ML20057D176
| ML20057D176 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 09/30/1993 |
| From: | Rosenblum R SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20057D177 | List: |
| References | |
| NUDOCS 9310010222 | |
| Download: ML20057D176 (3) | |
Text
.
l 1
Southern California Edison Company 23 PARKE R STREET 1RVIN E, C AL lr ORNIA 92718
"'"^"",,,"S'"*""
September 30, 1993
[fl[.Co l
i U.S. Nuclear Regulatory Commission l
Attention: Document Control Desk l
Washington, D.C. 20555 Gentlemen:
Subject:
Docket Nos. 50-361 and 50-362 Amendment Application Nos. 136 and 120 Change to Technical Specifications 3/4.3.2, " Engineered Safety Features Actuation Systems,"
San Onofre Nuclear Generating Station Units 2 and 3
References:
1)
April 24,1990, letter from F. R. Nandy (SCE) to Document Control Desk (NRC),
Subject:
Electrical Safety System Functional Inspection 2)
March 14, 1991, letter from R. M. Rosenblum (SCE) to Document Control Desk (NRC),
Subject:
Electrical Safety System Functional Inspection 3)
April 7,1992, letter from Harold B. Ray (SCE) to Document Control Desk (NRC),
Subject:
Amendment Applications 115 and 99, Change to Technical Specifications Tables 3.3-3, 3.3-4, 3.3-5, and 4.3-2, " Engineered Safety Features Actuation Systems." San Onofre Nuclear Generating Station, Units 2 and 3 4)
December 30, 1992, letter from Harold B. Ray (SCE) to Document Control Desk (NRC), Amendment Applications 129 and 113, Changes to Technical Specifications 3/4.3.2 and 3/4.3.3, San Onofre Nuclear Generating Station, Units 2 & 3.
5)
September 16, 1993, letter from Richard M. Rosenblum (SCE) to Document Control Desk (NRC),
Subject:
Amendment Applications 134 and 118, Automatic Removal of Low Pressurizer Pressure Trip Bypass, San Onofre Nuclear Generating Station, Units 2 and 3. provides Amendment Application Nos. 136 and 120 to Facility Operating Licenses NPF-10 and NPF-15, respectively, for the San Onofre Nuclear r~-
,e s
9310010222 930930 3i PDR ADOCK 05000361
(
p PDR v
1
Document Control Desk Generating Station, Units 2 and 3.
These Amendment Applications consist of Proposed Change Number (PCN) 429. PCN 429 is a request to revise the Technical Specifications (TSs) to reflect the planned enhancement to the degraded voltage protection scheme to protect against the recently recognized possibility of sustained degraded grid voltage conditions.
Following implementation of this change, the loss of voltage and degraded voltage protection scheme will transfer the Class 1E buses to the standby power source (emergency diesel generator), without first attempting to transfer to the alternate preferred power source when a Safety Injection Actuation Signal is detected concurrent with an undervoltage condition.
PCNs 401, 405, and 431, (References 3, 4, and 5) also requested changes to portions of TS 3/4.3.2.
Both the proposed changes from PCNs 401, 405, and 431 which affect the pages of this PCN-429 and the proposed changes of this PCN-429 are marked in Enclosure 2.
Southern California Edison (SCE) requests NRC approval of this amendment request in time to allow for installation and testing of the enhanced degraded voltage scheme, during the Unit 3 Cycle 7 refueling outage, scheduled to begin in October 1993. SCE plans to install the Unit 2 enhanced degraded voltage protection scheme during the first outage of sufficient duration to allow completion of installation and testing, but no later than the Unit 2 Cycle 8 refueling outage.
In References 1 ano 2, SCE identified actions we would be taking in response to the NRC Electrical Safety System Functional Inspection (SSFI) conducted in 1989 for San Onofre Units 2 and 3.
One of these actions related to performing new electrical design calculations. All of these calculations have been completed except for the motor starter control circuit voltages.
The remaining calculation (one for each unit) will be completed concurrent with installation of the planned enhancement to the undervoltage trip scheme on both units, so that the calculation will accurately reflect the minimum expected voltages to be seen by the onsite distribution system.
If you would like additional information regarding this Technical Specification change request, please let me know.
/
Sincerely,
//
2;N y ) %) # L
,i
/ /,
i l
Enclosures cc:
B. H. Faulkenberry, Regional Administrator, NRC Region V NRC Senior Resident Inspector's Office, San Onofre Units 1, 2 & 3 l
M. B. Fields, NRC Project Manager, San Onofre Units 2 and 3 H. Kocol, California Department of Health Services
i
)
l I
i ENCLOSURE 1 i
PCN 429 DEGRADED GRID VOLTAGE i
l h
.