ML13330A857
| ML13330A857 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 09/19/1979 |
| From: | Head J SOUTHERN CALIFORNIA EDISON CO. |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| IEB-79-18, NUDOCS 8002140229 | |
| Download: ML13330A857 (5) | |
Text
Southern California Edison Company l""
P. 0. BOX 800 2244 WALNUT GROVE AVENUE J.T. HEAD, JR.
ROSEMEAD, CALIFORNIA 91770 TELEPHONE viCe PRESIDENT 213-572-1472 September 19, 1979 U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region V Suite 202, Walnut Creek Plaza 1990 North California Boulevard Walnut Creek, California 94596 Attention:
Mr. R. H. Engelken, Director Docket No. 50-206 San Onofre Unit 1
Dear Sir:
IE Bulletin 79-18 Audibility Problems Encountered on Evacuation of Personnel From Hih Noise Areas Reference is made to your correspondence of August 7, 1979, forwarding the subject IE Bulletin.
Identified therein were potential deficiencies in the evacuation alarm systems.
This letter documents the results of our in vestigation into this matter.
Response to individual items specified in the Bulletin are listed below:
Item 1 Determine whether current alarm systems and evacuation announcement systems are clearly audible or visible throughout all plant areas with erphasis on high-noise areas.
Determination in high noise areas must be made with the maximun anticipated noise level.
Response
The San Onofre Nuclear Generating Station Unit 1 Emergency Plan and asso ciated inplementing procedures divide evacuations-of the station into three categories: Local Area, Plant, and General Evacuations. Notification to evacuate in the event of an emergency limited to a local area is accom plished by automatic or manual initiation of the Area Radiation Monitoring System (ARMS) alarrs and/or by use of the Station PAX Telephone/Public Address System (hereinafter referred to as the Plant Public Address System).
/
00 021.40 00'
U. S. Nuclear Regulatory Cormission Page 2 Should evacuation of non-essential personnel within the Plant Protected Area become necessary, notification of a plant evacuation is made over the Plant Public Address System.
A general evacuation, which includes evacuation of non-essential personnel from all plant areas, is initiated by automatic or manual control of the siren and horns which comprise the Inmediate Evacuation Signal.
In accordance with IE Bulletin 79-18, acoustic surveys were conducted at San Onofre Unit 1 to determine the audibility of the ARMS alarms, Public Address System, and Immediate Evacuation Signal in the affected plant areas.
The survey was performed using calibrated sound level meters in the dBA band.
Each point of the survey included a background noise level reading and additional readings with the appropriate warning system(s) functioning. During the surveys, equipment was operated in such a manner as to produce the maximum anticipated noise level in the selected areas.
The results of the surveys are detailed below.
Systems were considered audible if they were a minimum of 2 dB above background noise.
The Plant Public Address System was considered functional if the 2dB criteria was met and if a test announcement could be clearly heard and understood above the background noise.
A.
The coverage of the Immediate Evacuation Signal was tested and the following plant areas identified as having minimal or inadequate coverage:
- 1.
The area extending from the sea wall to the diesel generator building between the Unit 1 containment and the north bluff.
- 2.
The circulating water pump pit area.
- 3.
The west side of the containment/auxiliary building.
- 4.
The area adjacent to the south side of the containment.
- 5.
The interior of the control building.
B.
Testing of the coverage of the Area Radiation Mbnitoring System (ARMS) identified the following areas where the alarm are either inaudible or are not sufficiently different from background audible levels to be clearly understood:
- 1. Behind the control panel in the control room.
- 2.
The radio chemistry sampling and counting room.
- 3.
The reactor auxiliary building, including the charging pup room.
- 4.
The new fuel storage rocm.
U. S. Nuclear Regulatory Commission Page 3 C.
The coverage of the Public Address System was tested and the following plant areas identified as having minimal or inadequate coverage:
- 1.
The control room behind the control panel.
- 2.
The radio chemistry counting room.
- 3. The solid waste baling roam.
- 4. The auxiliary building near the hold up tank pumps.
- 5. The charging pump room.
- 6. The resin slurry tank room.
- 7. The radioactive laundry storage roam.
- 8. The control building HVAC room.
- 9. The isotopic analysis conputer roon.
- 10.
The controlled area near the refueling water pumps.
- 11. The penetration structure (dog house).
- 12.
Inside the sphere enclosure building.
- 13. The controlled areas directly north of the containment.
- 14. The feedwater mezzanine.
- 15. Under the main steam reheaters.
- 16.
The circulating water pump pit.
- 17.
The area extending from the sea wall to the diesel generator building between the Unit I containment and the north bluff.
- 18.
The diesel generator building with the diesel operating.
- 19.
The controlled area pipe trench.
Item 2 Determine what corrective action is necessary to assure that areas identi fied as inaudible areas in (1) above, will receive adequate audible/visual evacuation signals.
In areas where adequate audible/visual evacuation signals
U. S. Nuclear Regulatory Conmission Page 4 cannot be assured by hardware changes, determine what additional adminis trative measures are necessary to assure personnel evacuation.
Response
A.
The Immediate Evacuation Signal will be expanded to provide coverage for the areas identified above.
The expansion will consist of an additional large warning siren plus several local alarm horns in in terior spaces.
Additions to the system will be activated along with the existing siren.
B. The ARMS alarms in each area indicated will be modified to insure complete and distinct coverage by addition of new alarm devices or modification of existing alarms.
C.
The Plant Public Address System will be upgraded to provide coverage in the areas listed by installation of additional equipment.
In ex tremely high noise areas (> 100 dBA) consideration will be given to providing visual in lieu of audible warning devices for evacuation notification.
Item 3 Submit within 45 days of the date of issuance of this Bulletin, a written report of the findings on item (1),
and delineate completed or proposed corrective actions per item (2).
For operating facilities in a refueling or extended outage, the written report must be submitted within 30 days after plant startup following the outage.
Response
This letter constitutes our response to this item.
Item 4 For accessible areas, all corrective actions determined per item (2) must be completed within 120 days of the date of issuance of this Bulletin.
For inaccessible areas, the written report must include a time schedule for completion of corrective actions in this area.
Response
Coverage of the Immediate Evacuation Signal, the ARMS, and the Plant Public Address System will be expanded to include the areas listed above by
U. S. Nuclear Regulatory Comission Page 5 December 7, 1979.
Since at this time comitments for material delivery are not available from suppliers and installation times are unknown, the December 7, 1979 date is subject to confirmation.
In the event that delays in material delivery or installation result in a completion date after December 7, 1979 for same of the items listed, we will inform you by letter of the revised schedule.
Sincerely, cc:
Director, Office of Inspection and Enforcement Division of Reactor Operations Inspection