ML20236H879
| ML20236H879 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 07/02/1998 |
| From: | Rainsberry J SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9807070401 | |
| Download: ML20236H879 (3) | |
Text
- _ _ - - -. _ _ _ _ - _ _ - - - - - _ _ _ _ _ _ =. -. - _ _ _ _ - - _. _ _ - _ _ _ _ _ _. - - - - _. - _ _ _ _ _ _ = _ -
JW EDISON W"n%ne h
50tJ1Hi RN C.At11 ORNI A An LDISO4 INTIRNAll0N41.* Company a
i July 2, 1998 U.S. Nuclear Regulatory Connission Attention: Document. Control Desk Washington, D.C.
20555-Gentlemen:.
Subject:
Docket Nos. 50-361 and 50-362
~
Radiation Monitor System Digital Upgrade San Onofre Nuclear Generating Station, Units 2 & 3
References:
- 1) Letter dated April 17, 1995, from J. L. Rainsberry (SCE) to Document Control Desk (NRC),
Subject:
Docket No. 50-361 and 50-362, Application of Leak-Before-Break Technology to Reactor Coolant System Piping.. San Onofre Nuclear Generating Station, Units 2 and 3.
- 2) Letter dated January 2,1997, from J. L.' Rainsberry (SCE) to Document Control Desk (NRC),
Subject:
Docket Nos. 50-361 and 50-362, Radiation Monitoring System Digital Upgrade, San Onofre Nuclear Generating Station, Units 2 and 3.
- 3) Letter dated July 14,.1997, from J. L. Rainsberry (SCE) to Document Control Desk '(NRC),
Subject:
Docket Nos. 50-361 and 50-362 Radiation Monitoring System Digital Upgrade, San Onofre Nuclear Generating Station, Units 2 and 3.
- 4) Letter dated October 17, 1997, from D. E. Nunn (SCE) to p
i
-Document Control Desk (NRC),
Subject:
Docket Nos. 50-361 and 50-362,ProposedChangeNumberNPF-10/15-459, Radiation i
Monitoring System Digital Upgrade, San Onofre Nuclear j
Generating Station Units 2 and 3.
T$)
l This letter provides an update to the schedule for the completion of the digital upgrade to the Radiation Monitoring System (RMS).
j By letter dated April 17, 1995 (Reference 1), Southern California Edison (SCE) submitted a request to eliminate the dynamic effects associated with high energy pipe ruptures in the Reactor Coolant System (RCS) piping from the San Onofre Nuclear Generating Station P. O. Box 128 San Clemente, CA 92674-0128 1 990702.1 PDR ADOCK 05000361' P
PDR 1 2
Document Control Desk.
licensing and design bases of San Onofre Units 2 and 3 by application of
" leak-before-break" technology. The request to apply leak-before-break technology was approved on the basis that the current leakage detection systems and radiation monitoring systems are consistent with Regulatory Guide 1.45.
In addition, as part of this request, SCE indicated its intent to implement a digital upgrade of the " gas channel monitors" to further improve the San Onofre radiation monitoring system design.
As a point of clarification, the only gas channel monitors which impact leak-before-break considerations are the Containment Purge Isolation Signal (CPIS) Monitors. Therefore, this letter clarifies that the above mentioned commitment only applies to the CPIS monitors and provides information related to the schedule for the upgrade of the CPIS monitors.
The schedule indicated in Reference 1 for completion of the digital upgrade was December 31, 1996.
This date was extended to July 1,1998 by letter dated January 2,1997 (Reference 2) to reflect the updated project schedule and to allow for a Technical Specification (TS) change, Proposed Change Number (PCN) 459, to be submitted and approved by the NRC.
In Reference 3, which updated the schedule for PCN 459, SCE informed the NRC that final installation of digital radiation monitors upgrade would be scheduled as soon as practical following receipt of NRC approval (Reference 3). PCN 459 was submitted by letter dated October 17, 1997 (Reference 4) and is currently undergoing NRC review.
PCN 459 allows for installation of both trains of digital radiation monitors for the CPIS and CRIS functions.
Completion of the digital upgrades for both trains of the CPIS radiation monitors is dependent upon NRC approval of PCN 459.
If approval of PCN 459 has not been received by the time work is scheduled to begin on the second train of CPIS monitors, provisions have been made to retain one train of the CPIS monitors in the current analog configuration.
In this case, completion of upgrades to both trains of the CPIS monitors will be delayed ur.til the earliest time following approval of PCN 459 that plant status and construction work schedules will allow.
Assuming NRC approval of PCN 459 is received by the end of 1998, based on the current schedule, the digital upgrade of the Unit 3 CPIS gas channel monitors would be ready in the second quarter of 1999. The current schedule for completing the digital upgrades to the Unit 2 CPIS gas channel monitors is at the end of calendar year 1999.
/...e.
=
Document Control Desk.
If you have any questions on this subject, please call me.
Sincerely, Enclosure-cc:
E. W. Merschoff, Regional Administrator, NRC Region IV K.- E. Perkins, Jr., Director, Walnut Creek Field Office,.NRC Region IV J. A. Sloan, NRC Senior Resident Inspector, San Onofre Units 2 & 3 J. W. Clifford, NRC Project Manager, San Onofre Units 2 and 3 i
I i
n I
\\
J