NG-17-0233, Submittal of License Amendment Request (TSCR-178) Application to Reduce the Required Number of Operable Suppression Chamber-to-Drywell Vacuum Breakers: Difference between revisions
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{{#Wiki_filter:Attachment 6 Contains Proprietary Information Withhold Attachme11t 6 from P11blic Disclos11re i11Accorda11ce1vith 10 CFR 2.390 | {{#Wiki_filter:Attachment 6 Contains Proprietary Information Withhold Attachme11t 6 from P11blic Disclos11re i11Accorda11ce1vith 10 CFR 2.390 NEXTera ENERGY ~ | ||
Application to Reduce the Required Number of Operable Suppression Chamber-to-Di-ywell Vacuum Breakers Pursuant to 10 CFR 50.90, NextEra Energy Duane Arnold, LLC (NextEra) is submitting a request for an amendment to the Technical Specifications (TS) for the Duane Arnold Energy Center (DAEC). The proposed change will modify TS 3.6.1.7, "Suppression Chamber-to-Drywell Vacuum Breakers," by revising the required number of operable vacuum breakers for opening from six to five. The Enclosure to this letter provides NextEra's evaluation of the proposed change. Attachment 1 to the enclosure provides a markup of the TS showing the proposed change, and Attachment 2 provides the clean TS page containing the proposed TS change. The change to the TS Bases is provided for information in Attachment 3 and will be incorporated in accordance with the TS Bases Control Program upon implementation of the approved amendment. | DUANE ARNOLD December 15, 2017 NG-17-0233 10 CFR50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Duane Arnold Energy Center Docket No. 50-331 Renewed Facility Operating License No. DPR-49 License Amendment Request (TSCR-178) | ||
Attachments 4 and 6 contain non-proprietary and proprietary versions, respectively, of GE-Hitachi document 003N7091, "NextEra Energy Duane Arnold (DAEC) Vacuum Breaker Sizing Analysis." | Application to Reduce the Required Number of Operable Suppression Chamber-to-Di-ywell Vacuum Breakers Pursuant to 10 CFR 50.90, NextEra Energy Duane Arnold, LLC (NextEra) is submitting a request for an amendment to the Technical Specifications (TS) for the Duane Arnold Energy Center (DAEC). The proposed change will modify TS 3.6.1.7, "Suppression Chamber-to-Drywell Vacuum Breakers," by revising the required number of operable vacuum breakers for opening from six to five. | ||
The affidavit sets forth the basis on which the information may be withheld from public disclosure by the Commission and addresses with specificity the considerations listed in paragraph (b)(4) of 10 CFR 2.390. Accordingly, it is requested that the information that is proprietary to GEH be withheld from public disclosure in accordance with 10 CFR 2.390. N extEra requests approval of the proposed license amendment by December 31, 2018, and implementation within 90 days. In accordance with 10 CFR 50.91, a copy ofthis application with enclosures is being provided to the designated State of Iowa official. | The Enclosure to this letter provides NextEra's evaluation of the proposed change. Attachment 1 to the enclosure provides a markup of the TS showing the proposed change, and Attachment 2 provides the clean TS page containing the proposed TS change. The change to the TS Bases is provided for information in Attachment 3 and will be incorporated in accordance with the TS Bases Control Program upon implementation of the approved amendment. | ||
Attachments 4 and 6 contain non-proprietary and proprietary versions, respectively, of GE-Hitachi document 003N7091, "NextEra Energy Duane Arnold (DAEC) Vacuum Breaker Sizing Analysis." contains information proprieta1y to GE-Hitachi Nuclear Energy Americas, LLC (GEH) and is supported by an affidavit in Attachment 5, signed by GEH, the owner of the information. The affidavit sets forth the basis on which the information may be withheld from public disclosure by the Commission and addresses with specificity the considerations listed in paragraph (b)(4) of 10 CFR 2.390. Accordingly, it is requested that the information that is proprietary to GEH be withheld from public disclosure in accordance with 10 CFR 2.390. | |||
N extEra requests approval of the proposed license amendment by December 31, 2018, and implementation within 90 days. In accordance with 10 CFR 50.91, a copy ofthis application with enclosures is being provided to the designated State of Iowa official. | |||
Docwnent Control Desk NG-17-0233 Page 2of2 As discussed in the Enclosure, the proposed change does not involve a significant hazards consideration pursuant to 10 CFR 50.92, and there are no significant environmental impacts associated with the change. The DAEC Onsite Review Group has reviewed the proposed license amendment. | Docwnent Control Desk NG-17-0233 Page 2of2 As discussed in the Enclosure, the proposed change does not involve a significant hazards consideration pursuant to 10 CFR 50.92, and there are no significant environmental impacts associated with the change. The DAEC Onsite Review Group has reviewed the proposed license amendment. | ||
This letter contains no new or revised regulat01y commitments. | This letter contains no new or revised regulat01y commitments. | ||
If you have any questions or require additional information, please contact Michael Davis, Licensing Manager, at 319-851-7032. | If you have any questions or require additional information, please contact Michael Davis, Licensing Manager, at 319-851-7032. | ||
I declare under penalty of perjury that the foregoing is true and correct. Executed on December 15, 2017 Dean Curtland Site Director NextEra Energy Duane Arnold, LLC Enclosure cc: Regional Administrator, USNRC, Region III, Project Manager, USNRC, Duane Arnold Energy Center Resident Inspector, USNRC, Duane Arnold Energy Center A. Leek (State of Iowa) | I declare under penalty of perjury that the foregoing is true and correct. | ||
NEXTERA ENERGY DUANE ARNOLD, LLC DUANE ARNOLD ENERGY CENTER License Amendment Request (TSCR-178) | Executed on December 15, 2017 Dean Curtland Site Director NextEra Energy Duane Arnold, LLC Enclosure cc: Regional Administrator, USNRC, Region III, Project Manager, USNRC, Duane Arnold Energy Center Resident Inspector, USNRC, Duane Arnold Energy Center A. Leek (State of Iowa) | ||
NG-17-0233 Enclosure Page 1 of7 NEXTERA ENERGY DUANE ARNOLD, LLC DUANE ARNOLD ENERGY CENTER License Amendment Request (TSCR-178) | |||
-** | Application to Reduce the Required Number of Operable Suppression Chamber-to-Drywell Vacuum Breakers EVALUATION OF PROPOSED CHANGE 1.0 Summaty Description 2.0 Detailed Desctiption 2.1 Vacuum Breaker Design and Operation 2.2 Cutrent TS Requirements 2.3 Reason for the Proposed Change 2.4 Description of the Proposed Change 3.0 Technical Evaluation 4.0 Regulatoty Evaluation 4.1 Applicable Regulatory Requitements/Critetia 4.2 No Significant Hazatds Considetation 4.3 Conclusions 5.0 Envitonmental Considerations 6.0 References - Proposed Technical Specification Change (Mark-Up) - Revised Technical Specification Page - Proposed Technical Specification Bases Change (Matk-Up) - NextEra Energy Duane Arnold (DAEC) Vacuum Breaker Sizing Analysis (Non-proprietaty) - GE-Hitachi Affidavit for Withholding of Proprietary Information - N extEra Energy Duane Arnold (DAEC) Vacuum Breaker Sizing Analysis (Proptietary) | ||
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1.0 | -** --~---*~******---~-~-~- .. ***~-****---------~------------------------ | ||
NG-17-0233 Enclosure Page 2 of7 1.0 | |||
==SUMMARY== | ==SUMMARY== | ||
DESCRIPTION | DESCRIPTION NextEra Energy Duane Arnold, LLC (NextEra) requests an amendment to the Technical Specifications (TS) for the Duane Arnold Energy Center (DAEC). The proposed change will modify TS 3.6.1.7, "Suppression Chamber-to-Dqwell Vacuum Breakers," by revising the required number of operable vacuum breakers for opening from SL'>: to five. | ||
Automatic vacuum relief devices are used to prevent any unacceptable pressure differential. | 2.0 DETAILED DESCRIPTION 2.1 Vacuum Breaker Design and Operation The prima1y containment is designed for an external pressure not more than 2 psi greater than the concurrent internal pressure. Automatic vacuum relief devices are used to prevent any unacceptable pressure differential. There are two groups of vacuum breakers: the suppression chamber-to-drywell group, which is connected to the vent header inside the torus and prevents dtywell pressure from being significantly less than torus pressure; and the reactor building-to-suppression group, which prevents tlle torus pressure from being significantly lower than building pressure. | ||
There are two groups of vacuum breakers: | The purpose of the suppression chamber-to-dqwell vacuum breakers is to relieve vacuum, preventing an excessive negative differential pressure. A negative differential pressure across the dtywell wall is caused by rapid depressurization of tlle d1)7well. Events that cause this rapid depressurization are cooling cycles, inadvertent dtywell spray actuation, and steam condensation from sprays or subcooled re-flood water flowing out of a postulated break in the primaq system. Cooling cycles result in minor pressure transients in the drywell that occur slowly and are normally controlled by heating and ventilation equipment. Spray actuation or spill of subcooled water out of a break results in more significant pressure transients and becomes important in sizing these vacuum breakers. | ||
the suppression chamber-to-drywell group, which is connected to the vent header inside the torus and prevents dtywell pressure from being significantly less than torus pressure; and the reactor building-to-suppression group, which prevents tlle torus pressure from being significantly lower than building pressure. | 2.2 Current TS Requirements TS 3.6.1.7, "Suppression Chamber-to-D1ywell Vacuum Breakers," currently requires the following in Modes 1, 2, and 3: | ||
The purpose of the suppression chamber-to-dqwell vacuum breakers is to relieve vacuum, preventing an excessive negative differential pressure. | Six suppression chamber-to-drywell vacuum breakers shall be OPERABLE for operung. | ||
A negative differential pressure across the dtywell wall is caused by rapid depressurization of tlle d1)7well. | Seven suppression chamber-to-dtywell vacuum breakers shall be closed, except when performing their intended function. | ||
Events that cause this rapid depressurization are cooling cycles, inadvertent dtywell spray actuation, and steam condensation from sprays or subcooled re-flood water flowing out of a postulated break in the primaq system. Cooling cycles result in minor pressure transients in the drywell that occur slowly and are normally controlled by heating and ventilation equipment. | |||
Spray actuation or spill of subcooled water out of a break results in more significant pressure transients and becomes important in sizing these vacuum breakers. | NG-17-0233 Enclosure Page3of7 2.3 Reason for the Proposed Change TS 3.6.1.7 currently requires sL-x suppression chamber-to-drywell vacuum breakers operable for opening. With one vacuum breaker inoperable for opening, the TS provides a 72-hour completion time to restore operability before a plant shutdown is required. However, a DAEC calculation shows tlrnt there is margin available in the current vacuum breaker design, which suggests tl1at the current TS has excess conse1vatism with respect to the number of vacuum breakers required to open to maintain suppression pool-to-drywell differential pressure. In addition, an analysis performed by GE-Hitachi Nuclear Energy Americas, LLC (GEH) concluded tlrnt with four vacuum breakers open, there is margin available to meet the most linllting design basis accident conditions. Therefore, NextEra is requesting a reduction in the required number of operable vacuum breakers for opening from six to five. | ||
2.2 Current TS Requirements TS 3.6.1.7, "Suppression Chamber-to-D1ywell Vacuum Breakers," currently requires the following in Modes 1, 2, and 3: Six suppression chamber-to-drywell vacuum breakers shall be OPERABLE for operung. Seven suppression chamber-to-dtywell vacuum breakers shall be closed, except when performing their intended function. | This change will provide operational flexibility while maintaining the capability to meet the limiting design basis accident conditions. The proposed change will eliminate the unnecessary transient and operational risks that would result from initiating a plant shutdown in accordance witl1 the current TS witl1 one of six vacuum breakers inoperable for longer than 72 hours. | ||
2.3 Reason for the Proposed Change | 2.4 Description of the Proposed Change TS 3.6.1.7, "Suppression Chamber-to-Dqwell Vacuum Breakers," is revised as shown below. | ||
However, a DAEC calculation shows tlrnt there is margin available in the current vacuum breaker design, which suggests tl1at the current TS has excess conse1vatism with respect to the number of vacuum breakers required to open to maintain suppression pool-to-drywell differential pressure. | Five fu suppression chamber -to-drywell vacuum breakers shall be OPERABLE for opemng. | ||
In addition, an analysis performed by GE-Hitachi Nuclear Energy Americas, LLC (GEH) concluded tlrnt with four vacuum breakers open, there is margin available to meet the most linllting design basis accident conditions. | Seven suppression chamber -to-diywell vacuum breakers shall be closed, except when performing their intended function | ||
Therefore, NextEra is requesting a reduction in the required number of operable vacuum breakers for opening from six to five. This change will provide operational flexibility while maintaining the capability to meet the limiting design basis accident conditions. | |||
The proposed change will eliminate the unnecessary transient and operational risks that would result from initiating a plant shutdown in accordance witl1 the current TS witl1 one of six vacuum breakers inoperable for longer than 72 hours. 2.4 Description of the Proposed Change TS 3.6.1.7, "Suppression Chamber-to-Dqwell Vacuum Breakers," is revised as shown below. Five fu suppression chamber -to-drywell vacuum breakers shall be OPERABLE for opemng. Seven suppression chamber -to-diywell vacuum breakers shall be closed, except when performing their intended function 3.0 TECHNICAL EVALUATION The proposed change revises the mininmm number of operable suppression diywell vacuum breakers for opening contained in TS 3.6.1.7 from sL-x to five. The proposed change is based on GEH document "NextEra Energy Duane Arnold (DAEC) Vacuum Breaker Sizing Analysis," which is provided in Attachment 4 (non-proprieta1y) and Attachment 6 (proprietaq). | ==3.0 TECHNICAL EVALUATION== | ||
The proposed change revises the mininmm number of operable suppression chamber-to-diywell vacuum breakers for opening contained in TS 3.6.1.7 from sL-x to five. The proposed change is based on GEH document "NextEra Energy Duane Arnold (DAEC) Vacuum Breaker Sizing Analysis," which is provided in Attachment 4 (non-proprieta1y) and Attachment 6 (proprietaq). | |||
Information supporting the change in the mininmm number of operable suppression chamber-to-diywell vacuum breakers for opening is included in Attachments 4 and 6. These attachments summarize the methodology, inputs, and results for the proposed change to the mininmm number of operable suppression chamber-to-di7well vacuum breakers for opemng. | Information supporting the change in the mininmm number of operable suppression chamber-to-diywell vacuum breakers for opening is included in Attachments 4 and 6. These attachments summarize the methodology, inputs, and results for the proposed change to the mininmm number of operable suppression chamber-to-di7well vacuum breakers for opemng. | ||
NG-17-0233 Enclosure Page4of7 The required number of vacuum breakers is calculated using an NRC accepted methodology described in NEDC-33004P-A Revision 4, "Constant Pressure Power Uprate" (Reference 2). A discussion on the methodology for calculating the required number of vacuum breakers is provided in Section 2.1, Containment Response Methodology, of Attachments 4 and 6. Three analysis cases were performed for the DAEC vacuum breaker sizing evaluation. | |||
These cases simulated events developed from a review of the analyses performed in Reference | NG-17-0233 Enclosure Page4of7 The required number of vacuum breakers is calculated using an NRC accepted methodology described in NEDC-33004P-A Revision 4, "Constant Pressure Power Uprate" (Reference 2). A discussion on the methodology for calculating the required number of vacuum breakers is provided in Section 2.1, Containment Response Methodology, of Attachments 4 and 6. | ||
Three analysis cases were performed for the DAEC vacuum breaker sizing evaluation. | |||
These cases simulated events developed from a review of the analyses performed in Reference 2. For all three cases, a single failure of a suppression chamber-to-drywell vacuum breaker and two suppression chamber-to-drywell vacuum breakers out-of-se1vice are assumed. Only one of the two reactor building-to-suppression chamber vacuum breakers is used. The specific inputs for these three cases are listed in Appendix A of Attachments 4 and 6. The analysis concludes that the size and number of vacuum breakers are sufficient to prevent exceeding the differential pressure design limit with two vacuum breakers out of se1vice and the failure of one vacuum breaker to open. | |||
==4.0 REGULATORY EVALUATION== | ==4.0 REGULATORY EVALUATION== | ||
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4.1 Applicable Regulatory Requirements/Criteria The DAEC Updated Final Safety Analyses Report contains an evaluation of the design basis of DAEC as measured against the AEC General Design Criteria (GDC) for nuclear power plants, Appendix A of 10 CFR 50, effective May 21, 1971, and subsequently amended July 7, 1971. The GDC applicable to the proposed change include: | 4.1 Applicable Regulatory Requirements/Criteria The DAEC Updated Final Safety Analyses Report contains an evaluation of the design basis of DAEC as measured against the AEC General Design Criteria (GDC) for nuclear power plants, Appendix A of 10 CFR 50, effective May 21, 1971, and subsequently amended July 7, 1971. The GDC applicable to the proposed change include: | ||
* GDC 16, Containment Design, states that reactor containment and associated systems shall be provided to establish an essentially leak-tight barrier against the uncontrolled release of radioactivity to the environment and to assure that the containment design conditions important to safety are not exceeded for as long as postulated accident conditions require. | * GDC 16, Containment Design, states that reactor containment and associated systems shall be provided to establish an essentially leak-tight barrier against the uncontrolled release of radioactivity to the environment and to assure that the containment design conditions important to safety are not exceeded for as long as postulated accident conditions require. | ||
* GDC 38, Containment Heat Removal, states that a system to remove heat from the reactor containment shall be provided. | * GDC 38, Containment Heat Removal, states that a system to remove heat from the reactor containment shall be provided. The system safety function shall be to reduce rapidly, consistent with the functioning of other associated systems, the containment pressure and temperature following any LOCA and maintain them at acceptably low levels. Suitable redundancy in components and features and suitable interconnections, leak detection, isolation, and containment capabilities shall be provided to ensure that ... the system safety function can be accomplished, assuming a single failure. | ||
The system safety function shall be to reduce rapidly, consistent with the functioning of other associated systems, the containment pressure and temperature following any LOCA and maintain them at acceptably low levels. Suitable redundancy in components and features and suitable interconnections, leak detection, isolation, and containment capabilities shall be provided to ensure that ... the system safety function can be accomplished, assuming a single failure. | * GDC 50, Containment Design Basis, states that the reactor containment stiucture, including access openings, penetrations, and the containment heat removal system shall be designed so that the containment structure and its internal compartments can accommodate, without exceeding the design leakage rate and with sufficient margin, the calculated pressure and temperature conditions resulting from any loss-of-coolant accident. This margin shall reflect consideration of (1) the effects of | ||
* GDC 50, Containment Design Basis, states that the reactor containment stiucture, including access openings, penetrations, and the containment heat removal system shall be designed so that the containment structure and its internal compartments can accommodate, without exceeding the design leakage rate and with sufficient margin, the calculated pressure and temperature conditions resulting from any of-coolant accident. | |||
This margin shall reflect consideration of (1) the effects of NG-17-0233 Enclosure Page 5 of7 potential energy sources which have not been included in the determination of the peak conditions, such as energy in steam generators and as required by§ 50.44 energy from metal-water and other chemical reactions that may result from degradation but not total failure of emergency core cooling functioning, (2) the limited experience and experimental data available for defining accident phenomena and containment responses, and (3) the conse1-vatism of the calculation model and input parameters. | NG-17-0233 Enclosure Page 5 of7 potential energy sources which have not been included in the determination of the peak conditions, such as energy in steam generators and as required by§ 50.44 energy from metal-water and other chemical reactions that may result from degradation but not total failure of emergency core cooling functioning, (2) the limited experience and experimental data available for defining accident phenomena and containment responses, and (3) the conse1-vatism of the calculation model and input parameters. | ||
The analysis of this change, which credits opening of four of the seven suppression chamber-to-drywell vacuum breakers, shows that the design pressure of the primary containment is not exceeded even under worst case accident scenarios. | The analysis of this change, which credits opening of four of the seven suppression chamber-to-drywell vacuum breakers, shows that the design pressure of the primary containment is not exceeded even under worst case accident scenarios. One of the operable vacuum breakers is assumed to fail to open, thus, only four of the five operable vacuum breakers are credited. In addition, the requirement for all suppression chamber-to-drywell vacuum breakers to be closed (except when performing their intended design function) ensures that there is no excessive bypass leakage should a LOCA occur. Therefore, the requirements of GDC 16, 38 and 50 will continue to be met with the implementation of this proposed change. | ||
One of the operable vacuum breakers is assumed to fail to open, thus, only four of the five operable vacuum breakers are credited. | 4.2 No Significant Hazards Consideration NextEra Energy Duane Arnold, LLC (NextEra) requests an amendment to the Technical Specifications (TS) for the Duane Arnold Energy Center (DAEC). The proposed change will modify TS 3.6.1.7, "Suppression Chamber-to-Drywell Vacuum Breakers," by revising the required number of operable vacuum breakers from six to five. | ||
In addition, the requirement for all suppression chamber-to-drywell vacuum breakers to be closed (except when performing their intended design function) ensures that there is no excessive bypass leakage should a LOCA occur. Therefore, the requirements of GDC 16, 38 and 50 will continue to be met with the implementation of this proposed change. 4.2 No Significant Hazards Consideration NextEra Energy Duane Arnold, LLC (NextEra) requests an amendment to the Technical Specifications (TS) for the Duane Arnold Energy Center (DAEC). The proposed change will modify TS 3.6.1.7, "Suppression Chamber-to-Drywell Vacuum Breakers," by revising the required number of operable vacuum breakers from six to five. NextEra has evaluated the proposed change against the criteria of 10 CFR 50.92(c) to determine if the proposed change results in any significant hazards. The following is the evaluation of each of the 10 CFR 50.92(c) criteria: | NextEra has evaluated the proposed change against the criteria of 10 CFR 50.92(c) to determine if the proposed change results in any significant hazards. The following is the evaluation of each of the 10 CFR 50.92(c) criteria: | ||
: 1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated? | : 1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated? | ||
Response: | Response: No Operable suppression chamber-to-di-ywell vacuum breakers are required for accident mitigation. Failure of the vacuum breakers is not assumed as an accident initiator for any accident previously evaluated. Therefore, any potential failure of a vacuum breaker to perform when necessa1y will not affect the probability of an accident previously evaluated. | ||
No Operable suppression chamber-to-di-ywell vacuum breakers are required for accident mitigation. | The proposed change maintains a sufficient number of operable vacuum breakers to meet the limiting design basis accident conditions. The consequences of an accident previously evaluated while utilizing the proposed change are no different than the consequences of an accident prior to the proposed change. As a result, the consequences of an accident previously evaluated are not significantly increased | ||
Failure of the vacuum breakers is not assumed as an accident initiator for any accident previously evaluated. | |||
Therefore, any potential failure of a vacuum breaker to perform when necessa1y will not affect the probability of an accident previously evaluated. | NG-17-0233 Enclosure Page 6 of7 Therefore, the proposed TS change does not involve an increase in the probability or consequences of a previously evaluated accident. | ||
The proposed change maintains a sufficient number of operable vacuum breakers to meet the limiting design basis accident conditions. | |||
The consequences of an accident previously evaluated while utilizing the proposed change are no different than the consequences of an accident prior to the proposed change. As a result, the consequences of an accident previously evaluated are not significantly increased NG-17-0233 Enclosure Page 6 of7 Therefore, the proposed TS change does not involve an increase in the probability or consequences of a previously evaluated accident. | |||
: 2. Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated? | : 2. Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated? | ||
Response: | Response: No The proposed change does not alter the protection system design, create new failure modes, or change any modes of operation. The proposed change does not involve a physical alteration of the plant; and no new or different kind of equipment will be installed. Consequently, there are no new initiators that could result in a new or different kind of accident. | ||
No The proposed change does not alter the protection system design, create new failure modes, or change any modes of operation. | |||
The proposed change does not involve a physical alteration of the plant; and no new or different kind of equipment will be installed. | |||
Consequently, there are no new initiators that could result in a new or different kind of accident. | |||
Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated. | Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated. | ||
: 3. Does the proposed change involve a significant reduction in a margin of safety? Response: | : 3. Does the proposed change involve a significant reduction in a margin of safety? | ||
No The proposed change to the minimum number of operable suppression drywell vacuum breakers for opening ensures that an excessive negative differential pressure between the suppression chamber and the drywell will be prevented during the most limiting postulated design-basis event. The minimum number of operable suppression chamber-to-drywell vacuum breakers for opening is set appropriately to ensure adequate margin based on tl1e number of available vacuum breakers not having an effect on the containment system analysis report. Therefore, the proposed change does not involve a significant reduction in a margin of safety. Based on tl1e above, NextEra concludes that the proposed change presents no significant hazards consideration under the standards set fortl1 in 10 CPR 50.92, and, accordingly, a finding of "no significant hazards consideration" is justified. | Response: No The proposed change to the minimum number of operable suppression chamber-to-drywell vacuum breakers for opening ensures that an excessive negative differential pressure between the suppression chamber and the drywell will be prevented during the most limiting postulated design-basis event. The minimum number of operable suppression chamber-to-drywell vacuum breakers for opening is set appropriately to ensure adequate margin based on tl1e number of available vacuum breakers not having an effect on the containment system analysis report. | ||
Therefore, the proposed change does not involve a significant reduction in a margin of safety. | |||
Based on tl1e above, NextEra concludes that the proposed change presents no significant hazards consideration under the standards set fortl1 in 10 CPR 50.92, and, accordingly, a finding of "no significant hazards consideration" is justified. | |||
4.3 Conclusions Based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public. | 4.3 Conclusions Based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public. | ||
However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or a significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. | NG-17-0233 Enclosure Page 7 of7 | ||
Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). | |||
Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment. | ==5.0 ENVIRONMENTAL CONSIDERATION== | ||
S A review has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or su1veillance requirement. However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or a significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment. | |||
==6.0 REFERENCES== | ==6.0 REFERENCES== | ||
: 1. GE Company, "Mark I Containment Program Mark I Wetwell-to-Di-ywell Vacuum Breaker Functional Requirements, Task 9.4.3," NEDE-24802, April 1980. 2. GE Nuclear Energy, "Constant Pressure Power Uprate," NEDC-33004P-A, Revision 4, July 2003. | : 1. GE Company, "Mark I Containment Program Mark I Wetwell-to-Di-ywell Vacuum Breaker Functional Requirements, Task 9.4.3," NEDE-24802, April 1980. | ||
: 2. GE Nuclear Energy, "Constant Pressure Power Uprate," NEDC-33004P-A, Revision 4, July 2003. | |||
ATTACHMENT 1 Proposed Technical Specification Change (Mark-Up) | ATTACHMENT 1 Proposed Technical Specification Change (Mark-Up) | ||
One page follows Suppression Chamber-to-Drywell Vacuum Breakers 3.6.1.7 3.6 CONTAINMENT SYSTEMS 3.6.1. 7 Suppression Chamber-to-Drywell Vacuum Breakers LCO chamber-to-drywell vacuum breakers shall be | One page follows | ||
MODES 1, 2, and 3. ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One required A.1 Restore one vacuum 72 hours suppression chamber-breaker to OPERABLE to-drywell vacuum status. breaker inoperable for opening. B. One suppression B.1 Close the open 2 hours chamber-to-d rywell vacuum breaker. vacuum breaker not closed. C. Required Action and C.1 Be in MODE 3. 12 hours associated Completion Time not met. AND C.2 Be in MODE 4. 36 hours DAEC 3.6-22 ATTACHMENT 2 Revised Technical Specification Page One page follows Suppression Chamber-to-Drywell Vacuum Breakers 3.6.1.7 3.6 CONTAINMENT SYSTEMS 3.6.1. 7 Suppression Chamber-to-Drywell Vacuum Breakers LCO 3.6.1.7 Five suppression chamber-to-drywell vacuum breakers shall be OPERABLE for opening. Seven suppression chamber-to-drywell vacuum breakers shall be closed, except when performing their intended function. | |||
APPLICABILITY: | Suppression Chamber-to-Drywell Vacuum Breakers 3.6.1.7 3.6 CONTAINMENT SYSTEMS 3.6.1. 7 Suppression Chamber-to-Drywell Vacuum Breakers LCO ~ 3.6.1 . 7 ~ suppression chamber-to-drywell vacuum breakers shall be | ||
MODES 1, 2, and 3. ACTIONS CONDITION REQUIRED ACTION A. One required A.1 Restore one vacuum suppression chamber-breaker to OPERABLE to-drywell vacuum status. breaker inoperable for opening. B. One suppression B.1 Close the open chamber-to-d rywell vacuum breaker. vacuum breaker not closed. C. Required Action and C.1 Be in MODE 3. associated Completion Time not met. AND C.2 Be in MODE4. DAEC 3.6-22 | . OPERABLE for opening. | ||
Two pages follow | F1ve AND Seven suppression chamber-to-drywell vacuum breakers shall be closed, except when performing their intended function . | ||
APPLICABILITY: MODES 1, 2, and 3. | |||
This will result in an increase in the water clearing inertia in the event of a postulated LOCA, resulting in an increase in the peak drywell pressure. | ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One required A.1 Restore one vacuum 72 hours suppression chamber- breaker to OPERABLE to-drywell vacuum status. | ||
This in turn will result in an increase in the pool swell dynamic loads. The internal vacuum breakers limit the height of the waterleg in the vent system during normal operation. | breaker inoperable for opening. | ||
Analytical methods and assumptions involving the suppression chamber-to-drywell vacuum breakers are presented in Reference 1 as part of the accident response of the primary containment systems. Internal (suppression chamber-to-drywell) and external (reactor building-to-suppression chamber) vacuum breakers are provided as part of the primary containment to limit the negative differential pressure across the drywell and suppression chamber walls that form part of the primary containment boundary. | B. One suppression B.1 Close the open 2 hours chamber-to-d rywell vacuum breaker. | ||
The safety analyses assume that the internal vacuum breakers are closed initially and are fully open at a differential pressure of 0.5 psid (Ref. 2). Additionally, 1 of the 7 internal vacuum breakers f is assumed to fail in a closed position (Ref. 1 ). The results of the analyses show that the design pressure is not exceeded even under the worst case accident scenario. | vacuum breaker not closed. | ||
The vacuum breaker opening differential pressure setting is a result of the requirement placed on the vacuum breakers to prevent excessive water-level variations in the submerged portion of the vent downcomer lines. The vacuum breaker capacity, with one of the valves failed, is adequate to limit the pressure differential between the suppression chamber and the drywell during post accident drywell cooling operations to a value that is within the suppression chamber design values. The suppression chamber-to-drywell vacuum breakers satisfy , | C. Required Action and C.1 Be in MODE 3. 12 hours associated Completion Time not met. AND C.2 Be in MODE 4. 36 hours DAEC 3.6-22 Amendment ~ | ||
Five LCO | |||
B 3.6-44 TSCR-Q44A | ATTACHMENT 2 Revised Technical Specification Page One page follows | ||
However, overall system reliability is reduced because a single failure in one of remaining vacuum breakers could result in an exces. i* five suppression chamber -to-drywell differe | Suppression Chamber-to-Drywell Vacuum Breakers 3.6.1.7 3.6 CONTAINMENT SYSTEMS 3.6.1. 7 Suppression Chamber-to-Drywell Vacuum Breakers LCO 3.6.1.7 Five suppression chamber-to-drywell vacuum breakers shall be OPERABLE for opening. | ||
* essure during a OBA. Therefore, with one of quired vacuum breakers inoperable, 72 hours is allowed to restore at least one of the inoperable vacuum breakers to OPERABLE status so that plant conditions are consistent with those assumed for the design basis analysis. The 72 hour Completion Time is considered acceptable due to the low probability of an event in which the remaining vacuum breaker capability would not be adequate. | Seven suppression chamber-to-drywell vacuum breakers shall be closed, except when performing their intended function. | ||
An open vacuum breaker allows communication between the drywell and suppression chamber airspace, and, as a result , there is the potential for suppression chamber overpressurization due to* this bypass leakage if a LOCA were to occur. Therefore, the open vacuum breaker must be closed. A short time is allowed to close the vacuum breaker due to the low probability of an event that would pressurize primary containment. | APPLICABILITY: MODES 1, 2, and 3. | ||
If vacuum breaker position indication is not reliable, an alternate method of verifying that the vacuum breakers are closed is to verify that a drywell to suppression chamber differential pressure of 0.5 psid is maintained for 1 hour without makeup. The required 2 hour Completion Time is considered adequate to perform this test. C.1 and C.2 If the inoperable suppression chamber-to-drywell vacuum breaker cannot be closed or restored to OPERABLE status within the required Completion Time, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant (continued) B 3.6-46 ATTACHMENT 4 NextEra Energy Duane Arnold (DAEC) Vacuum Breaker Sizing Analysis (Non-proprietaty) e HITACHI GE Hitachi Nuclear Energy Non-Proprietmy Information | ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One required A.1 Restore one vacuum 72 hours suppression chamber- breaker to OPERABLE to-drywell vacuum status. | ||
-Class I (Public) | breaker inoperable for opening. | ||
-Class I (Public) INFORMATION NOTICE This is a non-proprietary version of the document 003N7091-P Revision 1, which has the proprietary information removed. Portions of the document that have been removed are indicated by an open and closed bracket as shown here [[ ]]. IMPORTANT NOTICE REGARDING CONTENTS OF THIS REPORT Please Read Carefully The design, engineering, and other information contained in this document is furnished for the purposes of supporting the NextEra in proceedings before the U.S. Nuclear Regulatory Commission (NRC). The only unde1iakings of GEH with respect to information in this document are contained in the contract between NextEra and GEH and nothing contained in this contract shall be construed as changing that contract. | B. One suppression B.1 Close the open 2 hours chamber-to-d rywell vacuum breaker. | ||
The use of this information by anyone other than NextEra for any purpose other than that for which it is intended, is not authorized; and with respect to any unauthorized use, GEH makes no representation or warranty, and assumes no liability as to the completeness, accuracy, or usefulness of the information contained in this document. | vacuum breaker not closed. | ||
ll | C. Required Action and C.1 Be in MODE 3. 12 hours associated Completion Time not met. AND C.2 Be in MODE4. 36 hours DAEC 3.6-22 Amendment | ||
-Class I (Public) Revision Summary Required Changes to Achieve Revision Identified specific instances of GEH proprietary information and prepared the report for submittal to the NRC. Ill | |||
1 2.0 Contain1nent Response Analysis .......................................................................................... | ATTACHMENT 3 Proposed Technical Specification Bases Change (J\1ark-Up) | ||
2 2.1 Containment Response Methodology | Two pages follow | ||
...................................................................... | |||
2 2.2 Analysis Inputs and Assumptions | Suppression Chamber-to-Drywell Vacuum Breakers B3.6.1.7 BASES BACKGROUND chamber pressure, there will be an increase in the vent waterleg. | ||
............................................................................ | (continued) This will result in an increase in the water clearing inertia in the event of a postulated LOCA, resulting in an increase in the peak drywell pressure. This in turn will result in an increase in the pool swell dynamic loads. The internal vacuum breakers limit the height of the waterleg in the vent system during normal operation. | ||
2 2.3 Results ...................................................................................................................... | APPLICABLE Analytical methods and assumptions involving the SAFETY suppression chamber-to-drywell vacuum breakers are presented ANALYSES in Reference 1 as part of the accident response of the primary containment systems. Internal (suppression chamber-to-drywell) and external (reactor building- to-suppression chamber) vacuum breakers are provided as part of the primary containment to limit the negative differential pressure across the drywell and suppression chamber walls that form part of the primary containment boundary. | ||
4 3.0 WW-to-DW VB Number Reduction Impact ...................................................................... | The safety analyses assume that the internal vacuum breakers are closed initially and are fully open at a differential pressure of 0.5 psid (Ref. 2) . Additionally, 1 of the 7 internal vacuum breakers f is assumed to fail in a closed position (Ref. 1). The results of the analyses show that the design pressure is not exceeded even under the worst case accident scenario. The vacuum breaker opening differential pressure setting is a result of the requirement placed on the vacuum breakers to prevent excessive water-level variations in the submerged portion of the vent downcomer lines. | ||
.4 3.1 DAEC EPU NPSH and Overpressure Analysis ...................................................... | The vacuum breaker capacity, with one of the valves failed, is adequate to limit the pressure differential between the suppression chamber and the drywell during post accident drywell cooling operations to a value that is within the suppression chamber design values. | ||
.4 3.2 Containment Hydrodynamic Loads and PULD ....................................................... | The suppression chamber-to-drywell vacuum breakers satisfy | ||
5 3.3 Containment Bypass Analysis ................................................................................. | ,__ _,,,, riterion 3 of 10 CFR 50.36(c)(2)(ii). | ||
6 4.0 Conclusions | Five LCO Only @of the 7 vacuum breakers must be OPERABLE for opening. All suppression chamber-to-drywell vacuum breakers, however, are required to be closed (except during testing, (continued) | ||
.......................................................................................................................... | DAEC B 3.6-44 TSCR-Q44A | ||
7 5.0 References | |||
............................................................................................................................ | Suppression Chamber-to-Drywell Vacuum Breakers B3.6.1.7 BASES (continued) | ||
8 Appendix A Summary of Case Input Parameters | ACTIONS With one of the equired vacuum breakers inoperable for opening (e.g., the vacu1 m breaker is not open and may be stuck closed or not within its Gpening setpoint limit, so that it would not function as designed du ' g an event that depressurized the drywell), the remaining five OPERABLE vacuum breakers are capable of providing the vacuum relief function. However, overall system reliability is reduced because a single failure in one of the.~~ | ||
...................................................................... | remaining vacuum breakers could result in an exces. i* five suppression chamber - to-drywell differe | ||
13 | * essure during a OBA. Therefore, with one of the ~ quired vacuum breakers inoperable, 72 hours is allowed to restore at least one of the inoperable vacuum breakers to OPERABLE status so that plant conditions are consistent with those assumed for the design basis analysis. The 72 hour Completion Time is considered acceptable due to the low probability of an event in which the remaining vacuum breaker capability would not be adequate. | ||
9 List of Figures Case I Containment Differential Pressure Responses | An open vacuum breaker allows communication between the drywell and suppression chamber airspace, and, as a result, there is the potential for suppression chamber overpressurization due to | ||
.......................................... .I 0 Case 2 Containment Differential Pressure Responses | * this bypass leakage if a LOCA were to occur. Therefore, the open vacuum breaker must be closed. A short time is allowed to close the vacuum breaker due to the low probability of an event that would pressurize primary containment. If vacuum breaker position indication is not reliable, an alternate method of verifying that the vacuum breakers are closed is to verify that a drywell to suppression chamber differential pressure of 0.5 psid is maintained for 1 hour without makeup. The required 2 hour Completion Time is considered adequate to perform this test. | ||
........................................... | C.1 and C.2 If the inoperable suppression chamber-to-drywell vacuum breaker cannot be closed or restored to OPERABLE status within the required Completion Time, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant (continued) | ||
11 Case 3 Containment Differential Pressure Responses | DAEC B 3.6-46 Amendment ~ | ||
.......................................... | |||
12 v 003N7091-NP Revision I Non-Proprietary Information | ATTACHMENT 4 NextEra Energy Duane Arnold (DAEC) Vacuum Breaker Sizing Analysis (Non-proprietaty) | ||
-Class I (Public) 1.0 Introduction and Scope Vacuum breaker (VB) valves installed in the Duane Arnold Energy Center (DAEC) containment systems prevent potential negative differential pressure exceeding design limits between the wetwell (WW) and drywell (DW). Functional requirements established during the Mark I containment program (Reference I) include a VB load definition, based upon dynamic modeling of the vent pressure transient, and VB number and size for predicting integrated containment response to prescribed events. Prior to the Mark I program, a general design requirement derived from the Bodega Bay Preliminary Hazards Summary Report included specification of VB area being no less than 1/16 of the total vent flow cross-sectional area. A number of plants revised their VB sizing technical bases by implementing the more systematic approach developed in the Mark I program (Reference I). Calculations were performed using an approach similar to that applied for the Reference I analyses to serve as the technical basis supporting DAEC VB size and number requirements for operation. | |||
These analysis cases performed for the DAEC VB sizing evaluation simulate events developed from a review of the analyses performed in Reference I and include: Case I: Inadvertent actuation of DW spray with one (1) DW spray header during normal plant operation. | e HITACHI GE Hitachi Nuclear Energy 003N7091-NP Revision 1 September 2017 Non-Proprietmy Information - Class I (Public) | ||
Case 2: DW spray following a small steam line break loss-of-coolant accident (LOCA) with [[ ]] and use of two (2) DW spray headers. Case 3: Emergency core cooling system (ECCS) vessel reflood into the DW following a large liquid break LOCA with [[ ]] The design inputs for each case are summarized in Appendix A. I 003N7091-NP Revision 1 Non-Proprietary Information | NextEra Energy Duane Arnold (DAEC) | ||
-Class I (Public) 2.0 Containment Response Analysis 2.1 Containment Response Methodology The GE Hitachi Nuclear Energy (GEH) computer code SHEX was used to perform the containment pressure and temperature response analysis presented in this report. The SHEX code is the code currently used by GEH to perform analyses of the containment pressure and temperature response including analyses performed to evaluate VB sizing adequacy for events resulting in negative DW-to-WW differential pressure, negative DW-to-Reactor Building (DW-to-RB) and negative WW-to-RB differential pressures. | Vacuum Breaker Sizing Analysis Copyright 2017 GE-Hitachi Nuclear Energy Americas LLC All Rights Reserved | ||
[[ ]] SHEX is the standard code used by GEH for containment response calculations for boiling water reactor (BWR) Mark I, Mark II and Mark III plants where safety systems such as ECCS and residual heat removal (RHR) pump operation or use of containment spray is simulated. | |||
A licensing topical repo1i (L TR) was not issued for SHEX, and therefore an NRC safety evaluation (SE) report with formal NRC approval for SHEX was not issued. However, the NRC has accepted the use of SHEX for United States (US) BWR Mark I containment analyses (Reference 2), in paiiicular containment analyses performed in suppmi of power uprates performed for US BWR Mark I plants. GEH report NEDC-33004P-A Revision 4 (Reference | 003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) | ||
INFORMATION NOTICE This is a non-proprietary version of the document 003N7091-P Revision 1, which has the proprietary information removed. Portions of the document that have been removed are indicated by an open and closed bracket as shown here [[ ]]. | |||
IMPORTANT NOTICE REGARDING CONTENTS OF THIS REPORT Please Read Carefully The design, engineering, and other information contained in this document is furnished for the purposes of supporting the NextEra in proceedings before the U.S. Nuclear Regulatory Commission (NRC). The only unde1iakings of GEH with respect to information in this document are contained in the contract between NextEra and GEH and nothing contained in this contract shall be construed as changing that contract. The use of this information by anyone other than NextEra for any purpose other than that for which it is intended, is not authorized; and with respect to any unauthorized use, GEH makes no representation or warranty, and assumes no liability as to the completeness, accuracy, or usefulness of the information contained in this document. | |||
ll | |||
003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) | |||
Revision Summary Revision Required Changes to Achieve Revision 0 NIA Identified specific instances of GEH proprietary information and prepared the 1 | |||
report for submittal to the NRC. | |||
Ill | |||
003N7091-NP Revision 1 Non-Proprietary Information- Class I (Public) | |||
Acronyms and Abbreviations Term Definition AOR Analysis of Record BWR Boiling Water Reactor co Condensation Oscillation DAEC Duane Arnold Energy Center DBA Design Basis Accident DW Drywell ECCS Emergency Core Cooling System EPU Extended Power Uprate GEH GE Hitachi Nuclear Energy IBA Intermediate Break Accident LLS Low-Low-Set LOCA Loss-of-Coolant Accident LPCI Low Pressure Coolant Injection LTR Licensing Topical Report NPSH Net Positive Suction Head NRC Nuclear Regulatory Commission oos Out-of-Service PULD Plant Unique Load Definition RB Reactor Building RHR Residual Heat Removal SBA Small Break Accident SE Safety Evaluation Report SRV Safety Relief Valve SRVDL SRV Discharge Line UFSAR Updated Final Safety Analysis Report us United States VB Vacuum Breaker WG Water Gauge WW Wetwell iv | |||
003N7091-NP Revision I Non-Proprietary Information- Class I (Public) | |||
TABLE OF CONTENTS Section 1.0 Introduction and Scope ........................................................................................................ 1 2.0 Contain1nent Response Analysis .......................................................................................... 2 2.1 Containment Response Methodology ...................................................................... 2 2.2 Analysis Inputs and Assumptions ............................................................................ 2 2.3 Results ...................................................................................................................... 4 3.0 WW-to-DW VB Number Reduction Impact ...................................................................... .4 3.1 DAEC EPU NPSH and Overpressure Analysis ...................................................... .4 3.2 Containment Hydrodynamic Loads and PULD ....................................................... 5 3.3 Containment Bypass Analysis ................................................................................. 6 4.0 Conclusions .......................................................................................................................... 7 5.0 References ............................................................................................................................ 8 Appendix A Summary of Case Input Parameters ...................................................................... 13 List of Tables Table I Summary ofDAEC Vacuum Breaker Sizing Analysis Results ............................... 9 List of Figures Figure 1 Case I Containment Differential Pressure Responses .......................................... .I 0 Figure 2 Case 2 Containment Differential Pressure Responses ........................................... 11 Figure 3 Case 3 Containment Differential Pressure Responses .......................................... 12 v | |||
003N7091-NP Revision I Non-Proprietary Information - Class I (Public) 1.0 Introduction and Scope Vacuum breaker (VB) valves installed in the Duane Arnold Energy Center (DAEC) containment systems prevent potential negative differential pressure exceeding design limits between the wetwell (WW) and drywell (DW). Functional requirements established during the Mark I containment program (Reference I) include a VB load definition, based upon dynamic modeling of the vent pressure transient, and VB number and size for predicting integrated containment response to prescribed events. Prior to the Mark I program, a general design requirement derived from the Bodega Bay Preliminary Hazards Summary Report included specification of VB area being no less than 1/16 of the total vent flow cross-sectional area. A number of plants revised their VB sizing technical bases by implementing the more systematic approach developed in the Mark I program (Reference I). Calculations were performed using an approach similar to that applied for the Reference I analyses to serve as the technical basis supporting DAEC VB size and number requirements for operation. | |||
These analysis cases performed for the DAEC VB sizing evaluation simulate events developed from a review of the analyses performed in Reference I and include: | |||
Case I: Inadvertent actuation of DW spray with one (1) DW spray header during normal plant operation. | |||
Case 2: DW spray following a small steam line break loss-of-coolant accident (LOCA) with [[ ]] and use of two (2) DW spray headers. | |||
Case 3: Emergency core cooling system (ECCS) vessel reflood into the DW following a large liquid break LOCA with [[ | |||
]] | |||
The design inputs for each case are summarized in Appendix A. | |||
I | |||
003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) 2.0 Containment Response Analysis 2.1 Containment Response Methodology The GE Hitachi Nuclear Energy (GEH) computer code SHEX was used to perform the containment pressure and temperature response analysis presented in this report. The SHEX code is the code currently used by GEH to perform analyses of the containment pressure and temperature response including analyses performed to evaluate VB sizing adequacy for events resulting in negative DW-to-WW differential pressure, negative DW-to-Reactor Building (DW-to-RB) and negative WW-to-RB differential pressures. [[ | |||
]] | |||
SHEX is the standard code used by GEH for containment response calculations for boiling water reactor (BWR) Mark I, Mark II and Mark III plants where safety systems such as ECCS and residual heat removal (RHR) pump operation or use of containment spray is simulated. | |||
A licensing topical repo1i (L TR) was not issued for SHEX, and therefore an NRC safety evaluation (SE) report with formal NRC approval for SHEX was not issued. However, the NRC has accepted the use of SHEX for United States (US) BWR Mark I containment analyses (Reference 2), in paiiicular containment analyses performed in suppmi of power uprates performed for US BWR Mark I plants. | |||
GEH report NEDC-33004P-A Revision 4 (Reference 3) documents the GEH guidelines for extended thermal power uprates while maintaining the current plant operating reactor pressure. | |||
This L TR was reviewed and approved by the NRC and includes a copy of the NRC SE with approval of the L TR. Included within the NRC SE is the NRC basis for acceptance of SHEX containment analysis applications. | This L TR was reviewed and approved by the NRC and includes a copy of the NRC SE with approval of the L TR. Included within the NRC SE is the NRC basis for acceptance of SHEX containment analysis applications. | ||
The NRC SE approval for use of SHEX for power uprate containment analyses cited the Reference 2 NRC letter which included a requirement for benchmarking analyses. | The NRC SE approval for use of SHEX for power uprate containment analyses cited the Reference 2 NRC letter which included a requirement for benchmarking analyses. However, per the NRC SE approval for NEDC-33004P-A Revision 4, the NRC accepted the use of SHEX without need for benchmark analyses for Mark I containments, as originally stipulated in the cited NRC letter. This was based on NRC comparisons of their own benchmark cases results with SHEX results for Mark I plants. | ||
However, per the NRC SE approval for NEDC-33004P-A Revision 4, the NRC accepted the use of SHEX without need for benchmark analyses for Mark I containments, as originally stipulated in the cited NRC letter. This was based on NRC comparisons of their own benchmark cases results with SHEX results for Mark I plants. 2.2 Analysis Inputs and Assumptions The sizing evaluation for the DAEC WW-to-DW VBs and RB-to-WW VB are based on the results of the GEH analysis of the DAEC containment system response to potentially limiting events for negative DW-to-WW differential pressure as well as for negative DW-to-RB differential pressure and WW-to-RB differential pressure. | 2.2 Analysis Inputs and Assumptions The sizing evaluation for the DAEC WW-to-DW VBs and RB-to-WW VB are based on the results of the GEH analysis of the DAEC containment system response to potentially limiting events for negative DW-to-WW differential pressure as well as for negative DW-to-RB differential pressure and WW-to-RB differential pressure. These analyses were performed for a set of cases which were [[ ]] presented originally in Reference 1. | ||
These analyses were performed for a set of cases which were [[ ]] presented originally in Reference | 2 | ||
-Class I (Public) The following three cases were performed for DAEC. For all three cases, a single failure of one WW-DW VB and two VBs out-of-service (OOS) are assumed and only one (1) RB-to-WW VB is used. The specific inputs for those three cases are listed in Appendix A. Case I: Inadvertent Actuation ofDW Spray During Normal Plant Operation. | 003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) | ||
Case I assumes that one DW spray header is inadvertently actuated with [[ ]] during plant normal operation. | The following three cases were performed for DAEC. For all three cases, a single failure of one WW-DW VB and two VBs out-of-service (OOS) are assumed and only one (1) RB-to-WW VB is used. The specific inputs for those three cases are listed in Appendix A. | ||
Case 2: Actuation of Two DW Spray Headers Following a Small Steam Line Break LOCA. Case 2 assumes that two DW spray headers are actuated [[ ]] Case 3: ECCS Reflood into the DW Following a Large Liquid Break LOCA. [[ ]] Key assumptions for the analyses are presented below. Case specific inputs are summarized in Appendix A. Other analysis inputs not listed in Appendix A are based on Reference | Case I: Inadvertent Actuation ofDW Spray During Normal Plant Operation. | ||
Case I assumes that one DW spray header is inadvertently actuated with [[ | |||
I. Single failure of one (1) WW-to-DW VB and two (2) WW-DW VBs OOS are assumed for all cases. For all cases in the report, only one RB-to-WW VB is used. 2. [[ ]] 3. [[ ]] 4. [[ ]] throughout the transient event analysis period. 5. [[ ]] 3 003N7091-NP Revision 1 Non-Proprietary Information-Class I (Public) 6. The VB flow component mass flow rates are calculated based on [[ ]] from the source volume, which is the WW for the WW-to-DW VBs and is the RB for the RB-to-WW VB. 7. [[ ]] 2.3 Results Table 1 summarizes the results of the containment response analyses, showing peak values for DW-to-WW differential pressure, DW-to-RB and WW-to-RB differential pressures. | ]] during plant normal operation. | ||
Figures 1 through 3 show the plots of DW-to-WW differential pressure, DW-to-RB differential pressure and WW-to-RB differential pressure for those three cases. Case 1 produces the most severe response with respect to the maximum negative DW-to-RB and WW-to-RB differential pressures, with a predicted DW-to-RB differential pressure of [[ ]] and predicted WW-to-RB differential pressure of [[ ]]. The LOCA cases, Cases 2 and 3, produce the more severe response with respect to maximum negative DW-to-WW differential pressure, with Case 2 limiting with a predicted DW-to-WW differential pressure of [[ ]]. For the LOCA cases, the predicted maximum values of negative DW-to-WW differential pressure occur within 20 seconds. DW-to-RB and WW-to-RB differential pressures remain greater than zero for Case 3. The results presented in Table 1 demonstrate that all predicted differential pressure values for DW-to-RB differential pressure, WW-to-RB differential pressure and DW-to-WW differential pressure are below the design limit of 2 psid. 3.0 WW-to-DW VB Number Reduction Impact The following discussion is limited to the change in the number of available WW-to-DW VBs and the changes in WW-to-DW inputs. All the other conditions for a particular analysis remain the same as analysis of record (AOR) to be discussed. | Case 2: Actuation of Two DW Spray Headers Following a Small Steam Line Break LOCA. | ||
3.1 DAEC EPU NPSH and Overpressure Analysis The DAEC net positive suction head (NPSH) analysis at extended power uprate (EPU) conditions can be found in Reference | Case 2 assumes that two DW spray headers are actuated [[ | ||
]] | |||
Case 3: ECCS Reflood into the DW Following a Large Liquid Break LOCA. | |||
[[ | |||
]] | |||
Key assumptions for the analyses are presented below. Case specific inputs are summarized in Appendix A. Other analysis inputs not listed in Appendix A are based on Reference 4. | |||
Key Assumptions for Analyses: | |||
I. Single failure of one (1) WW-to-DW VB and two (2) WW-DW VBs OOS are assumed for all cases. For all cases in the report, only one RB-to-WW VB is used. | |||
: 2. [[ | |||
]] | |||
: 3. [[ | |||
]] | |||
: 4. [[ | |||
]] throughout the transient event analysis period. | |||
: 5. [[ | |||
]] | |||
3 | |||
003N7091-NP Revision 1 Non-Proprietary Information- Class I (Public) | |||
: 6. The VB flow component mass flow rates are calculated based on [[ | |||
]] from the source volume, which is the WW for the WW-to-DW VBs and is the RB for the RB-to-WW VB. | |||
: 7. [[ | |||
]] | |||
2.3 Results Table 1 summarizes the results of the containment response analyses, showing peak values for DW-to-WW differential pressure, DW-to-RB and WW-to-RB differential pressures. Figures 1 through 3 show the plots of DW-to-WW differential pressure, DW-to-RB differential pressure and WW-to-RB differential pressure for those three cases. | |||
Case 1 produces the most severe response with respect to the maximum negative DW-to-RB and WW-to-RB differential pressures, with a predicted DW-to-RB differential pressure of | |||
[[ ]] and predicted WW-to-RB differential pressure of [[ ]]. | |||
The LOCA cases, Cases 2 and 3, produce the more severe response with respect to maximum negative DW-to-WW differential pressure, with Case 2 limiting with a predicted DW-to-WW differential pressure of [[ ]]. For the LOCA cases, the predicted maximum values of negative DW-to-WW differential pressure occur within 20 seconds. DW-to-RB and WW-to-RB differential pressures remain greater than zero for Case 3. | |||
The results presented in Table 1 demonstrate that all predicted differential pressure values for DW-to-RB differential pressure, WW-to-RB differential pressure and DW-to-WW differential pressure are below the design limit of 2 psid. | |||
3.0 WW-to-DW VB Number Reduction Impact The following discussion is limited to the change in the number of available WW-to-DW VBs and the changes in WW-to-DW inputs. All the other conditions for a particular analysis remain the same as analysis of record (AOR) to be discussed. | |||
3.1 DAEC EPU NPSH and Overpressure Analysis The DAEC net positive suction head (NPSH) analysis at extended power uprate (EPU) conditions can be found in Reference 5. [[ | |||
]] | |||
4 | |||
003N7091-NP Revision 1 Non-Proprietary Information- Class I (Public) | |||
Overpressure analysis refers to containment overpressure analyses in Reference 5. Specifically, those analyses refer to containment short-term analysis (using M3CPT) for peak containment pressure and temperature, and long-term design basis accident (DBA) analyses. | |||
Reference 5 Section 2.3.1 M3CPT DAEC Short-Term Analysis: | Reference 5 Section 2.3.1 M3CPT DAEC Short-Term Analysis: | ||
The Reference 5 M3CPT short-term analysis only lasts seconds, and ECCS flow is not modeled. [[ ]] Reference 5 Section 2.3.2 SHEX DAEC Long-Term DBA Analysis: | The Reference 5 M3CPT short-term analysis only lasts ~30 seconds, and ECCS flow is not modeled. [[ | ||
For the long-term DBA-LOCA analysis in Reference 5 Section 2.3.2, the parameters of interest are peak suppression pool temperature, peak WW temperature and peak containment pressures as shown in Tables 3-3 and 3-4 of Reference | ]] | ||
Reference 5 Section 2.3.2 SHEX DAEC Long-Term DBA Analysis: | |||
UFSAR Case 4 used low pressure coolant injection (LPCI) cooling and UFSAR Case 3 used containment spray. Other inputs are the same for those two cases. [[ ]] It is therefore concluded that changing the number of available VBs for DAEC from 6 to 4 (or the input changes for those VBs) has no effect on DAEC short-term and long-term containment overpressure analyses. | For the long-term DBA-LOCA analysis in Reference 5 Section 2.3.2, the parameters of interest are peak suppression pool temperature, peak WW temperature and peak containment pressures as shown in Tables 3-3 and 3-4 of Reference 5. Updated Final Safety Analysis Report (UFSAR) | ||
3.2 Containment Hydrodynamic Loads and PULD Containment hydrodynamic loads consist of LOCA loads and safety relief valve (SRV) loads. LOCA loads include pool swell, vent thrust, condensation oscillation (CO) and chugging. | Case 3 and Case 4 in Reference 5 are essentially the same (Section 2.3.2.l A discussion). | ||
[[ ]] The SRV air-clearing loads include SRV discharge line (SRVDL) loads, suppression pool boundary pressure loads and drag loads on submerged structures. | UFSAR Case 4 used low pressure coolant injection (LPCI) cooling and UFSAR Case 3 used containment spray. Other inputs are the same for those two cases. | ||
These loads are influenced by the SRV opening setpoint pressure, the initial water leg in the SRVDL, the SRVDL geometry, 5 003N7091-NP Revision 1 Non-Proprietary Information | [[ | ||
-Class I (Public) and the suppression pool geometry. | ]] | ||
VB operation would not have any effect on those parameters, and therefore, the number of available VBs will have no effect on the SRV loads. For the times when DW pressure is lower than WW (e.g., following DW spray initiation), the smaller number of VBs can slightly increase the WW-to-DW pressure difference for a very short duration immediately after VB opening. This would make the water level in the SRV tailpipe slightly higher at the time of SRV actuation. | It is therefore concluded that changing the number of available VBs for DAEC from 6 to 4 (or the input changes for those VBs) has no effect on DAEC short-term and long-term containment overpressure analyses. | ||
[[ ]] For example, for LOCA conditions, it is assumed in References 8 and 9 that [[ ]] Therefore, the number ofVBs has no effect on the Mark I SRV loads defined for DAEC. Plant Unique Load Definition (PULD) analyses for intermediate break accidents (IBAs) and small break accidents (SB As) can be found in Reference 5 Section 3 .1.3 .5. [[ ]] Therefore, there is no effect on those analyses from the VBs. 3.3 Containment Bypass Analysis The steam bypass analysis is discussed in Section 2.3.2.6 of Reference | 3.2 Containment Hydrodynamic Loads and PULD Containment hydrodynamic loads consist of LOCA loads and safety relief valve (SRV) loads. | ||
LOCA loads include pool swell, vent thrust, condensation oscillation (CO) and chugging. | |||
6 | [[ | ||
-Class I (Public) Table 1 Summary ofDAEC Vacuum Breaker Sizing Analysis Results Case No. 1 2 3 Inadvertent Actuation DW Spray During Small ECCS Reflood Case Description ofDW Spray during | ]] | ||
The SRV air-clearing loads include SRV discharge line (SRVDL) loads, suppression pool boundary pressure loads and drag loads on submerged structures. These loads are influenced by the SRV opening setpoint pressure, the initial water leg in the SRVDL, the SRVDL geometry, 5 | |||
-Class I (Public) Case 2 Containment Differential Pressure Responses 11 | 003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) and the suppression pool geometry. VB operation would not have any effect on those parameters, and therefore, the number of available VBs will have no effect on the SRV loads. | ||
For the times when DW pressure is lower than WW (e.g., following DW spray initiation), the smaller number of VBs can slightly increase the WW-to-DW pressure difference for a very short duration immediately after VB opening. This would make the water level in the SRV tailpipe slightly higher at the time of SRV actuation. [[ | |||
-Class I (Public) Case 3 Containment Differential Pressure Responses 12 | ]] | ||
003N7091-NP Revision 1 Non-Proprietary Information | For example, for LOCA conditions, it is assumed in References 8 and 9 that [[ | ||
-Class I (Public) Appendix A Summary of Case Input Parameters easel Case2 Item No. Case | ]] | ||
(°F) 135 266.93 15.2 minimum 2.b. Initial DW Pressure (psia) 15.7 maximum 39.8 (Note 1) 2.c. Initial DW Relative Humidity(%) | Therefore, the number ofVBs has no effect on the Mark I SRV loads defined for DAEC. | ||
100 ---2.d. Initial DW Quality ---1.0 | Plant Unique Load Definition (PULD) analyses for intermediate break accidents (IBAs) and small break accidents (SB As) can be found in Reference 5 Section 3 .1.3 .5. [[ | ||
(°F) 15.2 minimum 2.g. Initial WW Pressure (psia) 15.7 maximum 38.5 (Note 1) 2.h. Initial WW Relative Humidity(%) | ]] Therefore, there is no effect on those analyses from the VBs. | ||
100 100 | 3.3 Containment Bypass Analysis The steam bypass analysis is discussed in Section 2.3.2.6 of Reference 5. [[ | ||
NIA 0 3.b. Vessel Steam Enthalpy (Btu/lbm) | ]] Therefore, the number of available VBs has no effect on the Reference 5 steam bypass capacity analysis. | ||
NIA NIA 4 WETWELL-DRYWELL VACCUM BREAKER PARAMETERS 4.a. WW-DW VB Loss Coefficient (K) 2.41 2.41 4.b. Number of Installed WW-DW VBs 7 7 (Note 2) 4.c. WW-to-DW VB Area per Valve ( | 6 | ||
003N7091-NP Revision 1 Non-Proprietary Information- Class I (Public) 4.0 Conclusions The results presented in Table I confirm that the size and number of WW-to-DW VBs and RB-to-WW VBs for DAEC, accounting for two (2) WW-to-DW VB OOS, and one (1) WW-to-DW VB failure, are sufficient to adequately mitigate negative DW-to-WW, DW-to-RB and WW-to-RB differential pressures and prevent exceeding the differential pressure design limits of 2 psid. | |||
It is further concluded that the number of available WW-to-DW VB reduction does not have an effect on the containment analysis repmied in the DAEC EPU containment system analysis report (Reference 5). | |||
7 | |||
Distance WW Spray Header to DW | |||
(°F) NIA NIA 14 | 003N7091-NP Revision 1 Non-Proprietary Information- Class I (Public) 5.0 References | ||
: 1. GE Company, "Mark I Containment Program Mark I Wetwell-to-Drywell Vacuum Breaker Functional Requirements, Task 9.4.3," NEDE-24802, April 1980. | |||
( | : 2. Letter to G. L. Sozzi (GE) from A. Thadani (NRC), "Use of SHEX Computer Program | ||
. and ANSI/ANS 5.1-1979 Decay Heat Source Term for Containment Long-Term Pressure and Temperature Analysis," MFN-117-93, July 13, 1993. | |||
: 3. GE Nuclear Energy, "Constant Pressure Power Uprate," NEDC-33004P-A, Revision 4, July 2003. | |||
: 4. Letter from R. McGee (IES) to W. F. Farrel (GE), "DAEC EPU OPL-4A," NG-00-1653, September 28, 2000. | |||
It is | : 5. GE Nuclear Energy, "Project Task Report Duane Arnold Energy Center Asset Enhancement Program Task T0400: Containment System Response," GE-NE-A22-00100-23-01-R2, Revision 2, December 2002. | ||
: 6. GE Company, "Mark I Containment Program Load Definition Repo1i," NED0-21888, Revision 2, November 1981. | |||
: 7. GE Company, "Mark I Containment Program Application Guide 3 Safety Relief Valve Discharge Line Clearing Transient," NEDE-24555-P, Volume I, Revision 2, September 1980. | |||
: 8. GE Company, "Mark I Containment Program Application Guide 9 Safety Relief Valve Discharge Line Reflood Transient," NEDE-24555-P, Volume III, Revision 2, September 1980. | |||
(2) The information sought to be withheld is contained in GEH proprietary report 003N7091-P, "NextEra Energy Duane Arnold (DAEC) Vacuum Breaker Sizing Analysis," Revision 1, dated September 2017. GEH proprietary information in 003N709 l-P Revision 1 is identified by a dotted underline placed within double square brackets. | : 9. GE Company, "Mark I Containment Program, Analytical Model for Computing Water Rise in a Safety/Relief Valve Discharge Line Following Valve Closure Task 7.1.2.2," | ||
.. GEH proprietary information in figures and large objects is identified by double square brackets before and after the object. In all cases, the superscript notation (3) refers to Paragraph (3) of this affidavit, which provides the basis for the proprietary determination. | NEDE-23898-P, October 1978. | ||
(3) In making this application for withholding of proprietary information of which it is the owner or licensee, GEH relies upon the exemption from disclosure set forth in the Freedom of Information Act ("FOIA"), 5 U.S.C. §552(b)(4), and the Trade Secrets Act, 18 U.S.C. §1905, and NRC regulations 10 CFR 9.17(a)(4), and 2.390(a)(4) for trade secrets (Exemption 4). The material for which exemption from disclosure is here sought also qualifies under the narrower definition of trade secret, within the meanings assigned to those terms for purposes of FOIA Exemption 4 in, respectively, Critical Mass Energy Project v. Nuclear Regulatory Commission, 975 F.2d 871 (D.C. Cir. 1992), and Public Citizen Health Research Group v. FDA, 704 F.2d 1280 (D.C. Cir. | : 10. GE Company, "Evaluation of Mark I S/RV Load Cases C3.l, C3.2, and C3.3 for the Duane Arnold Energy Center," NEDC-22204, September 1982. | ||
1983). ( 4) The information sought to be withheld is considered to be proprietary for the reasons set f01ih in paragraphs (4)a and (4)b. Some examples of categories of information that fit into the definition of proprietary information are: a. Information that discloses a process, method, or apparatus, including supporting data and analyses, where prevention of its use by GEH's competitors without a license from GEH constitutes a competitive economic advantage over other companies; | : 11. CAL-MOl-152, "Drywell Torus Vacuum Breaker System," February 26, 2002. | ||
: b. Information that, if used by a competitor, would reduce its expenditure of resources or improve its competitive position in the design, manufacture, shipment, installation, assurance of quality, or licensing of a similar product; c. Information that reveals aspects of past, present, or future GEH customer-funded development plans and programs, resulting in potential products to GEH; 003N7091-P Revision 1 Affidavit Page 1 of 3 GE-Hitachi Nuclear Energy Americas LLC d. Information that discloses trade secret or potentially patentable subject matter for which it may be desirable to obtain patent protection. | 8 | ||
(5) To address 10 CPR 2.390(b)(4), the information sought to be withheld is being submitted to NRC in confidence. | |||
The information is of a s01i customarily held in confidence by GEH, and is in fact so held. The information sought to be withheld has, to the best of my knowledge and belief, consistently been held in confidence by GEH, not been disclosed publicly, and not been made available in public sources. All disclosures to third parties, including any required transmittals to the NRC, have been made, or must be made, pursuant to regulatory provisions for proprietary or confidentiality agreements or both that provide for maintaining the information in confidence. | 003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) | ||
The initial designation of this information as proprietary information, and the subsequent steps taken to prevent its unauthorized disclosure, are as set f01ih in the following paragraphs (6) and (7). (6) Initial approval of proprietary treatment of a document is made by the manager of the originating component, who is the person most likely to be acquainted with the value and sensitivity of the information in relation to industry knowledge, or who is the person most likely to be subject to the terms under which it was licensed to GEH. (7) The procedure for approval of external release of such a document typically requires review by the staff manager, project manager, principal scientist, or other equivalent authority for technical content, competitive effect, and determination of the accuracy of the proprietary designation. | Table 1 Summary ofDAEC Vacuum Breaker Sizing Analysis Results Case No. 1 2 3 Inadvertent Actuation DW Spray During Small ECCS Reflood Case Description ofDW Spray during Steam Line Break Following DBA-LOCA Normal Operation Failure of one WW- Failure ofone WW-DW Failure of one WW-DW Single Failure DW VB to open and VB to open and two VB to open and two OOS two OOS oos Number ofWW-DW VBs 4 4 4 Number of RB-WW VB System Branch Lines I I I Open Spray or ECCS Reflood Temp (°F) [[ ]] | ||
Disclosures outside GEH are limited to regulatory bodies, customers, and potential customers, and their agents, suppliers, and licensees, and others with a legitimate need for the information, and then only in accordance with appropriate regulatory provisions or proprietary and/or confidentiality agreements. | Number of Spray Headers I 2 NIA Peak Negative 1*2 DW-to-RB Differential Pressure [[ | ||
(8) The information identified in paragraph (2) is classified as proprietary because it contains details of GEH's design and licensing methodology for the GEH Boiling Water Reactor (BWR). The development of this methodology, along with the testing, development, and approval, was achieved at a significant cost to GEH. The development of the design and licensing methodology along with the interpretation and application of the analytical results is derived from the extensive experience databases that constitute a major GEH asset. (9) Public disclosure of the information sought to be withheld is likely to cause substantial harm to GEH's competitive position and foreclose or reduce the availability of making opp01iunities. | (psid) | ||
The information is paii of GEH's comprehensive BWR safety and technology base, and its commercial value extends beyond the original development cost. The value of the technology base goes beyond the extensive physical database and analytical methodology and includes development of the expe1iise to determine and apply 003N7091-P Revision 1 Affidavit Page 2 of 3 GE-Hitachi Nuclear Energy Americas LLC the appropriate evaluation process. In addition, the technology base includes the value derived from providing analyses done with NRC-approved methods. The research, development, engineering, analytical and NRC review costs comprise a substantial investment of time and money by GEH. The precise value of the expertise to devise an evaluation process and apply the correct analytical methodology is difficult to quantify, but it clearly is substantial. | Peak Negative 1*2 WW-to-RB Differential Pressure (psid) | ||
GEH's competitive advantage will be lost if its competitors are able to use the results of the GEH experience to normalize or verify their own process or if they are able to claim an equivalent understanding by demonstrating that they can arrive at the same or similar conclusions. | Peak Negative 2 DW-to-WW Differential Pressure (psid) ]] | ||
The value of this information to GEH would be lost if the information were disclosed to the public. Making such information available to competitors without their having been required to undertake a similar expenditure of resources would unfairly provide competitors with a windfall, and deprive GEH of the opportunity to exercise its competitive advantage to seek an adequate return on its large investment in developing and obtaining these very valuable analytical tools. I declare under penalty of pe1jury that the foregoing is true and correct. Executed on this | Notes: | ||
: 1. DW-to-RB and WW-to-RB differential pressures are based on a RB pressure ofl4.7 psia. | |||
: 2. Times shown are relative to the stmt time ofDW spray for Cases I and 2 and relative to start ofECCS reflood for Case 3. | |||
: 3. [[ | |||
]] | |||
9 | |||
~-------- | |||
003N7091-NP Revision I Non-Proprietary Information- Class I (Public) | |||
[[ | |||
]] | |||
Figure 1 Case 1 Containment Differential Pressure Responses IO | |||
003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) | |||
[[ | |||
]] | |||
Figure 2 Case 2 Containment Differential Pressure Responses 11 | |||
003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) | |||
[[ | |||
]] | |||
Figure 3 Case 3 Containment Differential Pressure Responses 12 | |||
003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) | |||
Appendix A Summary of Case Input Parameters easel Case2 Case3 Inadvertent Item No. Case Drywell Spray Vessel Reflood Spray AfterLOCA Through Break Operation CONTAIMENT GEOMETRY 1 PARAMETERS l.a. DW Volume (ft3) 130,000 130,000 130,000 3 | |||
l.b. WW Airspace Volume (ft ) 94,070 94,070 94,070 Initial Suppression Pool Volume - | |||
l.c. 61,500 61,500 61,500 (HWL) (ft3) 2 INITIAL CONDITIONS 2.a. Initial DW Temperature (°F) 135 266.93 266.93 15.2 minimum 2.b. Initial DW Pressure (psia) 15.7 maximum 39.8 39.8 (Note 1) 2.c. Initial DW Relative Humidity(%) 100 --- --- | |||
2.d. Initial DW Quality --- 1.0 1.0 Initial WW Airspace Temperature 2.e. 95 143 143.3 | |||
(°F) | |||
Initial Suppression Pool (SP) 2.f. 95 143 143 Temperature (°F) 15.2 minimum 2.g. Initial WW Pressure (psia) 15.7 maximum 38.5 38.5 (Note 1) 2.h. Initial WW Relative Humidity(%) 100 100 100 VESSEL STEAM BREAKFLOW 3 PARAMETERS 3.a. Vessel Steaming Rate (Ibmlsec) NIA 0 NIA 3.b. Vessel Steam Enthalpy (Btu/lbm) NIA NIA NIA 4 WETWELL-DRYWELL VACCUM BREAKER PARAMETERS 4.a. WW-DW VB Loss Coefficient (K) 2.41 2.41 2.41 4.b. Number of Installed WW-DW VBs 7 7 7 (Note 2) 4.c. WW-to-DW VB Area per Valve (ft2) 1.396 1.396 1.396 4.d. WW-to-DW VB Opening Pressure 0.35 0.35 0.35 Differential (psid) 4.e. WW-to-DW VB Full Open Pressure 0.5 0.5 0.5 Differential (psid) 13 | |||
003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) | |||
Casel Case2 Case3 Inadvertent Item No. Case Drywell Spray Vessel Reflood Spray AfterLOCA Through Break Operation 4.f. WW-to-DW VB Opening Time from Starting Opening to Full Open 2 2 2 (seconds) 5 REACTOR BUILDING-TO-WETWELL VACUUM BREAKER PARAMETERS 5.a. Number of RB-to-WW VBs 1 1 1 5.b. RB-to-WW VB Area per Valve (ft2) 1.623 1.623 1.623 5.c. RB-to-WW VB Opening Setpoint 0.35 0.35 0.35 Pressure Differential (psid) 5.d. RB-to-WW VB Full Open Pressure 0.5 0.5 0.5 Differential (psid) 5.e. RB-to-WW VB Opening Time from Starting Opening to Full Open 2 2 2 (seconds) 5.f. RB-DW VB Loss Coefficient (K) 2.86 2.86 2.86 6 CONTAINMENT SPRAY PARAMETERS 6.a. Number of RHR DW Spray Headers 1 2 NIA 6.b. Maximum RHR DW Spray Flow Rate per Header, (gpm) 4,560 4,560 NIA 6.c. RHR DW Spray Temperature {°F) [[ ]] [[ ]] | |||
(Note 3) (Note 4) | |||
Minimum Minimum Service Water Service Water Temperature Temperature 35°F 35°F Minimum Torus Minimum Torus NIA Water Water Temperature Temperature 55°F 55°F Heat Exchanger Heat Exchanger k-value: k-value: | |||
141 Btu/sec-°F 141 Btu/sec-°F 6.d. Number of RHR WW Spray Headers NIA NIA NIA 6.e. RHR WW Spray Flow Rate, (lbm/sec) | |||
NIA NIA NIA 6.f. Distance WW Spray Header to DW Floor (ft) | |||
NIA NIA NIA 6.g. RHR WW Spray Temperature (°F) NIA NIA NIA 14 | |||
003N7091-NP Revision I Non-Proprietary Information - Class I (Public) | |||
Case 1 Case2 Case3 Inadvertent Item No. Case Drywell Spray Vessel Reflood Spray AfterLOCA Through Break Operation 6.h. DW and WW Spray Efficiency 100% 100% NIA 6.i. Average DW and WW Spray Droplet Diameter {ft) [[ ]] NIA 7 ECCS VESSEL REFLOOD PARAMETERS 7.a. ECCS Vessel Reflood Flow Through NIA NIA 35,000 Break (gpm) 7.b. ECCS Reflood Vessel Break Flow Temperature (°F) | |||
NIA NIA [[ ]] | |||
7.c. ECCS Reflood Vessel Break Flow NIA NIA 100% | |||
Mixing Efficiency 8 REACTOR BUILDING INITIAL CONDITIONS (NOTE 5) 8.a. Pressure 0.87 to 0.32 inch 0.87 to 0.32 inch 0.87 to 0.32 inch water gauge (wg) wgvacuum wgvacuum vacuum 8.b. Temperature (°F) 68 to 100 68 to 100 68 to 100 8.c. Relative Humidity (-) 90%-20% 90%-20% 90%-20% | |||
Notes: | |||
I. [[ ]] | |||
: 2. Four (4) WW-to-DW VBs are used for all cases in this report (See Table 1). | |||
: 3. The spray liquid temperature is determined by assuming that one heat exchanger is in operation. With one heat exchanger running, the minimum liquid temperature would be | |||
[[ | |||
]] | |||
15 | |||
003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) | |||
: 4. The spray liquid temperature is determined by assuming that two heat exchangers are in operation. It is estimated in Reference 11 and also by GEH that [[ | |||
]] Therefore the pool temperature would be [[ ]] when containment spray is initiated. With two heat exchangers running, the minimum liquid spray temperature would be | |||
[[ | |||
]] | |||
: 5. Some iterations are made and the following RB initial conditions are used for the analysis. It is wo1ih to note that the RB-to-WW VB is only used for Case 1. For Cases 2 and 3, the RB-to-WW VB does not open during the transient. | |||
: a. [[ | |||
]] | |||
16 | |||
ATTACHMENT 5 GE-Hitachi Affidavit for Withholding of Proprietary Information | |||
GE-Hitachi Nuclear Energy Americas LLC AFFIDAVIT I, Lisa K. Schichlein, state as follows: | |||
(1) I am a Senior Project Manager, NPP/Services Licensing, Regulatory Affairs, GE-Hitachi Nuclear Energy Americas LLC (GEH), and have been delegated the function of reviewing the information described in paragraph (2) which is sought to be withheld, and have been authorized to apply for its withholding. | |||
(2) The information sought to be withheld is contained in GEH proprietary report 003N7091-P, "NextEra Energy Duane Arnold (DAEC) Vacuum Breaker Sizing Analysis," Revision 1, dated September 2017. GEH proprietary information in 003N709 l-P Revision 1 is identified by a dotted underline placed within double square brackets. [[Jhi~..~~nt~m:.~j~,;:m | |||
~~~mP.!~,~:!.J] GEH proprietary information in figures and large objects is identified by double square brackets before and after the object. In all cases, the superscript notation (3) refers to Paragraph (3) of this affidavit, which provides the basis for the proprietary determination. | |||
(3) In making this application for withholding of proprietary information of which it is the owner or licensee, GEH relies upon the exemption from disclosure set forth in the Freedom of Information Act ("FOIA"), 5 U.S.C. §552(b)(4), and the Trade Secrets Act, 18 U.S.C. | |||
§1905, and NRC regulations 10 CFR 9.17(a)(4), and 2.390(a)(4) for trade secrets (Exemption 4). The material for which exemption from disclosure is here sought also qualifies under the narrower definition of trade secret, within the meanings assigned to those terms for purposes of FOIA Exemption 4 in, respectively, Critical Mass Energy Project v. Nuclear Regulatory Commission, 975 F.2d 871 (D.C. Cir. 1992), and Public Citizen Health Research Group v. FDA, 704 F.2d 1280 (D.C. Cir. 1983). | |||
(4) The information sought to be withheld is considered to be proprietary for the reasons set f01ih in paragraphs (4)a and (4)b. Some examples of categories of information that fit into the definition of proprietary information are: | |||
: a. Information that discloses a process, method, or apparatus, including supporting data and analyses, where prevention of its use by GEH's competitors without a license from GEH constitutes a competitive economic advantage over other companies; | |||
: b. Information that, if used by a competitor, would reduce its expenditure of resources or improve its competitive position in the design, manufacture, shipment, installation, assurance of quality, or licensing of a similar product; | |||
: c. Information that reveals aspects of past, present, or future GEH customer-funded development plans and programs, resulting in potential products to GEH; 003N7091-P Revision 1 Affidavit Page 1 of 3 | |||
GE-Hitachi Nuclear Energy Americas LLC | |||
: d. Information that discloses trade secret or potentially patentable subject matter for which it may be desirable to obtain patent protection. | |||
(5) To address 10 CPR 2.390(b)(4), the information sought to be withheld is being submitted to NRC in confidence. The information is of a s01i customarily held in confidence by GEH, and is in fact so held. The information sought to be withheld has, to the best of my knowledge and belief, consistently been held in confidence by GEH, not been disclosed publicly, and not been made available in public sources. All disclosures to third parties, including any required transmittals to the NRC, have been made, or must be made, pursuant to regulatory provisions for proprietary or confidentiality agreements or both that provide for maintaining the information in confidence. The initial designation of this information as proprietary information, and the subsequent steps taken to prevent its unauthorized disclosure, are as set f01ih in the following paragraphs (6) and (7). | |||
(6) Initial approval of proprietary treatment of a document is made by the manager of the originating component, who is the person most likely to be acquainted with the value and sensitivity of the information in relation to industry knowledge, or who is the person most likely to be subject to the terms under which it was licensed to GEH. | |||
(7) The procedure for approval of external release of such a document typically requires review by the staff manager, project manager, principal scientist, or other equivalent authority for technical content, competitive effect, and determination of the accuracy of the proprietary designation. Disclosures outside GEH are limited to regulatory bodies, customers, and potential customers, and their agents, suppliers, and licensees, and others with a legitimate need for the information, and then only in accordance with appropriate regulatory provisions or proprietary and/or confidentiality agreements. | |||
(8) The information identified in paragraph (2) is classified as proprietary because it contains details of GEH's design and licensing methodology for the GEH Boiling Water Reactor (BWR). The development of this methodology, along with the testing, development, and approval, was achieved at a significant cost to GEH. | |||
The development of the design and licensing methodology along with the interpretation and application of the analytical results is derived from the extensive experience databases that constitute a major GEH asset. | |||
(9) Public disclosure of the information sought to be withheld is likely to cause substantial harm to GEH's competitive position and foreclose or reduce the availability of profit-making opp01iunities. The information is paii of GEH's comprehensive BWR safety and technology base, and its commercial value extends beyond the original development cost. | |||
The value of the technology base goes beyond the extensive physical database and analytical methodology and includes development of the expe1iise to determine and apply 003N7091-P Revision 1 Affidavit Page 2 of 3 | |||
GE-Hitachi Nuclear Energy Americas LLC the appropriate evaluation process. In addition, the technology base includes the value derived from providing analyses done with NRC-approved methods. | |||
The research, development, engineering, analytical and NRC review costs comprise a substantial investment of time and money by GEH. The precise value of the expertise to devise an evaluation process and apply the correct analytical methodology is difficult to quantify, but it clearly is substantial. GEH's competitive advantage will be lost if its competitors are able to use the results of the GEH experience to normalize or verify their own process or if they are able to claim an equivalent understanding by demonstrating that they can arrive at the same or similar conclusions. | |||
The value of this information to GEH would be lost if the information were disclosed to the public. Making such information available to competitors without their having been required to undertake a similar expenditure of resources would unfairly provide competitors with a windfall, and deprive GEH of the opportunity to exercise its competitive advantage to seek an adequate return on its large investment in developing and obtaining these very valuable analytical tools. | |||
I declare under penalty of pe1jury that the foregoing is true and correct. | |||
Executed on this 15th day of September 2017. | |||
Lisa K. Schichlein Senior Project Manager, NPP/Services Licensing Regulatory Affairs GE-Hitachi Nuclear Energy Americas LLC 3901 Castle Hayne Road Wilmington, NC 28401 Lisa.Schichlein@ge.com 003N7091-P Revision 1 Affidavit Page 3 of 3}} |
Revision as of 08:40, 22 October 2019
ML17352A335 | |
Person / Time | |
---|---|
Site: | Duane Arnold ![]() |
Issue date: | 12/15/2017 |
From: | Dean Curtland NextEra Energy Duane Arnold |
To: | Document Control Desk, Office of Nuclear Reactor Regulation |
Shared Package | |
ML17352A424 | List: |
References | |
NG-17-0233 | |
Download: ML17352A335 (42) | |
Text
{{#Wiki_filter:Attachment 6 Contains Proprietary Information Withhold Attachme11t 6 from P11blic Disclos11re i11Accorda11ce1vith 10 CFR 2.390 NEXTera ENERGY ~ DUANE ARNOLD December 15, 2017 NG-17-0233 10 CFR50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Duane Arnold Energy Center Docket No. 50-331 Renewed Facility Operating License No. DPR-49 License Amendment Request (TSCR-178) Application to Reduce the Required Number of Operable Suppression Chamber-to-Di-ywell Vacuum Breakers Pursuant to 10 CFR 50.90, NextEra Energy Duane Arnold, LLC (NextEra) is submitting a request for an amendment to the Technical Specifications (TS) for the Duane Arnold Energy Center (DAEC). The proposed change will modify TS 3.6.1.7, "Suppression Chamber-to-Drywell Vacuum Breakers," by revising the required number of operable vacuum breakers for opening from six to five. The Enclosure to this letter provides NextEra's evaluation of the proposed change. Attachment 1 to the enclosure provides a markup of the TS showing the proposed change, and Attachment 2 provides the clean TS page containing the proposed TS change. The change to the TS Bases is provided for information in Attachment 3 and will be incorporated in accordance with the TS Bases Control Program upon implementation of the approved amendment. Attachments 4 and 6 contain non-proprietary and proprietary versions, respectively, of GE-Hitachi document 003N7091, "NextEra Energy Duane Arnold (DAEC) Vacuum Breaker Sizing Analysis." contains information proprieta1y to GE-Hitachi Nuclear Energy Americas, LLC (GEH) and is supported by an affidavit in Attachment 5, signed by GEH, the owner of the information. The affidavit sets forth the basis on which the information may be withheld from public disclosure by the Commission and addresses with specificity the considerations listed in paragraph (b)(4) of 10 CFR 2.390. Accordingly, it is requested that the information that is proprietary to GEH be withheld from public disclosure in accordance with 10 CFR 2.390. N extEra requests approval of the proposed license amendment by December 31, 2018, and implementation within 90 days. In accordance with 10 CFR 50.91, a copy ofthis application with enclosures is being provided to the designated State of Iowa official.
Docwnent Control Desk NG-17-0233 Page 2of2 As discussed in the Enclosure, the proposed change does not involve a significant hazards consideration pursuant to 10 CFR 50.92, and there are no significant environmental impacts associated with the change. The DAEC Onsite Review Group has reviewed the proposed license amendment. This letter contains no new or revised regulat01y commitments. If you have any questions or require additional information, please contact Michael Davis, Licensing Manager, at 319-851-7032. I declare under penalty of perjury that the foregoing is true and correct. Executed on December 15, 2017 Dean Curtland Site Director NextEra Energy Duane Arnold, LLC Enclosure cc: Regional Administrator, USNRC, Region III, Project Manager, USNRC, Duane Arnold Energy Center Resident Inspector, USNRC, Duane Arnold Energy Center A. Leek (State of Iowa)
NG-17-0233 Enclosure Page 1 of7 NEXTERA ENERGY DUANE ARNOLD, LLC DUANE ARNOLD ENERGY CENTER License Amendment Request (TSCR-178) Application to Reduce the Required Number of Operable Suppression Chamber-to-Drywell Vacuum Breakers EVALUATION OF PROPOSED CHANGE 1.0 Summaty Description 2.0 Detailed Desctiption 2.1 Vacuum Breaker Design and Operation 2.2 Cutrent TS Requirements 2.3 Reason for the Proposed Change 2.4 Description of the Proposed Change 3.0 Technical Evaluation 4.0 Regulatoty Evaluation 4.1 Applicable Regulatory Requitements/Critetia 4.2 No Significant Hazatds Considetation 4.3 Conclusions 5.0 Envitonmental Considerations 6.0 References - Proposed Technical Specification Change (Mark-Up) - Revised Technical Specification Page - Proposed Technical Specification Bases Change (Matk-Up) - NextEra Energy Duane Arnold (DAEC) Vacuum Breaker Sizing Analysis (Non-proprietaty) - GE-Hitachi Affidavit for Withholding of Proprietary Information - N extEra Energy Duane Arnold (DAEC) Vacuum Breaker Sizing Analysis (Proptietary)
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SUMMARY
DESCRIPTION NextEra Energy Duane Arnold, LLC (NextEra) requests an amendment to the Technical Specifications (TS) for the Duane Arnold Energy Center (DAEC). The proposed change will modify TS 3.6.1.7, "Suppression Chamber-to-Dqwell Vacuum Breakers," by revising the required number of operable vacuum breakers for opening from SL'>: to five. 2.0 DETAILED DESCRIPTION 2.1 Vacuum Breaker Design and Operation The prima1y containment is designed for an external pressure not more than 2 psi greater than the concurrent internal pressure. Automatic vacuum relief devices are used to prevent any unacceptable pressure differential. There are two groups of vacuum breakers: the suppression chamber-to-drywell group, which is connected to the vent header inside the torus and prevents dtywell pressure from being significantly less than torus pressure; and the reactor building-to-suppression group, which prevents tlle torus pressure from being significantly lower than building pressure. The purpose of the suppression chamber-to-dqwell vacuum breakers is to relieve vacuum, preventing an excessive negative differential pressure. A negative differential pressure across the dtywell wall is caused by rapid depressurization of tlle d1)7well. Events that cause this rapid depressurization are cooling cycles, inadvertent dtywell spray actuation, and steam condensation from sprays or subcooled re-flood water flowing out of a postulated break in the primaq system. Cooling cycles result in minor pressure transients in the drywell that occur slowly and are normally controlled by heating and ventilation equipment. Spray actuation or spill of subcooled water out of a break results in more significant pressure transients and becomes important in sizing these vacuum breakers. 2.2 Current TS Requirements TS 3.6.1.7, "Suppression Chamber-to-D1ywell Vacuum Breakers," currently requires the following in Modes 1, 2, and 3: Six suppression chamber-to-drywell vacuum breakers shall be OPERABLE for operung. Seven suppression chamber-to-dtywell vacuum breakers shall be closed, except when performing their intended function.
NG-17-0233 Enclosure Page3of7 2.3 Reason for the Proposed Change TS 3.6.1.7 currently requires sL-x suppression chamber-to-drywell vacuum breakers operable for opening. With one vacuum breaker inoperable for opening, the TS provides a 72-hour completion time to restore operability before a plant shutdown is required. However, a DAEC calculation shows tlrnt there is margin available in the current vacuum breaker design, which suggests tl1at the current TS has excess conse1vatism with respect to the number of vacuum breakers required to open to maintain suppression pool-to-drywell differential pressure. In addition, an analysis performed by GE-Hitachi Nuclear Energy Americas, LLC (GEH) concluded tlrnt with four vacuum breakers open, there is margin available to meet the most linllting design basis accident conditions. Therefore, NextEra is requesting a reduction in the required number of operable vacuum breakers for opening from six to five. This change will provide operational flexibility while maintaining the capability to meet the limiting design basis accident conditions. The proposed change will eliminate the unnecessary transient and operational risks that would result from initiating a plant shutdown in accordance witl1 the current TS witl1 one of six vacuum breakers inoperable for longer than 72 hours. 2.4 Description of the Proposed Change TS 3.6.1.7, "Suppression Chamber-to-Dqwell Vacuum Breakers," is revised as shown below. Five fu suppression chamber -to-drywell vacuum breakers shall be OPERABLE for opemng. Seven suppression chamber -to-diywell vacuum breakers shall be closed, except when performing their intended function
3.0 TECHNICAL EVALUATION
The proposed change revises the mininmm number of operable suppression chamber-to-diywell vacuum breakers for opening contained in TS 3.6.1.7 from sL-x to five. The proposed change is based on GEH document "NextEra Energy Duane Arnold (DAEC) Vacuum Breaker Sizing Analysis," which is provided in Attachment 4 (non-proprieta1y) and Attachment 6 (proprietaq). Information supporting the change in the mininmm number of operable suppression chamber-to-diywell vacuum breakers for opening is included in Attachments 4 and 6. These attachments summarize the methodology, inputs, and results for the proposed change to the mininmm number of operable suppression chamber-to-di7well vacuum breakers for opemng.
NG-17-0233 Enclosure Page4of7 The required number of vacuum breakers is calculated using an NRC accepted methodology described in NEDC-33004P-A Revision 4, "Constant Pressure Power Uprate" (Reference 2). A discussion on the methodology for calculating the required number of vacuum breakers is provided in Section 2.1, Containment Response Methodology, of Attachments 4 and 6. Three analysis cases were performed for the DAEC vacuum breaker sizing evaluation. These cases simulated events developed from a review of the analyses performed in Reference 2. For all three cases, a single failure of a suppression chamber-to-drywell vacuum breaker and two suppression chamber-to-drywell vacuum breakers out-of-se1vice are assumed. Only one of the two reactor building-to-suppression chamber vacuum breakers is used. The specific inputs for these three cases are listed in Appendix A of Attachments 4 and 6. The analysis concludes that the size and number of vacuum breakers are sufficient to prevent exceeding the differential pressure design limit with two vacuum breakers out of se1vice and the failure of one vacuum breaker to open.
4.0 REGULATORY EVALUATION
4.1 Applicable Regulatory Requirements/Criteria The DAEC Updated Final Safety Analyses Report contains an evaluation of the design basis of DAEC as measured against the AEC General Design Criteria (GDC) for nuclear power plants, Appendix A of 10 CFR 50, effective May 21, 1971, and subsequently amended July 7, 1971. The GDC applicable to the proposed change include:
- GDC 16, Containment Design, states that reactor containment and associated systems shall be provided to establish an essentially leak-tight barrier against the uncontrolled release of radioactivity to the environment and to assure that the containment design conditions important to safety are not exceeded for as long as postulated accident conditions require.
- GDC 38, Containment Heat Removal, states that a system to remove heat from the reactor containment shall be provided. The system safety function shall be to reduce rapidly, consistent with the functioning of other associated systems, the containment pressure and temperature following any LOCA and maintain them at acceptably low levels. Suitable redundancy in components and features and suitable interconnections, leak detection, isolation, and containment capabilities shall be provided to ensure that ... the system safety function can be accomplished, assuming a single failure.
- GDC 50, Containment Design Basis, states that the reactor containment stiucture, including access openings, penetrations, and the containment heat removal system shall be designed so that the containment structure and its internal compartments can accommodate, without exceeding the design leakage rate and with sufficient margin, the calculated pressure and temperature conditions resulting from any loss-of-coolant accident. This margin shall reflect consideration of (1) the effects of
NG-17-0233 Enclosure Page 5 of7 potential energy sources which have not been included in the determination of the peak conditions, such as energy in steam generators and as required by§ 50.44 energy from metal-water and other chemical reactions that may result from degradation but not total failure of emergency core cooling functioning, (2) the limited experience and experimental data available for defining accident phenomena and containment responses, and (3) the conse1-vatism of the calculation model and input parameters. The analysis of this change, which credits opening of four of the seven suppression chamber-to-drywell vacuum breakers, shows that the design pressure of the primary containment is not exceeded even under worst case accident scenarios. One of the operable vacuum breakers is assumed to fail to open, thus, only four of the five operable vacuum breakers are credited. In addition, the requirement for all suppression chamber-to-drywell vacuum breakers to be closed (except when performing their intended design function) ensures that there is no excessive bypass leakage should a LOCA occur. Therefore, the requirements of GDC 16, 38 and 50 will continue to be met with the implementation of this proposed change. 4.2 No Significant Hazards Consideration NextEra Energy Duane Arnold, LLC (NextEra) requests an amendment to the Technical Specifications (TS) for the Duane Arnold Energy Center (DAEC). The proposed change will modify TS 3.6.1.7, "Suppression Chamber-to-Drywell Vacuum Breakers," by revising the required number of operable vacuum breakers from six to five. NextEra has evaluated the proposed change against the criteria of 10 CFR 50.92(c) to determine if the proposed change results in any significant hazards. The following is the evaluation of each of the 10 CFR 50.92(c) criteria:
- 1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No Operable suppression chamber-to-di-ywell vacuum breakers are required for accident mitigation. Failure of the vacuum breakers is not assumed as an accident initiator for any accident previously evaluated. Therefore, any potential failure of a vacuum breaker to perform when necessa1y will not affect the probability of an accident previously evaluated. The proposed change maintains a sufficient number of operable vacuum breakers to meet the limiting design basis accident conditions. The consequences of an accident previously evaluated while utilizing the proposed change are no different than the consequences of an accident prior to the proposed change. As a result, the consequences of an accident previously evaluated are not significantly increased
NG-17-0233 Enclosure Page 6 of7 Therefore, the proposed TS change does not involve an increase in the probability or consequences of a previously evaluated accident.
- 2. Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?
Response: No The proposed change does not alter the protection system design, create new failure modes, or change any modes of operation. The proposed change does not involve a physical alteration of the plant; and no new or different kind of equipment will be installed. Consequently, there are no new initiators that could result in a new or different kind of accident. Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.
- 3. Does the proposed change involve a significant reduction in a margin of safety?
Response: No The proposed change to the minimum number of operable suppression chamber-to-drywell vacuum breakers for opening ensures that an excessive negative differential pressure between the suppression chamber and the drywell will be prevented during the most limiting postulated design-basis event. The minimum number of operable suppression chamber-to-drywell vacuum breakers for opening is set appropriately to ensure adequate margin based on tl1e number of available vacuum breakers not having an effect on the containment system analysis report. Therefore, the proposed change does not involve a significant reduction in a margin of safety. Based on tl1e above, NextEra concludes that the proposed change presents no significant hazards consideration under the standards set fortl1 in 10 CPR 50.92, and, accordingly, a finding of "no significant hazards consideration" is justified. 4.3 Conclusions Based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
NG-17-0233 Enclosure Page 7 of7
5.0 ENVIRONMENTAL CONSIDERATION
S A review has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or su1veillance requirement. However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or a significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.
6.0 REFERENCES
- 1. GE Company, "Mark I Containment Program Mark I Wetwell-to-Di-ywell Vacuum Breaker Functional Requirements, Task 9.4.3," NEDE-24802, April 1980.
- 2. GE Nuclear Energy, "Constant Pressure Power Uprate," NEDC-33004P-A, Revision 4, July 2003.
ATTACHMENT 1 Proposed Technical Specification Change (Mark-Up) One page follows
Suppression Chamber-to-Drywell Vacuum Breakers 3.6.1.7 3.6 CONTAINMENT SYSTEMS 3.6.1. 7 Suppression Chamber-to-Drywell Vacuum Breakers LCO ~ 3.6.1 . 7 ~ suppression chamber-to-drywell vacuum breakers shall be
. OPERABLE for opening.
F1ve AND Seven suppression chamber-to-drywell vacuum breakers shall be closed, except when performing their intended function . APPLICABILITY: MODES 1, 2, and 3. ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One required A.1 Restore one vacuum 72 hours suppression chamber- breaker to OPERABLE to-drywell vacuum status. breaker inoperable for opening. B. One suppression B.1 Close the open 2 hours chamber-to-d rywell vacuum breaker. vacuum breaker not closed. C. Required Action and C.1 Be in MODE 3. 12 hours associated Completion Time not met. AND C.2 Be in MODE 4. 36 hours DAEC 3.6-22 Amendment ~
ATTACHMENT 2 Revised Technical Specification Page One page follows
Suppression Chamber-to-Drywell Vacuum Breakers 3.6.1.7 3.6 CONTAINMENT SYSTEMS 3.6.1. 7 Suppression Chamber-to-Drywell Vacuum Breakers LCO 3.6.1.7 Five suppression chamber-to-drywell vacuum breakers shall be OPERABLE for opening. Seven suppression chamber-to-drywell vacuum breakers shall be closed, except when performing their intended function. APPLICABILITY: MODES 1, 2, and 3. ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One required A.1 Restore one vacuum 72 hours suppression chamber- breaker to OPERABLE to-drywell vacuum status. breaker inoperable for opening. B. One suppression B.1 Close the open 2 hours chamber-to-d rywell vacuum breaker. vacuum breaker not closed. C. Required Action and C.1 Be in MODE 3. 12 hours associated Completion Time not met. AND C.2 Be in MODE4. 36 hours DAEC 3.6-22 Amendment
ATTACHMENT 3 Proposed Technical Specification Bases Change (J\1ark-Up) Two pages follow
Suppression Chamber-to-Drywell Vacuum Breakers B3.6.1.7 BASES BACKGROUND chamber pressure, there will be an increase in the vent waterleg. (continued) This will result in an increase in the water clearing inertia in the event of a postulated LOCA, resulting in an increase in the peak drywell pressure. This in turn will result in an increase in the pool swell dynamic loads. The internal vacuum breakers limit the height of the waterleg in the vent system during normal operation. APPLICABLE Analytical methods and assumptions involving the SAFETY suppression chamber-to-drywell vacuum breakers are presented ANALYSES in Reference 1 as part of the accident response of the primary containment systems. Internal (suppression chamber-to-drywell) and external (reactor building- to-suppression chamber) vacuum breakers are provided as part of the primary containment to limit the negative differential pressure across the drywell and suppression chamber walls that form part of the primary containment boundary. The safety analyses assume that the internal vacuum breakers are closed initially and are fully open at a differential pressure of 0.5 psid (Ref. 2) . Additionally, 1 of the 7 internal vacuum breakers f is assumed to fail in a closed position (Ref. 1). The results of the analyses show that the design pressure is not exceeded even under the worst case accident scenario. The vacuum breaker opening differential pressure setting is a result of the requirement placed on the vacuum breakers to prevent excessive water-level variations in the submerged portion of the vent downcomer lines. The vacuum breaker capacity, with one of the valves failed, is adequate to limit the pressure differential between the suppression chamber and the drywell during post accident drywell cooling operations to a value that is within the suppression chamber design values. The suppression chamber-to-drywell vacuum breakers satisfy
,__ _,,,, riterion 3 of 10 CFR 50.36(c)(2)(ii).
Five LCO Only @of the 7 vacuum breakers must be OPERABLE for opening. All suppression chamber-to-drywell vacuum breakers, however, are required to be closed (except during testing, (continued) DAEC B 3.6-44 TSCR-Q44A
Suppression Chamber-to-Drywell Vacuum Breakers B3.6.1.7 BASES (continued) ACTIONS With one of the equired vacuum breakers inoperable for opening (e.g., the vacu1 m breaker is not open and may be stuck closed or not within its Gpening setpoint limit, so that it would not function as designed du ' g an event that depressurized the drywell), the remaining five OPERABLE vacuum breakers are capable of providing the vacuum relief function. However, overall system reliability is reduced because a single failure in one of the.~~ remaining vacuum breakers could result in an exces. i* five suppression chamber - to-drywell differe
- essure during a OBA. Therefore, with one of the ~ quired vacuum breakers inoperable, 72 hours is allowed to restore at least one of the inoperable vacuum breakers to OPERABLE status so that plant conditions are consistent with those assumed for the design basis analysis. The 72 hour Completion Time is considered acceptable due to the low probability of an event in which the remaining vacuum breaker capability would not be adequate.
An open vacuum breaker allows communication between the drywell and suppression chamber airspace, and, as a result, there is the potential for suppression chamber overpressurization due to
- this bypass leakage if a LOCA were to occur. Therefore, the open vacuum breaker must be closed. A short time is allowed to close the vacuum breaker due to the low probability of an event that would pressurize primary containment. If vacuum breaker position indication is not reliable, an alternate method of verifying that the vacuum breakers are closed is to verify that a drywell to suppression chamber differential pressure of 0.5 psid is maintained for 1 hour without makeup. The required 2 hour Completion Time is considered adequate to perform this test.
C.1 and C.2 If the inoperable suppression chamber-to-drywell vacuum breaker cannot be closed or restored to OPERABLE status within the required Completion Time, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant (continued) DAEC B 3.6-46 Amendment ~
ATTACHMENT 4 NextEra Energy Duane Arnold (DAEC) Vacuum Breaker Sizing Analysis (Non-proprietaty)
e HITACHI GE Hitachi Nuclear Energy 003N7091-NP Revision 1 September 2017 Non-Proprietmy Information - Class I (Public) NextEra Energy Duane Arnold (DAEC) Vacuum Breaker Sizing Analysis Copyright 2017 GE-Hitachi Nuclear Energy Americas LLC All Rights Reserved
003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) INFORMATION NOTICE This is a non-proprietary version of the document 003N7091-P Revision 1, which has the proprietary information removed. Portions of the document that have been removed are indicated by an open and closed bracket as shown here [[ ]]. IMPORTANT NOTICE REGARDING CONTENTS OF THIS REPORT Please Read Carefully The design, engineering, and other information contained in this document is furnished for the purposes of supporting the NextEra in proceedings before the U.S. Nuclear Regulatory Commission (NRC). The only unde1iakings of GEH with respect to information in this document are contained in the contract between NextEra and GEH and nothing contained in this contract shall be construed as changing that contract. The use of this information by anyone other than NextEra for any purpose other than that for which it is intended, is not authorized; and with respect to any unauthorized use, GEH makes no representation or warranty, and assumes no liability as to the completeness, accuracy, or usefulness of the information contained in this document. ll
003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) Revision Summary Revision Required Changes to Achieve Revision 0 NIA Identified specific instances of GEH proprietary information and prepared the 1 report for submittal to the NRC. Ill
003N7091-NP Revision 1 Non-Proprietary Information- Class I (Public) Acronyms and Abbreviations Term Definition AOR Analysis of Record BWR Boiling Water Reactor co Condensation Oscillation DAEC Duane Arnold Energy Center DBA Design Basis Accident DW Drywell ECCS Emergency Core Cooling System EPU Extended Power Uprate GEH GE Hitachi Nuclear Energy IBA Intermediate Break Accident LLS Low-Low-Set LOCA Loss-of-Coolant Accident LPCI Low Pressure Coolant Injection LTR Licensing Topical Report NPSH Net Positive Suction Head NRC Nuclear Regulatory Commission oos Out-of-Service PULD Plant Unique Load Definition RB Reactor Building RHR Residual Heat Removal SBA Small Break Accident SE Safety Evaluation Report SRV Safety Relief Valve SRVDL SRV Discharge Line UFSAR Updated Final Safety Analysis Report us United States VB Vacuum Breaker WG Water Gauge WW Wetwell iv
003N7091-NP Revision I Non-Proprietary Information- Class I (Public) TABLE OF CONTENTS Section 1.0 Introduction and Scope ........................................................................................................ 1 2.0 Contain1nent Response Analysis .......................................................................................... 2 2.1 Containment Response Methodology ...................................................................... 2 2.2 Analysis Inputs and Assumptions ............................................................................ 2 2.3 Results ...................................................................................................................... 4 3.0 WW-to-DW VB Number Reduction Impact ...................................................................... .4 3.1 DAEC EPU NPSH and Overpressure Analysis ...................................................... .4 3.2 Containment Hydrodynamic Loads and PULD ....................................................... 5 3.3 Containment Bypass Analysis ................................................................................. 6 4.0 Conclusions .......................................................................................................................... 7 5.0 References ............................................................................................................................ 8 Appendix A Summary of Case Input Parameters ...................................................................... 13 List of Tables Table I Summary ofDAEC Vacuum Breaker Sizing Analysis Results ............................... 9 List of Figures Figure 1 Case I Containment Differential Pressure Responses .......................................... .I 0 Figure 2 Case 2 Containment Differential Pressure Responses ........................................... 11 Figure 3 Case 3 Containment Differential Pressure Responses .......................................... 12 v
003N7091-NP Revision I Non-Proprietary Information - Class I (Public) 1.0 Introduction and Scope Vacuum breaker (VB) valves installed in the Duane Arnold Energy Center (DAEC) containment systems prevent potential negative differential pressure exceeding design limits between the wetwell (WW) and drywell (DW). Functional requirements established during the Mark I containment program (Reference I) include a VB load definition, based upon dynamic modeling of the vent pressure transient, and VB number and size for predicting integrated containment response to prescribed events. Prior to the Mark I program, a general design requirement derived from the Bodega Bay Preliminary Hazards Summary Report included specification of VB area being no less than 1/16 of the total vent flow cross-sectional area. A number of plants revised their VB sizing technical bases by implementing the more systematic approach developed in the Mark I program (Reference I). Calculations were performed using an approach similar to that applied for the Reference I analyses to serve as the technical basis supporting DAEC VB size and number requirements for operation. These analysis cases performed for the DAEC VB sizing evaluation simulate events developed from a review of the analyses performed in Reference I and include: Case I: Inadvertent actuation of DW spray with one (1) DW spray header during normal plant operation. Case 2: DW spray following a small steam line break loss-of-coolant accident (LOCA) with [[ ]] and use of two (2) DW spray headers. Case 3: Emergency core cooling system (ECCS) vessel reflood into the DW following a large liquid break LOCA with [[
]]
The design inputs for each case are summarized in Appendix A. I
003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) 2.0 Containment Response Analysis 2.1 Containment Response Methodology The GE Hitachi Nuclear Energy (GEH) computer code SHEX was used to perform the containment pressure and temperature response analysis presented in this report. The SHEX code is the code currently used by GEH to perform analyses of the containment pressure and temperature response including analyses performed to evaluate VB sizing adequacy for events resulting in negative DW-to-WW differential pressure, negative DW-to-Reactor Building (DW-to-RB) and negative WW-to-RB differential pressures. [[
]]
SHEX is the standard code used by GEH for containment response calculations for boiling water reactor (BWR) Mark I, Mark II and Mark III plants where safety systems such as ECCS and residual heat removal (RHR) pump operation or use of containment spray is simulated. A licensing topical repo1i (L TR) was not issued for SHEX, and therefore an NRC safety evaluation (SE) report with formal NRC approval for SHEX was not issued. However, the NRC has accepted the use of SHEX for United States (US) BWR Mark I containment analyses (Reference 2), in paiiicular containment analyses performed in suppmi of power uprates performed for US BWR Mark I plants. GEH report NEDC-33004P-A Revision 4 (Reference 3) documents the GEH guidelines for extended thermal power uprates while maintaining the current plant operating reactor pressure. This L TR was reviewed and approved by the NRC and includes a copy of the NRC SE with approval of the L TR. Included within the NRC SE is the NRC basis for acceptance of SHEX containment analysis applications. The NRC SE approval for use of SHEX for power uprate containment analyses cited the Reference 2 NRC letter which included a requirement for benchmarking analyses. However, per the NRC SE approval for NEDC-33004P-A Revision 4, the NRC accepted the use of SHEX without need for benchmark analyses for Mark I containments, as originally stipulated in the cited NRC letter. This was based on NRC comparisons of their own benchmark cases results with SHEX results for Mark I plants. 2.2 Analysis Inputs and Assumptions The sizing evaluation for the DAEC WW-to-DW VBs and RB-to-WW VB are based on the results of the GEH analysis of the DAEC containment system response to potentially limiting events for negative DW-to-WW differential pressure as well as for negative DW-to-RB differential pressure and WW-to-RB differential pressure. These analyses were performed for a set of cases which were [[ ]] presented originally in Reference 1. 2
003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) The following three cases were performed for DAEC. For all three cases, a single failure of one WW-DW VB and two VBs out-of-service (OOS) are assumed and only one (1) RB-to-WW VB is used. The specific inputs for those three cases are listed in Appendix A. Case I: Inadvertent Actuation ofDW Spray During Normal Plant Operation. Case I assumes that one DW spray header is inadvertently actuated with [[
]] during plant normal operation.
Case 2: Actuation of Two DW Spray Headers Following a Small Steam Line Break LOCA. Case 2 assumes that two DW spray headers are actuated [[
]]
Case 3: ECCS Reflood into the DW Following a Large Liquid Break LOCA. [[
]]
Key assumptions for the analyses are presented below. Case specific inputs are summarized in Appendix A. Other analysis inputs not listed in Appendix A are based on Reference 4. Key Assumptions for Analyses: I. Single failure of one (1) WW-to-DW VB and two (2) WW-DW VBs OOS are assumed for all cases. For all cases in the report, only one RB-to-WW VB is used.
- 2. [[
]]
- 3. [[
]]
- 4. [[
]] throughout the transient event analysis period.
- 5. [[
]]
3
003N7091-NP Revision 1 Non-Proprietary Information- Class I (Public)
- 6. The VB flow component mass flow rates are calculated based on [[
]] from the source volume, which is the WW for the WW-to-DW VBs and is the RB for the RB-to-WW VB.
- 7. [[
]]
2.3 Results Table 1 summarizes the results of the containment response analyses, showing peak values for DW-to-WW differential pressure, DW-to-RB and WW-to-RB differential pressures. Figures 1 through 3 show the plots of DW-to-WW differential pressure, DW-to-RB differential pressure and WW-to-RB differential pressure for those three cases. Case 1 produces the most severe response with respect to the maximum negative DW-to-RB and WW-to-RB differential pressures, with a predicted DW-to-RB differential pressure of [[ ]] and predicted WW-to-RB differential pressure of [[ ]]. The LOCA cases, Cases 2 and 3, produce the more severe response with respect to maximum negative DW-to-WW differential pressure, with Case 2 limiting with a predicted DW-to-WW differential pressure of [[ ]]. For the LOCA cases, the predicted maximum values of negative DW-to-WW differential pressure occur within 20 seconds. DW-to-RB and WW-to-RB differential pressures remain greater than zero for Case 3. The results presented in Table 1 demonstrate that all predicted differential pressure values for DW-to-RB differential pressure, WW-to-RB differential pressure and DW-to-WW differential pressure are below the design limit of 2 psid. 3.0 WW-to-DW VB Number Reduction Impact The following discussion is limited to the change in the number of available WW-to-DW VBs and the changes in WW-to-DW inputs. All the other conditions for a particular analysis remain the same as analysis of record (AOR) to be discussed. 3.1 DAEC EPU NPSH and Overpressure Analysis The DAEC net positive suction head (NPSH) analysis at extended power uprate (EPU) conditions can be found in Reference 5. [[
]]
4
003N7091-NP Revision 1 Non-Proprietary Information- Class I (Public) Overpressure analysis refers to containment overpressure analyses in Reference 5. Specifically, those analyses refer to containment short-term analysis (using M3CPT) for peak containment pressure and temperature, and long-term design basis accident (DBA) analyses. Reference 5 Section 2.3.1 M3CPT DAEC Short-Term Analysis: The Reference 5 M3CPT short-term analysis only lasts ~30 seconds, and ECCS flow is not modeled. [[
]]
Reference 5 Section 2.3.2 SHEX DAEC Long-Term DBA Analysis: For the long-term DBA-LOCA analysis in Reference 5 Section 2.3.2, the parameters of interest are peak suppression pool temperature, peak WW temperature and peak containment pressures as shown in Tables 3-3 and 3-4 of Reference 5. Updated Final Safety Analysis Report (UFSAR) Case 3 and Case 4 in Reference 5 are essentially the same (Section 2.3.2.l A discussion). UFSAR Case 4 used low pressure coolant injection (LPCI) cooling and UFSAR Case 3 used containment spray. Other inputs are the same for those two cases. [[
]]
It is therefore concluded that changing the number of available VBs for DAEC from 6 to 4 (or the input changes for those VBs) has no effect on DAEC short-term and long-term containment overpressure analyses. 3.2 Containment Hydrodynamic Loads and PULD Containment hydrodynamic loads consist of LOCA loads and safety relief valve (SRV) loads. LOCA loads include pool swell, vent thrust, condensation oscillation (CO) and chugging. [[
]]
The SRV air-clearing loads include SRV discharge line (SRVDL) loads, suppression pool boundary pressure loads and drag loads on submerged structures. These loads are influenced by the SRV opening setpoint pressure, the initial water leg in the SRVDL, the SRVDL geometry, 5
003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) and the suppression pool geometry. VB operation would not have any effect on those parameters, and therefore, the number of available VBs will have no effect on the SRV loads. For the times when DW pressure is lower than WW (e.g., following DW spray initiation), the smaller number of VBs can slightly increase the WW-to-DW pressure difference for a very short duration immediately after VB opening. This would make the water level in the SRV tailpipe slightly higher at the time of SRV actuation. [[
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For example, for LOCA conditions, it is assumed in References 8 and 9 that [[
]]
Therefore, the number ofVBs has no effect on the Mark I SRV loads defined for DAEC. Plant Unique Load Definition (PULD) analyses for intermediate break accidents (IBAs) and small break accidents (SB As) can be found in Reference 5 Section 3 .1.3 .5. [[
]] Therefore, there is no effect on those analyses from the VBs.
3.3 Containment Bypass Analysis The steam bypass analysis is discussed in Section 2.3.2.6 of Reference 5. [[
]] Therefore, the number of available VBs has no effect on the Reference 5 steam bypass capacity analysis.
6
003N7091-NP Revision 1 Non-Proprietary Information- Class I (Public) 4.0 Conclusions The results presented in Table I confirm that the size and number of WW-to-DW VBs and RB-to-WW VBs for DAEC, accounting for two (2) WW-to-DW VB OOS, and one (1) WW-to-DW VB failure, are sufficient to adequately mitigate negative DW-to-WW, DW-to-RB and WW-to-RB differential pressures and prevent exceeding the differential pressure design limits of 2 psid. It is further concluded that the number of available WW-to-DW VB reduction does not have an effect on the containment analysis repmied in the DAEC EPU containment system analysis report (Reference 5). 7
003N7091-NP Revision 1 Non-Proprietary Information- Class I (Public) 5.0 References
- 1. GE Company, "Mark I Containment Program Mark I Wetwell-to-Drywell Vacuum Breaker Functional Requirements, Task 9.4.3," NEDE-24802, April 1980.
- 2. Letter to G. L. Sozzi (GE) from A. Thadani (NRC), "Use of SHEX Computer Program
. and ANSI/ANS 5.1-1979 Decay Heat Source Term for Containment Long-Term Pressure and Temperature Analysis," MFN-117-93, July 13, 1993.
- 3. GE Nuclear Energy, "Constant Pressure Power Uprate," NEDC-33004P-A, Revision 4, July 2003.
- 4. Letter from R. McGee (IES) to W. F. Farrel (GE), "DAEC EPU OPL-4A," NG-00-1653, September 28, 2000.
- 5. GE Nuclear Energy, "Project Task Report Duane Arnold Energy Center Asset Enhancement Program Task T0400: Containment System Response," GE-NE-A22-00100-23-01-R2, Revision 2, December 2002.
- 6. GE Company, "Mark I Containment Program Load Definition Repo1i," NED0-21888, Revision 2, November 1981.
- 7. GE Company, "Mark I Containment Program Application Guide 3 Safety Relief Valve Discharge Line Clearing Transient," NEDE-24555-P, Volume I, Revision 2, September 1980.
- 8. GE Company, "Mark I Containment Program Application Guide 9 Safety Relief Valve Discharge Line Reflood Transient," NEDE-24555-P, Volume III, Revision 2, September 1980.
- 9. GE Company, "Mark I Containment Program, Analytical Model for Computing Water Rise in a Safety/Relief Valve Discharge Line Following Valve Closure Task 7.1.2.2,"
NEDE-23898-P, October 1978.
- 10. GE Company, "Evaluation of Mark I S/RV Load Cases C3.l, C3.2, and C3.3 for the Duane Arnold Energy Center," NEDC-22204, September 1982.
- 11. CAL-MOl-152, "Drywell Torus Vacuum Breaker System," February 26, 2002.
8
003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) Table 1 Summary ofDAEC Vacuum Breaker Sizing Analysis Results Case No. 1 2 3 Inadvertent Actuation DW Spray During Small ECCS Reflood Case Description ofDW Spray during Steam Line Break Following DBA-LOCA Normal Operation Failure of one WW- Failure ofone WW-DW Failure of one WW-DW Single Failure DW VB to open and VB to open and two VB to open and two OOS two OOS oos Number ofWW-DW VBs 4 4 4 Number of RB-WW VB System Branch Lines I I I Open Spray or ECCS Reflood Temp (°F) [[ ]] Number of Spray Headers I 2 NIA Peak Negative 1*2 DW-to-RB Differential Pressure [[ (psid) Peak Negative 1*2 WW-to-RB Differential Pressure (psid) Peak Negative 2 DW-to-WW Differential Pressure (psid) ]] Notes:
- 1. DW-to-RB and WW-to-RB differential pressures are based on a RB pressure ofl4.7 psia.
- 2. Times shown are relative to the stmt time ofDW spray for Cases I and 2 and relative to start ofECCS reflood for Case 3.
- 3. [[
]]
9
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003N7091-NP Revision I Non-Proprietary Information- Class I (Public) [[
]]
Figure 1 Case 1 Containment Differential Pressure Responses IO
003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) [[
]]
Figure 2 Case 2 Containment Differential Pressure Responses 11
003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) [[
]]
Figure 3 Case 3 Containment Differential Pressure Responses 12
003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) Appendix A Summary of Case Input Parameters easel Case2 Case3 Inadvertent Item No. Case Drywell Spray Vessel Reflood Spray AfterLOCA Through Break Operation CONTAIMENT GEOMETRY 1 PARAMETERS l.a. DW Volume (ft3) 130,000 130,000 130,000 3 l.b. WW Airspace Volume (ft ) 94,070 94,070 94,070 Initial Suppression Pool Volume - l.c. 61,500 61,500 61,500 (HWL) (ft3) 2 INITIAL CONDITIONS 2.a. Initial DW Temperature (°F) 135 266.93 266.93 15.2 minimum 2.b. Initial DW Pressure (psia) 15.7 maximum 39.8 39.8 (Note 1) 2.c. Initial DW Relative Humidity(%) 100 --- --- 2.d. Initial DW Quality --- 1.0 1.0 Initial WW Airspace Temperature 2.e. 95 143 143.3 (°F) Initial Suppression Pool (SP) 2.f. 95 143 143 Temperature (°F) 15.2 minimum 2.g. Initial WW Pressure (psia) 15.7 maximum 38.5 38.5 (Note 1) 2.h. Initial WW Relative Humidity(%) 100 100 100 VESSEL STEAM BREAKFLOW 3 PARAMETERS 3.a. Vessel Steaming Rate (Ibmlsec) NIA 0 NIA 3.b. Vessel Steam Enthalpy (Btu/lbm) NIA NIA NIA 4 WETWELL-DRYWELL VACCUM BREAKER PARAMETERS 4.a. WW-DW VB Loss Coefficient (K) 2.41 2.41 2.41 4.b. Number of Installed WW-DW VBs 7 7 7 (Note 2) 4.c. WW-to-DW VB Area per Valve (ft2) 1.396 1.396 1.396 4.d. WW-to-DW VB Opening Pressure 0.35 0.35 0.35 Differential (psid) 4.e. WW-to-DW VB Full Open Pressure 0.5 0.5 0.5 Differential (psid) 13
003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public) Casel Case2 Case3 Inadvertent Item No. Case Drywell Spray Vessel Reflood Spray AfterLOCA Through Break Operation 4.f. WW-to-DW VB Opening Time from Starting Opening to Full Open 2 2 2 (seconds) 5 REACTOR BUILDING-TO-WETWELL VACUUM BREAKER PARAMETERS 5.a. Number of RB-to-WW VBs 1 1 1 5.b. RB-to-WW VB Area per Valve (ft2) 1.623 1.623 1.623 5.c. RB-to-WW VB Opening Setpoint 0.35 0.35 0.35 Pressure Differential (psid) 5.d. RB-to-WW VB Full Open Pressure 0.5 0.5 0.5 Differential (psid) 5.e. RB-to-WW VB Opening Time from Starting Opening to Full Open 2 2 2 (seconds) 5.f. RB-DW VB Loss Coefficient (K) 2.86 2.86 2.86 6 CONTAINMENT SPRAY PARAMETERS 6.a. Number of RHR DW Spray Headers 1 2 NIA 6.b. Maximum RHR DW Spray Flow Rate per Header, (gpm) 4,560 4,560 NIA 6.c. RHR DW Spray Temperature {°F) [[ ]] [[ ]] (Note 3) (Note 4) Minimum Minimum Service Water Service Water Temperature Temperature 35°F 35°F Minimum Torus Minimum Torus NIA Water Water Temperature Temperature 55°F 55°F Heat Exchanger Heat Exchanger k-value: k-value: 141 Btu/sec-°F 141 Btu/sec-°F 6.d. Number of RHR WW Spray Headers NIA NIA NIA 6.e. RHR WW Spray Flow Rate, (lbm/sec) NIA NIA NIA 6.f. Distance WW Spray Header to DW Floor (ft) NIA NIA NIA 6.g. RHR WW Spray Temperature (°F) NIA NIA NIA 14
003N7091-NP Revision I Non-Proprietary Information - Class I (Public) Case 1 Case2 Case3 Inadvertent Item No. Case Drywell Spray Vessel Reflood Spray AfterLOCA Through Break Operation 6.h. DW and WW Spray Efficiency 100% 100% NIA 6.i. Average DW and WW Spray Droplet Diameter {ft) [[ ]] NIA 7 ECCS VESSEL REFLOOD PARAMETERS 7.a. ECCS Vessel Reflood Flow Through NIA NIA 35,000 Break (gpm) 7.b. ECCS Reflood Vessel Break Flow Temperature (°F) NIA NIA [[ ]] 7.c. ECCS Reflood Vessel Break Flow NIA NIA 100% Mixing Efficiency 8 REACTOR BUILDING INITIAL CONDITIONS (NOTE 5) 8.a. Pressure 0.87 to 0.32 inch 0.87 to 0.32 inch 0.87 to 0.32 inch water gauge (wg) wgvacuum wgvacuum vacuum 8.b. Temperature (°F) 68 to 100 68 to 100 68 to 100 8.c. Relative Humidity (-) 90%-20% 90%-20% 90%-20% Notes: I. [[ ]]
- 2. Four (4) WW-to-DW VBs are used for all cases in this report (See Table 1).
- 3. The spray liquid temperature is determined by assuming that one heat exchanger is in operation. With one heat exchanger running, the minimum liquid temperature would be
[[
]]
15
003N7091-NP Revision 1 Non-Proprietary Information - Class I (Public)
- 4. The spray liquid temperature is determined by assuming that two heat exchangers are in operation. It is estimated in Reference 11 and also by GEH that [[
]] Therefore the pool temperature would be [[ ]] when containment spray is initiated. With two heat exchangers running, the minimum liquid spray temperature would be
[[
]]
- 5. Some iterations are made and the following RB initial conditions are used for the analysis. It is wo1ih to note that the RB-to-WW VB is only used for Case 1. For Cases 2 and 3, the RB-to-WW VB does not open during the transient.
- a. [[
]]
16
ATTACHMENT 5 GE-Hitachi Affidavit for Withholding of Proprietary Information
GE-Hitachi Nuclear Energy Americas LLC AFFIDAVIT I, Lisa K. Schichlein, state as follows: (1) I am a Senior Project Manager, NPP/Services Licensing, Regulatory Affairs, GE-Hitachi Nuclear Energy Americas LLC (GEH), and have been delegated the function of reviewing the information described in paragraph (2) which is sought to be withheld, and have been authorized to apply for its withholding. (2) The information sought to be withheld is contained in GEH proprietary report 003N7091-P, "NextEra Energy Duane Arnold (DAEC) Vacuum Breaker Sizing Analysis," Revision 1, dated September 2017. GEH proprietary information in 003N709 l-P Revision 1 is identified by a dotted underline placed within double square brackets. [[Jhi~..~~nt~m:.~j~,;:m
~~~mP.!~,~:!.J] GEH proprietary information in figures and large objects is identified by double square brackets before and after the object. In all cases, the superscript notation (3) refers to Paragraph (3) of this affidavit, which provides the basis for the proprietary determination.
(3) In making this application for withholding of proprietary information of which it is the owner or licensee, GEH relies upon the exemption from disclosure set forth in the Freedom of Information Act ("FOIA"), 5 U.S.C. §552(b)(4), and the Trade Secrets Act, 18 U.S.C.
§1905, and NRC regulations 10 CFR 9.17(a)(4), and 2.390(a)(4) for trade secrets (Exemption 4). The material for which exemption from disclosure is here sought also qualifies under the narrower definition of trade secret, within the meanings assigned to those terms for purposes of FOIA Exemption 4 in, respectively, Critical Mass Energy Project v. Nuclear Regulatory Commission, 975 F.2d 871 (D.C. Cir. 1992), and Public Citizen Health Research Group v. FDA, 704 F.2d 1280 (D.C. Cir. 1983).
(4) The information sought to be withheld is considered to be proprietary for the reasons set f01ih in paragraphs (4)a and (4)b. Some examples of categories of information that fit into the definition of proprietary information are:
- a. Information that discloses a process, method, or apparatus, including supporting data and analyses, where prevention of its use by GEH's competitors without a license from GEH constitutes a competitive economic advantage over other companies;
- b. Information that, if used by a competitor, would reduce its expenditure of resources or improve its competitive position in the design, manufacture, shipment, installation, assurance of quality, or licensing of a similar product;
- c. Information that reveals aspects of past, present, or future GEH customer-funded development plans and programs, resulting in potential products to GEH; 003N7091-P Revision 1 Affidavit Page 1 of 3
GE-Hitachi Nuclear Energy Americas LLC
- d. Information that discloses trade secret or potentially patentable subject matter for which it may be desirable to obtain patent protection.
(5) To address 10 CPR 2.390(b)(4), the information sought to be withheld is being submitted to NRC in confidence. The information is of a s01i customarily held in confidence by GEH, and is in fact so held. The information sought to be withheld has, to the best of my knowledge and belief, consistently been held in confidence by GEH, not been disclosed publicly, and not been made available in public sources. All disclosures to third parties, including any required transmittals to the NRC, have been made, or must be made, pursuant to regulatory provisions for proprietary or confidentiality agreements or both that provide for maintaining the information in confidence. The initial designation of this information as proprietary information, and the subsequent steps taken to prevent its unauthorized disclosure, are as set f01ih in the following paragraphs (6) and (7). (6) Initial approval of proprietary treatment of a document is made by the manager of the originating component, who is the person most likely to be acquainted with the value and sensitivity of the information in relation to industry knowledge, or who is the person most likely to be subject to the terms under which it was licensed to GEH. (7) The procedure for approval of external release of such a document typically requires review by the staff manager, project manager, principal scientist, or other equivalent authority for technical content, competitive effect, and determination of the accuracy of the proprietary designation. Disclosures outside GEH are limited to regulatory bodies, customers, and potential customers, and their agents, suppliers, and licensees, and others with a legitimate need for the information, and then only in accordance with appropriate regulatory provisions or proprietary and/or confidentiality agreements. (8) The information identified in paragraph (2) is classified as proprietary because it contains details of GEH's design and licensing methodology for the GEH Boiling Water Reactor (BWR). The development of this methodology, along with the testing, development, and approval, was achieved at a significant cost to GEH. The development of the design and licensing methodology along with the interpretation and application of the analytical results is derived from the extensive experience databases that constitute a major GEH asset. (9) Public disclosure of the information sought to be withheld is likely to cause substantial harm to GEH's competitive position and foreclose or reduce the availability of profit-making opp01iunities. The information is paii of GEH's comprehensive BWR safety and technology base, and its commercial value extends beyond the original development cost. The value of the technology base goes beyond the extensive physical database and analytical methodology and includes development of the expe1iise to determine and apply 003N7091-P Revision 1 Affidavit Page 2 of 3
GE-Hitachi Nuclear Energy Americas LLC the appropriate evaluation process. In addition, the technology base includes the value derived from providing analyses done with NRC-approved methods. The research, development, engineering, analytical and NRC review costs comprise a substantial investment of time and money by GEH. The precise value of the expertise to devise an evaluation process and apply the correct analytical methodology is difficult to quantify, but it clearly is substantial. GEH's competitive advantage will be lost if its competitors are able to use the results of the GEH experience to normalize or verify their own process or if they are able to claim an equivalent understanding by demonstrating that they can arrive at the same or similar conclusions. The value of this information to GEH would be lost if the information were disclosed to the public. Making such information available to competitors without their having been required to undertake a similar expenditure of resources would unfairly provide competitors with a windfall, and deprive GEH of the opportunity to exercise its competitive advantage to seek an adequate return on its large investment in developing and obtaining these very valuable analytical tools. I declare under penalty of pe1jury that the foregoing is true and correct. Executed on this 15th day of September 2017. Lisa K. Schichlein Senior Project Manager, NPP/Services Licensing Regulatory Affairs GE-Hitachi Nuclear Energy Americas LLC 3901 Castle Hayne Road Wilmington, NC 28401 Lisa.Schichlein@ge.com 003N7091-P Revision 1 Affidavit Page 3 of 3}}