ML091280130
| ML091280130 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 04/28/2009 |
| From: | Harrison W South Texas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NOC-AE-09002424, STI: 32463350 | |
| Download: ML091280130 (6) | |
Text
V Nuclear Operating Company South Texas Prolect Electric Generating Station P.. Box 289 Wadsworth. Texas 77483 April 28, 2009 NOC-AE-09002424 10CFR50.59 U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852 South Texas Project Units 1 & 2 Docket Nos. STN 50-498, STN 50-499 10CFR50.59 Summary Report Pursuant to the requirements of I OCFR50.59, the attached report contains a brief description and summary of the 10CFR50.59 evaluations of changes, tests and experiments conducted at the South Texas Project.
There are no commitments in this letter.
If there are any questions regarding this summary report, please contact J. R. Morris at (361) 972-8652 or me at (361) 972-7298.
ager, Licensing jrm
Attachment:
1 OCFR50.59 Evaluation Summaries, April 2007 - April 2009 STI: 32463350
I,,
NOC-AE-09002424 Page 2 of 2 cc:
(paper copy)
(electronic copy)
Regional Administrator, Region IV U. S. Nuclear Regulatory Commission 612 East Lamar Blvd, Suite 400 Arlington, Texas 76011-4125 Mohan C. Thadani Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North (MS 7 D I) 11555 Rockville Pike Rockville, MD 20852 Senior Resident Inspector U. S. Nuclear Regulatory Commission P. O. Box 289, Mail Code: MN116 Wadsworth, TX 77483 C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704 A. H. Gutterman, Esquire Morgan, Lewis & Bockius LLP Mohan C. Thadani U. S. Nuclear Regulatory Commission Kevin Howell Catherine Callaway Jim von Suskil NRG South Texas LP Ed Alarcon J. J. Nesrsta R. K. Temple Kevin Pollo City Public Service Jon C. Wood Cox Smith Matthews C. Mele City of Austin Richard A. Ratliff Texas Department of State Health Services Alice Rogers Texas Department of State Health Services
kI, NOC-AE-09002424 Attachment Page 1 of 4 10CFR50.59 Evaluation Summaries April 2007 - April 2009 Summaries of the following 10CFR50.59 Evaluations are provided in this attachment:
No.
Condition Report Subject Number
- 1.
01-11345-28 Replacement of Fuel Handling Building Exhaust Filtration Unit Outlet Isolation Damper Controllers
- 2.
03-15405-12 Reactor Coolant System Zinc Addition
- 3.
09-809-5 Replacement of Wide Range Reactor Coolant System Pressure Transmitter PT-406
NOC-AE-09002424 Attachment Page 2 of 4 10CFR50.59 Evaluation Summaries Replacement of Fuel Handling Building Exhaust Filtration Unit Outlet Isolation Damper Controllers
==
Description:==
Summary:
The proposed change involves the replacement of the Fuel Handling Building (FHB) HVAC Exhaust Filtration Units Outlet Isolation Dampers (HV-9507 and HV-9507A) single loop analog controllers with new, single loop digital controllers.
It should also be noted that STP's Exemption from the Special Treatment Requirements of 10 CFR 21, 50 and 100 (reference letter from NRC to William T. Cottle, STPNOC, dated August 3, 2001, "Safety Evaluation on Exemption Requests from Special Treatment Requirements of 10 CFR Parts 21, 50, and 100 (TAC Nos. MA6057 and MA6058)" was applied for this application. STP has determined these controllers to be low risk, safety related components and therefore subject to the special treatment exemption.
EPRI performed a Generic Qualification of the Bailey-Fischer &
Porter (B-F&P) 53SL6000 series Single Loop Controller for Nuclear Safety Applications. The EPRI qualification is based primarily on TR-106439, "Guideline on Evaluation and Acceptance of Commercial Grade Digital Equipment for Nuclear Safety Applications". The EPRI qualification effort also followed the supplemental guidance provided in EPRI TR-107339, "Evaluating Commercial Digital Equipment for High Integrity Applications".
This qualification effort includes seismic testing, thermal aging, design adequacy review, critical digital review, operating history review, and electromagnetic compatibility (EMC) testing. The general EPRI conclusion is that the 53SL6000 series controller is acceptable as a replacement controller for applications of lower safety significance. The following are specific critical attributes that were evaluated either by EPRI (generic) or STP (application specific) and found to be acceptable: human factors, software, cyber security, electromagnetic compatibility, seismic qualification, environmental qualification, design/operational margin, and the failure modes and effects analysis.
The proposed new equipment is inherently more reliable, designed and built to applicable standards and quality processes, qualified to applicable standards and regulatory guidance, and is not changed with respect to redundancy, diversity, separation, or independence. The proposed modification does not have an impact on the safety analysis.
The new digital controller will perform the same functions as the
NOC-AE-09002424 Attachment Page 3 of 4 existing analog controller. All existing design and qualification requirements are met with the new controller. Assumptions and results in the accident analysis are therefore unaffected by the proposed change.
The proposed change can be performed with no adverse affects on any UFSAR described functions and can therefore be implemented without prior NRC approval.
- 2.
Reactor Coolant System Zinc Addition
==
Description:==
Summary:
The Reactor Coolant System (RCS) chemistry control programs for Unit 1 and 2 has been modified to allow addition of a soluble zinc compound, zinc acetate dehydrate, to the reactor coolant during normal plant operation. The beneficial effects of zinc addition include reduction in shutdown radiation fields, reduction in the general corrosion rate of RCS component materials, reduction in both the initiation and propagation of Primary Water Stress Corrosion Cracking (PWSCC) of Alloy 600 and other austenitic stainless steel alloys, and reduction in the long-term potential for Crud Induced Power Shift (CIPS). The incorporation of zinc into the reactor coolant system chemistry represents a change to the design of the plant.
Evaluation under 10 CFR 50.59 concluded that modification of the RCS chemistry control programs to allow zinc addition to the reactor coolant in Units 1 and 2 has no effect on accidents or malfunctions previously evaluated in the UFSAR, no impact on fission product barriers described in the UFSAR, and no impact on evaluation methodologies described in the UFSAR.
- 3.
Replacement of Wide Range Reactor Coolant System Pressure Transmitter PT-406
==
Description:==
Replace Wide Range Reactor Coolant System (RCS) Pressure Transmitter (PT) 406 (presently a Barton 753) with the same manufacturer and model transmitter as is used in PT-407 (Rosemount model 1153).
This change reduces the equipment diversityof the open prevent interlock (OPI) on the Residual Heat Removal (RHR) suction isolation valves which isolate the low pressure RHR system from the high pressure RCS system. As such, this activity involves a change to a System, Structure, or Component (SSC) that adversely affects a UFSAR described design function and thus a 50.59 evaluation is required.
NOC-AE-09002424 Attachment Page 4 of 4 Summary:
Evaluation under 10 CFR 50.59 concluded that through a combination of design and procedural controls, the functional diversity of the RHR suction isolation valve interlock is assured to preclude RCS high pressure from affecting the RHR system, and that prior NRC approval was not required.