case.
i During the pre-evolution test briefing, operations supervision was not aware
of required technical specification (TS) limiting condition for operation (LCO)
entries until it was brought to their attention by the test engineers. As a result, testing was delayed for about 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> while operations department personnel verified the TS LCOs which were required to be entered and the impact on shutdown risk.
During performance of the portion of the test which confirmed proper
operation of the backwash strainer relay, both the "C" and "D" RHRSW pump discharge pressure indicator stop valves could not be isolated sufficiently to allow the testing to proceed as written. As a result, the test engineer conservatively discontinued the test to revise the procedure, prior to proceeding further.
A test engineer identified that a portion of the test could not be performed
since RHRSW system pressure had decreased to below the division 2 RHRSW system low pressure alarm setpoint.
The inspector identified that the test engineer pl3nned to perform the post-
modification testing under a general radiation work permit (RWP) although an RWP specific for the post-modification testing was directed by the procedure. The inspector discussed this with the test engineer who subsequently signed onto the correct RWP.
The inspector identified that RHRSW strainer control panel 1E12-P450 was
missing a nut intended to secure a terminal board to the control panel casing. The licensee subsequently initiated an action request (AR) to identify this condition.
i Following the problems encountered regarding stop valve leakage discussed above, the test engineers initiated a revision to the procedure to allow testing of the dirision 2 RHRSW system low pressure alarm and backwash strainer relay. The
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inspector discussed the licensee's progress with the test engineers the next
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morning. The inspector identified the following additional issues:
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The procedure revision required an exceesive amount of time, about 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />, j-to complete.. As a result, both test engineers were close to exceeding TS
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. overtime requirements when the test revision was approved.
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l The backshift engineer was requested to complete the post-modification test
i in the absence of the assigned test engineers since they had worked about 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> contirmously. However, the backshift engineer expressed '
significant concerns regarding his unfamiliarity with the test. As a result, one of the test engineers was authorized to work up to 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> to support the testing. That same engineer returned to work about 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> later and under the cognizance of licensee management worked an additional 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> before leaving the site.
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- The backshift engineer approved' the test procedure revision although it was stillin draft form,'and relied upon the test engineer to ensure that the
changes were properly incorporated, The RHRSW keep-fill system post-modification testing was originally
scheduled to begin on Monday, May 6. However, on the afternoon of Friday, April 25, the test engineers were informed that the test had been moved up a week and would be conducted the following Mondayi April 28.
I This resulted in a very limited amount of time for the test engineers to prepare for the testing.
Although the system engineering supervisor was promptly inforr.ed of
problems encountered during the testing, senior management was not made aware of any problems until well after testing was expected to have been completed.
The inspector discussed these issues with licensee management who performed a prompt investigation of the events discussed above. The inspector reviewed the results of the licensee's prompt investigation in conjunction with the information already obtained and concluded the following:
Test Scheduling and Preparation was Poor
The test engineers responsible for conducting the post-modification testing were provided minimal time to adequately prepare for the test. In addition, the test was inappropriately classified as critical path work. As a result,
when problems were encountered, the decision to push forward with the '
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testing was inappropriate.
Coordination of Resources was Poor
Although the testing was expected to require 12 to 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> to complete, two test engineers were assigned to support the testing at the same time.
In addition,' when problems were encountered, both test engineers remained
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onsite to revise the post-modification test procedure. As a result, when unexpected delays occurred during the test revision process, no provisions had been established to allow testing to continue without the approval of excessive overtime.
Use and Approval of Overtime was Poor
The inspector concluded that the' implementation of the licensee's overtime approval requirements was poor. The inspector was particularly concerned that management authorized a test engineer to work hours in excess of TS overtime requirements, although the testing was not urgent. The inspector also determined that overtime work without authorized approval occurred despite a recent memorandum from the Plant General Manager regarding an adverse trend in overtime management. A detailed explanation of the circumstances regarding this issue are discussed below.
The inspector obtained an April 15,1997, memorandum from the Plant General Manager regarding overtime adherence. The inspector noted that the memorandum identified concerns regarding violations of the overtime pulici which, as characterized in the memorandum, indicated a lack of adhe ace to technical specification requirements regarding overtime man jement, as well as a lack of control by the licensee's management tean in particular, the memorandum directed that authorization to exceed overt me limits must be prudent and not allowed out of convenience, could not be after the fact, and was designed to prevent personal injury and to assure nuclear safety.
LaSalle Administrative Procedure (LAP) 100-17, " Overtime Guidelines For Personnel That Perform Safety-Related Functions," Revision 10, dated June 19,1996, stated the following:
The purpose of the procedure was to establish guidelines for working
overtime at LaSalle Station that would minimize the possibility of fatigue of plant staff who perform safety-related functions.
lt was station policy not to routinely schedule overtime beyond a 16-
hour shift for any personnel, even for extended outages.
Work should be scheduled in advance to ensure that the potential for
exceeding the overtime guidelines was minimized.
In the event that overtime must be used, the following overtime
guidelines shall be followed:
1)
An individual should not be permitted to work more than 16 consecutive hours, not including the time necessary for shift i
turnover.
l 2)
The following criteria should normally be used:
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less than or equal to 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> in a 24-hour period.
- less than or equal to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in a 48-hour period.
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less than or equal to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> in a 7-day period.
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A break of at least 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> should be allowed between work periods.
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Authorization for overtime in excess of the above guidelines must be
obtained from the Plant General Manager or designee.
Similarly, Technical Specification 6.1.C.7 required that the amount of overtime worked by unit staff members performing safety-related functions shall be limited and controlled in accordance with the NRC Policy Statement on working hours (Generic Letter 82-12). Generic Letter 82-12, " Nuclear Power Plant Staff Working Hours," dated June 15,1985, stated, in part, that a break of at least 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> should be allowed between work periods (including shift turnover time), and in the event that very unusual circumstances arise which may require deviation from the above guidelines, such deviation shall be authorized by the Plant General Manager or designee, or higher levels of management.
The inspector reviewed the hours worked by test engineers and actions taken by station management to authorize overtime deviation and determined that one test engineer had worked 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> in a 24-hour period with documented approval from a Plant General Manager designee.
However, the inspector also determined that the test engineer returned to work with less than an 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> break between work periods without documented approval although licensee management was aware that the individual had returned to work.
The inspector concluded that the licensee failed to meet the requirements of TS 6.1.C.7 which was a violation (50-373/374/97008-01).
In response to the event described above, the licensee planned and/or completed the following corrective actions:
An article was placed in the June 19,1997 station newsletter to
communicate to station personnel licensee management expectations regarding overtime requirement deviations.
Department communication meetings were planned for June 30,
1997, to ensure that both workers and supervisors understood their responsibilities for implementing LAP-100-17, " Overtime Guidelines For Personnel That Perform Safety-Related Functions."
Appropriate disciplinary action was planned for any future violations
of the overtime guidelines, to include a review of the performance of both the worker and supervisor involved in the event.
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lhe number of personnel with Plant General Manager designee
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authority was significantly reduced.
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The inspector concluded that the licensee's corrective actions were appropriate.
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. Responsibilities of the Backshift Engineer Were Unclear
The inspector concluded that the roles and responsibilities of the backshift l
engineer were unclear since expectations differed between the test engineers and the backshift engineer regarding the backshift engineer's role in post-modification testing. :n addition, the actions of the backshift engineer to approve the test revision while in draft form was considered a
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poor practice.
Communications were Poor
Overall, communications between the system engineering department and
other organizations were poor. The following examples illustrate this conclusion:
The operations department was not aware of required TS LCO entries
until after the pre-evolution test briefing had begun, t
Plant management was not adequately apprised of problems
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encountered during the post-modification testing.
i Test engineers were not aware of why the testing was considered
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critical path work or why the testing had been rescheduled.
c.
Conclusions The inspector concluded that the performance of testing for the Unit 1 division 2 RHRSW keep-fill system modifications was poor. Problems regarding test scheduling and preparation, coordination of resources, management approval of overtime, expectations of the backshift engineer, and communications were identified by the inspector.
E4.2 Licensee Promot Investiaation of RHRSW Keeo-Fill Modification Test a.
Inspection Scope The inspector reviewed the results of the licensee's prompt investigation in response to problems encountered during the Unit 1 division 2 RHRSW keep-fill system post-modification testing.
b.
Observations and Findinas The inspector reviewed the licensee's prompt investigation report and discussed the information with licensee personnel. The following was noted:
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The report failed to clearly identify that certain overtime approval
requirements had not been met.
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The report properly identified that a test engineer had worked 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> in a 24-hour period, with Plant General Manager designee approval. However, the report failed to clearly identify that the test engineer returned to work
.l within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> without written approval, which was a violation of
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TS 6.1.C 7.
The report failed to identify issues identified by the inspector regarding the
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performance of the backshift engineer.
The issue identified by the inspector regarding the roles and responsibilities of the backshift engineer were not addressed in the licensee's report. In addition, the actions of the backshif t engineer to approve the test revision while in draft form was not identified by the licensee.
i One report inconsistency was noted.
- The preliminary conclusions of the report stated that two test engineers were authorized to work hours in excess of Generic Letter (GL) 82-12 limits.
However, the report details indicated that only one test engineer was authorized to exceed GL 82-12 limits.
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Conclusions The inspector concluded that the licensee's investigation was incomplete and failed to identify significant problems identified by the inspector. In particular, the licensee failed to clearly identify that TS requirements for overtime approval had not
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been met.
V. Manaaement Meetinas X1 Exit Meeting Summary The inspector presented the results of the inspection activities to licensee management at an exit meeting on June 20,1997. The licensee acknowledged the findings presented.
The inspector asked the licensee if any materials examined during the inspection should be considered proprietary. No proprietary information was identified.
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PARTIAL LIST OF PERSONS CONTACTED Lige_psee P. Barnes Regulatory Assurance J. Drago Regulatory A.ssurance R. Gremchuk System Engineering
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T. Hammerich System Engineering P. Hildebrandt Engineering Manager A. Javorik System Engineering Supervisor D. Kapinus System Engineering J. Rommel Design Engineering C. Snyder System Engineering INSPECTION PROCEDURES USED IP 37550:
Engineering J
IP 37551:
Onsite Engineering IP 40500:
Effectiveness of Licensee Controls in Identifying, Resolving, and Preventing Problems IP 92701:
Followup ITEMS OPENED, CLOSED, AND DISCUSSED l
Opened 50 373/374/97008-01 VIO Overtime approval requirements not met Closed 50-373/374/97004-04 URI RHRSW system waterhammer
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50-373/374/97008-02 NCV RHRSW system waterhammer Discussed 50-373/374/96011-19 URI Determination of the effects of waterhammer on the RHR heat exchanger i
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LIST OF ACRONYMS USED AIR Action item Request l
AR Action Request l
CAL Confirmatory Action Letter CFR Code of Federal Regulations
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DGCW Diesel Generator Cooling Water EDG Emergency Diesel Generator EOP Emergency Operating Procedure-ER Engineering Request GPM Gallons Per Minute GE General Electric GL Generic Letter IP inspection Procedure LAP LaSalle Administrative Procedure LCO Limiting Condition for Operation LER Licensee Event Report LOOP Loss-Of-Offsite-Power
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LOP LaSalle Operating Procedure-l LST LaSalle Special Test NOV Notice of Violation NRC Nuclear Regulatory Commission NRR Nuclear Reactor Regulation-PDR Public Document Room PIF Problem identification Form PSIG Pounds Per Square Inch Gauge RHR Residual Heat Removal RHRSW Residual Heat Removal Service Water RWP Radiation Work Permit SMRC Senior Management Review Committee SOPl System Operational Performance inspection SRV Safety Relief Valve S&L Sargent and Lundy TIA Task Interface Activity TRC Technical Review Committee TS Technical Specification URI Unresolved item VIO Violation WS Nonsafety-Related Service Water
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