RS-17-146, Additional Information Regarding License Amendment Request to Revise Suppression Pool Swell Design Analysis
| ML17293A169 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 10/19/2017 |
| From: | Gullott D Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RS-17-146 | |
| Download: ML17293A169 (4) | |
Text
RS-17-146 10 CFR 50.90 October 19, 2017 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 LaSalle County Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-11 and NPF-18 NRC Docket Nos. 50-373 and 50-374
Subject:
Additional Information Regarding LaSalle County Station License Amendment Request to Revise Suppression Pool Swell Design Analysis
References:
- 1) Letter from P. R. Simpson (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "License Amendment Request to Revise Suppression Pool Swell Design Analysis," dated October 27, 2016 (ADAMS Accession No. ML16305A295)
- 2) Letter from D. M. Gullatt (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "Response to Request for Additional Information Regarding LaSalle County Station License Amendment Request to Revise Suppression Pool Swell Design Analysis," dated July 28, 2017 (ADAMS Accession No. ML17209A733)
By a letter dated October 27, 2016 (Reference 1), Exelon Generation Company, LLC (EGC) submitted an amendment request for LaSalle County Station (LSCS), Units 1 and 2. The proposed amendment would revise the suppression pool swell analysis for a design basis loss-of-coolant accident (LOCA). These changes are necessary because the current design analysis determining the suppression pool swell response to a LOCA was determined to be non-conservative. This request was supplemented by EGC letter dated July 28, 2017 (Reference 2).
As discussed with the NRC on October 16 and 17, 2017, supplemental information is being provided to support the NRC's review of the EGC request submitted on October 27, 2016, as supplemented on July 28, 2017. The Attachment to this letter provides the supplemental information.
EGC has reviewed the information supporting a finding of no significant hazards consideration that was previously provided to the NRC in Attachment 1 of Reference 1. The supplemental information provided in this submittal does not affect the bases for concluding that the proposed license amendment request does not involve a significant hazards consideration. In accordance with 10 CFR 50.91, "Notice for public comment; State consultation," paragraph (b), EGC is
October 19, 2017 U.S. Nuclear Regulatory Commission Page 2 notifying the State of Illinois of this application for license amendment by transmitting a copy of this letter and its Attachment to the designated State Official.
There are no regulatory commitments contained within this letter. Should you have any questions concerning this letter, please contact Ms. Lisa A. Simpson at (630) 657-2815.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 19th day of October 2017.
Respectfully, David M. Gullett Manager - Licensing Exelon Generation Company, LLC
Attachment:
Supplemental Information cc:
NRC Regional Administrator, Region Ill NRC Senior Resident Inspector, LaSalle County Station Illinois Emergency Management Agency-Division of Nuclear Safety
ATTACHMENT Supplemental Information By letter to the Nuclear Regulatory Commission (NRC) dated October 27, 2016 (Reference 1),
Exelon Generation Company, LLC (EGC) requested a license amendment to revise the suppression pool swell analysis for a design basis loss-of-coolant accident (LOCA) for LaSalle County Station (LSCS), Units 1 and 2. This request was supplemented by EGC letter dated July 28, 2017 (Reference 2).
References:
- 1) Letter from P. R. Simpson (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "License Amendment Request to Revise Suppression Pool Swell Design Analysis," dated October 27, 2016 (ADAMS Accession No. ML16305A295)
- 2) Letter from D. M. Gullatt (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "Response to Request for Additional Information Regarding LaSalle County Station License Amendment Request to Revise Suppression Pool Swell Design Analysis," dated July 28, 2017 (ADAMS Accession No. ML17209A733)
As discussed with the NRC on October 16 and 17, 2017, supplemental information is being provided to support the NRC's review of Reference 1 as supplemented by Reference 2. It has been recognized that a value (i.e., specifically, a 0.7 ft adder to the PICSM prediction) was inaccurately identified as GEH proprietary information. This supplement is provided for the purpose of correcting and clarifying the non-proprietary nature of that information.
Reference 1. Attachment 1. Section 4.3, Table 6. "Compliance with NRC Acceptance Criteria" Line item 2 of Table 6 of Reference 1, Attachment 1, "Pool-Swell Velocity," LaSalle Compliance was documented as follows (non-proprietary information):
The pool-swell velocity was determined by GEH Report 003N9278-RO-P (Reference 5) using their computer code PICSM multiplied by a factor of 1.1. To account for the increase in the initial LOCA pool elevation associated with vent clearing, 0.7 ft was added to the PICSM elevation prediction.
The PICSM models are described in NEDE-21544-P and were accepted by the NRC for use in predicting the Mark II suppression pool swell in NUREG-0487, NUREG-0487 Supplement 1, and NUREG-0808.
Reference 1. Attachment 2, Section 6.2.2, "Pool Swell Response Data" Section 6.2.2 of Reference, Attachment 2, included the following information (non-proprietary information):
The elevations also include a 0.7 ft adder to the PICSM prediction to account for the difference between initial pre-LOCA elevation and initial PICSM elevation which corresponds to the elevation after vent clearing.
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ATTACHMENT Supplemental Information Reference 2, Attachment I, SRXB - [Request for Additional Information] RAI 3 SRXB - RAI 3 from Reference 2, Attachment I states as follows:
Reference I, item 2 of Table 6 in Attachment I, Section 6.2.2, and Tables 6-1 through 6-4 in Attachment 2.
(a)
Explain how the 0.7 ft [foot] adder to the PICSM [General Electric-Hitachi pool swell response code] predicted pool swell height which accounts for the difference between initial pre-LOCA elevation and initial PICSM elevation which corresponds to the elevation after vent clearing was determined.
(b)
In Tables 6-1 through 6-4, explain if the 0.7 ft adder is included in the data for pool swell elevation above initial elevation.
EGC's Response to SRXB - RAI 3, parts (a) and (b), which was provided in Attachment 2 of Reference 2, "GEH Responses to SRXB RAls in Support of LaSalle Pool Swell Design Analysis LAR," inaccurately referenced the 0.7 ft adder value as GEH proprietary information.
Conclusion After review, EGC concludes, with GEH concurrence, that the 0.7 ft adder value is no longer proprietary information. Proprietary markings associated with this value may be removed, and this value may be released to the public.
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