ML20237F152
| ML20237F152 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 08/26/1998 |
| From: | Gordon Peterson DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 50-413-98-07, 50-413-98-7, 50-414-98-07, 50-414-98-7, NUDOCS 9809020093 | |
| Download: ML20237F152 (8) | |
Text
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Duke Power Company A tho,Eney Comper W.
Catawba Nudear Station m i-, cm 4800 Concord Road York. SC 29745 Gary R. Peterson (803) 831-4251 omCE Vice 1%sident (803) 831-3426 fax August 26, 1998 l
l U.
S.
Nuclear Regulatory Commission l
ATTN:
Document Control Desk j
Washington, D.C.
20555
Subject:
Duke Energy Corporation Catawba Nuclear Station Dockets 50-413 and 50-414 Reply to Notice of Violation (NOV) l Inspection Report 50-413, 414/98-07 l
Pursuant to the provisions of 10 CFR 2.201, attached is l
Duke Energy Corporation's response to a Notice of Violation l
dated July 27, 1998.
Inspection Report 50-413, 414/98-07 l
identifies two Level IV violations.
The first violation, 98-07-01, identifies a Failure to Have Adequate Operations Procedures Addressing Auxiliary Feedwater (AFW) System Design Temperature Limits and Operation of Valve 1CM-127.
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The second violation, 98-07-05, identifies a Failure to
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take Prompt Corrective Actions to Prevent Recurrence of Upper Surge Tank (UST) Over-Temperature Events and AFW System Inoperability.
These violations were identified
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during an NRC inspection period between May 24, 1998 and July 4, 1998.
Duke Energy Corporation acknowledges these violations.
Section 3 in each response lists the only regulatory commitments associated with this response.
If there are any questions concerning this response, please contact M.
S. Purser at (803) 831-4015.
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Peterson Attachment 9809020093 980826 l
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Nuclear Regulatory Commission
. August 26, 1998 Page 3 bxc: ELL EC050 NSRB Staff ECOSN CN-815.01 CN04DM I
K.
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NCMPA-1 SREC PMPA-j l
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Catawba Nuclear Station Reply to Notice of Violation Statement of Violation 50-413,414 98-07-01 Technical Specification 6.8.1.a requires in part, that written procedures shall be established, implemented and maintained for applicable procedures in Appendix A to Regulatory Guide (RG) 1.33, Quality Assurance Program Requirements (Operation), Revision 2, 1978.
As referenced in Sections 2 and 5 of RG 1.33, this includes general operating procedures, as well as those for abnormal
-operating conditions.
Contrary to the above, as of May 7, 1998, the licensee failed to establish. adequate operating and abnormal operating procedures related to excessive auxiliary feedwater system suction source temperatures as indicuted by l
the following examples:
1.
Abnormal Operations Procedure AP/1/A/5500/006, Loss of Steam Generator Feedwater, did not provide instructions to manually realign auxiliary feedwater pump suction to the assured safety-related source when preferred source temperatures exceeded the 138"F design value used in Updated Final Safety Analysis Report (UFSAR) accident analyses.
2.
Operations Procedure OP/1/A/6250/002, Auxiliary Feedwater, did not include guidance to ensure auxiliary feedwater suction source temperatures did not exceed j
the 138 F design temperature value used for UFSAR l
accident analyses.
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3.
Operations Procedure, OP/1/A/6250/001, Condensate and l
Feedwater, did not contain detailed instructions to ensure proper operation of the digital controller for valve 1CM-127.
This deficiency resulted in extended operation with the controller outside of prescribed parameters, which led to degradation of the auxiliary feedwater system on May 7, 1998.
This is a Severity Level IV Violation.
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Response to Violation 98-07-01 1.
Reason for Violation Duke Energy Corporation acknowledges the violation.
On May 7,
1998 a power reduction to 30% was initiated on Unit 1 to repair a Main Feedwater Control Valve.
The condensate system flow was reduced as part of the power reduction causing the condensate recirculation control valve, 1CM-127, to open.
This allowed heated water to flow to the Upper Surge Tanks (UST) which provide one of the condensate (non-safety) grade suction supplies to the Auxiliary Feedwater (CA) System.
The root cause of this event occurred due to inadequate training, procedures and job aids relative to the uniqueness of the controller for 1CM-127.
2.
Corrective Actions Taken and Results Achieved Previously completed corrective actions addressed in LER 413/98-002 will not be restated here since that information has been previously submitted to the NRC and docketed.
The issues addressed will consist of_the status of the planned corrective' actions outlined in the LER.
In addition, although the event occurred on Unit 1 and all nomenclature addresses Unit 1 issues, the same corrective actions are being made for Unit 2.
- 1. AP/1/A/5500/006 has been revised to no longer allow makeup to the upper surge tank with potentially high energy condensate sources unless the Unit is in a Mode in which Auxiliary Feedwater is not required operable.
The strategy of swapping CA to Nuclear Service Water (RN) if the suction temperature reached a predefined limit is not creditable.
i The swap would require a manual action within the first 30 minutes of the accident which is not consistent with our current licensing basis per SER 10.4.9.3. Catawba has identified the high energy inputs to the condensate grade auxiliary feedwater sources.
Operating procedures have been revised to maintain the high energy. flow path (CM-127) to the-auxiliary feed-water condensate sources isolated in order to maintain the operability of_the auxiliary feedwater system.
- 2. OP/1/A/6250/002 has been revised to verify the maximum auxiliary feedwater supply temperature using limits and precautions.
Temperature limits are specified in a new j
enclosure to this procedure for Placing the CA System in i
Standby Readiness.
- 3. OP/1/A/6250/001 and other operating procedures have been revised to maintain high energy inputs to the upper surge tank isolated under conditions where these inputs contain high energy condensate.
Lower energy inputs such as auxiliary stear tank heating have been identified in the operator aid computer alarm response procedures to be isolated in the event tank temperatures exceed limits below the operability limits.
An enclosure has been added to this procedure, CM-127 Flow Controller Operation, to provide detailed instructions for operation of the controller.
This enclosure will not be required as long as CM-127 remains isolated.
In addition to the above corrective actions,' Operator Aid Computer alarm response procedures for hotwell discharge temperature, upper surge tank temperature and condensate storage tank temperature have been revised to assure the condensate sources are monitored and maintained below the operability limits.
Job Aids include a label for 1CM-127 on the control board to remind personnel to consult the operating procedure for the condensate system when resetting the setpoint if the valve is taken to manual and then returned to automatic.
Training on operation of the controller for ICM-127 was provided to the operators and procedure writers.
- 3. Corrective Actions to be Taken to Avoid Future Violations No additional corrective actions are required to prevent recurrence of this event.
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- 4. Date of Full Compliance Duke Energy is in full compliance.
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Statement of Violation 50-413,414 98-07-05 10 CFR 50 Appendix B, Criterion XVI, Corrective Actions, as implemented by the Duke Energy Corporation Topical Report Quality Assurance Program, Revision 22, requires in part, that measures shall be established to assure that conditions adverse to quality are promptly corrected, and in the case of significant conditions adverse to quality, that measures be established to assure that the cause of the condition is determined and corrective action taken to preclude l
recurrence.
Contrary to the above, the licensee failed to identify and take prompt corrective action following unit 1 upper surge tank over-temperature events on January 20, 1996, and January 11, 1998, to preclude recurrence of an adverse system interaction and significant condition adverse to quality.
Consequently, Unit 1 auxiliary feedwater system became degraded and was declared inoperable for approximately three hours on May 7, 1998.
This is a Severity Level IV Violation.
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Response to Violation 98-07-05 1.
Reason for Violation Duke acknowledges the violation.
Duke missed several opportunities to identify the possibility that a fault in valve CM-127 on either unit could cause an over-temperature event on Auxiliary Feedwater The initial review of the root causes for each previous event were different which prevented identification of a recurring problem.
The January 20, 1996 feedwater transient was caused by an instrument line freezing and failing 1CM-127 open.
The January 11, 1998 event was due to leakage through valves ICM-127 and 1CM-126. Trouble shooting progressed on both j
valves and the CA temperature was stabilized.
In spite of both of these events, the possibility of an over-temperature event was believed to be self limiting due to the 16-inch vent line between the Condenser Hotwell and the UST which should have kept the UST from exceeding saturation temperature for condenser vacuum.
I The May 7, 1998 event, caused by setpoint error, in which the UST temperatures exceeded 200 degrees, disproved this
I belief and corrective actions have been taken to ensure this event does not recur.
In conclusion, the root cause. of the failure to identify and take prompt corrective actions has been determined to be due to insufficient trending of data from the previous events, unclear information in the Design Basis Documents regarding the temperature limits on the UST and a design that allowed contents of the UST to reach higher limits than previously recognized.
2.
Corrective Actions Taken and Results Achieved
'Previously completed corrective actions addressed in LER 413/98-002 will not be restated tare since that information has been previously submitted to'the NRC and docketed.
The irsues addressed will consist of the status of the planned j
corrective actions outlined in the LER.
1.
The strategy.of swapping CA to RN if the suction temperature reached a predefined limit was not creditable.
l The swap would require a manual action within the first 30 minutes.of the accident which is'not consistent with the j
current licensing basis per SER 10.4.9.3.
This option will l
not be pursued further at his time.
- 2. A caution statement has been added to the Removal &
Restoration (R&R) for CM-127 to include the controller setpoint for CM-127 as one of the required pieces of information and to refer to the Condensate Feedwater (CM) procedure for guidance.
-3 Additional R&Rs have been established to isolate other high energy inputs to the UST until further engineering l
evaluations determine.the final configuration.
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4.
Training is ongoing as part of the Engineering Continuing Education Process to reinforce expectations for operability evaluations.
Operations training has been performed for operability evaluations.
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- 5. Trending of the temperature data is ongoing to prevent recurrence of this event.
3.
Corrective Actions to be Taken to Avoid Future Violations
- 1. A review of the complexity of the CA system and secondary system components such as the UST, hotwell and condensate storage tanks is being performed and may result in future modifications.
This is a long term review and will need to
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1 be coordinated with other Duke plants to establish milestone dates..
2.
Various other design inputs to the CA system will be evaluated to determine if alarm response guidelines need to be developed.
This review should be completed by the end of 1998.
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- 3. A review of design basis information is ongoing to determine if temperature limits for all sources of the CA i
system including the upper surge tank are clearly l
communicated.
This review should be completed by the end of 1998.
- 4. Date of Full Compliance Duke Energy is in full compliance.
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