ML20012C372
| ML20012C372 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 03/07/1990 |
| From: | Chrzanowski R, Schuster T COMMONWEALTH EDISON CO. |
| To: | Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| NUDOCS 9003210137 | |
| Download: ML20012C372 (3) | |
Text
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I March 7, 1990
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Mr. A. Bert Davis i
Regionni Administrator U.S. Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137 1
Subject - Zion Station Unit 2 License Number DPR-48 Temporary Walver of Compliance Extension Request Diesel Generator Operability Requirements NR0_Doche LHoJ0-304
Reference:
a) March 2, 1990 letter from R.A. Chrzanowski to A.B. Davis requesting a Temporary Waiver of Compliance to Diesel Generator Operability Requirements.
Dear Mr. Davis:
The purpose of this letter is to document the Temporary Waiver of Compilance Extension Request made on March 6, 1990 for Zion Station Unit 2 for the "0" Diesel Generator operability requirements.
Extension was~ verbally granted at 11:45 AM on March 6, 1990 by Mr. Tom Martin (NRC) to Mr. Tom Joyce (CECO, Station Manager, Zion Station).
Reason for the Requeal:
Zion Station is requesting an extension of time to the originni 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br /> as requested in reference (a) and granted by the Temporary Waiver of Compliance on March 2, 1990, as documented in the NRC letter of March 6, 1990.
This request is for an additional 144 hours0.00167 days <br />0.04 hours <br />2.380952e-4 weeks <br />5.4792e-5 months <br /> to allow Unit 2 to remain in llot Shutdown before placing the unit in Cold Shutdown to comply with Item B.6 of Appendix A of the Confirmatory Order for Zion Station dated February 29, 1980.
At'1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> on March 6, 1990, Zion started the cooldown of Unit 1 to Cold Shutdown in accordance with the requirements of the Confirmatory Order and the-Temporary Waiver of Compliance.
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Mr. A. Bert Davis March 7, 1990 Zion Station will utilize this extension of time to continue troubleshooting and repair of the "0" Diesel Generator.
However, the decision has been made to enter the refueling outage for Unit 2.
Therefore,'the primary purpose for this extension of time is to allow for testing to be performed on various Unit 2 safety related systems, which are required to be conducted with the plant at normal operating temperature and pressure.
Briefly these tests are as follows:
1.
Special Leak Rate Testing 2.
Safety Injection and Residual Heat Removal Check Valve Testing 3.
Visual Leak Examination of Class 1 Components 4.
Endurance Testing of Diesel Generators During Refueling 5.
Manual Actuation of Safety Injection and Safe Shutdown Systems 6.
Special Leak Rate Test RC Sample Piping 7.
Safeguard Actuation and Spurious Valve Actuation Group Valve Testing CiICumRLanC.RS 1eEdingJP_1D_the_gxtension requeet _since thg_gEBRiiDg of the Temporary Waiver of Compliance at_1200 on March 2. 1990:
Troubleshooting of the "0" Diesel Generator was being performed on a continuing around-the-clock basis. On March 3, 1990, at 1330 hours0.0154 days <br />0.369 hours <br />0.0022 weeks <br />5.06065e-4 months <br />, the reason for the failure of "0" Diesel Generator to start was determined to be delayed o11' pressure response at the diesel lube oil shutdown valve. This was due to air trapped in the main turbocharger lube all filters,_which then acted as accumulators delaying the oil pressure increase. The air was vented from the filters. Seven successful local starts were then conducted on the "0" Diesel Generator. At 2025 hours0.0234 days <br />0.563 hours <br />0.00335 weeks <br />7.705125e-4 months <br /> on March 5,1990, while performing PT-11 to return the "0" Diesel Generator to service, the diesel tripped on a high bearing temperature condition.
Inspection revealed 1 out of 2 thermal sensors on the number 7 Main bearing to be tripped.
(Setpoint 2280F).
Inspection of this bearing showed minor babbit wear-through, which may have caused a localized hot spot, thus causing the thermal sensor to trip. As a precautionary and conservative measure all 10 Main Bearing will be replaced.
l In conclusion, upon completion of the additional 144 hours0.00167 days <br />0.04 hours <br />2.380952e-4 weeks <br />5.4792e-5 months <br />, Unit 2 will commence cooldown by 1200 hours0.0139 days <br />0.333 hours <br />0.00198 weeks <br />4.566e-4 months <br /> on March 12, 1990.
Unit 2 will then be placed in Cold Shutdown by 0600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br /> on March 13, 1990, and enter the refueling outage.
The original request of reference (a) contained the basis for the Temporary Waiver of Compliance with the conclusion that the no significant hazards consideration criteria was met.
The basis and findings of that request.are also valid for this extension request.
+.
-Mr. ' A. Bert Davis March 7, 1990 This request for an extension of time and the course of action for the "0" Diesel Generator ineperability has been approved by Zion On-Site Review (OSR/014/90).
If you have any further questions regarding this matter, please contact this office.
Very truly yours, MM T. K. Schuster Nuclear Licensing Administrator l'
fhW/]I R. A. Chtsanows i Nuclear Licansing Administrator
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cc: C. Patel Zion Senior Resident inspector
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