ML13309A142
| ML13309A142 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 12/05/1991 |
| From: | Rosenblum R SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TASK-3.D.3.4, TASK-TM NUDOCS 9112090228 | |
| Download: ML13309A142 (2) | |
Text
Southern Calfornia Edison Company 23 PARKER STREET IRVINE, CALIFORNIA 92718 R. M. ROSENBLUM TELEPHONE MANAGER OF (714) 454-4505 NUCLEAR REGULATORY AFFAIRS December 5, 1991 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555 Gentlemen:
Subject:
Docket No. 50-206 TMI Item III.D.3.4 Control Room Habitability San Onofre Nuclear Generating Station, Unit 1 As part of our response to TMI Item III.D.3.4, "Control Room Habitability," we had committed to provide additional information regarding six open items by November 22, 1991.
The purpose of this letter is to reschedule the submittal of these items. We have discussed this delay with our NRC Project Manager, George Kalman, and informed him that we would provide this revised schedule letter.
ITEMS TO BE SUBMITTED BY JANUARY 31, 1992
- 1.
We will provide the results of the revised control room operator thyroid and whole body dose assessment for the case when the emergency filter unit, A-33, is operating and remains in operation during the LOCA and 30 day recovery period. We had submitted the dose assessment for this case on April 10, 1991.
Subsequently, we received new guidance from the NRC for modeling atmospheric dispersion of radioisotopes. We have incorporated the NRC guidance and have revised several assumptions.
For example, the assumptions for operator breathing rate, control room inleakage, and equipment available to respond during an accident, have been revised. A revision to the design basis thyroid and whole body dose assessments will be provided to the NRC.
- 2.
During the April 10, 1991 meeting with the NRC staff, SCE committed to provide an evaluation of the procedures used to notify the control room operators to activate the Control Room Emergency Air Treatment System during a fuel handling accident or a waste gas accident. We will complete our evaluation of the operating procedures and provide the results to the NRC.
- 3.
During the April 10, 1991 meeting with the NRC staff, SCE committed to provide an evaluation of the ammonia concentration in the control room, following an ammonia spill at the Units 2 and 3 ammonia tank, if manual isolation of the control room HVAC system occurs within two minutes from the time the ammonia is sensed by the control room operators. We will complete our evaluation and provide the results to the NRC.
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-2 ITEMS TO BE SUBMITTED BY AUGUST 30, 1992
- 1.
During the April 10, 1991 meeting with the NRC staff, SCE committed to provide an evaluation of the thyroid dose and the whole body dose for the case when the emergency filter unit, A-33, does not operate during the LOCA and 30 day recovery period. Since our proposed design was not single failure proof, the NRC was interested in the consequences of the failure of this component. The results from this assessment will not be used as our design basis.
Our analysis will model the time operators spend in the control room by incorporating the control room operator shift rotation schedule in the SONGS-1 Emergency Operating Instructions. To complete our analysis, we will be incorporating additional upgrades to the proposed design and also revising the assumptions for which equipment would operate during a LOCA. We require additional time to develop and incorporate these changes into our analysis. Our evaluation will be completed and the whole body and thyroid dose assessments provided to the NRC.
- 2.
During the April 19, 1991 telephone conversation with the NRC, SCE committed to provide an evaluation of the requirements for control room operator use of respirators during an accident. Once the thyroid dose assessment which assumes failure of the A-33 unit is completed, we can determine the respirator requirements. Our evaluation will be completed and the respirator requirements provided to the NRC.
- 3.
In our April 10, 1991 submittal we indicated we would provide an evaluation of the impact of offsite toxic gas hazards on control room habitability. Unlike our previous analysis, we will determine the aggregate risk to the plant, consistent with the guidelines of Standard Review Plan 2.2.3. This approach requires us to reassess some chemicals that were previously excluded based on there extremely low individual risk the control room. We will complete our evaluation and submit the results to the NRC.
If you have any questions regarding this information, please let me know.
Very truly yours, cc:
J. B. Martin, Regional Administrator, NRC Region V George Kalman, NRC Senior Project Manager, San Onofre Units 1, 2&3 J. 0. Bradfute, NRC Project Manager, San Onofre Unit 1 C. W. Caldwell, NRC Senior Resident Inspector, San Onofre Units 1, 2&3