L-MT-12-028, License Amendment Request: Revise Allowable Value for the Automatic Depressurization System Bypass Timer

License Amendment Request: Revise Allowable Value for the Automatic Depressurization System Bypass Timer

ML12100A011
Person / Time
Site:	Monticello
Issue date:	04/05/2012
From:	O'Connor T Northern States Power Co, Xcel Energy
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
L-MT-12-028
Download: ML12100A011 (20)

Text

@ Xcel EnergyB April 5, 2012 Monticello Nuclear Generating Plant 2807 W County Road 75 Monticello, MN 55362 L-MT-12-028 10 CFR 50.90 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Monticello Nuclear Generating Plant Docket 50-263 Renewed Facility Operating License No. DPR-22 License Amendment Request: Revise Allowable Value for the Automatic Depressurization System Bvpass Timer In accordance with 10 CFR 50.90, Northern States Power Company - Minnesota, doing business as Xcel Energy, Inc., proposes to revise Monticello Nuclear Generating Plant (MNGP) Technical Specification 3.3.5.1, "Emergency Core Cooling System (ECCS)

Instrumentation." Specifically, it is proposed to revise the lower allowable value limit for Functions I

.e and 2.e, "Reactor Steam Dome Pressure Permissive - Bypass Timer (Pump Permissive)," in Table 3.3.5.1-1 of Specification 3.3.5.1. This function was added in response to one of the Three Mile Island NUREG-0737 action items, specifically Item ll.K.3.18 -Automatic Depressurization System [ADS] Logic Modifications.

In conjunction with the Extended Power Uprate (EPU) under U. S. Nuclear Regulatory Commission (NRC) review, calculations and associated analyses are being reviewed by NSPM and upgraded 1 revised as appropriate. During these reviews it was identified that there is a possibility that the Reactor Steam Dome Pressure Permissive - Bypass Timer (Pump Permissive) (hereafter referred to as the ADS bypass timer), analytical limit may decrease with EPU, and after setpoint calculations, the allowable value may not be within the current TS band of "2 18 minutes and 5 22 minutes". General Electric is petforming analyses for NSPM of the ADS bypass timer under EPU conditions.

A non-conservative TS allowable value can normally be treated in accordance with NRC Administrative Letter (AL) 98-1 0, "Dispositioning of Technical Specifications that are Insufficient to Assure Plant Safety." The presentation of the ADS bypass timer allowable value, as a double-sided limit, significantly restricts the ability to address a non-conservative value in accordance with AL 98-1 0. NSPM considers it prudent to remove this lower allowable value limit. A review of other licensee's TS and the improved standard TS NUREGs indicate that the ADS bypass timer allowable value lower limit is not required to be included in the TS.

Document Control Desk L-MT-12-028 Page 2 of 3 NSPM requests NRC approval of the proposed license amendment request by June 6, 2012. A 14 day implementation period is requested for this license amendment. provides a description of the proposed changes and includes the technical evaluation and associated no significant hazards determination and environmental evaluations. Enclosure 2 provides a marked-up copy of the TS pages showing the proposed changes.

The MNGP Plant Operations Review Committee has reviewed this application. In accordance with 10 CFR 50.91, a copy of this application, with enclosures, is being provided to the designated Minnesota Official.

Summaw of Commitments This letter proposes no new commitments and does not revise any existing commitments.

Document Control Desk L-MT-12-028 Page 3 of 3 I declare under erjury that the foregoing is true and correct.

Ilo Nuclear Generating Plant pany - Minnesota Enclosures (9 cc:

Administrator, Region Ill, USNRC Project Manager, Monticello, USNRC Resident Inspector, Monticello, USNRC Minnesota Department of Commerce

L-MT-12-028 Table of Contents Page 1 of 1 TABLE OF CONTENTS SECTION TITLE PAGE 1.0

SUMMARY

DESCRIPTION 1

2.0 BACKGROUND

2 3.0 DETAILED DESCRIPTION 3

4.0 ADS DESCRIPTION AND DESIGN 1 LICENSING FUNCTIONS 3

5.0 TECHNICAL EVALUATION

5 5.1 Discussion of the ADS Bvpass Timer and Determination of 5

the Analvtical Limit 5.2 Review of Other BWR Technical Specifications With Respect 6

to the ADS Bypass Timer 5.3 BWRI4 Improved STS Presentation for the ADS Bvpass 7

Timer 5.4 TSTF-493 Considerations 7

5.5 Conclusion 8

6.0 REGULATORY ANALYSIS

6.1 No Significant Hazards Determination 6.2 Applicable Regulatory Requirements 7.0 ENVIRONMENTAL EVALUATION 12

8.0 REFERENCES

13

L-MT-12-028 Page1 of13 REVISE ALLOWABLE VALUE FOR THE AUTOMATIC DEPRESSURIZATION SYSTEM BYPASS TIMER 1.0

SUMMARY

DESCRIPTION In accordance with 10 CFR 50.90, the Northern States Power Company - Minnesota (NSPM), doing business as Xcel Energy, Inc., proposes to revise Monticello Nuclear Generating Plant (MNGP) Technical Specification (TS) 3.3.5.1, "Emergency Core Cooling System (ECCS) Instrumentation." Specifically, it is proposed to revise the lower allowable value limit of "2 18 minutes" for Functions 1.e and 2.e, "Reactor Steam Dome Pressure Permissive - Bypass Timer (Pump Permissive)," (hereafter C

referred to as the Automatic Depressurization System (ADS) bypass timer) in Table 3.3.5.1-1 of Specification 3.3.5.1. This function was added in response to Three Mile Island (TMI) Action Plan, Item ll.K.3.18, which concerns logic modifications to eliminate manual ADS actuation for some postulated event sequences.

In conjunction with the Extended Power Uprate (EPU) under U. S. Nuclear Regulatory Commission (NRC) review, calculations and associated analyses are being reviewed by NSPM and upgraded / revised as appropriate. During these reviews it was identified that there is a possibility that the Reactor Steam Dome Pressure Permissive - Bypass Timer (Pump Permissive) (the ADS bypass timer), analytical limit may decrease with EPU, and after setpoint calculations, the allowable value may not be within the current TS band of "2 18 minutes and 1 2 2 minutes". General Electric (GE) is performing analyses for NSPM of the ADS bypass timer under EPU conditions.

A non-conservative TS allowable value can normally be treated in accordance with NRC Administrative Letter (AL) 98-1 0, "Dispositioning of Technical Specifications that are Insufficient to Assure Plant safety."(') The presentation of the ADS bypass timer allowable value, as a double-sided limit, significantly restricts the ability to address a non-conservative value in accordance with AL 98-1 0.

NSPM has determined that the majority (see Section 5.2) of Boiling Water Reactor (BWR) licensees TS do not include a lower allowable value for the ADS bypass timer function, as it pertains to providing adequate margin to unwanted pump starts during reactor water level transients. The upper allowable value limit provides sufficient time for an operator to assess the situation and inhibit ADS actuation, if prudent, before an automatic Reactor Pressure Vessel (RPV) blowdown is initiated by the ADS logic.

NSPM considers it prudent to remove this lower allowable value limit. This lower allowable value limit is not credited in the safety analyses. A review of other licensee's TS and the improved standard TS NUREGs indicate that the ADS bypass timer allowable value lower limit is not required to be included in the TS.

1.

With both divisions of ADS inoperable an immediate plant shutdown would be required.

L-MT-12-028 Page 2 of 13

2.0 BACKGROUND

In response to NUREG-0737, ltem ll.K.3.18, "Modification of Automatic Depressurization System Logic - Feasibility for Increased Diversity for Some Event Sequences" (Reference I), Northern States Power (NSP)(*) participated in a BWR Owners Group program to study ADS logic alternatives which would eliminate the need for manual actuation to assure adequate core cooling for some postulated event sequences. The TMI Action Plan Item ll.K.3.18 position states:

The automatic depressurization system (ADS) actuation logic should be modified to eliminate the need for manual actuation to assure adequate core cooling. A feasibility and risk assessment study is required to determine the optimum approach. One possible scheme that should be considered is ADS actuation on low reactor-vessel water level provided no high-pressure coolant injection (HPCI) or high-pressure coolant system (HPCS) flow exists and a low-pressure emergency core cooling (ECC) system is running.

This logic was designed to complement, not replace, the then existing ADS actuation logic. In 1983, the BWR Owners Group proposed ADS logic modifications to satisfy NUREG-0737, ltem ll.K.3.18 requirements (Reference 2). The NRC Staff reviewed the ADS logic alternatives and transmitted to NSP their evaluation in a letter dated June 13, 1983 (Reference 3) indicating the NRC approved choices. For BWRl3 plants, such as Monticello, to implement the options found acceptable by the Staff, further work was required to develop modifications to the start logic for the low pressure ECCS pumps.

By letter dated October 24, 1984, "Implementation of NUREG-0737, ltem ll.K.3.18, ADS Logic Modifications", (Reference 4), NSP indicated that Option 2B from a GE report, "Modification of ECCS Pump Start Logic," (Reference 5), had been chosen for implementation at Monticello. In support of Option 2B a detailed analysis to determine the ADS bypass timer setting was performed by GE for NSP (Reference 6). Both GE reports were provided to the NRC in the October 24, 1984, NSP letter. The NRC Staff found the proposed modifications acceptable (Reference 7) and the modifications were installed during the 1986 refueling outage. Subsequently, TS changes to incorporate the ADS bypass timer function in the Monticello TS were submitted and approved by the NRC on March 31, 1989, as Amendment 62 to the Monticello Facility Operating License (Reference 8).

2.

Northern States Power was a predecessor licensee to Northern States Power Company - Minnesota.

L-MT-12-028 Page3of 13 3.0 DETAILED DESCRIPTION The proposed TS change revises the allowable value for Functions 1.e and 2.e, "Reactor Steam Dome Pressure Permissive - Bypass Timer (Pump Permissive), in Table 3.3.5.1-1, "Emergency Core Cooling System Instrumentation." The proposed change to the allowable value for the Core Spray and Low Pressure Coolant Injection (LPCI) Systems is summarized below:

APPLICABLE CONDITIONS MODES REQUIRED REFERENCED OR OTHER CHANNELS FROM SPECIFIED PER REQUIRED SURVEILLANCE ALLOWABLE FUNCTION CONDITIONS FUNCTION ACTION A.l REQUIREMENTS VALUE

1. Core Spray System (Table entries for the Core Spray System are the same as shown below for LPCI.)

2. LPCI System 1,2,3 2

C SR 3.3.5.1.7

e.

Reactor Steam Dome Pressure SR 3.3.5.1.8 4

Permissive -

1 22 minutes Bypass Timer (Pump 4(a), 5(a) 2 B

SR 3.3.5.1.7 Permissive)

SR 3.3.5.1.8 4

5 22 minutes (a)

When associated ECCS subsystem(s) are required to be OPERABLE per LC0 3.5.2.

The TS change (mark-ups) associated with this change are provided in Enclosure 2.

4.0 ADS DESCRIPTION AND DESIGN 1 LICENSING FUNCTIONS

SUMMARY

The ADS, a part of the ECCS network, is an automatic actuation logic system that through operation of selected safetylrelief valves (SIRVs), provides a backup to the high pressure injection systems, e.g., High Pressure Coolant Injection (HPCI),

feedwater, and Reactor Core Isolation Cooling (RCIC) systems, although only HPCI is credited in the accident analysis. Three S/RVs (RV-2-71A, C and D) perform the ADS function. The ADS is designed to depressurize the reactor durin a small break Loss of Coolant Accident (LOCA) so the low pressure systems(# can inject if HPCI fails or is unable to maintain RPV water level. ADS monitors the discharge pressures of the four LPCI and two Core Spray pumps. These signals are used as a permissive for ADS actuation, indicating there is a source of coolant available once ADS has depressurized the vessel.

3.

The low pressure systems are the LPCI mode of Residual Heat Removal (RHR) and Core Spray.

L-MT-12-028 Enclosure I Page 4 of 13 Prior to the addition of the ADS logic modifications (includes the ECCS pump start modifications) for Monticello, ADS activated automatically upon coincident signals of reactor low-low water level, high drywell pressure, and a low pressure ECCS (Core Spray or LPCI) pump running, Following the ADS (and ECCS pump start) logic modifications, ADS activates upon signals indicating:

1) reactor low-low water level, and

2) at least one LPCl or Core Spray pump running with a nominal discharge pressure of 100 psig (blowdown permissive interlock)

The LPCl and Core Spray pumps automatically start on high drywell pressure alone or reactor low-low water level sustained for approximately 20 minutes (ADS bypass timer).

This logic arrangement maintains the original design philosophy of minimizing the potential for unnecessary ECCS pump starts at high reactor pressure. A time delay of approximately 2 minutes after receipt of the signals allows the operator to reset the logic and prevent an automatic blowdown if the water level in the RPV is being restored or if the signals are erroneous. A manual inhibit switch was added to the ADS initiation logic to provide the operator sufficient time to assess the situation and inhibit ADS actuation if reactor water level is expected to be recovered (e.g.,

injection systems are being restored), the event does not require rapid reactor depressurization, or depressurization by ADS should not be performed.(4)

The additional logic does not affect the high drywell pressure-reactor low-low water level initiation sequence insofar as it responds to pipe breaks inside the drywell on automatic ADS response to isolation or LOCA events.

The time delay of approximately 20 minutes for the ADS bypass timer allowable value setpoint was chosen to be long enough so that HPCl has sufficient time to recover RPV water level to above low-low, yet not so long that LPCI and Core Spray are unable to adequately cool the core (limit Peak Cladding Temperature (PCT) to less than 2200°F) if HPCl fails to maintain level.

4.

ADS operation precludes the operator from being able to direct events and control the rate of blowdown. Slower depressurization is desirable in that it reduces the possibility of exceeding vessel integrity limits by rapid cooldown. Also, in many Emergency Operating Procedure (EOP) scenarios, action is taken by an operator to inhibit ADS.

Additionally, depressurization is not prudent in some scenarios, such as during some Anticipated Transients Without Scram (ATWS) events and should be avoided.

L-MT-12-028 Page 5 of 13

5.0 TECHNICAL EVALUATION

In response to NUREG-0737, Item ll.K.3.18, "Modification of Automatic Depressurization System Logic - Feasibility for Increased Diversity for Some Event Sequences" (Reference I), various ADS actuation alternatives were developed by the BWR Owner's Group, approved by the NRC, and selected by licensees to meet TMI Action Plan requirements. To implement the option chosen by Monticello, Option 2B, modifications were required to the low pressure ECCS pump start logic, and analysis was required to determine the analytical limit for the ADS bypass timer setting. From this analytical limit the instrument setpoint determination process establishes the TS allowable value.

The allowable value for the ADS bypass timer, also known as the "Reactor Steam Dome Pressure Permissive - Bypass Timer (Pump Permissive)," Functions 1.e and 2.e in Table 3.3.5.1-1, is currently expressed in the Monticello TS as a two-sided limit. This led to questions about why the Monticello TS includes these functions expressed as a two-sided allowable value, when the majority of BWRs (see Section 5.2) present the function as a single-sided allowable value.

A review of the analysis discussed above for determination of the analytical limit, a review of many other licensee's TSs for the corresponding function, and a review of the presentation of the allowable value for the corresponding function in the BWRl4 improved Standard Technical Specifications (ITS) (NUREG-1433) (Reference 9),

indicate that the allowable value is properly expressed as a one-sided allowable value. There is no reason for a distinction between the MNGP and other BWR licensees, the analysis bases are the same. In other words, MNGP was not required to and should not have included the lower allowable value limit within the custom TS originally. NSPM proposes to remove the lower allowable value limit of "1 18 minutes" for this function. The lower allowable value limit is not assumed within the safety analyses performed by GE for the MNGP and this lower limit is not required to be included within the TS.

5.1 Discussion of the ADS Bypass Timer and Determination of the Analvtical Limit Analyses were performed to determine the analytical limit for the ADS bypass timer. Approved ECCS evaluation models were used for these ADS bypass timer analyses. Sensitivity studies were performed to determine limiting events for the analytical limit determination. The studies included transient and LOCA events which do not result in a release of steam to the drywell but which may require depressurization of the RPV to maintain adequate core cooling. The studies assumed that all high pressure makeup systems were lost.

L-MT-12-028 Page 6 of 13 In order to establish the maximum allowable bypass time, the ADS bypass timer setting was varied. Plant response for different bypass time settings was determined to be similar except that PCT increased with increasing ADS bypass timer settings, as expected. An ADS bypass timer setting analytical limit was determined that would maintain the PCT less than 2200°F for these events. The safety analysis is only concerned with the determination of maximum time delay (analytical limit) that allows the PCT to be maintained less than 2200°F.

From this analytical limit the instrument setpoint determination process establishes an acceptable TS allowable value. Maintaining the instrument setting less than the allowable value limit (the upper limit in the current TS) ensures that the PCT will remain less than 2200°F, the safety basis for this function in the safety analyses. Hence, the TS allowable value is properly expressed as a single-sided limit and meets the safety analysis requirement.

NSPM has determined that the lower allowable value limit for the ADS bypass timer function, pertains to providing adequate margin to unwanted pump starts during reactor water level transients. The upper allowable value provides the operator sufficient time to assess the situation and inhibit ADS actuation if the event does not require rapid reactor depressurization. The lower allowable value limit is not associated with the safety analysis.

NSPM is not proposing any change to the evaluation of the ADS and low pressure ECCS pump start logic modifications approved by the NRC for Monticello on January 29, 1985 (Reference 7). Also, no change is proposed to the evaluation approving the associated TS changes to incorporate the modifications into the TS -Amendment 62 to the Monticello Operating License, dated March 31, 1989 (Reference 8). It is only proposed to remove the ADS bypass timer lower allowable value limit from the TS since it is not assumed in the safety analysis. As discussed in the following sections a lower allowable value limit for the ADS bypass timer is not included in the majority of other BWR licensees TS (see Section 5.2) and is not included in the BWRI4 ITS NUREG.

5.2 Review of Other BWR Technical Specifications With Respect to the ADS Bypass Timer A review of the 22 BWR units TS listed below identified that approximately 75%

of the plants(5) express the allowable value for the ADS bypass timer as a one-sided limit, i.e., 5 [xx] minutes (or seconds) as determined by a plant specific analysis, i.e., the same presentation as that in the BWRl4 ITS NUREG. A

5.

Note, that some BWRs (e.g., Duane Arnold) chose another option to address this scenario for ADS operation and hence this function is not included within their TSs.

L-MT-12-028 Enclosure I Page 7 of 13 handful of plants were identified as having a double-sided allowable value limit for the function in their TS corresponding to the ADS bypass timer:

0 Peach Bottom, Units 2 and 3 Pilgrim Monticello A review of the available safety evaluations for the plants above indicated that there was no inherent reason for them to maintain a double-sided allowable value limit.

The following plants were identified as having a single-sided allowable value limit for the function in their TS corresponding to the ADS bypass timer:

Browns Ferry, Units 2 and 3 La Salle, Units 1 and 2 Clinton 0

Quad Cities, Units 1 and 2 Dresden, Units 2 and 3 River Bend Fermi o

Susquehanna, Units 1 and 2 Grand Gulf Vermont Yankee Hatch, Units I and 2 This indicates, as expanded upon in the next section, that there is no inherent reason for a double-sided allowable value limit within the TS. A single-sided allowable value presentation is acceptable to the NRC.

5.3 BWR14 ITS Presentation for the ADS Bvpass Timer In the BWRI4 ITS NUREG (Reference 9), the ADS bypass timer is referred to as the "Automatic Depressurization System Low Water Level Actuation Timer," in Table 3.3.5.1-1, Functions 4.g and 5.g, ADS Trip System A and B, respectively.

The allowable value for this Function is expressed as a one-sided limit. The value specified in the ITS NUREG is required to be less than or equal to a limit determined by plant specific analysis - r [ I 31 minutes.

Therefore, the NRC approved standard presentation for the ADS bypass timer limit is a one-sided allowable value within the NUREG.

5.4 TSTF-493 Considerations NSPM is aware of the NRC position to encourage TSTF-493 (Reference 1 O),

adoption by requiring licensees to provide a determination for each instrumentation function proposed for revision, as to whether the function is a Limiting Safety System Setting (LSSS) that protects a safety limit. It has been indicated in several previous instrumentation related submittals that the company intended to adopt TSTF-493 for Monticello, once approved.

L-MT-12-028 Page 8 of 13 A review of the TSTF-493 traveler for this particular instrument function indicates that this function is not an LSSS that protects a safety limit.

Attachment A to TSTF-493, Revision 4, entitled "Identification of Functions to be Annotated with TSTF-493 Footnotes," identifies those functions that are LSSS. Under the Attachment A listing for NUREG-1433 (BWRl4 plants),

Specification 3.3.5.1, "Emergency Core Cooling System Instrumentation," for the corresponding function, "Automatic Depressurization System Low Water Level Actuation Timer," it is stated that it is "Actuation logic excluded from footnotes." Consequently, this function is not a LSSS and no change to the TS is required with respect to this function.

5.5 Conclusion From the analytical limit the instrument setpoint determination process establishes an acceptable TS allowable value. Maintaining an allowable value below this limit ensures that the PCT will remain less than 2200°F, the safety basis for this function in the safety analyses. Hence, the TS allowable value can be established as a single-sided limit and meet the safety analysis requirement. Also, this is consistent with the NRC approved presentation for this function in the BWRl4 ITS NUREG.

6.0 REGULATORY ANALYSIS

The applicable regulatory requirements, together with the no significant hazards determination and environmental evaluations are provided in the following sections.

6.1 No Significant Hazards Determination In accordance with the requirements of 10 CFR 50.90, the Northern States Power Company - Minnesota (NSPM) requests an amendment to facility Renewed Operating License DPR-22, to revise the Monticello Nuclear Generating Plant (MNGP) Technical Specifications (TSs). Specifically, the allowable value for Functions I

.e and 2.e, "Reactor Steam Dome Pressure Permissive - Bypass Timer (Pump Permissive)," in Table 3.3.5.1-1 of Specification 3.3.5.1, "Emergency Core Cooling System (ECCS)

Instrumentation," is proposed to be revised.

The NSPM has evaluated the proposed change to the TS in accordance with 10 CFR 50.91 against the standards in 10 CFR 50.92 and has determined that the operation of the MNGP in accordance with the proposed amendment presents no significant hazards. NSPMJs evaluation against each of the criteria in 10 CFR 50.92 follows.

L-MT-12-028 Page 9 of 13

1.

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

Response: No.

The proposed change does not physically impact the plant nor does it impact any design or functional requirements of the Automatic Depressurization System (ADS). The proposed change does not degrade the performance or increase the challenges to any safety systems assumed to function in the accident analysis. There is no effect on the probability of any event initiators. There is no change to normal plant operating parameters or accident mitigation performance.

Therefore, there is not 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 hardware changes nor are there any changes in the method by which plant systems perform a safety function. This request does not affect the normal method of plant operation. No new equipment is introduced which could create a new or different kind of accident. No new equipment failure modes are created. No new accident scenarios, transient precursors, failure mechanisms, or limiting single failures are introduced.

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

3.

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

Response: No The proposed change does not affect the assumptions of the safety analysis or the availability or operability of any plant equipment. There is no reduction in the margin of safety because the criteria for the performance of the ADS are not changed and there are no changes to those plant systems necessary to assure the accomplishment of protection functions.

L-MT-12-028 Page 10 of 13 For these reasons, the proposed amendment does not involve a significant reduction in a margin of safety.

Based on the above, the NSPM has determined that operation of the facility in accordance with the proposed change does not involve a significant hazards consideration as defined in 10 CFR 50.92(c), in that it does not: (1) involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety.

6.2 Applicable Regulatow Requirements 10 CFR 50.36, "Technical specifications," provides the regulatory requirements for the content required in the TSs. As stated in 10 CFR 50.36, the TSs will include Surveillance Requirements (SRs) to assure that the limiting conditions for operation (LCO) (and associated remedial actions) are met.

The MNGP was designed largely before the publishing of the 70 General Design Criteria (GDC) for Nuclear Power Plant Construction Permits proposed by the Atomic Energy Commission for public comment in July 1967, and constructed prior to the 1971 publication of Appendix A, "General Design Criteria for Nuclear Power PlantsJ1, to 10 CFR Part 50. As such, the MNGP was not licensed to the Appendix A, General Design Criteria (GDC).

The MNGP USAR, Section 1.2, lists the principal design criteria (PDCs) for the design, construction and operation of the plant. USAR Appendix E provides a plant comparative evaluation with the proposed AEC 70 design criteria. It was concluded that the plant conforms to the intent of the GDCs. Therefore, the applicable GDCs are discussed below.

Criterion 13 -- lnstrumentation and control. lnstrumentation shall be provided to monitor variables and systems over their anticipated ranges for normal operation, for anticipated operational occurrences, and for accident conditions as appropriate to assure adequate safety, including those variables and systems that can affect the fission process, the integrity of the reactor core, the reactor coolant pressure boundary, and the containment and its associated systems. Appropriate controls shall be provided to maintain these variables and systems within prescribed operating ranges.

Criterion 20 -- Protection system functions. The protection system shall be designed (1) to initiate automatically the operation of appropriate systems including the reactivity control systems, to assure that specified acceptable fuel design limits are not exceeded as a result of anticipated operational

L-MT-12-028 Page 11 of 13 occurrences and (2) to sense accident conditions and to initiate the operation of systems and components important to safety.

Criterion 21 -- Protection system reliability and testability. The protection system shall be designed for high functional reliability and inservice testability commensurate with the safety functions to be performed.

Redundancy and independence designed into the protection system shall be sufficient to assure that (1) no single failure results in loss of the protection function and (2) removal from service of any component or channel does not result in loss of the required minimum redundancy unless the acceptable reliability of operation of the protection system can be otherwise demonstrated. The protection system shall be designed to permit periodic testing of its functioning when the reactor is in operation, including a capability to test channels independently to determine failures and losses of redundancy that may have occurred.

Criterion 22 -- Protection system independence. The protection system shall be designed to assure that the effects of natural phenomena, and of normal operating, maintenance, testing, and postulated accident conditions on redundant channels do not result in loss of the protection function, or shall be demonstrated to be acceptable on some other defined basis.

Design techniques, such as functional diversity or diversity in component design and principles of operation, shall be used to the extent practical to prevent loss of the protection function.

Criterion 29 -- Protection against anticipated operational occurrences. The protection and reactivity control systems shall be designed to assure an extremely high probability of accomplishing their safety functions in the event of anticipated operational occurrences.

NSPM has evaluated the proposed changes against the applicable regulatory requirements and acceptance criteria. The design of the ADS is consistent with the applicable regulatory criteria described above. The technical analysis in Section 5.0 above concludes that with the proposed changes the system will continue to assure that the design requirements and acceptance criteria of the ECCS are met. Based on this, there is reasonable assurance that the health and safety of the public, following approval of this change, is unaffected.

L-MT-12-028 Page 12 of 13 ENVIRONMENTAL EVALUATION NSPM has determined that the proposed change would not revise a requirement with respect to installation or use of a facility or component located within the restricted area, as defined in 10 CFR 20, nor would it change an inspection or surveillance requirement. The proposed amendment does not involve (i) a significant hazards consideration, or (ii) authorize a significant change in the types or a significant increase in the amounts of any effluent that may be released offsite, or (iii) result in a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed amendment meets the eligibility criterion for a categorical exclusion set forth in 10 CFR 51.22(~)(9). Therefore, NSPM concludes that pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.

L-MT-I 2-028 Page 13 of 13 REFERENCES NUREG-0737, "Clarification of TMI Action Plan Requirements", November 1980.

"BWR Owner's Group Evaluation of NUREG-0737 ltem ll.K.3.18, Modification of Automatic Depressurization System Logic", General Electric Company, NEDE-30045, February 1983.

NRC (D. B. Vassallo) letter to NSP (D. M. Musolf), "NUREG-0737, ltem ll.K.3.18, "ADS Logic Modifications", dated June 13, 1983.

NSP (D. M. Musolf) letter to NRC, "Implementation of NUREG-0737, ltem ll.K.3.18, ADS Logic Modifications", dated October 24, 1984.

General Electric Report AE-06-0184, Revision 1, "Modification of ECCS Pump Start Logic", dated July 1984.

General Electric Report AE-79-0884, "Bypass Timer Calculation for the ADSIECCS Modification for Monticello," dated August 29, 1984.

NRC (D. B. Vassallo) letter to NSP (D. M. Musolf), "NUREG-0737, ltem ll.K.3.18, ADS Logic Modification", dated January 29, 1985.

NRC (D. B. Vassallo) letter to NSP (D. M. Musolf), "Amendment No. 62 to Facility Operating License No. DPR-22 (TAC No. 65572)," dated March 31, 1989.

U. S. NRC NUREG-1433, Volumes 1 and 2, Revision 3.0, Standard Technical Specifications General Electric Plants, BWR14, Published June 2003.

Technical Specification Taskforce Traveler Improved Standard Technical Specifications Change Traveler, TSTF - 493, Revision 4, "Clarify Application of Setpoint Methodology for LSSS Functions."

ENCLOSURE 2 MONTICELLO NUCLEAR GENERATING PLANT LICENSE AMENDMENT REQUEST REVISE ALLOWABLE VALUE FOR THE AUTOMATIC DEPRESSURIZATION SYSTEM BYPASS TIMER MARKED-UP TECHNICAL SPECIFICATION PAGES (2 pages follow)

ECCS lnstrumentation 3.3.5.1 Table 3.3.5.1-1 (page I of 6)

Emergency Core Cooling System Instrumentation APPLICABLE CONDITIONS MODES REQUIRED REFERENCED OR OTHER CHANNELS FROM SPECIFIED PER REQUIRED SURVEILLANCE ALLOWABLE FUNCTION CONDITIONS FUNCTION ACTION A.l REQUIREMENTS VALUE

1. Core Spray System

a.

Reactor Vessel 1 2 3 4(b)

Water Level - Low 4(a), ',(a)

Low

b.

Drywell Pressure -

1,2,3 4(b)

High

c.

Reactor Steam 1,2,3 2

Dome Pressure -

Low (Injection Permissive) 4(a), 5(a) 2

d.

Reactor Steam 1,2,3 Dome Pressure Permissive - Low (Pump Permissive) 4(a), 5(a)

e.

Reactor Steam 1, 2,3 Dome Pressure Permissive - Bypass Timer (Pump Permissive) 4(a), 5(a)

B SR 3.3.5.1.1 2 -48 inches SR 3.3.5.1.2 SR 3.3.5.1.3 SR 3.3.5.1.7 SR 3.3.5.1.8 B

SR 3.3.5.1.2 s 2 psig SR 3.3.5.1.4 SR 3.3.5.1.8 C

SR 3.3.5.1.2 2 397 psig and

, SR 3.3.5.1.4"")

5 440 psig SR 3.3.5.1.8 B

SR 3.3.5.1.2 2 397 psig and SR 3.3.5.1.4(C)(d) s 440 psig SR 3.3.5.1.8 2 397 psig 2 397 psig s 22 minutes I

s 22 minutes % I (a)

When associated ECCS subsystem(s) are required to be OPERABLE per LC0 3.5.2, "ECCS - Shutdown."

(b)

Also required to initiate the associated emergency diesel generator (EDG).

(c)

If the as-found channel setpoint is conservative with respect to the Allowable Value but outside its predefined as-found tolerance, then the channel shall be evaluated to verify that it is functioning as required before returning the channel to service.

(d)

The instrunient channel setpoint shall be reset to a value that is within the as-leff tolerance of the nominal trip setpoint; otherwise, the channel shall be declared inoperable. The nominal trip setpoint and the methodology used to detenine the as-found tolerance and the as-left tolerance are specified in the Technical Requirements Manual (TRM).

Monticello 3.3.5.1-6 Amendment No.

ECCS Instrumentation 3.3.5.1 Table 3.3.5.1-1 (page 3 of 6)

Emergency Core Cooling S y s t e m Instrumentation APPLICABLE CONDITIONS MODES REQUIRED REFERENCED OR OTHER CHANNELS FROM SPECIFIED PER REQUIRED SURVEILLANCE ALLOWABLE FUNCTION CONDITIONS FUNCTION ACTION A1 REQUIREMENTS VALUE

2.

LPCl System

e.

Reactor Steam 1,2,3 Dome Pressure Permissive - Bypass Timer (Pump Permissive) 4(a), 5(8)

f.

Low Pressure 1,2 3 Coolant Injection 4(a),

Pump Start - Time Delay Relay Pumps A, B Pumps C, D

g.

Low Pressure 1 2 3 Coolant Injection 41a), k(S Pump Discharge Flow - Low (Bypass)

h.

Reactor Steam 1,2,3, Dome Pressure -

Low (Break Detection)

i.

Recirculation Pump 1,2,3 Differential Pressure

- High (Break Detection)

j.

Recirculation Riser f,2,3 Differential Pressure

- High (Break Detection) 2 B

SR 3.3.5.1.7 SR 3.3.5.1.8 2 22 minutes I

4 per pump B

SR 3.3.5.1.7 SR 3.3.5.1.8 15.33 seconds 1

10.59 seconds 1 per pump E

SR 3.3.5.1.2 2 360 gpm and SR 3.3.5.1.7 1745 gpm SR 3.3.5.1.8 4

B SR 3.3.5.1.2 1 873.6 psig SR 3.3.5.1.7 and SR 3.3.5.1.8

< 923.4 psig 4 per pump C

SR 3.3.5.1.2 r 63.5 Inches SR 3.3.5.1.7 wc SR 3.3.5.1.8 4

C SR 3.3.5.1.2 2 100.0 inches SR 3.3.5.1.7(C1(d' wc SR 3.3.5.1.8 (a)

When associated ECCS subsystern(s) are required to be OPERABLE per LC0 3.5.2.

(c)

If the as-found channel setpoint is conservative with respect to the Allowable Value but outside its predefined as-found tolerance, then the channel shall be evaluated to verify that it is functioning as required before returning the channel to service.

(d)

The instrument channel setpoint shall be reset to a value that is within the as-lefl tolerance of the nominal trip setpoint; otherwise, the channel shall be declared inoperable. The nominal trip setpoint and the methodology used to determine the as-found tolerance and the as-left tolerance are specified in the TRM.

Monticello 3.3.5.1-8 Amendment No. M-&W+l-

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