ML20207N211
| ML20207N211 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 10/13/1988 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8810190028 | |
| Download: ML20207N211 (8) | |
Text
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l TENNECCEE VALLEY AUTHORITY CH ATTANOOGA. TENNESSEE 374ot
$N 1578 Lookout Place 1
00T 18 388 U.S. Nuclear Regulatory Cossaission ATTN Document Control Desk Washington, D.C.
20555 Centlement In ** %tter of
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Docket Nos. 50-327 Tennessee Valley Authority
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50-328 SEQL'OYAH NUCt. EAR PLANT (SQN) UNITS 1 AND 2 - NRC INSPECTION REPORT NOS. 50-327, 328/88 RESPONSE TO NOTICE OF VIO!ATION Enclosed is IVA'r, response to F. R. McCoy's letter to S. A. White dated September 15, 1 H 8, that transmitted violacions 50-327, 328/88-34-02, 03, and 04 provides TVA's response to the notice of violation.
Sunusary statements of connaitments contained in this submittal are provided in enclosure 2.
If you have any questions, please tel phone M. A. Cooper at (615) 870-6549.
Very truly yours, TENNESSEE VAE1.EY AUTHORITY R. Cridley, nager Nuclear Licensing and Regulatory Affairs Enclosures cc See page 2 h
881019002C 881013 PDR ADOCK 0500 7
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Ari Eg ist Opportunity Employer i
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- ()hhf }h jhhh U.S. Nuclear Regulatory Commissicn cc (Enclosures):
Ms. S. C. Black, Ass 12t4nt Director for Projects TVA Projects Division U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 Mr. F. R. McCoy Assistant Director for Inspection Programs TVA Projects Division U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Sequoyah Realdent Inepactor Sequoyaii Nuclear Plant 2600 Igou Ferry Road Soddy Daisy. Tennessee 37379 i
ENCLOSURE 1 RESPONSE TO NRC INSPECTION REPORT NOS. 50-327/88-34 AND 50-328/83-34 F. R. McC0Y'S LETTER TO S. A. WHITE DATED SEPTEMbr2 15, 1988 Violation 50-327, 328/88-34-02 4
"A.
Technical Specifications 3.5.1.2 requires, in part, that with the Upper Head Injection system INOPERA!LLE restore the system to OPERABLE within one hour or be in at least HOT STANDBY within the next six hours and in NOT SHUTDOWN within the following six hours.
Contrary to the above, on July 9 and 10, 1988, tha licensee was in noncospliance with the Action Statement of Technical Specification 3.5.1.2. for over 17 hours1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br /> Nhen existing data reflected inoperability of the hydraulic accumulator for Upper Head Injection system isolation valve 2-87-21.
This hydraulic accumulator is attendant 4
auxiliary equipment for the Upper Head It.jection system which is required i
for the system to fulfill its safety function.
1 This is a Severity Level IV violation (Supplement I) "
Admission or Denial of the Alleited Violation TVA admits the vislation.
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Reason for the Violation t
I This violation occurred because Surveillance Instruction (SI) 744, "Monitoring of UH! Isolation Valve Accumulator Pressure," did not contain sufficient information to perform an adequate assessment of upper head injection (UHI) isolation valve operability. T;.e procedure was written in a manner that it l
could be icterpreted that i nitrogen precharge check could be used as an t
alternative to the responso time test.
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~i An additional problem is that the acceptance criteria for anst non technical specification (non-TS) sis do not clearly state the actions that shall be l
taken in the event the acceptance criteria are not met.
This lack of 7
prescribed actions did not provide a method for prompt decisions to be made on the status of the associated equipment.
Corrective Steps That Have Been Taken and Rebu'ts Achieved I
I The leaking Schrader valve saa repaired and the leekage problem corrected.
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SI-744 has been revised to clariff what actions are required after three charges for determination of UH! valve operability.
Procedural guidance has been provided to enable the system engineer to relate pressure changes to
'l equivalent number of charges.
Trsining letters and night orders have been issued to licensed Operations personnel that provide specific guidance for 5
determination of UHI valve accumulator operability.
The training letters and night orders detail how pressure changes relate to the number of accumulator i
charges and provide specific directions regarding when a response time test is j
required.
I
y Systems Engineering has investigated increasing the nitrogen precharge pressure on the UHI accumulators so that additional charges could occur before a precharge check / response t*me test is required.
It was determined that a higher nitrogen precharge would not appreciably add to the reliability of the UHI system.
Corrective Steps That Will Be Taken to Avoid Further Violations As long-term recurrence control, Nuclear Engineering (NE) shall investigate the removal of the UHI system. This system has been removed at Watts Bar Nuclear Plant and at other utilities. Westinghouse Electric Corporation has previously performed an analysis that indicates the UHI system can be removed at SQN.
This action is part of the long-term planning for future refueling cycles as committed to in Licensee Event Report (LER) SQRO-50-328/88031.
In addition, the non-TS sis will be reviewed and revised as appropriate to clarify the actions that shall be taken the event the acceptance criteria are not met.
This will be completed b; Gctober 31, 1989, as committed to in LER SQRO-50-328/88031.
Date When Full Compliance Will Be Achieved TVA is in full compliance.
Violation 50-327, 328/88-34-03 "B.
Technical Specification 3.8.1.1 action A requires that with one diesel generator inoperable the operability of the remaining AC sources must be damcastrated by performance of surveillance requirements 4.8.1.1.1.a and 4.8.1.2.a.4 within one hour and at least once per eight hours thereafter.
Contrary to the above, on June 3, 1988 diesel generator 1A-A was inoperable for approximately three hours and the operability of the remaining AC sources was not demonstrated by the performance of survelliance requirements 4.8.1.1.1.a and 4.8.1.2.a.4 within one hour of diesel generator IA-A being declared inoperabic.
This is a Severity Level IV violation (Supplement I)."
Admission or Denial of the Alleged Violation TVA admits the violation.
Reason for the Violation The immediate cause of this event was attributed to the delays that were experienced during the performance of SI-307.1, "Degraded Voltage Relay Response Time Test and Timer Calibration." Electrical Maintenance personnel responsible for performing the subject SI had originally estimated that the test would take approximately 30 minutes to perform.
However, when deficiencies were identified during the performance of the SI, the time
required to complete the test extended beyond the original 30-minute estimate. As a result, the 1-hour time requirement assnciated with action statement (a) of limiting condition for operation (LCO) 3.8.1.1 was exceeded.
The root cause of this event was the failure of Operations personnel to adequately consider the action requirements associated with LCO 3.8.1.1.
The shif t operations supervisor (SOS) stated that he was aware of the requirement to verify the operability of the three remaining diesel generators (D/Gs) when the initial entry into LCO 3.8.1.1 was made; however, an action plan was not developed to comply with this requirement because it was thought the subject SI could be completed'in less than one hour.
When the time to complete the SI approached the LCO time limit Operations personnel failed to take the appropriate actions to verify the operability of the remaining three D/Gs.
A contributing cause to this event was the failure to utilize all available personnel resources during the decisionmaking process. The SOS did not involve the shift technical advisor (STA) when the acceptability / consequences of removing D/G 1A-A from service were being discussed.
In addition, an Operations group manager representative was on shift during the event; 4
however, he was also not included in the decisionmaking process.
Corrective Steps That Have Been Taken and Results Achieved TVA has issued a training letter to all SQN licensed personnel describing this event. The letter emphasizes the importance of technical specification (TS) compliance at all times, particularly during plant evolutions such as SI performances when the potential for TS noncompliance is heightened.
The letter also stresses the importance of Operations shift crews utilizing s11 available resources such as other operators, the STA, management personnel, and other members of the plant staff in the decisionmaking process.
Additionally, TVA has submitted a request to change TS 3.8.1.1 to reduce the number of potentially harmful D/G starts, thereby improving the overall reliability of the SQN D/Gs. The proposed TS change is consistent with NRC l
Generic Letter 84-15 "Proposed Staf f Actions to Improve and Maintain Diesel Generator Reliability."
Corrective Steps That Will Be Taken to Avoid Further Violations There is no further corrective action planned.
Date When Full Compliance Will Be Achieved TVA is in full compliance.
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Violation 50-327, 328/88-34-04 "C.
Technical Specification 6.8.1.e states that written procedures shall be established, implemented and maintained covering site Radiological Emergency Plan (REP) implementation.
The Sequoyah Radiological Emergency Plan IP-1, Emergency Pian Classification Logic which implements these requirements, requires that the operators enter a Notification of Unusual Event if the primary system leak rate is greater than that allowed in the Technical Specifications.
Sequoyah Radiological Procedure, IP-2, Notification of Unusual Event, requires that the notification of the Operations Duty Specialist be made within 5 minutes after the daclaration of the event.
In addition, REP Implementing Procedure IP-1, also states, if there is any reason to doubt whether a given condition has actually occurred, the shif t engineer or Site Emergency Director will proceed with the required notification without waiting for formal confirmation.
Contrary to the above, on April 6, 1988 at 7:55 a.m. the licensee entered LCO 3.4.5.2 acknowledging that the RCS leakrate was greater than the TS allowable limits and did not enter a NOUE until 8:20 a.m. when licensee and NRC management reviewed the event. This is a violation of the above requirements.
This is a Severity Level IV violation (Supplement VIII)."
Admission or Denial of the Alleged Violation TVA admits the violation.
It should be noted that a leak was identified at 7:55 a.m.; however, LCO 3.4.6.2 was entered and notification of unusual event (N0'JE) was declared at 8:20 a.m.
Reason for the Violation The root cause of this violation was that the method used to calculate unidentified RCS icakage was cumbersome and caused unnecessary entries into LCO 3.4.6.2 previously.
Because of past experiences, the SOS had reason to doubt the results obtained from performance of SI-137.2, "Reactor Coolant System Water Inventory."
Corrective Steps That Have Been Taken and Results Achieved SI-137.5, "Primary-To-Secondary Leakage Via Steam Generators," has been written to cover leak rate determination and is run approximately 8 to ;2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> before performance of SI-137.2 so that Operations will have the required data availabic to complete the SI-137.2 package in a timely manner.
Additionally, SI-137.2 has been revised to rearrange the sequence of steps to calculate the additional identified leakage before calculating the total RCS leakage. The total identified leakage is then subtracted from the total RCS Icakage to yield the total unidentified leakage.
-5 By cover letter, NRC indicated that a concern exists that TVA's operating staff is responding to alarms and conditions in a manner that is less conservative than is required and expected.
In this violation, as detailed in the reason for the violation, TVA had procedural complexities.
Additionally.
TVA nomenclature referred to unclassified leakage.
Some of the unclassified leakage was actually identified leakage and should have been subtracted from the unclassified leakage.
TVA has previously subtracted this known leakage out of the unidentified leakage at the end of the calculation to yield the true unidentified leakage. TVA management viewed this approach as unacceptable and concurred with NRC that the value obtained in the SI-137.2 unclassified leakage exceeded TS allowance, and the LCO and the NOUE were I
simultaneously entered. As described above, procedural revisions have been implemented to ensure reliable leakage rate data is available to make determinations in a timely manner.
The SOSs are aware of this violation and violation 50-327, 328/88-33-01; and they understand that prompt implementation of the Radiological Emergency Plan is essential.
TVA considers actions taken are effective.
Corrective Steps That Will Be Taken to Avoid Further Violations Corrective actions taken in response to this violation and corrective actions committed to in violation response 50-327, 328/88-33-01 are sufficient to resolve NRC's concern. There is no further corrective action planned-Date When Full Compliance Will Be Achieved TVA is in full compliance.
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List of Commitments 1.
NE shall investigate the removal of the UHI system as committed to in LER SQRO-50-328/88031.
2.
Non-TS sis will be reviewed and revised as committed to in LER SQRO-50-328/88031.
3.
Implementing Procedure 1 will be revised as-committed to in TVA response to violation 50-327, 328/88-33-01.
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