WO 20-0050, License Amendment Request to Revise Technical Specification 3.6.3 and Surveillance Requirement 3.6.3.1 to Allow Use of a Blind Flange

License Amendment Request to Revise Technical Specification 3.6.3 and Surveillance Requirement 3.6.3.1 to Allow Use of a Blind Flange

ML20315A433
Person / Time
Site:	Wolf Creek
Issue date:	11/10/2020
From:	Mccoy J Wolf Creek
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
WO 20-0050
Download: ML20315A433 (23)

Text

Jaime H. McCoy Site Vice President November 10, 2020 WO 20-0050 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555

Subject:

Docket No. 50-482: License Amendment Request to Revise Technical Specification 3.6.3 and Surveillance Requirement 3.6.3.1 to Allow Use of a Blind Flange Commissioners and Staff:

Pursuant to 10 CFR 50.90, Application for amendment of license, construction permit, or early site permit, Wolf Creek Nuclear Operating Corporation (WCNOC) hereby requests an amendment to Renewed Facility Operating License Number NPF-42 for the Wolf Creek Generating Station (WCGS). The license amendment request (LAR) proposes to revise Technical Specification (TS) 3.6.3.

The proposed amendment would modify TS 3.6.3 Containment Isolation Valves, Condition D to allow the use of a blind flange for Required Action D.1. In addition, a change to Surveillance Requirement (SR) 3.6.3.1 is proposed to allow the use of a blind flange.

Attachment I provides a description of the proposed change and supporting technical evaluation.

Attachment II provides the existing TS pages marked up to show the proposed change.

Attachment III provides revised (clean) TS pages. Attachment IV provides the existing TS Bases pages marked up to show the proposed changes and is for information only. Final TS Bases changes will be implemented pursuant to TS 5.5.14, Technical Specification (TS) Bases Control Program, at the time the amendment is implemented.

It has been determined that this amendment application does not involve a significant hazard consideration as determined per 10 CFR 50.92, Issuance of amendment. Pursuant to 10 CFR 51.22(b), Criterion of categorical exclusion; identification of licensing and regulatory actions eligible for categorical exclusion or otherwise not requiring environmental review, no environmental impact statement or environmental assessment needs to be prepared in connection with the issuance of this amendment.

The amendment application was reviewed by the WCNOC Plant Safety Review Committee. In accordance with 10 CFR 50.91, Notice for public comment, State consultation, a copy of this amendment application, with attachments, is being provided to the designated Kansas State official.

P.O. Box 411 l Burlington, KS 66839 l 620-364-8831

WO 20-0050 Page 2 of 3 The changes proposed are not required to address an immediate safety concern. As such, WCNOC requests approval of this proposed license amendment by October 1, 2021. It is anticipated that the license amendment, as approved, will be effective upon issuance, to be implemented within 90 days from the date of issuance.

This letter contains no commitments. If you have any questions concerning this matter, please contact me at (620) 364-4156, or Ron Benham at (620) 364-4204.

Sincerely, Jaime H. McCoy JHM/rlt Attachments: I - Evaluation of Proposed Changes II - Proposed Technical Specification Changes (Mark-Up)

III - Revised Technical Specification Pages IV - Proposed Technical Specification Bases Changes (Mark-Up) (for information only) cc: S. S. Lee (NRC), w/a S. A. Morris (NRC), w/a N. OKeefe (NRC), w/a K. S. Steves (KDHE), w/a Senior Resident Inspector (NRC), w/a

WO 20-0050 Page 3 of 3 STATE OF KANSAS )

) ss COUNTY OF COFFEY )

Jaime H. McCoy, of lawful age, being first duly sworn upon oath says that he is Site Vice President of Wolf Creek Nuclear Operating Corporation; that he has read the foregoing document and knows the contents thereof; that he has executed the same for and on behalf of said Corporation with full power and authority to do so; and that the facts therein stated are true and correct to the best of his knowledge, information and belief.

By_~ "J-/ a;;JICI _ _ _ __

Jaime H. McCoy Site Vice President Expiration Date _7 /23/2023 _ __

Attachment I to WO 20-0050 Page 1 of 9 ATTACHMENT I EVALUATION OF PROPOSED CHANGES

Attachment I to WO 20-0050 Page 2 of 9 EVALUATION OF PROPOSED CHANGES

Subject:

License Amendment Request to Revise Technical Specification TS 3.6.3 Containment Isolation Valves to Allow Use of a Blind Flange for Required Action D.1 and Surveillance Requirement 3.6.3.1 1.0

SUMMARY

DESCRIPTION 2.0 DETAILED DESCRIPTION 2.1 System Design and Operation 2.2 Current Technical Specifications Requirements 2.3 Reason for the Proposed Change 2.4 Description of the Proposed Change

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria 4.2 No Significant Hazards Consideration Determination 4.3 Conclusion

6.0 REFERENCES

Attachment I to WO 20-0050 Page 3 of 9 EVALUATION OF PROPOSED CHANGES 1.0

SUMMARY

DESCRIPTION This evaluation supports a request to amend Renewed Facility Operating License No. NPF-42 for the Wolf Creek Generating Station (WCGS).

The proposed change will revise Technical Specification (TS) 3.6.3, Containment Isolation Valves, to allow the use of a blind flange as an additional option to meet Required Action D.1.

Accordingly, Surveillance Requirement (SR) 3.6.3.1 will also be revised to allow verification that the containment isolation valve is closed and blind flange is installed as an option to meet the SR.

2.0 DETAILED DESCRIPTION 2.1 System Design and Operation The containment isolation valves form part of the containment pressure boundary and provide a means for fluid penetration flow path not serving accident consequence limiting systems to be provided with two isolation barriers that are closed on a containment isolation signal. These isolation devices are either passive or active (automatic). Manual valves, de-activated automatic valves secured in their closed position, blind flanges, and closed systems are considered passive devices. Automatic valves designed to close without operator action following an accident are considered active devices. Two barriers in series are provided for each penetration flow path so that no single credible failure or malfunction of an active component can result in a loss of isolation or leakage that exceeds limits assumed in the safety analyses.

The Containment Purge and Exhaust System operates to supply outside air into the containment for ventilation and cooling or heating needed for prolonged containment access following a shutdown and during refueling. The system may also be used to reduce the concentration of noble gases within containment prior to and during personnel access. The supply and exhaust lines each contain two isolation valves (1 inside and 1 outside containment). Because of their large size, the 36-inch containment purge supply and exhaust valves are not qualified for automatic closure from their open position under design basis accident conditions. The safety analyses assume that the 36-inch shutdown purge valves are closed at event initiation.

Therefore, the 36-inch containment purge supply and exhaust isolation valves are normally sealed closed in Modes 1, 2, 3, and 4 to ensure the containment boundary is maintained. Sealed closed means the valves are closed and deactivated.

The Mini-purge System operates to reduce the concentration of noble gases within the containment prior to and during personnel access or to equalize internal and external pressures.

The Mini-purge System shares the containment penetration piping with the Containment Purge and Exhaust System on both the supply and exhaust sides of the system. However, the Mini-purge system branches off the Containment Purge and Exhaust System line such that the Mini-purge System has its own 18-inch containment isolation valves. Like the Containment Purge and Exhaust System, the supply and exhaust lines each contain 2 isolation valves (1 inside and 1 outside containment). Since the 18-inch valves used in the Mini-Purge System are designed to meet the requirements for automatic containment isolation valves, these valves may be opened as needed, for a limited time as specified in procedures, in Modes 1, 2, 3, and 4. Containment purge valves shall refer to both the Containment Shutdown Purge and Mini-purge isolation valves.

Attachment I to WO 20-0050 Page 4 of 9 Blind flanges are installed inboard of the inside containment isolation valves and outboard of the outside containment isolation valves. These are provided to facilitate integrated leak rate testing of each individual valve.

2.2 Current Technical Specifications Requirements TS Limiting Condition for Operation (LCO) 3.6.3 requires that each containment isolation valve shall be operable. This LCO is applicable in Modes 1, 2, 3, and 4. Condition D is entered when one or more penetration flow paths with one or more containment purge valves are not within leakage limits. Required Action D.1 currently states:

Isolate the affected penetration flow path by use of at least one closed and de-activated automatic valve or closed manual valve.

Required Action D.1 has a Completion Time of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

SR 3.6.3.1 currently states:

Verify each containment purge valve is sealed closed except for one purge valve in a penetration flow path while in Condition D of this LCO.

SR 3.6.3.1 has a frequency of once per 31 days for isolation devices outside containment. For isolation devices inside containment, SR 3.6.3.1 must be performed prior to entering Mode 4 from Mode 5 if not performed within the previous 92 days.

2.3 Reason for the Proposed Change The blind flanges that are installed adjacent to the containment purge isolation valves could be used to provide containment isolation if one or more isolation valves experience leakage beyond acceptable limits. However, these blind flanges were designed and constructed in accordance with codes and standards comparable with quality group D. This is not consistent with the level of safety required for containment penetration isolation.

The piping beyond the containment isolation valves, up to and including the blind flanges, has been reclassified as safety-related. This will allow the use of blind flanges to maintain containment isolation in the event one or more isolation valves have leakage rates above acceptable limits.

2.4 Description of the Proposed Change TS 3.6.3, Required Action D.1 is revised to state:

Isolate the affected penetration flow path by use of at least one closed and de-activated automatic valve, closed manual valve, or blind flange.

SR 3.6.3.1 is revised to state:

Verify each containment shutdown purge valve is sealed closed or closed and blind flange installed except for one purge valve in a penetration flow path while in Condition D of this LCO.

Attachment I to WO 20-0050 Page 5 of 9

3.0 TECHNICAL EVALUATION

WCNOC submitted a license amendment request (LAR) to remove the use of blind flanges from TS LCO 3.6.3 and SR 3.6.3.1 dated February 25, 2019 (Reference 1). The Nuclear Regulatory Commission (NRC) approved this change in License Amendment 223 issued with a safety evaluation dated January 6, 2020 (Reference 2). This was done because the blind flanges that were installed were not safety-related, and therefore, could not be relied upon for containment isolation.

Subsequent to issuance of License Amendment 223, WCNOC Engineering performed Change Package 20390, along with Safety Classification Analysis (SCA) 20-0004. These provided the evaluation and justification for reclassifying the piping beyond the containment isolation valves, up to and including the blind flanges, as safety-related. These evaluations apply to both the Containment Purge Supply and Exhaust System as well as the Mini-purge System. The evaluations provide the following justifications:

1) The material specifications used for both the American Society of Mechanical Engineers (ASME) Class 2 and American National Standards Institute (ANSI) B31.1 portions of piping up to and including the flanges identify that the same materials were used for both.

In addition, because the ANSI portions were identified as Special Scope, Certified Materials Test Reports (CMTRs) were provided during construction for those sections of piping.

2) The ANSI portions of piping up to, and including the flanges, are within the seismic restraints and are bounded by the seismic evaluation for the Seismic Category I section of piping.

3) The ASME and ANSI materials (e.g. piping, flanges, fittings, etc.) used in construction of the containment isolation piping are the same as the piping beyond the isolation valve up to and including the flanges. As such, the SCA documents that the only credible failure mechanism is a seismic event. Because the seismic evaluation bounds the ANSI portions of piping, the containment isolation function would be maintained in the event of a design basis seismic event.

As such, this LAR is proposing to return TS LCO 3.6.3, Required Action D.1 and SR 3.6.3.1 to their state prior to License Amendment 223 such that the blind flanges may be used to satisfy Required Action D.1 and SR 3.6.3.1.

NRC Regulatory Guide 1.141 NRC Regulatory Guide (RG) 1.141, Containment Isolation Provisions for Fluid Systems provides guidance for licensees in meeting General Design Criteria 54-56 of Appendix A of 10 CFR 50 for containment isolation. RG 1.141 endorses ANSI N271 (1976) as the basis for the design requirements for containment isolation, subject to the conditions described in Section C of the RG.

The following presents relevant sections of ANSI N271 (1976) and how the blind flanges meet those criteria:

Section 3.2: Containment Isolation Barriers Blind flanges are listed as one of several acceptable types of mechanical isolation barriers.

Attachment I to WO 20-0050 Page 6 of 9 Section 3.3: General Design Criteria Change Package 20390 and SCA 20-0004 provide the evaluations and justification for reclassifying the piping as safety-related, such that the blind flanges and associated piping meet GDC 54-57.

Section 4.4.10: Containment Isolation Barrier Design; Safety Class Containment isolation barriers which are not part of the reactor coolant pressure boundary shall be at least Safety Class 2 in accordance with ANSI N18.2-1973, N18.2a-1975. N-18.2 correlates safety classifications to ASME classifications (e.g. Safety Class 2 is equivalent to ASME Class 2).

The portion of the piping between the containment isolation valves uses ASME Class 2 criteria, while the blind flanges and its piping were designed and constructed to ANSI B31.1 criteria.

However, a review of the material specifications shows the materials are the same for both the ANSI and ASME portions of the piping. In addition, review of the original construction documents shows the piping was installed to meet the construction requirements for Special Scope, which requires additional documentation, such as CMTRs.

The SCA for the piping evaluates the credible failure modes and safety significance. The SCA determined the piping and blind flange are safety-related and that seismic event is the only credible failure mode. The blind flange and piping are within the analyzed seismic boundary. The piping analysis performed for this system shows that the piping extending out to the blind flanges is all seismically qualified.

Although the materials, installation, and design are not ASME Class 2, the available documentation, design, credible failure mode, and evaluations/analyses show that the installed ANSI B31.1 blind flange and piping provide reasonable assurance that the piping will perform the design function of maintaining containment integrity during and following a seismic event.

Section 4.5.3: Isolation Barrier Protection; Earthquakes Containment isolation valves are designated as Seismic Category I. Containment isolation provisions shall be capable of operation during the Safe Shutdown Earthquake and of maintaining the isolation function afterwards. Because the ANSI piping up to and including the blind flanges are bounded by the seismic analysis performed for the containment penetrations, there is reasonable assurance that containment isolation would be maintained by the blind flanges in the case of a seismic event.

Section 4.10 Flanged Closures Flanged closures (blinds) are administratively controlled and are to be tested in accordance with Appendix J. The portions of the piping will be added to the Appendix J testing programs as necessary.

Section 7 Materials Isolation barriers and piping between them shall meet the material requirements for metal parts as specified by ASME B&PV Code,Section III, Division 1, Subsection NA. The SCA and change package document that ASME B&PV Code,Section III, Division 1, Subsection NA allows for

Attachment I to WO 20-0050 Page 7 of 9 material that is produced under an ASTM specification may be accepted as complying with the corresponding ASME specification provided the ASME specification is designated as being identical with the ASTM specification for the grade, class, or type produced and provided that the material is confirmed as complying with the ASTM specification by a CMTR or Certification from the Material Manufacturer. From the available construction documentation, the ANSI portions of piping up to and including the blind flanges were the same materials as those used for the ASME portions. In addition, these sections of piping were designated as special scope to ensure the material and workmanship met seismic requirements. Therefore, the portions of the ANSI piping up to and including the blind flanges provide reasonable assurance that containment isolation would be preserved during and following a seismic event.

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria The following regulatory requirements apply to the Containment Purge and Exhaust System and Mini-purge System containment penetrations:

• GDC 2 requires that SSCs important to safety be designed to withstand the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, floods, tsunami, and seiches without the loss of the capability to perform their safety functions.

• GDC 54 requires that piping systems penetrating primary reactor containment shall be provided with leak detection, isolation and containment capabilities having redundancy, reliability, and performance capabilities which reflect the importance to safety of isolating these piping systems. Such piping systems shall be designed with a capability to test periodically the operability of the isolation valves and associated apparatus and to determine if valve leakage is within acceptable limits.

• GDC 56 requires, in part, that each line that connects directly to the containment atmosphere and penetrates primary reactor containment shall be provided with containment isolation valves as follows:

(1) One locked closed isolation valve inside and one locked closed isolation valve outside containment; or (2) One automatic isolation valve inside and one locked closed isolation valve outside containment; or (3) One locked closed isolation valve inside and one automatic isolation valve outside containment; or (4) One automatic isolation valve inside and one automatic isolation valve outside containment.

There will be no changes to the Containment Purge and Exhaust System or Mini-purge System containment penetrations such that compliance with any of the above regulatory requirements would come into question.

4.2 No Significant Hazards Consideration Determination The proposed amendment revises Technical Specification (TS) 3.6.3, Containment Isolation Valves, Required Action D.1 and Surveillance Requirement (SR) 3.6.3.1 to allow the use of blind flanges.

Attachment I to WO 20-0050 Page 8 of 9 WCNOC has evaluated whether or not a significant hazards consideration is involved with the proposed amendment(s) by focusing on the three standards set forth in 10 CFR 50.92, Issuance of amendment, Part 50.92(c), as discussed below:

1. Does the proposed amendment involve a significant increase in the probability or consequence of an accident previously evaluated?

Response: No.

The proposed change revises TS 3.6.3, Required Action D.1 and SR 3.6.3.1 to allow the use of blind flanges. The blind flanges and the piping on which they are installed have been qualified as safety-related and are bounded by the seismic analysis performed for the containment penetrations associated with the Containment Purge and Exhaust System and Mini-purge System. In the case that one of the containment purge isolation valves is not within leakage limits, using a blind flange to isolate that penetration flow path will provide reasonable assurance that containment integrity would be maintained.

Therefore, the proposed change does not represent a significant increase in the probability of an accident previously evaluated.

2. Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No.

No new accident scenarios, failure mechanisms, or limiting single failures are introduced as a result of the proposed changes. The systems, structures, and components previously required for the mitigation of a transient remain capable of fulfilling their intended design functions. The proposed changes have no adverse effects on a safety-related system or components and do not challenge the performance or integrity of safety-related systems. As such it does not introduce a mechanism for initiating a new or different accident than those described in the Updated Safety Analysis Report.

Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.

3. Does the proposed change involve a significant reduction in a margin of safety?

Response: No.

The proposed change does not alter the manner in which safety limits, limiting safety systems or limiting conditions for operation are determined. The safety analysis acceptance criteria are not impacted by this change. The proposed change will not result in plant operation in a configuration outside the design basis.

Therefore, it is concluded that the proposed change does not involve a significant reduction in a margin of safety.

Based on the above, WCNOC concludes that the proposed amendment does not involve a 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.

Attachment I to WO 20-0050 Page 9 of 9 4.3 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 the 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 the health and safety of the public.

5.0 ENVIRONMENTAL CONSIDERATION

WCNOC has evaluated the proposed amendment for environmental considerations. The review has determined that the proposed amendment would change requirements with respect to installation or use of a facility component located within the restricted area, as defined 10 CFR 20, and 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.

6.0 REFERENCES

1. WCNOC letter ET 19-0003, License Amendment Request to Revise Technical Specification 3.6.3 and Surveillance Requirement 3.6.3.1 to remove use of a blind flange, dated February 25, 2019. ADAMS accession number ML19064A591.

2. Letter dated January 6, 2020, from B. K. Singal, USNRC, to C. Reasoner, WCNOC, Wolf Creek Generating Station, Unit 1 - Issuance of Amendment re: Revision to Technical Specification 3.6.3, Containment Isolation Valves, and Surveillance Requirement 3.6.3.1 to Remove Use of a Blind Flange (EPID L-2019-LLA-0036). ADAMS accession number ML19311C643.

Attachment II to WO 20-0050 Page 1 of 3 ATTACHMENT II PROPOSED TECHNICAL SPECIFICATION CHANGES (MARK-UP)

Attachment II to WO 20-0050 Containment Isolation Valves Page 2 of 3 3.6.3 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME D. One or more D.1 Isolate the affected 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> penetration flow penetration flow path by paths with one or use of at least one closed more containment and de-activated purge valves not automatic valve, or closed within leakage limits. manual valve, or blind flange.

AND D.2 -------------NOTES------------

1. Isolation devices in high radiation areas may be verified by use of administrative means.

2. Isolation devices that are locked, sealed, or otherwise secured may be verified by administrative means.

Verify the affected Once per 31 days penetration flow path is for isolation isolated. devices outside containment AND Prior to entering MODE 4 from MODE 5 if not performed within the previous 92 days for isolation devices inside containment AND (continued)

Wolf Creek - Unit 1 3.6-10 Amendment No. 123, 167, 223

Attachment II to WO 20-0050 Containment Isolation Valves Page 3 of 3 3.6.3 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME D. (continued) D.3 Perform SR 3.6.3.6 or Once per 92 days SR 3.6.3.7 for the resilient seal purge valves closed to comply with Required Action D.1.

E. Required Action and E.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion Time not met. AND E.2 Be in MODE 5. 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.3.1 Verify each containment shutdown purge valve is Once per 31 days sealed closed or closed and blind flange installed for isolation except for one purge valve in a penetration flow path devices outside while in Condition D of this LCO. containment AND Prior to entering MODE 4 from MODE 5 if not performed within the previous 92 days for isolation devices inside containment (continued)

Wolf Creek - Unit 1 3.6-11 Amendment No. 123, 131, 167, 223

Attachment III to WO 20-0050 Page 1 of 3 ATTACHMENT III REVISED TECHNICAL SPECIFICATION PAGES

Containment Isolation Valves 3.6.3 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME D. One or more D.1 Isolate the affected 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> penetration flow penetration flow path by paths with one or use of at least one closed more containment and de-activated purge valves not automatic valve, closed within leakage limits. manual valve, or blind flange.

AND D.2 -------------NOTES------------

1. Isolation devices in high radiation areas may be verified by use of administrative means.

2. Isolation devices that are locked, sealed, or otherwise secured may be verified by administrative means.

Verify the affected Once per 31 days penetration flow path is for isolation isolated. devices outside containment AND Prior to entering MODE 4 from MODE 5 if not performed within the previous 92 days for isolation devices inside containment AND (continued)

Wolf Creek - Unit 1 3.6-10 Amendment No. 123, 167

Containment Isolation Valves 3.6.3 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME D. (continued) D.3 Perform SR 3.6.3.6 or Once per 92 days SR 3.6.3.7 for the resilient seal purge valves closed to comply with Required Action D.1.

E. Required Action and E.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion Time not met. AND E.2 Be in MODE 5. 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.3.1 Verify each containment shutdown purge valve is Once per 31 days sealed closed or closed and blind flange installed for isolation except for one purge valve in a penetration flow path devices outside while in Condition D of this LCO. containment AND Prior to entering MODE 4 from MODE 5 if not performed within the previous 92 days for isolation devices inside containment (continued)

Wolf Creek - Unit 1 3.6-11 Amendment No. 123, 131, 167

Attachment Attachment IVIVtotoWO WO 20-0050 20-0050 Page 11of Page of51 ATTACHMENT IV PROPOSED TECHNICAL SPECIFICATION BASES CHANGES (FOR INFORMATION ONLY)

TEXT

Attachment IV to WO 20-0050 Containment Isolation Valves Page 2 of 5 B 3.6.3 BASES BACKGROUND within containment prior to and during personnel access. The supply and (continued) exhaust lines each contain two isolation valves. Because of their large size, the 36 inch containment purge supply and exhaust valves are not qualified for automatic closure from their open position under DBA conditions. Therefore, the 36 inch containment purge supply and exhaust isolation valves are normally maintained closed and blind flange installed or sealed closed in MODES 1, 2, 3, and 4 to ensure the containment boundary is maintained.

Mini-Purge System (18 inch purge valves)

The Mini-purge System operates to:

a. Reduce the concentration of noble gases within containment prior to and during personnel access, and

b. Equalize containment internal and external pressures.

Since the 18 inch valves used in the Mini-purge System are designed to meet the requirements for automatic containment isolation valves, these valves may be opened as needed, for a limited time as specified in procedures, in MODES 1, 2, 3, and 4.

APPLICABLE The containment isolation valve LCO was derived from the assumptions SAFETY ANALYSES related to minimizing the loss of reactor coolant inventory and establishing the containment boundary during major accidents. As part of the containment boundary, containment isolation valve OPERABILITY supports leak tightness of the containment. Therefore, the safety analyses of any event requiring isolation of containment is applicable to this LCO.

The DBAs that result in a release of radioactive material within containment are a loss of coolant accident (LOCA) and a rod ejection accident (Ref. 1). In the analyses for each of these accidents, it is assumed that containment isolation valves are either closed or function to close within the required isolation time following event initiation. This ensures that potential paths to the environment through containment isolation valves (including containment purge valves) are minimized. The safety analyses assume that the 36 inch shutdown purge valves are closed at event initiation.

The DBA analysis assumes that, after the accident, isolation of the containment is complete and leakage terminated except for the design leakage rate, La.

Wolf Creek - Unit 1 B 3.6.3-2 Revision 83

Attachment IV to WO 20-0050 Containment Isolation Valves Page 3 of 5 B 3.6.3 BASES APPLICABLE The LOCA and rod ejection offsite dose analyses assumes leakage from SAFETY ANALYSES the containment at a maximum leak rate of 0.20 percent of the (continued) containment volume per day for the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and at 0.10 percent of the containment volume per day for the duration of the accident.

The single failure criterion required to be imposed in the conduct of plant safety analyses was considered in the original design of the 18 inch containment mini-purge valves. Two valves in series on each purge line provide assurance that both the supply and exhaust lines could be isolated even if a single failure occurred. The inboard and outboard isolation valves on each line are provided with independent electrical power sources to solenoids that open the pneumatically operated spring closed actuators. The actuators fail closed on the loss of power or air.

This arrangement was designed to preclude common mode failures from disabling both valves on a purge line.

The 36 inch purge valves may be unable to close against the buildup of pressure following a LOCA. Therefore, each of the purge valves is required to remain sealed closed or closed and blind flange installed during MODES 1, 2, 3, and 4. The Containment Shutdown Purge System valve design precludes a single failure from compromising the containment boundary as long as the system is operated in accordance with the subject LCO.

The containment isolation valves satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).

LCO Containment isolation valves form a part of the containment boundary.

The containment isolation valves' safety function is related to minimizing the loss of reactor coolant inventory and establishing the containment boundary during a DBA.

The automatic power operated isolation valves are required to have isolation times within limits and to actuate on an automatic isolation signal.

The 36 inch containment purge supply and exhaust valves must be maintained sealed closed or closed and blind flange installed. The valves covered by this LCO are listed along with their associated stroke times in the USAR (Ref. 2).

The normally closed containment isolation valves are considered OPERABLE when manual valves are closed, automatic valves are de-activated and secured in their closed position, blind flanges are in place, and closed systems are intact. These passive isolation valves/devices are those listed in Reference 2.

Wolf Creek - Unit 1 B 3.6.3-3 Revision 83

Attachment IV to WO 20-0050 Containment Isolation Valves Page 4 of 5 B 3.6.3 BASES ACTIONS C.1 and C.2 (continued)

In the event one containment isolation valve in two or more separate penetration flow paths is inoperable, except for purge valve leakage not within limit, all but one of the affected penetration flow path(s) must be isolated. The method of isolation must include the use of at least one isolation barrier that cannot be adversely affected by a single active failure. Isolation barriers that meet this criterion are a closed and de-activated automatic containment isolation valve, a closed manual valve, a blind flange, and a check valve with flow through the valve secured. For a penetration flow path isolated in accordance with C.1, the device used to isolate the penetration should be the closest available one to containment.

Required Action C.1 must be completed within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. For the penetration flow paths isolated in accordance with Required Action C.1, the affected penetration(s) must be verified to be isolated on a periodic basis per Required Action A.2, which remains in effect. This periodic verification is necessary to assure that the penetrations requiring isolation following an accident are isolated. The 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> Completion Time is reasonable, considering the time required to isolate the penetration and the relative importance of supporting Containment OPERABILITY during MODES 1, 2, 3, and 4.

This Condition is applicable when multiple containment isolation valves in separate flow paths are inoperable. For subsequent containment isolation valve inoperabilities, the Required Action and Completion Time continue to apply to each additional containment isolation valve inoperability, with the Completion Time based on each subsequent entry into the Condition consistent with Note 2 to the ACTIONS Table (e.g., for each entry into the Condition). The containment isolation valve(s) inoperable as a result of that entry shall meet the Required Action and Completion Time.

D.1, D.2, and D.3 In the event one or more containment shutdown or mini-purge valves in one or more penetration flow paths are not within the leakage limits, leakage must be restored to within limits, or the affected penetration flow path must be isolated. The method of isolation must be by the use of at least one isolation barrier that cannot be adversely affected by a single active failure. Isolation barriers that meet this criterion are a closed and de-activated automatic valve or closed manual valve (this includes power operated valves with power removed), or blind flange. A containment shutdown purge or mini-purge valve with resilient seals utilized to satisfy Required Action D.1 must have been demonstrated to meet the leakage requirements of SR 3.6.3.6 or SR 3.6.3.7. The specified Completion Time is reasonable, considering that one containment purge valve remains closed so that a gross breach of containment does not exist.

Wolf Creek - Unit 1 B 3.6.3-7 Revision 83

Attachment IV to WO 20-0050 Containment Isolation Valves Page 5 of 5 B 3.6.3 BASES ACTIONS E.1 and E.2 (continued)

If the Required Actions and associated Completion Times are not met, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

SURVEILLANCE SR 3.6.3.1 REQUIREMENTS Each 36 inch containment shutdown purge supply and exhaust valve is required to be verified sealed closed or closed and blind flange installed at 31 day intervals. Each 36 inch containment shutdown purge supply and exhaust valve inside containment must be verified sealed closed or blind flange installed prior to entering MODE 4 from MODE 5, if the surveillance has not been performed in the previous 92 days. This Surveillance is designed to ensure that a gross breach of containment is not caused by an inadvertent or spurious opening of a containment shutdown purge valve. Detailed analysis of these valves failed to conclusively demonstrate their ability to close during a LOCA in time to limit offsite doses. Therefore, these valves are required to be in the sealed closed position or closed and blind flange installed during MODES 1, 2, 3, and 4.

A containment shutdown purge valve that is sealed closed must have motive power to the valve operator removed. This can be accomplished by de-energizing the source of electric power or by removing the air supply to the valve operator. In this application, the term "sealed" has no connotation of leak tightness. The Frequency is a result of an NRC initiative, Multi-Plant Action No. B-24 (Ref. 4), related to containment purge valve use during plant operations. In the event valve leakage requires entry into Condition D, the Surveillance permits opening one purge valve in a penetration flow path to perform repairs.

SR 3.6.3.2 This SR ensures that the mini-purge valves are closed as required or, if open, open for an allowable reason. If a mini-purge valve is open in violation of this SR, the valve is considered inoperable. If the inoperable valve is not otherwise known to have excessive leakage when closed, it is not considered to have leakage outside of limits. The SR is not required to be met when the mini-purge valves are open for the reasons stated.

The valves may be opened for pressure control, ALARA or air quality Wolf Creek - Unit 1 B 3.6.3-9 Revision 83