View source for L-PI-15-030, Application to Revise Technical Specifications to Adopt TSTF-523, Generic Letter 2008-01, Managing Gas Accumulation, Using the Consolidated Line Item Improvement Process

{{Adams
| number = ML15187A259
| issue date = 06/29/2015
| title = Application to Revise Technical Specifications to Adopt TSTF-523, Generic Letter 2008-01, Managing Gas Accumulation, Using the Consolidated Line Item Improvement Process
| author name = Sharp S
| author affiliation = Northern States Power Co, Xcel Energy
| addressee name = 
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000282, 05000306
| license number = DPR-042, DPR-060
| contact person = 
| case reference number = GL-08-001, L-PI-15-030
| document type = Letter type:L, License-Application for Facility Operating License (Amend/Renewal) DKT 50, Technical Specifications
| page count = 64
| project = 
| stage = Request
}}

=Text=
{{#Wiki_filter:XceIEnergy&deg; JIUN 2992015                                                            L-PI-1 5-030 10 CFR 50.90 U S Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Prairie Island Nuclear Generating Plant Units 1 and 2 Dockets 50-282 and 50-306 Renewed License Nos. DPR-42 and DPR-60 Application to Revise Technical Specifications to Adopt TSTF-523, "Generic Letter 2008-01. Managiing Gas Accumulation", Using the Consolidated Line Item Improvement Process Pursuant to 10 CFR 50.90, Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), hereby submits a request for an amendment to revise the Technical Specifications (TS) for Prairie Island Nuclear Generating Plant (PINGP), Units 1 and 2. provides a description and assessment of the proposed change. provides the existing TS pages marked up to show the proposed change. provides revised (clean) TS pages. Attachment 4 provides existing TS Bases pages marked to show the proposed change. Changes to the existing TS Bases, consistent with the technical and regulatory analyses, will be implemented under the Technical Specification Bases Control Program. They are provided in Attachment 4 for information only.
By letter dated January 15, 2015 (ML15015A404), NSPM committed to evaluate the impact of adopting Technical Specification Task Force (TSTF) Traveler 523 by June 30, 2015 and submit an LAR for its adoption if necessary. This submittal satisfies the commitment.
Approval of the proposed amendment is requested by June 30, 2016. Once approved, the amendment shall be implemented within 90 days.
In accordance with 10 CFR 50.91, a copy of this application, with attachments, is being provided to the designated State of Minnesota Official.
1717 Wakonade Drive East a Welch, Minnesota 55089-9642 Telephone: 651.388.1121                                A-r/*I*

Document Control Desk Page 2 If there are any questions or if additional information is needed, please contact Mr.
Bryan Willard at 651--267-6829.
Summary of Commitments This letter contains no new commitments and no revisions to existing commitments.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on              2"e,     oI'-T Scott Sharp Director Site Operations, Prairie Island Nuclear Generating Plant Northern States Power Company - Minnesota Attachments (4) cc:     Administrator, Region Ill, USNRC Project Manager, PINGP, USNRC Resident Inspector, PINGP, USNRC State of Minnesota

ATTACHMENT 1 Description and Assessment Application to Revise Technical Specifications to Adopt TSTF-523, "Generic Letter 2008-01, Managing Gas Accumulation," Using the Consolidated Line Item Improvement Process

==1.0      DESCRIPTION==

The proposed change revises or adds Surveillance Requirements to verify that the system locations susceptible to gas accumulation are sufficiently filled with water and to provide allowances which permit performance of the verification. The changes are being made to address the concerns discussed in Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems."
The proposed amendment is consistent with TSTF-523, Revision 2, "Generic Letter 2008-01, Managing Gas Accumulation."
2.0     ASSESSMENT 2.1     Applicability of Published Safety Evaluation Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), has reviewed the model safety evaluation dated January 15, 2014 as part of the Federal Register Notice of Availability. This review included a review of the NRC staff's evaluation, as well as the information provided in TSTF-523, Revision 2. As described in the subsequent paragraphs,' NSPM concluded that the justifications presented in the TSTF-523, Revision 2, proposal and the model safety evaluation prepared by the NRC staff are applicable to Prairie Island Nuclear Generating Plant (PINGP), Units 1 and 2, and justify this amendment for the incorporation of the changes to the PINOP TS.
TSTF-523, Revision 2, and the model safety evaluation discuss the applicable regulatory requirements and guidance, including the 10 CFR 50, Appendix A, General Design Criteria (GDC). PINGP Units 1 and 2 were not licensed to the 10 CFR 50, Appendix A, GDC. The PINGP equivalent of the referenced GDC are discussed in the Updated Safety Evaluation Report (USAR) Section 1.2, Principal Design Criteria. The PINGP design criterion that equates to 10 CFR 50 Appendix A, GDC 1 s addressed in USAR Section 1.2.1, Overall Plant Requirements (GDC 1 - GDC 5) and the design criteria that equate to 10 CFR 50 Appendix A, GDC 34 through GDC 40 are addressed in USAR Section 1.2.6, Reactor Coolant Pressure Boundary (GDC 33 - GDC 36), and USAR Section 1.2.7, Engineered Safety Features (GDC 37 - GDC 65). This difference Page 1 of 6*
NSPM Adopt TSTF-523 does not alter the conclusion that the proposed change is applicable to PINGP, Units 1 and 2.
2.2     Optional Changes and Variations NSPM proposes the following variations from the TS changes described in the TSTF-523, Revision 2, or~the applicable parts of the NRC staff's model safety evaluation dated January 15, 2014.
The PINGP TS utilize different numbering than the NUREG-1431, Standard Technical Specifications (STS), on which TSTF-523, Revision 2, was based. PINGP TS do not have the existing TS 3.5.2, EGGS - Operating, Surveillance Requirements revised by TSTF-523, Revision 2. This difference does not affect the applicability of TSTF-523, Revision 2, to the PINGP TS. Specifically, numbering and content differences are provided in the following table.
NUREG-1431, STS                  TSTF-523 Change           PINGP TS Change Differences 3.5.2, EGCS - Operating          Revise SR 3.5.2.3 and     Add new SR 3.5.2.4, SR associated Bases.         3.5.2.5, and new associated Bases. Renumber subsequent SRs.
3.5.3, EGOS - Shutdown           Revise LCO Bases          Revise SR 3.5.3.1 to include only.                     two additional SRs.
3.6.6A, Containment Spray        Add new SR 3.6.6A.4       Add new SR 3.6.5.3 and and Cooling Systems              and associated Bases. associated Bases.
With the exception of the SR 3.5.2.5 addition, these differences are administrative in nature. None of the proposed variations affect the applicability of TSTF-523 to the PINGP TS.
NSPM is proposing the addition of new SR 3.5.2.5, with an associated Frequency of "Prior to entering Mode 3 after exiting shutdown cooling" in lieu of the specified 31 day Frequency. The justification for the additional SR and extended Frequency is provided below:
      *Safety injection system inaccessible location configuration The four inaccessible locations (two locations per unit) are designated 1SI-44, 1SI-45 for Unit 1 and 2S1-14A, 2S1-14B for Unit 2. The inaccessible locations are located on corresponding line numbers 2-SI-35A, 2-SI-35B, 2-2SI-35A and 2-2SI-35B. These locations are adjacent to the RCS first-off pressure isolation check valves and are inaccessible during normal operations due to dose and temperature concerns.'
Page 2 of 6 NSPM Adopt TSTF-523 The Safety Injection system piping injects into each of the RCS cold legs through a single common pipe that branches into two separate 2" lines. On each of the 2" branches, there are two check valves installed that are the pressure boundary valves for the RCS. The first-off check valves (SI1-9-1, SI-9-2, 2SI-9-I, and 2SI        2) are 6" swing disc check valves. The second-off check valves (S1-I16-4, SI-i16-5, 2S1-16-4, and 2S1-16-6) are 2" spring loaded piston type check valves.
The geometry of the four inaccessible locations consists of a vertically oriented 6" check valve that connects to the RCS loop piping with RCS pressure on the downstream side of the disc. These locations are all high points that would allow gas to accumulate inside the check valve on the upstream side of the disc.
The locations are inaccessible due to high dose rates during power operation and close proximity to the RCS loop piping. These areas are examined at the piping adjacent to the check valve due to the valve configuration and examination limitations.
* Gas intrusion source The Safety Injection piping connects directly to a pressurized Reactor Coolant System. Dissolved gases in the reactor coolant are controlled by the Chemical and Volume Control System (VC) that maintains the concentration of hydrogen or nitrogen gas present through the Volume Control Tank (VCT). The current Gas Accumulation Management Program (GAMP) indicates if back-leakage
      \were to occur, the lower pressure on the upstream side of the check valve would result in hydrogen gas coming out of solution and a void formation. Thus, these locations meet the definition of susceptible locations per the program documents.
Site engineering personnel have determined that a very specific leakage condition must exist for a void to form at the inaccessible locations. For void formation to occur, both the first-off and second-off pressure boundary check valves need to be leaking. If only a single check valve is leaking, a void cannot form due to pressurization between the check valves. If the first-off check valve is leaking at a rate that is greater than the second-off check valve, then the area between the check valves will pressurize and a void cannot form. A void will only form if the second-off check valve is leaking at a greater rate than the first-off check valve since that is the only condition that will simultaneously allow leakage from the RCS and also prevent pressure buildup between the check valves.
Per USAR Section 6, the design leakage limit for these valves is stated as 3 cc/hr per inch of nominal pipe size. This means that the 6" first-off check valves would have a design leakage rate of 18 cc/hr and the 2" second-off check valves would have a design leakage rate of 6 cc/hr. This design leakage rate is important to consider since it is impossible to design a zero leakage check valve with hard seats. Since the first-off check valves have a higher design leakage Page 3 of 6 NSPM Adopt TSTF-523 rate than the second-off check valves, it supports the position that void formation is unlikely. This is because a higher leakage through the first-off check valves, when compared to the second-off check valves, would tend to pressurize the piping between the check valves, which would effectively prevent void formation.
* Alternative monitoring PINGP will monitor the locations prior to entering Mode 3 after exiting shutdown cooling during startup in lieu of the specified 31 day frequency.
In addition to the proposed TS 3.2.5.2 Surveillance Frequency, the inaccessible locations are checked for voids at the earliest possible shutdown condition. This as-found testing occurs in accordance with the PINGP GAMP, under conditions that ensure the check valves at the inaccessible locations are properly seated.
During refueling outages, PINGP will verify the relative leakage rates of the check valves are maintained such that void formation during the cycle is mitigated. The check valve leakage rates will be validated to ensure no leakage is present, or the leakage rate of the first-off check valves (SI-9-I, SI-9-2, 2SI         1, and 2SI-9-2) is greater than the corresponding second-off check valves (SI-16-4, SI-I16-5, 2S1-16-4, and 2S1-16-6).
By verifying the conditions necessary for void formation are not present, maintaining the as left condition during the cycle, and monitoring of the locations when accessible, reasonable assurance of safety is maintained for the system.

==3.0    REGULATORY ANALYSIS==

3.1    No Significant Hazards Consideration Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), requests adoption of TSTF-523, Revision 2, "Generic Letter 2008-01, Managing Gas Accumulation," which is an approved change to the standard technical specifications (STS), into the Prairie Island Nuclear Generating Plant, Units I and 2, technical specifications (TS). The proposed change adds Surveillance Requirements to verify that the system locations susceptible gas accumulation are sufficiently filled with water and to provide allowances which permit performance of the verification.
Northern States Power Company, a Minnesota corporation (NSPM), evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment,"
as discussed below:
Page 4 of 6 NSPM Adopt TSTF-523
: 1. Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No The proposed change adds Surveillance Requirements (SRs) that require verification that the Emergency Core Cooling System (ECCS), the Residual Heat Removal (RHR) System, and the Containment Spray (CS) System are not rendered inoperable due to accumulated gas and to provide allowances which permit performance of the revised verification. Gas accumulation in the subject systems is not an initiator of any accident previously evaluated. As a result, the probability of any accident previously evaluated is not significantly increased.
The proposed SIRs ensure that the subject systems continue to be capable to perform their assumed safety function and are not rendered inoperable due to gas accumulation. Thus, the consequences of any accident previously evaluated are not significantly increased.
Therefore, the proposed licensing basis change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
: 2. Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?
Response: No The proposed change adds SRs that require verification that the ECCS, the RHR System, and the CS System are not rendered inoperable due to accumulated gas and to provide allowances which permit performance of the revised verification. The proposed change does not involve a physical alteration of the plant (i.e., no new or different type of equipment will be installed) or a change in the methods governing normal plant operation. In addition, the proposed change does not impose any new or different requirements that could initiate an accident. The proposed change does not alter assumptions made in the safety analysis and is consistent with the safety analysis assumptions.
Therefore, the proposed licensing basis change does not create the possibility of a new or different kind of accident from any previously evaluated.
: 3. Does the proposed amendment involve a significant reduction in a margin of safety?
Response: No The proposed change adds SRs that require verification that the ECCS, the RHR System, and the CS System are not rendered inoperable due to accumulated gas and to provide allowances which permit performance of the revised Page 5 of 6

Attachment I                                                                             NSPM Adopt TSTF-523 verification. The proposed change adds new requirements to manage gas accumulation in order to ensure the subject systems are capable of performing their assumed safety functions. The proposed SRs will ensure that the assumptions of the safety analysis are protected. The proposed change does not adversely affect any current plant safety margins or the reliability of the equipment assumed in the safety analysis. Therefore, there are no changes being made to any safety analysis assumptions, safety limits or limiting safety system settings that would adversely affect plant safety as a result of the proposed change.
Therefore, the proposed licensing basis change does not involve a significant reduction in a margin of safety.
Based on the above, Northern States Power Company, a Minnesota corporation (NSPM), 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.
4.0      ENVIRONMENTAL EVALUATION The proposed change 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 CER 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.
Page 6 of 6

ATTACHMENT 2 Technical Specification Pages (Markup) 3.4.6-3 3.4.7-4 3.4.8-3 3.5.2-2 3.5.2-3 3.5.2-4 3.5.3-2 3.6.5-3 3.6.5-4 3.9.5-3 3.9.6-3 11 pages follow

RCS Loops - MODE 4 3.4.6 SURVEILLANCEREQUIREMENTS______
SURVEILLANCE                                    FREQUENCY SR 3.4.6.1       Verify required RHR or RCS loop is in                 12 hours operation.
SR 3.4.6.2       Verify required SG capable of removing decay          12 hours heat.
SR 3.4.6.3----------NOTE--------
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated        7 days power are available to each required pump.
SR 3.4.6,4                            NOTE---------------..
NOT Not reauired to be performed until 12 hours after entering MODE 4.
Verify required RHR looo locations susceptible to     31dy gas accumulation are sufficiently filled with water.
Prairie Island                                             Unit 1 - Amendment No. 58 Units 1 and 2                              3.4.6-3         Unit 2 - Amendment No. 9

RCS Loops - MODE 5, Loops Filled 3.4.7 SURVEILLANCEREQUIREMENTS______
SURVEILLANCE                                   FREQUENCY SR 3.4.7.1        Verify required RHR loop is in operation.             12 hours SR 3.4.7.2        Verify required SG capable of removing decay          12 hours heat.
SR 3.4.7.3-----------NOTE--------
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated        7 days power are available to each required RHR pump.
SR 3.4.7,4         Verify required RHR loop, locations susceptible to   31dy
                   *,as accumulation are sufficiently filled with Prairie Island                                              Unit 1 - Amendment No. 58 Units 1 and 2                              3.4.7-4          Unit 2 - Amendment No. 4149

RCS Loops - MODE 5, Loops Not Filled 3.4.8 SURVEILLANCEREQUIREMENTS______
SURVEILLANCE                                 FREQUENCY SR 3.4.8.1       Verify required RHIR loop is in operation.           12 hours SR 3.4.8.2----------NOTE---------
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated       7 days power are available to each required RHR pump.
SR 3.4.8.3      Verify RHR looD locations susceptible to gas           1dy accumulation are sufficiently filled with water.
Prairie Island                                            Unit 1 - Amendment No. 4-58 Units 1 and 23483                         3.4.8-3         Unit 2 - Amendment No. 449

ECCS    - Operating 3.5.2 SURVEILLANCE REQUIREMENTS SURVEILLANCE                                  FREQUENCY SR 3.5.2.1      Verify the following valves are in the listed position. 12 hours Westing-Unit 1        house Valve         Valve Number        Number      Position                   Function 32070         8801A       OPEN          SI Injection to RCS Cold Leg A 32068         8801B       OPEN          SI Injection to RCS Cold Leg B 32073         8806A       OPEN          SI Cold Leg Injection Line 32206         881 6A      CLOSED        SI Pump Suction from RIIR 32207         881 6B      CLOSED        SI Pump Suction from RHIR Westing-Unit 2        house Valve         Valve Number        Number      Position                  Function 32173         8801A       OPEN          SI Injection to RCS Cold Leg A 32171         8801B       OPEN          SI Injection to RCS Cold Leg B 32176         8806A       OPEN          SI Cold Leg Injection Line 32208         881 6A      CLOSED        SI Pump Suction from RHR 32209         881 6B      CLOSED        SI Pump Suction from RHTR SR 3.5.2.2                                    -~~~NOTE--------           31 days Not required to be met for system vent flow oaths opened under administrative control.
Verify each ECCS manual, power operated, and automatic valve in the flow path that is not locked, sealed, or otherwise secured in position, is in the correct position.
Prairie Island                                         Unit 1 - Amendment No. 4-58 4-82 Units 1 and 2                               3.5.2-2    Unit 2 - Amendment No. 49 4-7-2

ECCS   - Operating 3.5.2 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE                                  FREQUENCY SR 3.5.2.3    Verify power to the valve operator has been removed      31 days for each valve listed in SR 3.5.2.1.
SR 3.5,2.4    Verify ECCS accessible locations susceptible to &#xa2;*as     31dy accumulation are sufficiently filled with water.
SR 3.5,2.5    Verify ECCS inaccessible locations sulsceptible to *.asProtOeein.
accumulation are sufficiently filled with water.        MD          fe extigsutow cooing SR 3.5.2.(!4 Verify each ECCS pump's developed head at the test       In accordance flow point is greater than or equal to the required     with the Inservice developed head.                                         Testing Program SR 3.5.2.7$ Verify each ECCS automatic valve in the flow path         24 months that is not locked, sealed, or otherwise secured in position, actuates to the correct position on an actual or simulated actuation signal.
Prairie Island                                       Unit 1 Amendment No. -8 4-82 Units 1 and 2                             3.5.2-3    Unit 2 -Amendment No. -14947

ECCS    -  Operating 3.5.2 SURVEILLANCE REQUIREMENTS (continued)_______
SURVEILLANCE                                  FREQUENCY SR 3.5.2.86 Verify each ECCS pump starts automatically on an            24 months actual or simulated actuation signal.
SR 3.5.2.9-7 Verify each ECCS throttle valve listed below is in the     24 months correct position.
Unit 1 Valve Number                 Unit 2 Valve Number SI-15-6                             2SI-15-6 SI-15-7                             2SI-15-7 SI-15-8                             2SI-15-8 SI-15-9                             2SI-15-9 SR 3.5.2.1Q8 Verify, by visual inspection, each ECCS train              24 months containment sump suction inlet is not restricted by debris and the suction inlet strainers show no evidence of structural distress or abnormal corrosion.
Prairie Island                                        Unit 1 - Amendment No. 4-58s 4-82 Units 1 and 2                              3.5.2-4    Unit 2 - Amendment No. 449 4-7-2

ECCS - Shutdown 3.5.3 ACTIONS (continued)                                                   ________
CONDITION                    REQUIRED ACTION                  COMPLETION TIME C. Required Action and        C.l1   Be in MODE 5.                24 hours associated Completion Time of Condition B not met.
SURVEILLANCE REQUIREMENTS SURVEILLANCE                                   FREQUENCY SR 3.5.3.1     The following SRs are applicable for all equipment     In accordance required to be OPERABLE:                               with applicable SRs SR 3.5.2.1                  SR 3.5.2.*
SR 3.5.2.3                  SR 3.5.2.98, SR 3.5.2.4 Prairie Island                                          Unit 1 - Amendment No. 4--58 6 Units 1 and 2                            3.5.3-2        Unit 2 - Amendment No. 49 447

Containment Spray and Cooling Systems 3.6.5 SURVEILLANCE REQUIREMENTS SURVEILLANCE                                       FREQUENCY SR 3.6.5.1           ----------...- NOTE---------
Not required to be met for system vent flow oaths onened under administrative control.
Verify each containment spray manual, power 31 days operated, and automatic valve in the flow path that is not locked, sealed, or otherwise secured in position is in the correct position.
SR 3.6.5.2 Operate each containment fan coil unit on low motor              31 days speed for > 15 minutes.
SR 3.6.5.3     Verify containment snrav locations susceptible to *as        31dy accumulation are sufficiently filled with water.
SR 3.6.5._____ Verify cooling water flow rate to each containment           24 months fan coil unit is >900 gpm.
SR 3.6.5.54 Verify each containment spray pump's developed                  In accordance head at the flow test point is greater than or equal to      with the the required developed head.                                 Inservice Testing Program Prairie Island                                          Unit 1 - Amendment No. -5l-t7-Units 1 and 2                               3.6.5-3     Unit 2 -Amendment No. 49 4                                                      Reiocd by,lett--,r datd,. Augu,- 2,,, 2006)FIA

Containment Spray and Cooling Systems 3.6.5 SURVEILLANCE REQUIREMENTS (continued)                                   ______
SURVEILLANCE                                     FREQUENCY SR 3.6.5._fa- Verify each automatic containment spray valve in the     24 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 3.6.5.76 Verify each containment spray pump starts                  24 months automatically on an actual or simulated actuation signal.
SR 3.6.5.8g7 Verify each containment cooling train starts              24 months automatically on an actual or simulated actuation signal.
SR 3.6.5._9g Verify each spray nozzle is unobstructed.                 Following maintenance which could result in nozzle blockage Prairie Island                                        Unit 1 - Amendment No. 58 4190 Units 1 and 2                              3.6.5-4    Unit 2 - Amendment No. -1494-79

RHR and Coolant Circulation-High Water Level 3.9.5 SURVEILLANCE REQUIREMENTS______
SURVEILLANCE                                  FREQUENCY SR 3.9.5.1    Verify one RHR loop is in operation.                   12 hours SR 3.9.5.2    Verify required RLHR loon locations susceptible to     31dy gas accumulation are sufficiently filled with water.
Prairie Island                                           Unit 1 - Amendment No. 41-58 Units 1 and 2                           3.9.5-3          Unit 2 - Amendment No. 449

RLIR and Coolant Circulation-Low Water Level 3.9.6 ACTIONS                                                                 ______
CONDITION                      REQUIRED ACTION                  COMPLETION TIME B. (continued)                     B.5.1 Close each penetration        4 hours providing direct access from the containment atmosphere to the outside atmosphere with a manual or automatic isolation valve, or blind flange.
OR B.5.2 Verify each penetration is     4 hours capable of being closed by an OPERABLE Containment Ventilation Isolation System.
SURVEILLANCE REQUIREMENTS S URVEILLANCE                                  FREQUENCY SR 3.9.6.1    Verify one RHLR loop is in operation.                    12 hours SR 3.9.6.2    Verify correct breaker alignment and indicated power     7 days available to the required RIIR pump that is not in operation.
SR 3.9.6.3     Verify. RHR looD locations susceptible to *as31dy accumulation are sufficiently filled with water.
Prairie Island                                            Unit 1 - Amendment No. 4-58 Units 1 and 2                                             Unit 2 - Amendment No. 4-49 3.9.6-3

ATTACHMENT 3 Technical Specification Pages (Retyped) 3.4.6-3 3.4.7-4 3.4.8-3 3.5.2-2 3.5.2-3 3.5.2-4 3.5.3-2 3.6.5-3 3.6.5-4 3.9.5-3 3.9.6-3 11 pages follow

RCS Loops - MODE 4 3.4.6 SURVEILLANCE REQUIREMENTS SURVEILLANCE                                  FREQUENCY SR 3.4.6.1       Verify required RHR or RCS loop is in                12 hours operation.
SR 3.4.6.2       Verify required SG capable of removing decay         12 hours heat.
SR 3.4.6.3-----------NOTE--------
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated        7 days power are available to each required pump.
SR 3.4.6.4-----------NOTE--------
Not required to be performed until 12 hours after entering MODE 4.
Verify required RUR loop locations susceptible to     31 days gas accumulation are sufficiently filled with water.
Prairie Island                                          Unit 1 - Amendment No. 58 Units 1 and 23463                         3.4.6-3       Unit 2 - Amendment No. 4-49

RCS Loops - MODE 5, Loops Filled 3.4.7 SURVEILLANCE REQUIREMENTS SURVEILLANCE                                 FREQUENCY SR 3.4.7.1        Verify required RHIR loop is in operation.          12 hours SR 3.4.7.2        Verify required SG capable of removing decay        12 hours heat.
SR 3.4.7.3-----------NOTE--------
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated      7 days power are available to each required RHR pump.
SR 3.4.7.4        Verify required RHR loop locations susceptible to   31 days gas accumulation are sufficiently filled with water.
Prairie Island                                           Unit 1 - Amendment No. 5-s Units 1 and 2                              3.4.7-4       Unit 2 - Amendment No. 4-49

RCS Loops - MODE 5, Loops Not Filled 3.4.8 SURVEILLANCE REQUIREMENTS                                              ______
SURVEILLANCE                                   FREQUENCY SR 3.4.8.1       Verify required RIIR loop is in operation.            12 hours SR 3.4.8.2----------NOTE---------
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated       7 days power are available to each required RHR pump.
SR 3.4.8.3       Verify RHIR loop locations susceptible to gas        31 days accumulation are sufficiently filled with water.
Prairie Island                                           Unit 1 - Amendment No. 4-58 Units 1 and 2                              3.4.8-3       Unit 2 - Amendment No. 4-49

ECCS   -  Operating 3.5.2 SURVEILLANCE REQUIREMENTS SURVEILLANCE                                  FREQUENCY SR 3.5.2.1      Verify the following valves are in the listed position. 12 hours Westing-Unit 1        house Valve         Valve Number        Number      Position                  Function 32070         8801A       OPEN          SI Injection to RCS Cold Leg A 32068         8801B       OPEN          SI Injection to RCS Cold Leg B 32073         8806A       OPEN         SI Cold Leg Injection Line 32206         881 6A      CLOSED        SI Pump Suction from RIIR 32207         881 6B      CLOSED        SI Pump Suction from RHR Westing-Unit 2        house Valve         Valve Number       Number       Position                  Function 32173         8801A       OPEN         SI  Injection to RCS Cold Leg A 32171         8801B       OPEN         SI  Injection to RCS Cold Leg B 32176         8806A       OPEN         SI  Cold Leg Injection Line 32208         881 6A      CLOSED       SI  Pump Suction from RIIR 32209         881 6B      CLOSED       SI  Pump Suction from RHR SR 3.5.2.2                                    -~~~NOTE--------           31 days Not required to be met for system vent flow paths opened under administrative control.
Verify each ECCS manual, power operated, and automatic valve in the flow path that is not locked, sealed, or otherwise secured in position, is in the correct position.
Prairie Island                                         Unit 1 - Amendment No. 4-58 41-82 Units 1 and 2                              3.5.2-2     Unit 2 - Amendment No. -1491-72

ECCS    - Operating 3.5.2 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE                                 FREQUENCY SR 3.5.2.3    Verify power to the valve operator has been removed     31 days for each valve listed in SR 3.5.2.1.
SR 3.5.2.4    Verify ECCS accessible locations susceptible to gas     31 days accumulation are sufficiently filled with water.
SR 3.5.2.5    Verify ECCS inaccessible locations susceptible to gas   Prior to entering accumulation are sufficiently filled with water.        MODE 3 after exiting shutdown cooling SR 3.5.2.6    Verify each ECCS pump's developed head at the test      In accordance flow point is greater than or equal to the required     with the Inservice developed head.                                         Testing Program SR 3.5.2.7    Verify~each ECCS automatic valve in the flow path       24 months that is not locked, sealed, or otherwise secured in position, actuates to the correct position on an actual or simulated actuation signal.
Prairie Island                                       Unit 1 - Amendment No. 4-5% 4-1-S Units 1 and 2                              3.5.2-3   Unit 2 -Amendment No. 4-49 4-72

ECCS      - Operating 3.5.2 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE                                 FREQUENCY SR 3.5.2.8      Verify each ECCS pump starts automatically on an        24 months actual or simulated actuation signal.
SR 3.5.2.9      Verify each ECCS throttle valve listed below is in the  24 months correct position.                                                               I Unit 1 Valve Number                 Unit 2 Valve Number SI-15-6                              2SI-15-6 SI-15-7                              2SI-15-7 SI- 15-8                             2SI- 15-8 SI-15-9                              2SI-15-9 SR 3.5.2.1i0 Verify, by visual inspection, each ECCS train              24 months containment sump suction inlet is not restricted by debris and the suction inlet strainers show no evidence of structural distress or abnormal corrosion.
Prairie Island                                         Unit 1 - Amendment No. 5-s 4-82 Units 1 and 2                               3.5.2-4    Unit 2 -Amendment No. 4-4-9 1-72

ECCS   -   Shutdown 3.5.3 ACTIONS (continued)
CONDITION                    REQUIRED ACTION                COMPLETION TIME C. Required Action and        C. 1   Be in MODE 5.               24 hours associated Completion Time of Condition B not met.
SURVEILLANCE REQUIREMENTS SURVEILLANCE                                 FREQUENCY SR 3.5.3.1     The following SRs are applicable for all equipment    In accordance required to be OPERABLE:                              with applicable SRs SR 3.5.2.1                  SR 3.5.2.6 SR 3.5.2.3                  SR 3.5.2.9 SR 3.5.2.4                  SR 3.5.2.10 SR 3.5.2.5 Prairie Island                                      Unit 1 - Amendment No. -4~1--847 Units 1 and 2                            3.5.3-2    Unit 2 -Amendment No.1-4914

Containment Spray and Cooling Systems 3.6.5 SURVEILLANCE REQUIREMENTS SURVEILLANCE                                  FREQUENCY SR 3.6.5.1          ---------        NOTE--------
Not required to be met for system vent flow paths opened under administrative control.
Verify each containment spray manual, power 31 days operated, and automatic valve in the flow path that is not locked, sealed, or otherwise secured in position is in the correct position.
SR 3.6.5.2    Operate each containment fan coil unit on low motor      31 days speed for > 15 minutes.
SR 3.6.5.3    Verify containment spray locations susceptible to gas    31 days accumulation are sufficiently filled with water.
SR 3.6.5.4    Verify cooling water flow rate to each containment       24 months fan coil unit is&#x17d;>900 gpm.
SR 3.6.5.5    Verify each containment spray pump's developed           In accordance head at the flow test point is greater than or equal to  with the the required developed head.                             Inservice Testing Program Prairie Island                                        Unit 1 - Amendment No. 4-5 -t-7-3 Units 1 and 2                              3.6.5-3    Unit 2 - Amendment No. 4149 6

Containment Spray and Cooling Systems 3.6.5 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE                                    FREQUENCY SR 3.6.5.6 Verify each automatic containment spray valve in the        24 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 3.6.5.7    Verify each containment spray pump starts                24 months automatically on an actual or simulated actuation signal.
SR 3.6.5.8    Verify each containment cooling train starts             24 months automatically on an actual or simulated actuation signal.
SR 3.6.5.9    Verify each spray nozzle is unobstructed.                Following maintenance which could result in nozzle blockage Prairie Island                                       Unit 1 - Amendment No. 4-5-s 4-9 Units 1 and 2                              3.6.5-4   Unit 2 - Amendment No.4-494--7-9

RHIR and Coolant Circulation-High Water Level 3.9.5 SURVEILLANCE REQUIREMENTS SURVEILLANCE                                  FREQUENCY SR 3.9.5.1    Verify one RHTR loop is in operation.                  12 hours SR 3.9.5.2    Verify required RJIR loop locations susceptible to     31 days gas accumulation are sufficiently filled with water.
Prairie Island                                          Unit 1 - Amendment No. 58 Units 1 and 2                            3.9.5-3        Unit 2 - Amendment No. 4-49

RHR and Coolant Circulation-Low Water Level 3.9.6 ACTIONS CO~NDITION                     REQUIRED ACTION                 COMPLETION TIME B. (continued)                    B.5.1 Close each penetration        4 hours providing direct access from the containment atmosphere to the outside atmosphere with a manual or automatic isolation valve, or blind flange.
OR B.5.2 Verify each penetration is    4 hours capable of being closed by an OPERABLE Containment Ventilation Isolation System.
SURVEILLANCE REQUIREMENTS______
SURVEILLANCE                                 FREQUENCY SR 3.9.6.1    Verify one RHR toop is in operation.                    12 hours SR 3.9.6.2    Verify correct breaker alignment and indicated power    7 days available to the required RIHR pump that is not in operation.
SR 3.9.6.3     Verify RHR loop locations susceptible to gas           31 days accumulation are sufficiently filled with water.
Prairie Island                                           Unit 1 - Amendment No. 45-g Units 1 and 2                              3.9.6-3       Unit 2 - Amendment No. 4149

ATTACHMENT 4 Technical Specification Bases (Markup)
B 3.4.6-3                     B 3.5.2-14 B 3.4.6-6                     B 3.5.3-2 B 3.4.6-7                     B 3.6.5-6 B 3.4.6-8                     B 3.6.5-11 B 3.4.7-4                    B 3.6.5-12 B 3.4.7-7                    B 3.6.5-13 B 3.4.7-8                    B 3.6.5-14 B 3.4.8-2                    B 3.6.5-15 B 3.4.8-4                     B 3.9.5-2 B 3.4.8-5                     B 3.9.5-5 B 3.4.8-6                     B 3.9.5-6 B 3.5.2-6                     B 3.9.5-7 B 3.5.2-10                    B 3.9.6-2 B 3.5.2-11                    B 3.9.6-6 B 3.5.2-12                    B 3.9.6-7 B 3.5.2-13 31 pages follow

RCS Loops - MODE 4 B 3.4.6 BASES LCO             b. Core outlet temperature is maintained at least 10&deg;F below (continued)        saturation temperature, so that no vapor bubble may form and possibly cause a natural circulation flow obstruction.
Note 2 requires a steam or gas bubble in the pressurizer or that the secondary side water temperature of each SG be _<50F above each of the RCS cold leg temperatures before the start of an RCP with any RCS cold leg temperature < the OPPS enable temperature specified in the PTLR. A steam or gas bubble ensures that the pressurizer will accommodate the swell resulting from an RCP start. Either of these restraints prevents a low temperature overpressure event due to a thermal transient when an RCP is started.
An OPERABLE RCS loop comprises an OPERABLE RCP and an OPERABLE SG which is capable of removing decay heat as specified in SR 3.4.6.2.
Similarly for the RHJR System, an OPERABLE RHR loop comprises an OPERABLE RHR pump capable of providing forced flow to an OPERABLE RHIR heat exchanger. RCPs and RHR pumps are OPERABLE if they are capable of being powered and are able to provide forced flow if required. Management of *,as voids is imtoortant to RHR System OPERABIIATY.
APPLICABILITY  In MODE 4, this LCO ensures forced circulation of the reactor coolant to remove decay heat from the core and to provide proper boron mixing.
Operation in other MODES is covered by:
LCO 3.4.4,   "RCS Loops - MODES 1 and 2";
LCO 3.4.5,   "RCS Loops - MODE 3";
LCO 3.4.7,   "RCS Loops - MODE 5, Loops Filled";
LCO 3.4.8,   "RCS Loops - MODE 5, Loops Not Filled";
LCO 3.9.5,   "Residual Heat Removal (RHR) and Coolant Circulation - High Water Level" (MODE 6); and Prairie Island                                    Unt1- Revyision` ....................
Units 1 and 2                       B 3.4.6-3 Unit2 - Revision,...endm.ent No. 49

RCS Loops - MODE 4 B 3.4.6 BASES SURVEILLANCE    SR 3.4.6.2 REQUIREMENTS (continued)    SR 3.4.6.2 requires verification that the required SG has the capability to remove decay heat. The ability to remove decay heat requires the ability to pressurize and control pressure in the RCS, sufficient secondary side water level in the SG relied on for decay heat removal, and an available supply of feedwater (Ref. 2). The ability of the SG to provide an adequate heat sink for decay heat removal further ensures that the SG tubes remain covered. The 12 hour Frequency is considered adequate in view of the other indications available in the control room to alert the operator to a loss of capability of the SG to remove decay heat.
SR 3.4.6.3 Verification that each required pump is OPERABLE ensures that an additional RCS or RHTR pump can be placed in operation, if needed, to maintain decay heat removal and reactor coolant circulation.
Verification is performed by verifying proper breaker alignment and power available to each required pump. Alternatively, verification that a pump is in operation also verifies proper breaker alignment and power availability. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a pump is not in operation.
SRi34.6.
RHR System pitting and components have the potential to develop voids and pockets of entrained gases. Preventing and managing, aas intrusion and accumulation is necessary for proper operation of the Prairie Island                                 Unitl1-       * * ^*,Aendmn.-N A          I1-Units 1 and 2                       B 3.4.6-6 Unit 2-_yj,,i*m,*       dine.it-,, e-449 l

RCS Loops - MODE 4 B 3.4.6 BASES qT TI*S7"I* T A*tl-'q*
QTTD.
LP.J  V&#xa5;JL    IIT AMC BASES    .LL..U    1 .*$. k*%   ..j*-1 11 "T 1,%ALI J 1.l.*. t required RHR loon(s) and may also orevent water hammer. Dump cavitation, and pumping of noncondensible *,as into the reactor Selection of RHR System locations susceptible to *as accumulation is based onl a review of system design information, including, pi~ing, and instrumentation drawings, isometric drawings. olan and elevation drawings, and calculations. The design review is su~olemented by system waLk downs to validate the system high points and to confirm the location and orientation of imtortant comoonents that can become sources of *.as or could otherwise cause gas to be traooed or difficult to remove during system maintenance or restoration. Susceptible locations denend on olant and system configuration, such as stand-by versus ooerating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water. Acceotance criteria are established for the volume of accumulated gas at susceptible locations. If accumulated *as is discovered that exceeds the acceotance criteria for the susceptible location (or the volume of accumulated *as at one or more susceptible locations exceeds an acceotance criteria for gas volume at the suction or discharge of a oump). the Surveillance is not met.
If it is determined by subsecuent evaluation that the RHIR System is not rendered inoperable by the accumulated gas (i.e.. the system is sufficiently filled with water). the Surveillance may be declared met.
Accumulated gas should be eliminated or brought within the acceptance criteria limits.
RHR System locations susceptible to gas accumulation are monitored and. if *as is found. the *as volume is comoared to the acceptance criteria for the location. Susceptible locations in the same system flow path which are subject to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set Prairie Island                                                  Unit 1 - u,.,j*;,,-Amend.m,.,nt No. 158o Units 1 and 2                                         B 3.4.6-7 Unt2_o*,            *.,**.--     t.!t

RCS Loops - MODE 4 B 3.4.6 BASES qT TDX/-I*'TT T ANTI*'I*'
~t.J.,Jk%.
BASES  TO~           A~C V _3.LALL4..--1 *l.' "  LJI. .J .-. '.) % .- U'..1%JiIL~t11L4.'.. I of susceptible locations. Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions. the plant config~uration. or nersonnel safety. For these locations alternative methods (e.g.. operating parameters. remote monitoring) may be used to monitor the suscetntible location.
Monitoring is not required for suscetptible locations where the maximum notential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.
The SR can be met by virtue of having an RHR subsystem inservice in accordance with operating procedures.
This SR is modified by a Note that states the SR is not required to be nerformed until 12 hours after entering MODE 4. In a rapid shutdown, there may be insufficient time to verify all susceptible locations nrior to entering MODE 4.
The 31 day Frequencv takes into consideration the gradual nature of gas accumulation in the RHR System piping and the procedural controls governing' system operation, REFERENCES                        1. License Amendment Request Dated November 19, 1999.
(Approved by License Amendment 152/143, July 14, 2000.)
: 2. NRC Information Notice 95-35, "Degraded Ability of Steam Generator to Remove Decay Heat by Natural Circulation."
Prairie Island                                                                  Unit 1 - ,&#xa2;*,.A   *   *+   r.1d Units 1 and 2                                                          B3.4.6-8 Unit2-    i~
                                                                                          *
* Amendment.+Ne-   ,,9

RCS Loops - MODE 5, Loops Filled B 3.4.7 BASES LCO            Note 4 provides for an orderly transition from MODE 5 to MODE 4 (continued)   during a planned heatup by permitting removal of RHiR loops from operation when at least one RCS loop is in operation. This Note provides for the transition to MODE 4 where an RCS loop is permitted to be in operation and replaces the RCS circulation function provided by the RHR loops.
RHR pumps are OPERABLE if they are capable of being powered and are able to provide flow if required. A SG is capable of removing decay heat via natural circulation when: 1) there is the ability to pressurize and control pressure in the RCS; 2) there is sufficient secondary side water level in the SG relied on for decay heat removal; and 3) there is an available supply of feedwater (Ref.
1). An OPERABLE SG can perform as a heat sink via natural circulation when it has the capability to remove decay heat as specified in SR 3.4.7.2. Management of *,as voids is important to RHR System OPERABILITY.
APPLICABILITY  In MODE 5 with RCS loops filled, this LCO requires forced circulation of the reactor coolant to remove decay heat from the core and to provide proper boron mixing. One loop of RHR provides sufficient circulation for these purposes. However, one additional RHIR loop is required to be OPERABLE, or a SG is capable of removing decay heat.
Operation in other MODES is covered by:
LCO   3.4.4, "RCS Loops-MODES 1 and 2";
LCO   3.4.5, "RCS Loops-MODE 3";
LCO   3.4.6, "RCS Loops-MODE 4";
LCO   3.4.8, "RCS Loops-MODE 5, Loops Not Filled";
LCO   3.9.5, "Residual Heat Removal (RHR) and Coolant Circulation-High Water Level" (MODE 6); and LCO 3.9.6, "Residual Heat Removal (RHR) and Coolant Circulation-Low Water Level" (MODE 6).
Prairie Island                              3474Unit 12-    *       *          *A Units 1 and 2                            B74Unt2Revlsgmlo
                                             ..                   n   dm......... No. 119.

RCS Loops - MODE 5, Loops Filled B 3.4.7 BASES SURVEILLANCE   SR 3.4.7.3 (continued)
REQUIREMENTS controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a pump is not in operation.
SR .47.
RHR System piping and comoonents have the potential to develop voids and nockets of entrained gases. Preventing and managing *as intrusion and accumulation is necessary, for oroner operation of the required RHR looo(s) and may also Prevent water hammer. oump cavitation. and pumping of noncondensible *as into the reactor vessel.
Selection of RHR System locations susceptible to *as accumulation is based on a review of system design information, including piping and instrumentation drawings, isometric drawings. olan and elevation drawings, and calculations. The design review is suoplemented by system walk downs to validate the system high Points and to confirm the location and orientation of important comoonents that can become sources of gas or could otherwise cause gas to be tranoed or difficult to remove during system maintenance or restoration. Susceptible locations depend on slant and system configuration, such as stand-by versus operating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water. Acceptance Criteria are established for the volume of accumulated gas at susceptible locations. If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceotance criteria for *,as volume at the suction or discharge of a pump), the Surveillance is not met.
If it is determined by subseauent evaluation that the RHR System is Prairie Island                                  Unit 1 - uy,;*,j, me.ndment
                                                                  ^           Nc. 158:
Units 1 and 2                       B 3.4.7-7 Unit 2          * * ^mendment N. 11*9

RCS Loops - MODE 5, Loops Filled B 3.4.7 SURVEILLANCE   SR 3.4.7.4 (continued) not rendered inoperable by the accumulated *as (i.e.. the system is sufficiently filled with water), the Surveillance may be declared met.
Accumulated *as should be eliminated or brou.ght within the acceptance criteria limits.
RHIR System locations susceptible to *as accumulation are monitored and. if gas is found, the *as volume is compared to the acceotance criteria for the location. Susceotible locations in the same system flow oath which are subject to the same *as intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations. Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions. the plant configuration, or personnel safety. For these locations alternative methods (e.g.. operating parameters, remote monitoring) may be used to monitor the suscentible location.
Monitoring is not required for susceptible locations where the maximum notential accumulated *as void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the Susceptible locations and trending, of the results should be sufficient to assure System OPERABILITY during the Surveillance interval.
The SR can be met by virtue of having an RHR subsystem inservice in accordance with operating nrocedures.
The 31 day Freauency takes into consideration the gradual nature of gas accumulation in the RHR System tpiping and theporocedural controls *,ovemnin* system operation.
REFERENCES     1. NRC Information Notice 95-3 5, "Degraded Ability of Steam Generators to Remove Decay Heat by Natural Circulation".
: 2. License Amendment Request Dated November 19, 1999.
(Approved by License Amendment 152/143, July 14, 2000.)
Prairie Island                                  Unit 1-       *
* e.., fflen*-Ne 48 Units 1 and 2                        B 3.4.7-8 Unit 2 - R__evsi     nL.edmen't No. 11!9

RCS Loops - MODE 5, Loops Not Filled B 3.4.8 BASES LCO            Note 1 permits all RHR pumps to be de-energized < 1 hour per 8 (continued)   hour period. The circumstances for stopping both RHR pumps are to be limited to situations when the outage time is short and core outlet temperature is maintained > 10&deg;F below saturation temperature. The Note prohibits boron dilution with coolant at boron concentrations less than required to assure SDM is maintained or draining operations when RHR forced flow is stopped.
Note 2 allows one RHR loop to be inoperable for a period of
_<2 hours, provided that the other loop is OPERABLE and in operation. This permits periodic surveillance tests to be performed on the inoperable loop during the only time when these tests are safe and possible.
An OPERABLE RHR loop is comprised of an OPERABLE RHR pump capable of providing forced flow to an OPERABLE RHR heat exchanger. RHR pumps are OPERABLE if they are capable of being powered and are able to provide flow if required.
Management of *as voids is imoortant to RI-R System OPERABILITY.
APPLICABILITY  In MODE 5 with loops not filled, this LCO requires core heat removal and coolant circulation by the RHR System.
Operation in other MODES is covered by:
LCO    3.4.4, "RCS Loops-MODES 1 and 2";
LCO    3.4.5, "RCS Loops-MODE 3";
LCO    3.4.6, "RCS Loops-MODE 4";
LCO    3.4.7, "RCS Loops-MODE 5, Loops Filled";
LCO    3.9.5, "Residual Heat Removal (RHR) and Coolant Circulation-High Water Level" (MODE 6); and LCO 3.9.6, "Residual Heat Removal (RHR) and Coolant Circulation-Low Water Level" (MODE 6).
Prairie Island                                 Unit 1       **       ,,,   . T Units 1 and 2                       B 3.4.8-2 Unit 2 -Revlsl~nme.............-...

RCS Loops - MODE 5, Loops Not Filled B 3.4.8 BASES (continued)
SURVEIlLANCE       SR 3.4.8.1 REQUIREMENTS This SR requires verification every 12 hours that the required loop is in operation. Verification may include flow rate, temperature, or pump status monitoring, which helps ensure that forced flow is providing heat removal. The Frequency of 12 hours is sufficient considering other indications and alarms available to the operator in the control room to monitor RHR loop performance.
SR 3.4.8.2 Verification that each required pump is OPERABLE ensures that an additional pump can be placed in operation, if needed, to maintain decay heat removal and reactor coolant circulation. Verification is performed by verifying proper breaker alignment and power available to each required pump. Alternatively, verification that a pump is in operation also verifies proper breaker alignment and power availability. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a pump is not in operation.
RUR System piping and comnonents have the potential to develop voids and nockets of entrained gases. Preventing and managing gas intrusion and accumulation is necessary, for proper operation of the RHIR loops and may also prevent water hammer. oumn cavitation.
and pumnping, of noncondensible gas into the reactor vessel.
Selection of RHR System locations susceptible to *,as accumulation is based on a review of system design information, including tpiting and instrumentation drawings, isometric drawings. tnlan and elevation drawings, and calculations. The design review is Prairie Island                                   Unit 1 - B,,;yi,-k^ .. mend..i eT..1-5 Units 1 and 2                         B 3.4.8-4 Unit 2-     i.,,n,,,,,me,,-NT-1,4.9

RCS Loops - MODE 5, Loops Not Filled B 3.4.8 BASBS SI JR!V~ .1.ANCP7: S*R     _4 Ri (continiie~d' supplemented by System walk downs to validate the system high points and to confirm the location and orientation of imoortant comnonents that can become sources of gas or could otherwise cause gas to be tratwed or difficult to remove during system maintenance or restoration. Susceptible locations depend on nlant and system configuration, such as stand-by versus operating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water. Accertance criteria are established for the volume of accumulated gas at susceptible locations. If accumulated gas is discovered that exceeds the acceotance criteria for the susceptible location (or the volume of accumulated *,as at one or more susceptible locations exceeds an accentance criteria for gas volume at the suction or discharge ofas numnVb the Suirveillance is not met.
If it is determined by subseauent evaluation that the RHR System is not rendered inoperable by the accumulated gas (i.e.. the System is sufficiently filled with water). the Surveillance may be declared met. H Accumulated gas should be eliminated or brought within the acceptance criteria limits.
RHR System locations susceptible to gas accumulation are monitored and. if gas is found. the *as volume is compared to the accentance criteria for the location. Susceptible locations in the same system flow nath which are subiect to the same gas intrusion mechanisms may be verified by monitoring, a representative sub-set of susceptible locations. Monitoring may not be practical for locations that are inaccessible due to radiological or envirotnmental conditions. the tnlant configuration, or personnel safety. For these locations alternative methods (e.g.. operating parameters. remote monitoring) may he used to monitor the suscentible location Prairie Island                                      Unit 1 - Reviiok~     nn ie........Neo.1 58 Units 1 and 2                             B 3.4.8-5 Unit 2- *,,,j;,, ^e-"n"dmcn *t.o. 119t

RCS Loops - MODE 5, Loops Not Filled B 3.4.8 BASES SURVEILLANCE RFO.UIRIZVlENTS SR 3.4.8.3 (continued)
Monitoring is not required for susceptible locations where the maximum notential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITy.
The accuracy of the method used for monitoring the suscentible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.
This SR can be met by virtue of having an RHR subsystem inservice in accordance with operating procedures.
The 31 day Freauency takes into consideration the gradual nature of gas accumulation in the RHIR System piping and the orocedural controls governing system operation.
REFERENCES      None.
Prairie Island Units 1 and 2                       B 3.4.8-6 Unit 2 - ReviiorAmendmer' Nc. 119

ECCS-Operating B 3.5.2 BASES LCO            In MODES 1, 2, and 3, an ECCS train consists of an SI subsystem (continued)   and an RHR subsystem. Each train includes the piping, instruments, and controls to ensure an OPERABLE flow path capable of taking suction from the RWST upon an SI signal and RHIR capable of being transferred to take suction from containment Sump B.
During an event requiring ECCS actuation, a flow path is required to provide an abundant supply of water from the RWST to the RCS via the ECCS pumps and their respective supply headers to each of the two cold leg injection nozzles and the reactor vessel upper plenum.
In the long term, this flow path may be switched to take its supply from the containment sump and to supply its flow to the RCS cold legs or directly into the reactor vessel upper plenum. Management of as voids is imorattECSO RALTY The flow path for each train must maintain its designed independence to ensure that no single failure can disable both ECCS trains.
Manual valves that could, if improperly positioned, reduce injection flow below that assumed for accident analyses, are blocked and tagged or locked in the proper position for injection. Changes in valve position must be under direct administrative control.
A block is a device that can be unclipped or unsnapped to allow a status change of the component to which it is applied. A lock is a device that must be unlocked, destroyed or mechanically removed (such as a cap or blank) to allow a status change of the component to which it is applied.
As indicated in the LCO Note, the SI flow paths may be isolated for 2 hours in MODE 3, under controlled conditions, to perform pressure isolation valve testing per SR 3.4.15.1. The flow path is readily restorable from the control room.
Prairie Island                                  Unit 1 - Revisioi m... d....... Nov. 158 Units 1 and 2                       B 3.5.2-6 Unit 2         " "isi
                                                                 'Acnden N. 119

ECCS-Operating B 3.5.2 BASES SURVEII1ANCE    SR 3.5.2.2 REQUIREMENTS (continued)   Verifying the correct alignment for manual, power operated, and automatic valves in the ECCS flow paths provides assurance that the proper flow paths will exist for ECCS operation. This SR does not apply to valves that are locked, sealed, or otherwise secured in position, since these were verified to be in the correct position prior to locking, sealing, or securing (A seal is a device that must be destroyed to allow a status change of the component to which it is applied). A valve that receives an actuation signal is allowed to be in a nonaccident position provided the valve will automatically reposition within the proper stroke time. This Surveillance does not require any testing or valve manipulation. Rather, it involves verification that those valves capable of being mispositioned are in the correct position. The 31 day Frequency is appropriate because the valves are operated under administrative control, and an improper valve position would only affect a single train. This Frequency has been shown to be acceptable through operating experience.
The Surveillance is modified by a Note which exempts system venlt flow paths opened under administrative control. The administrative control should be oroceduralized and include stationing, a dedicated individual at the system vent flow oath who is in continuous communication with the onerators in the control room. This individual will have a method to rapidly close the system vent flow SR 3.5.2.3 Verification every 31 days that the motor control center supply breakers are physically locked in the off position for each valve specified in SR 3.5.2.1 ensures that an active failure could not result in an undetected misposition of a valve. Since power is removed under administrative control and valve position is verified every 12 hours, the 31 day Frequency will provide adequate assurance that power is removed.
Prairie Island                                 Unit 1 - Revisioru ............ No. 158,,
Units 1 and 2                      B 3.5.2-10 Unit 2 - Re,,sio-,' ^m..dme.n- No. 11*9

ECCS-Operating B 3.5.2 BASES SURVEILLANCE    SR 3.5.2.4 and SRJ35.2.5 REQUIREMENTS (continued)   ECCS opinng and comoonents have the potential to develop voids and nockets of entrained gases. Preventing and mana~in* *as inruio adaccumulation is necessary for uroner ooeration of the          [
ECCS and may also orevent water hammer. tnumo cavitation, and Pumpin2 of noncondensible *as into the reactor vessel.
Selection of ECCS locations susceotible to *as accumulation is based on a review of system design information, including oining, and instrumentation drawings, isometric drawings. nlan and elevation drawings, and calculations. The design review is sunolemented by system walk downs to validate the system high points and to confirm the location and orientation of important comoonents that can become sources of *,as or could otherwise cause gas to be traoped or difficult to remove during system maintenance or restoration. Susceptible locations denend on olant and system configuration, such as stand-by versus operating, conditions.
The ECCS is OPERABLE when it is sufficiently filled with water.
Acceptance criteria are established for the volume of accumulated
               *,as at susceptible locations. If accumulated *as is discovered that exceeds the accentance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an accentance criteria for gas volume at the suction or discharge of a oumon, the Surveillance is not met. If it is determined by subseauent evaluation that the ECCS is not rendered inoperable by the accumulated gas (i.e.. the system is sufficiently filled with water). the Surveillance may be declared met. Accumulated gas should be eliminated or brought within the accentance criteria limits.
ECCS locations susceptible to gas accumulation are monitored and.
if *as is found. the gas volume is comnared to the accentance criteria for the location. Susceptible locations in the same system flow nath which are subject to the same gas intrusion mechanisms may be verified by monitoring a repgresentative sub-set of susceptible locations. Monitoring may not be practical for locations that are Prairie Island                                  Unit 1 - E,=,,;;,-,,-A..end.*..e.I x-Ne *1-Units 1 and 2                       B 3.5.2-11 Unit 2-_Bi,;j;,nA.m.nd ..,.i.-NeAA..

ECCS-Operating B 3.5.2 BASES SURVElACE       SR 3.5.2.4 and SR 3.5.2.5 (continued) inaccessible due tO radiological or environmental conditions, the plant configuration, or nersonnel safety. For these locatfions alternative methods (e.g.. operating narameters. remote monitoring,)
may be used to monitor the susceptible location. Monitoring is not required for susceptible locations where the maximum potential accumulated *,as void volume has been evaluated and determined to not challenge system OPERABILITY. The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITy during the Surveillance interval.
Both the 31 day Freauencv for accessible locations and event-based Freauencv for inaccessible locations take into consideration the gradual nature of gas accumulation in the ECCS piping,and the orocedural controls governing, system operation. Additionally, the Freauencv for inaccessible locations allows this Surveillance to be performed under olant conditions that enable direct monitoring,.
The as-found conditions of the inaccessible locations are monitored at the earliest possible shutdown condition according to the Gas Accumulation Management program. In a rapid shutdown, there may be insufficient time to verify the as-found condition of the inaccessible locations orior to RCS deoressurization.
SR3.52.6 Periodic surveillance testing of ECCS pumps to detect gross degradation caused by impeller structural damage or other hydraulic component problems is required by the ASME Code. This type of testing may be accomplished by measuring the pump developed head at a single point of the pump characteristic curve. This verifies both that the measured performance is within an acceptable tolerance of the original pump baseline performance and that the performance at the test flow is within the performance assumed in the plant safety analysis. SRs are specified in the Inservice Testing Program of the Prairie Island                                  Unit 1 - RevisionAm-cndment No. 158, Units 1 and 2                       B 3.5.2-12 Unit 2 - Revisiormendment-Ne.!A49

ECCS-Operating B 3.5.2 BASES SURVEILLANCE   SR 3.5.2.6 (continued)
REQUIREMENTS ASME Code. The ASME Code provides the activities and Frequencies necessary to satisfy the requirements.
SR 3.5.2.J5* and SR 3.5.2.86 These Surveillances demonstrate that each automatic ECCS valve actuates to the required position on an actual or simulated SI signal and that each ECCS pump starts on receipt of an actual or simulated SI signal. This test is met when control board indications and visual observations indicate that all components have received the safety injection signal in the proper sequence and timing, the appropriate pump breakers have opened and closed, and all automatic valves have been placed in the proper position required to establish a safety injection flow path to the reactor coolant system.
This Surveillance is not required for valves that are locked, sealed, or otherwise secured in the required position under administrative controls. The 24 month Frequency is based on the need to perform these Surveillances under the conditions that apply during a plant outage and the potential for unplanned plant transients if the Surveillances were performed with the reactor at power. The 24 month Frequency is also acceptable based on consideration of the design reliability (and confirming operating experience) of the equipment. The actuation logic is tested as part of Engineered Safety Feature (ESF) Actuation System testing, and equipment performance is monitored as part of the Inservice Testing Program.
SR 3.5.2.9=7 Surveillance Requirements on ECCS throttle valves provide assurance that proper ECCS flows are maintained in the event of a LOCA. Proper flow resistance and pressure drop in the piping system to each injection point in the SI System is necessary to: 1) prevent total pump flow from exceeding runout conditions when the system is in its minimum resistance configuration; Prairie Island                                 Unit 1 - Ry,,i*,,, ^ . dmn.N-.,*.
r.1 4 Units 1 and 2                       B 3.5.2-13 Unit 2 -R    " " ^ *mn*meI4+NeA9

ECCS-Operating B 3.5.2 BASES SURVEILLANCE   SR 3.5.2. 9i7 (continued)
REQUIREMENTS
: 2) provide the proper flow split between injection points in accordance with the assumptions used in the ECCS LOCA analyses; and 3) provide an acceptable level of total ECCS flow to all injection points equal to or above that assumed in the ECCS LOCA analyses.
The 24 month Frequency is based on the same reasons as those stated in SR 3.5.2.75 and SR 3...@
SR 3.5.2.R0 Periodic inspections of the containment sump suction inlet to the RHR System ensure that it is unrestricted and stays in proper operating condition. The 24 month Frequency allows this Surveillance to be performed under the conditions that apply during a plant outage. This Frequency has been found to be sufficient to detect abnormal degradation and is confirmed by operating experience.
BASES REFERENCES     1. AEC "General Design Criteria for Nuclear Power Plant Construction Permits," Criterion 44, issued for comment July 10, 1967, as referenced in USAR Section 1.2.
: 2. USAR, Section 6.2.
: 3. USAR, Section 14.
: 4. NRC Memorandum to V. Stello, Jr., from R.L. Baer, "Recommended Interim Revisions to LCOs for ECCS Components," December 1, 1975.
: 5. IE Information Notice No. 87-01.
Prairie Island                                Unit 1 - Bxi*,i,  ^.me...d-ie ,e-1-5o Units 1 and 2                       B3.5.2-14 Unt**             ^-..* * +x-1t

ECCS   - Shutdown B 3.5.3 BASES (continued)
LCO               In MODE 4, one of the two independent (and redundant) ECCS trains is required to be OPERABLE to ensure that sufficient ECCS flow is available to the core following a DBA.
In MODE 4, an ECCS train consists of an SI subsystem and an RHR subsystem. Each train includes the piping, instruments, and controls to ensure an OPERABLE flow path capable of taking suction from the RWST and transferring suction to the containment sump.
During an event requiring ECCS actuation, a flow path is required to provide an abundant supply of water from the RWST to the RCS via the SI subsystem capable (through manual actions) of injecting into each of the cold leg inj ection nozzles and reactor vessel upper plenum nozzles. In the long term, a flow path is required to provide recirculation flow via the RHR subsystem from the containment sump into each of the reactor vessel upper plenum nozzles.
Mana*,ement of *as voids is imtnortant to ECCS OPERABILITY.
This LCO is modified by two Notes. Note 1 allows an RHR train to be considered OPERABLE during alignment and operation for decay heat removal, if capable of being manually realigned (remote or local) to the ECCS mode of operation and not otherwise inoperable. This allows operation in the RHIR mode during MODE 4.
Note 2 allows an SI train to be considered OPERABLE when the pump is capable of being manually started for ECCS injection from the control room.
APPLICABILITY     In MODES 1, 2, and 3, the OPERABILITY requirements for ECCS are covered by LCO 3.5.2.
In MODE 4 with RCS temperature below 3500 F and both RCS cold leg temperatures above the SI pump disable temperature specified in the PTLR, one OPERABLE ECCS train is acceptable without single failure consideration, on the basis of the stable reactivity of the reactor and the limited core cooling requirements Prairie Island                                                      Unit 1 -Revision 4-Units 1 and 2                          B 3.5.3-2                    Unit 2 - Revision 40-93

Containment Spray and Cooling Systems B 3.6.5 BASES APPLICABLE     Containment Cooling System air and safety grade cooling water SAFElY         flow. The Containment Cooling System total response time ANALYSES       incorporates delays to account for load restoration and motor (continued)   windup (Ref. 3).
The Containment Spray System and the Containment Cooling System satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).
LCO            During a LOCA or SLB, a minimum of one containment cooling train and one containment spray train are required to maintain the containment peak pressure and temperature below the design limits (Ref. 4). Additionally, one containment spray train is also required to supply sufficient sodium hydroxide to containment to ensure that the pH of the sump liquid is alkaline. To ensure that 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.
Each Containment Spray System 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 a containment spray actuation signal. Manual valves in this system that could, if improperly positioned, reduce the spray flow below that assumed for accident analysis, are blocked and tagged in the proper position and maintained under administrative control.
Containment Spray System motor operated valves, MV-32096 and MV-32097 (Unit 1), and MV-32108 and MV-32109 (Unit 2) are closed with the motor control center supply breakers in the off position. Mana*,ement of *,as voids is important to Containment Sorav System OPERABILITY.
Each Containment Cooling System typically includes cooling coils, dampers, fans, and controls to ensure an OPERABLE flow path.
With one CL strainer isolated, the containment cooling train on the associated CL header is OPERABLE at CL supply temperatures Prairie Island                                                   Unit 1 - Revision 2-20 Units 1 and 2                      B 3.6.5-6                     Unit 2 - Revision 2-2-0

Containment Spray and Cooling Systems B 3.6.5 BASES SURVELACE       SR 3.6.5.12 (cotiue)
REQUIREMENTS (c..nt.nue.) The Surveillance is modified by a Note which exemots system vent flow oaths ooened under administrative control. The administrative control should be oroceduralized and include stationing, a dedicated individual at the system vent flow oath who is in continuous communication with the onerators in the control room. This individual will have a method to raoidlv close the system vent flow Operating each containment fan coil unit on low motor speed for
               > 15 minutes ensures that all trains are OPERABLE and that all associated controls are functioning properly.
Motor current is measured and compared to the nominal current expected for the test condition. It also ensures that blockage, fan or motor failure, or excessive vibration can be detected for corrective action. The 31 day Frequency was developed considering the known reliability of the fan coil unaits 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 3.6.5.3 Containment Sorav System oioing and com oonents have the potential to develon voids and nockets of entrained gases.
Preventing and managing gas intrusion and accumulation is necessary, for oroper ooeration of the containment soray trains and may also orevent water hammer and oumo cavitation.
Seeto of Containmen oavSstem loain sucoil to1 a accumulation is based on a review of system design information.
Prairie Island                                                     Unit 1 - Revision 4-9-5 Units 1 and 2                       B 3.6.5-11                     Unit 2 - Revision 4-9-5

Containment Spray and Cooling Systems B 3.6.5 BASES SURVEILLANCE   SR 3.6.5.3 (continued) including, piping, and instrumentation drawings, isometric drawings.
elan and elevation drawings, and calculations. The design review is sun~lemented by system walk downs to validate the system high points and to confirm the location and orientation of important comnonents that can become sources of *as or could otherwise cause aas to be tranoed or difficult to remove during, system maintenance or restoration, Susceptible locations depend on nlant and system configuration, such as stand-by versus otperating conditions.
The Containment Snrav System is OPERABLE when it is sufficiently filled with water. Accentance criteria are established for the volume of accumulated *as at susceptible locations. If accumulated *,as is discovered that exceeds the accentance criteria for the susceptible location (or the volume of accumulated *as at one or more susceptible locations exceeds an accentance criteria for gas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseauent evaluation that the Containment Sorav System is not rendered inoperable by the accumulated gas (i.e.. the system is sufficiently filled with water).
the Surveillance may be declared met. Accumulated *as should be eliminated or brought within the accentance criteria limits.
Containment Snray System locations susceptible to gas accumulation are monitored and. if gas is found, the *,as volume is compared to the acceptance criteria for the location. Susceptible locations in the same system flow path which are subject to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations. Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the nlant configuration, or nersonnel safety. For these locations alternative methods (e.g,.. operatin&#xa2; narameters, remote monitoring) may be used to monitor the susceptible location. Monitoring is not required for susceptible Prairie Island                                                   Unit 1 - Revision 4-9-5 Units 1 and 2                       B 3.6.5-12                   Unit 2 -Revision 4-9-5

Containment Spray and Cooling Systems B 3.6.5 SURVEILACE     SR 3.6.5.3 (continued) locations where the maximum potential accumulated *,as void volume has been evaluated and determined to not challenge systemr OPERABILITY. The accuracy of the method used for monitoring the susceptible locations and trending, of the results should be sufficient to assure system OPERABILITY during, the Surveillance The 31 day Freauencv takes into consideration the gradual nature of gas accumulation in the Containment Spray System pining and the procedural controls governing system operation.
Verifying that cooling water flow rate to each containment fan coil unit is > 900 gpm provides assurance that the design flow rate assumed in the safety analyses will be achieved (Ref. 4).
Terminal temperatures of each fan coil unit are also observed. This test includes verifying operation of all essential features including low motor speed, cooling water valves and normal ventilation system dampers. The 24 month Frequency is based on; the need to perform these Surveillances under the conditions that apply during a plant outage; the known reliability of the Cooling Water System; the two train redundancy available; and, the low probability of a significant degradation of flow occurring between Surveillances.
SR 3.6.5.54 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. Flow and differential pressure are normal tests of centrifugal pump performance required by the ASMiE Code (Ref. 6). Since the Prairie Island                                                   Unit 1 - Revision 9-5 Units 1 and 2                       B 3.6.5-13                   Unit 2 -Revision ---

Containment Spray and Cooling Systems B 3.6.5 BASES SURVEILLANCE    SR 3.6.5.54 (continued)
REQULREMENT containment spray pumps cannot be tested with flow through the spray headers, they are tested on recirculation flow. 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.
SR 3.6.5.65~and SR 3.6.5.76_
These SRs require verification that each automatic containment spray valve actuates to its correct position and that each containment spray pump starts upon receipt of an actual or simulated actuation of a containment High-High pressure signal. This Surveillance is not required for valves that are locked, sealed, or otherwise secured in the required position under administrative controls. To prevent inadvertent spray in containment, containment spray pump testing with a simulated actuation signal will be performed with the isolation valves in the spray supply lines at the containment and the spray additive tank isolation valves blocked closed. These tests will be considered satisfactory if visual observations indicate all components have operated satisfactorily. The 24 month Frequency is based on the need to perform these Surveillances under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillances were performed with the reactor at power. Operating experience has shown that these components usually pass the Surveillances when performed.
Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.
Prairie Island                                                   Unit 1 - Revision 4184 Units 1 and 2                      B 3.6.5-14                    Unit 2 - Revision 84

Containment Spray and Cooling Systems B 3.6.5 BASES SURVEILLANCE    SR 3.6.5.8:7 REQUIREMENrS (continued)   This SR requires verification that each containment cooling train actuates upon receipt of an actual or simulated safety injection signal. The 24 month Frequency is based on engineering judgment.
See SR 3.6.5.*-5 and SR 3.6.5.76, above, for further discussion of the basis for the 24 month Frequency.
SR 3.6.5.98g With the spray header drained, low pressure air or smoke can be blown through test connections. This SR ensures that each spray nozzle is unobstructed and provides assurance that spray coverage of the containment during an accident is not degraded. Due to the passive design of the nozzle, confirmation of operability following maintenance activities that can result in obstruction of spray is considered adequate to detect obstruction of the nozzles.
Confirmation that the spray nozzles are unobstructed may be obtained by such means as foreign materials exclusion (FME) controls during maintenance, a visual inspection of the affected portions of the system, or by an air or smoke test following maintenance involving opening portions of the system downstream of the containment isolation valves, or by draining and flushing the filled portions of the system inside containment, as appropriate.
Maintenance that could result in nozzle blockage is generally a result of a loss of FME control or a flow of borated water through a nozzle.
Should either of these events occur, an engineering evaluation will be performed to determine whether nozzle blockage is a possible result of the event.
If loss of FME control occurs, an inspection or flush of the affected portions of the system should be adequate to confirm that the spray nozzles are unobstructed since water flow would be required to transport any debris to the spray nozzles. An air flow or smoke test may be appropriate when borated water has inadvertently flowed through a nozzle.
Prairie Island                                                  Unit 1 - Revision 99 Units 1 and 2                       B 3.6.5-15                  Unit 2 -Revision 4-99

RHR and Coolant Circulation-High Water Level B 3.9.5 BASES (continued)
LCO               Only one RHR loop is required for decay heat removal in MODE 6, with the water level > 20 ft above the top of the reactor vessel flange. Only one RHR loop is required to be OPERABLE, because the volume of water above the reactor vessel flange provides backup decay heat removal capability.
At least one RHR loop must be OPERABLE and in operation to provide:
: a. Removal of decay heat;
: b. Mixing of borated coolant to minimize the possibility of criticality; and
: c. Indication of reactor coolant temperature.
An OPERABLE RHR loop includes a RHR pump, a heat exchanger, valves, piping, instruments, and controls to ensure an OPERABLE flow path and to determine the low end temperature. The flow path starts in one of the RCS hot legs and is returned to a RCS cold leg.
Management of *,as voids is imoortant to RI-R System OPEABILITY.
The LCO is modified by a Note that allows the required operating RHR loop to be removed from service for up to 1 hour per 8 hour period, provided no operations are permitted that would dilute the RCS boron concentration with coolant at boron concentrations less than required to meet the minimum boron concentration of LCO 3.9.1. Boron concentration reduction, with coolant at boron concentrations less than required to assure the RCS boron concentration is maintained, is prohibited because uniform concentration distribution cannot be ensured without forced circulation. This permits operations such as core mapping or alterations in the vicinity of the reactor vessel hot leg nozzles and RCS to RHR isolation valve testing. During this 1 hour period, decay heat is removed by natural convection to the large mass of water in the refueling cavity.
Prairie Island                                     Unit 1 - Ri,*,,,,n .f.ie.A..mei.. eA4&*
Units 1 and 2                           B 3.9.5-2 Unit 2 - RevisiorAmeiqdmezit-N.e.--49

RI-R and Coolant Circulation-High Water Level B 3.9.5 BASES ACTIONS         A.4. A.5, A.6.1, and A.6.2 (continued)
: b. One door in each air lock must be closed; and
: c. Each penetration providing direct access from the containment atmosphere to the outside atmosphere must be either closed by a manual or automatic isolation valve, blind flange, or equivalent, or verified to be capable of being closed by an OPERABLE Containment Ventilation Isolation System.
With the RHR loop requirements not met, the potential exists for the coolant to boil, clad to fail, and release radioactive gas to the containment atmosphere. Performing the actions described above ensures that all containment penetrations are either closed or can be closed so that the dose limits are not exceeded.
The Completion Time of 4 hours allows adequate time to fulfill the Required Actions and not exceed dose limits.
SURVEILLANCE   SR 3.9.5.1 REQtUIEMENIS This Surveillance demonstrates that the RHR loop is in operation in order to provide sufficient decay heat removal capability and to prevent thermal and boron stratification in the core. The Frequency of 12 hours is sufficient, considering the flow, temperature, pump control, and alarm indications available to the operator in the control room for monitoring the RHJR System.
RHR System ninin*, and comoonents have the notential to develon voids and nockets of entrained gases. Preventing, and managing gas intrusion and accumulation is necessary for proner operation of the Prairie Island                                  Unit 1 - R*,,y;-,.j...n.A.,,,dn.e iTe45 8 Units 1 and 2                       B 3.9.5-5 Unit 2- Revisi~r^n.eiidnienit-Ne,.419

RH{R and Coolant Circulation-High Water Level B 3.9.5 BASES SURVEILLANCE   SR 3.9.5.2 (continued)
RHR IOODS and may also prevent water hammer. pump cavitation.
and pumping, of noncondensible gas into the reactor vessel.
Selection of RHR System locations susceotible to *as accumulation is based on a review of system design information, including piping and instrumentation drawings, isometric drawings. olan and elevation drawings, and calculations. The design review is suoolemented by system walk downs to validate the system high points and to confirm the location and orientation of imoortant components that can become sources of *,as or could otherwise cause gas to be tranoed or difficult to remove during, system maintenance or restoration. Susceptible locations depend on olant and system configuration, such as stand-by versus operating conditions.
The RHR System is OPERAB3LE when it is sufficiently filled with water. Acceotance criteria are established for the volume of accumulated gas at susceptible locations. If accumulated gas is discovered that exceeds the acceotance criteria for the Susceptible location (.or the volume of accumulated gas at one or more Susceptible locations exceeds an acceotance criteria for gas volume at the suction or discharge of a pumo). the Surveillance is not met.
If it is determined by subseouent evaluation that the RHR System is not rendered inoperable by the accumulated gas (i.e.. the system is sufficiently filled with water). the Surveillance may be declaredl met.
Accumulated *,as should be eliminated or brought within the acceptance criteria limits.
RHIR System locations susceptible to gas accumulation are monitored and. if *as is found. the gas volume is comnared to the acceptance criteria for the location. Susceptible locations in the same system flow oath which are subjiect to the same gas intrusion mechanisms may be verified by monitoring, a representative sub-set of suscentible locations. Monitoring, may not be practical for Prairie Island                                  Unit 1 - ReviskonA................ 15 Units 1 and 2                        B 3.9.5-6 Unit 2 - RevsioAmecdmcne~t NoT. 11t9

RH-R and Coolant Circulation-High Water Level B 3.9.5 BASES SURVEILLANCE 8FD2JIKEMI*t*  SR 3.9.5.2 (continued) locations that are inaccessible due to radiological or environmental conditions, the nlant confi~uration. or personnel safety. For these locations alternative methods (e.g.. operating, narameters. remote monitorinQ) may be used to monitor the suscep~tible location.
Monitorin2 is not reauired for susceotible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitorin2 the suscentible locations and trendin2 of the results should be sufficient to assure system OPERABLITY during, the Surveillance interval.
This SR can be met by virtue of having an RH subsystemn inservice in accordance with operating nrocedures.
The 31 day Freauencv takes into consideration the gradual nature of
               *as accumulation in the RIIR System oinin*, and the procedural controls governing system oneration.
REFERENCES     None.
Prairie Island                                 Unit 1 - Revyslr ............      No....5~
Units 1 and 2                       B 3.9.5-7 Unit2-9 _     ' Amendment-.*.a...*.. N. 119n

RHIR and Coolant Circulation-Low Water Level B 3.9.6 BASES LCO             a. Removal of decay heat; (continued)
: b. Mixing of borated coolant to minimize the possibility of criticality; and
: c. Indication of reactor coolant temperature.
An OPERABLE RHR loop consists of an RHR pump, a heat exchanger, valves, piping, instruments and controls to ensure an OPERABLE flow path and to determine the low end temperature.
The flow path starts in one of the RCS hot legs and is returned to the RCS cold leg. Management of gas voids is imoortant to RHR System OPERABILITY.
Either RHR pump may be aligned to the Refueling Water Storage Tank (RWST) to support filling or draining the refueling cavity or for performance of required testing.
The LCO contains two Notes which provide clarification of the LCO.
Note 1 permits the RHR pumps to be de-energized for up to 1 hour per 8 hour period. The circumstances for stopping both RHR pumps are to be limited to situations when the outage time is short and the core outlet temperature is maintained > 10 degrees F below saturation temperature. The Note prohibits boron dilution or draining operations when RHR forced flow is stopped.
Note 2 allows one RHR loop to be inoperable for a period of 2 hours provided the other loop is OPERABLE and in operation. Prior to declaring the loop inoperable, consideration should be given to the existing plant configuration. This consideration should include that the core time to boil is short, there is no draining operation to further reduce RCS water level and that the capability exists to inject borated water into the reactor vessel. This permits surveillance tests to be performed on the inoperable loop during a time when these tests are safe and possible.
Prairie Island                                  Unit 1 --RevisionAmentdnentNe.-l-5.
Units 1 and 2                        B 3.9.6-2 Unit 2 - RevisionAmend.menit-Ne,.-! 49

RHIR and Coolant Circulation-Low Water Level B 3.9.6 St VE.JANa E REOtflREMENI   SR 3.9.6.3 (continued)   RIHR System niping and comoonents have the potential to develon voids and rockets of entrained gases. Preventing and managing *,as intrusion and accumulation is necessary for proper otneration of the RHR loons and may also nrevent water hammer. tnumio cavitation.
and pumping, of noncondensible *as into the reactor vessel.
Selection of RHR System locations suscentible to *as accumulation is based on a review of System design information, including piping and instrumentation drawings, isometric drawings. tolan and elevation drawings, and calculations. The design review is Suo~lemented by system walk downs to validate the system high points and to confrm the location and orientation of imtportant components that can become sources of *,as or could otherwise cause
               *as to be tratn~ed or difficult to remove during, system maintenance or restoration. Susceptible locations detnend on nlant and system configuration, such as stand-by versus operating conditions.
The RHIR System is OPERABLE when it is sufficiently filled with water. Acceptance criteria are established for the volume of accumulated *as at susceptible locations. If accumulated gas is discovered that exceeds the acceptance criteria for the susceotible location (or the volume of accumulated gas at one or more susceptible locations exceeds an accetntance criteria for gas volume at the suction or discharge of a pumtp), the Surveillance is not met.
If it is determined by subseauent evaluation that the RHR System is not rendered inop~erable by the accumulated gas (i.e.. the system is sufficiently filled with water), the Surveillance may be declared met.
Accumulated gas should be eliminated or brought within the accentance criteria limits.
RHR System locations susceptible to gas accumulation are monitored and. if *,as is found. the gas volume is comtoared to the accet~tance criteria for the location. Susceptible locations in the Prairie Island                                  Unit 1 - R~yiis;     edmi 4-Ne-,=**..xr,1-<o Units 1 and 2                        B 3.9.6-6 Unit 2 -RevisioAmendm:ent Nor. 1/19

RHTR and Coolant Circulation-Low Water Level B 3.9.6 BASES SURVEI1,1ANCE  SR     9_6_ 3 (cnntinuied'I REOUIREMENrS same system flow oath which are subject to the same *as intrusion mechanisms may be verified by monitoring, a representative sub-set of suscentible locations. Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions. the nlant configuration, or nersonnel safety. For these locations alternative methods (e.g.. onerating parameters. remote monitoring) may be used to monitor the susceptible location.
Monitoring is not required for susceptible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.
This SR can be met by virtue of having an RHR subsystema nservice in accordance with operating procedures.
The 31! day Freauency takes into consideration the..gradual nature of gas accumulation in the RHR System piping and the procedural controls governing system operation.
REFERENCES     None.
Prairie Island                                 Unit 1 -     *         .,,*. T.
* Units 1 and 2                       B 3.9.6-7 Unit 2-Revision* ............ Ne. 49}}

=Text=
{{#Wiki_filter:XceIEnergy&deg; JIUN 2992015                                                            L-PI-1 5-030 10 CFR 50.90 U S Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Prairie Island Nuclear Generating Plant Units 1 and 2 Dockets 50-282 and 50-306 Renewed License Nos. DPR-42 and DPR-60 Application to Revise Technical Specifications to Adopt TSTF-523, "Generic Letter 2008-01. Managiing Gas Accumulation", Using the Consolidated Line Item Improvement Process Pursuant to 10 CFR 50.90, Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), hereby submits a request for an amendment to revise the Technical Specifications (TS) for Prairie Island Nuclear Generating Plant (PINGP), Units 1 and 2. provides a description and assessment of the proposed change. provides the existing TS pages marked up to show the proposed change. provides revised (clean) TS pages. Attachment 4 provides existing TS Bases pages marked to show the proposed change. Changes to the existing TS Bases, consistent with the technical and regulatory analyses, will be implemented under the Technical Specification Bases Control Program. They are provided in Attachment 4 for information only.
By letter dated January 15, 2015 (ML15015A404), NSPM committed to evaluate the impact of adopting Technical Specification Task Force (TSTF) Traveler 523 by June 30, 2015 and submit an LAR for its adoption if necessary. This submittal satisfies the commitment.
Approval of the proposed amendment is requested by June 30, 2016. Once approved, the amendment shall be implemented within 90 days.
In accordance with 10 CFR 50.91, a copy of this application, with attachments, is being provided to the designated State of Minnesota Official.
1717 Wakonade Drive East a Welch, Minnesota 55089-9642 Telephone: 651.388.1121                                A-r/*I*

Document Control Desk Page 2 If there are any questions or if additional information is needed, please contact Mr.
Bryan Willard at 651--267-6829.
Summary of Commitments This letter contains no new commitments and no revisions to existing commitments.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on              2"e,     oI'-T Scott Sharp Director Site Operations, Prairie Island Nuclear Generating Plant Northern States Power Company - Minnesota Attachments (4) cc:     Administrator, Region Ill, USNRC Project Manager, PINGP, USNRC Resident Inspector, PINGP, USNRC State of Minnesota

ATTACHMENT 1 Description and Assessment Application to Revise Technical Specifications to Adopt TSTF-523, "Generic Letter 2008-01, Managing Gas Accumulation," Using the Consolidated Line Item Improvement Process

==1.0      DESCRIPTION==

The proposed change revises or adds Surveillance Requirements to verify that the system locations susceptible to gas accumulation are sufficiently filled with water and to provide allowances which permit performance of the verification. The changes are being made to address the concerns discussed in Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems."
The proposed amendment is consistent with TSTF-523, Revision 2, "Generic Letter 2008-01, Managing Gas Accumulation."
2.0     ASSESSMENT 2.1     Applicability of Published Safety Evaluation Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), has reviewed the model safety evaluation dated January 15, 2014 as part of the Federal Register Notice of Availability. This review included a review of the NRC staff's evaluation, as well as the information provided in TSTF-523, Revision 2. As described in the subsequent paragraphs,' NSPM concluded that the justifications presented in the TSTF-523, Revision 2, proposal and the model safety evaluation prepared by the NRC staff are applicable to Prairie Island Nuclear Generating Plant (PINGP), Units 1 and 2, and justify this amendment for the incorporation of the changes to the PINOP TS.
TSTF-523, Revision 2, and the model safety evaluation discuss the applicable regulatory requirements and guidance, including the 10 CFR 50, Appendix A, General Design Criteria (GDC). PINGP Units 1 and 2 were not licensed to the 10 CFR 50, Appendix A, GDC. The PINGP equivalent of the referenced GDC are discussed in the Updated Safety Evaluation Report (USAR) Section 1.2, Principal Design Criteria. The PINGP design criterion that equates to 10 CFR 50 Appendix A, GDC 1 s addressed in USAR Section 1.2.1, Overall Plant Requirements (GDC 1 - GDC 5) and the design criteria that equate to 10 CFR 50 Appendix A, GDC 34 through GDC 40 are addressed in USAR Section 1.2.6, Reactor Coolant Pressure Boundary (GDC 33 - GDC 36), and USAR Section 1.2.7, Engineered Safety Features (GDC 37 - GDC 65). This difference Page 1 of 6*
NSPM Adopt TSTF-523 does not alter the conclusion that the proposed change is applicable to PINGP, Units 1 and 2.
2.2     Optional Changes and Variations NSPM proposes the following variations from the TS changes described in the TSTF-523, Revision 2, or~the applicable parts of the NRC staff's model safety evaluation dated January 15, 2014.
The PINGP TS utilize different numbering than the NUREG-1431, Standard Technical Specifications (STS), on which TSTF-523, Revision 2, was based. PINGP TS do not have the existing TS 3.5.2, EGGS - Operating, Surveillance Requirements revised by TSTF-523, Revision 2. This difference does not affect the applicability of TSTF-523, Revision 2, to the PINGP TS. Specifically, numbering and content differences are provided in the following table.
NUREG-1431, STS                  TSTF-523 Change           PINGP TS Change Differences 3.5.2, EGCS - Operating          Revise SR 3.5.2.3 and     Add new SR 3.5.2.4, SR associated Bases.         3.5.2.5, and new associated Bases. Renumber subsequent SRs.
3.5.3, EGOS - Shutdown           Revise LCO Bases          Revise SR 3.5.3.1 to include only.                     two additional SRs.
3.6.6A, Containment Spray        Add new SR 3.6.6A.4       Add new SR 3.6.5.3 and and Cooling Systems              and associated Bases. associated Bases.
With the exception of the SR 3.5.2.5 addition, these differences are administrative in nature. None of the proposed variations affect the applicability of TSTF-523 to the PINGP TS.
NSPM is proposing the addition of new SR 3.5.2.5, with an associated Frequency of "Prior to entering Mode 3 after exiting shutdown cooling" in lieu of the specified 31 day Frequency. The justification for the additional SR and extended Frequency is provided below:
      *Safety injection system inaccessible location configuration The four inaccessible locations (two locations per unit) are designated 1SI-44, 1SI-45 for Unit 1 and 2S1-14A, 2S1-14B for Unit 2. The inaccessible locations are located on corresponding line numbers 2-SI-35A, 2-SI-35B, 2-2SI-35A and 2-2SI-35B. These locations are adjacent to the RCS first-off pressure isolation check valves and are inaccessible during normal operations due to dose and temperature concerns.'
Page 2 of 6 NSPM Adopt TSTF-523 The Safety Injection system piping injects into each of the RCS cold legs through a single common pipe that branches into two separate 2" lines. On each of the 2" branches, there are two check valves installed that are the pressure boundary valves for the RCS. The first-off check valves (SI1-9-1, SI-9-2, 2SI-9-I, and 2SI        2) are 6" swing disc check valves. The second-off check valves (S1-I16-4, SI-i16-5, 2S1-16-4, and 2S1-16-6) are 2" spring loaded piston type check valves.
The geometry of the four inaccessible locations consists of a vertically oriented 6" check valve that connects to the RCS loop piping with RCS pressure on the downstream side of the disc. These locations are all high points that would allow gas to accumulate inside the check valve on the upstream side of the disc.
The locations are inaccessible due to high dose rates during power operation and close proximity to the RCS loop piping. These areas are examined at the piping adjacent to the check valve due to the valve configuration and examination limitations.
* Gas intrusion source The Safety Injection piping connects directly to a pressurized Reactor Coolant System. Dissolved gases in the reactor coolant are controlled by the Chemical and Volume Control System (VC) that maintains the concentration of hydrogen or nitrogen gas present through the Volume Control Tank (VCT). The current Gas Accumulation Management Program (GAMP) indicates if back-leakage
      \were to occur, the lower pressure on the upstream side of the check valve would result in hydrogen gas coming out of solution and a void formation. Thus, these locations meet the definition of susceptible locations per the program documents.
Site engineering personnel have determined that a very specific leakage condition must exist for a void to form at the inaccessible locations. For void formation to occur, both the first-off and second-off pressure boundary check valves need to be leaking. If only a single check valve is leaking, a void cannot form due to pressurization between the check valves. If the first-off check valve is leaking at a rate that is greater than the second-off check valve, then the area between the check valves will pressurize and a void cannot form. A void will only form if the second-off check valve is leaking at a greater rate than the first-off check valve since that is the only condition that will simultaneously allow leakage from the RCS and also prevent pressure buildup between the check valves.
Per USAR Section 6, the design leakage limit for these valves is stated as 3 cc/hr per inch of nominal pipe size. This means that the 6" first-off check valves would have a design leakage rate of 18 cc/hr and the 2" second-off check valves would have a design leakage rate of 6 cc/hr. This design leakage rate is important to consider since it is impossible to design a zero leakage check valve with hard seats. Since the first-off check valves have a higher design leakage Page 3 of 6 NSPM Adopt TSTF-523 rate than the second-off check valves, it supports the position that void formation is unlikely. This is because a higher leakage through the first-off check valves, when compared to the second-off check valves, would tend to pressurize the piping between the check valves, which would effectively prevent void formation.
* Alternative monitoring PINGP will monitor the locations prior to entering Mode 3 after exiting shutdown cooling during startup in lieu of the specified 31 day frequency.
In addition to the proposed TS 3.2.5.2 Surveillance Frequency, the inaccessible locations are checked for voids at the earliest possible shutdown condition. This as-found testing occurs in accordance with the PINGP GAMP, under conditions that ensure the check valves at the inaccessible locations are properly seated.
During refueling outages, PINGP will verify the relative leakage rates of the check valves are maintained such that void formation during the cycle is mitigated. The check valve leakage rates will be validated to ensure no leakage is present, or the leakage rate of the first-off check valves (SI-9-I, SI-9-2, 2SI         1, and 2SI-9-2) is greater than the corresponding second-off check valves (SI-16-4, SI-I16-5, 2S1-16-4, and 2S1-16-6).
By verifying the conditions necessary for void formation are not present, maintaining the as left condition during the cycle, and monitoring of the locations when accessible, reasonable assurance of safety is maintained for the system.

==3.0    REGULATORY ANALYSIS==

3.1    No Significant Hazards Consideration Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), requests adoption of TSTF-523, Revision 2, "Generic Letter 2008-01, Managing Gas Accumulation," which is an approved change to the standard technical specifications (STS), into the Prairie Island Nuclear Generating Plant, Units I and 2, technical specifications (TS). The proposed change adds Surveillance Requirements to verify that the system locations susceptible gas accumulation are sufficiently filled with water and to provide allowances which permit performance of the verification.
Northern States Power Company, a Minnesota corporation (NSPM), evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment,"
as discussed below:
Page 4 of 6 NSPM Adopt TSTF-523
: 1. Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No The proposed change adds Surveillance Requirements (SRs) that require verification that the Emergency Core Cooling System (ECCS), the Residual Heat Removal (RHR) System, and the Containment Spray (CS) System are not rendered inoperable due to accumulated gas and to provide allowances which permit performance of the revised verification. Gas accumulation in the subject systems is not an initiator of any accident previously evaluated. As a result, the probability of any accident previously evaluated is not significantly increased.
The proposed SIRs ensure that the subject systems continue to be capable to perform their assumed safety function and are not rendered inoperable due to gas accumulation. Thus, the consequences of any accident previously evaluated are not significantly increased.
Therefore, the proposed licensing basis change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
: 2. Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?
Response: No The proposed change adds SRs that require verification that the ECCS, the RHR System, and the CS System are not rendered inoperable due to accumulated gas and to provide allowances which permit performance of the revised verification. The proposed change does not involve a physical alteration of the plant (i.e., no new or different type of equipment will be installed) or a change in the methods governing normal plant operation. In addition, the proposed change does not impose any new or different requirements that could initiate an accident. The proposed change does not alter assumptions made in the safety analysis and is consistent with the safety analysis assumptions.
Therefore, the proposed licensing basis change does not create the possibility of a new or different kind of accident from any previously evaluated.
: 3. Does the proposed amendment involve a significant reduction in a margin of safety?
Response: No The proposed change adds SRs that require verification that the ECCS, the RHR System, and the CS System are not rendered inoperable due to accumulated gas and to provide allowances which permit performance of the revised Page 5 of 6

Attachment I                                                                             NSPM Adopt TSTF-523 verification. The proposed change adds new requirements to manage gas accumulation in order to ensure the subject systems are capable of performing their assumed safety functions. The proposed SRs will ensure that the assumptions of the safety analysis are protected. The proposed change does not adversely affect any current plant safety margins or the reliability of the equipment assumed in the safety analysis. Therefore, there are no changes being made to any safety analysis assumptions, safety limits or limiting safety system settings that would adversely affect plant safety as a result of the proposed change.
Therefore, the proposed licensing basis change does not involve a significant reduction in a margin of safety.
Based on the above, Northern States Power Company, a Minnesota corporation (NSPM), 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.
4.0      ENVIRONMENTAL EVALUATION The proposed change 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 CER 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.
Page 6 of 6

ATTACHMENT 2 Technical Specification Pages (Markup) 3.4.6-3 3.4.7-4 3.4.8-3 3.5.2-2 3.5.2-3 3.5.2-4 3.5.3-2 3.6.5-3 3.6.5-4 3.9.5-3 3.9.6-3 11 pages follow

RCS Loops - MODE 4 3.4.6 SURVEILLANCEREQUIREMENTS______
SURVEILLANCE                                    FREQUENCY SR 3.4.6.1       Verify required RHR or RCS loop is in                 12 hours operation.
SR 3.4.6.2       Verify required SG capable of removing decay          12 hours heat.
SR 3.4.6.3----------NOTE--------
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated        7 days power are available to each required pump.
SR 3.4.6,4                            NOTE---------------..
NOT Not reauired to be performed until 12 hours after entering MODE 4.
Verify required RHR looo locations susceptible to     31dy gas accumulation are sufficiently filled with water.
Prairie Island                                             Unit 1 - Amendment No. 58 Units 1 and 2                              3.4.6-3         Unit 2 - Amendment No. 9

RCS Loops - MODE 5, Loops Filled 3.4.7 SURVEILLANCEREQUIREMENTS______
SURVEILLANCE                                   FREQUENCY SR 3.4.7.1        Verify required RHR loop is in operation.             12 hours SR 3.4.7.2        Verify required SG capable of removing decay          12 hours heat.
SR 3.4.7.3-----------NOTE--------
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated        7 days power are available to each required RHR pump.
SR 3.4.7,4         Verify required RHR loop, locations susceptible to   31dy
                   *,as accumulation are sufficiently filled with Prairie Island                                              Unit 1 - Amendment No. 58 Units 1 and 2                              3.4.7-4          Unit 2 - Amendment No. 4149

RCS Loops - MODE 5, Loops Not Filled 3.4.8 SURVEILLANCEREQUIREMENTS______
SURVEILLANCE                                 FREQUENCY SR 3.4.8.1       Verify required RHIR loop is in operation.           12 hours SR 3.4.8.2----------NOTE---------
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated       7 days power are available to each required RHR pump.
SR 3.4.8.3      Verify RHR looD locations susceptible to gas           1dy accumulation are sufficiently filled with water.
Prairie Island                                            Unit 1 - Amendment No. 4-58 Units 1 and 23483                         3.4.8-3         Unit 2 - Amendment No. 449

ECCS    - Operating 3.5.2 SURVEILLANCE REQUIREMENTS SURVEILLANCE                                  FREQUENCY SR 3.5.2.1      Verify the following valves are in the listed position. 12 hours Westing-Unit 1        house Valve         Valve Number        Number      Position                   Function 32070         8801A       OPEN          SI Injection to RCS Cold Leg A 32068         8801B       OPEN          SI Injection to RCS Cold Leg B 32073         8806A       OPEN          SI Cold Leg Injection Line 32206         881 6A      CLOSED        SI Pump Suction from RIIR 32207         881 6B      CLOSED        SI Pump Suction from RHIR Westing-Unit 2        house Valve         Valve Number        Number      Position                  Function 32173         8801A       OPEN          SI Injection to RCS Cold Leg A 32171         8801B       OPEN          SI Injection to RCS Cold Leg B 32176         8806A       OPEN          SI Cold Leg Injection Line 32208         881 6A      CLOSED        SI Pump Suction from RHR 32209         881 6B      CLOSED        SI Pump Suction from RHTR SR 3.5.2.2                                    -~~~NOTE--------           31 days Not required to be met for system vent flow oaths opened under administrative control.
Verify each ECCS manual, power operated, and automatic valve in the flow path that is not locked, sealed, or otherwise secured in position, is in the correct position.
Prairie Island                                         Unit 1 - Amendment No. 4-58 4-82 Units 1 and 2                               3.5.2-2    Unit 2 - Amendment No. 49 4-7-2

ECCS   - Operating 3.5.2 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE                                  FREQUENCY SR 3.5.2.3    Verify power to the valve operator has been removed      31 days for each valve listed in SR 3.5.2.1.
SR 3.5,2.4    Verify ECCS accessible locations susceptible to &#xa2;*as     31dy accumulation are sufficiently filled with water.
SR 3.5,2.5    Verify ECCS inaccessible locations sulsceptible to *.asProtOeein.
accumulation are sufficiently filled with water.        MD          fe extigsutow cooing SR 3.5.2.(!4 Verify each ECCS pump's developed head at the test       In accordance flow point is greater than or equal to the required     with the Inservice developed head.                                         Testing Program SR 3.5.2.7$ Verify each ECCS automatic valve in the flow path         24 months that is not locked, sealed, or otherwise secured in position, actuates to the correct position on an actual or simulated actuation signal.
Prairie Island                                       Unit 1 Amendment No. -8 4-82 Units 1 and 2                             3.5.2-3    Unit 2 -Amendment No. -14947

ECCS    -  Operating 3.5.2 SURVEILLANCE REQUIREMENTS (continued)_______
SURVEILLANCE                                  FREQUENCY SR 3.5.2.86 Verify each ECCS pump starts automatically on an            24 months actual or simulated actuation signal.
SR 3.5.2.9-7 Verify each ECCS throttle valve listed below is in the     24 months correct position.
Unit 1 Valve Number                 Unit 2 Valve Number SI-15-6                             2SI-15-6 SI-15-7                             2SI-15-7 SI-15-8                             2SI-15-8 SI-15-9                             2SI-15-9 SR 3.5.2.1Q8 Verify, by visual inspection, each ECCS train              24 months containment sump suction inlet is not restricted by debris and the suction inlet strainers show no evidence of structural distress or abnormal corrosion.
Prairie Island                                        Unit 1 - Amendment No. 4-58s 4-82 Units 1 and 2                              3.5.2-4    Unit 2 - Amendment No. 449 4-7-2

ECCS - Shutdown 3.5.3 ACTIONS (continued)                                                   ________
CONDITION                    REQUIRED ACTION                  COMPLETION TIME C. Required Action and        C.l1   Be in MODE 5.                24 hours associated Completion Time of Condition B not met.
SURVEILLANCE REQUIREMENTS SURVEILLANCE                                   FREQUENCY SR 3.5.3.1     The following SRs are applicable for all equipment     In accordance required to be OPERABLE:                               with applicable SRs SR 3.5.2.1                  SR 3.5.2.*
SR 3.5.2.3                  SR 3.5.2.98, SR 3.5.2.4 Prairie Island                                          Unit 1 - Amendment No. 4--58 6 Units 1 and 2                            3.5.3-2        Unit 2 - Amendment No. 49 447

Containment Spray and Cooling Systems 3.6.5 SURVEILLANCE REQUIREMENTS SURVEILLANCE                                       FREQUENCY SR 3.6.5.1           ----------...- NOTE---------
Not required to be met for system vent flow oaths onened under administrative control.
Verify each containment spray manual, power 31 days operated, and automatic valve in the flow path that is not locked, sealed, or otherwise secured in position is in the correct position.
SR 3.6.5.2 Operate each containment fan coil unit on low motor              31 days speed for > 15 minutes.
SR 3.6.5.3     Verify containment snrav locations susceptible to *as        31dy accumulation are sufficiently filled with water.
SR 3.6.5._____ Verify cooling water flow rate to each containment           24 months fan coil unit is >900 gpm.
SR 3.6.5.54 Verify each containment spray pump's developed                  In accordance head at the flow test point is greater than or equal to      with the the required developed head.                                 Inservice Testing Program Prairie Island                                          Unit 1 - Amendment No. -5l-t7-Units 1 and 2                               3.6.5-3     Unit 2 -Amendment No. 49 4                                                      Reiocd by,lett--,r datd,. Augu,- 2,,, 2006)FIA

Containment Spray and Cooling Systems 3.6.5 SURVEILLANCE REQUIREMENTS (continued)                                   ______
SURVEILLANCE                                     FREQUENCY SR 3.6.5._fa- Verify each automatic containment spray valve in the     24 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 3.6.5.76 Verify each containment spray pump starts                  24 months automatically on an actual or simulated actuation signal.
SR 3.6.5.8g7 Verify each containment cooling train starts              24 months automatically on an actual or simulated actuation signal.
SR 3.6.5._9g Verify each spray nozzle is unobstructed.                 Following maintenance which could result in nozzle blockage Prairie Island                                        Unit 1 - Amendment No. 58 4190 Units 1 and 2                              3.6.5-4    Unit 2 - Amendment No. -1494-79

RHR and Coolant Circulation-High Water Level 3.9.5 SURVEILLANCE REQUIREMENTS______
SURVEILLANCE                                  FREQUENCY SR 3.9.5.1    Verify one RHR loop is in operation.                   12 hours SR 3.9.5.2    Verify required RLHR loon locations susceptible to     31dy gas accumulation are sufficiently filled with water.
Prairie Island                                           Unit 1 - Amendment No. 41-58 Units 1 and 2                           3.9.5-3          Unit 2 - Amendment No. 449

RLIR and Coolant Circulation-Low Water Level 3.9.6 ACTIONS                                                                 ______
CONDITION                      REQUIRED ACTION                  COMPLETION TIME B. (continued)                     B.5.1 Close each penetration        4 hours providing direct access from the containment atmosphere to the outside atmosphere with a manual or automatic isolation valve, or blind flange.
OR B.5.2 Verify each penetration is     4 hours capable of being closed by an OPERABLE Containment Ventilation Isolation System.
SURVEILLANCE REQUIREMENTS S URVEILLANCE                                  FREQUENCY SR 3.9.6.1    Verify one RHLR loop is in operation.                    12 hours SR 3.9.6.2    Verify correct breaker alignment and indicated power     7 days available to the required RIIR pump that is not in operation.
SR 3.9.6.3     Verify. RHR looD locations susceptible to *as31dy accumulation are sufficiently filled with water.
Prairie Island                                            Unit 1 - Amendment No. 4-58 Units 1 and 2                                             Unit 2 - Amendment No. 4-49 3.9.6-3

ATTACHMENT 3 Technical Specification Pages (Retyped) 3.4.6-3 3.4.7-4 3.4.8-3 3.5.2-2 3.5.2-3 3.5.2-4 3.5.3-2 3.6.5-3 3.6.5-4 3.9.5-3 3.9.6-3 11 pages follow

RCS Loops - MODE 4 3.4.6 SURVEILLANCE REQUIREMENTS SURVEILLANCE                                  FREQUENCY SR 3.4.6.1       Verify required RHR or RCS loop is in                12 hours operation.
SR 3.4.6.2       Verify required SG capable of removing decay         12 hours heat.
SR 3.4.6.3-----------NOTE--------
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated        7 days power are available to each required pump.
SR 3.4.6.4-----------NOTE--------
Not required to be performed until 12 hours after entering MODE 4.
Verify required RUR loop locations susceptible to     31 days gas accumulation are sufficiently filled with water.
Prairie Island                                          Unit 1 - Amendment No. 58 Units 1 and 23463                         3.4.6-3       Unit 2 - Amendment No. 4-49

RCS Loops - MODE 5, Loops Filled 3.4.7 SURVEILLANCE REQUIREMENTS SURVEILLANCE                                 FREQUENCY SR 3.4.7.1        Verify required RHIR loop is in operation.          12 hours SR 3.4.7.2        Verify required SG capable of removing decay        12 hours heat.
SR 3.4.7.3-----------NOTE--------
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated      7 days power are available to each required RHR pump.
SR 3.4.7.4        Verify required RHR loop locations susceptible to   31 days gas accumulation are sufficiently filled with water.
Prairie Island                                           Unit 1 - Amendment No. 5-s Units 1 and 2                              3.4.7-4       Unit 2 - Amendment No. 4-49

RCS Loops - MODE 5, Loops Not Filled 3.4.8 SURVEILLANCE REQUIREMENTS                                              ______
SURVEILLANCE                                   FREQUENCY SR 3.4.8.1       Verify required RIIR loop is in operation.            12 hours SR 3.4.8.2----------NOTE---------
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated       7 days power are available to each required RHR pump.
SR 3.4.8.3       Verify RHIR loop locations susceptible to gas        31 days accumulation are sufficiently filled with water.
Prairie Island                                           Unit 1 - Amendment No. 4-58 Units 1 and 2                              3.4.8-3       Unit 2 - Amendment No. 4-49

ECCS   -  Operating 3.5.2 SURVEILLANCE REQUIREMENTS SURVEILLANCE                                  FREQUENCY SR 3.5.2.1      Verify the following valves are in the listed position. 12 hours Westing-Unit 1        house Valve         Valve Number        Number      Position                  Function 32070         8801A       OPEN          SI Injection to RCS Cold Leg A 32068         8801B       OPEN          SI Injection to RCS Cold Leg B 32073         8806A       OPEN         SI Cold Leg Injection Line 32206         881 6A      CLOSED        SI Pump Suction from RIIR 32207         881 6B      CLOSED        SI Pump Suction from RHR Westing-Unit 2        house Valve         Valve Number       Number       Position                  Function 32173         8801A       OPEN         SI  Injection to RCS Cold Leg A 32171         8801B       OPEN         SI  Injection to RCS Cold Leg B 32176         8806A       OPEN         SI  Cold Leg Injection Line 32208         881 6A      CLOSED       SI  Pump Suction from RIIR 32209         881 6B      CLOSED       SI  Pump Suction from RHR SR 3.5.2.2                                    -~~~NOTE--------           31 days Not required to be met for system vent flow paths opened under administrative control.
Verify each ECCS manual, power operated, and automatic valve in the flow path that is not locked, sealed, or otherwise secured in position, is in the correct position.
Prairie Island                                         Unit 1 - Amendment No. 4-58 41-82 Units 1 and 2                              3.5.2-2     Unit 2 - Amendment No. -1491-72

ECCS    - Operating 3.5.2 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE                                 FREQUENCY SR 3.5.2.3    Verify power to the valve operator has been removed     31 days for each valve listed in SR 3.5.2.1.
SR 3.5.2.4    Verify ECCS accessible locations susceptible to gas     31 days accumulation are sufficiently filled with water.
SR 3.5.2.5    Verify ECCS inaccessible locations susceptible to gas   Prior to entering accumulation are sufficiently filled with water.        MODE 3 after exiting shutdown cooling SR 3.5.2.6    Verify each ECCS pump's developed head at the test      In accordance flow point is greater than or equal to the required     with the Inservice developed head.                                         Testing Program SR 3.5.2.7    Verify~each ECCS automatic valve in the flow path       24 months that is not locked, sealed, or otherwise secured in position, actuates to the correct position on an actual or simulated actuation signal.
Prairie Island                                       Unit 1 - Amendment No. 4-5% 4-1-S Units 1 and 2                              3.5.2-3   Unit 2 -Amendment No. 4-49 4-72

ECCS      - Operating 3.5.2 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE                                 FREQUENCY SR 3.5.2.8      Verify each ECCS pump starts automatically on an        24 months actual or simulated actuation signal.
SR 3.5.2.9      Verify each ECCS throttle valve listed below is in the  24 months correct position.                                                               I Unit 1 Valve Number                 Unit 2 Valve Number SI-15-6                              2SI-15-6 SI-15-7                              2SI-15-7 SI- 15-8                             2SI- 15-8 SI-15-9                              2SI-15-9 SR 3.5.2.1i0 Verify, by visual inspection, each ECCS train              24 months containment sump suction inlet is not restricted by debris and the suction inlet strainers show no evidence of structural distress or abnormal corrosion.
Prairie Island                                         Unit 1 - Amendment No. 5-s 4-82 Units 1 and 2                               3.5.2-4    Unit 2 -Amendment No. 4-4-9 1-72

ECCS   -   Shutdown 3.5.3 ACTIONS (continued)
CONDITION                    REQUIRED ACTION                COMPLETION TIME C. Required Action and        C. 1   Be in MODE 5.               24 hours associated Completion Time of Condition B not met.
SURVEILLANCE REQUIREMENTS SURVEILLANCE                                 FREQUENCY SR 3.5.3.1     The following SRs are applicable for all equipment    In accordance required to be OPERABLE:                              with applicable SRs SR 3.5.2.1                  SR 3.5.2.6 SR 3.5.2.3                  SR 3.5.2.9 SR 3.5.2.4                  SR 3.5.2.10 SR 3.5.2.5 Prairie Island                                      Unit 1 - Amendment No. -4~1--847 Units 1 and 2                            3.5.3-2    Unit 2 -Amendment No.1-4914

Containment Spray and Cooling Systems 3.6.5 SURVEILLANCE REQUIREMENTS SURVEILLANCE                                  FREQUENCY SR 3.6.5.1          ---------        NOTE--------
Not required to be met for system vent flow paths opened under administrative control.
Verify each containment spray manual, power 31 days operated, and automatic valve in the flow path that is not locked, sealed, or otherwise secured in position is in the correct position.
SR 3.6.5.2    Operate each containment fan coil unit on low motor      31 days speed for > 15 minutes.
SR 3.6.5.3    Verify containment spray locations susceptible to gas    31 days accumulation are sufficiently filled with water.
SR 3.6.5.4    Verify cooling water flow rate to each containment       24 months fan coil unit is&#x17d;>900 gpm.
SR 3.6.5.5    Verify each containment spray pump's developed           In accordance head at the flow test point is greater than or equal to  with the the required developed head.                             Inservice Testing Program Prairie Island                                        Unit 1 - Amendment No. 4-5 -t-7-3 Units 1 and 2                              3.6.5-3    Unit 2 - Amendment No. 4149 6

Containment Spray and Cooling Systems 3.6.5 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE                                    FREQUENCY SR 3.6.5.6 Verify each automatic containment spray valve in the        24 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 3.6.5.7    Verify each containment spray pump starts                24 months automatically on an actual or simulated actuation signal.
SR 3.6.5.8    Verify each containment cooling train starts             24 months automatically on an actual or simulated actuation signal.
SR 3.6.5.9    Verify each spray nozzle is unobstructed.                Following maintenance which could result in nozzle blockage Prairie Island                                       Unit 1 - Amendment No. 4-5-s 4-9 Units 1 and 2                              3.6.5-4   Unit 2 - Amendment No.4-494--7-9

RHIR and Coolant Circulation-High Water Level 3.9.5 SURVEILLANCE REQUIREMENTS SURVEILLANCE                                  FREQUENCY SR 3.9.5.1    Verify one RHTR loop is in operation.                  12 hours SR 3.9.5.2    Verify required RJIR loop locations susceptible to     31 days gas accumulation are sufficiently filled with water.
Prairie Island                                          Unit 1 - Amendment No. 58 Units 1 and 2                            3.9.5-3        Unit 2 - Amendment No. 4-49

RHR and Coolant Circulation-Low Water Level 3.9.6 ACTIONS CO~NDITION                     REQUIRED ACTION                 COMPLETION TIME B. (continued)                    B.5.1 Close each penetration        4 hours providing direct access from the containment atmosphere to the outside atmosphere with a manual or automatic isolation valve, or blind flange.
OR B.5.2 Verify each penetration is    4 hours capable of being closed by an OPERABLE Containment Ventilation Isolation System.
SURVEILLANCE REQUIREMENTS______
SURVEILLANCE                                 FREQUENCY SR 3.9.6.1    Verify one RHR toop is in operation.                    12 hours SR 3.9.6.2    Verify correct breaker alignment and indicated power    7 days available to the required RIHR pump that is not in operation.
SR 3.9.6.3     Verify RHR loop locations susceptible to gas           31 days accumulation are sufficiently filled with water.
Prairie Island                                           Unit 1 - Amendment No. 45-g Units 1 and 2                              3.9.6-3       Unit 2 - Amendment No. 4149

ATTACHMENT 4 Technical Specification Bases (Markup)
B 3.4.6-3                     B 3.5.2-14 B 3.4.6-6                     B 3.5.3-2 B 3.4.6-7                     B 3.6.5-6 B 3.4.6-8                     B 3.6.5-11 B 3.4.7-4                    B 3.6.5-12 B 3.4.7-7                    B 3.6.5-13 B 3.4.7-8                    B 3.6.5-14 B 3.4.8-2                    B 3.6.5-15 B 3.4.8-4                     B 3.9.5-2 B 3.4.8-5                     B 3.9.5-5 B 3.4.8-6                     B 3.9.5-6 B 3.5.2-6                     B 3.9.5-7 B 3.5.2-10                    B 3.9.6-2 B 3.5.2-11                    B 3.9.6-6 B 3.5.2-12                    B 3.9.6-7 B 3.5.2-13 31 pages follow

RCS Loops - MODE 4 B 3.4.6 BASES LCO             b. Core outlet temperature is maintained at least 10&deg;F below (continued)        saturation temperature, so that no vapor bubble may form and possibly cause a natural circulation flow obstruction.
Note 2 requires a steam or gas bubble in the pressurizer or that the secondary side water temperature of each SG be _<50F above each of the RCS cold leg temperatures before the start of an RCP with any RCS cold leg temperature < the OPPS enable temperature specified in the PTLR. A steam or gas bubble ensures that the pressurizer will accommodate the swell resulting from an RCP start. Either of these restraints prevents a low temperature overpressure event due to a thermal transient when an RCP is started.
An OPERABLE RCS loop comprises an OPERABLE RCP and an OPERABLE SG which is capable of removing decay heat as specified in SR 3.4.6.2.
Similarly for the RHJR System, an OPERABLE RHR loop comprises an OPERABLE RHR pump capable of providing forced flow to an OPERABLE RHIR heat exchanger. RCPs and RHR pumps are OPERABLE if they are capable of being powered and are able to provide forced flow if required. Management of *,as voids is imtoortant to RHR System OPERABIIATY.
APPLICABILITY  In MODE 4, this LCO ensures forced circulation of the reactor coolant to remove decay heat from the core and to provide proper boron mixing.
Operation in other MODES is covered by:
LCO 3.4.4,   "RCS Loops - MODES 1 and 2";
LCO 3.4.5,   "RCS Loops - MODE 3";
LCO 3.4.7,   "RCS Loops - MODE 5, Loops Filled";
LCO 3.4.8,   "RCS Loops - MODE 5, Loops Not Filled";
LCO 3.9.5,   "Residual Heat Removal (RHR) and Coolant Circulation - High Water Level" (MODE 6); and Prairie Island                                    Unt1- Revyision` ....................
Units 1 and 2                       B 3.4.6-3 Unit2 - Revision,...endm.ent No. 49

RCS Loops - MODE 4 B 3.4.6 BASES SURVEILLANCE    SR 3.4.6.2 REQUIREMENTS (continued)    SR 3.4.6.2 requires verification that the required SG has the capability to remove decay heat. The ability to remove decay heat requires the ability to pressurize and control pressure in the RCS, sufficient secondary side water level in the SG relied on for decay heat removal, and an available supply of feedwater (Ref. 2). The ability of the SG to provide an adequate heat sink for decay heat removal further ensures that the SG tubes remain covered. The 12 hour Frequency is considered adequate in view of the other indications available in the control room to alert the operator to a loss of capability of the SG to remove decay heat.
SR 3.4.6.3 Verification that each required pump is OPERABLE ensures that an additional RCS or RHTR pump can be placed in operation, if needed, to maintain decay heat removal and reactor coolant circulation.
Verification is performed by verifying proper breaker alignment and power available to each required pump. Alternatively, verification that a pump is in operation also verifies proper breaker alignment and power availability. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a pump is not in operation.
SRi34.6.
RHR System pitting and components have the potential to develop voids and pockets of entrained gases. Preventing and managing, aas intrusion and accumulation is necessary for proper operation of the Prairie Island                                 Unitl1-       * * ^*,Aendmn.-N A          I1-Units 1 and 2                       B 3.4.6-6 Unit 2-_yj,,i*m,*       dine.it-,, e-449 l

RCS Loops - MODE 4 B 3.4.6 BASES qT TI*S7"I* T A*tl-'q*
QTTD.
LP.J  V&#xa5;JL    IIT AMC BASES    .LL..U    1 .*$. k*%   ..j*-1 11 "T 1,%ALI J 1.l.*. t required RHR loon(s) and may also orevent water hammer. Dump cavitation, and pumping of noncondensible *,as into the reactor Selection of RHR System locations susceptible to *as accumulation is based onl a review of system design information, including, pi~ing, and instrumentation drawings, isometric drawings. olan and elevation drawings, and calculations. The design review is su~olemented by system waLk downs to validate the system high points and to confirm the location and orientation of imtortant comoonents that can become sources of *.as or could otherwise cause gas to be traooed or difficult to remove during system maintenance or restoration. Susceptible locations denend on olant and system configuration, such as stand-by versus ooerating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water. Acceotance criteria are established for the volume of accumulated gas at susceptible locations. If accumulated *as is discovered that exceeds the acceotance criteria for the susceptible location (or the volume of accumulated *as at one or more susceptible locations exceeds an acceotance criteria for gas volume at the suction or discharge of a oump). the Surveillance is not met.
If it is determined by subsecuent evaluation that the RHIR System is not rendered inoperable by the accumulated gas (i.e.. the system is sufficiently filled with water). the Surveillance may be declared met.
Accumulated gas should be eliminated or brought within the acceptance criteria limits.
RHR System locations susceptible to gas accumulation are monitored and. if *as is found. the *as volume is comoared to the acceptance criteria for the location. Susceptible locations in the same system flow path which are subject to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set Prairie Island                                                  Unit 1 - u,.,j*;,,-Amend.m,.,nt No. 158o Units 1 and 2                                         B 3.4.6-7 Unt2_o*,            *.,**.--     t.!t

RCS Loops - MODE 4 B 3.4.6 BASES qT TDX/-I*'TT T ANTI*'I*'
~t.J.,Jk%.
BASES  TO~           A~C V _3.LALL4..--1 *l.' "  LJI. .J .-. '.) % .- U'..1%JiIL~t11L4.'.. I of susceptible locations. Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions. the plant config~uration. or nersonnel safety. For these locations alternative methods (e.g.. operating parameters. remote monitoring) may be used to monitor the suscetntible location.
Monitoring is not required for suscetptible locations where the maximum notential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.
The SR can be met by virtue of having an RHR subsystem inservice in accordance with operating procedures.
This SR is modified by a Note that states the SR is not required to be nerformed until 12 hours after entering MODE 4. In a rapid shutdown, there may be insufficient time to verify all susceptible locations nrior to entering MODE 4.
The 31 day Frequencv takes into consideration the gradual nature of gas accumulation in the RHR System piping and the procedural controls governing' system operation, REFERENCES                        1. License Amendment Request Dated November 19, 1999.
(Approved by License Amendment 152/143, July 14, 2000.)
: 2. NRC Information Notice 95-35, "Degraded Ability of Steam Generator to Remove Decay Heat by Natural Circulation."
Prairie Island                                                                  Unit 1 - ,&#xa2;*,.A   *   *+   r.1d Units 1 and 2                                                          B3.4.6-8 Unit2-    i~
                                                                                          *
* Amendment.+Ne-   ,,9

RCS Loops - MODE 5, Loops Filled B 3.4.7 BASES LCO            Note 4 provides for an orderly transition from MODE 5 to MODE 4 (continued)   during a planned heatup by permitting removal of RHiR loops from operation when at least one RCS loop is in operation. This Note provides for the transition to MODE 4 where an RCS loop is permitted to be in operation and replaces the RCS circulation function provided by the RHR loops.
RHR pumps are OPERABLE if they are capable of being powered and are able to provide flow if required. A SG is capable of removing decay heat via natural circulation when: 1) there is the ability to pressurize and control pressure in the RCS; 2) there is sufficient secondary side water level in the SG relied on for decay heat removal; and 3) there is an available supply of feedwater (Ref.
1). An OPERABLE SG can perform as a heat sink via natural circulation when it has the capability to remove decay heat as specified in SR 3.4.7.2. Management of *,as voids is important to RHR System OPERABILITY.
APPLICABILITY  In MODE 5 with RCS loops filled, this LCO requires forced circulation of the reactor coolant to remove decay heat from the core and to provide proper boron mixing. One loop of RHR provides sufficient circulation for these purposes. However, one additional RHIR loop is required to be OPERABLE, or a SG is capable of removing decay heat.
Operation in other MODES is covered by:
LCO   3.4.4, "RCS Loops-MODES 1 and 2";
LCO   3.4.5, "RCS Loops-MODE 3";
LCO   3.4.6, "RCS Loops-MODE 4";
LCO   3.4.8, "RCS Loops-MODE 5, Loops Not Filled";
LCO   3.9.5, "Residual Heat Removal (RHR) and Coolant Circulation-High Water Level" (MODE 6); and LCO 3.9.6, "Residual Heat Removal (RHR) and Coolant Circulation-Low Water Level" (MODE 6).
Prairie Island                              3474Unit 12-    *       *          *A Units 1 and 2                            B74Unt2Revlsgmlo
                                             ..                   n   dm......... No. 119.

RCS Loops - MODE 5, Loops Filled B 3.4.7 BASES SURVEILLANCE   SR 3.4.7.3 (continued)
REQUIREMENTS controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a pump is not in operation.
SR .47.
RHR System piping and comoonents have the potential to develop voids and nockets of entrained gases. Preventing and managing *as intrusion and accumulation is necessary, for oroner operation of the required RHR looo(s) and may also Prevent water hammer. oump cavitation. and pumping of noncondensible *as into the reactor vessel.
Selection of RHR System locations susceptible to *as accumulation is based on a review of system design information, including piping and instrumentation drawings, isometric drawings. olan and elevation drawings, and calculations. The design review is suoplemented by system walk downs to validate the system high Points and to confirm the location and orientation of important comoonents that can become sources of gas or could otherwise cause gas to be tranoed or difficult to remove during system maintenance or restoration. Susceptible locations depend on slant and system configuration, such as stand-by versus operating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water. Acceptance Criteria are established for the volume of accumulated gas at susceptible locations. If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceotance criteria for *,as volume at the suction or discharge of a pump), the Surveillance is not met.
If it is determined by subseauent evaluation that the RHR System is Prairie Island                                  Unit 1 - uy,;*,j, me.ndment
                                                                  ^           Nc. 158:
Units 1 and 2                       B 3.4.7-7 Unit 2          * * ^mendment N. 11*9

RCS Loops - MODE 5, Loops Filled B 3.4.7 SURVEILLANCE   SR 3.4.7.4 (continued) not rendered inoperable by the accumulated *as (i.e.. the system is sufficiently filled with water), the Surveillance may be declared met.
Accumulated *as should be eliminated or brou.ght within the acceptance criteria limits.
RHIR System locations susceptible to *as accumulation are monitored and. if gas is found, the *as volume is compared to the acceotance criteria for the location. Susceotible locations in the same system flow oath which are subject to the same *as intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations. Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions. the plant configuration, or personnel safety. For these locations alternative methods (e.g.. operating parameters, remote monitoring) may be used to monitor the suscentible location.
Monitoring is not required for susceptible locations where the maximum notential accumulated *as void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the Susceptible locations and trending, of the results should be sufficient to assure System OPERABILITY during the Surveillance interval.
The SR can be met by virtue of having an RHR subsystem inservice in accordance with operating nrocedures.
The 31 day Freauency takes into consideration the gradual nature of gas accumulation in the RHR System tpiping and theporocedural controls *,ovemnin* system operation.
REFERENCES     1. NRC Information Notice 95-3 5, "Degraded Ability of Steam Generators to Remove Decay Heat by Natural Circulation".
: 2. License Amendment Request Dated November 19, 1999.
(Approved by License Amendment 152/143, July 14, 2000.)
Prairie Island                                  Unit 1-       *
* e.., fflen*-Ne 48 Units 1 and 2                        B 3.4.7-8 Unit 2 - R__evsi     nL.edmen't No. 11!9

RCS Loops - MODE 5, Loops Not Filled B 3.4.8 BASES LCO            Note 1 permits all RHR pumps to be de-energized < 1 hour per 8 (continued)   hour period. The circumstances for stopping both RHR pumps are to be limited to situations when the outage time is short and core outlet temperature is maintained > 10&deg;F below saturation temperature. The Note prohibits boron dilution with coolant at boron concentrations less than required to assure SDM is maintained or draining operations when RHR forced flow is stopped.
Note 2 allows one RHR loop to be inoperable for a period of
_<2 hours, provided that the other loop is OPERABLE and in operation. This permits periodic surveillance tests to be performed on the inoperable loop during the only time when these tests are safe and possible.
An OPERABLE RHR loop is comprised of an OPERABLE RHR pump capable of providing forced flow to an OPERABLE RHR heat exchanger. RHR pumps are OPERABLE if they are capable of being powered and are able to provide flow if required.
Management of *as voids is imoortant to RI-R System OPERABILITY.
APPLICABILITY  In MODE 5 with loops not filled, this LCO requires core heat removal and coolant circulation by the RHR System.
Operation in other MODES is covered by:
LCO    3.4.4, "RCS Loops-MODES 1 and 2";
LCO    3.4.5, "RCS Loops-MODE 3";
LCO    3.4.6, "RCS Loops-MODE 4";
LCO    3.4.7, "RCS Loops-MODE 5, Loops Filled";
LCO    3.9.5, "Residual Heat Removal (RHR) and Coolant Circulation-High Water Level" (MODE 6); and LCO 3.9.6, "Residual Heat Removal (RHR) and Coolant Circulation-Low Water Level" (MODE 6).
Prairie Island                                 Unit 1       **       ,,,   . T Units 1 and 2                       B 3.4.8-2 Unit 2 -Revlsl~nme.............-...

RCS Loops - MODE 5, Loops Not Filled B 3.4.8 BASES (continued)
SURVEIlLANCE       SR 3.4.8.1 REQUIREMENTS This SR requires verification every 12 hours that the required loop is in operation. Verification may include flow rate, temperature, or pump status monitoring, which helps ensure that forced flow is providing heat removal. The Frequency of 12 hours is sufficient considering other indications and alarms available to the operator in the control room to monitor RHR loop performance.
SR 3.4.8.2 Verification that each required pump is OPERABLE ensures that an additional pump can be placed in operation, if needed, to maintain decay heat removal and reactor coolant circulation. Verification is performed by verifying proper breaker alignment and power available to each required pump. Alternatively, verification that a pump is in operation also verifies proper breaker alignment and power availability. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a pump is not in operation.
RUR System piping and comnonents have the potential to develop voids and nockets of entrained gases. Preventing and managing gas intrusion and accumulation is necessary, for proper operation of the RHIR loops and may also prevent water hammer. oumn cavitation.
and pumnping, of noncondensible gas into the reactor vessel.
Selection of RHR System locations susceptible to *,as accumulation is based on a review of system design information, including tpiting and instrumentation drawings, isometric drawings. tnlan and elevation drawings, and calculations. The design review is Prairie Island                                   Unit 1 - B,,;yi,-k^ .. mend..i eT..1-5 Units 1 and 2                         B 3.4.8-4 Unit 2-     i.,,n,,,,,me,,-NT-1,4.9

RCS Loops - MODE 5, Loops Not Filled B 3.4.8 BASBS SI JR!V~ .1.ANCP7: S*R     _4 Ri (continiie~d' supplemented by System walk downs to validate the system high points and to confirm the location and orientation of imoortant comnonents that can become sources of gas or could otherwise cause gas to be tratwed or difficult to remove during system maintenance or restoration. Susceptible locations depend on nlant and system configuration, such as stand-by versus operating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water. Accertance criteria are established for the volume of accumulated gas at susceptible locations. If accumulated gas is discovered that exceeds the acceotance criteria for the susceptible location (or the volume of accumulated *,as at one or more susceptible locations exceeds an accentance criteria for gas volume at the suction or discharge ofas numnVb the Suirveillance is not met.
If it is determined by subseauent evaluation that the RHR System is not rendered inoperable by the accumulated gas (i.e.. the System is sufficiently filled with water). the Surveillance may be declared met. H Accumulated gas should be eliminated or brought within the acceptance criteria limits.
RHR System locations susceptible to gas accumulation are monitored and. if gas is found. the *as volume is compared to the accentance criteria for the location. Susceptible locations in the same system flow nath which are subiect to the same gas intrusion mechanisms may be verified by monitoring, a representative sub-set of susceptible locations. Monitoring may not be practical for locations that are inaccessible due to radiological or envirotnmental conditions. the tnlant configuration, or personnel safety. For these locations alternative methods (e.g.. operating parameters. remote monitoring) may he used to monitor the suscentible location Prairie Island                                      Unit 1 - Reviiok~     nn ie........Neo.1 58 Units 1 and 2                             B 3.4.8-5 Unit 2- *,,,j;,, ^e-"n"dmcn *t.o. 119t

RCS Loops - MODE 5, Loops Not Filled B 3.4.8 BASES SURVEILLANCE RFO.UIRIZVlENTS SR 3.4.8.3 (continued)
Monitoring is not required for susceptible locations where the maximum notential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITy.
The accuracy of the method used for monitoring the suscentible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.
This SR can be met by virtue of having an RHR subsystem inservice in accordance with operating procedures.
The 31 day Freauency takes into consideration the gradual nature of gas accumulation in the RHIR System piping and the orocedural controls governing system operation.
REFERENCES      None.
Prairie Island Units 1 and 2                       B 3.4.8-6 Unit 2 - ReviiorAmendmer' Nc. 119

ECCS-Operating B 3.5.2 BASES LCO            In MODES 1, 2, and 3, an ECCS train consists of an SI subsystem (continued)   and an RHR subsystem. Each train includes the piping, instruments, and controls to ensure an OPERABLE flow path capable of taking suction from the RWST upon an SI signal and RHIR capable of being transferred to take suction from containment Sump B.
During an event requiring ECCS actuation, a flow path is required to provide an abundant supply of water from the RWST to the RCS via the ECCS pumps and their respective supply headers to each of the two cold leg injection nozzles and the reactor vessel upper plenum.
In the long term, this flow path may be switched to take its supply from the containment sump and to supply its flow to the RCS cold legs or directly into the reactor vessel upper plenum. Management of as voids is imorattECSO RALTY The flow path for each train must maintain its designed independence to ensure that no single failure can disable both ECCS trains.
Manual valves that could, if improperly positioned, reduce injection flow below that assumed for accident analyses, are blocked and tagged or locked in the proper position for injection. Changes in valve position must be under direct administrative control.
A block is a device that can be unclipped or unsnapped to allow a status change of the component to which it is applied. A lock is a device that must be unlocked, destroyed or mechanically removed (such as a cap or blank) to allow a status change of the component to which it is applied.
As indicated in the LCO Note, the SI flow paths may be isolated for 2 hours in MODE 3, under controlled conditions, to perform pressure isolation valve testing per SR 3.4.15.1. The flow path is readily restorable from the control room.
Prairie Island                                  Unit 1 - Revisioi m... d....... Nov. 158 Units 1 and 2                       B 3.5.2-6 Unit 2         " "isi
                                                                 'Acnden N. 119

ECCS-Operating B 3.5.2 BASES SURVEII1ANCE    SR 3.5.2.2 REQUIREMENTS (continued)   Verifying the correct alignment for manual, power operated, and automatic valves in the ECCS flow paths provides assurance that the proper flow paths will exist for ECCS operation. This SR does not apply to valves that are locked, sealed, or otherwise secured in position, since these were verified to be in the correct position prior to locking, sealing, or securing (A seal is a device that must be destroyed to allow a status change of the component to which it is applied). A valve that receives an actuation signal is allowed to be in a nonaccident position provided the valve will automatically reposition within the proper stroke time. This Surveillance does not require any testing or valve manipulation. Rather, it involves verification that those valves capable of being mispositioned are in the correct position. The 31 day Frequency is appropriate because the valves are operated under administrative control, and an improper valve position would only affect a single train. This Frequency has been shown to be acceptable through operating experience.
The Surveillance is modified by a Note which exempts system venlt flow paths opened under administrative control. The administrative control should be oroceduralized and include stationing, a dedicated individual at the system vent flow oath who is in continuous communication with the onerators in the control room. This individual will have a method to rapidly close the system vent flow SR 3.5.2.3 Verification every 31 days that the motor control center supply breakers are physically locked in the off position for each valve specified in SR 3.5.2.1 ensures that an active failure could not result in an undetected misposition of a valve. Since power is removed under administrative control and valve position is verified every 12 hours, the 31 day Frequency will provide adequate assurance that power is removed.
Prairie Island                                 Unit 1 - Revisioru ............ No. 158,,
Units 1 and 2                      B 3.5.2-10 Unit 2 - Re,,sio-,' ^m..dme.n- No. 11*9

ECCS-Operating B 3.5.2 BASES SURVEILLANCE    SR 3.5.2.4 and SRJ35.2.5 REQUIREMENTS (continued)   ECCS opinng and comoonents have the potential to develop voids and nockets of entrained gases. Preventing and mana~in* *as inruio adaccumulation is necessary for uroner ooeration of the          [
ECCS and may also orevent water hammer. tnumo cavitation, and Pumpin2 of noncondensible *as into the reactor vessel.
Selection of ECCS locations susceotible to *as accumulation is based on a review of system design information, including oining, and instrumentation drawings, isometric drawings. nlan and elevation drawings, and calculations. The design review is sunolemented by system walk downs to validate the system high points and to confirm the location and orientation of important comoonents that can become sources of *,as or could otherwise cause gas to be traoped or difficult to remove during system maintenance or restoration. Susceptible locations denend on olant and system configuration, such as stand-by versus operating, conditions.
The ECCS is OPERABLE when it is sufficiently filled with water.
Acceptance criteria are established for the volume of accumulated
               *,as at susceptible locations. If accumulated *as is discovered that exceeds the accentance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an accentance criteria for gas volume at the suction or discharge of a oumon, the Surveillance is not met. If it is determined by subseauent evaluation that the ECCS is not rendered inoperable by the accumulated gas (i.e.. the system is sufficiently filled with water). the Surveillance may be declared met. Accumulated gas should be eliminated or brought within the accentance criteria limits.
ECCS locations susceptible to gas accumulation are monitored and.
if *as is found. the gas volume is comnared to the accentance criteria for the location. Susceptible locations in the same system flow nath which are subject to the same gas intrusion mechanisms may be verified by monitoring a repgresentative sub-set of susceptible locations. Monitoring may not be practical for locations that are Prairie Island                                  Unit 1 - E,=,,;;,-,,-A..end.*..e.I x-Ne *1-Units 1 and 2                       B 3.5.2-11 Unit 2-_Bi,;j;,nA.m.nd ..,.i.-NeAA..

ECCS-Operating B 3.5.2 BASES SURVElACE       SR 3.5.2.4 and SR 3.5.2.5 (continued) inaccessible due tO radiological or environmental conditions, the plant configuration, or nersonnel safety. For these locatfions alternative methods (e.g.. operating narameters. remote monitoring,)
may be used to monitor the susceptible location. Monitoring is not required for susceptible locations where the maximum potential accumulated *,as void volume has been evaluated and determined to not challenge system OPERABILITY. The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITy during the Surveillance interval.
Both the 31 day Freauencv for accessible locations and event-based Freauencv for inaccessible locations take into consideration the gradual nature of gas accumulation in the ECCS piping,and the orocedural controls governing, system operation. Additionally, the Freauencv for inaccessible locations allows this Surveillance to be performed under olant conditions that enable direct monitoring,.
The as-found conditions of the inaccessible locations are monitored at the earliest possible shutdown condition according to the Gas Accumulation Management program. In a rapid shutdown, there may be insufficient time to verify the as-found condition of the inaccessible locations orior to RCS deoressurization.
SR3.52.6 Periodic surveillance testing of ECCS pumps to detect gross degradation caused by impeller structural damage or other hydraulic component problems is required by the ASME Code. This type of testing may be accomplished by measuring the pump developed head at a single point of the pump characteristic curve. This verifies both that the measured performance is within an acceptable tolerance of the original pump baseline performance and that the performance at the test flow is within the performance assumed in the plant safety analysis. SRs are specified in the Inservice Testing Program of the Prairie Island                                  Unit 1 - RevisionAm-cndment No. 158, Units 1 and 2                       B 3.5.2-12 Unit 2 - Revisiormendment-Ne.!A49

ECCS-Operating B 3.5.2 BASES SURVEILLANCE   SR 3.5.2.6 (continued)
REQUIREMENTS ASME Code. The ASME Code provides the activities and Frequencies necessary to satisfy the requirements.
SR 3.5.2.J5* and SR 3.5.2.86 These Surveillances demonstrate that each automatic ECCS valve actuates to the required position on an actual or simulated SI signal and that each ECCS pump starts on receipt of an actual or simulated SI signal. This test is met when control board indications and visual observations indicate that all components have received the safety injection signal in the proper sequence and timing, the appropriate pump breakers have opened and closed, and all automatic valves have been placed in the proper position required to establish a safety injection flow path to the reactor coolant system.
This Surveillance is not required for valves that are locked, sealed, or otherwise secured in the required position under administrative controls. The 24 month Frequency is based on the need to perform these Surveillances under the conditions that apply during a plant outage and the potential for unplanned plant transients if the Surveillances were performed with the reactor at power. The 24 month Frequency is also acceptable based on consideration of the design reliability (and confirming operating experience) of the equipment. The actuation logic is tested as part of Engineered Safety Feature (ESF) Actuation System testing, and equipment performance is monitored as part of the Inservice Testing Program.
SR 3.5.2.9=7 Surveillance Requirements on ECCS throttle valves provide assurance that proper ECCS flows are maintained in the event of a LOCA. Proper flow resistance and pressure drop in the piping system to each injection point in the SI System is necessary to: 1) prevent total pump flow from exceeding runout conditions when the system is in its minimum resistance configuration; Prairie Island                                 Unit 1 - Ry,,i*,,, ^ . dmn.N-.,*.
r.1 4 Units 1 and 2                       B 3.5.2-13 Unit 2 -R    " " ^ *mn*meI4+NeA9

ECCS-Operating B 3.5.2 BASES SURVEILLANCE   SR 3.5.2. 9i7 (continued)
REQUIREMENTS
: 2) provide the proper flow split between injection points in accordance with the assumptions used in the ECCS LOCA analyses; and 3) provide an acceptable level of total ECCS flow to all injection points equal to or above that assumed in the ECCS LOCA analyses.
The 24 month Frequency is based on the same reasons as those stated in SR 3.5.2.75 and SR 3...@
SR 3.5.2.R0 Periodic inspections of the containment sump suction inlet to the RHR System ensure that it is unrestricted and stays in proper operating condition. The 24 month Frequency allows this Surveillance to be performed under the conditions that apply during a plant outage. This Frequency has been found to be sufficient to detect abnormal degradation and is confirmed by operating experience.
BASES REFERENCES     1. AEC "General Design Criteria for Nuclear Power Plant Construction Permits," Criterion 44, issued for comment July 10, 1967, as referenced in USAR Section 1.2.
: 2. USAR, Section 6.2.
: 3. USAR, Section 14.
: 4. NRC Memorandum to V. Stello, Jr., from R.L. Baer, "Recommended Interim Revisions to LCOs for ECCS Components," December 1, 1975.
: 5. IE Information Notice No. 87-01.
Prairie Island                                Unit 1 - Bxi*,i,  ^.me...d-ie ,e-1-5o Units 1 and 2                       B3.5.2-14 Unt**             ^-..* * +x-1t

ECCS   - Shutdown B 3.5.3 BASES (continued)
LCO               In MODE 4, one of the two independent (and redundant) ECCS trains is required to be OPERABLE to ensure that sufficient ECCS flow is available to the core following a DBA.
In MODE 4, an ECCS train consists of an SI subsystem and an RHR subsystem. Each train includes the piping, instruments, and controls to ensure an OPERABLE flow path capable of taking suction from the RWST and transferring suction to the containment sump.
During an event requiring ECCS actuation, a flow path is required to provide an abundant supply of water from the RWST to the RCS via the SI subsystem capable (through manual actions) of injecting into each of the cold leg inj ection nozzles and reactor vessel upper plenum nozzles. In the long term, a flow path is required to provide recirculation flow via the RHR subsystem from the containment sump into each of the reactor vessel upper plenum nozzles.
Mana*,ement of *as voids is imtnortant to ECCS OPERABILITY.
This LCO is modified by two Notes. Note 1 allows an RHR train to be considered OPERABLE during alignment and operation for decay heat removal, if capable of being manually realigned (remote or local) to the ECCS mode of operation and not otherwise inoperable. This allows operation in the RHIR mode during MODE 4.
Note 2 allows an SI train to be considered OPERABLE when the pump is capable of being manually started for ECCS injection from the control room.
APPLICABILITY     In MODES 1, 2, and 3, the OPERABILITY requirements for ECCS are covered by LCO 3.5.2.
In MODE 4 with RCS temperature below 3500 F and both RCS cold leg temperatures above the SI pump disable temperature specified in the PTLR, one OPERABLE ECCS train is acceptable without single failure consideration, on the basis of the stable reactivity of the reactor and the limited core cooling requirements Prairie Island                                                      Unit 1 -Revision 4-Units 1 and 2                          B 3.5.3-2                    Unit 2 - Revision 40-93

Containment Spray and Cooling Systems B 3.6.5 BASES APPLICABLE     Containment Cooling System air and safety grade cooling water SAFElY         flow. The Containment Cooling System total response time ANALYSES       incorporates delays to account for load restoration and motor (continued)   windup (Ref. 3).
The Containment Spray System and the Containment Cooling System satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).
LCO            During a LOCA or SLB, a minimum of one containment cooling train and one containment spray train are required to maintain the containment peak pressure and temperature below the design limits (Ref. 4). Additionally, one containment spray train is also required to supply sufficient sodium hydroxide to containment to ensure that the pH of the sump liquid is alkaline. To ensure that 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.
Each Containment Spray System 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 a containment spray actuation signal. Manual valves in this system that could, if improperly positioned, reduce the spray flow below that assumed for accident analysis, are blocked and tagged in the proper position and maintained under administrative control.
Containment Spray System motor operated valves, MV-32096 and MV-32097 (Unit 1), and MV-32108 and MV-32109 (Unit 2) are closed with the motor control center supply breakers in the off position. Mana*,ement of *,as voids is important to Containment Sorav System OPERABILITY.
Each Containment Cooling System typically includes cooling coils, dampers, fans, and controls to ensure an OPERABLE flow path.
With one CL strainer isolated, the containment cooling train on the associated CL header is OPERABLE at CL supply temperatures Prairie Island                                                   Unit 1 - Revision 2-20 Units 1 and 2                      B 3.6.5-6                     Unit 2 - Revision 2-2-0

Containment Spray and Cooling Systems B 3.6.5 BASES SURVELACE       SR 3.6.5.12 (cotiue)
REQUIREMENTS (c..nt.nue.) The Surveillance is modified by a Note which exemots system vent flow oaths ooened under administrative control. The administrative control should be oroceduralized and include stationing, a dedicated individual at the system vent flow oath who is in continuous communication with the onerators in the control room. This individual will have a method to raoidlv close the system vent flow Operating each containment fan coil unit on low motor speed for
               > 15 minutes ensures that all trains are OPERABLE and that all associated controls are functioning properly.
Motor current is measured and compared to the nominal current expected for the test condition. It also ensures that blockage, fan or motor failure, or excessive vibration can be detected for corrective action. The 31 day Frequency was developed considering the known reliability of the fan coil unaits 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 3.6.5.3 Containment Sorav System oioing and com oonents have the potential to develon voids and nockets of entrained gases.
Preventing and managing gas intrusion and accumulation is necessary, for oroper ooeration of the containment soray trains and may also orevent water hammer and oumo cavitation.
Seeto of Containmen oavSstem loain sucoil to1 a accumulation is based on a review of system design information.
Prairie Island                                                     Unit 1 - Revision 4-9-5 Units 1 and 2                       B 3.6.5-11                     Unit 2 - Revision 4-9-5

Containment Spray and Cooling Systems B 3.6.5 BASES SURVEILLANCE   SR 3.6.5.3 (continued) including, piping, and instrumentation drawings, isometric drawings.
elan and elevation drawings, and calculations. The design review is sun~lemented by system walk downs to validate the system high points and to confirm the location and orientation of important comnonents that can become sources of *as or could otherwise cause aas to be tranoed or difficult to remove during, system maintenance or restoration, Susceptible locations depend on nlant and system configuration, such as stand-by versus otperating conditions.
The Containment Snrav System is OPERABLE when it is sufficiently filled with water. Accentance criteria are established for the volume of accumulated *as at susceptible locations. If accumulated *,as is discovered that exceeds the accentance criteria for the susceptible location (or the volume of accumulated *as at one or more susceptible locations exceeds an accentance criteria for gas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseauent evaluation that the Containment Sorav System is not rendered inoperable by the accumulated gas (i.e.. the system is sufficiently filled with water).
the Surveillance may be declared met. Accumulated *as should be eliminated or brought within the accentance criteria limits.
Containment Snray System locations susceptible to gas accumulation are monitored and. if gas is found, the *,as volume is compared to the acceptance criteria for the location. Susceptible locations in the same system flow path which are subject to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations. Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the nlant configuration, or nersonnel safety. For these locations alternative methods (e.g,.. operatin&#xa2; narameters, remote monitoring) may be used to monitor the susceptible location. Monitoring is not required for susceptible Prairie Island                                                   Unit 1 - Revision 4-9-5 Units 1 and 2                       B 3.6.5-12                   Unit 2 -Revision 4-9-5

Containment Spray and Cooling Systems B 3.6.5 SURVEILACE     SR 3.6.5.3 (continued) locations where the maximum potential accumulated *,as void volume has been evaluated and determined to not challenge systemr OPERABILITY. The accuracy of the method used for monitoring the susceptible locations and trending, of the results should be sufficient to assure system OPERABILITY during, the Surveillance The 31 day Freauencv takes into consideration the gradual nature of gas accumulation in the Containment Spray System pining and the procedural controls governing system operation.
Verifying that cooling water flow rate to each containment fan coil unit is > 900 gpm provides assurance that the design flow rate assumed in the safety analyses will be achieved (Ref. 4).
Terminal temperatures of each fan coil unit are also observed. This test includes verifying operation of all essential features including low motor speed, cooling water valves and normal ventilation system dampers. The 24 month Frequency is based on; the need to perform these Surveillances under the conditions that apply during a plant outage; the known reliability of the Cooling Water System; the two train redundancy available; and, the low probability of a significant degradation of flow occurring between Surveillances.
SR 3.6.5.54 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. Flow and differential pressure are normal tests of centrifugal pump performance required by the ASMiE Code (Ref. 6). Since the Prairie Island                                                   Unit 1 - Revision 9-5 Units 1 and 2                       B 3.6.5-13                   Unit 2 -Revision ---

Containment Spray and Cooling Systems B 3.6.5 BASES SURVEILLANCE    SR 3.6.5.54 (continued)
REQULREMENT containment spray pumps cannot be tested with flow through the spray headers, they are tested on recirculation flow. 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.
SR 3.6.5.65~and SR 3.6.5.76_
These SRs require verification that each automatic containment spray valve actuates to its correct position and that each containment spray pump starts upon receipt of an actual or simulated actuation of a containment High-High pressure signal. This Surveillance is not required for valves that are locked, sealed, or otherwise secured in the required position under administrative controls. To prevent inadvertent spray in containment, containment spray pump testing with a simulated actuation signal will be performed with the isolation valves in the spray supply lines at the containment and the spray additive tank isolation valves blocked closed. These tests will be considered satisfactory if visual observations indicate all components have operated satisfactorily. The 24 month Frequency is based on the need to perform these Surveillances under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillances were performed with the reactor at power. Operating experience has shown that these components usually pass the Surveillances when performed.
Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.
Prairie Island                                                   Unit 1 - Revision 4184 Units 1 and 2                      B 3.6.5-14                    Unit 2 - Revision 84

Containment Spray and Cooling Systems B 3.6.5 BASES SURVEILLANCE    SR 3.6.5.8:7 REQUIREMENrS (continued)   This SR requires verification that each containment cooling train actuates upon receipt of an actual or simulated safety injection signal. The 24 month Frequency is based on engineering judgment.
See SR 3.6.5.*-5 and SR 3.6.5.76, above, for further discussion of the basis for the 24 month Frequency.
SR 3.6.5.98g With the spray header drained, low pressure air or smoke can be blown through test connections. This SR ensures that each spray nozzle is unobstructed and provides assurance that spray coverage of the containment during an accident is not degraded. Due to the passive design of the nozzle, confirmation of operability following maintenance activities that can result in obstruction of spray is considered adequate to detect obstruction of the nozzles.
Confirmation that the spray nozzles are unobstructed may be obtained by such means as foreign materials exclusion (FME) controls during maintenance, a visual inspection of the affected portions of the system, or by an air or smoke test following maintenance involving opening portions of the system downstream of the containment isolation valves, or by draining and flushing the filled portions of the system inside containment, as appropriate.
Maintenance that could result in nozzle blockage is generally a result of a loss of FME control or a flow of borated water through a nozzle.
Should either of these events occur, an engineering evaluation will be performed to determine whether nozzle blockage is a possible result of the event.
If loss of FME control occurs, an inspection or flush of the affected portions of the system should be adequate to confirm that the spray nozzles are unobstructed since water flow would be required to transport any debris to the spray nozzles. An air flow or smoke test may be appropriate when borated water has inadvertently flowed through a nozzle.
Prairie Island                                                  Unit 1 - Revision 99 Units 1 and 2                       B 3.6.5-15                  Unit 2 -Revision 4-99

RHR and Coolant Circulation-High Water Level B 3.9.5 BASES (continued)
LCO               Only one RHR loop is required for decay heat removal in MODE 6, with the water level > 20 ft above the top of the reactor vessel flange. Only one RHR loop is required to be OPERABLE, because the volume of water above the reactor vessel flange provides backup decay heat removal capability.
At least one RHR loop must be OPERABLE and in operation to provide:
: a. Removal of decay heat;
: b. Mixing of borated coolant to minimize the possibility of criticality; and
: c. Indication of reactor coolant temperature.
An OPERABLE RHR loop includes a RHR pump, a heat exchanger, valves, piping, instruments, and controls to ensure an OPERABLE flow path and to determine the low end temperature. The flow path starts in one of the RCS hot legs and is returned to a RCS cold leg.
Management of *,as voids is imoortant to RI-R System OPEABILITY.
The LCO is modified by a Note that allows the required operating RHR loop to be removed from service for up to 1 hour per 8 hour period, provided no operations are permitted that would dilute the RCS boron concentration with coolant at boron concentrations less than required to meet the minimum boron concentration of LCO 3.9.1. Boron concentration reduction, with coolant at boron concentrations less than required to assure the RCS boron concentration is maintained, is prohibited because uniform concentration distribution cannot be ensured without forced circulation. This permits operations such as core mapping or alterations in the vicinity of the reactor vessel hot leg nozzles and RCS to RHR isolation valve testing. During this 1 hour period, decay heat is removed by natural convection to the large mass of water in the refueling cavity.
Prairie Island                                     Unit 1 - Ri,*,,,,n .f.ie.A..mei.. eA4&*
Units 1 and 2                           B 3.9.5-2 Unit 2 - RevisiorAmeiqdmezit-N.e.--49

RI-R and Coolant Circulation-High Water Level B 3.9.5 BASES ACTIONS         A.4. A.5, A.6.1, and A.6.2 (continued)
: b. One door in each air lock must be closed; and
: c. Each penetration providing direct access from the containment atmosphere to the outside atmosphere must be either closed by a manual or automatic isolation valve, blind flange, or equivalent, or verified to be capable of being closed by an OPERABLE Containment Ventilation Isolation System.
With the RHR loop requirements not met, the potential exists for the coolant to boil, clad to fail, and release radioactive gas to the containment atmosphere. Performing the actions described above ensures that all containment penetrations are either closed or can be closed so that the dose limits are not exceeded.
The Completion Time of 4 hours allows adequate time to fulfill the Required Actions and not exceed dose limits.
SURVEILLANCE   SR 3.9.5.1 REQtUIEMENIS This Surveillance demonstrates that the RHR loop is in operation in order to provide sufficient decay heat removal capability and to prevent thermal and boron stratification in the core. The Frequency of 12 hours is sufficient, considering the flow, temperature, pump control, and alarm indications available to the operator in the control room for monitoring the RHJR System.
RHR System ninin*, and comoonents have the notential to develon voids and nockets of entrained gases. Preventing, and managing gas intrusion and accumulation is necessary for proner operation of the Prairie Island                                  Unit 1 - R*,,y;-,.j...n.A.,,,dn.e iTe45 8 Units 1 and 2                       B 3.9.5-5 Unit 2- Revisi~r^n.eiidnienit-Ne,.419

RH{R and Coolant Circulation-High Water Level B 3.9.5 BASES SURVEILLANCE   SR 3.9.5.2 (continued)
RHR IOODS and may also prevent water hammer. pump cavitation.
and pumping, of noncondensible gas into the reactor vessel.
Selection of RHR System locations susceotible to *as accumulation is based on a review of system design information, including piping and instrumentation drawings, isometric drawings. olan and elevation drawings, and calculations. The design review is suoolemented by system walk downs to validate the system high points and to confirm the location and orientation of imoortant components that can become sources of *,as or could otherwise cause gas to be tranoed or difficult to remove during, system maintenance or restoration. Susceptible locations depend on olant and system configuration, such as stand-by versus operating conditions.
The RHR System is OPERAB3LE when it is sufficiently filled with water. Acceotance criteria are established for the volume of accumulated gas at susceptible locations. If accumulated gas is discovered that exceeds the acceotance criteria for the Susceptible location (.or the volume of accumulated gas at one or more Susceptible locations exceeds an acceotance criteria for gas volume at the suction or discharge of a pumo). the Surveillance is not met.
If it is determined by subseouent evaluation that the RHR System is not rendered inoperable by the accumulated gas (i.e.. the system is sufficiently filled with water). the Surveillance may be declaredl met.
Accumulated *,as should be eliminated or brought within the acceptance criteria limits.
RHIR System locations susceptible to gas accumulation are monitored and. if *as is found. the gas volume is comnared to the acceptance criteria for the location. Susceptible locations in the same system flow oath which are subjiect to the same gas intrusion mechanisms may be verified by monitoring, a representative sub-set of suscentible locations. Monitoring, may not be practical for Prairie Island                                  Unit 1 - ReviskonA................ 15 Units 1 and 2                        B 3.9.5-6 Unit 2 - RevsioAmecdmcne~t NoT. 11t9

RH-R and Coolant Circulation-High Water Level B 3.9.5 BASES SURVEILLANCE 8FD2JIKEMI*t*  SR 3.9.5.2 (continued) locations that are inaccessible due to radiological or environmental conditions, the nlant confi~uration. or personnel safety. For these locations alternative methods (e.g.. operating, narameters. remote monitorinQ) may be used to monitor the suscep~tible location.
Monitorin2 is not reauired for susceotible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitorin2 the suscentible locations and trendin2 of the results should be sufficient to assure system OPERABLITY during, the Surveillance interval.
This SR can be met by virtue of having an RH subsystemn inservice in accordance with operating nrocedures.
The 31 day Freauencv takes into consideration the gradual nature of
               *as accumulation in the RIIR System oinin*, and the procedural controls governing system oneration.
REFERENCES     None.
Prairie Island                                 Unit 1 - Revyslr ............      No....5~
Units 1 and 2                       B 3.9.5-7 Unit2-9 _     ' Amendment-.*.a...*.. N. 119n

RHIR and Coolant Circulation-Low Water Level B 3.9.6 BASES LCO             a. Removal of decay heat; (continued)
: b. Mixing of borated coolant to minimize the possibility of criticality; and
: c. Indication of reactor coolant temperature.
An OPERABLE RHR loop consists of an RHR pump, a heat exchanger, valves, piping, instruments and controls to ensure an OPERABLE flow path and to determine the low end temperature.
The flow path starts in one of the RCS hot legs and is returned to the RCS cold leg. Management of gas voids is imoortant to RHR System OPERABILITY.
Either RHR pump may be aligned to the Refueling Water Storage Tank (RWST) to support filling or draining the refueling cavity or for performance of required testing.
The LCO contains two Notes which provide clarification of the LCO.
Note 1 permits the RHR pumps to be de-energized for up to 1 hour per 8 hour period. The circumstances for stopping both RHR pumps are to be limited to situations when the outage time is short and the core outlet temperature is maintained > 10 degrees F below saturation temperature. The Note prohibits boron dilution or draining operations when RHR forced flow is stopped.
Note 2 allows one RHR loop to be inoperable for a period of 2 hours provided the other loop is OPERABLE and in operation. Prior to declaring the loop inoperable, consideration should be given to the existing plant configuration. This consideration should include that the core time to boil is short, there is no draining operation to further reduce RCS water level and that the capability exists to inject borated water into the reactor vessel. This permits surveillance tests to be performed on the inoperable loop during a time when these tests are safe and possible.
Prairie Island                                  Unit 1 --RevisionAmentdnentNe.-l-5.
Units 1 and 2                        B 3.9.6-2 Unit 2 - RevisionAmend.menit-Ne,.-! 49

RHIR and Coolant Circulation-Low Water Level B 3.9.6 St VE.JANa E REOtflREMENI   SR 3.9.6.3 (continued)   RIHR System niping and comoonents have the potential to develon voids and rockets of entrained gases. Preventing and managing *,as intrusion and accumulation is necessary for proper otneration of the RHR loons and may also nrevent water hammer. tnumio cavitation.
and pumping, of noncondensible *as into the reactor vessel.
Selection of RHR System locations suscentible to *as accumulation is based on a review of System design information, including piping and instrumentation drawings, isometric drawings. tolan and elevation drawings, and calculations. The design review is Suo~lemented by system walk downs to validate the system high points and to confrm the location and orientation of imtportant components that can become sources of *,as or could otherwise cause
               *as to be tratn~ed or difficult to remove during, system maintenance or restoration. Susceptible locations detnend on nlant and system configuration, such as stand-by versus operating conditions.
The RHIR System is OPERABLE when it is sufficiently filled with water. Acceptance criteria are established for the volume of accumulated *as at susceptible locations. If accumulated gas is discovered that exceeds the acceptance criteria for the susceotible location (or the volume of accumulated gas at one or more susceptible locations exceeds an accetntance criteria for gas volume at the suction or discharge of a pumtp), the Surveillance is not met.
If it is determined by subseauent evaluation that the RHR System is not rendered inop~erable by the accumulated gas (i.e.. the system is sufficiently filled with water), the Surveillance may be declared met.
Accumulated gas should be eliminated or brought within the accentance criteria limits.
RHR System locations susceptible to gas accumulation are monitored and. if *,as is found. the gas volume is comtoared to the accet~tance criteria for the location. Susceptible locations in the Prairie Island                                  Unit 1 - R~yiis;     edmi 4-Ne-,=**..xr,1-<o Units 1 and 2                        B 3.9.6-6 Unit 2 -RevisioAmendm:ent Nor. 1/19

RHTR and Coolant Circulation-Low Water Level B 3.9.6 BASES SURVEI1,1ANCE  SR     9_6_ 3 (cnntinuied'I REOUIREMENrS same system flow oath which are subject to the same *as intrusion mechanisms may be verified by monitoring, a representative sub-set of suscentible locations. Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions. the nlant configuration, or nersonnel safety. For these locations alternative methods (e.g.. onerating parameters. remote monitoring) may be used to monitor the susceptible location.
Monitoring is not required for susceptible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.
This SR can be met by virtue of having an RHR subsystema nservice in accordance with operating procedures.
The 31! day Freauency takes into consideration the..gradual nature of gas accumulation in the RHR System piping and the procedural controls governing system operation.
REFERENCES     None.
Prairie Island                                 Unit 1 -     *         .,,*. T.
* Units 1 and 2                       B 3.9.6-7 Unit 2-Revision* ............ Ne. 49}}