ML15224B572: Difference between revisions
StriderTol (talk | contribs) (Created page by program invented by StriderTol) |
StriderTol (talk | contribs) (Created page by program invented by StriderTol) |
||
(One intermediate revision by the same user not shown) | |||
Line 3: | Line 3: | ||
| issue date = 08/12/2015 | | issue date = 08/12/2015 | ||
| title = Submits Supplement to License Amendment Request Proposed Changes to the Technical Specifications to Address Administrative Control of Secondary Containment Access Openings | | title = Submits Supplement to License Amendment Request Proposed Changes to the Technical Specifications to Address Administrative Control of Secondary Containment Access Openings | ||
| author name = Helker D | | author name = Helker D | ||
| author affiliation = Exelon Generation Co, LLC | | author affiliation = Exelon Generation Co, LLC | ||
| addressee name = | | addressee name = | ||
Line 17: | Line 17: | ||
=Text= | =Text= | ||
{{#Wiki_filter:ZOO Exelon W*y | {{#Wiki_filter:ZOO Exelon W*y Kc lnett <:;quar* PA 19348 Exelon Generation www.exelo:1ror J.com 10 CFR 50.90 August 12, 2015 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Peach Bottom Atomic Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-44 and DPR-56 NRG Docket Nos. 50-277 and 50-278 | ||
==Subject:== | ==Subject:== | ||
Supplement to License Amendment Request Proposed Changes to the Technical Specifications to Address Administrative Control of Secondary Containment Access Openings | |||
==References:== | ==References:== | ||
: 1) License Amendment Request-Proposed Changes to the Technical Specifications to Address Administrative Control of Secondary Containment Access Openings dated February 23, 2015 2) Email correspondence from R. Ennis (U.S. Nuclear Regulatory Commission) to S. Hanson (Exelon Generation Company, LLC), "Peach Bottom Atomic Power Station, Units 2 and 3 -DRAFT Request for Additional Information regarding Proposed License Amendment for Administrative Control of Secondary Containment Access Openings (TAC NOS. MF5783 & MF5784)," dated June 4, 2015 On February 23, 2015, in accordance with the provisions of 10 CFR 50.90, "Application for amendment of license, construction permit, or early site permit," Exelon Generation Company, LLC (Exelon), submitted a request for an amendment to the Technical Specifications (TS), Appendix A of Renewed Facility Operating License Nos. DPR-44 and DPR-56 for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3, respectively (Reference 1 ). The proposed amendment requested U.S. Nuclear Regulatory Commission (NRG) approval to modify a Technical Specification (TS) Limiting Condition for Operation (LCO) and certain Surveillance Requirements (SRs) to allow secondary containment access openings to be opened intermittently under administrative control. The NRG reviewed the license amendment request and identified the need for additional information in order to complete its evaluation of the amendment request. The draft request for additional information (RAI) was sent from the NRG to Exelon by electronic mail message on June 4, 2015 (Reference 2). The additional questions were discussed during a conference call with the NRG on June 9, 2015. During the conference call, Exelon indicated that a reduction in the scope of the original changes requested was being considered in lieu of responding to the RAI. Subsequently, Exelon has decided to reduce the scope of the Reference 1 submittal. | : 1) License Amendment Request- Proposed Changes to the Technical Specifications to Address Administrative Control of Secondary Containment Access Openings dated February 23, 2015 | ||
The reduced scope only involves opening of secondary containment personnel access doors during normal entry and exit conditions. | : 2) Email correspondence from R. Ennis (U.S . Nuclear Regulatory Commission) to S. Hanson (Exelon Generation Company, LLC), | ||
U.S. Nuclear Regulatory Commission License Amendment Request Secondary Containment Access Openings Docket Nos. 50-277 and 50-278 August 12, 2015 Page 2 All other proposed changes in the Reference 1 submittal are hereby withdrawn. | "Peach Bottom Atomic Power Station, Units 2 and 3 - DRAFT Request for Additional Information regarding Proposed License Amendment for Administrative Control of Secondary Containment Access Openings (TAC NOS. MF5783 & MF5784)," dated June 4, 2015 On February 23, 2015, in accordance with the provisions of 10 CFR 50.90, "Application for amendment of license, construction permit, or early site permit," Exelon Generation Company, LLC (Exelon), submitted a request for an amendment to the Technical Specifications (TS), Appendix A of Renewed Facility Operating License Nos. DPR-44 and DPR-56 for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3, respectively (Reference 1). | ||
The proposed amendment requested U.S. Nuclear Regulatory Commission (NRG) approval to modify a Technical Specification (TS) Limiting Condition for Operation (LCO) and certain Surveillance Requirements (SRs) to allow secondary containment access openings to be opened intermittently under administrative control. | |||
There are no additional commitments contained within this letter. In accordance with 10 CFR 50.91, "Notice for public comment; State consultation," paragraph (b), Exelon is notifying the Commonwealth of Pennsylvania of this supplement by transmitting a copy of this letter and its attachments to the designated State Official. | The NRG reviewed the license amendment request and identified the need for additional information in order to complete its evaluation of the amendment request. The draft request for additional information (RAI) was sent from the NRG to Exelon by electronic mail message on June 4, 2015 (Reference 2). The additional questions were discussed during a conference call with the NRG on June 9, 2015. During the conference call, Exelon indicated that a reduction in the scope of the original changes requested was being considered in lieu of responding to the RAI. Subsequently, Exelon has decided to reduce the scope of the Reference 1 submittal. The reduced scope only involves opening of secondary containment personnel access doors during normal entry and exit conditions. | ||
If you have any questions or require additional information, please contact Stephanie J. Hanson at 610-765-5143. | |||
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 12'h day of August 2015. Respectfully, David P. Helker Manager, Licensing | U.S. Nuclear Regulatory Commission License Amendment Request Secondary Containment Access Openings Docket Nos. 50-277 and 50-278 August 12, 2015 Page 2 All other proposed changes in the Reference 1 submittal are hereby withdrawn. provides the evaluation of the proposed change. Attachment 2 provides a copy of the marked up TS pages that reflect the proposed change. Attachment 3 provides a copy of the marked up TS Bases pages that reflect the proposed change (information only). | ||
& Regulatory Affairs Exelon Generation Company, LLC Attachments | Exelon has reviewed the information supporting a finding of no significant hazards consideration, and the environmental consideration, that were previously provided to the NRC in Attachment 1 of the Reference 1 letter. Although changes have been made to the no significant hazards consideration to reflect the reduced scope, Exelon has concluded that the information provided in this supplement does not affect the bases for concluding that the proposed license amendment does not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92. In addition, Exelon has concluded that the information in this supplement does not affect the bases for concluding that neither an environmental impact statement nor an environmental assessment needs to be prepared in connection with the proposed amendment. | ||
: 1. Evaluation of Proposed Changes 2. Markup of Proposed Technical Specifications Pages 3. Markup of Proposed Technical Specifications Bases Pages (Information Only) cc: Regional Administrator | There are no additional commitments contained within this letter. | ||
-NRC Region I w/attachments NRC Senior Resident Inspector | In accordance with 10 CFR 50.91, "Notice for public comment; State consultation," | ||
-Peach Bottom Atomic Power Station " NRC Project Manager, NRR -Peach Bottom Atomic Power Station " Director, Bureau of Radiation Protection, Pennsylvania Department of Environmental Protection " S. T. Gray , State of Maryland " | paragraph (b), Exelon is notifying the Commonwealth of Pennsylvania of this supplement by transmitting a copy of this letter and its attachments to the designated State Official. | ||
ATTACHMENT 1 EVALUATION OF PROPOSED CHANGES Supplement to License Amendment Request Peach Bottom Atomic Power Station, Units 2 and 3 Docket Nos. 50-277 and 50-278 | If you have any questions or require additional information, please contact Stephanie J. | ||
Hanson at 610-765-5143. | |||
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 12'h day of August 2015. | |||
Respectfully, David P. Helker Manager, Licensing & Regulatory Affairs Exelon Generation Company, LLC Attachments: 1. Evaluation of Proposed Changes | |||
: 2. Markup of Proposed Technical Specifications Pages | |||
: 3. Markup of Proposed Technical Specifications Bases Pages (Information Only) cc: Regional Administrator - NRC Region I w/attachments NRC Senior Resident Inspector - Peach Bottom Atomic Power Station " | |||
NRC Project Manager, NRR - Peach Bottom Atomic Power Station " | |||
Director, Bureau of Radiation Protection, Pennsylvania Department of Environmental Protection " | |||
S. T. Gray, State of Maryland " | |||
ATTACHMENT 1 EVALUATION OF PROPOSED CHANGES Supplement to License Amendment Request Peach Bottom Atomic Power Station, Units 2 and 3 Docket Nos. 50-277 and 50-278 | |||
==Subject:== | ==Subject:== | ||
Supplement to License Amendment Request to Change the Technical Specifications to Address Administrative Control of Secondary Containment Access Openings | Supplement to License Amendment Request to Change the Technical Specifications to Address Administrative Control of Secondary Containment Access Openings 1.0 | ||
1.0 | |||
==SUMMARY== | ==SUMMARY== | ||
DESCRIPTION | DESCRIPTION 2.0 DETAILED DESCRIPTION | ||
==3.0 TECHNICAL EVALUATION== | |||
== | ==4.0 REGULATORY EVALUATION== | ||
4.1 Applicable Regulatory Requirements/Criteria 4.2 Precedence 4.3 No Significant Hazards Consideration 4.4 Conclusions | |||
==5.0 ENVIRONMENTAL CONSIDERATION== | |||
==6.0 REFERENCES== | |||
Supplement to License Amendment Request Attachment 1 Secondary Containment Access Openings Page 1 of 8 Docket Nos. 50-277 and 50-278 Evaluation of Proposed Changes 1.0 | |||
Supplement to License Amendment Request | |||
1.0 | |||
==SUMMARY== | ==SUMMARY== | ||
DESCRIPTION On February 23, 2015, in accordance with the provisions of 10 CFR 50.90, Exelon Generation Company, LLC (Exelon), submitted a request for an amendment to the Technical Specifications (TS), Appendix A of Renewed Facility Operating License Nos. DPR-44 and DPR-56 for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3, respectively (Reference 1). | DESCRIPTION On February 23, 2015, in accordance with the provisions of 10 CFR 50.90, Exelon Generation Company, LLC (Exelon), submitted a request for an amendment to the Technical Specifications (TS), Appendix A of Renewed Facility Operating License Nos. DPR-44 and DPR-56 for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3, respectively (Reference 1). | ||
The proposed amendment requested U.S. Nuclear Regulatory Commission (NRC) approval to modify a Technical Specification (TS) Limiting Condition for Operation (LCO) and certain Surveillance Requirements (SRs) to allow secondary containment access openings to be opened intermittently under administrative control. | |||
The proposed amendment requested U.S. Nuclear Regulatory Commission (NRC) approval to modify a Technical Specification (TS) Limiting Condition for Operation (LCO) and certain Surveillance Requirements (SRs) to allow secondary containment access openings to be opened intermittently under administrative control. | |||
The NRC reviewed the license amendment request and identified the need for additional information in order to complete its evaluation of the amendment request. The draft request for additional information (RAI) was sent from the NRC to Exelon by electronic mail message on June 4, 2015 (Reference 2). The questions were discussed during a conference call with the NRC on June 9, 2015. During the conference call, Exelon indicated that a reduction in the scope of the original changes requested was being considered in lieu of responding to the RAI. | The NRC reviewed the license amendment request and identified the need for additional information in order to complete its evaluation of the amendment request. The draft request for additional information (RAI) was sent from the NRC to Exelon by electronic mail message on June 4, 2015 (Reference 2). The questions were discussed during a conference call with the NRC on June 9, 2015. During the conference call, Exelon indicated that a reduction in the scope of the original changes requested was being considered in lieu of responding to the RAI. | ||
Subsequently, Exelon has decided to reduce the scope of the Reference 1 submittal. The reduced scope only involves opening of secondary containment personnel access doors during normal entry and exit conditions. | Subsequently, Exelon has decided to reduce the scope of the Reference 1 submittal. The reduced scope only involves opening of secondary containment personnel access doors during normal entry and exit conditions. | ||
2.0 DETAILED DESCRIPTION The proposed change addresses an issue related to the secondary containment access openings. The secondary containment is a single system that performs a safety function. There is no redundant train or system that can perform the secondary containment function should the secondary containment become inoperable. The Required Actions of TS 3.6.4.1 provide a 4-hour Completion Time to restore an inoperable secondary containment to an Operable status. | |||
2.0 DETAILED DESCRIPTION | |||
The proposed change addresses an issue related to the secondary containment access openings. The secondary containment is a single | |||
As stated in the PBAPS TS Bases, "The 4 hour Completion Time provides a period of time to correct the problem that is commensurate with the importance of maintaining secondary containment during MODES 1, 2, and 3. This time period also ensures that the probability of an accident (requiring secondary containment OPERABILITY) occurring during periods where secondary containment is inoperable is minimal." | As stated in the PBAPS TS Bases, "The 4 hour Completion Time provides a period of time to correct the problem that is commensurate with the importance of maintaining secondary containment during MODES 1, 2, and 3. This time period also ensures that the probability of an accident (requiring secondary containment OPERABILITY) occurring during periods where secondary containment is inoperable is minimal." | ||
The purpose of the proposed change is to provide an allowance for brief, inadvertent, simultaneous openings of redundant secondary containment doors for normal passage. The original licensed design of the Peach Bottom Secondary Containment airlock system consists of inner and outer doors on the access points on each elevation, such that opening of any inner door on any elevation causes a blue light to be illuminated on every outer airlock door on all access point elevations as described in PBAPS Updated Final Safety Analysis Report (UFSAR) Section 5.3.1.3 (Reference 3). The original approved plant design does not prevent simultaneous openings through mechanical or electrical interlocks; therefore, occasional brief, simultaneous door openings are expected to occur and do not constitute a personnel error or equipment failure. Therefore, declaring secondary containment inoperable for these brief occurrences is not warranted. The change to the Surveillance Requirement (SR) description would resolve this inconsistency | The purpose of the proposed change is to provide an allowance for brief, inadvertent, simultaneous openings of redundant secondary containment doors for normal passage. The original licensed design of the Peach Bottom Secondary Containment airlock system consists of inner and outer doors on the access points on each elevation, such that opening of any inner door on any elevation causes a blue light to be illuminated on every outer airlock door on all access point elevations as described in PBAPS Updated Final Safety Analysis Report (UFSAR) | ||
Section 5.3.1.3 (Reference 3). The original approved plant design does not prevent simultaneous openings through mechanical or electrical interlocks; therefore, occasional brief, simultaneous door openings are expected to occur and do not constitute a personnel error or equipment failure. Therefore, declaring secondary containment inoperable for these brief occurrences is not warranted. The change to the Surveillance Requirement (SR) description would resolve this inconsistency. | |||
Supplement to License Amendment Request Attachment 1 Secondary Containment Access Openings Page 2 of 8 Docket Nos. 50-277 and 50-278 Evaluation of Proposed Changes PBAPS SR 3.6.4.1.2 requires verification that at least one door is closed in each secondary containment penetration. The intent of this requirement is to not breach secondary containment at any time when secondary containment is required. This is achieved by maintaining the inner or outer portion of the barrier closed at all times. All secondary containment access doors are normally kept closed, except when the access opening is being used for entry and exit or when maintenance is being performed on an access opening. | |||
This Supplement requests a revision to the wording of SR 3.6.4.1.2 to address brief, unintentional, simultaneous opening of both an inner and outer secondary containment access door. Opening both an inner and outer door in an access opening at the same time would result in a failure to meet PBAPS SR 3.6.4.1.2, which requires one access door in each access opening to be closed. This situation would require declaring the secondary containment inoperable, which involves administrative processing by licensed operators. The BWR/6 ISTS (NUREG-1434) SR 3.6.4.1.3 contains an exception for both doors in an access opening to be open simultaneously for normal entry and exit, but the PBAPS SR does not since it is a BWR/4 ISTS (NUREG-1433) plant (Reference 4). The proposed change adds the BWR/6 exception to the PBAPS SR. | |||
Proposed Bases Revision: The current combined Bases for SR 3.6.4.1.1 and SR 3.6.4.1.2 are being separated and the Bases of SR 3.6.4.1.2 are being revised to be consistent with the proposed revised SR. | |||
==3.0 TECHNICAL EVALUATION== | |||
The | The secondary containment is a structure that completely encloses the primary containment and those components that may contain primary system fluid. It is possible for the secondary containment pressure to rise relative to the environmental pressure during design basis events. | ||
To prevent ground level exfiltration of radioactive material while allowing the secondary containment to be designed as a conventional structure, the secondary containment requires support systems to maintain the control volume pressure at less than atmospheric pressure during design basis events. During normal operation, non-accident systems are used to maintain the secondary containment at a negative pressure. SR 3.6.4.1.3 requires verification that the secondary containment can be drawn down to be 0.25 inch of vacuum water gauge in 180 seconds using one standby gas treatment (SGT) subsystem. SR 3.6.4.1.4 requires verification that the secondary containment can be maintained 0.25 inch of vacuum water gauge for 1 hour using one SGT subsystem at a flow rate 10,500 cfm. Following an accident, the SGT System ensures the secondary containment pressure is less than the external atmospheric pressure. | |||
The secondary containment boundary is the combination of walls, floor, roof, ducting, doors, hatches, penetrations and equipment that physically form the secondary containment. For penetrations that contain doors, there exists at least one inner and one outer door. In some cases, secondary containment access openings are shared such that there are multiple inner or outer doors. All secondary containment access doors are normally kept closed, except when the access opening is being used for entry and exit of personnel or equipment or when maintenance is being performed on an access opening. | |||
The secondary containment and the SGT System together ensure radioactive material is processed. As long as a SGT subsystem can draw down and maintain the required vacuum on the secondary containment when needed (as demonstrated by SR 3.6.4.1.3 and SR 3.6.4.1.4), the secondary containment can perform its safety function. | Supplement to License Amendment Request Attachment 1 Secondary Containment Access Openings Page 3 of 8 Docket Nos. 50-277 and 50-278 Evaluation of Proposed Changes The safety function of the secondary containment is to contain, dilute, and hold up fission products that may leak from primary containment following a Design Basis Accident (DBA) to ensure the control room operator and offsite doses are within the regulatory and NRC-approved limits. In conjunction with operation of the SGT System and closure of certain valves whose lines penetrate the secondary containment, the secondary containment is designed to contain the fission products that bypass or leak from primary containment, or are released from the reactor coolant pressure boundary components located in secondary containment prior to release to the environment. For the secondary containment to be considered Operable, it must have adequate leak tightness to ensure that the required vacuum can be established and maintained by a single SGT subsystem, when that subsystem is in operation. | ||
The secondary containment and the SGT System together ensure radioactive material is processed. As long as a SGT subsystem can draw down and maintain the required vacuum on the secondary containment when needed (as demonstrated by SR 3.6.4.1.3 and SR 3.6.4.1.4), | |||
the secondary containment can perform its safety function. | |||
In these and similar cases, the secondary containment remains capable of processing fission products that may leak from primary containment following a DBA, which will ensure the control room operator and offsite doses are within the regulatory and NRC-approved limits. | |||
PBAPS has adopted alternative source term (AST) in accordance with 10 CFR 50.67 and using the methodology described in NRC Regulatory Guide 1.183. This resulted in revising the PBAPS SR 3.6.4.1.3 allowing a 180-second draw down time to ensure the secondary containment is > 0.25 inches of water vacuum. Because the typical draw down time using one SGT subsystem is well under 60 seconds, substantial margin exists to ensure that the secondary containment can be re-established during brief simultaneous opening of secondary containment redundant barriers. | |||
PBAPS SR 3.6.4.1.2 requires verification that at least one door is closed in each secondary containment penetration. The intent of these requirements is to not breach secondary containment at any time when secondary containment is required. This is achieved by maintaining the inner or outer portion of the barrier closed at all times. All secondary containment access doors are normally kept closed, except when the access opening is being used for entry and exit or when maintenance is being performed on an access opening. | |||
Proposed PBAPS SR 3.6.4.1.2 Revision The PBAPS SR 3.6.4.1.2 is proposed to be revised to be consistent with the similar BWR/6 (NUREG-1434) SR 3.6.4.1.3. The text in italics, below, is proposed to be added. | |||
Verify one secondary containment access door in each access opening is closed, except when the access opening is being used for entry or exit. | |||
The BWR/6 ISTS (NUREG-1434) SR 3.6.4.1.3 contains an exception for both doors in an access opening being opened simultaneously for normal entry and exit, but the current PBAPS SR does not. This allowance is reasonable because the doors will be promptly closed following entry or exit, restoring the secondary containment boundary. | |||
Supplement to License Amendment Request Attachment 1 Secondary Containment Access Openings Page 4 of 8 Docket Nos. 50-277 and 50-278 Evaluation of Proposed Changes Personnel are trained in Nuclear General Employee Training (NGET) to not open a secondary containment door if the blue light is illuminated. However, as licensed by the NRC, there is no physical interlock associated with these doors. Proceeding through a door requires an individual to look up at the condition of the blue light, then card in/out (if applicable), re-look at the status of the blue light and then look down again and proceed to open the door. Occasionally, an individual attempts access through the opposite airlock entry point, and an alarm sounds due to a simultaneous door opening by another individual. Well-intended individuals may end up in this simultaneous situation, which cannot be prevented under the original licensed design. | |||
Supplement to License Amendment Request | |||
Personnel are trained in Nuclear General Employee Training (NGET) to not open a secondary containment door if the blue light is illuminated. However, as licensed by the NRC, there is no physical interlock associated with these doors. Proceeding through a door requires an individual to look up at the condition of the blue light, then card in/out (if applicable), re-look at the status of the blue light and then look down again and proceed to open the door. Occasionally, an individual attempts access through the opposite airlock entry point, and an alarm sounds due to a simultaneous door opening by another individual. Well-intended individuals may end up in this simultaneous situation, which cannot be prevented under the original licensed design. | |||
From a safety perspective (see UFSAR Table 8.5.1), during a design basis accident (LOCA with simultaneous LOOP), Emergency Diesel Generators start and restore 4 kV Bus power in 13 seconds after the event, followed by 480 V Load Center restoration 3 seconds later, such that SGT start will occur no earlier than 16 seconds after initiation of the event. In addition, no credit is taken for any negative pressure in the building at the time of the event. The AST analysis assumptions are such that no credit is taken for secondary containment for the first 180 seconds following a Design Basis LOCA or fuel handling accidents. Based on the original licensed design of the Peach Bottom Secondary Containment and the allowances of AST, it can be concluded that brief simultaneous opening of an inner and outer secondary containment blue light door is an expected possible occurrence in the PBAPS secondary containment design and, therefore, a declaration of inoperability is not warranted. | From a safety perspective (see UFSAR Table 8.5.1), during a design basis accident (LOCA with simultaneous LOOP), Emergency Diesel Generators start and restore 4 kV Bus power in 13 seconds after the event, followed by 480 V Load Center restoration 3 seconds later, such that SGT start will occur no earlier than 16 seconds after initiation of the event. In addition, no credit is taken for any negative pressure in the building at the time of the event. The AST analysis assumptions are such that no credit is taken for secondary containment for the first 180 seconds following a Design Basis LOCA or fuel handling accidents. Based on the original licensed design of the Peach Bottom Secondary Containment and the allowances of AST, it can be concluded that brief simultaneous opening of an inner and outer secondary containment blue light door is an expected possible occurrence in the PBAPS secondary containment design and, therefore, a declaration of inoperability is not warranted. | ||
Proposed Bases Revisions | Proposed Bases Revisions The current combined Bases for PBAPS SR 3.6.4.1.1 and SR 3.6.4.1.2 are being separated and the Bases of SR 3.6.4.1.2 are being revised to be consistent with the proposed revised SR. | ||
==4.0 REGULATORY EVALUATION== | |||
4.1 Applicable Regulatory Requirements/Criteria The following regulatory requirements have been considered: | |||
Title 10 of the Code of Federal Regulations (10 CFR), Section 50.36, "Technical specifications," in which the Commission established its regulatory requirements related to the contents of the TS. Specifically, 10 CFR 50.36(c)(2) states, in part, "Limiting conditions for operation are the lowest functional capability or performance levels of equipment required for safe operation of the facility." 10 CFR 50.36(c)(3) states, "Surveillance requirements are requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the limiting conditions of operation will be met." | |||
The proposed change to the secondary containment LCO and SR does not affect compliance with these regulations. | |||
Supplement to License Amendment Request Attachment 1 Secondary Containment Access Openings Page 5 of 8 Docket Nos. 50-277 and 50-278 Evaluation of Proposed Changes The applicable 10 CFR Part 50, Appendix A, General Design Criteria, was considered as follows: | |||
The applicable PBAPS principal design criteria predate these criteria. The PBAPS principal design criteria is listed in UFSAR Section 1.5, "Principal Design Criteria." In 1967, the Atomic Energy Commission (AEC) published for public comment a revised set of proposed General Design Criteria (Federal Register 32 FR 10213, July 11, 1967). Although not explicitly licensed to the AEC proposed General Design Criteria published in 1967, Philadelphia Electric Company (PECO), the predecessor to Exelon, performed a comparative evaluation of the design basis of PBAPS Units 2 and 3 against the AEC proposed General Design Criteria of 1967. The PBAPS UFSAR, Appendix H, "Conformance to AEC (NRC) Criteria," contains this comparative evaluation. UFSAR Appendix H provides a comparative evaluation with each of the groups of criteria set out in the July 1967 AEC release. As to each group of criteria, there is a statement of Exelons understanding of the intent of the criteria in that group and a discussion of the plant design conformance with the intent of the group of criteria. Following a restatement of each of the proposed criteria is a list of references to locations in the PBAPS UFSAR where there is subject matter relating to the intent of that particular criteria. | |||
Engineered Safety Feature (ESF) atmosphere cleanup systems are designed for fission product removal in post-accident environments. These systems generally include primary systems (e.g., in-containment recirculation) and secondary systems (e.g., standby gas treatment systems and emergency or post-accident air-cleaning systems) for the fuel-handling building, control room, shield building, and areas containing ESF components. The NRCs acceptance criteria for ESF atmosphere cleanup systems were based on (1) final GDC-19, insofar as it requires that adequate radiation protection be provided to permit access and occupancy of the control room under accident conditions without personnel receiving radiation exposures in excess of 5 rem whole body, or its equivalent, to any part of the body, for the duration of the accident; (2) draft GDC-69, insofar as it requires that systems that may contain radioactivity be designed to assure adequate safety under normal and postulated accident conditions; and (3) final GDC-64, insofar as it requires that means be provided for monitoring effluent discharge paths and the plant environs for radioactivity that may be released from normal operations, including anticipated operational occurrences (AOOs), and postulated accidents. | |||
The proposed change does not alter the design of the secondary containment or its ability to establish an essentially leak-tight barrier against the uncontrolled release of radioactivity. | |||
4.2 Precedence The proposed change to modify SR 3.6.4.1.2 to allow brief, inadvertent, simultaneous opening of redundant secondary containment doors for entry and exit is consistent with the improved Standard Technical Specifications endorsed by the NRC in NUREG-1434, Standard Technical Specifications - General Electric BWR/6 Plants, Revision 4 (Reference 5). | |||
Supplement to License Amendment Request | |||
The applicable 10 CFR Part 50, Appendix A, General Design Criteria, was considered as follows: | |||
Engineered Safety Feature (ESF) atmosphere cleanup systems are designed for fission product removal in post-accident environments. These systems generally include primary systems (e.g., in-containment recirculation) and secondary systems (e.g., standby gas treatment systems and emergency or post-accident air-cleaning systems) for the fuel-handling building, control room, shield building, and areas containing ESF components. The | |||
The proposed change does not alter the design of the secondary containment or its ability to establish an essentially leak-tight barrier against the uncontrolled release of | |||
radioactivity. | |||
4.2 Precedence | |||
The proposed change to modify SR 3.6.4.1.2 to allow brief, inadvertent, simultaneous opening of redundant secondary containment doors for entry and exit is consistent with the improved Standard Technical Specifications endorsed by the NRC in NUREG-1434, Standard Technical Specifications - General Electric BWR/6 Plants, Revision 4 (Reference 5) | |||
Supplement to License Amendment Request Attachment 1 Secondary Containment Access Openings Page 6 of 8 Docket Nos. 50-277 and 50-278 Evaluation of Proposed Changes 4.3 No Significant Hazards Consideration Exelon Generation Company, LLC (Exelon) is proposing a change to the Technical Specifications (TS), Appendix A of Renewed Facility Operating License Nos. DPR-44 and DPR-56 for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3, respectively. | |||
The proposed change revises PBAPS TS Surveillance Requirement (SR) 3.6.4.1.2. SR 3.6.4.1.2 is modified to match the standard improved TS for BWR/6 plants (NUREG-1434) to recognize that due to the PBAPS secondary containment design, brief, inadvertent, simultaneous openings of redundant secondary containment doors during entry and exit are an expected occurrence and do not render secondary containment inoperable. | The proposed change revises PBAPS TS Surveillance Requirement (SR) 3.6.4.1.2. SR 3.6.4.1.2 is modified to match the standard improved TS for BWR/6 plants (NUREG-1434) to recognize that due to the PBAPS secondary containment design, brief, inadvertent, simultaneous openings of redundant secondary containment doors during entry and exit are an expected occurrence and do not render secondary containment inoperable. | ||
Exelon has evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below: | Exelon has evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below: | ||
: 1. Do the proposed changes involve a significant increase in the probability or consequences of an accident previously evaluated? | : 1. Do the proposed changes involve a significant increase in the probability or consequences of an accident previously evaluated? | ||
Response: | Response: No. The proposed change allows temporary conditions during which the secondary containment SR is not met. The secondary containment is not an initiator of any accident previously evaluated. As a result, the probability of any accident previously evaluated is not increased. The consequences of an accident previously evaluated while utilizing the proposed change is no different than the consequences of an accident while utilizing the existing 4-hour Completion Time for an inoperable secondary containment. As a result, the consequences of an accident previously evaluated are not significantly increased. | ||
The proposed change allows temporary conditions during which the secondary containment SR is not met. The secondary containment is not an initiator of any accident previously evaluated. As a result, the probability of any accident previously evaluated is not increased. The consequences of an accident previously evaluated while utilizing the proposed change is no different than the consequences of an accident while utilizing the existing 4-hour Completion Time for an inoperable secondary containment. As a result, the | |||
consequences of an accident previously evaluated are not significantly increased. | |||
Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated. | Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated. | ||
: 2. Do the proposed changes create the possibility of a new or different kind of accident from any accident previously evaluated? Response: | : 2. Do the proposed changes 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 | Response: No. The proposed change does not alter the protection system design, create new failure modes, or change any modes of operation. The proposed changes do 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. | |||
Supplement to License Amendment Request Attachment 1 Secondary Containment Access Openings Page 7 of 8 Docket Nos. 50-277 and 50-278 Evaluation of Proposed Changes | |||
: 3. Do the proposed changes involve a significant reduction in a margin of safety? | |||
Response: No. The proposed change allows temporary conditions during which the secondary containment SR is not met. Temporary conditions in which the secondary containment is open are acceptable provided the conditions do not affect the ability of the Standby Gas Treatment System to create a lower pressure in the secondary containment than in the outside environment if required. The allowance for both an inner and outer secondary containment door to be open simultaneously for entry and exit does not affect the safety function of the secondary containment as the doors are promptly closed after entry or exit, thereby restoring the secondary containment boundary. | |||
Therefore, the proposed change does not involve a significant reduction in a margin of safety. | |||
Based on the above, Exelon concludes that the proposed amendment presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of "no significant hazards consideration" is justified. | Based on the above, Exelon concludes that the proposed amendment presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of "no significant hazards consideration" is justified. | ||
4.4 Conclusions In conclusion, 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 | 4.4 Conclusions In conclusion, 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 Commissions 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. | ||
==5.0 ENVIRONMENTAL CONSIDERATION== | ==5.0 ENVIRONMENTAL CONSIDERATION== | ||
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 surveillance requirement. However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluent 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. | 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 surveillance requirement. However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluent 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. | ||
Supplement to License Amendment Request | Supplement to License Amendment Request Attachment 1 Secondary Containment Access Openings Page 8 of 8 Docket Nos. 50-277 and 50-278 Evaluation of Proposed Changes | ||
==6.0 REFERENCES== | ==6.0 REFERENCES== | ||
: 1. License Amendment Request concerning Proposed Changes to the Technical Specifications to Address Administrative Control of Secondary Containment Access Openings dated February 23, 2015. | : 1. License Amendment Request concerning Proposed Changes to the Technical Specifications to Address Administrative Control of Secondary Containment Access Openings dated February 23, 2015. | ||
: 2. Email correspondence from R. Ennis (U.S. Nuclear Regulatory Commission) to S. Hanson (Exelon Generation Company, LLC), "Peach Bottom Atomic Power Station, Units 2 and 3 - DRAFT Request for Additional Information regarding Proposed License Amendment for Administrative Control of Secondary Containment Access Openings (TAC NOS. MF5783 & MF5784)," dated June 4, 2015. | : 2. Email correspondence from R. Ennis (U.S. Nuclear Regulatory Commission) to S. | ||
Hanson (Exelon Generation Company, LLC), "Peach Bottom Atomic Power Station, Units 2 and 3 - DRAFT Request for Additional Information regarding Proposed License Amendment for Administrative Control of Secondary Containment Access Openings (TAC NOS. MF5783 & MF5784)," dated June 4, 2015. | |||
: 3. Peach Bottom Atomic Power Station, Updated Final Safety Analysis Report, Revision 24. | : 3. Peach Bottom Atomic Power Station, Updated Final Safety Analysis Report, Revision 24. | ||
: 4. NUREG-1433, "Standard Technical | : 4. NUREG-1433, "Standard Technical Specifications General Electric Plants, BWR/4," | ||
: 5. NUREG-1434, "Standard Technical | Revision 4. | ||
: 5. NUREG-1434, "Standard Technical Specifications General Electric Plants, BWR/6," | |||
Revision 4. | |||
ATTACHMENT 2 | ATTACHMENT 2 Markup of Proposed Technical Specifications Pages Supplement to License Amendment Request Peach Bottom Atomic Power Station, Units 2 and 3 Docket Nos. 50-277 and 50-278 Proposed Changes to the Technical Specifications to Address Administrative Control of Secondary Containment Access Openings Unit 2 TS Page 3.6-35 Unit 3 TS Page 3.6-35 | ||
Secondary Containment 3.6.4.1 ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME C. (continued) C.2 Initiate action to Immediately suspend OPDRVs. | |||
SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.4.1.1 Verify all secondary containment In accordance equipment hatches are closed and sealed. with the Surveillance Frequency Control Program. | |||
SR 3.6.4.1.2 Verify one secondary containment access In accordance door in each access opening is closed. with the | |||
, except when the access opening is being used for entry or exit. Surveillance Frequency Control Program. | |||
SR 3.6.4.1.3 Verify secondary containment can be drawn In accordance down to 0.25 inch of vacuum water gauge with the in 180 seconds using one standby gas Surveillance treatment (SGT) subsystem. Frequency Control Program. | |||
SR 3.6.4.1.4 Verify the secondary containment can be In accordance maintained 0.25 inch of vacuum water with the gauge for 1 hour using one SGT subsystem Surveillance at a flow rate 10,500 cfm. Frequency Control Program. | |||
PBAPS UNIT 2 3.6-35 Amendment No. 278 | |||
Secondary Containment 3.6.4.1 ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME C. (continued) C.2 Initiate action to Immediately suspend OPDRVs. | |||
SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.4.1.1 Verify all secondary containment In accordance equipment hatches are closed and sealed. with the Surveillance Frequency Control Program. | |||
SR 3.6.4.1.2 Verify one secondary containment access In accordance door in each access opening is closed. with the | |||
, except when the access opening is being used for entry or exit. Surveillance Frequency Control Program. | |||
SR 3.6.4.1.3 Verify secondary containment can be drawn In accordance down to 0.25 inch of vacuum water gauge with the in 180 seconds using one standby gas Surveillance treatment (SGT) subsystem. Frequency Control Program. | |||
SR 3.6.4.1.4 Verify the secondary containment can be In accordance maintained 0.25 inch of vacuum water with the gauge for 1 hour using one SGT subsystem Surveillance at a flow rate 10,500 cfm. Frequency Control Program. | |||
PBAPS UNIT 3 3.6-35 Amendment No. 281 | |||
Markup of Proposed Technical Specifications Bases Pages (Information Only) | ATTACHMENT 3 Markup of Proposed Technical Specifications Bases Pages (Information Only) | ||
Supplement to License Amendment Request Peach Bottom Atomic Power Station, Units 2 and 3 | Supplement to License Amendment Request Peach Bottom Atomic Power Station, Units 2 and 3 Docket Nos. 50-277 and 50-278 Proposed Changes to the Technical Specifications to Address Administrative Control of Secondary Containment Openings Unit 2 TS Bases Page B 3.6-76 Unit 3 TS Bases Page B 3.6-76 | ||
Secondary Containment B 3.6.4.1 BASES (continued) | |||
SURVEILLANCE SR 3.6.4.1.1 and SR 3.6.4.1.2 REQUIREMENTS Verifying that secondary containment equipment hatches and one access door in each access opening are closed ensures that the infiltration of outside air of such a magnitude as to prevent maintaining the desired negative pressure does not occur. Verifying that all such openings are closed provides adequate assurance that exfiltration from the secondary containment will not occur. In this application, the term "sealed" has no connotation of leak tightness. | |||
Maintaining secondary containment OPERABILITY requires and verifying one door in the access opening is closed. An access opening contains one inner and one outer door. In some cases, secondary containment access openings are shared such that a secondary containment barrier may have multiple inner or multiple outer doors. The intent is to not breach secondary containment at any time when secondary containment is required. This is achieved by maintaining the inner or outer portion of the barrier closed at all times. However, all secondary containment access doors are normally kept closed, except when the access opening is being used for entry and exit or when maintenance is being performed on an access opening. The Surveillance Frequency is controlled Insert Revised SR here under the Surveillance Frequency Control Program. | |||
SR 3.6.4.1.3 and SR 3.6.4.1.4 The SGT System exhausts the secondary containment atmosphere to the environment through appropriate treatment equipment. | |||
Each SGT subsystem is designed to draw down pressure in the secondary containment to 0.25 inches of vacuum water gauge in 180 seconds and maintain pressure in the secondary containment at 0.25 inches of vacuum water gauge for 1 hour at a flow rate 10,500 cfm. To ensure that all fission products released to the secondary containment are treated, SR 3.6.4.1.3 and SR 3.6.4.1.4 verify that a pressure in the secondary containment that is less than the lowest postulated pressure external to the secondary containment boundary can rapidly be established and maintained. When the SGT System is operating as designed, the establishment and maintenance of secondary containment pressure cannot be accomplished if the secondary containment boundary is not intact. | |||
Establishment of this pressure is confirmed by SR 3.6.4.1.3 which demonstrates that the secondary containment can be drawn down to 0.25 inches of vacuum water gauge in 180 (continued) | |||
PBAPS UNIT 2 B 3.6-76 Revision No. 86 | |||
Secondary Containment B 3.6.4.1 BASES (continued) | |||
SURVEILLANCE SR 3.6.4.1.1 and SR 3.6.4.1.2 REQUIREMENTS Verifying that secondary containment equipment hatches and one access door in each access opening are closed ensures that the infiltration of outside air of such a magnitude as to prevent maintaining the desired negative pressure does not occur. Verifying that all such openings are closed provides adequate assurance that exfiltration from the secondary containment will not occur. In this application, and the term "sealed" has no connotation of leak tightness. | |||
Maintaining secondary containment OPERABILITY requires verifying one door in the access opening is closed. An access opening contains one inner and one outer door. In some cases, secondary containment access openings are shared such that a secondary containment barrier may have multiple inner or multiple outer doors. The intent is to not breach secondary containment at any time when secondary containment is required. This is achieved by maintaining the inner or outer portion of the barrier closed at all times. However, all secondary containment access doors are normally kept closed, except when the access opening is being used for entry and exit or when maintenance is being performed on an access opening. The Surveillance Frequency is controlled under the Surveillance Frequency Control Program. | |||
Insert Revised SR here SR 3.6.4.1.3 and SR 3.6.4.1.4 The SGT System exhausts the secondary containment atmosphere to the environment through appropriate treatment equipment. | |||
Each SGT subsystem is designed to draw down pressure in the secondary containment to 0.25 inches of vacuum water gauge in 180 seconds and maintain pressure in the secondary containment at 0.25 inches of vacuum water gauge for 1 hour at a flow rate 10,500 cfm. To ensure that all fission products released to the secondary containment are treated, SR 3.6.4.1.3 and SR 3.6.4.1.4 verify that a pressure in the secondary containment this is less than the lowest postulated pressure external to the secondary containment boundary can rapidly be established and maintained. When the SGT System is operating as designed, the establishment and maintenance of secondary containment pressure cannot be accomplished if the secondary containment boundary is not intact. | |||
Establishment of this pressure is confirmed by SR 3.6.4.1.3 which demonstrates that the secondary containment can be drawn down to 0.25 inches of vacuum water gauge in 180 (continued) | |||
PBAPS UNIT 3 B 3.6-76 Revision No. 87 | |||
Supplement to License Amendment Request Secondary Containment Access Openings | Supplement to License Amendment Request Secondary Containment Access Openings Docket Nos. 50-277 and 50-278 PBAPS Unit 2 and Unit 3 TSB Insertion Revised SR: | ||
-277 and 50 | SR 3.6.4.1.2 Verifying that one secondary containment access door in each access opening is closed provides adequate assurance that exfiltration from the secondary containment will not occur. An access opening contains at least one inner and one outer door. In some cases, secondary containment access openings are shared such that there are multiple inner or outer doors. The intent is to not breach the secondary containment, which is achieved by maintaining the inner or outer portion of the barrier closed. SR 3.6.4.1.2 provides an exception to allow brief, unintentional, simultaneous opening of both an inner and outer secondary containment access door. | ||
-278 | |||
The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.}} | The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.}} |
Latest revision as of 07:59, 31 October 2019
ML15224B572 | |
Person / Time | |
---|---|
Site: | Peach Bottom |
Issue date: | 08/12/2015 |
From: | David Helker Exelon Generation Co |
To: | Document Control Desk, Office of Nuclear Reactor Regulation |
References | |
Download: ML15224B572 (18) | |
Text
ZOO Exelon W*y Kc lnett <:;quar* PA 19348 Exelon Generation www.exelo:1ror J.com 10 CFR 50.90 August 12, 2015 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Peach Bottom Atomic Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-44 and DPR-56 NRG Docket Nos. 50-277 and 50-278
Subject:
Supplement to License Amendment Request Proposed Changes to the Technical Specifications to Address Administrative Control of Secondary Containment Access Openings
References:
- 1) License Amendment Request- Proposed Changes to the Technical Specifications to Address Administrative Control of Secondary Containment Access Openings dated February 23, 2015
- 2) Email correspondence from R. Ennis (U.S . Nuclear Regulatory Commission) to S. Hanson (Exelon Generation Company, LLC),
"Peach Bottom Atomic Power Station, Units 2 and 3 - DRAFT Request for Additional Information regarding Proposed License Amendment for Administrative Control of Secondary Containment Access Openings (TAC NOS. MF5783 & MF5784)," dated June 4, 2015 On February 23, 2015, in accordance with the provisions of 10 CFR 50.90, "Application for amendment of license, construction permit, or early site permit," Exelon Generation Company, LLC (Exelon), submitted a request for an amendment to the Technical Specifications (TS), Appendix A of Renewed Facility Operating License Nos. DPR-44 and DPR-56 for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3, respectively (Reference 1).
The proposed amendment requested U.S. Nuclear Regulatory Commission (NRG) approval to modify a Technical Specification (TS) Limiting Condition for Operation (LCO) and certain Surveillance Requirements (SRs) to allow secondary containment access openings to be opened intermittently under administrative control.
The NRG reviewed the license amendment request and identified the need for additional information in order to complete its evaluation of the amendment request. The draft request for additional information (RAI) was sent from the NRG to Exelon by electronic mail message on June 4, 2015 (Reference 2). The additional questions were discussed during a conference call with the NRG on June 9, 2015. During the conference call, Exelon indicated that a reduction in the scope of the original changes requested was being considered in lieu of responding to the RAI. Subsequently, Exelon has decided to reduce the scope of the Reference 1 submittal. The reduced scope only involves opening of secondary containment personnel access doors during normal entry and exit conditions.
U.S. Nuclear Regulatory Commission License Amendment Request Secondary Containment Access Openings Docket Nos. 50-277 and 50-278 August 12, 2015 Page 2 All other proposed changes in the Reference 1 submittal are hereby withdrawn. provides the evaluation of the proposed change. Attachment 2 provides a copy of the marked up TS pages that reflect the proposed change. Attachment 3 provides a copy of the marked up TS Bases pages that reflect the proposed change (information only).
Exelon has reviewed the information supporting a finding of no significant hazards consideration, and the environmental consideration, that were previously provided to the NRC in Attachment 1 of the Reference 1 letter. Although changes have been made to the no significant hazards consideration to reflect the reduced scope, Exelon has concluded that the information provided in this supplement does not affect the bases for concluding that the proposed license amendment does not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92. In addition, Exelon has concluded that the information in this supplement does not affect the bases for concluding that neither an environmental impact statement nor an environmental assessment needs to be prepared in connection with the proposed amendment.
There are no additional commitments contained within this letter.
In accordance with 10 CFR 50.91, "Notice for public comment; State consultation,"
paragraph (b), Exelon is notifying the Commonwealth of Pennsylvania of this supplement by transmitting a copy of this letter and its attachments to the designated State Official.
If you have any questions or require additional information, please contact Stephanie J.
Hanson at 610-765-5143.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 12'h day of August 2015.
Respectfully, David P. Helker Manager, Licensing & Regulatory Affairs Exelon Generation Company, LLC Attachments: 1. Evaluation of Proposed Changes
- 2. Markup of Proposed Technical Specifications Pages
- 3. Markup of Proposed Technical Specifications Bases Pages (Information Only) cc: Regional Administrator - NRC Region I w/attachments NRC Senior Resident Inspector - Peach Bottom Atomic Power Station "
NRC Project Manager, NRR - Peach Bottom Atomic Power Station "
Director, Bureau of Radiation Protection, Pennsylvania Department of Environmental Protection "
S. T. Gray, State of Maryland "
ATTACHMENT 1 EVALUATION OF PROPOSED CHANGES Supplement to License Amendment Request Peach Bottom Atomic Power Station, Units 2 and 3 Docket Nos. 50-277 and 50-278
Subject:
Supplement to License Amendment Request to Change the Technical Specifications to Address Administrative Control of Secondary Containment Access Openings 1.0
SUMMARY
DESCRIPTION 2.0 DETAILED DESCRIPTION
3.0 TECHNICAL EVALUATION
4.0 REGULATORY EVALUATION
4.1 Applicable Regulatory Requirements/Criteria 4.2 Precedence 4.3 No Significant Hazards Consideration 4.4 Conclusions
5.0 ENVIRONMENTAL CONSIDERATION
6.0 REFERENCES
Supplement to License Amendment Request Attachment 1 Secondary Containment Access Openings Page 1 of 8 Docket Nos. 50-277 and 50-278 Evaluation of Proposed Changes 1.0
SUMMARY
DESCRIPTION On February 23, 2015, in accordance with the provisions of 10 CFR 50.90, Exelon Generation Company, LLC (Exelon), submitted a request for an amendment to the Technical Specifications (TS), Appendix A of Renewed Facility Operating License Nos. DPR-44 and DPR-56 for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3, respectively (Reference 1).
The proposed amendment requested U.S. Nuclear Regulatory Commission (NRC) approval to modify a Technical Specification (TS) Limiting Condition for Operation (LCO) and certain Surveillance Requirements (SRs) to allow secondary containment access openings to be opened intermittently under administrative control.
The NRC reviewed the license amendment request and identified the need for additional information in order to complete its evaluation of the amendment request. The draft request for additional information (RAI) was sent from the NRC to Exelon by electronic mail message on June 4, 2015 (Reference 2). The questions were discussed during a conference call with the NRC on June 9, 2015. During the conference call, Exelon indicated that a reduction in the scope of the original changes requested was being considered in lieu of responding to the RAI.
Subsequently, Exelon has decided to reduce the scope of the Reference 1 submittal. The reduced scope only involves opening of secondary containment personnel access doors during normal entry and exit conditions.
2.0 DETAILED DESCRIPTION The proposed change addresses an issue related to the secondary containment access openings. The secondary containment is a single system that performs a safety function. There is no redundant train or system that can perform the secondary containment function should the secondary containment become inoperable. The Required Actions of TS 3.6.4.1 provide a 4-hour Completion Time to restore an inoperable secondary containment to an Operable status.
As stated in the PBAPS TS Bases, "The 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> Completion Time provides a period of time to correct the problem that is commensurate with the importance of maintaining secondary containment during MODES 1, 2, and 3. This time period also ensures that the probability of an accident (requiring secondary containment OPERABILITY) occurring during periods where secondary containment is inoperable is minimal."
The purpose of the proposed change is to provide an allowance for brief, inadvertent, simultaneous openings of redundant secondary containment doors for normal passage. The original licensed design of the Peach Bottom Secondary Containment airlock system consists of inner and outer doors on the access points on each elevation, such that opening of any inner door on any elevation causes a blue light to be illuminated on every outer airlock door on all access point elevations as described in PBAPS Updated Final Safety Analysis Report (UFSAR)
Section 5.3.1.3 (Reference 3). The original approved plant design does not prevent simultaneous openings through mechanical or electrical interlocks; therefore, occasional brief, simultaneous door openings are expected to occur and do not constitute a personnel error or equipment failure. Therefore, declaring secondary containment inoperable for these brief occurrences is not warranted. The change to the Surveillance Requirement (SR) description would resolve this inconsistency.
Supplement to License Amendment Request Attachment 1 Secondary Containment Access Openings Page 2 of 8 Docket Nos. 50-277 and 50-278 Evaluation of Proposed Changes PBAPS SR 3.6.4.1.2 requires verification that at least one door is closed in each secondary containment penetration. The intent of this requirement is to not breach secondary containment at any time when secondary containment is required. This is achieved by maintaining the inner or outer portion of the barrier closed at all times. All secondary containment access doors are normally kept closed, except when the access opening is being used for entry and exit or when maintenance is being performed on an access opening.
This Supplement requests a revision to the wording of SR 3.6.4.1.2 to address brief, unintentional, simultaneous opening of both an inner and outer secondary containment access door. Opening both an inner and outer door in an access opening at the same time would result in a failure to meet PBAPS SR 3.6.4.1.2, which requires one access door in each access opening to be closed. This situation would require declaring the secondary containment inoperable, which involves administrative processing by licensed operators. The BWR/6 ISTS (NUREG-1434) SR 3.6.4.1.3 contains an exception for both doors in an access opening to be open simultaneously for normal entry and exit, but the PBAPS SR does not since it is a BWR/4 ISTS (NUREG-1433) plant (Reference 4). The proposed change adds the BWR/6 exception to the PBAPS SR.
Proposed Bases Revision: The current combined Bases for SR 3.6.4.1.1 and SR 3.6.4.1.2 are being separated and the Bases of SR 3.6.4.1.2 are being revised to be consistent with the proposed revised SR.
3.0 TECHNICAL EVALUATION
The secondary containment is a structure that completely encloses the primary containment and those components that may contain primary system fluid. It is possible for the secondary containment pressure to rise relative to the environmental pressure during design basis events.
To prevent ground level exfiltration of radioactive material while allowing the secondary containment to be designed as a conventional structure, the secondary containment requires support systems to maintain the control volume pressure at less than atmospheric pressure during design basis events. During normal operation, non-accident systems are used to maintain the secondary containment at a negative pressure. SR 3.6.4.1.3 requires verification that the secondary containment can be drawn down to be 0.25 inch of vacuum water gauge in 180 seconds using one standby gas treatment (SGT) subsystem. SR 3.6.4.1.4 requires verification that the secondary containment can be maintained 0.25 inch of vacuum water gauge for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> using one SGT subsystem at a flow rate 10,500 cfm. Following an accident, the SGT System ensures the secondary containment pressure is less than the external atmospheric pressure.
The secondary containment boundary is the combination of walls, floor, roof, ducting, doors, hatches, penetrations and equipment that physically form the secondary containment. For penetrations that contain doors, there exists at least one inner and one outer door. In some cases, secondary containment access openings are shared such that there are multiple inner or outer doors. All secondary containment access doors are normally kept closed, except when the access opening is being used for entry and exit of personnel or equipment or when maintenance is being performed on an access opening.
Supplement to License Amendment Request Attachment 1 Secondary Containment Access Openings Page 3 of 8 Docket Nos. 50-277 and 50-278 Evaluation of Proposed Changes The safety function of the secondary containment is to contain, dilute, and hold up fission products that may leak from primary containment following a Design Basis Accident (DBA) to ensure the control room operator and offsite doses are within the regulatory and NRC-approved limits. In conjunction with operation of the SGT System and closure of certain valves whose lines penetrate the secondary containment, the secondary containment is designed to contain the fission products that bypass or leak from primary containment, or are released from the reactor coolant pressure boundary components located in secondary containment prior to release to the environment. For the secondary containment to be considered Operable, it must have adequate leak tightness to ensure that the required vacuum can be established and maintained by a single SGT subsystem, when that subsystem is in operation.
The secondary containment and the SGT System together ensure radioactive material is processed. As long as a SGT subsystem can draw down and maintain the required vacuum on the secondary containment when needed (as demonstrated by SR 3.6.4.1.3 and SR 3.6.4.1.4),
the secondary containment can perform its safety function.
In these and similar cases, the secondary containment remains capable of processing fission products that may leak from primary containment following a DBA, which will ensure the control room operator and offsite doses are within the regulatory and NRC-approved limits.
PBAPS has adopted alternative source term (AST) in accordance with 10 CFR 50.67 and using the methodology described in NRC Regulatory Guide 1.183. This resulted in revising the PBAPS SR 3.6.4.1.3 allowing a 180-second draw down time to ensure the secondary containment is > 0.25 inches of water vacuum. Because the typical draw down time using one SGT subsystem is well under 60 seconds, substantial margin exists to ensure that the secondary containment can be re-established during brief simultaneous opening of secondary containment redundant barriers.
PBAPS SR 3.6.4.1.2 requires verification that at least one door is closed in each secondary containment penetration. The intent of these requirements is to not breach secondary containment at any time when secondary containment is required. This is achieved by maintaining the inner or outer portion of the barrier closed at all times. All secondary containment access doors are normally kept closed, except when the access opening is being used for entry and exit or when maintenance is being performed on an access opening.
Proposed PBAPS SR 3.6.4.1.2 Revision The PBAPS SR 3.6.4.1.2 is proposed to be revised to be consistent with the similar BWR/6 (NUREG-1434) SR 3.6.4.1.3. The text in italics, below, is proposed to be added.
Verify one secondary containment access door in each access opening is closed, except when the access opening is being used for entry or exit.
The BWR/6 ISTS (NUREG-1434) SR 3.6.4.1.3 contains an exception for both doors in an access opening being opened simultaneously for normal entry and exit, but the current PBAPS SR does not. This allowance is reasonable because the doors will be promptly closed following entry or exit, restoring the secondary containment boundary.
Supplement to License Amendment Request Attachment 1 Secondary Containment Access Openings Page 4 of 8 Docket Nos. 50-277 and 50-278 Evaluation of Proposed Changes Personnel are trained in Nuclear General Employee Training (NGET) to not open a secondary containment door if the blue light is illuminated. However, as licensed by the NRC, there is no physical interlock associated with these doors. Proceeding through a door requires an individual to look up at the condition of the blue light, then card in/out (if applicable), re-look at the status of the blue light and then look down again and proceed to open the door. Occasionally, an individual attempts access through the opposite airlock entry point, and an alarm sounds due to a simultaneous door opening by another individual. Well-intended individuals may end up in this simultaneous situation, which cannot be prevented under the original licensed design.
From a safety perspective (see UFSAR Table 8.5.1), during a design basis accident (LOCA with simultaneous LOOP), Emergency Diesel Generators start and restore 4 kV Bus power in 13 seconds after the event, followed by 480 V Load Center restoration 3 seconds later, such that SGT start will occur no earlier than 16 seconds after initiation of the event. In addition, no credit is taken for any negative pressure in the building at the time of the event. The AST analysis assumptions are such that no credit is taken for secondary containment for the first 180 seconds following a Design Basis LOCA or fuel handling accidents. Based on the original licensed design of the Peach Bottom Secondary Containment and the allowances of AST, it can be concluded that brief simultaneous opening of an inner and outer secondary containment blue light door is an expected possible occurrence in the PBAPS secondary containment design and, therefore, a declaration of inoperability is not warranted.
Proposed Bases Revisions The current combined Bases for PBAPS SR 3.6.4.1.1 and SR 3.6.4.1.2 are being separated and the Bases of SR 3.6.4.1.2 are being revised to be consistent with the proposed revised SR.
4.0 REGULATORY EVALUATION
4.1 Applicable Regulatory Requirements/Criteria The following regulatory requirements have been considered:
Title 10 of the Code of Federal Regulations (10 CFR), Section 50.36, "Technical specifications," in which the Commission established its regulatory requirements related to the contents of the TS. Specifically, 10 CFR 50.36(c)(2) states, in part, "Limiting conditions for operation are the lowest functional capability or performance levels of equipment required for safe operation of the facility." 10 CFR 50.36(c)(3) states, "Surveillance requirements are requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the limiting conditions of operation will be met."
The proposed change to the secondary containment LCO and SR does not affect compliance with these regulations.
Supplement to License Amendment Request Attachment 1 Secondary Containment Access Openings Page 5 of 8 Docket Nos. 50-277 and 50-278 Evaluation of Proposed Changes The applicable 10 CFR Part 50, Appendix A, General Design Criteria, was considered as follows:
The applicable PBAPS principal design criteria predate these criteria. The PBAPS principal design criteria is listed in UFSAR Section 1.5, "Principal Design Criteria." In 1967, the Atomic Energy Commission (AEC) published for public comment a revised set of proposed General Design Criteria (Federal Register 32 FR 10213, July 11, 1967). Although not explicitly licensed to the AEC proposed General Design Criteria published in 1967, Philadelphia Electric Company (PECO), the predecessor to Exelon, performed a comparative evaluation of the design basis of PBAPS Units 2 and 3 against the AEC proposed General Design Criteria of 1967. The PBAPS UFSAR, Appendix H, "Conformance to AEC (NRC) Criteria," contains this comparative evaluation. UFSAR Appendix H provides a comparative evaluation with each of the groups of criteria set out in the July 1967 AEC release. As to each group of criteria, there is a statement of Exelons understanding of the intent of the criteria in that group and a discussion of the plant design conformance with the intent of the group of criteria. Following a restatement of each of the proposed criteria is a list of references to locations in the PBAPS UFSAR where there is subject matter relating to the intent of that particular criteria.
Engineered Safety Feature (ESF) atmosphere cleanup systems are designed for fission product removal in post-accident environments. These systems generally include primary systems (e.g., in-containment recirculation) and secondary systems (e.g., standby gas treatment systems and emergency or post-accident air-cleaning systems) for the fuel-handling building, control room, shield building, and areas containing ESF components. The NRCs acceptance criteria for ESF atmosphere cleanup systems were based on (1) final GDC-19, insofar as it requires that adequate radiation protection be provided to permit access and occupancy of the control room under accident conditions without personnel receiving radiation exposures in excess of 5 rem whole body, or its equivalent, to any part of the body, for the duration of the accident; (2) draft GDC-69, insofar as it requires that systems that may contain radioactivity be designed to assure adequate safety under normal and postulated accident conditions; and (3) final GDC-64, insofar as it requires that means be provided for monitoring effluent discharge paths and the plant environs for radioactivity that may be released from normal operations, including anticipated operational occurrences (AOOs), and postulated accidents.
The proposed change does not alter the design of the secondary containment or its ability to establish an essentially leak-tight barrier against the uncontrolled release of radioactivity.
4.2 Precedence The proposed change to modify SR 3.6.4.1.2 to allow brief, inadvertent, simultaneous opening of redundant secondary containment doors for entry and exit is consistent with the improved Standard Technical Specifications endorsed by the NRC in NUREG-1434, Standard Technical Specifications - General Electric BWR/6 Plants, Revision 4 (Reference 5).
Supplement to License Amendment Request Attachment 1 Secondary Containment Access Openings Page 6 of 8 Docket Nos. 50-277 and 50-278 Evaluation of Proposed Changes 4.3 No Significant Hazards Consideration Exelon Generation Company, LLC (Exelon) is proposing a change to the Technical Specifications (TS), Appendix A of Renewed Facility Operating License Nos. DPR-44 and DPR-56 for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3, respectively.
The proposed change revises PBAPS TS Surveillance Requirement (SR) 3.6.4.1.2. SR 3.6.4.1.2 is modified to match the standard improved TS for BWR/6 plants (NUREG-1434) to recognize that due to the PBAPS secondary containment design, brief, inadvertent, simultaneous openings of redundant secondary containment doors during entry and exit are an expected occurrence and do not render secondary containment inoperable.
Exelon has evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:
- 1. Do the proposed changes involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No. The proposed change allows temporary conditions during which the secondary containment SR is not met. The secondary containment is not an initiator of any accident previously evaluated. As a result, the probability of any accident previously evaluated is not increased. The consequences of an accident previously evaluated while utilizing the proposed change is no different than the consequences of an accident while utilizing the existing 4-hour Completion Time for an inoperable secondary containment. As a result, the consequences of an accident previously evaluated are not significantly increased.
Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
- 2. Do the proposed changes 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 changes do 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.
Supplement to License Amendment Request Attachment 1 Secondary Containment Access Openings Page 7 of 8 Docket Nos. 50-277 and 50-278 Evaluation of Proposed Changes
- 3. Do the proposed changes involve a significant reduction in a margin of safety?
Response: No. The proposed change allows temporary conditions during which the secondary containment SR is not met. Temporary conditions in which the secondary containment is open are acceptable provided the conditions do not affect the ability of the Standby Gas Treatment System to create a lower pressure in the secondary containment than in the outside environment if required. The allowance for both an inner and outer secondary containment door to be open simultaneously for entry and exit does not affect the safety function of the secondary containment as the doors are promptly closed after entry or exit, thereby restoring the secondary containment boundary.
Therefore, the proposed change does not involve a significant reduction in a margin of safety.
Based on the above, Exelon concludes that the proposed amendment presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of "no significant hazards consideration" is justified.
4.4 Conclusions In conclusion, 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 Commissions 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.
5.0 ENVIRONMENTAL CONSIDERATION
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 surveillance requirement. However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluent 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.
Supplement to License Amendment Request Attachment 1 Secondary Containment Access Openings Page 8 of 8 Docket Nos. 50-277 and 50-278 Evaluation of Proposed Changes
6.0 REFERENCES
- 1. License Amendment Request concerning Proposed Changes to the Technical Specifications to Address Administrative Control of Secondary Containment Access Openings dated February 23, 2015.
- 2. Email correspondence from R. Ennis (U.S. Nuclear Regulatory Commission) to S.
Hanson (Exelon Generation Company, LLC), "Peach Bottom Atomic Power Station, Units 2 and 3 - DRAFT Request for Additional Information regarding Proposed License Amendment for Administrative Control of Secondary Containment Access Openings (TAC NOS. MF5783 & MF5784)," dated June 4, 2015.
- 3. Peach Bottom Atomic Power Station, Updated Final Safety Analysis Report, Revision 24.
- 4. NUREG-1433, "Standard Technical Specifications General Electric Plants, BWR/4,"
Revision 4.
- 5. NUREG-1434, "Standard Technical Specifications General Electric Plants, BWR/6,"
Revision 4.
ATTACHMENT 2 Markup of Proposed Technical Specifications Pages Supplement to License Amendment Request Peach Bottom Atomic Power Station, Units 2 and 3 Docket Nos. 50-277 and 50-278 Proposed Changes to the Technical Specifications to Address Administrative Control of Secondary Containment Access Openings Unit 2 TS Page 3.6-35 Unit 3 TS Page 3.6-35
Secondary Containment 3.6.4.1 ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME C. (continued) C.2 Initiate action to Immediately suspend OPDRVs.
SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.4.1.1 Verify all secondary containment In accordance equipment hatches are closed and sealed. with the Surveillance Frequency Control Program.
SR 3.6.4.1.2 Verify one secondary containment access In accordance door in each access opening is closed. with the
, except when the access opening is being used for entry or exit. Surveillance Frequency Control Program.
SR 3.6.4.1.3 Verify secondary containment can be drawn In accordance down to 0.25 inch of vacuum water gauge with the in 180 seconds using one standby gas Surveillance treatment (SGT) subsystem. Frequency Control Program.
SR 3.6.4.1.4 Verify the secondary containment can be In accordance maintained 0.25 inch of vacuum water with the gauge for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> using one SGT subsystem Surveillance at a flow rate 10,500 cfm. Frequency Control Program.
PBAPS UNIT 2 3.6-35 Amendment No. 278
Secondary Containment 3.6.4.1 ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME C. (continued) C.2 Initiate action to Immediately suspend OPDRVs.
SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.4.1.1 Verify all secondary containment In accordance equipment hatches are closed and sealed. with the Surveillance Frequency Control Program.
SR 3.6.4.1.2 Verify one secondary containment access In accordance door in each access opening is closed. with the
, except when the access opening is being used for entry or exit. Surveillance Frequency Control Program.
SR 3.6.4.1.3 Verify secondary containment can be drawn In accordance down to 0.25 inch of vacuum water gauge with the in 180 seconds using one standby gas Surveillance treatment (SGT) subsystem. Frequency Control Program.
SR 3.6.4.1.4 Verify the secondary containment can be In accordance maintained 0.25 inch of vacuum water with the gauge for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> using one SGT subsystem Surveillance at a flow rate 10,500 cfm. Frequency Control Program.
PBAPS UNIT 3 3.6-35 Amendment No. 281
ATTACHMENT 3 Markup of Proposed Technical Specifications Bases Pages (Information Only)
Supplement to License Amendment Request Peach Bottom Atomic Power Station, Units 2 and 3 Docket Nos. 50-277 and 50-278 Proposed Changes to the Technical Specifications to Address Administrative Control of Secondary Containment Openings Unit 2 TS Bases Page B 3.6-76 Unit 3 TS Bases Page B 3.6-76
Secondary Containment B 3.6.4.1 BASES (continued)
SURVEILLANCE SR 3.6.4.1.1 and SR 3.6.4.1.2 REQUIREMENTS Verifying that secondary containment equipment hatches and one access door in each access opening are closed ensures that the infiltration of outside air of such a magnitude as to prevent maintaining the desired negative pressure does not occur. Verifying that all such openings are closed provides adequate assurance that exfiltration from the secondary containment will not occur. In this application, the term "sealed" has no connotation of leak tightness.
Maintaining secondary containment OPERABILITY requires and verifying one door in the access opening is closed. An access opening contains one inner and one outer door. In some cases, secondary containment access openings are shared such that a secondary containment barrier may have multiple inner or multiple outer doors. The intent is to not breach secondary containment at any time when secondary containment is required. This is achieved by maintaining the inner or outer portion of the barrier closed at all times. However, all secondary containment access doors are normally kept closed, except when the access opening is being used for entry and exit or when maintenance is being performed on an access opening. The Surveillance Frequency is controlled Insert Revised SR here under the Surveillance Frequency Control Program.
SR 3.6.4.1.3 and SR 3.6.4.1.4 The SGT System exhausts the secondary containment atmosphere to the environment through appropriate treatment equipment.
Each SGT subsystem is designed to draw down pressure in the secondary containment to 0.25 inches of vacuum water gauge in 180 seconds and maintain pressure in the secondary containment at 0.25 inches of vacuum water gauge for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> at a flow rate 10,500 cfm. To ensure that all fission products released to the secondary containment are treated, SR 3.6.4.1.3 and SR 3.6.4.1.4 verify that a pressure in the secondary containment that is less than the lowest postulated pressure external to the secondary containment boundary can rapidly be established and maintained. When the SGT System is operating as designed, the establishment and maintenance of secondary containment pressure cannot be accomplished if the secondary containment boundary is not intact.
Establishment of this pressure is confirmed by SR 3.6.4.1.3 which demonstrates that the secondary containment can be drawn down to 0.25 inches of vacuum water gauge in 180 (continued)
PBAPS UNIT 2 B 3.6-76 Revision No. 86
Secondary Containment B 3.6.4.1 BASES (continued)
SURVEILLANCE SR 3.6.4.1.1 and SR 3.6.4.1.2 REQUIREMENTS Verifying that secondary containment equipment hatches and one access door in each access opening are closed ensures that the infiltration of outside air of such a magnitude as to prevent maintaining the desired negative pressure does not occur. Verifying that all such openings are closed provides adequate assurance that exfiltration from the secondary containment will not occur. In this application, and the term "sealed" has no connotation of leak tightness.
Maintaining secondary containment OPERABILITY requires verifying one door in the access opening is closed. An access opening contains one inner and one outer door. In some cases, secondary containment access openings are shared such that a secondary containment barrier may have multiple inner or multiple outer doors. The intent is to not breach secondary containment at any time when secondary containment is required. This is achieved by maintaining the inner or outer portion of the barrier closed at all times. However, all secondary containment access doors are normally kept closed, except when the access opening is being used for entry and exit or when maintenance is being performed on an access opening. The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.
Insert Revised SR here SR 3.6.4.1.3 and SR 3.6.4.1.4 The SGT System exhausts the secondary containment atmosphere to the environment through appropriate treatment equipment.
Each SGT subsystem is designed to draw down pressure in the secondary containment to 0.25 inches of vacuum water gauge in 180 seconds and maintain pressure in the secondary containment at 0.25 inches of vacuum water gauge for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> at a flow rate 10,500 cfm. To ensure that all fission products released to the secondary containment are treated, SR 3.6.4.1.3 and SR 3.6.4.1.4 verify that a pressure in the secondary containment this is less than the lowest postulated pressure external to the secondary containment boundary can rapidly be established and maintained. When the SGT System is operating as designed, the establishment and maintenance of secondary containment pressure cannot be accomplished if the secondary containment boundary is not intact.
Establishment of this pressure is confirmed by SR 3.6.4.1.3 which demonstrates that the secondary containment can be drawn down to 0.25 inches of vacuum water gauge in 180 (continued)
PBAPS UNIT 3 B 3.6-76 Revision No. 87
Supplement to License Amendment Request Secondary Containment Access Openings Docket Nos. 50-277 and 50-278 PBAPS Unit 2 and Unit 3 TSB Insertion Revised SR:
SR 3.6.4.1.2 Verifying that one secondary containment access door in each access opening is closed provides adequate assurance that exfiltration from the secondary containment will not occur. An access opening contains at least one inner and one outer door. In some cases, secondary containment access openings are shared such that there are multiple inner or outer doors. The intent is to not breach the secondary containment, which is achieved by maintaining the inner or outer portion of the barrier closed. SR 3.6.4.1.2 provides an exception to allow brief, unintentional, simultaneous opening of both an inner and outer secondary containment access door.
The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.