ULNRC-05804, Facility Operating License NPF-30 - Proposed Revision to Technical Specification 3.6.6, Containment Spray and Cooling Systems, (License Amendment Request LDCN 09-0025)

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Facility Operating License NPF-30 - Proposed Revision to Technical Specification 3.6.6, Containment Spray and Cooling Systems, (License Amendment Request LDCN 09-0025)
ML111820367
Person / Time
Site: Callaway Ameren icon.png
Issue date: 06/30/2011
From: Maglio S
Ameren Missouri
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
ULNRC-05804, LDCN 09-0025
Download: ML111820367 (29)
v • d • e


Text

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VAmeren MISSOURI Callawav Plant June 30, 2011 ULNRC-05804 u.s. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 10 CFR 50.90 Ladies and Gentlemen:

DOCKET NUMBER 50-483 CALLAWAY PLANT UNIT 1 UNION ELECTRIC CO.

FACILITY OPERATING LICENSE NPF-30 PROPOSED REVISION TO TECHNICAL SPECIFICATION 3.6.6, "CONTAINMENT SPRAY AND COOLING SYSTEMS" (LICENSE AMENDMENT REQUEST LDCN 09-0025)

Pursuant to 10 CFR 50.90, "Application for amendment of license or construction permit," Union Electric (dba Ameren Missouri) hereby requests an amendment to the Facility Operating License (NPF-30) for Callaway Plant in order to incorporate a proposed change to Technical Specification (TS) 3.6.6, "Containment Spray and Cooling Systems."

The proposed amendment would revise TS Surveillance Requirement (SR) 3.6.6.3 for verifying the minimum required containment cooling train cooling water flow rate. Rather than require verifying each containment cooling train has a cooling water flow rate greater than or equal to 2200 gpm, TS SR 3.6.6.3 would be revised to require verification that the flow rate is "within limits." This change is supported by a change in the TS Bases for SR 3.6.6.3 to indicate where the flow rate limits are specified as well as to note that these limits provide assurance that the heat removal rate assumed in the Callaway Plant safety analyses will be achieved. The reason for the proposed change to TS SR 3.6.6.3 is to ensure that the surveillance verifies each containment cooling train has a flow rate capable of removing 141.4 x 10"6 Btulhr as assumed in the Callaway Plant safety analyses of record. The assumed heat removal rate does not vary; however, the cooling water flow rate does change based on changing system conditions/parameters (e.g. tube plugging and tube fouling), and therefore the cooling water flow rate should not be quantified in the Technical Specifications.

Essential and supporting information for the proposed TS change is provided in the attachments to this letter. Attachment 1 provides a detailed description and technical evaluation of the proposed change, including Ameren Missouri's determination that the proposed change involves no significant hazards

......................................................................................................................... PO Box 620 Fulton, MO 65251 AmerenMissouri.com

ULNRC-05804 June 30, 2011 Page 2 consideration. Attachment 2 provides mark-ups of the current, affected TS page to show the proposed change; Attachment 3 provides a copy of the affected TS page retyped with the proposed change incorporated (if approved); and Attachment 4 provides mark-ups of the current, affected TS Bases pages for information only. Final TS Bases changes will be processed under the program for updates per TS 5.5.14, "Technical Specifications Bases Control Program," at the time this amendment is implemented.

It has been determined that this amendment application involves no significant hazards consideration as determined per 10 CFR 50.92, "Issuance of amendment." Pursuant to 10 CFR 51.22, "Criterion for categorical exclusion or otherwise not requiring environmental review," Section (b), no environmental impact statement or environmental assessment need be prepared in connection with issuance of this amendment.

The Callaway Plant Onsite Review Committee and a subcommittee of the Nuclear Safety Review Board have reviewed and approved the proposed changes and have approved the submittal of this amendment application.

In accordance with 10 CFR 50.91, "Notice for public comment; State consultation," Section (b)(1),

Ameren Missouri is providing the State of Missouri with a copy of this proposed amendment.

Ameren Missouri respectfully requests approval of the proposed license amendment prior to July 1, 2012. Ameren Missouri further requests that the license amendment be made effective upon NRC issuance, to be implemented within 90 days from the date of issuance.

This letter does not contain new commitments. Please contact Scott Maglio, Regulatory Affairs Manager, at (573) 676-8719 for any questions you may have regarding this amendment application.

I declare under penalty of perjury that the foregoing and attached are true and correct.

Sincerely,

-;t> I

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La I '20 ( ,

Executed on: -----------------------

Regulatory Affairs Manager DJW/nis

ULNRC-05804 June 30, 2011 Page 3 Attachments: 1) Evaluation

2) Mark-up of Technical Specification Page
3) Retyped Technical Specification Page
4) TS Bases Changes (For Infonnation Only)

ULNRC-05804 June 30, 2011 Page 4 cc: U.S. Nuclear Regulatory Commission (Original and 1 copy)

Attn: Document Control Desk Washington, DC 20555-0001 Mr. Elmo E. Collins, Jr.

Regional Administrator U.S. Nuclear Regulatory Commission Region IV 612 E. Lamar Blvd., Suite 400 Arlington, TX 76011-4125 Senior Resident Inspector Callaway Resident Office U.S. Nuclear Regulatory Commission 8201 NRC Road Steedman, MO 65077 Mr. Mohan C. Thadani (2 copies)

Senior Project Manager, Callaway Plant Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 0-8G 14 Washington, DC 20555-2738 Mr. James Polickoski Project Manager, Callaway Plant Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 0-8BIA Washington, DC 20555-2738

ULNRC-05804 June 30, 2011 Page 5 Index and send hardcopy to QA File A160.0761 Hardcopy:

Certrec Corporation 4200 South Hulen, Suite 422 Fort Worth, TX 76109 (Certrec receives ALL attachments as long as they are non-safeguards and may be publicly disclosed.)

Electronic distribution for the following can be made via Tech Spec ULNRC Distribution:

A. C. Heflin F. M. Diya C. O. Reasoner III L. H. Graessle S. A. Maglio S. L. Gallagher NSRB Secretary T. B. Elwood Ms. Diane M. Hooper (WCNOC)

Mr. Tim Hope (Luminant Power)

Mr. Ron Barnes (APS)

Mr. Tom Baldwin (PG&E)

Mr. Wayne Harrison (STPNOC)

Ms. Linda Conklin (SCE)

Mr. John O'Neill (Pillsbury Winthrop Shaw Pittman LLP)

Missouri Public Service Commission Mr. Dru Buntin (DNR) to ULNRC-05804 Page 6 ULNRC-05804 ATTACHMENT 1 EVALUATION to ULNRC-05804 Page 1 EVALUATION

1.0 DESCRIPTION

This amendment application is being submitted for proposed changes to Technical Specification (TS) 3.6.6, "Containment Spray and Cooling Systems." Specifically, the proposed amendment would revise TS Surveillance Requirement (SR) 3.6.6.3 for verifying that the minimum required containment cooling train cooling water flow rate is met. Rather than require verifying each containment cooling train has a cooling water flow rate greater than or equal to 2200 gpm, TS SR 3.6.6.3 will require verification that the flow rate is "within limits."

The intent is to ensure that in lieu of meeting a flow rate limit expressed as a specific value in gpm, the surveillance would verify each containment cooling train has a flow rate capable of removing 141.4 x 101\6 Btulhr as assumed in the Callaway Plant safety analyses of record.

Though the assumed heat removal rate does not vary, the cooling water flow rate corresponding to heat removal rate of 141.4 x 101\6 Btulhr does change based on system parameters (e.g. tube plugging and tube fouling). As such, the cooling water flow rate should not be quantified in the Technical Specifications.

This change is supported by a change in the TS Bases for SR 3.6.6.3 which will indicate where the flow rate limits are specified as well as note that these limits provide assurance that the heat removal rate assumed in the Callaway Plant safety analyses will be achieved.

2.0 PROPOSED CHANGE

TS SR 3.6.6.3 currently reads:

"Verify each containment cooling train cooling water flow rate is 2: 2200 gpm."

After approval ofthis proposed amendment request, TS SR 3.6.6.3 would be revised to read as follows:

"Verify each containment cooling train cooling water flow rate is within limits."

The proposed change to TS SR 3.6.6.3 would ensure that the surveillance verifies each containment cooling train to have flow rate capable of removing 141.4 x 101\6 Btulhr as assumed in the Callaway Plant safety analyses of record. The assumed heat removal rate used in the safety analyses of record does not vary; however, the cooling water flow rate does change based on system parameters (e.g. tube plugging and tube fouling) and as such the cooling water flow rate should not be quantified in the Technical Specifications.

For information, the corresponding TS Basis for SR 3.6.6.3 currently reads, in part:

"Verifying that each containment cooling train ESW cooling flow rate is 2: 2200 gpm provides assurance that the design flow rate assumed in the safety analyses will be achieved ... "

to ULNRC-05804 Page 2 Upon approval and implementation of this proposed amendment request, the TS Basis for SR 3.6.6.3 would be revised to read as follows:

"Verifying that each containment cooling train ESW cooling flow rate is within limits specified in plant flow balance procedures and calculations provides assurance that the heat removal rate assumed in the safety analyses will be achieved ... "

The TS mark-up is provided in Attachment 2, and the retyped page is included in Attachment 3. The corresponding TS Basis change is provided, for information only, in Attachment 4.

3.0 BACKGROUND

The containment cooling system (CtCS) and the containment spray system (CSS) are Engineered Safety Feature (ESF) systems intended to reduce the containment temperature and pressure following a loss of coolant accident (LOCA) or main steam line break (MSLB) accident by removing thermal energy from the containment atmosphere. Subsequent to a design basis accident (DBA) within the containment, the CtCS operates together with the CSS to maintain the containment temperature and pressure within design limits. Actual containment fan cooler system parameters are such that those used in the analyses are equal to or more conservative than the actual containment fan cooler system capability. As one of the containment heat removal systems, following the DBA, the CtCS also serves to limit offsite radiation levels by reducing the pressure differential between the containment atmosphere and the external environment, thereby diminishing the driving force for the leakage of fission products from the containment to the environment.

The CtCS, in conjunction with the containment ventilation systems, functions during normal plant operation to maintain a suitable atmosphere for equipment located within the containment and to maintain the containment conditions within the bounds of the initial conditions assumed in the safety analyses.

System Description

The CtCS consists of two independent trains of two cooling units each. Within each train two cooling units are located in parallel as shown in Figure 1. Each (either) of the two CtCS trains is of sufficient capacity to supply 100% of the design cooling requirement. Each cooling unit consists of an air-to-water heat exchanger and a two-speed fan. The CtCS provides cooling by recirculation of the containment air across the air-to-water heat exchangers. Containment air is drawn into the coolers by the cooler fans and then discharged through ducts to steam generator compartments, the pressurizer compartment, and instrument tunnel, and outside the secondary shield in the lower areas of containment.

In the fan exhaust duct are fusible link plates. The fusible link plates are steel plates which are hinged to the ductwork and held in a closed position by fusible links. The plates to ULNRC-05804 Page 3 employ a release mechanism so that after fusion of the links the plates will release from the ductwork. The fusible links soften at high containment temperatures (approximately 160 0 F).

This allows the hinged plates to fall, thus opening an area that is larger than the cross-sectional area of the fan exhaust duct and giving a free flow path from the fan exhaust to containment.

Because the open area vacated by the plates exceeds the cross-sectional area of the fan, an unrestricted flow path is provided. The fusible link plates ensure air flow through the coolers in post-LOCA or MSLB accident conditions at high containment temperatures.

Normal Operation During normal plant operation, all four fan units (i.e., both units in each train) may be operating. The fans are normally operated at high speed with cooling water supplied to the cooling coils from the non-safety related Service Water system via a cross-connection between the Service Water (SW) and safety related Essential Service Water (ESW) systems. The CtCS, operating in conjunction with the containment ventilation systems, is designed to limit the ambient containment air temperature during normal unit operation to less than the limit specified in TS 3.6.5, "Containment Air Temperature." This temperature limitation ensures that the containment temperature does not exceed the initial temperature conditions assumed for the applicable DBAs.

Only three containment coolers are required to provide the proper cooling during normal operation; however, four coolers are operated to maintain proper air flow distribution.

Post Accident Operation Following a safety injection signal (SIS), the fans are designed to start automatically in slow speed, if not already running. If running in high (normal) speed, the fans automatically shift to slow speed. The fans are operated at the lower speed during accident conditions to prevent motor overload from the higher mass containment atmosphere.

Assuming loss of offsite power, the fans are started 45 seconds after generation of the SIS. To compensate for the reduced air flow over the coils and to maximize heat removal, the cooling water flow through the cooling coils for each unit is automatically re-aligned from the SW system for supply from the ESW system. The flow rate for each unit is established based on controlled plant flow balance procedures and calculations.

At high containment temperature, the fusible link plates open to allow unrestricted flow through the air coolers. Each containment cooler train is capable of removing at least 141.4 x 101\6 Btulhr under design post-LOCA conditions. The coil heat removal capabilities were designed assuming a tube fouling factor of 0.002.

to ULNRC-05804 Page 4 Safety Analyses of Record The Callaway Plant safety analyses of record assume a heat removal rate per containment cooling train (i.e. two coolers), rather than a heat removal rate per containment cooler. As noted previously, the assumed heat removal rate per containment cooling train is 141.4 x 1Q/'6 Btulhr. This assumption does not vary. Also, a per-train heat removal rate is consistent with the fact that the Limiting Condition for Operation (LCO) section ofTS 3.6.6 requires two CtCS trains to be operable. (That is, the LCO is structured on a per-train basis, not a per-unit basis.) Therefore, in conjunction with the proposed TS changes, the TS Bases and FSAR are being clarified to reflect the per-train assumption used in the safety analyses of record.

The TS Bases and FSAR would also be revised to state that the specified ESW flow rate is controlled by plant flow balance procedures and calculations. The Basis for SR 3.6.6.3 would be enhanced to recognize that with the containment cooling train ESW cooling flow rate "within limits," there is assurance that the heat removal rate assumed in the safety analyses (i.e., 141.4x 1Q/'6 BtuIhr) will be achieved (on a per-train basis). This provides consistency with the safety analyses of record described in the FSAR Section 6.2.

In summary, the proposed amendment will ensure consistency between the assumption in the safety analyses of record (heat removal rate) and the minimum flow requirement ofTS SR 3.6.6.3 which, as currently written, could be viewed as not providing a proper acceptance criterion for ensuring that the safety analyses assumption is met. (See discussion below.) By specifying that the cooling train cooling water flow rate is to be "within limits," and by maintaining plant procedures and calculations consistent with changes in system parameters, the heat removal rate assumed in the safety analyses of record is assured.

4.0 TECHNICAL ANALYSIS

TS SR 3.6.6.3 currently reads:

"Verify each containment cooling train cooling water flow rate is 2: 2200 gpm."

After approval of this amendment request, TS SR 3.6.6.3 would be revised to read as follows:

"Verify each containment cooling train cooling water flow rate is within limits."

Rather than require verifying each containment cooling train has a cooling water flow rate greater than or equal to 2200 gpm, TS SR 3.6.6.3 will require verification that the flow rate is "within limits."

The reason for the proposed change to TS SR 3.6.6.3 is to ensure that the surveillance verifies each containment cooling train has a flow rate capable of removing 141.4 x 10"'6 to ULNRC-05804 Page 5 Btulhr as assumed in the Callaway Plant safety analyses of record. Because the assumed heat removal rate does not vary and the cooling water flow rate may change based on system conditions/parameters (e.g. tube plugging and tube fouling), the cooling water flow rate should not be quantified in the Technical Specifications. The proposed license amendment would remove the specific cooling water flow rate value from TS SR 3.6.6.3. Consistent with that change, specific flow values would also be removed from TS Bases SR 3.6.6.3 and the FSAR, as references to the appropriate design-basis document would be incorporated.

The ESW flow rate to the CtCS trains/units is adjustable and is set according to plant flow balance procedures and calculations. (Changes to plant flow balance procedures and calculations resulting in changes to the cooling water flow rate are subject to IOCFR50.59 program review.) Further, the nominal value of the flow rate may change based on system conditions/parameters such as tube plugging and tube fouling. With a specific minimum flow value specified in the TS or other licensing documents, there is the potential for the specified flow rate to not be in agreement with the most current flow rates determined in the governing flow balance procedures and calculations. The current TS SR 3.6.6.3 may be too restrictive when containment coolers are newly installed, recently cleaned, or otherwise in excellent condition. Conversely, the current TS SR 3.6.6.3 has the potential to be non-conservative as tube plugging and tube fouling occurs during the service life of the containment coolers.

As documented in the corrective action program for Callaway, the impact of the potential discrepancy between the assumption used in the safety analyses of record (based on CtCS per-train heat removal rate) and the current TS SR 3.6.6.3 requirement (based on CtCS per-train quantified flow rate) could result in plant surveillances and trending activities (involving the containment coolers) being less than robust in demonstrating that the containment coolers are capable of performing their design bases safety function of removing the prescribed amount of thermal energy during a design bases accident.

The proposed changes enhance TS SR 3.6.6.3 to require the cooling train cooling water flow rate to be "within limits." This way of wording and specifying the acceptance criterion for the surveillance is consistent with the guidance given in Technical Specifications Task Force TSTF-GG-05-01, "Writer's Guide for Plant Specific Improved Technical Specifications," June 2005, Section 4.1.7 Chapter 3 Surveillance Requirements (SRs) Content:

"b. Surveillances on parameter limits will specify, to the extent practical, the limit.

This applies whether or not the LCO also requires the precise limit. Reference to where the limit(s) may be located is an acceptable alternative ... "

Thus, in lieu of specifying a specific value for the cooling water flow rate limit, the alternative of referencing where the limit may be located (via the TS Bases) is proposed to be taken, as reflected in the proposed revision ofTS SR 3.6.6.3.

The TS Bases and FSAR would be revised to state that the specified ESW flow rate is controlled by plant flow balance procedures and calculations. The Basis for SR 3.6.6.3 would to ULNRC-05804 Page 6 also be enhanced to recognize that the containment cooling train ESW cooling flow rate provides assurance that the heat removal rate assumed in the safety analyses will be achieved (on a per-train basis). This provides consistency with the safety analyses of record described in the FSAR Section 6.2. No changes are necessary for the current accident analyses as a result of this amendment request. Since the proposed amendment reflects what is already contained in the accident analyses.

In summary, the requested amendment will resolve the discrepancy between the assumption in the safety analyses of record (heat removal rate) and the way in which the acceptance criterion is specified in the current TS SR 3.6.6.3 (quantified flow rate) which may not always properly represent the safety analyses assumption. The current SR may be too restrictive when containment coolers are newly installed, recently cleaned, or otherwise in excellent condition. Conversely, the current TS SR 3.6.6.3 has potential to be non-conservative as tube plugging and tube fouling occurs during the service life ofthe containment coolers. By specifying that the cooling train cooling water flow rate is to be "within limits," and by maintaining plant procedures and calculations up to date with changes in system conditions/parameters, the heat removal rate assumption in the safety analyses of record will be assured.

5.0 REGULATORY ANALYSIS

This section addresses the standards of 10 CFR 50.92 as well as the applicable regulatory requirements and acceptance criteria.

As described above, the proposed changes would revise a part of Technical Specification (TS) 3.6.6, "Containment Spray and Cooling Systems." Specifically the proposed amendment would revise TS Surveillance Requirement (SR) 3.6.6.3 for verifying the minimum required containment cooling train cooling water flow rate. Rather than require verifying each containment cooling train has a cooling water flow rate greater than or equal to 2200 gpm, TS SR 3.6.6.3 would be revised to require verification that the flow rate is "within limits."

5.1 No Significant Hazards Consideration (NSHC)

Ameren Missouri 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," Part 50.92(c), as discussed below:

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

Response: No to ULNRC-05804 Page 7 The proposed changes for verifying the minimum required containment cooling train cooling water flow rate have no impact on the frequency of occurrence of any of the accidents evaluated in the FSAR. Changing from a specific flow rate to a flow rate "within limits" based on current system parameters has no impact on the likelihood of occurrence of a loss of coolant accident (LOCA), steam line break (SLB), plant transient, loss of offsite power (LOOP), or any such accident because the precursors for such accidents do not involve containment cooling.

The failure or malfunction of a containment cooling train (due, for example, to an inadequate cooling flow rate) is not itself an initiator or precursor of any accident previously evaluated.

The CtCS and CSS provide complementary methods of containment atmosphere cooling to limit post accident pressure and temperature in containment to less than the design values. They are designed to ensure that the heat removal capability required during the post accident period can be attained. Changing the limit for the minimum required CtCS cooling train flow from a specified value to "within limits" appropriately accounts for changes in system conditions while still requiring the heat removal rate specified in the accident analysis to be met. Consequently, the proposed changes do not involve a change in the required performance of the CtCS and therefore do not adversely affect the accident mitigation function of the CtCS.

The CtCS, operating in conjunction with the containment ventilation systems, is also designed to limit the ambient containment air temperature during normal unit operation to less than the limit specified in LCO 3.6.5, "Containment Air Temperature." This temperature limitation ensures that the containment temperature does not exceed the initial temperature conditions assumed for the DBAs. The proposed change does not impact the capability of the CtCS to maintain containment temperature to within this initial temperature condition for DBAs.

The proposed changes will not affect accident initiators or precursors nor alter the design assumptions, conditions, and configuration of the facility or the manner in which the plant is operated and maintained. The manner in which the ESW system is flow balanced to ensure adequate cooling water flow to all loads required for accident mitigation, including the containment coolers, will not be changed and is in fact supported by the proposed changes. In general, therefore, the proposed changes will not alter or prevent the ability of structures, systems, and components (SSCs) to perform their intended functions to mitigate the consequences of an initiating event within the assumed acceptance limits.

All accident analysis acceptance criteria will continue to be met with the proposed changes. The proposed changes will not affect the source term, containment isolation, or radiological release assumptions used in evaluating the radiological consequences of an accident previously evaluated. The proposed changes will not alter any assumptions or change any mitigation actions in the radiological consequence evaluations in the FSAR.

Consequently, the applicable radiological dose acceptance criteria will continue to be met.

to ULNRC-05804 Page 8 Therefore, the proposed changes do not involve a significant increase in the probability or consequences 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 There are no proposed changes in the method by which any safety-related plant SSC performs its safety function. The proposed changes will not affect the normal method of plant operation or change any operating parameters. No equipment design or performance requirements will be affected, including the design and performance requirements for the CtCS and ESW system. The proposed changes will not alter any assumptions made in the safety analyses.

No new accident scenarios, transient precursors, failure mechanisms, or limiting single failures will be introduced as a result of this amendment. There will be no adverse effect or challenges imposed on any safety-related system as a result of this amendment.

Therefore, the proposed changes do not create the possibility of a new or different accident from any accident previously evaluated.

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

Response: No The margin of safety is related to the confidence in the ability of the fission product barriers to perform their design functions during and following an accident. These barriers include the fuel cladding, the reactor coolant system, and the containment system. The proposed change will have no effect on those plant systems necessary to assure the accomplishment of protection functions. There will be no impact on the overpower limit, departure from nucleate boiling ratio (DNBR) limits, heat flux hot channel factor (FQ), nuclear enthalpy rise hot channel factor (F b.H), loss of coolant accident peak cladding temperature (LOCA PCT), peak local power density, or any other limit or margin of safety. The applicable radiological dose consequence acceptance criteria will continue to be met since the proposed changes have no impact on the radiological consequences of any design basis accident.

With respect to the containment, and as already noted, changing the limit for the minimum required CtCS cooling train flow from a specified value to "within limits" appropriately accounts for changes in system conditions/parameters while still requiring the heat removal rate specified in the accident analysis to be met. Consequently, the CtCS function for limiting post-accident pressure and temperature in the containment building is not adversely affected, and the margins between the calculated peak accident pressure and to ULNRC-05804 Page 9 temperature in the containment and the corresponding containment design limits are unchanged.

The proposed changes do not eliminate any surveillance or alter the frequency of surveillances required by the Technical Specifications. None of the acceptance criteria for any accident analysis will be changed.

Therefore, the proposed changes do not involve a significant reduction in a margin of safety.

Conclusion:

Based on the above evaluation, Ameren Missouri 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.

5.2 Applicable Regulatory Requirements / Criteria Applicable regulatory requirements and associated guidance documents are as follows:

A system to remove heat from the reactor containment shall be provided The system safety function shall be to reduce rapidly, consistent with the functioning of other associated systems, the containment pressure and temperature following any loss-of-coolant accident and maintain them at acceptably low levels.

Suitable redundancy in components and features, and suitable interconnections, leak detection, isolation, and containment capabilities shall be provided to assure that for onsite electric power system operation (assuming ojJsite electric power is not available) andfor ojJsite electric power system operation (assuming onsite electric power is not available) the system safety function can be accomplished, assuming a single failure.

The containment heat removal system shall be designed to permit appropriate periodic inspection of important components, such as the torus, sumps, spray nozzles, and piping to assure the integrity and capability of the system.

requires the following:

to ULNRC-05804 Page 10 The containment heat removal system shall be designed to permit appropriate periodic pressure andfunctional testing to assure (1) the structural and leaktight integrity of its components, (2) the operability and performance of the active components of the system, and (3) the operability of the system as a whole, and under conditions as close to the design as practical the performance of the full operational sequence that brings the system into operation, including operation of applicable portions of the protection system, the transfer between normal and emergency power sources, and the operation of the associated cooling water system.

Systems to control fission products, hydrogen, oxygen, and other substances which may be released into the reactor containment shall be provided as necessary to reduce, consistent with the functioning of other associated systems, the concentration and quality offission products released to the environment following postulated accidents, and to control the concentration of hydrogen or oxygen and other substances in the containment atmosphere following postulated accidents to assure that containment integrity is maintained Each system shall have suitable redundancy in components and features, and suitable interconnections, leak detection, isolation, and containment capabilities to assure that for onsite electric power system operation (assuming offsite power is not available) and for offsite electric power system operation (assuming onsite power is not available) its safety function can be accomplished, assuming a single failure.

The containment atmosphere cleanup systems shall be designed to permit appropriate periodic inspection of important components, such as filter frames, ducts, and piping to assure the integrity and capability of the systems.

The containment atmosphere cleanup systems shall be designed to permit appropriate periodic pressure andfunctional testing to assure (1) the structural and leaktight integrity of its components, (2) the operability and performance of the active components of the systems such as fans, filters, dampers, pumps, and valves and (3) the operability of the systems as a whole and, under conditions as close to design as practical, the performance of the full operational sequence that brings the systems into operation, including operation of applicable portions of the protection system, the to ULNRC-05804 Page 11 transfer between normal and emergency power sources, and the operation of associated systems.

The reactor containment structure, including access openings, penetrations, and the containment heat removal system shall be designed so that the containment structure and its internal compartments can accommodate, without exceeding the design leakage rate and with sufficient margin, the calculated pressure and temperature conditions resulting from any 10ss-oJcoolant accident. This margin shall reflect consideration of (1) the effects ofpotential energy sources which have not been included in the determination of the peak conditions, such as energy in steam generators and as required by § 50.44 energy from metal-water and other chemical reactions that may result from degradation but not total failure of emergency core cooling functioning, (2) the limited experience and experimental data available for defining accident phenomena and containment responses, and (3) the conservatism of the calculational model and input parameters.

10 CFR 50, Appendix K, "ECCS Evaluation Models," requires an evaluation of mass

° and energy releases to the containment be performed with an approved evaluation model meeting the requirements of 1 CFR 50, Section 46 and Appendix K, which demonstrates that the containment design pressure has not been violated.

The CtCS is designed and fabricated to codes consistent with the quality group classification, the seismic category, and the power supply and control functions in accordance with the following Regulatory Guides:

  • Regulatory Guide 1.26, Revision 3, "Quality Group Classifications and Standards for Water-, Steam-, and Radioactive-Waste-Containing Components of Nuclear Power Plants."
  • Regulatory Guide 1.32, Revision 2, "Criteria for Safety-Related Electric Power Systems for Nuclear Power Plants."

The proposed changes involve no change to the existing design for the CtCS, CSS, and containment ventilation systems. No changes to the performance requirements for these systems are involved, nor are there any changes to the designed capability of these systems to meet their performance requirements. Consequently, there are no changes to how the above noted regulatory requirements and guidance are met with respect to the potentially affected systems.

to ULNRC-05804 Page 12 5.3 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 Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

6.0 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).

7.0 REFERENCES

7.1 Callaway Plant Technical Specification, 3.6.6, "Containment Spray and Cooling Systems."

7.2 Callaway Plant Technical Specification, 3.6.5, "Containment Air Temperature."

7.3 FSAR Section 6.2, Containment Systems.

7.4 FSAR Section 6.2.2.2, Containment Cooling System.

7.5 FSAR Figure 6.2.1-15, "Containment Cooling Train Duty Curve."

7.6 FSAR Table 6.2.1-3, "Engineered Safety Features Design Parameters For Containment Analysis."

7.7 FSAR Section 9.2.5, Ultimate Heat Sink.

7.8 FSAR Section 15, Accident Analysis.

Attachment 1 to ULNRC-05804 Figure 1 CONTAINMENT COOLING TRAINS FIGURE 1 SGN01A TRAINA

~~ '~ FlOW 4~

(approx 2200 gpm)

...... SGN01C

... SGN01D TRAIN B

......... " . , Flow til"'"

~

4~

(approx 2200 gpm)

SGN01B

ULNRC-005804 ATTACHMENT 2 MARKED-UP TECHNICAL SPECIFICATION PAGE

(JAR :2009 o4B J 9 For tn~f"~~ c9nG Containment Spray and Cooling Systems 3.6.6 3.6 CONTAINMENT SYSTEMS 3.6.6 Containment Spray and Cooling Systems LCO 3.6.6 Two containment spray trains and two containment cooling trains shall be OPERABLE.

APPLICABILITY: MODES 1, 2, 3, and 4.

ACTIONS COMPLETION CONDITION REQUIRED ACTION TIME A. One containment spray A.1 Restore containment 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> train inoperable. spray train to OPERABLE status. AND 10 days from discovery of failure to meet the LCO B. Required Action and B.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 of Condition A not AND met B.2 Be in MODE 5. 84 hours9.722222e-4 days <br />0.0233 hours <br />1.388889e-4 weeks <br />3.1962e-5 months <br /> C. One containment cooling C.1 Restore containment 7 days train inoperable. cooling train to OPERABLE status. AND 10 days from discovery of failure to meet the LCO (continued)

CALLAWAY PLANT 3.6-18 Amendment No. 133

Containment Spray and Cooling Systems 3.6.6 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.6.6.3 Verify each containment cooliOQ train cOQl.i!:lq water 31 days flow rate is,,,c4VJII'_~ 1t!~~ \\~~

SR 3.6.6.4 Verify each containment spray pump's developed In accordance with head at the flow test point is greater than or equal to the Inservice the required developed head. Testing Program SR 3.6.6.5 Verify each automatic containment spray valve in the 18 months flow path that is not locked, sealed, or otherwise secured in position, actuates to the correct position on an actual or simulated actuation signal.

SR 3.6.6.6 Verify each containment spray pump starts 18 months automatically on an actual or simulated actuation signal.

SR 3.6.6.7 Verify each containment cooling train starts 18 months automatically and minimum cooling water flow rate is established on an actual or simulated actuation signal.

SR 3.6.6.8' Verify each spray nozzle is unobstructed. 10 years CALLAWAY PLANT 3.6-20 Amendment No. 133

ULNRC-05804 ATTACHMENT 3 RETYPED TECHNICAL SPECIFICATION PAGE

Containment Spray and Cooling Systems 3.6.6 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.6.6.3 Verify each containment cooling train cooling water 31 days flow rate is within limits.

SR 3.6.6.4 Verify each containment spray pump's developed In accordance with head at the flow test pOint is greater than or equal to the Inservice the required developed head. Testing Program SR 3.6.6.5 Verify each automatic containment spray valve in the 18 months flow path that is not locked, sealed, or otherwise secured in position, actuates to the correct position on an actual or simulated actuation signal.

SR 3.6.6.6 Verify each containment spray pump starts 18 months automatically on an actual or simulated actuation signal.

SR 3.6.6.7 Verify each containment cooling train starts 18 months automatically and minimum cooling water flow rate is established on an actual or simulated actuation signal.

SR 3.6.6.8 Verify each spray nozzle is unobstructed. 10 years CALLAWAY PLANT 3.6-20 Amendment No. ###

ULNRC-05804 ATTACHMENT 4 TS BASES CHANGES (FOR INFORMATION ONLy)

Containment Spray and Cooling Systems B 3.6.6 BASES APPLICABLE For certain aspects of transient accident analyses, maximizing the SAFETY calculated containment pressure is not conservative. In particular, the ANALYSES effectiveness of the Emergency Core Cooling System during the core (continued) reflood phase of a LOCA analysis increases with increasing containment f backpressure .. For these calculations, the containment backpressure is')

calculated in a manner designed to conservatively minimize, rather than maximize. the calculated transient containment pressures in accordance with 10 CFR 50, Appendix K (Ref. 2).

The effect of an inadvertent containment spray actuation has been analyzed. An inadvertent spray actuation results in a -2.98 psig containment pressure and is associated with the sudden cooling effect in the interior ofthe leak tight containment. Additional discussion is provided in the Bases for LCD 3.6.4.

The modeled Containment Spray System actuation from the containment analysis is based on a response time associated with exceeding the containment High-3 pressure setpoint to achieving full flow through the containment spray nozzles.

The Containment Spray System total response time includes diesel generator (DG) startup (for loss of offsite power), sequenced loading of equipment, containment spray pump startup, and spray line filling (Ref. 4).

Containment cooling train performance for post accident conditions is given in Reference 4. The result of the analysiS is that each train can provide 100% of the required peak cooling capacity during the post accident condition. The train post accident cooling capacity under varying containment ambient conditions, required to perform the accident analyses, is also shown in Reference 4.

The modeled Containment Cooling System actuation from the containment analysis is based upon a response time associated with exceeding the containment High-3 pressure setpoint to achieving full Containment Cooling System air and safety grade cooling water flow.

The Containment Cooling System total response time includes signal delay, DG startup (for loss of offsite power). and Essential Service Water pump startup times.

The Containment Spray System and the Containment Cooling System satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii).

LCD During a DBA, a minimum of one containment cooling train and one containment spray train are required to maintain the containment peak (continued)

CALLAWAY PLANT B 3.6.6-4 Revision 8

Containment Spray and Cooling Systems B 3.6.6 BASES LCO pressure and temperature below the design limits (Refs. 3). Additionally, (continued) one containment spray train is also required to remove iodine from the containment atmosphere and retain volatile iodine species in the sumps, consistent with the safety analysis. To ensure that this these requirements are met, two containment spray trains and two containment

<'cooling trains must be OPERABLE. Therefore, in the event of an ,.

accident, at least one train in each system operates, assuming the worst case single active failure occurs.

A Containment Spray train typically includes a spray pump, spray headers, nozzles, valves, piping, instruments, and controls to ensure an OPERABLE flow path capable of taking suction from the RWST upon an ESF actuation signal and manually transferring to the containment sump.

A Containment Cooling train typically includes cooling coils, dampers, two fans, instruments, and controls to ensure an OPERABLE flow path.

APPLICABI LlTY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material to containment and an increase in containment pressure and temperature requiring the operation of the containment spray trains and containment cooling trains.

In MODES 5 and 6, the probability and consequences of these events are reduced due to the pressure and temperature limitations of these MODES. Thus, the Containment Spray System and the Containment Cooling System are not required to be OPERABLE in MODES 5 and 6.

ACTIONS With one containment spray train inoperable, the inoperable containment spray train must be restored to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. In this Condition, the remaining OPERABLE spray and cooling trains are adequate to perform the iodine removal and containment cooling functions. The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Completion lime takes into account the redundant temperature and pressure reducing capability afforded by the Containment Spray System, reasonable time for repairs, and low probability of a DBA occurring during this period.

The 10 day portion of the Completion Time for Required Action A.1 is based upon engineering jUdS'ment. It takes into account the low probability of coincident entry into two Conditions in this Specification coupled with the low probability of an accident occurring during this time.

(continued)

CALLAWAY PLANT B 3.6.6-5 Revision 8

Containment Spray and Cooling Systems B 3.6.6 BASES SURVEILLANCE SR 3.6.6.1 (continued)

REQUIREMENTS The 31.day frequency is based on engineering judgement. is consistent with procedural controls governing valve operation, and ensures correct valve positions.

SR 3.6.6.2 Operating each containment cooling train fan unit for ~ 15 minutes ensures that all fan units are OPERABLE. It also ensures that abnormal conditions or degradation of the fan unit can be detected for corrective action. The 31 day Frequency was developed considering the known reliability of the fan units and controls, the two train redundancy available, and the low probability of significant degradation of the containment cooling train occurring between surveillances. It has also been shown to be acceptable through operating experience.

SR 3.6.6.3 Veri ing that each containment cooling train ESW coolin flow rate is

~~~~~provides assurance that the te assumed in the sa ety analyses will be achieved (Ref. 3). The Frequency was developed considering the known reliability of the Essential Service Water System, the two train redundancy available, and the low probability of a significant degradation of flow occurring between surveillances.

SR 3.6.6.4 Verifying each containment spray pump's developed head at the flow test point is greater than or equal to the required developed head ensures that spray pump performance has not degraded during the cycle. Flow and differential pressure are normal tests of centrifugal pump performance required by the ASME Code (Ref. 5). Since the containment spray pumps cannot be tested with flow through the spray headers, they are tested on recirculation flow. This test ensures that each pump develops a discharge pressure of greater than or equal to 250 psig. This test confirms one point on the pump design curve and is indicative of overall performance. Such inservice tests confirm component OPERABILITY. trend performance, and detect incipient failures by abnormal performance. The Frequency of the SR is in accordance with the Inservice Testing Program.

(continued)

CALLAWAY PLANT B 3.6.6-8 Revision 8

~o~. *Pro\Jidftl ~( CAl( tocJ1 0'-f'1) \q Containment Spray and Cooling Systems

  • ~~OY\~~ B 3.6.6 BASES (Continued)

REFERENCES 1. 10 CFR 50, Appendix A, GOC 38, GOC 39, GOC 40, GOC 41, GOC 42, GOC 43 and GOC 50.

2. 10 CFR 50, Appendix K.
3. FSAR, Section 6.2.1.
4. FSAR, Section 6.2.2.
5. ASME Code for Operation and Maintenance of Nuclear Power Plants.

CALLAWAY PLANT B 3.6.6-10 Revision 8

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