TXX-0614, Supplement to License Amendment Request (LAR) 05-010 and Response to Request for Information
| ML062440420 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 08/25/2006 |
| From: | Madden F TXU Power |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| CPSES-20061695, TAC MC9494, TAC MC9495, TXX-06144 | |
| Download: ML062440420 (5) | |
Text
t TXU Power TXU Power Mike Blevins Comanche Peak Steam Senior Vice President &
Ref: I OCFR50.90 Electric Station Chief Nuclear Officer P. O. Box 1002 (E01)
Glen Rose, TX 76043 Tel: 254 897 5209 Fax: 254 897 6652 mike.blevins@txu.com CPSES-200601695 Log # TXX-06144 August 25, 2006 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET NOS. 50-445 AND 50-446 SUPPLEMENT TO LICENSE AMENDMENT REQUEST (LAR)05-010 AND RESPONSE TO REQUEST FOR INFORMATION (TAC Nos. MC9494 and MC9495)
REF:
- 1.
Letter logged TXX-05199, dated December 16, 2005 from Mr. Mike Blevins of TXU Power to the NRC
- 2.
Letter logged TXX-06097, dated June 26, 2006 from Mr. Mike Blevins of TXU Power to the NRC
- 3.
Letter logged TXX-05162, dated September 1, 2005 from Mr. Mike Blevins of TXU Power to the NRC Gentlemen:
In Reference 1, TXU Generation Company LP (TXU Power) requested an amendment to the CPSES Unit 1 Operating License (NPF-87) and CPSES Unit 2 Operating License (NPF-89) to revise Technical Specifications 3.3.2, 3.5.2, and 3.6.7 entitled "ESFAS Instrumentation," "ECCS-Operating," and "Spray Additive System," respectively, in the CPSES Units I and 2 Technical Specifications (TS).
TXU Power supplemented the License Amendment Request via Reference 2. This proposed License Amendment was requested to support resolution of Generic Safety Issue (GSI) 191 pursuant to the requirements of NRC Generic Letter 2004-02 as described in Reference 3.
A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway
- Comanche Peak Diablo Canyon
- Palo Verde
- South Texas Project Wolf Creek
TXX-06144 Page 2 of 3 During an August 22, 2006, teleconference with the NRC, TXU Power discussed the requested modification to the Surveillance Requirements for Technical Specification 3.6.7. TXU Power informed the NRC that current CPSES plans were to retain sodium hydroxide (NaOH) for the containment spray system buffering agent (spray additive). TXU Power further explained that by subsequently reducing the required amount of NaOH, positive safety benefits could be realized by reducing chemical effects of the buffering agent and aid in the final resolution of GSI-191. During this teleconference, the NRC informed TXU Power that they would require retention of the existing Technical Specification 3.6.7 Surveillance Requirements.
TXU Power believes that retaining the existing Surveillance Requirements will result in extending the final resolution of GSI-191 since an additional license amendment will be required after completion of chemical effects analyses. Although TXU Power believes that the original proposed changes to Technical Specification 3.6.7 Surveillance Requirements (ensuring that sump pH remains above 7.1) provide a viable and acceptable solution, TXU Power agrees to modify the License Amendment Request of Reference I to continue NaOH as a buffering agent and retain the current Surveillance Requirements for Technical Specification 3.6.7 (and associated Technical Specification Bases). Although discussions regarding Technical Specification 3.6.7 are included in the Significance Hazard Consideration provided in Reference 1, the essential arguments regarding the remainder of the proposed changes to the Technical Specifications remain valid and the final conclusions reached are unchanged.
During the same teleconference, the NRC informed TXU Power of additional questions (RAIs) which were later forwarded to TXU Power via email. Responses to these questions are provided in the Attachment to this letter.
TXU Power originally requested approval of the proposed License Amendment by July 1, 2006 in order to support the schedule for the plant modifications to be implemented during the ninth refueling outage for Unit 2. Since these plant modifications are required to resolve GSI-191, delays in approving the LAR could result in our inability to complete the modifications as scheduled and may require CPSES to seek an NRC Generic Letter 2004-02 schedule extension. This outage is scheduled to start on October 7, 2006. Therefore, your prompt attention to this required proposed License Amendment is requested.
In accordance with I OCFR50.9 1(b), TXU Power is providing the State of Texas with a copy of this proposed supplement.
This communication contains no new licensing basis commitments regarding CPSES Units 1 and 2.
TXX-06144 Page 3 of 3 Should you have any questions, please contact Mr. J. D. Seawright at (254) 897-0140.
I state under penalty of perjury that the foregoing is true and correct.
Executed on August 25, 2006.
Sincerely, TXU Generation Company LP By:
TXU Generation Management Company LLC Its General Partner Mike BI vins By:
M L, -
/Fred*W. Madden
/
Director, Regulatory Affairs JDS Attachment c -
B. S. Mallett, Region IV M. C. Thadani, Region IV Resident Inspectors, CPSES Ms. Alice Rogers Bureau of Radiation Control Texas Department of Public Health 1100 West 49th Street Austin, Texas 78756-3189
Attachment to TXX-06144 Page 1 of 2 Response to NRC Request for Additional Information Regarding LAR 05-010 NRC ReQuest:
I.
Under section 4.1 RWST Setpoint, on page 4 of the submittal, in the second full paragraph, the following sentence appears: "The RWST Empty alarm is also being lowered from 12% to 9% to provide a conservative volume of water for ECCS transfer assuming no credit for containment backpressure and the worst single active failure."
Operator actions associated with the response to this alarm are also being revised, as indicated by the proposed revision to CPSES/FSAR Section 6.3.2.8 Step 8. When combined, these steps will increase the overall amount of water pumped into the containment from the RWST. No technical evaluation is provided in terms of potential environmental effects on equipment in lower levels of containment from increased water level or RWST outflow (CPSES/FSAR Table 6.3-11 does not contain data in the "RWST Outflow" and "Cumulative Change" columns for the steps affected by the change in RWST Empty setpoint and change in operator actions). This also appears to contradict the statement in Section
5.0 REGULATORY ANALYSIS
, under 5.1.1, in the third paragraph justifying a "No" response to question one, on page 13 of the submittal, which states: "Although the water level in the containment flood plain will be higher at the start of ECCS switchover, the maximum water levels observed for the duration of the accident are unchanged by the nominal setpoint changes." Please clarify the meaning of these statements.
CPSES Response:
The calculation of maximum containment water levels is based on the full contained volume of the RWST, maximum inventory from the Loss of Coolant Accident, and conservative modeling of the containment to maximize the flood level for the design and environmental qualification of equipment. This analysis is unchanged by the change in RWST setpoints. This analysis is based on the physical characteristics of the RWST and does not use setpoints. Since the calculation of maximum containment water level is unchanged, there is no contradiction in Section 5.1.1 of Reference 1 and no further technical evaluation is necessary.
The calculation of minimum containment water levels is based on minimum delivered volume of the RWST, minimum inventories from the spectrum of Loss of Coolant Accidents, and conservative modeling of the containment to minimize the flood level for the design and analysis of the ECCS and Containment Spray systems for NPSHa, etc. and for the design of the new sump strainers. This analysis is based on the physical characteristics of the RWST setpoints and minimum Tech Spec Volume. This calculation also assumes that RWST injection is stopped when the sump isolation valves are opened. This is due to closure of the tank suction check valves caused by the overpressure in containment.
Attachment to TXX-06144 Page 2 of 2 Response to NRC Request for Additional Information Regarding LAR 05-010 The FSAR Section on switchover from injection to recirculation and FSAR Table 6.3-11 are being revised in accordance with I OCFR50.59 under the modification which changes the RWST setpoints.
NRC Request:
- 2.
In section 4.1 RWST Setpoint, on page 3 of the submittal, the licensee states that: "The change in delivered water volume between the current RWST Low-Low nominal setpoint at 45% and the proposed 33% ensures an additional 60,900 gallons of water in the flood plane at the beginning of ECCS switchover." Please provide the revised flood-up calculation for both containment structures given the additional water present.
CPSES Response:
The RWST level instrument span is 513 inches. The contained volume per inch of height is 989 gallons. (45%-33%) X 513 inches X 989 gallons per inch is approximately 60,900 gallons. The revised containment flood level calculation is available for NRC audit or review NRC Request:
- 3.
The licensee states that the amount of TSP in the containment baskets will be verified during outages, but will not be monitored during power operation. Please discuss any precautions or design features in place that would prevent an overhead leak from occurring which could dissolve the TSP through the course of an operating cycle, resulting in falling below the minimum required amount?
CPSES Response:
Per the transmittal letter for this attachment, TSP has been removed as an option for consideration as a buffering agent for pH control. Therefore, the request for information is not applicable.