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| {{#Wiki_filter:}} | | {{#Wiki_filter:Charles R. Pierce Southern Nuclear Regulatory Affairs Director Operating Company, Inc. |
| | 40 inverness Center Parkway Post Office Box 1295 Birmingham, AL 35242 Tel 205.992.7872 SOUTHERN * \ |
| | Fax 205.992.7601 NUCLEAR A SOUTHERN COMPANY MAY 0 9 2016 Docket Nos.: 50-321 NL-16-0655 50-366 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant Unit 1 and 2 Response to Request for Additional Information on Secondary Containment Drawdown Time Technical Specifications Amendment Request Ladies and Gentlemen: |
| | By letter dated October 15, 2015, and as supplemented by letter dated March 16, 2016, Southern Nuclear Operating Company (SNC) submitted a license amendment request for the Edwin I. Hatch Nuclear Plant (HNP), Units 1 and 2. |
| | The proposed amendment would revise Unit 1 and 2 HNP Technical Specifications Surveillance Requirement (SA) 3.6.4.1.3 to increase the allowable time for the Standby Gas Treatment System (SGTS) to draw down the secondary containment to the required negative pressure from 2 minutes to 10 minutes. |
| | By letters dated February 18, 2016 and April 15, 2016, the Nuclear Regulatory Commission (NRC) issued requests for additional information (RAJ). The enclosure to this letter provides SNC's response to the April 15, 2016 RAI. |
| | Please note that the remaining SNC response to the NRC RAJ dated February 18, 2016 will be provided to NRC no later than May 18, 2016. |
| | This letter contains no NRC commitments. If you have any questions, please contact Ken McElroy at (205) 992-7369. |
| | |
| | U.S. Nuclear Regulatory Commission NL-16-0655 Page2 Mr. C. R. Pierce states he is Regulatory Affairs Director of Southern Nuclear Operating Company, is authorized to execute this oath on behalf of Southern Nuclear Operating Company and, to the best of his knowledge and belief, the facts set forth in this letter are true. |
| | Respectfully submitted, |
| | ~ f{. fJp_ |
| | C. R. Pierce Regulatory Affairs Director CRP/OCV/ |
| | q 1?- day ot--'M....:......I.-~---\oo---' |
| | 6 2016. |
| | My commission expires: /0 |
| | * 8*do t1 |
| | |
| | ==Enclosure:== |
| | Response to Request for Additional Information cc: Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, President & CEO Mr. D. G. Bast, Executive Vice President & Chief Nuclear Officer Mr. D. R. Vineyard, Vice President- Hatch Mr. M. D. Meier, Vice President- Regulatory Affairs Mr. D. R. Madison, Vice President- Fleet Operations Mr. B. J. Adams, Vice President- Engineering Mr. G. L. Johnson, Regulatory Affairs Manager- Hatch RType: CHA02.004 U. S. Nuclear Regulatorv Commission Ms. C. Haney, Regional Administrator Mr. M. D. Orenak, NRR Project Manager- Hatch Mr. D. H. Hardage, Senior Resident Inspector- Hatch State of Georgia Mr. J. H. Turner, Director- Environmental Protection Division |
| | |
| | Edwin I. Hatch Nuclear Plant Unit 1 and 2 Response to Request for Additional Information on Secondary Containment Drawdown Time Technical Specifications Amendment Request Enclosure Response to Request for Additional Information |
| | |
| | Enclosure to NL-16-0655 Response to Request for Additional Information |
| | |
| | ===RAI-10=== |
| | In the response to RAI-7 of the March 16, 2016, supplement, SNC states: |
| | This reduction was justified by noting that wind speeds of greater than 24 mph are not frequent, based on Plant Hatch meteorological conditions. At this wind speed, exfiltration would occur at 0.12 inches of water vacuum. |
| | a) Please provide further detail as to what "exfiltration would occur at 0.12 inches of water vacuum" means. Does it mean that the exfiltration would not occur at 0.125 inches of water vacuum? |
| | b) Please provide the basis for the required 0.12 inches of water vacuum with 24 mph wind speed in the form of a one-page summary of the test or analysis. |
| | SNC Response: |
| | a) The effect of wind blowing on a side of a building will result in positive pressure on that side; this is referred to as the windward side of the building. The opposite side of the building, the leeward side, will be at a negative pressure. The original design consideration of a 35 mph wind will result in a pressure of -0.25 inches of water (wg) on the leeward side. |
| | So, by maintaining a pressure of -0.25 wg inside the building, the differential pressure between the inside of the building and the leeward side of the building will be zero. Consequently, there will be no infiltration or exfiltration to or from the building. |
| | The required pressure with a 24 mph wind speed is determined by the square of the ratio of the 24 and 35 mph wind speeds. Therefore, for a wind speed of 24 mph, the pressure at the leeward side of the building will be: |
| | [(24 mph/35 mph) 2 x (-0.25 inches wg)] =-0.12 inches wg. |
| | This means that if the building is maintained at a pressure which is more negative than -0.12 inches wg there will be no exfiltration from the building, but there will be infiltration, which is acceptable. Hence, if the building is maintained at -0.125 inches wg, corresponding to the 24 mph wind, there will be no exfiltration. |
| | b) As described in the above response to a., the required pressure with a 24 mph wind speed is determined by the square of the ratio of the 24 and 35 mph wind speeds. As described in the RAI response of March 16, 2016, the 24 mph wind speed was used in the original submittal (which reduced the Technical Specification required vacuum from 0.25 inches wg to 0.20 inches wg) because wind speeds in excess of 24 mph are rare at HNP. |
| | E-1 |
| | |
| | Charles R. Pierce Southern Nuclear Regulatory Affairs Director Operating Company, Inc. |
| | 40 inverness Center Parkway Post Office Box 1295 Birmingham, AL 35242 Tel 205.992.7872 SOUTHERN * \ |
| | Fax 205.992.7601 NUCLEAR A SOUTHERN COMPANY MAY 0 9 2016 Docket Nos.: 50-321 NL-16-0655 50-366 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant Unit 1 and 2 Response to Request for Additional Information on Secondary Containment Drawdown Time Technical Specifications Amendment Request Ladies and Gentlemen: |
| | By letter dated October 15, 2015, and as supplemented by letter dated March 16, 2016, Southern Nuclear Operating Company (SNC) submitted a license amendment request for the Edwin I. Hatch Nuclear Plant (HNP), Units 1 and 2. |
| | The proposed amendment would revise Unit 1 and 2 HNP Technical Specifications Surveillance Requirement (SA) 3.6.4.1.3 to increase the allowable time for the Standby Gas Treatment System (SGTS) to draw down the secondary containment to the required negative pressure from 2 minutes to 10 minutes. |
| | By letters dated February 18, 2016 and April 15, 2016, the Nuclear Regulatory Commission (NRC) issued requests for additional information (RAJ). The enclosure to this letter provides SNC's response to the April 15, 2016 RAI. |
| | Please note that the remaining SNC response to the NRC RAJ dated February 18, 2016 will be provided to NRC no later than May 18, 2016. |
| | This letter contains no NRC commitments. If you have any questions, please contact Ken McElroy at (205) 992-7369. |
| | |
| | U.S. Nuclear Regulatory Commission NL-16-0655 Page2 Mr. C. R. Pierce states he is Regulatory Affairs Director of Southern Nuclear Operating Company, is authorized to execute this oath on behalf of Southern Nuclear Operating Company and, to the best of his knowledge and belief, the facts set forth in this letter are true. |
| | Respectfully submitted, |
| | ~ f{. fJp_ |
| | C. R. Pierce Regulatory Affairs Director CRP/OCV/ |
| | q 1?- day ot--'M....:......I.-~---\oo---' |
| | 6 2016. |
| | My commission expires: /0 |
| | * 8*do t1 |
| | |
| | ==Enclosure:== |
| | Response to Request for Additional Information cc: Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, President & CEO Mr. D. G. Bast, Executive Vice President & Chief Nuclear Officer Mr. D. R. Vineyard, Vice President- Hatch Mr. M. D. Meier, Vice President- Regulatory Affairs Mr. D. R. Madison, Vice President- Fleet Operations Mr. B. J. Adams, Vice President- Engineering Mr. G. L. Johnson, Regulatory Affairs Manager- Hatch RType: CHA02.004 U. S. Nuclear Regulatorv Commission Ms. C. Haney, Regional Administrator Mr. M. D. Orenak, NRR Project Manager- Hatch Mr. D. H. Hardage, Senior Resident Inspector- Hatch State of Georgia Mr. J. H. Turner, Director- Environmental Protection Division |
| | |
| | Edwin I. Hatch Nuclear Plant Unit 1 and 2 Response to Request for Additional Information on Secondary Containment Drawdown Time Technical Specifications Amendment Request Enclosure Response to Request for Additional Information |
| | |
| | Enclosure to NL-16-0655 Response to Request for Additional Information |
| | |
| | ===RAI-10=== |
| | In the response to RAI-7 of the March 16, 2016, supplement, SNC states: |
| | This reduction was justified by noting that wind speeds of greater than 24 mph are not frequent, based on Plant Hatch meteorological conditions. At this wind speed, exfiltration would occur at 0.12 inches of water vacuum. |
| | a) Please provide further detail as to what "exfiltration would occur at 0.12 inches of water vacuum" means. Does it mean that the exfiltration would not occur at 0.125 inches of water vacuum? |
| | b) Please provide the basis for the required 0.12 inches of water vacuum with 24 mph wind speed in the form of a one-page summary of the test or analysis. |
| | SNC Response: |
| | a) The effect of wind blowing on a side of a building will result in positive pressure on that side; this is referred to as the windward side of the building. The opposite side of the building, the leeward side, will be at a negative pressure. The original design consideration of a 35 mph wind will result in a pressure of -0.25 inches of water (wg) on the leeward side. |
| | So, by maintaining a pressure of -0.25 wg inside the building, the differential pressure between the inside of the building and the leeward side of the building will be zero. Consequently, there will be no infiltration or exfiltration to or from the building. |
| | The required pressure with a 24 mph wind speed is determined by the square of the ratio of the 24 and 35 mph wind speeds. Therefore, for a wind speed of 24 mph, the pressure at the leeward side of the building will be: |
| | [(24 mph/35 mph) 2 x (-0.25 inches wg)] =-0.12 inches wg. |
| | This means that if the building is maintained at a pressure which is more negative than -0.12 inches wg there will be no exfiltration from the building, but there will be infiltration, which is acceptable. Hence, if the building is maintained at -0.125 inches wg, corresponding to the 24 mph wind, there will be no exfiltration. |
| | b) As described in the above response to a., the required pressure with a 24 mph wind speed is determined by the square of the ratio of the 24 and 35 mph wind speeds. As described in the RAI response of March 16, 2016, the 24 mph wind speed was used in the original submittal (which reduced the Technical Specification required vacuum from 0.25 inches wg to 0.20 inches wg) because wind speeds in excess of 24 mph are rare at HNP. |
| | E-1}} |
Letter Sequence Response to RAI |
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NL-19-0009, Supplemental Response to Alternative Request HNP-ISI-ALT-05-042019-01-0808 January 2019 Supplemental Response to Alternative Request HNP-ISI-ALT-05-04 NL-18-1480, Response to NRC Request for Additional Information on Alternative Request (HNP-ISI-ALT-05-04)2018-11-29029 November 2018 Response to NRC Request for Additional Information on Alternative Request (HNP-ISI-ALT-05-04) NL-18-0639, Response to Request for Information Regarding Safety Relief Valve Main Valve Body Testing Extension2018-05-10010 May 2018 Response to Request for Information Regarding Safety Relief Valve Main Valve Body Testing Extension NL-18-0541, Response to Request for Additional Information for Alternative RR-V-11 Regarding Main Steam Safety Valve Testing Requirements2018-04-17017 April 2018 Response to Request for Additional Information for Alternative RR-V-11 Regarding Main Steam Safety Valve Testing Requirements ML18088A0802018-03-29029 March 2018 Response to Request for Additional Information for Alternative RR-V-11 Regarding Main Steam Safety Valve Testing Requirements NL-18-0211, Response to Request for Additional Information Regarding Alternative HNP-181-ALT-05-05 to Adopt Code Case N-7022018-02-20020 February 2018 Response to Request for Additional Information Regarding Alternative HNP-181-ALT-05-05 to Adopt Code Case N-702 NL-18-0085, Response to NRC RAIs Regarding Generic Letter 2016-012018-02-0505 February 2018 Response to NRC RAIs Regarding Generic Letter 2016-01 NL-17-2015, Response to NRC RAIs Regarding Decommissioning Funding Status Reports2018-01-22022 January 2018 Response to NRC RAIs Regarding Decommissioning Funding Status Reports NL-17-1161, License Amendment Request to Revise Technical Specification Section 5.5.12 for Permanent Extension of Type a and Type C Leak Rate Test Frequencies Supplemental Responses to NRC Second Set of Requests for Additional Information2017-07-12012 July 2017 License Amendment Request to Revise Technical Specification Section 5.5.12 for Permanent Extension of Type a and Type C Leak Rate Test Frequencies Supplemental Responses to NRC Second Set of Requests for Additional Information NL-17-0766, License Amendment Request to Revise Technical Specification Section 5.5.12 for Permanent Extension of Type a and Type C Leak Rate Test Frequencies, Responses to NRC Second Set of Requests for Additional Information2017-06-0101 June 2017 License Amendment Request to Revise Technical Specification Section 5.5.12 for Permanent Extension of Type a and Type C Leak Rate Test Frequencies, Responses to NRC Second Set of Requests for Additional Information NL-17-0917, Response to Request for Additional Information Regarding Relief Requests RR-16, RR-17. RR-21 and RR-222017-05-31031 May 2017 Response to Request for Additional Information Regarding Relief Requests RR-16, RR-17. RR-21 and RR-22 NL-17-0063, Response to Verbal Request for Additional Information on Technical Specifications Revision Request to Implement TSTF-500, DC Electrical Re-write2017-02-0606 February 2017 Response to Verbal Request for Additional Information on Technical Specifications Revision Request to Implement TSTF-500, DC Electrical Re-write NL-16-2494, Units 1 and 2 - Spent Fuel Pool Evaluation Supplemental Report, Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.1 of the Near-Term Task Force Review of Insights from ...2016-12-15015 December 2016 Units 1 and 2 - Spent Fuel Pool Evaluation Supplemental Report, Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.1 of the Near-Term Task Force Review of Insights from ... NL-16-2457, Supplemental Information Regarding Proposed Safety Limit Minimum Critical Power Ratio (SLMCPR) License Amendment2016-11-18018 November 2016 Supplemental Information Regarding Proposed Safety Limit Minimum Critical Power Ratio (SLMCPR) License Amendment NL-16-2109, Response to Request for Additional Information on Technical Specifications Revision Request to Implement TSTF-500. DC Electrical Re-write2016-11-16016 November 2016 Response to Request for Additional Information on Technical Specifications Revision Request to Implement TSTF-500. DC Electrical Re-write NL-16-1830, Southern Nuclear Operating Company Response to RAI for License Amendment Regarding Emergency Action Level Schemes to Adopt NEI 99-01 Rev 6 and to Modify Radiation Monitors at Farley Nuclear Plant, Part 1B of 1C2016-11-0303 November 2016 Southern Nuclear Operating Company Response to RAI for License Amendment Regarding Emergency Action Level Schemes to Adopt NEI 99-01 Rev 6 and to Modify Radiation Monitors at Farley Nuclear Plant, Part 1B of 1C NL-16-1830, Southern Nuclear Operating Company Response to RAI for License Amendment Regarding Emergency Action Level Schemes to Adopt NEI 99-01 Rev 6 and to Modify Radiation Monitors at Farley Nuclear Plant, Part 1C of 1C2016-11-0303 November 2016 Southern Nuclear Operating Company Response to RAI for License Amendment Regarding Emergency Action Level Schemes to Adopt NEI 99-01 Rev 6 and to Modify Radiation Monitors at Farley Nuclear Plant, Part 1C of 1C ML16314A5052016-11-0303 November 2016 Southern Nuclear Operating Company Response to RAI for License Amendment Regarding Emergency Action Level Schemes to Adopt NEI 99-01 Rev 6 and to Modify Radiation Monitors at Farley Nuclear Plant, Part 1B of 1C NL-16-1169, Response to Request for Additional Information on Technical Specifications - Revision Request to Implement TSTF-500, DC Electrical Re-Write.2016-08-12012 August 2016 Response to Request for Additional Information on Technical Specifications - Revision Request to Implement TSTF-500, DC Electrical Re-Write. NL-16-0628, Southern Nuclear Operating Company Response to Third Request for Additional Information Regarding Standard Emergency Plan: Cover Letter, Attachment 1 and Enclosures 1 - 102016-06-0909 June 2016 Southern Nuclear Operating Company Response to Third Request for Additional Information Regarding Standard Emergency Plan: Cover Letter, Attachment 1 and Enclosures 1 - 10 NL-16-0739, Corrected Response to Second Request for Additional Information Regarding Standard Emergency Plan2016-05-26026 May 2016 Corrected Response to Second Request for Additional Information Regarding Standard Emergency Plan NL-16-0660, Response to Request for Additional Information on Secondary Containment Drawdown Time Technical Specification Amendment Request2016-05-16016 May 2016 Response to Request for Additional Information on Secondary Containment Drawdown Time Technical Specification Amendment Request NL-16-0655, Response to Request for Additional Information on Secondary Containment Drawdown Time Technical Specifications Amendment Request2016-05-0909 May 2016 Response to Request for Additional Information on Secondary Containment Drawdown Time Technical Specifications Amendment Request NL-16-0292, Response to Request for Additional Information on Revision to Secondary Containment Drawdown Time Technical Specifications Amendment Request2016-03-16016 March 2016 Response to Request for Additional Information on Revision to Secondary Containment Drawdown Time Technical Specifications Amendment Request NL-16-0169, Southern Nuclear Operating Company Response to First Request for Additional Information Re Standard Emergency Plan. Attachment 1: SNC Response to NRC RAI-1 Fleet Standard Emergency Plan and Enclosure 1: Evaluation of Proposed Changes Encl2016-02-17017 February 2016 Southern Nuclear Operating Company Response to First Request for Additional Information Re Standard Emergency Plan. Attachment 1: SNC Response to NRC RAI-1 Fleet Standard Emergency Plan and Enclosure 1: Evaluation of Proposed Changes Enclos ML16060A3282016-02-17017 February 2016 Southern Nuclear Operating Company Response to First Request for Additional Information Re Standard Emergency Plan. Attachment 1: SNC Response to NRC RAI-1 Fleet Standard Emergency Plan and Enclosure 1: Evaluation of Proposed Changes Enclos NL-16-0172, Response to Request for Information Regarding Changes to Technical Specification Section 1.0, 3.4.9, and 5.02016-02-0909 February 2016 Response to Request for Information Regarding Changes to Technical Specification Section 1.0, 3.4.9, and 5.0 NL-15-2270, Response to Request for Additional Information for Alternative HNP-ISI-ALT-5-012015-12-16016 December 2015 Response to Request for Additional Information for Alternative HNP-ISI-ALT-5-01 NL-15-2047, Response to Second Request for Additional Information Regarding SNC License Amendment Request for TSTF-523, Revision 22015-11-24024 November 2015 Response to Second Request for Additional Information Regarding SNC License Amendment Request for TSTF-523, Revision 2 ML15322A0902015-11-12012 November 2015 Enclosure 4, Non-Proprietary Version of the Epri/Bwrvip Information Requested in RAI 1 2024-01-30
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Charles R. Pierce Southern Nuclear Regulatory Affairs Director Operating Company, Inc.
40 inverness Center Parkway Post Office Box 1295 Birmingham, AL 35242 Tel 205.992.7872 SOUTHERN * \
Fax 205.992.7601 NUCLEAR A SOUTHERN COMPANY MAY 0 9 2016 Docket Nos.: 50-321 NL-16-0655 50-366 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant Unit 1 and 2 Response to Request for Additional Information on Secondary Containment Drawdown Time Technical Specifications Amendment Request Ladies and Gentlemen:
By letter dated October 15, 2015, and as supplemented by letter dated March 16, 2016, Southern Nuclear Operating Company (SNC) submitted a license amendment request for the Edwin I. Hatch Nuclear Plant (HNP), Units 1 and 2.
The proposed amendment would revise Unit 1 and 2 HNP Technical Specifications Surveillance Requirement (SA) 3.6.4.1.3 to increase the allowable time for the Standby Gas Treatment System (SGTS) to draw down the secondary containment to the required negative pressure from 2 minutes to 10 minutes.
By letters dated February 18, 2016 and April 15, 2016, the Nuclear Regulatory Commission (NRC) issued requests for additional information (RAJ). The enclosure to this letter provides SNC's response to the April 15, 2016 RAI.
Please note that the remaining SNC response to the NRC RAJ dated February 18, 2016 will be provided to NRC no later than May 18, 2016.
This letter contains no NRC commitments. If you have any questions, please contact Ken McElroy at (205) 992-7369.
U.S. Nuclear Regulatory Commission NL-16-0655 Page2 Mr. C. R. Pierce states he is Regulatory Affairs Director of Southern Nuclear Operating Company, is authorized to execute this oath on behalf of Southern Nuclear Operating Company and, to the best of his knowledge and belief, the facts set forth in this letter are true.
Respectfully submitted,
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C. R. Pierce Regulatory Affairs Director CRP/OCV/
q 1?- day ot--'M....:......I.-~---\oo---'
6 2016.
My commission expires: /0
Enclosure:
Response to Request for Additional Information cc: Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, President & CEO Mr. D. G. Bast, Executive Vice President & Chief Nuclear Officer Mr. D. R. Vineyard, Vice President- Hatch Mr. M. D. Meier, Vice President- Regulatory Affairs Mr. D. R. Madison, Vice President- Fleet Operations Mr. B. J. Adams, Vice President- Engineering Mr. G. L. Johnson, Regulatory Affairs Manager- Hatch RType: CHA02.004 U. S. Nuclear Regulatorv Commission Ms. C. Haney, Regional Administrator Mr. M. D. Orenak, NRR Project Manager- Hatch Mr. D. H. Hardage, Senior Resident Inspector- Hatch State of Georgia Mr. J. H. Turner, Director- Environmental Protection Division
Edwin I. Hatch Nuclear Plant Unit 1 and 2 Response to Request for Additional Information on Secondary Containment Drawdown Time Technical Specifications Amendment Request Enclosure Response to Request for Additional Information
Enclosure to NL-16-0655 Response to Request for Additional Information
RAI-10
In the response to RAI-7 of the March 16, 2016, supplement, SNC states:
This reduction was justified by noting that wind speeds of greater than 24 mph are not frequent, based on Plant Hatch meteorological conditions. At this wind speed, exfiltration would occur at 0.12 inches of water vacuum.
a) Please provide further detail as to what "exfiltration would occur at 0.12 inches of water vacuum" means. Does it mean that the exfiltration would not occur at 0.125 inches of water vacuum?
b) Please provide the basis for the required 0.12 inches of water vacuum with 24 mph wind speed in the form of a one-page summary of the test or analysis.
SNC Response:
a) The effect of wind blowing on a side of a building will result in positive pressure on that side; this is referred to as the windward side of the building. The opposite side of the building, the leeward side, will be at a negative pressure. The original design consideration of a 35 mph wind will result in a pressure of -0.25 inches of water (wg) on the leeward side.
So, by maintaining a pressure of -0.25 wg inside the building, the differential pressure between the inside of the building and the leeward side of the building will be zero. Consequently, there will be no infiltration or exfiltration to or from the building.
The required pressure with a 24 mph wind speed is determined by the square of the ratio of the 24 and 35 mph wind speeds. Therefore, for a wind speed of 24 mph, the pressure at the leeward side of the building will be:
[(24 mph/35 mph) 2 x (-0.25 inches wg)] =-0.12 inches wg.
This means that if the building is maintained at a pressure which is more negative than -0.12 inches wg there will be no exfiltration from the building, but there will be infiltration, which is acceptable. Hence, if the building is maintained at -0.125 inches wg, corresponding to the 24 mph wind, there will be no exfiltration.
b) As described in the above response to a., the required pressure with a 24 mph wind speed is determined by the square of the ratio of the 24 and 35 mph wind speeds. As described in the RAI response of March 16, 2016, the 24 mph wind speed was used in the original submittal (which reduced the Technical Specification required vacuum from 0.25 inches wg to 0.20 inches wg) because wind speeds in excess of 24 mph are rare at HNP.
E-1
Charles R. Pierce Southern Nuclear Regulatory Affairs Director Operating Company, Inc.
40 inverness Center Parkway Post Office Box 1295 Birmingham, AL 35242 Tel 205.992.7872 SOUTHERN * \
Fax 205.992.7601 NUCLEAR A SOUTHERN COMPANY MAY 0 9 2016 Docket Nos.: 50-321 NL-16-0655 50-366 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant Unit 1 and 2 Response to Request for Additional Information on Secondary Containment Drawdown Time Technical Specifications Amendment Request Ladies and Gentlemen:
By letter dated October 15, 2015, and as supplemented by letter dated March 16, 2016, Southern Nuclear Operating Company (SNC) submitted a license amendment request for the Edwin I. Hatch Nuclear Plant (HNP), Units 1 and 2.
The proposed amendment would revise Unit 1 and 2 HNP Technical Specifications Surveillance Requirement (SA) 3.6.4.1.3 to increase the allowable time for the Standby Gas Treatment System (SGTS) to draw down the secondary containment to the required negative pressure from 2 minutes to 10 minutes.
By letters dated February 18, 2016 and April 15, 2016, the Nuclear Regulatory Commission (NRC) issued requests for additional information (RAJ). The enclosure to this letter provides SNC's response to the April 15, 2016 RAI.
Please note that the remaining SNC response to the NRC RAJ dated February 18, 2016 will be provided to NRC no later than May 18, 2016.
This letter contains no NRC commitments. If you have any questions, please contact Ken McElroy at (205) 992-7369.
U.S. Nuclear Regulatory Commission NL-16-0655 Page2 Mr. C. R. Pierce states he is Regulatory Affairs Director of Southern Nuclear Operating Company, is authorized to execute this oath on behalf of Southern Nuclear Operating Company and, to the best of his knowledge and belief, the facts set forth in this letter are true.
Respectfully submitted,
~ f{. fJp_
C. R. Pierce Regulatory Affairs Director CRP/OCV/
q 1?- day ot--'M....:......I.-~---\oo---'
6 2016.
My commission expires: /0
Enclosure:
Response to Request for Additional Information cc: Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, President & CEO Mr. D. G. Bast, Executive Vice President & Chief Nuclear Officer Mr. D. R. Vineyard, Vice President- Hatch Mr. M. D. Meier, Vice President- Regulatory Affairs Mr. D. R. Madison, Vice President- Fleet Operations Mr. B. J. Adams, Vice President- Engineering Mr. G. L. Johnson, Regulatory Affairs Manager- Hatch RType: CHA02.004 U. S. Nuclear Regulatorv Commission Ms. C. Haney, Regional Administrator Mr. M. D. Orenak, NRR Project Manager- Hatch Mr. D. H. Hardage, Senior Resident Inspector- Hatch State of Georgia Mr. J. H. Turner, Director- Environmental Protection Division
Edwin I. Hatch Nuclear Plant Unit 1 and 2 Response to Request for Additional Information on Secondary Containment Drawdown Time Technical Specifications Amendment Request Enclosure Response to Request for Additional Information
Enclosure to NL-16-0655 Response to Request for Additional Information
RAI-10
In the response to RAI-7 of the March 16, 2016, supplement, SNC states:
This reduction was justified by noting that wind speeds of greater than 24 mph are not frequent, based on Plant Hatch meteorological conditions. At this wind speed, exfiltration would occur at 0.12 inches of water vacuum.
a) Please provide further detail as to what "exfiltration would occur at 0.12 inches of water vacuum" means. Does it mean that the exfiltration would not occur at 0.125 inches of water vacuum?
b) Please provide the basis for the required 0.12 inches of water vacuum with 24 mph wind speed in the form of a one-page summary of the test or analysis.
SNC Response:
a) The effect of wind blowing on a side of a building will result in positive pressure on that side; this is referred to as the windward side of the building. The opposite side of the building, the leeward side, will be at a negative pressure. The original design consideration of a 35 mph wind will result in a pressure of -0.25 inches of water (wg) on the leeward side.
So, by maintaining a pressure of -0.25 wg inside the building, the differential pressure between the inside of the building and the leeward side of the building will be zero. Consequently, there will be no infiltration or exfiltration to or from the building.
The required pressure with a 24 mph wind speed is determined by the square of the ratio of the 24 and 35 mph wind speeds. Therefore, for a wind speed of 24 mph, the pressure at the leeward side of the building will be:
[(24 mph/35 mph) 2 x (-0.25 inches wg)] =-0.12 inches wg.
This means that if the building is maintained at a pressure which is more negative than -0.12 inches wg there will be no exfiltration from the building, but there will be infiltration, which is acceptable. Hence, if the building is maintained at -0.125 inches wg, corresponding to the 24 mph wind, there will be no exfiltration.
b) As described in the above response to a., the required pressure with a 24 mph wind speed is determined by the square of the ratio of the 24 and 35 mph wind speeds. As described in the RAI response of March 16, 2016, the 24 mph wind speed was used in the original submittal (which reduced the Technical Specification required vacuum from 0.25 inches wg to 0.20 inches wg) because wind speeds in excess of 24 mph are rare at HNP.
E-1