U-602662, Provides Response to follow-up Questions Re Proposed Amend to Change TSs to Incorporate Revised SLMCPR Calculated by GE for Cycle 7,per 961108 Telcon Re Difference in Uncertainties Used in Analyzing Dual & Single Loop Operation
| ML20134M753 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 11/15/1996 |
| From: | Telthorst P ILLINOIS POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| L47-96(11-15)LP, U-602662, NUDOCS 9611260031 | |
| Download: ML20134M753 (2) | |
Text
1 Ilknots Power Company Chnton Power Station P,0. Box 678 Chnton. IL 61727 Tel 217 935-8881 L4 11 - 15)LP 8E.100a November 15, 1996 Docket No. 50-461 10CFP30.90 Document Control Desk Nuclear Regulatory Commission Washington, D.C. 20555
Subject:
Response to Follow-up Questions on Clinton Power Station Proposed Amendment of Facility Operatina License No. NPF-62 (NS-96-004)
Dear Madam or Sir:
By letter dated August 15,1996, [ Illinois Power (IP) letter U-602624], IP submitted an application for amendment ofFacility Operating License No. NPF-62, Appendix A - Technical Specifications, for Clinton Power Station. The proposed amendment, currently under review by the NRC staff, consists of a change to the Technical Specifications to incorporate a revised Safety Limit Minimum Critical Power Ratio (SLMCPR) calculated by General Electric (GE) for Cycle 7. On October 28,1996, IP submitted a second letter (IP letter U-602651) which provided the formal response to a number of specific questions resulting from the NRC review of the proposed amendment.
In continued support of the NRC review of the proposed amendment, IP was requested to respond to a follow-up NRC question. On November 8,1996, IP participated in a conference call with the NRC and GE to address a question from an NRC reviewer concerning the differences in uncertainties used for the SL'MCPR statistical analyses performed for dual and single recirculation loop operation. As follow-up to the conference call, IP and GE agreed to provide a formal response to the NRC documenting the resolution of this issue. The following provides the requested information.
As discussed in IP letter U-602624, the CPS SLMCPR for Cycle 7 was calculated to be 1.09 for dual loop operation and 1.10 for single loop operation. These values were determined by GE using the analysis basis documented in GESTAR II (NEDE-24011-P-A-13), with the exceptions noted in the proposed license amendment. The analysis for T @l 9 single loop operation was performed in a manner similar to that for dual loop operation j
except that the uncertainties assumed for total core flow and Traversing Incore Probe (TIP) readings were larger.
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U-602662 Page 2 Section 4.3.1.1.1'of GESTAR II states that the uncertainties used in the statistical analyses are presented in the GE Fuel Bundle Designs document (NEDE-31152P, Revision 5). Table 3-3 of this document lists the uncertainties for the total core flow and TIP readings for reload cores as follows:
Dual Loop Operation Single Loop Operation Standard Deviation Standard Deviation
(% of ooint)
(% ofooin:)
Total Core Flow 2.5 6.0 TIP Readings
- 8.7 9.1
- The values for TIP readings are root-mean-square combinatior.s of the total uncertainty due to power distribution and TIP location (8.6%), and TIP reproducibility error during either dual loop operation (1.2%) or single loop operation (2.85%).
As stated above, these uncertainties were used in the cycle-specific SLMCPR calculations performed by GE for CPS Cycle 7.
As noted in the August 15,1996 IP letter, the proposed amendment is required to support startup from the sixth (i.e., the current) refueling outage which began on October 13,1996. As such, IP again respectfully requests review and approval of the subject amendment in a timeframe that supports that requirement.
Sincerely yours,
/'
2 Paul J. Telthorst Director-Licensing TAB /csm cc:
NRC Clinton Licensing Project Manager NRC Resident Office, V-690 Regional Administrator, Region III, USNRC Illinois Department ofNuclear Safety l
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