ML20058G630
| ML20058G630 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 06/17/1982 |
| From: | Beckham J GEORGIA POWER CO. |
| To: | Robert Lewis NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| Shared Package | |
| ML20058G617 | List: |
| References | |
| NUDOCS 8208030379 | |
| Download: ML20058G630 (2) | |
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- s. T. Beckham. Jr.
June 17, 1982 United States Nuclear Regulatory Commission Office of Inspection and Enforcement
REFERENCE:
Region II - Suite 3100 RII: RFR 101 Marietta Street, N. W.
50-321/50-366 Atlanta, Georgia 30303 Inspection Report 82-09 ATTENTION:
MR. R. C. LEWIS Gentlemen:
Georgia Power Company (GPC) submits the following information in response to the Notice of Deviation in Appendix B of your letter dated May 18, 1982.
GPC has reviewed the alleged deviation and hereby responds as.
follows:
DEVIATION Paragraph 3.4.5.2 (sic) of the Final Safety Analysis Report states that the withdrawal speed control valve is set to otve a control rod a shim withdrawal speed of 3 inches per second.
This withdrawal speed corresponds to a nominal full core withdrawal time of 48 seconds.
Cantrary to the above, the unit was started up on June 4, 1981 following a refueling outage with eight control rod drive withdrawal times outside of the acceptance band of 40 to 60 seconds.
RESPONSE
The GPC actions of June 4,1981 as stated in the Notice of Deviation did not deviate from our safety commitments to the Commission.
Section 3.4.5.4.2 of the Hatch Unit 1 Final Safety Analysis Report (FSAR) does state that the withdrawal speed control valve is set for 3 inches /second of rod travel, however, this number is only intended to represent a nominal value as is stated in FSAR section 3.4.6.4.11.
Transient analyses have been performed both at low power (Rod Drop Accident) and at high power (Rod Withdrawal Error Accident).
The Rod Drop Accident analysis assumes that the highest worth control rod is 8208030379 820723 PDR ADOCK 05000321 G
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- a GeorgiaPower A U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement June 17, 1982 Page Two dropped from the core during startup at a
rod speed of 60 inches /second.
This is an order of magnitude above the value of 6 inches /second given in FSAR Section 3.4.6.4.11 as the approximate maximum velocity possible for any incorrect setting of the withdrawal speed control valve.
The Rod Withdrawal Error Accident analysis does not assume a speed, but instead uses a series of steady state calculations; thus, it is unaffected by the speed setting.
Therefore, since the control rod withdrawal speed setting does not affect any safety analysis mentioned in the FSAR, then deviation from this nominal value is not a safety concern.
The control rod drive vendor, General Electric Company, has stated that the present procedural acceptance band of 40 to 60 seconds for full length rod withdrawal is optimal.
This statement is based on operational considerations rather than a core safety analysis.
Though a fast withorawal rate for a control rod may require extra operator attention, there are sufficient reactor safeguards such that an errant speed setting is not a safety concern.
In the future, Georgia Power intends to adjust the withdrawal speed control valves to comply with the present procedural acceptance band to
-the extent that is practical.
Any control rod drives not meeting this criteria will be reviewed by the Plant Review Board and any operational considerations will be resolved.
Should you have any questions concerning this response, please contact this office.
Yours very truly, h
N_
. T. Beckham, Jr.
1 CBS/b1m xc:
H. C. Nix R. F. Rogers, III 1
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